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   14852篇
  免费   819篇
  国内免费   125篇
耳鼻咽喉   190篇
儿科学   325篇
妇产科学   188篇
基础医学   2264篇
口腔科学   356篇
临床医学   1351篇
内科学   2847篇
皮肤病学   548篇
神经病学   1156篇
特种医学   687篇
外科学   2088篇
综合类   61篇
一般理论   2篇
预防医学   670篇
眼科学   392篇
药学   1345篇
中国医学   189篇
肿瘤学   1137篇
  2023年   101篇
  2022年   320篇
  2021年   517篇
  2020年   285篇
  2019年   364篇
  2018年   408篇
  2017年   347篇
  2016年   494篇
  2015年   652篇
  2014年   765篇
  2013年   843篇
  2012年   1315篇
  2011年   1187篇
  2010年   753篇
  2009年   642篇
  2008年   840篇
  2007年   868篇
  2006年   753篇
  2005年   673篇
  2004年   561篇
  2003年   455篇
  2002年   422篇
  2001年   315篇
  2000年   301篇
  1999年   227篇
  1998年   93篇
  1997年   75篇
  1996年   52篇
  1995年   75篇
  1994年   37篇
  1993年   34篇
  1992年   89篇
  1991年   75篇
  1990年   87篇
  1989年   83篇
  1988年   70篇
  1987年   61篇
  1986年   58篇
  1985年   55篇
  1984年   35篇
  1983年   35篇
  1981年   28篇
  1980年   25篇
  1979年   40篇
  1978年   44篇
  1977年   27篇
  1976年   21篇
  1975年   31篇
  1974年   28篇
  1973年   21篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
It is important to acknowledge the harmful effects of environmental chemicals in human’s lives. The toxic effects of Diethylstilbestrol (DES), one of the endocrine-disrupting chemicals (EDCs), have been documented in many studies. As expected, DES affect male gendal hormone as well as female’s; therefore, epigenetic study should be considered. In this study, microarray technology was used to study harmful effects on the level of genomics, and here, two types of microarray chips- the Agilent mouse genome 4 × 44 K array for gene expression profiling and the Agilent mouse miRNA v13 for miRNA expression profiling-was used to study the relation between gene and miRNA expression profiles. As a result, we identified 4 miRNAs (miR 203, 350, 421, and 466i) that were similarly expressed at 3 hrs and 24 hrs of DES treat times. Twenty one genes matched between predicted target for 4 miRNAs and 118 genes expressed similarly. These genes have functions related to cell differentiation and cell cycle. Therefore, DES affects cellular function and induces toxicity in TM4 cells. In future studies, it is necessary to find more related functions and mechanisms of DES in the system.  相似文献   
44.
45.
Sensitization of striatal N-methyl- -aspartate receptors (NMDAR) has been linked to events leading to the motor response changes associated with the administration of dopaminomimetics to parkinsonian animals and patients. To determine whether tyrosine phosphorylation of NMDAR subunits contributes to the apparent long-term enhancement in synaptic efficacy of these receptors, we examined the effect of unilateral nigrostriatal dopamine system ablation with 6-hydroxydopamine followed by twice-daily treatment with -DOPA on the phosphorylation state of rat striatal NR2A and NR2B subunits. Three weeks of intermittent -DOPA administration produced a shortening in the duration of the rotational response to dopaminergic challenge and other changes mimicking those occurring in patients with Parkinson's disease. Concurrently, tyrosine phosphorylation of NR2A and especially of NR2B subunits increased ipsilateral to the lesion (20±5% and 46±7% of intact striatum, respectively; p<0.01) without attendant changes in subunit protein levels. Selective blockade of NR2B subunits with ACEA 10-1244, but not of NR2A subunits with MDL 100,453, reversed the -DOPA-induced response alterations. The intrastriatal injection of a tyrosine kinase inhibitor, genistein, at a dose (2.0 μg) that normalized the response shortening, attenuated the NR2A and NR2B phosphorylation increase by about 12% and 24%, respectively (p<0.01). Taken together, these results suggest that augmented tyrosine phosphorylation of NR2B subunits, alone or in combination with the smaller rise in NR2A subunit phosphorylation, contributes to the apparent enhancement in striatal NMDAR sensitivity and thus to the plastic alterations in dopaminergic responses in -DOPA-treated parkinsonian rats.  相似文献   
46.

Background  

Statin-related skeletal muscle disorders range from benign myalgias – such as non-specific muscle aches or joint pains without elevated serum creatinine kinase (CK) concentration – to true myositis with >10-fold elevation of serum CK, to rhabdomyolysis and myoglobinuria. The genetic basis of statin-related muscle disorders is largely unknown. Because mutations in the COQ2 gene are associated with severe inherited myopathy, we hypothesized that common, mild genetic variation in COQ2 would be associated with inter-individual variation in statin intolerance. We studied 133 subjects who developed myopathy on statin monotherapy and 158 matched controls who tolerated statins without incident or complaint.  相似文献   
47.
OBJECTIVES: To analyze the clinical characteristics and treatment results between bilateral (bi-) and unilateral (uni-) sudden sensorineural hearing loss (SSNHL). STUDY DESIGN AND SETTING: A retrospective study. METHODS: Three hundred twenty-four patients with SSNHL were classified into two groups; simultaneous bi-SSNHL (n = 16) and uni-SSNHL (n = 308). We compared clinical characteristics, medical history, hearing level, and treatment results between the 2 groups. RESULTS: The incidence of bi-SSNHL was 4.9 percent of overall patients with SSNHL. Bi-SSNHL occurs more commonly in patients of older age, with preexisting diabetes mellitus, and lipid panel abnormalities compared with uni-SSNHL. Ten patients (62.5%) in the bi-SSNHL group showed hearing recovery in 1 or both ears compared with 56.5 percent of patients with uni-SSNHL. Only 12 (37.5%) of all 32 ears recovered in bi-SSNHL, which was significantly lower than in uni-SSNHL. CONCLUSION: Bi-SSNHL has a very low incidence and lower recovery rate than uni-SSNHL. Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.  相似文献   
48.
49.
50.
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