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   23859篇
  免费   987篇
  国内免费   170篇
耳鼻咽喉   186篇
儿科学   464篇
妇产科学   210篇
基础医学   2836篇
口腔科学   452篇
临床医学   1548篇
内科学   6290篇
皮肤病学   515篇
神经病学   1925篇
特种医学   824篇
外科学   3893篇
综合类   83篇
一般理论   4篇
预防医学   511篇
眼科学   1061篇
药学   1516篇
中国医学   40篇
肿瘤学   2658篇
  2023年   130篇
  2022年   309篇
  2021年   539篇
  2020年   262篇
  2019年   359篇
  2018年   436篇
  2017年   362篇
  2016年   499篇
  2015年   522篇
  2014年   656篇
  2013年   775篇
  2012年   1376篇
  2011年   1426篇
  2010年   862篇
  2009年   726篇
  2008年   1260篇
  2007年   1403篇
  2006年   1373篇
  2005年   1493篇
  2004年   1490篇
  2003年   1341篇
  2002年   1408篇
  2001年   481篇
  2000年   456篇
  1999年   484篇
  1998年   370篇
  1997年   286篇
  1996年   278篇
  1995年   245篇
  1994年   220篇
  1993年   217篇
  1992年   287篇
  1991年   250篇
  1990年   239篇
  1989年   247篇
  1988年   210篇
  1987年   141篇
  1986年   178篇
  1985年   164篇
  1984年   121篇
  1983年   110篇
  1982年   67篇
  1981年   65篇
  1979年   103篇
  1978年   78篇
  1977年   71篇
  1974年   56篇
  1973年   59篇
  1972年   51篇
  1971年   63篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
33.
SPECT of the skull was performed on twelve patients with histologically proven nasopharyngeal carcinoma using newly developed three detectors SPECT system (Toshiba GCA 9300A) mounted with fan-beam collimators, for the purpose of early detection of skull base involvement of the disease. This SPECT system has extremely improved resolution with FWHM of 8 mm in the center, and it provides clear tomographic images of the skull which has anatomically complex structure. SPECT image was taken 3 hours after injection of 740 MBq (20 mCi) of 99mTc-MDP following whole body skeletal survey. In twelve patients with confirmed nasopharyngeal carcinoma, 8 patients showed positive findings on SPECT. Three of SPECT positive patients also showed destructive findings on CT. Other five positive patients did not show destructive findings on CT at their initial examinations, but in three of them CT findings turned to positive later. SPECT was superior to CT in early detection of skull base involvement. We believe that SPECT of the skull is a diagnostic tool for early detection of skull base involvement of nasopharyngeal carcinoma.  相似文献   
34.
Whether or not compromised host defense prior to surgical treatment is related to development of infection with methicillin-resistant staphylococcus aureus (MRSA) following major surgery was examined. Of 22 patients undergoing esophagectomy for cancer between 1989 and 1990, 5 were free from MRSA colonization and infection (group I) while 8 had MRSA colonization without infection (group II) and 9 had MRSA infection (group III). Levels of neutrophil cytocidal functions, complements, immunoglobulins and cell-mediated immunity were not significantly different among these three groups. The mean of anti pneumococcal polysaccharide (PPS)-IgG was significantly lower in group III than in group I (p < 0.05) and tended to be lower than in group II (P = 0.08). All infected patients showed a titer < 600 EU while all but one non-infected patient did so > 600 EU. Serum IgG2 levels positively correlated with anti-PSS IgG levels. Thus, we concluded that a preoperative evaluation of antibody response against polysaccharides and serum IgG2 levels can serve to predict development of MRSA-related infection following esophageal surgery.  相似文献   
35.
Microendoscopic observation of methylene blue-stained urothelial surfaces, so-called microscopic chromocystoscopy (MCC), was undertaken in 65 patients with superficial bladder cancer (Ta and T1) and its effectiveness in detecting concurrent urothelial dysplasia or carcinoma in situ was studied. A total of 166 biopsy samples were taken from 75 stained and 91 non-stained portions. Of 75 methylene blue-stained areas, 21 were judged to be abnormal (MCC-positive) by microscopic observation. Fourteen of these 21 MCC-positive areas (67%) were proven to be abnormal histologically, while 7 of 54 MCC-negative portions (13%) were histologically abnormal. Only 4 of 91 biopsies (4%) from non-stained mucosa were proven to have urothelial atypia. In per patient figures, 1 or more concurrent field changes were detected in 15 of 65 cases (23%). MCC contributed to the diagnosis in 10 of these 15 patients.  相似文献   
36.
37.
Hypertrophic scars (HS) are a consequence of abnormal wound healing. We examined fatty acids that are contained within, and participate in, every reaction through the membrane; then, we analyzed the percentage composition of the fatty acids in deepithelialized normal dermis (ND) and HS. In vivo HS samples were obtained from six patients undergoing surgical excision, and ND samples from five patients undergoing skin grafting surgery for excess. In vitro, cultured fibroblasts from HS and ND were also analyzed. The percentage composition of fatty acids extracted from all the samples was analyzed. In vivo, arachidonic acid (20:4) was significantly more abundant in HS than in ND, in the phospholipids from both whole tissue and cell membranes. In vitro, there were no significant differences among ND, HS, and 10% fetal calf serum. The results suggest that HS formation does not necessarily involve simple excess of 20:4; however, there are considerable differences in the percentage composition of 20:4 between ND and HS. Arachidonic acid probably participates in the formation and maintenance of HS, whereas in vitro cultured fibroblasts are affected largely by fetal calf serum.  相似文献   
38.
A 40-year-old woman noticed blurred vision of the right eye. The optic disc edema of bilateral eyegrounds was noted, and brain MRI showed abnormal signals of the brainstem at a neurosurgical clinic. On her first visit, blood pressure was as remarkably high as 250/130 mmHg. Neurologically, only optic disc edema of bilateral eye-grounds was found. Both T2-weighted MRI and FLAIR showed hyperintense signal areas mainly from the ventral pons to medulla oblongata. These areas were not enhanced with gadolinium. About three weeks after the administration of an antihypertensive agent, brain MRI revealed no abnormal signal. About three months later, the blurred vision disappeared and ophthalmological abnormalities subsided. We diagnosed her with a brainstem variant of RPLS, presenting with visual disturbance caused by hypertensive retinopathy.  相似文献   
39.
Purpose: Rehabilitation professionals do not appear to be sufficiently prepared to deal with the sexual issues of people with a physical disability, although they have recognized the value of discussing them during the rehabilitation process. This commentary argues that the sexuality of people with a disability should be evaluated from the two viewpoints of sexual function and sexual concern. With regard to people with a limb amputation, their sexual life has not attracted researchers' or clinicians' interest because their sexual function is usually preserved, is the same as that of able-bodied persons, and there is a perception that assistance is not required. Indeed, the number of published studies on the sexuality of this population is apparently fewer than the number of studies on the sexuality of persons with central nervous system impairment.

Conclusion: Investigation of the body image of people with a limb amputation and recognition of their needs are considered to be necessary for further discussion of this theme. Discussion of sexuality with some realistic statistical figures should also have great value in assisting with the re-integration of people with a limb amputation.  相似文献   
40.
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