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   122914篇
  免费   7251篇
  国内免费   1586篇
耳鼻咽喉   1626篇
儿科学   3061篇
妇产科学   4156篇
基础医学   18861篇
口腔科学   3662篇
临床医学   9833篇
内科学   22371篇
皮肤病学   2468篇
神经病学   8443篇
特种医学   4109篇
外国民族医学   3篇
外科学   17067篇
综合类   5261篇
一般理论   34篇
预防医学   9290篇
眼科学   2897篇
药学   10526篇
中国医学   840篇
肿瘤学   7243篇
  2021年   1086篇
  2019年   1135篇
  2018年   1730篇
  2017年   1256篇
  2016年   1298篇
  2015年   1545篇
  2014年   2027篇
  2013年   2664篇
  2012年   3911篇
  2011年   4130篇
  2010年   2452篇
  2009年   2194篇
  2008年   3644篇
  2007年   3921篇
  2006年   3839篇
  2005年   3439篇
  2004年   3248篇
  2003年   2981篇
  2002年   2844篇
  2001年   6764篇
  2000年   6949篇
  1999年   5724篇
  1998年   1870篇
  1997年   1406篇
  1996年   954篇
  1995年   881篇
  1992年   3734篇
  1991年   3819篇
  1990年   3562篇
  1989年   3566篇
  1988年   3440篇
  1987年   3288篇
  1986年   3099篇
  1985年   2975篇
  1984年   2067篇
  1983年   1804篇
  1982年   996篇
  1979年   1911篇
  1978年   1187篇
  1977年   991篇
  1976年   920篇
  1975年   1194篇
  1974年   1363篇
  1973年   1417篇
  1972年   1363篇
  1971年   1253篇
  1970年   1141篇
  1969年   1127篇
  1968年   1027篇
  1967年   899篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Previous pharmacological studies with the pituitary gland have suggested that acetylcholine (ACh) might be involved in the regulation of intermediate lobe (IL) function. Whether ACh is endogenous to the IL cells or provided from an extrinsic source is unclear. The present experiments tested the possibility that the endocrine cells of the IL may be a source of ACh by measuring certain cholinergic markers in a primary culture of dissociated porcine cells. The endogenous ACh content was readily measurable in both the freshly dissociated IL cells and in 2- or 4-day primary cultures. Choline acetyltransferase activity was also measurable in the freshly dissociated and cultured IL cells and was reduced by 53% in the presence of a specific inhibitor, napthylvinylpyridine (50 μM). IL cells incubated in the presence of [14C]choline (1 μM) were able to synthesize [14C]ACh and the accumulation of the new ACh was inhibited by hemicholinium-3 (30 μM), a competitive inhibitor of high affinity choline uptake at cholinergic nerve terminals. In conclusion, these results demonstrate that the endocrine cells of the IL are capable of synthesizing and storing ACh.  相似文献   
73.
74.
75.
Periodic, lateralized, epileptiform discharges (PLEDs) in the electroencephalogram have been reported in association with a variety of structural lesions of the brain. Although a great deal of attention has been directed to the neuropathological basis of PLEDs, little emphasis has been placed on the functional basis of this EEG syndrome. In this paper, we reported a patient with multiple systemic problems whose EEG showed PLEDs. However, radiological and pathological studies revealed no neuropathological basis for the occurrence of this EEG syndrome. Thus, we presented evidence that metabolic factors may play a part in the pathogenesis of PLEDs.  相似文献   
76.
Previously we have shown that the dorsal lateral geniculate body (LGB), which is strictly visual in sighted mammals, receives a strong auditory input in the naturally blind mole rat (Spalax ehrenbergi). Here we show with the 2-deoxyglucose technique and with single-unit recordings that in this species the initially non-degenerated visual cortex, as defined by its connection with LGB, is also activated by the auditory modality. These findings suggest that cross-modal compensation may occur as a natural consequence of the degeneration of a sense organ.  相似文献   
77.
78.
79.
80.
Duchenne and Becker muscular dystrophies are among the most severe and frequent inherited disorders. Being still incurable, medical treatment is concentrated on the carrier diagnosis of the members of the affected families. Here we report the results of the studies of 151 members of 41 Hungarian families, obtained with multiplex PCR amplification of 18 exons as well as the muscle specific promoter region, and haplotype analysis of two polymorphic (CA)n repeat microsatellite loci in introns 45 and 49 of the dystrophin gene. The analysis of 15 deletion-type families revealed a frequency of new mutations not differing significantly from that in the other regions of Europe. We also compared the allele distributions of the two microsatellites in randomly selected normal individuals and affected family members. The allele distribution of STRP45 shows interesting differences between the two populations.  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