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   1596篇
  免费   96篇
  国内免费   96篇
耳鼻咽喉   3篇
儿科学   80篇
妇产科学   17篇
基础医学   166篇
口腔科学   171篇
临床医学   180篇
内科学   382篇
皮肤病学   25篇
神经病学   82篇
特种医学   210篇
外科学   150篇
综合类   56篇
预防医学   81篇
眼科学   9篇
药学   106篇
中国医学   2篇
肿瘤学   68篇
  2021年   11篇
  2019年   11篇
  2018年   13篇
  2017年   15篇
  2016年   16篇
  2015年   20篇
  2014年   29篇
  2013年   37篇
  2012年   35篇
  2011年   46篇
  2010年   37篇
  2009年   35篇
  2008年   50篇
  2007年   104篇
  2006年   46篇
  2005年   59篇
  2004年   37篇
  2003年   41篇
  2002年   36篇
  2001年   49篇
  2000年   41篇
  1999年   37篇
  1998年   55篇
  1997年   54篇
  1996年   44篇
  1995年   41篇
  1994年   40篇
  1993年   53篇
  1992年   41篇
  1991年   44篇
  1990年   36篇
  1989年   56篇
  1988年   54篇
  1987年   53篇
  1986年   52篇
  1985年   59篇
  1984年   26篇
  1983年   19篇
  1982年   24篇
  1981年   18篇
  1980年   25篇
  1979年   27篇
  1978年   17篇
  1977年   19篇
  1974年   18篇
  1973年   9篇
  1972年   11篇
  1970年   15篇
  1968年   8篇
  1967年   9篇
排序方式: 共有1788条查询结果,搜索用时 15 毫秒
1.
顺铂聚乳酸微球的药物释放特性及肝动脉栓塞研究   总被引:5,自引:0,他引:5  
对顺铂聚乳酸微球进行了体外药物释放和家犬肝动脉栓塞研究。该微球粒径范围为50~200μm,平均粒径为115.76±35.94μm,顺铂含量为37.16%(W/W);体外药物释放机制符合Higuchi方程;肝动脉栓塞后8h,肝组织顺铂浓度高达21.55±12.18μg/g,明显高于肝动脉灌注顺铂组:3.16±0.09μg/g(P<0.05);肝动脉栓塞组的顺铂血浓峰值、各取血点浓度及曲线下面积AUC皆低于肝动脉灌注顺铂组。可望达到提高栓塞部位的药物疗效,降低全身毒副反应的作用。  相似文献   
2.
Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.  相似文献   
3.
From July 18 through November 27, 1989, 12 anaphylactoid reactions (ARs) occurred in 10 patients at a hemodialysis center in Virginia. One patient required hospitalization; no patients died. ARs occurred within minutes of initiating dialysis and were characterized by peripheral numbness and tingling, laryngeal edema or angioedema, facial or generalized sensation of warmth, and/or nausea or vomiting. All 12 ARs occurred with dialyzers that had been reprocessed with an automated reprocessing system. A cohort study, including all patients undergoing dialysis sessions on the six days when an AR occurred, showed that the patients who experienced ARs were significantly more likely than patients who did not to be treated with angiotensin-converting enzyme (ACE) inhibitors (7/10 vs. 3/33; relative risk = 7.9; 95% confidence interval = 2.5 to 25.2) and to have been exposed to reused dialyzers rather than to new dialyzers (12/70 sessions vs. 0/31; P = 0.016). In those sessions using a reused dialyzer, the mean number of dialyzer uses in case-sessions was significantly higher than for noncase-sessions (10.3 vs. 6.2; P = 0.016). After reuse of dialyzers was discontinued at the center, no further ARs occurred, despite the continued administration of ACE inhibitors. This is the first report of an outbreak of ARs associated exclusively with reused dialyzers. We hypothesize that interactions between a dialyzer that has been repeatedly reprocessed and reused, blood, and additional factors, such as ACE inhibitors, increased the risk of developing ARs.  相似文献   
4.
BACKGROUND: Many patients with asthma or chronic obstructive pulmonary diseaseuse their medication inhalers incorrectly. General practitioners,pharmacists and other health care providers do not always havethe opportunity to instruct patients in correct inhaler technique. OBJECTIVE: To find out whether the inhaler technique and respiratory symptomsof patients can be improved after instruction by practice assistants. METHODS: Single blind, randomized intervention study in which 48 patientswho had been using a dry powder inhaler for at least one monthtook part. Their inhaler technique was videotaped on two visitswith a two-week interval between visits. The inhaler techniqueon the videos was subsequently scored by two experts on ninecriteria. At both visits the patients completed a questionnaireabout their respiratory symptoms. After the first video, 25patients were randomly chosen to receive instruction from oneof six practice assistants who had followed a one evening courseabout inhaler instruction, and who had been issued an instruction-set. RESULTS: The patients who received instruction had a significantly greaterreduction in number of mistakes at the second visit than thepatients who did not (P = 0.01). The instructed patients alsoreported less dyspnoea at the second visit (P = 0.03). No effectof instruction was found on wheezing, cough and sputum production. CONCLUSION: The inhaler technique of patients can be improved significantlyby the instruction of patients by trained practice assistants,possibly resulting in less dyspnoea. Keywords. Administration-inhalation, obstructive lung diseases, airways symptoms, patient-education, general practice.  相似文献   
5.
6.
In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.  相似文献   
7.
The Ca antigen has been reported to be present on the surface of malignant but not, with few exceptions, non-malignant cells. We investigated the potential usefulness of the monoclonal Ca 1 antibody in differentiating oral squamous cell carcinoma from non-malignant or premalignant oral neoplasms. Paraffin-embedded sections from 33 biopsy specimens of 12 hyperplastic and 21 neoplastic oral lesions were examined by immunohistochemical staining. Seven of the 33 specimens showed positive staining for Ca antigen. Fifteen of 21 specimens of oral squamous cell carcinoma were negative for Ca antigen, and one case of focal keratosis was positive. The results indicate that the use of the Ca 1 antibody to distinguish oral squamous cell carcinoma from non-malignant or premalignant oral lesions is highly unreliable.  相似文献   
8.
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy.  相似文献   
9.
10.
A case of clear-cell chondrosarcoma occurred in the proximal femur of a 32-year-old man. The tumor was complicated by a focus of myositis ossificans resulting from a previous intralesional biopsy. Histologic findings included an unusual marrow infiltration by the tumor. The patient was treated with wide resection and has no evidence of local recurrence or distant spread of disease 18 months later.  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