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   1073篇
  免费   71篇
  国内免费   1篇
耳鼻咽喉   12篇
儿科学   20篇
妇产科学   33篇
基础医学   131篇
口腔科学   16篇
临床医学   92篇
内科学   264篇
皮肤病学   6篇
神经病学   62篇
特种医学   26篇
外科学   156篇
综合类   25篇
预防医学   59篇
眼科学   168篇
药学   42篇
中国医学   2篇
肿瘤学   31篇
  2023年   8篇
  2022年   17篇
  2021年   25篇
  2020年   20篇
  2019年   27篇
  2018年   45篇
  2017年   33篇
  2016年   21篇
  2015年   22篇
  2014年   29篇
  2013年   43篇
  2012年   66篇
  2011年   68篇
  2010年   45篇
  2009年   31篇
  2008年   59篇
  2007年   55篇
  2006年   48篇
  2005年   40篇
  2004年   50篇
  2003年   38篇
  2002年   37篇
  2001年   40篇
  2000年   36篇
  1999年   25篇
  1998年   6篇
  1997年   7篇
  1996年   15篇
  1994年   6篇
  1992年   9篇
  1991年   8篇
  1989年   9篇
  1988年   8篇
  1987年   6篇
  1986年   8篇
  1985年   8篇
  1984年   11篇
  1983年   8篇
  1982年   7篇
  1979年   7篇
  1978年   4篇
  1977年   4篇
  1975年   9篇
  1974年   9篇
  1972年   11篇
  1971年   4篇
  1969年   8篇
  1968年   6篇
  1967年   5篇
  1966年   10篇
排序方式: 共有1145条查询结果,搜索用时 15 毫秒
81.
PURPOSE: To describe a simplified new technique for repositioning and attaching a suture to the haptic of a displaced posterior chamber intraocular lens (IOL). METHODS: We describe a double-knot technique for repositioning and transscleral suture fixation of a subluxed posterior chamber IOL after penetrating keratoplasty. Two 10-0 Prolene transscleral sutures on straight needles are passed around the IOL haptic, tied extraocularly, and used to secure the repositioned haptic of the IOL. A second knot ties the transscleral suture in the scleral bed, stabilizing the haptic in the ciliary sulcus. RESULTS: In the case described, the IOL was stable and well positioned 2 months after surgery. CONCLUSION: The double-knot technique for intraocular repositioning and transscleral suture fixation of displaced posterior chamber IOLs reduces the extensive intraocular manipulation and scleral incisions required for IOL exchange and may reduce chronic irritation associated with iris fixation.  相似文献   
82.
83.
84.
85.
The diagnostic accuracy of the following methods of analysing exercise tests were evaluated: (a) the cumulative area of ST segment depression during exercise normalised for workload and heart rate (exercise score); (b) discriminant analysis of electrocardiographic exercise variables, workload, and symptoms; and (c) ST segment amplitude changes during exercise adjusted for heart rate. Three hundred and forty five men without a history of myocardial infarction were studied. One hundred and twenty three were apparently healthy. Less than half (170) had coronary artery disease. All had a normal electrocardiogram at rest. A Frank lead electrocardiogram was computer processed during symptom limited bicycle ergometry. The accuracy of the exercise score (a) was low (sensitivity 67%, specificity 90%). Discriminant analysis (b) and ST segment amplitude changes adjusted for heart rate (c) had excellent diagnostic characteristics (sensitivity 80%, specificity 90%), which were little affected by concomitant use of beta blockers. Both methods seem well suited for diagnostic application in clinical practice.  相似文献   
86.
The in vitro inhibitory activity of a nitrofurazone-coated urinary catheter (NFC) against 86 recently obtained susceptible and multidrug-resistant (MDR) clinical isolates of Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Staphylococcus aureus, coagulase-negative staphylococci, and Enterococcus faecium, which are species implicated in catheter-associated urinary tract infection and which traditionally have been susceptible to nitrofuran derivatives, was determined using an agar diffusion assay. In a subset of these strains, the activity of the NFC was compared with that of a silver hydrogel urinary catheter (SHC), and the durability of each catheter's inhibitory activity was assessed during serial daily transfers of catheter segments to fresh culture plates. Except for vancomycin-resistant E. faecium, the NFC was active against all isolates tested and showed comparable inhibition zones with susceptible and MDR strains of each species. In contrast, the SHC inhibited only certain staphylococci (P < 0.01 versus the NFC), and among these strains, the SHC produced smaller inhibition zones than did the NFC (P < 0.01). Inhibition was evident for up to 5 days with the NFC, but for only 1 day (if at all) with the SHC (P < 0.01). These data document that, for most genera which traditionally have been susceptible to nitrofuran derivatives, the NFC remains active against contemporary MDR isolates. They also demonstrate that the in vitro antibacterial activity of the NFC is markedly superior to that of the SHC in several respects. Thus, the NFC shows promise for clinical use in the current era of MDR bacteria.  相似文献   
87.
The epidemiological and economic burden of diabetes poses one of the main challenges for health systems worldwide. This is particularly relevant in middle-income countries because of the constant growing trends that have been observed in recent years. In order to identify trends and challenges on epidemiological and economic burden from diabetes in a middle-income country we developed a longitudinal analysis on costs and trends in the number of cases of diabetes in Mexico. The study population included total annual cases of diabetes at national level. Regarding the annual cumulative incidence for 2016 versus 2018, depending on the institution there is an increase of 9–13% (p?p?相似文献   
88.
89.
To determine whether a nonsocial enrichment program affects cardiovascular responses of individually housed male Sprague-Dawley (SD) and spontaneously hypertensive (SH) rats under basal conditions and after potentially stressful procedures, we used radiotelemetry to record heart rate (HR), systolic blood pressure (SBP), and activity in the cage. Enrichment comprised a simulated burrow (Rodent Retreat), then a food foraging item ("rat cannoli") 2 days later, and a paper bag of bedding for shredding (Nestpak) after another 2 days. Data were collected under undisturbed conditions and before and after several acute and chronic manipulations mimicking common husbandry, experimental, and stressful procedures. Enrichment often, but not always, reduced HR and SBP in male rats, suggesting decreased arousal and stress, and the effects depended on the parameter measured, strain of rat, and nature of the procedure to which animals were exposed. In general, HR varied more than SBP; enrichment affected SH rats more than SD rats; effects of enrichment were more consistently observed under undisturbed conditions than after manipulations of the rats; moderate responses to acute husbandry and experimental procedures were affected more than the larger changes produced by very stressful procedures; and responses to social interactions were unaffected by the enrichment program. What accounts for these variable effects of enrichment is unclear, and more studies are required to resolve the mechanisms. Whether this enrichment program should be used in an animal facility depends on several factors, particularly the professional judgment of the research, veterinary, and animal care staffs involved.  相似文献   
90.
Objective : This study describes and compares prevalence trends of markers for hepatitis B (HBV) from 2004 to 2013 and HBV risk factors between Indigenous and non‐Indigenous prison entrants. Methods : A cross‐sectional survey carried out over two weeks in 2004, 2007, 2010 and 2013 in reception prisons in New South Wales, Queensland, Western Australia and Tasmania. Results : The study included 2,223 prison entrants; 544 were Indigenous. Indigenous prison entrants had significantly higher hepatitis B core antibody (anti‐HBc) prevalence than non‐Indigenous prisoners in 2004 (29% vs. 18%, P=0.026), 2007 (40% vs. 15%, P<0.001) and 2010 (21% vs. 16% 2010, P=0.002), and similar anti‐HBc prevalence to non‐Indigenous entrants in 2013 (14% vs. 14%, P=0.888), with a significant decline from 2007 for Indigenous entrants (P=0.717)?. Being more than 30 years old and coming from an area classified as ‘non‐highly accessible’ were associated with anti‐HBc positivity in both populations. For Indigenous prison entrants, first time in prison and survey year was associated with anti‐HBc positivity. For non‐Indigenous participants, a history of injecting drug use and body piercings was associated with anti‐HBc positivity. Conclusion : There are unique risk factors associated with HBV prevalence for both Indigenous and non‐Indigenous prison entrants. Implications for public health : In developing public health programs and policies for HBV, consideration of similarities and differences of associated HBV risk factors between Indigenous and non‐Indigenous offenders is required.  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