Both perforin and FasL are required for optimal CD8 T cell control of autoreactive B cells and autoantibody production in parent-into-F1 lupus mice

Publication date: Available online 22 June 2018
Source:Clinical Immunology
Author(s): Kateryna Soloviova, Maksym Puliaiev, Roman Puliaev, Irina Puliaeva, Charles S. Via
To test the relative roles of perforin (pfp) vs. FasL in CTL control of autoreactive B cell expansion, we used the parent-into-F1 model of murine graft-vs.–host disease in which donor CD8 CTL prevent lupus like disease by eliminating activated autoreactive B cells. F1 mice receiving either pfp or FasL defective donor T cells exhibited an intermediate short-term phenotype. Pairing of purified normal CD4 T cells with either pfp or FasL defective CD8 T cell subsets resulted in impaired host B cell elimination and mild lupus like disease that was roughly equivalent in the two experimental groups. Thus, in addition to major roles in tumor and intracellular pathogen control, pfp mediated CD8 CTL killing plays a significant role in controlling autoreactive B cell expansion and lupus downregulation that is comparable to that mediated by FasL killing. Importantly, both pathways are required for optimal elimination of activated autoreactive B cells.



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Soluble ST2 suppresses IL-5 production by human basophilic KU812 cells, induced by epithelial cell-derived IL-33

Publication date: Available online 22 June 2018
Source:Allergology International
Author(s): Koji Matsumoto, Hideaki Kouzaki, Hirotaka Kikuoka, Tomohisa Kato, Ichiro Tojima, Shino Shimizu, Takeshi Shimizu
BackgroundEpithelial cell-derived IL-33 has an important role in the initiation and activation of innate allergic inflammation. IL-33 acts as a cytokine through the ST2 receptor (ST2L) and it stimulates the production of Th2 cytokines. Soluble ST2 (sST2) may regulate Th2 responses by neutralizing the activity of IL-33. Basophils express ST2L and produce IL-5 in response to IL-33. However, the role of the epithelial cell–basophil interaction and sST2 in IL-5 production remains unclear.MethodsCultured human bronchial epithelial (hBE33) cells, that contained the human IL-33 gene (i.e., hBE33 cells) and a human basophilic cell line, KU812 cells, were used to study the epithelial cell–basophil interaction in the production of IL-5 induced by HDM.ResultsAt 15 min after incubation, HDM stimulated the rapid release of IL-33 from cultured hBE33 cells. IL-33 and the supernatant of HDM-treated hBE33 cells stimulated IL-5 production from KU812 cells. Anti-IL-33 antibody and anti-ST2 antibody treatment of KU812 cells suppressed IL-5 production, which had been induced by the supernatant of HDM-treated hBE33 cells. The hBE33 cells secreted sST2 in a time-dependent manner. The production of sST2 by KU812 cells co-cultured with hBE33 cells was significantly increased, compared with KU812 cells cultured with the supernatant of hBE33 cells. Soluble ST2 suppressed IL-5 production by KU812 cells, which was induced by the supernatant of HDM-treated hBE33 cells.ConclusionsEpithelial cell-derived IL-33 promoted IL-5 production by KU812 cells. The subsequently produced sST2 has important roles in regulating Th2 responses.



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Highly sensitive pressure sensors employing 3C-SiC nanowires fabricated on a free standing structure

Publication date: 15 October 2018
Source:Materials & Design, Volume 156
Author(s): Hoang-Phuong Phan, Karen M. Dowling, Tuan Khoa Nguyen, Toan Dinh, Debbie G. Senesky, Takahiro Namazu, Dzung Viet Dao, Nam-Trung Nguyen
This paper presents highly sensitive pressure sensors using piezoresistive nanowires. Our approach is based on nanowires locally fabricated on free standing structures with a high strain concentration. This strain concentration phenomenon amplifies the strain induced into nano-scaled sensing elements while the bulk materials are still at small strain regime, therefore enhancing the sensitivity of the sensors. For proof of concept, we utilized SiC nanowire fabricated using focused ion beam from an epitaxially grown thin film. Experimental results show significant 3-fold enhancement in the sensitivity in comparison to conventional structures, which is in good agreement with analytical modeling and numerical simulation. The proposed design shows potential for the development of miniaturized highly sensitive but robust nano mechanical-sensors.

Graphical abstract

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Temperature-dependent modelling of a HNBR O-ring seal above and below the glass transition temperature

Publication date: 15 October 2018
Source:Materials & Design, Volume 156
Author(s): J. Troufflard, H. Laurent, G. Rio, B. Omnès, S. Javanaud
Sealing products can undergo many different atmospheric conditions and hence large variations in the in-service temperatures. These products, typically made of elastomer, are known to have heat sensitive mechanical characteristics. Since the reliability of sealing systems can be affected by cyclic temperature conditions, it is essential to predict seal performances depending on the temperature in order to prevent the occurrence of interfacial leaks. The aim of the present study is to simulate the thermo-mechanical behavior of a HNBR O-ring seal during a temperature cycle ranging from room temperature to low temperatures down to −34 °C. The main objective is to present the construction and the thermal dependency of a hyperelasto-visco-hysteresis (HVH) model so as to be able to predict the mechanical behavior of the elastomer in function of temperature. This phenomenological model is designed in the form of a combination of hyperelastic, viscoelastic and elasto-hysteretic stress contributions. The relevant parameters are identified using a material database based on the results of classical homogeneous isothermal relaxation tests and anisothermal relaxation tests. The predictions of the HVH model obtained shows good agreement with the experimental contact force during a 20% squeezed O-ring test under cyclic thermal loading below the glass transition temperature.

Graphical abstract

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Carbon quantum dots/TiO2 nanocomposite for sensing of toxic metals and photodetoxification of dyes with kill waste by waste concept

Publication date: 5 October 2018
Source:Materials & Design, Volume 155
Author(s): Akansha Mehta, Amit Mishra, Shagun Kainth, Soumen Basu
The exposure of even low amount of heavy metals and industrial dyes in wastewater leads to cardiovascular, neurological and developmental disorders. Consequently, millions of inorganic and organic pollutants containing toxic heavy metals have been accounted as water contaminants. In this report, a novel approach has been designed based on the methodology to "kill waste by waste". Firstly the toxic metals like lead (Pb) ions were detected using fluorescence carbon quantum dots (CQDs) and after impregnation of TiO2 into the same Pb-CQDs composite, it was further used for photodegradation of harmful industrial dyes. The CQDs have been designed as a nanosensor for Pb ion detection and its fluorescence is effectively quenched with good sensitivity (0.070 μM) and selectivity. This Pb-CQDs solution was further immersed in TiO2 by wet impregnation method to fabricate Pb-CQDs-TiO2 (PCT) nanocomposite with a change in the energy gap (3.2 to 2.8 eV) making the composite active in visible light irradiation. The degradation efficiency achieved ~100% mark for RBX dye and 1.8 μmols of CO2 evolution was observed in 60 min. The plausible mechanism is proposed based on GCMS studies suggesting the formation of intermediates like triazine and aryl sodium sulphonates before complete decomposing into CO2 and water.

Graphical abstract

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Corrigendum to “Microsphere lithography for scalable polycrystalline diamond-based near-infrared photonic crystals fabrication” [Materials and Design 139 (2018) 363–371]

Publication date: 5 October 2018
Source:Materials & Design, Volume 155
Author(s): Mária Domonkos, Marián Varga, Lukáš Ondič, Lenka Gajdošová, Alexander Kromka




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Photoelectrocatalytic degradation of atrazine by boron-fluorine co-doped TiO 2 nanotube arrays

Abstract

Atrazine, one of the most widespread herbicides in the world, is considered as an environmental estrogen and has potential carcinogenicity. In this study, atrazine was degraded on boron-fluorine co-doped TiO₂ nanotube arrays (B, F-TiO₂ NTAs), which had similar morphology with the pristine TiO₂ NTAs. The structure and morphology of TiO₂ nanotube samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-visible diffuse reflectance spectroscopy (DRS). It showed that the decoration of fluorine and boron made both the absorption in the visible region enhanced and the band edge absorption shifted. The efficiency of atrazine degradation by B, F-TiO₂ NTAs through photoelectrocatalysis was investigated by current, solution pH, and electrolyte concentration, respectively. The atrazine removal rate reached 76% through photoelectrocatalytic reaction by B, F-TiO₂ NTAs, which was 46% higher than that under the photocatalysis process. Moreover, the maximum degradation rate was achieved at pH of 6 in 0.01 M of Na₂SO₄ electrolyte solution under a current of 0.02 A and visible light for 2 h in the presence of B, F-TiO₂ NTAs. These results showed that B, F-TiO₂ NTAs exhibit remarkable photoelectrocatalytic activity in degradation of atrazine.

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