全文获取类型
收费全文 | 102547篇 |
免费 | 7077篇 |
国内免费 | 3569篇 |
专业分类
耳鼻咽喉 | 330篇 |
儿科学 | 1742篇 |
妇产科学 | 905篇 |
基础医学 | 8428篇 |
口腔科学 | 1596篇 |
临床医学 | 11469篇 |
内科学 | 15191篇 |
皮肤病学 | 1926篇 |
神经病学 | 8226篇 |
特种医学 | 1905篇 |
外国民族医学 | 8篇 |
外科学 | 5035篇 |
综合类 | 14332篇 |
现状与发展 | 3篇 |
预防医学 | 9624篇 |
眼科学 | 650篇 |
药学 | 20840篇 |
126篇 | |
中国医学 | 7852篇 |
肿瘤学 | 3005篇 |
出版年
2024年 | 345篇 |
2023年 | 1719篇 |
2022年 | 2835篇 |
2021年 | 3989篇 |
2020年 | 3772篇 |
2019年 | 3081篇 |
2018年 | 2969篇 |
2017年 | 3319篇 |
2016年 | 3636篇 |
2015年 | 3859篇 |
2014年 | 7339篇 |
2013年 | 8254篇 |
2012年 | 6807篇 |
2011年 | 7087篇 |
2010年 | 5236篇 |
2009年 | 4806篇 |
2008年 | 4791篇 |
2007年 | 4814篇 |
2006年 | 4042篇 |
2005年 | 3485篇 |
2004年 | 2949篇 |
2003年 | 2435篇 |
2002年 | 1994篇 |
2001年 | 1704篇 |
2000年 | 1456篇 |
1999年 | 1283篇 |
1998年 | 1190篇 |
1997年 | 1116篇 |
1996年 | 1088篇 |
1995年 | 993篇 |
1994年 | 885篇 |
1993年 | 738篇 |
1992年 | 735篇 |
1991年 | 676篇 |
1990年 | 660篇 |
1989年 | 618篇 |
1988年 | 579篇 |
1987年 | 509篇 |
1986年 | 527篇 |
1985年 | 783篇 |
1984年 | 728篇 |
1983年 | 539篇 |
1982年 | 538篇 |
1981年 | 498篇 |
1980年 | 457篇 |
1979年 | 317篇 |
1978年 | 239篇 |
1977年 | 189篇 |
1976年 | 165篇 |
1975年 | 117篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The spinal cord dorsal horn contains neural mechanisms which can greatly facilitate pain. We have recently shown that ‘illness’-inducing agents, such as intraperitoneally administered lipopolysaccharide (LPS; bacterial endotoxin), can produce prolonged hyperalgesia. This hyperalgesic state is mediated at the level of the spinal cord via activation of the NMDA-nitric oxide cascade. However, prolonged neuronal depolarization is required before such a cascade can occur. The present series of experiments were aimed at identifying spinal neurotransmitters which might be responsible for creating such a depolarized state. These studies show that LPS hyperalgesia is mediated at the level of the spinal cord by substance P, cholecystokinin and excitatory amino acids acting at non-NMDA sites. No apparent role for serotonin or kappa opiate receptors was found. 相似文献
82.
Intraperitoneal injection of free valproic acid (VPA) suppressed amygdaloid-kindled seizure 1 h after injection in rats, but had no effect at 24 h. VPA entrapped in positively charged liposomes showed a prolonged anticonvulsant effect lasting for 2 days, while the effect evaluated at 1 h was not different from that with free VPA. VPA entrapped in negatively charged liposomes exerted a significantly stronger effect at 1 h than did free VPA, while it had no significant effect at 24 h. These results suggest that surface charges on liposomes play an important role in modifying the anticonvulsant effect of VPA. 相似文献
83.
D. Mannini P. Maver E. Aiello G. Corrado F. Vecchi B. Bellanova M. Marengo 《Urological research》1988,16(1):9-12
Summary Spontaneous circadian variations of prostate specific antigen (PSA) and prostatic acid phosphatase (PAP), determined simultaneously by radioimmunoassay (RIA), were investigated by multiple sampling, over a 24-hour period, in 32 patients with prostatic cancer. In 29/32 patients (91%), the coefficient of variation of 24-hour values, for either marker, was greater than that of the RIA method at the same range of values; stage D patients showed the greatest spontaneous variability. Fluctuations around the mean of 24-hour values ranged from-65% to +85% for PAP, from-72% to +190% for PSA, occurring random and independently for each marker. Variability was about 20% greater for PSA than for PAP. The existence of spontaneous fluctuations should be considered in multiple marker evaluation of prostatic cancer patients.Preliminary results of this study have been presented at the International Symposium on Hormonal Therapy of Prostatic Diseases —Basic and Clinical Aspects, April 6–8, 1987, Milan, Italy 相似文献
84.
研究了吡哌酸与四氯苯醌间的荷移反应.两者在硼砂缓冲溶液中形成1∶1的络合物,其λ_(max)为330.8nm,摩尔吸光系数ε=1.66×10~4,RSD为2.2%。用于测定制剂含量,结果与药典方法一致。 相似文献
85.
86.
D. A. Basketter E. W. Scholes M. Cumberbatch C. D. Evans I. Kimber 《Contact dermatitis》1992,27(4):209-213
The guinea pig maximization test (GPMT) has proven to be a valuable tool for the identification of the skin sensitization potential of chemicals. The method identifies a hazard which can lead in the EC to compulsory labelling of that chemical. In the present study, data on sulphanilic acid derived from the GPMT has been compared with results from a second guinea pig assay (the cumulative contact enhancement test) and the murine local lymph node assay, both of which require only topical application of chemical. Except for the GPMT, no test identified any sensitizing activity associated with exposure to sulphanilic acid. These latter results are consistent with the experience gained from substantial human exposure in an occupational setting and from which no cases of allergic contact dermatitis to sulphanilic acid have arisen over a 20-year period. In consequence, it is questioned which test protocol in practice has given the more accurate identification of sensitization hazard relevant to man. 相似文献
87.
Antagonists of the N-methyl-D-aspartate (NMDA) type of excitatory amino acid (EAA) receptors blocked cocaine-induced stereotypy, locomotor stimulation and convulsions. These effects in general appear to involve selectively NMDA type of receptors. The results suggest that NMDA-activated systems are an integral component in the reaction sequences involved in the expression of several behavioral effects of cocaine. 相似文献
88.
89.
The incidence of Type 1 diabetes is increasing worldwide, imposing enormous public health costs, as well as profoundly affecting individual quality of life. There is evidence that psychological problems are increased in children with diabetes and this morbidity is often associated with poor metabolic control. Specific risk factors for this dual morbidity are emerging from empirical studies. The next challenge is to identify effective interventions for use with children at risk for adverse mental and physical health outcomes. The intervention literature is reviewed. It is noted that most studies have used diabetes-specific, unstandardized interventions in groups of adolescents, with few interventions trialled with younger children. No study has targeted a specific psychological disorder such as behaviour problems or depression, both of which are known to be increased in children with diabetes and for which effective standardized interventions are available. Attention is drawn to methodological limitations in many of the studies conducted to date and suggestions made to reduce these in future interventions attempting to reduce the burden of illness in children with diabetes. 相似文献
90.