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Synthesis and Crystal Structure of Dehydroandrographolide Dipolycyclophosphate

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Chinese Journal of Structural Chemistry 2005年第10期24卷 1198-1202页

作者： XU hai-Wei WANG jun-feng LIU Hong-Min ZHANG Jian-Ye New Drug Research ＆ Development Center Zhengzhou University Zhengzhou 450052 China

The title compound was synthesized and characterized by IR, NMR, HRSI-MS and MS, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic system （C40H52O11P2, Mr= 770.76）, space group P21212, with a = 22.562（5）, b = 29.224（6）, c = 7.1953（14） A, V = 4744.2（16） A^3, Z = 4, Dc = 1.079 g/cm^3, F（000） = 1640 and μ = 0.141 mm^-1. The final R = 0.0758 and wR = 0.1778 for 2794 observed reflections with I 〉 20（I）. Intermolecular hydrogen bonds are found between the O atom of carbonyl group and H atoms of olefinic carbon. The absolute configuration of this molecule was confirmed by comparison with that of the original material.

关键词： crystal structure andrographolide cyciophosphate synthesis

Image stabilization with support vector machine

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第6期12卷 478-485页

作者： Wen-de DONG Yue-ting CHEN Zhi-hai XU Hua-jun feng Qi LI State Key Laboratory of Optical Instrumentation Zhejiang University Hangzhou 31002 7 China

We propose an image stabilization method based on support vector machine (SVM). Since SVM is very effective in solving nonlinear regression problems, an SVM model was constructed and trained to simulate the vibration characteristic. Then this model was used to predict and compensate for the vibration. A simulation system was built and four assessment metrics including the signal-to-noise ratio (SNR), gray mean gradient (GMG), Laplacian (LAP), and modulation transfer function (MTF) were used to verify our approach. Experimental results showed that this new method allows the image plane to locate stably on the CCD, and high quality images can be obtained.

关键词： Support vector machine (SVM) Vibration Displacement Prediction Compensation

Simultaneous Determination of Gold and Platinum by Double Artificial Neural Network Analysis with Flow-injection Chemiluminescence

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Chinese Chemical Letters 2006年第10期17卷 1343-1346页

作者： Ming Yang LIU hai Tao ZHANG jun feng LI Shu Gui CHEN Hong Yan WANG College of chemistry Jilin University Changchun 130012

A highly sensitive double artificial neural network （DANN） analysis with flow-injection chemiluminescence （FI-CL） has been developed to simultaneously determine the trace amounts of the gold and platinum in simula... 详细信息

关键词： Double artificial neural networks flow-injection chemiluminescence simultaneous determination gold and platinum.

Novel linear search for support vector machine parameter selection

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第11期12卷 885-896页

作者： Hong-xia PANG Wen-de DONG Zhi-hai XU Hua-jun feng Qi LI Yue-ting CHEN State Key Laboratory of Optical Instrumentation Zhejiang University Hangzhou 310027 China

Selecting the optimal parameters for support vector machine (SVM) has long been a hot research topic. Aiming for support vector classification/regression (SVC/SVR) with the radial basis function (RBF) kernel, we summarize the rough line rule of the penalty parameter and kernel width, and propose a novel linear search method to obtain these two optimal parameters. We use a direct-setting method with thresholds to set the epsilon parameter of SVR. The proposed method directly locates the right search field, which greatly saves computing time and achieves a stable, high accuracy. The method is more competitive for both SVC and SVR. It is easy to use and feasible for a new data set without any adjustments, since it requires no parameters to set.

关键词： Support vector machine (SVM) Rough line rule Parameter selection Linear search Motion prediction

Supermassive black holes triggered by QCD axion bubbles

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Communications in Theoretical Physics 2024年第5期76卷 134-139页

作者： hai-jun Li Ying-Quan Peng Wei Chao Yu-feng Zhou Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing/HangzhouChina

Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still *** this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QCD)axion *** this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QCD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after *** QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase *** consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))*** PBHs at this mass region may account for the seeds of SMBHs.

关键词： supermassive black holes primordial black holes quantum chromodynamics axion

The association between orthostatic blood pressure changes and subclinical target organ damage in subjects over 60 years old

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Journal of Geriatric Cardiology 2019年第5期16卷 387-394页

作者： Hong-Jie CHI hai-jun feng Xiao-Jiao CHEN Xiao-Tao ZHAO En-Xiang ZHANG Yi-Fan FAN Xian-Chen MENG Jiu-Chang ZHONG Shou-Ling WU jun CAI Heart Center&Beijing Key Laboratory of Hypertension Beijing Chaoyang HospitalCapital Medical UniversityBeijingChina Respiratory Department Beijing First Hospital of Integrated Chinese and Western MedicineBeijingChina Cardiology Department Beijing Liangxiang HospitalCapital Medical UniversityBeijingChina Department of Statistics Beijing Chaoyang HospitalCapital Medical UniversityBeijingChina Department of Cardiology Kailuan General HospitalHebei United UniversityTangshanChina Hypertension Center Fuwai HospitalState Key Laboratory of Cardiovascular Disease of ChinaNational Center for Cardiovascular Diseases of ChinaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Background Although recent studies have indicated that both orthostatic hypotension and orthostatic hypertension independently predict cardiovascular events,the underlying mechanisms are still *** aim of the study was to investigate the relationships between orthostatic changes and organ damage in subjects over 60 years *** This is a prospective observational cohort *** thousand nine hundred and ninety-seven subjects over 60 years old were *** were grouped according to whether they had a drop>20 mmHg in systolic or>10 mmHg in diastolic BP(orthostatic hypotension),an increase in mean orthostatic systolic blood pressure>20 mm Hg(orthostatic hypertension),or normal changes within 3 min of *** regression modeling was used to investigate the relationship between orthostatic hypotension,orthostatic hypertension and subclinical organ damage with adjustment for *** Orthostatic hypotension and orthostatic hypertension were found in 461(23.1%)and 189(9.5%)participants,*** of carotid intima-media thickness(IMT),brachial-ankle pulse wave velocity(baPWV),clearance of creatinine,and microalbuminuria were associated with orthostatic hypotension;measurement of IMT and baPWV were associated with orthostatic hypertension in a cruse *** adjustment,IMT[odds ratio(OR),95%confidence interval(CI)per one-SD increment:1.385,1.052-1.823;P=0.02],baPWV(OR=1.627,95%CI:1.041-2.544;P=0.033)and microalbuminuria(OR=1.401,95%CI:1.002-1.958;P=0.049)were still associated with orthostatic hypotension,while orthostatic hypertension was only associated with IMT(OR=1.730,95%CI:1.143-2.618;P=0.009).Conclusions Orthostatic hypotension seems to be independently correlated with increased carotid atherosclerosis,arterial stiffness and renal damage in subjects over 60 years *** hypertension correlates with carotid atherosclerosis only.

关键词： Atherosclerosis Blood pressure Orthostatic Organ damage

Caseinolytic mitochondrial matrix peptidase X is essential for homologous chromosome synapsis and recombination during meiosis of male mouse germ cells

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Asian Journal of Andrology 2024年第2期26卷 165-174页

作者： hai-Wei feng Yu Zhao Yan-Ling Gao Dong-Teng Liu Li-jun Huo Key Laboratory of Agricultural Animal Genetics Breeding and ReproductionEducation Ministry of ChinaCollege of Animal Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China Shenzhen Key Laboratory of Fertility Regulation Reproductive Medicine CenterThe University of Hong Kong-Shenzhen HospitalShenzhen 518053China Maternal-Fetal Medicine Institute Department of Obstetrics and GynaecologyShenzhen Baoan Women's and Children's HospitalJinan UniversityShenzhen 518100China Department of Obstetrics and Gynaecology Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong SARChina

Meiosis is the process of producing haploid gametes through a series of complex chromosomal events and the coordinated action of various *** mitochondrial protease complex(ClpXP),which consists of caseinolytic mitochondrial matrix peptidase X(ClpX)and caseinolytic protease P(ClpP)and mediates the degradation of misfolded,damaged,and oxidized proteins,is essential for maintaining mitochondrial *** has been implicated in meiosis regulation,but its precise role is currently *** this study,we engineered an inducible male germ cell-specific knockout caseinolytic mitochondrial matrix peptidase X(Clpx^(cKO))mouse model to investigate the function of ClpX in *** found that disrupting Clpx in male mice induced germ cell apoptosis and led to an absence of sperm in the ***,it caused asynapsis of homologous chromosomes and impaired meiotic recombination,resulting in meiotic arrest in the zygotene-to-pachytene transition *** loss of ClpX compromised the double-strand break(DSB)repair machinery by markedly reducing the recruitment of DNA repair protein RAD51 homolog 1(RAD51)to DSB *** dysfunction may be due to an insufficient supply of energy from the aberrant mitochondria in Clpx^(cKO) spermatocytes,as discerned by electron ***,ubiquitination signals on chromosomes and the expression of oxidative phosphorylation subunits were both significantly attenuated in Clpx^(cKO) *** together,we propose that ClpX is essential for maintaining mitochondrial protein homeostasis and ensuring homologous chromosome pairing,synapsis,and recombination in spermatocytes during meiotic prophase I.

关键词： ClpX homologous chromosome meiosis mitochondrial recombination synapsis

Recent Advances in Deciphering the Mechanisms and Biological Functions of DNA Demethylation

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Chinese Journal of Chemistry 2024年第6期42卷 645-651页

作者： Yang feng Sheng-jun Chen Bi-feng Yuan Key Laboratory of Aquatic Product Processing Ministry of Agriculture and Rural AffairsNational R&D Center for Aquatic Product ProcessingSouth China Sea Fisheries Research InstituteChinese Academy of Fishery SciencesGuangzhouGuangdong510300 China School of Public Health Research Center of Public HealthRenmin Hospital of Wuhan UniversityWuhan UniversityWuhanHubei430071 China

5-Methylcytosine (5mC) is a dynamic and reversible epigenetic modification in genomic DNA of higher *** has been well-established that the demethylation of 5mC occurs through the ten-eleven translocation (TET)-mediated oxidation of 5mC followed by thymine DNA glycosylase (TDG)-initiated base excision repair (BER).Recent findings also have identified an alternative pathway of DNA *** this pathway,TET enzymes directly oxidize 5mC to form 5-formylcytosine (5fC) or 5-carboxylcytosine (5caC).These modified bases can undergo direct deformylation or decarboxylation,***,DNA demethylation can also occur through the deamination of 5mC and 5hmC,resulting in the production of thymine and 5-hydroxymethyluracil (5hmU),*** DNA demethylation pathways possess critical functional implications and roles in biological *** Recent Advances article will focus on the studies of mechanisms and biological functions of DNA demethylation,shedding light on the reversible nature of the epigenetic modification of 5mC.

关键词： Epigenetics DNA DNA methylation 5-Methylcytosine Demethylation Mechanisms Biological functions C—C bond cleavage Mass spectrometry

Self-Triggered Set Stabilization of Boolean Control Networks and Its Applications

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1631-1642页

作者： Rong Zhao jun-e feng Dawei Zhang the School of Mathematics Shandong UniversityShandong UniversityJinan 250100China

Set stabilization is one of the essential problems in engineering systems, and self-triggered control(STC) can save the storage space for interactive information, and can be successfully applied in networked control systems with limited communication resources. In this study, the set stabilization problem and STC design of Boolean control networks are investigated via the semi-tensor product technique. On the one hand, the largest control invariant subset is calculated in terms of the strongly connected components of the state transition graph, by which a graph-theoretical condition for set stabilization is derived. On the other hand, a characteristic function is exploited to determine the triggering mechanism and feasible controls. Based on this, the minimum-time and minimum-triggering open-loop, state-feedback and output-feedback STCs for set stabilization are designed,respectively. As classic applications of self-triggered set stabilization, self-triggered synchronization, self-triggered output tracking and self-triggered output regulation are discussed as well. Additionally, several practical examples are given to illustrate the effectiveness of theoretical results.

关键词： Boolean control networks(BCNs) output regulation self-triggered control semi-tensor product of matrices set stabilization synchronization