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   2335650篇
  免费   175206篇
  国内免费   3280篇
耳鼻咽喉   32220篇
儿科学   75832篇
妇产科学   62912篇
基础医学   346083篇
口腔科学   63659篇
临床医学   210080篇
内科学   453471篇
皮肤病学   51849篇
神经病学   184106篇
特种医学   88202篇
外国民族医学   494篇
外科学   353502篇
综合类   47338篇
现状与发展   12篇
一般理论   849篇
预防医学   181565篇
眼科学   54181篇
药学   174925篇
  9篇
中国医学   4409篇
肿瘤学   128438篇
  2019年   19594篇
  2018年   27122篇
  2017年   20402篇
  2016年   22823篇
  2015年   25726篇
  2014年   36214篇
  2013年   54101篇
  2012年   74904篇
  2011年   79635篇
  2010年   47209篇
  2009年   44730篇
  2008年   74841篇
  2007年   79725篇
  2006年   80542篇
  2005年   78024篇
  2004年   74603篇
  2003年   71814篇
  2002年   69375篇
  2001年   108696篇
  2000年   111342篇
  1999年   93001篇
  1998年   25416篇
  1997年   22018篇
  1996年   22400篇
  1995年   22599篇
  1994年   20794篇
  1993年   19619篇
  1992年   71966篇
  1991年   70126篇
  1990年   68446篇
  1989年   65731篇
  1988年   60318篇
  1987年   59169篇
  1986年   55265篇
  1985年   53044篇
  1984年   39301篇
  1983年   33335篇
  1982年   19800篇
  1981年   17799篇
  1979年   35848篇
  1978年   25621篇
  1977年   21192篇
  1976年   20299篇
  1975年   21819篇
  1974年   26160篇
  1973年   24832篇
  1972年   23244篇
  1971年   22062篇
  1970年   20258篇
  1969年   19345篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Vaccination is a vital health care initiative to prevent individual and population infection. To increase vaccination rates the federal government implemented the ‘No Jab, No Pay’ policy, where eligibility for several government benefits required children to be fully vaccinated by removing ‘conscientious objections’ and expanding the age range of children whose families receive benefits. This study assesses the impact of this policy at a local area within a single medical practice community in NSW, Australia. A retrospective clinical audit was performed between 2012 and 2017 on a single general practice's vaccination records for children ≤19 years. Catch-up vaccinations were assessed based on age at vaccination. Incidence of catch-up vaccinations was assessed for each of four years before and two years after the implementation of the ‘No Jab, No Pay’ policy in January 2016, along with the age of children and vaccination(s) given. Catch-up vaccinations were assessed temporally either side of implementation of ‘No Jab, No Pay’. Comparing the average annual vaccination catch-up incidence rate of 6.2% pre-implementation (2012–2015), there was an increase to 9.2% in 2016 (p < .001) and 7.8% in 2017 (p = .027). Secondary outcome measurement of catch-up vaccination incidence rates before (2012–2015) and after (2016–2017) ‘No Jab, No Pay’ implementation showed statistically significant increases for children aged 8–11 years (3.2%–5.6%, p = .038), 12–15 years (7.5%–14.7%, p < .001) and 16–19 years (3.3%–10.2%, p < .001) along with a statistically significant reduction in children aged 1–3 years (11.4%–6.2%, p = .015). Also, catch-up rates for DTPa significantly increased after program implementation. This study demonstrates that the Australian federal government vaccination policy ‘No Jab, No Pay’ was coincident with an increase in catch-up vaccinations within a rural NSW community served by one medical practice, especially for older children.  相似文献   
22.
Münch  F.  Purbojo  A.  Wenzel  F.  Kohl  M.  Dittrich  S.  Rauh  M.  Zimmermann  R.  Kwapil  N. 《Der Anaesthesist》2022,71(11):882-892
Die Anaesthesiologie - Die Transfusion von Erythrozytenkonzentraten (EK) ist mit verschiedenen Nebenwirkungen assoziiert, die u. a. durch Lagerungsschäden an Erythrozyten hervorgerufen...  相似文献   
23.
During first outburst of COVID-19, several strategies had been applied for surgical oncology patients to minimize COVID-19 transmission. COVID-19 infection seemed to compromise survival and major complication rates of surgical oncology patients. However, survival, tumor progression and recurrence rates of surgical oncology patients were associated to the consequences of COVID-19 pandemic on their management. In addition, the severity of COVID-19 infections has been downgraded. Therefore, management of surgical oncology patients should be reconsidered.  相似文献   
24.
25.
26.
27.
28.
Journal of Medical Ultrasonics - Chronic liver disease is still a major problem because disease progression will ultimately lead to liver cirrhosis. Portal hypertension is the hallmark in advanced...  相似文献   
29.
30.
BackgroundThe purpose of this study was to compare initial fixation strength between various stemless and stemmed humeral components and to correlate implant fixation strength with bone mineral density (BMD).MethodsFive humeral stem designs were investigated: Stemless-A (four hollow fins), Stemless-B (central body, three solid fins), Stemless-C (central screw, peripheral rim-fit), Short stem (50 mm), and Standard stem (130 mm). Fifty cadaveric human humerii were obtained and divided into five groups. BMD within the humeral head was determined for all samples. The mean BMD was similar between groups. The 25 samples with the lowest and highest BMDs were categorized as “Low” and “High,” respectively, with a BMD threshold of 0.35 g/cm2, creating BMD subgroups. After implantation, each sample underwent a standardized biomechanical testing protocol, with axial loading followed by torsional loading. Sensors attached to the specimen recorded micromotion throughout testing. Axial loading consisted of cyclic loading for 100 cycles at 3 peak forces (220, 520, and 820 N). Torsional loading consisted of 100 cycles of internal/external rotation at 0.1 Hz at 6 peak torques, or until failure (±2.5, 5, 7.5, 10, 12.5, and 15 Nm). Failure was defined as the torque at which any bone fracture, implant detachment from anchor/stem, or an excess of 50° internal/external rotation occurred. Groups and BMD subgroups were compared.ResultsAt maximal axial loading, Stemless-B demonstrated greater micromotion (540 μm) than Stemless-C (192 μm) (P = .003). Stemless-B and Stemless-A (387 μm) also had greater micromotion than Short stem (118 μm, P < .001, P = .03) and Standard stem (85 μm, P < .001, P = .01). When comparing low-BMD samples at maximal axial loading, these differences were accentuated, but comparison of high-BMD samples showed no significant differences between groups. Torsional testing demonstrated that Standard stem failed at greater torque (7.2 Nm) than Stemless-B (2.3 Nm, P < .001), Stemless-A (1.9 Nm, P < .001), and Stemless-C (3.9 Nm, P = .01). When comparing torsional testing results of low-BMD samples, both Standard stem and Short stem failed at greater torque than Stemless-B (P = .02, P = .003) and Stemless-A (P = .03, P = .004) but failed at a similar torque to Stemless-C. Torsional testing of high-BMD samples showed that Standard stem failed at a greater torque than all stemless designs.ConclusionStemless humeral implants should be used with caution in low-BMD settings (<0.35 g/cm2). A central screw and peripheral rim-fit stemless anchor design demonstrated greater fixation strength at low BMD when compared with other designs, while all stemless designs performed similarly at high BMD.Level of evidenceBasic Science Study; Cadaveric Study  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