A facile wet chemistry approach towards unilamellar tin sulfide nanosheets from Li4xSn1-xS2 solid solutions

We report on the facile production of single-layered tin sulfide nanosheets by a direct solid-state reaction, followed by quantitative liquid exfoliation in water. The new solid solution of SnS2 and Li2S with composition Li4xSn1-xS2 serves as a versatile solid-state precursor with tunable relative lithium and tin content. The end member Li2SnS3, corresponding to the solid solution composition Li-3xLixSn1-xS2], crystallizes in the well-known A(2)BO(3) structure type with mixed Li/Sn layers alternating with pure Li layers in the cationic substructure, which is interleaved with sulfur layers. The bonding in the Li layers can be regarded as ionic, while the Sn-S bonds have substantial covalent character. The resulting inherent anisotropy allows for the facile production of unilamellar chalcogenide nanosheets with thicknesses below 1 nm and lateral sizes of tens of microns, simply by shaking the crystalline precursor in water. The quantitative exfoliation into single-layered nanosheets was confirmed using optical microscopy, AFM, TEM, as well as X-ray diffraction of freestanding films produced from the colloidal suspension by centrifugation. Upon annealing, the as-obtained nanosheets are converted into SnS2 without sacrificing their favorable dispersion properties in water. The presented method allows for the cheap and scalable production of unilamellar chalogenide nanosheets for various potential applications, such as in electronic devices, solar cells, sensors, or battery technology. We expect this method to be generic and transferable to the synthesis of other metal chalcogenides. The use of solid solutions as solid-state precursors, featuring a large compositional range and potential for doping with other metals, may ultimately allow for the controlled introduction of defect levels and rational band-gap engineering in nanosheet materials

Nanosilver/DCOIT-containing surface coating effectively and constantly reduces microbial load in emergency room surfaces

Background Colonization of near-patient surfaces in hospitals plays an important role as a source of healthcare-associated infections. Routine disinfection methods only result in short-term elimination of pathogens. Aim To investigate the efficiency of a newly developed antimicrobial coating containing nanosilver in long-term reduction of bacterial burden in hospital surfaces to close the gap between routine disinfection cycles. Methods In this prospective, double-blinded trial, frequently touched surfaces of a routinely used treatment room in an emergency unit of a level-I hospital were treated with a surface coating (nanosilver/DCOIT-coated surface, NCS) containing nanosilver particles and another organic biocidal agent (4,5-dichloro-2-octyl-4-isothiazolin-3-one, DCOIT), whereas surfaces of another room were treated with a coating missing both the nanosilver- and DCOIT-containing ingredient and served as control. Bacterial contamination of the surfaces was examined using contact plates and liquid-based swabs daily for a total trial duration of 90 days. After incubation, total microbial counts and species were assessed. Findings In a total of 2880 antimicrobial samples, a significant reduction of the overall bacterial load was observed in the NCS room (median: 0.31 cfu/cm2; interquartile range: 0.00–1.13) compared with the control coated surfaces (0.69 cfu/cm2; 0.06–2.00; P 5 cfu/cm2) by 60% (odds ratio 0.38, P < 0.001). No significant difference in species distribution was detected between NCS and control group. Conclusion Nanosilver-/DCOIT-containing surface coating has shown efficiency for sustainable reduction of bacterial load of frequently touched surfaces in a clinical setting

Comparable cellular and humoral immunity upon homologous and heterologous COVID-19 vaccination regimens in kidney transplant recipients

BackgroundKidney transplant recipients (KTRs) are at high risk for a severe course of coronavirus disease 2019 (COVID-19); thus, effective vaccination is critical. However, the achievement of protective immunogenicity is hampered by immunosuppressive therapies. We assessed cellular and humoral immunity and breakthrough infection rates in KTRs vaccinated with homologous and heterologous COVID-19 vaccination regimens.MethodWe performed a comparative in-depth analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–specific T-cell responses using multiplex Fluorospot assays and SARS-CoV-2-specific neutralizing antibodies (NAbs) between three-times homologously (n = 18) and heterologously (n = 8) vaccinated KTRs.ResultsWe detected SARS-CoV-2-reactive T cells in 100% of KTRs upon third vaccination, with comparable frequencies, T-cell expression profiles, and relative interferon γ and interleukin 2 production per single cell between homologously and heterologously vaccinated KTRs. SARS-CoV-2-specific NAb positivity rates were significantly higher in heterologously (87.5%) compared to homologously vaccinated (50.0%) KTRs (P &lt; 0.0001), whereas the magnitudes of NAb titers were comparable between both subcohorts after third vaccination. SARS-CoV-2 breakthrough infections occurred in equal numbers in homologously (38.9%) and heterologously (37.5%) vaccinated KTRs with mild-to-moderate courses of COVID-19.ConclusionOur data support a more comprehensive assessment of not only humoral but also cellular SARS-CoV-2-specific immunity in KTRs to provide an in-depth understanding about the COVID-19 vaccine–induced immune response in a transplant setting

A facile wet chemistry approach towards unilamellar tin sulfide nanosheets from Li4xSn1-xS2 solid solutions

We report on the facile production of single-layered tin sulfide nanosheets by a direct solid-state reaction, followed by quantitative liquid exfoliation in water. The new solid solution of SnS2 and Li2S with composition Li4xSn1-xS2 serves as a versatile solid-state precursor with tunable relative lithium and tin content. The end member Li2SnS3, corresponding to the solid solution composition Li-3xLixSn1-xS2], crystallizes in the well-known A(2)BO(3) structure type with mixed Li/Sn layers alternating with pure Li layers in the cationic substructure, which is interleaved with sulfur layers. The bonding in the Li layers can be regarded as ionic, while the Sn-S bonds have substantial covalent character. The resulting inherent anisotropy allows for the facile production of unilamellar chalcogenide nanosheets with thicknesses below 1 nm and lateral sizes of tens of microns, simply by shaking the crystalline precursor in water. The quantitative exfoliation into single-layered nanosheets was confirmed using optical microscopy, AFM, TEM, as well as X-ray diffraction of freestanding films produced from the colloidal suspension by centrifugation. Upon annealing, the as-obtained nanosheets are converted into SnS2 without sacrificing their favorable dispersion properties in water. The presented method allows for the cheap and scalable production of unilamellar chalogenide nanosheets for various potential applications, such as in electronic devices, solar cells, sensors, or battery technology. We expect this method to be generic and transferable to the synthesis of other metal chalcogenides. The use of solid solutions as solid-state precursors, featuring a large compositional range and potential for doping with other metals, may ultimately allow for the controlled introduction of defect levels and rational band-gap engineering in nanosheet materials

Impaired Immune Responses and Prolonged Allograft Survival in Sly1 Mutant Mice

Adaptive immunity is crucial for protective host defense and the development of immunological disorders. SLY1 was recently identified as an X-chromosomal SH3 protein that is serine phosphorylated (Ser27) upon B-and T-cell receptor engagement. Here, we demonstrate that SLY1 is localized in the cytoplasm and the nucleus of immunocytes. We generated mice expressing a mutant version of SLY1 lacking Ser27 and a functional nuclear localization signal. The defective SLY1 (SLY1(d)) protein is localized exclusively in the cytoplasm. B- and T-cell proliferation is attenuated and T-cell cytokine production is severely reduced. Sly1(d/d) mice exhibit reduced lymphoid organ sizes, diminished marginal zone B-cell numbers, and severely impaired antibody responses against T-dependent and -independent antigens. Importantly, survival of semi-identical cardiac allografts was substantially prolonged in Sly1(d/d) mice. These results define SLY1 as an essential molecular component for the full activation of adaptive immunity