全文获取类型
收费全文 | 2034篇 |
免费 | 228篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 65篇 |
妇产科学 | 47篇 |
基础医学 | 221篇 |
口腔科学 | 31篇 |
临床医学 | 208篇 |
内科学 | 327篇 |
皮肤病学 | 71篇 |
神经病学 | 135篇 |
特种医学 | 157篇 |
外科学 | 355篇 |
综合类 | 54篇 |
一般理论 | 5篇 |
预防医学 | 363篇 |
眼科学 | 10篇 |
药学 | 104篇 |
中国医学 | 1篇 |
肿瘤学 | 108篇 |
出版年
2021年 | 29篇 |
2020年 | 20篇 |
2019年 | 28篇 |
2018年 | 34篇 |
2017年 | 37篇 |
2016年 | 40篇 |
2015年 | 44篇 |
2014年 | 49篇 |
2013年 | 103篇 |
2012年 | 90篇 |
2011年 | 80篇 |
2010年 | 62篇 |
2009年 | 81篇 |
2008年 | 68篇 |
2007年 | 77篇 |
2006年 | 62篇 |
2005年 | 59篇 |
2004年 | 70篇 |
2003年 | 61篇 |
2002年 | 67篇 |
2001年 | 61篇 |
2000年 | 58篇 |
1999年 | 41篇 |
1998年 | 48篇 |
1997年 | 40篇 |
1996年 | 45篇 |
1995年 | 32篇 |
1994年 | 40篇 |
1993年 | 32篇 |
1992年 | 35篇 |
1991年 | 39篇 |
1990年 | 39篇 |
1989年 | 46篇 |
1988年 | 40篇 |
1987年 | 38篇 |
1986年 | 32篇 |
1985年 | 31篇 |
1984年 | 23篇 |
1983年 | 25篇 |
1981年 | 17篇 |
1979年 | 19篇 |
1978年 | 31篇 |
1977年 | 25篇 |
1976年 | 19篇 |
1975年 | 19篇 |
1974年 | 28篇 |
1972年 | 23篇 |
1970年 | 17篇 |
1968年 | 17篇 |
1966年 | 19篇 |
排序方式: 共有2268条查询结果,搜索用时 15 毫秒
1.
2.
Kimberly B. Glazer Kendrin R. Sonneville Nadia Micali Sonja A. Swanson Ross Crosby Nicholas J. Horton Kamryn T. Eddy Alison E. Field 《The Journal of adolescent health》2019,64(2):165-171
Purpose
To quantify eating disorder (ED) stability and diagnostic transition among a community-based sample of adolescents and young adult females in the United States.Methods
Using 11 prospective assessments from 9,031 U.S. females ages 9–15 years at baseline of the Growing Up Today Study, we classified cases of the following EDs involving bingeing and purging: bulimia nervosa (BN), binge ED, purging disorder (PD), and subthreshold variants defined by less frequent (monthly vs. weekly) bingeing and purging behaviors. We measured number of years symptomatic and probability of maintaining symptoms, crossing to another diagnosis, or resolving symptoms across consecutive surveys.Results
Study lifetime disorder prevalence was 2.1% for BN and roughly 6% each for binge ED and PD. Most cases reported symptoms during only one survey year. Twenty-six percent of cases crossed between diagnoses during follow-up. Among participants meeting full threshold diagnostic criteria, transition from BN was most prevalent, crossing most frequently from BN to PD (12.9% of BN cases). Within each disorder phenotype, 20%–40% of cases moved between subthreshold and full threshold criteria across consecutive surveys.Conclusions
Diagnostic crossover is not rare among adolescent and young adult females with an ED. Transition patterns from BN to PD add support for considering these classifications in the same diagnostic category of disorders that involve purging. The prevalence of crossover between monthly and weekly symptom frequency suggests that a continuum or staging approach may increase utility of ED classification for prognostic and therapeutic intervention. 相似文献3.
Liver hemangioma: US-guided 18-gauge core-needle biopsy 总被引:6,自引:0,他引:6
4.
D. L. Crosby G. A. Rees J. Gill 《Annals of the Royal College of Surgeons of England》1990,72(5):309-312
The current experience of a high dependency unit established 5 years ago for the postoperative care of high-risk patients undergoing surgery is reported. The resource implications and contributions to the safety and quality of post-operative care, particularly pain relief, are described. 相似文献
5.
Edward T. Crosby Stephen H. Halpern Stephen H. Rolbin 《Journal canadien d'anesthésie》1989,36(6):701-704
The safety of epidural anaesthesia in patients with active, recurrent genital herpes simplex (HSV) infections is controversial. We reviewed the six-year experience of the use of epidural anaesthesia in this patient population in two institutions. Eighty-nine parturients with active genital HSV were administered epidural anaesthesia for Caesarean section. No patient suffered an adverse outcome related to either the anaesthetic or the virus. The theoretical risks of regional anaesthesia in the parturient with active herpes genitalis are reviewed. We conclude from available data that the risk of an adverse outcome is small and does not contraindicate the use of epidural anaesthesia in patients with recurrent infection. 相似文献
6.
7.
BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors. 相似文献
8.
9.
Edward T. Crosby 《Journal canadien d'anesthésie》1992,39(7):695-707
The practice of transfusion medicine has undergone substantial change over the last decade. Much of the impetus for the change has come from the isolation of human immunodeficiency virus (HIV) and the linkage of HIV transmission to blood transfusion. The purpose of this paper is to collate and review the literature relating to the indications for blood transfusion and provide recommendations for the appropriate utilization of blood products. Peer-reviewed and published studies and reviews relating to aspects of clinical blood transfusion were identified through computer searches and searching of the bibliographies of identified articles. Emphasis was placed on the literature published within the last decade and particularly in the years 1985-91. Material was chosen which was of proved clinical importance and in which findings were consistent among different investigators or different centres. Less emphasis was placed on material reporting new findings of uncertain clinical relevance or findings that were not consistent with majority reports. It is concluded that the only indication for red cell transfusion is to increase the oxygen carrying capacity of the blood and that an adjustment downwards in the haemoglobin concentration at which blood is transfused (transfusion trigger) from the traditional level of 100 g.L-1 is supported by the physiological and clinical data. Perioperative haemoglobin concentrations of 80 g.L-1 are acceptable in otherwise healthy young patients. The transfusion trigger should be adjusted upwards from this in medically compromised patients and in the elderly (greater than 60 yr). Fresh frozen plasma (FFP) is only indicated when there are documented deficiencies of coagulation factors. Platelet concentrates (PC) are indicated for the treatment of clinical coagulopathy resulting from thrombocytopaenia or platelet dysfunction. Routine or prophylactic administration of either FFP or PC after cardiopulmonary bypass or during resuscitation from haemorrhage is not indicated. 相似文献
10.