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激发态下甘氨酸与水分子间氢键性质研究

原子与分子物理学报 2024年第3期41卷 1-8页

作者：刘启帆布玛丽亚·阿布力米提向梅安桓郑敬严新疆师范大学物理与电子工程学院乌鲁木齐830054

在生物体中氨基酸通常以水作为溶剂,是形成细胞的重要成分.在该环境下,分子间氢键的产生会对氨基酸分子与水分子的结构和性质产生影响.为了研究其在基态和激发态下的性质,本文利用密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)对甘氨酸... 详细信息

在生物体中氨基酸通常以水作为溶剂,是形成细胞的重要成分.在该环境下,分子间氢键的产生会对氨基酸分子与水分子的结构和性质产生影响.为了研究其在基态和激发态下的性质,本文利用密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)对甘氨酸分子和H_(2)O分子在基态和激发态下的分子间氢键的静电势、键长、自然键轨道(NBO)电荷、分子中的原子理论(AIM)分析、Wiberg键级b、红外(IR)光谱、空穴-电子轨道和基态与激发态之间的电子转移进行了理论研究.结果表明:分子间氢键的形成会导致分子结构的改变和红外光谱振动频率的移动.在激发态下,分子间氢键有不同程度的增强或减弱.该计算结果为氢键的形成和激发态下分子间氢键的研究提供理论依据.

关键词：甘氨酸氢键激发态光谱 TD-DFT

Zigzag Hydrocarbon Belts

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CCS Chemistry 2021年第2期3卷 916-931页

作者： Tan-Hao Shi mei-xiang Wang MOE Key Laboratory of Bioorganic Phosphorous and Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084

Zigzag hydrocarbon belts have been fascinating chemists and materials scientists for decades because of their aesthetically appealing molecular structures,outstanding physical properties and intriguing chemical reactivities predicted by theoretical calculations,and potential applications as unique macrocyclic hosts in supramolecular *** may also serve as templates or seeds to grow structurally well-defined uniform zigzag carbon *** there have been continuous computational studies on the structures and properties of belt[n]arenes or[n]cyclacenes since they were proposed as hypothetical molecules in 1954,the synthesis of(partially)conjugated zigzag hydrocarbon belts remains a great challenge,with no progress being reported in the past 20 *** recently,we have been witnessing the renaissance of synthetic interest in zigzag hydrocarbon belts,and the formation of the first fully conjugated one is on the *** minireview focuses on the understanding of belt[n]arenes based on theoretical calculations and the synthesis and structure of zigzag hydrocarbon *** on the strategies to isolate and characterize the fully conjugated belt[n]arenes and on the applications of zigzag hydrocarbon belts are also discussed.

关键词： zigzag hydrocarbon belt belt[n]arene [n]cyclacene macrocycle carbon nanotube cyclization Diels–Alder reaction intramolecular alkylation

恶性肿瘤患者多药耐药菌感染部位分布及其易感因素

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中华医院感染学杂志 2024年第17期34卷 2604-2608页

作者：王英刘心航王天琪刘凤娟黄美香青岛市肿瘤医院感染管理科山东青岛266042 青岛大学附属青岛市中心医院感染管理科山东青岛266042

目的研究恶性肿瘤患者多药耐药菌(MDRO)感染部位分布情况及其易感因素。方法采用回顾性分析方法,纳入2019年3月-2022年12月青岛市肿瘤医院收治的980例恶性肿瘤患者的临床资料。根据是否发生多药耐药菌(MDRO)感染,将研究对象分为感染组19... 详细信息

目的研究恶性肿瘤患者多药耐药菌(MDRO)感染部位分布情况及其易感因素。方法采用回顾性分析方法,纳入2019年3月-2022年12月青岛市肿瘤医院收治的980例恶性肿瘤患者的临床资料。根据是否发生多药耐药菌(MDRO)感染,将研究对象分为感染组196例和非感染组784例,统计恶性肿瘤患者MDRO感染的发生情况、感染部位及病原菌谱,并通过单因素分析和多因素Logistic回归分析筛选恶性肿瘤患者MDRO感染的易感因素。结果980例恶性肿瘤患者发生MDRO感染的为196例,发生率为20.00%;恶性肿瘤患者MDRO感染的发生部位主要为呼吸道感染101例(51.53%)、泌尿系统感染62例(31.63%);196例感染患者临床送检样本中,共鉴定出201株多药耐药菌,革兰阴性菌占据了主导地位,占检出总数的72.64%,其中,CRAB、CRPA、CRE的比例分别为33.83%、22.39%和16.42%,革兰阳性菌MRSA占比达到27.36%,VRE未在本次研究中检出;多因素Logistic分析结果显示,恶性肿瘤患者MDRO感染的易感因素包括长期卧床、年龄≥60岁、贫血、侵入性操作、合并基础疾病≥3种、使用抗菌药物时间≥14 d、体质量指数(BMI)≥25 kg/m~2(OR=3.300、3.330、3.501、3.425、2.689、2.291、3.691,P<0.05)。结论恶性肿瘤患者MDRO感染的发生率较高,感染的发生部位主要为呼吸道感染和泌尿系统感染,主要感染的病原菌以革兰阴性菌为主,贫血、年龄≥60岁、侵入性操作、合并基础疾病≥3种、BMI≥25 kg/m~2、长期卧床、使用抗菌药物时间≥14 d为恶性肿瘤患者MDRO感染的易感因素。

关键词：恶性肿瘤多药耐药菌感染部位易感因素病原菌

Construction of TiO2/silane nanofilm on AZ31 magnesium alloy for controlled degradability and enhanced biocompatibility

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Rare Metals 2019年第6期38卷 588-600页

作者： Lei Huang Kun Su Yu-Feng Zheng Kelvin Wai-Kwok Yeung xiang-mei Liu School of Materials Science and Engineering Hubei UniversityWuhan 430062China State Key Laboratory for Turbulence and Complex System Department of Materials Science and EngineeringCollege of EngineeringPeking UniversityBeijing 100871China Department of Orthopaedics and Traumatology Li Ka Shing Faculty of MedicineThe University of Hong KongPokfulam 999077Hong KongChina

A TiO2 nanofilm was prepared on the surface of AZ31 magnesium alloy with controllable thickness through atomic layer deposition(ALD) technique, which can adjust the corrosion behaviors of AZ31 Mg *** with the untreated Mg alloys, corrosion current densities(icorr)can decline by 58% in the 200-cycles TiO2-covered Mg alloy and further decline by up to 74% with the thickness of nanofilm up to 63 nm(400 cycles).The subsequent modification with a cross-linked conversion layer of 3-aminopropyltriethoxysilane(APTES) by a dipping method can produce a compact silane coating on TiO2 nanofilm, which can seal pinholes of TiO2 nanofilm and serve as a barrier to further adjust the corrosion behavior of the *** icorrcan decline about two orders of magnitude in the TiO2/silane composite *** the adjustable corrosion rate come true, which can be attributed to the precise control on the thickness of metal oxide nanofilm and additional protection from the compact silane *** vitro study discloses that the TiO2/silane hybrid coating shows higher expression of alkaline phosphatase(ALP)and can promote cellular adhesion and proliferation with better cytocompatibility than untreated Mg alloy.

关键词： Magnesium alloy TiO2 Biodegradability Atomic layer deposition Hybrid coating Biocompatibility

VEGFA、HIF-1α在老年肺癌组织表达及对肺癌细胞血管管腔形成的影响

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中国老年学杂志 2024年第6期44卷 1489-1493页

作者：王清武香梅刘福升宫理达陈震陆爱萍北京老年医院病理科北京100095 北京肿瘤医院病理科

目的探究血管内皮生因子(VEGF)A、缺氧诱导因子(HIF)-1α在老年肺癌组织中表达及对肺癌细胞血管管腔形成的影响。方法选取进行根治手术的100例肺癌患者所切除的肺部病理组织作为研究标本,使用免疫组织化学染色法检测VEGFA、HIF-1α阳... 详细信息

目的探究血管内皮生因子(VEGF)A、缺氧诱导因子(HIF)-1α在老年肺癌组织中表达及对肺癌细胞血管管腔形成的影响。方法选取进行根治手术的100例肺癌患者所切除的肺部病理组织作为研究标本,使用免疫组织化学染色法检测VEGFA、HIF-1α阳性表达,并分析VEGFA、HIF-1α与患者淋巴转移关系。将培养和转染后的肺癌细胞分为SPC-A-1细胞组、Axitinib组、YC-1组、Axitinib+YC-1组,使用基质胶小管形成实验检测血管生成,Western印迹检测VEGF、微血管密度(MVD)蛋白,PCR检测肺癌细胞中HIF-1α、VEGFA mRNA表达。结果与肺癌组织比较,癌旁组织中VEGFA、HIF-1α阳性表达明显较高(P<0.05)。发生淋巴结转移中,肺癌组织中的HIF-1α阳性率为60.23%、VEGFA阳性率为70.89%;未发生淋巴结转移中,肺癌组织中的HIF-1α阳性率为39.76%、VEGFA阳性率为29.11%,差异具有统计学意义(P<0.05)。与SPC-A-1细胞组比较,Axitinib组与YC-1组管腔形成数量、VEGF、MVD、VEGFA、HIF-1α mRNA表达均明显降低(P<0.05);与Axitinib组、YC-1组比较,Axitinib+YC-1组上述指标均明显降低(P<0.05)。结论 VEGFA、HIF-1α在老年肺癌组织中的表达较癌旁组织明显上调,并与肺癌细胞血管管腔形成密切相关,VEGFA、HIF-1α可作为评估肺癌患者的重要指标。

关键词：肺癌血管管腔血管内皮生长因子A 缺氧诱导因子1α

Influence of Y151 F mutation in loop B on the agonist potency in insect nicotinic acetylcholine receptor

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Insect Science 2009年第5期16卷 365-369页

作者： Feng Song Yi-Xi Zhang xiang-mei Yao Ze-Wen Liu Key Laboratory of Monitoring and Management of Plant Disease and Insects Ministry of Agriculture Nanjing Agricultural UniversityNanjing China

Nicotinic acetylcholine receptors （nAChRs） are ligand-gated ion channels, which mediate fast cholinergic synaptic transmission in insect and vertebrate nervous systems. The nAChR agonist-binding site is present at the interface of adjacent subunits and is formed by loops A-C present in α subunits together with loops D-F present in either non-α subunits or homomer-forming α subunits. Although Y151 in loop B has been identified as important in agonist binding, various residues at the 151-site are found among vertebrate and invertebrate nAChR α subunits, such as F 151. In Xenopus oocytes expressing Nlα1 or Nlα1^Y151F plus rat β2, Y151F mutation was found to significantly change the rate of receptor desensitization and altered the pharmacological properties of acetylcholine, but not imidacloprid, including the decrease Of Imax, the increase of EC50 （the concentration causing 50% of the maximum response） and the fast time-constant of decay （τf）. By comparisons of residue structure, the hydroxyl group in the side chain of Y151 was thought to be important in the interaction between Nlα1/β2 nAChRs and acetylcholine, and the phenyl group to be important between Nlα1/β2 nAChRs and imidacloprid.

关键词： acetylcholine agonist potency imidacloprid nicotinic acetylcholine receptor Nilaparvata lugens Xenopus oocytes

A new lignan derivative from the root of Ilex pubescens

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Chinese Chemical Letters 2008年第5期19卷 550-552页

作者： Yu Bo Zhou Jin Hui Wang xiang mei Li Xian Li School of Traditional Chinese Materia Medica Shenyang Pharmaceutical University Shenyang 110016 China

One new compound, ilexlignan A （1）, was isolated from the root of llex pubescens. Its structure was elucidated by the combination of one- and two-dimensional NMR analysis, mass spectrometry, CD spectrum measurement ... 详细信息

关键词： llex pubescens llexlignan A Lignan

Association between SNP rs1800875,serum chymase and immunoglobulin E levels in patients with coronary heart disease

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第8期12卷 660-667页

作者： Chun-na JIN Hong MA Yan LIN Jian-an WANG mei-xiang XIAN Department of Cardiology the Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 China Cardiovascular Key Lab of Zhejiang Province the Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 China

Objective:The gene for mast cell chymase (CMA1) is an ideal candidate for investigating the genetic predisposition to coronary heart disease (CHD),as activated mast cells have been found to be present in a greater proportion in the shoulder region of atheroma than in normal coronary *** studies have indicated that CMA1 promoter polymorphism rs1800875 may be involved in regulating immunoglobulin E (IgE) levels in patients with eczema,and it is associated with the progression of immunoglobulin A ***:The association between single nucleotide polymorphism (SNP) rs1800875,serum chymase,and serum IgE levels was examined in 175 CHD subjects and 95 non-CHD ***:Statistical analysis indicated no significant difference in allele frequency between CHD and ***,a significant association was found between CMA1 genotypes and total IgE levels in CHD ***,crossover analysis revealed that,in GG homozygotes,CHD risk was nearly six times higher in those with IgE (U/ml) level <2.58 (natural logarithm conversion),while no association was found with chymase ***:Polymorphism rs1800875 of CMA1 may be associated with serum IgE level in CHD subjects,but not with chymase level in both *** GG homozygotes,high IgE level is a protective factor against coronary disease.

关键词： Coronary heart disease CMA 1 Serum immunoglobulin E (IgE) Serum chymase

数字普惠金融与乡村产业高质量发展——基于区域品牌价值与平台经济的双调节研究

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江西农业学报 2024年第6期36卷 127-134页

作者：翟怡璇朱向梅李子豪中北大学经济与管理学院山西太原030051 中国建设银行太原亲贤街支行山西太原030006

在数字普惠金融兴起的背景下,区域品牌价值与平台经济在乡村产业高质量发展中扮演着重要角色,平台经济为乡村产业高质量发展提供了生产要素基础和信息化市场,而区域品牌价值则成为乡村产业在市场竞争中的优势。本研究通熵值法和稳健回... 详细信息

在数字普惠金融兴起的背景下,区域品牌价值与平台经济在乡村产业高质量发展中扮演着重要角色,平台经济为乡村产业高质量发展提供了生产要素基础和信息化市场,而区域品牌价值则成为乡村产业在市场竞争中的优势。本研究通熵值法和稳健回归模型,深入探究了数字普惠金融、平台经济、区域品牌价值以及乡村产业高质量发展的相互作用。结果表明:数字普惠金融对乡村产业高质量发展具有显著的正向影响;区域品牌价值与平台经济在数字普惠金融对乡村产业高质量发展作用机制中起到显著调节作用。研究结果对数字普惠金融在乡村产业中的推广与发展具有重要意义,为构建健康、有机的数字金融生态系统提供了实践指导。

关键词：数字普惠金融区域品牌价值平台经济乡村产业高质量发展