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   2386743篇
  免费   173898篇
  国内免费   3483篇
耳鼻咽喉   32451篇
儿科学   76810篇
妇产科学   63285篇
基础医学   352966篇
口腔科学   64615篇
临床医学   214976篇
内科学   464499篇
皮肤病学   52314篇
神经病学   189044篇
特种医学   89947篇
外国民族医学   495篇
外科学   359129篇
综合类   47954篇
现状与发展   12篇
一般理论   879篇
预防医学   185896篇
眼科学   55291篇
药学   177408篇
  11篇
中国医学   4631篇
肿瘤学   131511篇
  2021年   19580篇
  2019年   20131篇
  2018年   27775篇
  2017年   20950篇
  2016年   23406篇
  2015年   26425篇
  2014年   37206篇
  2013年   55539篇
  2012年   76989篇
  2011年   81890篇
  2010年   48488篇
  2009年   45862篇
  2008年   76906篇
  2007年   81862篇
  2006年   82658篇
  2005年   80026篇
  2004年   76509篇
  2003年   73787篇
  2002年   71376篇
  2001年   109181篇
  2000年   111845篇
  1999年   93955篇
  1998年   27448篇
  1997年   24019篇
  1996年   24384篇
  1995年   23021篇
  1994年   21127篇
  1993年   19924篇
  1992年   72241篇
  1991年   70320篇
  1990年   68580篇
  1989年   65889篇
  1988年   60504篇
  1987年   59326篇
  1986年   55401篇
  1985年   53231篇
  1984年   39542篇
  1983年   33619篇
  1982年   20100篇
  1979年   36036篇
  1978年   25830篇
  1977年   21384篇
  1976年   20474篇
  1975年   21961篇
  1974年   26286篇
  1973年   24917篇
  1972年   23309篇
  1971年   22122篇
  1970年   20323篇
  1969年   19380篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.

Background and aims

Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.

Methods and results

In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.

Conclusion

SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE.  相似文献   
42.
The Latin American population has a double way of immigration, one toward the United States by proximity and another toward Spain by sociocultural affinity. This population increase is affecting organ donation and transplantation in receiving countries.

Objective

To analyze the brain death (BD) concept knowledge in the Dominican Republic immigrant population in Florida (United States) and Spain.

Method

Population under study: Population born in the Dominican Republic, resident in Florida (United States) and in Spain. Inclusion criteria: Population older than 15 years stratified by age and sex. Assessment instrument: Donation attitude questionnaire PCID-DTO-Ríos. Fieldwork: Random selection based on stratification. Immigration support association collaboration in Florida and Spain was needed to locate potential respondents. Completion was anonymous and self-administered, with verbal consent.

Results

A total of 123 respondents, 57 residents in Spain and 66 in Florida, have been included in the study. The 27% (n = 33) of the respondents knowledgeable of the BD concept consider it the death of an individual. Of the remainder, 52% (n = 64) do not know about it, and the remaining 21% (n = 26) believe it does not mean the death of a patient. No differences were observed regarding migration countries (P > .05). There was no association of the BD concept with other psychosocial factors analyzed or with the attitude toward organ donation.

Conclusions

Knowledge of the BD concept among the Dominican immigrant population is similar in Spain and Florida, and, unlike most studies, there is no objective association with the attitude toward organ donation.  相似文献   
43.

Introduction

In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.

Methods

We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.

Results

A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.

Conclusion

The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department.  相似文献   
44.
Type 1 diabetes is one of the commonest chronic disorders encountered in children and adolescents. When it first becomes apparent in children, approximately 20% of them have clinical and biochemical signs of ketoacidosis (DKA). In the presence of unusual clinical symptoms it is necessary to consider the possibility of associated conditions, such as coeliac disease, immunothyroiditis and Addison’s disease. Children with diabetes must be treated by a multidisciplinary team made up of paediatrician, paediatric diabetes specialist, psychologist, social worker, ophthalmologist, dietitian, nurse and diabetes counsellor, making it essential for them to be treated in regional specialised centres. They are treated in their own psychosocial environment and their families are involved in the therapy. Comprehensive, multidisciplinary treatment strategies have now made it possible for these patients to enjoy normal physical wellbeing and near-normal psychosocial development. Prevention and early treatment of of disturbances associated with diabetes remain an important concern. The fact that type 2 diabetes must now be looked for in overweight children and adolescents is a new aspect of diabetes medicine.  相似文献   
45.
According to the current nutritional recommendations issued by professional diabetes and nutrition associations, diabetic patients should keep to a diet consisting of 45–60% carbohydrates, 10–20% protein, and not more than 35% fat. However, not all of these nutritional recommendations are evidence based. For example, current studies show that the intake of insoluble roughage may be underrepresented. It is also possible that diabetic patients could benefit from keeping to the lower end of the recommended range for carbohydrates (45%) and the upper end of the range advised for protein (20%).  相似文献   
46.
BACKGROUND: Presently, complementary and alternative medicine, including both therapies and herbal/oral supplements, is used globally. Few studies have examined the use of specific therapies, separate from herbal/oral supplements, in cardiac rehabilitation. This paper presents a systematic evaluation of current research evidence related to use of specific complementary and alternative medicine therapies in secondary prevention of cardiovascular disease, with a view to making recommendations for cardiac rehabilitation. DESIGN AND METHODS: A literature search was conducted using complementary and alternative medicine websites, Medline, Allied and Complementary Medicine, CINAHL, Cochrane databases, EMBASE, SportDiscus, Clinical Evidence, and Evidence-Based Practice to locate research-based scientific evidence related to the use of complementary and alternative medicine in cardiac rehabilitation. Search keywords included heart, cardiac, cardiovascular, coronary, myocardial and rehabilitation, combined with particular therapies. Herbal/oral supplements were not included in this evaluation. RESULTS: Some complementary and alternative medicine therapies may be useful to patients by themselves or coupled with traditional cardiac rehabilitation. Tai chi, as a complement to existing exercise interventions, can be utilized for low and intermediate risk patients. transcendental meditation may be used as a stress reduction technique. There was insufficient evidence found for the use of acupuncture or chelation therapy in cardiac rehabilitation or secondary prevention. CONCLUSIONS: Some complementary and alternative medicine therapies hold promise for patients in cardiac rehabilitation. Further research is essential, however, in all areas of complementary and alternative medicine to confirm its usefulness as an adjunct to cardiac rehabilitation.  相似文献   
47.
48.
Zusammenfassung In Deutschland leiden 25% der über 70-Jährigen unter einem Diabetes mellitus. Biologisch ältere, multimorbide und in ihren Funktionen beeinträchtigte geriatrische Patienten benötigen spezielle Vorgehensweisen bei Zielplanung, Allgemeinmaßnahmen und Pharmakotherapie. Auf der Basis der vorhandenen Leitlinien werden gesicherte Erkenntnisse dargestellt und Empfehlungen zu den Besonderheiten der Therapie des geriatrischen Diabetespatienten gegeben. Besonderes Augenmerk liegt dabei auf der Interaktion von geriatrischen Syndromen und Diabetes sowie der Verbesserung der Lebensqualität.  相似文献   
49.
50.
Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS.  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