首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   115篇
  免费   1篇
儿科学   1篇
妇产科学   7篇
基础医学   16篇
临床医学   14篇
内科学   31篇
神经病学   2篇
外科学   18篇
综合类   5篇
预防医学   12篇
药学   7篇
肿瘤学   3篇
  2023年   1篇
  2022年   4篇
  2021年   7篇
  2020年   8篇
  2019年   5篇
  2018年   3篇
  2017年   1篇
  2016年   7篇
  2015年   4篇
  2014年   7篇
  2013年   4篇
  2012年   7篇
  2011年   6篇
  2010年   3篇
  2009年   3篇
  2008年   4篇
  2007年   13篇
  2006年   7篇
  2005年   9篇
  2004年   3篇
  2003年   5篇
  2002年   1篇
  2001年   2篇
  1999年   1篇
  1998年   1篇
排序方式: 共有116条查询结果,搜索用时 296 毫秒
81.
Staphylococcus sciuri is a principally animal-associated bacterial species, but its clinical relevance for humans is increasing. Our study aimed to provide the first insight into the prevalence of this bacterium in a hospital environment. A 3-month surveillance was conducted in a hospital located in Belgrade, Serbia, and 1,028 samples taken from hands of medical personnel, medical devices, and various hospital surfaces were screened for S. sciuri presence. In total, 108 isolates were obtained, which resulted in a relatively high rate of colonization (10.5%). These isolates, along with 7 S. sciuri strains previously isolated in the same hospital (n = 115), were phenotypically and genotypically characterized. Antimicrobial susceptibility testing revealed that 73% of the strains were resistant to one or more antibiotics, with 4.3% strains displaying multiresistance. Examination of 16S-23S ribosomal DNA intergenic spacer length polymorphism identified the strains at the subspecies level, and 74 (64.3%) strains of S. sciuri subsp. sciuri, 37 (32.2%) strains of S. sciuri subsp. rodentium, and 4 (3.5%) strains of S. sciuri subsp. carnaticus were established. Pulsed-field gel electrophoresis (PFGE) analysis showed 21 distinct pulsotypes, including 17 main types and 4 subtypes. One dominant cluster with 62 strains was found, while 19 (90.5%) of the PFGE types and subtypes identified had 5 or fewer strains. The predominance of small PFGE clusters suggests that the ubiquitous presence of S. sciuri in the outside environment presents the continuous source for colonization of the hospital environment. The presence of one dominant PFGE cluster of strains indicates that some S. sciuri strains may be capable for adaptation to hospital environment conditions and continuous existence in this environment.  相似文献   
82.
83.
An increased incidence of prostate cancer among African-American men (now the second most common cause of cancer death) has been attributed mainly to the introduction of screening techniques, which have enabled earlier diagnosis of patients. This study reviewed male cancer patients recorded in a Nigerian cancer registry to assess the current trends in prostate cancer in Nigeria. For comparison, data were broken into two groups: 1980-1988 and 1989-1996. Only the top 10 cancers occurring in both periods were considered initially in this report. For emphasis, an analysis of adult male cancers was done per decade since 1960. Results show that prostate cancer has become the number one cancer in Nigerian men and constitutes 11% of all male cancers. The median age of patients was 67.5 years (variance 5.6), and the mean age was 71.4 years (variance 14.3). These results indicate that despite the absence of screening programs in Nigeria, the number of prostate cancer cases has increased. The known risk factors probably contribute to a varying degree among Nigerians, who are generally of average build or in the low-normal range for body mass index. Moreover, the role of genetics cannot be underplayed. Given its biological characteristics, more cases of prostate cancer probably would be recorded among this population if screening were undertaken.  相似文献   
84.
Intensive studies on extracts and biologically active compounds isolated from medicinal plants have doubled in the last decade worldwide. However, as a result of paucity of knowledge and folkloric claim on the effectiveness of sesame leaves in infectious disease treatments, we aimed to determine the synergistic antimicrobial activity of essential oils and lignans present in the crude leaves extracts of Sesame radiatum and Sesame indicum. Ethanolic, methanolic and aqueous extracts of both leaves were studied for their in-vitro synergistic antimicrobial activity against both Gram positive and Gram negative micro-organisms, and Yeast using Agar diffusion method. The GC-MS phytochemical screening of methanolic extract showed that the major compounds in essential oils are of carboxylic acids and phenolic groups especially, the most potent antioxidants known to man like sesamol, sesamolin and sesamin among others. Methanolic and ethanolic extracts have broad spectrum antimicrobial effect against all the tested pathogenic micro-organisms except Streptococcus pneumoniae and Staphylococcus aureus respectively, while the aqueous extract exhibited inhibitory activity on Staphylococcus aureus, Streptococcus pneumoniae and Candida albicans. The result confirmed the folkloric claims of the antimicrobial effectiveness of locally consumed sesame leaves extracts especially against bacterial and common skin infection in many areas of Nigeria.  相似文献   
85.
We report on the isolation, molecular identification, and characterization of 5 mannitol-negative methicillin-resistant Staphylococcus aureus (MRSA) from clinical samples in KwaZulu-Natal (KZN) province, South Africa. Identification based on phenotypic testing and polymerase chain reaction detection of the S. aureus species-specific nuc gene and the coagulase gene indicated that the mannitol-negative isolates were S. aureus. Furthermore, they were mecA positive, and SCCmec typing demonstrated that all the isolates harbored type IV SCCmec. API STAPH (Biomerieux, Marcy-l'Etoile, France) misidentified 2 mannitol-negative MRSA that belonged to the major clone in KZN province, as Staphylococcus lugdunensis. Although the prevalence and mechanism of mannitol-negative MRSA is unknown, laboratories are encouraged to investigate S. aureus with atypical characteristics.  相似文献   
86.
A novel liquid crystal homologous series based on the benzene sulphonic acid moiety, namely (E)-4-((4-((4-(alkoxy)benzoyl)oxy)benzylidene)amino)benzenesulfonic acid (Sn), was synthesized and examined via different experimental and theoretical measurements. The four synthesized members have terminally connected alkoxy chain groups, which vary between 6 and 12 carbons. FT-IR and NMR spectroscopy, as well as elemental analyses, were used to confirm their molecular structures. Mesomorphic and optical investigations of the prepared homologues were also conducted using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The DSC and POM characterization revealed that all of the synthesized sulphonic acid members are monomorphic, exhibiting a pure smectic A (SmA) mesophase with enantiotropic properties. Moreover, all compounds in the group have high thermal transition temperatures. The terminal electron-withdrawing group –SO3H plays a considerable role in the stabilization of the molecule, which in return resulted in high thermal SmA stability. Furthermore, the experimental data relating to the mesophase behavior were substantiated via computational studies using the DFT approach. In addition, the terminal –SO3H moiety has an essential impact on the thermal and physical parameters of possible geometries. All members of the synthesized Sn series exhibit ohmic behavior with electrical resistance in the GΩ range, as revealed by electrical measurements. The S10 electrode had the highest electrical conductivity: 35.16 pS. It also showed two direct optical band gaps of 3.58 and 3.23 eV with Urbach energies of 1261.1 and 502.4 meV. Upon decreasing the number of carbon atoms to n = 6, the main bandgap for S6 reduced to 3.3 eV. The highest conductivity, good absorption, and two large bandgaps recorded for the chain derivative S10 make it suitable for investigations relating to energy-based applications.

A novel liquid crystal homologous series based on the benzene sulphonic acid moiety, namely (E)-4-((4-((4-(alkoxy)benzoyl)oxy)benzylidene)amino)benzenesulfonic acid (Sn), was synthesized and examined via different experimental and theoretical measurements.  相似文献   
87.
OBJECTIVES: The tumour suppressor gene p16INK4a is a cyclin-dependent kinase inhibitor, for which inactivation attributable to promoter hypermethylation or homozygous deletion has been described in malignancies. Little is known about p16INK4a protein levels in renal cell carcinoma (RCC) and its association with clinicopathologic parameters or disease progression. METHODS: The expression of the p16INK4a gene was analysed with the use of immunohistochemistry and tissue microarrays (TMA). Tissue cores were obtained from the primary tumour itself, the tumoural invasion front, and histologically benign peritumoural tissue of 397 nephrectomies. For statistical analysis, sections were classified into four groups according to the relative amount of positively stained cells: negative (0%), low (1-10%), intermediate (11-50%), and high positivity (>50%). Follow-up data were analyzed for 198 patients (follow-up period: 2-240 mo; median: 138 mo). RESULTS: Absent or low expression of p16INK4a was observed in 82% of tumour samples. No statistically significant association was found between protein levels detected in tumour, invasion front, or normal renal tissues and any of the clinicopathologic variables. Survival analysis by Kaplan-Meier revealed a significant association between high expression (>50%) of p16INK4a in tumours and better disease-specific survival (p=0.03, log-rank test). Cox regression analysis showed that p16INK4a expression is an independent covariate in disease-specific survival (p<0.01). CONCLUSIONS: The absence of p16INK4a expression in most tumour cells indicates that p16INK4a could be involved in the tumourigenesis of RCC. Immunohistochemically detected positivity for p16INK4a is a positive prognosticator for specific survival in both uni- and multivariate analyses.  相似文献   
88.
The objective was to determine the prevalence of parasitic agents among under-five children with diarrhea in Ilesa, Nigeria and the clinical correlates of diarrhea associated with parasitic infestation. All under-five children presenting with diarrhea in the hospital had stool microscopic examination. Children with parasites in diarrheic stools (cases) were compared with those without (controls) for clinical features. Out of 300 under-five children with diarrhea, 70 (23.3%) had parasites. There were 18 (6%) helminthes and 52 (17.3%) protozoas. These included the ova ofAscaris lumbricoides (13; 18.6%), cysts and trophozoites ofEntamoeba. histolytica (46; 65.7%), cysts ofEntamoeba coli (1; 1.4%),Giardia Lamblia (5; 7.1%),Necator american us (1; 1.4%) andTrichuris trichiuria (4; 5.7%). As against the controls, the cases were older (t=4.88; p=0:0000017), more undernourished (OR=2.04; 95% Cl=1.14 to 3.63; p=0.009) and belonged to the lower socio-economic classes (OR=7.15; 95% Cl=3.83 to 13.43; p=0.0000). It is concluded that parasitic infestations are commonly associated with childhood diarrhoea in Nigeria. Malnutrition and low socio-conomic status are risk factors.  相似文献   
89.
90.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号