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   1765篇
  免费   56篇
  国内免费   11篇
耳鼻咽喉   58篇
儿科学   12篇
妇产科学   21篇
基础医学   158篇
口腔科学   36篇
临床医学   117篇
内科学   433篇
皮肤病学   6篇
神经病学   79篇
特种医学   136篇
外科学   332篇
综合类   5篇
预防医学   114篇
眼科学   50篇
药学   101篇
肿瘤学   174篇
  2023年   9篇
  2022年   7篇
  2021年   20篇
  2020年   13篇
  2019年   24篇
  2018年   18篇
  2017年   24篇
  2016年   23篇
  2015年   30篇
  2014年   37篇
  2013年   65篇
  2012年   76篇
  2011年   88篇
  2010年   45篇
  2009年   64篇
  2008年   77篇
  2007年   92篇
  2006年   99篇
  2005年   114篇
  2004年   96篇
  2003年   148篇
  2002年   130篇
  2001年   52篇
  2000年   53篇
  1999年   56篇
  1998年   26篇
  1997年   23篇
  1996年   24篇
  1995年   15篇
  1994年   12篇
  1993年   19篇
  1992年   25篇
  1991年   23篇
  1990年   27篇
  1989年   30篇
  1988年   28篇
  1987年   20篇
  1986年   16篇
  1985年   11篇
  1984年   8篇
  1983年   7篇
  1982年   4篇
  1981年   4篇
  1980年   4篇
  1979年   8篇
  1976年   4篇
  1969年   3篇
  1968年   6篇
  1966年   7篇
  1965年   3篇
排序方式: 共有1832条查询结果,搜索用时 15 毫秒
1.
The leukocyte-endothelium interaction is known to contribute to reperfusion injury, which is considered to participate in the pathophysiology of pressure ulcers, and integrin alphaV beta3 (alphavbeta3) has been shown to mediate the processes of cellular adhesion in various types of cells. This study aims to clarify leukocyte behavior in our original microcirculatory pressure-induced reperfusion model, which can visualize the microcirculation in vivo. We also estimated the effect of alphavbeta3 integrin inhibition on the reduction of the leukocyte-endothelium interaction. Mice with dorsal skinfold chambers were divided into three groups: the baseline group (n=6), in which animals received no compression; the compression-reperfusion group (n=6), in which animals underwent 2-hour compression of the dorsal skin, followed by release, and the inhibitor-treated group (n=7), in which an alphavbeta3 inhibitor, CP4715, was administered in addition to the compression-release procedure. Staining with rhodamine 6G quantitatively visualized leukocyte behavior under the intravital fluorescent microscope. Compression-reperfusion induced a significant increase in rolling, sticking, and extravasation of the leukocytes. Treatment with the inhibitor strikingly reduced leukocyte sticking and extravasation. The present experiment has provided evidence that alphavbeta3 inhibition reduces leukocyte-endothelium interaction in our original pressure-induced reperfusion model.  相似文献   
2.
A 75-year-old man had been admitted to another hospital because of left abdominal pain, and was given a diagnosis of left hydronephrosis and acute pancreatitis. After a JJ stent insertion and medication, he was transferred to our hospital for further examinations. US and EUS revealed a chronic pancreatitis-like pattern and multicystic lesion in the pancreas head and body. At that time enhanced CT findings showed an extrapancreatic low density area to be inflammatory change, extending from the pancreas body to the left crus of the diaphragm and posteriorly the spreading from the left crus of the diaphragm via the left urinary duct into the left iliopsoas muscle, in which MRI revealed partial high intensity. ERCP and MRCP showed focal irregular narrowing of the pancreatic duct of unknown cause, and we decided that an internal pancreatic fistula due to pancreatitis had induced left ureteral obstruction, caused by a protein plug or alcohol. Follow-up 6 months later showed that extrapancreatic spreading of the low density area had markedly regressed without any change in the ureteral obstruction.  相似文献   
3.
4.
Summary Total body bone mineral (TBBM) content in rats was measured by dual photon absorptiometry (DPA). TBBM showed significant increases over 4 weeks in control groups with significant bone loss over the same time in prednisolone-injected rats on low calcium feed. Daily injections of calcitonin significantly reduced loss of bone mass. Both prednisolone- and prednisolone-calcitonin-injected groups showed significantly elevated serum alkaline phosphatase with the prednisolone-calcitonin group also exhibiting elevated serum calcium and phosphate levels, confirming the impact of the experimental protocol. TBBM measured by DPA in all groups correlated well (r=0.928,P<0.001 n=20) with the total ash weight suggesting that the method reflects total skeletal mineral content in the small animal. TBBM measurement by DPA proves well-suited to monitoring bone mineral in a small animal experimental setting.  相似文献   
5.
Summary In order to investigate possible effects of smoking and drinking on the metabolism of toluence in occupational settings, 206 toluene-exposed men (mean age: 31.4 years) in shoemaking, painting, or surface-coating workshops together with 246 nonexposed control men (36.8 years) were studied for the time-weighted average intensities of exposure to toluene, hippuric acid concentration in shift-end urine samples, and the two social habits of smoking and drinking. The mean daily consumptions of cigarettes and ethanol were about 20 pieces and 10 g among smokers and drinkers, respectively. The geometric mean toluene concentration among the exposed subjects was about 20 ppm, with a maximum of 521 ppm. Regression analysis after classification of the subjects by smoking and drinking clearly demonstrated that the two social habits, when combined, markedly reduce the hippuric acid level in the urine of workers exposed to was a significant association between smoking and drinking habits, which hindered separate evaluation of the effects of the two habits on toluene metabolism. Comparison of the present results with the findings reported in the literature, however, suggested that the observed effects may be attributable to smoking rather than to drinking habits.  相似文献   
6.
The aim of this study was to establish a pressure ulcer model that visualizes the microcirculation, and to examine the participation of ischemia-reperfusion injury in the pathophysiology of pressure ulcers. An original system composed of a new skin fold chamber and compression device allowed loading quantitative vertical stress to the skin. An intravital microscopic technique enabled direct visualization of the microcirculation in the physiological condition and in response to pressure application. To estimate the effect of ischemia-reperfusion injury, animals were divided into two groups: the compression-release group (n = 8), in which the animals received four cycles of compression-release which consisted of 2 hours of compression followed by 1 hour of pressure release; and the compression alone group (n = 8) in which the animals underwent continuous compression for 8 hours. Functional capillary density was quantified before the compression procedure and on day 1 (35 hours) after the first evaluation. The cyclic compression-release procedure significantly decreased functional capillary density as compared to continuous compression, indicating that in our experimental setting repetition of ischemia-reperfusion cycle more severely damaged the microcirculation than single prolonged ischemic insult. This finding supports the significant contribution of ischemia-reperfusion injury to the pathophysiology of pressure ulcers at the level of dynamic in vivo microcirculation.  相似文献   
7.
By the combined use of agar diffusion, agar vapor and agar vapor-inhibitory assays, contribution of the vapor activity of essential oils was quantitatively estimated. The test organisms were Trichophyton mentagrophytes and Aspergillus fumigatus. Agar vapor assay was used to confirm the vapor activity of the oils. The parameter delta defined as a contribution index of the vapor activity was calculated by (1 - b-c/a-c) x 100, where a is inhibitory diameter in the diffusion assay, b is inhibitory diameter in the vapor-inhibitory assay and c is diameter of the sealed ring in the vapor-inhibitory assay (21 mm). Many of the essential oils examined showed a delta value near 100, thus providing the major contribution of the vapor activity to the inhibitory diameter. Essential oils containing aldehyde as major constituent showed low delta value, indicating the major inhibition was due to agar diffusion. Major essential oil components behaved similarly; the delta value was increased in the following order: aldehyde < phenol < alcohol < ester, oxide, hydrocarbon, indicating the enhanced contribution of the vapor activity in that order.  相似文献   
8.
We report satisfactory results with a new operative treatment, conducted via an extensive anterolateral approach, involving 360 degree circumferential capsulotomy, for residual subluxation in congenital dislocation of the hip (CDH). Long-term radiographic results of this procedure (group A) were compared retrospectively with the results of partial capsulotomy (group B), which preserved the posteroinferior joint capsule. The mean center edge angle in group A (22.5°) was greater than that in group B (16.0°). Satisfactory results were achieved in 11 of 15 hips (73%) (Severin class I or II) in group A, and in 5 of 12 hips (42%) in group B. These results suggest that whole circumferential capsulotomy can remove obstacles to complete reduction, and that acetabular development can be expected in hips reduced by the procedure, without the performance of innominate osteotomy. We believe that our technique is a useful alternative for the treatment of residual subluxation in CDH.  相似文献   
9.
10.
Technetium-99m Methylene Diphosphonate (Tc-99m MDP) has often been used to assess revascularisation of bone, because positive uptake of Tc-99m MDP reflects patent anastomoses and viability of the grafted bone. However, the sequential evaluation of bone scintigraphy has seldom been reported, especially in clinical cases. We carried out sequential evaluation in 17 patients with revascularised bone grafts. In this series, intense or maximal uptake in the grafted bone was observed in the early days after surgery (1-2 weeks postoperatively), with considerable reduction after 4 weeks. Furthermore, it was found that there was no uptake of Tc-99m MDP when the anastomosed vessels were occluded, even after 6 weeks, and these three cases all developed fracture or sequestrum. We therefore believe that bone scintigraphy is reliable in the postoperative monitoring of revascularised bone for at least 4 or 6 weeks postoperatively.  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