农业保险在农产品贸易中的信用保障机制

随着全球经济的发展和农业经济规模的扩大,农产品贸易作为农业经济的重要组成部分,面临着较为严重的信用风险,影响着农民和涉农企业的经济利益,甚至整个农产品供应链。基于此,将农业保险应用在农产品贸易中可以减轻农民和涉农企业经营风险,提供贷款担保,以及保证产品质量和安全。本文针对农业保险在农产品贸易中的信用保障机制展开探究,以期为相关领域人员提供理论参考。

Unveiling the promotion of accelerated water dissociation kinetics on the hydrogen evolution catalysis of NiMoO_(4) nanorods

Nickel molybdate(NiMoO_(4))attracts superior hydrogen desorption behavior but noticeably poor for efficiently driving the hydrogen evolution reaction(HER)in alkaline media due to the sluggish water dissociation step.Herein,we successfully accelerate the water dissociation kinetics of NiMoO_(4)for prominent HER catalytic properties via simultaneous in situ interfacial engineering with molybdenum dioxide(MoO_(2))and doping with phosphorus(P).The as-synthesized P-doped NiMoO_(4)/MoO_(2)heterostructure nanorods exhibit outstanding HER performance with an extraordinary low overpotential of-23 m V at a current density of 10 m A cm^(-2),which is highly comparable to the performance of the state-of-art Pt/C coated on nickel foam(NF)catalyst.The density functional theory(DFT)analysis reveals the enhanced performance is attributed to the formation of MoO_(2)during the in situ epitaxial growth that substantially reduces the energy barrier of the Volmer pathway,and the introduction of P that provides efficient hydrogen desorption of Ni MoO_(2).This present work creates valuable insight into the utilization of interfacial and doping systems for hydrogen evolution catalysis and beyond.

Investigation of Cultivated Woody Plant Resources in Ping’an District of Qinghai Province in China

[Objectives]To investigate and find the characteristics and distribution of woody plant resources in Ping'an District of Qinghai Province.[Methods]The investigation was carried out by interview method,literature method and route method.[Results]There were 22 families,40 genera and 84 species of woody plants in Ping'an District of Qinghai Province,and their life forms were mainly shrubs.Cultivated woody plants in the study area were dominated by trees;the distribution of families and genera were mainly concentrated in single families,few families,single genera and few genera,the families and genera were narrow;economic value was mainly manifested in ornamental value.[Conclusions]The investigation results are expected to provide a certain reference for the economic development of cultivated woody plants in the study area.

Discovery and engineering of ChCas12b for precise genome editing

Many clustered regularly interspaced short palindromic repeat and CRISPR-associated protein 12b(CRISPR-Cas12b)nucleases have been computationally identified,yet their potential for genome editing remains largely unexplored.In this study,we conducted a GFP-activation assay screening 13 Cas12b nucleases for mammalian genome editing,identifying five active candidates.Candidatus hydrogenedentes Cas12b(ChCas12b)was found to recognize a straightforward WTN(W=T or A)proto-spacer adjacent motif(PAM),thereby dramatically expanding the targeting scope.Upon optimization of the single guide RNA(sgRNA)scaffold,ChCas12b exhibited activity comparable to SpCas9 across a panel of nine endogenous loci.Additionally,we identified nine mutations enhancing ChCas12b specificity.More importantly,we demonstrated that both ChCas12b and its high-fidelity variant,ChCas12b-D496A,enabled allelespecific disruption of genes harboring single nucleotide polymorphisms(SNPs).These data position ChCas12b and its high-fidelity counterparts as promising tools for both fundamental research and therapeutic applications.

基于数据挖掘的中药复方专利治疗血管性痴呆用药规律研究

目的运用数据挖掘方法分析血管性痴呆(VD)复方专利用药规律。方法检索国家知识产权局中国专利公布公告网站及中国知识资源总库(CNKI)建库至2022年3月31日发布的治疗VD的中药复方专利,采用中医传承辅助平台(V2.5)进行频次统计、聚类分析和关联分析,探讨用药规律。结果共纳入复方专利154个,涉及中药227味,应用最多的中药为石菖蒲(44次,28.57%),常用药对有丹参-石菖蒲(17次,11.03%)等,用药药性多属温,药味多属甘,归经以肝经为主;关联规则置信度较高的有“山萸肉-石菖蒲”(0.90)、“山萸肉-熟地黄”(0.90),基于复杂网络得出核心药物有“熟地黄-肉苁蓉-山萸肉”等14组,通过熵聚类分析提取新处方有“熟地黄、肉苁蓉、山萸肉、天冬”等7组。结论中药复方专利治疗VD以补益亏虚、活血化瘀、祛痰化湿、祛风通络、开窍醒神为主,可为临床实践和新药研发提供参考。

Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration

Stem cell transplantation has been proved a promising therapeutic instrument in intervertebral disc degeneration(IVDD).However,the elevation of oxidative stress in the degenerated region impairs the efficiency of mesenchymal stem cells(BMSCs)transplantation treatment via exaggeration of mitochondrial ROS and promotion of BMSCs apoptosis.Herein,we applied an emulsion-confined assembly method to encapsulate Coenzyme Q10(Co-Q10),a promising hydrophobic antioxidant which targets mitochondria ROS,into the lecithin micelles,which renders the insoluble Co-Q10 dispersible in water as stable colloids.These micelles are injectable,which displayed efficient ability to facilitate Co-Q10 to get into BMSCs in vitro,and exhibited prolonged release of Co-Q10 in intervertebral disc tissue of animal models.Compared to mere use of Co-Q10,the Co-Q10 loaded micelle possessed better bioactivities,which elevated the viability,restored mitochondrial structure as well as function,and enhanced production of ECM components in rat BMSCs.Moreover,it is demonstrated that the injection of this micelle with BMSCs retained disc height and alleviated IVDD in a rat needle puncture model.Therefore,these Co-Q10 loaded micelles play a protective role in cell survival and differentiation through antagonizing mitochondrial ROS,and might be a potential therapeutic agent for IVDD.

Corrigendum to“Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration”[Bioact.Mater.23(2023)247-260]

This corrects the article“Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration”in volume 23 on page 247.The authors regret that the printed version of the above article contains some errors which are not identified during the proofing stage.

蜱传脑炎病毒跨过血脑屏障的体外实验

【目的】构建蜱传脑炎病毒(Tick-borne encephalitis virus,TBEV)跨血脑屏障研究的体外细胞模型,研究2种不同细胞的TBEV培养物在病毒跨过血脑屏障中的主要差异,从而为进一步TBEV跨血脑屏障的分子机制研究奠定基础。【方法】利用人脑微血管内皮细胞(Human brain microvascular endothelial cells,hCMEC/D3)构建体外血脑屏障的细胞模型。用BHK-21细胞中培养的蜱传脑炎病毒感染人脑微血管内皮细胞,检测TBEV在hCMEC/D3中的复制增殖情况;将TBEV加入体外血脑屏障模型的上层微孔中,用实时荧光定量PCR和噬斑测定的方法检测跨过血脑屏障的病毒量;将感染TBEV的人单核细胞加入血脑屏障模型的上层微孔中,观察渗漏进下层孔中的淋巴细胞,并用实时荧光定量PCR和噬斑测定的方法检测跨过血脑屏障的病毒量。利用伊文思蓝标记的白蛋白确定血脑屏障细胞的渗透率变化。【结果】实时荧光定量PCR和病毒滴度测定结果表明,TBEV不能在hCMEC/D3细胞中复制增殖,也不能直接跨过血脑屏障;然而,人单核细胞THP-1感染TBEV后,尽管单核细胞不能直接携带TBEV跨过血脑屏障,但THP-1中产生的病毒却能跨过血脑屏障模型进入下层孔中,并引起血脑屏障渗透率的增高。【结论】单核细胞有助于TBEV跨过血脑屏障。

Synthesis of high-purity silver nanorods with tunable plasmonic properties and sensor behavior

Through anisotropic Ag overgrowth on the surface of Au nanobipyramids(Au NBPs), high-purity and sizecontrolled Ag nanorods(Au/Ag NRs) are obtained by a simplified purification process. The diameters of the Au/Ag NRs are determined by the size of the as-prepared Au NBPs, and the lengths of the Au/Ag NRs are tunable using different amounts of Ag precursor in the growth solution. Surface-enhanced Raman scattering(SERS) studies using Rhodamine-6G(R6G) as a test molecule indicate that the Au/Ag NRs have excellent sensing potential. The tunable optical properties and strong electromagnetic effect of the Au/Ag NRs, along with their superior SERS signal enhancement, show that Au/Ag NRs are promising for further applications in plasmon sensing and biomolecular detection.

Genetically engineered materials:Proteins and beyond

Information-rich molecules provide opportunities for evolution.Genetically engineered materials are superior in that their properties are coded within genetic sequences and could be fine-tuned.In this review,we elaborate the concept of genetically engineered materials(GEMs)using examples ranging from engineered protein materials to engineered living materials.Proteinbased materials are the materials of choice by nature.Recent progress in protein engineering has led to opportunities to tune their sequences for optimal material performance.Proteins also play a central role in living materials where they act in concert with other biological components as well as nonbiological cofactors,giving rise to living features.While the existing GEMs are often limited to those constructed by building blocks of biological origin,being genetically engineerable does not preclude nonbiologic or synthetic materials,the latter of which have yet to be fully explored.

Targeted chemotherapy for subcutaneous and orthotopic non-small cell lung tumors with cyclic RGD-functionalized and disulfide-crosslinked polymersomal doxorubicin

Lung cancer, with its high mortality and increasing morbidity, has become one of the most lethal malignancies worldwide. Here, we developed cyclic RGD peptide-directed and disulfide-crosslinked polymersomal doxorubicin (cRGD-PS-Dox) as a targeted chemotherapy for human non-small cell lung cancer (NSCLC). Notably, cRGD-PS-Dox exhibited a high Dox loading (15.2 wt.%), small hydrodynamic diameter (96 nm), superb stability, prominent targetability to αvβ3 integrin overexpressing A549 human lung cancer cells, and rapid release of the drug into nuclei, leading to a significantly improved antitumor activity compared with the control groups, i.e., PS-Dox and Lipo-Dox (a liposome injection employed in clinical settings). The pharmacokinetic and biodistribution results for cRGD-PS-Dox revealed similar elimination half-lives but two-fold enhanced tumor accumulation compared with PS-Dox and Lipo-Dox. Intriguingly, cRGD-PS-Dox effectively suppressed the growth of A549 lung tumors in both subcutaneous and orthotopic models with minimal adverse effects at a Dox dose of 12 mg/kg, leading to significant survival benefits compared with PS-Dox and Lipo-Dox. This αvβ3 integrin-targeting multifunctional polymersomal doxorubicin is highly promising for targeted chemotherapy of human NSCLC.

Native conjugation between proteins and [60]fullerene derivatives using SpyTag as a reactive handle

Herein,we report the facile conjugation between proteins and water-soluble [60]fullerene derivatives(DC_(60)) under native conditions using SpyTag as a reactive handle.Water-soluble [60] fullerene derivatives were first prepared via sequential Bingel-Hirsch reaction and "clicked" with SpyTag to give DC_(60)-SpyTag for native conjugation with proteins by the highly efficient SpyTag-SpyCatcher chemistry.The bioconjugation was confirmed by MALDI-TOF MS spectra and SDS-PAGE analysis.The TEM and UVvis spectroscopic study further revealed that the DC_(60) could alter the optical performance and induce aggregation of the target proteins.It thus provides a general and robust method for modifying proteins with C_(60) derivatives and could potentially be adapted for native conjugation between proteins and other nonbiological motifs as well.

DYNAMICS OF SIS EPIDEMIC MODEL WITH THE STANDARD INCIDENCE RATE AND SATURATED TREATMENT FUNCTION

An SIS epidemic model with the standard incidence rate and saturated treatment func- tion is proposed. The dynamics of the system are discussed, and the effect of the capacity for treatment and the recruitment of the population are also studied. We find that the effect of the maximum recovery per unit of time and the recruitment rate of the popula- tion over some level are two factors which lead to the backward bifurcation, and in some cases, the model may undergo the saddle-node bifurcation or Bogdanov-Takens bifurca- tion. It is shown that the disease-free equilibrium is globally asymptotically stable under some conditions, Numerical simulations are consistent with our obtained results in the- orems, which show that improving the efficiency and capacity of treatment is important for control of disease.

Integrative self-assembly of covalent organic frameworks and fluorescent molecules for ultrasensitive detection of a nerve agent simulant

Binding of fluorescent molecules to the porous matrix through noncovalent interactions will synergistically expand their application spectrum. In this regard, we report an integrative self-assembly of molecule 1 with benzothiadizole and 9,9-dihexyl fluorene units, and covalent organic frameworks(COFs) via an emulsion-modulated polymerization process, within which molecules of 1 are able to interact with the scaffolds of COFs through CH-π interactions. Thus the π-πinteractions between the fluorescent molecules are largely suppressed, giving rise to their remarkable monomer-like optical properties. Of particular interest is that, given by the specific interaction between COFs and a nerve agent simulant diethyl chlorophosphite(DCP), these assembled composites show the ability of ultrasensitive detection of DCP with a detection limit of ~40 ppb. Moreover, the present integrative assembly strategy can be extended to encapsulate multiple fluorescent molecules, enabling the assemblies with white light emission. Our results highlight opportunities for the development of highly emissive porous materials by molecular selfassembly of fluorophores and molecular units of COFs.

Learning from context： a mutual reinforcement model for Chinese microblog opinion retrieval

This study addresses the problem of Chinese microblog opinion retrieval, which aims to retrieve opinionated Chinese microblog posts relevant to a target specified by a user query. Existing studies have shown that lexicon-based approaches employed online public sentiment resources to rank sentiment words relying on the document features. However, this approach could not be effectively applied to mi- croblogs that have typical user-generated content with valu- able contextual information： ＂user-user＂ interpersonal interactions and ＂user-post/comment＂ intrapersonal interactions. This contextual information is very helpful in estimating the strength of sentiment words more accurately. In this study, we integrate the social contextual relationships among users, posts/comments, and sentiment words into a mutual reinforcement model and propose a unified three-layer heterogeneous graph, on which a random walk sentiment word weighting algorithm is presented to measure the strength of opinion of the sentiment words. Furthermore, the weights of sentiment words are incorporated into a lexicon-based model for Chinese microblog opinion retrieval. Comparative experiments are conducted on a Chinese microblog corpus, and the results show that our proposed mutual reinforcement model achieves significant improvement over previous methods.

软外延生长法构筑纳米粒子超晶格材料

由纳米粒子自下而上自组装而成、高度有序的纳米粒子超晶格材料是近年来兴起的一类新型材料.本文主要概述了软外延生长法构筑纳米粒子超晶格材料的概念及组装策略,结合近几年本课题组的相关研究工作,主要介绍了几种不同的基底材料,以及通过调控基底与纳米粒子之间的相互作用来构建纳米粒子超晶格材料.具体包括以纳米粒子超晶格、有机分子笼晶体以及超分子组装体等作为基底诱导纳米粒子软外延生长.通过软外延生长法可实现对纳米粒子超晶格维度(包括一维、二维以及三维)的有效调控.同时,阐明了纳米粒子与基底材料的弱键相互作用机制,该机制也成为构筑无机纳米粒子/有机分子有序组装体重要的物理化学基础.

Photocatalyzed Dual-Oxidative Trifluoromethylthio-Trifluoromethylation of Alkenes with CF3SO2Na

A novel photocatalyzed trifluoromethylthio-trifluoromethylation of alkenes has been developed,using CF_(3)SO_(2)Na as both CF_(3) and SCF_(3) source.This photocatalyzed dual-oxidative strategy,which combines two parallel oxidative events,provides a facile method to synthesize a series of vicinal trifluoromethylthio-trifluoromethylated compounds.This reaction is operationally simple,proceeds under mild conditions and exhibits exceptional substrate generality and functional group compatibility.