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   252篇
  免费   8篇
耳鼻咽喉   7篇
儿科学   40篇
妇产科学   4篇
基础医学   12篇
口腔科学   6篇
临床医学   12篇
内科学   39篇
皮肤病学   4篇
神经病学   12篇
特种医学   4篇
外科学   59篇
综合类   6篇
预防医学   3篇
眼科学   28篇
药学   8篇
中国医学   1篇
肿瘤学   15篇
  2024年   3篇
  2023年   4篇
  2022年   8篇
  2021年   18篇
  2020年   7篇
  2019年   42篇
  2018年   31篇
  2017年   12篇
  2016年   2篇
  2015年   1篇
  2014年   1篇
  2010年   1篇
  2009年   2篇
  2008年   4篇
  2007年   2篇
  2006年   1篇
  2003年   2篇
  2002年   2篇
  1998年   1篇
  1997年   1篇
  1992年   1篇
  1989年   1篇
  1988年   1篇
  1986年   1篇
  1985年   8篇
  1984年   12篇
  1983年   10篇
  1982年   5篇
  1981年   17篇
  1980年   14篇
  1979年   15篇
  1978年   7篇
  1977年   8篇
  1976年   3篇
  1975年   4篇
  1974年   4篇
  1973年   4篇
排序方式: 共有260条查询结果,搜索用时 78 毫秒
21.
Reye syndrome in siblings was seen in three of 85 families; the incidence of RS in these family groups appears to exceed that of the general population. The interval between development of RS in the first and second siblings was two to 11 days and related to the incubation period of the initial viral infection. In five of the children this infection was chickenpox and in two, an unspecified upper respiratory illness. To assess the role of genetic factors, HLA typing was performed on these siblings; a common genetic marker indicating susceptibility to RS was not identified. All families resided in rural and suburban areas; exposure to a common environmental toxin was not identified.  相似文献   
22.
When intestinal obstruction is caused by an adhesive band, unsuspected pressure necrosis of the intestinal wall may be hidden by the band. Isolation of the lesion by proximal and distal noncrushing bowel clamps before the adhesive band is divided effectively prevents gross contamination and fecal peritonitis with their prohibitive mortality.  相似文献   
23.
24.
25.
Ten preterm infants (birth weight 0.970 to 2.495 kg) with apnea due to periodic breathing (apneic interval = 5 to 10 seconds) or with "serious apnea" (greater than or equal to 20 seconds) were studied before and after the administration of theophylline. We determined the incidence of apnea, respiratory minute volume, alveolar gases, arterial gases and pH, "specific" compliance, functional residual capacity, and work of breathing. Theophylline decreased the incidence of apnea (P less than .05), increased respiratory minute volume (P less than 0.001), decreased (PACO2 (and PaCO2 P less than 0.001), increased the slope of the CO2 response curve (P less than 0.02) with a significant shift to the left (P less than 0.02). These findings suggest that the decreased incidence of apnea after theophylline is associated with an increase in alveolar ventilation and increased sensitivity to CO2 with a pronounced shift of the CO2 response curve to the left. These data are consistent with the idea that apnea is a reflection of a depressed respiratory system.  相似文献   
26.
27.
28.
29.
Administration of the isoflavone genistein (GEN) has been described to result in bone protection but also to induce uterotrophic responses. To compare bone protective effects of GEN with an isoflavone-rich diet (IRD) and to further elucidate molecular mechanisms involved in bone-protection, ovariectomized rats (OVX) received either a diet low in isoflavone content (IDD) enriched with GEN (42 mg kg−1 b.wt d−1) (GENd), an IRD (14 mg kg−1 b.wt d−1 GEN, 14 mg kg−1 b.wt d−1 daidzein) or were treated subcutaneously (s.c.) with GEN (10 mg kg−1 b.wt d−1) (GENsc) for 12 weeks. Intact (SHAM), vehicle treated OVX animals and those substituted with 17β-estradiol (2 μg kg−1 b.wt d−1) (E2), served as controls.  相似文献   
30.
The basis of neuronal vulnerability, degeneration, and sparing in PD are unknown, but there is increasing evidence to suggest that the ubiquitin‐proteasome system (UPS) plays an important role in the pathogenesis of the disorder. In this study, we employed an immunocytochemical approach to determine if the differential expression of key UPS components in various brain regions and cells might underlie the pattern of neuronal degeneration and survival seen in PD. We showed that the ubiquitin activating enzyme (E1), ubiquitin conjugating enzyme (E2), and 26/20S proteasome α‐ and β‐subunits, are abundantly expressed in the substantia nigra pars compacta (SNc) and in cultured dopaminergic neurons. Although the proteasome activator PA700 is expressed in the medial SNc, levels are low in the lateral region, and expression of the other proteasome activator, PA28, is near absent in the entire SNc. PA28 (but not PA700) was found to be poorly expressed in noradrenergic neurons in the locus coeruleus (LC) compared with adjacent cells in the mesencephalic nucleus. PA700 and PA28 are also poorly expressed in dopaminergic neurons compared with other cell types in culture. Inhibition of proteasomal function, generation of misfolded proteins, induction of oxidative stress or impairment of mitochondrial complex I activity, caused a compensatory upregulation in PA700 and PA28 in a variety of cells but not in dopaminergic neurons in culture. These findings are consistent with the demonstration that, in sporadic PD, proteasomal activity and levels of PA700/PA28 are reduced in the SNc butare markedly upregulated in regions/cells that are spared from the neurodegenerative process. Thus, the differential distribution and activity of proteasome activations could play a significant role in the pathogenesis of PD. Synapse 64:241–250, 2010. © 2009 Wiley‐Liss, Inc.  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