检索结果-南通市图书馆

Deciphering fungal metabolon coupling tandem inverse-electrondemand diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong di Man-Cheng Tang ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-Bo yang Zhi-Li Zuo Han Guo zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词：

同方期刊数据库

广州地区3种不同生境的蚊感染沃尔巴克氏体的系统发育分析

在线全文

学校读者我要写书评

暂无评论

现代预防医学 2019年第14期46卷 2542-2546+2562页

作者：杨菂子倪卫桂赖祺王佳甜郑学礼南方医科大学公共卫生学院病原生物学系

目的了解广州地区3种生境不同蚊种沃尔巴克氏体的分布。方法利用沃尔巴克氏体的16S rDNA和主要表面蛋白基因(wsp)的w AlbA,w AlbB基因型序列建立PCR检测方法,对不同种类蚊虫沃尔巴克氏体感染进行检测,同时利用Mega6.06软件对所获基因序... 详细信息

目的了解广州地区3种生境不同蚊种沃尔巴克氏体的分布。方法利用沃尔巴克氏体的16S rDNA和主要表面蛋白基因(wsp)的w AlbA,w AlbB基因型序列建立PCR检测方法,对不同种类蚊虫沃尔巴克氏体感染进行检测,同时利用Mega6.06软件对所获基因序列进行系统发育分析。结果共检测广州市3种不同生境的4种常见蚊,用16S r DNA基因PCR扩增检测小区白纹伊蚊的沃尔巴克氏体阳性率为100.0%,检测公园致倦库蚊的沃尔巴克氏体阳性率亦为100.0%。4种蚊沃尔巴克氏体核酸检测阳性率为50.0%～100.0%。wsp基因的检出有3种情况:仅检出wAlbA或wAlbB基因型,或同时检出w AlbA和w AlbB 2个基因型。经PCR扩增,获得14条蚊感染沃尔巴克氏体的16S r DNA基因序列长度为441 bp;14条蚊感染沃尔巴克氏体的w AlbA基因序列长度为351 bp;12条蚊感染沃尔巴克氏体的wAlbB基因序列长度为481 bp。系统发育分析显示不同生境不同蚊种的沃尔巴克氏体基因型存在差异。结论广州市学校、小区、公园3种生境的白纹伊蚊、致倦库蚊和骚扰阿蚊普遍感染沃尔巴克氏体,有wAlbA或wAlbB单感染,也有wAlbA与wAlbB共感染;不同生境不同蚊种沃尔巴克氏体基因型存在差异。

关键词：沃尔巴克氏体生境蚊种基因型

主要气候因素变化影响2017-2018年广州蚊密度与登革流行趋势分析

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

现代预防医学 2020年第9期47卷 1570-1574页

作者：何玉兰杨菂子李晓宁罗雷魏勇郑学礼南方医科大学公共卫生学院病原生物学系广州市疾病预防控制中心

目的了解年度气候变化对广州蚊密度与登革流行趋势的影响。方法 2017年5月至2018年5月采用BG-Sentinel trap(BG-trap)在广州市校园、公园、小区三种不同生境开展蚊虫种群密度调查。采用广义估计方程(GEE)分析每月登革发病人数与温度、... 详细信息

目的了解年度气候变化对广州蚊密度与登革流行趋势的影响。方法 2017年5月至2018年5月采用BG-Sentinel trap(BG-trap)在广州市校园、公园、小区三种不同生境开展蚊虫种群密度调查。采用广义估计方程(GEE)分析每月登革发病人数与温度、降雨量和白纹伊蚊密度的关系。结果三种生境共捕获成蚊6 853只,其中白纹伊蚊1 028只,雌蚊534只。模型分析结果显示:月最高温度升高1℃,1个月后的登革发病数增加1.806倍;月降雨量每增加1 mm,当月登革发病数减少0.012倍;每个BG-trap诱捕的白纹伊蚊雌蚊密度增加1只/天,当月登革发病数增加0.779倍。结论广州市学校、公园、小区三种生境的蚊种种群构成有统计学差异,三种生境的白纹伊蚊每月密度变化和雌雄构成比均无统计学差异,但登革发病人数与前推一个月的最高温度和当月的白纹伊蚊雌蚊密度有正相关关系。

关键词：生境成蚊密度白纹伊蚊广义估计方程

Fractal and microscopic quantitative characterization of unclassified tailings flocs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第9期28卷 1429-1439页

作者： di Zheng Wei-dong Song Yu-ye Tan Shuai Cao zi-long yang Li-juan Sun State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education University of Science and Technology BeijingBeijing 100083China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory for Nonlinear Mechanics(LNM) Institute of Mechanics Chinese Academy of ScienceBeijing 100190China

A series of laboratory investigations are conducted to analyze the effect of flocculant type on the spatial morphology and microstructural characteristics of flocs during the flocculation and settling of *** flocculant types(i.e.,ZYZ,JYC-2,ZYD,and JYC-1)are considered in this *** fractal characteristics and internal structures of tailings flocs with different flocculant types and settlement heights are analyzed by conducting scanning electron microscopy and X-ray micro-computed tomography scanning experiments based on the fractal *** show that unclassified tailings flocs are irregular clusters with fractal characteristics,and the flocculation effect of the four flocculant types has the following trend:ZYZ>JYC-2>ZYD>*** size and average grayscale value of tailings flocs decrease with the increase in settlement *** average grayscale values at the top and bottom are 144 and 103,*** settlement height remarkably affects the pore distribution pattern,as reflected in the constructed three-dimensional pore model of tailings *** top part of flocs has relatively good penetration,whereas the bottom part of flocs has mostly dispersed *** number of pores increases exponentially with the increase in settlement *** contrast,the size of pores initially increases and subsequently decreases with the increase in settlement height.

关键词： tailings flocs fractal dimension settlement height grayscale value three-dimensional pore model

Characteristics of shell thickness in a slab continuous casting mold

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2009年第1期16卷 25-31页

作者： di-feng Wu Shu-sen Cheng zi-jian Cheng School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Steelmaking Plant Jiuquan Iron and Steel Co. Ltd. Jiayuguan 735100 China

The key to reduce shell breakout in the continuous casting process is to control shell thickness in the mold. A numerical simulation on the turbulent flow and heat transfer coupled with solidification in the slab mold using the volume of fluid （VOF） model and the enthalpy-porosity scheme was conducted and the emphasis was put upon the flow effect on the shell thickness profiles in longitudinal and transverse directions. The results show that the jet acts a stronger impingement on the shell of narrow face, which causes a zero-increase of shell thickness in a certain range near the impingement point. The thinnest shell on the slab cross-section locates primarily in the center of the narrow face, and secondly near the comer of the wide face. Nozzle optimization can obviously increase the shell thickness and make it more uniform.

关键词： continuous casting slab mold shell thickness nozzle optimization

Considerations for routine coagulation monitoring with rivaroxaban:A case report and review of the literature

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2019年第3期7卷 382-388页

作者： Hai-di Wu Hong-Yan Cao zi-Kai Song Shuo yang Ming-Long Tang yang Liu Ling Qin Department of Cardiology First Hospital of Jilin University

BACKGROUND Rivaroxaban is a non-vitamin K antagonist oral anticoagulant that does not require coagulation monitoring based on current recommendations. Our goal is to explore whether routine coagulation monitoring should not be required for all patients receiving oral rivaroxaban, what relationship between routine coagulation abnormalities and bleeding, and how to deal with the above clinical situations through our case and review of the *** SUMMARY We report a 67-year-old woman with a history of atrial fibrillation who presented to the hospital with worsening dyspnea and cough. Based on electrocardiogram,venous compression ultrasonography, and computed tomography pulmonary angiography, the diagnosis of atrial fibrillation, deep venous thrombosis, and acute pulmonary embolism was confirmed. Her coagulation assays and renal function were normal on admission; she was not underweight, did not have a history of hemorrhagic disease, and her CHA2 DS2-VAS, HAS-BLED, and simplified Pulmonary Embolism Severity Index scores were 3, 0, and 0,respectively. Oral rivaroxaban(15 mg twice daily) was administered. The following day, she presented gastrointestinal and gum bleeding, combined with coagulation abnormalities. Following cessation of rivaroxaban, her bleeding stopped and tests improved over the next 2 d. Rivaroxaban was begun again 3 d after recovery. However, she again presented with gastrointestinal and gum bleeding and the abnormal tests, and the therapy was discontinued. At 30-d follow-up after discharge, she presented normal coagulation tests without *** Although current guidelines recommend that using non-vitamin K antagonist oral anticoagulants including rivaroxaban do not require coagulation monitoring,a small number of patients may develop routine coagulation test changes and bleeding during rivaroxaban therapy, especially in the elderly. Clinicians should pay attention to these patients and further obtain evidence in practice.

关键词： Rivaroxaban Routine coagulation monitoring Anticoagulation Bleeding Case report

Insight into Crosstalk Between Mitophagy and Apoptosis/Necroptosis:Mechanisms and Clinical Applications in Ischemic Stroke

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Medical Science 2022年第2期42卷 237-248页

作者： Yan-di yang zi-xin LI Xi-min HU Hao WAN Qi ZHANG Rui XIAO Kun XIONG Department of Anatomy and Neurobiology School of Basic Medical ScienceCentral South UniversityChangsha 410013China Clinical Medicine Eight-year Program 03 Class18 GradeXiangya School of MedicineCentral South UniversityChangsha 410013China Clinical Medicine Eight-Year Program 02 Class17 GradeXiangya School of MedicineCentral South UniversityChangsha 410013China Administrative Office the Third Xiangya HospitalCentral South UniversityChangsha 410013China Hunan Key Laboratory of Ophthalmology Changsha 410008China Key Laboratory of Emergency and Trauma Ministry of EducationCollege of Emergency and TraumaHainan Medical UniversityHaikou 571199China

Ischemic stroke is a serious cerebrovascular disease with high morbidity and *** a result of ischemia-reperfusion,a cascade of pathophysiological responses is triggered by the imbalance in metabolic supply and demand,resulting in cell *** cellular injuries follow various molecular mechanisms solely or in combination with this *** play a driving role in the pathophysiological processes of ischemic *** ischemic stroke occurs,damaged cells would respond to such stress through *** is known as a conservatively selective autophagy,contributing to the removal of excessive protein aggregates and damaged intracellular components,as well as aging *** mitophagy may exert neuroprotection against *** pathways associated with the mitochondrial network collectively contribute to recovering the homeostasis of the neurovascular ***,excessive mitophagy would also promote ischemia-reperfusion ***,mitophagy is a double-edged sword,which suggests that maximizing the benefits of mitophagy is one of the direction of future *** review emphasized the role of mitophagy in ischemic stroke,and highlighted the crosstalk between mitophagy and apoptosis/necroptosis.

关键词： mitophagy ischemic stroke apoptosis necroptosis clinical application crosstalk

开封地区模拟野外条件下的白纹伊蚊生命量表研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国病原生物学杂志 2020年第10期15卷 1177-1182,1187页

作者：王国英杨菂子刘彬彬王家豪刘威位广帅范青文郑千一徐志喜张军郑学礼河南大学基础医学院河南开封475004 南方医科大学附属深圳妇幼保健院广东深圳518048 南方医科大学公共卫生学院广东广州510515

目的通过开封地区模拟野外条件下的白纹伊蚊生命量表研究,了解开封地区白纹伊蚊自然条件下的发育。方法设置室外和室内两种实验条件,进行白纹伊蚊幼虫和成虫生命表实验,记录实验期间温度、相对湿度、光周期(光照强度)的变化状况。比较... 详细信息

目的通过开封地区模拟野外条件下的白纹伊蚊生命量表研究,了解开封地区白纹伊蚊自然条件下的发育。方法设置室外和室内两种实验条件,进行白纹伊蚊幼虫和成虫生命表实验,记录实验期间温度、相对湿度、光周期(光照强度)的变化状况。比较室内与室外蚊虫发育与生存情况,绘制白纹伊蚊幼虫和成蚊生命表。结果在开封地区,夏季末期室内条件下的白纹伊蚊孵化率(86.3%)和化蛹率(63.0%)均高于室外(t孵化率=3.571,t化蛹率=2.566,均P0.05);夏季末期室内条件是白纹伊蚊幼虫适宜的生长发育条件。室内条件下,成蚊平均存活12.6~18.9 d,其中以秋季初期成蚊存活时间较长,达18.9 d;夏季末期成蚊存活时间较短,为12.6 d。夏季中期的成蚊终身产卵量为39个,高于夏季末期的10.8个和秋季初期的11.45个。结论开封地区的气候条件适宜白纹伊蚊的生长发育和繁殖,温度、相对湿度、光周期(光照强度)是影响卵孵化、化蛹、羽化,及成蚊生存时间和产卵量的重要因素。

关键词：白纹伊蚊模拟野外蚊发育开封地区,河南

Influence of CeO_2 addition on the preparation of foamed glass-ceramics from high-titanium blast furnace slag

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2018年第6期25卷 689-695页

作者： Hong-ling Zhou Ke-qin Feng Chang-hong Chen zi-di Yan School of Manufacturing Science and Engineering Sichuan University

Foamed glass-ceramics doped with cerium oxide（CeO_2）were successfully prepared from high-titanium blast furnace slag by one-step *** influence of CeO_2 addition（1.5wt%–3.5wt%）on the crystalline phases,microstructure,and properties of foamed glass-ceramics was *** show that CeO_2 improves the stability of the glass phase and changes the two-dimensional crystallization mechanism into three-dimensional *** analysis indicates the presence of Ca（Mg,Fe）Si_2O_6 and Ca（Ti,Mg,Al）（Si,Al）_2O_（6 ）in all sintered *** with CeO_2,Ti CeO_4 precipitates,and crystallinity increases,leading to increased thickness of pore walls and uniform *** comprehensive properties of foamed glass-ceramics are better than that of samples without CeO_*** particular,the sample added with a suitable amount of CeO_2（2.5wt%）exhibits bulk density that is similar to and compressive strength（14.9 MPa）that is more than twice of foamed glass-ceramics without CeO_2.

关键词： foamed glass-ceramics cerium oxide blast furnace slag sintering crystallization