全文获取类型
收费全文 | 3543篇 |
免费 | 85篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 122篇 |
妇产科学 | 26篇 |
基础医学 | 129篇 |
口腔科学 | 15篇 |
临床医学 | 134篇 |
内科学 | 396篇 |
皮肤病学 | 7篇 |
神经病学 | 75篇 |
特种医学 | 16篇 |
外科学 | 118篇 |
综合类 | 50篇 |
预防医学 | 2373篇 |
眼科学 | 24篇 |
药学 | 62篇 |
中国医学 | 2篇 |
肿瘤学 | 81篇 |
出版年
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 17篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 25篇 |
2017年 | 17篇 |
2016年 | 15篇 |
2015年 | 23篇 |
2014年 | 16篇 |
2013年 | 44篇 |
2012年 | 205篇 |
2011年 | 350篇 |
2010年 | 85篇 |
2009年 | 47篇 |
2008年 | 250篇 |
2007年 | 265篇 |
2006年 | 301篇 |
2005年 | 272篇 |
2004年 | 335篇 |
2003年 | 363篇 |
2002年 | 284篇 |
2001年 | 171篇 |
2000年 | 192篇 |
1999年 | 101篇 |
1998年 | 11篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 13篇 |
1992年 | 12篇 |
1991年 | 31篇 |
1990年 | 22篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1971年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有3634条查询结果,搜索用时 15 毫秒
1.
OBJECTIVE: This study was conducted to compare an otolaryngologist's experience with a cohort of epilepsy patients implanted with a vagal nerve stimulator (VNS) to previously published data. METHODS: Demographics, preoperative seizure frequency, medications, and complications were retrospectively collected from patients implanted by the senior author. Postoperative medications and seizure frequency were obtained from referring neurologists. RESULTS: Seventeen patients were implanted over a 24-month period. Average age was 28.3 years. Patients presented with petit mal (n = 3), tonic-clonic (n = 6), complex partial (n = 5), and grand mal (n = 8) seizures. Mean follow-up postimplantation was 13.5 months. Most patients had at least a 50% reduction of seizure frequency, with 3 patients being seizure free. There were no postoperative infections. One patient had left vocal cord immobility. The most common side effect was voice disturbance during device activation. CONCLUSION: Otolaryngologists are well equipped to perform VNS implantation and to diagnose and treat possible laryngeal side effects. EBM rating: C-4. 相似文献
2.
3.
To investigate pain that occurs in the absence of painful stimulation, normal subjects were connected to a sham stimulator and were told that a headache could occur as a result of the electrical current they would receive. Half of the subjects who received this suggestion reported pain. The frequency and intensity of pain reports in a group which was given prior pain experience as a reference point in reporting pain and in a group which was exposed to a manipulation designed to reduce intentional deception were not significantly different from the pain reports of a group not exposed to these manipulations. The frequency of pain reports in subjects not connected to the sham stimulator but still asked to report pain was 25% which was significantly less than the frequency for subjects who were told there would be stimulation to the head. Pain ratings increased as the settings of the sham stimulator were increased. Subjects who reported pain had significantly fewer electrodermal responses to tones signaling them to prepare for a reaction time task. The results suggest that pain can be produced in the absence of peripheral stimulation. The pain does not appear to be due to intentional deception or the lack of a standard for comparison, but is strongly influenced by environmental cues. Psychophysiologically, pain responders were less attentive to signal stimuli. 相似文献
4.
Kristiansen OP Karlsen AE Larsen ZM Johannesen J Pociot F Mandrup-Poulsen T;Danish IDDM Epidemiology Genetics Group Danish Study Group of IDDM in Childhood 《Scandinavian journal of immunology》2004,59(6):582-591
CD4 is a candidate gene in autoimmune diseases, including Type 1 diabetes mellitus (T1DM), because the CD4 receptor is crucial for appropriate antigen responses of CD4(+) T cells. We previously found linkage between a CD4-1188(TTTTC)(5-14) promoter polymorphism and T1DM. In the present study, we screened the human CD4 promoter for mutations and identified three frequent single nucleotide polymorphisms (SNPs): CD4-181C/G, CD4-521C/G and CD4-1050T/C. The SNPs are in strong linkage disequilibrium (LD) and association with the CD4-1188(TTTTC)(5-14) alleles, and we observed nine CD4 promoter haplotypes, of which four are frequent. We genotyped the SNPs in 253 Danish T1DM families (1129 individuals) and found evidence for linkage and association of a CD4 (A4(-1188)T(-1050)G(-521)C(-181)) haplotype to T1DM. In reporter studies, we show that (1) the T1DM-associated CD4 haplotype encodes high constitutive promoter activity and (2) the CD4-181G variant encodes higher stimulated promoter activity than the CD4-181C variant. This difference is in part neutralized in the frequently occurring CD4 promoter haplotypes by the more upstream genetic variants. Thus, we report functional impact of a novel CD4-181C/G SNP on stimulated CD4 promoter activity and the identification of a novel CD4 haplotype with high constitutive promoter activity that is linked and associated with T1DM. 相似文献
5.
6.
7.
8.
Centers for Disease Control Prevention 《MMWR. Morbidity and mortality weekly report》1999,48(8):159-162
Immune globulin intravenous (IGIV) is a lifesaving treatment for patients with primary immunodeficiency. Since November 1997, a shortage of IGIV has existed in the United States. In 1998, the Food and Drug Administration (FDA) required pharmaceutical companies to increase the frequency of reporting on IGIV distribution from biannually to monthly; in addition, FDA facilitated IGIV distribution and informed clinicians about the ongoing shortage. To assess the impact of the IGIV shortage on patient care, in 1998 the Immune Deficiency Foundation (IDF) surveyed physicians caring for immunodeficient patients about whether they have had difficulty obtaining IGIV, measures they have taken because of the shortage, and the effect of the shortage on their patients. This report summarizes data reported to FDA and data obtained from the IDF survey and provides recommendations for IGIV use during the shortage. 相似文献
9.
Centers for Disease Control Prevention 《MMWR. Morbidity and mortality weekly report》1999,48(7):140-143
In November 1996, residents of Oregon approved a ballot measure increasing the cigarette tax by 30 cents (to 68 cents per pack). The measure stipulated that 10% of the additional tax revenue be allocated to the Oregon Health Division (OHD) to develop and implement a tobacco-use prevention program. In 1997, OHD created Oregon's Tobacco Prevention and Education Program (TPEP), a comprehensive, community-based program modeled on the successful tobacco-use prevention programs in California and Massachusetts. To assess the effects of the tax increase and TPEP in Oregon, OHD evaluated data on the number of packs of cigarettes taxed before (1993-1996) and after (1997-1998) the ballot initiative and implementation of the program. Oregon's results also were compared with national data. This report summarizes the results of the analysis, which indicate that consumption of cigarettes in Oregon declined substantially after implementation of the excise tax and TPEP and exceeded the national rate of decline. 相似文献
10.
Centers for Disease Control Prevention 《MMWR. Morbidity and mortality weekly report》1999,48(38):859-860
The United Nations (UN) estimates that the world's population will reach six billion on October 12, 1999. The world's population reached one billion in 1804; subsequently, one billion increases came at intervals of 123, 33, 14, 13, and 12 years. Population growth rates increased over time because of high fertility rates and declines in mortality rates, especially since the early to mid-1900s. The UN projects that it will take 14 years for the world's population to reach 7 billion and another 15 years to reach 8 billion. 相似文献