Head and Neck Diseases by Alexandros G.Sfakianakis: 03/20/18

Τρίτη 20 Μαρτίου 2018

Effect of simulated acid rain on fluorine mobility and the bacterial community of phosphogypsum

Abstract

Contamination of soil and water with fluorine (F) leached from phosphogypsum (PG) stacks is a global environmental issue. Millions of tons of PG is produced each year as a by-product of fertilizer manufacture, and in China, weathering is exacerbated by acid rain. In this work, column leaching experiments using simulated acid rain were run to evaluate the mobility of F and the impact of weathering on native bacterial community composition in PG. After a simulated summer rainfall, 2.42–3.05 wt% of the total F content of PG was leached and the F concentration in leachate was above the quality standard for surface water and groundwater in China. Acid rain had no significant effect on the movement of F in PG. A higher concentration of F was observed at the bottom than the top section of PG columns suggesting mobility and reprecipitation of F. Throughout the simulation, the PG was environmentally safe according the TCLP testing. The dominant bacteria in PG were from the Enterococcus and Bacillus genus. Bacterial community composition in PG leached by simulated acid rain (pH 3.03) was more abundant than at pH 6.88. Information on F mobility and bacterial community in PG under conditions of simulated rain is relevant to management of environmental risk in stockpiled PG waste.

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Biochemical and morphological biomarkers of the liver damage in the Neotropical fish, Piaractus mesopotamicus , injected with crude extract of cyanobacterium Radiocystis fernandoi

Abstract

Cyanobacterial proliferation in river and lakes is the result of eutrophication. The cyanobacterium Radiocystis fernandoi strain R28 produces mostly two MC variants MC-RR and MC-YR and small amounts of other oligopeptides, but does not produce MC-LR. The present study investigated the hepatotoxic potential of the crude extract of the R. fernandoi strain R28 on the Neotropical fish, Piaractus mesopotamicus, at 3, 6, and 24 h after intraperitoneal injection (100 μg MC-LR equivalent per kg⁻¹ body mass) using biochemical and morphological biomarkers of liver damage. Although the protein phosphatases PP1 and PP2A were not inhibited during the 24-h treatment, liver parenchyma and hepatocyte structure were disrupted. Alkaline phosphatase increased at 3 h post-injection and decreased after 24 h; alanine aminotransferase and aspartate aminotransferase increased in a time-dependent manner up to 24 h indicating impaired liver function. Progressive histopathological changes were consistent with biochemical results demonstrating alterations in liver structure and function. In conclusion, the crude extract of R. fernandoi strain R28 has high hepatotoxic potential and can severely compromise fish health.

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Effect of photobiomodulation on connective tissue remodeling and regeneration of skeletal muscle in elderly rats

Abstract

The purpose of this study was to evaluate the effects of low-level laser therapy (LLLT) on morphological aspects, IL-6 and IL-1β expressions, as well as the distribution and organization of collagen in the tibialis anterior (TA) muscle of elderly rats submitted to cryoinjury. Histological photomicrographs were taken of TA muscles stained with HE and picrosirius red. Immunohistochemistry was used for the evaluation of IL-6 and IL-1β. Male Wistar rats, aged 20 months, were distributed into three groups: (1) control animals not injured or treated with LLLT (n = 5), (2) cryoinjury without LLLT treatment (n = 15), and (3) cryoinjury treated with infrared LLLT (n = 15). LLLT was applied to the TA 2 h after of the injury induction and consisted of daily applications until the sacrifice (1, 3, and 7 days). The following parameters were used: λ = 780 nm, power density 1 W/cm², output power 40 mW, 10 s per point, 8 points, and 3.2 J of total energy. In the histomorphological analysis, the treated group exhibited a significant decrease in inflammatory infiltrate (p < 0.001) as well as an increase immature fibers and new blood vessels at 7 days compared to the untreated group (p < 0.05). Furthermore, treatment induced a better collagen distribution and organization at 7 days in comparison to the untreated group (p < 0.05). In conclusion, LLLT demonstrated a modulatory effect on the muscle repair process in elderly animals with regard to the collagen remodeling and morphological aspects of muscle tissue.

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Photobiomodulation effect on children’s scars

Abstract

The management of burn scars has become one of the major clinical challenges in the developing countries which involve enormous treatment cost; this needs new methods for better cost benefit relationship. The objective of the study is to analyze the effectiveness of low-level laser therapy on post-burn scar tissue in children. A randomized controlled study included 15 children, ranging from 2 to 10 years of age, presenting with burn scars. They received diode laser and topical treatment. Each scar was divided into two halves. One half was treated with laser therapy and topical treatment (study area), and the other half was treated with topical treatment only (control area). The children were evaluated before and after 3 months of the study by Vancouver Scar Scale (VSS), ultrasonography (U/S), and laser Doppler perfusion imaging. Significant improvement was reported in the studied area compared to the control area for patients with P values (P = 0.005) and (P = 0.0001) for VSS and U/S scores, respectively. No difference was detected for blood perfusion to the scar between both areas (P = 0.18). In addition, no adverse effect was reported. Photobiomodulation is an efficient and safe therapeutic modality for post-burn hypertrophic scars in children and should be considered a part of combination therapy for better results.

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Comparison of the effect of root surface modification with citric acid, EDTA, and aPDT on adhesion and proliferation of human gingival fibroblasts and osteoblasts: an in vitro study

Abstract

Root demineralization is used in Periodontics as an adjuvant for mechanical treatment. The aim of this study was to evaluate the effects of root surface modification with mechanic, chemical, and photodynamic treatments on adhesion and proliferation of human gingival fibroblasts and osteoblasts. Root fragments were treated by scaling and root planing (C—control group), EDTA (pH 7), citric acid plus tetracycline (CA—pH 1), and antimicrobial photodynamic therapy (aPDT) with toluidine blue O and red laser (pH 4). Cells were seeded (104 cells/well, 6th passage) on root fragments of each experimental group and cultured for 24, 48, and 72 h. Cells were counted in scanning electron microscopy images by a calibrated examiner. For fibroblasts, the highest number of cells were present at 72-h period (p < 0.05). EDTA group showed a very low number of cells in relation to CA group (p < 0.05). CA and aPDT group presented higher number of cells in all periods, but without differences between other treatment groups (p > 0.05). For osteoblasts, there was a significant increase in cell numbers for aPDT group at 72 h (p < 0.05). In conclusion, aPDT treatment provided a positive stimulus to osteoblast growth, while for fibroblasts, aPDT and CA had a tendency for higher cell growth.

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aPDT for periodontitis treatment in ovariectomized rats under systemic nicotine

Publication date: June 2018
Source:Photodiagnosis and Photodynamic Therapy, Volume 22
Author(s): Valdir Gouveia Garcia, Erivan Clementino Gualberto, Edilson Ervolino, Maria José Hitomi Nagata, Juliano Milanezi de Almeida, Letícia Helena Theodoro
BackgroundThis study evaluated the antimicrobial photodynamic therapy (aPDT) as an adjunctive therapy to scaling and root planning (SRP) for the treatment of experimental periodontitis (EP) in ovariectomized rats under systemic nicotine.MethodsFemale ovariectomized rats (n = 180) were divided into two groups: vehicle administration (Veh) and nicotine administration (Nic). Mini-pumps containing either vehicle or nicotine were inserted in the rats 30 days before the induction of EP, which was induced by placing a ligature around the left mandibular first molar. The rats were randomly divided into three treatment subgroups: SRP, SRP plus low-level laser therapy (LLLT), and SRP plus aPDT. aPDT consisted of the application of a phenothiazine photosensitizer followed by LLLT. Ten animals from each group were euthanized at days 7, 15, and 30 after periodontal treatment. The furcation region was evaluated using histological, histometric analyses and immunolabelling for PCNA, TRAP, RANKL, and OPG.ResultsNicotine administration resulted in greater bone loss (BL). aPDT resulted in lower BL compared to SRP. aPDT showed higher quantities of PCNA-positive cells compared to SRP, regardless of the nicotine status. aPDT resulted in less recruitment of osteoclasts and lower RANKL immunolabelling compared to LLLT and SRP.ConclusionaPDT was effective in animals treated with nicotine.

Graphical abstract

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Multifunctional manganese-doped Prussian blue nanoparticles for two-photon photothermal therapy and magnetic resonance imaging

Publication date: June 2018
Source:Photodiagnosis and Photodynamic Therapy, Volume 22
Author(s): Lamiaa M.A. Ali, Emna Mathlouthi, Marilyn Kajdan, Morgane Daurat, Jérôme Long, Rahima Sidi-Boulenouar, Maïda Cardoso, Christophe Goze-Bac, Nourredine Amdouni, Yannick Guari, Joulia Larionova, Magali Gary-Bobo
Here we demonstrate for the first time that Mn²⁺-doped Prussian blue nanoparticles of c.a. 70 nm act as effective agents for photothermal therapy under two-photon excitation with an almost total eradication of malignant cells (97 and 98%) at a concentration of 100 μg mL⁻¹ 24 h after NIR excitation. This effect combined with interesting longitudinal NMR relaxivity values offer new perspectives for effective imaging and cancer treatment.

Graphical abstract

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Editorial Board

Publication date: March 2018
Source:Photodiagnosis and Photodynamic Therapy, Volume 21

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Angiomyolipoma of the Kidneys: Current Perspectives and Challenges in Diagnostic Imaging and Image-Guided Therapy

Publication date: Available online 20 March 2018
Source:Current Problems in Diagnostic Radiology
Author(s): Abdul Razik, Chandan J. Das, Sanjay Sharma
Angiomyolipomas (AML) are benign tumors of the kidneys frequently encountered in radiologic practice in large tertiary centers. In comparison to renal cell carcinomas (RCC), AML are seldom treated unless they are large, undergo malignant transformation or develop complications like acute hemorrhage. The common garden triphasic (classic) AML is an easy diagnosis, however some variants lack macroscopic fat in which case the radiologic differentiation from RCC becomes challenging. Several imaging features, both qualitative and quantitative, have been described in differentiating the two entities. Although minimal fat AML is not entirely a radiologic diagnosis, the suspicion raised on imaging necessitates sampling and potentially avoids an unwanted surgery. Recently a new variant, epitheloid AML has been described which often has atypical imaging features and is at a higher risk for malignant transformation. Apart from the diagnosis, the radiologist also needs to convey information regarding nephrometric scores which help in surgical decision making. Recently, more and more AMLs are managed with selective arterial embolization and percutaneous ablation, both of which lack the amount of morbidity associated with surgery. The purpose of this article is to review the imaging and pathologic features of classic AML as well as the differentiation of minimal fat AML from RCC. In addition, an overview of nephrometric scoring and image-guided interventions is also provided.

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Antibody–Drug Conjugates for the Treatment of Hematological Malignancies: A Comprehensive Review

Abstract

Antibody–drug conjugates (ADCs) are an emerging class of therapeutic agents that bring new opportunities for the treatment of hematological malignancies by meeting unmet medical needs. These drugs consist of a cytotoxic agent connected by a linker to a human, humanized, or chimeric antibody targeting a surface antigen specifically expressed by tumor cells. These ADCs are being developed to specifically deliver the cytotoxic agent into tumor cells. The cytotoxic payload is released from the ADC after internalization and cleavage of the linker, ultimately triggering the death of the cancer cell. Second- and even third-generation ADCs are currently being developed and have more stable linkers and more potent payloads, which should improve ADC efficacy even further. In this review, we analyze the results for the main ADCs currently developed and discuss the advantages and drawbacks of this therapeutic option.

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Design of a multistable composite laminate by variable cross-section method and applying the displacement constraint

Publication date: 5 June 2018
Source:Materials & Design, Volume 147
Author(s): Weihong Jiang, Ming Li, Yongtao Yao, Fuhong Dai
This paper presents a multistable variable cross-section laminate (MVCL), which is designed by applying the displacement constraint at the two opposing ends of the laminate. A theoretical model describing the MVCL as rigid bars connected with compliant hinges is built to predict the equilibrium configurations and snap-through loads of the MVCL. The snap-through process of the multistable structure is investigated via experiment and finite element analysis (FEA). Subsequently, the theoretical model is improved by simplifying the middle segment of the MVCL as an elastic beam. Good agreement is obtained between the experimental test, FEA, and improved theoretical model results. It is shown that the current approach can be successfully applied to predict the equilibrium configurations and snap-through loads of an MVCL. The snap-through loads can be adjusted by changing the middle segment length of an MVCL.

Graphical abstract

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Time-effective synthesis of rhombohedral CuAlO2 from mesoporous alumina substrate

Publication date: 5 June 2018
Source:Materials & Design, Volume 147
Author(s): Ali Saffar Shamshirgar, Marina Aghayan, Tripurari S. Tripathi, Maarit Karppinen, Michael Gasik, Irina Hussainova
The development of p-type transparent semiconductors with large optical bandgaps and high electrical conductivity is needed for a wide range of applications in optoelectronics and solar cell technologies. The experimental techniques currently used are limited to complex procedures and time consuming processing. In this work, we propose a versatile, simple and reproducible method of rapid reactive dip-coating using a mesoporous network of highly aligned γ-alumina nanofibers for synthesis of delafossite CuAlO2 by a time-effective process of 2h duration. The rhombohedral CuAlO2 was densified with the help of spark plasma sintering in vacuum. Electrical conductivity improves with increase in annealing temperature while its room temperature value for a sample annealed at 1100°C was 0.07Sm⁻¹ measured with four-probe method. Direct optical bandgap of 3.79eV was estimated with the help of diffuse reflection data for the sample sintered at optimal temperature. Both Seebeck coefficient and Hall measurements confirmed the p-type conductivity of the material.NoveltyThe major number of CuAlO2 synthesis approaches require complex instrumentation, templating, and long processing time. Therefore, scalable and cost-effective production of CuAlO2 remains a challenge. Herein, we report a rapid synthesis of CuAlO2, in a straightforward and scalable approach, which reduces the processing cost and overal energy consumption of the process.

Graphical abstract

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Microstructural and micromechanical investigations of surface strengthening mechanisms induced by repeated impacts on pure iron

Publication date: 5 June 2018
Source:Materials & Design, Volume 147
Author(s): David Tumbajoy-Spinel, Xavier Maeder, Gaylord Guillonneau, Sergio Sao-Joao, Sylvie Descartes, Jean-Michel Bergheau, Cécile Langlade, Johann Michler, Guillaume Kermouche
Mechanical surface treatments based on repeated impacts are known to create a graded strengthening in-depth by the means of severe plastic deformation. However microstructural evolution mechanisms leading local progressive grain refinement and the resulting surface mechanical hardening are not yet fully understood. It is shown in this paper that micro-percussion testing represents an interesting case scenario to emulate conventional treatments such as shot peening and better characterize microstructural changes at local and global scales. For this technique, every impact is made at the same position by a rigid conical indenter, controlling the number, angle and velocity of each impact. The main issue of this work is as follows: (i) to describe the transformed microstructures by the means of SEM microscopy and EBSD mapping; (ii) to quantify the mechanical gradient in-depth using the micro-pillar compression testing; and (iii) to converge both descriptions to understand the mechanisms involved on the strengthening of refined structures. This coupled experimental analysis would reveal the influence of different strengthening effects as the Hall-Petch effect or the dislocation hardening. This investigation is carried out in pure α-iron.

Graphical abstract

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Effects of low-temperature transformation and transformation-induced plasticity on weld residual stresses: Numerical study and neutron diffraction measurement

Publication date: 5 June 2018
Source:Materials & Design, Volume 147
Author(s): Wenchun Jiang, Wei Chen, Wanchuck Woo, Shan-Tung Tu, Xian-Cheng Zhang, Vyacheslav Em
In this study, the weld residual stresses (RS) in a 25mm thick ferrite steel plate with newly developed low-temperature transformation (LTT) welding wire were investigated by finite element method and neutron diffraction (ND) measurement. A thermo-elastic–plastic finite element model coupled with solid-state phase transformation (SSPT) was developed to investigate the distribution and formation mechanism of RS, which has been verified by ND measurement. The results demonstrate that the developed LTT alloy can significantly reduce the RS and even generate compressive RS in the weld zone, due to the interrupted cooling shrinkage caused by the LTT. The higher inter-pass temperatures related to the microstructure evolution result in an increased region of compressive stress within the weldment. Moreover, the longitudinal RS in the weld zone gradually changes to tension as the initial temperature of martensitic transformation increases. Notably, the relaxation effect of transformation-induced plasticity on RS and its influence on model accuracy were discussed.

Graphical abstract

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“Adding fuel to the fire”? Does exposure to non-consenting adult or to child pornography increase risk of sexual aggression?

Publication date: Available online 21 March 2018
Source:Aggression and Violent Behavior
Author(s): Neil Malamuth
This article is the first to integrate the vast research literatures on non-consenting adult and on child pornography (also a form of non-consenting pornography) by using the framework of the Confluence Model of sexual aggression. In contrast to the contradictory conclusions reached by various reviewers and commentators who have typically emphasized a particular methodology or parts of the literature, this review finds a great deal of consistency and convergence among the differing methodologies and literatures that have examined the impact of pornography on individuals. It is concluded that pornography use may add to risk of sexual aggression only for those men already predisposed to aggress sexually due to more primary causes than pornography use.

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A case of disseminated sporotrichosis caused by Sporothrix brasiliensis

Publication date: Available online 21 March 2018
Source:Medical Mycology Case Reports
Author(s): Rachel Basques Caligiorne, Blenda Fernandes, Dayana Monteiro Coutinho, Renata R. Gomes, Amanda Sanchez Machado, Emanoelle Fernandes Rutren La Santrer, Maria Silvia Laborne, Mauricio Buzelin Nunes, Vania A. Vicente, Sybren de Hoog
This paper presents a case of disseminated sporotrichosis in a 13-year-old female, originating from a rural area in Minas Gerais state, Brazil. The patient was hospitalized with hyporexia, prostration, fever and disseminated ulcerative lesions, besides anemia, leucopenia and sepsis of probable cutaneous focus. The patient was admitted without proven immunosuppression. She was diagnosed with cutaneous-disseminated sporotrichosis. The drug therapy chosen was itraconazole during 12 months, leading to important clinical improvement and healing of cutaneous lesions.

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Performance and mechanism of fluoride adsorption from groundwater by lanthanum-modified pomelo peel biochar

Abstract

To obtain an economical and effective adsorbent for fluoride removal, lanthanum-loaded pomelo peel biochar (PPBC-La) was synthesized using a facile approach. The batch adsorption experiments were investigated to determine adsorbent performance. The PPBC-La and its pristine biochar (PPBC) were characterized by scanning electronic microscopy (SEM), zeta potential, Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) methods. Experimental results showed that the adsorption data were described well by the pseudo-second-order kinetic and Freundlich isotherm models. The maximum fluoride adsorption capacity for PPBC-La was found to be 19.86 mg/g at 25 °C and pH 6.5. The PPBC-La worked well at pH 2.4–9.6 and carried positive charge at pH < 5.8. The presence of SO₄²⁻, Cl⁻, and NO₃⁻ had a slight effect on fluoride uptake except HCO₃⁻ and PO₄³⁻. The real groundwater study testified that 9.8 mg/L of fluoride was removed effectively at 1.0 g/L of dosage and pH 5.2. The regeneration results revealed that the PPBC-La had a good reusability. According to FTIR, XPS analysis and the anion exchange experiment, anions (NO₃⁻ and OH⁻) exchange with fluoride ions was mainly responsible for fluoride adsorption.

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Predicting fundamental and realized distributions based on thermal niche: A case study of a freshwater turtle

Publication date: April 2018
Source:Acta Oecologica, Volume 88
Author(s): João Fabrício Mota Rodrigues, Marco Túlio Pacheco Coelho, Bruno R. Ribeiro
Species distribution models (SDM) have been broadly used in ecology to address theoretical and practical problems. Currently, there are two main approaches to generate SDMs: (i) correlative, which is based on species occurrences and environmental predictor layers and (ii) process-based models, which are constructed based on species' functional traits and physiological tolerances. The distributions estimated by each approach are based on different components of species niche. Predictions of correlative models approach species realized niches, while predictions of process-based are more akin to species fundamental niche. Here, we integrated the predictions of fundamental and realized distributions of the freshwater turtle Trachemys dorbigni. Fundamental distribution was estimated using data of T. dorbigni's egg incubation temperature, and realized distribution was estimated using species occurrence records. Both types of distributions were estimated using the same regression approaches (logistic regression and support vector machines), both considering macroclimatic and microclimatic temperatures. The realized distribution of T. dorbigni was generally nested in its fundamental distribution reinforcing theoretical assumptions that the species' realized niche is a subset of its fundamental niche. Both modelling algorithms produced similar results but microtemperature generated better results than macrotemperature for the incubation model. Finally, our results reinforce the conclusion that species realized distributions are constrained by other factors other than just thermal tolerances.

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Initial response of human bone marrow–derived stem cells after contact with ultrahigh-molecular-weight polyethylene (UHMWPE) material: An in vitro study on cell viability and interleukin-6 expression

Iwan B Anwar, Asep Santoso, Eko Saputra, Rifky Ismail, J Jamari, Emile van der Heide

Journal of Pharmacy And Bioallied Sciences 2018 10(1):43-47

Introduction: Ultrahigh-molecular-weight polyethylene (UHMWPE) is a thermoplastic polymer useful in biomaterial applications, especially in orthopedic field. Yet, little is known concerning its initial effect on human bone marrow stem cells (hBMSCs) after implantation. Materials and Methods: A cytotoxicity analysis was performed with a 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium assay after 24, 48, and 72h of incubation of hBMSC culture. Expression of interleukin-6 (IL-6) was measured using enzyme-linked immunosorbent assay. Cell viability was measured with Inhibitory concentration 50% (IC50) formula. Results: All treatment groups showed a cell viability of >50% ranging from 78% to >100%. Lower expression of IL-6 of hBMSC compared to control group was found in 48h of incubation period. Conclusion: hBMSC showed high cell viability after initial contact with UHMWPE material. Modulation of IL-6 expression was present at the initial stage as a response to foreign material.

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Knowledge and attitude of health-care professionals toward adverse drug reactions reporting at King Saud Medical City

Khaja Moinuddin, Sheraz Ali, Amal Qadri Al-Aqqad, Sara Osama Salem, Maram Abdullah Al-Dossari, Abdullah Mohammad Ananzeh, Jaffer Bin Baqar

Journal of Pharmacy And Bioallied Sciences 2018 10(1):29-34

Background: Health-care professionals across the globe are obligated to report adverse drug reactions (ADRs). The knowledge of ADRs and attitude of health-care professionals toward ADRs reporting is vital for patient safety. This study intends to investigate the knowledge of ADRs and attitude of health-care professionals toward ADRs reporting. Materials and Methods: A cross-sectional study using an anonymous questionnaire was conducted over a period of 3 months (September 2016 to November 2016) at King Saud Medical City, Riyadh, Saudi Arabia. This study included 399 questionnaires submitted by health-care professionals. Results: A total of 399 questionnaires were submitted by health-care professionals, of which only 14.8% knew the term "ADR" and 55.1% of the respondents reported ADRs during their practice. A total of 93.8% of the respondents agreed that ADR reporting should be made mandatory for health-care professionals, and 94.5% agreed that it improves the patient safety. Conclusion: The findings generally indicate that health-care professionals in a tertiary care setting have low awareness regarding the term "ADR." Lack of pharmacovigilance training, amount of workload, and legal liabilities are the main causes of underreporting. More than half of the respondents agreed that ADR reporting eventually improves patient safety.

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Knowledge, attitude, and practice regarding the risk of cardiovascular diseases in patients attending outpatient clinic in Kuantan, Malaysia

Nursyafiza B Mohammad, Nor Azlina A Rahman, Mainul Haque

Journal of Pharmacy And Bioallied Sciences 2018 10(1):7-14

Background: Cardiovascular disease (CVD) is a leading cause of death around the world including Malaysia. Ischemic heart disease (IHD) is the single largest cause of death in the developed countries and is one of the main contributors to the disease burden in developing countries. Materials and Methods: This was a cross-sectional study conducted to determine knowledge, attitude, and practice (KAP) regarding the risk of CVD in patients attending an outpatient clinic in Kuantan, Malaysia. A total of 100 patients comprising 52 male and 48 female subjects were selected through convenient sampling method. Results: Of the total subjects, 86% were Malays. The mean scores (standard deviation) for KAP were 60.75±4.823, 54.36±8.711, and 33.43±4.046, respectively, whereas the maximum scores obtained by the subjects for KAP were 71, 65, and 43, respectively. Regarding questions related to knowledge, 88% subjects knew irregular eating pattern can cause disease and the benefits of vegetable intake. Most subjects recognized that smoking and obesity were CVD risk factors. Regarding questions related to attitude, 96% agreed that exercise can prevent CVD. More than half of the subjects followed healthy lifestyle. There were statistically significant differences observed in knowledge level between sexes (P = 0.046) and races (P = 0.001). Nevertheless, there was no statistically significant difference observed in KAP across different education levels of the subjects regarding the risk of CVD (P-value = 0.332, 0.185, and 0.160, respectively). Conclusion: This study revealed that patients had good knowledge and attitude regarding CVD risk factors. Yet, the number of smokers is still quite high. Development of better public information system is essential for the well-being of the society.

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Evaluation of bloodletting cupping therapy in the management of hypertension

Moawia M Al-Tabakha, Farah Tariq Sameer, Mai Hafiz Saeed, Rahaf Montaser Batran, Nada Tarek Abouhegazy, Alaa A Farajallah

Journal of Pharmacy And Bioallied Sciences 2018 10(1):1-6

Background: Bloodletting cupping therapy (Hijama) is a traditional alternative medicine practiced in different cultures. Claims about the therapeutic efficacy of Hijama in hypertension are contradictory. The aim of this project was to determine if Hijama therapy is beneficial in the treatment of patients with hypertension. Materials and Methods: In this retrospective study, 60 files for patients treated for hypertension, aged 40–60 years and whose systolic blood pressure (SBP) is at least 140mm Hg, were used. The data from 30 patient files were obtained from three licensed Hijama centers (study group), whereas data from the rest of 30 patient files were collected from a hospital (control group). The data from Hijama centers included age, date of Hijama therapy, and blood pressure measured before each Hijama session. Both diastolic blood pressure (DBP) and SBP data were obtained over 3-month period. Results: The results showed a significant reduction in SBP (P value < 0.01) over three sessions of wet cupping (from 149.2 to 130.8mm Hg), but this was not significant for DBP over three sessions (P = 0.074). The study also found that the mean SBP in the study group was 9.6mm Hg less than that in the control group (130.8 vs. 140.4mm Hg, P = 0.019), whereas there was no significant difference in DBP between the study group and the control group (87.0 vs. 86.0mm Hg, P = 0.75). Conclusions: Our study shows clear relationship between Hijama and the reduction and control of SBP in patients with hypertension. Therefore, Hijama can be used as an adjunct to conventional therapy, which may allow downtitration of given doses of antihypertensive drugs. The possible association of SBP reduction by Hijama and pain reduction needs an investigation.

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In vivo evaluation of the anticancer activity of the gemcitabine and doxorubicin combined in a nanoemulsion

Mayson H Alkhatib, Wafa S Alshehri, Faiza B Abdu

Journal of Pharmacy And Bioallied Sciences 2018 10(1):35-42

Context: Doxorubicin (DOX) and gemcitabine (GEM) are anticancer drugs that were combined in a nanoemulsion (NE) to reduce their adverse side effects. Aim: To detect the antitumor activity of the combination formulas of GEM and DOX, loaded either in water (GEM+DOX-Sol) or in NEs (GEM–DOX combination/loaded NE [GEM+DOX/LNE]), in female Swiss albino mice inoculated with Ehrlich ascites carcinoma (EAC). Settings and Design: The anticancer assessment of the NE formulas was implemented in 200 mice, which were divided into 10 groups. Materials and Methods: It includes the detection of the change in body weight, analysis of the hematological and serum biochemical profiles, and study of the histopathologic alterations of the heart tissues. Statistical Analysis: One-factor analysis of variance was used. Results: Mice treated with GEM + DOX/LNE, which have an z-average of 155.38±2.33nm and zeta potential of −38.5±1.3 mV, recorded a considerable improvement in the mean survival time (MST), which was 60 days, as compared to the EAC control group, which has an MST of 28 days. It also restored the hematological and serum biochemical parameters toward normal values. Conclusions: The combination of GEM and DOX in NE has significantly diminished the cardiotoxicity of DOX and hematotoxicity of GEM while improving their antitumor properties.

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Safety evaluation of various vector repellents in combination with deltamethrin in Wistar rats

Anitha Magesh, Senthilkumar Sivanesan, Vijayaraghavan Rajagopalan, Royapuram Veeraragavan Geetha, Anitha Roy

Journal of Pharmacy And Bioallied Sciences 2018 10(1):21-28

Background: Vector repellents are used globally to avoid insect bites and control transmission of diseases. It is important to ensure safety levels of these compounds, although they are noxious to insects. Vector repellents when used in combination are known to bring additional benefits in getting rid of the harmful insects. Unfortunately, the safety levels of various vector repellents such as Deet (N,N-diethyl-m-toluamide), Depa (N,N-diethyl phenylacetamide), and Deb (N,N-diethylbenzamide) are not studied in combination with the widely used pyrethroid deltamethrin (Del). Materials and Methods: In this study, safety evaluation of various vector repellents by oral route in combination with Del was studied by assessing body weight and organ weight changes, hematological parameters, and biochemical parameters in Wistar rats. Results: The results revealed significant changes in liver marker enzymes in Del, Deb, Del + Depa, and Del + Deet groups. Urea levels were significantly altered after treatment with various repellents and in combination with Del, except Deb-alone group. Hematological and rest of the biochemical parameters were found to be unaltered in all the treatment groups. Significant changes in the liver weight were found in Deb, Depa, Deet, Del + Deb, and Del + Deet groups. Conclusions: Taken together, the overall results of this study indicate that single, high oral dose of various insect repellents did not show any additive toxicity.

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Hypnotic effect of red cabbage (Brassica oleracea) on pentobarbital-induced sleep in mice

Azar Hosseini, Mohammad-Ali Sobhanifar, Fatemeh Forouzanfar, Azita Aghaee, Hassan Rakhshandeh

Journal of Pharmacy And Bioallied Sciences 2018 10(1):48-53

Objective: The present study was performed to investigate the effect of hydroalcoholic extract of red cabbage and its fractions on sleeping behavior in mice. Materials and Methods: The extract and its fractions were injected to mice and sleep duration as well as sleep latency were recorded. Furthermore, toxicity of the extract was determined both in vivo and in vitro. Results: The extract increased sleep duration at doses of 50–200mg/kg (P < 0.001). This observed hypnotic effect was comparable to that of diazepam (3mg/kg) (P < 0.001 in comparison with control group). Ethyl acetate, n-butanol, and aqueous fractions could increase sleep duration (P < 0.001). The sleep latency was decreased by the extract (P < 0.001) and only ethyl acetate fraction (P < 0.001). LD50 value for red cabbage extract was 2.4g/kg. There was no toxic effect on viability of cultured neuronal cells (PC12). Rotarod test results showed that there were no significant differences between the extract groups and the control group. Conclusion: The results suggest that red cabbage potentiates pentobarbital hypnosis without any toxic effect. The main component(s) responsible for this effect is most likely to be intermediate polar agent(s) such as flavonoids, which are found in ethyl acetate fraction of this plant.

http://ift.tt/2HNHrcQ

Decrease of Plasma Soluble (Pro)renin Receptor by Bariatric Surgery in Patients with Obstructive Sleep Apnea and Morbid Obesity

Metabolic Syndrome and Related Disorders, Ahead of Print.

http://ift.tt/2FZCaOV

Letter from the Editor: Abdominal Imaging

Publication date: April 2018
Source:Seminars in Ultrasound, CT and MRI, Volume 39, Issue 2
Author(s): Gabriela Gayer

http://ift.tt/2u6ERwh

The anuran skin peptide bradykinin mediates its own absorption across epithelial barriers of the digestive tract

Publication date: Available online 20 March 2018
Source:Peptides
Author(s): Constantijn Raaymakers, Elin Verbrugghe, Benoit Stijlemans, An Martel, Frank Pasmans, Kim Roelants
When faced with a potential predator, a wide range of frog species secrete a mixture of peptide toxins from their skin to defend themselves. We have recently shown that antimicrobial peptides (AMPs) in a frog's defensive poison enhance the uptake of these peptides across epithelia, thereby speeding up the process of predator intoxication. This study provides evidence that bradykinin, a widespread peptide toxin in anurans (frogs), is capable to pass through epithelial barriers independent of this delivery system. We quantified bradykinin peptides secreted by Bombina orientalis during acute stress, and found that at biologically relevant concentrations, bradykinin passage across model epithelia occurs even in the absence of AMPs. Monitoring of transepithelial electric resistance showed that bradykinin treatment caused a subtle yet prolonged reduction in barrier function, indicating that the peptide itself is capable to increase the permeability of epithelia. Yet, bradykinin does not cause cells to leak lactate dehydrogenase, suggesting that it does not damage cell membranes. Moreover, imaging of bradykinin-treated monolayers shows no endocytosis of fluorescent propidium iodide, indicating that the peptide does not perforate cell membranes at smaller scale and therefore is unlikely to cross epithelia via a transcellular passage. Together, these observations suggest that bradykinin, unlike other amphibian neuropeptide toxins, mediates its own passage across mucosal barriers, possibly through a paracellular route. This "self-administering" property, combined with the fact that bradykinins can potently disturb multiple physiological processes, could explain why these peptides are one of the most widespread antipredator peptides in the defensive secretions of frogs.

http://ift.tt/2HNDIvS

Ongoing brain rhythms shape I-wave properties in a computational model

Publication date: Available online 20 March 2018
Source:Brain Stimulation
Author(s): Natalie Schaworonkow, Jochen Triesch
BackgroundResponses to transcranial magnetic stimulation (TMS) are notoriously variable. Previous studies have observed a dependence of TMS-induced responses on ongoing brain activity, for instance sensorimotor rhythms. This suggests an opportunity for the development of more effective stimulation protocols through closed-loop TMS-EEG. However, it is not yet clear how features of ongoing activity affect the responses of cortical circuits to TMS.Objective/HypothesisHere we investigate the dependence of TMS-responses on power and phase of ongoing oscillatory activity in a computational model of TMS-induced I-waves.MethodsThe model comprises populations of cortical layer 2/3 (L2/3) neurons and a population of cortical layer 5 (L5) neurons and generates I-waves in response to TMS. Oscillatory input to the L2/3 neurons induces rhythmic fluctuations in activity of L5 neurons. TMS pulses are simulated at different phases and amplitudes of the ongoing rhythm.ResultsThe model shows a robust dependence of I-wave properties on phase and power of ongoing rhythms, with the strongest response occurring for TMS at maximal L5 depolarization. The amount of phase-modulation depends on stimulation intensity, with stronger modulation for lower intensity.ConclusionThe model predicts that responses to TMS are highly variable for low stimulation intensities if ongoing brain rhythms are not taken into account. Closed-loop TMS-EEG holds promise for obtaining more reliable TMS effects.

http://ift.tt/2FPWLcj

Coming into Focus: Mechanisms of Microtubule Minus-End Organization

Publication date: Available online 20 March 2018
Source:Trends in Cell Biology
Author(s): Maud Martin, Anna Akhmanova
Microtubule organization has a crucial role in regulating cell architecture. The geometry of microtubule arrays strongly depends on the distribution of sites responsible for microtubule nucleation and minus-end attachment. In cycling animal cells, the centrosome often represents a dominant microtubule-organizing center (MTOC). However, even in cells with a radial microtubule system, many microtubules are not anchored at the centrosome, but are instead linked to the Golgi apparatus or other structures. Non-centrosomal microtubules predominate in many types of differentiated cell and in mitotic spindles. In this review, we discuss recent advances in understanding how the organization of centrosomal and non-centrosomal microtubule networks is controlled by proteins involved in microtubule nucleation and specific factors that recognize free microtubule minus ends and regulate their localization and dynamics.

http://ift.tt/2pt6kCV

Comprehensive Protocol to Sample and Process Bone Marrow for Measuring Measurable Residual Disease and Leukemic Stem Cells in Acute Myeloid Leukemia.

Comprehensive Protocol to Sample and Process Bone Marrow for Measuring Measurable Residual Disease and Leukemic Stem Cells in Acute Myeloid Leukemia.

J Vis Exp. 2018 Mar 05;(133):

Authors: Cloos J, Harris JR, Janssen JJWM, Kelder A, Huang F, Sijm G, Vonk M, Snel AN, Scheick JR, Scholten WJ, Carbaat-Ham J, Veldhuizen D, Hanekamp D, Oussoren-Brockhoff YJM, Kaspers GJL, Schuurhuis GJ, Sasser AK, Ossenkoppele G

Abstract
Response criteria in acute myeloid leukemia (AML) has recently been re-established, with morphologic examination utilized to determine whether patients have achieved complete remission (CR). Approximately half of the adult patients who entered CR will relapse within 12 months due to the outgrowth of residual AML cells in the bone marrow. The quantitation of these remaining leukemia cells, known as minimal or measurable residual disease (MRD), can be a robust biomarker for the prediction of these relapses. Moreover, retrospective analysis of several studies has shown that the presence of MRD in the bone marrow of AML patients correlates with poor survival. Not only is the total leukemic population, reflected by cells harboring a leukemia associated immune-phenotype (LAIP), associated with clinical outcome, but so is the immature low frequency subpopulation of leukemia stem cells (LSC), both of which can be monitored through flow cytometry MRD or MRD-like approaches. The availability of sensitive assays that enable detection of residual leukemia (stem) cells on the basis of disease-specific or disease-associated features (abnormal molecular markers or aberrant immunophenotypes) have drastically improved MRD assessment in AML. However, given the inherent heterogeneity and complexity of AML as a disease, methods for sampling bone marrow and performing MRD and LSC analysis should be harmonized when possible. In this manuscript we describe a detailed methodology for adequate bone marrow aspirate sampling, transport, sample processing for optimal multi-color flow cytometry assessment, and gating strategies to assess MRD and LSC to aid in therapeutic decision making for AML patients.

PMID: 29553571 [PubMed - in process]

http://ift.tt/2G6PFzo

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy.

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy.

J Vis Exp. 2018 Feb 20;(132):

Authors: Rosenberry R, Chung S, Nelson MD

Abstract
Exercise represents a major hemodynamic stress that demands a highly coordinated neurovascular response in order to match oxygen delivery to metabolic demand. Reactive hyperemia (in response to a brief period of tissue ischemia) is an independent predictor of cardiovascular events and provides important insight into vascular health and vasodilatory capacity. Skeletal muscle oxidative capacity is equally important in health and disease, as it determines the energy supply for myocellular processes. Here, we describe a simple, non-invasive approach using near-infrared spectroscopy to assess each of these major clinical endpoints (reactive hyperemia, neurovascular coupling, and muscle oxidative capacity) during a single clinic or laboratory visit. Unlike Doppler ultrasound, magnetic resonance images/spectroscopy, or invasive catheter-based flow measurements or muscle biopsies, our approach is less operator-dependent, low-cost, and completely non-invasive. Representative data from our lab taken together with summary data from previously published literature illustrate the utility of each of these end-points. Once this technique is mastered, application to clinical populations will provide important mechanistic insight into exercise intolerance and cardiovascular dysfunction.

PMID: 29553570 [PubMed - in process]

http://ift.tt/2HQWTF2

Titration ELISA as a Method to Determine the Dissociation Constant of Receptor Ligand Interaction.

Titration ELISA as a Method to Determine the Dissociation Constant of Receptor Ligand Interaction.

J Vis Exp. 2018 Feb 15;(132):

Authors: Eble JA

Abstract
The dissociation constant describes the interaction between two partners in the binding equilibrium and is a measure of their affinity. It is a crucial parameter to compare different ligands, e.g., competitive inhibitors, protein isoforms and mutants, for their binding strength to a binding partner. Dissociation constants are determined by plotting concentrations of bound versus free ligand as binding curves. In contrast, titration curves, in which a signal that is proportional to the concentration of bound ligand is plotted against the total concentration of added ligand, are much easier to record. The signal can be detected spectroscopically and by enzyme-linked immunosorbent assay (ELISA). This is exemplified in a protocol for a titration ELISA that measures the binding of the snake venom-derived rhodocetin to its immobilized target domain of α2β1 integrin. Titration ELISAs are versatile and widely used. Any pair of interacting proteins can be used as immobilized receptor and soluble ligand, provided that both proteins are pure, and their concentrations are known. The difficulty so far has been to determine the dissociation constant from a titration curve. In this study, a mathematical function underlying titration curves is introduced. Without any error-prone graphical estimation of a saturation yield, this algorithm allows processing of the raw data (signal intensities at different concentrations of added ligand) directly by mathematical evaluation via non-linear regression. Thus, several titration curves can be recorded simultaneously and transformed into a set of characteristic parameters, among them the dissociation constant and the concentration of binding-active receptor, and they can be evaluated statistically. When combined with this algorithm, titration ELISAs gain the advantage of directly presenting the dissociation constant. Therefore, they may be used more efficiently in the future.

PMID: 29553569 [PubMed - in process]

http://ift.tt/2GeAV1k

Cryopreservation of Zebrafish Spermatogonia by Whole Testes Needle Immersed Ultra-Rapid Cooling.

Cryopreservation of Zebrafish Spermatogonia by Whole Testes Needle Immersed Ultra-Rapid Cooling.

J Vis Exp. 2018 Mar 04;(133):

Authors: Marinović Z, Lujić J, Kása E, Csenki Z, Urbányi B, Horváth Á

Abstract
Current trends in science and biotechnology lead to creation of thousands of new lines in model organisms thereby leading to the necessity for new methods for safe storage of genetic resources beyond the common practices of keeping breeding colonies. The main purpose of this study was to adapt the needle immersed vitrification (NIV) procedure to cryopreserve whole zebrafish testes. Cryopreservation of early-stage germ cells by whole testes NIV offers possibilities for the storage of zebrafish genetic resources, especially since after transplantation they can mature into both male and female gametes. Testes were excised, pinned on an acupuncture needle, equilibrated in two cryoprotective media (equilibration solution containing 1.5 M methanol and 1.5 M propylene glycol; and vitrification solution containing 3 M dimethyl sulfoxide and 3 M propylene glycol) and plunged into liquid nitrogen. Samples were warmed in a series of three consequent warming solutions. The main advantages of this technique are (1) the lack of spermatozoa after digestion of warmed testes thus facilitating downstream manipulations; (2) ultra-rapid cooling enabling the optimal exposure of tissues to liquid nitrogen therefore maximizing the cooling and reducing the required concentration of cryoprotectants, thereby reducing their toxicity; (3) synchronous exposure of several testes to cryoprotectants and liquid nitrogen; and (4) repeatability demonstrated by obtaining viability of above 50% in five different zebrafish strains.

PMID: 29553568 [PubMed - in process]

http://ift.tt/2HSaf3L

Piezo High Accuracy Surgical Osteal Removal (PHASOR): A Technique for Improved Cranial Window Surgery in Mice.

Piezo High Accuracy Surgical Osteal Removal (PHASOR): A Technique for Improved Cranial Window Surgery in Mice.

J Vis Exp. 2018 Mar 02;(133):

Authors: Clark SD, Mikofsky R, Lawson J, Sulzer D

Abstract
Multiphoton microscopy has been widely adapted for imaging neurons in vivo. Repeated imaging requires implantation of a cranial window or repeated thinning of the skull. Cranial window surgery is typically performed with a high speed rotary drill, and many investigators find it challenging to prevent the drill from damaging the delicate dura and blood vessels. Extensive training and practice is required to remove the bone without damage to underlying tissue and thus cranial window surgery can be difficult, time consuming, and produce tissue damage. Piezoelectric surgery, which is extensively used for maxillofacial and dental surgery, utilizes ultrasonic vibrations to remove bone without damaging soft tissues. We have developed a method applying piezoelectric surgery to improve cranial window surgery in mice in preparation for multiphoton imaging. Comparisons within our lab find that the method requires less surgery time and has a lower average rate of complications due to dural bleeding than cranial window surgery with a rotary drill.

PMID: 29553567 [PubMed - in process]

http://ift.tt/2FPwgUv

A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites.

A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites.

J Vis Exp. 2018 Mar 01;(133):

Authors: Xie L, Chen L, Gu P, Wei L, Kang X

Abstract
The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and related diseases, but their precise measurement is still a challenge. Many protocols have been described for neurotransmitter measurement by a variety of instruments, including high-pressure liquid chromatography (HPLC). However, there are shortcomings, such as complicated operation or hard-to-detect multiple targets, which cannot be avoided, and presently, the dominant analysis technique is still HPLC coupled with sensitive electrochemical or fluorimetric detection, due to its high sensitivity and good selectivity. Here, a detailed protocol is described for the pretreatment and detection of catecholamines with high pressure liquid chromatography with electrochemical detection (HPLC-ECD) in real urine samples of infants, using electrospun composite nanofibers composed of polymeric crown ether with polystyrene as adsorbent, also known as the packed-fiber solid phase extraction (PFSPE) method. We show how urine samples can be easily precleaned by a nanofiber-packed solid phase column, and how the analytes in the sample can be rapidly enriched, desorbed, and detected on an ECD system. PFSPE greatly simplifies the pretreatment procedures for biological samples, allowing for decreased time, expense, and reduction of the loss of targets. Overall, this work illustrates a simple and convenient protocol for solid-phase extraction coupled to an HPLC-ECD system for simultaneous determination of three monoamine neurotransmitters (norepinephrine (NE), epinephrine (E), dopamine (DA)) and two of their metabolites (3-methoxy-4-hydroxyphenylglycol (MHPG) and 3,4-dihydroxy-phenylacetic acid (DOPAC)) in infants' urine. The established protocol was applied to assess the differences of urinary catecholamines and their metabolites between high-risk infants with perinatal brain damage and healthy controls. Comparative analysis revealed a significant difference in urinary MHPG between the two groups, indicating that the catecholamine metabolites may be an important candidate marker for early diagnosis of cases at risk for brain damage in infants.

PMID: 29553566 [PubMed - in process]

http://ift.tt/2FWKi2o

Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells (NPCs).

Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells (NPCs).

J Vis Exp. 2018 Mar 02;(133):

Authors: Williams M, Prem S, Zhou X, Matteson P, Yeung PL, Lu CW, Pang Z, Brzustowicz L, Millonig JH, Dicicco-Bloom E

Abstract
Human brain development proceeds through a series of precisely orchestrated processes, with earlier stages distinguished by proliferation, migration, and neurite outgrowth; and later stages characterized by axon/dendrite outgrowth and synapse formation. In neurodevelopmental disorders, often one or more of these processes are disrupted, leading to abnormalities in brain formation and function. With the advent of human induced pluripotent stem cell (hiPSC) technology, researchers now have an abundant supply of human cells that can be differentiated into virtually any cell type, including neurons. These cells can be used to study both normal brain development and disease pathogenesis. A number of protocols using hiPSCs to model neuropsychiatric disease use terminally differentiated neurons or use 3D culture systems termed organoids. While these methods have proven invaluable in studying human disease pathogenesis, there are some drawbacks. Differentiation of hiPSCs into neurons and generation of organoids are lengthy and costly processes that can impact the number of experiments and variables that can be assessed. In addition, while post-mitotic neurons and organoids allow the study of disease-related processes, including dendrite outgrowth and synaptogenesis, they preclude the study of earlier processes like proliferation and migration. In neurodevelopmental disorders, such as autism, abundant genetic and post-mortem evidence indicates defects in early developmental processes. Neural precursor cells (NPCs), a highly proliferative cell population, may be a suitable model in which to ask questions about ontogenetic processes and disease initiation. We now extend methodologies learned from studying development in mouse and rat cortical cultures to human NPCs. The use of NPCs allows us to investigate disease-related phenotypes and define how different variables (e.g., growth factors, drugs) impact developmental processes including proliferation, migration, and differentiation in only a few days. Ultimately, this toolset can be used in a reproducible and high-throughput manner to identify disease-specific mechanisms and phenotypes in neurodevelopmental disorders.

PMID: 29553565 [PubMed - in process]

http://ift.tt/2DEOSjP

Posterior Semicircular Canal Approach for Inner Ear Gene Delivery in Neonatal Mouse.

Posterior Semicircular Canal Approach for Inner Ear Gene Delivery in Neonatal Mouse.

J Vis Exp. 2018 Mar 02;(133):

Authors: Isgrig K, Chien WW

Abstract
Inner ear gene therapy offers great promise as a potential treatment for hearing loss and dizziness. One of the critical determinants of the success of inner ear gene therapy is to find a delivery method which results in consistent transduction efficiency of targeted cell types while minimizing hearing loss. In this study, we describe the posterior semicircular canal approach as a viable method for inner ear gene delivery in neonatal mice. We show that gene delivery through the posterior semicircular canal is able to perfuse the entire inner ear. The easy anatomic identification of the posterior semicircular canal, as well as minimal manipulation of the temporal bone required, make this surgical approach an attractive option for inner ear gene delivery.

PMID: 29553564 [PubMed - in process]

http://ift.tt/2GbKjmA

Preparation, Purification, and Use of Fatty Acid-containing Liposomes.

Preparation, Purification, and Use of Fatty Acid-containing Liposomes.

J Vis Exp. 2018 Feb 09;(132):

Authors: Jin L, Engelhart AE, Adamala KP, Szostak JW

Abstract
Liposomes containing single-chain amphiphiles, particularly fatty acids, exhibit distinct properties compared to those containing diacylphospholipids due to the unique chemical properties of these amphiphiles. In particular, fatty acid liposomes enhance dynamic character, due to the relatively high solubility of single-chain amphiphiles. Similarly, liposomes containing free fatty acids are more sensitive to salt and divalent cations, due to the strong interactions between the carboxylic acid head groups and metal ions. Here we illustrate techniques for preparation, purification, and use of liposomes comprised in part or whole of single chain amphiphiles (e.g., oleic acids).

PMID: 29553563 [PubMed - in process]

http://ift.tt/2HQzCTL

Combustion Chemistry of Fuels: Quantitative Speciation Data Obtained from an Atmospheric High-temperature Flow Reactor with Coupled Molecular-beam Mass Spectrometer.

Combustion Chemistry of Fuels: Quantitative Speciation Data Obtained from an Atmospheric High-temperature Flow Reactor with Coupled Molecular-beam Mass Spectrometer.

J Vis Exp. 2018 Feb 19;(132):

Authors: Köhler M, Oßwald P, Krueger D, Whitside R

Abstract
This manuscript describes a high-temperature flow reactor experiment coupled to the powerful molecular beam mass spectrometry (MBMS) technique. This flexible tool offers a detailed observation of chemical gas-phase kinetics in reacting flows under well-controlled conditions. The vast range of operating conditions available in a laminar flow reactor enables access to extraordinary combustion applications that are typically not achievable by flame experiments. These include rich conditions at high temperatures relevant for gasification processes, the peroxy chemistry governing the low temperature oxidation regime or investigations of complex technical fuels. The presented setup allows measurements of quantitative speciation data for reaction model validation of combustion, gasification and pyrolysis processes, while enabling a systematic general understanding of the reaction chemistry. Validation of kinetic reaction models is generally performed by investigating combustion processes of pure compounds. The flow reactor has been enhanced to be suitable for technical fuels (e.g. multi-component mixtures like Jet A-1) to allow for phenomenological analysis of occurring combustion intermediates like soot precursors or pollutants. The controlled and comparable boundary conditions provided by the experimental design allow for predictions of pollutant formation tendencies. Cold reactants are fed premixed into the reactor that are highly diluted (in around 99 vol% in Ar) in order to suppress self-sustaining combustion reactions. The laminar flowing reactant mixture passes through a known temperature field, while the gas composition is determined at the reactors exhaust as a function of the oven temperature. The flow reactor is operated at atmospheric pressures with temperatures up to 1,800 K. The measurements themselves are performed by decreasing the temperature monotonically at a rate of -200 K/h. With the sensitive MBMS technique, detailed speciation data is acquired and quantified for almost all chemical species in the reactive process, including radical species.

PMID: 29553561 [PubMed - in process]

http://ift.tt/2FPV9zh

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures.

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures.

J Vis Exp. 2018 Feb 08;(132):

Authors: Vaz DC, Lesne E, Sander A, Naganuma H, Jacquet E, Santamaria J, Barthélémy A, Bibes M

Abstract
The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide electronics community. One of its hallmark features is the existence of a critical LAO thickness of 4 unit-cells (uc) for interfacial conductivity to emerge. Although electrostatic mechanisms have been proposed in the past to describe the existence of this critical thickness, the importance of chemical defects has been recently accentuated. Here, we describe the growth of metal/LAO/STO heterostructures in an ultra-high vacuum (UHV) cluster system combining pulsed laser deposition (to grow the LAO), magnetron sputtering (to grow the metal) and X-ray photoelectron spectroscopy (XPS). We study step by step the formation and evolution of the q2DES and the chemical interactions that occur between the metal and the LAO/STO. Additionally, magnetotransport experiments elucidate on the transport and electronic properties of the q2DES. This systematic work not only demonstrates a way to study the electrostatic and chemical interplay between the q2DES and its environment, but also unlocks the possibility to couple multifunctional capping layers with the rich physics observed in two-dimensional electron systems, allowing the fabrication of new types of devices.

PMID: 29553560 [PubMed - in process]

http://ift.tt/2FYjY8i

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine.

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine.

J Vis Exp. 2018 Feb 16;(132):

Authors: Fossey-Jouenne A, Vergne-Vaxelaire C, Zaparucha A

Abstract
Amino alcohols are versatile compounds with a wide range of applications. For instance, they have been used as chiral scaffolds in organic synthesis. Their synthesis by conventional organic chemistry often requires tedious multi-step synthesis processes, with difficult control of the stereochemical outcome. We present a protocol to enzymatically synthetize amino alcohols starting from the readily available L-lysine in 48 h. This protocol combines two chemical reactions that are very difficult to conduct by conventional organic synthesis. In the first step, the regio- and diastereoselective oxidation of an unactivated C-H bond of the lysine side-chain is catalyzed by a dioxygenase; a second regio- and diastereoselective oxidation catalyzed by a regiodivergent dioxygenase can lead to the formation of the 1,2-diols. In the last step, the carboxylic group of the alpha amino acid is cleaved by a pyridoxal-phosphate (PLP) decarboxylase (DC). This decarboxylative step only affects the alpha carbon of the amino acid, retaining the hydroxy-substituted stereogenic center in a beta/gamma position. The resulting amino alcohols are therefore optically enriched. The protocol was successfully applied to the semipreparative-scale synthesis of four amino alcohols. Monitoring of the reactions was conducted by high performance liquid chromatography (HPLC) after derivatization by 1-fluoro-2,4-dinitrobenzene. Straightforward purification by solid-phase extraction (SPE) afforded the amino alcohols with excellent yields (93% to >95%).

PMID: 29553559 [PubMed - in process]

http://ift.tt/2GbUqb1

On-Site Molecular Detection of Soil-Borne Phytopathogens Using a Portable Real-Time PCR System.

On-Site Molecular Detection of Soil-Borne Phytopathogens Using a Portable Real-Time PCR System.

J Vis Exp. 2018 Feb 23;(132):

Authors: DeShields JB, Bomberger RA, Woodhall JW, Wheeler DL, Moroz N, Johnson DA, Tanaka K

Abstract
On-site diagnosis of plant diseases can be a useful tool for growers for timely decisions enabling the earlier implementation of disease management strategies that reduce the impact of the disease. Presently in many diagnostic laboratories, the polymerase chain reaction (PCR), particularly real-time PCR, is considered the most sensitive and accurate method for plant pathogen detection. However, laboratory-based PCRs typically require expensive laboratory equipment and skilled personnel. In this study, soil-borne pathogens of potato are used to demonstrate the potential for on-site molecular detection. This was achieved using a rapid and simple protocol comprising of magnetic bead-based nucleic acid extraction, portable real-time PCR (fluorogenic probe-based assay). The portable real-time PCR approach compared favorably with a laboratory-based system, detecting as few as 100 copies of DNA from Spongospora subterranea. The portable real-time PCR method developed here can serve as an alternative to laboratory-based approaches and a useful on-site tool for pathogen diagnosis.

PMID: 29553557 [PubMed - in process]

http://ift.tt/2FPvYwT

Purification of Hepatocytes and Sinusoidal Endothelial Cells from Mouse Liver Perfusion.

Purification of Hepatocytes and Sinusoidal Endothelial Cells from Mouse Liver Perfusion.

J Vis Exp. 2018 Feb 12;(132):

Authors: Cabral F, Miller CM, Kudrna KM, Hass BE, Daubendiek JG, Kellar BM, Harris EN

Abstract
This protocol demonstrates a method for obtaining high yield and viability for mouse hepatocytes and sinusoidal endothelial cells (SECs) suitable for culturing or for obtaining cell lysates. In this protocol, the portal vein is used as the site for catheterization, rather than the vena cava, as this limits contamination of other possible cell types in the final liver preparation. No special instrumentation is required throughout the procedure. A water bath is used as a source of heat to maintain the temperature of all the buffers and solutions. A standard peristaltic pump is used to drive the fluid, and a refrigerated table-top centrifuge is required for the centrifugation procedures. The only limitation of this technique is the placement of the catheter within the portal vein, which is challenging on some of the mice in the 18 - 25 g size range. An advantage of this technique is that only one vein is utilized for the perfusion and the access to the vein is quick, which minimizes ischemia and reperfusion of the liver that reduces hepatic cell viability. Another advantage to this protocol is that it is easy to distinguish live from dead hepatocytes by eyesight due to the difference in cellular density during the centrifugation steps. Cells from this protocol may be used in cell culture for any downstream application as well as processed for any biochemical assessment.

PMID: 29553556 [PubMed - in process]

http://ift.tt/2HQD1lv

An Objective and Child-friendly Assessment of Arm Function by Using a 3-D Sensor.

An Objective and Child-friendly Assessment of Arm Function by Using a 3-D Sensor.

J Vis Exp. 2018 Feb 12;(132):

Authors: Chen X, Wolf D, Siebourg-Polster J, Czech C, Bonati U, Fischer D, Khwaja O, Strahm M

Abstract
Progressive and irreversible muscle atrophy characterizes Spinal Muscular Atrophy (SMA) and other similar muscle disorder diseases. Objective assessment of muscle functions is an essential and important, although challenging, prerequisite for successful clinical trials. Current clinical rating scales restrain the movement abnormalities to certain predefined coarse-grained individual items. The Kinect 3-D sensor has emerged as a low-cost and portable motion sensing technology used to capture and track people's movement in many medical and research fields. A novel approach using this 3-D sensor was developed and a game-like test was designed to objectively measure the upper limb function of patients with SMA. The prototype test targeted joint movement capability. While sitting in a virtual scene, the patient was instructed to extend, flex, and lift the whole arm in order to reach and place some objects. Both kinematic and spatiotemporal characteristics of upper limb movement were extracted and analyzed, e.g., elbow extension and flexion angles, hand velocity, and acceleration. The first study included a small cohort of 18 ambulant SMA patients and 19 age- and gender-matched healthy controls. A comprehensive analysis of arm movement was achieved; however, no significant difference between the groups were found due to the mismatch of patient's capability and the test difficulty. Based on this experience, a second version of the test consisting of a modified version of the first game with increased difficulties and a second game targeting muscle endurance were designed and implemented. The new test has not been conducted in any patient groups yet. Our work has demonstrated the potential capability of the 3-D sensor in assessing such muscle function and suggested an objective approach to complement the clinical rating scales.

PMID: 29553555 [PubMed - in process]

http://ift.tt/2Gd1UdG

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases.

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases.

J Vis Exp. 2018 Feb 24;(132):

Authors: Mailloux RJ, Young A, O'Brien M, Gill RM

Abstract
It has been reported that mitochondria can contain up to 12 enzymatic sources of reactive oxygen species (ROS). A majority of these sites include flavin-dependent respiratory complexes and dehydrogenases that produce a mixture of superoxide (O2●-) and hydrogen peroxide (H2O2). Accurate quantification of the ROS-producing potential of individual sites in isolated mitochondria can be challenging due to the presence of antioxidant defense systems and side reactions that also form O2●-/H2O2. Use of nonspecific inhibitors that can disrupt mitochondrial bioenergetics can also compromise measurements by altering ROS release from other sites of production. Here, we present an easy method for the simultaneous measurement of H2O2 release and nicotinamide adenine dinucleotide (NADH) production by purified flavin-linked dehydrogenases. For our purposes here, we have used purified pyruvate dehydrogenase complex (PDHC) and α-ketoglutarate dehydrogenase complex (KGDHC) of porcine heart origin as examples. This method allows for an accurate measure of native H2O2 release rates by individual sites of production by eliminating other potential sources of ROS and antioxidant systems. In addition, this method allows for a direct comparison of the relationship between H2O2 release and enzyme activity and the screening of the effectiveness and selectivity of inhibitors for ROS production. Overall, this approach can allow for the in-depth assessment of native rates of ROS release for individual enzymes prior to conducting more sophisticated experiments with isolated mitochondria or permeabilized muscle fiber.

PMID: 29553554 [PubMed - in process]

http://ift.tt/2u5uF7s

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area.

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area.

J Vis Exp. 2018 Feb 19;(132):

Authors: Li C, Jin S, Guan W, Tsang CW, Chu WK, Lau WK, Liang C

Abstract
We demonstrate a method for the synthesis of NixNb1-xO catalysts with sponge-like and fold-like nanostructures. By varying the Nb:Ni ratio, a series of NixNb1-xO nanoparticles with different atomic compositions (x = 0.03, 0.08, 0.15, and 0.20) have been prepared by chemical precipitation. These NixNb1-xO catalysts are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The study revealed the sponge-like and fold-like appearance of Ni0.97Nb0.03O and Ni0.92Nb0.08O on the NiO surface, and the larger surface area of these NixNb1-xO catalysts, compared with the bulk NiO. Maximum surface area of 173 m2/g can be obtained for Ni0.92Nb0.08O catalysts. In addition, the catalytic hydroconversion of lignin-derived compounds using the synthesized Ni0.92Nb0.08O catalysts have been investigated.

PMID: 29553553 [PubMed - in process]

http://ift.tt/2FPUNIX

Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty.

Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty.

J Vis Exp. 2018 Feb 27;(132):

Authors: Kutzner KP, Pfeil J

Abstract
Bone- and soft-tissue sparing short stems are increasingly used in total hip arthroplasty (THA). However, there are a large variety of models of short stems, differing in design and function. Calcar-guided short stems provide an anatomical curvature in the medial calcar region, thus, positioning is done individually alongside the calcar in the "round-the-corner" technique. Depending on the level of the neck's osteotomy, stems can be aligned individually in a large bandwidth of varus- and valgus anatomies. This differs from conventional total hip arthroplasty and potentially includes a severe learning curve. Given that a great variety of caput-collum-diaphyseal (CCD)-angles can be retained, the reconstruction of femoro-acetabular offsets can be achieved precisely. However, particularly extensive varus- and valgus positioning has raised concerns in regard to stability and bone remodeling. The purpose of the present manuscript is to showcase the implantation technique in calcar-guided short-stem THA and to summarize short-term clinical and radiological results.

PMID: 29553552 [PubMed - in process]

http://ift.tt/2u5DCh1

Assessment of dosimetric errors induced by deformable image registration methods in 4D pencil beam scanned proton treatment planning for liver tumours

Publication date: Available online 20 March 2018
Source:Radiotherapy and Oncology
Author(s): Cássia O. Ribeiro, Antje Knopf, Johannes A. Langendijk, Damien C. Weber, Antony J. Lomax, Ye Zhang
PurposeRespiratory impacts in pencil beam scanned proton therapy (PBS-PT) are accounted by extensive 4D dose calculations, where deformable image registration (DIR) is necessary for estimating deformation vector fields (DVFs). We aim here to evaluate the dosimetric errors induced by different DIR algorithms in their resulting 4D dose calculations by using ground truth(GT)-DVFs from 4DMRI.Materials and methodsSix DIR methods: ANACONDA, Morfeus, B-splines, Demons, CT Deformable, and Total Variation, were respectively applied to nine 4DCT-MRI liver data sets. The derived DVFs were then used as input for 4D dose calculation. The DIR induced dosimetric error was assessed by individually comparing the resultant 4D dose distributions to those obtained with GT-DVFs. Both single-/three-field plans and single/rescanned strategies were investigated.ResultsDifferences in 4D dose distributions among different DIR algorithms, and compared to the results using GT-DVFs, were pronounced. Up to 40 % of clinically relevant dose calculation points showed dose differences of 10 % or more between the GT. Differences in V95(CTV) reached up to 11.34 ± 12.57 %. The dosimetric errors became in general less substantial when applying multiple-field plans or using rescanning.ConclusionIntrinsic geometric errors by DIR can influence the clinical evaluation of liver 4D PBS-PT plans. We recommend the use of an error bar for correctly interpreting individual 4D dose distributions.

http://ift.tt/2G7n6ls

The transition from HLA-I positive to HLA-I negative primary tumors: the road to escape from T-cell responses

Natalia Aptsiauri | Francisco Ruiz-Cabello | Federico Garrido

http://ift.tt/2u648qv

Lead and cadmium excretion in feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia

Publication date: July 2018
Source:Chemosphere, Volume 202
Author(s): John Yabe, Shouta M.M. Nakayama, Yoshinori Ikenaka, Yared B. Yohannes, Nesta Bortey-Sam, Abel Nketani Kabalo, John Ntapisha, Hazuki Mizukawa, Takashi Umemura, Mayumi Ishizuka
Lead (Pb) and cadmium (Cd) are toxic metals that exist ubiquitously in the environment. Children in polluted areas are particularly vulnerable to metal exposure, where clinical signs and symptoms could be nonspecific. Absorbed metals are excreted primarily in urine and reflect exposure from all sources. We analyzed Pb and Cd concentrations in blood, feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia, to determine concurrent childhood exposure to the metals. Moreover, the study determined the Pb and Cd relationships among urine, feces and blood as well as accessed the potential of urine and fecal analysis for biomonitoring of Pb and Cd exposure in children. Fecal Pb (up to 2252 mg/kg, dry weight) and urine Pb (up to 2914 μg/L) were extremely high. Concentrations of Cd in blood (Cd-B) of up to 7.7 μg/L, fecal (up to 4.49 mg/kg, dry weight) and urine (up to 18.1 μg/L) samples were elevated. metal levels were higher in younger children (0–3 years old) than older children (4–7). Positive correlations were recorded for Pb and Cd among blood, urine and fecal samples whereas negative correlations were recorded with age. These findings indicate children are exposed to both metals at their current home environment. Moreover, urine and feces could be useful for biomonitoring of metals due to their strong relationships with blood levels. There is need to conduct a clinical evaluation of the affected children to fully appreciate the health impact of these metal exposure.

http://ift.tt/2IBZoMy

Chemical and biological evaluation of moxifloxacin-benzimidazole mixed ligands complexes: Anti-cancer and anti-oxidant activities

Publication date: 5 July 2018
Source:Journal of Molecular Structure, Volume 1163
Author(s): Heba M. Refaat, Doaa A. Noor El-Din
Novel complexes of the formula [M(MOX)(Ben)Cl(H2O)m].nH2O and [Ag(MOX)(Ben)] 3.5H2O; M = Co, Ni, and Zn, n = 1.5, 2 and 1, m = 0 or 2, MOX; Moxifloxacin and Ben; benzimidazole, were synthesized. Their effect on different cancer cells together with bacterial and fungal activity was determined. Formulation of the complexes was based on elemental analyses, different spectrophotometric methods (FT-IR, UV/Vis, NMR), and magnetic studies. FT-IR data indicated that the bonding of the Co(II), Ni(II) and Zn(II) ions with MOX to be achieved through the quinolone and carboxylate oxygen atoms. On the other hand Ag(I) bonded to the MOX through hydro-pyrrolopyridine nitrogen atom. TGA and DTA studies for the metal complexes showed them to possess considerable stability. Thermodynamic parameters ΔE*, ΔS* and ΔH* were evaluated and the appearance of fractional orders suggested that the reactions proceed via complicated mechanisms. The novel mixed ligands complexes were evaluated for their biological activity against the bacterial species (S. aureus) and (E. coli) and the fungal species Aspergillus flavus and Candida albicans. The complexes were found to possess better antibacterial and antifungal activities compared to the Moxifloxacin ligand. The compounds' effects were also screened for their anti-oxidant activity by DPPH method and were tested for their cytotoxicity activity against Breast cancer cell lines (MCF-7), Colon carcinoma cells (HCT) and Hepatocellular carcinoma cells (HepG2) by viability assay method.

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N,N′-dimethyl-N,N′-dicyclohexylsuccinamide: A novel molecule for the separation and recovery of Pd(II) by liquid-liquid extraction

Publication date: 7 August 2018
Source:Separation and Purification Technology, Volume 201
Author(s): Maria Clara Costa, Ana Assunção, Ruben Almeida, Ana Maria Rosa da Costa, Carlos Nogueira, Ana Paula Paiva
N,N′-dimethyl-N,N′-dicyclohexylsuccinamide (DMDCHSA) is investigated as a potential molecule for the liquid-liquid extraction of Pd(II) from chloride solutions for the first time. The effect of several parameters on Pd(II) extraction, such as the contact period between both phases, hydrochloric acid, extractant and hydrogen ion concentrations, is evaluated. Pd(II) extraction equilibrium is very fast (30 s) and the extraction percentage (%E) increases with the HCl concentration in the aqueous phases, being higher than 60% for [HCl] > 5 M. The loading capacity of DMDCHSA for Pd(II) is reasonable (molar ratio extractant/metal higher than 16). Several stripping agents (e.g. distilled water, 1 M HCl, seawater and 20 g/L chloride solution as NaCl) were successfully used to transfer Pd(II) to a new aqueous phase, and data obtained from five successive extraction-stripping cycles suggest a good DMDCHSA stability pattern. Attempts to replace 1,2-dichloroethane (1,2-DCE) by commercial and more environmentally friendly diluents showed much worse %E for Pd(II). Selectivity tests with binary, ternary and more complex metal ion solutions were carried out to evaluate the performance of DMDCHSA towards Pd(II) recovery from 6 M HCl, when in presence of Pt(IV), Fe(III), Zn(II), Al(III) and Ce(III), metal ions usually present in solutions that may result from the hydrometallurgical treatment of spent automobile catalytic converters. It was generally observed that the additional metal ions do not affect the recovery of Pd(II) by DMDCHSA, although Fe(III) and Pt(IV) were co-extracted in a great extent. A solvent extraction (SX) scheme is proposed, based on a previous separation of Fe(III) with tributylphosphate (TBP) and on the selective and sequential stripping of Pt(IV) and Pd(II) from the loaded DMDCHSA with 0.01 M thiourea in 0.5 M HCl and seawater, respectively. The dependence of the Pd(II) distribution ratios on DMDCHSA and acidity, complemented with UV–Visible spectroscopy data, points out to DMDCHSA:Pd(II) extracted species with a 2:1 molar ratio and suggests the occurrence of an outer-sphere ion pair reaction, in which both [PdCl4]²⁻ and HCl are extracted.

http://ift.tt/2pujhfH

Chronopotentiometry of an anion-exchange membrane for treating a synthesized free-cyanide effluent from brass electrodeposition with EDTA as chelating agent

Publication date: 7 August 2018
Source:Separation and Purification Technology, Volume 201
Author(s): Kayo Santana Barros, Denise Crocce Romano Espinosa
The promising substitution of cyanide by EDTA as chelating agent in brass electrodeposition has been evaluated by many researchers in the last few years. This is very interesting for treating the effluent generated, since the presence of EDTA facilitates the recovery of the metals using electrodialysis, for example. Hence, using chronopotentiometry, our aim was to investigate the transport properties of the chelates involved in the potential treatment by electrodialysis of the effluent generated in the free-cyanide brass electrodeposition. We assessed the limiting current density, ohmic resistance, plateau length, concentration polarization and the undesirable precipitate formation in function of the solution pH, Cu²⁺/Zn²⁺ proportion and EDTA/Cu²⁺ molar ratio using the anionic HDX200 membrane. The pH solution showed a strong relation with all the properties and under higher pH, precipitate formation by the curves behavior was verified. Besides, the precipitate formation was also observed for the lower proportion of Cu²⁺, while no unexpected behavior was verified for Cu²⁺ concentrations ≥ Zn²⁺. Finally, the EDTA concentration altered only the limiting current density, since similar typical chronopotentiograms and current-voltage curves were obtained. It was found that the better conditions of the effluent to be treated may be pH 9/10, Cu²⁺ proportion = 50% and EDTA/Cu²⁺ = 2.5.

http://ift.tt/2FE15KL

Photoactivity inhibition of zinc phthalocyanine choline derivatives (Cholosens) by sodium alginate

Publication date: August 2018
Source:Dyes and Pigments, Volume 155
Author(s): Vladimir B. Sheinin, Olga M. Kulikova, Irina M. Lipatova, Anna A. Yusova, Oscar I. Koifman
With the aim of achieving supramolecular structures with controlled phototoxicity of photosensitizer the features of formation, stoichiometry, spectral and aggregation properties of alginate polyelectrolyte complex of Zn-phthalocyanine hepta- and octacholine derivatives were investigated. Chlorides of such Zn-phthalocyanine choline derivatives enter into the composition of photosensitizer Cholosens, developed for photodynamic therapy of oncological and infectious diseases. Cholosens cations possessed high, but different resistance to aggregation. In an aqueous solution saturated with sodium chloride, heptacations exist as H-dimers, in contrast to more hydrophilic octacations. Cholosens interaction with sodium alginate leads to a rapid self-assembly of the alginate polyelectrolyte complex with octacations and heptacations H-dimers. At the equivalence point, a jump-like collapse of the polymer coils occurs to form a suspension of the electroneutral nanogel of polyelectrolyte complex. Cholosens cations fluorescence in obtained nanogel is completely quenched. This fluorescence quenching is due to the H-dimerization of heptacathions, and the octacations interaction with alginate environment inside the polymer coil. Result of this work demonstrates the possibility of the Cholosens phototoxicity inhibition, promising for "on/off" systems developing.

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http://ift.tt/2ppNX1R

Analysis of metal(loid)s contamination and their continuous input in soils around a zinc smelter: Development of methodology and a case study in South Korea

Publication date: July 2018
Source:Environmental Pollution, Volume 238
Author(s): Sung-Wook Yun, Philippe C. Baveye, Dong-Hyeon Kim, Dong-Hyeon Kang, Si-Young Lee, Min-Jae Kong, Chan-Gi Park, Hae-Do Kim, Jinkwan Son, Chan Yu
Soil contamination due to atmospheric deposition of metals originating from smelters is a global environmental problem. A common problem associated with this contamination is the discrimination between anthropic and natural contributions to soil metal concentrations: In this context, we investigated the characteristics of soil contamination in the surrounding area of a world class smelter. We attempted to combine several approaches in order to identify sources of metals in soils and to examine contamination characteristics, such as pollution level, range, and spatial distribution. Soil samples were collected at 100 sites during a field survey and total concentrations of As, Cd, Cr, Cu, Fe, Hg, Ni, Pb, and Zn were analyzed. We conducted a multivariate statistical analysis, and also examined the spatial distribution by 1) identifying the horizontal variation of metals according to particular wind directions and distance from the smelter and 2) drawing a distribution map by means of a GIS tool. As, Cd, Cu, Hg, Pb, and Zn in the soil were found to originate from smelter emissions, and As also originated from other sources such as abandoned mines and waste landfill. Among anthropogenic metals, the horizontal distribution of Cd, Hg, Pb, and Zn according to the downwind direction and distance from the smelter showed a typical feature of atmospheric deposition (regression model: y = y0 + αe^−βx). Lithogenic Fe was used as an indicator, and it revealed the continuous input and accumulation of these four elements in the surrounding soils. Our approach was effective in clearly identifying the sources of metals and analyzing their contamination characteristics. We believe this study will provide useful information to future studies on soil pollution by metals around smelters.

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http://ift.tt/2ptHRxl

Fluoroimmunoassays for the detection of zearalenone in maize using CdTe/CdS/ZnS quantum dots

Publication date: 30 July 2018
Source:Food Chemistry, Volume 255
Author(s): Fuyuan Zhang, Bing Liu, Wei Sheng, Yan Zhang, Qi Liu, Shijie Li, Shuo Wang
CdTe/CdS/ZnS quantum dots (QDs) were synthesized in aqueous phase and conjugated with a new anti-zearalenone (ZEN) monoclonal antibody. Using this novel fluorescent probe, a fluoroimmunoassay (FLISA) and a rapid immunochromatographic strip (ICTS) were developed for the detection of ZEN in maize. Our proposed FLISA allowed for ZEN determination in the range of 0.038–0.977 ng/mL with an IC50 of 0.162 ng/mL and a limit of detection (LOD) of 0.012 ng/mL occurring in maize. The rapid ICTS had a visual LOD of 1.0 ng/mL in buffer solution and 1.5 ng/mL in maize extract. These two QDs-based immunoassays were all successfully verified by commercial ELISA kits. The results confirmed that: firstly, the FLISA can be used as a robust method for the sensitive detection of ZEN; and secondly, the ICTS is ideally suited for rapidly screening large numbers of samples.

http://ift.tt/2IFsTxc

Syntheses, crystal structures and photoluminescence properties of five Cd/Zn–organic frameworks

Publication date: 15 July 2018
Source:Journal of Molecular Structure, Volume 1164
Author(s): Qing Li, Dong-Xu Xue, Yu-Feng Zhang, Zong-Hui Zhang, Ziwei Gao
Luminescent metal–organic frameworks (MOFs) have displayed extensively potential applications for photocatalysis, photoluminescence, electroluminescence, chemical sensors et al. Herein, five new Cd/Zn−organic frameworks of [Cd(HL)C2H5OH] (1), [Cd(HL)(2,2′-Bpy)H2O] (2), [Cd2(HL)2(Phen)2] (3), [Zn(HL)BIMB] (4), [Cd3(HL)3(4,4′-Bpy)DMF]·(H2O) (5) have been deliberately constructed via solvothermal reactions of d¹⁰ transition metal salts, i.e. Cd(NO3)2∙4H2O or Zn(NO3)2·6H2O, and a V-shaped semi-rigid organic linker of 4,4'-(hydroxymethanediyl) dibenzoic acid (H3L) along with the auxiliary poly-nitrogen ligands of 2,2′-Bpy(2,2′-bipyridine), Phen(phenanthroline), BIMB(1,1′-benzene-1,4-diyldimethanediyl-bis-1H-imidazole) and 4,4′-Bpy(4,4′-bipyridine). The crystal structures of compounds 1–5 were precisely determined by single-crystal X-ray diffraction (SC-XRD), Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR) and Thermogravimetic analysis (TGA). As revealed by SC-XRD, the isolated 1 presents a 2-periodic framework encompassing side-by-side channel-typed helical tubes. Compounds 2–4 display Z-shaped 1-periodic single chains, concomitant with twin chains and tubular structure, respectively. Interestingly, compound 5 demonstrates a two-fold interpenetrated 3-periodic skeleton in the presence of a rigid pillar of 4,4′-Bpy. Additionally, photoluminescence properties of 1–5 were lastly investigated.

Graphical abstract

http://ift.tt/2ICYdwi

Spectroscopic characteristic (FT-IR, 1H, 13C NMR and UV–Vis) and theoretical calculations (MEP, DOS, HOMO-LUMO, PES, NBO analysis and keto–enol tautomerism) of new tetradentate N,N′-bis(4-hydroxysalicylidene)-1,4-phenylenediamine ligand as chelating agent for the synthesis of dinuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes

Publication date: 5 July 2018
Source:Journal of Molecular Structure, Volume 1163
Author(s): Iman Rajaei, Seyed Nezamoddin Mirsattari
The synthesis and characterization of a novel symmetrical Schiff base ligand N,Nʹ-bis(4-hydroxysalicylidene)-1,4-phenylenediamine (BHSP) was presented in this study and characterized by FT-IR, NMR (¹H and ¹³C) and UV–Vis spectroscopy experimentally and theoretically. Also a series of binuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes of BHSP ligand have been synthesized by conventional sequential route in 1:1 equivalent of L:M ratio and characterized by routine physicochemical characterizations. The molecular geometry and vibrational frequencies of the BHSP in the ground state were calculated by using density functional theory (DFT) B3LYP method invoking 6-31G(d,p) and 6–31++G(d,p) basis sets. To study different conformations of the molecule, potential energy surface (PES) scan investigations were performed. The energetic behavior of the ligand compound (BHSP) in solvent media has been examined using B3LYP method with the 6-31G(d,p) and 6–31++G(d,p) basis sets by applying the polarized continuum model (PCM). In addition, DFT calculations of the BHSP ligand, molecular electrostatic potential (MEP), contour map, natural bond orbital (NBO) analysis, frontier molecular orbitals (FMO) analysis, NMR analysis and TD-DFT calculations were conducted. The calculated properties are in agreement with the available experimental data and closely related molecule BSP. The calculated results show that the optimized geometry can well reproduce the crystal structural parameters.

Graphical abstract

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Synthesis, characterization, antimicrobial activity and DFT studies of 2-(pyrimidin-2-ylamino)naphthalene-1,4-dione and its Mn(II), Co(II), Ni(II) and Zn(II) complexes

Publication date: 5 July 2018
Source:Journal of Molecular Structure, Volume 1163
Author(s): Festus Chioma, Anthony C. Ekennia, Collins U. Ibeji, Sunday N. Okafor, Damian C. Onwudiwe, Aderoju A. Osowole, Oguejiofo T. Ujam
A pyrimidine-based ligand, 2-(pyrimidin-2-ylamino)naphthalene-1,4-dione (L), has been synthesized by the reaction of 2-aminopyrimidine with 2-hydroxy-1,4-napthoquinone. Reaction of the ligand with Ni(II), Co(II), Mn(II) and Zn(II) acetate gave the corresponding metal complexes which were characterized by spectroscopic techniques, (infrared, electronic), elemental analysis, room-temperature magnetometry, conductance measurements and thermogravimetry-differential scanning calorimetry (TG-DSC) analyses. The room-temperature magnetic data and electronic spectral measurements of the complexes gave evidence of 4-coordinate square planar/tetrahedral geometry. The thermal analyses values obtained indicated the monohydrate complexes. The antimicrobial screening of the compounds showed mild to very good results. The Mn(II) complex showed the best result within in the range of 11.5–29 mm. The electronic, structural and spectroscopic properties of the complexes were further discussed using density functional theory. Molecular docking studies showed significant binding affinity with the drug targets and the metal complexes have potentials to be used as drugs.

Graphical abstract

http://ift.tt/2ICYf7o

Αρχειοθήκη ιστολογίου

! # Ola via Alexandros G.Sfakianakis on Inoreader

Η λίστα ιστολογίων μου

Τρίτη 20 Μαρτίου 2018

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