全文获取类型
收费全文 | 34574篇 |
免费 | 2664篇 |
国内免费 | 94篇 |
专业分类
耳鼻咽喉 | 298篇 |
儿科学 | 902篇 |
妇产科学 | 632篇 |
基础医学 | 5018篇 |
口腔科学 | 614篇 |
临床医学 | 3377篇 |
内科学 | 7926篇 |
皮肤病学 | 761篇 |
神经病学 | 3089篇 |
特种医学 | 1044篇 |
外国民族医学 | 3篇 |
外科学 | 4946篇 |
综合类 | 587篇 |
一般理论 | 35篇 |
预防医学 | 2910篇 |
眼科学 | 757篇 |
药学 | 2123篇 |
1篇 | |
中国医学 | 58篇 |
肿瘤学 | 2251篇 |
出版年
2022年 | 186篇 |
2021年 | 465篇 |
2020年 | 331篇 |
2019年 | 505篇 |
2018年 | 574篇 |
2017年 | 419篇 |
2016年 | 461篇 |
2015年 | 544篇 |
2014年 | 805篇 |
2013年 | 1261篇 |
2012年 | 1784篇 |
2011年 | 1974篇 |
2010年 | 1156篇 |
2009年 | 1162篇 |
2008年 | 1849篇 |
2007年 | 2024篇 |
2006年 | 2021篇 |
2005年 | 2105篇 |
2004年 | 1946篇 |
2003年 | 1801篇 |
2002年 | 1818篇 |
2001年 | 676篇 |
2000年 | 603篇 |
1999年 | 640篇 |
1998年 | 465篇 |
1997年 | 420篇 |
1996年 | 378篇 |
1995年 | 351篇 |
1994年 | 328篇 |
1993年 | 301篇 |
1992年 | 510篇 |
1991年 | 471篇 |
1990年 | 468篇 |
1989年 | 444篇 |
1988年 | 403篇 |
1987年 | 358篇 |
1986年 | 377篇 |
1985年 | 376篇 |
1984年 | 318篇 |
1983年 | 307篇 |
1982年 | 297篇 |
1981年 | 290篇 |
1980年 | 234篇 |
1979年 | 252篇 |
1978年 | 229篇 |
1977年 | 216篇 |
1976年 | 178篇 |
1974年 | 173篇 |
1973年 | 189篇 |
1972年 | 178篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
1.
Meir Steiner Richard J. Katz Giulio Baldrighi Bernard J. Carroll 《Psychoneuroendocrinology》1981,6(1):81-90
(1) The estrous cycle in the rat may be used to study recurrent changes in motor behaviors and motivation which are strongly related to cyclic hormonal and CNS changes. (2) The peak in motivated behaviors occurs during a sharply defined period on the night between proestrus and estrus and is evident in facilitated wheel-running, lordosis, and intracranial self-stimulation. (3) Behaviors without a clearly motivated character do not show an estrous cyclicity. (4) The estrous cyclic variation in intracranial self-stimulation was observed at a specific locus — the pars campacta of the substantia nigra. (5) A neurochemical link between sexually motivated behavior, wheel running and intracranial self-stimulation is suggested. This link is in part dopaminergic but is probably also activated by many other systems. 相似文献
2.
3.
P M Doraiswamy K R Krishnan O B Boyko M M Husain G S Figiel V J Palese P R Escalona S A Shah W M McDonald W J Rockwell 《Progress in neuro-psychopharmacology & biological psychiatry》1991,15(3):351-356
1. The frequent occurrence of hypothalamo-pituitary dysfunction in patients with eating disorders as well as prior reports that nutritional and endocrine status influence pituitary morphology, led us to hypothesize that pituitary size and shape may be altered in patients with eating disorders. 2. Magnetic resonance imaging (MRI) does not use ionizing radiation and is currently one of the most feasible modalities available to study the pituitary gland in vivo. Using MRI, we have previously reported in a preliminary study that female patients with eating disorders had significantly smaller pituitary glands than controls. In addition MRI excluded any pituitary mass lesions. 3. In this report, we confirm our previous MRI findings and provide further evidence of pituitary abnormalities in an expanded sample of eating disorder patients. Preliminary data on pituitary volume estimates from MRI scans are provided for a subset of patients and controls. 相似文献
4.
J W McDonald E A Garofalo T Hood J C Sackellares S Gilman P E McKeever J C Troncoso M V Johnston 《Annals of neurology》1991,29(5):529-541
We examined binding to excitatory amino acid and inhibitory amino acid receptors in frozen hippocampal sections prepared from surgical specimens resected from 8 individuals with medically refractory temporal lobe epilepsy. The excitatory receptors studied included N-methyl-D-aspartate (NMDA), strychnine-insensitive glycine, phencyclidine, and quisqualate. The inhibitory receptors studied were gamma-aminobutyric acid type A (GABAA) and benzodiazepine. Excitatory and inhibitory amino acid receptor binding were differentially altered in the patients with temporal lobe epilepsy in comparison to 8 age-comparable autopsy control subjects, and changes in receptor binding were regionally selective in four areas. Binding to phencyclidine receptors associated with the NMDA channel was reduced by 35 to 70% in all regions in the hippocampi of the patients. In contrast, binding to the NMDA recognition site and its associated glycine modulatory site was elevated by 20 to 110% in the cornu ammonis (CA) 1 area and dentate gyrus of the hippocampus of the patients. Binding to these sites was unaffected in area CA4. Binding to the quisqualate-type excitatory amino acid receptor was unchanged in all regions except the stratum lacunosum moleculare CA1, where it was increased by 63%. GABAA and benzodiazepine receptor binding was reduced by 20 to 60% in CA1 and CA4, but unchanged in dentate gyrus. The data indicate that excitatory and inhibitory amino acid receptors are altered in the hippocampus of patients with temporal lobe epilepsy. 相似文献
5.
ImmunoCyt/uCyt is a fluorescent test combining three monoclonal antibodies. In this study, it has been tested as a complement to cytology in the detection of urothelial carcinoma in urine. It has been performed simultaneously with standard cytology and cystoscopy on 870 urine analyses from one hospital. In 136 cases, one or more bladder tumors were found. Overall sensitivity of cytology, ImmunoCyt/uCyt and combined analyses reached 29, 74 and 84%, respectively, and overall specificity was 98, 62 and 61%. The negative predictive value of cytology, ImmunoCyt/uCyt and both analyses was 88, 93 and 95%, respectively, and the positive predictive value was 70, 26 and 29%. The sensitivity of cytology for low malignant potential neoplasms, low- and high-grade papillary carcinomas was 6, 18 and 53%, while it reached 71, 79 and 93% when combined with ImmunoCyt/uCyt. The sensitivity of cytology for stages Ta, T1, T2 and over and Tis tumors was 12, 67, 47 and 50%, while it reached 78, 83, 79 and 100% when combined with ImmunoCyt/uCyt. In the absence of tumor on cystoscopy but with positive ImmunoCyt/uCyt, 18% of patients developed a tumor, 2-6 months later. Of the 109 cases diagnosed as suspicious for malignancy by cytology, a tumor was present in 30 cases and ImmunoCyt/uCyt was positive in 22 (73%) of them. In conclusion, ImmunoCyt/uCyt may be used to postpone cystoscopies in patients followed for bladder cancer and may help to save cytologist and pathologist screening time. 相似文献
6.
7.
Ruth McDonald BA MSc PhD Stephen Harrison BSc MPhil PhD 《Health & social care in the community》2004,12(3):194-201
Recent New Labour policy for the ‘modernisation’ of Government places a good deal of emphasis on decentralisation. This emphasis is particularly marked in relation to the organisation of primary care. However, like hospitals and other National Health Service institutions, primary care trusts (PCTs) are subject to a substantial raft of centrally established performance targets and indicators, including those which contribute to the public award of between zero and three performance ‘stars’. This raises questions about the extent to which employees can exercise autonomy in the context of rigid top‐down directives. This paper presents findings from a study using participant observation and interviews to examine the impact of a training course aimed ostensibly at increasing employee autonomy in an English PCT. The suggestion is that attempts to make employees more autonomous can be seen as a strategy for increasing central control based upon the internalisation by the employees of centrally promulgated values. The attraction of such strategies is that they may be potentially more effective and less costly than alternative strategies of direct control. However, the study suggests that the outcome of attempts by such methods as programmes to increase employee autonomy may be very different from those intended. 相似文献
8.
9.
Bernard Gitler 《Journal of nuclear cardiology》2007,14(6):904; author reply 904-904; author reply 905
10.