We report on accelerated degradation testing of MAPbX3 films (X = I or Br) by exposure to concentrated sunlight of 100 suns and show that the evolution of light absorption and the corresponding ...structural modifications are dependent on the type of halide ion and the exposure temperature. One hour of such exposure provides a photon dose equivalent to that of one sun exposure for 100 hours. The degradation in absorption of MAPbI3 films after exposure to 100 suns for 60 min at elevated sample temperature (∼45–55 °C), due to decomposition of the hybrid perovskite material, is documented. No degradation was observed after exposure to the same sunlight concentration but at a lower sample temperature (∼25 °C). No photobleaching or decomposition of MAPbBr3 films was observed after exposure to similar stress conditions (light intensity, dose, and temperatures). Our results indicate that the degradation is highly dependent on the hybrid perovskite composition and can be light- and thermally enhanced.
We report on the quantitative proteomic analysis of single mammalian cells. Fluorescence‐activated cell sorting was employed to deposit cells into a newly developed nanodroplet sample processing ...chip, after which samples were analyzed by ultrasensitive nanoLC‐MS. An average of circa 670 protein groups were confidently identified from single HeLa cells, which is a far greater level of proteome coverage for single cells than has been previously reported. We demonstrate that the single‐cell proteomics platform can be used to differentiate cell types from enzyme‐dissociated human lung primary cells and identify specific protein markers for epithelial and mesenchymal cells.
Single‐cell proteomics: A microfluidic platform coupled to nanoLC‐MS was developed to enable quantitative proteomic analysis of single mammalian cells containing only 0.1–0.2 ng of total protein. Label‐free cell differentiation was enabled by quantifying protein expression in individual cells.
Three‐dimensional (3 D) perovskite has attracted a lot of attention owing to its success in photovoltaic (PV) solar cells. However, one of its major crucial issues lies in its stability, which has ...limited its commercialization. An important property of organic–inorganic perovskite is the possibility of forming a layered material by using long organic cations that do not fit into the octahedral cage. These long organic cations act as a “barrier” that “caps” 3 D perovskite to form the layered material. Controlling the number of perovskite layers could provide a confined structure with chemical and physical properties that are different from those of 3 D perovskite. This opens up a whole new batch of interesting materials with huge potential for optoelectronic applications. This Minireview presents the synthesis, properties, and structural orientation of low‐dimensional perovskite. It also discusses the progress of low‐dimensional perovskite in PV solar cells, which, to date, have performance comparable to that of 3 D perovskite but with enhanced stability. Finally, the use of low‐dimensional perovskite in light‐emitting diodes (LEDs) and photodetectors is discussed. The low‐dimensional perovskites are promising candidates for LED devices, mainly because of their high radiative recombination as a result of the confined low‐dimensional quantum well.
Peeling back the layers: The synthesis, properties, and structural orientation of low‐dimensional perovskite are surveyed. Controlling the number of perovskite layers can provide a confined structure with chemical and physical properties that are different from those of 3 D perovskite. The use of low‐dimensional perovskite in photovoltaic solar cells is discussed, as is its use in light‐emitting diodes and photodetectors.
'LungGENS', our previously developed web tool for mapping single-cell gene expression in the developing lung, has been well received by the pulmonary research community. With continued support from ...the 'LungMAP' consortium, we extended the scope of the LungGENS database to accommodate transcriptomics data from pulmonary tissues and cells from human and mouse at different stages of lung development. Lung Gene Expression Analysis (LGEA) web portal is an extended version of LungGENS useful for the analysis, display and interpretation of gene expression patterns obtained from single cells, sorted cell populations and whole lung tissues. The LGEA web portal is freely available at http://research.cchmc.org/pbge/lunggens/mainportal.html.
Ulcerative colitis (UC) is an autoimmune disease associated with both intestinal and extraintestinal manifestations. The latter may include heart complications, such as myopericarditis leading to ...life-threatening arrythmias. Nowadays, UC is commonly treated with biologic medications and infliximab is the first line therapy in an outpatient setting, while it is also used as rescue therapy in acute severe UC. However, it has been associated with severe immunosuppression, cytomegalovirus (CMV) reactivation and drug-induced hepatitis. We report a case of UC flare in a biologic naïve patient admitted with myopericarditis, which was further complicated by positive CMV biopsies and infliximab-induced transaminitis.
In acute inflammatory bowel disease (IBD) flare presentation with tachycardia and chest pain, an underlying myocardial injury should be investigated.Mucosal healing should be evaluated endoscopically in cases of partial response to biologics.Both cytomegalovirus (CMV) infection and infliximab-induced liver injury may lead to acute hepatitis.
The photochemical stability of encapsulated films of mixed halide perovskites with a range of MAPb(I1−xBrx)3 (MA=methylammonium) compositions (solid solutions) was investigated under accelerated ...stressing using concentrated sunlight. The relevance of accelerated testing to standard operational conditions of solar cells was confirmed by comparison to degradation experiments under outdoor sunlight exposure. We found that MAPbBr3 films exhibited no degradation, while MAPbI3 and mixed halide MAPb(I1−xBrx)3 films decomposed yielding crystallization of inorganic PbI2 accompanied by degradation of the perovskite solar light absorption, with faster absorption degradation in mixed halide films. The crystal coherence length was found to correlate with the stability of the films. We postulate that the introduction of Br into the mixed halide solid solution stressed its structure and induced more structural defects and/or grain boundaries compared to pure halide perovskites, which might be responsible for the accelerated degradation. Hence, the cause for accelerated degradation may be the increased defect density rather than the chemical composition of the perovskite materials.
To be or not to be (efficient and stable): Photochemical stability studies of MAPb(I1−xBrx)3 (MA=methylammonium) photovoltaic materials show that mixed halide compositions are less stable than pure halide ones. We postulate that these solid solutions contain internal stresses and structural defects, which might be responsible for their accelerated degradation.
Although viral infections elicit robust interferon-γ (IFN-γ) and long-lived antibody-secreting cell (ASC) responses, the roles for IFN-γ and IFN-γ-induced transcription factors (TFs) in ASC ...development are unclear. We showed that B cell intrinsic expression of IFN-γR and the IFN-γ-induced TF T-bet were required for T-helper 1 cell-induced differentiation of B cells into ASCs. IFN-γR signaling induced Blimp1 expression in B cells but also initiated an inflammatory gene program that, if not restrained, prevented ASC formation. T-bet did not affect Blimp1 upregulation in IFN-γ-activated B cells but instead regulated chromatin accessibility within the Ifng and Ifngr2 loci and repressed the IFN-γ-induced inflammatory gene program. Consistent with this, B cell intrinsic T-bet was required for formation of long-lived ASCs and secondary ASCs following viral, but not nematode, infection. Therefore, T-bet facilitates differentiation of IFN-γ-activated inflammatory effector B cells into ASCs in the setting of IFN-γ-, but not IL-4-, induced inflammatory responses.
•Differentiation of Th1-activated B (Be1) cells requires B intrinsic T-bet and IFN-γR•Be1 differentiation requires T-bet repression of NF-κB, TLR, and STAT pathways•Plasma cell formation in Be2 cultures and nematode infection is T-bet independent•T-bet controls formation of long-lived and secondary plasma cells in flu infection
T-bet-expressing B cells are expanded in autoimmunity and viral infection; however, whether these cells represent early plasma cells was unknown. Stone et al. identify T-bet-repressed pathways that permit plasma cell differentiation in the presence of IFN-γ. They show that T-bet-expressing B cells are required for long-lived immunity to flu.
Systems biology uses computational approaches to integrate diverse data types to understand cell and organ behavior. Data derived from complementary technologies, for example transcriptomic and ...proteomic analyses, are providing new insights into development and disease. We compared mRNA and protein profiles from purified endothelial, epithelial, immune, and mesenchymal cells from normal human infant lung tissue. Signatures for each cell type were identified and compared at both mRNA and protein levels. Cell-specific biological processes and pathways were predicted by analysis of concordant and discordant RNA-protein pairs. Cell clustering and gene set enrichment comparisons identified shared versus unique processes associated with transcriptomic and/or proteomic data. Clear cell-cell correlations between mRNA and protein data were obtained from each cell type. Approximately 40% of RNA-protein pairs were coherently expressed. While the correlation between RNA and their protein products was relatively low (Spearman rank coefficient
~0.4), cell-specific signature genes involved in functional processes characteristic of each cell type were more highly correlated with their protein products. Consistency of cell-specific RNA-protein signatures indicated an essential framework for the function of each cell type. Visualization and reutilization of the protein and RNA profiles are supported by a new web application, "LungProteomics," which is freely accessible to the public.
Purpose: Thoracic irradiation injures lung parenchyma, triggering inflammation and immune cell activation, leading to pneumonitis and fibrosis. Macrophage polarization contributes to these processes. ...Since IL-4 promotes pro-fibrotic macrophage activation, its role in radiation-induced lung injury was investigated.
Materials and methods: Lung macrophage subpopulations were characterized from 3-26 weeks following exposure of WT and IL-4−/− mice to 0 or 12.5 Gray single dose thoracic irradiation.
Results: Loss of IL-4 did not prevent fibrosis, but blunted macrophage accumulation within the parenchyma. At 3 weeks following exposure, cell numbers and expression of F4/80 and CD206, an alternative activation marker, decreased in alveolar macrophages but increased in infiltrating macrophages in WT mice. Loss of IL-4 impaired recovery of these markers in alveolar macrophages and blunted expansion of these populations in infiltrating macrophages. CD206+ cells were evident in fibrotic regions of WT mice only, however Arg-1+ cells increased in fibrotic regions in IL-4−/− mice only. Radiation-induced proinflammatory Ly6C expression was more apparent in alveolar and interstitial macrophages from IL-4−/− mice.
Conclusions: IL-4 loss did not prevent alternative macrophage activation and fibrosis in irradiated mice. Instead, a role is indicated for IL-4 in maintenance of macrophage populations in the lung following high single dose thoracic irradiation.
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