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   70597篇
  免费   7660篇
  国内免费   2091篇
耳鼻咽喉   673篇
儿科学   1006篇
妇产科学   991篇
基础医学   3382篇
口腔科学   2345篇
临床医学   11718篇
内科学   6577篇
皮肤病学   787篇
神经病学   2795篇
特种医学   1819篇
外国民族医学   5篇
外科学   5196篇
综合类   10112篇
现状与发展   1篇
一般理论   5篇
预防医学   12131篇
眼科学   1346篇
药学   8917篇
  238篇
中国医学   7198篇
肿瘤学   3106篇
  2024年   169篇
  2023年   1732篇
  2022年   2054篇
  2021年   3430篇
  2020年   3832篇
  2019年   3185篇
  2018年   2944篇
  2017年   3286篇
  2016年   3193篇
  2015年   3122篇
  2014年   5451篇
  2013年   6136篇
  2012年   4926篇
  2011年   4920篇
  2010年   3721篇
  2009年   3594篇
  2008年   3667篇
  2007年   3472篇
  2006年   3079篇
  2005年   2502篇
  2004年   1996篇
  2003年   1680篇
  2002年   1344篇
  2001年   1139篇
  2000年   880篇
  1999年   678篇
  1998年   479篇
  1997年   453篇
  1996年   365篇
  1995年   386篇
  1994年   336篇
  1993年   268篇
  1992年   239篇
  1991年   151篇
  1990年   129篇
  1989年   131篇
  1988年   94篇
  1987年   91篇
  1986年   52篇
  1985年   102篇
  1984年   120篇
  1983年   66篇
  1982年   67篇
  1981年   62篇
  1980年   75篇
  1979年   41篇
  1978年   37篇
  1976年   30篇
  1943年   29篇
  1938年   30篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
目的探讨职业倦怠的主要影响因素及与教学质量的相关性。方法对97名参与临床教学的医护人员进行调查,分析职业倦怠现状、影响因素,及职业倦怠与教学质量的相关性。结果97名临床教师中,存在轻度倦怠41例(42.27%),中度倦怠23例(23.71%),重度倦怠9例(9.28%),合计共有73名临床教师存在职业倦怠(75.26%)。女性情感耗竭维度得分高于男性(P<0.05)。不同职称者情感耗竭、人格解体和成就感降低3个维度得分均差异有统计学意义(P<0.05)。多因素Logistic回归分析结果显示:婚姻状况和职称为职业倦怠的风险因素(P<0.05)。轻度倦怠与重度倦怠者社会支持利用度得分差异有统计学意义(P<0.01)。Spearman等级相关分析结果显示:职业倦怠程度与教学质量评议分数无相关性(P>0.05),职称与教学质量评议分数有正相关关系(P<0.05)。结论临床教师职业倦怠强度与职称、婚姻状况有关。临床教师职称与教学质量正相关。  相似文献   
102.
IntroductionOrgan-based tube current modulation (OBTCM) is designed for anterior dose reduction in Computed Tomography (CT). The purpose was to assess dose reduction capability in chest CT using three organ dose modulation systems at different kVp settings. Furthermore, noise, diagnostic image quality and tumour detection was assessed.MethodsA Lungman phantom was scanned with and without OBTCM at 80–135/140 kVp using three CT scanners; Canon Aquillion Prime, GE Revolution CT and Siemens Somatom Flash. Thermo-luminescent dosimeters were attached to the phantom surface and all scans were repeated five times. Image noise was measured in three ROIs at the level of the carina. Three observers visually scored the images using a fivestep scale. A Wilcoxon Signed-Rank test was used for statistical analysis of differences.ResultsUsing the GE revolution CT scanner, dose reductions between 1.10 mSv (12%) and 1.56 mSv (24%) (p < 0.01) were found in the anterior segment and no differences posteriorly and laterally. Total dose reductions between 0.64 (8%) and 0.91 mSv (13%) were found across kVp levels (p < 0.00001). Maximum noise increase with OBTCM was 0.8 HU. With the Canon system, anterior dose reductions of 6–10% and total dose reduction of 0.74–0.76 mSv across kVp levels (p < 0.001) were found with a maximum noise increase of 1.1 HU. For the Siemens system, dose increased by 22–51% anteriorly; except at 100 kVp where no dose difference was found. Noise decreased by 1 to 1.5 HU.ConclusionOrgan based tube current modulation is capable of anterior and total dose reduction with minimal loss of image quality in vendors that do not increase posterior dose.Implications for practiceThis research highlights the importance of being familiar with dose reduction technologies.  相似文献   
103.
ObjectiveThis cohort study aimed to assess the associations between sleep duration and quality with the risk of incident chronic kidney disease (CKD) in middle-aged and older Chinese.MethodsWe used the 2011 and 2015 surveys of the China Health and Retirement Longitudinal Study (CHARLS). Nighttime sleep duration was categorized into five groups: ≤4, (4–6], (6–8], (8–10], and >10 h/night. Sleep quality was assessed by restless days in the past week (<1, 1–2, 3–4, and 5–7 days/week). Multivariate logistic regression was used to assess the association between sleep duration and quality with incident CKD.ResultsA total of 11,339 participants free of CKD at baseline were included in this study. After four years follow-up, the incidence of CKD was 7.8%. There was a “U-shaped” association between sleep duration and risk of CKD. Compared to 6–8 h of nighttime sleep duration, those who slept ≤4 h/night (RR: 1.639, 95% CI: 1.287–2.087) or >10 h/night (RR: 2.342, 95% CI: 1.007–5.451) had increased risk of developing CKD after adjustment for confounders. Participants with 5–7 restless days per week had significantly increased risk of CKD (adjusted RR: 1.686, 95% CI: 1.352–2.102), compared to those who rarely or never had a restless sleep.ConclusionsExtreme nighttime sleep duration and poor sleep quality were associated with increased risk of CKD in middle-aged and older Chinese. Obtaining an optimal nighttime sleep duration and better sleep quality might reduce the risk of CKD.  相似文献   
104.
BackgroundMedical child abuse (MCA) is challenging to diagnose. Although young children are often affected, adolescents can be victims through caregiver coercion. Presentation is highly variable. Diagnosis is essential because of high associated morbidity and mortality.CaseWe describe the case of a 12-year-old girl who presented to multiple subspecialty clinics with reported menorrhagia. Despite reassuring clinical examinations, the family described menorrhagia that failed to respond to standard treatment. After an urgent evaluation for reported heavy bleeding revealed only scant blood, the diagnosis of MCA was made.Summary and ConclusionVaginal bleeding is a rare presentation of MCA, but must be considered whenever reported symptomatology does not follow physiologic patterns, respond to standard medical treatment, or correspond to clinical evaluation. Prompt identification is important to prevent further harm.  相似文献   
105.
106.
107.
Background: Community mobility (CM) is considered a part of community reintegration that enhances Quality of Life (QoL). Achieving an appropriate gait speed is essential in attaining an independent outdoor ambulation and satisfactory CM.

Objective: The aim of this study was to identify whether gait speed is a predictor of CM and QoL in patients with stroke following a multimodal rehabilitation program (MRP).

Methods: This was a baseline control trial with 6-months follow-up in an outpatient rehabilitation setting at a university hospital. Twenty-six stroke survivors completed the MRP (24 sessions, 2 days/wk, 1 hr/session). The MRP consisted of aerobic exercise, task-oriented exercises, balance exercises and stretching. Participants also performed an ambulation program at home. Outcome variables were: walking speed (10-m walking test) and QoL (physical and psychosocial domains of Euroquol and Sickness Impact Profile).

Results: At the end of the intervention, comfortable and fast walking speed increased by an average of 0.16 (SD 0.21) (*p < .05) and 0.40 (SD 0.51) (**p < .001) m/s, respectively. After the intervention, all participants achieved independent outdoor ambulation with an increase of 34.14 of walking minutes/day in the community and a decrease of sitting time of 95.45 minutes/day. Regarding QoL there were increased mean scores on the physical and psychosocial dimensions of Euroquol and the Sickness Impact Profile, respectively (**p < .001).

Conclusions: The results suggest that improved walking speed after the MRP is associated with CM and higher scores in QoL. These findings support the need to implement rehabilitation programs to promote increased speed.  相似文献   

108.
109.
110.
Exercise intolerance is the cardinal symptom of heart failure (HF) and is of crucial relevance, because it is associated with a poor quality of life and increased mortality. While impaired cardiac reserve is considered to be central in HF, reduced exercise and functional capacity are the result of key patient characteristics and multisystem dysfunction, including aging, impaired pulmonary reserve, as well as peripheral and respiratory skeletal muscle dysfunction. We herein review the different modalities to quantify exercise intolerance, the pathophysiology of HF, and comorbid conditions as they lead to reductions in exercise and functional capacity, highlighting the fact that distinct causes may coexist and variably contribute to exercise intolerance in patients with HF.  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