全文获取类型
收费全文 | 13786篇 |
免费 | 801篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 111篇 |
儿科学 | 520篇 |
妇产科学 | 252篇 |
基础医学 | 2092篇 |
口腔科学 | 171篇 |
临床医学 | 1265篇 |
内科学 | 2833篇 |
皮肤病学 | 275篇 |
神经病学 | 1439篇 |
特种医学 | 434篇 |
外国民族医学 | 1篇 |
外科学 | 1918篇 |
综合类 | 87篇 |
一般理论 | 3篇 |
预防医学 | 1064篇 |
眼科学 | 235篇 |
药学 | 939篇 |
中国医学 | 17篇 |
肿瘤学 | 991篇 |
出版年
2023年 | 89篇 |
2022年 | 131篇 |
2021年 | 288篇 |
2020年 | 155篇 |
2019年 | 264篇 |
2018年 | 394篇 |
2017年 | 251篇 |
2016年 | 309篇 |
2015年 | 338篇 |
2014年 | 439篇 |
2013年 | 636篇 |
2012年 | 973篇 |
2011年 | 1045篇 |
2010年 | 529篇 |
2009年 | 577篇 |
2008年 | 832篇 |
2007年 | 890篇 |
2006年 | 861篇 |
2005年 | 817篇 |
2004年 | 875篇 |
2003年 | 738篇 |
2002年 | 724篇 |
2001年 | 272篇 |
2000年 | 224篇 |
1999年 | 202篇 |
1998年 | 145篇 |
1997年 | 83篇 |
1996年 | 80篇 |
1995年 | 93篇 |
1994年 | 68篇 |
1993年 | 49篇 |
1992年 | 100篇 |
1991年 | 90篇 |
1990年 | 66篇 |
1989年 | 57篇 |
1988年 | 69篇 |
1987年 | 68篇 |
1986年 | 59篇 |
1985年 | 57篇 |
1984年 | 39篇 |
1983年 | 41篇 |
1982年 | 34篇 |
1979年 | 45篇 |
1974年 | 35篇 |
1971年 | 44篇 |
1970年 | 36篇 |
1969年 | 39篇 |
1968年 | 36篇 |
1967年 | 35篇 |
1966年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 24 毫秒
71.
Lalonde R Joyal CC Guastavino JM Côté C Botez MI 《Restorative neurology and neuroscience》1993,5(5):367-370
The effects of amantadine and ketamine were compared to a placebo in a coat-hanger test on lurcher mutant mice. This test measures motor coordination and is dependent on cerebellar functioning. Both drugs improved motor coordination of the cerebellar mutants in that the time taken to reach the side-bar according to a 2 paw criterion was decreased during the drugged condition in comparison to the non-drugged condition. This result indicates that NMDA receptor antagonists may improve motor coordination in animals with cerebellar disease. 相似文献
72.
A pyrolytic gaschromatographic process was developed for the routine assay of both cyclodextrin inclusion complexes, and for the differentiation of the mechanical mixture of the same oil with beta-cyclodextrin. The method is a direct assay of low material demand. 相似文献
73.
J. Kasalický O. Mrhová V. Štýs 《European journal of nuclear medicine and molecular imaging》1983,8(7):288-291
The uptake of 42K, 86Rb and 201Tl by non-ischaemic and ischaemic myocardium was determined in rats with coronary artery ligature lasting 10, 30, 60 and 120 min, and in control rats without ischaemia. Whereas the myocardial concentration of 201Tl and 42K in control rats was similar and higher than that of 86Rb, 201Tl was superior to the other two radionuclides due to its significantly higher accumulation in non-ischaemic myocardium and the higher ratio of non-ischaemic to ischaemic radioactivity.The 86Rb accumulation in non-ischaemic myocardium and non-ischaemic/ischaemic ratio began to decrease from its maximum at 10 min. 201Tl, 42K and 86Rb blood levels in intact animals decreased rapidly after intravenous injection to low and nearly stabilized values at 5 min.Na+K+-ATPase activity in the ischeamic myocardium was high in the acutely ischaemic myocardium and decreased to below control levels after 4 h of ischaemia; changes in activity could not influence the low uptake of potassium analogues in fresh ischaemic myocardium. 相似文献
74.
Delumeau JC Tencé M Marin P Cordier J Glowinski J Prémont J 《The European journal of neuroscience》1991,3(6):539-550
Adenosine has a broad array of actions on neurons but astrocytes also possess adenosine receptors. We have previously shown that adenosine, by acting on astrocytes in the striatum, can modulate neuronal responses mediated by receptors coupled to phospholipase C through an astrocyto - neuronal interaction. In addition, adenosine was found to potentiate the alpha1-adrenergic production of inositol phosphates in astrocytes. The mechanism involved in this potentiation was further investigated by examining the effects of adenosine and alpha1-adrenergic receptor agonists on cytosolic Ca2+ in cultured striatal astrocytes from the embryonic mouse in primary culture. When used alone, methoxamine, a selective agonist of alpha-adrenergic receptors or 2-chloroadenosine, a stable analogue of adenosine, induced a transitory increase in cytosolic Ca2+, but their combined addition led to a sustained increase in cytosolic Ca2+, which seems to be due to a Ca2+ influx, because it was not observed in the absence of external Ca2+. Voltage independent Ca2+ channels contribute to this process and different blockers of voltage-operated calcium channels, such as dihydropyridines, phenylalkylamines, La3+ or Co2+ were ineffective in suppressing the sustained cytosolic Ca2+ elevation. Three observations suggest the implication of arachidonic acid in the observed potentiation: (i) arachidonic acid induced a sustained elevation of cytosolic Ca2+ similar to that evoked by the coapplication of methoxamine and 2-chloroadenosine; (ii) the addition of arachidonic acid during the calcic plateau produced by the combined application of the agonists did not increase further cytosolic Ca2+ levels; (iii) in the presence of methoxamine, 2-chloroadenosine induced a release of arachidonic acid. The stimulation of phospholipase C and the resulting activation of protein kinase C induced by methoxamine seem to be required for the potentiating effect of 2-chloroadenosine on cytosolic Ca2+. In fact, the direct activation of protein kinase C by an exogenous diacylglycerol analogue mimicked the effect of methoxamine because, in this condition, 2-chloroadenosine alone evoked a sustained elevation of cytosolic Ca2+. Therefore, methoxamine, through the successive activation of phospholipase C and protein kinase C, could allow a lipase, probably phospholipase A2, to be stimulated by 2-chloroadenosine. Arachidonic acid has already been shown to trigger the opening of K+ channels and the formation of inositol phosphates in other cell types. Therefore, in striatal astrocytes, 2-chloroadenosine, through an arachidonic acid-mediated hyperpolarization, could increase the Ca2+ driving force and thus improve Ca2+ influx through inositol phosphate-gated channels. This hypothesis is further supported by the suppressing effect of a 50 mM KCI-induced depolarization on the long lasting elevation of cytosolic Ca2+ seen in the combined presence of 2-chloroadenosine and methoxamine. 相似文献
75.
76.
Health-related quality of life parameters as prognostic factors in a nonmetastatic breast cancer population: an international multicenter study. 总被引:4,自引:0,他引:4
Fabio Efficace Patrick Therasse Martine J Piccart Corneel Coens Kristel van Steen Marzena Welnicka-Jaskiewicz Tanja Cufer Jaroslaw Dyczka Michail Lichinitser Lois Shepherd Hanneke de Haes Mirjam A Sprangers Andrew Bottomley 《Journal of clinical oncology》2004,22(16):3381-3388
PURPOSE: The purpose of this research was to evaluate whether baseline health-related quality of life (HRQOL) parameters are prognostic factors for survival in locally advanced breast cancer patients. Although the literature highlights the important role of HRQOL parameters in predicting survival in advanced metastatic disease, little evidence exists for earlier stages. PATIENTS AND METHODS: The overall sample consisted of 448 patients randomly assigned to receive cyclophosphamide, epirubicin, and fluorouracil versus epirubicin, cyclophosphamide, and granulocyte colony-stimulating factor. Patients were enrolled in 12 countries. HRQOL baseline scores were assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30. The Cox proportional hazards regression model was used for both univariate and multivariate analyses of survival. In addition, a bootstrap resampling technique was used to assess the stability of the outcomes. Bootstrap results were then applied for model averaging purposes as a means to account for the observed model selection uncertainty. RESULTS: The final multivariate model retained inflammatory breast cancer (T4d) as the only factor predicting overall survival (OS) with a hazard ratio of 1.375 (95% CI, 1.027 to 1.840; P =.03). The presence of inflammatory breast cancer lowers the median survival time from 6.6 to 4.2 years (36% reduction). None of the preselected HRQOL variables were prognostic for OS or disease-free survival, in either the univariate or multivariate analysis. CONCLUSION: Our findings suggest that baseline HRQOL parameters have no prognostic value in a nonmetastatic breast cancer population. 相似文献
77.
Velraeds MM van de Belt-Gritter B Busscher HJ Reid G van der Mei HC 《World journal of urology》2000,18(6):422-426
The ability of three Lactobacillus strains to inhibit the adhesion and growth of naturally occurring uropathogens on silicone rubber was investigated in human
urine. The importance of biosurfactant production by Lactobacillus in discouraging uropathogen growth was determined in relation to the binding affinities of the lactobacilli for silicone
rubber. L. fermentum B54 markedly inhibited uropathogen growth on the silicone rubber disks after 8 days for all five men included in the study,
albeit to various extents ranging from 77% to 100%. In urine from women, however, this inhibition was less clear, as it was
absent for two of the four women participating in this study. L. casei rhamnosus 36 completely discouraged uropathogen growth on the disks after 8 days for three of the four women, whereas its effect in
urine from men was less pronounced (inhibition ranged from 48% to 100% and was absent for one man). L. casei rhamnosus ATCC 7469T was the least inhibitory Lactobacillus strain tested and inhibition was absent for a number of both male and female participants, possibly as a result of the low
binding affinity of this strain for silicone rubber and of its inability to release biosurfactants. We conclude that the inhibition
of uropathogen growth is dependent on the Lactobacillus strain involved, and for L. fermentum B54 it was demonstrated to be sex-related. Hence, inhibition must be considered a multifactorial process. 相似文献
78.
79.
80.
Potential use of different auditory evoked brain responses for determining cerebral lateralization of speech function was evaluated. Cortical magnetic fields elicited by plosive syllables or complex non-speech sounds analogous to them were recorded with 122-channel magnetometer. We estimated parameters of magnetic P1, N1 and P2 responses to both stimuli in the two hemispheres and found no hemispheric asymmetry for any of the responses. No correlation between the right-ear advantage, determined with dichotic listening test, and any of asymmetry indexes, calculated for the speech-elicited responses, was observed. These results suggest that P1, N1 and P2 responses to speech signals do not indicate lateralization of speech function in the brain. The results are discussed in relation to previous studies suggesting that the mismatch negativity (MMN) seems to be the only early auditory cortex response sensitive to the lateralization of speech function. 相似文献