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   525篇
  免费   26篇
  国内免费   9篇
耳鼻咽喉   18篇
儿科学   5篇
妇产科学   1篇
基础医学   56篇
口腔科学   12篇
临床医学   28篇
内科学   157篇
皮肤病学   6篇
神经病学   40篇
特种医学   60篇
外科学   82篇
综合类   4篇
预防医学   6篇
眼科学   3篇
药学   26篇
中国医学   2篇
肿瘤学   54篇
  2023年   2篇
  2022年   4篇
  2021年   8篇
  2020年   7篇
  2019年   5篇
  2018年   11篇
  2017年   14篇
  2016年   9篇
  2015年   11篇
  2014年   19篇
  2013年   23篇
  2012年   25篇
  2011年   26篇
  2010年   20篇
  2009年   14篇
  2008年   32篇
  2007年   33篇
  2006年   27篇
  2005年   21篇
  2004年   33篇
  2003年   11篇
  2002年   14篇
  2001年   7篇
  2000年   20篇
  1999年   12篇
  1998年   3篇
  1997年   4篇
  1996年   9篇
  1995年   3篇
  1993年   2篇
  1992年   5篇
  1991年   5篇
  1990年   15篇
  1989年   19篇
  1988年   12篇
  1987年   13篇
  1986年   11篇
  1985年   6篇
  1984年   6篇
  1983年   10篇
  1982年   6篇
  1981年   3篇
  1979年   5篇
  1978年   2篇
  1977年   3篇
  1976年   2篇
  1973年   2篇
  1972年   2篇
  1968年   1篇
  1967年   1篇
排序方式: 共有560条查询结果,搜索用时 15 毫秒
1.
To examine species differences in the distribution pattern of guanosine triphosphate (GTP)-binding protein (Go) within the vertebrate retina, paraffin-embedded retinae from a number of vertebrate species, including the goldfish, frog, turtle, chicken, monkey, and human, were immunohistochemically stained with affinity-purified antibody against the alpha-subunit of Go. Go-immunoreactive products were found to be located in the neuropil, but not in the cell bodies of neurons, in the retina of all these species. However, some species differences were observed. In the frog, monkey and human, the inner plexiform layer (IPL) was homogeneously stained with this antibody, but in the goldfish, turtle and chicken, the IPL was heterogeneously stained. In the frog, chicken, turtle and human, the outer plexiform layer (OPL) was densely stained with this antibody, but in the goldfish and monkey, the OPL was rather faintly immunoreactive to the antibody. In the goldfish, monkey and human, the outer nuclear layer (ONL) was not immunoreactive to the Go-antibody, whereas in the frog, turtle and chicken, the ONL was immunoreactive to it. The implications of these species differences in Go localization in the vertebrate retina are discussed.  相似文献   
2.
Adult Still's disease reflects a Th2 rather than a Th1 cytokine profile   总被引:2,自引:0,他引:2  
Adult Still's disease (ASD) is a chronic multisystemic disease. Extraordinarily high serum levels of IL-18 in ASD patients have been described, whereas the mechanism remains to be clarified. This study aimed to evaluate proinflammatory cytokines and to consider their pathological roles. In patients with rheumatic diseases (n = 151), blood samples were taken at the active phase and the serum levels of IL-18 and other proinflammatory cytokines were measured by ELISA. The extra-high levels of IL-18 were confirmed selectively in ASD patients (n = 10). In the active phase of ASD patients, the levels of IL-6 were elevated accordingly, but IL-1beta and TNF-alpha were undetectable. As to Th1-Th2 cytokines, the levels of IL-4 and IL-13, but not INF-gamma, IL-12, or IL-2, were elevated in all ASD patients examined. Moreover, the serum levels of IL-18 showed a good correlation with those of IL-4, suggesting that ASD reflects a Th2 rather than a Th1 cytokine profile.  相似文献   
3.
4.
AIM: The aim of the present study was to explore whether heme oxygenase-1 (HO-1) is involved in the hyperthermia-provided protection of the small intestine from ischemia/reperfusion injury in rats. METHODS: Intestinal damage was induced in male Sprague-Dawley rats by clamping both the superior mesenteric artery and the celiac trunk for 30 min, followed by reperfusion. Whole-body hyperthermia was induced in anesthetized rats by placement in a temperature-controlled water bath. Whole-body hyperthermia to a core temperature of 42-43 degrees C for 15 min was followed by passive cooling. We started the hyperthermic treatment 6 h before the vascular clamping. The severity of the mucosal injury was evaluated by several biochemical markers and histological findings. Hyperthermia-induced heat-shock proteins were detected by Western blotting. We also investigated the effect of zinc protoporphyrin IX (an HO-1 inhibitor) on the protective effect of hyperthermia. RESULTS: The rats, which were killed after ischemia/reperfusion, had severe intestinal inflammation. Hyperthermia significantly induced the production of Hsp70 and HO-1 in intestinal mucosa and significantly reduced ischemia/reperfusion-induced mucosal injury. The combination of zinc protoporphyrin IX with hyperthermia extinguished the protective effects of hyperthermia on ischemia/reperfusion injury. CONCLUSION: Hyperthermia protects against ischemia/reperfusion injury in rat small intestine through the expression of heat-shock proteins, especially HO-1.  相似文献   
5.
6.
Although oropharyngeal and laryngeal structures are essential for swallowing, the three‐dimensional (3D) anatomy is not well understood, due in part to limitations of available measuring techniques. This study uses 3D images acquired by 320‐row area detector computed tomography (‘320‐ADCT’), to measure the pharynx and larynx and to investigate the effects of age, gender and height. Fifty‐four healthy volunteers (30 male, 24 female, 23–77 years) underwent one single‐phase volume scan (0·35 s) with 320‐ADCT during resting tidal breathing. Six measurements of the pharynx and two of larynx were performed. Bivariate statistical methods were used to analyse the effects of gender, age and height on these measurements. Length and volume were significantly larger for men than for women for every measurement (P < 0·05) and increased with height (P < 0·05). Multiple regression analysis was performed to understand the interactions of gender, height and age. Gender, height and age each had significant effects on certain values. The volume of the larynx and hypopharynx was significantly affected by height and age. The length of pharynx was associated with gender and age. Length of the vocal folds and distance from the valleculae to the vocal folds were significantly affected by gender (P < 0·05). These results suggest that age, gender and height have independent and interacting effects on the morphology of the pharynx and larynx. Three‐dimensional imaging and morphometrics using 320‐ADCT are powerful tools for efficiently and reliably observing and measuring the pharynx and larynx.  相似文献   
7.
8.

Purpose  

Extraperitoneal spaces, such as the mesenteric space and the retroperitoneal space, can serve as areas that enable a reduction in the pressure exerted by extraperitoneal fluid collection and infiltrating diseases. In clinical practice, understanding the existence of these decompression spaces (or pathways) is very important for making accurate diagnoses. Here, we evaluated potential anatomical extraperitoneal spaces based on the extraluminal gas distribution in patients with pneumatosis intestinalis without intestinal ischemia.  相似文献   
9.
Patent ductus venosus   总被引:1,自引:0,他引:1  
BACKGROUND: Patent ductus venosus is extremely rare with only 14 cases reported in the world literature. We present a case of patent ductus venosus. METHODS AND RESULTS: A 29-year-old male was admitted with melaena stool caused by gastric haemorrhagic ulcers. Laboratory data disclosed severe anaemia; however, liver function tests were normal. Serum ammonia was also within the normal range. Serological viral markers for hepatitis B or C were all negative. The abdominal ultrasonography and computed tomography indicated a 12 mm diameter shunt located in the left lobe of the liver, which connected the portal vein with the left hepatic vein. After treatment for gastric ulcers, percutaneous transhepatic portography was performed and an enormous shunt connecting the umbilical portion of the portal vein with the left hepatic vein was revealed. CONCLUSIONS: Histological findings of the liver biopsy showed that portal venules could not be observed in the portal areas and that no fibrosis or inflammatory cell infiltration were shown. Because of the anatomical position of the shunt, the case was diagnosed as patent ductus venosus.  相似文献   
10.
Further evaluation of the pancreatic excretion test with 5,5-dimethyl-2,4-oxazolidinedione (dimethadione, DMO) was made in comparison with the pancreozymin-secretin (PS) test on 100 normal subjects, 79 patients with chronic pancreatitis, and 83 patients with nonpancreatic disease. The diagnostic sensitivity of the oralN-benzoyl-l-tyrosyl-PABA (BT-PABA) test was estimated in 42 patients with chronic pancreatitis, on whom both PS and DMO excretion tests were performed as test of reference for exocrine pancreatic function. Pancreatic DMO excretion after secretin injection was significantly diminished in chronic pancreatitis. The DMO excretion test was more sensitive than the PS test to detect chronic pancreatitis and to distinguish between mild to moderate and advanced noncalcific chronic pancreatitis. The specificity of the DMO excretion test was more than adequate to find out pancreatic disease. The 6-hr urinary PABA excretion was significantly reduced in chronic pancreatitis. The BT-PABA test, however, showed the low sensitivity in mild to moderate chronic pancreatitis.  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