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   933560篇
  免费   67768篇
  国内免费   1359篇
耳鼻咽喉   12989篇
儿科学   24404篇
妇产科学   23280篇
基础医学   133345篇
口腔科学   28293篇
临床医学   80738篇
内科学   183910篇
皮肤病学   19314篇
神经病学   72324篇
特种医学   36906篇
外国民族医学   79篇
外科学   152547篇
综合类   18050篇
现状与发展   1篇
一般理论   234篇
预防医学   61757篇
眼科学   21397篇
药学   72864篇
  3篇
中国医学   2182篇
肿瘤学   58070篇
  2018年   9035篇
  2017年   7080篇
  2016年   7852篇
  2015年   8938篇
  2014年   12072篇
  2013年   17613篇
  2012年   24275篇
  2011年   25254篇
  2010年   14930篇
  2009年   14353篇
  2008年   24759篇
  2007年   25870篇
  2006年   26675篇
  2005年   25633篇
  2004年   24752篇
  2003年   23787篇
  2002年   23324篇
  2001年   54807篇
  2000年   56616篇
  1999年   47029篇
  1998年   10768篇
  1997年   9512篇
  1996年   9631篇
  1995年   8961篇
  1994年   8299篇
  1993年   7619篇
  1992年   35529篇
  1991年   33950篇
  1990年   32781篇
  1989年   31913篇
  1988年   29037篇
  1987年   28287篇
  1986年   26342篇
  1985年   25169篇
  1984年   17868篇
  1983年   15165篇
  1982年   7805篇
  1981年   6783篇
  1979年   15804篇
  1978年   10607篇
  1977年   9065篇
  1976年   7879篇
  1975年   8642篇
  1974年   10479篇
  1973年   9872篇
  1972年   9369篇
  1971年   8871篇
  1970年   8446篇
  1969年   7931篇
  1968年   7212篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Respiratory cysts are benign lesions lined by normal respiratory epithelium. There are few reported cases localized to the orbit, while those of the eyelid are exceedingly rare. Respiratory cysts usually arise either from a non‐hereditary congenital malformation, where they are distinguished as choristomatous, or from trauma. Here, we report a case of a 53‐year‐old man who presented with a large right lower eyelid cyst that was histopathologically diagnosed as a respiratory cyst.  相似文献   
63.
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   
64.
65.

Background

There were few studies assessed the postoperative sarcopenia in patients with cancers. The objective of present study was to assess whether postoperative development of sarcopenia could predict a poor prognosis in patients with adenocarcinoma of esophagogastric junction, (AEG) and upper gastric cancer (UGC).

Methods

Patients with AEG and UGC who were judged as non-sarcopenic before surgery were reassessed the presence of postoperative development of sarcopenia 6 months after surgery. Patients were divided into the development group or non-development group, and clinicopathological factors and prognosis between these two groups were analyzed.

Results

The 5-year overall survival rates were significantly poorer in the development group than non-development group (68.0% vs. 92.6%, P?=?0.0118). Multivariate analyses showed that postoperative development of sarcopenia was an independent prognostic factor for poor overall survival (P?=?0.0237).

Conclusions

Postoperative development of sarcopenia was associated with a poor prognosis in patients with AEG and UGC.  相似文献   
66.
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   
67.
68.
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   
69.
70.

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   
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