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   1702037篇
  免费   127194篇
  国内免费   3818篇
耳鼻咽喉   21867篇
儿科学   55856篇
妇产科学   46279篇
基础医学   242712篇
口腔科学   48903篇
临床医学   152101篇
内科学   335152篇
皮肤病学   38799篇
神经病学   132270篇
特种医学   64329篇
外国民族医学   243篇
外科学   258836篇
综合类   39018篇
现状与发展   4篇
一般理论   535篇
预防医学   124802篇
眼科学   40406篇
药学   124571篇
  7篇
中国医学   4513篇
肿瘤学   101846篇
  2021年   12966篇
  2019年   13712篇
  2018年   20183篇
  2017年   15348篇
  2016年   16794篇
  2015年   19188篇
  2014年   26521篇
  2013年   38405篇
  2012年   53383篇
  2011年   56128篇
  2010年   33221篇
  2009年   31101篇
  2008年   52239篇
  2007年   55527篇
  2006年   55990篇
  2005年   53286篇
  2004年   51431篇
  2003年   48761篇
  2002年   46943篇
  2001年   91920篇
  2000年   93703篇
  1999年   77089篇
  1998年   19869篇
  1997年   17386篇
  1996年   17496篇
  1995年   16830篇
  1994年   15362篇
  1993年   14150篇
  1992年   57470篇
  1991年   55346篇
  1990年   53039篇
  1989年   50825篇
  1988年   46176篇
  1987年   44987篇
  1986年   42288篇
  1985年   40049篇
  1984年   29412篇
  1983年   24970篇
  1982年   13957篇
  1979年   25564篇
  1978年   17599篇
  1977年   14935篇
  1976年   13894篇
  1975年   14587篇
  1974年   17646篇
  1973年   16975篇
  1972年   15698篇
  1971年   14468篇
  1970年   13446篇
  1969年   12528篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
992.
K Nagai  T Suda  K Kawasaki  S Mathuura 《Surgery》1986,100(5):815-821
In rats treat-given hydrocortisone to suppress healing, tensile strength of the skin at the site of an incision wound was significantly higher in rats locally treated with carnosine than in untreated animals. Similar effects on the tensile strength of the skin were observed by the administration of beta-alanine and histidine, but not of beta-alanine alone. Exogenous carnosine was degraded in the body by carnosinase and histidine decarboxylase to yield histamine. Since beta-alanine, the other degradation product of carnosine, was found to stimulate the biosynthesis of nucleic acids and collagen, histamine derived from carnosine is considered to have enhanced the process of wound healing by stimulating effusion at the initial stage of inflammation. Thus, the enhancement by carnosine of wound healing may be ascribed to stimulation of early effusion by histamine and of collagen biosynthesis by beta-alanine. The wound-healing effects of carnosine were further demonstrated by the observation that carnosine significantly increased granulation suppressed by cortisone, mitomycin C, 5-fluorouracil, and bleomycin.  相似文献   
993.
Using the buttock flap in 29 white Yorkshire pigs, blood flow and O2 consumption were measured at dermal temperatures between 35 degrees C and 15 degrees C. Flow was measured with an electromagnetic flowmeter and O2 consumption was calculated as the product of blood flow and the difference in flap A-VO2. Baseline flow was 6.6 +/- .9 (SE) ml/100 g/min at 35 degrees C and 3.1 +/- .02 (SE) ml/10 g/min at 15 degrees C. Blood flow through the flap stopped completely at a dermal temperature of 14 degrees C. Oxygen consumption was 0.16 +/- .02 (SE) ml/100 g/min at 35 degrees C and 0.04 +/- 0.01 (SE) ml/100 g/min at 15 degrees C. At 20 degrees C blood flow was 4.3 ml/100 g/min and metabolism was .04 ml/100 g/min. In other words, blood flow was 65% of baseline, while O2 consumption was only 25% of baseline. The therapeutic effect of local cooling at 20 degrees C deserves further investigation. The cessation of flow at 14 degrees C may be caused by increased plasma viscosity.  相似文献   
994.
995.
In this study, the lamination pattern of the main olfactory bulb (MOB) of P. hispanica has been described using EM and Golgi-impregnation techniques. Six layers could be distinguished from the external surface to the ventricles: olfactory nerve layer (ONL), glomerular layer (GL), external plexiform layer (EPL), mitral layer (ML), internal plexiform layer (IPL), and granular cell layer (GCL). In ONL unmyelinated axonic bundles from the olfactory mucosa are seen. The GL is defined by the presence of terminal ramifications of the mitral primary dendrites and by axonic terminals of the olfactory nerve. The EPL is a dendritic articulation layer between the mitral and granule cells, where a great density of dendrodendritic synaptic contacts has been found. The ML is defined by the large mitral cell somata, and the IPL by myelinated axonic bundles that run rostro-caudally. Finally, the GCL is characterized by the presence of granule cells. Using the Golgi-impregnation method, five different neuronal types have been described. In the glomerular layer, a small cell population is located; these neurons seem the periglomerular cells described in mammals. The second type corresponds to the mitral cell population and the morphological features of these cells resemble to those of mammals. The three remaining types constitute the granule cell population; this population is characterized by a great morphological heterogeneousness. However, these types have been differentiated according to their dendritic tree morphology and location of the cell body. A morphological gradient depending on the distance of cell body for each type to the ependymal layer, has been observed. In EM, four different types of neuronal cell bodies according to their location and ultrastructure have been defined. The laminar organization of the MOB of Podarcis is similar to that in all vertebrates. The results for the fine structure and dendritic tree morphology have revealed a high similarity between these reptiles and mammals.  相似文献   
996.
997.
998.
MK-0787 (Imipenem)/MK-0791 (Cilastatin sodium), a new compound of Thienamycin, was administered in treatment of 35 patients (36 cases) with chronic complicated UTI or for prevention of serious infections with much complicated factors. The patients were principally treated at a daily dose of 1 g for over 10 days. The efficacy rate of 26 patients who were evaluable in the early phase (4-7 days) was 88.5%, while it became up to 92.3% in the final phase judgment. As for clinical usefulness, the result was obtained to be as high as that of the clinical efficacy. In bacteriological study, 35 strains were clinically isolated including 7 strains of P. aeruginosa from UTI. All the strains disappeared with an eradication rate of 100% after treatment. Strains appearing after Imipenem/Cilastatin sodium treatment mainly consisted of fungi. Usefulness judgements tended to be greater in the final phase than in the early phase. As for side effects, vomiting was recorded in one case, in which the administration was discontinued. In laboratory findings there were 3 cases with elevated GPT, 2 cases with elevated GOT, one case with elevated gamma-GTP, one with thrombocytopenia, and one with eosinophilia each, but these abnormal values were slight and transient. In summary our clinical study showed that Imipenem/Cilastatin sodium was a very effective antibiotic in treatment on moderate or serious UTI or preventive use for infections in compromised hosts. Considering the features of this agent, it might be more effective and useful for clinical use in treatment on polymicrobial infections including stubborn organisms than any other antimicrobial compounds. Furthermore, it was safe and well tolerable in a long term treatment.  相似文献   
999.
The exact location of hemorrhage complicating anticoagulant therapy is sometimes difficult to establish. We present a case in which imaging with 99mTc-labeled red cells had a significant role in the diagnosis of soft-tissue bleeding in a paraplegic patient receiving long-term anticoagulation.  相似文献   
1000.
Preadmission testing programs have been developed to recognize and treat medical abnormalities prior to hospitalization, thus reducing preoperative hospital day costs. A preadmission testing program's objectives can be expanded by combining with a discharge planning program. The two programs combined can facilitate discharge planning and patient education prior to hospitalization and coordinate the nursing process. This article will discuss the purposes, organization, and benefits of a preadmission discharge planning program.  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