全文获取类型
收费全文 | 3395篇 |
免费 | 182篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 116篇 |
妇产科学 | 39篇 |
基础医学 | 279篇 |
口腔科学 | 114篇 |
临床医学 | 277篇 |
内科学 | 836篇 |
皮肤病学 | 54篇 |
神经病学 | 152篇 |
特种医学 | 178篇 |
外科学 | 679篇 |
综合类 | 102篇 |
一般理论 | 1篇 |
预防医学 | 268篇 |
眼科学 | 60篇 |
药学 | 219篇 |
中国医学 | 16篇 |
肿瘤学 | 187篇 |
出版年
2023年 | 30篇 |
2022年 | 54篇 |
2021年 | 108篇 |
2020年 | 61篇 |
2019年 | 77篇 |
2018年 | 104篇 |
2017年 | 61篇 |
2016年 | 69篇 |
2015年 | 64篇 |
2014年 | 142篇 |
2013年 | 161篇 |
2012年 | 187篇 |
2011年 | 236篇 |
2010年 | 153篇 |
2009年 | 143篇 |
2008年 | 168篇 |
2007年 | 188篇 |
2006年 | 170篇 |
2005年 | 166篇 |
2004年 | 145篇 |
2003年 | 155篇 |
2002年 | 152篇 |
2001年 | 66篇 |
2000年 | 74篇 |
1999年 | 56篇 |
1998年 | 35篇 |
1997年 | 18篇 |
1996年 | 30篇 |
1995年 | 27篇 |
1994年 | 27篇 |
1993年 | 17篇 |
1992年 | 35篇 |
1991年 | 38篇 |
1990年 | 37篇 |
1989年 | 28篇 |
1988年 | 36篇 |
1987年 | 38篇 |
1986年 | 31篇 |
1985年 | 30篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1981年 | 10篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 9篇 |
1973年 | 11篇 |
1970年 | 9篇 |
1969年 | 13篇 |
1968年 | 9篇 |
1966年 | 9篇 |
排序方式: 共有3601条查询结果,搜索用时 15 毫秒
111.
Growth retardation and cysteine deficiency in gamma-glutamyl transpeptidase-deficient mice. 总被引:9,自引:0,他引:9 下载免费PDF全文
M W Lieberman A L Wiseman Z Z Shi B Z Carter R Barrios C N Ou P Chévez-Barrios Y Wang G M Habib J C Goodman S L Huang R M Lebovitz M M Matzuk 《Proceedings of the National Academy of Sciences of the United States of America》1996,93(15):7923-7926
gamma-Glutamyl transpeptidase (GGT) is an ectoenzyme that catalyzes the first step in the cleavage of glutathione (GSH) and plays an essential role in the metabolism of GSH and GSH conjugates of carcinogens, toxins, and eicosanoids. To learn more about the role of GGT in metabolism in vivo, we used embryonic stem cell technology to generate GGT-deficient (GGTm1/GGTm1) mice. GGT-deficient mice appear normal at birth but grow slowly and by 6 weeks are about half the weight of wild-type mice. They are sexually immature, develop cataracts, and have coats with a gray cast. Most die between 10 and 18 weeks. Plasma and urine GSH levels in the GGTm1/GGTm1 mice are elevated 6-fold and 2500-fold, respectively, compared with wild-type mice. Tissue GSH levels are markedly reduced in eye, liver, and pancreas. Plasma cyst(e)ine levels in GGTm1/GGTm1 mice are reduced to approximately 20% of wild-type mice. Oral administration of N-acetylcysteine to GGTm1/GGTm1 mice results in normal growth rates and partially restores the normal agouti coat color. These findings demonstrate the importance of GGT and the gamma-glutamyl cycle in cysteine and GSH homeostasis. 相似文献
112.
Transurethral microwave thermotherapy of the prostate has been touted as a minimally invasive means of treating symptomatic prostatism. High temperatures (>55 degrees C) appear to yield improved results but require general anesthesia. To determine if high temperature thermotherapy of the prostate was feasible in an outpatient, nonanesthetic setting, we subjected men with symptomatic prostatism secondary to benign prostatic hyperplasia to treatment with a newly developed circumferentially cooled transurethral microwave thermotherapy device, the UroWave. Intraprostatic temperatures were measured on-line and treatment was targeted to achieve temperatures ranging from 45 degrees C-65 degrees C. Fifty-five men with benign prostatic hyperplasia underwent transurethral microwave thermotherapy using the UroWave in an outpatient setting without general anesthesia. Baseline mean peak urinary flow rates were 8.0 cc/sec and mean American Urology Association of the prostate displayed three distinct phases: an initial slow heating phase, a plateau phase of variable duration and a rapid secondary heating phase. The final intraprostatic temperature did not correlate with urethral or rectal temperatures or the amount of power applied. At six months, peak flow increased by 50% and symptoms score declined by 52%. Ninety-four percent of patients had a transurethral resection of the prostate-like defect at cystoscopy with a greater proportion at higher temperatures. Side effects were rare and no patients had to be admitted to hospital. Transurethral microwave thermotherapy at high intraprostatic temperatures can be achieved with general anesthesia. Symptom relief was considerable and anatomic changes resembling a transurethral resection of the prostate were noted in the majority of patients. Intraprostatic temperatures are the only means of assessing the thermal damage to the prostate and thus the effectiveness if therapy. Future studies must develop less invasive means of monitoring intraprostatic temperatures and define the role of the bladder neck. Ultimately, randomized controlled trials will define the value of this treatment. 相似文献
113.
114.
Iris Schuster Gilbert Habib Christophe Jego Franck Thuny Jean-Fran?ois Avierinos Geneviève Derumeaux Lionel Beck Christine Medail Frederic Franceschi Sebastien Renard Ange Ferracci Jean Lefevre Roger Luccioni Jean-Claude Deharo Pierre Djiane 《Journal of the American College of Cardiology》2005,46(12):2250-2257
OBJECTIVES: To compare the incidence of diastolic and systolic asynchrony, assessed by tissue Doppler imaging (TDI), in patients with congestive heart failure (CHF) and severe left ventricular (LV) dysfunction, and to assess TDI changes induced by cardiac resynchronization therapy (CRT). BACKGROUND: Thirty percent of CRT candidates are nonresponders. Besides QRS width, the presence of echographic systolic asynchrony has been used to identify future responders. Little is known about diastolic asynchrony and its change after CRT. METHODS: Tissue Doppler imaging was performed in 116 CHF patients (LV ejection fraction 26 +/- 8%). Systolic and diastolic asynchrony was calculated using TDI recordings of right ventricular and LV walls. RESULTS: The CHF group consisted of 116 patients. Diastolic asynchrony was more frequent than systolic, concerning both intraventricular (58% vs. 47%; p = 0.0004) and interventricular (72 vs. 45%; p < 0.0001) asynchrony. Systolic and diastolic asynchrony were both present in 41% patients, but one-third had isolated diastolic asynchrony. Although diastolic delays increased with QRS duration, 42% patients with narrow QRS presented with diastolic asynchrony. Conversely, 27% patients with large QRS had no diastolic asynchrony. Forty-two patients underwent CRT. Incidence of systolic intraventricular asynchrony decreased from 71% to 33% after CRT (p < 0.0001), but diastolic asynchrony decreased only from 81% to 55% (p < 0.0002). Cardiac resynchronization therapy induced new diastolic asynchrony in eight patients. CONCLUSIONS: Diastolic asynchrony is weakly correlated with QRS duration, is more frequent than systolic asynchrony, and may be observed alone. Diastolic asynchrony is less improved by CRT than systolic. Persistent diastolic asynchrony may explain some cases of lack of improvement after CRT despite good systolic resynchronization. 相似文献
115.
Belshe RB Stevens C Gorse GJ Buchbinder S Weinhold K Sheppard H Stablein D Self S McNamara J Frey S Flores J Excler JL Klein M Habib RE Duliege AM Harro C Corey L Keefer M Mulligan M Wright P Celum C Judson F Mayer K McKirnan D Marmor M Woody G;National Institute of Allergy Infectious Diseases AIDS Vaccine Evaluation Group HIV Network for Prevention Trials 《The Journal of infectious diseases》2001,183(9):1343-1352
Live attenuated viral vectors that express human immunodeficiency virus (HIV) antigens are being developed as potential vaccines to prevent HIV infection. The first phase 2 trial with a canarypox vector (vCP205, which expresses gp120, p55, and protease) was conducted in 435 volunteers with and without gp120 boosting, to expand the safety database and to compare the immunogenicity of the vector in volunteers who were at higher risk with that in volunteers at lower risk for HIV infection. Neutralizing antibodies to the MN strain were stimulated in 94% of volunteers given vCP205 plus gp120 and in 56% of volunteers given vCP205 alone. CD8(+) cytotoxic T lymphocyte cells developed at some time point in 33% of volunteers given vCP205, with or without gp120. Phase 3 field trials with these or similar vaccines are needed, to determine whether efficacy in preventing HIV infection or in slowing disease progression among vaccinees who become infected is associated with the level and types of immune responses that were induced by the vaccines in this study. 相似文献
116.
Bures R Gaitan A Zhu T Graziosi C McGrath KM Tartaglia J Caudrelier P El Habib R Klein M Lazzarin A Stablein DM Deers M Corey L Greenberg ML Schwartz DH Montefiori DC 《AIDS research and human retroviruses》2000,16(18):2019-2035
Antibodies generated by candidate HIV-1 vaccines in a phase I clinical trial were assessed for neutralizing activity with a panel of eight well-characterized, genetically diverse clade B primary isolates having an R5 phenotype. The vaccines consisted of one of three different recombinant canarypox vectors expressing membrane-anchored HIV-1(MN)gp120 (ALVAC vCP205, vCP1433, and vCP1452) followed by boosting with a soluble gp160 hybrid consisting of MNgp120 and the majority of gp41 from strain IIIB. Serum samples from a subset of volunteers in each arm of the trial, containing moderate to high titers of neutralizing antibodies to HIV-1 MN, were analyzed. Competition assays with peptides revealed that the majority of neutralizing activity was specific for the MN-V3 loop. Despite MN-specific neutralization titers that sometimes exceeded 1:500, no neutralization of primary isolates was detected and, in some cases, mild infection enhancement was observed. In addition, little or no neutralization of the HIV-1 IIIB heterologous T cell line-adapted strain of virus was detected. These results reinforce the notion that monovalent HIV-1 ENV is a poor immunogen for generating cross-reactive neutralizing antibodies. 相似文献
117.
James W. Harrison Tran Thi Ngoc Dung Fariha Siddiqui Sunee Korbrisate Habib Bukhari My Phan Vu Tra Nguyen Van Minh Hoang Juan Carrique-Mas Juliet Bryant James I. Campbell David J. Studholme Brendan W. Wren Stephen Baker Richard W. Titball Olivia L. Champion 《Emerging infectious diseases》2014,20(6):1026-1029
A novel protein translocation system, the type-6 secretion system (T6SS), may play a role in virulence of Campylobacter jejuni. We investigated 181 C. jejuni isolates from humans, chickens, and environmental sources in Vietnam, Thailand, Pakistan, and the United Kingdom for T6SS. The marker was most prevalent in human and chicken isolates from Vietnam. 相似文献
118.
119.
120.