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   126990篇
  免费   7577篇
  国内免费   1108篇
耳鼻咽喉   1954篇
儿科学   1938篇
妇产科学   1882篇
基础医学   20272篇
口腔科学   3085篇
临床医学   11834篇
内科学   22839篇
皮肤病学   3974篇
神经病学   10328篇
特种医学   7293篇
外科学   16673篇
综合类   552篇
现状与发展   3篇
一般理论   27篇
预防医学   6710篇
眼科学   3191篇
药学   11420篇
中国医学   1455篇
肿瘤学   10245篇
  2023年   905篇
  2022年   2715篇
  2021年   4392篇
  2020年   2104篇
  2019年   2944篇
  2018年   3677篇
  2017年   2990篇
  2016年   3904篇
  2015年   5446篇
  2014年   6450篇
  2013年   7510篇
  2012年   11249篇
  2011年   10780篇
  2010年   6192篇
  2009年   5310篇
  2008年   7534篇
  2007年   7168篇
  2006年   6466篇
  2005年   5987篇
  2004年   5214篇
  2003年   4540篇
  2002年   3907篇
  2001年   3037篇
  2000年   2793篇
  1999年   2144篇
  1998年   934篇
  1997年   684篇
  1996年   532篇
  1995年   462篇
  1994年   400篇
  1993年   345篇
  1992年   751篇
  1991年   707篇
  1990年   644篇
  1989年   570篇
  1988年   478篇
  1987年   474篇
  1986年   338篇
  1985年   375篇
  1984年   262篇
  1983年   195篇
  1982年   139篇
  1981年   171篇
  1980年   134篇
  1979年   225篇
  1978年   163篇
  1976年   135篇
  1975年   123篇
  1974年   139篇
  1973年   119篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Background/ObjectiveRecent prospective studies have shown poorer oncologic outcomes following minimally invasive surgery, which has led many surgeons to deeply inspect their practices. We reviewed our experience and evaluated the results of radical hysterectomy in patients with early stage cervical cancer.MethodsThis retrospective study included patients with early stage cervical cancer (Ia1 - IIa1) who were treated with radical hysterectomy from May 2006 to Dec 2016. Patients were divided into three groups according to the surgical approach: radical abdominal hysterectomy (RAH), laparoscopic radical hysterectomy (LRH), and robot-assisted radical hysterectomy (RRH).ResultsLearning curves of each type of surgery were obtained using the cumulative sum method. Survival rates were compared using Kaplan–Meier curves. To analyze the learning curve of a single surgeon, 89 patients were selected from the whole population. Learning curves of each group showed two distinct phases. The minimum number of cases required to achieve surgical improvement were 16 in RAH, 13 in LRH, and 21 in RRH. Progression-free survival (PFS) and overall survival did not vary between RAH and minimally invasive surgery (MIS) (p = .828 and p = .757, respectively). However, when stratified by the phases of the learning curves, patients included in the early phase of MIS showed a poorer PFS (p = .014).ConclusionsSurgical proficiency could significantly affect the oncologic outcome in MIS. A prospective study regarding sufficient surgical competence is necessary for elaborate analysis of the feasibility of minimally invasive radical hysterectomy.  相似文献   
992.
993.
994.
995.
996.
One reported complication of the arthroscopic modified Broström operation is pain caused by the suture anchoring knot. We hypothesized that a knotless technique could reduce such pain. Therefore, in this study we evaluated the clinical and radiological outcomes after knotless all-inside arthroscopic modified Broström operation for lateral ankle instability. From July 2017 to November 2017, 28 patients were treated. Clinical and radiological features were evaluated preoperatively and 3, 6, and 12 months postoperatively using the American Orthopaedic Foot & Ankle Society ankle-hindfoot scale score, visual analogue scale score for pain, anterior talar drawer test, and talar tilt angle. The mean age of the 28 patients (14 men, 14 women) was 41.71 ± 17.19 years. Three (10.7%) complications, but no knot-associated pain, occurred. The clinical and radiological outcomes were significantly improved 12 months postoperatively compared with preoperative outcomes (all p < .05). Knotless all-inside arthroscopic modified Broström operation for lateral ankle instability avoided knot-associated pain and improved not only patient satisfaction but also clinical and radiological outcomes.  相似文献   
997.
The treatment of syndesmotic injuries with ankle fractures is controversial. The purpose of this study was to compare the biomechanical properties of open anterior syndesmotic repair with those of screw fixation. Ten matched pairs of human cadaver specimens were subjected to open syndesmotic repair or screw fixation. Each specimen underwent initial intact physiologic loading, consisting of 10 cycles of external torsional loading with a peak torque of 7.5 Nm at 0.05 Hz. Injuries of the anterior inferior tibiofibular ligament, tibiofibular interosseous membrane, and deltoid ligament were applied to each specimen. Postfixation cyclic loading consisted of 50 cycles of combined axial and external rotation loading with peak torques of 750 N and 7.5 Nm at a rate of 0.05 Hz. After postfixation loading, each specimen underwent failure loading by external rotation at 0.25 degrees/second. Failure torque and failure angle were measured. The paired t test and Wilcoxon signed-rank test were used to analyze the data. Mean failure torques were 95.63 Nm in the open anterior syndesmotic repair augmented with suture-tape group and 108.61 Nm in the screw group. Mean failure angles were 34.93 degrees in the open anterior syndesmotic repair augmented with suture-tape group and 43.55 degrees in the screw group. These data were not statistically significantly different between the groups (p= .7682 and .4133, respectively). Open anterior syndesmotic repair augmented with suture tape for ankle syndesmotic injury provides similar torsional strength to that of screw fixation. Therefore, this technique can be considered as an alternative treatment option for syndesmosis injury.  相似文献   
998.
Annals of Surgical Oncology - Biomarker changes in patients with residual disease (RD) after neoadjuvant systemic therapy (NAT) have unclear consequences. This study examined the prevalence of...  相似文献   
999.
PurposeTo define how much of renal function was determined by the preserved renal parenchymal volume and the ischemic insult during partial nephrectomy (PN) long after surgery.MethodsWe analyzed the data of 530 consecutive patients who had undergone PN. For all patients, renal function was measured preoperatively and again at 3 postoperative months, then annually using 99mTc-diethylenetriaminepentaacetic acid renal scan. Perioperative variables potentially affecting the long-term ipsilateral glomerular filtration rate (GFR) and their time-varying contribution were assessed using a linear mixed model.ResultsThe mean preoperative ipsilateral GFR was 42.9 ml/min, which decreased by 27.3% at 3 months but began to recover thereafter continuing until 4 years (Δ% GFR at 1, 2, 3, 4, and 5 years: 22.3%, 18.5%, 14.7%, 10.0%, and 9.6%, respectively). Parenchymal volume reduction and ischemic time were significantly associated with postoperative ipsilateral GFR throughout observation period unvarying with time. Diabetes and proteinuria were not significant determinants of ipsilateral function at 3 months but became significant at 5 years. In multivariate analysis regarding recovery slope, volume reduction (β = ?0.026, SE 0.006, P < 0.0001), preoperative ipsilateral GFR (β = ?0.021, SE 0.007, P = 0.0012), proteinuria (β = ?0.942, SE 0.372, P = 0.0116), and diabetes (β = ?0.396, SE 0.197, P = 0.0447) were independently significant.ConclusionIpsilateral renal function continued to improve until 5 years after PN. Parenchymal volume loss was the major determinant and its impact on long-term ipsilateral renal function remained constant while ischemic time affected early GFR reduction with its impact diminishing over time. Patient-related factors including diabetes and proteinuria gained significance over time and became independent determinants of recovery slope.  相似文献   
1000.
BackgroundThere is an increasing demand for prognostic immune biomarkers of cancer. The prognostic significance of immune markers has been shown for various cancers, but biomarkers of bladder cancer (BCa) have not been fully evaluated. To clarify the role of human leukocyte antigen DR alpha chain (HLA-DRA) in BCa development, we examined expression of HLA-DRA mRNA in tissue samples of non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC).Materials and MethodsTissues of 96 NMIBC, 43 MIBC and 59 controls comprising noncancerous BCa surrounding tissues were used to examine the expression of HLA-DRA gene by real-time polymerase chain reaction. The expression of up-stream genes regulating HLA-DRA were also measured to explain the role of HLA-DRA in BCa.ResultsPatients with high grade NMIBC showed higher expression of HLA-DRA than those with low grade NMIBC (P < 0.05). In addition, NMIBC patients who progressed to MIBC showed high expression of HLA-DRA mRNA. Kaplan-Meier analysis showed that NMIBC patients with low expression of HLA-DRA had better progression-free survival than those with high expression (P = 0.004). Moreover, the expression of genes regulating HLA-DRA varied in NMIBC and MIBC, indicating a different immunoregulation effect of HLA-DRA in both cancers.ConclusionsHigh expression of HLA-DRA in NMIBC patients has implications for patient stratification strategies, as well as for BCa tumor immunology.  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