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   2115篇
  免费   125篇
  国内免费   9篇
耳鼻咽喉   4篇
儿科学   106篇
妇产科学   64篇
基础医学   234篇
口腔科学   29篇
临床医学   162篇
内科学   412篇
皮肤病学   33篇
神经病学   97篇
特种医学   65篇
外科学   397篇
综合类   45篇
预防医学   73篇
眼科学   155篇
药学   186篇
中国医学   18篇
肿瘤学   169篇
  2023年   11篇
  2022年   33篇
  2021年   81篇
  2020年   49篇
  2019年   65篇
  2018年   93篇
  2017年   52篇
  2016年   78篇
  2015年   71篇
  2014年   104篇
  2013年   134篇
  2012年   160篇
  2011年   191篇
  2010年   91篇
  2009年   102篇
  2008年   148篇
  2007年   153篇
  2006年   133篇
  2005年   121篇
  2004年   101篇
  2003年   81篇
  2002年   52篇
  2001年   22篇
  2000年   10篇
  1999年   18篇
  1998年   10篇
  1997年   11篇
  1996年   10篇
  1995年   3篇
  1994年   11篇
  1993年   3篇
  1992年   6篇
  1991年   6篇
  1990年   1篇
  1989年   5篇
  1988年   5篇
  1987年   3篇
  1986年   3篇
  1985年   2篇
  1984年   4篇
  1982年   1篇
  1981年   3篇
  1980年   2篇
  1979年   1篇
  1972年   1篇
  1960年   1篇
  1934年   1篇
  1928年   1篇
  1909年   1篇
排序方式: 共有2249条查询结果,搜索用时 9 毫秒
91.
Purpose:Chronic uveitis can lead to hypotony that may result in severe visual impairment. We highlight the use of ultrasound biomicroscopy (UBM) as an imaging tool to decide the modality of therapy and management of uveitic hypotony.Methods:This was a retrospective hospital-based interventional case-series study that included a total of 36 eyes of 25 patients with uveitic hypotony seen between January 1997 and January 2020.Results:Thirty-six eyes of 25 patients with uveitic ocular hypotony were included. Unilateral involvement was seen in 56%. The median age of presentation was 21 years with a median follow-up of 21.5 months. Anterior uveitis was noted in 13.88%, intermediate uveitis in 52.77%, and panuveitis in 33.33% eyes. UBM findings commonly noted were pars plana membranes, supraciliary effusion, blunted ciliary process, and ciliary body traction. Other findings included ciliochoroidal detachment and ciliary body edema. Moreover, 22.2% eyes were managed with medical therapy alone, whereas 77.8% eyes received both medical and surgical intervention based on UBM findings. Furthermore, 66.7% eyes showed improvement in intraocular pressure, 13.9% eyes maintained the same IOP, whereas 19.4% eyes had worsening of IOP at final follow-up.Conclusion:We found UBM as a useful imaging tool in evaluating and judiciously deciding the mode of management of uveitic hypotony.  相似文献   
92.
This review discusses the unmet needs of patients with attention deficit/hyperactivity disorder (ADHD) who are transitioning into adulthood. Although awareness and recognition of ADHD in children, adolescents, and adults have improved in recent years, there is often an interruption in management of the disorder when adolescent patients transition to adult health care services. This review has the following objectives: (1) to identify key issues patients with ADHD (with or without an early diagnosis) face during transition into adulthood; (2) to review the current clinical practice and country‐specific approaches to the management of the transition into adulthood for patients with ADHD; (3) to discuss challenges facing clinicians and their patients when drug treatment for ADHD is initiated; (4) to review current ADHD guidelines on transition management in Hong Kong, Singapore, South Korea, Turkey, and Africa; and (5) to examine economic consequences associated with ADHD. The review suggests that the transition period to adult ADHD may be an underresearched and underserved area. The transition period plays an important role regarding how ADHD symptoms may be perceived and acted upon by adult psychiatrists. Further studies are needed to explore the characteristics of the transition period. If only a fraction of adolescents go on to have mental disorders during adulthood, especially ADHD, it is crucial to identify their characteristics to target appropriate interventions at the beginning of the course of illness. There continues to be low recognition of adult ADHD and a severe lack of medical services equipped to diagnose and care for patients with ADHD transitioning from child to adult services.  相似文献   
93.
Small cell neuroendocrine carcinoma of the prostate is a rare variant of prostatic cancer that shares morphologic similarity with prostatic adenocarcinoma of Gleason 5 pattern. It has also been considered morphologically and immunohistochemically indistinguishable from small cell neuroendocrine carcinomas of other origins. CD44 is a cell-surface molecule proposed to identify cancer stem/progenitor cells in prostate cancer. We performed immunohistochemical study for CD44 expression in 11 cases of prostatic small cell neuroendocrine carcinoma and compared its patterns of expression with 73 cases of prostatic adenocarcinoma and 47 cases of small cell neuroendocrine carcinomas of other organs. Strong and diffuse membrane staining for CD44 was observed in 100% of the prostatic small cell neuroendocrine carcinomas. In conventional adenocarcinomas of the prostate, positive staining was only seen in rare, scattered tumor cells; and CD44 staining was negative in most of the small cell neuroendocrine carcinomas of nonprostate origin. The difference in CD44 expression between small cell neuroendocrine carcinomas of the prostate and those of other organs are statistically significant (P < .001). Our study demonstrates the utility of immunohistochemical staining for CD44 in distinguishing prostatic small cell neuroendocrine carcinoma from its mimickers including prostatic adenocarcinoma of Gleason 5 pattern and small cell neuroendocrine carcinomas of other organs. CD44 is the first marker that shows a high degree of tissue/organ specificity for small cell neuroendocrine carcinomas. Because CD44 is a putative marker of prostate cancer stem cells, the strong and diffuse expression of CD44 and the lack of expression of prostate luminal differentiation markers androgen receptor and prostatic specific antigen in prostatic small cell neuroendocrine carcinomas suggest that the tumor cells may retain cancer stem cell features.  相似文献   
94.
Laparoscopic approach for treatment of colorectal malignancy is gaining acceptance gradually; however the benefits of laparoscopic surgery in colonic and rectal tumours is still open to debate. This study aims at a retrospective analysis of operative and short term outcome of patients with rectosigmoid tumours. A retrospective analysis of operative, postoperative and short-term outcome of 62 patients who underwent laparoscopic colorectal resection for cancer of rectosigmoid region were compared with a same number of parameters-matched patients who underwent open colorectal resection. Blood transfusion requirement was significantly more in the open group compared to the laparoscopy group (38.7% versus 6.4%, p = 0.001). ICU stay was less in the laparoscopy group (p = <0.05) and they were started on oral liquid diet earlier (p = 0.013). The number of the lymph nodes retrieved, positive distal margin and radial involvement were similar in both groups. The hospital stay was significantly shorter in laparoscopy group (8.4 versus 13.8 days, p < 0.05). Radical operation for rectosigmoid tumors is technically feasible with laparoscopic surgery. Laparoscopic approach is associated with less blood loss, transfusion and significantly less ICU stay. Laparoscopic group recovers early and needs less hospital stay  相似文献   
95.
96.
97.
The prevalence of diverticular disease of colon of colon is reportedly low in Asian compared to Western countries. We analyzed the prevalence of colonic diverticulosis in a selected cohort of patients undergoing colonoscopy. Retrospective study of records of patients undergoing colonoscopy in a tertiary hospital in southern India.  相似文献   
98.
Background: Barrett esophagus (BE) is a premalignant condition resulting from chronic acid gastroesophageal reflux and is associated with increased epithelial cell proliferation. Elimination of acid reflux might decrease cancer risk by affecting cell proliferation in BE. The effect of elimination of acid reflux on epithelial cell proliferation in BE was studied. Methods: Forty-five patients with long segment Barrett esophagus were treated in a randomized 2-year follow-up study with either omeprazole 40 mg b.i.d. (OME) or ranitidine 150 mg b.i.d. (RAN) and were compared for the effect on epithelial cell proliferation. Biopsies were taken 3 cm above the GE junction and just below the Z-line, at 0, 3, 9, and 24 months. Epithelial cell proliferation was determined by in vitro labeling with 5-bromo-2-deoxyuridine and immunohistochemistry. Labeling indices (LI) were established for luminal and crypt epithelium separately. Ambulatory 24-h esophageal pH-metry was performed at 0 and 3 months. Comparisons were made for the timeframes 0-3 months, 3-24 months, and 0-24 months. Results: OME reduced mean acid reflux to 0.1%/24 h, RAN to 9.4%. In the distal and the proximal biopsies, change in LI after 3 months was n.s. at either level for both treatments. In the distal biopsies (OME 22, RAN 23 patients) luminal LI increased significantly for RAN from 3 to 24 months (+ 12.64% month, mean area under the curve (AUC)), while that for OME remained stable, RAN versus OME P &lt; 0.05. Crypt LI increased in both groups, only in RAN significantly so (+ 30.75% month), RAN versus OME n.s. In the proximal biopsies luminal LI at 24 months (OME 20, RAN 21 patients) had increased slightly but not significantly in RAN (+ 8.86% month), RAN versus OME n.s., whereas in the crypts LI in OME it had increased significantly (+ 28.80% month), OME versus RAN n.s. Conclusion: Elimination ofacid reflux resulted in a stabilization of luminal cell proliferative activity of Barrett epithelium in the distal esophagus, whereas this activity increased during continued acid reflux. Whether this finding has any implication for the cancer risk in Barrett esophagus remains to be seen.  相似文献   
99.
100.
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