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   993723篇
  免费   72244篇
  国内免费   2657篇
耳鼻咽喉   13810篇
儿科学   26490篇
妇产科学   24649篇
基础医学   140050篇
口腔科学   30671篇
临床医学   87098篇
内科学   194836篇
皮肤病学   20649篇
神经病学   76543篇
特种医学   38686篇
外国民族医学   87篇
外科学   159816篇
综合类   22617篇
现状与发展   11篇
一般理论   255篇
预防医学   66470篇
眼科学   22835篇
药学   77915篇
  19篇
中国医学   4067篇
肿瘤学   61050篇
  2021年   7407篇
  2019年   7374篇
  2018年   11005篇
  2017年   8744篇
  2016年   9399篇
  2015年   10782篇
  2014年   14307篇
  2013年   20597篇
  2012年   28924篇
  2011年   30606篇
  2010年   17885篇
  2009年   16506篇
  2008年   29048篇
  2007年   30244篇
  2006年   30876篇
  2005年   29603篇
  2004年   28251篇
  2003年   27066篇
  2002年   26353篇
  2001年   56044篇
  2000年   57900篇
  1999年   47825篇
  1998年   11125篇
  1997年   9840篇
  1996年   9899篇
  1995年   9207篇
  1994年   8518篇
  1993年   7785篇
  1992年   35705篇
  1991年   34090篇
  1990年   32891篇
  1989年   32007篇
  1988年   29103篇
  1987年   28335篇
  1986年   26370篇
  1985年   25204篇
  1984年   17899篇
  1983年   15191篇
  1982年   7851篇
  1979年   15820篇
  1978年   10635篇
  1977年   9100篇
  1976年   7895篇
  1975年   8646篇
  1974年   10486篇
  1973年   9881篇
  1972年   9373篇
  1971年   8864篇
  1970年   8430篇
  1969年   7932篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
71.
A local pedicled vascularized bone flap can prevent the morbidity and cost of free bone flap surgery in small segmental bone defects or long cartilaginous defects of the head and neck. Such flaps can also be useful in patients who are high risk for surgery. The periosteal vascularity of the mandible can be used to design islanded facial artery-based bone flaps, which can be utilized to that extent. Two patients with a small segmental mandibulectomy defect and one patient with a long cricotracheal resection defect underwent reconstruction using three different designs of islanded facial artery osteomyomucosal/osseous flap (iFOMM). The patients had a minimum follow-up period of 18 months. All flaps were successful, with satisfactory healing and without any functional deficit or disease at last follow-up.  相似文献   
72.
73.
Blecha  S.  Weber-Carstens  S.  Bein  T. 《Der Anaesthesist》2019,68(6):343-352
Die Anaesthesiologie - Die Versorgungsforschung (VF) ist ein fachübergreifendes multidisziplinäres Forschungsgebiet, das die Kranken- und Gesundheitsversorgung sowie ihre...  相似文献   
74.
75.
Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.  相似文献   
76.
77.

Background

Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.

Methods

A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.

Results

The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).

Conclusion

Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.

Level of Evidence

Therapeutic Level IV.  相似文献   
78.
Hillermann  T.  Homburg  K.  Rainer  M.  Budde  U. 《Der Anaesthesist》2022,71(4):299-302
Die Anaesthesiologie - Eine junge Patientin erleidet während der Anlage einer axillären Plexusblockade einen generalisierten Krampfanfall. Die Mechanismen, im Wesentlichen die vermutlich...  相似文献   
79.
80.
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