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1.
Drug resistance of Pseudomonas aeruginosa is a leading problem in hospital infections. The aim of this study was to determine the best molecular genetic discrimination method for Pseudomonas spp. isolates among 94 outpatients and inpatients and see their grouping by phenotype characteristics (biofilm formation, frequency of serotypes, pigmentation, production of different class of beta-lactamases, and susceptibility to different antibiotic classes) and genotype. The most common serotypes were P1, P6, and P11, while co-productions of pyoverdine and pyocyanin were observed in 70 % of isolates. A total of 77.66 % isolates were mostly weak and moderate biofilm producers. Isolates were susceptible to colistin (100 %), aztreonam (97.87 %), imipenem (91.49 %), doripenem (90.43 %), and meropenem (84.04 %). MICs values confirmed susceptibility to ceftazidime and cefepime and singled out meripenem as the most effective inhibitor. Most isolates were resistant to aminoglycosides and fluoroquinolones. Only two isolates produced ESBL, eight were carbapenemase producers, and five isolates produced MBLs. Twenty-nine isolates were multidrug-resistant; 82.8 % of which produced both pigments, 58.3 % were non-typeable, while the P6 and P11 serotypes were equally distributed (16.7 %). Thirteen MDR isolates were strong enzyme producers. RAPD PCR analysis using primer 272 proved the best at discriminatory fingerprinting for Pseudomonas isolates, as it allocated 12 clusters. A correlation between DNA patterns and antibiotic resistance, production of pigments, serotypes distribution, and biofilm formation was not observed, and only confirmed higher genetic heterogeneity among P. aeruginosa isolates, which suggests that other molecular methods are needed to reveal potential relations between genotypic patterns and phenotypic characteristics.  相似文献   
2.
目的 了解张家口地区健康儿童呼吸道流感嗜血杆菌(Haemophilus infiuenzae,HI)带菌现状、对常用抗生素的耐药情况及流行特征,为预防、控制流感嗜血杆菌感染提供科学依据.方法 从健康儿童咽拭子标本中分离鉴定流感嗜血杆菌,采用K-B法测定其对抗生素的敏感性,用cefinase纸片检测菌株的β-内酰胺酶;对分离菌株进行生物分型,同时用随机扩增多态性DNA (RAPD)技术进行多态性分析.结果 100份标本中分离出流感嗜血杆菌31株,分离率为31%.所分离菌株中对亚胺培南、氯霉素、头孢克罗等9种抗生素100%敏感,对磺胺甲恶唑-甲氧苄啶耐药率为38.7%,对氨苄西林耐药率为16.1%.菌株β-内酰胺酶产酶率16.1%;生物学分型以Ⅵ型(32.4%)、Ⅷ型(22.6%)为主.RAPD聚类分析显示在95%的相似性水平上,31株HI可以分为8型,每个型有3~5个菌株,分布较平均,没有两个菌株的带型完全相同,没有明显的集中分布趋势.结论 与该地区10年前的研究结果相比,HI分离率、生物型、耐药性均发生了改变.RAPD聚类分析表明该地区正常儿童呼吸道中的流流感嗜血杆菌较少有交叉感染,没有明显的集中分布趋势.  相似文献   
3.
目的分析6个不同居群白芍的遗传多样性,为白芍的种质鉴定及遗传多样性分析提供依据。方法运用随机扩增多态性DNA(RAPD)技术,对浙江磐安、四川中江、安徽亳州、上海崇明、江苏宿迁和山东荷泽居群白芍的基因组DNA进行随机扩增,利用NTsys2.10e软件计算遗传相似性,运用UPGMA法进行聚类分析并构建树状图。结果共筛选了70个随机引物,从中挑选出8条多态性强、重复性好的引物,共检测出215个位点,多态性位点137个,多态位点比率为63.7%,UPGMA聚类可以将不同来源的白芍很好地区分开。结论不同产地间的白芍存在丰富的遗传多样性,RAPD分子标记方法可以用来鉴定不同产地的白芍。  相似文献   
4.
Enterococcus faecalis (E. faecalis) is a common cause of nosocomial infection in immunocompromised patients. The presence and dissemination of high‐risk clonal complexes, such as CC2, is an ongoing problem in hospitals. The aim of this work was to characterize 24 E. faecalis isolates from ICU patients undergoing selective decontamination of the digestive tract (SDD) by phenotypical (antimicrobial susceptibility) and genotypical (presence of virulence genes, RAPD‐PCR and MLST) methods. Our results showed high prevalence of the ST6 E. faecalis clone (91.6%), especially adapted to the hospital environment, with a multidrug resistance pattern and a multitude of putative virulence genes. In addition, ST179 (4.2%) and ST191 (4.2%) were detected. By RAPD–PCR analysis, the 22 isolates identified as ST6 showed six different DNA patterns, while the two remaining isolates, ST179 and ST191, showed two additional profiles. CC2 is a known clonal complex with high adaptability to hospital environment and worldwide distribution. The high prevalence of the ST6 clone in the studied population could be related to the presence of gentamicin in the SDD mixture since most strains were gentamicin resistant. Consequently, strict surveillance should be applied for rapid detection and control of this clone to prevent future spread outside the ICU.  相似文献   
5.
Identifying Lactobacillus species using only phenotypic and genotypic (16S rDNA sequence analysis) techniques yields inaccurate results. The objective of this study was to develop species-specific primers based on randomly amplified polymorphic DNA (RAPD) fingerprinting to distinguish species within the closely related Lactobacillus plantarum group. One of these primers, OPD-3, produced a species-specific band that was found only in the tested Lactobacillus pentosus. This specific fragment was isolated from agarose gel and ligated into a vector for DNA sequencing. A pair of primers, SpOPD3Lpen-F1/R1, that were highly specific sequence-characterized-amplified-regions (SCARs) were designed according to the nucleotide sequences of the specific RAPD marker. These primers were used for PCR analysis of the template DNA of the Lactobacillus strains, and a single 542 bp species-specific band was found only in L. pentosus. Using PCR, a novel species-specific primer pair is shown to rapidly, accurately and effectively distinguish L. pentosus from other species in the L. plantarum group of probiotic bacteria.  相似文献   
6.
野生红景天的RAPD和ISSR遗传多样性分析   总被引:1,自引:0,他引:1  
目的采用RAPD和ISSR分子标记进行野生红景天种间亲缘关系及种内的遗传多样性分析。方法用CTAB法提取基因组DNA,然后通过筛选得到的11个RAPD及11个ISSR引物对不同采集地的4种野生红景天进行遗传多样性分析。结果 11条RAPD引物共扩增出96条条带,多态性百分比为90.62%;11条ISSR引物共扩增出102条条带,多态性百分比为100%。ISSR多态性的检测能力优于RAPD;聚类分析结果表明,ISSR法、RAPD和ISSR联用法均将17个样品聚为3大类;RAPD将样品聚为4大类。结论 2种标记均可用于红景天属植物种间亲缘关系与种内遗传多样性研究;4种红景天种内存在一定的遗传差异,种间基因流较小。  相似文献   
7.
Purpose: Current study was aimed to enhance the confidence of consumers as well as entrepreneurs towards food irradiation program.

Materials and methods: In this work, safety of high dose (25?kGy) irradiated meat samples (HDIMS) was ascertained by scoring mutation frequency through a long-term sub-culturing study in Escherichia coli MG1655 cells (ATCC 700926) up to 1500 generations (at 1%), 250 generations (at 5% and 10%) and human lymphoblast thymidine kinase heterozygote (TK6) cell line (ATCC CRL-8015) [at two gene loci, tk?/+ (thymidine kinase) and hprt+ (Hypoxanthine Phosphoribosyltransferase)] up to 156 generations using goat meat sample. Also these samples were assayed at further radiation doses of 10, 45 and 70?kGy at 2% concentration (in cell line), and 1% (in E. coli). Study was also performed with other meat samples such as chicken, fishes (pomfret and rohu) and shrimps by carrying out limited long-term sub-culturing trials in human lymphoblast cell line. Mutation analysis was also carried out using a novel DPAR (Differential loss of Plasmid Antibiotic Resistance) assay followed by sequencing of tcR (tetracycline resistance) gene of pBR322 plasmid isolated from E. coli cells grown for 1500 generations on HDIMS medium and RAPD (Random Amplified Polymorphic DNA) analysis of the genome.

Results and conclusion: None of the assays exhibited any induced mutation when analyzed at regular time intervals. RAPD analysis also did not indicate any change in its nucleotide sequence, ruling out the occurrence of any silent mutation. Thus, the present findings report absence of mutagenic effect of high dose irradiated meat samples.  相似文献   

8.
Objective To determine the geographical distribution of Leishmania species causing cutaneous leishmaniasis (CL) and to study the genetic heterogeneity of Leishmania major isolates from different endemic areas of Iran. Methods A total of 341 isolates from lesions of patients living in 11 provinces of Iran were grown in culture medium and inoculated to BALB/c mice to detect possible visceralisation. The species were identified by isoenzyme analysis using a battery of six enzymes and kinetoplast (k) DNA‐PCR technique. Genetic variation among L. major isolates was analysed by random amplified polymorphic DNA (RAPD) technique. Results Of the total 341 isolates, 283 isolates were L. major and 58 isolates were Leishmania tropica. In rural areas, the causative agent of CL was mainly L. major (95%L. major vs. 5%L. tropica), in urban areas it was L. tropica (65%L. tropica vs. 35%L. major). All isolates of L. major and 8.6% of L. tropica isolates showed visceralisation in BALB/c mice. There is considerable genetic diversity between L. major strains from different endemic areas and even between some isolates of the same endemic area. Conclusion Leishmania major is the most frequent species in the endemic areas of CL in eleven provinces of Iran, and genetic diversity is a common feature of L. major in the country.  相似文献   
9.
目的总结本地区2010年1月-2011年12月共6400份临床细菌标本的培养及药敏结果,了解铜绿假单胞菌医院感染现状;建立随机扩增多态性DNA(RAPD)基因分型方法检测铜绿假单胞菌,调查铜绿假单胞菌医院感染流行病学的情况,为控制院内感染提供直接可靠的参考依据。方法对2010年至2011分离的240株铜绿假单胞菌进行统计分析及其临床分布;采用PAPD基因分型方法进行分析。结果 240株标本主要来自ICU,呼吸内科,普外科等;铜绿假单胞菌感染标本分布依次为:痰标本占72.5%,伤口分泌物标本占15.0%、中段尿占10.0%,其它类型标本占2.5%;240株铜绿假单胞菌的多重耐药情况非常严重,对亚胺培南/美罗培南耐药率分别为32.0%和35.0%,对其它大多数抗菌药物的耐药率为70%以上;240株PA用RAPD分型共分为7种类型:A-G。结论分离的铜绿假单胞菌多具有多重耐药性;本地区铜绿假单胞菌分为7个基因型,其中主要以A、B 2型为主,表明本地区医院感染铜绿假单胞菌可能存在院内的克隆传播。  相似文献   
10.
Molecular-epidemiological analysis of Pseudomonas aeruginosa isolated from cockroaches captured in hospitals and from patient urine was performed, employing randomly amplified polymorphic DNA (RAPD) analysis to investigate the usefulness of RAPD analysis. Four specific bands at positions of 993, 875, 521, and 402 bp were commonly detected using primer 272 in 16 of 45 cockroach-derived strains (35.6%), but not in 21 urine-derived strains. On analysis using primer 208, 4 specific bands at positions of 1,235, 1,138, 1,068, and 303 bp were commonly detected in 15 of the 45 cockroach-derived (33.3%) and 10 of the 21 patient urine-derived (47.6%) strains, in a total of 25 of 66 strains (37.8%). On cluster analysis, 12 (48.5%) and 16 (66.7%) clusters were grouped based on a homology of 89% or greater, using primer 272 and primer 208, respectively, showing that primer 208 was suitable for the confirmation of diversity. Seven patterns were clustered based on 100% homology using either primer, and 6 of these consisted of only cockroach-derived strains. In the individual groups with 100% homology, all strains in the group were isolated at an identical site during the same period. P. aeruginosa isolated from cockroaches showed diverse genotypes suggesting several sources of contamination, indicating the necessity for investigating infection control targeting cockroaches inhabiting hospitals.  相似文献   
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