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   1245篇
  免费   71篇
  国内免费   2篇
耳鼻咽喉   3篇
儿科学   23篇
妇产科学   28篇
基础医学   224篇
口腔科学   8篇
临床医学   85篇
内科学   299篇
皮肤病学   36篇
神经病学   79篇
特种医学   37篇
外科学   224篇
综合类   4篇
预防医学   27篇
眼科学   15篇
药学   100篇
中国医学   6篇
肿瘤学   120篇
  2023年   4篇
  2022年   7篇
  2021年   19篇
  2020年   11篇
  2019年   16篇
  2018年   22篇
  2017年   14篇
  2016年   15篇
  2015年   22篇
  2014年   29篇
  2013年   50篇
  2012年   70篇
  2011年   74篇
  2010年   42篇
  2009年   46篇
  2008年   67篇
  2007年   76篇
  2006年   73篇
  2005年   95篇
  2004年   83篇
  2003年   56篇
  2002年   58篇
  2001年   17篇
  2000年   9篇
  1999年   21篇
  1998年   27篇
  1997年   29篇
  1996年   22篇
  1995年   25篇
  1994年   11篇
  1993年   15篇
  1992年   12篇
  1991年   15篇
  1990年   11篇
  1989年   17篇
  1988年   10篇
  1987年   11篇
  1986年   7篇
  1985年   11篇
  1984年   7篇
  1981年   6篇
  1979年   6篇
  1978年   10篇
  1977年   8篇
  1976年   8篇
  1975年   4篇
  1974年   8篇
  1973年   7篇
  1965年   5篇
  1961年   4篇
排序方式: 共有1318条查询结果,搜索用时 15 毫秒
941.
Wavefront-supported photorefractive keratectomy: 12-month follow-up   总被引:2,自引:0,他引:2  
PURPOSE: To evaluate safety, efficacy, predictability, and stability of wavefront-supported photorefractive keratectomy (PRK) for correction of myopia and myopic astigmatism, with 12-month follow-up. METHODS: Thirty eyes of 23 patients with myopia less than -8.00 D (mean -3.76 +/- 1.90 D) and cylinder less than -3.50 D (mean -0.81 +/- 0.71 D) were selected. Aberrometry measurements were taken with the Asclepion aberrometer in order to perform customized wavefront-supported PRK. Eyes were treated with the Asclepion MEL 70 excimer laser and were followed for 12 months. RESULTS: UCVA of 20/16 or better was achieved by 47% (14 eyes) at 1 month, 67% (20 eyes) at 3 months, 77% (23 eyes) at 6 months, 90% (27 eyes) at 9 months, and 83% (25 eyes) after 1 year. No eye lost more than 1 line of BSCVA at 3, 6, 9, or 12 months. Two eyes (7%) gained more than 2 lines 1 month postoperatively, and 13% (4 eyes) gained more than 2 lines at 6, 9, and 12 months postoperatively. BSCVA of 20/10 or better was achieved in nine eyes (30%) at 1 and 12 months. Visual acuity under low contrast at 3 and 12 months after PRK was unchanged in 87% (26 eyes). Visual acuity under glare remained unchanged at 3 months after PRK in 86% (26 eyes) and at 12 months in 83% (25 eyes). CONCLUSION: Excimer laser wavefront-supported PRK with the Asclepion MEL 70 laser was safe and effective for the treatment of myopia and myopic astigmatism. Daylight visual acuity and mesopic visual acuity outcomes remained stable over 1 year.  相似文献   
942.
PURPOSE: To evaluate safety and cost benefits of the percutaneous technique for treatment of aortic aneurysm, a prospective randomized study was performed that compared the endovascular suture technique with conventional cutdown access and repair. Materials and Methods: From January 2002 through July 2002, 30 endografts, including 14 Talent stent-grafts (Medtronic, Sunrise, Fla) and 16 Zenith endografts (Cook, Bloomington, Ind) were implanted in 30 patients for endovascular aneurysm treatment. The patients were randomized to either percutaneous technique (group A) or conventional cutdown (group B). Fifty-five femoral arteries were cannulated with large-bore (14F-25F) introducers and were included in the study. Safety and efficiency of both techniques were assessed by recording the complication rates, operation time, discharge, and time to ambulation. Comparison of selected estimated costs included both variable and fixed costs for femoral access and expenses for treatment of complications. RESULTS: No operative deaths occurred. The complication rates were similar and included 1 arterial thrombosis in each group, 3 lymphoceles in group B, and 1 conversion to cutdown because of bleeding in group A. Mean surgery time (86.7 +/- 27 minutes vs 107.8 +/- 38.5 minutes; P <.05) and time to ambulation (20.1 +/- 4.3 hours vs 33.1 +/- 18.4 hours; P <.001) were significantly shorter in the group treated percutaneously. Because of the cost of the closure device, total cost of the percutaneous technique averaged 99.2 euro; more than cutdown. CONCLUSIONS: The percutaneous technique decreases the invasiveness of endovascular therapy of aortic aneurysm and reduces operative time and time to ambulation. Complications were roughly equivalent in severity. The additional cost for the device appears to justify its use for this form of aneurysm treatment.  相似文献   
943.
944.
In search of novel nonsteroidal mimics of steroidal inhibitors of 5 alpha reductase, 4-(2-phenylethyl)cyclohex-1-ene carboxylic acids 1-5 were synthesized with different substituents in para position of the phenyl ring (1: N, N-diisopropylcarbamoyl, 2: phenyl, 3: phenoxy, 4: benzoyl, and 5: benzyl). The principal synthetic approach for the desired compounds consisted of a Wittig olefination between 1, 4-dioxaspiro [4.5]-decane-8-carbaldehyde (4g and the appropriate phosphonium salts. The compounds were tested for inhibition of human 5 alpha reductase isozymes 1 and 2 using DU 145 cells and preparations from prostatic tissue, respectively. They turned out to be good inhibitors of the prostatic isozyme 2 with compound 1 being the most potent one (IC(50) = 760 nM). Isozyme 1 was only slightly inhibited. It is concluded that the novel structures are appropriate for being further optimized, aiming at the development of a novel drug for the treatment of benign prostatic hyperplasia.  相似文献   
945.
A novel series of 9-benzylidene-naphtho[2,3-b]thiophen-4-ones and structurally related compounds were synthesized and evaluated for their ability to inhibit tubulin polymerization. The 4-hydroxy-3,5-dimethoxy-benzylidene analogue 15d was identified as a potent cytotoxic agent in an assay based on K562 leukemia cells. Antiproliferative activity of 15d and the 2,4-dimethoxy-3-hydroxy-benzylidene analogue 15e was additionally evaluated against a panel of 12 tumor cell lines, including multidrug resistant phenotypes. All resistant cell lines were sensitive to these compounds. Concentration-dependent flow cytometric studies showed that K562 cells as well as KB/HeLa cells treated by 15d were arrested in the G2/M phases of the cell cycle. Moreover, four compounds strongly inhibited tubulin polymerization with activities higher or comparable to those of the reference compounds. In competition experiments, the most active compounds strongly displaced radiolabeled colchicine from its binding site in the tubulin, showing IC50 values virtually 3- to 4-fold lower than that of colchicine.  相似文献   
946.
The new analogue 2 of combretastatin A-4 was discovered to be an inhibitor of tubulin polymerization with an IC50 of 7.6 microM and reduced angiogenesis in the in vivo chick embryo model. Interestingly, in a series of 2,3-diarylmaleimides closely related to this lead, no other compound was found to be active in the tubulin polymerization assay. However, by screening in the in vivo chick embryo assay 10 was identified as a potent angiogenesis inhibitor indicating an alternative target. Indeed, molecular modeling studies suggest a reasonable binding mode of 10 at the ATP-binding site of the model kinase CDK2. Motivated by these results, analogues of 10 were screened for inhibitory activity in a panel of 12 selected protein kinases and a high affinity of 10 to VEGF-R2 was found showing an IC50 of 2.5 nM. Structure-activity relationships (SAR) for this compound series with the isolated enzyme and equivalent antiangiogenic activity in the chick embryo assay are presented herein.  相似文献   
947.
To determine the in vitro susceptibility of fungal organisms to beta-cyclodextrin (CD) complexes with the antifungal agents econazole-nitrate (EC) and ciclopirox-olamine (CI), a fast, rapid and simple method using laser nephelometry in 96-microtiter plate is used. The antimycotic influence of the complexes against Candida albicans DSM 11225 and Candida krusei ATCC 6258 species was determined using this method. A rapid inhibition and even killing of both fungi was observed only above certain concentrations of complex ranged between 12.5 and 100 microg/ml for beta-CD-econazole complex (CD-EC), while for the complex with ciclopirox-olamine (CD-CI) the range was between 150 and 400 microg/ml. The stability constants of the CD complexes with the two antimycotic derivatives are given. In addition, the nephelometric method allows the determination of solubilities of active agents. Thus, the improvement of solubility of both antimycotic agents in PBS buffer solution was observed by complexation with CD.  相似文献   
948.
949.
950.
Zusammenfassung Todesfall durch elektrischen Strom bei Umwicklung einer blanken Kupferlitze um die Wurzel des männlichen Gliedes und nachfolgender Schließung des Stromkreises. Auf Grund des Sektionsergebnisses und der Auffindungssituation kann es sich nur um abwegige sexuelle Betätigung eines sonst völlig unauffälligen Menschen handeln. Diese Form der sexuellen Abartigkeit kommt äußerst selten vor.  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