Determination of cadmium in sediments by diluted HCI extraction and isotope dilution ICP-MS

Publication date: 15 August 2018
Source:Talanta, Volume 186
Author(s): Javier Terán-Baamonde, Rosa-María Soto-Ferreiro, Alatzne Carlosena, José-Manuel Andrade, Darío Prada
Isotope dilution ICP-MS is proposed to measure the mass fraction of Cd extracted by diluted HCl in marine sediments, using a fast and simple extraction procedure based on ultrasonic probe agitation. The ¹¹¹Cd isotope was added before the extraction to achieve isotope equilibration with native Cd solubilized from the sample. The parameters affecting trueness and precision of isotope ratio measurements were evaluated carefully and subsequently corrected in order to minimize errors; they were: detector dead time, spectral interferences, mass discrimination factor and optimum sample/spike ratio. The mass fraction of Cd extracted was compared with the sum of the certified contents of the three steps of the sequential extraction procedure of the Standards, Measurements and Testing Programme (SM&T) analysing the BCR 701 sediment to validate the method. The certified and measured values agreed, giving a measured / certified mass fraction ratio of 1.05. Further, the extraction procedure itself was studied by adding the enriched isotope after the extraction step, which allowed verifying that analyte losses occurred during this process. Two additional reference sediments with certified total cadmium contents were also analysed. The method provided very good precision (0.9%, RSD) and a low detection limit, 1.8 ng g⁻¹. The procedural uncertainty budget was estimated following the EURACHEM Guide by means of the 'GUM Workbench' software, obtaining a relative expanded uncertainty of 1.5%. The procedure was applied to determine the bioaccessible mass fraction of Cd in sediments from two environmentally and economically important areas of Galicia (rias of Arousa and Vigo, NW of Spain).

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Short-probe-based duplex-specific nuclease signal amplification strategy enables imaging of endogenous microRNAs in living cells with ultrahigh specificity

Publication date: 15 August 2018
Source:Talanta, Volume 186
Author(s): Yingjun Ma, Jun Chen, Danping Chen, Yuzhi Xu, Li Zhang, Zong Dai, Xiaoyong Zou
Specific nucleic acids amplification at a constant and mild temperature is important for imaging assay of endogenous microRNAs (miRNAs) in living cells. Duplex-specific nuclease (DSN) is attractive in one-step isothermal assay of miRNA; however, its intrinsic limitations of low amplification specificity and high reaction temperature greatly restrict the application scope. Herein, we present a short-probe-based DSN signal amplification (spDSNSA) strategy enabling analysis of miRNAs at body temperature with significantly high specificity. From systematic investigation of amplification reaction on different types of DNA probes, we revealed that the annealing rate between probe and target miRNA greatly affects the dynamics of amplification process. By simply shortening the length of DNA probe, the spDSNSA remarkably improved specificity without loss of amplification efficiency at 37 °C. As a proof-of-concept, let-7a was sensitively detected by spDSNSA with a limit of detection down to 30 p.M., and a specificity 10² ‒ 10⁴ folds higher than those of traditional DSNSA methods. The analysis of the let-7a in the lysates of A549 human lung cancer cells and BEAS-2B human lung normal bronchial epithelial cells exhibited well agreement with rt-qPCR method. Furthermore, the endogenous let-7a in A549 and BEAS-2B living cells was clearly imaged without damaging the original morphology of cells. The method provide a facile idea for extension of DNS related signal amplification strategies in the application in living cells and POCTs, and would pose a great impact on the development of simple and rapid molecular diagnostic applications for short oligonucleotides.

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A sensitively non-enzymatic amperometric sensor and its application in living cell superoxide anion radical detection

Publication date: 15 August 2018
Source:Talanta, Volume 186
Author(s): Xinhe Liu, Miaomiao Ran, Guoan Liu, Xiuhui Liu, Zhonghua Xue, Xiaoquan Lu
Here, we report a nanocomposite composed of silver nanoparticles and multi-walled carbon nanotubes (AgNPs/MWNTs) utilized as an efficient electrode material for sensitive detection superoxide anion (O2^•−). The procedure to synthesize AgNPs/MWNTs nanocomposites was green and facile. In the presence of functionalized multi-wall carbon nanotubes (MWNTs), silver nanoparticles (AgNPs) were in situ generated by chemical reduction of silver nitrate with glucose as a reducing and stabilizing agent to give the desired AgNPs/MWNTs nanocomposites. The nanocomposites can be easily used for the construction of an electrochemical sensor on glassy carbon electrode (GCE). The characterization of sensor and experimental parameters affecting its activity were investigated employing scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), X-ray diffraction (XRD), and cyclic voltammetry (CV). The resulted sensor exhibited favorable electrochemical performance for O2^•− sensing with a low detection limit of 0.1192 nM and wide linear range of 6 orders of magnitude, which guarantees the capacity of sensitive and credible detection of O2^•− released from living cells. Notably, a simulation experiment indicated the capacity to resist oxidative stress is limited in biological milieu. Thus this work has great potential for further applications in biological researches.

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Facile fabrication of ternary TiO2-gold nanoparticle-graphene oxide nanocomposites for recyclable surface enhanced Raman scattering

Publication date: 15 August 2018
Source:Talanta, Volume 186
Author(s): Lu-Lu Qu, Na Wang, Gen Zhu, T.P. Yadav, Xinting Shuai, Dandan Bao, Guohai Yang, Dawei Li, Haitao Li
A bi-functional ternary nanocomposite was developed by decorating TiO2 and gold nanoparticles on the reduced graphene oxide nanosheets (TiO2-Au-rGO) for recyclable surface enhanced Raman scattering (SERS) detection. TiO2-Au-rGO nanocomposites have been shown to demonstrate the superior SERS performances, which can be used for highly sensitive detection of rhodamine 6 G with a limit of detection of 1.2 × 10⁻¹⁰ M. Subsequently, the surface can be cleaned automatically by the photocatalytic degradation of the adsorbed analytes into inorganic small molecules under visible light irradiation. This can be attributed to the excellent photocatalytic degradation ability, leading to a recyclable SERS application. After being used four times, their excellent SERS and catalytic performances can still be retained. These results suggest that the TiO2-Au-rGO nanocomposites can provide a new strategy for fabricating recyclable SERS substrates, which are highly desirable for SERS practical application.

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Regulatory T cells increase after treatment with poly (ADP-ribose) polymerase-1 inhibitor in ischemic stroke patients

Publication date: July 2018
Source:International Immunopharmacology, Volume 60
Author(s): Min-Young Noh, Won Moo Lee, Su-Jung Lee, Hyun Young Kim, Seung Hyun Kim, Young Seo Kim
BackgroundRegulatory T cells (Tregs) are thought to play a modulatory role in immune responses and to improve outcomes after ischemic stroke. Thus, various strategies for increasing Tregs in animal models of ischemic stroke have yielded successful results. The aim of this study was to examine the potential effect of poly (ADP-ribose) polymerase-1 (PARP-1) inhibitor on Treg proportion in stroke patients.MethodsPeripheral blood samples were collected from 12 ischemic stroke patients (within 72 h of stroke onset) and 5 healthy control subjects. Flow cytometry analyses and quantitative reverse transcription polymerase chain reactions (qRT-PCR) were performed on peripheral blood mononuclear cells (PBMCs) before and after treating them with PARP-1 inhibitor (3-AB; JPI-289 1 μm, JPI-289 10 μm) for 24 h.ResultsTreg proportions were significantly higher in healthy controls (median 2.8%, IQR 2.6–5.0%) than ischemic stroke patients (median 1.6%, IQR 1.25–2.2%) (p < 0.001). In the latter, Treg proportions were positively correlated with age (r = 0.595, p = 0.041), but not with infarct volume (r = 0.367, p = 0.241). After PARP-1 inhibitor treatment, Treg proportions among PBMCs increased in response to high dose (10 μm) JPI-289 (median 2.3%, IQR 2.0–2.9%) as did Treg-associated transcription factors such as FoxP3 and CTLA-4 mRNA. PARP-1 inhibitor treatment also decreased pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-17) and increased anti-inflammatory cytokines (IL-4, IL-10, and TGF-β1).ConclusionTreg proportions are reduced in ischemic stroke patients and increased by treatment with high-dose PARP-1 inhibitor JPI-289. The PARP-1 inhibitor also had a possible anti-inflammatory effect on cytokine levels, and may ameliorate the outcome of ischemic stroke by up-regulating Tregs.



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Phonological processes in the speech of school-age children with hearing loss: Comparisons with children with normal hearing

Publication date: Available online 27 April 2018
Source:Journal of Communication Disorders
Author(s): Areej Nimer Asad, Suzanne C Purdy, Elaine Ballard, Liz Fairgray, Caroline Bowen
PurposeIn this descriptive study, phonological processes were examined in the speech of children aged 5;0-7;6 (years; months) with mild to profound hearing loss using hearing aids (HAs) and cochlear implants (CIs), in comparison to their peers. A second aim was to compare phonological processes of HA and CI users.MethodChildren with hearing loss (CWHL, N = 25) were compared to children with normal hearing (CWNH, N = 30) with similar age, gender, linguistic, and socioeconomic backgrounds. Speech samples obtained from a list of 88 words, derived from three standardized speech tests, were analyzed using the CASALA (Computer Aided Speech and Language Analysis) program to evaluate participants' phonological systems, based on lax (a process appeared at least twice in the speech of at least two children) and strict (a process appeared at least five times in the speech of at least two children) counting criteria.ResultsDevelopmental phonological processes were eliminated in the speech of younger and older CWNH while eleven developmental phonological processes persisted in the speech of both age groups of CWHL. CWHL showed a similar trend of age of elimination to CWNH, but at a slower rate. Children with HAs and CIs produced similar phonological processes. Final consonant deletion, weak syllable deletion, backing, and glottal replacement were present in the speech of HA users, affecting their overall speech intelligibility.ConclusionsDevelopmental and non-developmental phonological processes persist in the speech of children with mild to profound hearing loss compared to their peers with typical hearing. The findings indicate that it is important for clinicians to consider phonological assessment in pre-school CWHL and the use of evidence-based speech therapy in order to reduce non-developmental and non-age-appropriate developmental processes, thereby enhancing their speech intelligibility.



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Treatment of post-intubation laryngeal granulomas: systematic review and proportional meta-analysis.

Related Articles

Treatment of post-intubation laryngeal granulomas: systematic review and proportional meta-analysis.

Braz J Otorhinolaryngol. 2018 Apr 14;:

Authors: Rimoli CF, Martins RHG, Catâneo DC, Imamura R, Catâneo AJM

Abstract
INTRODUCTION: Laryngeal granulomas post intubation are benign but recurrent lesions. There is no consensus for its treatment.
OBJECTIVE: To describe the effectiveness of different treatment modalities for primary or recurrent laryngeal granulomas resulting from endotracheal intubation.
METHODS: Systematic review and proportional meta-analysis. Eligibility criteria - experimental or observational studies with at least five subjects. Outcomes studied - granuloma resolution, recurrence, and time for resolution. Databases used - Pubmed, Embase, Lilacs, and Cochrane. The Stats Direct 3.0.121 program was used.
RESULTS: Six studies were selected, with 85 patients. The treatments registered were: antireflux therapy, speech therapy, anti-inflammatory drugs, steroids, antibiotics, zinc sulfate and surgery. 85 patients from six studies had primary treatment: surgery±associations (41 patients), resolution chance 75% (95% CI: 0.3-100%, I2=90%), absolute relapse risk 25% (95% CI: 0.2-71%); medical treatment (44 patients), resolution chance 86% (95% CI: 67-97%); and absolute relapse risk 14% (95% CI: 3-33%). There was no significant difference between groups. Three studies, encompassing 19 patients, analyzed secondary treatment (failure or recurrence after primary treatment); three subjects presented new recurrence. The time needed to resolve the lesions varied from immediate, after surgery, to 23 months, for inhaled steroid.
CONCLUSION: There is no evidence of high quality that proves the efficacy of any treatment for laryngeal granulomas resulting from endotracheal intubation.

PMID: 29699879 [PubMed - as supplied by publisher]

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