全文获取类型
收费全文 | 1324篇 |
免费 | 134篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 22篇 |
妇产科学 | 7篇 |
基础医学 | 127篇 |
口腔科学 | 7篇 |
临床医学 | 112篇 |
内科学 | 548篇 |
皮肤病学 | 5篇 |
神经病学 | 60篇 |
特种医学 | 15篇 |
外科学 | 239篇 |
综合类 | 56篇 |
预防医学 | 106篇 |
眼科学 | 9篇 |
药学 | 46篇 |
肿瘤学 | 77篇 |
出版年
2022年 | 6篇 |
2021年 | 17篇 |
2020年 | 15篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 14篇 |
2016年 | 17篇 |
2015年 | 18篇 |
2014年 | 34篇 |
2013年 | 48篇 |
2012年 | 64篇 |
2011年 | 73篇 |
2010年 | 60篇 |
2009年 | 32篇 |
2008年 | 78篇 |
2007年 | 83篇 |
2006年 | 109篇 |
2005年 | 105篇 |
2004年 | 90篇 |
2003年 | 93篇 |
2002年 | 63篇 |
2001年 | 28篇 |
2000年 | 19篇 |
1999年 | 21篇 |
1998年 | 17篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 15篇 |
1994年 | 11篇 |
1993年 | 15篇 |
1992年 | 20篇 |
1991年 | 12篇 |
1990年 | 21篇 |
1989年 | 14篇 |
1988年 | 11篇 |
1987年 | 13篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 14篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 17篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1973年 | 6篇 |
1968年 | 8篇 |
1967年 | 11篇 |
排序方式: 共有1463条查询结果,搜索用时 15 毫秒
1.
L C Harlan B F Polk S Cooper T P Blaszkowski J Ignatius-Smith M Stromer H Mull 《American journal of preventive medicine》1986,2(5):256-261
The effects of labeling a person as hypertensive have important implications for hypertension screening. The Hypertension Detection and Follow-up Program (HDFP) provides an opportunity to examine the effects of labeling, treatment, and study assignment on a large group of hypertensives (n = 10,070). Their answers to questions regarding perceived health and general well-being asked at baseline and again one year later were analyzed. There was no significant change in the perceived health status of persons who were unaware of their hypertension at baseline and remained untreated at one year (labeling alone). The effect of labeling plus treatment was associated with a significant decrease in perceived health. The effect of antihypertensive drug therapy on perceived health status was examined in persons who were aware of their hypertension but not on treatment at baseline, and on treatment at one year. The stepped care group (SC) had a significant improvement in their perceived health and a significant decrease in the amount of time spent worrying about their health. The referred care group (RC) had no change. Program assignment effects were studied in individuals aware of their hypertension and on treatment both at baseline and one year later. Both the SC and RC groups had a significant improvement in their perceptions of their health status. The SC group had a significant decrease in time spent worrying about their health, while the RC group showed no change. These reassuring results fail to support the suggestion that labeling persons as hypertensive is necessarily followed by negative psychological consequences.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
2.
Saif S Rathore Andrew J Epstein Brahmajee K Nallamothu Harlan M Krumholz 《Journal of the American College of Cardiology》2006,47(7):1346-1349
A uniform policy for regionalization of ST-segment elevation myocardial infarction (STEMI) care raises several concerns. Transferring all STEMI patients to obtain primary percutaneous coronary intervention (PCI) may be less effective than transferring only high-risk STEMI patients. Delays in time to treatment >60 min associated with transferring patients for primary PCI may result in increased mortality for the average patient as compared with providing immediate fibrinolytic therapy at their initial hospital; yet more than 95% of patients transferred for primary PCI in the U.S. exceed this 60-min benchmark. Superior outcomes associated with treatment at higher-volume regional STEMI centers are inconsistent among centers, and there is no direct evidence that patients will benefit by a transfer to a high-volume hospital from a low-volume hospital. Published data suggest as many as 800 PCI patients would need to be transferred to a high-volume PCI hospital to avoid a single death at a low-volume PCI hospital. Although European randomized trial data suggest transferring patients with STEMI for primary PCI may be superior to immediate fibrinolytic therapy, these findings are unlikely to generalize to the U.S. health care system given size, geography, and organization. ST segment elevation myocardial infarction care regionalization would require a massive redistribution of health care resources, depriving several hospitals of advanced cardiac care facilities, expertise, and associated revenue. Clearer evidence of the benefits and discussion of potential harms are needed before adopting a national STEMI regionalization policy. 相似文献
3.
4.
5.
Dendritic cells pulsed with a recombinant chlamydial major outer membrane protein antigen elicit a CD4(+) type 2 rather than type 1 immune response that is not protective 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chlamydia trachomatis is an obligate intracellular bacterium that infects the oculogenital mucosae. C. trachomatis infection of the eye causes trachoma, the leading cause of preventable blindness. Infections of the genital mucosae are a leading cause of sexually transmitted diseases. A vaccine to prevent chlamydial infection is needed but has proven difficult to produce by using conventional vaccination approaches. Potent immunity to vaginal rechallenge in a murine model of chlamydial genital infection has been achieved only by infection or by immunization with dendritic cells (DC) pulsed ex vivo with whole inactivated organisms. Immunity generated by infection or ex vivo antigen-pulsed DC correlates with a chlamydia-specific interleukin 12 (IL-12)-dependent CD4(+) Th1 immune response. Because of the potent antichlamydial immunizing properties of DC, we hypothesized that DC could be a powerful vehicle for the delivery of individual chlamydial antigens that are thought to be targets for more conventional vaccine approaches. Here, we investigated the recombinant chlamydial major outer membrane protein (rMOMP) as a target antigen. The results demonstrate that DC pulsed with rMOMP secrete IL-12 and stimulate infection-sensitized CD4(+) T cells to proliferate and secrete gamma interferon. These immunological properties implied that rMOMP-pulsed DC would be potent inducers of MOMP-specific CD4(+) Th1 immunity in vivo; however, we observed the opposite result. DC pulsed ex vivo with rMOMP and adoptively transferred to naive mice generated a Th2 rather than a Th1 anti-MOMP immune response, and immunized mice were not protected following infectious challenge. We conclude from these studies that the immunological properties of ex vivo pulsed DC are not necessarily predictive of the immune response generated in vivo following adoptive transfer. These findings suggest that the nature of the antigen used to pulse DC ex vivo influences the Th1-Th2 balance of the immune response in vivo. 相似文献
6.
Thomas M Morgan Lan Xiao Patrick Lyons Bethany Kassebaum Harlan M Krumholz John A Spertus 《BMC medical genetics》2008,9(1):66
Background
Many candidate genes have been reported to be risk factors for acute coronary syndrome (ACS), but their impact on clinical prognosis following ACS is unknown. 相似文献7.
Polymorphisms in the Chlamydia trachomatis cytotoxin locus associated with ocular and genital isolates
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Carlson JH Hughes S Hogan D Cieplak G Sturdevant DE McClarty G Caldwell HD Belland RJ 《Infection and immunity》2004,72(12):7063-7072
Chlamydia trachomatis is a strict human pathogen producing infections that cause medically important chronic inflammatory diseases, such as blinding trachoma and tubal factor infertility. Isolates exist as serotypes that fall into distinct biologic and pathological groups corresponding to differences in infection tissue tropism and invasion properties. Paradoxically, genome sequencing of several diverse strains has revealed a remarkable level of genomic synteny, suggesting that minor genetic differences determine the pathogen host- and tissue-specific infection characteristics. To better understand the genetic basis of chlamydial pathobiologic diversity, we performed comparative DNA-DNA microarray genomic hybridizations with all 15 C. trachomatis serovariants. We found there are few major genetic differences among the 15 serovars. An exception was the cytotoxin locus located in the plasticity zone, a region that exhibited significant polymorphisms among serovars. We therefore sequenced this region from all 15 serovars. The cytotoxin gene was interrupted by extensive mutations and deletions among the different serovars; however, three basic open reading frame motifs were discovered that correlated with noninvasive oculotropic, urogenitotropic, and invasive serovars. Of interest, only noninvasive genitotropic serovars possessed an intact N-terminal portion of the putative toxin gene. This region contains the UDP-glucose binding domain and the glycosyltransferase domain required for enzymatic activity of the clostridial toxin homologs, suggesting a role in urogenital infection or pathogenesis. 相似文献
8.
9.
10.
Sharon Medcalf Laura Bilek Teresa Hartman Peter C. Iwen Patricia Leuschen Hannah Miller Anne O’Keefe Harlan Sayles Philip W. Smith 《Emerging infectious diseases》2015,21(8):1437-1439
To evaluate the need to revaccinate laboratory workers against smallpox, we assessed regular revaccination at the US Laboratory Response Network’s variola testing sites by examining barriers to revaccination and the potential for persistence of immunity. Our data do not provide evidence to suggest prolonging the recommended interval for revaccination. 相似文献