全文获取类型
收费全文 | 970篇 |
免费 | 41篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 21篇 |
妇产科学 | 18篇 |
基础医学 | 157篇 |
口腔科学 | 76篇 |
临床医学 | 78篇 |
内科学 | 255篇 |
皮肤病学 | 10篇 |
神经病学 | 99篇 |
特种医学 | 72篇 |
外科学 | 88篇 |
综合类 | 14篇 |
预防医学 | 37篇 |
眼科学 | 3篇 |
药学 | 62篇 |
中国医学 | 3篇 |
肿瘤学 | 27篇 |
出版年
2022年 | 9篇 |
2021年 | 11篇 |
2020年 | 21篇 |
2019年 | 18篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 13篇 |
2015年 | 24篇 |
2014年 | 37篇 |
2013年 | 35篇 |
2012年 | 50篇 |
2011年 | 47篇 |
2010年 | 24篇 |
2009年 | 25篇 |
2008年 | 39篇 |
2007年 | 50篇 |
2006年 | 39篇 |
2005年 | 18篇 |
2004年 | 28篇 |
2003年 | 33篇 |
2002年 | 22篇 |
2001年 | 14篇 |
2000年 | 23篇 |
1999年 | 17篇 |
1998年 | 28篇 |
1997年 | 23篇 |
1996年 | 20篇 |
1995年 | 19篇 |
1994年 | 9篇 |
1993年 | 14篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 18篇 |
1989年 | 19篇 |
1988年 | 24篇 |
1987年 | 19篇 |
1986年 | 21篇 |
1985年 | 24篇 |
1984年 | 15篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 16篇 |
1978年 | 4篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1973年 | 5篇 |
排序方式: 共有1025条查询结果,搜索用时 0 毫秒
51.
A D Wagner P Buechner-Steudel A Wein H Schmalenberg U Lindig M Moehler R Behrens G Kleber O Kuss W E Fleig 《Annals of oncology》2007,18(1):82-87
BACKGROUND: Combinations of gemcitabine-oxaliplatin, gemcitabine-5-fluorouracil (5-FU) and 5-FU-oxaliplatin have synergistic activity and nonoverlapping adverse effect profiles. This trial assessed efficacy and safety of the triple combination gemcitabine-oxaliplatin and infusional 5-FU in patients with locally advanced (n=11) or metastatic (n=32) pancreatic adenocarcinoma. PATIENTS AND METHODS: A total of 43 eligible patients were treated with intravenous infusions of gemcitabine (900 mg/m2 over 30 min), followed by oxaliplatin (65 mg/m2 over 2 h) and 5-FU (1500 mg/m2 over 24 h) on days 1 and 8 of a 21-day cycle. RESULTS: Among all 43 patients, the tumor response rate was 19% [95% confidence interval 7% to 30%]. Nine patients were nonassessable for response because they did not complete the first two cycles of chemotherapy due to rapid disease progression, early death or treatment refusal. One patient was lost to follow-up. Median time to progression and overall survival were 5.7 and 7.5 months. Principal grade III/IV toxic effects were leucopenia in 11 (2%), thrombocytopenia in 13 (2%), nausea in 13 (0%), anorexia 16 (7%) and sensory neuropathy in 18 (0%) of patients. Unexpected cardiotoxicity was observed in this trial. CONCLUSION: Response rates and survival of the three-drug combination compare favorably with single-agent gemcitabine, but do not exceed results for doublets. 相似文献
52.
Comparative studies on the irritation potential of 18 surfactants were performed using the same stock solution of surfactant for each study. The ocular irritation potential of surfactants was studied using the red blood cell test (RBC), the hen's egg test-chorioallantoic membrane (HET-CAM) and the Skinethic ocular tissue model. The skin irritation potential was assessed based on data obtained from human studies using a 24h epicutaneous patch test (ECT) and a soap chamber test (SCT). The same pH and active substance (AS) content for all surfactants tested was used depending on the test conducted. In general, clusters of substances with varying irritation potential were identified similarly by most tests. These results show that when using standardized test conditions in which pH and % AS are the same for each surfactant tested, there is a good correlation between the in vitro ocular irritation assays themselves as well as between the dermal and ocular irritation assays. In particular the RBC test seems to be not only highly predictive for ocular irritation (H(50)/DI) but also for dermal irritation and changes in barrier function (DI) induced by surfactants. 相似文献
53.
Alkyl polyglucosides are non-ionic surfactants which are mainly used in laundry detergents, hard surface cleaners and personal care products. Two in vitro screening test systems were used to investigate the endocrine modulating potential of alkyl polyglucosides. No indications were observed for any estrogenic or anti-estrogenic effects in an MCF-7 E-Screen assay and a reporter gene assay using luciferase-transfected MCF-7 cells. Concentrations exceeding the effect concentration of estradiol by a factor of 1000 did not reveal any indication for an estrogenic activity. Furthermore, in a combination assay investigating the effects of estradiol in the presence of alkyl polyglucoside, no anti-estrogenic potential was observed. In an one-generation screening assay in rats no effects on the fertility were observed up to the highest dose of 1000 mg/kg bw/day alkyl glucoside. Potential embryo-/fetotoxicity and/or teratogenicity was investigated in a segment II study in rats. No effects were noted up to the limit dose of 1000 mg/kg bw/day. All parameters of the treatment groups were comparable with those of the control group. Skeletal and visceral investigations did not detect any treatment-related malformations. For the embryo/fetotoxicity, the teratogenicity and the maternal toxicity a NOAEL of 1000 mg/kg was deduced. 相似文献
54.
Hemodynamic and neurohumoral effects of continuous infusion of levosimendan in patients with congestive heart failure 总被引:11,自引:0,他引:11
Nieminen MS Akkila J Hasenfuss G Kleber FX Lehtonen LA Mitrovic V Nyquist O Remme WJ 《Journal of the American College of Cardiology》2000,36(6):1903-1912
OBJECTIVES: We sought to define the therapeutic dose range of levosimendan in patients with New York Heart Association class II-IV heart failure of ischemic origin. BACKGROUND: Levosimendan is a calcium sensitizer for treatment of acute decompensated heart failure. METHODS: A double-blind, placebo-controlled, randomized, multicenter, parallel-group study included 151 adult patients. Levosimendan was given as a 10-min intravenous bolus of 3, 6, 12, 24 or 36 microg/kg, followed by a 24-h infusion of 0.05, 0.1, 0.2, 0.4 or 0.6 microg/kg/min, respectively. Dobutamine, for comparative purposes, was given as an open-label infusion (6 microg/kg/min). The primary efficacy variable was the proportion of patients achieving in each treatment group at least one of the following: 1) a > or =15% increase in stroke volume (SV) at 23 h to 24 h; 2) a > or =25% decrease in pulmonary capillary wedge pressure (PCWP) (and > or =4 mm Hg) at 23 h to 24 h; 3) a > or =40% increase in cardiac output (CO) (with change in heart rate [HR] <20%); 4) a > or =50% decrease in PCWP during two consecutive measurements. RESULTS: The response rate to levosimendan ranged from 50% at the lowest dose to 88% at the highest dose (compared with placebo 14%, dobutamine 70%). A dose-response relationship was demonstrated for levosimendan on increases in CO and SV, and reductions in PCWP during the infusion (for all, p< or =0.001). Headache (9%), nausea (5%) and hypotension (5%) were the most frequently reported adverse events at higher dosages. CONCLUSIONS: Dosing of levosimendan with a 10-min bolus of 6 to 24 microg/kg followed by an infusion of 0.05 to 0.2 microg/kg/min is well tolerated and leads to favorable hemodynamic effects. 相似文献
55.
56.
The best should not be the enemy of the good 总被引:1,自引:1,他引:0
Kleber HD 《Addiction (Abingdon, England)》2002,97(6):660-661
57.
SJ KANG HD WOO JY CHOI YJ LEE HW CHUNG 《中国药理学与毒理学杂志》2006,20(3):224-247
5-Flourouracil(5-FU) is one of well known anti-cancer drugs, but its toxicity in normal lymphocytes remains a major problem in chemotherapy. The eastern traditional drug, Bupleuri radix(BR), has been used for the treatment of liver diseases and contains series of triterpene saponins. 相似文献
58.
Dehydroepiandrosterone (DHEA) is an intermediate product in the synthesis
of male and female sex hormones in the adrenal cortex of man. In livers of
rats and mice DHEA increases the levels of cytochrome P450 IVA and
peroxisomal beta-oxidation enzymes associated with peroxisome
proliferation. Prolonged treatment of rats with DHEA induces liver tumors
that are more frequent in females arising mainly in the periportal regions
of the liver lobule (Metzger et al., Toxicol. Pathol. 23, 591-605, 1995).
Because of paucity of information on hepatic zonation of peroxisomal
response to DHEA and controversial reports on gender-specific differences
of its effects the present study was undertaken using qualitative
immunohistochemical and quantitative immunoelectron microscopical
techniques in addition to Western blotting. Rats were treated for 24 weeks
with 0.6% DHEA supplied with diet. Immunoblot analysis revealed marked
induction of peroxisomal beta- oxidation enzymes, which by quantitative
analysis was equally strong in male and female animals, whilst catalase and
urate-oxidase were not increased. Cytochrome P450 IVA, in contrast, was
induced significantly stronger in male than in female rats.
Immunohistochemistry confirmed the induction of cytochrome P450 IVA showing
a marked lobular gradient in female animals with strong induction in
pericentral and almost no induction in periportal regions of the liver
lobule. In male animals cytochrome P450 IVA was expressed more uniformly
across the liver lobule. A similar sex specific zone-dependent response was
observed for peroxisomes. DHEA induced in females a significant zonal
gradient with marked peroxisome proliferation and a strong induction of
peroxisomal hydratase/dehydrogenase in pericentral hepatocytes and a much
smaller response in periportal regions. Livers of male animals, in
contrast, showed a uniform peroxisomal proliferation to DHEA with only
slight zonal differences. The striking homologies of the induction patterns
of cytochrome P450 IVA and the peroxisome proliferation in both sexes
support the notion of a functional relationship. In view of the almost
exclusive periportal localization of DHEA-induced tumors in female rats in
contrast to the pericentral localization of the peroxisomal proliferation
shown by this study, it seems likely that other factors in addition to
peroxisome proliferation may contribute to the hepatocarcinogenic effect of
DHEA.
相似文献
59.
The present work sought to determine adolescent rates of smoking and binge-drinking co-occurrence. Secondary analyses were conducted on the interview responses of more than 4,000 adolescents between the ages of 13 and 18 who took part in the 1995 National Household Survey on Drug Abuse. Results revealed that not only are adolescent smokers likely to be binge drinkers, but adolescent binge drinkers are also likely to be smokers. Conversely, those who abstain from involvement with one of these substances generally abstain from the other as well. The discussion highlighted race/ethnic and gender differences in co-occurrence rates as well as prevention and intervention implications. 相似文献
60.
B M Kleber 《Stomatologie der DDR》1988,38(5):301-307