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   2295篇
  免费   147篇
  国内免费   4篇
耳鼻咽喉   13篇
儿科学   56篇
妇产科学   35篇
基础医学   332篇
口腔科学   63篇
临床医学   210篇
内科学   524篇
皮肤病学   70篇
神经病学   229篇
特种医学   19篇
外科学   279篇
综合类   4篇
一般理论   2篇
预防医学   199篇
眼科学   32篇
药学   181篇
中国医学   6篇
肿瘤学   192篇
  2024年   2篇
  2023年   18篇
  2022年   40篇
  2021年   130篇
  2020年   51篇
  2019年   114篇
  2018年   118篇
  2017年   71篇
  2016年   59篇
  2015年   70篇
  2014年   112篇
  2013年   135篇
  2012年   215篇
  2011年   191篇
  2010年   121篇
  2009年   108篇
  2008年   143篇
  2007年   111篇
  2006年   114篇
  2005年   127篇
  2004年   85篇
  2003年   84篇
  2002年   72篇
  2001年   16篇
  2000年   13篇
  1999年   7篇
  1998年   14篇
  1997年   14篇
  1996年   5篇
  1995年   7篇
  1994年   5篇
  1993年   6篇
  1992年   5篇
  1991年   3篇
  1989年   3篇
  1988年   6篇
  1987年   10篇
  1986年   4篇
  1985年   4篇
  1983年   2篇
  1982年   2篇
  1981年   3篇
  1979年   2篇
  1978年   5篇
  1975年   2篇
  1939年   2篇
  1932年   2篇
  1931年   1篇
  1930年   2篇
  1929年   1篇
排序方式: 共有2446条查询结果,搜索用时 31 毫秒
1.
European Journal of Clinical Microbiology & Infectious Diseases - We compared the performance of an in-house-developed flow cytometry assay for intracellular cytokine staining (FC-ICS) and a...  相似文献   
2.
3.
4.
A strong correlation exists between the presence of specifictypes of human papillomavirus (HPV) and the development of anogenitalcancer, as well as significant epidemiologic evidence suggestingsmokers are at increased risk of developing cervical, vulvarand/or anal carcinomas. Primary and human papillomavirus type18 (HPV-8)-immortalized human keratinocytes were used to addressthe co-carcinogenic potential of HPV and nitrosomethylurea (NMU)in tumorigenesis. Only cells containing HPV-18 and treated withNMU and the tumor-promoting phorbol ester, TPA, were transformedto a malignant phenotype. An in vitro system is described whichinitiates studies involving the mechanisms of HPV and chemicalcarcinogen co-operation in the etiology of squamous cell carcinomas.  相似文献   
5.
Eight normal male volunteers received 80 mg doses of propranolol by the oral and rectal routes and 2.2 mg by intravenous administration in a crossover fashion. Plasma concentrations of propranolol were measured by a gas chromatographic method using an electron capture detector. Individual subject concentration-time data were analysed and results indicated that the data fit a two compartment model with first order absorption. An approximately two-fold higher plasma propranolol concentration was observed after rectal administration as compared with oral dosing. Statistical analysis of the difference in the total AUCs indicates a significantly higher bioavailability of propranolol administered by the rectal route. The reduced bioavailability after oral administration indicates a substantial first pass effect but that it is possible to bypass the liver, at least partially, by giving the drug rectally to man.  相似文献   
6.
The human rod and cone systems have different spectral and adaptive sensitivities. Ganzfeld electroretinogram responses show that chronic eyelid closure, such as extensive symblepharon, can lead to dark-adaptation of the rods but simultaneously permit light-adaptation of the cones of the same eye. This effect is due to the red-filtering properties of the closed eyelid and the differential sensitivity of the two photoreceptor systems to the long wavelengths.  相似文献   
7.
8.
9.
BACKGROUND: Gastropod consumption is quite frequent in the Mediterranean countries and cross-reactivities with crustaceans have been described, but the mechanism of this allergenic cross-reactivity has not been studied in detail. This study aimed to produce recombinant Helix aspersa (brown garden snail) tropomyosin and investigate its implication for cross-reactivity among invertebrates. METHODS: A tropomyosin-specific cDNA encoding H. aspersa tropomyosin was synthetized, and recombinant allergen was overexpressed in Escherichia coli as nonfusion protein. IgE-binding reactivity was studied by immunoblotting and immunoblot inhibition experiments with sera from snail-allergic patients. RESULTS: Cloned brown garden snail tropomyosin shares high homology with other edible mollusk tropomyosins (84-69% identity) as well as with those from arthropods (65-62%), and less homology with vertebrate ones (56% identity). Tropomyosin reacted with 18% of the sera from patients with snail allergy. Inhibition experiments, using natural and recombinant tropomyosins, showed different degrees of cross-reactivity between invertebrate tropomyosins. Sera from snail-allergic subjects recognized tropomyosins in both mollusks and crustacean extracts. CONCLUSIONS: Tropomyosin represents a minor allergen in snail extracts, but it is clearly involved in invertebrate cross-reactivity.  相似文献   
10.
The familial paraganglioma syndrome is an autosomal dominant disorder characterized by the presence of carotid body paragangliomas and, less frequently, paragangliomas of the glomus jugulare, glomus vagale, and adrenal pheochromocytomas. Germline mutations of the genes for succinate dehydrogenase subunits D, B, or C (SDHD, SDHB, SDHC) have been identified in some kindreds with familial paraganglioma. In this study, we report the clinicopathologic features of four different kindreds with familial paraganglioma, which were screened for germline mutations in the SDHD gene. DNA was obtained from tumor and normal tissue, as well as from peripheral blood. Mutation analysis was performed by single-strand conformation polymorphism analysis and DNA sequencing. SDHD germline mutations were detected in the affected family members of the four families, as well as in several asymptomatic carriers. An identical mutation in exon 4 of SDHD (334-337delACTG) was identified in two apparently unrelated kindreds. The third family showed a germline mutation in exon 2 (W43X). The mutations present in these three families had been previously described in Spanish families, suggesting a founder effect. The fourth family exhibited a mutation in exon 2 of SDHD (170-171delTT), which had not been previously identified. The affected family members of the four kindreds showed paragangliomas, located in the head and neck region, and all of them were benign. These results confirm that genetic testing of SDHD may be a powerful tool for the identification of the syndrome in patients with multiple or bilateral paragangliomas.  相似文献   
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