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The 2219 aluminum alloy thin-walled complex components manufactured by spin forming are frequently applied to the bottom end of rocket fuel tanks. However, fracture and quality problems (large part-mold contact gap, low roundness, thickness accuracy) are prone to occur during their multi-pass spin forming. While the material anisotropy, complicated components geometry and the complex stress state evolution make it difficult to obtain the appropriate forming process parameters in spin forming. With the help of finite element methods, it is possible to solve this difficulty. Thus, based on the anisotropic Barlat89 yield function and the DF2016 fracture criterion, a spin forming finite element model considering material anisotropy and damage evolution is established first for the components. Then, a method by using multi-pass involute spinning track with variable diameter base circle to form the components is proposed, and also the spinning passes are determined. Finally, taking the non-fracture as the constraint condition and the forming quality indexes (part-mold contact gap, roundness, and thickness accuracy) as the optimization objectives, a multi-objective optimization model based on orthogonal experimental design and response surface model is established. The optimized process parameters are solved and determined by a combination of the Archive-Based Micro Genetic Algorithm, and the optimized results are verified by the experiments. [ABSTRACT FROM AUTHOR]

TiO2 materials are considered one of the promising candidates for lithium/sodium-ion batteries (L/SIBs) due to its excellent safety and abundant resources. However, the low ion diffusion coefficient becomes a bottleneck in restrict its development. In this work, three-dimensional (3D) porous hydrangea-shaped anatase TiO2 (ATO) was synthesized through the synergistic effect of de-alloying and SO42− induced chemical synthesis. During the chemical synthesis process, SO42− and TiO62− octahedra are bound by static electricity, as the spatial effect of SO42− can influence the octahedral arrangement in favor of precipitating anatase TiO2. In the SIBs, ATO as anode material provided an excellent capacity of 190 mAh g−1 after 100 cycles at a current density of 50 mA g−1. Electrochemical kinetic tests show that the pseudocapacitive behavior contributes to 86% of the capacity at a scan rate of 1 mV s−1, mainly due to the high specific surface area provided by its unique microstructure, and also shows excellent electrochemical performance in the LIBs tests. This study provides a novel strategy for the simple and large-scale production of TiO2 anode materials with high-performance L/SIBs. [ABSTRACT FROM AUTHOR]

Geminal and vicinal borosilanes are useful building blocks in synthetic chemistry and material science. Hydrosilylation/hydroborylation of unsaturated systems offer expedient access to these motifs. In contrast to the well-established transition-metal-catalyzed methods, radical approaches are rarely explored. Herein we report the synthesis of geminal borosilanes from α-selective hydrosilylation of alkenyl boronates via photoinduced hydrogen atom transfer (HAT) catalysis. Mechanistic studies implicate that the α-selectivity originates from a kinetically favored radical addition and an energetically favored HAT process. We further demonstrate selective synthesis of vicinal borosilanes through hydrosilylation of allyl boronates via 1,2-boron radical migration. These strategies exhibit broad scopes across primary, secondary, and tertiary silanes and various boron compounds. The synthetic utility is evidenced by access to multi-borosilanes in a diverse fashion and scaling up by continuous-flow synthesis. Geminal and vicinal borosilanes are useful building blocks in synthetic chemistry. But in contrast to the well-established transition-metal catalyzed methods, radical approaches are rarely explored. Here, the authors report the synthesis of geminal borosilanes from α-selective hydrosilylation of alkenyl boronates via photoinduced hydrogen atom transfer (HAT) catalysis [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a kind of central nervous system (CNS) autoimmune disease, which mainly damages nerves, the brain, and the spinal cord. Recently, several clinical cases reported the relativity between Coronavirus Disease 2019 (COVID-19) and the development of MS, but the mechanism of how COVID-19 affects the occurrence of MS was still not clear. It is bioinformatics technology that we use to explore the potential association at the gene level. The genetic information related to the two diseases was collected from the DisGNET platform for functional protein network analysis and used STRING to identify the complete gene set. The protein–protein interaction (PPI) network was analyzed by STRING. Finally, in the GEO database, we selected peripheral blood mononuclear cell (PBMC) RNA sequencing data (GSE164805, GSE21942) from COVID-19 patients and MS patients to verify the potential cross mechanism between the two diseases. The similar gene set of immune or inflammation existed between the patients with COVID-19 and ones with MS, including L2RA, IFNG, IL1B, NLRP3, and TNF. Interaction network analysis among proteins revealed that IL1B, P2RX7, IFNB1, IFNB1, TNF, and CASP1 enhanced the network connectivity between the combined gene set of COVID-19 and MS associated with NOD-like receptor (NLR) signaling. The involvement of NLR signaling in both diseases was further confirmed by comparing peripheral blood monocyte samples from COVID-19 and MS patients. Activation of NLR signaling was found in both COVID-19 and MS. The PBMC samples analyses also indicated the involvement of the NLR signaling pathway. Taken together, our data analyses revealed that the NLR signaling pathway might play a critical role in the COVID-19-related MS. [ABSTRACT FROM AUTHOR]

Catalyst support of air cathode requires stable structure and high specific surface area, due to the unique semi open structure of metal-air battery. Herein, we prepare a novel 3D Copper/Carbon film catalyst support with dual 3D porous structure by nonsolvent induced phase separation and heat treatment process. During the heat treatment process in inert atmosphere, copper atom diffuses and recrystallizes to form the 3D porous structure with the support of polyacrylonitrile, and the polyacrylonitrile is carbonized to construct superimposed 3D carbon networks. This dual 3D porous Copper/Carbon film shows a high specific surface area of 7.61 m2 g−1, suitable mesopores pore size (2–10 nm), good conductivity (2.2 Ω) and mechanical properties. The as-prepared composites are used as air-cathode in aluminum-air battery, which exhibits good water resistance and air permeability after 3604 s discharging process with KOH electrolyte. This novel catalyst support could provide stable three-dimensional structure for high performance nano-sized catalyst, which supplies a new solution to develop high performance metal-air battery. [ABSTRACT FROM AUTHOR]

Excessive inflammatory responses induced upon SARS-CoV-2 infection are associated with severe symptoms of COVID-19. Inflammasomes activated in response to SARS-CoV-2 infection are also associated with COVID-19 severity. Here, we show a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation to induce hyperinflammation. N protein facilitates maturation of proinflammatory cytokines and induces proinflammatory responses in cultured cells and mice. Mechanistically, N protein interacts directly with NLRP3 protein, promotes the binding of NLRP3 with ASC, and facilitates NLRP3 inflammasome assembly. More importantly, N protein aggravates lung injury, accelerates death in sepsis and acute inflammation mouse models, and promotes IL-1β and IL-6 activation in mice. Notably, N-induced lung injury and cytokine production are blocked by MCC950 (a specific inhibitor of NLRP3) and Ac-YVAD-cmk (an inhibitor of caspase-1). Therefore, this study reveals a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation and induces excessive inflammatory responses. SARS-CoV-2 infection has been shown to drive NLRP3 inflammasome activation and thereby cytokine storm, but how it does so is unclear. Here the authors show that the viral N protein can bind to NLRP3, resulting in enhanced interaction with ASC and thereby with the NLRP3 inflammasome. [ABSTRACT FROM AUTHOR]

Background: Poly-brominated diphenyl ethers (PBDEs) and heavy metals are persistent pollutants in Yangtze River basin, China and also around the globe. In the exposure reality, they may have sequential exposures and long-term outcomes. Yet, the effects combining these two aspects remained largely unexplored. At present, the effects of 2,2′,4,4′-tetra-brominated diphenyl ether (BDE47) and lead (Pb) on Caenorhabditis elegans were studied with two sequential arrangements. One was first exposure to BDE47 and then to Pb (or vice versa) in one generation, and the other one was an early exposure to BDE47 in the parent generation (F0) and then a later exposure to Pb in the offspring (F1) (or vice versa). Results: On growth, sequential Pb-BDE47 exposure caused inhibition in exposure but stimulation in recovery, showing similarity to individual Pb results. Meanwhile, the opposite sequential BDE47-Pb exposure showed inhibition in both exposure and recovery, similar to those of individual BDE47 results. On behavior, the effects of sequential exposure were significantly different from individual results without any similarity. In transgenerational effects, F0 Pb exposure with F1 BDE47 exposure (Pb-F1-BDE47) inhibited growth, similar to the transgenerational results of individual Pb exposure. Meanwhile, the recovery effects were similar to the transgenerational results of individual BDE47. At the same time, Pb-F1-BDE47 exposure significantly hindered the recovery of behavior while the opposite BDE47-F1-Pb exposure resulted in different results. The behavioral effects in F1 showed negative correlation with the contents of γ-aminobutyric acid (GABA), while those in F1 were positively correlated with the activities of acetylcholine esterase (AChE). Conclusions: Sequential exposure to BDE47 and Pb within one generation or over generations showed significant different effects from individual results. Further studies are still needed to investigate the toxicity patterns and underlying mechanisms. [ABSTRACT FROM AUTHOR]

In this study, PCR-denaturing gradient gel electrophoresis (DGGE) was applied to analyze the microbial communities in lake sediments from Lake Xuanwu, Lake Mochou in Nanjing and Lake Taihu in Wuxi. Sediment samples from seven locations in three lakes were collected and their genomic DNAs were extracted. The DNA yields of the sediments of Lake Xuanwu and Lake Mochou were high (10 μg/g), while that of sediments in Lake Taihu was relatively low. After DNA purification, the 16S rDNA genes (V3 to V5 region) were amplified and the amplified DNA fragments were separated by parallel DGGE. The DGGE profiles showed that there were five common bands in all the lake sediment samples indicating that there were similarities among the populations of microorganisms in all the lake sediments. The DGGE profiles of Lake Xuanwu and Lake Mochou were similar and about 20 types of microorganisms were identified in the sediment samples of both lakes. These results suggest that the sediment samples of these two city lakes (Xuanwu, Mochou) have similar microbial communities. However, the DGGE profiles of sediment samples in Lake Taihu were significantly different from these two lakes. Furthermore, the DGGE profiles of sediment samples in different locations in Lake Taihu were also different, suggesting that the microbial communities in Lake Taihu are more diversified than those in Lake Xuanwu and Lake Mochou. The differences in microbial diversity may be caused by the different environmental conditions, such as redox potential, pH, and the concentrations of organic matters. Seven major bands of 16S rDNA genes fragments from the DGGE profiles of sediment samples were further re-amplified and sequenced. The results of sequencing analysis indicate that five sequences shared 99%–100% homology with known sequences ( Bacillus and Brevibacillus, uncultured bacteria), while the other two sequences shared 93%–96% homology with known sequences ( Acinetobacter, and Bacillus). The study shows that the PCR-DGGE technique combined with sequence analysis is a feasible and efficient method for the determination of microbial communities in sediment samples. [ABSTRACT FROM AUTHOR]

These authors contributed equally: Pan Pan, Miaomiao Shen, Zhenyang Yu. The original version of this Article omitted the following from the Acknowledgements: Science & Technology Planning Project of Guangdong Province Office of Education (2018KCXTD007, 2021XK16), Special project for the prevention and control of new crown pneumonia in Guangdong colleges and universities (2020KZDZX1060). [Extracted from the article]