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   3310183篇
  免费   255900篇
  国内免费   5822篇
耳鼻咽喉   48878篇
儿科学   105694篇
妇产科学   91816篇
基础医学   472660篇
口腔科学   95488篇
临床医学   296112篇
内科学   640890篇
皮肤病学   69037篇
神经病学   273661篇
特种医学   132553篇
外国民族医学   1184篇
外科学   504217篇
综合类   74772篇
现状与发展   2篇
一般理论   1216篇
预防医学   259284篇
眼科学   78347篇
药学   249026篇
  5篇
中国医学   6214篇
肿瘤学   170849篇
  2018年   33547篇
  2016年   28961篇
  2015年   32867篇
  2014年   46110篇
  2013年   70273篇
  2012年   95719篇
  2011年   100931篇
  2010年   59443篇
  2009年   56332篇
  2008年   96306篇
  2007年   103356篇
  2006年   104522篇
  2005年   102383篇
  2004年   98580篇
  2003年   95359篇
  2002年   94166篇
  2001年   148865篇
  2000年   153751篇
  1999年   130326篇
  1998年   38002篇
  1997年   34189篇
  1996年   33979篇
  1995年   32651篇
  1994年   30715篇
  1993年   28552篇
  1992年   104615篇
  1991年   101822篇
  1990年   99100篇
  1989年   95734篇
  1988年   88902篇
  1987年   87446篇
  1986年   83093篇
  1985年   79618篇
  1984年   60178篇
  1983年   51505篇
  1982年   31265篇
  1981年   27808篇
  1980年   26097篇
  1979年   56923篇
  1978年   40262篇
  1977年   34101篇
  1976年   32240篇
  1975年   34580篇
  1974年   41995篇
  1973年   39996篇
  1972年   37855篇
  1971年   35049篇
  1970年   32898篇
  1969年   30874篇
  1968年   28629篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
Medical therapy is currently the most popular treatment choice for lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Because medical therapy of BPH-related LUTS is considered a life-long strategy, short- and long-term cost considerations should play a major role in therapeutic decision-making. The effectiveness in terms of long and short amelioration of symptoms, flow rate, and quality of life are well documented for 5α-blockers and 5α-reductase inhibitors as well as for the gold standard treatment for BPH, transurethral resection of the prostate and minimally invasive therapies. Short-and long-term safety concerns also are well documented for these various treatment options. On the contrary, short- and long-term costs have been less well studied and comparisons depend on the model or analyses undertaken in the few studies available. However, the economic studies based on prospective clinical trial data that have become available throughout the past several decades allow us to rationalize our use of α-blockers, 5α -reductase inhibitors, and combination therapy, taking into consideration age, severity of symptoms, prostate volume, prostate-specific antigen, and the differential response of the various medications (and combination) in selected patients. Based on current studies, 5α -blockers generally provide cost-effective therapy for most patients, whereas 5α-reductase therapy and combination therapy provide cost-effective treatment for patients with larger prostate glands or higher baseline prostate-specific antigen levels.  相似文献   
997.
PURPOSE: The aim of this study was to determine the reproducibility of measurements made using the Sonogage Corneo-Gage Plus 2 (Cleveland, Ohio) ultrasound pachymeter of total corneal and corneal epithelial thickness in 5 different regions of the cornea. METHODS: Twenty-seven subjects at the New England College of Optometry (NECO) and 20 subjects at the Southern College of Optometry (SCO) were enrolled in this study. Measurements were taken of the central cornea as well as the nasal and temporal regions of the midperipheral and peripheral regions of the right cornea of each subject. Identical measurements were again taken in these subjects 1 week later at approximately the same time of day. Within-subject variations were then assessed using paired t tests. RESULTS: The only significant measurement differences that were found between visits were for full corneal thickness at both the nasal and temporal midperipheral locations. The mean differences for these locations were 13.5 microm and 13.7 microm, respectively. CONCLUSIONS: Epithelial corneal thickness and central and peripheral total corneal thickness measurements using the Corneo-Gage Plus 2 pachymeter were reproducible; however, midperipheral total corneal thickness measurements showed poor reproducibility.  相似文献   
998.
Rehabilitative and palliative measures in the follow-up care of pancreatic cancer patients will remain the dominant medical focus as long as potentially curative measures (recurrence prophylaxis, early detection and therapy of recurrence) have failed to show a significant survival benefit. Rehabilitative measures are possible for patients undergoing potentially curative as well as palliative treatment. Their aim is to alleviate the negative effects of the cancer and its therapy, not only physically, but also psychologically, socially and vocationally. The spectrum of possible somatic handicaps ranges from metabolic disorders, malnutrition and under-nutrition, as well as gastrointestinal symptoms to pain. Assistance in coping with illness, alleviating fears and depression and strengthening compliance are the main areas which are dealt with in psycho-oncology. Assessment of vocational fitness and the capacity to work depends on tumor location, whether R0 or R1 resection has taken place, the extent of pancreas resection, accompanying illnesses, whether or not adjuvant therapy has been given, and the physical condition of the patient  相似文献   
999.
1000.
Gonadotropins have been implicated in the development of epithelial ovarian cancers. These tumors are derived from ovarian surface epithelium (OSE). The purpose of this study was to determine the effects of these hormones on DNA synthesis and spontaneous cell death in primary cultures of OSE and three immortalized OSE cultures. Primary cultures of OSE cells were generated from the ovaries of women with benign disease. The effects of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on DNA synthesis and cell death were determined using [(3)H]thymidine incorporation and JAM assays. Significant inductions of DNA synthesis were demonstrated with LH in 4/12 (33%) primary cultures of OSE and 2/3 OSE cell lines and with FSH in 4/11 (36%) primary cultures of OSE and 2/3 OSE cell lines. A significant protection from cell death was also observed in the presence of FSH in 2/4 primary cultures of OSE and 1/3 OSE cell lines and in the presence of LH in 1/4 primary cultures of OSE and 2/3 OSE cell lines. The results indicate that while gonadotropins have the potential to induce cell proliferation and protect from cell death in OSE cells in vitro, their effects are variable in OSE cells from different women.  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