检索结果-南通市图书馆

Engineering of cofactor preference and catalytic activity of methanol dehydrogenase by growth-coupled directed evolution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Carbon 2024年第2期2卷 242-251页

作者： jinxing yang Liwen Fan Guimin Cheng Tao Cai Jibin Sun Ping Zheng Shuang Li Yu Wang School of Biology and Biological Engineering South China University of TechnologyGuangzhou 510006China Haihe Laboratory of Synthetic Biology Tianjin 300308China Key Laboratory of Engineering Biology for Low-Carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China National Technology Innovation Center of Synthetic Biology Tianjin 300308China College of Biotechnology Tianjin University of Science and TechnologyTianjin 300222China

Methanol,produced from carbon dioxide,natural gas,and biomass,has drawn increasing attention as a promising green carbon feedstock for biomanufacturing due to its sustainable and energy-rich *** adenine dinucleotide(NAD^(+))-dependent methanol dehydrogenase(MDH)catalyzes the oxidation of methanol to formaldehyde via NADH generation,providing a highly active C1 intermediate and reducing power for subsequent ***,the unsatisfactory catalytic efficiency and cofactor bias of MDH significantly impede methanol valorization,especially in nicotinamide adenine dinucleotide phosphate(NADP^(+))-dependent ***,we employed synthetic NADH and NADPH auxotrophic Escherichia coli strains as growth-coupled selection platforms for the directed evolution of MDH from Bacillus stearothermophilus DSM *** or NADPH generated by MDH-catalyzed methanol oxidation enabled the growth of synthetic cofactor auxotrophs,establishing a positive correlation between the cell growth rate and MDH *** this principle,MDH mutants exhibiting a 20-fold improvement in catalytic efficiency(k_(cat)/K_(m))and a 90-fold cofactor specificity switch from NAD^(+)to NADP+without a decrease in specific enzyme activity,were efficiently screened from random and semi-rationally designed *** envision that these mutants will advance methanol valorization and that the synthetic cofactor auxotrophs will serve as versatile selection platforms for the evolution of NAD(P)^(+)-dependent enzymes.

关键词： Growth-coupled screening Methanol dehydrogenase Cofactor engineering Directed evolution C1 bioconversion

Dynamic Simulation and Test Verifcation of Hydraulic Automatic Tensioner for an Engine Timing Chain Drive System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2023年第5期36卷 291-303页

作者： Zengming Feng jinxing yang Fei Wang School of Mechanical and Aerospace Engineering Jilin UniversityChangchun 130022China

As a fundamental component of an automobile engine’s timing chain drive system, the hydraulic automatic tensioner signifcantly enhances fuel economy while minimizing system vibrations and noise. However, there is a noticeable lack of research on automatic hydraulic tensioners. This study presents a comprehensive calculation approach for the principal parameters of a hydraulic automatic tensioner. An efective method, grounded in hydraulics and multibody dynamics, was introduced for estimating the dynamic response of such a tensioner. The simulation model developed for the hydraulic tensioner is characterized by its rapid dynamic response, consistent operation, and high accuracy. The dynamic behavior of the tensioner was analyzed under varying boundary conditions, using sinusoidal signal excitation. It was observed that the maximum damping force increases with a decreasing leakage gap. Conversely, an increase in oil temperature or air content leads to a decrease in the maximum damping force. The reaction forces derived from these calculations align well with experimental results. This calculation and simulation approach ofers considerable value for the design of innovative hydraulic tensioners. It not only streamlines the design phase, minimizes the number of trials, and reduces product costs, but also provides robust insights for evaluating the performance of hydraulic tensioners.

关键词： Hydraulic automatic tensioner Timing chain Leakage gap Hysteresis curve

基于惯性数据融合的串联机械臂运动状态估计方法

在线全文

学校读者我要写书评

暂无评论

传感器与微系统 2024年第5期43卷 125-128页

作者：段一凡杨进兴李俊徐敏厦门理工学院电气工程与自动化学院福建厦门361000 泉州装备制造研究所福建泉州362216

在串联机械臂运动跟踪中,将惯性测量单元(IMU)的运动信息映射到机械臂运动链上,针对IMU测量时的安装误差和随机噪声会影响到测量信息准确性的问题,提出了一种基于IMU数据融合的运动状态估计方法。该方法首先对传感器与旋转关节坐标系进... 详细信息

在串联机械臂运动跟踪中,将惯性测量单元(IMU)的运动信息映射到机械臂运动链上,针对IMU测量时的安装误差和随机噪声会影响到测量信息准确性的问题,提出了一种基于IMU数据融合的运动状态估计方法。该方法首先对传感器与旋转关节坐标系进行校准,再通过融合IMU中陀螺仪和加速计信息,建立了基于扩展卡尔曼滤波(EKF)算法的运动姿态最优估计模型。与机械臂实际输出的角度信息相比,所提方法的平均角度和位姿均方根误差(RMSE)为0.19°和0.45 mm,均优于单目相机惯性传感器联合标定方法。实验结果表明:该方法能够精确地估计机械臂运动状态,并且具有精度更高且运动空间不受限制的优点。

关键词：机械臂信息融合状态估计卡尔曼滤波

HIV核酸定量检测在“艾滋病一站式诊疗服务”模式中的应用和效果

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

中国艾滋病性病 2024年第6期30卷 591-595页

作者：杨涛杨孝敬刘亦菲姚仁敏周彦君杨金星杜仕林黄家艳周顺林元康蔡毅媛王应刚贵州医科大学公共卫生与健康学院环境污染与疾病监控教育部重点实验室贵阳561113 安顺市疾病预防控制中心贵州安顺561000 安顺市普定县人民医院贵州安顺562100

目的探讨HIV核酸定量检测在“艾滋病一站式诊疗服务”模式中的应用效果和可行性,为HIV/AIDS患者早期诊断、早期治疗和科学管理提供参考依据。方法在普定县人民医院开展“艾滋病一站式诊疗服务”模式探索,对HIV初筛有反应血液进行院内... 详细信息

目的探讨HIV核酸定量检测在“艾滋病一站式诊疗服务”模式中的应用效果和可行性,为HIV/AIDS患者早期诊断、早期治疗和科学管理提供参考依据。方法在普定县人民医院开展“艾滋病一站式诊疗服务”模式探索,对HIV初筛有反应血液进行院内核酸定量试验,并将HIV初筛有反应血液送至贵州省疾病预防控制中心进行抗体确证试验,将院内检测结果与复核结果进行比较,以验证核酸定量检测的可行性;同时对“艾滋病一站式诊疗服务”开展前后抗体初筛有反应到抗体确证或核酸定量试验结果的时间间隔、抗体初筛有反应到接受cART时间间隔、30天内接受cART比例进行对比分析。结果对新检测发现的HIV抗体初筛有反应就诊者血液进行核酸定量检测,结果>5 000拷贝/mL占比为94.97%(189/199),≤5 000拷贝/mL占比为4.02%(8/199),≤5 000拷贝/mL后期经随访均为阳性,未检出占比为1.01%(2/199);将HIV初筛有反应血液送至贵州省疾病预防控制中心进行复核,结果阳性197份,阴性2份;院内检测结果与复核结果的一致性较好(Kappa=1,P<0.001),总符合率为100.00%(199/199);核酸定量检测的灵敏度较好,为95.94%(189/197),特异度为100.00%(2/2);“艾滋病一站式诊疗服务”开展前后新报告病例抗体初筛有反应到抗体确证或核酸定量试验结果中位时间由8天缩短至1天、抗体初筛有反应到接受cART中位时间由16天缩短至1天,差异有统计学意义(P <0.001);开展前后新报告病例30天内接受cART比例由68.00%提升至99.49%(196/197),差异有统计学意义(P<0.001)。结论通过HIV核酸定量检测在“艾滋病一站式诊疗服务”模式中的应用,HIV核酸定量检测用于HIV感染诊断的可行性得到了有效验证,可以显著缩短HIV/AIDS患者从检测到治疗的时间,及时接受抗病毒治疗。

关键词：艾滋病病毒核酸定量检测艾滋病一站式诊疗服务应用效果

Corrigendum to“MXene-coated silk-derived carbon cloth toward flexible electrode for supercapacitor application”[***.27(2018)161–166]

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第8期31卷 652-654页

作者： Minmin Hu Tao Hua Renfei Cheng jinxing yang Cong Cui Chao Zhang Xiaohui Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

The authors regret that the printed version of the above article contained some errors.(1)The SEM images of CSC and CSC@Ti3C2Tx electrode in Fig.1 are corrected to reflect the originality of the images.

关键词： electrode corrected MXene

医院内智慧化静脉血栓栓塞症防控系统的构建与实现

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

深圳中西医结合杂志 2024年第11期34卷 7-11,I0004页

作者：桂敏韩云黄俊锋张梦春杨金星喻婉莹深圳大学第一附属医院深圳市第二人民医院广东深圳518035

静脉血栓栓塞症(VTE)的发生,不仅威胁医疗质量与安全,也给医院管理带来重大挑战。但VTE具有可防可控的特性。随着医院信息化的深入发展,深圳市第二人民医院引入智慧化VTE防控系统,利用人工智能对住院患者进行全程管理,为医护人员提供决... 详细信息

静脉血栓栓塞症(VTE)的发生,不仅威胁医疗质量与安全,也给医院管理带来重大挑战。但VTE具有可防可控的特性。随着医院信息化的深入发展,深圳市第二人民医院引入智慧化VTE防控系统,利用人工智能对住院患者进行全程管理,为医护人员提供决策支持。医疗管理部门通过实时监测和分析,形成标准化、规范化的VTE防治管理体系,有效提升防治效率,为医疗安全及质量提供了有力保障。在VTE系统逐步深化的运行过程中,医院的各项能力和标准均持续得到提高。

关键词：静脉血栓栓塞症智慧化信息化风险评估智能监控

在线全文

学校读者我要写书评

暂无评论

机车提门传感器装置的改进

冶金设备管理与维修 2024年第4期42卷 11-13页

作者：杨金星丁伟于庆泉崔金林崔思强代成鞍钢股份鲅鱼圈钢铁分公司炼焦部辽宁营口115007 鞍钢股份鲅鱼圈钢铁分公司制造管理部辽宁营口115007

对推焦车、拦焦车提门系统进行了介绍,针对提门传感器更换难度大时间长等问题,提出了用外置液压缸传感器取代内置液压缸传感器的技术改进措施。措施实施后,减小了提门传感器的更换难度,缩短了更换时间,年节约费用约55万元。

关键词：炼焦推焦车拦焦车提门传感器

Computational fluid dynamics simulation and experimental study on mixing performance of a three-dimensional circular cyclone-type microreactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第4期35卷 382-388页

作者： Shiyu Hou Maolin Sun Liming Cao Chaoming Liang Jiaxin yang Xinggui Zhou jinxing Ye Ruihua Cheng School of Chemical Engineering East China University of Science and TechnologyShanghai 200237China School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China School of Pharmacy East China University of Science and TechnologyShanghai 200237China

Microchannels enable the fast and efficient mixing of multiphase *** this study, a millimeter-scale three-dimensional(3D) circular cyclone-type microreactor was designed for the *** flow characteristics and mixing intensity were simulated by computational fluid dynamics simulations at a flow rate range of 12–96 m L/min using a water/ethyl acetate *** the 3D variable-diameter structure,the microreactor induced paired opposite vortices and abruptly changed the local pressure to achieve a stable turbulent effect within the theoretical range of laminar *** injection simulations indicated that sufficient mixing units successfully promote fluid ***-coupling experiments showed a segregation index of X_S= 0.00,039 within a residence time of 9 *** experiments on the nbutanol/succinic acid/water system showed that the 3D circular cyclone-type microreactor achieved 100%extraction efficiency(E) in 4.25 s, and the overall volume mass transfer coefficient(K_La) reached 0.05–1.5s^(-1) in 12–96 m L/*** isolated yield of the phase transfer alkylation and oxidation reactions in the 3D circular cyclone-type microreactor achieved 99% within 36 s, which was superior to the coil microreactor and batch reactor.

关键词： Microfluidics Passive microreactor CFD simulation Extraction Liquid-liquid biphase reaction

Directed evolution of a neutrophilic and mesophilic methanol dehydrogenase based on high-throughput and accurate measurement of formaldehyde

在线全文

学校读者我要写书评

暂无评论

Synthetic and Systems Biotechnology 2023年第3期8卷 386-395页

作者： Jin Qian Liwen Fan jinxing yang Jinhui Feng Ning Gao Guimin Cheng Wei Pu Wenjuan Zhou Tao Cai Shuang Li Ping Zheng Jibin Sun Depei Wang Yu Wang College of Biotechnology Tianjin University of Science and TechnologyTianjin300222China Haihe Laboratory of Synthetic Biology Tianjin300308China Key Laboratory of Engineering Biology for Low-carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin300308China National Technology Innovation Center of Synthetic Biology Tianjin300308China University of Chinese Academy of Sciences Beijing100049China School of Biology and Biological Engineering South China University of TechnologyGuangzhou510006China

Methanol is a promising one-carbon feedstock for biomanufacturing,which can be sustainably produced from carbon dioxide and natural ***,the efficiency of methanol bioconversion is limited by the poor catalytic properties of nicotinamide adenine dinucleotide(NAD^(+))-dependent methanol dehydrogenase(Mdh)that oxidizes methanol to ***,the neutrophilic and mesophilic NAD^(+)-dependent Mdh from Bacillus stearothermophilus DSM 2334(Mdh_(Bs))was subjected to directed evolution for enhancing the catalytic *** combination of formaldehyde biosensor and Nash assay allowed high-throughput and accurate measurement of formaldehyde and facilitated efficient selection of desired ***_(Bs)variants with up to 6.5-fold higher K_(cat)/K_(M)value for methanol were screened from random mutation *** T153 residue that is spatially proximal to the substrate binding pocket has significant influence on enzyme *** beneficial T153P mutation changes the interaction network of this residue and breaks theα-helix important for substrate binding into two shortα-*** the interaction network of T153 with surrounding residues may represent a promising strategy to further improve Mdh_(Bs),and this study provides an efficient strategy for directed evolution of Mdh.

关键词： Methanol dehydrogenase Formaldehyde biosensor Directed evolution C1 bioconversion Methanol oxidation Methylotrophy