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   191篇
  免费   4篇
  国内免费   7篇
儿科学   10篇
妇产科学   8篇
基础医学   10篇
口腔科学   7篇
临床医学   11篇
内科学   39篇
皮肤病学   3篇
神经病学   8篇
特种医学   48篇
外科学   17篇
综合类   3篇
预防医学   6篇
眼科学   4篇
药学   19篇
肿瘤学   9篇
  2023年   2篇
  2021年   2篇
  2017年   1篇
  2016年   3篇
  2015年   5篇
  2014年   5篇
  2013年   8篇
  2012年   1篇
  2011年   2篇
  2010年   7篇
  2009年   5篇
  2008年   5篇
  2007年   6篇
  2006年   4篇
  2005年   5篇
  2004年   6篇
  2003年   8篇
  2002年   2篇
  2001年   2篇
  2000年   5篇
  1999年   5篇
  1998年   8篇
  1997年   8篇
  1996年   10篇
  1995年   8篇
  1994年   5篇
  1993年   8篇
  1992年   2篇
  1991年   3篇
  1990年   4篇
  1989年   9篇
  1988年   9篇
  1987年   4篇
  1986年   6篇
  1985年   4篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   5篇
  1980年   1篇
  1978年   2篇
  1977年   4篇
  1976年   3篇
  1975年   2篇
  1969年   1篇
  1930年   1篇
排序方式: 共有202条查询结果,搜索用时 15 毫秒
61.
Cranial chondrosarcomas. Report of four cases and review of the literature   总被引:1,自引:0,他引:1  
Bahr  AL; Gayler  BW 《Radiology》1977,124(1):151
  相似文献   
62.
63.
To define the potential of iodine-123 heptadecanoic acid (IHA) for the noninvasive assessment of myocardial fatty acid metabolism with gamma camera imaging, the influence of myocardial oxygen consumption (MVO2) and blood flow (MBF) on extraction and half-times of IHA were investigated in dogs. Following IHA injection into the left circumflex coronary artery, extraction fraction and half-times were derived from the peak and slope of the IHA time activity curve, which consisted of a vascular, early, and late phase. Single-pass extraction fraction of IHA averaged 0.53 +/- 0.11 s.d. at control and was not influenced by MVO2 and MBF. The half-time of the early phase (T = 9.3 min +/- 2.8 s.d. in controls) as well as the ratio between the size of the early and late phase increased with MVO2 (r = 0.82, r = 0.87, respectively). Thus, early phase intracellular turnover of IHA increased, yet clearance of 123I activity was slowed by augmented cardiac work. Preliminary data of HPLC and electrophoretic analysis of myocardial arterial and venous blood samples over time indicate that the early phase is characterized by a decreasing washout of IHA and a relative increase of radioiodine washout. The half-time of the late phase (T = 245 min +/- 156 s.d. at control) was not related to MVO2 and MBF. In conclusion, myocardial fatty acid metabolism cannot be measured from the half-time of the early phase but might be analyzed from the ratio between the size of the early and late phase when using IHA.  相似文献   
64.
65.
We compared the effects of misoprostol, omeprazole and methylcellulose (control) on gastric mucosal injury induced by nicotine and/or ethanol. The results demonstrate that misoprostol and omeprazole each significantly reduce macroscopic injury and deep injury at a microscopic level (P < 0.05) induced by nicotine alone, ethanol alone or a combination of ethanol and nicotine. Misoprostol and omeprazole each reduced the leakage of fluorescein isothiocyanate-albumin into the interstitium in the gastric mucosa. Misoprostol and omeprazole are each effective in preventing injury induced by nicotine and ethanol and vascular factors are involved.  相似文献   
66.
Cytotoxic activity of natural killer (NK) cells in peripheral blood was studied in 60 patients with renal cell carcinoma (RCC) by means of a 51Cr release assay against K 562 cells, homologous and autologous RCC. All patients were tested prior to surgery and thereafter followed up for 1 year. Immunostimulating agents as interferon, levamisole, OMPI, and various bacterial extracts were tested for their boosting capacity on NK cells. Patients with localized tumor showed increased activity in comparison to age-matched controls, whereas NK cell activity and interferon-boosted activity in patients with advanced disease and tumor spread was decreased. Augmentation of NK activity could only be achieved by interferon, while application of levamisole, OMPI, and bacterial extracts resulted rather in suppression of cytotoxic activity.  相似文献   
67.
辽西蜂胶中一新的桂皮酸酯成分的分离与鉴定   总被引:1,自引:0,他引:1  
A new cinnamate ester drivitive (II) and three flavonoids (I, III, IV) were isolated from Liaoxi propolis. Their chemical structures were established as benzyl caffeate (II), 7-O-methylchrysin (I), genkwanin (III) and rhamnazin (IV) by spectral analysis. II is a new natural compound; I, III and IV were found from the propolis for the first time.  相似文献   
68.
Three patients with histologically confirmed sarcoidosis with spinal cord involvement were examined with high-field-strength magnetic resonance imaging (1.5 T) before and after the administration of gadolinium diethylenetriaminepentaacetic acid. In addition to intramedullary expansion, areas of patchy, multifocal, parenchymal enhancement and areas of linear peripheral enhancement were seen in all three patients; these findings have not been previously reported and are unusual for other more common spinal cord lesions. This observation led to a correct diagnosis and a limitation of the extent of biopsy in two of the cases. Unfortunately, this enhancement pattern is not specific for sarcoidosis, as the authors have observed similar findings in two cases of biopsy-proved myelitis and multiple sclerosis. The peripheral enhancement is thought to be located in the leptomeninges due to leptomeningeal involvement, which was proved histologically in one case. This pattern of involvement, while not specific, is certainly consistent with and, in the appropriate clinical setting, highly suggestive of sarcoidosis.  相似文献   
69.
脉冲电流对胰岛素经皮渗透的促进作用   总被引:4,自引:0,他引:4  
实验结果表明,脉冲电流能有效地提高胰岛素的透皮扩散速率,并随着释放池中胰岛素浓度的递增,透皮扩散速率呈线性增加。同时,胰岛素在pH值偏离等电点的酸性溶液(pH3.6)中透皮速率最高,为324.2±33.4μU/(cm2·h),而在pH值高于等电点的溶液(pH7.4)中其透皮速率降至143.7±27.3μU/(cm2·h),在pH值接近等电点(pH5.3)时,胰岛素的透皮速率最低,为78.4±21.9μU/(cm2·h)。  相似文献   
70.
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