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   1084篇
  免费   74篇
  国内免费   63篇
耳鼻咽喉   3篇
儿科学   59篇
妇产科学   3篇
基础医学   119篇
口腔科学   24篇
临床医学   112篇
内科学   212篇
皮肤病学   29篇
神经病学   34篇
特种医学   264篇
外科学   91篇
综合类   60篇
预防医学   50篇
眼科学   22篇
药学   102篇
中国医学   4篇
肿瘤学   33篇
  2023年   2篇
  2022年   11篇
  2021年   23篇
  2020年   6篇
  2019年   4篇
  2018年   12篇
  2017年   7篇
  2016年   13篇
  2015年   14篇
  2014年   23篇
  2013年   24篇
  2012年   9篇
  2011年   22篇
  2010年   31篇
  2009年   31篇
  2008年   30篇
  2007年   53篇
  2006年   37篇
  2005年   47篇
  2004年   27篇
  2003年   38篇
  2002年   24篇
  2001年   29篇
  2000年   16篇
  1999年   29篇
  1998年   58篇
  1997年   65篇
  1996年   58篇
  1995年   58篇
  1994年   37篇
  1993年   45篇
  1992年   16篇
  1991年   22篇
  1990年   23篇
  1989年   49篇
  1988年   37篇
  1987年   33篇
  1986年   18篇
  1985年   21篇
  1984年   12篇
  1983年   8篇
  1982年   15篇
  1981年   18篇
  1980年   19篇
  1979年   11篇
  1978年   5篇
  1977年   14篇
  1976年   10篇
  1975年   7篇
排序方式: 共有1221条查询结果,搜索用时 15 毫秒
11.
Specificity of acupoints remains a crucial question in acupuncture research. The aim was to investigate whether acupuncture of specific points influences the Cortical Auditory Evoked Potentials (CAEP). Ten healthy volunteers were enrolled in this study according to inclusion criteria. One of 4 acupoints: TH3, GB43 (both claimed as specific for auditory system by Traditional Chinese Medicine) and non-specific points H7 and ST44, was stimulated during one session. Each volunteer received 4 sessions of acupuncture with an interval of 1 week between the sessions. The latencies and amplitudes of CAEP were registered before and after the acupuncture during each session. The mean peak latencies of P2 component decreased after stimulation of TH3 by 11 ms and GB43 by 14 ms whereas the peak latencies of N2 component increased after stimulation of TH3 by 9 ms and GB43 by 4 ms compared to baseline values (p<0.05). The stimulation of H7 and ST44 did not produce any changes. These findings confirm the specificity of acupuncture points TH3 and GB43 in relation to auditory system.  相似文献   
12.
Bone scintigraphy in the reflex sympathetic dystrophy syndrome   总被引:1,自引:0,他引:1  
  相似文献   
13.
14.
锌酞菁脂质体光动力作用引起小鼠肿瘤的细胞程序性死亡   总被引:3,自引:1,他引:3  
电镜观察了锌酞菁脂质体光动力作用引起小鼠MS-2纤维肉瘤的形态学变化。发现其作用很强,并对肿瘤细胞有明显的直接影响。肿瘤细胞的结构表现出明显的程序性细胞死亡(apoptosis,programmedceldeath)的特点:胞核染色质凝聚边集、核固缩、核破裂、染色质凝块流失、胞质内吞噬现象、胞膜表面肿胀粗钝的胞突形成、细胞碎裂等。加深了对锌酞菁脂质体光敏作用机理的认识,但其详细的发生机制和调节途径有待阐明。  相似文献   
15.
16.
17.
OBJECTIVE: The treatment of peripheral tears of the triangular fibrocartilage complex is radically different from the more typical central, degenerative tears. To our knowledge, no reports in the imaging literature specifically evaluate tears of the ulnar attachment of the triangular fibrocartilage complex. We evaluated the accuracy of MR imaging in these patients. MATERIALS AND METHODS: Eighty-six MR imaging examinations of the wrist (41 indirect MR arthrograms and 45 unenhanced MR images) were evaluated: 20 wrists with surgically confirmed peripheral triangular fibrocartilage complex tears and 66 wrists with surgically documented normal ulnar attachment. These cases were evaluated by three experienced musculoskeletal radiologists, who were unaware of the surgical findings, to assess the presence of peripheral triangular fibrocartilage complex tears or fluid signal at the ulnar attachment of the triangular fibrocartilage complex. RESULTS: The sensitivity for evaluation of the peripheral triangular fibrocartilage complex tear was 17%, with a specificity of 79% and an accuracy of 64%. High signal intensity at the ulnar insertion of the triangular fibrocartilage complex as a marker for tear showed a sensitivity of 42%, a specificity of 63%, and an accuracy of 55%. Weighted kappa values revealed only fair agreement among the three observers. CONCLUSION: MR imaging does not adequately reveal the peripheral attachment of the triangular fibrocartilage complex.  相似文献   
18.
Low serum albumin and low serum cholesterol levels are among the most consistent predictors of mortality in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Hypoalbuminemia is often interpreted as a marker of poor nutrition, but serum albumin and cholesterol levels can also be low as part of a cytokine-mediated acute-phase reaction to acute or chronic inflammation. Here we report the results from a 900-day prospective study designed to determine whether tumor necrosis factor-alfa (TNF-alpha) and interleukin-6 (IL-6) predict serum albumin and cholesterol levels and mortality in a group of 90 ambulatory, adult hemodialysis patients with no acute infection, hospitalization or surgery, and no known acquired immunodeficiency syndrome (AIDS), malignancy, or liver disease. Measurable levels of TNF-alpha and/or IL-6 were found in 89 of 90 patients. Significant relationships were found between TNF-alpha and IL-6 and the degree of hypoalbuminemia and dyslipoproteinemia. IL-6 was the strongest predictor of mortality in univariate and multivariate analysis, followed by age, albumin level, and body mass index (BMI). Although the cause of hypercytokinemia was not addressed in this study, the data support the view that hypoalbuminemia and hypocholesterolemia are negative acute-phase responses to inflammatory stimuli. These results suggest that efforts to identify the nature of the stimuli for cytokine production and to lower cytokine levels in hemodialysis patients might be effective in improving the survival of patients undergoing hemodialysis.  相似文献   
19.

Background

In breast cancer treatment, sentinel lymph node (SLN) evaluation is used to identify patients who may benefit from axillary lymph node dissection (ALND). Intraoperative evaluation (IE) of SLNs facilitates immediate ALND. Controversy exists regarding the accuracy of intraoperative SLN evaluation for patients with invasive lobular carcinoma (ILC) compared to invasive ductal carcinoma (IDC).

Methods

Using breast cancer registry data from January 2003 to March 2008, the intraoperative SLN evaluation of 66 ILC and 810 IDC patients was compared to the final SLN pathology result and to the performance of ALND.

Results

In ILC, the sensitivities of IE for isolated tumor cells (≤.2 mm, N0[i+], n = 9), micrometastases (>.2 mm and ≤ 2.0 mm, N1mi, n = 6), and macrometastases (>2.0 mm, N1a-3a, n = 21) were 0%, 17%, and 71%, respectively. The specificity was 100%. IE identified 16/27 (59%) of SLN-positive (N1mi, N1a-3a) axillae, resulting in synchronous ALND. Delayed ALND for false negative IEs (11/27, 41%) occurred in 7/11 patients (64%). In IDC, the sensitivities of IE for N0(i+) (n = 60), N1mi (n = 75), and N1a-3a (n = 129) metastases were 0%, 7%, and 71%, respectively. The specificity was 99.6%. IE identified 97/204 (48%) of SLN-positive (N1mi, N1a-3a) axillae, resulting in synchronous ALND. Delayed ALND for false negative IEs (107/204, 52%) occurred in 38/107 patients (36%).

Conclusions

Sensitivity and specificity of intraoperative SLN evaluation is very similar in ILC and IDC patients. Intraoperative SLN evaluation facilitated synchronous ALND in concordance with recommended practice guidelines.  相似文献   
20.
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