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Spontaneous mutations and mutational responses to penicillin treatment in the bacterial pathogen Streptococcus pneumoniae D39

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Marine Life Science & Technology 2024年第2期6卷 198-211页

作者： Wanyue Jiang tongtong lin Jiao Pan Caitlyn ERivera Clayton Tincher Yaohai Wang Yu Zhang Xiang Gao Yan Wang Ho‑Ching T.Tsui Malcolm E.Winkler Michael Lynch Hongan Long Institute of Evolution and Marine Biodiversity KLMMEOcean University of ChinaQingdao 266003China Laboratory for Marine Biology and Biotechnology Laoshan LaboratoryQingdao 266237China Department of Biology Indiana UniversityBloomingtonIN 47405USA School of Mathematics Science Ocean University of ChinaQingdao 266000China State Key Laboratory of Microbial Technology Microbial Technology InstituteSchool of Life ScienceShandong UniversityQingdao 266237China Biodesign Center for Mechanisms of Evolution Arizona State UniversityTempeAZ 85281USA

Bacteria with functional DNA repair systems are expected to have low mutation rates due to strong natural selection for genomic ***,our study of the wild-type Streptococcus pneumoniae D39,a pathogen responsible for many common diseases,revealed a high spontaneous mutation rate of 0.02 per genome per cell division in mutation-accumulation(MA)*** rate is orders of magnitude higher than that of other non-mutator bacteria and is characterized by a high mutation bias in the A/T *** high mutation rate may have resulted from a reduction in the overall efficiency of selection,conferred by the tiny effective population size in *** line with this,*** D39 also exhibited the lowest DNA mismatch-repair(MMR)efficiency among *** with the antibiotic penicillin did not elevate the mutation rate,as penicillin did not induce DNA damage and *** lacks a stress response *** findings suggested that the MA results are applicable to within-host scenarios and provide insights into pathogen evolution.

关键词： Neutral evolution Mutation spectrum Antibiotics DNA mismatch repair Oxidative damage repair

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Contribution of the SOS response and the DNA repair systems to norfloxacin induced mutations in ***

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Marine Life Science & Technology 2023年第4期5卷 538-550页

作者： tongtong lin Jiao Pan Colin Gregory Yaohai Wang Clayton Tincher Caitlyn Rivera Michael Lynch Hongan Long Yu Zhang Institute of Evolution and Marine Biodiversity KLMMEOcean University of ChinaQingdao 266003China Laboratory for Marine Biology and Biotechnology Laoshan LaboratoryQingdao 266237China Department of Biology Indiana UniversityBloomington 47405USA Biodesign Center for Mechanisms of Evolution Arizona State UniversityTempe 85281USA School of Mathematics Science Ocean University of ChinaQingdao 266000China

Antibiotic-resistant bacteria severely threaten human *** spontaneous mutations generated by endogenous factors,the resistance might also originate from mutations induced by certain antibiotics,such as the *** antibiotics increase the genome-wide mutation rate by introducing replication errors from the SOS response pathway or decreasing the efficiency of the DNA repair ***,the relative contributions of these molecular mechanisms remain unclear,hindering understanding of the generation of resistant ***,using newly-accumulated mutations of wild-type and SOS-uninducible Escherichia coli strains,as well as those of the strains deficient for the mismatch repair(MMR)and the oxidative damage repair pathways,we find that the SOS response is the major mutagenesis contributor in mutation elevation,responsible for~30–50%of the total base-pair substitution(BPS)mutation-rate elevation upon treatment with sublethal levels of norfloxacin(0~50 ng/mL).We further estimate the significance of the effects on other mutational features of these mechanisms(i.e.,transversions,structural variations,and mutation spectrum)in *** using linear *** SOS response plays a positive role in all three mutational features(mutation rates of BPSs,transversions,structural variations)and affects the mutational *** repair systems significantly reduce the BPS mutation rate and the transversion rate,regardless of whether antibiotics are present,while significantly increasing the structural variation rate in *** results quantitatively disentangle the contributions of the SOS response and DNA repair systems in antibiotic-induced mutagenesis.

关键词： Stress response Antibiotic-induced mutagenesis Mutation spectrum linear model

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An integrative protocol for one‑step PCR amplicon library construction and accurate demultiplexing of pooled sequencing data

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Marine Life Science & Technology 2023年第4期5卷 564-572页

作者： Jiahao Ni Jiao Pan Yaohai Wang Tianhao Chen Xinshi Feng Yichen Li tongtong lin Michael Lynch Hongan Long Weiyi Li Institute of Evolution and Marine Biodiversity KLMMEOcean University of ChinaQingdao 266003China Laboratory for Marine Biology and Biotechnology Laoshan LaboratoryQingdao 266237China Biodesign Center for Mechanisms of Evolution Arizona State UniversityTempeAZ 85281USA Department of Biology Indiana UniversityBloomingtonIN 47401USA Present Address:SLAC National Accelerator Laboratory Stanford UniversityStanford 94305USA

High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures,greatly promoting biological studies involving large amounts of complex samples,especially those involving environmental and pathogen-monitoring *** library preparation kits for amplicon sequencing,which generally require multiple steps,including adapter ligation and indexing,are expensive and time-consuming,especially for applications at a large *** overcome these limitations,a“one-step PCR approach”has been previously proposed for constructions of amplicon libraries using long fusion ***,efficient amplifications of target genes and accurate demultiplexing of pooled sequencing data remain to be *** tackle these,we present an integrative protocol for one-step PCR amplicon library construction(OSPALC).High-quality reads have been generated by this approach to reliably identify species compositions of mock bacterial communities and environmental *** this protocol,the amplicon library is constructed through one regular PCR with long primers,and the total cost per DNA/cDNA sample decreases to just 7%of the typical cost via the multi-step PCR *** tested primers and optimized PCR conditions to construct OSPALC libraries for 16S rDNA V4 regions are demonstrated as a case *** to design primers targeting at any genomic regions are also *** principle,OSPALC can be readily applied to construct amplicon libraries of any target genes using DNA or RNA samples,and will facilitate research in numerous fields.

关键词： Amplicon library preparation Lab-made protocol Long-primer PCR Cost efficiency

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Millimeter waves in medical applications:status and prospects

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Intelligent Medicine 2024年第1期4卷 16-21页

作者： Honglin Wang lin Lu Pengran Liu Jiayao Zhang Songxiang Liu Yi Xie tongtong Huo Hong Zhou Mingdi Xue Ying Fang Jiaming Yang Zhewei Ye Department of Orthopedics Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei 430022China Departments of Orthopedics Renmin Hospital of Wuhan UniversityWuhanHubei 430060China

Millimeter waves are electromagnetic waves with wavelengths of 1–10 mm,which have characteristics of high frequency and short *** have gradually and widely been used in engineering and medical *** have identified studies related to millimeter waves in the biomedical field and summarized the biological effects of millimeter waves and their current status in medical ***,the shortcomings of existing studies and future developments were analyzed and discussed,with the aim of providing a reference for further research and development of millimeter waves in the medical field.

关键词： Millimeter wave Biological effects Medical applications Vital signs monitoring

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大学生公益创新创业育人路径:基于案例分析

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科技创业月刊 2024年第3期37卷 61-65页

作者：郭炎华蓝永胜陈林林林彤彤桂林航天工业学院外语外贸学院桂林航天工业学院国有资产管理处广西桂林541004

基于多重螺旋式公益创业协同创新育人框架模型,利用案例分析法分析创业者在思维激活、模式构建和实施评估方面是如何进行社会认知与创新的。研究发现,《理解当代中国》教材的育人理念有助于大学生认识经济社会存在的问题并萌生社会创新... 详细信息

基于多重螺旋式公益创业协同创新育人框架模型,利用案例分析法分析创业者在思维激活、模式构建和实施评估方面是如何进行社会认知与创新的。研究发现,《理解当代中国》教材的育人理念有助于大学生认识经济社会存在的问题并萌生社会创新创业意识。通过分析该公益创业的协同模式构架、资金筹募和养老公益积分储蓄系统构建,发现其有着公益协同创新、“客制化”管理、蝴蝶效应创新和公益接力棒传承特色等创新点。对社会创新类公益创业朝着融合型、协同化的持续性发展有一定参考作用。

关键词：创业教育公益创业协同创新

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横风下车体运动对高速列车气动性能的影响

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铁道科学与工程学报 2023年第7期20卷 2419-2430页

作者：鲁寨军王甲强梁习锋张梓轩蔺童童刘东润中南大学交通运输工程学院轨道交通安全教育部重点实验室湖南长沙410075 中南大学轨道交通安全关键技术国际合作联合实验室湖南长沙410075 中南大学轨道交通列车安全保障技术国家地方联合工程研究中心湖南长沙410075

为揭示横风下车体运动对高速列车气动性能的影响规律,通过数值模拟对典型车体运动形态下的横风气动性能开展研究。首先基于实车试验确定了横风下的车体典型运动形态并定义研究工况,然后通过改进的延迟分离涡模拟(IDDES)方法详细分析不... 详细信息

为揭示横风下车体运动对高速列车气动性能的影响规律,通过数值模拟对典型车体运动形态下的横风气动性能开展研究。首先基于实车试验确定了横风下的车体典型运动形态并定义研究工况,然后通过改进的延迟分离涡模拟(IDDES)方法详细分析不同工况下的车体与转向架的气动载荷,以及列车周围的流场结构与表面压力变化情况。研究结果表明:横风下高速列车车体运动主要表现为侧滚与横移,车体的侧滚运动对列车升力的影响最明显,头、中、尾车升力均随着车体从迎风侧向背风侧运动而增大,并且车体向背风侧运动时,头车升力增大的幅度大于车体向迎风侧运动相同角度时减小的幅度;当车体运动时,第1转向架横向力、升力与倾覆力矩均增大;车体运动对列车头部、背风侧以及尾部的流动均有较明显的影响,车体向背风侧运动时,头车鼻尖区域流速降低,尾车鼻尖位置的高速流区扩大,并且由头部位置分离在背风侧形成的旋涡结构与车体的夹角呈增大趋势,旋涡流速减小;车体向迎风侧运动时,头车鼻尖区域流速增大,尾车鼻尖位置的高速流区缩小,并且从头部位置分离在背风侧形成的旋涡结构与车体的夹角呈减小趋势,而旋涡流速增大。

关键词：车体运动横风列车空气动力学高速列车

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Luteolin promotes neuronogenesis in hippocampus of chronic unpredictable mild stress rats and primary hippocampus of fetal rats

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Journal of Traditional Chinese Medicine 2024年第4期44卷 670-679页

作者： LIU tongtong ZHANG Xi YANG Hui lin Xiaoyuan LIU Jian ZHANG Xiuli GUO Dongwei ZHAO Hongqing ZOU Manshu LEI Chang LONG Hongping LUO Yan XIANG Yun GE Jinwen WANG Yuhong MENG Pan Institute of Innovation and Applied Research in Chinese Medicine Hunan University of Chinese Medicine the Second People's Hospital of Hunan Province The First Affiliated Hospital Hunan University of Chinese Medicine Hunan Academy of Chinese Medicine

OBJECTIVE: To investigate the effects of luteolin on chronic unpredictable mild stress(CUMS)-induced depressive rats and corticosterone(CORT)-induced depressive primary hippocampal neurons, and to elucidate the mechanism behind the ***: The antidepressant mechanism of luteolin was studied by using CUMS rat model and primary hippocampal neurons in fetal rats. In vivo, novelty suppressed feeding, open-field and sucrose preference tests as well as Morris water maze were evaluated. The content of brain derived neurotrophic factor(BDNF), 5-hydroxytryptamine(5-HT), norepinephrine(NE), and dopamine(DA) in serum were detected by enzyme-linked immunosorbent assay. The mechanisms of luteolin were explored based on neurotrophin and hippocampal neurogenesis, and proliferation. Survival of the septotemporal axis in hippocampus was assayed using the 5-bromo-2-deoxyuridine(BrdU), the expression of BDNF,neurotrophin-3(NT-3), and nerve growth factor(NGF) in hippocampus dentate gyrus region were measured by Western-blotting. In vitro, BDNF, NT-3, tropomyosin receptor kinase B(TrkB), and phosphorylated cyclic adenosine monophosphate responsive element binding protein(p-CREB) were detected through the high content analysis(HCA) to investigate neurotrophin and ***: Induction of CUMS in rats induced depressive symptoms, while luteolin significantly enhanced sucrose consumption, decreased feeding latency, increased locomotor activity, escape latency, distance of target quadrant and regulated the content of depressive-like biomarkers. Histology analysis revealed that luteolin increased the abundance of new born neurons that had been labeled with BrdU, BrdU + neuronal nuclear antigen,and BrdU + doublecortin in septo-temporal axis of S2(mid-septal) and T3(mid-temporal). Moreover,expression of BDNF, NT-3, and NGF increased significantly in the septo-temporal axis of S2 and T3. HCA showed increased expression of BDNF, NT-3, TrkB and p-CREB in primary hippocampal neuron

关键词： chronic unpredicted mild stress depression hippocampal neurogenesis luteolin septo-temporal axis

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高速磁浮列车流线型头部拱形结构对列车与隧道耦合气动特性的影响

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铁道科学与工程学报 2022年第9期19卷 2515-2523页

作者：蔺童童杨明智张雷钟沙陶羽马江川中南大学交通运输工程学院轨道交通安全教育部重点实验室湖南长沙410075

采用重叠网格方法,基于三维非定常可压缩的N-S方程和SST k-ω湍流模型,探索时速600 km/h高速磁浮列车流线型头部拱形结构参数对列车与隧道耦合气动特性的影响。分析单拱、双拱和三拱3种不同拱形结构列车穿越隧道时车体表面压力、初始压... 详细信息

采用重叠网格方法,基于三维非定常可压缩的N-S方程和SST k-ω湍流模型,探索时速600 km/h高速磁浮列车流线型头部拱形结构参数对列车与隧道耦合气动特性的影响。分析单拱、双拱和三拱3种不同拱形结构列车穿越隧道时车体表面压力、初始压缩波、微气压波和气动升力。研究结果表明:头车拱形结构能有效改善高速磁悬浮列车的空气动力学参数,拱形结构参数对车体表面及隧道壁面最大压力峰值的影响较小,但对隧道内初始压缩波的影响较为明显,相比单拱磁悬浮列车,双拱磁悬浮列车和三拱磁悬浮列车通过隧道时,隧道内初始压缩波压力梯度分别减少5.67%和8.75%;磁悬浮列车拱形结构的增加对隧道出口的微气压波幅值也有缓解作用,相较单拱磁悬浮列车距隧道出口20 m处的微气压波峰值,双拱和三拱磁悬浮列车微气压波峰值分别减少10.9%和14.0%,相较单拱磁悬浮列车距隧道出口50 m处的微气压波峰值,双拱和三拱磁悬浮列车微气压波峰值分别减少12.5%和16.7%;拱形结构数量的增加使得头车和尾车的气动升力分配更加均衡,相较单拱磁悬浮列车,双拱磁悬浮列车头车和尾车的气动升力分别减少3.80%和增加6.19%,三拱磁悬浮列车头车和尾车的气动升力分别减少8.86%和增加17.01%。

关键词：高速磁悬浮列车隧道拱形结构初始压缩波微气压波气动升力

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基于机器学习的盾构掘进地表沉降回归预测模型

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合肥工业大学学报（自然科学版） 2023年第9期46卷 1224-1229页

作者：方诗圣苏一恒林彤彤修贤好李建豪合肥工业大学土木与水利工程学院安徽宣城242000 合肥工业大学计算机与信息学院安徽宣城242000

针对地铁盾构掘进引起的地表沉降预测问题,经验和半经验公式预测差异性大,解析法预测过程复杂,数值模拟无法运用于实时预测。基于线性回归、岭回归、套索算法(least absolute shrinkage and selection operator,LASSO)、分裂决策树算法(... 详细信息

针对地铁盾构掘进引起的地表沉降预测问题,经验和半经验公式预测差异性大,解析法预测过程复杂,数值模拟无法运用于实时预测。基于线性回归、岭回归、套索算法(least absolute shrinkage and selection operator,LASSO)、分裂决策树算法(classification and regression tree,CART)、随机森林算法、支持向量机(support vector machine,SVM)、XGBoost(extreme gradient boosting)、多层感知机(multi-layer perceptron,MLP)8种机器学习算法的拟合能力,文章提出盾构掘进沿线地表最大沉降值预测模型。采用均方误差(mean square error,MSE)、均方根误差(root mean square error,RMSE)、绝对均值误差(mean absolute error,MAE)、决定系数R 2进行模型评估。结果表明:支持向量回归(support vector regression,SVR)模型取得的效果最优,其次是回归MLP模型;在树模型中,随机森林的表现效果好于CART和XGBoost;线性模型中表现最好的是岭回归。

关键词：地铁盾构掘进地表沉降机器学习回归预测

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蜡烛火焰耦合振荡的研究

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合肥工业大学学报（自然科学版） 2023年第8期46卷 1146-1152页

作者：方莲宋家乐王雅萍潘刚苏一恒林彤彤合肥工业大学基础部安徽宣城242000 合肥工业大学土木与水利工程学院安徽合肥230009 合肥工业大学计算机与信息学院安徽合肥230601

文章研究了2组全同蜡烛火焰的耦合振荡情况。通过高速摄影机拍摄和、Origin软件图像处理,得到蜡烛耦合振荡情况与距离、直径等因素的关系;利用MATLAB软件仿真和纹影法,探讨热辐射、热对流在耦合中的作用,明确了热对流是蜡烛耦合振荡的... 详细信息

文章研究了2组全同蜡烛火焰的耦合振荡情况。通过高速摄影机拍摄和、Origin软件图像处理,得到蜡烛耦合振荡情况与距离、直径等因素的关系;利用MATLAB软件仿真和纹影法,探讨热辐射、热对流在耦合中的作用,明确了热对流是蜡烛耦合振荡的主导因素;结合涡动力学理论,对蜡烛火焰耦合振荡的机理做进一步解释。该文为研究蜡烛火焰耦合振荡现象提供了一定的理论依据。

关键词：蜡烛火焰耦合振荡热辐射热对流涡动力学理论

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