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   5828篇
  免费   405篇
  国内免费   21篇
耳鼻咽喉   84篇
儿科学   112篇
妇产科学   121篇
基础医学   765篇
口腔科学   146篇
临床医学   599篇
内科学   1012篇
皮肤病学   86篇
神经病学   541篇
特种医学   256篇
外科学   739篇
综合类   88篇
一般理论   4篇
预防医学   689篇
眼科学   108篇
药学   371篇
中国医学   5篇
肿瘤学   528篇
  2023年   32篇
  2022年   66篇
  2021年   140篇
  2020年   70篇
  2019年   131篇
  2018年   147篇
  2017年   122篇
  2016年   93篇
  2015年   106篇
  2014年   178篇
  2013年   278篇
  2012年   468篇
  2011年   521篇
  2010年   250篇
  2009年   210篇
  2008年   380篇
  2007年   399篇
  2006年   374篇
  2005年   369篇
  2004年   325篇
  2003年   294篇
  2002年   292篇
  2001年   68篇
  2000年   51篇
  1999年   61篇
  1998年   59篇
  1997年   32篇
  1996年   34篇
  1995年   38篇
  1994年   42篇
  1993年   45篇
  1992年   31篇
  1991年   26篇
  1990年   20篇
  1989年   24篇
  1987年   19篇
  1986年   29篇
  1985年   15篇
  1984年   22篇
  1983年   23篇
  1982年   27篇
  1981年   31篇
  1980年   40篇
  1979年   18篇
  1978年   21篇
  1977年   20篇
  1976年   21篇
  1975年   16篇
  1974年   16篇
  1971年   14篇
排序方式: 共有6254条查询结果,搜索用时 15 毫秒
101.
102.
A 78-year-old man was referred for anterior wall motion abnormality on echocardiogram. In anticipation of the urgent surgery for stomach cancer, an endothelial progenitor cell Genous capture stent (Orbus Neich Medical Technology) was implanted. After 2 weeks, optical coherence tomography was done to confirm the coverage of stent struts and all struts were fully covered by reendothelialization. The patient could undergo stomach surgery without antiplatelet therapy successfully.  相似文献   
103.

Background

Patients with castration-resistant prostate cancer (CRPC) and bone metastases have an unmet clinical need for effective treatments that improve quality of life and survival with a favorable safety profile.

Objective

To prospectively evaluate the efficacy and safety of three different doses of radium chloride (Ra 223) in patients with CRPC and bone metastases.

Design, setting, and participants

In this phase 2 double-blind multicenter study, 122 patients were randomized to receive three injections of Ra 223 at 6-wk intervals, at doses of 25 kBq/kg (n = 41), 50 kBq/kg (n = 39), or 80 kBq/kg (n = 42). The study compared the proportion of patients in each dose group who had a confirmed decrease of ≥50% in baseline prostate-specific antigen (PSA) levels.

Outcome measurements and statistical analysis

Efficacy was evaluated using blood samples to measure PSA and other tumor markers, recorded skeletal-related events, and pain assessments. Safety was evaluated using adverse events (AEs), physical examination, and clinical laboratory tests. The Jonckheere-Terpstra test assessed trends between groups.

Results and limitations

The study met its primary end point with a statistically significant dose–response relationship in confirmed ≥50% PSA declines for no patients (0%) in the 25-kBq/kg dose group, two patients (6%) in the 50-kBq/kg dose group, and five patients (13%) in the 80-kBq/kg dose group (p = 0.0297). A ≥50% decrease in bone alkaline phosphatase levels was identified in six patients (16%), 24 patients (67%), and 25 patients (66%) in the 25-, 50-, and 80-kBq/kg dose groups, respectively (p < 0.0001). The most common treatment-related AEs (≥10%) occurring up to week 24 across all dose groups were diarrhea (21%), nausea (16%), and anemia (14%). No difference in incidence of hematologic events was seen among dose groups. Potential limitations include small patient numbers and differences among dose groups at baseline.

Conclusions

Ra 223 had a dose-dependent effect on serum markers of CRPC activity, suggesting that control of bone disease with Ra 223 may affect cancer-related outcomes. Ra 223 was well tolerated at all doses.

Trial registration

ClinicalTrials.gov: NCT00337155.  相似文献   
104.

Background and Objectives:

Differences in postoperative outcomes comparing robotic-assisted laparoscopic myomectomy (RALM) with abdominal myomectomy (AM) have rarely been reported. The objective of this study was to compare surgical, quality-of-life, and residual fibroid outcomes after RALM and AM.

Methods:

Consecutive patients who underwent RALM (n = 16) were compared with AM patients (n = 23) presenting with a uterine size of <20 weeks. Study patients participated in a telephone interview at 6 weeks and underwent a no-cost ultrasonographic examination at 12 weeks after surgery to obtain quality-of-life and residual fibroid outcomes. Medical records were reviewed to obtain surgical outcomes.

Results:

Longer operative times (261.1 minutes vs 124.8 minutes, P < .001) and a 3-fold unfavorable difference in operative efficiency (73.7 g vs 253.0 g of specimen removed per hour, P < .05) were observed with RALM compared with AM. Patients undergoing RALM had shorter lengths of hospital stay (1.5 days vs 2.7 days, P < .001). Reduction of patient symptoms and overall satisfaction were equal. RALM patients were more likely to be back to work within 1 month (85.7% vs 45.0%, P < .05). Residual fibroid volume in the RALM group was 5 times greater than that in the AM group (17.3 cm3 vs 3.4 cm3, P < .05).

Conclusion:

RALM and AM were equally efficacious in improving patient symptoms. Although operative times were significantly longer with RALM, patients had a quicker recovery, demonstrated by shortened lengths of stay and less time before returning to work. However, greater residual fibroid burden was observed with RALM when measured 12 weeks after surgery.  相似文献   
105.
The aim of this study was to investigate the prosthodontic maintenance requirements of patients rehabilitated with maxillary and mandibular implant-retained overdentures using the Locator Attachment System by retrospectively reviewing case records. Fifty patients made 112 unplanned return visits over a 3-year period. The most common reasons for returning were denture adjustments (n = 45), inadequate retention (n = 39), and loosening of the implant abutments (n = 14). Implant-retained overdentures using the Locator Attachment System have comparable prosthodontic maintenance requirements to other attachment systems. Problems associated with these prostheses are usually simple to resolve chairside.  相似文献   
106.
PurposeTo identify clinical and imaging variables associated with symptomatic recurrence of osteoid osteomas (OOs) treated with computerized tomography (CT)–guided radiofrequency (RF) ablation.Materials and MethodsSeventy-one patients treated with the use of CT-guided RF ablation for OO at a single institution from July 2005 to May 2018 were included in this retrospective cohort analysis. Clinical data, including patient age, sex, race, and clinical outcomes, were collected from institutional electronic health records and telephone follow-up. Imaging variables regarding tumor characteristics were gathered from imaging reports and a blinded review of preprocedural images by an experienced musculoskeletal radiologist. Logistic regression, Cox proportional hazards, and Kaplan-Meier analyses were used to identify variables that are significantly associated with symptomatic recurrence, which was defined as pain occurring > 2 weeks after RF ablation.ResultsTen patients (14.1%) experienced symptomatic recurrence at a median of 21.5 months after RF ablation. Univariable logistic regression classified young age (≤ 13 years), female sex, maximum tumor length, and “eccentricity index” (EI) ≥ 3 as predictive variables significantly associated with symptomatic recurrence. Multivariable logistic regression identified female sex and EI ≥ 3 to be significant predictors for symptomatic recurrence. A multivariable proportional hazards Cox regression of time to recurrence revealed EI ≥ 3 to be the only significant predictor of symptomatic recurrence.ConclusionsFemale patients with OOs with an EI ≥ 3 have a greater risk of symptomatic recurrence following RF ablation. The EI is a useful tool to identify OOs with elongated 3-dimensional morphology, which may warrant more extensive ablation.  相似文献   
107.
108.
The RTS,S/AS02A protein-based vaccine consistently demonstrates significant protection against infection with Plasmodium falciparum malaria and also against clinical malaria and severe disease in children in areas of endemicity. Here we demonstrate with rhesus macaques that priming with a replication-defective human adenovirus serotype 35 (Ad35) vector encoding circumsporozoite protein (CS) (Ad35.CS), followed by boosting with RTS,S in an improved MPL- and QS21-based adjuvant formulation, AS01B, maintains antibody responses and dramatically increases levels of T cells producing gamma interferon and other Th1 cytokines in response to CS peptides. The increased T-cell responses induced by the combination of Ad35.CS and RTS,S/AS01B are sustained for at least 6 months postvaccination and may translate to improved and more durable protection against P. falciparum infection in humans.  相似文献   
109.
110.
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