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   1829篇
  免费   105篇
  国内免费   20篇
耳鼻咽喉   19篇
儿科学   18篇
妇产科学   7篇
基础医学   190篇
口腔科学   32篇
临床医学   113篇
内科学   546篇
皮肤病学   17篇
神经病学   166篇
特种医学   49篇
外科学   445篇
综合类   3篇
预防医学   41篇
眼科学   10篇
药学   82篇
中国医学   2篇
肿瘤学   214篇
  2024年   2篇
  2023年   16篇
  2022年   24篇
  2021年   64篇
  2020年   45篇
  2019年   52篇
  2018年   61篇
  2017年   59篇
  2016年   62篇
  2015年   61篇
  2014年   71篇
  2013年   63篇
  2012年   114篇
  2011年   142篇
  2010年   79篇
  2009年   42篇
  2008年   107篇
  2007年   113篇
  2006年   133篇
  2005年   126篇
  2004年   113篇
  2003年   81篇
  2002年   81篇
  2001年   19篇
  2000年   18篇
  1999年   28篇
  1998年   26篇
  1997年   16篇
  1996年   17篇
  1995年   18篇
  1994年   10篇
  1993年   4篇
  1992年   8篇
  1991年   5篇
  1990年   8篇
  1989年   5篇
  1988年   8篇
  1987年   5篇
  1986年   2篇
  1985年   3篇
  1984年   5篇
  1983年   8篇
  1982年   3篇
  1981年   6篇
  1980年   4篇
  1979年   4篇
  1978年   2篇
  1977年   3篇
  1974年   2篇
  1973年   2篇
排序方式: 共有1954条查询结果,搜索用时 31 毫秒
991.
We report a rare case of metachronous double cancer of the biliary tract. At age 59 years, a man had undergone a cholecystectomy and resection of the liver bed for gallbladder cancer pathologically diagnosed as papillary adenocarcinoma, in 1997. Four years later, he was admitted to our hospital with jaundice. At first, we suspected lymph node metastasis of the gallbladder cancer along the common bile duct. But abdominal computed tomography demonstrated circular wall thickness of the common bile duct, so primary bile duct cancer was strongly suspected. Thus, extended right hepatectomy and pancreaticoduodenectomy were performed after right portal vein embolization. The pathological diagnosis of the resected specimen was well-differentiated tubular adenocarcinoma, and this case was clarified to be metachronous double cancer. A review of the literature regarding double cancer of the biliary tract is presented following this case report. We showed that half of 30 cases of double cancer of the biliary tract were not associated with pancreaticobiliary maljunction, including all 6 metachronous cases.  相似文献   
992.
We have reported that interleukin-1 beta (IL-1 beta) upregulates cardiac expression of vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2), raising the possibility that IL-1 beta plays an important role in VEGF-mediated neovascularization. In this study, we examined the cellular mechanism for ischemia-induced neovascularization using IL-1 beta knock-out (-/-) mice. Recovery of blood perfusion in ischemic hindlimb in IL-1 beta-/- mice was markedly (43% decrease) impaired as compared with the wild-type mice. CD31(+) vessel numbers and Ki-67(+) neo-capillaries were significantly (P < 0.01) decreased 44% and 68%, respectively. IL-1 beta expression was localized in the capillary vessels in ischemic limb muscles. Ischemia-induced expressions of hypoxia-inducible factor 1 alpha (HIF-1 alpha), VEGF, its receptor VEGFR-2 and vascular cell adhesion molecule-1 (VCAM-1) were markedly inhibited in the IL-1 beta-/- mice. Hindlimb ischemia-induced an increase (1.22% out of total nuclear cell) in CD34(-)/B220(-)/CD3(-)/Flk-1(+) hematopoietic stem cell population in peripheral blood in the wild-type mice, whereas in the IL-1 beta-/- mice such increase was only 0.09%. Injection of IL-1 beta protein into the wild-type mice markedly increased the ratio of the CD34(-)/B220(-)/CD3(-)/Flk-1(+) cell population (from 0.03% to 0.7%) in the peripheral blood associated with an increase in the number of endothelial cells. Such IL-1 beta-mediated increases in cell numbers were blocked by co-injection of anti-VEGF antibody. CD34(-)/B220(-)CD3(-)Flk-1(+) cells trans-differentiated into eNOS- and CD31-expressing endothelial cells in vivo and in vitro. This study demonstrates that IL-1 beta plays a key role in ischemia-induced neovascularization by mobilizing CD34(-)/B220(-)CD3(-)Flk-1(+) endothelial precursor cells in a VEGF-dependent manner as well as by upregulating expressions of VEGF, VEGFR-2 and adhesion molecules on endothelial cells.  相似文献   
993.
BACKGROUND AND AIMS OF THE STUDY: The study aim was to elucidate the impact of the maze procedure on late outcome after valve replacement. METHODS: Between 1992 and 2000, 241 patients underwent the maze procedure combined with valve replacement. Patients were allocated to three groups: aortic valve replacement (AVR/maze, n = 16); mitral valve replacement (MVR/maze, n = 148); and combined aortic and mitral valve replacement (DVR/maze, n = 77). RESULTS: Mean follow up was 3.9 +/- 2.3 years. Hospital mortality was 0% in the AVR/maze group, 2.0% (n = 3) in the MVR/maze group, and 3.9% (n = 3) in the DVR/maze group. Elimination of atrial fibrillation (AF) at discharge was achieved in 74.3-75.9% of cases. Freedom from recurrence of AF/atrial flutter was 71.2% in the AVR/maze group, 68.2% in the MVR/maze group, and 64.0% in the DVR/maze group at five-year follow up. By multivariate analysis, risk factors for recurrence of AF/atrial flutter included preoperative enlarged left atrial dimension >70 mm, decreased postoperative fractional shortening <30%, and absence of postoperative left atrial contraction. Freedom from stroke was 93.6% in patients who achieved regular rhythm (normal sinus rhythm or junctional rhythm), and 80.9% in those with recurrence of AF at five years after surgery (p = 0.03). CONCLUSION: The combined maze procedure and valve replacement is safe and effective in selected patients. Restoration of regular rhythm significantly reduced the incidence of late stroke.  相似文献   
994.
BACKGROUND/AIMS: We investigated the effects of TS-1 on the survival of nude mice developing peritoneal dissemination of gastric cancer. METHODOLOGY: MKN-45 cells were injected into the peritoneal cavity of nude mice and a model of peritoneal dissemination was developed. TS-1 was administered orally every day from day 1 to day 10 or day 10 to day 19. RESULTS: Survival time of these treatment groups was significantly longer than untreated controls. In a pharmacokinetic study, TS-1 was administered on day 10 and the 5-fluorouracil levels were retained and maintained for a longer time, in the ascites and tumor than in plasma. The area under the concentration curve for 5-FU in the tumor was higher, than in plasma or ascites. CONCLUSIONS: TS-1 could be effective in treating peritoneal dissemination of gastric cancer, due to the supply of 5-fluorouracil in the tumor by systemic and intraperitoneal circulation.  相似文献   
995.
The association between p53 immunohistochemistry and TP53 mutation status has been controversial. The present study aims to re‐evaluate the efficacy of p53 immunohistochemistry to predict the mutational status of TP53. A total of 157 diffuse gliomas (World Health Organization grades II–IV) were assessed by exon‐by‐exon DNA sequencing from exon 4 through 10 of TP53 using frozen tissue samples. Immunohistochemistry with a p53 antibody (DO‐7) on paired formalin‐fixed paraffin‐embedded materials was assessed for the extent and intensity of reactivity in all cases. A total of 72 mutations were detected in 66 samples. They included 60 missense mutations, five nonsense mutations, four deletions and three alterations in the splicing sites. A receiver operating characteristic curve analysis revealed that strong p53 immunoreactivity in more than 10% of cells provided the most accurate prediction of mutation. Using this cutoff value, 52 of 55 immunopositive cases harbored a mutation, whereas only 14 of 102 immunonegative cases showed mutations, sensitivity and specificity being 78.8% and 96.7%. Tumors with frameshift mutations frequently showed negative immunostaining. Staining interpretation by an independent observer yielded comparable accuracy. We thus propose p53 immunohistochemistry as a moderately sensitive and highly specific marker to predict TP53 mutation.  相似文献   
996.
OBJECTIVES: To clarify clinical features of M. kansasii pulmonary disease in women. METHODS: We performed a retrospective analysis of M. kansasii pulmonary disease in women compairing with that in men. We focused on 8 female cases of M. kansasii pulmonary disease during the past 7 years from June 1998 to August 2005. RESULTS: The cases of M. kansasii pulmonary disease in women have increased in the latter few years. The mean age of female cases was higher than that of male cases, 65.6 and 53.1 years old, respectively. The number of female cases with smoking history was lower than that of male cases, 37.5% and 90.0%, respectively. Two female cases had underlying pulmonary diseases, as compared with 10 male cases, 25.0% and 33.3%, respectively. The radiological findings in female cases included 2 cavitary opacities, 1 infiltrative opacity and 5 nodular, bronchiectatic opacities, as compared with 27 cavitary opacities, 1 infiltrative opacity, 1 solitary nodular opacity and 1 nodular, bronchiectatic opacity in male cases. MAC was also detected in 2 female cases, who presented with nodular, bronchiectatic opacities. On the other hand, there were 6 female cases, in which no other NTM was detected. 3 cases showed cavitary or infiltrative opacities, which improved with the following 3 tuberculous drugs INH, RFP, and EB (HRE), while others showed nodular, bronchiectatic opacities, in which 2 cases showed radiological exacerbations without any treatment and another one revealed an improvement with HRE. CONCLUSIONS: M. kansasii pulmonary disease in women tends to be identified in elderly who smoke less and have no underlying pulmonary diseases, and most of radiological findings in female cases revealed nodular, bronchiectatic opacities. Summing up all these findings, clinical features of M. kansasii pulmonary disease in women was considered to resemble that of MAC infection, and it was speculated that the increase of M. kansasii pulmonary disease in women has some relationship with that of MAC infection in middle or lingular lobe. However, it was confirmed that some cases of M. kansasii pulmonary disease in women might primarily present with nodular, bronchiectatic lesions, regardless of MAC infection.  相似文献   
997.
998.
999.
1000.
A 57-year-old woman without any past medical history underwent abdominoperineal resection for rectal cancer in our department. On postoperative day 15, the patient complained of sudden abdominal pain, and high fever was noted in addition to the appearance of erythema around the stoma. The diagnosis of phlegmon was made, and antibiotic infusion was started. However, a few days later, the patient developed hypovolemic shock with hypoalbuminemia and hemoconcentration. Fasciotomy was performed to exclude the necrotizing fasciitis, though all cultures were negative. Upon exclusion of the differential diagnoses, idiopathic systemic capillary leak syndrome (ISCLS) was diagnosed. She was successfully treated with massive fluid infusion under ventilation and continuous hemodiafiltration. Here, we report the first case of ISCLS that occurred during the postoperative period of colorectal surgery.Key words: Idiopathic systemic capillary leak syndrome (ISCLS), Surgery, Abdominoperineal resectionIdiopathic systemic capillary leak syndrome (ISCLS) is a rare disease characterized by severe hyperpermeability of unknown cause, followed by hemoconcentration and hypoalbuminemia. During such episodes, approximately 70% of the plasma acutely shifts from the intravascular area into the interstitial space causing severe hypovolemic shock. The first case of ISCLS was described by Clarkson et al in 1960. Since then approximately 150 cases of ISCLS have been reported worldwide. To the best of our knowledge, this is the first report of a case of ISCLS that occurred during the postoperative period of colorectal surgery.  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