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   1535篇
  免费   97篇
  国内免费   5篇
耳鼻咽喉   33篇
儿科学   24篇
妇产科学   35篇
基础医学   349篇
口腔科学   38篇
临床医学   81篇
内科学   291篇
皮肤病学   22篇
神经病学   190篇
特种医学   33篇
外科学   114篇
综合类   14篇
预防医学   153篇
眼科学   37篇
药学   100篇
中国医学   2篇
肿瘤学   121篇
  2022年   11篇
  2021年   16篇
  2020年   7篇
  2019年   20篇
  2018年   16篇
  2017年   26篇
  2016年   29篇
  2015年   32篇
  2014年   34篇
  2013年   60篇
  2012年   65篇
  2011年   62篇
  2010年   49篇
  2009年   31篇
  2008年   65篇
  2007年   74篇
  2006年   68篇
  2005年   70篇
  2004年   80篇
  2003年   68篇
  2002年   65篇
  2001年   52篇
  2000年   55篇
  1999年   38篇
  1998年   17篇
  1997年   25篇
  1996年   18篇
  1995年   16篇
  1994年   13篇
  1993年   13篇
  1992年   29篇
  1991年   34篇
  1990年   29篇
  1989年   41篇
  1988年   34篇
  1987年   31篇
  1986年   29篇
  1985年   23篇
  1984年   17篇
  1983年   12篇
  1982年   7篇
  1979年   13篇
  1978年   7篇
  1974年   12篇
  1973年   11篇
  1972年   11篇
  1970年   9篇
  1969年   8篇
  1968年   11篇
  1965年   6篇
排序方式: 共有1637条查询结果,搜索用时 15 毫秒
1.
Jahn  P. 《Der Onkologe》2020,26(11):1040-1046
Die Onkologie - Die Pflegepersonaluntergrenzen als rote Linien zur Abgrenzung einer gefährlichen Pflegepraxis sind nicht geeignet, die dringend benötigte Trendwende einzuleiten und...  相似文献   
2.
4260 conjunctival specimens of 2850 outpatients with keratoconjunctivitis of presumed infectious etiology were studied. Two thousand six hundred sixty-eight specimens (63%) revealed growth of bacteria, and 80 (2%) growth of fungi. One hundred ninety-nine specimens (5%) were McCoy cell culture or direct stain (monoclonal antibody or Giemsa) positive for Chlamydia trachomatis. two patients had a C. psittaci infection (ELISA techniques). In patients with keratoconjunctivitis of bacterial etiology, overall incidence of McCoy cell culture-proven chlamydial infections was 7%; in the 20 to 30-year age group it was 12.5%. Simultaneous infections of chlamydiae and other bacteria were seen in 34 patients. Since sensitive and specific tests to diagnose chlamydial infections are available, ophthalmologists may be able to prevent these infections by agent-specific antibiotic therapy.  相似文献   
3.
Apolipoprotein E isoforms were determined in 139 unrelated patients with retinitis pigmentosa (RP). When compared to prevalence rates for the general population in Germany, an increased prevalence was observed for phenotypes E2/E2: 10.1 vs. 1.0% (p less than 0.001), E2/E3: 19.4 vs. 12.0% (p less than 0.05), and E2/E4: 5.8 vs. 1.5% (n.s.), while the prevalence appeared to be reduced for phenotypes E3/E3: 48.9 vs. 59.8% (n.s.) E3/E4: 13.7 vs. 22.9% (p less than 0.05), and E4/E4: 2.2 vs. 2.8% (n.s.). These findings suggest that genetically determined abnormalities of plasma lipoprotein metabolism may be associated with some forms of RP.  相似文献   
4.
Observations on time-dependent localization of tetra(3-hydroxyphenyl)porphin (3-THPP) in human malignant melanoma transplanted to athymic nude mice from 1 to 120 h after intraperitoneal (i.p.) 10 mg kg–1 b.w. administration were made by means of fluorescence microscopy. Fluorescence was found on the membrane of the melanoma cells and in the cytoplasm with a peak fluorescence intensity at 24 h post-injection of 3-THPP. The growth of the tumour cells was obviously inhibited at an early stage after PCT. Morphological changes of the tumour at various intervals after treatment by PCT with 3-THPP were also observed. Diffuse degeneration of the tumour cells with swelling of mitochondria and endoplasmic reticulum, heterochromatin aggregation and margination, etc., and subsequently diffuse necrosis with little or no the background of tumorous vascular response were found at an early stage after PCT. On the other hand, it was also observed that the necrosis of the melanoma areas was caused as a consequence of tumorous vascular injury at a later stage after PCT. Thus, two tumoricidal processes caused by PCT with 3-THPP were seen: a direct phototoxic action on tumour cells at an early stage after PCT and an indirect effect secondary to tumorous vascular injury at a later period after PCT.  相似文献   
5.
During seven years, 212 small bowel examinations are made on patients with suspected small bowel obstruction by barium infusion. We find all the main small bowel pathology: Crohn's disease (16.5%), carcinomatosis (14.6%), neoplasia (10.3%), vascular disease (17.8%), actinic enteritis (9.5%) and miscellanous (18%). The small bowel infusion is normal in 15%. Surgery is avoided in 51% of the cases. There is non complications associated with the examination but in 12% of the cases, the examination is unsuccessful.  相似文献   
6.
7.
8.
9.
The accumulation of blood monocytes at sites of predilection of the vessel wall is an early cellular event of atherogenesis. Proteins of the vessel wall may facilitate monocyte adhesion and thus promote their recruitment. It has been shown that the relative content of extracellular fibrinogen increases during lesion development, and this study investigated the contribution of immobilized fibrinogen to monocyte adhesion and the underlying mechanism. Freshly isolated human blood monocytes were cultivated in serum-free RPMI 1640 in tissue culture wells precoated with albumin, fibrinogen, or fibrin. After 16 h the plates were washed and adherent cells enumcrated. Immobilized fibrinogen enhanced monocyte adhesion more than 1.9-fold compared to immobilized albumin or fibrin (P<0.05). Concomitant addition of the protein kinase C (PKC) inhibitors staurosporine or H7 suppressed monocyte adherence to immobilized fibrinogen but exerted no significant effect upon adhesion to any other surface tested. Stimulation of monocytes using phorbol myristate acetate resulted in increased binding of monocytes on fibrinogen but not on bovine serum albumin. When PKC activity was reduced through prolonged incubation with PMA for 16h, a significant reduction of monocyte adhesion on fibrinogen was observed. Peptides containing RGD sequences, which have been demonstrated to be ligands for certain integrins, did not inhibit monocyte adhesion. The data suggest that fibrinogen promotes monocyte adhesion in vitro by a PKC-dependent mechanism. PKC appears to be important not only for the initial cell adhesion but also for sustained binding of monocytes to fibrinogen.Abbreviations BSA Bovine serum albumin - ECM Extracellular matrix - PKC Protein kinase C - PMA Phorbol myristate acetate  相似文献   
10.
Follicular lymphomas (FLs) are a heterogeneous group of tumors, but prognostic factors are evaluated insufficiently in this common hematologic neoplasm. While bcl-6 and CD10 are expressed characteristically in FLs, their significance for biologic behavior of FL has not been studied previously. Samples from 73 patients with FL and clinical follow-up from 7 to 231 months were evaluated by immunohistochemical analysis. Patients with high levels of bcl-6 expression had favorable overall survival (OS) (P = .003), disease-specific survival (DSS) (P = .033), and time to treatment failure (P = .003) compared with patients with low levels of bcl-6 expression. Multivariate analysis showed that the results for OS, DSS, and time to treatment failure were independent of the international prognostic index. Patients with CD10+ FLs also had longer OS (P = .001), DSS (P = .007), and time to treatment failure (P = .004), and grade 1 FL was associated with better OS (P = .01) and a statistical trend for longer DSS (P = .05) and time to treatment failure (P = .05), but these results were not independent of bcl-6 expression or the international prognostic index in multivariate analysis.  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