Vascular endothelial cells (VECs) that line the interiors of blood vessels participate in physiological and inflammatory processes. All skin cell types express the aryl hydrocarbon receptor (AhR), which is involved in the pathogenesis of psoriasis. However, the role of the cutaneous VEC AhR in the pathogenesis of psoriasis remains elusive. In the present study, we found that AhR protein expression and activation were downregulated in psoriatic VECs. Furthermore, cutaneous VEC-specific AhR-knockout (AhR(cVECs-KO)) mice were established. Using imiquimod and IL-23-induced psoriasis models, we found that skin inflammation was exacerbated with excessive neutrophil recruitment in AhR(cVECs-KO) mice. Furthermore, neutrophil neutralization alleviates exacerbated inflammation in imiquimod-treated AhR(cVECs-KO) mice. In addition, cutaneous VECs in AhR(cVECs-KO) mice exhibited increased dilation and activation compared with those in control mice. Finally, AhR-deficient microvascular endothelial cells stimulated by proinflammatory cytokines showed increased ICAM-1 expression in vivo and in vitro, which may have facilitated neutrophil recruitment. In summary, our study demonstrates that AhR in dermal VECs restricts psoriasis development by negatively regulating neutrophil recruitment, thereby providing insight into the pathogenesis of psoriasis.

Background & Aims: Liver enzyme abnormalities are common in patients with coronavirus disease 2019 (COVID-19). Whether or not severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to liver damage per se remains unknown. Herein, we reported the clinical characteristics and liver pathological manifestations of COVID-19 patients with liver enzyme abnormalities. Methods: We analyzed 156 patients diagnosed with COVID-19 from 2 designated centers in China and compared clinical features between patients with or without elevated aminotransferases. Postmortem liver biopsies were obtained from 2 cases who had elevated aminotransferases. We investigated the patterns of liver impairment by electron microscopy, immunohistochemistry, TUNEL assay and pathological studies. Results: Sixty-four out of 156 (41.0%) patients with COVID-19 had elevated aminotransferases. The median levels of alanine aminotransferase were 50 la vs. 19 UAL, respectively, aspartate aminotransferase were 45.5 la vs. 24 la, respectively in abnormal and normal aminotransferase groups. Liver enzyme abnormalities were associated with disease severity, as well as a series of laboratory tests including higher alveolar-arterial oxygen partial pressure difference, higher gammaglutamyltransferase, lower albumin, decreased CD4+ T cells and B lymphocytes. Ultrastructural examination identified typical coronavirus particles, characterized by spike structures, in the cytoplasm of hepatocytes in 2 COVID-19 cases. SARS-CoV-2-infected hepatocytes displayed conspicuous mitochondrial swelling, endoplasmic reticulum dilatation and glycogen granule decrease. Histologically, massive hepatic apoptosis and some binuclear hepatocytes were observed. Taken together, both ultrastructural and histological evidence indicated a typical lesion of viral infection. Immunohistochemical results showed scarce CD4+ and CD8+ lymphocytes. No obvious eosinophil infiltration, cholestasis, fibrin deposition, granuloma, massive central necrosis, or interface hepatitis were observed. Conclusions: SARS-CoV-2 infection in the liver directly contributes to hepatic impairment in patients with COVID-19. Hence, a surveillance of viral clearance in liver and long-term outcome of COVID-19 is required. Lay summary: Liver enzyme abnormalities are common in patients with coronavirus disease 2019 (COVID-19). We reported the clinical characteristics and liver pathological manifestations of COVID-19 patients with elevated liver enzymes. Our findings suggested that SARS-CoV-2 infection of the liver is a crucial factor contributing to hepatic impairment in patients with COVID-19. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Atopic dermatitis (AD) is often concomitant with increased levels of IgE against not only foreign allergens but also autoallergens. AD patients with autoallergy are likely to be more severe and difficult to treat, and self-reactive IgE might be a contributing factor in the pathogenesis of AD. However, how autoallergens are recognized by the immune system and what immune responses are induced subsequently remain largely unknown. We found that the serum level of IgE against transglutaminase 3 (TGase3) was significantly higher in AD patients than in healthy individuals and was positively correlated with disease severity. The expression of TGase3 in the lesional skin of AD patients was markedly increased compared with that of the controls, and Th2 cytokines and/or allergen promoted the expression of TGase3 in keratinocytes. TGase3 bond monocytes-derived dendritic cells (MoDCs) via dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN), which resulted in the production of IL-6 and activation of the NF-kappa B signaling pathway in MoDCs; and TGase3-treated MoDCs facilitated Th1 polarization. Moreover, skin inflammation in the mouse model of MC903-induced AD was attenuated when TGase3 was inhibited. In conclusion, TGase3 was revealed as an autoallergen in AD and actively involved in skin inflammation; TGase3-targeting might be a therapeutic strategy for the treatment of AD.

The chain arrangement within the crystalline lamellae has been the focus of polymer crystallization. In this study, a series of protiated (H) and deuterated (D) poly(e-caprolactone) (PCL) blends, block and random copolymers were investigated by small-angle neutron scattering (SANS) measurements. The spatial inhomogeneities of block copolymers were analyzed via Debye-Bueche method and temperature dependence of Flory-Huggins interaction parameter. in the melt was extracted from fitting the scattering data to the random phase approximation model. Studying the changes of SANS signals further revealed that the copolymers exhibit cooling rate-dependent crystallization behaviors. A unique SANS double-peak pattern was found in D4/D10 50/50 blend and D10-D0-D10 triblock copolymers (where D0, D4, and D10 indicate PCL with different levels of deuteration), as a result of two types of contrasts: scattering length density (SLD) difference between lamellae of different components and density difference between amorphous and lamellar domains. These detailed findings complement our understanding of the complex crystallization processes of deuterated polyesters, which also suggest an avenue for fine control of crystal structures that adds to materials design.

The adoption of Accident Tolerant Fuels in the US will only likely be realized through improving economics of existing commercial reactors. For this reason, the Nuclear Energy Institute refers to such concepts as Advanced Technology Fuel. This work provides an insight into the performance of the fuel rod with high-density uranium-nitride (UN) pellet in silicon-carbide (SiC) composite cladding for a pressurized water reactor. The UN higher uranium density is one way to overcome the higher cost of SiC relative to current Zirconium based claddings. The material properties and irradiation behavior models of UN and SiC have been incorporated into the BISON fuel performance code. The modeling capability of BISON for SiC cladding is extended with irradiation creep and post-irradiation thermal annealing models. The fuel rod performance during normal operation is evaluated across three fuel cycles with each cycle 24-month long. Selected accident scenarios include a large-break loss-of-coolant accident and a station blackout accident where the potential effects of SiC irradiation creep and annealing rate are emphasized. This work motivates further experimental investigation on irradiation properties of dense UN, SiC irradiation creep and nonisothermal annealing. (C) 2020 Elsevier B.V. All rights reserved.

We report a first-principles investigation of the Sigma 3(112) grain boundary (GB) in body-centered cubic Fe-rich Fe1-xCrx alloy as a function of chemical composition and temperature. The equilibrium amount of Cr at the GB undergoes a sharp transition from slight enrichment in low-alloyed Fe-Cr (x <= 0.06-0.08) to complete Cr saturation for 0.08 <= x <= 0.15. The GB chemistry at room-temperature and below is characterized by miscibility gaps, destabilizing a Fe-Cr interfacial solid solution towards decomposition into Fe-rich and Cr-rich clusters. The Cr-rich clusters at the GB may serve as nucleation centers for secondary phases in Fe-Cr alloys. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.