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Temperature regulates negative supercoils to modulate meiotic crossovers and chromosome organization

Science China Life Sciences 2024年

作者： Yingjin Tan Taicong Tan Shuxian Zhang Bo Li Beiyi Chen Xu Zhou Ying Wang xiao Yang Binyuan Zhai Qilai Huang Liangran Zhang Shunxin Wang Research Unit of Gametogenesis and Health of ART-Offspring Chinese Academy of Medical Sciences (No.2021RU001) Advanced Medical Research Institute Shandong University State Key Laboratory of Reproductive Medicine and Offspring Health Center for Reproductive Medicine Institute of Women Children and Reproductive Health Shandong University Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology School of Life Sciences Shandong University Center for Cell Structure and Function Shandong Provincial Key Laboratory of Animal Resistance Biology College of Life Sciences Shandong Normal University National Research Center for Assisted Reproductive Technology and Reproductive Genetics Shandong University Key Laboratory of Reproductive Endocrinology (Shandong University) Ministry of Education Shandong Technology Innovation Center for Reproductive Health Shandong Provincial Clinical Research Center for Reproductive Health Shandong Key Laboratory of Reproductive Medicine Shandong Provincial Hospital Affiliated to Shandong First Medical University

Crossover recombination is a hallmark of meiosis that holds the paternal and maternal chromosomes(homologs) together for their faithful segregation, while promoting genetic diversity of the progeny. The pattern of crossover is mainly controlled by the architecture of the meiotic chromosomes. Environmental factors, especially temperature, also play an important role in modulating crossovers. However, it is unclear how temperature affects crossovers. Here, we examined the distribution of budding yeast axis components(Red1, Hop1, and Rec8)and the crossover-associated Zip3 foci in detail at different temperatures, and found that both increased and decreased temperatures result in shorter meiotic chromosome axes and more crossovers. Further investigations showed that temperature changes coordinately enhanced the hyperabundant accumulation of Hop1 and Red1 on chromosomes and the number of Zip3 foci. Most importantly, temperature-induced changes in the distribution of axis proteins and Zip3 foci depend on changes in DNA negative supercoils. These results suggest that yeast meiosis senses temperature changes by increasing the level of negative supercoils to increase crossovers and modulate chromosome organization. These findings provide a new perspective on understanding the effect and mechanism of temperature on meiotic recombination and chromosome organization, with important implications for evolution and breeding.

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Effect of NPK Application on Yield,Nutrients and Water Utilization Under Sudangrass and Ryegrass Rotation Regime

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Agricultural Sciences in China 2010年第7期9卷 1026-1034页

作者： LI wen-xi LU Jian-wei CHEN Fang LI xiao-kun College of Resources and Environment Huazhong Agricultural University Wuhan 430070 P.R.China Wuhan Botanical Garden Chinese Academy of Sciences Wuhan 430074 P.R.China

Sudangrass and ryegrass rotation is a new type of cropping system in Jianghan Plain,which develops very fast in recent ***,it is essential to work out the optimal nutrients and water management measures in this new *** effect of NPK fertilizer on yield of forage grass,nutrients and water utilization under sudangrass and ryegrass rotation was studied through continuous pot experiments for three *** results showed that NPK combination could significantly improve the yield of forage *** total yields during the periods of 2005-2006,2006-2007 and 2007-2008 were 1 690.0,2 091.3 and 1 770.7 g/pot,*** yields in PK treatment were 700.7,1 256.9 and 856.3% lower than those of NPK treatment,while the yields in NK treatment were 426.3,384.9 and 792.3% lower than those of NPK treatment,***,the yields in NP treatment were 15.9,4.4 and 10.6% lower than those of NPK treatment,*** NPK combination was found to improve the nutrients uptake,and the total N uptakes during the above periods were 10.0,14.8 and 10.6 times higher than that of PK treatment,respectively,and 3.7,1.8 and 5.1 times higher than those of NK treatment,respectively,but,were similar to NP *** total P uptakes were 4.6,6.8 and 5.3 times higher than those of PK treatment,and were 2.4,2.3 and 2.9 times higher than those of NK treatment,respectively,but were similar to NP *** total K uptakes were 5.2,8.4 and 4.9 times higher than that of PK treatment,3.9,2.3 and 3.9 times higher than those of NK treatment,and 80.9,57.4 and 200.5% higher than those of NP treatment,*** productivity for three years time periods were 16.5,16.1 and 16.2 kg m-3,and were 3.8,5.4 and 4.2 times higher than those of PK treatment,2.3,1.3 and 2.6 times higher than those of NK treatment,and were 16.4,8.8 and 22.4% higher than those of NP treatment,*** soil pH was decreased and soil organic matter was increased in all treatments with in

关键词： sudangrass and ryegrass rotation system NPK fertilizer nutrient uptake water productivity soil nutrition

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Single-centre study comparing standard apical dissection with a modified technique to facilitate vesico-urethral anastomosis during laparoscopic radical prostatectomy

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Asian Journal of Andrology 2011年第3期13卷 494-498,515页

作者： Xin Gao xiao-Yong Pu Jie Si-Tu wen-Tao Huang Department of Urology the Third Affiliated Hospital Sun Yat-Sen University Guangzhou 510630 China

A modified apical dissection of the prostate to improve the efficiency of vesico-urethral anastomosis （VUA） in laparoscopic radical prostatectomy （LRP） was reported. A total of 42 patients were randomly selected and enrolled in this study. A standard LRP was performed in 21 patients （group 1）, whereas a novel, modified apical dissection of the prostate in LRP was performed in another 21 patients （group 2）. Surgical data, total operative time, VUA time, extravasation rate, catheterisation time, occurrence of anastomotic strictures, and the early and late continence rates were analysed statistically. No differences in clinical or pathological characteristics were determined between the two groups. The total operative time, VUA time, blood loss and catheterisation time were lower in group 2, which received the novel, modified technique compared with group 1, which received the standard technique to dissect the apex of the prostate （P〈0.01 for each variable）. Regarding the extravasation rate and the occurrence of anastomotic strictures, no significant differences were found between the two groups （P〉0.0.05 for each）. After catheter removal, a statistically significant difference in the continence rates was present at 3 and 30 days post operation in the two groups （P〈0.01, respectively）. At 90 days post operation, the difference, although still present, was no longer statistically significant （P〉0.05）. The novel, modified apical dissection of the prostate facilitates the VUA and significantly improves the efficacy of the procedure and early restoration of continence.

关键词： continence laparoscopic technique radical prostatectomy vesico-urethral anastomosis

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Gallic acid ameliorates colitis by modulating the Treg/Th17 balance via microbiota-derived secondary bile acids

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Food Science and Human Wellness 2024年

作者： xiao Zhang Yun Leng Qian Zhang Hansheng Yu Ziqiong Liao Jiaxuan Xia Chong Ma Kun Liu Yuefeng Zhang Yanjun Hong Hao Li Zhiyong Xie School of Pharmaceutical Sciences (Shenzhen)， Sun Yat-sen University The Seventh Affiliated Hospital， Sun Yat-sen University Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research， Sun Yat-sen University

Gallic acid (GA)， a plant phenol ubiquitously present in fruits and vegetables， has demonstrated efficacy in ameliorating ulcerative colitis (UC). Despite previous reports， the precise mechanism of GA's therapeutic action remains elusive. Herein， the present work aims to delineate the mechanism underlying the anti-UC effects of GA by focusing on the interplay of gut microbiota， microbial and host cometabolites， and gut immune regulation. The findings revealed that GA treatment improved the colitis symptoms and systematic inflammatory response， reliant on gut microbiota， as evidenced by microbiota depletion and fecal microbiota transplantation. According to the 16s rDNA sequencing results， GA altered the gut microbiota community structure and upregulated the biosynthesis of secondary bile acids (SBAs). Metabolomics and flow cytometry analysis (FCS) revealed a substantial increase in SBAs production， including UDCA， LCA， 3-oxo-LCA and IsoalloLCA， which further upregulated the proportion of regulatory T (Treg) cells and downregulated the proportion of T helper type 17 (Th17) cells in the colon， ultimately resulting in an improved Treg/Th17 balance. Further FCS and real-time quantitative PCR assays provided mechanistic insights， demonstrating that UDCA and IsoalloLCA facilitate Treg cell differentiation through the upregulation of nuclear hormone receptor 4A1 (NR4A1). This research elucidated that GA effectively mitigates colitis by modulating the Treg/Th17 balance， facilitated by the enhanced synthesis of microbiota-derived SBAs. These insights unveil innovative pathways through which GA exerts its anti-UC effects， emphasizing the potential therapeutic benefits of incorporating a GA-enriched diet into UC management.

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有机物对铸造粘土废旧砂再生质量的影响研究

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铸造 2024年第4期73卷 527-531页

作者：胡胜利龚小龙蔡关翎任文强樊自田华中科技大学材料科学与工程学院材料成形与模具技术国家重点实验室湖北武汉430074 柳晶科技集团股份有限公司江苏常州213300

铸造粘土废旧砂通常采用高温焙烧结合机械摩擦方法进行再生回用,为了得到高质量的再生砂,废旧砂再生过程中要求焙烧温度相对精确和稳定,但粘土废旧砂中存在的煤粉及有机树脂砂壳芯混入的有机物使焙烧温度出现巨大波动,特别是细颗粒废旧... 详细信息

铸造粘土废旧砂通常采用高温焙烧结合机械摩擦方法进行再生回用,为了得到高质量的再生砂,废旧砂再生过程中要求焙烧温度相对精确和稳定,但粘土废旧砂中存在的煤粉及有机树脂砂壳芯混入的有机物使焙烧温度出现巨大波动,特别是细颗粒废旧砂中的有机物,影响再生砂质量和再生效率。本文首先将粘土废旧砂进行100目筛分分级,研究100目筛上和100目筛下两种粒级废旧砂中有机物对燃烧速率的影响,然后确立废旧砂中有机物燃值贡献的计算公式,并通过实际生产测试,获得有机物燃值贡献阀值和废旧砂的再生最优投入量,为粘土废旧砂的高效率和高质量再生提供理论参考。

关键词：铸造粘土废旧砂有机物再生回用燃烧阈值

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Tunable electronic structure and magnetic coupling in strained two-dimensional semiconductor MnPSe3

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Frontiers of physics 2018年第4期13卷 167-174页

作者： Qi Pei xiao-Cha Wang Ji-Jun ZOU wen-Bo Mi Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology School of Science Tianjin University Tianjin 300354 China School of Electrical and Electronic Engineering Tianjin University of Technology Tianjin 300384 China Key Laboratory for Green Chemical Technology of the Ministry of Education School of Chemical Engineering and Technology Tianjin University Tianjin 300354 China

The electronic structures and magnetic properties of strained monolayer MnPSe3 are investigated sys- tematically via first-principles calculations. It is found that the magnetic ground state of monolayer MnPSe3 can be significantly affected by biaxial strain engineering, while the semiconducting char- acteristics are well-preserved. Owing to the sensitivity of the magnetic coupling towards structural deformation, a biaxial tensile strain of approximately 13% can lead to an antiferromagnetic （AFM）- ferromagnetic （FM） transition. The strain-dependent magnetic stability is mainly attributed to the competition of the direct AFM interaction and indirect FM superexchange interaction between the two nearest-neighbor Mn atoms. In addition, we find that FM MnPSe3 is an intrinsic half semiconductor with large spin exchange splitting in the conduction bands, which is crucial for the spin-polarized carrier injection and detection. The sensitive interdependence among the external stimuli, electronic structure, and magnetic coupling makes monolayer MnPSe3 a promising candidate for spintronics.

关键词： two-dimensional semiconductor MnPSe3 strain engineering electronic structure magnetic coupling

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基于格子玻尔兹曼方法的双液滴撞击壁面液膜的热特性演化过程

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科学技术与工程 2024年第3期24卷 1207-1215页

作者：宋翔何小泷重庆交通大学河海学院重庆400074 重庆交通大学西南水运工程科学研究所重庆400074

为了研究并排双液滴撞击覆有液膜的高温壁面过程中壁面热流密度分布特征,基于水热耦合双分布函数格子玻尔兹曼伪势模型,探究了液滴间距、撞击速度和液相黏滞系数在不同时刻对壁面瞬时热流密度分布的影响。结果表明:低温液滴的扩散与下... 详细信息

为了研究并排双液滴撞击覆有液膜的高温壁面过程中壁面热流密度分布特征,基于水热耦合双分布函数格子玻尔兹曼伪势模型,探究了液滴间距、撞击速度和液相黏滞系数在不同时刻对壁面瞬时热流密度分布的影响。结果表明:低温液滴的扩散与下潜导致撞击区和中心射流区的壁面与液膜之间的温度梯度上升,引起撞击区和中心射流区壁面热流密度骤增。撞击区传热形式以对流传热为主,静态区受液冠处速度不连续性影响,其传热形式以扩散传热为主。双液滴撞击速度增大导致液滴下潜和扩展程度加深,液膜内部对流传热增强。双液滴间距增加引起双液滴内侧液冠在液膜内扩展空间增大,造成瞬时壁面高热流密度区域面积增加,利于散热。此外,更大的液相黏滞系数增大了液滴撞击液膜过程中的黏滞耗散,降低低温液滴的下潜程度和撞击区的液膜流场对流强度,导致壁面热流密度峰值减小。

关键词：格子玻尔兹曼方法伪势模型双液滴撞击热流密度特征

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中微子事件IC220624A候选射电对应体J1458+4121的VLBI观测研究

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天文学进展 2024年第2期42卷 276-285页

作者：曾艾玲杨小龙赵薇洪晓瑜上海科技大学物质科学与技术学院上海201210 中国科学院上海天文台上海200030 中国科学院大学天文与空间科学学院北京100049

收集并分析了中微子发射事件IC-220624A的候选体J1458+4121仅有的几次甚大天线阵(VLA)的历史数据;在此基础上,利用甚长基线阵列(VLBA)对其进行首次VLBI观测,观测波段为L和C波段。通过数据处理和分析研究,得到J1458+4121 VLBA的射电辐射... 详细信息

收集并分析了中微子发射事件IC-220624A的候选体J1458+4121仅有的几次甚大天线阵(VLA)的历史数据;在此基础上,利用甚长基线阵列(VLBA)对其进行首次VLBI观测,观测波段为L和C波段。通过数据处理和分析研究,得到J1458+4121 VLBA的射电辐射形态。此外,利用相位参考技术,还获得J1458+4121更精确的坐标(α=14:58:20.772, δ=41:21:01.911)。VLA观测的射电总流量强度在1.4~8.4 GHz范围内呈下降趋势,说明J1458+4121的射电能谱可能是幂律谱;而VLBA观测的射电总流量强度在1.5~5 GHz范围内呈上升趋势,意味着其射电能谱在GHz波段是反转谱。因此,J1458+4121极有可能是一个年轻射电源,其中微子产生可能是由于新喷流成分的出现。该结果有助于J1458+4121的后续研究,并将中微子起源的关注对象从明亮的耀变体扩展至其他类型的活动星系核。

关键词：中微子活动星系核甚长基线干涉测量

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Transmission Considerations with QoS Support to Deliver Real-Time Distributed Speech Recognition Applications

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Wuhan University Journal of Natural Sciences 2002年第1期7卷 65-70页

作者： Zhu xiao-gang Zhu Hong-wen Rong Meng-tian Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200030 China

Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.

关键词： distributed speech recognition quality of service real-time transmission protocol resource reservation protocol wireless application protocol

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1974—2018年福建省森林碳储量特征及动态变化

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植物资源与环境学报 2024年第4期33卷 101-108页

作者：肖嘉文刘金福郑雯王智苑方梦凡洪宇谭芳林福建农林大学福建福州350002 福建省金皇环保科技有限公司福建福州350001 福建省数字经济发展促进中心福建福州350003 昌吉学院新疆昌吉831199 福建省林业科学研究院福建福州350012

基于福建省1974—2018年共9期的森林资源清查数据,采用生物量转换因子法和平均生物量法,分析福建省森林碳储量动态变化,并对2014—2018年乔木林各优势树种(组)的碳储量情况进行分析。结果表明:1974—2018年,福建省森林总体碳储量从13539... 详细信息

基于福建省1974—2018年共9期的森林资源清查数据,采用生物量转换因子法和平均生物量法,分析福建省森林碳储量动态变化,并对2014—2018年乔木林各优势树种(组)的碳储量情况进行分析。结果表明:1974—2018年,福建省森林总体碳储量从13539.64×10^(4)t增长到33962.34×10^(4)t,平均碳密度从25.75 t·hm^(-2)增长到39.86 t·hm^(-2)。乔木林中,幼龄林和中龄林的面积较大,而近熟林、成熟林和过熟林的面积逐期增加;中龄林的碳储量最高;成熟林和过熟林的碳密度整体较大。天然林和人工林的面积、碳储量和碳密度逐期增加,且天然林各指标均高于人工林。2014—2018年,天然林中阔叶混交林的碳储量最高,锥栗〔Castanea henryi(Skan)Rehder et ***〕的碳密度最大;人工林中杉木〔Cunninghamia lanceolata(Lamb.)Hook.〕的碳储量最高,木麻黄(Casuarina equisetifolia Linn.)的碳密度最大。综上所述,福建省森林有较高的碳储量和碳汇能力,阔叶混交林和杉木是乔木林碳储量的主要贡献者,因此,可通过改善这2个树种(组)的林龄结构并加强经营管理来提升福建省森林碳汇能力;并通过合理的采伐和种植策略,优化幼龄林和中龄林的比例,以提高福建省森林碳汇能力,保持成熟林和过熟林面积占比,以维持福建省较高的森林碳密度。

关键词：福建省森林碳储量碳密度碳汇能力

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