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Two New Styryllactones from Goniothalamus cheliensis

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Chinese Chemical Letters 2003年第5期14卷 487-488页

作者： Si WANG Sheng Jun dai Ruo Yun CHEN Shi Shan YU De Quan YU Institute of Materia Medica Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050

Two new styryllactones, iso-goniopypyrone and 8-acetyl-9-deoxygoniopypyrone, were isolated from the roots of Goniothalamus cheliensis. Their structure were elucidated on the basis of spectroscopic and chemical eviden... 详细信息

关键词： Goniothalamus cheliensis iso-goniopypyrone 8-acetyl-9-deoxygoniopypyrone.

不同程度帕金森病患者黄斑中心凹下视网膜内外层及脉络膜厚度分析

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眼科新进展 2023年第3期43卷 234-237页

作者：赵颖戴惟葭刘大川首都医科大学宣武医院眼科北京市100053

目的观察不同程度帕金森病(PD)患者黄斑中心凹下视网膜内外层及脉络膜厚度的变化。方法选择2021年1月至2022年1月首都医科大学宣武医院神经内科确诊的30例(30眼)原发性PD患者为研究对象,按照Hoehn-Yahr分级法分为轻中度PD组(15例)及重... 详细信息

目的观察不同程度帕金森病(PD)患者黄斑中心凹下视网膜内外层及脉络膜厚度的变化。方法选择2021年1月至2022年1月首都医科大学宣武医院神经内科确诊的30例(30眼)原发性PD患者为研究对象,按照Hoehn-Yahr分级法分为轻中度PD组(15例)及重度PD组(15例),纳入同期健康志愿者30例(30眼)为正常对照组,采用海德堡频域光学相干断层扫描(SD-OCT)的增强扫描模式(EDI-OCT)对所有受检眼黄斑中心凹下视网膜内外层及脉络膜厚度进行分层扫描,分析随着PD严重程度的增加,受检眼黄斑中心凹下视网膜内外层及脉络膜厚度的变化特点。结果轻中度PD组、重度PD组及正常对照组受检眼黄斑中心凹下视网膜全层厚度分别为(237.17±18.32)μm、(217.55±17.89)μm、(278.66±18.56)μm,黄斑中心凹下视网膜内层厚度分别为(47.15±16.36)μm、(38.53±19.32)μm、(68.45±12.28)μm,黄斑中心凹下视网膜外层厚度分别为(200.15±17.36)μm、(185.02±17.32)μm、(210.26±12.36)μm;三组受检眼黄斑中心凹下视网膜全层厚度、内层厚度、外层厚度差异均有统计学意义(均为P<0.05)。轻中度PD组、重度PD组患者黄斑中心凹下视网膜全层厚度、内层厚度、外层厚度均明显小于正常对照组,重度PD组患者黄斑中心凹下视网膜全层厚度、内层厚度、外层厚度均明显小于轻中度PD组,差异均有统计学意义(均为P<0.05)。轻中度PD组、重度PD组及正常对照组受检眼黄斑中心凹下脉络膜厚度分别为(279.15±78.36)μm、(257.02±58.32)μm、(373.26±82.36)μm;三组受检眼黄斑中心凹下脉络膜厚度差异有统计学意义(P<0.05)。轻中度PD组患者受检眼黄斑中心凹下脉络膜厚度均明显小于正常对照组,重度PD组患者黄斑中心凹下脉络膜厚度均明显小于轻中度PD组、正常对照组,组间差异均有统计学意义(均为P<0.05)。结论 PD患者黄斑中心凹下视网膜内外层厚度及脉络膜厚度随着PD严重程度的增加进行性变薄,对不同严重程度PD患者黄斑中心凹下视网膜及脉络膜厚度的探究,为探讨PD患者临床多样性提供依据。

关键词：视网膜内层厚度视网膜外层厚度脉络膜厚度帕金森病

A photo-elutable and template-free isothermal amplification strategy for sensitive fluorescence detection of 5-formylcytosine in genomic DNA

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Chinese Chemical Letters 2023年第3期34卷 166-170页

作者： Hongling Yang Yanfei Zhang Zhenning Yu Si-Yang Liu Yuzhi Xu Zong dai Xiaoyong Zou School of Chemistry Sun Yat-sen UniversityGuangzhou 510275China Guangdong Provincial Key Laboratory of Sensing Technology and Biomedical Instrument School of Biomedical EngineeringSun Yat-sen UniversityShenzhen 518107China Scientific Research Center The Seventh Affiliated HospitalSun Yat-sen UniversityShenzhen 518107China

5-Formylcytosine(5fC), as an important epigenetic modification, plays a vital role in diverse biological processes and multiple diseases by regulating gene expression. Owing to the extremely low abundance of 5fC in all mammalian tissues and high structural similarity with other cytosine derivatives, the precise and sensitive detection of 5fC is challenging. Herein, a photo-elutable and template-free isothermal amplification strategy has been proposed for the sensitive detection of 5fC in genomic DNA based on5fC-specific biotinylation, enrichment, photocleavage, and terminal deoxynucleotidyl transferase(Td T)-assisted fluorescence signal amplification, which is termed 5fC-PTIAS. By introducing the highly specific chemolabeling and the one-step photoelution processes, this strategy possesses a minimal nonspecific background as well as a much higher amplification efficiency. With the high signal-to-noise ratio, this strategy can achieve the accurate quantification of 5fC in various biological samples including mouse brain, kidney, and liver, with a limit of detection(LOD) of 0.025‰ in DNA(S/N=3). These results not only confirm the widespread distribution of 5fC but also indicate its significant variation in different tissues and ages. The bisulfite-and mass spectrometry-free strategy is highly sensitive, selective, and easily mastered, holding great promise in detecting other epigenetic modifications with much lower levels.

关键词： 5-Formylcytosine DNA demethylation Fluorescence detection Isothermal amplification Magnetic separation

A valveless piezoelectric pump with novel flow path design of function of rectification to improve energy efficiency

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Frontiers of Mechanical Engineering 2022年第3期17卷 177-193页

作者： Jianhui ZHANG Xiaosheng CHEN Zhenlin CHEN Jietao dai Fan ZHANG Mingdong MA Yuxuan HUO Zhenzhen GUI School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou510006China

Existing valveless piezoelectric pumps are mostly based on the flow resistance mechanism to generate unidirectional fluid pumping,resulting in inefficient energy conversion because the majority of mechanical energy is consumed in terms of parasitic *** this paper,a novel tube structure composed of a Y-shaped tube and aȹ-shaped tube was proposed considering theory of jet inertia and vortex dissipation for the first time to improve energy *** verifying its feasibility through the flow field simulation,the proposed tubes were integrated into a piezo-driven chamber,and a novel valveless piezoelectric pump with the function of rectification(NVPPFR)was *** previous pumps,the reported pump directed the reflux fluid to another flow channel different from the pumping fluid,thus improving pumping ***,mathematical modeling was established,including the kinetic analysis of vibrator,flow loss analysis of fluid,and pumping ***,experiments were designed,and results showed that NVPPFR had the function of rectification and net pumping *** maximum flow rate reached 6.89 mL/min,and the pumping efficiency was up to 27%.The development of NVPPFR compensated for the inefficiency of traditional valveless piezoelectric pumps,broadening the application prospect in biomedicine and biology fields.

关键词： composite tube valveless piezoelectric pump rectification energy efficiency

Strategies that regulate LSD1 for novel therapeutics

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1494-1507页

作者： Meng Li Mengge dai Bing Cheng Shaotong Li Enhui Guo Junwei Fu Ting Ma Bin Yu School of Pharmaceutical Sciences&Key Laboratory of Advanced Drug Preparation Technologies Ministry of EducationZhengzhou UniversityZhengzhou 450001China College of Chemistry Zhengzhou UniversityZhengzhou 450001China Tianjian Laboratory of Advanced Biomedical Sciences Institute of Advanced Biomedical SciencesZhengzhou UniversityZhengzhou 450000China Pingyuan Laboratory State Key Laboratory of Antiviral DrugsHenan Normal UniversityXinxiang 453007China State Key Laboratory of Pharmaceutical Biotechnology Nanjing UniversityNanjing 210023China

Histone methylation plays crucial roles in regulating chromatin structure and gene transcrip-tion in epigenetic ***-specific demethylase 1(LSD1),the first identified histone de-methylase,is universally overexpressed in various ***1 dysregulation is closely associated with cancer,viral infections,and neurodegenerative diseases,etc.,making it a promising therapeutic *** LSD1 inhibitors and two small-molecule degraders(UM171 and BEA-17)have entered the clinical ***1 can remove methyl groups from histone 3 at lysine 4 or lysine 9(H3K4 or H3K9),resulting in either transcription repression or *** the roles of LSD1 in transcrip-tional regulation are well-established,studies have revealed that LSDl can also be dynamically regulated by other *** example,the expression or activity of LSD1 can be regulated by many proteins that form transcriptional corepressor complexes with ***,some post-transcriptional modifica-tions and cellular metabolites can also regulate LSD1 expression or its demethylase ***,in this review,we will systematically summarize how proteins involved in the transcriptional corepressor complex,various post-translational modifications,and metabolites act as regulatory factors for LSD1 ac-tivity.

关键词： LSD1 regulation Transcription repression Transcription activation the Corepressor complex Post-transcriptional modifications Metabolites

Unsourced Multiple Access for 6G Massive Machine Type Communications

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China Communications 2022年第3期19卷 70-87页

作者： Yuanjie Li Jincheng dai Zhongwei Si Kai Niu Chao Dong Jiaru Lin Sen Wang Yifei Yuan Key Laboratory of Universal Wireless Communications Beijing University of Posts and TelecommunicationsBeijing 100876China China Mobile Research Institute Beijing 100053China

Unsourced multiple access(UMA)is a multi-access technology for massive,low-power,uncoordinated,and unsourced Machine Type Communication(MTC)*** ensures transmission reliability under the premise of high energy *** on the analysis of the 6G MTC key performance indicators(KPIs)and scenario characteristics,this paper summarizes its requirements for radio access *** this,the existing multiple access models are analyzed under these standards to determine UMA's advantages for 6G MTC according to its design *** critical technology of UMA is the design of its multiple-access coding ***,the existing UMA coding schemes from different coding paradigms are further summarized and *** particular,this paper comprehensively considers the energy efficiency and computational complexity of these schemes,studies the changes of the above two indexes with the increase of access scale,and considers the trade-off between the *** is revealed by the above analysis that some guiding rules of UMA coding ***,the open problems and potentials in this field are given for future research.

关键词： unsourced multiple access machine type communications 6G massive random access uncoordinated

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中国英语学习者心理动词习得实证研究

外语学刊 2008年第5期 114-122页

作者：戴曼纯刘晓英北京外国语大学北京100089

本研究从心理动词论元结构及其子语类特征角度考察中国学生习得英语心理动词的规律。心理动词按其体验者的投射位置大致可以分为主语体验者类(SE)和宾语体验者类(OE)。体验者论元投射的任意性引发可学性问题。本项调查试图揭示心理动词... 详细信息

本研究从心理动词论元结构及其子语类特征角度考察中国学生习得英语心理动词的规律。心理动词按其体验者的投射位置大致可以分为主语体验者类(SE)和宾语体验者类(OE)。体验者论元投射的任意性引发可学性问题。本项调查试图揭示心理动词的句法-语义属性与二语习得之间的关系,调查结果表明:PH动词习得优于PSY动词;SE动词的习得优于OE动词;OE习得表现出S类>N类>A类>H类的规律;学习者L2水平影响习得效果。研究结果证明心理动词的论元结构、子语类特征复杂性与其习得密切相关。

关键词：心理动词二语习得论元结构子语类特征

Characterization of ploidy levels in Chrysanthemum L. by flow cytometry

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Journal of Forestry Research 2015年第3期26卷 771-775页

作者： Yue-ping Ma Jiang-xue Wei Zhi-yang Yu Bing Qin Si-lan dai College of Life and Health Sciences Northeastern University College of Landscape Architecture Beijing Forestry University

Analyzing the ploidy levels of plants is important for identifying species, selecting parental lines, identifying the relationships between species, and determining evolutionary patterns. The genus Chrysanthemum is widely distributed throughout the world and exhibits different ploidy levels. We used flow cytometry to analyze the ploidy levels of nine species of Chrysanthemum L. collected from different regions and geographical locations in China. Three diploids from Henan and Wuhan provinces corresponded to Chrysanthe- mum lavandulifolium and two species of C. nankingense, while three tetraploids from various regions corresponded to C. indicum and two species of C. chanetii. Two hexaploids corresponding to C. vestitum were collected at Funiu moun- tain （Henan province）, and C. zawadskii was collected at Huangshan mountain （Anhui province）. We found that OTTO extraction buffer was suitable for extracting nuclei from most species, apart from C. zawadskii. Flow cytometry proved to bea simple, rapid, and highly accurate method for identifying ploidy levels in Chrysanthemum species.

关键词： Chrysanthemum L. Flow cytometry - OTTOextraction buffer Ploidy identification

Explosion limits for combustible gases

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Mining Science and Technology 2009年第2期19卷 182-184页

作者： TONG Min-ming WU Guo-qing HAO Ji-fei dai Xin-lian School of lnformation and Electrical Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit （LEL） and Upper Explosion-Limit （UEL） of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of HE increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.

关键词： coal mine gas explosive gases explosion limits