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   1178篇
  免费   44篇
  国内免费   75篇
耳鼻咽喉   3篇
儿科学   58篇
妇产科学   17篇
基础医学   89篇
口腔科学   15篇
临床医学   160篇
内科学   246篇
皮肤病学   34篇
神经病学   106篇
特种医学   264篇
外科学   85篇
综合类   29篇
一般理论   1篇
预防医学   61篇
眼科学   22篇
药学   61篇
中国医学   3篇
肿瘤学   43篇
  2023年   7篇
  2021年   8篇
  2020年   5篇
  2019年   11篇
  2018年   12篇
  2017年   6篇
  2016年   9篇
  2015年   13篇
  2014年   17篇
  2013年   23篇
  2012年   23篇
  2011年   28篇
  2010年   38篇
  2009年   53篇
  2008年   25篇
  2007年   67篇
  2006年   41篇
  2005年   35篇
  2004年   20篇
  2003年   19篇
  2002年   22篇
  2001年   24篇
  2000年   31篇
  1999年   12篇
  1998年   83篇
  1997年   71篇
  1996年   61篇
  1995年   56篇
  1994年   46篇
  1993年   45篇
  1992年   27篇
  1991年   20篇
  1990年   31篇
  1989年   37篇
  1988年   37篇
  1987年   27篇
  1986年   24篇
  1985年   22篇
  1984年   19篇
  1983年   13篇
  1982年   19篇
  1981年   10篇
  1980年   13篇
  1979年   9篇
  1978年   6篇
  1977年   18篇
  1976年   16篇
  1975年   13篇
  1974年   4篇
  1972年   4篇
排序方式: 共有1297条查询结果,搜索用时 15 毫秒
31.
Sensitivity of cervical cytology is suboptimal, especially in developing countries such as Mexico, despite available guidelines aimed at improving this. When obtaining cervical samples, whether the samples are taken from the transformation zone and whether abnormal cells are missing must be considered. Cervical secretions (CS) are always present in variable proportions, and when cleaning the cervix, better samples may be obtained. In this study, we analyzed samples obtained with or without cleaning the cervix, and compared their contents in order to determine the sensitivity and specificity of these two methods. Methods: Of 500 patients who underwent cytology and colposcopy, 271 (54.2%) required a second opinion due to a diagnosis of cervical intraepithelial neoplasia (CIN). CS was removed and compared with the clean, second sample (SS) using in both liquid-based cytology. The quality of samples according to the Bethesda System, the presence of CIN, and inflammatory reactions were recorded. The sensitivity and specificity were calculated using biopsy as the gold standard. Results: The SS resulted in a higher proportion of adequate samples being obtained (97.6% vs. 44.8%), and in increased sensitivity (88.2% vs. 58.8%). CIN was detected in the SS 26% more often than in the CS (34 vs. 27 samples), whereas inflammatory reactions were noted more often in the CS (91.4% vs. 74%). Conclusion: Cervical sampling including CS results in lower sensitivity and CIN detection rates, and in more inflammatory reactions. By excluding CS from cervical samples, the sensitivity could be improved and the false negative rate could be reduced.  相似文献   
32.
33.
34.
35.
Tumor-induced angiogenesis is necessary to sustain radial growth of tumors. Increased microvascularity has been correlated with increased metastatic potential in breast, gastrointestinal, and gynecologic tumors, but has not been well studied in cartilaginous tumors. Grade II and Grade III chondrosarcomas have increased metastatic potential compared with Grade I tumors. One reason for this may be pathologic neovascularization. The purpose of the current study was to quantify the microvessel density of cartilage tumors. Seven Grade III, 17 Grade II, and eight Grade I chondrosarcomas, and 22 benign cartilage tumors were examined. Specimens were stained with antiCD34 antibody. Microvessel densities then were determined by direct counting and estimated using the Chalkley technique. Microvessel densities for Grade III and Grade II chondrosarcomas were 45.9 and 46.2 per high-power field and for Grade I and benign tumors the microvessel densities were 9.3 and 10.3. Microvessel densities of the aggressive tumors (Grades III and II) were greater than the microvessel densities of the nonaggressive tumors (Grade I and benign). Chalkley estimates confirmed the results. Microvascularity in cartilage tumors correlates with their biologic aggressiveness and seems promising as a variable to help with histopathologic grading and as a target for new treatment modalities.  相似文献   
36.
37.
38.
39.
40.
Numerous structures are included in the irradiated volume of patients presenting with head and neck cancer: skin, mucosa, bone, teeth, cartilage, muscles, salivary glands, etc. Curative intent treatment of such tumours requires aggressive approach which can lead to severe sequellae. These sequellae are in most cases dose-dependent and volume-dependent. However, an appropriate technique might decrease the severity of such sequellae. Details of these late changes are presented, including their pathophysiology, clinical syndromes, potential treatment, and prevention.  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