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   1815篇
  免费   120篇
  国内免费   4篇
耳鼻咽喉   31篇
儿科学   152篇
妇产科学   117篇
基础医学   212篇
口腔科学   165篇
临床医学   188篇
内科学   372篇
皮肤病学   21篇
神经病学   170篇
特种医学   89篇
外科学   161篇
综合类   6篇
预防医学   71篇
眼科学   36篇
药学   67篇
肿瘤学   81篇
  2023年   19篇
  2022年   38篇
  2021年   55篇
  2020年   36篇
  2019年   66篇
  2018年   75篇
  2017年   44篇
  2016年   57篇
  2015年   55篇
  2014年   76篇
  2013年   92篇
  2012年   138篇
  2011年   114篇
  2010年   71篇
  2009年   72篇
  2008年   116篇
  2007年   100篇
  2006年   108篇
  2005年   93篇
  2004年   94篇
  2003年   64篇
  2002年   60篇
  2001年   15篇
  2000年   25篇
  1999年   19篇
  1998年   6篇
  1997年   5篇
  1996年   7篇
  1995年   5篇
  1994年   8篇
  1993年   4篇
  1992年   18篇
  1991年   20篇
  1990年   15篇
  1989年   15篇
  1988年   13篇
  1987年   14篇
  1986年   17篇
  1985年   14篇
  1984年   18篇
  1983年   5篇
  1982年   4篇
  1981年   6篇
  1980年   4篇
  1978年   3篇
  1977年   4篇
  1974年   5篇
  1973年   3篇
  1965年   3篇
  1964年   2篇
排序方式: 共有1939条查询结果,搜索用时 27 毫秒
71.
It is plausible that infections post‐hematopoietic SCT play a role in the pathogenesis of BOS. A prospective study for children with history, questionnaire, examination, PFTs, and blood counts at one, three, six, nine, 12, 18, and 24 months post‐SCT was conducted. Between September 2009 and September 2011 (n = 39), six developed BOS at 200 days (range 94–282), three patients had probable clinical respiratory infection, and all six had higher neutrophil count compared to non‐BOS patients (4.7 vs. 2.4 at three months and 6.3 vs. 2.9 at six months ×109/L, p = 0.03). Contribution of clinical and subclinical infection needs to be considered in the pathogenesis of BOS.  相似文献   
72.

Background

Professional skills and academic records of the highest degree are essential requirements for the chairmanship of internal medicine departments. Whether the new generation and future successors of Israeli chairmen is endowed with these attributes is not known.

Purpose

To determine whether there is a lack of future suitable successors for the current heads of internal medicine departments in Israel and to compare the demographic, academic and professional characteristics of the older and newer generations of department heads.

Methods

An online anonymous questionnaire was nationally distributed during 2016 to all active heads of internal medicine departments in Israel (n?=?101). First round was followed by two runs of personal phone calls to promote participation.

Results

Sixty-seven (67%) of chairmen responded. The vast majority of current chairs of internal medicine departments are males (N?=?59, 88%) over 50 years of age (N?=?58, 86%) with established academic background with lecturer degree or higher (N?=?57, 85%).Only 19 (28%) of current heads assigned a future successor. Comparison of chairmen who did and did not assigned successors demonstrated that assignment of successors was associated with higher academic status (P?<?0.02) and longer chairmanship (p?<?0.01) but not with mean age of current chairmen (p?<?0.08). Nevertheless, most assignments (55%) were done by chairmen in the 61 to 67 years age group. As compared to current chairmen, the designated successors have lesser academic status (p?<?0.01) and are characterized by a higher female prevalence (P?<?0.03).

Conclusions

Significant demographic, professional and academic differences exist between the current chairs of internal medicine departments in Israeli hospitals and their future successors. This underscores the need for reassessment of the availability and requirements of this crucial position.
  相似文献   
73.
Computed-assisted surgery (CAS) has been designed to improve oral implant planning and positioning and to increase safety and operator comfort. This is especially important in the esthetic zone, at sites with bone deficiency, and when minimally invasive implant placement is the therapy of choice. Current available CAS systems are relatively large and expensive and require a lengthy learning period. This report presents a novel tactile imaging and registration concept that enables the operation of a newly developed computerized implant locating system. An intraoral bone-sounding device maps the surface of the jaw through the soft tissue. Bone contour data are registered over the computerized tomographic image. Guided by treatment preplanning software, a chairside robotic manipulator fabricates guiding sleeves that direct the drill and implant during the osteotomy and implant placement, respectively. The authors' clinical experience shows that tactile registration based the Implant Locating System is simple to use and provides accurate implant design and placement that requires only basic computer experience, minimal operational space, and low infrastructure investment. The system allows final adjustments at the time of operation, transforming each implant surgery into a fully monitored procedure.  相似文献   
74.
75.
ObjectiveTo evaluate the association between bezafibrate, a drug used to treat hypertriglyceridemia, and long-term cancer incidence in patients with coronary artery disease (CAD).Patients and MethodsThe study comprised 2980 patients with CAD (mean age, 60 years; 2729 [91.6%] men) who were free of cancer and were enrolled in the Bezafibrate Infarction Prevention study, a double-blind trial conducted between May 1, 1990, and January 31, 1993, in 18 cardiology departments in Israel. Patients randomized to receive 400 mg of bezafibrate (n=1486) or placebo (n=1494) daily for a median of 6.2 years (range, 4.7-7.6 years) were followed up for incidence of cancer through the Israeli National Cancer Registry and all-cause death through the Population Registry of the State of Israel until December 31, 2013. Cox proportional hazards and Fine and Gray survival models were used to assess the bezafibrate-cancer association.ResultsClinical characteristics and laboratory values were well balanced between the 2 groups at the study entry. Over a median follow-up of 22.5 years (range, 21.2-23.9 years), cancer developed in 753 patients. With death considered a competing event, the cumulative incidence of cancer at the end of the follow-up was lower in the bezafibrate vs the placebo group (23.9%; 95 CI, 21.9%-26.1% vs 27.2%; 95 CI, 25.1%-29.4%; P=.04). The hazard ratio for cancer in the bezafibrate vs placebo groups was 0.86 (95% CI, 0.74-0.99). In mediation analysis, the association between bezafibrate treatment and cancer incidence was not sensitive to adjustment for on-trial lipid levels but was attenuated on adjustment for on-trial fibrinogen levels.ConclusionBezafibrate treatment is associated with reduced risk of cancer among patients with CAD. Fibrinogen, but not lipid lowering, is linked to this association.  相似文献   
76.
77.

Background

Subglottic stenosis (SGS) is the most common congenital and/or acquired laryngotracheal anomaly requiring tracheotomy in infants. We sought to determine factors associated with a greater likelihood of tracheotomy in symptomatic infants with SGS who underwent laryngotracheoplasty (LTP).

Methods

Retrospective case series with chart review of patients undergoing single-stage LTP for SGS over a 10-year period (2001–2010) in a tertiary-care pediatric hospital.

Results

Twenty-two children (15 boys, 7 girls), with a mean gestational age of 32.5 weeks, underwent LTP with and without interpositional grafting, at a median age of 89 days. Ten patients (43%) required postoperative tracheotomy. Of patients weighing < 2.5 kg, 7 of 8 eventually required tracheotomy, while none weighing > 5 kg needed tracheotomy (p = 0.003). The average length of stay for patients with a tracheotomy was 125 days, while those without tracheotomy required only 58 days (p = 0.011). The grade of SGS (p = 0.809), gender (p = 0.968), age at surgery (p = 0.178), and gestational age (p = 0.117) were not significantly associated with the need for tracheotomy. Weight at surgery was significantly correlated with the likelihood of needing tracheotomy (p = 0.003).

Conclusions

Patients who weighed less than 2.5 kg at the time of LTP procedures were more likely to require a postoperative tracheotomy. Children who required tracheotomy had longer lengths of hospital stay.  相似文献   
78.
ABSTRACT

The effects of particulate matter (PM) air pollution on adipose tissue have mainly been studied in animal models. The aim of this study was to examine the potential associations between PM exposure and 25 cellular markers in human omental (OM) and subcutaneous (SC) adipose tissue. The PM exposure assessments for both PM2.5 (PM <2.5 μm in diameter) and PM10 (<10 μm) were based upon a novel hybrid satellite-based spatio-temporally resolved model. We calculated the PM exposure above the background threshold for 1 week (acute phase), 3 and 6 months (intermediate phase), and 1 year (chronic phase) prior to tissue harvesting and tested the associations with adipose cell metabolic effects using multiple linear regressions and heat maps strategy. Chemokine levels were found to increase after acute and intermediate exposure duration to PM10. The levels of stress signaling biomarkers in the SC and OM tissues rose after acute exposure to PM10 and PM2.5. Macrophage and leucocyte counts were associated with severity of PM exposure in all three duration groups. Adipocyte diameter decreased in all exposure periods. Our results provide evidence for significant contribution of air pollutants exposure to adipose tissue inflammation as well as for pathophysiological mechanisms of metabolic dysregulation that may be involved in the observed responses.  相似文献   
79.
Conjugate gaze deviation is associated with acute ischemic stroke (AIS), although previously only measured on a 2D plane. The current study evaluates 3D imaging efficacy to assess conjugate gaze deviation and correlate direction and strength of deviation to neuro-clinical findings.A retrospective analysis of 519 patients who had CT scans for suspected AIS at our institution. Direction and angle of eye deviation were calculated based on 2D axial images. Volumetric reconstruction of CT scans allowed for calculation of 3D conjugate gaze adjusted length (CGAL). Angle, direction, and vector strength of both 2D and 3D scans were calculated by an artificial intelligence algorithm and tested for agreement with hemispheric ischemia location. CGAL measurements were correlated to NIHSS scores. Follow up MRI data was used to evaluate the sensitivity and specificity of CGAL in the identification of AIS.The final analysis included 122 patients. A strong agreement was found between 3D gaze direction and hemispheric ischemia location. CGAL measurements were highly correlated with NIHSS score (r = .72, P = .01). A CGAL >0.25, >0.28, and >0.35 exhibited a sensitivity of 91%, 86%, and 82% and specificity of 66%, 89%, and 89%, respectively, in AIS identification. A CGAL >0.28 has the best sensitivity-specificity balance in the identification of AIS. A CGAL >0.25 has the highest sensitivity.Given CED''s correlation with NIHSS score a 1/4 deviation in the ipsilateral direction is a sensitive ancillary radiographic sign to assist radiologists in making a correct diagnosis even when not presented with full clinical data.  相似文献   
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