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   2875篇
  免费   161篇
  国内免费   7篇
耳鼻咽喉   22篇
儿科学   75篇
妇产科学   60篇
基础医学   382篇
口腔科学   169篇
临床医学   194篇
内科学   624篇
皮肤病学   41篇
神经病学   332篇
特种医学   90篇
外科学   436篇
综合类   21篇
预防医学   261篇
眼科学   41篇
药学   157篇
中国医学   17篇
肿瘤学   121篇
  2023年   13篇
  2022年   37篇
  2021年   79篇
  2020年   55篇
  2019年   62篇
  2018年   82篇
  2017年   52篇
  2016年   77篇
  2015年   80篇
  2014年   93篇
  2013年   162篇
  2012年   219篇
  2011年   238篇
  2010年   137篇
  2009年   121篇
  2008年   185篇
  2007年   203篇
  2006年   172篇
  2005年   170篇
  2004年   144篇
  2003年   138篇
  2002年   113篇
  2001年   44篇
  2000年   49篇
  1999年   28篇
  1998年   23篇
  1997年   10篇
  1996年   19篇
  1995年   10篇
  1994年   11篇
  1993年   8篇
  1992年   14篇
  1991年   15篇
  1990年   20篇
  1989年   14篇
  1988年   11篇
  1987年   9篇
  1986年   14篇
  1985年   11篇
  1984年   6篇
  1983年   5篇
  1982年   5篇
  1980年   5篇
  1979年   8篇
  1978年   9篇
  1977年   5篇
  1976年   5篇
  1975年   5篇
  1972年   8篇
  1969年   7篇
排序方式: 共有3043条查询结果,搜索用时 15 毫秒
1.
2.
3.
Submitral ventricular aneurysm is a thoroughly studied pathology but is not well known due to its rarity. Clinically, it is manifested by symptoms and signs of heart failure, mitral regurgitation and/or ventricular arrhythmias, and may be associated with thromboembolic phenomena and myocardial ischemia due to compression of the coronary arteries by the aneurysm. A rare complication of this type of aneurysm is rupture into the left atrium. Transthoracic echocardiography plays an important role in the definitive diagnosis of this pathology, although the role of transesophageal echocardiography in the evaluation of these patients is less known. We report a case of a submitral ventricular aneurysm complicated by rupture into the left atrium, which was diagnosed by transesophageal echocardiography.  相似文献   
4.
Percutaneous transvenous mitral commissurotomy was performed successfully via the transjugular approach in a patient with severe rheumatic mitral stenosis and obstruction of the inferior vena cava due to prior liver transplantation. This case demonstrates the advantage of the jugular approach in patients with difficult anatomy.  相似文献   
5.
A 56-yr-old woman with long-standing rheumatoid arthritis exhibited jaundice, pruritus and abdominal discomfort after 8 yr of periodic gold sodium thiomalate injections amounting to a cumulative dose in excess of 2.5 gm. Histopathological examination of the liver biopsy specimen showed submassive loss of parenchyma, collapse of reticulin and mixed cellular inflammatory infiltrates. Macrophages contained dark granules, which displayed the characteristics of aurosomes when examined by transmission electron microscopy and electron microprobe analysis. It is likely that hepatocellular injury occurred when the lysosomal storage capacity for gold was exceeded.  相似文献   
6.
对30例稳定性心衰患者进行放射性核素心室造影和时相分析,确定基线时和最大耐受剂量卡维地洛治疗6个月后左心室和心室间的收缩同步性。与正常人群相比,心衰患者具有明显的心室不同步。基线时具有最显著不同步的患者中第50位百分位数表明,接受卡维地洛治疗后心室同步性得到显著改善,这与舒张末期左心室容量降低呈正相关。卡维地洛对慢性心衰患者心室内和心室间同步性的影响@Castro P. F.$Dr. Faculty of Medicine, P. Catholic University of Chile, University of Chile, Santiago, Chile @Mc-Nab P. @Quintana J. C. @王…  相似文献   
7.
Background: We performed a phase I study of a novel system of complete hepatic venous isolation and extracorporeal chemofiltration in patients with unresectable hepatocellular carcinoma (HCC) to determine (a) whether systemic exposure to doxorubicin could be limited after high-dose hepatic arterial infusion (HAI), and (b) the hepatic maximum tolerated dose (MTD) of doxorubicin. Methods: Ten patients with biopsy-proven HCC were treated with 20-min HAI of doxorubicin (17 total treatments). Two patients were treated with doxorubicin 60 mg/m2, three patients were treated at 90 mg/m2, and five patients received 120 mg/m2. A newly developed dual-balloon vena cava catheter was advanced from the femoral vein, and the balloons were inflated to isolate and capture total hepatic venous outflow. The hepatic venous blood was pumped through extracorporeal carbon chemofilters before return of the blood to the systemic circulation. Results: Peak systemic doxorubicin levels were an average 85.6% lower than were peak prefilter levels (p<0.01). Because all catheters were placed percutaneously and because the chemofiltration markedly limited systemic chemotherapy exposure, patients were discharged 1 day after 16 of the 17 treatments. The hepatic and systemic MTD of doxorubicin in this treatment protocol was 120 mg/m2. Conclusions: This novel system of complete hepatic venous isolation and chemofiltration limits systemic chemotherapy toxicity and will allow use of higher doses of chemotherapeutic agents to treat HCC. The results of this study were presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles, California, March 18–21, 1993.  相似文献   
8.

Background  

To develop a sensitive and specific screening tool for knee and hip osteoarthritis in the general population of elderly people.  相似文献   
9.
10.
B cell neoplasms present heterogeneous patterns of lymphoid organ involvement, which may be a result of the differential expression of chemokine receptors. We found that chemokine receptor (CCR)7, CXC chemokine receptor (CXCR)4, or CXCR5, the main chemokine receptors that mediate B cell entry into secondary lymphoid tissues and their homing to T cell and B cell zones therein, were highly expressed in B malignancies with widespread involvement of lymph nodes. Conversely, those pathologies with little or no nodular dissemination showed no expression to very low levels of CCR7 and CXCR5 and low to moderate levels of CXCR4. These findings provide evidence for the role of CCR7, CXCR4, and CXCR5 in determining the pattern of lymphoid organ involvement of B tumors. Functional studies were performed on B malignancies expressing different levels of CCR7, CXCR5, and CXCR4. Multiple myeloma (MM) cells did not express CCR7 nor CXCR5 and did not migrate in response to their ligands; a moderate expression of CXCR4 on MM cells was accompanied by a migratory response to its ligand, CXCL12. By contrast, cells from B cell chronic lymphocytic leukemia (B-CLL) expressed the highest levels of these chemokine receptors and efficiently migrated in response to all ligands of CCR7, CXCR4, and CXCR5. In addition, the migration index of B-CLL cells in response to both of the CCR7 ligands correlated with the presence of clinical lymphadenopathy, thus indicating that the high expression of functional chemokine receptors justifies the widespread character of B-CLL, representing a clinical target for the control of tumor cell dissemination.  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