Hydrogen-nitrogen plasma assisted synthesis of titanium dioxide with enhanced performance as anode for sodium ion batteries

Sodium ion batteries are considered as one of the most promising energy storage devices as lithium ion batteries due to the natural abundance of sodium. TiO2 is very popular as anode materials for both lithium and sodium ion batteries because of the nontoxicity, safety and great stabilities. However, the low electronic conductivities and inferior sodium ion diffusion make it becoming a great challenge to develop advanced TiO2 anodes. Doping heteroatoms and incorporation of defects are believed to be great ways to improve the electrochemical performance of TiO2 anodes. In this work, commercial TiO2 (P25) nanoparticles was modified by hydrogen and nitrogen high-power plasma resulting in a disordered surface layer formation and nitrogen doping as well. The electrochemical performances of the samples as anode materials for sodium ion batteries was measured and the results indicated that after the hydrogen–nitrogen plasma treatment, H–N-TiO2 electrode shows a 43.5% of capacity higher than the P-TiO2 after 400 cycles long-term discharge/charge process, and the samples show a good long cycling stability as well, the Coulombic efficiencies of all samples are nearly 99% after 50 cycles which could be sustained to the end of long cycling. In addition, hydrogen–nitrogen plasma treated TiO2 electrode reached the stable high Coulombic efficiency earlier than the pristine material. High resolution TEM images and XPS results indicate that there is a disordered surface layer formed after the plasma treatment, by which defects (oxygen vacancies) and N-doping are also introduced into the crystalline structure. All these contribute to the enhancement of the electrochemical performance

Adaptive Value Decomposition with Greedy Marginal Contribution Computation for Cooperative Multi-Agent Reinforcement Learning

Real-world cooperation often requires intensive coordination among agents simultaneously. This task has been extensively studied within the framework of cooperative multi-agent reinforcement learning (MARL), and value decomposition methods are among those cutting-edge solutions. However, traditional methods that learn the value function as a monotonic mixing of per-agent utilities cannot solve the tasks with non-monotonic returns. This hinders their application in generic scenarios. Recent methods tackle this problem from the perspective of implicit credit assignment by learning value functions with complete expressiveness or using additional structures to improve cooperation. However, they are either difficult to learn due to large joint action spaces or insufficient to capture the complicated interactions among agents which are essential to solving tasks with non-monotonic returns. To address these problems, we propose a novel explicit credit assignment method to address the non-monotonic problem. Our method, Adaptive Value decomposition with Greedy Marginal contribution (AVGM), is based on an adaptive value decomposition that learns the cooperative value of a group of dynamically changing agents. We first illustrate that the proposed value decomposition can consider the complicated interactions among agents and is feasible to learn in large-scale scenarios. Then, our method uses a greedy marginal contribution computed from the value decomposition as an individual credit to incentivize agents to learn the optimal cooperative policy. We further extend the module with an action encoder to guarantee the linear time complexity for computing the greedy marginal contribution. Experimental results demonstrate that our method achieves significant performance improvements in several non-monotonic domains.Comment: This paper is accepted by aamas 202

Vasopressin and epinephrine versus epinephrine in management of patients with cardiac arrest: a meta-analysis

Objective. A combination of vasopressin and epinephrine may be more effective than epinephrine alone in cardiopulmonary resuscitation (CPR), but evidence is lacking to make clinical recommendations. This meta-analysis compares the efficacy of vasopressin and epinephrine used together versus epinephrine alone in cardiac arrest (CA). Methods. We searched MEDLINE and EMBASE for randomized trials comparing the efficacy of vasopressin and epinephrine versus epinephrine alone in adults with cardiac arrest. The primary outcome was the return of spontaneous circulation (ROSC) and the survival rate on admission and discharge .We also analyzed ROSC in subgroups of patients presenting with different arrest rhythms, such as asystole, pulseless electrical activity (PEA), ventricular fibrillation (VF). Results. We analyzed 6 randomized trials out of 485 articles. We did not find evidence supporting the superiority of vasopressin and epinephrine used in combination, except for the survival rate at 24h 2.99 95% CI(1.43,6.28). No evidence supports the conclusion that vasopressin combined with epinephrine is better than epinephrine alone for ROSC, even amongst subgroups of patients. Conclusion. This systematic review of the efficacy of vasopressin and epinephrine use found that its combined use is better for 24h survival rate but only in one study which included 122 patients. Further investigation will be needed to support the use of this combination for cardiac arrest management

catena-Poly[[dichloridozinc(II)]-μ-2,5-di-4-pyridyl-1,3,4-thia­diazole-κ2 N 2:N 5]

The title compound, [ZnCl2(C12H8N4S)]n, was obtained by crystallization of 2,5-di-4-pyridyl-1,3,4-thia­diazole with ZnCl2 in an MeOH/CHCl3 solvent system. The structure contains infinite chains of ZnCl2 units connected by the bifunctional thia­diazole ligands, with ZnII adopting a distorted tetra­hedral coordination geometry. The dihedral angle between the two pyridyl rings in each ligand is 34.3 (1)°, and the dihedral angles between the thia­diazole ring and the two pyridyl rings are 18.3 (2) and 16.1 (2)°. The shortest Zn⋯Zn distance within each polymeric chain is 11.862 (3) Å, while the shortest inter­chain Zn⋯Zn distance is 7.057 (3) Å

Characterization of a Superconducting Microstrip Single-Photon Detector Shunted with an External Resistor

A superconducting microstrip single-photon detector (SMSPD) generally requires a shunt resistor to avoid latching, caused by its high current-carrying capacity and low kinetic inductance. Here, the effect of the shunt resistor on the behaviors of microbridge SMSPDs was investigated. We analyzed the change in equivalent switching current at different shunt resistances in two ways and determined the operating current range using intrinsic dark count rate (iDCR) curves. We observed that the reduction in shunt resistance can increase the operating current range, which helps to improve the internal detection efficiency (IDE) and reduce the iDCR. However, the reduction in the shunt resistance can reduce the pulse amplitude and increase the pulse decay time, which can degrade the timing jitter and count rate performance of the SMSPD. The trends of the experimental results can be qualitatively reproduced using a circuit model for an SMSPD with a shunt resistor, which provides useful information for the selection of shunt resistors. Furthermore, we report the improved detection performance of a helium-ion-irradiated SMSPD shunted with a small resistance of 5.2 {\Omega}. We observed a weak IDE saturation with a bias current at a wavelength up to 2000 nm and a nonlinear relation between detection current and photon energy.Comment: 13 pages, 8 figures, 1 tabl

Unconventional secretion of unglycosylated ORF8 is critical for the cytokine storm during SARS-CoV-2 infection

Coronavirus disease 2019 is a respiratory infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence on the pathogenesis of SARS-CoV-2 is accumulating rapidly. In addition to structural proteins such as Spike and Envelope, the functional roles of non-structural and accessory proteins in regulating viral life cycle and host immune responses remain to be understood. Here, we show that open reading frame 8 (ORF8) acts as messenger for inter-cellular communication between alveolar epithelial cells and macrophages during SARS-CoV-2 infection. Mechanistically, ORF8 is a secretory protein that can be secreted by infected epithelial cells via both conventional and unconventional secretory pathways. Conventionally secreted ORF8 is glycosylated and loses the ability to recognize interleukin 17 receptor A of macrophages, possibly due to the steric hindrance imposed by N-glycosylation at Asn78. However, unconventionally secreted ORF8 does not undergo glycosylation without experiencing the ER-Golgi trafficking, thereby activating the downstream NF-κB signaling pathway and facilitating a burst of cytokine release. Furthermore, we show that ORF8 deletion in SARS-CoV-2 attenuates inflammation and yields less lung lesions in hamsters. Our data collectively highlights a role of ORF8 protein in the development of cytokine storms during SARS-CoV-2 infection

Transfer-free, lithography-free and fast growth of patterned CVD graphene directly on insulators by using sacrificial metal catalyst

Chemical vapor deposited graphene suffers from two problems: transfer from metal catalysts to insulators, and photoresist induced degradation during patterning. Both result in macroscopic and microscopic damages such as holes, tears, doping, and contamination, translated into property and yield dropping. We attempt to solve the problems simultaneously. A nickel thin film is evaporated on SiO2 as a sacrificial catalyst, on which surface graphene is grown. A polymer (PMMA) support is spin-coated on the graphene. During the Ni wet etching process, the etchant can permeate the polymer, making the etching efficient. The PMMA/graphene layer is fixed on the substrate by controlling the surface morphology of Ni film during the graphene growth. After etching, the graphene naturally adheres to the insulating substrate. By using this method, transfer-free, lithography-free and fast growth of graphene realized. The whole experiment has good repeatability and controllability. Compared with graphene transfer between substrates, here, no mechanical manipulation is required, leading to minimal damage. Due to the presence of Ni, the graphene quality is intrinsically better than catalyst-free growth. The Ni thickness and growth temperature are controlled to limit the number of layers of graphene. The technology can be extended to grow other two-dimensional materials with other catalysts

Association of the GALNT2 gene polymorphisms and several environmental factors with serum lipid levels in the Mulao and Han populations

<p>Abstract</p> <p>Background</p> <p>The association of UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase 2 gene (<it>GALNT2</it>) single nucleotide polymorphisms (SNPs) and serum lipid profiles in the general population is not well known. The present study was undertaken to detect the association of <it>GALNT2 </it>polymorphisms and several environmental factors with serum lipid levels in the Guangxi Mulao and Han populations.</p> <p>Method</p> <p>A total of 775 subjects of Mulao nationality and 699 participants of Han nationality were randomly selected from our stratified randomized cluster samples. Genotyping of the <it>GALNT2 </it>rs2144300 and rs4846914 SNPs was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.</p> <p>Results</p> <p>There were no significant differences in the genotypic and allelic frequencies of both SNPs between the two ethnic groups, or between the males and females. The subjects with TT genotype of rs2144300 in Mulao had lower serum triglyceride (TG) levels than the subjects with CC genotype in females (<it>P </it>< 0.01). The participants with CT/TT genotype of rs2144300 in Han had lower TG and apolipoprotein (Apo) B levels, and higher high-density lipoprotein cholesterol (HDL-C), ApoA1 levels and the ratio of ApoA1 to ApoB in males; and higher low-density lipoprotein cholesterol (LDL-C) and ApoB levels in females than the participants with CC genotype (<it>P </it>< 0.05-0.001). The individuals with GA/AA genotype of rs4846914 in Mulao had higher total cholesterol (TC) and LDL-C levels than the individuals with GG genotype in males (<it>P </it>< 0.05 for each). The subjects with AA genotype of rs4846914 in Han had higher LDL-C and ApoB levels, and lower HDL-C levels and the ratio of ApoA1 to ApoB than the subjects with GG genotype (<it>P </it>< 0.05 for each). The levels of TC in Mulao were correlated with the genotypes of rs4846914 in males (<it>P </it>< 0.05). The levels of ApoA1 in Han were correlated with the genotypes of both SNPs, and the levels of HDL-C and ApoB and the ratio of ApoA1 to ApoB were associated with the genotypes of rs2144300 in males (<it>P </it>< 0.05-0.001). The levels of LDL-C in Han were correlated with the genotypes of rs4846914 in females (<it>P </it>< 0.05). Serum lipid parameters were also correlated with several enviromental factors.</p> <p>Conclusions</p> <p>The associations of both <it>GALNT2 </it>rs2144300 and rs4846914 SNPs and serum lipid levels are different in the Mulao and Han populations. These discrepancies might partly result from different <it>GALNT2 </it>gene-enviromental interactions.</p