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Photoluminescence and Ce^(3+)→Tb^(3+)→Eu^(3+) Energy Transfer Processes of the Ce^(3+)/Tb^(3+)/Eu^(3+)-doped β-NaYF_(4) Phosphors with Broadened Excitation Spectrum 被引量:3
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作者 HUANG Jianhua CHEN Nan +2 位作者 WANG Xiaojing DU Guoping ZHANG Aisheng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2021年第1期33-43,共11页
Ce^(3+)/Tb^(3+) co-doped and Ce^(3+)/Tb^(3+)/Eu^(3+) tri-doped β-NaYF_(4) photoluminescent microcrystals using oleic acid as surfactant were synthesized using the solvothermal method.Their microstructural characteris... Ce^(3+)/Tb^(3+) co-doped and Ce^(3+)/Tb^(3+)/Eu^(3+) tri-doped β-NaYF_(4) photoluminescent microcrystals using oleic acid as surfactant were synthesized using the solvothermal method.Their microstructural characteristics and photoluminescence properties were investigated in detail.They have the shape of hexagonal prism bipyramids with uniform particle size,which decreases with the concentrations of Tb^(3+) and Eu^(3+).The energy transfer processes of both the Ce^(3+)→Tb^(3+) and the Ce^(3+)→Tb^(3+)→Eu^(3+) were systematically studied.Compared with Eu^(3+) or Tb^(3+) single-doped β-NaYF_(4) microcrystals,the sensitization by Ce^(3+) for the photoluminescence of Tb^(3+) and Eu^(3+) leads to a broad excitation spectral bandwidth in the ultraviolet (UV) range.Meanwhile,the corresponding optical absorption efficiency is greatly enhanced.High energy transfer efficiencies have been observed from Ce^(3+) to Tb^(3+) and from Tb^(3+) to Eu^(3+). 展开更多
关键词 lanthanide dopedβ-NaYF_(4) PHOTOLUMINESCENCE energy transfer broad excitation spectrum solvothermal method
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High efficient broad-spectrum Bradyrhizobium elkanii Y63-1 被引量:2
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作者 Piao Leng Fuxiao Jin +13 位作者 Song Li Yi Huang Chanjuan Zhang Zhihui Shan Zhonglu Yang Limiao Chen Dong Cao Qingnan Hao Wei Guo Hongli Yang Shuilian Chen Xinan Zhou Songli Yuan Haifeng Chen 《Oil Crop Science》 CSCD 2023年第4期228-235,共8页
Soybean(Glycine max),the primary source of high-quality plant protein,plays a crucial role as a grain and oil crop in China.Harnessing the full potential of symbiotic nitrogen fixation in soybean production holds imme... Soybean(Glycine max),the primary source of high-quality plant protein,plays a crucial role as a grain and oil crop in China.Harnessing the full potential of symbiotic nitrogen fixation in soybean production holds immense significance for agriculture and ecology alike.Zhongdou 63,a newly developed early-maturing summer soybean cultivar in 2021,exhibits remarkable traits such as high yield,superior quality,multi-resistance,and wide adaptability.In this study,eight distinct rhizobia strains from diverse regions were meticulously screened to identify highly effective strains specifically suited for Zhongdou 63.The aboveground biomass,plant height,chlorophyll content,root length,nodule number,and nodule dry weight of Zhongdou 63 were measured and the data were subjected to statistical analysis.The results demonstrated that Y63-1 is a predominant strain of Zhongdou 63.Subsequently,we conducted further investigations on the broad-spectrum nodulation characteristics of Y63-1.Ten representative soybean cultivars were individually inoculated with Y63-1 and subsequently analyzed for nodule numbers and nodule dry weight in their symbiotic systems with rhizobia.The findings revealed that Y63-1 effectively formed nodules with all ten soybean varieties tested.In summary,our current study identified highly efficient broad-spectrum Bradyrhizobium elkanii strain Y63-1 as the predominant strain in Zhongdou 63 and provided a theoretical foundation for enhancing yield potential not only in Zhongdou 63 but also in other varieties through inoculation with highly efficient rhizobia in production. 展开更多
关键词 Soybean RHIZOBIUM Nodule symbiosis NODULATION broad spectrum
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Screening of Broad-spectrum Resistance Resources against Rice Bacterial Leaf Streak 被引量:1
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作者 Hong Dengwei Zhao Yan +3 位作者 Luo Dengjie Shi Lijun Li Rongbai Liu Fang 《Plant Diseases and Pests》 CAS 2017年第3期16-20,共5页
[ Objectives] Rice materials with broad-spectrum resistance against several pathogenic strains of Xanthomans oryzae pv. Oryzicola (Xooc) at multiple growth stages were screened, in order to provide reliable resistan... [ Objectives] Rice materials with broad-spectrum resistance against several pathogenic strains of Xanthomans oryzae pv. Oryzicola (Xooc) at multiple growth stages were screened, in order to provide reliable resistance sources for variety breeding against rice bacterial leaf streak. [ Methods] A total of 1 100 rice lines with rich genetic background were offered as selective objects, and highly susceptible cultivar Jingang 30 was used as the control. Inoculation was carried out with five strong pathogenic strains of Xooc through acupuncture method at various growth stages for resistance identification. [ Results] Fourteen disease-resistant materials were obtained through preliminary screening, accounting for 1.27% of the total materials. Nine materials moderately resistant to bacterial leaf streak were obtained via secondary screening, accounting for 0.82% of the total materials. Besides, three of them ( RL6, RL9 and RLL4) were resistant to a number of pathogenic strains of Xooc at three growth stages. In particular, RL16 presented broad-spectrum resistance to multi-strains with high resistance levels. Six of them ( RI2, RIA, RIS, RL8, RL11 and RL12) were resistant to single strain at single growth stage. [ Conclusions] The obtained three materials have broad-spectrum resistance to bacterial leaf streak at multiple growth stages, which can be served as an important source to cultivate disease-resistant rice varieties. RL6 maintains high broad-spectrum resistance at all growth stages, which can be used as a prior resistance source for rice variety breeding. Six materials obtained with resistance against bacterial leaf streak at particular growth stages can be used as candidate resistance sources. 展开更多
关键词 RICE Bacterial leaf streak broad-spectrum resistance Resistance resources
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Forming of Space Charge Wave with Broad Frequency Spectrum in Helical Relativistic Two-Stream Electron Beams 被引量:1
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作者 A.Lysenko I.Volk +1 位作者 A.Serozhko O.Rybalko 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期150-154,共5页
We elaborate a quadratic nonlinear theory of plural interactions of growing space charge wave (SCW) harmonics during the development of the two-stream instability in helical relativistic electron beams. It is found ... We elaborate a quadratic nonlinear theory of plural interactions of growing space charge wave (SCW) harmonics during the development of the two-stream instability in helical relativistic electron beams. It is found that in helical two-stream electron beams the growth rate of the two-stream instability increases with the beam entrance angle. An SCW with the broad frequency spectrum, in which higher harmonics have higher amplitudes, forms when the frequency of the first SCW harmonic is much less than the critical frequency of the two-stream instability. For helical electron beams the spectrum expands with the increase of the beam entrance angle. Moreover, we obtain that utilizing helical electron beams in multiharmonic two-stream superheterodyne free-electron lasers leads to the improvement of their amplification characteristics, the frequency spectrum broadening in multiharmonic signal generation mode, and the reduction of the overall system dimensions. 展开更多
关键词 SCW Forming of Space Charge Wave with broad Frequency spectrum in Helical Relativistic Two-Stream Electron Beams
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Co-production of Multiple Antimicrobial Compounds by Bacillus amyloliquefaciens WY047,a Strain with Broad-Spectrum Activity
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作者 Ye Han Xingxing Li +2 位作者 Yanyun Guo Weining Sun Qiaoge Zhang 《Transactions of Tianjin University》 EI CAS 2018年第2期160-171,共12页
A bacterial strain WY047 was isolated from fermented grains and the bacterium was identified as Bacillus amyloliquefaciens, based on morphological, biochemical, and physiological tests, and analysis of 16S rRNA and gy... A bacterial strain WY047 was isolated from fermented grains and the bacterium was identified as Bacillus amyloliquefaciens, based on morphological, biochemical, and physiological tests, and analysis of 16S rRNA and gyr A sequences. The culture supernatant of WY047 demonstrated inhibition ofa wide spectrum ofbacteria(Gram positive and Gram negative) and fungi. Nine pairs ofprimers were designed and six genes( bmyD, fenA, hag, ituA, mrsA, and tasA) ofantimicrobial substances were detected by PCR, one ofwhich was isolated by 80% ammonium sulfate precipitation, D201 resin anion-exchange chromatography, and Sephadex G-75 filtration column. The purified peptide was estimated to be 35,207 Da and identified as flagellin by MALDI-TOF mass spectrometry. Another four antimicrobial substances were extracted with methanol and identified as iturin A, fengycin, bacillomycin D, and mersacidin through the liquid chromatography–mass spectrometry(LC–MS) method. The sixth possible peptide encoded by tas A could not be isolated in this study; however, the broader spectrum suggested huge application prospects. 展开更多
关键词 ANTIMICROBIAL substances Purifi CATION Identifi CATION broad spectrum
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Increasing Incidence of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae (ESBL) and the Relation to Consumption of Broad-Spectrum Antimicrobial Agents 2003-2011 in a Large Area of Copenhagen, Denmark
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作者 Lene Nielsen Anne Kjerulf Magnus Arpi 《Open Journal of Medical Microbiology》 2015年第1期28-42,共15页
Purpose: To investigate 1) the development in the incidence of ESBL-producing bacteria in hospitals and primary health care, 2) the contribution of primary health care to the incidence of ESBL-producing bacteria, and ... Purpose: To investigate 1) the development in the incidence of ESBL-producing bacteria in hospitals and primary health care, 2) the contribution of primary health care to the incidence of ESBL-producing bacteria, and 3) the development in resistance patterns for all Escherichia coli and Klebsiella pneumoniae isolates in relation to antimicrobial consumption in hospitals and primary health care. Methods: ESBL-data were retrospectively collected from bacterial isolates from all specimens received at the Department of Clinical Microbiology from 2003 to 2011 together with the corresponding patient data. ESBL-production was detected in isolates from 1067 of 59,373 patients (1.8%) with an E. coli infection and in 263 of 8660 patients (3.0%) with a K. pneumoniae infection. Results: From 2003 to 2009, an increase in patients with an ESBL-producing isolate occurred in both hospitals and primary health care at the same time as an increased consumption of broad-spectrum antimicrobial agents was seen. Interventions to reduce prescription of cephalosporins and ciprofloxacin at the hospitals from 2010 resulted in a remarkable decrease in patients with ESBL-producing K. pneumoniae whereas a continuing increase was seen in patients with ESBL-producing E. coli both at hospitals and in primary health care. The proportion of patients with community-acquired ESBL-producing E. coli was stable with an increase of only 1.4% from 2007 to 2011. Conclusions: Reduction in prescription of broad-spectrum antimicrobial agents at the hospital level had an important impact on the incidence of ESBL-producing K. pneumoniae, but not on ESBL-producing E. coli. 展开更多
关键词 Incidence of ESBL-Producing E. coli and K. pneumoniae Hospital CARE Primary Health CARE ANTIMICROBIAL CONSUMPTION broad-spectrum ANTIMICROBIAL Agents
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Effectiveness of a Broad-Spectrum Sunscreen in the Prevention of Melasma in Asian Pregnant Women
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作者 Sophie Seité Seok Beom Park 《Journal of Cosmetics, Dermatological Sciences and Applications》 2013年第3期4-7,共4页
Chloasma, or melasma, is a commonly acquired pigmentary disorder among Asian women. It may be considered as a physiological change during pregnancy. The incidence in Asian women is higher than that in other ethnic gro... Chloasma, or melasma, is a commonly acquired pigmentary disorder among Asian women. It may be considered as a physiological change during pregnancy. The incidence in Asian women is higher than that in other ethnic groups but further epidemiologic data are needed. There are very few studies related to the benefits of sunscreens to prevent this dermatosis. The aim of this study was to assess the effectiveness of a broad-spectrum sunscreen in the prevention of melasma in Korean pregnant women. We tested the effectiveness and tolerance of a sunscreen product (SPF 50+, UVA-PF 30) during a 12-month clinical trial including 220 Korean parturients with skin type III and IV. 217 women completed the study. Only 3 (1%) of the study population developed melasma, which was mild (MASI grade between 1.2 and 2.7). In addition, the clinical effectiveness of the evaluated sunscreen was judged “good to excellent” by the majority of study participants and by the research dermatologists. The “excellent” tolerance of the sunscreen under evaluation was confirmed “good” to “excellent” in 95% and 97% of cases. This study clearly demonstrates that this broad-spectrum sunscreen is well tolerated and effective in the prevention of melasma in Korean pregnant women. Although treatment remains elusive, prevention is possible. 展开更多
关键词 broad-spectrum SUNSCREEN CHLOASMA MELASMA Pregnancy PHOTOPROTECTION SPF UVA-PF
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Study of characteristics of long-period ground motion response spectra by using broad-band records of the Chinese Digital Seismograph Network 被引量:1
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作者 汪素云 俞言祥 吕红山 《Acta Seismologica Sinica(English Edition)》 EI CSCD 1998年第5期41-48,共8页
Broad band and very broad band (BB and VBB) records of Chinese Digital Seismograph Network (CDSN) from 65 earthquakes are used to calculate the horizontal relative displacement, relative velocity and absolute accelera... Broad band and very broad band (BB and VBB) records of Chinese Digital Seismograph Network (CDSN) from 65 earthquakes are used to calculate the horizontal relative displacement, relative velocity and absolute acceleration response spectra with critical damping ratio ζ =0.005, 0.01, 0.02, 0.05 and 0.10, respectively. The results show that it is insufficient to obtain the credible characteristics of long-period ground motion response spectra only with the common ground acceleration records in engineering, while the broad band records of CDSN, as an important supplementary to ground acceleration records, can be used to study the characteristics of long-period ground motion response spectra. 展开更多
关键词 CDSN broad band digital seismic record long-period response spectrum
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Electronic structure and infrared spectrum of a W_n C^(0,±) (n = 1-6) cluster 被引量:1
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作者 张秀荣 康张李 郭文录 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第10期204-211,共8页
WnC0'± (n= 1-6) clusters are investigated by using the density functional theory (DFT) at the B3LYP/LANL2DZ level. We find that the neutral, anionic and cationic ground state structures are similar within th... WnC0'± (n= 1-6) clusters are investigated by using the density functional theory (DFT) at the B3LYP/LANL2DZ level. We find that the neutral, anionic and cationic ground state structures are similar within the same size, and constituted by substituting a C atom for one W atom in the structures of Wn+1 clusters. The natural bond orbital (NBO) charge analyses indicate that the direction of electron transfer is from the W atom to the 2p orbital of the C atom. In addition, the calculated infrared spectra of the WnC0'± (n= 2-6) clusters manifest that the vibrational frequencies of neutral, anionic and cationic clusters are similar in a range of 80 cm-1-864 cm-1. The high frequency, strong peak modes are found to be an almost stretched deformation of the carbide atom. Finally, the polarizabilities of WnC0'± (n= 1-6) clusters are also discussed. 展开更多
关键词 WnC0'± (n= 1-6) clusters electronic structure infrared spectrum density functionaltheory
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A Broad Spectrum Identification Approach for Two Generations of epsps GM Soybeans
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作者 Qiuchi SONG Xiwei LIU +2 位作者 Yiwei MOU Yuan JING Jun SONG 《Asian Agricultural Research》 2017年第12期59-63,共5页
In order to accurately identify the first and second generations of epsps genetically modified(GM) soybeans and related products,a broad spectrum identification approach was established using the real time Polymerase ... In order to accurately identify the first and second generations of epsps genetically modified(GM) soybeans and related products,a broad spectrum identification approach was established using the real time Polymerase Chain Reaction(PCR) principle according to the homology of epsps genes of the first and second generations of GM soybeans.A pair of primer and probe was designed to simultaneously identify exogenous gene epsps of two generations of GM soybeans.Besides,evaluation was carried out on this approach from the accuracy,specificity,sensitivity and reproducibility.The experimental results indicated that(ⅰ) although there is certain difference in epsps gene sequence between the first and second generations of epsps genetically modified(GM) soybeans,the established approach can simultaneously detect the epsps genes of the bean curd using two generations of soybean as raw materials;(ⅱ) in the accuracy and specificity experiment,only cp4-epsps genes of two generations of GM soybeans were detected,so this approach has high specificity and accuracy;(ⅲ) in the experiment of 5 copies of epsps genes of 40 repeated identification reaction systems,5 copies of epsps genes can be detected each time,therefore at 100% confidence level,this approach can identify 5 copies of epsps genes,showing that this approach has high sensitivity and reproducibility. 展开更多
关键词 Genetically modified(GM) soybeans epsps gene broad spectrum SPECIFICITY Sensitivity
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Spectrum and Electrochemical Properties of Nanosized Ce_(1-x)Bi_xO_(2-δ) Solid Solutions 被引量:1
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作者 张国芳 李莉萍 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第4期529-535,共7页
Ce1-xBixO2-δ (x = 0.00, 0.03, 0.05, 0.07, 0.10, 0.15, 0.30) solid solutions were synthesized via a hydrothermal method. The structure, spectra and electrochemical transport properties of the samples were characteri... Ce1-xBixO2-δ (x = 0.00, 0.03, 0.05, 0.07, 0.10, 0.15, 0.30) solid solutions were synthesized via a hydrothermal method. The structure, spectra and electrochemical transport properties of the samples were characterized systematically. The powder X-ray diffraction analysis showed that all of the doped samples exhibited single phase fluorite structure. The particle sizes decreased from 18 to 9 nm and the lattice parameters increased gradually with the dopant content increasing from x = 0.03 to x = 0.30. The Bi^3+ doping also induced the F2g Raman peak to shift from 463 to 455 cm^-1, and caused a red shift of the band gap energies calculated from UV-Vis spectra. The impedance plots at different temperature demonstrated that the boundary resistance was much larger than the grain resistance, and two activation energy values were obtained in different temperature range. 展开更多
关键词 Ce1-xBixO2-δ hydrothermal method spectrum impedance
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Suboptimal State Feedback H2/H∞ Controller Design with Spectrum Constraint for Discrete-time Stochastic Systems
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作者 侯婷 张维海 马宏基 《Journal of Measurement Science and Instrumentation》 CAS 2011年第1期67-71,共5页
With the aid of the spectnnn techique, a new concept named-α-stabilizability (0≤α≤1) is intnxhged and its suffident and necessary canditions are also prvposed. Especially, it is identical with the asymptotically... With the aid of the spectnnn techique, a new concept named-α-stabilizability (0≤α≤1) is intnxhged and its suffident and necessary canditions are also prvposed. Especially, it is identical with the asymptotically mean square stabilizability when α = 1. As an application, the suboptimal state feedback H2/H∞ controller that satisfies the additional Spectrum canstmint via solving a convex optimization problem is delt with. 展开更多
关键词 spectrum technique asymptotically mean square stabi lizability α - stabilizability H2/ H∞ oontroller design
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基于改进T-B法的宽带高斯过程疲劳损伤分析
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作者 袁奎霖 孙卓成 《船舶力学》 EI CSCD 北大核心 2024年第2期261-272,共12页
针对宽带高斯随机应力过程造成的疲劳损伤问题,本文提出一种基于改进Tovo-Benasciutti(T-B)法的疲劳损伤频域分析方法。通过不同参数形式的功率谱进行时域的疲劳损伤分析,针对T-B法中的关键参数bTB提出一个新的非线性函数模型。与原T-B... 针对宽带高斯随机应力过程造成的疲劳损伤问题,本文提出一种基于改进Tovo-Benasciutti(T-B)法的疲劳损伤频域分析方法。通过不同参数形式的功率谱进行时域的疲劳损伤分析,针对T-B法中的关键参数bTB提出一个新的非线性函数模型。与原T-B法相比,新提出的函数模型bMTB可以考虑S-N曲线斜率参数m的影响,并以此为基础提出基于改进T-B法的疲劳损伤分析方法。以时域的雨流计数法结果作为基准,分别采用参数化功率谱和真实响应谱进行数值试验,并与现有的多种宽带高斯疲劳损伤分析方法进行对比,验证本文所提出的改进T-B法的准确性和适用性。 展开更多
关键词 宽带高斯随机过程 疲劳损伤 改进T-B谱方法 数值模拟
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对比黏液型肺克超广谱β-内酰胺酶(ESBLs)表达和毒力基因分布的相关性并对其耐药性进行分析
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作者 韩进辉 余秉贤 周冰 《中国医学工程》 2024年第2期42-46,共5页
目的分析黏液型肺克(MT-KPN)的超广谱β-内酰胺酶(ESBLs)表达、耐药性、毒力基因分布情况。方法收集郑州市第一人民医院2021年3月至2022年3月非重复性KPN 725株,黏液丝试验分离出123株MT-KPN,对其ESBLs表达、耐药性使用CITEK 2 Compact... 目的分析黏液型肺克(MT-KPN)的超广谱β-内酰胺酶(ESBLs)表达、耐药性、毒力基因分布情况。方法收集郑州市第一人民医院2021年3月至2022年3月非重复性KPN 725株,黏液丝试验分离出123株MT-KPN,对其ESBLs表达、耐药性使用CITEK 2 Compact系统分析,毒力基因分布情况使用聚合酶链式反应(PCR)实验分析。结果肺炎克雷伯菌(KPN)检出率最高的科室是重症医学科;同一科室检出KPN类型差异较大的是重症医学科、全科医学科、神经外科,肾内科只检出cKPN;123株MT-KPN包括ESBLs阳性菌34株、ESBLs阴性菌89株。ESBLs阳性菌耐药性高达100.00%的7种药物(头孢呋辛、头孢噻肟、头孢他啶、头孢吡肟、头孢西丁、氨曲南、阿莫西林/克拉维酸),ESBLs阴性菌对上述药物耐药性显著低于ESBLs阳性菌(P<0.05);妥布霉素、亚胺培南、阿米卡星、哌拉西林/他唑巴坦耐药性ESBLs阳性菌>ESBLs阴性菌(P<0.05);庆大霉素、美罗培南、环丙沙星、左氧氟沙星耐药性ESBLs阳性菌>ESBLs阴性菌(P>0.05);MT-KPN的荚膜血清型基因检出率wzyK2最高;荚膜血清型基因检出率ESBLs阳性菌、ESBLs阴性菌相比差异无统计学意义(P>0.05);MT-KPN毒力基因检出率最高的是mrkD;aerobactin、iroN、wcaG检出率相比ESBLs阳性菌<ESBLs阴性菌(P<0.05);其他毒力基因检出率ESBLs阳性菌、ESBLs阴性菌相比差异无统计学意义(P>0.05)。结论MT-KPN携带毒力基因检出率较高,临床需结合其耐药性和毒力基因分布情况合理用药。 展开更多
关键词 黏液型 肺克 超广谱Β-内酰胺酶 毒力基因分布 耐药性
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产超广谱β-内酰胺酶细菌耐药性基因型分析 被引量:14
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作者 张晓丽 张吉生 +3 位作者 斗章 张敬凯 王宇超 付成显 《微生物学杂志》 CAS CSCD 2010年第1期51-55,共5页
检测我院产超广谱β-内酰胺酶(ESBLs)大肠埃希菌和肺炎克雷伯菌的耐药性和基因型。表型确定临床分离产ESBLs的大肠埃希菌和肺炎克雷伯菌56株,应用PCR基因扩增技术及双脱氧DNA测序方法,分别对TEM、SHV、CTX-M-1、CTX-M-2和CTX-M-9编码基... 检测我院产超广谱β-内酰胺酶(ESBLs)大肠埃希菌和肺炎克雷伯菌的耐药性和基因型。表型确定临床分离产ESBLs的大肠埃希菌和肺炎克雷伯菌56株,应用PCR基因扩增技术及双脱氧DNA测序方法,分别对TEM、SHV、CTX-M-1、CTX-M-2和CTX-M-9编码基因进行分析。产酶菌株对亚胺培南、美洛培南、阿米卡星、头孢吡肟耐药性较低,对其他16种抗生素耐药性较高。在56株菌株中有50株为CTX-M型,占89%,34株为TEM型(60.7%),20株SHV型(35.7%);其中CTX-M-9型共计39株占78%,CTX-M-1型19株占38%,CTX-M-2型16株占32%。产ESBLs大肠埃希菌和肺炎克雷伯菌的耐药性值得关注,主要临床流行基因型是CTX-M型。 展开更多
关键词 大肠埃希菌 肺炎克雷伯菌 超广谱Β-内酰胺酶 基因型
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广谱拮抗菌B96-Ⅱ的分子鉴定及GFP标记 被引量:5
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作者 郝变青 马利平 乔雄梧 《华北农学报》 CSCD 北大核心 2009年第5期188-191,共4页
用PCR方法扩增的广谱拮抗菌B96-Ⅱ的16S rDNA经序列测定和BLAST同源序列比较,结合传统的形态观察、生理生化特征鉴定,确定了B96-Ⅱ分类地位为枯草芽孢杆菌(Bacillus subtilis)。将含有绿色荧光蛋白基因和氯霉素抗性基因标记的大肠杆菌... 用PCR方法扩增的广谱拮抗菌B96-Ⅱ的16S rDNA经序列测定和BLAST同源序列比较,结合传统的形态观察、生理生化特征鉴定,确定了B96-Ⅱ分类地位为枯草芽孢杆菌(Bacillus subtilis)。将含有绿色荧光蛋白基因和氯霉素抗性基因标记的大肠杆菌一枯草芽孢杆菌穿梭表达载体(pNW33N-gfp-B96-Ⅱ-N)通过原生质体法转化B96-Ⅱ,获得表达GFP的4株标记菌株,在荧光显微镜下发出明亮的绿色荧光。室内平板抑菌试验结果表明,GFP标记对B96-Ⅱ的广谱抑菌活性没有影响。 展开更多
关键词 广谱拮抗菌 分子鉴定 绿色荧光蛋白 原生质体转化
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产超广谱β-内酰胺酶大肠埃希菌的耐药性分析及其产酶的危险因素调查 被引量:3
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作者 李雪清 朱凤霞 +2 位作者 李小林 刘烁秋 梁成典 《北京医学》 CAS 2006年第7期408-411,共4页
目的探讨超广谱β"内酰胺酶(ESBLs)细菌产生的因素,为防止其传播及治疗提供依据。方法依据美国2005年临床和实验室标准协会(CLSI)和2003年美国临床实验室标准化委员会(NCCLS)推荐的纸片扩散法(KB法)及VITEK"Jr仪器法,收集民... 目的探讨超广谱β"内酰胺酶(ESBLs)细菌产生的因素,为防止其传播及治疗提供依据。方法依据美国2005年临床和实验室标准协会(CLSI)和2003年美国临床实验室标准化委员会(NCCLS)推荐的纸片扩散法(KB法)及VITEK"Jr仪器法,收集民航总医院和北京隆福医院2003年1月至2005年12月分离的住院患者不同标本的大肠埃希菌155株,对其进行耐药性检测;随机选择大肠埃希菌感染患者129例,其中产ESBLs者41例,不产ESBLs者88例,对其进行治疗用药的溯源调查。结果3年内在所测的155株大肠埃希菌中,检出产ESBLs大肠埃希菌59株,检出率38.1%;所有产ESBLs大肠埃希菌对亚胺培喃和阿米卡星敏感,对呋喃妥因、哌拉西林/他唑巴坦、头孢西丁的耐药率低于10%,且3年的逐年耐药率无太大变化。连续使用抗生素时间越长、连续用药次数越多、使用三代头孢、联合用药和多次更换用药均易造成细菌产ESBLs。结论产ESBLs大肠埃希菌对亚胺培南、阿米卡星、呋喃妥因、哌拉西林/他唑巴坦、头孢西丁的敏感率高于90.0%,对其他抗生素具有较高的交叉耐药性和多重耐药性。抗生素应用的时间、次数、种类和联合用药等因素可使产ESBLs大肠埃希菌的检出率增加。 展开更多
关键词 耐药性 大肠埃希菌 超广谱Β-内酰胺酶
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阿片生长因子Met-ENK对多种肿瘤细胞的生长抑制作用研究 被引量:2
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作者 杨峥维 李彦博 樊春艳 《中国临床药理学与治疗学》 CAS CSCD 2016年第2期130-133,共4页
目的:研究阿片生长因子Met-ENK(methionine enkephalin,Met-ENK)对多种肿瘤细胞的抑制作用,分析其对不同肿瘤细胞系的抑制作用差异性及特点。方法:采用CCK-8法考察不同浓度Met-ENK对SH-SY5Y细胞的增殖抑制活性;采用细胞计数法计数相同浓... 目的:研究阿片生长因子Met-ENK(methionine enkephalin,Met-ENK)对多种肿瘤细胞的抑制作用,分析其对不同肿瘤细胞系的抑制作用差异性及特点。方法:采用CCK-8法考察不同浓度Met-ENK对SH-SY5Y细胞的增殖抑制活性;采用细胞计数法计数相同浓度Met-ENK作用下,SHSY5Y细胞随时间的生长曲线;采用CCK-8法检测不同浓度的Met-ENK对8种不同的肿瘤细胞系细胞的抑制作用。结果:不同浓度的Met-ENK对SH-SY5Y细胞具有不同的抑制作用,IC50为5.1×10^(-5)mol/L;Met-ENK作用后SH-SY5Y在48 h生长抑制明显(P<0.01);不同浓度的MetENK对8种不同的肿瘤细胞系细胞均有抑制作用,其中对SMCC-7721抑制作用最为明显。结论:Met-ENK具有广谱抗肿瘤作用,但抑制强度不同,具有时间依赖性,其对8种不同的肿瘤细胞系细胞均有不同强度的抑制作用。 展开更多
关键词 Met-ENK SH-SY5Y 肿瘤生长抑制 广谱作用
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S-腺苷高半胱氨酸水解酶及其抑制剂的研究近况 被引量:6
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作者 纪宇 李振涛 +1 位作者 朱奇 李爱秀 《药学进展》 CAS 2005年第11期481-486,共6页
综述近年来国内外有关S-腺苷高半胱氨酸水解酶分子水平的催化机制及其抑制剂的作用机制研究和产品开发状况。S-腺苷高半胱氨酸水解酶是大多数病毒复制所依赖的细胞酶,它作为广谱抗病毒药物设计的重要靶点,已引起科学家们的广泛关注,其... 综述近年来国内外有关S-腺苷高半胱氨酸水解酶分子水平的催化机制及其抑制剂的作用机制研究和产品开发状况。S-腺苷高半胱氨酸水解酶是大多数病毒复制所依赖的细胞酶,它作为广谱抗病毒药物设计的重要靶点,已引起科学家们的广泛关注,其抑制剂的开发目前主要围绕对腺苷类似物的结构改造,以获得高活性、低毒性的抗病毒新药。 展开更多
关键词 S-腺苷高半胱氨酸水解酶 抑制剂 广谱抗病毒药物 结构改造
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PCR-DGGE结合测序在检测混合细菌感染中的价值 被引量:3
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作者 黄君华 张书婉 张宁 《海南医学》 CAS 2014年第8期1154-1156,共3页
目的探讨变性梯度凝胶电泳(Denaturing gradient gel electrophoresis,DGGE)结合测序在检测混合细菌感染中的作用,为细菌多重感染的诊断提供新的思路。方法以3份临床培养鉴定为混合感染的胆囊穿刺引流液为对象,提取细菌总DNA并扩增16S r... 目的探讨变性梯度凝胶电泳(Denaturing gradient gel electrophoresis,DGGE)结合测序在检测混合细菌感染中的作用,为细菌多重感染的诊断提供新的思路。方法以3份临床培养鉴定为混合感染的胆囊穿刺引流液为对象,提取细菌总DNA并扩增16S rDNA-V3区,后进行DGGE分析,将所得条带切胶纯化再扩增,扩增产物进行测序及BLAST比对,比较比对结果与临床培养结果的一致性。结果 DGGE可以很好地分离16S rDNA-V3区混合PCR产物,每一个扩增子的测序比对结果与临床培养结果一致。结论 PCR-DGGE结合测序的方法可以很好地鉴定临床混合感染标本中的病原菌,可作为快速检测方法在临床应用。 展开更多
关键词 混合细菌感染 通用引物PCR 变性梯度凝胶电泳 测序 快速检测
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