钒掺杂钨青铜内通道氨配位的钌单原子用于高效析氢反应

通过电解水制备氢气是实现“碳中和”目标的理想途径之一.因此,可在全p H条件下使用的氢析出(HER)催化剂的研发是近年来电催化领域的研究热点.原子级分散的催化剂,能够在保留铂族金属(PGM)固有活性的同时,降低催化剂中PGM的用量.虽然可以通过X射线吸收光谱(XAS)来表征原子分散的PGM电催化剂的配位环境,但目前对原子空间分布的控制仍然具有挑战.本文制备了钒掺杂钨青铜内通道氨配位的钌单原子催化剂(Ru/V-NHWO),用于全p H范围内的HER反应.采用X射线衍射(XRD)、高角环形暗场扫描透射电镜(HAADF-STEM)、X射线光电子能谱(XPS)和原位X射线吸收光谱(XAS)等进行表征,研究了钌单原子与V-NHWO载体的结合方式以及构效关系,并采用密度泛函理论(DFT)计算探索了催化剂中诸多位点的活性贡献.在1 mol/LKOH, 0.5 mol/L H_(2)SO_(4)和1 mol/L磷酸盐缓冲溶液中,其在10 m Acm^(-2)下的过电位分别为28.0, 29.6和40.6 m V.同时,在过电位100 m V时,质量活性分别达到3930, 1941和602.8 m Amg^(-1)Ru,数倍于同等条件下的商业铂碳.XRD结果表明,钌的引入可以确保催化剂在氩气条件下热解后仍保持六方钨铵青铜晶相,证明钌与钨铵青铜六方晶体通道内氨物种,即“通道氨”的结合.HAADF-STEM结果表明,钌原子与NHWO间存在强烈相互作用,有助于提升HER性能.XPS和XAS结果表明, W5+信号出现在引入钌后,峰位置的结合能增加且峰面积降低,说明钌与通道氨之间存在相互作用.N的XPS结果表明,钌的引入导致了金属氨键的形成.XAS结果表明, Ru/V-NHWO/CC中钌单原子和钌团簇共存,钌单原子与通道氨配位,并且钒的引入会诱发V-NHWO中金属键长缩短,这表明催化剂的金属性得到了提升,有利于改善其导电性.采用DFT计算进一步研究了HER活性的来源.相比于V-NHWO载体和钌团簇修饰的V-NHWO,以单原子形式结合的钌具有更低的水解离能垒,该能垒在氨桥接的钌双原子垂直插入、钒掺杂和多通道插入等多种因素作用下进一步降低.同时,氢中间体结合能得到了相应的优化而趋近于0 e V.此外,差分电荷密度模拟结果表明,氢中间体结合后, V-NHWO对于钌单原子存在明显的供电子行为,有利于HER动力学过程.综上,本工作报道了金属载体对于高分散金属原子空间分布调控的重要作用,可为设计和构筑可应用于诸多能源转换过程的新型原子级分散催化剂提供参考.

Impact of preoperative therapy on surgical outcomes of laparoscopic total gastrectomy for gastric/gastroesophageal junction cancer

Objective: As laparoscopic surgery is widely applied for primarily treated gastric cancer(GC)/gastroesophageal junction cancer(GEJC) and gains many advantages, the feasibility of laparoscopic total gastrectomy(LTG) for GC/GEJC patients who have received preoperative therapy(PT) has come to the fore. This study aims to analyze the safety and feasibility of LTG after PT for GC/GEJC patients.Methods: We retrospectively analyzed the data of 511 patients with GC/GEJC undergoing LTG, of which 405received LTG(LTG group) and 106 received PT+LTG(PT-LTG group) at Nanfang Hospital between June 2018and September 2022. The surgical outcomes were compared between the two groups.Results: The surgical duration was significantly longer in the PT-LTG group(P<0.001), while the incidence of intraoperative complications(P=1.000), postoperative complications(LTG group vs. PT-LTG group: 26.2% vs.23.6%, P=0.587), the classification of complication severity(P=0.271), and postoperative recovery was similar between two groups. Notably, the incidence of anastomotic complications of esophagojejunostomy was also comparable between the two groups(LTG group vs. PT-LTG group: 5.9% vs. 5.7%, P=0.918). The univariate and multivariate analysis confirmed that positive proximal margin [positive vs. negative: odds ratio(OR)=14.094, 95%confidence interval(95% CI): 2.639-75.260, P=0.002], rather than PT, has an impact on anastomotic complications after LTG(OR=0.945, 95% CI: 0.371-2.408, P=0.905).Conclusions: PT did not increase the surgical risk of LTG for GC/GEJC. Therefore, considering the positive effect of PT on long-term survival, the broader application of PT and LTG for GC/GEJC is supported by our findings.

通过鉴定关键靶标蛋白探究青蒿素抗疟机制

The widespread use of artemisinin(ART)and its derivatives has significantly reduced the global burden of malaria;however,malaria still poses a serious threat to global health.Although significant progress has been achieved in elucidating the antimalarial mechanisms of ART,the most crucial target proteins and pathways of ART remain unknown.Knowledge on the exact antimalarial mechanisms of ART is urgently needed,as signs of emerging ART resistance have been observed in some regions of the world.Here,we used a combined strategy involving mass spectrometry-coupled cellular thermal shift assay(MS-CETSA)and transcriptomics profiling to identify a group of putative antimalarial targets of ART.We then conducted a series of validation experiments on five prospective protein targets,demonstrating that ART may function against malaria parasites by interfering with redox homeostasis,lipid metabolism,and protein synthesis processes.Taken together,this study provides fresh perspectives on the antimalarial mechanisms of ART and identifies several crucial proteins involved in parasite survival that can be targeted to combat malaria.

GhWRKY33 negatively regulates jasmonate-mediated plant defense to Verticillium dahliae

Verticillium wilt,caused by Verticillium dahliae,seriously restricts the yield and quality improvement of cotton.Previous studies have revealed the involvement of WRKY members in plant defense against V.dahliae,but the underlying mechanisms involved need to be further elucidated.Here,we demonstrated that Gossypium hirsutum WRKY DNA-binding protein 33(GhWRKY33) functions as a negative regulator in plant defense against V.dahliae.GhWRKY33 expression is induced rapidly by V.dahliae and methyl jasmonate,and overexpression of GhWRKY33 reduces plant tolerance to V.dahliae in Arabidopsis.Quantitative RT-PCR analysis revealed that expression of several JA-associated genes was significantly repressed in GhWRKY33 overexpressing transgenic plants.Yeast one-hybrid analysis revealed that GhWRKY33 may repress the transcription of both AtERF1 and GhERF2 through its binding to their promoters.Protein-protein interaction analysis suggested that GhWRKY33 interacts with G.hirsutum JASMONATE ZIM-domain protein 3(GhJAZ3).Similarly,overexpression of GhJAZ3 also decreases plant tolerance to V.dahliae.Furthermore,GhJAZ3 acts synergistically with GhWRKY33 to suppress both AtERF1 and GhERF2 expression.Our results imply that GhWRKY33 may negatively regulate plant tolerance to V.dahliae via the JA-mediated signaling pathway.

Camellia oil (Camellia oleifera Abel.) alleviates gastric injury induced by ethanol associated with modulation of gut microbiota in mice

Oil from Camellia oleifera Abel. seed is a popular edible oil in Asia, which has gained much attention for itsmedicinal applications on relieving various inflammation, however, the mechanism is still unknown. The presentstudy was to investigate the gastroprotective effect of camellia oil against ethanol-induced gastric mucosal injuryin mice. The results showed that camellia oil pretreatment significantly reduced gastric ulcer injury. A remarkableinhibited oxidative stress by reducing the concentration of malondialdehyde and a significant decrease of thelevels of pro-inflammatory factors in gastric tissue were observed in camellia oil pretreated group. In addition,camellia oil improved the diversity of gut microbiota and changed the community structure and composition byincreasing Bacteriodes and Dorea. And the feces metabolomics found that metabolism of cofactors and vitamins,and lipid, carbohydrate and amino acid metabolism were modulated by admiration of camellia oil. Takentogether, the findings of this study suggested that camellia oil could ease the ethanol-induced gastric mucosalinjury via the improvement of anti-oxidant and anti-inflammatory status, as well as the regulation of gutmicrobiota and its metabolites.

教育现代化视域下社区教育品牌发展路径探析

高质量的社区教育是建设教育强国的助推器,社区教育品牌是社区教育高质量发展的可视化成果之一。在教育现代化视域下,社区教育品牌迸发出新内容新活力。从教育现代化角度,分析社区教育品牌的教育价值、实践价值、质量价值、治理价值、社会价值,从教学内容、教学方式、品牌传播、社会治理、科研工作等方面探究社区教育品牌发展的新路径。

《金瓶梅词话》方言俗语札记

《金瓶梅词话》运用了许多方言俗语来表现人物关系、事情因果,反映市井百态、社会风情;但其中不少令今人难以领会。不过,倘将中国传统的训诂方法与古代社会实践(包括农业生产)以及至今犹存的乡土风物联系起来,则不难破解。

Investigation of the characteristics and deactivation of catalytic active center of Cr-Al_2O_3 catalysts for isobutane dehydrogenation

Deactivation mechanism of Cr-Al2O3catalyst and the interaction of Cr-A1 in the dehydrogenation of isobutane, as well as the nature of the catalytic active center, were studied using XRD, SEM, XPS, H2-TPR, isobutane-TPR and TPO techniques. The results revealed that the deactivation of Cr-Al2O3 catalyst was mainly caused by carbon deposition on its surface. The Cr3＋ ion could not be reduced by hydrogen but could be reduced to Cr2＋ by hydrocarbons and monoxide carbon. The active center for isobutane dehydrogenation could be Cr2＋/Cr3＋ produced from Cr6＋ by the on line reduction of hydrocarbon and carbon monoxide. The binding energy of Al3＋ was strongly affected by the state of chromium cations in the catalysts.

Co-transport of dissolved organic matter and heavy metals in soils induced by excessive phosphorus applications

To evaluate the effects of long-term applications of phosphorus fertilizers on mobility of dissolved organic matter （DOM） and heavy metals in agricultural soils, a sandy soil and a loamy soil were spiked with ammonium phosphate at application rates of 0, 25, 50, 100, 250, and 500 mg P per kilogram of soil. A series of 15-cm long soil columns were constructed by packing incubated soils of varying concentrations of P. The soil columns were consecutively leached by simulated rainfalls for six cycles. The contents of water extractable organic carbon in both sandy and loamy soils increased significantly with increasing rates of P applications. Relatively high rates of P applications could induce a marked increase in DOM concentrations in the leachates, the effects were larger with the sandy soil rather than with the loamy soil. Applications of P changed the partitioning of trace metals in the soil solids and the soil solutions. The increased P application rates also seemed to elevate the leaching of Cu, Cd, and Zn from soils. The concentrations of Cu, Cd, and Zn in the leachates were positively correlated with DOM, probably due to the formation of metal-DOM complexes. In contrast, Pb concentrations in the leachates were negatively correlated with DOM, and decreased with increasing rates of P applications. The boosted leaching of DOM induced by high rates of P applications was probably due to the added phosphate ions competing for adsorption sites in the soil solids with the indigenous DOM.

A three-parameter single-step time integration method for structural dynamic analysis

The existing three-parameter single-step time integration methods, such as the Generalized-a method, improve numerical dissipation by modifying equilibrium equation at time points, which cause them to lose accuracy due to the interpolation of load vectors. Moreover, these three-parameter methods do not present an available formulation applied to a general secondorder non linear differential equatio n. To solve these problems, this paper proposes an innovative three-parameter single-step method by introducing an additional variable into update equations. Although the present method is spectrally identical to the Generalized-cx method for undamped systems, it possesses higher accuracy since it strictly satisfies the equilibrium equation at time points, and can be readily used to solve nonlinear equations. By the analysis of accuracy, stability, numerical dissipation and dispersion, the optimal second-order implicit and explicit schemes are generated, which can maximize low-frequency accuracy when high-frequency dissipation is specified. To check the performance of the proposed method, several numerical experiments are conducted and the proposed method is compared with a few up-to-date methods.

Synthesis and applications of mesoporous Cu-Zn-Al_2O_3 catalyst for dehydrogenation of 2-butanol

A series of mesoporous Cu-Zn-Al2O3 materials have been synthesized at ambient temperature and their structure was characterized by XRD, N2 physical adsorption and TPR techniques. Their catalytic applications for the dehydrogenation of 2-butanol to methyl ethyl ketone （MEK） were evaluated in a fixed-bed flow reactor at atmospheric pressure. It is demonstrated from the XRD patterns that both the as-synthesized samples and calcined samples have the typical XRD patterns of meso-structured materials and the results of N20 chemical adsorption showed that Cu was embedded in the framework of the mesoporous materials and homogeneously dispersed in the mesoporous Cu-Zn-Al2O3 materials. The catalytic activity of 2-butanol dehydrogenation was varied in the order of CZA（10） 〈 CZA（CP） 〈 CZA（20） 〈 CZA（30）; while the selectivity of MEK was increased in the order of CZA（CP） 〈 CZA（10） 〈 CZA（20） 〈CZA（30）.

Time-Programmed Delivery of Sorafenib and Anti-CD47 Antibody via a Double-Layer-Gel Matrix for Postsurgical Treatment of Breast Cancer

The highly immunosuppressive microenvironment after surgery has a crucial impact on the recurrence and metastasis in breast cancer patients.Programmable delivery of immunotherapy-involving combinations through a single drug delivery system is highly promising,yet greatly challenging,to reverse postoperative immunosuppression.Here,an injectable hierarchical gel matrix,composed of dual lipid gel(DLG)layers with different soybean phosphatidylcholine/glycerol dioleate mass ratios,was developed to achieve the time-programmed sequential delivery of combined cancer immunotherapy.The outer layer of the DLG matrix was thermally responsive and loaded with sorafenib-adsorbed graphene oxide(GO)nanoparticles.GO under manually controlled near-infrared irradiation generated mild heat and provoked the release of sorafenib first to reeducate tumor-associated macrophages(TAMs)and promote an immunogenic tumor microenvironment.The inner layer,loaded with anti-CD47 antibody(aCD47),could maintain the gel state for a much longer time,enabling the sustained release of aCD47 afterward to block the CD47-signal regulatory proteinα(SIRPα)pathway for a long-term antitumor effect.In vivo studies on 4T1 tumor-bearing mouse model demonstrated that the DLG-based strategy efficiently prevented tumor recurrence and metastasis by locally reversing the immunosuppression and synergistically blocking the CD47-dependent immune escape,thereby boosting the systemic immune responses.

Micro-Service-Based Radio Access Network

The convergence of information,communication,and data technologies(ICDT)has been identified as one of the developing trends of the sixth generation(6G)network.Service-based architecture(SBA)as one of the promising information technology,has been preliminarily introduced into the fifth generation(5G)core network(CN)and successfully commercialized,which verifies its feasibility and effectiveness.However,SBA mainly focuses on the control plane of CN at present and the SBA-CN user plane is being studied by the industry.In addition to further evolving the SBA-CN,SBA radio access network(RAN)should also be considered to enable an end-toend SBA,so as to meet more comprehensive and extreme requirements of future applications,as well as support fast rollout requirements of RAN devices.

6G移动信息网络架构:从通信到一切皆服务的变迁

5G与大数据、云计算和AI等技术的融合正在赋能千行百业的数字化转型,加速整个社会走向数字化和智慧化.面向2030年,社会发展的愿景将是“数字孪生、智慧泛在”,更加差异化和碎片化的业务场景将对移动通信网络提出全新的挑战,未来网络将从提供信息传输服务,拓展到信息感知、传输、存储、处理、利用等全过程服务,实现从传统通信网络向移动信息网络的重大转变.为了高效实现这一转变,6G网络将通过通信、感知、大数据、计算、AI和安全等多领域技术的跨界融合,实现柔性、按需服务、至简、智慧内生、数字孪生和安全内生的网络设计,带来“按需服务”和“一切皆服务”的范式转变.本文从面向2030年的新应用需求、新技术趋势,以及5G网络面临的问题与挑战出发,分析6G网络发展的三大驱动力,提出6G网络架构的整体设计思路,并设计了“三层六面”6G网络逻辑功能架构和实际部署架构,打造一站式提供通信、感知、计算、AI、大数据和安全等服务的全新能力,全面提升6G网络的业务和场景适应能力,实现面向全行业、全场景、全生态的按需服务,在有效解决5G网络面临的高成本、高功耗、操作和维护难等主要问题的同时,全面赋能“数字孪生、智慧泛在”社会发展愿景的实现.

Iron-doped Ag/Ni_(2)(CO_(3))(OH)_(2)hierarchical microtubes for highly efficient water oxidation

Doping of foreign atoms and construction of unique structures are considered as effective approaches to design high-activity and strongdurability electrocatalysts.Herein,we report Fe-doped nickel hydroxide carbonate hierarchical microtubes with Ag nanoparticles(denoted Ag/NiFeHC HMTs)through hydrolysis precipitation process.Experimental tests and density functional theory calculations reveal that Fe doping can tune the electron configuration to enhance the conductivity,markedly improve the electrochemical surface area to expose more active sites,and act as reactive centers to lower the free energy of the rate determination step.In addition,the unique hierarchical structure can also offer active sites and excellent cycling stability.Benefitting from these advantages,the as-obtained Ag/NiFeHC HMTs show excellent oxygen evolution reaction activity,with an overpotential of 208 mV at 10 mA cm^(−2)in 1.0M KOH.Also,it could achieve long-term stability at a current density of 20 mA cm^(−2)for 24 h.

Relationship between Cr-Al Interaction and the Performance of Cr-Al₂O₃Catalysts for Isobutane Dehydrogenation

A series of catalysts were prepared using the kneading molding method and the impregnation method as well as the dry mix method by using different raw materials. By using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR) techniques, we studied the relationship between the catalyst performance and the Cr-Al interaction in the catalytic dehydrogenation of isobutane. The results demonstrated that the Cr-Al interaction in the catalyst had a direct influence on the catalytic activity and the selectivity of isobutene. The catalysts prepared using the kneading molding method had higher catalytic activity and isobutene selectivity than those prepared using the dry mix method. By comparison, XRD, XPS, and TPR results showed that the greater the Cr-Al interaction in the catalyst was, the higher the catalytic activity was. Here, we propose a mechanism of isobutane dehydrogenation.

Exploring alkylthiol additives in PBDB-T:ITIC blended active layers for solar cell applications

Bulk heterojunction,non-fullerene PBDB-T:ITIC blend polymer solar cells have been fabricated.The active layers consisting of PBDB-T as a donor and ITIC as an acceptor are optimized using a series of alkylthiol additives(1,3-propanedithiol,1,4-butanedithiol,and 1,8-octanedithiol).It is found that the donor and acceptor are phase separated with different crystalline domains.The additives effectively re-organize the morphology and extend the molecule ordering in lamellar structure with increased correlation length in ITIC domain,benefiting the generation and dissociation of exciton and reducing charge recombination.A substantial improvement in power conversion efficiency of the devices from 8.13%to 9.44%is observed.This study shows that the application of alkylthiol additives is a simple and effective approach to improve the device performance in solar cells based on polymer/non-fullerene blend system.

Liac arterial fibromuscular dysplasia:a systematic review

Background liac arterial fibromuscular dysplasia(FMD)were rarely reported and their demographic,clinical and imaging features have not been precisely described resulting in uncertain therapeutic methods.Methods A literature review was performed using Pubmed,Web of Science and Embase database.Original articles in English published since 1990 with full-text and detailed demographic,clinical,imaging and therapeutic information regarding iliac arterial FMD were included.

Physiological Responses of Different Kinds of Vegetable Seedlings to Polycyclic Aromatic Hydrocarbons Stress

This study was conducted to explore the effects of polycyclic aromatic hydrocarbons (PAHs) on the growth and physiological characteristics of vegetable seedlings.Cucumber,Chinese cabbage and radish were cultured under the stress of 16 PAHs at different concentrations of 0.3,0.6 and 0.9 mg/L,respectively,with the seedlings cultured without PAHs as the control,to study the growth and physiological responses of various vegetable seedlings under PAHs stress.The results showed that the leaf width,fresh weight,CAT activity and POD activity of cucumber and the chlorophyll b content and CAT activity of radish reached the minimum values when treated with 0.3 mg/L PAHs.When the treatment concentration was 0.6 mg/L,the POD activity of cucumber,the vitamin C content of Chinese cabbage and the MDA content of radish were the smallest.The dry weight of cucumber,the fresh weight of Chinese cabbage and the fresh weight and POD activity of radish reached the minimums under the treatment of 0.9 mg/L PAHs.Different concentrations of PAHs could promote the synthesis and photosynthesis of chlorophyll in cucumber and Chinese cabbage leaves and the vitamin C content in radish.With the increase of PAHs treatment concentration,the MDA contents of cucumber and Chinese cabbage were on the increase,and reached the maximums under the treatment of 0.9 mg/L PAHs.One of the reasons why different kinds of vegetable seedlings have different physiological responses to PAHs may be related to the differences in the amount of PAHs absorbed by different leaf structures.