全文获取类型
收费全文 | 812篇 |
免费 | 42篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 6篇 |
妇产科学 | 4篇 |
基础医学 | 56篇 |
口腔科学 | 20篇 |
临床医学 | 25篇 |
内科学 | 46篇 |
皮肤病学 | 20篇 |
神经病学 | 35篇 |
特种医学 | 17篇 |
外科学 | 28篇 |
综合类 | 69篇 |
预防医学 | 119篇 |
眼科学 | 7篇 |
药学 | 350篇 |
中国医学 | 40篇 |
肿瘤学 | 22篇 |
出版年
2022年 | 8篇 |
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 13篇 |
2018年 | 15篇 |
2017年 | 17篇 |
2016年 | 15篇 |
2015年 | 21篇 |
2014年 | 45篇 |
2013年 | 63篇 |
2012年 | 42篇 |
2011年 | 55篇 |
2010年 | 39篇 |
2009年 | 31篇 |
2008年 | 32篇 |
2007年 | 37篇 |
2006年 | 26篇 |
2005年 | 26篇 |
2004年 | 26篇 |
2003年 | 23篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 24篇 |
1999年 | 15篇 |
1998年 | 18篇 |
1997年 | 13篇 |
1996年 | 5篇 |
1995年 | 15篇 |
1994年 | 14篇 |
1993年 | 14篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 18篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 16篇 |
1981年 | 14篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1974年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有866条查询结果,搜索用时 46 毫秒
1.
William A. Corrigall Mary Ann Linseman RoseMarie D'Onofrio Hau Lei 《Psychopharmacology》1986,89(3):327-333
A previously reported paradigm in which rats run down a runway for food reward followed by morphine injection was analyzed to assess the utility of the paradigm in studies of opiate reinforcement. One experiment replicated the original report that post-trial morphine caused both an increase in runway speed and a decrease in food consumption (taste aversion) over successive trials, and showed in addition that the increase in runway speed did not occur as a result of food deprivation alone, but required the animals to have consumed food in the goal box. A second study using the quaternary opiate antagonist methyl naltrexone to block the peripheral effects of morphine suggested that the increase in runway speed has a peripheral locus while the taste aversion has a central one. A third experiment in which morphine was microinjected into either the lateral ventricle or the ventral tegmental area supported these observations, in that intracranial morphine failed to result in an increased runway speed, but did produce taste aversion after microinjection into either site. These findings also suggest that the increase in runway speed caused by post-trial morphine in this experiment has a peripheral locus of effect, which is probably distinct from the central effect that supports morphine self-administration and conditioned place preference.
Offprint requests to: W.A.CorrigallThe views expressed in this publication are those of the authors and do not necessarily reflect those of the Addiction Research Foundation 相似文献
2.
A. Green 《Diabetologia》1987,30(3):188-192
Summary To determine whether adenosine is involved in long-term regulation of glucose transport in adipose tissue, we have investigated effects of administration of an adenosine receptor antagonist (theophylline) on adipocyte glucose transport. Rats were injected with theophylline (30 mg/kg, dissolved in 0.9% NaCl) daily for 7 days. Controls were injected with saline. The rats were then killed, and epididymal adipocytes were isolated. Insulin-stimulated glucose transport rates were decreased by about 25%–30% in the cells from theophylline-treated rats at all insulin concentrations tested. The half-maximally effective concentration of insulin was not altered (6.5±0.5 and 6.7±0.5 mU/l in control and treated cells respectively), suggesting a post-insulin binding defect. This was confirmed by the finding that 125I-insulin binding to the cells was not altered. Adenosine receptor number and affinity (measured on detergent-solubilized adipocyte extracts using 125I-hydroxyphenylisopropyl adenosine) was also not changed by theophylline treatment. We conclude that theophylline administration causes decreased glucose transport rates in rat adipocytes at a post-insulin binding level. Thus, chronic adenosine receptor blockade impairs adipocyte glucose transport, suggesting that adenosine is involved in long-term regulation of glucose metabolism in adipose tissue. 相似文献
3.
Biochemical and ultrastructural alterations produced by miconazole and econazole in Trypanosoma cruzi 总被引:6,自引:0,他引:6
R Docampo S N Moreno J F Turrens A M Katzin S M Gonzalez-Cappa A O Stoppani 《Molecular and biochemical parasitology》1981,3(3):169-180
Miconazole and econazole, two fungicide imidazole derivatives, completely inhibited growth of Trypanosoma cruzi (Tulahuen strain) at concentrations of about 20 muM. Culturing of T. cruzi in the presence of lower doses of imidazole derivatives produced: decrease of 5,7-diene sterol content in epimastigotes (including ergosterol); disappearance of the nuclear chromatin, vacuolization and decrease in the electron density of the cytoplasm; selective surface alterations as revealed by an increased response to wheat-germ- and phytohemagglutinin. At variance with the effect of miconazole on Candida (De Nollin et al. (1977) Antimicrobial. Agents Chemother. 11, 500-513), miconazole and econazole, under the experimental conditions used, did not increase the rate of hydrogen peroxide generation by T. cruzi. 相似文献
4.
Y Wahbi R Caujolle C Tournaire M Payard M.D. Linas J.P. Seguela 《European journal of medicinal chemistry》1995,30(12)
Aromatic ethers related to antifungal azole miconazole were synthesized and tested against various strains of Candida. We found that activity is related to the nature of the aromatic ring and the position of substituents on this ring. Activity is more strongly dependent on the substituent in the 2 position of the ethyl chain than on the aromatic group linked through the oxygen. Triazoles were always less potent than the corresponding imidazole analogues. 相似文献
5.
甲基叔丁基醚无铅汽油肾脏毒性的实验研究 总被引:6,自引:0,他引:6
目的:了解甲基叔丁基醚(MTBE)无铅汽油对肾脏的毒性及毒作用机制。方法:昆明种小鼠经呼吸道静式染毒,MTBE无铅汽油22.9、11.4及2.3g/m^3每天一次,连续2h,共22d亚急性染毒。日立-7150型全自动生化仪检测血清中尿素氮(BUN)、肌酐(Cr)含量;肾组织均浆中丙二醛(MDA)和超氧化物歧化酶(SOD)含量分别用荧光法,邻苯三酚自氧化固定时间法测定;电镜观察肾皮质区超微结构的变化,结果:22.9g/m^3染毒组雌性小鼠血清中BUN含量与阴性对照组间比较差异有显著性(P<0.05);电镜观察到22.9g/m^3染色毒对照组雌雄性小鼠的肾小球基底膜,肾小管细胞线粒体及绒毛均未见显著异常改变。结论:MTBE无铅汽油对肾小球的滤过功能有一定的影响,雌性小鼠可能更为敏感。 相似文献
6.
Patrice Venault Georges Chapouthier Jacques Simiand Robert H. Dodd Jean Rossier 《Brain research bulletin》1987,19(3)
Benzodiazepines are known to induce a profound anterograde amnesia in man. In this report, it is shown that methyl β-carboline-3-carboxylate (β-CCM), an inverse agonist of the benzodiazepine receptor, has the opposite effect; it enhances performance in learning and memory tasks. Three different learning models were used: habituation to a new environment and passive avoidance in mice and imprinting in chicks. The opposite effects of both β-CCM and the benzodiazepine diazepam were blocked by administration of the benzodiazepine receptor antagonist Ro 15-1788, provicling evidence that the benzodiazepine receptor is involved in these effects. 相似文献
7.
8.
Ernst Hallier Thomas Langhof Doris Dannappel Monika Leutbecher Klaus Schröder Hans Werner Goergens Andreas Müller Hermann M. Bolt 《Archives of toxicology》1993,67(3):173-178
A hitherto unknown glutathione-S-transferase in human erythrocytes displays polymorphism: three quarters of the population (conjugators) possess, whereas one quarter (non-conjugators) lack this specific activity. A standard method for the identification of conjugators and non-conjugators with the use of methyl bromide and gas chromatography (head space technique) is described. Three substrates of the polymorphic enzyme, methyl bromide, ethylene oxide and dichloromethane (methylene chloride), were incubated in vitro with individual whole blood samples of conjugators and non-conjugators. All three substances led to a marked increase of sister chromatid exchanges (SCE) in the lymphocytes of the non-conjugators but not in those of conjugators. A protective effect of the glutathione-S-transferase activity in human erythrocytes for the cytogenetic toxicity of these chemicals in vitro is thus confirmed. Since the enzyme activity is not found in erythrocytes of laboratory animals, species extrapolations for risk assessment of methyl bromide, ethylene oxide and dichloromethane should be reconsidered. 相似文献
9.
目的 :对比、观察科素亚在治疗高血压中的临床疗效及不良反应。方法 :将 3 0例轻、中度高血压病人随机分为科素亚 L组及卡托普利 C组。在治疗前、后观察血压变化及不良反应并记录之。结果 :1科素亚组在治疗后 SBP下降 1 .3 3~ 2 k Pa(P<0 .0 5 ) ,DBP下降 0 .67k Pa(P>0 .0 5 )。 2科素亚组起效时间在用药后 1 0~ 1 4d,卡托普利组在治疗后 5~ 7d起效。3科素亚组未见不良反应 ,卡托普利组有 3例出现不良反应。结论 :科素亚对于轻、中度高血压有肯定的降压效果 (尤其 SBP) ;降压作用较为平和、缓慢 ,适合老年人使用 ;不良反应少 ,是一安全有效的药物。 相似文献
10.
加杨雄花序的化学成分研究 总被引:8,自引:0,他引:8
首次对加杨雄花序了条统从其撮物的石油醚(60~90℃)部分,乙酸乙酯部分分离并鉴定了15个化合物,本语文报道8个黄酮类成分,乔松酮(pinostrobin,1),高良姜素-3-甲氧基(ga/langin 3 methoxy,2),乔松索(pinocermbin,2),白杨素(chrysin,4)槲皮素-3,7-二甲氧基(quercetin0-3,7-dimethoxy,5),鼠李素(rhammet 相似文献