全文获取类型
收费全文 | 1006篇 |
免费 | 96篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 74篇 |
妇产科学 | 31篇 |
基础医学 | 96篇 |
口腔科学 | 37篇 |
临床医学 | 170篇 |
内科学 | 210篇 |
皮肤病学 | 27篇 |
神经病学 | 47篇 |
特种医学 | 156篇 |
外科学 | 73篇 |
综合类 | 26篇 |
预防医学 | 66篇 |
眼科学 | 12篇 |
药学 | 56篇 |
1篇 | |
中国医学 | 9篇 |
肿瘤学 | 51篇 |
出版年
2023年 | 2篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 22篇 |
2017年 | 24篇 |
2016年 | 26篇 |
2015年 | 28篇 |
2014年 | 36篇 |
2013年 | 44篇 |
2012年 | 18篇 |
2011年 | 30篇 |
2010年 | 41篇 |
2009年 | 68篇 |
2008年 | 28篇 |
2007年 | 47篇 |
2006年 | 19篇 |
2005年 | 25篇 |
2004年 | 11篇 |
2003年 | 16篇 |
2002年 | 10篇 |
2001年 | 21篇 |
2000年 | 14篇 |
1999年 | 23篇 |
1998年 | 72篇 |
1997年 | 82篇 |
1996年 | 57篇 |
1995年 | 51篇 |
1994年 | 37篇 |
1993年 | 43篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 12篇 |
1989年 | 26篇 |
1988年 | 22篇 |
1987年 | 27篇 |
1986年 | 14篇 |
1985年 | 20篇 |
1984年 | 11篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1978年 | 5篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1934年 | 1篇 |
1931年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有1148条查询结果,搜索用时 0 毫秒
141.
Serial computed tomographic (CT) scans of 200 patients with malignant testicular teratomas were reviewed. Of the 200 patients, 120 were treated with chemotherapy for metastatic disease; 80 patients with no evidence of metastases (stage I disease) received no treatment and served as a control group. CT was performed at regular intervals for ongoing follow-up in both groups. Thymic enlargement occurred 3-14 months after initiation of treatment in 14 of the 120 patients (11.6%) who received chemotherapy but in only one patient in the control group. Histologic examination in one patient who received chemotherapy revealed that the thymic enlargement represented true hyperplasia. Thirteen of the 14 patients (93%) with thymic enlargement after chemotherapy were well and disease free on mean follow-up of 45 months, compared with 78% of the group that did not show thymic enlargement after chemotherapy (P less than .02). Rebound thymic hyperplasia in adults after chemotherapy for metastatic testicular teratoma may be a good prognostic feature and should be considered when an anterior mediastinal mass develops after chemotherapy for metastatic malignancy. 相似文献
142.
Temporal lobes: surface MR coil phased-array imaging 总被引:1,自引:0,他引:1
143.
144.
145.
K Oender† CM Lanschuetzer† M Laimer† A Klausegger† B Paulweber‡ B Kofler§ H Hintner† JW Bauer† 《Journal of the European Academy of Dermatology and Venereology》2006,20(4):396-400
BACKGROUND: Azathioprine, in combination with corticosteroids, is the first-line therapy of severe forms of pemphigus vulgaris. Patients with an impaired thiopurine S-methyltransferase (TPMT) activity are at risk of developing severe myelo-suppression upon treatment with thiopurines such as azathioprine. Analysis of the TPMT status prior to drug administration is therefore highly recommended. However, because of the limited availability of TPMT testing outside of specialized centres, pre-emptive TPMT testing is not widespread. To avoid laborious biochemical and sequencing assays, we evaluated a new restriction fragment length polymorphism (RFLP) analysis. METHODS: We designed a rapid genetic polymerase chain reaction (PCR)-RFLP screen for the most prevalent mutant TPMT*3A and TPMT*3C alleles that are known to result in reduced TPMT enzyme activity. RESULTS: Validating our fast system on 871 Caucasian DNA samples, we observed that 8.61% of our probands carried the TPMT*3A allele and 0.23% were heterozygous for the TPMT*3C allele, which is in concordance with previously reported allele frequencies. CONCLUSION: This simple and low-cost PCR-RFLP TPMT polymorphism testing approach can be performed in a standard laboratory. It should be applied to all patients prior to receiving thiopurine drug therapy to avoid the severe, but predictable, haematopoietic side-effects of thiopurine drug administration. 相似文献
146.
Robertson RT; Gallardo KA; Claytor KJ; Ha DH; Ku KH; Yu BP; Lauterborn JC; Wiley RG; Yu J; Gall CM; Leslie FM 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(2):142-155
The role of basal forebrain-derived cholinergic afferents in the
development of neocortex was studied in postnatal rats. Newborn rat pups
received intraventricular injections of 192 IgG-saporin. Following survival
periods ranging from 2 days to 6 months, the brains were processed to
document the cholinergic lesion and to examine morphological consequences.
Immunocytochemistry for choline acetyltransferase (ChAT) and in situ
hybridization for ChAT mRNA demonstrate a loss of approximately 75% of the
cholinergic neurons in the medial septum and nucleus of the diagonal band
of Broca in the basal forebrain. In situ hybridization for glutamic acid
decarboxylase mRNA reveals no loss of basal forebrain GABAergic neurons.
Acetylcholinesterase histochemistry demonstrates a marked reduction of the
cholinergic axons in neocortex. Cholinergic axons are reduced throughout
the cortical layers; this reduction is more marked in medial than in
lateral cortical areas. The thickness of neocortex is reduced by
approximately 10%. Retrograde labeling of layer V cortico-collicular
pyramidal cells reveals a reduction in cell body size and also a reduction
in numbers of branches of apical dendrites. Spine densities on apical
dendrites are reduced by approximately 20-25% in 192 IgG- saporin-treated
cases; no change was detected in number of spines on basal dendrites. These
results indicate a developmental or maintenance role for cholinergic
afferents to cerebral cortical neurons.
相似文献
147.
R Cruz-Aguado CI Fernández-Verdecia CM Díaz-Suárez O González-Monzón I Antúnez-Potashkina and J Bergado-Rosado 《Fundamental & clinical pharmacology》1998,12(5):538-545
Summary— Neurotrophins, like the nerve growth factor (NGF), trigger a variety of biological effects in their targets. Stimulating effects on antioxidant defenses have been postulated to underlie neurotrophic influence on neuron survival and maintenance. To test whether NGF is capable of inducing changes in glutathione-related enzymes in the aged cognitively impaired brain, glutathione reductase (GRD), glutathione S-transferase (GST) and total glutathione peroxidase (GPX) activities were measured in the striatum, septum, hippocampus and frontal cortex of four Sprague-Dawley rat groups: young (2 months old), aged (20 months old) untreated, aged cytochrome c-treated, and aged NGF-treated (icv delivery, 34 4mUg during 28 days). All the aged rats utilized in the study were memory impaired according to their performance in the Morris water maze test. These aged rats showed increases in the activities of septal and hippocampal GST, as well as, in the hippocampal, striatal and cortical GPX. These increases could be interpreted as compensatory responses to cope with the oxidative damage that has been accumulated by the aged brain. The increases in hippocampal and cortical GPX activity were attenuated by NGF treatment, whereas the neurotrophin induced an increase in GRD activity in the striatum of aged rats. These results point out GRD and GPX as possible targets of the neurotrophic effects. 相似文献
148.
149.
150.
CM Pirkle C Boileau V-K Nguyen N Machouf S Ag-Aboubacrine PA Niamba J Drabo S Koala C Tremblay S Rashed 《HIV medicine》2009,10(3):152-156