全文获取类型
收费全文 | 23678篇 |
免费 | 2213篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 187篇 |
儿科学 | 887篇 |
妇产科学 | 709篇 |
基础医学 | 3276篇 |
口腔科学 | 554篇 |
临床医学 | 3191篇 |
内科学 | 4301篇 |
皮肤病学 | 276篇 |
神经病学 | 2211篇 |
特种医学 | 635篇 |
外科学 | 2372篇 |
综合类 | 490篇 |
一般理论 | 42篇 |
预防医学 | 3342篇 |
眼科学 | 435篇 |
药学 | 1424篇 |
中国医学 | 7篇 |
肿瘤学 | 1613篇 |
出版年
2023年 | 127篇 |
2022年 | 136篇 |
2021年 | 455篇 |
2020年 | 288篇 |
2019年 | 435篇 |
2018年 | 511篇 |
2017年 | 402篇 |
2016年 | 406篇 |
2015年 | 514篇 |
2014年 | 681篇 |
2013年 | 1062篇 |
2012年 | 1445篇 |
2011年 | 1546篇 |
2010年 | 848篇 |
2009年 | 724篇 |
2008年 | 1397篇 |
2007年 | 1456篇 |
2006年 | 1467篇 |
2005年 | 1406篇 |
2004年 | 1261篇 |
2003年 | 1188篇 |
2002年 | 1273篇 |
2001年 | 386篇 |
2000年 | 362篇 |
1999年 | 392篇 |
1998年 | 293篇 |
1997年 | 222篇 |
1996年 | 194篇 |
1995年 | 188篇 |
1994年 | 202篇 |
1993年 | 186篇 |
1992年 | 205篇 |
1991年 | 220篇 |
1990年 | 231篇 |
1989年 | 226篇 |
1988年 | 199篇 |
1987年 | 183篇 |
1986年 | 202篇 |
1985年 | 204篇 |
1984年 | 177篇 |
1983年 | 160篇 |
1982年 | 159篇 |
1981年 | 128篇 |
1980年 | 144篇 |
1979年 | 151篇 |
1978年 | 140篇 |
1977年 | 124篇 |
1975年 | 103篇 |
1974年 | 105篇 |
1973年 | 114篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
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
72.
Perioperative hemodynamic and temperature changes were reviewed in 58 patients who underwent aortocoronary bypass grafting. Core temperature showed an immediate decline postoperatively, secondary to core temperature cooling during bypass. Subsequent rewarming occurred over the next 8 to 12 hours, with the temperature often increasing above normal. The reason for this pyrexial response is discussed. The cardiac index was depressed immediately postoperatively, again with substantial recovery within 8 hours. This improvement over time occurred not only because of recovery of intrinsic function but also because of reduction in myocardial work due to falling systemic vascular resistance. The latter was high immediately postoperatively and then consistently fell during the rewarming phase. During the first 8 hours postoperatively there were significant changes in temperature and cardiac and systemic vascular resistance indices. The hemodynamic data correlated strongly with changes in temperature. Falling systemic vascular resistance required the institution of alpha-agonist therapy in 25% of patients. 相似文献
73.
74.
Ruth Ladurner Gerald Brandacher Wolfgang Steurer Stefan Schneeberger Claudia Bösmüller Martin Clemens Freund Alfons Kreczy Alfred Königsrainer Raimund Margreiter 《Transplant international》2003,16(12):885-889
Fungal infections still represent a serious complication after organ transplantation. Early diagnosis and aggressive treatment are crucial. Because of the many diagnostic problems involved, we present a case of mucormycosis--primarily affecting the paranasal sinuses with later intracranial extension--in a highly immunized recipient of a third renal transplant. Although fungal infection was suspected from various imaging techniques, only the detection of typical fungal hyphae in the infected tissue was diagnostic. Neither the blood tests and cerebrospinal fluid examinations performed nor cultures from maxillary sinus fluid were of any diagnostic help. Surgical debridement from a transnasal as well as an intracranial approach and systemic amphotericin B together with the discontinuation of immunosuppression after removal of the rejected graft were able to save the patient. This case stresses the importance of early diagnosis that can only be made from tissue biopsies and allows appropriate timely treatment. 相似文献
75.
Rubella virus strains show no major antigenic differences. 总被引:7,自引:0,他引:7
To determine whether antigenic differences occur among rubella virus strains, five wild-type strains of rubella virus isolated in the UK, the USA, and in Japan between 1964 and 1987 and four attenuated vaccine strains were compared employing a panel of 28 monoclonal antibodies in neutralization, haemagglutination-inhibition, enzyme immunoassay, and indirect immunofluorescence assays. No antigenic differences were detected which confirms that rubella vaccines will protect against circulating strains and that rubella antigens used in serological tests for screening and diagnosis will detect antibodies induced by all strains. 相似文献
76.
A review of strategies for enhancing the completeness of notifiable disease reporting. 总被引:1,自引:0,他引:1
Notifiable disease surveillance systems provide essential data for infectious disease prevention and control programs at the local, state, and national levels. Given that reporting completeness is known to vary considerably, this review identifies methods that can reliably enhance completeness of reporting. These surveillance-related activities include initiating active surveillance when appropriate; implementing automated, electronic laboratory-based reporting; strengthening ties with clinicians and other key partners in notifiable disease reporting; and increasing the use of laboratory diagnostic tests in identifying new cases. Despite ample data in support of these strategies, notifiable disease surveillance continues to receive insufficient attention and resources. Recent attention to public health preparedness provides an opportunity to strengthen notifiable disease surveillance and enhance completeness of reporting. 相似文献
77.
R Snyder J Bishop G Brodie W Burns A Coates J Levi D Raghavan M Schwarz M Tattersall D Thomson 《Cancer treatment reports》1987,71(3):273-276
Epirubicin was studied in a phase I setting to find the maximum tolerated dose when given weekly for 3 of 4 weeks. Forty-one evaluable patients were treated in groups at doses increasing from 20 to 45 mg/m2. The highest dose level produced the maximum degree of myelosuppression (lowest neutrophil count, 1.9 X 10(9)/L; range, 0-3.7) recorded on Day 22. This was well-tolerated in this group of mainly pretreated patients. Nonhematologic side effects were minimal. This dose schedule allows a greater dose per unit time to be administered than other recommended schedules for epirubicin. 相似文献
78.
Dendritic Cells, Tolerance Induction and Transplant Outcome 总被引:3,自引:0,他引:3
79.
Ruth Dailey Grainger Clifford Levin Lois Allen-Byrd Ronald M. Doctor Howard Lee 《Journal of traumatic stress》1997,10(4):665-671
Controlled studies of treatments effective with victims of natural disasters are almost nonexistent. This is a small study conducted under difficult conditions to test the effectiveness of Eye Movement Desensitization and Reprocessing (EMDR) in treating trauma related reactions following Hurricane Andrew. The results were positive in that EMDR produced significant improvement over wail list controls in perceived posttraumatic avoidance behaviors and thoughts as measured by changes in the Impact of Event Scale and significant improvement in subjective aversive reactions to representative experiences of the hurricane. These results suggest and support other studies that EMDR can be an effective therapeutic intervention for trauma reactions. 相似文献
80.