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Potent in vitro Interference of Fleroxacin in DNA-binding,Unwinding and ATPase Activities of Bloom Helicase

Biomedical and Environmental Sciences 2013年第4期26卷 231-242页

作者： luo Heng xu Hou Qiang CHEN Xiang DING mei YANG Qi Xin LI Kun Key Laboratory of Animal Genetics Breeding and Reproduction in Plateau Mountainous RegionMinistry of EducationCollege of Animal ScienceGuizhou University Guizhou Key Laboratory of Animal Genetics Breeding and ReproductionCollege of Animal ScienceGuizhou University Provincial Key Laboratory for Agricultural Pest Management of Mountainous Region Guizhou University

Objective To study the effect of fleroxacin （FLRX） on biological properties of Bloom （BLM） helicase catalytic core （BLM 642-2290 helicase） in vitro and the molecular mechanism of interaction between the two molecules. Methods DNA-binding and unwinding activities of BLM 642-1290 helicase were assayed by fluorescence polarization and gel retardation assay under conditions that the helicase was subjected to different concentrations of FLRX. Effect of FLRX on helicase ATPase activity was analyzed by phosphorus-free assay based on a colorimetric estimation of ATP hydrolysis-produced inorganic phosphate. Molecular mechanism of interaction between the two molecules was assayed by ultraviolet and fluorescence spectra. Results The DNA unwinding and ATPase activities of BLM 642-1290 helicase were inhibited whereas the DNA-binding activity was promoted in vitro. A BLM-FLRX complex was formed through one binding site, electrostatic and hydrophobic interaction force. Moreover, the intrinsic fluorescence of the helicase was quenched by FLRX as a result of non-radioactive energy transfer. The biological activity of helicase was affected by FLRX, which may be through an allosteric mechanism and stabilization of enzyme conformation in low helicase activity state, disruption of the coupling of ATP hydrolysis to unwinding, and blocking helicase translocation on DNA strands. Conclusion FLRX may affect the biological activities and conformation of BLM 642-1290 helicase, and DNA helicase may be used as a promising drug target for some diseases.

关键词： Biological activity BLM helicase Fleroxacin Interaction mechanism

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Planning and Control for Passive Dynamics Based Walking of 3D Biped Robots

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Journal of Bionic Engineering 2012年第2期9卷 143-155页

作者： Xiang luo Wenlong xu School of Mechanical Engineering Southeast UniversityNanjing 211189P.R.China

Efficient walking is one of the main goals of research on biped robots. Passive Dynamics Based Walking （PDBW） has been proven to be an efficient pattern in numerous previous approaches to 2D biped walking. The goal of this study is to develop feasible method for the application of PDBW to 3D robots. First a hybrid control method is presented, where a previously proposed two-point-foot walking pattern is employed to generate a PDBW gait in the sagittal plane and, in the frontal plane, a systematic balance control algorithm is applied including online planning of the landing point of the swing leg and feedback control of the stance foot. Then a multi-space planning structure is proposed to implement the proposed method on a 13-link 3D robot. Related kinematics and planning details of the robot are presented. Furthermore, a simulation of the 13-link biped robot verifies that stable and highly efficient walking can be achieved by the proposed control method. In addition, a number of features of the biped walking, including the transient powers and torques of the joints are explored.

关键词： 3D biped robot passive dynamics based walking balance control multi-space planning simulation

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Moderate Deviation for the Single Point Catalytic Super-Brownian Motion

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Acta Mathematica Sinica,English Series 2012年第9期28卷 1799-1808页

作者： xu YANG mei ZHANG School of Mathematical Sciences Beijing Normal University

We establish the moderate deviation for the density process of the single point catalytic super-Brownian motion. The main tools are the abstract Gaertner-Ellis theorem, Dawson-Gaertner the- orem and the contraction principle. The rate function is expressed by the Fenchel-Legendre transform of log-exponential moment generation function.

关键词： Super-Brownian motion catalytic conditional log-Laplace functional locally uniform moderate deviation

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Advances in cryoablation for pancreatic cancer

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World Journal of Gastroenterology 2016年第2期22卷 790-800页

作者： Xiao-mei luo Li-Zhi Niu Ji-Bing Chen Ke-Cheng xu Medical College Jinan University Guangzhou Fuda Cancer Hospital School of Medicine Jinan University

Pancreatic carcinoma is a common cancer of the digestive system with a poor prognosis. It is characterized by insidious onset, rapid progression, a high degree of malignancy and early metastasis. Atpresent, radical surgery is considered the only curative option for treatment, however, the majority of patients with pancreatic cancer are diagnosed too late to undergo surgery. The sensitivity of pancreatic cancer to chemotherapy or radiotherapy is also poor. As a result, there is no standard treatment for patients with advanced pancreatic cancer. Cryoablation is generally considered to be an effective palliative treatment for pancreatic cancer. It has the advantages of minimal invasion and improved targeting, and is potentially safe with less pain to the patients. It is especially suitable in patients with unresectable pancreatic cancer. However, our initial findings suggest that cryotherapy combined with 125-iodine seed implantation, immunotherapy or various other treatments for advanced pancreatic cancer can improve survival in patients with unresectable or metastatic pancreatic cancer. Although these findings require further in-depth study, the initial results are encouraging. This paper reviews the safety and efficacy of cryoablation, including combined approaches, in the treatment of pancreatic cancer.

关键词： Pancreatic cancer Cryoablation Combinationtherapy Cryoimmunotherapy

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Retrospective analysis of pathological types and imaging features in pancreatic cancer: A comprehensive study

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World Journal of Gastrointestinal Oncology 2025年第1期17卷 121-129页

作者： Yang-Gang luo mei Wu Hong-Guang Chen Pathology Department Xuanhan County People’s HospitalDazhou 636150Sichuan ProvinceChina

BACKGROUND Pancreatic cancer remains one of the most lethal malignancies worldwide,with a poor prognosis often attributed to late *** the correlation between pathological type and imaging features is crucial for early detection and appropriate treatment *** To retrospectively analyze the relationship between different pathological types of pancreatic cancer and their corresponding imaging *** We retrospectively analyzed the data of 500 patients diagnosed with pancreatic cancer between January 2010 and December 2020 at our *** types were determined by histopathological examination of the surgical spe-cimens or biopsy *** imaging features were assessed using computed tomography,magnetic resonance imaging,and endoscopic *** analyses were performed to identify significant associations between pathological types and specific imaging *** There were 320(64%)cases of pancreatic ductal adenocarcinoma,75(15%)of intraductal papillary mucinous neoplasms,50(10%)of neuroendocrine tumors,and 55(11%)of other rare *** imaging features were identified in each pathological *** ductal adenocarcinoma typically presents as a hypodense mass with poorly defined borders on computed tomography,whereas intraductal papillary mucinous neoplasms present as characteristic cystic lesions with mural *** tumors often appear as hypervascular lesions in contrast-enhanced *** analysis revealed significant correlations between specific imaging features and pathological types(P<0.001).CONCLUSION This study demonstrated a strong association between the pathological types of pancreatic cancer and imaging *** findings can enhance the accuracy of noninvasive diagnosis and guide personalized treatment approaches.

关键词： Pancreatic cancer Pathological types Imaging features Retrospective analysis Diagnostic accuracy

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Largest 3d-4f 196-nuclear Gd_(158)Co_(38)clusters with excellent magnetic cooling

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Science China Chemistry 2022年第8期65卷 1577-1583页

作者： Ning-Fang Li Xi-Ming luo Jia Wang Ji-Lei Wang Hua mei You Song Yan xu College of Chemical Engineering State Key Laboratory of Materials-Oriented Chemical EngineeringNanjing Tech UniversityNanjing 210009China Coordination Chemistry Institute State Key Laboratory of Coordination ChemistryNanjing UniversityNanjing 210093China

It is a meaningful and challenging work for structural and synthetic chemists to isolate nano-sized high-nuclearity *** this work,two largest hetero-metallic nano-clusters Gd_(158)Co_(38) were obtained via the“multi-anions-template”*** from the reported giant hollow-nano-clusters,the Ln_(158) core in Gd_(158)Co_(38)(the protein-sized nano-clusters,ca.4.3 nm×3.6 nm×3.5 nm)has the highest Ln nuclear number,which is integrated by twelve halide ions(with the form of icosahedron)as key templates,while Co ions(as 3d metals)are located in its *** emergence indicates a novel structure form of non-open Ln-containing high-nuclearity clusters,and affords a consummate pattern to analyse and assemble the complex *** addition,Gd_(158)Co_(38)@Cl_(12)breaks the record magnetic entropy change of 3d-4f clusters with−∆S_(m)^(max)=46.95 J kg^(−1)K^(−1)at 7.0 T,2.0 K.

关键词： multi-anions template high-nuclearity 3d-4f cluster magnetic refrigeration

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Multi-Attribute Preferences Mining Method for Group Users with the Process of Noise Reduction

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Journal of Computer Science & Technology 2021年第4期36卷 944-960页

作者： Qing-mei Tan xu-Na Wang College of Economic and Management Nanjing University of Aeronautics and AstronauticsNanjing 211106China Research Base for Civilian-Military Integration Development in Jiangsu Province Nanjing 211106China

Traditional researches on user preferences mining mainly explore the user’s overall preferences on the project,but ignore that the fundamental motivation of user preferences comes from their attitudes on some attributes of the *** addition,traditional researches seldom consider the typical preferences combination of group users,which may have influence on the personalized service for group *** solve this problem,a method with noise reduction for group user preferences mining is proposed,which focuses on mining the multi-attribute preference tendency of group ***,both the availability of data and the noise interference on preferences mining are considered in the algorithm *** the process of generating group user preferences,a new path is used to generate preference keywords so as to reduce the noise ***,the Gibbs sampling algorithm is used to estimate the parameters of the ***,using the user comment data of several online shopping websites as experimental objects,the method is used to mine the multi-attribute preferences of different *** proposed method is compared with other methods from three aspects of predictive ability,preference mining ability and preference topic *** results show that the method is significantly better thap other existing methods.

关键词： preferences mining group user multi-attribute noise reduction noise interference

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Pyrite-hydrocarbon Interaction under Hydrothermal Conditions: an Alternative Origin of H_2S and Organic Sulfur Compounds in Sedimentary Environments

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Acta Geologica Sinica(English Edition) 2016年第6期90卷 2133-2148页

作者： DING Kangle mei Ping luo Yue Key Laboratory of Exploration Technologies for Oil and Gas Resources of Ministry of Education Yangtze University State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum School of Chemistry and Environmental Engineering Yangtze University

Sulfate rocks and organic sulfur from sedimentary organic matter are conventionally assumed as the original sulfur sources for hydrogen sulfide （H2S） in oil and gas reservoirs. However, a few recent experiments preliminarily indicate that the association of pyrite and hydrocarbons may also have implications for H2S generation, in which water effects and natural controls on the evolution of pyrite sulfur into OSCs and H2S have not been evaluated. In this study, laboratory experiments were conducted from 200 to 450°C to investigate chemical interactions between pyrite and hydrocarbons under hydrothermal conditions. Based on the experimental results, preliminary mechanism and geochemical implications were tentatively discussed. Results of the experiments showed that decomposition of pyrite produced H2S and thiophenes at as low as 330°C in the presence of water and n-pentane. High concentrations of H2S were generated above 450°C under closed pyrolysis conditions no matter whether there is water in the designed experiments. However, much more organic sulfur compounds （OSCs） were formed in the hydrous pyrolysis than in anhydrous pyrolysis. Generally, most of sulfur liberated from pyrite at elevated temperatures was converted to H2S. Water was beneficial to breakdown of pyrite and to decomposition of alkanes into olefins but not essential to formation of large amounts of H2S, given the main hydrogen source derived from hydrocarbons. In addition, cracking of pyrite in the presence of 1-octene under hydrous conditions was found to proceed at 200°C, producing thiols and alkyl sulfides. Unsaturated hydrocarbons would be more reactive intermediates involved in the breakdown of pyrite than alkanes. The geochemistry of OSCs is actually controlled by various geochemical factors such as thermal maturity and the carbon chain length of the alkanes. This study indicates that the scale of H2S gas generated in deep buried carbonate reservoirs via interactions between pyrite and natural

关键词： laboratory experiments pyrite hydrocarbon H2S OSCs geochemical implications

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Synthesis and anti-integrase evaluation of novel calix[4]arene derivatives containing the triazolyl 1,3-diketo moiety

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Chinese Chemical Letters 2014年第5期25卷 737-740页

作者： Zai-Gang luo Yu Zhao Chao Ma xue-mei xu Xiao-mei Zhang Nian-Yu Huang Hong-Qiu He College of Chemical Engineering Anhui University of Science & Technology College of Chemistry and Life Sciences China Three Gorges University Chongqing Center for Biomedicines and Medical Equipment Chongqing Academy of Science and Technology

A series of novel calix[4]arene derivatives incorporating two triazolyl 1 3-diketo subunits in alternate positions at the lower rim were synthesized and screened for HⅣ integrase inhibition *** chemical structures of these compounds were confirmed by means of1H NMR 13C NMR,and *** bioassays indicated that calix[4]arene derivatives proved to be more active than p-tertbutylcalix[4]arene *** particular,compound 4g presented the most potent integrase strand transfer inhibitory activity with an IC50value of 6.1 mmol/L.

关键词： HIV-1 integrase inhibitor Calixarene derivative 1 2 3-Triazole 1 3-Diketo Strand transfer

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Distribution pattern of pelagic amphipods and its affecting facors in the East China Sea

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Acta Oceanologica Sinica 2006年第5期25卷 112-119页

作者： xu Zhaoli JIANG mei Key and Open Laboratory of Marine and Estuary Fisheries of Ministry of Agriculture East China Sea Fisheries Research Insti-tute Chinese Academy of Fisheries Sciences Shanghai 200090 China

On the basis of data from four seasonal cruises in the East China Sea （23°30′-33°N, 118°30′-128°E） from 1997 to 2000, horizontal distribution of amphipods, seasonal variations of abundance and their dynamic mechanisms were approached with quantitative and qualitative methods. Results showed that the average value of amphipod abundance in autumn was 115× 10^-2 ind./m^3, the highest in four seasons. The second occurred in summer with a mean value of 44×10^-2 ind./m^3and the lowest occurred in spring with a mean of 10 × 10^-2 ind./m^3. Amphipods were hardly observed in the north nearshore （ 29° 30′- 33° N and 122°30′- 125°E） in winter and spring. In all seasons, except for the north of the sea in autumn and the south in summer, the abundance in the offshore area was higher than that nearshore. The major species influencing the amphipod abundance were Lestrigonus schizogeneios in spring, L. macrophthalmus and L schizogeneios in summer,L bengalensis and Hyperioides sibaginis in autumn and Gammarus sp. in winter. The amphiped abundance showed a prominent linear correlation with the surface water temperature, but no significant correlation with both other water temperatures and salinity in spring. It was found that water temperature and salinity were not significantly correlated with the variation of amphiped abundance in summer, autumn and winter. In addition, the amphiped abundance in all four seasons can be linearly correlated with the bottom water temperature. The highest abundance area was located in the mixture waters near the side of warm water current in summer. Peak of amphiped abundance in autumn, not in summer told a temporal process for amphipeds to develop their populations. The continuance of warm current was beneficial to the development of amphipod abundance from summer to autumn. Amphipeds are kinds of very important diets for fishes in the offshore East China Sea.

关键词： East China Sea zooplankton pelagic amphipods abundance distribution

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