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Spatial distribution features of sequence types of moderate and strong earthquake in Chinese mainland 被引量:5
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作者 蒋海昆 李永莉 +4 位作者 曲延军 华爱军 郑建常 代磊 侯海峰 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2006年第4期417-427,共11页
Based on 294 earthquake sequences with magnitude greater than or equal to 5.0 occurred in Chinese mainland since 1970, the spatial distribution features of sequence types have been studied. In southwestern China, it t... Based on 294 earthquake sequences with magnitude greater than or equal to 5.0 occurred in Chinese mainland since 1970, the spatial distribution features of sequence types have been studied. In southwestern China, it takes mainshock-aftershock sequence type (MAT) as the major in Chuan-Dian rhombic block and concerned Xianshuihe-Anninghe-Xiaojiang seismic belt, as well as in Jinshajiang-Honghe seismic belt. Multiple mainshock type (MMT) mainly distributes in western Yunnan, and Longlin and Lancang areas in Tengchong-Baoshan block in west of Nujiang-Lancangjiang fault zone. A few isolated earthquake type (IET) mainly occurred in northwestern Sichuan and there is no IET occurred in Yunnan region. In northwestern China, it takes mainshock-aftershock sequence type (MAT) as the major in west segment of South Tianshan in Xinjiang region. Some MMT also occurred in this area in the intersection of Kalpin block and the Puchang fault zone. It takes IET as the major in middle Tianshan in Xinjiang. Along the Qilianshan seismic belt, most of sequences are MAT. In Qinghai region, it takes MAT as the major, but the regional feature of the spatial distribution of sequence types is not very clear. In North China, it takes MAT as the major in Yinshan-Yanshan-Bohai seismic belt, north edge of North China, and in Hebei plain seismic belt, as well as in sub-plate of lower river area of Yangtze River. In intersection of north segment of Shanxi seismic belt and the NW-trending Yinshan-Yanshan-Bohai seismic belt, there are several moderate or strong MMT with magnitude from 5.0 to 6.0 occurred. In south of North China around the latitude line of 35°N, it takes IET as the major. The spatial distribution of sequence types is relevant to the patterns of tectonic movements. MAT is mostly produced by the ruptures of locked units or asperities or the neonatal separating segments inside the fault zones. MMT is generally relevant to the conjugate structures or intersection of many tectonic settings. Further extension of simple fault often produces IET. Spatial distribution of sequence types is also correlative to the regional and deep environment of crustal medium to some extent. MAT mainly distributes in high velocity area in upper crust or in the transition zone between high velocity area and low velocity area, MMT mostly occurred in the low velocity area in upper crust. 展开更多
关键词 spatial distribution of sequence types isolated earthquake malnshock-aftershock sequence multi-ple malnshock type patterns of tectonic movement medium environment in depth of the earth
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Sequence Types and Textual Production Teaching
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作者 Gisele Gomes Guedes Xella Ohana da Cunha do Nascimento 《Sino-US English Teaching》 2016年第10期783-791,共9页
Currently, Portuguese teaching prioritizes the study of text sequence types and genres. All the didactic material and activity in the classroom are guided by this study. Because the narrative text type is one of the f... Currently, Portuguese teaching prioritizes the study of text sequence types and genres. All the didactic material and activity in the classroom are guided by this study. Because the narrative text type is one of the first which the student has contact with, it will be the focus of this work. This article aims to present a didactic sequence along the lines of Dolz, Noverraz, and Schneuwly (2004), using the fable and tale genres in order to contribute to the development and appropriation, by the students, of the structural and linguistic characteristics of these genres and the type that makes it up. This sequence of activities is fundamental to work with text production, as it greatly contributes to the writing teaching. 展开更多
关键词 sequence types text genres WRITING
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Legionella from Environmental and Clinical Homes for the Mentally Disabled and Comparison of Their Sequence Types
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作者 Annalisa Bianchi Marina Tesauro Michela Consonni Fabrizio Pregliasco Maria Gabriella Galli 《Journal of Life Sciences》 2011年第1期53-58,共6页
In this study the authors compared the sequence types (STs) designed by sequence based typing (SBT) of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 (LP1) which were isolated from... In this study the authors compared the sequence types (STs) designed by sequence based typing (SBT) of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 (LP1) which were isolated from hospital facilities for the mentally disabled. The strains were selected after a retrospective surveillance of 565 clinical records (2002-2009) and investigations of water circuit. It was possible to correlate two clinical strains with the corresponding environment, which were collected from showers that had exposed the patients (ST685, ST16) and two clinical strains present in the same structure (STI). The other environmental strains were isolated from water in the department with confirmed or suspected clinical cases. All the strains (seven) from the first structure had ST188; two from the second structure had ST34; and the last from the third structure, gave an ST694. The results were compared with the European Working Group for Legionella Infections (EWGLI) database: the ST 1, 16, 34 and 188 were already known in literature, among clinical and nosocomial cases, especially for ST 1, the most distributed worldwide. Two STs were new to the database. ST685 was isolated both from a patient and from the water; ST694, which was found exclusively in the environmental compartment of a control structure (no cases of legionellosis and low number of nosocomial pneumonia), was unknown in the literature and the authors could only speculate on its possible minor virulence and/or distribution. The implementation of SBT and international comparisons may be useful to gain genotypic knowledge of circulating environmental strains, also verifying their presence in the clinical setting. 展开更多
关键词 Legionella pneumophila GENOTYPING sequence based typing nosocomial infections.
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Emergence of Klebsiella pneumoniae carbapenemase-producing Escherichia coli sequence type 131 in Hangzhou, China 被引量:1
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作者 Lou Zhengqing Qi Yan +2 位作者 Qian Xiang Yang Wei Wei Zeqing 《Chinese Medical Journal》 SCIE CAS CSCD 2014年第3期528-531,共4页
Background Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia (E.) coil has been reported in China since 2008.However,there is no information about the molecular epidemiology of KPC-producing E.coil i... Background Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia (E.) coil has been reported in China since 2008.However,there is no information about the molecular epidemiology of KPC-producing E.coil in China.In this study,we aimed to investigate the sequence type (ST) and characteristics of KPC-producing E.coil isolates in China.Methods Three carbapenem-resistant isolates of E.coil (E1,E2,and E3) from one teaching hospital in Hangzhou covering a one year period were analyzed.Antibiotic susceptibility was determined by Etest.Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used for epidemiological analysis.The genetic structure around blaKPC,the major plasmid incompatibility typing,and the identification of 3-lactamase gene types were performed by PCR and the positive products were subsequently sequenced.Plasmids were analyzed by transformation,restriction,and Southern blotting.Results PFGE demonstrated that patterns of isolates E1 and E2 were clonally-related and designated as patterns A1 and A2; pattern of isolate E3 was different and designated as pattern B.MLST analysis showed that the three isolates displayed one common sequence type ST131.The identification of bla gene types by PCR and sequencing showed that blaKPC-2,blaCTX-M-14,and blaTEM-1 were detected in all three isolates.All three isolates carried a KPC-2-encoding plasmid of the IncN replicon.Plasmid analysis and hybridization experiments showed that the isolates were found simultaneously to carry two or four plasmids.The blaKPc-2 gene in E1 and E2 was located in a plasmid with size of ca.50 kb.However,the blaKPC-2 gene in E3 was located in a plasmid with size of ca.130 kb.Conclusions E.coil ST131 with KPC-2 β-1actamase has emerged in China,which enlarges the geographical area where the ST131 KPC-oroducing E.coil strains have diffused. 展开更多
关键词 Klebsiella pneumoniae carbapenemase Escherichia coli sequence type
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ISHIKAWA TYPE ITERATIVE SEQUENCES WITH ERRORS FOR LIPSCHITZIAN φ-STRONGLY ACCRETIVE OPERATOR EQUATIONS IN ARBITRARY BANACH SPACES 被引量:2
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作者 曾六川 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2002年第1期25-33,共9页
In this paper, we investigate the problem of approximating solutions of the equations of Lipschitzian ψ-strongly accretive operators and fixed points of Lipschitzian ψ-hemicontractive operators by lshikawa type iter... In this paper, we investigate the problem of approximating solutions of the equations of Lipschitzian ψ-strongly accretive operators and fixed points of Lipschitzian ψ-hemicontractive operators by lshikawa type iterative sequences with errors. Our results unify, improve and extend the results obtained previously by several authors including Li and Liu (Acta Math. Sinica 41 (4)(1998), 845-850), and Osilike (Nonlinear Anal. TMA, 36(1)(1999), 1-9), and also answer completely the open problems mentioned by Chidume (J. Math. Anal. Appl. 151 (2)(1990), 453-461). 展开更多
关键词 φ-strongly accretive operator φ-hemicontractive operator Ishikawa type iterative sequences with errors
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Complet enucleotide sequence analyses of provirus gene of human T-lymphotropic virus TypeⅠfrom an inhabitant of shaotou region in southeast China
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《中国输血杂志》 CAS CSCD 2001年第S1期337-,共1页
关键词 from an inhabitant of shaotou region in southeast China gene Complet enucleotide sequence analyses of provirus gene of human T-lymphotropic virus type
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Characteristics of the May 12,2008 Wenchuan M_S8.0 Earthquake Sequence and Discussion on Relevant Problems 被引量:1
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作者 Jiang Haikun Li Mingxiao Wu Qiong Song Jin 《Earthquake Research in China》 2009年第1期34-47,共14页
The aftershock activity of the May 12, 2008 Wenchuan Ms8.0 Earthquake Sequence shows an obvious segmented feature. Most of the large aftershocks were distributed in the north and south parts of the aftershock zone. Th... The aftershock activity of the May 12, 2008 Wenchuan Ms8.0 Earthquake Sequence shows an obvious segmented feature. Most of the large aftershocks were distributed in the north and south parts of the aftershock zone. Thrusting was dominant with a small amount of strike-slip component in the south part. The aftershock activity decayed gradually, presenting the sequence features of a mainshock-aftershock pattern. The north part was the ending area of the malnshock fracture where strike-slipping was dominant, showing an obvious swarm feature. Therefore it became the major area for large aftershocks. The modulation of the earth tide on aftershock activity is remarkable; most large aftershocks occur during the period of flood and neap tide. The time period around 16:00 was the dominant occurring time for large aftershocks. The p-value, a parameter of modified Omori formula, increases gradually with time, and reaches about 1 at the end. Based on previous study, the sequence patterns, magnitude of maximum aftershock, as well as the duration of aftershock activity has been discussed. The primary results also show that the magnitude difference between the maiushock and the maximum aftershock is proportional to the rupture size of the maiushock for huge earthquakes of about Ms8.0. This means that when the magnitudes of the earthquakes are nearly the same, large rupture size corresponds to sufficient energy release. 展开更多
关键词 May 12 2008 Wenchuan earthquake with Ms8.0 Segmentation features sequence type Magnitude of maximum aftershock Duration of aftershock activity Rupture size
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Method discussion for quick response grey prediction of stronger aftershocks of an earthquake sequence
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作者 平建军 李永庆 张清荣 《Acta Seismologica Sinica(English Edition)》 CSCD 1999年第1期78-83,共6页
In this paper, we take occurrence process of early strong aftershocks of a main after shock type′s earthquake sequence as a complex grey system, and introduce predicting method for its stronger aftershocks by grey p... In this paper, we take occurrence process of early strong aftershocks of a main after shock type′s earthquake sequence as a complex grey system, and introduce predicting method for its stronger aftershocks by grey predicting theory. Through inspection prediction for 1998 Zhangbei M S=6.2 earthquake sequence, it shows that the grey predicting method maybe has active significance for the investigation of quick response prediction problems of stronger aftershocks of an earthquake sequence. 展开更多
关键词 MAIN after shock type′s earthquake sequence stronger aftershock grey prediction
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The age measures and its layer sequence tratigraphy of Late Quaternary sediment in Lushan Dajiaochang of China
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作者 Hu Dongsheng Hu Rong +5 位作者 Li Xiaoyu Hu Wenxuan Wang Xulong Tian Xingong Liu Weiguo Zhang Guowei 《Engineering Sciences》 EI 2013年第6期48-57,共10页
Through the scientific investigation on Lushan for a long time, detailed studies have been carried out on the geologic stratum section of Late Quaternary in Dajiaochang. The series age data of complete stratigraphic s... Through the scientific investigation on Lushan for a long time, detailed studies have been carried out on the geologic stratum section of Late Quaternary in Dajiaochang. The series age data of complete stratigraphic section and full time formation since 400 kaBP were based on the results of the analyses using the dating methods with various instruments such as the ancient geomagnetism, electronics spin resonance (ESR), 36C1 and lumines- cence dating, etc. Corresponding to these data, it identified the paleomagnetic polarity events including Biwa- III event (320 kaBP), Biwa- 1I event (260 kaBP), Biwa- I event (180 kaBP, scarcity due to the disturbance of the iron dish), Blake event (100 kaBP) and Laschamp event (20 kaBP, didn't grow due to the activities of the surface), etc. Combined with the sequence stratigraphy, layer type characteristics and its sediment environment, the strati- graphic can be divided into 4 stages of development respectively : Stage [ is the climate period of glacial epoch (200-400 kaBP); stage 11 is the climate period of interglacial epoch (100-200 kaBP); stage llI is the climate peri- od of periglacial epoch (10-100 kaBP); stage IV is the climate period ofpostglacial epoch (0-10 kaBP). 展开更多
关键词 sediment of Late Quaternary various instrument dating data layer type sequence and integrated ages Dajiaochang area of Lushan
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ST of Streptococcus pneumonia Circulating in Burkina Faso before the Introduction of PCV-13, 2013
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作者 Kambiré Dinanibè Tamboura Mamadou +14 位作者 Ouédraogo Oumarou Tondé Issa Ouédraogo W. H. Gautier Sanou Mahamoudou Zouré Abdou Azaque Compaoré Rebeca Sagna Tani Soubeiga R. S. Théophile Zida Sylvie Aké Flavien Abdoul-Salam Ouédraogo Sangaré Lassana Méda Isaïe Kouanda Séni Ouédraogo-Traoré Rasmata 《Advances in Microbiology》 CAS 2023年第5期237-248,共12页
Introduction: Burkina Faso experiences regular cases of Streptococcus pneumoniae meningitis. As part of the strategy to reduce cases of meningitis, the 13-valent pneumococcal conjugate vaccine (PCV-13) has been introd... Introduction: Burkina Faso experiences regular cases of Streptococcus pneumoniae meningitis. As part of the strategy to reduce cases of meningitis, the 13-valent pneumococcal conjugate vaccine (PCV-13) has been introduced in the Expanded Programme on Immunisation (EPI). Despite these efforts, there are some cases of pneumococcal meningitis including both vaccine and non-vaccine serotypes. The objective of this study was to describe the pneumococcal sequence types (ST) circulating in Burkina Faso before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV-13). Methods: It was a descriptive cross-sectional study that took place from 27th October 2013 to 7th January 2014. S. pneumoniae strains were collected in Burkina Faso and Multi Locus Sequence Typing (MLST) was performed at the Pneumococcal Laboratory at the Centers for Disease Control and Prevention (CDC) in the USA (United States of America). MLST consists of 4 steps: amplification, purification, sequencing and interpretative reading of the results. The amplification used 7 primers consisting of sequences of aroe, gdh, gki, recP, spi, xpt, ddl genes. Results: Of 37 strains tested, 10 serotypes were identified. Serotype 1 was prevalent in 48.7% (18/37) followed by serotype 25F in 10.8% (4/37). Serotypes 5 and 12F/12A/12B/44/46 were 8.1% (3/37) each. Serotype 1 contained 5 STs including ST303 24.3% (9/37), ST217 8.1% (3/37) and ST618 8.1% (3/37);followed by serotype 25F with ST105 10.8% (4/37), serotype 5 with ST289 8.1% (3/37) and serogroup 12F/12A/12B/44/46 with ST 989 8.1% (3/37). Conclusion: Pneumococci are characterised by their great variability both in number of serotypes and in ST within the same serotype. Thus, 10 serotypes have been identified. Also, within serotype 1, 5 different STs have been described. These data indicate the complexity of the pneumococcus which is strongly involved in purulent bacterial meningitis at national level. This requires continuous surveillance of pneumococcal meningitis through laboratory capacity building. 展开更多
关键词 Streptococcus pneumoniae Burkina Faso PCV-13 sequence types
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Disease burden,antimicrobial resistance and molecular characterization of invasive group B Streptococcus among non-pregnant adults in Malaysia:A protocol study
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作者 Abdulrahman Muthanna Nurul Hana Zainal Baharin +3 位作者 Mohd Nasir Mohd Desa Nurul Diana Dzaraly Mohammad Noor Amal Azmai Syafinaz Amin-Nordin 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2023年第11期498-505,共8页
and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study i... and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study is conducted in the selected hospitals with similar approaches.GBS isolates are subjected to phenotyping,serotyping by multiplex PCR,antimicrobial susceptibility testing and PCR-detection of GBS virulence and pilus genes.Seven housekeeping genes are amplified and sequenced for multi-locus sequence typing.Discussion:Findings from the study may contribute to the management of clinical practice to diagnose and prevent GBS related diseases in a timely manner.Prudent use of antibiotics is encouraged by monitoring antimicrobial resistance. 展开更多
关键词 Group B Streptococcus Incidence SEROtype Antimicrobial resistance Virulence gene Multi-locus sequence typing
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Antimicrobial resistance and molecular typing of Salmonella in the chicken production chain in Hubei Province, China
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作者 Cuirong Wu Lihui Liu +6 位作者 Yuxin Sui Lulu Huang Yang Chen Haihong Hao Yuanhu Pan Zhenli Liu Guyue Cheng 《Animal Diseases》 CAS 2023年第3期188-201,共14页
Salmonella is a significant foodborne zoonotic pathogen that endangers both human and animal health.The goal of this research is to gain a preliminary understanding of Salmonella contamination and antimicrobial resist... Salmonella is a significant foodborne zoonotic pathogen that endangers both human and animal health.The goal of this research is to gain a preliminary understanding of Salmonella contamination and antimicrobial resistance in the chicken production chain in Hubei Province,China.1149 animal and environmental samples were collected from chicken farms,slaughterhouses,and retail markets in six cities across Hubei Province in China from 2019 to 2020,yielding Salmonella isolation rates of 4.68%(28/598),12.21%(47/385),and 9.64%(16/166),respectively.Seventeen distinct serotypes were detected among 53 non-clonal Salmonella strains,of which Meleagridis(26.42%,14/53)was the dominant serotype.Almost half of the strains(49.06%,26/53)were multi-drug resistant(MDR).Whole-genome sequencing(WGS)showed that 10 resistance genes(tetA,bla_(TEM),parC,qnrs1,floR,aac(6'-ly,aph(6)-ld,aph(3")-b,aac(6')-laa and sul2)and 7 categories of virulence genes were present in all three links in 22 non-clonal dominant serotype strains.It was shown that Salmonella in the chicken production chain in Hubei Province had a high resist-ance rate to Tetracycline(TET,73.58%),Ofloxacin(OFL,69.81%),Florfenicol(FFC,60.38%)and Ampicillin(AMP,39.62%)which was consistent with the widespread use of these drugs in the husbandry industry in China.Salmonella ST types determined by MLST and serotypes determined by WGS had a one-to-one correlation.Minimum spanning tree analysis revealed that there was cross contamination of Salmonella in farms and slaughterhouses,slaughterhouses and markets,animal samples and environmental samples.This work provides useful information for the prevention and control of contamination and antimicrobial resistance of Salmonella in the chicken production chain,as well as demonstrating the dependable role of WGS in Salmonella molecular typing. 展开更多
关键词 SALMONELLA SEROtype Antimicrobial resistance Multi-locus sequence typing Whole genome sequencing
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Alcohol dehydrogenase coexisted solid-state electrochemiluminescence biosensor for detection of p53 gene 被引量:1
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作者 王晓英 王晓宁 +4 位作者 张相依 陈奋天 朱柯蕙 杨立刚 唐萌 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期145-151,共7页
An alcohol dehydrogenase (ADH)-coexisted solidstate electrochemiluminescence (ECL) biosensor for sensitive detection of the p53 gene was developed. The electrode modified by multiwalled carbon nanotubes, Ru(bpy... An alcohol dehydrogenase (ADH)-coexisted solidstate electrochemiluminescence (ECL) biosensor for sensitive detection of the p53 gene was developed. The electrode modified by multiwalled carbon nanotubes, Ru(bpy)]2+3 and polypyrrole ( MWNTs-Ru (bpy) ]2+3 -PPy ) was prepared to adsorb the ssDNA by electrostatic interactions. Then, the ssDNA recognized the gold nanoparticles (AuNPs)-labeled p53 gene and produced the AuNPs-dsDNA electrode with the AuNPs layer. The AuNPs layer adsorbed the ADH molecules for producing the ECL signal. Thus, the biosensor was based on coupling enzyme substrate reaction with solid-state ECL detection, and it displayed good sensitivity and specificity. The detection limit of the wild type p53 sequence (wtp53) is as low as 0. 1 pmol/L and the discrimination is up to 57. 1% between the wtp53 and the muted type p53 sequence (mtp53). The amenability of this method to the analyses of p53 from normal and cancer cell lysates is demonstrated. The signal of wtp53 in the MGC-803 gastric cancer cell lysates turns out to be about 61.8% that of the wtp53 in the GES-1 normal gastric mucosal cell lysates, and the concentration of the wtp53 is found to decrease about 59 times. The method is highly complementary to enzyme-linked immunosorbent assay (ELISA), and it holds promise for the diagnosis and management of cancer. 展开更多
关键词 MWNTs-Ru bpy )2+3 composite solid-stateelectrochemiluminescence alcohol dehydrogenase wild typep53 sequence muted type p53 sequence cell lysates
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On the Characteristics of the Convergence of Ishikawa Type Iterative Sequences for Strong Pseudocontractions and Strongly Accretive Operators
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作者 曾六川 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2003年第3期403-409,共7页
In this paper, the results characterize the convergence of Ishikawa type iterative sequences (with errors) for constructing the solutions of strongly accretive operator equations, the solutions of rn-accretive operato... In this paper, the results characterize the convergence of Ishikawa type iterative sequences (with errors) for constructing the solutions of strongly accretive operator equations, the solutions of rn-accretive operator equations, and the fixed points of strong pseudocontractions. These results extend and improve Theorems 1-3 of Chidume and Osilike (Nonlinear Anal. TMA, 1999, 36(7): 863-872). 展开更多
关键词 Ishikawa type iterative sequences strong pseudocontractions strongly accretive operators arbitrary Banach spaces.
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Characteristics of colistin-resistant Escherichia coli from pig farms in Central China
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作者 Zhong Peng Xiaoxue Zhang +7 位作者 Xiaosong Li Zizhe Hu Zugang Li Chaoying Jia Menghong Dai Chen Tan Huanchun Chen Xiangru Wang 《Animal Diseases》 2021年第2期84-94,共11页
The emergence and dissemination of colistin resistance in Enterobacterioceae mediated by plasmid-borne mcr genes in recent years now pose a threat to public health.In this study,we isolated and characterized colistin-... The emergence and dissemination of colistin resistance in Enterobacterioceae mediated by plasmid-borne mcr genes in recent years now pose a threat to public health.In this study,we isolated and characterized colistin-resistant and for mcr-positive£coli from pig farms in Central China.Between 2018 and 2019,594 samples were collected and recovered 445 E.coli isolates.Among them,33 with colistin resistance phenotypes and 37 that were positive for mcr genes were identified,including 34 positive for mcr-1,one positive for mcr-3,and two positive for both mcr-1 and mcr-3.An insertion of nine bases("CTGGATACG")into mcr-7 in four mcr-positive isolates led to gene dysfunction,and therefore did not confer the colistin resistance phenotype.Antimicrobial susceptibility testing revealed that 37 mcr-positive isolates showed severe drug resistance profiles,as 50% of them were resistant to 20 types of antibiotics.Multilocus sequence typing revealed a heterogeneous group of sequence types in mcr-positive isolates,among which ST10(5/37),ST156(5/37),and 5T617(4/37)were the predominant types.Plasmid conjugation assays showed that mcr-carrying plasmids of 25 mcr-positive isolates were conjugated with£coli recipient,with conjugation frequencies ranging from 1.7 × 10^(-6) to 4.1 × 10^(-3) per recipient.Conjugation of these mcr genes conferred a colistin resistance phenotype upon the recipient bacterium.PCR typing of plasmids harbored in the 25 transconjugants determined six types of plasmid replicons,including lncX4(14/25),FrepB(4/25),Incl2(3/25),lncHI2(2/25),FIB(1/25),and Inch(1/25).This study contributes to the current understanding of antibiotic resistance and molecular characteristics of colistin-resistant£coli in pig farms. 展开更多
关键词 Escherichia coli Colistin resistance mcr positivity Antimicrobial resistance sequence types Plasmid types Plasmid conjugation
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Molecular Characteristics of Neisseria meningitidis Isolated during an Outbreak in a Jail: Association with the Spread and Distribution of ST-4821 Complex Serogroup C Clone in China 被引量:5
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作者 ZHANG Ji ZHOU Hai Jian +5 位作者 XU Li HU Guang Chun ZHANG Xue Hua XU Sheng Ping LIU Zun Yu SHAO Zhu Jun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第5期331-337,共7页
Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyp... Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyperinvasive ST-4821 serogroup C clone associated with this outbreak. Methods The cases were described based on the clinical symptoms and laboratory results. Pharyngeal swabs were cultured for N. meningitidis from men in the jail. Meningococcal isolates were identified by serogrouping, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), respectively. Four hundred and sixteen serogroup C N. meningitidis strains were collected from 27 provinces between 2003 and 2010 for a nationwide survey and analyzed by PFGE and MLST. Results Three persons in a jail system were infected with invasive N. meningitidis serogroup C. All isolates tested had matching PFGE patterns and belonged to the multilocus sequence type (ST) 4821 clonal complex. All 47 N. meningitidis strains were identified from the pharyngeal swabs of 166 peoples in the jail, and 26 of them belonged to ST-4821 serogroup C clone, and 90.14% (375/416) serogroup C strains identified in the nationwide survey belonged to the ST-4821 complex. The ST-4821 serogroup C clone was spread nationwide, distributed in 24 provinces, especially in eastern provinces between 2003 and 2010. Conclusion Endemic transmission and carriage rate of ST-4821 serogroup C clone are high in this jail system. The ST-4821 serogroup C clone is spreading in China and nationwide distributed despite the existence of some effective vaccines. 展开更多
关键词 Pulsed-field gel electrophoresis Multilocus sequence typing Neisseria meningitidis ST-4821 Serogroup C
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Genetic Diversity, Antimicrobial Resistance, and Virulence Genes of Aeromonas Isolates from Clinical Patients, Tap Water Systems, and Food 被引量:5
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作者 MENG Shuang WANG Yong Lu +7 位作者 LIU Chen Geng YANG Jing YUAN Min BAI Xiang Ning JIN Dong LIANG Jun Rong CUI Zhi Gang LI Juan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2020年第6期385-395,共11页
Objective This study aimed to evaluate the genetic diversity,virulence,and antimicrobial resistance of Aeromonas isolates from clinical patients,tap water systems,and food.Methods Ninety Aeromonas isolates were obtain... Objective This study aimed to evaluate the genetic diversity,virulence,and antimicrobial resistance of Aeromonas isolates from clinical patients,tap water systems,and food.Methods Ninety Aeromonas isolates were obtained from Ma’anshan,Anhui province,China,and subjected to multi-locus sequence typing(MLST)with six housekeeping genes.Their taxonomy was investigated using concatenated gyr B-cpn60 sequences,while their resistance to 12 antibiotics was evaluated.Ten putative virulence factors and several resistance genes were identified by PCR and sequencing.Results The 90 Aeromonas isolates were divided into 84 sequence types,80 of which were novel,indicating high genetic diversity.The Aeromonas isolates were classified into eight different species.PCR assays identified virulence genes in the isolates,with the enterotoxin and hemolysin genes act,aer A,alt,and ast found in 47(52.2%),13(14.4%),22(24.4%),and 12(13.3%)of the isolates,respectively.The majority of the isolates(≥90%)were susceptible to aztreonam,imipenem,cefepime,chloramphenicol,gentamicin,tetracycline,and ciprofloxacin.However,several resistance genes were detected in the isolates,as well as a new mcr-3 variant.Conclusions Sequence type,virulence properties,and antibiotic resistance vary in Aeromonas isolates from clinical patients,tap water systems,and food. 展开更多
关键词 AEROMONAS Multi-locus sequence typing Multidrug resistance Virulence gene Antimicrobial resistance gene
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Genetic and Antibiotic Resistance Characteristics ofCampylobacterjejuni Isolated from Diarrheal Patients,Poultry and Cattle in Shenzhen 被引量:5
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作者 JU Chang Yan ZHANG Mao Jun +7 位作者 MA Yan Ping LU Jing Rang YU Mu Hua CHEN Hui LIU Chu Yun GU Yi Xin FU Yan Yan DUAN Yong Xiang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第8期579-585,共7页
Objective To investigate genetic and antibiotic resistance characteristics of Campylobacter jejuni(C. jejuni) isolated from Shenzhen. Methods Multilocs sequence typing and agar dilution methods were used to define the... Objective To investigate genetic and antibiotic resistance characteristics of Campylobacter jejuni(C. jejuni) isolated from Shenzhen. Methods Multilocs sequence typing and agar dilution methods were used to define the genotype and antibiotic resistance of C. jejuni, respectively. Results In total, 126 C. jejuni strains were isolated. The prevalence of C. jejuni was 5.3% in diarrheal patients. The prevalence in poultry meat(36.5%) was higher than that in cattle meat(1.1%). However, the prevalence in poultry cloacal swabs(27.0%) was lower than that in cattle stool(57.3%). Sixty-two sequence types were obtained, among which 27 of the STs and 10 alleles were previously unreported. The most frequently observed clonal complexes were ST-21(11.9%), ST-22(10.3%), and ST-403(7.1%). ST-21, ST-45, ST-354, ST-403, and ST-443 complexes overlapped between isolates from patients and cattle, whereas ST-45 and ST-574 complexes overlapped between isolates from patients and poultry. All C. jejuni were resistant to at least one antibiotic. The highest resistance rate was toward ciprofloxacin(89.7%), followed by tetracycline(74.6%), and nalidixic acid(69.0%). Conclusion This is the first report of the genotypes and antibiotic resistance of C. jejuni in Shenzhen. Overlapping clonal complexes were found between isolates from patients and cattle, and between patients and poultry. 展开更多
关键词 Campylobacter jejuni Multilocus sequence typing Antibiotic resistance POULTRY CATTLE Diarrheal patients
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Statistical features of aftershock distribution size for moderate and large earthquakes in Chinese mainland 被引量:3
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作者 蒋海昆 郑建常 +3 位作者 吴琼 曲延军 李永莉 代磊 《Acta Seismologica Sinica(English Edition)》 CSCD 2007年第2期158-171,共14页
Based on data of earthquake sequences with Ms≥5.0 in Chinese mainland from 1970 to 2004, for different sequence types and different rupture modes of the main shock, the relationship between aftershock distribution si... Based on data of earthquake sequences with Ms≥5.0 in Chinese mainland from 1970 to 2004, for different sequence types and different rupture modes of the main shock, the relationship between aftershock distribution size R and the magnitude of the main shock Mo has been studied statistically. Considering the rupture mode of the main shock, we give the quantitative statistical relationships between R and Mo under 95% confidence level for different sequence typos. Qualitatively, lgR, the logarithm of the aftershock distribution size, is positively correlative to the M0, but the data distribution is dispersed. Viewing from different sequence typos, the correlation between R and M0 is very weak for isolated earthquake type (lET) sequence, R distributes in the range from 5 to 60 km; For mainshock-aftershock type (MAT), lgR is positively correlative to M0; For multiple main shock type (MMT), the corelation between lgR and M0 is not very obvious when M0≤6.2 and R distributes in the range from 5 to 70 km, while it shows a linear correlation when M0≥6.3. The statistical results also show that the occupational ratios of different sequence types for strike-slip and oblique slip are almost the same. But for dip-slip (mostly are thrust mechanisms), the ratio of MAT is higher than that of IET and MMT. Comparing with previous results, it indicates that, when M0 is large enough, R is mainly determined by M0 and there is almost no relationship with the rupture mode of the main shock. 展开更多
关键词 Chinese mainland aftershock distribution size types of aftershock sequences rupture mode ofthe main shock
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Dismantling Marchandiomphalina into Agonimia(Verrucariaceae)and Lawreymyces gen.nov.(Corticiaceae):setting a precedent to the formal recognition of thousands of voucherless fungi based on type sequences 被引量:1
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作者 Robert Lücking Bibiana Moncada 《Fungal Diversity》 SCIE 2017年第3期119-138,共20页
Based on an unexpected result of obtaining molecular sequence data from tropical representatives of the genus Normandina,we revised the biological concept of the neotropical taxon Marchandiomphalina foliacea.The obtai... Based on an unexpected result of obtaining molecular sequence data from tropical representatives of the genus Normandina,we revised the biological concept of the neotropical taxon Marchandiomphalina foliacea.The obtained data let us conclude that M.foliacea is not a basidiomycete,as originally proposed,but belongs in Verrucariaceae,in the genus Agonimia,including its perithecia which had been identified with the lichenicolous Norrlinia peltigericola.The ITS(and nuLSU)sequences previously obtained from M.foliacea,seemingly confirming its status as a basidiomycete,are from an unmanifested lichenicolous fungus,present also in numerous specimens of Normandina.ITS data suggest the presence of seven lineages that can be recognized at the species level,forming two clusters:one cluster of three lineages found in thalli of M.foliacea,and a second cluster of four lineages found in thalli of Normandina.This pattern is similar to what has recently been found in the basidiomycete genus Cyphobasidium occurring predominantly in Parmeliaceae lichens.We propose the combination of Omphalina foliacea into the genus Agonimia,as Agonimia foliacea(P.M.Jørg.)Lucking&Moncada,comb.nov.,and place Marchandiomphalina in synonymy with Agonimia.To formally recognize the unnamed lichenicolous basidiomycete present in Agonimia and Normandina thalli,we take advantage of provision ICN Art.40.5 in the Code and describe the unmanifested fungus as a new genus,with seven new species,even if no physical type specimens can be preserved(except for the corresponding host lichens which,however,do not show the features of the fungus):Lawreymyces Lucking&Moncada,gen.nov.(Type:L.palicei),with L.bogotensis Lucking&Moncada,sp.nov.,L.columbiensis Lucking&Moncada,sp.nov.,L.confusus Lucking&Moncada,sp.nov.,L,foliaceae Lucking&Moncada,sp.nov.,L.palicei Lucking&Moncada,sp.nov.,L.pulchellae Lucking&Moncada,sp.nov.,and L.spribillei Lucking&Moncada,sp.nov.This opens the door to the formal recognition of thousands of species of voucherless fungi detected through environmental sequencing techniques under the current Code. 展开更多
关键词 ARTWORK International Code of Nomenclature for algae fungi and plants Illustration sequences as types TYPIFICATION Work of art
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