全文获取类型
收费全文 | 61571篇 |
免费 | 5708篇 |
国内免费 | 1322篇 |
专业分类
耳鼻咽喉 | 374篇 |
儿科学 | 2871篇 |
妇产科学 | 612篇 |
基础医学 | 6558篇 |
口腔科学 | 786篇 |
临床医学 | 5245篇 |
内科学 | 7591篇 |
皮肤病学 | 372篇 |
神经病学 | 16996篇 |
特种医学 | 1475篇 |
外国民族医学 | 1篇 |
外科学 | 2997篇 |
综合类 | 5712篇 |
现状与发展 | 6篇 |
一般理论 | 1篇 |
预防医学 | 5439篇 |
眼科学 | 321篇 |
药学 | 7463篇 |
27篇 | |
中国医学 | 2402篇 |
肿瘤学 | 1352篇 |
出版年
2024年 | 936篇 |
2023年 | 1603篇 |
2022年 | 2420篇 |
2021年 | 3188篇 |
2020年 | 2795篇 |
2019年 | 2466篇 |
2018年 | 2338篇 |
2017年 | 2426篇 |
2016年 | 2537篇 |
2015年 | 2382篇 |
2014年 | 3665篇 |
2013年 | 5205篇 |
2012年 | 3133篇 |
2011年 | 3439篇 |
2010年 | 2743篇 |
2009年 | 2671篇 |
2008年 | 2758篇 |
2007年 | 2576篇 |
2006年 | 2195篇 |
2005年 | 1892篇 |
2004年 | 1561篇 |
2003年 | 1446篇 |
2002年 | 1299篇 |
2001年 | 1065篇 |
2000年 | 853篇 |
1999年 | 723篇 |
1998年 | 766篇 |
1997年 | 695篇 |
1996年 | 621篇 |
1995年 | 517篇 |
1994年 | 493篇 |
1993年 | 446篇 |
1992年 | 453篇 |
1991年 | 415篇 |
1990年 | 385篇 |
1989年 | 359篇 |
1988年 | 349篇 |
1987年 | 313篇 |
1986年 | 233篇 |
1985年 | 319篇 |
1984年 | 309篇 |
1983年 | 176篇 |
1982年 | 240篇 |
1981年 | 183篇 |
1980年 | 164篇 |
1979年 | 163篇 |
1978年 | 136篇 |
1977年 | 122篇 |
1976年 | 107篇 |
1975年 | 93篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS. 相似文献
2.
The effect of interleukin-1 on iron metabolism in rats was evaluated. Plasma iron decreased from 184 +/- 16 micrograms/dl (mean +/- SE) to 24 +/- 12 at 6 hours after interleukin-1 intramuscular administration in non-fasting rats and 109 +/- 6 micrograms/dl to 12 +/- 1 micrograms/dl in fasting rats, which was significantly lower than in control rats. Ferrokinetic studies showed a more rapid disappearance rate and lower iron turnover in interleukin-1-injected rats. The release of iron from the mononuclear phagocyte system to plasma was studied at 3 h after interleukin-1 administration. Although the percent of radioactivity in plasma of the total injected dose was 3.2 +/- 0.6% in interleukin-1, which was significantly lower than in the control rats (5.4 +/- 0.6%) at 9 h after intravenous injection of 59Fe chondroitin ferrous sulfate, there was no difference between the amount of 59Fe released from the mononuclear phagocyte system over the first 9 h in interleukin-1 and control rats. These data appear to imply that iron release is unimpaired but that, for some reason, there is an enhanced rate of clearance of the 59Fe once it has been released from the mononuclear phagocyte system into the plasma. 相似文献
3.
Summary This study was undertaken to elucidate, using the Golgi method, the neuropathological change in the brain of the macular mutant mouse, whose hemizygote (Ml/y) is considered to be a model of Menkes kinky hair disease (MKHD). The hemizygote mice gradually lost weight after 10 days of age and died with emaciation and seizure around day 15. The normal littermate (+/y) was well developed. In the cerebrum, the arborization of pyramidal neurons in the layer V of the Ml/y was the same as that in the +/y on day 10. However, development of arborization in the Ml/y was delayed in comparison with that in the +/y on days 12 and 14. Purkinje cells with several somal sprouts were observed in the cerebellum in both the Ml/y and +/y on day 7. The somal sprouts in the +/y had regressed gradually by day 12, while they were still in the anterior and middle lobes of the Ml/y on day 14. Additionally, the trunks of Ml/y stem dendrites became thicker and a cactus formation was recognized on the branching portion of the dendrites on day 14. Arborization of these abnormal Purkinje cells was distinctly poor compared with that in the +/y. These results suggest that the growth of the neurons is delayed in the Ml/y and simultaneously their cytoskeletal developments are disturbed, especially in the Purkinje cells. There is a close similarity in many respects to the neuropathological change in MKHD. 相似文献
4.
5.
A boy with rhizomelic chondrodysplasia punctata, diagnosed on the laboratory evidence of a high plasma concentration of phytanic
acid and a low erythrocyte concentration of plasmalogens, has been followed from birth to the age of 16 years. The clinical
pattern (somatic, skeletal and neurological) tallies with published findings in this disease. Unusual findings are the associated
epilepsy, confirmed by EEG, and the long survival. CT brain scan and MRI showed cortical and subcortical atrophy but not gyral
abnormalities or demyelination.
Sommario Viene descritto il caso di un bambino affetto da condrodisplasia punctata rizomelica seguito dalla nascita fino ai 16 anni. La diagnosi clinica, efettuata in base alle caratteristiche somatiche, scheletriche e neurologiche del paziente è stata confermata dai reperti di laboratorio (alta concentrazione plasmatica di acido fitanico, bassa concentrazione di plasmalogeni eritrocitari). Come correlati inusuali del quadro clinico vanno segnalati l'associazione con epilessia e a la lunga sopravvivenza. La TAC e la RNM cerebrale hannovaltresì documentato atrofia corticale e sottocorticale ma non anomalie della girazione o demielinizzazione.相似文献
6.
Peter L. Forster Frank B. Schoenfeld Charles R. Marmar Ariel Janna Lang 《Journal of traumatic stress》1995,8(1):143-149
Irritability is often a problem for patients with Post-Traumatic Stress Disorder (PTSD). We describe two cases that illustrate the use of lithium in the treatment of veterans with PTSD who complained of serious problems with irritability or angry outbursts. These cases are discussed in the context of evidence that lithium may be useful in other patients with disorders of impulse control. The evidence linking disorders of anger and impulse control to a dysregulation in neurotransmitter regulation, particularly in serotonergic pathways, supports a psychopharmacologic approach to treatment. These findings should lead to further study of the role of lithium in the treatment of this symptom complex in patients with PTSD. 相似文献
7.
组织扩张术皮肤胶原的代谢改变 总被引:4,自引:0,他引:4
目的:研究常规扩张(ITE)和持续快速扩张(CTE)对皮肤胶原代谢的影响。方法用白色小家猪制作组织扩张术动物模型,用Gordeladze法测定血清和扩张组织的羟脯氨酸(HP)含量,藻酸盐印模材膜片法测量标记区面积;光镜测量真皮厚度。结果:ITE组血清HP含量升高,0.8倍,CTE组升高1.2倍,ITE和CTE组皮肤含量与正常皮肤相同,组织中HP总量均明显升高,持续扩张皮瓣组(CTEF)术后4wk皮 相似文献
8.
9.
R. Berkels A. Bertsch T. Zuther S. Dhein K. Stockklauser P. Rsen R. Rsen 《European journal of haematology》1997,58(5):307-313
Abstract: We tried to characterize the porcine platelet nitric oxide (NO) synthase and its L-arginine (L-arg)/NO metabolism. Using RT-PCR we could show a constitutive endothelial NOS (ecNOS) and an inducible NOS (iNOS) similar mRNA in platelets. The NOS protein could be evidenced by an ecNOS specific antibody which also bound in platelets. This finding could be confirmed by Western blot showing an ecNOS in the membrane but not the cytosolic fraction; iNOS protein could not be detected. Using NADPH-diaphorase staining we could show NO synthase in preactivated platelets but not in resting platelets, indicating that the platelet NOS may be activated during platelet activation/aggregation. Porcine L-arg plasma levels (9.31 × 10–5 mol/l ± 10%) could be shown to be in the same range as human plasma levels. Moreover, we could show that the NO precursor L-arg and hydroxy-L-arginine (OHarg) concentration dependently inhibited collagen induced platelet aggregation. Summarizing these results confirm the existence of and further characterize porcine platelet NO synthases. 相似文献
10.
Khema R. Sharma Jane Kent-Braun Mark A. Mynhier Michael W. Weiner Robert G. Miller 《Muscle & nerve》1995,18(12):1403-1411
The goals of this study were to investigate muscle fatigue in patients with multiple sclerosis (MS), and to determine the relationships between muscle fatigue, clinical status, and perceived fatigue. The fatigability of the anterior tibial muscle was quantitated in patients and controls during 9 min of intermittent stimulation (used to eliminate central sources of muscle fatigue). During exercise, the decline in tetanic force, phosphocreatine, and intracellular pH was greater in patients than in controls. The compound muscle action potential amplitude did not decrease during exercise, indicating that there was no failure of neuromuscular transmission during fatigue. Thus, the excessive fatigue in MS developed from sources beyond the muscle membrane. Following exercise, the recovery of tetanic force was delayed in patients (a pattern that suggests abnormal excitation–contraction coupling), whereas the recovery of metabolites was complete in both groups. Muscular fatigue was correlated with clinical disability but not with perceived fatigue. These results suggests that fatigue in MS has both central (perception, upper motor neuron dysfunction) and peripheral (impaired metabolism and excitation–contraction coupling) components.© 1995 John Wiley &Sons, Inc. 相似文献