关键词： 人工智能技术   客户配置多元化   人工智能创新应用先导区   供应链韧性  

摘要： 在外部环境高度不确定和我国企业普遍依赖少数大客户的现实状况下，构建多元化的客户网络是打造灵活可控、高韧性产业链供应链的重要途径。本文将人工智能创新应用先导区建设视为人工智能与实体经济深度融合的准自然实验，基于多时点双重差分倾向得分匹配法（PSM-DID）检验了人工智能应用对企业客户配置多元化的影响及其作用机制。研究发现，人工智能应用能有效推动企业客户配置多元化。机制检验证实，增强企业内在产品质量优势和削弱交易双方外部信息约束是人工智能应用推动企业客户配置多元化的关键所在。异质性检验表明，人工智能的客户优化效应在行业竞争激烈、中小规模、生产效率低的企业以及信息割裂程度高的地区中更为凸显。进一步讨论发现，人工智能客户优化效应的主要表现方式在于开拓新客户或向原有中小客户增加销售额，而非中断或缩减对大客户的销售额。此外，得益于人工智能应用的客户优化效应，企业的经营风险也随之下降。本文结论深化了人工智能应用与微观主体客户配置之间逻辑关系的理论认知，并为推动人工智能与实体经济深度融合、增强企业客户协调能力以及提升产业链供应链安全与韧性提供了重要的经验借鉴和政策参考。

关键词： essential oil   St John’s Wort   biological activities  

摘要： Since ancient times, essential oils obtained from various aromatic plants have been utilized as bioactive ingredients in medicines, foods and cosmetics. The present study aimed to investigate the chemical composition and biological activities of St John’s Wort (Hypericum perforatum L.) essential oil (SJW EO) from Bulgaria, which is known to possess various biological properties. Gas chromatography and mass spectrometry (GC–MS) analysis, determination of antioxidant activity (by the ABTS method), an antimicrobial activity test and an in vitro anti-inflammatory activity test were performed. The main classes of compounds identified by GC–MS analysis were monoterpenes (43.55%), followed by sesquiterpenes (36.81%) and alkanes (16.92%). The predominant chemical components of SJW EO were α-pinene (27.52%), followed by β-pinene (10.08%), β-caryophyllene (6.77%), germacrene D (6.37%) and caryophyllene oxide (4.48%). The highest antibacterial activity was observed against the Gram-negative bacteria Klebsiella pneumoniae ATCC 13883 (inhibition zone of 12.0 mm) and Pseudomonas aeruginosa ATCC 9027 (inhibition zone of 11.0 mm). SJW EO exhibited significant in vitro anti-inflammatory activity, as the results demonstrated that its anti-inflammatory effect was stronger than those of the conventional anti-inflammatory drugs Prednisolon Cortico and acetylsalicylic acid (Aspirin), which were used as controls (all in concentration of 1 mg/mL). The obtained results demonstrated that Bulgarian SJW EO can be used as an active ingredient in the composition of new products for the pharmaceutical and cosmetic industries.

关键词： 串联制造结构   装备制造   制造合格率   数量柔性   市场需求   制造总利润  

摘要： 随着装备产品精密化和商业环境复杂化,数量柔性化正在成为装备制造企业应对内外部制造环境干扰、实现最优制造总利润的重要途径.针对被忽略的制造结构、制造合格率、市场需求与数量柔性之间的内在逻辑关系,本文结合装备制造企业制造系统的串联结构特征进行理论建模与分析,以期回答“串联制造结构下装备制造企业如何选择最优匹配的柔性数量策略”这一问题.研究结果表明:与单环节制造结构相比,串联制造结构的最优数量柔性更大但制造总利润更低;串联制造结构的装备制造企业总有动机采用柔性数量策略;串联制造结构下,随着前序制造环节1的制造合格率提高,装备制造企业的最优数量柔性呈倒U型变化;随着数量柔性边际成本增加,装备制造企业的最优数量柔性与制造总利润降低.以上结论可为串联制造结构下装备制造企业柔性数量策略的制定与实施提供有益的参考.

关键词： carbapenem-resistant hypervirulent Klebsiella pneumoniae   bla(KPC-2)   multidrug resistance   plasmid   whole-genome sequence  

摘要： Carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) strains present a significant global public health threat due to their high mortality rates. This study investigated the genomic characteristics of seven ST11-K1 CR-hvKP isolates harboring highly homologous KPC-2-encoding multidrug-resistance plasmids. The strains were isolated from a Chinese tertiary hospital between 2017 and 2020. Whole-genome sequencing and bioinformatic analysis revealed various antibiotic resistance genes (ARGs) and virulence determinants. The bla(KPC-2)-bearing plasmids that contain multiple antibiotic-resistance genes were also identified in these strains. ISfinder and Orifinder were applied to identify insertion sequences (IS) and conjugation-related factors among these bla(KPC-2)-bearing plasmids. The bla(KPC-2) was highly consistent in seven bla(KPC-2)-bearing plasmids (ISKpn6-bla(KPC-2)-ISKpn27-ISYps3-IS26). In addition, we found a region composed of ISIR, Tn5393, and IS26. It was located upstream of the bla(CTX-M-15) gene and presented in six bla(KPC-2)-bearing plasmids, with pCR-hvKP221-KPC-P3 as an exception. Conjugation experiments demonstrated the horizontal transfer of resistance plasmids pCR-hvKP128-KPC-P1 and pCR-hvKP132-KPC-P1 across species. Notably, pLVPK-like virulence plasmids carrying virulence gene clusters pCR-hvKP173-Vir-P1, and pCR-hvKP221-Vir-P1 were also detected. A fusional plasmid pCR-hvKP221-Vir-P2, which carries virulence gene clusters and ARGs, was also identified. Five CR-hvKP strains displayed enhanced biofilm formation and high virulence in vivo infection models. Phylogenetic and single nucleotide polymorphism (SNP) analyses indicated a close genetic relationship among the isolates, suggesting a subclade. These findings highlight the complex genetic profiles and potential transmission mechanisms of CR-hvKP strains. IMPORTANCE We reported seven CR-hvKP strains all carried a highly homologous bla(KPC-2) integrated IncFII-resistant plasmid, and two

关键词： 产业链关联   制造业产业链   企业创新   吸收能力差距   出口贸易  

摘要： 在全球产业分工背景下,产业链上国内外各环节关联互动是企业持续推进技术创新的关键路径。围绕产业链国内关联和国际关联对企业创新的非线性影响及其影响机制,提出研究假设,以中国制造业产业链为研究对象进行实证检验,并从产业链类型出发,实证分析不同产业链关联方式对企业创新的异质性影响。研究发现:产业链国内关联、国际关联分别与企业创新呈U型关系和倒U型关系;在产业链国际关联与企业创新的非线性关系中,企业吸收能力差距和产业出口贸易均具有正向调节作用,在产业链国内关联与企业创新的非线性关系中,产业出口贸易具有正向调节作用;从产业链类型来看,资本密集型制造业产业链企业创新水平最高,劳动密集型产业链企业创新水平最低。最后,从提升产业链创新性、增强产业创新赋能效应等角度,提出相关政策建议。

关键词： 供水企业   问卷调查   满意度评价  

摘要： 为掌握供水企业存在的问题，针对性地提升服务质量和满足用户需求。采用问卷调查的方式对北京市15家主要供水企业开展供水企业服务满意度调查，覆盖北京市16个城区，最终收集14 117份问卷，并利用SPSS对2023年北京市供水企业服务满意度进行统计分析。结果表明：北京市供水企业总体满意度80.2分，整体表现良好，供水企业间服务水平存在一定差异，供水企业整体服务还有进一步提升空间；水质问题、监督投诉问题及应急供水保障为居民反映的主要问题，供水企业需加强关注，重点提升。为行业监管部门强化供水企业监管提供有力抓手，为供水企业改进服务质量水平指明方向，对提升北京供水企业服务水平有重要意义。

关键词： 数字经济   数字化转型   知识溢出   全球价值链融入   知识产权保护  

摘要： 企业数字化转型能够诱发知识溢出，是促进企业融入全球价值链的有效路径。本文利用2007～2016年中国制造业上市企业数据，探讨知识溢出视角下企业数字化转型对全球价值链融入的影响。结果表明：相较于非数字化转型的企业，数字化转型企业的知识溢出显著促进了企业融入全球价值链，在克服内生性问题和稳健性检验后，结论依然成立；异质性分析表明，数字化转型企业的知识溢出对国有企业、低IT投资企业和技术资本密集型企业融入全球价值链有显著正向影响；进一步讨论发现，知识产权保护的加强、融资约束的缓解强化了数字化转型企业知识溢出对企业融入全球价值链的积极作用。

关键词： corticosteroids   FK506   graft   immunosuppressant   mycophenolic acid   nitrogen mustards   omics   rapamycin   synthetic biology   tacrolimus  

摘要： The confluence of a large variety of factors, achievements and developments has resulted in the current long-term success in graft transplants. Some of these events are reviewed, paying special attention to immunosuppressant drugs, which are one of the most relevant milestones in the prevention of organ transplant rejection. The discovery, industrial exploitation, mechanisms of action and side effects of several drugs exhibiting immunosuppressive effects (e.g., corticosteroids, nitrogen mustards, mycophenolic acid, rapamycin) are deeply detailed. Furthermore, new trends in immunosuppressant research, improvement and reformulation are also reviewed. Nevertheless, the core of the manuscript is the immunosuppressant tacrolimus, also called FK506, which has been sought after due to the commercial success of cyclosporine and other immunosuppressant compounds, but also because of the side effects of those previous compounds. Thus, in the mid-1980s tacrolimus was described as a more potent immunosuppressive molecule, with less undesirable effects. Currently, tacrolimus is a well-stablished API that is used as a clinical treatment to avoid graft rejection, but also shows interesting properties in terms of decreasing the impact of some autoimmune diseases and acting as an enhancer of nerve regeneration treatments. Thus, in the 40th anniversary of its discovery, this paper describes the current state of the art of this drug and how it is adapting to new social needs and clinical trends.

摘要： Objectives To study the population structure and genomic characteristics, including antimicrobial resistance genes, plasmid types and surface polysaccharide type, of the globally distributed Acinetobacter baumannii belonging to ST32 (Institut Pasteur scheme).Methods Antibiotic resistance phenotype for 19 antibiotics was determined using Vitek 2. Whole-genome sequencing was performed using the Illumina MiSeq platform. Genomes were assembled using Newbler. Phylogenetic analysis was done by determining the core-genome alignments using Panaroo v1.3, analysed in IQ-Tree2 v2.***.0.3 to construct Maximum Likelihood trees using the RaxML software. Resistance genes and IS were identified using the Abricate programme, and ISFinder *** One hundred and thirty-three (n = 133) ST32 A. baumannii isolates were analysed in this study. These genomes originated mainly from US military treatment facilities (n = 113), but also included additional publicly available genomes in GenBank (n = 20) recovered from a broad geographic distribution extending to Asia and South America. Phylogenetic analysis of all 133 genomes revealed at least four clades, with over 80 genomes forming a tightly clustered branch, suggesting they are likely to represent outbreak strains. Analysis of the ampC region showed that ST32 strains played a significant role in the formation of the widely distributed ampC transposon, Tn6168, and supplying DNA segments containing an ISAba1-ampC from ST32s via homologous *** ST32 strains played a significant role in the evolution of antibiotic resistance in several widely distributed sequence types including ST1 (global clone 1) and ST3.

关键词： digital equity   digital technology   rural health research   rural population