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   1195篇
  免费   35篇
  国内免费   7篇
耳鼻咽喉   2篇
儿科学   38篇
妇产科学   11篇
基础医学   104篇
口腔科学   16篇
临床医学   120篇
内科学   245篇
皮肤病学   15篇
神经病学   32篇
特种医学   257篇
外科学   216篇
综合类   16篇
预防医学   24篇
眼科学   4篇
药学   64篇
  1篇
中国医学   9篇
肿瘤学   63篇
  2021年   3篇
  2018年   5篇
  2017年   5篇
  2016年   6篇
  2015年   13篇
  2014年   9篇
  2013年   18篇
  2012年   35篇
  2011年   37篇
  2010年   34篇
  2009年   32篇
  2008年   27篇
  2007年   35篇
  2006年   35篇
  2005年   41篇
  2004年   30篇
  2003年   24篇
  2002年   33篇
  2001年   30篇
  2000年   42篇
  1999年   36篇
  1998年   49篇
  1997年   42篇
  1996年   41篇
  1995年   50篇
  1994年   42篇
  1993年   40篇
  1992年   15篇
  1991年   13篇
  1990年   17篇
  1989年   45篇
  1988年   32篇
  1987年   40篇
  1986年   46篇
  1985年   26篇
  1984年   22篇
  1983年   23篇
  1982年   17篇
  1981年   21篇
  1980年   20篇
  1979年   15篇
  1978年   15篇
  1977年   15篇
  1976年   17篇
  1975年   12篇
  1971年   4篇
  1969年   3篇
  1958年   4篇
  1957年   6篇
  1954年   2篇
排序方式: 共有1237条查询结果,搜索用时 31 毫秒
1.
2.
The beStent is a new stainless steel, balloon-expandable mesh stent which has a unique serpentine design. Rotation of the unique low stress junctions upon expansion leads to orthogonal locking of the wires, maximizing radial strength and assuring zero shortening. The stent has delineating gold markers which assure precise positioning. We aim to present the initial acute results in a pilot registry for stent evaluation. Two hundred eighty-four stents were used in a total of 217 patients (age 57.9 ± 3.10 years; 178 males; 39 females) in seven centers, for variable indications. Stents of 15-, 25-, and 35-mm length were used. The arteries treated were the left anterior descending (n = 112, 42%), circumflex (n = 54, 20.2%), right coronary (n = 95, 35.5%), left main (n = 1, 0.4%), and vein graft (n = 5, 1.9%). Lesion types were: A in 42 patients (16.5%); B1 in 53 patients (20.7%); B2 in 81 patients (31.8%); and C in 79 patients (31%). One hundred fifty-nine patients required one stent, 40 patients required two stents, and 18 patients required three or more stents. Anticoagulation protocol included procedural heparin with aspirin with/without ticlopidine. Smooth angiographie results were obtained in all cases with no plaque herniation. Acute angiographic success was obtained in 97% of the patients, and acute clinical success in 95% of the patients. Complications within 30 days were: 3 deaths (1.4%) (2 noncardiac); 2 (0.9%) myocardial infarctions; and 2 (0.9%) stent thromboses. Therefore, the beStent is useful in treatment of complex lesions of variable length and complexity, providing excellent acute results with a low complication rate, in spite of unfavorable basic clinical and angiographie characteristics.  相似文献   
3.
4.
In order to evaluate the quality of life (QOL) in hypertensive outpatients, we selected 78 patients with hypertension of various degrees of severity (WHO Classification I: 29 cases, II: 15, III: 34), 59 not ill healthy persons (N1) and 22 normotensive outpatients (N2) aged at 50 years and over, using the self-completed questionnaire (QUIK) which we developed. QUIK covers four domains including physical functioning (20 questions), emotional adjustment (10), interpersonal relationships (10) and attitudes toward life (10) totaling 50 questions. In this study the internal consistency of QUIK was alpha = 0.95 by the Kuder-Richardson formula 20 and it's repeatability was r = 0.89 by the Spearman-Brown formula. The QOL in hypertensive outpatients was definitely worse in terms of total score (N1 5.1 +/- 4.4 vs WHO II 9.3 +/- 7.2 and III 12.1 +/- 5.6, p < 0.05), for physical functioning (N1 2.5 +/- 2.1 vs WHO I 3.7 +/- 2.8, II 4.7 +/- 3.8, III 5.4 +/- 2.8 p < 0.05), for emotional adjustment (N1 1.2 +/- 1.4 vs WHO III 2.3 +/- 1.7, p < 0.01), for interpersonal relationships (N1 0.8 +/- 1.3 vs WHO III 1.6 +/- 1.5, p < 0.01) and for attitudes toward life (N1 0.7 +/- 1.2 vs WHO III 2.7 +/- 2.0 p < 0.01). The total QUIK score increased according to the severity of symptoms (WHO I 5.8 +/- 4.4, WHO II 9.3 +/- 7.2 and WHO III 12.1 +/- 5.6), respectively. The total score of WHO I was significantly lower compared with that of WHO III (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
5.
In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients.  相似文献   
6.
7.
A new bone graft substitute made by conversion of the calcium carbonate exoskeleton of reef-building sea coral into hydroxyapatite has recently become clinically available. The normal radiographic appearance of two forms of this material is described. In the immediate postoperative period, the exoskeletal architecture of these implants is readily appreciated. With graft incorporation over the ensuing months, their intrinsic structure is gradually lost in association with poor marginal definition. Evolving radiographic findings reflect the biocompatible nature of these implants, which provides the potential for ingrowth of native bone with preservation of the coralline scaffold, resulting in enhanced biomechanical properties.  相似文献   
8.
We studied the long-term outcome of 268 patients suffering fromdiabetic end-stage renal disease (DM-ESRD) treated with long-termhaemodialysis between 1978 and 1991, with special emphasis onvisual acuity as well as the heterogeneity of DM-ESRD The 50%patient survival on haemodialysis was 60 months. Visual disturbanceswere found in 73.1% (392/536) of eyes at the start of haemodialysis.Chronological assess ment of visual acuity demonstrated thestabilization of visual acuity and 87.1% (364/418) of eyes werestable, 4.8% (20/418) were improved, and 8.1% (34/418) wereaggravated in the long term respectively. The change of visualacuity was frequently seen in the short term, and rapid shiftsof body fluid to correct overhydration induced abrupt changesof glycaemic control as well as retraction of macular oedema.Hence it might be one of the factors affecting rapid changeof visual acuity in the short term. Meanwhile, long-term deterioration of visual acuity resulted from either hyperten sionunresponsive to medical treatment or poor glycaemic control.Some DM-ESRD patients had only background retinopathy at thestart of haemodialysis and these were likely to have the nephroscleroticglomerular lesion. They were old, not nephrotic and had a milddegree of diabetes during the predialysis stage. Thus, DM-ESRDpatients seem to have some heterogeneity in their clinical characteristics,and old DM-ESRD patients with only background retinopathy havethe appearance of diabetic macroangiopathy rather than microangiopathy.  相似文献   
9.
The dominant cone-rod dystrophy gene CORD6 has previously been mapped to within an 8 cM interval on chromosome 17p12-p13. The retinal- specific guanylate cyclase gene (RETGC-1), which maps to within this genetic interval and previously was implicated in Leber's congenital amaurosis, was screened for mutations within this family and in a panel of small families and individuals with various cone and cone- rod dystrophy phenotypes. A missense mutation (E837D) was identified in affected members of the CORD6 family, as well as a second missense mutation (R838C) in three other families with dominant cone-rod dystrophy. RETGC-1 is only the fourth gene to be implicated in cone-rod dystrophy and this is the first report of dominant mutations in this gene.   相似文献   
10.
Injection of soluble protein antigen into the anterior chamber of the eye of primed mice induces anterior chamber-associated immune deviation (ACAID) which is manifested by suppression of delayed-type hypersensitivity (DTH) to the antigen. Recently, we found that ACAID induced in primed mice also results in a rapid rise in serum of soluble T lymphocyte-derived proteins specific for nominal antigen (TABM). Here, we demonstrate that serum TABM induced in primed mice during ACAID will transfer the suppression of DTH to mice primed to the same antigen. Sera from TNP-BSA-primed mice that received an anterior chamber injection of TNP-BSA, but not BSA alone, suppressed the DTH response to TNP when injected into other TNP-BSA-primed mice. Sera absorbed with Sepharose beads conjugated with either anti-TCR C(alpha), anti-TCR C(beta), anti-TABM or TNP-BSA did not contain TNP-specific TABM and did not transfer suppression of DTH. These results suggest that the antigen-specific, TCR C(alphabeta)+ TABM that appear in serum during ACAID are able to confer on or amplify the capacity of sensitized T cells to suppress DTH. We believe this to be the first demonstration of an in vivo immunologic function that is specifically associated with TABM produced in vivo.   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