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   58325篇
  免费   4979篇
  国内免费   197篇
耳鼻咽喉   532篇
儿科学   1923篇
妇产科学   1538篇
基础医学   8614篇
口腔科学   838篇
临床医学   8401篇
内科学   11156篇
皮肤病学   1257篇
神经病学   6301篇
特种医学   1347篇
外国民族医学   4篇
外科学   5479篇
综合类   579篇
现状与发展   1篇
一般理论   39篇
预防医学   6085篇
眼科学   894篇
药学   3803篇
中国医学   60篇
肿瘤学   4650篇
  2023年   518篇
  2022年   792篇
  2021年   1616篇
  2020年   1173篇
  2019年   1793篇
  2018年   2051篇
  2017年   1601篇
  2016年   1724篇
  2015年   1811篇
  2014年   2397篇
  2013年   3174篇
  2012年   4586篇
  2011年   4578篇
  2010年   2633篇
  2009年   2384篇
  2008年   3885篇
  2007年   3942篇
  2006年   3592篇
  2005年   3590篇
  2004年   3274篇
  2003年   2999篇
  2002年   2802篇
  2001年   459篇
  2000年   336篇
  1999年   507篇
  1998年   633篇
  1997年   509篇
  1996年   387篇
  1995年   383篇
  1994年   323篇
  1993年   294篇
  1992年   210篇
  1991年   201篇
  1990年   182篇
  1989年   181篇
  1988年   155篇
  1987年   123篇
  1986年   134篇
  1985年   125篇
  1984年   137篇
  1983年   118篇
  1982年   133篇
  1981年   140篇
  1980年   108篇
  1979年   62篇
  1978年   65篇
  1977年   80篇
  1976年   80篇
  1975年   56篇
  1974年   62篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.

Background  

Sleep problems are common effects of shift work. The aim of the present study was to evaluate how different types of shift affect sleep and sleepiness, and to relate sleepiness to urinary 6-sulfatoxymelatonin.  相似文献   
52.
Emphysematous pyelonephritis is a severe life-threatening infection which continues to carry significant morbidity and mortality. We present a case recently managed at our institution by laparoscopic nephrectomy. The patient survived, and in comparison to some of the more conventionally managed patients in the literature, made an extremely speedy recovery. We would advocate this option to be seriously considered when patients are suitable and appropriately trained surgeons are available.  相似文献   
53.
Evidence that genetic disposition for adult lactose intolerance significantly affects calcium intake, bone density, and fractures in postmenopausal women is presented. PCR-based genotyping of lactase gene polymorphisms may complement diagnostic procedures to identify persons at risk for both lactose malabsorption and osteoporosis. INTRODUCTION: Lactase deficiency is a common autosomal recessive condition resulting in decreased intestinal lactose degradation. A -13910 T/C dimorphism (LCT) near the lactase phlorizin hydrolase gene, reported to be strongly associated with adult lactase nonpersistence, may have an impact on calcium supply, bone density, and osteoporotic fractures in the elderly. MATERIALS AND METHODS: We determined LCT genotypes TT, TC, and CC in 258 postmenopausal women using a polymerase chain reaction-based assay. Genotypes were related to milk intolerance, nutritional calcium intake, intestinal calcium absorption, bone mineral density (BMD), and nonvertebral fractures. RESULTS: Twenty-four percent of all women were found to have CC genotypes and genetic lactase deficiency. Age-adjusted BMD at the hip in CC genotypes and at the spine in CC and TC genotypes was reduced by -7% to -11% depending on the site measured (p = 0.04). LCT(T/C-13910) polymorphisms alone accounted for 2-4% of BMD in a multiple regression model. Bone fracture incidence was significantly associated with CC genotypes (p = 0.001). Milk calcium intake was significantly lower (-55%, p = 0.004) and aversion to milk consumption was significantly higher (+166%, p = 0.01) in women with the CC genotype, but there were no differences in overall dietary calcium intake or in intestinal calcium absorption test values. CONCLUSION: The LCT(T/C-13910) polymorphism is associated with subjective milk intolerance, reduced milk calcium intake, and reduced BMD at the hip and the lumbar spine and may predispose to bone fractures. Genetic testing for lactase deficiency may complement indirect methods in the detection of individuals at risk for both lactose malabsorption and osteoporosis.  相似文献   
54.
55.
56.
Introduction As many as one quarter of all cancer survivors report traumatic stress symptoms from cancer-related experiences. While the majority of these patients do not meet the criteria for posttraumatic stress disorder (PTSD), there is growing evidence that subsyndromal symptoms can significantly contribute to functional impairment and negative health outcomes. Treatment options for the hallmark symptoms of traumatic stress—unpleasant, intrusive thoughts and avoidant behaviors—have not been well investigated for the cancer survivorship population. Materials and methods Seven female cancer survivors with traumatic stress symptoms from cancer-related experiences and no other major psychopathology, were enrolled to receive three sessions of Neuro-Emotional Technique (NET), a brief, targeted treatment that combines traditional desensitization principles with complementary modalities. Results Psychological outcome measures (Impact of Event Scale (IES) and Subjective Units of Distress (SUD) and physiological measures (Heart Rate (HR) and Skin Conductance Level (SCL) demonstrated the following changes: 71% on IES, 88% SUD, 74% on HR, and 65% on SCL following the intervention. Statistically significant changes were observed for all four parameters, and effect size g for proportion improved were 0.50 each for IES, SUD, and HR, and 0.20 for SCL. Conclusions These cases suggest feasibility of the NET intervention for cancer-related traumatic stress and the potential for change in symptoms and physiological reactivity. Further investigation is needed to determine the specific and long-term effects of such an approach. Implications for cancer survivors Traumatic stress from cancer-related experiences might represent a constellation of symptoms that are amenable to brief, targeted interventions. This study was supported by the O.N.E. Research Foundation  相似文献   
57.
We cared for a patient with methicillin-resistant Staphylococcus aureus bacteremia who experienced clinical failure with daptomycin. The failure was accompanied by progressive elevation of the daptomycin minimum inhibitory concentration during treatment. DNA fingerprinting confirmed that the minimum inhibitory concentration elevation occurred within the same strain of methicillin-resistant Staphylococcus aureus. This observation provides important new information to clinicians who adopt this promising drug for treatment of serious infections caused by methicillin-resistant Staphylococcus aureus.  相似文献   
58.
59.
60.
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