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   1447051篇
  免费   97987篇
  国内免费   3024篇
耳鼻咽喉   18899篇
儿科学   48866篇
妇产科学   39308篇
基础医学   223251篇
口腔科学   38617篇
临床医学   131645篇
内科学   273336篇
皮肤病学   32951篇
神经病学   107882篇
特种医学   55221篇
外国民族医学   355篇
外科学   215457篇
综合类   30298篇
现状与发展   2篇
一般理论   480篇
预防医学   111244篇
眼科学   33168篇
药学   106738篇
  4篇
中国医学   2959篇
肿瘤学   77381篇
  2018年   15253篇
  2017年   11579篇
  2016年   13374篇
  2015年   15001篇
  2014年   20375篇
  2013年   30851篇
  2012年   42012篇
  2011年   45454篇
  2010年   26950篇
  2009年   24952篇
  2008年   42097篇
  2007年   45281篇
  2006年   45273篇
  2005年   43435篇
  2004年   42385篇
  2003年   40791篇
  2002年   39393篇
  2001年   65206篇
  2000年   66637篇
  1999年   55846篇
  1998年   15582篇
  1997年   13730篇
  1996年   13783篇
  1995年   13220篇
  1994年   12159篇
  1993年   11508篇
  1992年   44171篇
  1991年   44646篇
  1990年   44288篇
  1989年   42827篇
  1988年   39238篇
  1987年   39366篇
  1986年   36505篇
  1985年   35374篇
  1984年   26340篇
  1983年   22326篇
  1982年   12847篇
  1981年   11657篇
  1979年   24542篇
  1978年   17731篇
  1977年   14726篇
  1976年   14509篇
  1975年   15968篇
  1974年   18798篇
  1973年   18128篇
  1972年   16695篇
  1971年   15689篇
  1970年   14585篇
  1969年   13602篇
  1968年   12714篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
3.
4.
5.
6.

Objective

Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.

Methods

Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.

Results

We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.

Conclusions

Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients.  相似文献   
7.
Abstract

The study examines Parental Feeding Practices (PFP) in relation to adherence to the Mediterranean Diet (MD) and children’s weight status. It’s a cross-sectional study of 402 parents (68.4% mothers), with children aged 2–12 years. Parents completed the Comprehensive Parental Feeding Questionnaire and the Mediterranean Diet Quality Index for children and adolescents (KIDMED), evaluating children’s adherence to the MD. Logistic regression showed that in children aged 2–<6 years, “emotion regulation/food as reward” and “pressure” decrease MD adherence (OR?=?0.186, p?<?0.0001 and OR?=?0.496, p?=?0.004), and “monitoring” decrease excess body weight (OR?=?0.284, p?=?0.009). In older children (6–12 years), “healthy eating guidance” and “monitoring” increase MD adherence (OR?=?3.262, p?=?0.001 and OR?=?3.147, p?<?0.0001), “child control” decreases MD adherence (OR?=?0.587, p?=?0.049), “pressure” decrease excess body weight (OR?=?0.495, p?<?0.0001) and “restriction” increase excess body weight (OR?=?1.784, p?=?0.015). “Healthy eating guidance” and “monitoring” seem to be the best PFP employed, in terms of children’s MD adherence and weight status.  相似文献   
8.

Introduction

Physician communication impacts patient outcomes. However, communication skills, especially around difficult conversations, remain suboptimal, and there is no clear way to determine the validity of entrustment decisions. The aims of this study were to 1) describe the development of a simulation-based mastery learning (SBML) curriculum for breaking bad news (BBN) conversation skills and 2) set a defensible minimum passing standard (MPS) to ensure uniform skill acquisition among learners.

Innovation

An SBML BBN curriculum was developed for fourth-year medical students. An assessment tool was created to evaluate the acquisition of skills involved in a BBN conversation. Pilot testing was completed to confirm improvement in skill acquisition and set the MPS.

Outcomes

A BBN assessment tool containing a 15-item checklist and six scaled items was developed. Students' checklist performance improved significantly at post-test compared to baseline (mean 65.33%, SD = 12.09% vs mean 88.67%, SD = 9.45%, P < 0.001). Students were also significantly more likely to have at least a score of 4 (on a five-point scale) for the six scaled questions at post-test. The MPS was set at 80%, requiring a score of 12 items on the checklist and at least 4 of 5 for each scaled item. Using the MPS, 30% of students would require additional training after post-testing.

Comments

We developed a SBML curriculum with a comprehensive assessment of BBN skills and a defensible competency standard. Future efforts will expand the mastery model to larger cohorts and assess the impact of rigorous education on patient care outcomes.  相似文献   
9.

Aims

To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.

Materials and methods

The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.

Results

In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).

Conclusions

We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis.  相似文献   
10.

Background

The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.

Objectives

The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.

Methods

PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.

Results

Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).

Conclusions

In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550)  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