全文获取类型
收费全文 | 1469篇 |
免费 | 77篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 65篇 |
妇产科学 | 23篇 |
基础医学 | 236篇 |
口腔科学 | 29篇 |
临床医学 | 155篇 |
内科学 | 255篇 |
皮肤病学 | 21篇 |
神经病学 | 57篇 |
特种医学 | 157篇 |
外科学 | 283篇 |
综合类 | 21篇 |
预防医学 | 75篇 |
眼科学 | 8篇 |
药学 | 136篇 |
肿瘤学 | 37篇 |
出版年
2021年 | 24篇 |
2020年 | 10篇 |
2019年 | 21篇 |
2018年 | 23篇 |
2017年 | 14篇 |
2016年 | 20篇 |
2015年 | 25篇 |
2014年 | 39篇 |
2013年 | 49篇 |
2012年 | 42篇 |
2011年 | 61篇 |
2010年 | 49篇 |
2009年 | 36篇 |
2008年 | 54篇 |
2007年 | 71篇 |
2006年 | 63篇 |
2005年 | 63篇 |
2004年 | 38篇 |
2003年 | 52篇 |
2002年 | 24篇 |
2001年 | 40篇 |
2000年 | 34篇 |
1999年 | 33篇 |
1998年 | 48篇 |
1997年 | 49篇 |
1996年 | 37篇 |
1995年 | 23篇 |
1994年 | 29篇 |
1993年 | 21篇 |
1992年 | 31篇 |
1991年 | 19篇 |
1990年 | 23篇 |
1989年 | 21篇 |
1988年 | 42篇 |
1987年 | 24篇 |
1986年 | 27篇 |
1985年 | 21篇 |
1984年 | 21篇 |
1983年 | 15篇 |
1982年 | 22篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 15篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 11篇 |
1973年 | 16篇 |
1972年 | 9篇 |
1971年 | 11篇 |
排序方式: 共有1570条查询结果,搜索用时 15 毫秒
91.
BACKGROUND: Lewy body disease is, after Alzheimer's disease, the second most common cause of senile degenerative dementia with progressive cognitive deterioration, fluctuation of cognitive and motoric functions and psychotic symptoms. It is characterized histologically by the occurrence of Lewy bodies in allocortical, neocortical and subcortical structures. The aim of this study was to measure the cortical glucose metabolism using FDG PET (2-[18F]fluoro-2-deoxy-D-glucose position emission tomography) compared to normal subjects. PATIENTS AND METHODS: Five patients (5 m, mean age 75 y) with clinically suspected diffuse Lewy body disease (DLB) were studied with FDG PET. PET studies of the head were performed with a Siemens ECAT-ART PET-scanner with attenuation correction using 137-Cs point sources. RESULTS: We found the same distribution pattern of diffuse glucose hypometabolism in the entire cortical region with relative sparing of the primary sensory-motor cortex in all the patients. The few cases reported in the literature so far describe findings similar to ours. CONCLUSION: The pattern of diffuse glucose hypometabolism in the entire cortex including the occipital region seems to be a typical feature of DLB that is distinctive from dementia of Alzheimer's disease. 相似文献
92.
Schenkel J Weimar C Knoll T Haberl RL Busse O Hamann GF Koennecke HC Diener HC;German Stroke Data Bank Collaborators 《Journal of neurology》2003,250(3):320-324
BACKGROUND: Systemic thrombolysis with tissue plasminogen activator (t-PA) for treatment of acute ischemic stroke was approved in Germany in 2000. Up to now, only data from single centers have been available for the study of the use of thrombolysis in a hospital-based approach outside controlled trials. We therefore sought to determine the frequency of application and complications as well as the patient outcome after t-PA treatment in clinical routine of specialized stroke centers in Germany. METHODS: Within the German Stroke Data Bank Collaboration, 6234 consecutive patients with ischemic stroke were prospectively documented in 20 stroke centers between 1998 and 1999. The patients were centrally followed via telephone interview after 3 months and 1 year to assess global functional outcome using the Modified Rankin Scale. RESULTS: 250 patients (4 %) received systemic t-PA treatment during the study period. The baseline characteristics of these patients were comparable to large clinical trials and phase IV studies. Symptomatic and asymptomatic parenchymal hemorrhage occurred in 22 patients (8.8 %) and was fatal in 3 patients. Follow-up data after 3 months were obtained in 82.4 % of all patients, of which 35 % had a favorable functional outcome (mRS = 1), while 23.8 % were severely disabled (mRS >/= 4) and 17 % had died. CONCLUSION: The results of our study agree with the assumption that thrombolytic therapy can be performed safely and effectively in daily clinical practice. Nevertheless, the small proportion of patients receiving thrombolysis even in specialized stroke centers calls for further improvement of acute stroke management in Germany. 相似文献
93.
Knoll J 《CNS drug reviews》2001,7(3):317-345
Hundreds of millions of people now die over the age of 80 years primarily due to twentieth century progress in hygiene, chemotherapy, and immunology. With a longer average lifespan, the need to improve quality of life during the latter decades is more compelling. "Aging--The Epidemic of the New Millenium," a recent international conference (Monte Carlo, June 17-18, 2000), showed with peculiar clarity that a safe and efficient drug strategy to slow the age-related decay of brain performance is still missing. This review summarizes the physiologic and pharmacologic arguments in favor of a peculiar lifelong prophylactic medication with reasonable chances to keep in check brain aging and decrease the precipitation of age-related neurological diseases. 相似文献
94.
Knoll T Schaub M Birck R Braun C Juenemann KP Rohmeiss P 《Expert opinion on investigational drugs》2000,9(5):1041-1052
The endothelin system has been identified as having a substantial role in renal failure, both acute and chronic. Beside its well characterised haemodynamic effects, its mitogenic and pro-fibrotic properties have gained increased interest in the pathophysiology of chronic renal failure. This review outlines the role of endothelin in the pathogenesis of various renal diseases with a special focus on the potential of blocking this system with endothelin receptor antagonists. So far, most data were derived from animal models, but they provide strong evidence that endothelin receptor antagonists may represent a powerful therapeutic strategy in ameliorating the course of acute and chronic renal failure. 相似文献
95.
目的:严重的黏膜损伤是诱发造血干细胞移植后出现并发症的一常见原因,已有证据显示谷氨酰胺能降低接受化疗患儿黏膜炎的发生率。观察谷氨酰胺对异基因外周造血干细胞移植患者并发症及恢复的影响。方法:选择于2002-03/2006-11在河南省血液病研究所接受同胞异基因外周造血干细胞移植的48例血液系统肿瘤患者。所有患者及其家属对治疗和实验均知情同意,并经医院伦理委员会批准。所有患者移植前均处于完全缓解状态,营养中等或良好,心、肝、肾功能正常,将48例患者随机分为标准化全胃肠外营养液组(标准组,n=13)和加用谷氨酰胺的全胃肠外营养液组(谷氨酰胺组,n=35)。待患者中性粒细胞升至1.0×109L-1,且无任何感染指征,进行异基因外周造血干细胞移植。造血干细胞输注后第1天开始给予全胃肠外营养与胃肠外营养联合谷氨酰胺双肽,至中性粒细胞≥1.0×109L-1,且无消化道症状时停用。观察两组患者中性粒细胞恢复时间、出层流室时间以及关于感染、急性移植物抗宿主病等情况有无差异。结果:48例患者均进入结果分析。两组患者营养物质的摄入基本相同,谷氨酰胺组有6例发生黏膜炎,标准组有11例,差异显著(P<0.05);谷氨酰胺组有1例发生严重腹泻,标准组有5例,差异显著(P<0.05);谷氨酰胺组有3例发生临床感染,标准组有7例,差异显著(P<0.05);标准组中性粒细胞≥0.5×109L-1的持续时间短于谷氨酰胺组(P>0.05);谷氨酰胺组抗生素治疗时间及无菌病房居住时间较标准组短(P<0.05);两组急性移植物抗宿主病发生率差异无统计学意义(P>0.05)。结论:添加谷氨酰胺的全胃肠外营养可改善异基因造血干细胞移植患者的营养状态,减少感染及肠损害,减少急性移植物抗宿主病的发生,有利于异基因移植患者恢复。 相似文献
96.
97.
98.
Braffman BH; Coleman BG; Ramchandani P; Arger PH; Nodine CF; Dinsmore BJ; Louie A; Betsch SE 《Radiology》1994,190(3):797
99.
MJ McKinley RM McAllen GL Pennington A. Smardencas RS Weisinger BJ Oldfield 《Clinical and experimental pharmacology & physiology》1996,23(Z3):99-104
- 1 Autoradiographic binding studies have shown that the AT1 receptor is the predominant angiotensin II (AngII) receptor subtype in the central nervous system (CNS). Major sites of AT1 receptors are the lamina terminalis, hypothalamic paraventricular nucleus, the lateral parabrachial nucleus, rostral and caudal ventrolateral medulla, nucleus of the solitary tract and the intermediolateral cell column of the thoraco-lumbar spinal cord.
- 2 While there are differences between species, AT2 receptors are found mainly in the cerebellum, inferior olive and locus coeruleus of the rat.
- 3 Circulating AngII acts on AT1 receptors in the subfornical organ and organum vasculosum of the lamina terminalis (OVLT) to stimulate neurons that may have a role in initiating water drinking.
- 4 Centrally administered AngII may act on AT1 receptors in the median preoptic nucleus and elsewhere to induce drinking, sodium appetite, a sympathetic vasoconstrictor response and vasopressin secretion.
- 5 Recent evidence shows that centrally administered AT1 antagonists inhibit dipsogenic, natriuretic, pressor and vasopressin secretory responses to intracerebroventricular infusion of hypertonic saline. This suggests that an angiotensinergic neural pathway has a role in osmoregulatory responses.
- 6 Central angiotensinergic pathways which include neural inputs to the rostral ventrolateral medulla may use AT1 receptors and play a role in the function of sympathetic pathways maintaining arterial pressure.
100.
Knoll GA Wells PS Young D Perkins SL Pilkey RM Clinch JJ Rodger MA 《Journal of the American Society of Nephrology : JASN》2005,16(4):1108-1114
Vascular access thrombosis is the most common and costly complication in hemodialysis patients. The role of thrombophilia in access thrombosis is not established. A case-control study was conducted of 419 hemodialysis patients to determine whether thrombophilia was associated with arteriovenous fistula or graft thrombosis. Participants were enrolled from three in-center and five satellite dialysis units associated with a Canadian academic health science center that provides dialysis services in a catchment area of one million. Patients were tested for factor V Leiden, prothrombin gene mutation, factor XIII genotype, methylenetetrahydrofolate reductase genotype, lupus anticoagulant, anticardiolipin antibody, factor VIII, homocysteine, and lipoprotein (a) concentrations. Overall, 59 (55%) patients with access thrombosis had at least one thrombophilia compared with 122 (39%) patients without access thrombosis (unadjusted odds ratio [OR], 1.91; 95% confidence interval [CI], 1.23 to 2.98). After controlling for important risk factors, the association between any thrombophilia and access thrombosis remained (adjusted OR, 2.42; 95% CI, 1.47 to 3.99). For each additional thrombophilic disorder, the odds of access thrombosis increased significantly (adjusted OR, 1.87; 95% CI, 1.34 to 2.61). This study suggests that thrombophilia is associated with access thrombosis in dialysis patients. Large, multicenter, prospective cohort studies are needed to confirm the observations from this case-control study. 相似文献