全文获取类型
收费全文 | 855篇 |
免费 | 72篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 79篇 |
妇产科学 | 9篇 |
基础医学 | 76篇 |
口腔科学 | 12篇 |
临床医学 | 106篇 |
内科学 | 210篇 |
皮肤病学 | 15篇 |
神经病学 | 50篇 |
特种医学 | 86篇 |
外科学 | 85篇 |
综合类 | 26篇 |
一般理论 | 6篇 |
预防医学 | 81篇 |
眼科学 | 3篇 |
药学 | 49篇 |
肿瘤学 | 43篇 |
出版年
2021年 | 14篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 10篇 |
2016年 | 10篇 |
2015年 | 14篇 |
2014年 | 21篇 |
2013年 | 27篇 |
2012年 | 19篇 |
2011年 | 30篇 |
2010年 | 18篇 |
2009年 | 21篇 |
2008年 | 24篇 |
2007年 | 34篇 |
2006年 | 16篇 |
2005年 | 25篇 |
2004年 | 19篇 |
2003年 | 23篇 |
2002年 | 16篇 |
2001年 | 15篇 |
2000年 | 22篇 |
1999年 | 22篇 |
1998年 | 18篇 |
1997年 | 23篇 |
1996年 | 27篇 |
1995年 | 21篇 |
1994年 | 21篇 |
1993年 | 14篇 |
1992年 | 15篇 |
1991年 | 11篇 |
1990年 | 27篇 |
1989年 | 29篇 |
1988年 | 23篇 |
1987年 | 19篇 |
1986年 | 16篇 |
1985年 | 15篇 |
1984年 | 10篇 |
1983年 | 18篇 |
1982年 | 14篇 |
1981年 | 12篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 15篇 |
1976年 | 9篇 |
1975年 | 14篇 |
1974年 | 12篇 |
1973年 | 20篇 |
1972年 | 9篇 |
1970年 | 8篇 |
1967年 | 17篇 |
排序方式: 共有943条查询结果,搜索用时 15 毫秒
1.
Alan. B. Franklin Sarah N. Bevins Jeremy W. Ellis Ryan S. Miller Susan A. Shriner J. Jeffrey Root Daniel P. Walsh Thomas J. Deliberto 《Transboundary and Emerging Diseases》2019,66(2):705-714
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security. 相似文献
2.
PURPOSE: Concern over stigma as a consequence of genetic testing has grown in response to the recent increase in genetic research and testing resulting from the Human Genome Project. However, whether a genetic or hereditary basis necessarily confers a stigma to a condition remains unexamined. METHODS: We performed a qualitative interview study with 86 individuals with one of four conditions: deafness or hearing loss, breast cancer, sickle cell disease, and cystic fibrosis. The first two groups were divided approximately between people who ascribed their conditions to a genetic or hereditary cause and those who did not. RESULTS: Respondents interpreted genetic or hereditary causes and nongenetic causes in a variety of ways. Subjects with breast cancer reported the most consistently negative interpretation of genetic cause. This response concerned future ill health, not an enduring sense of stigma. Deaf and hard of hearing subjects provided the most consistently positive comments about a genetic or hereditary basis to their condition, casting familial hearing loss as a vital component of group and individual identity. Respondents with sickle cell disease and cystic fibrosis offered similar and positive interpretations of the genetic cause of their condition insofar as it meant their conditions were not contagious. CONCLUSIONS: Although some subjects report feeling stigmatized as a result of their condition, this stigmatization is not uniformly associated with the condition's cause, genetic or otherwise. Instead, stigma emerges from a variety of sources in the context of the lived experience of a particular condition. 相似文献
3.
4.
5.
Abdominal trauma and diagnostic peritoneal lavage revisited 总被引:3,自引:0,他引:3
H D Root 《American journal of surgery》1990,159(4):363-364
6.
GP SCHWAB AL BLUM E BODNER B DALLEMAGNE K GLASER H KOOP F PACE W RÖSCH JR SIEWERT G WETSCHER 《Journal of gastroenterology and hepatology》1997,12(12):785-789
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper. 相似文献
7.
Women wish to continue to be sexually active long after their desire to bear children. The risks associated with unintended pregnancy easily can be avoided by providing women with information about, and access to, contraceptives that are safe and effective. Because fertility naturally declines with age, different contraceptives may be more suitable for women toward the end of their reproductive years than were appropriate at periods of peak fertility. This article discusses the risks and benefits of various contraceptives for midlife women and the implications of this information on nursing practice. 相似文献
8.
9.
Michael J. Root 《Calcified tissue international》1990,47(2):112-116
Summary The induction time for amorphous calcium phosphate (ACP) phase transformation was monitored at pH 7.4 and T=25°C with [Ca2+]0=[PO4]0=4.0×10−3 M, as a function of added crystal growth inhibitors Mg2+, Sr2+, Zn2+, pyrophosphate (PP), and tripolyphosphate (TPP). Metal ions increase the induction time for the initiation of the phase change
reaction in the order Zn2+<Sr2+<Mg2+. For polyphosphates it was observed that both PP and TPP are potent inhibitors with TPP more effective than PP as expected.
The combination of Mg2+ or Sr2+ and PP or TPP leads to a synergistic delay in the onset of the phase conversion. The greatest inhibition was observed for
Mg2+ and TPP. Reaction solutions containing 2.0×10−4 M Mg2+ and 4.0×10−5 M TPP resulted in a 90% increase in the induction time over what would be anticipated from an additive effect from these
species. 相似文献
10.
Low-artifact intravascular devices: MR imaging evaluation 总被引:2,自引:0,他引:2
Teitelbaum GP; Ortega HV; Vinitski S; Stern H; Tsuruda JS; Mitchell DG; Rifkin MD; Bradley WG Jr 《Radiology》1988,168(3):713-719
Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible. 相似文献