全文获取类型
收费全文 | 87207篇 |
免费 | 6089篇 |
国内免费 | 3947篇 |
专业分类
耳鼻咽喉 | 391篇 |
儿科学 | 1542篇 |
妇产科学 | 928篇 |
基础医学 | 14145篇 |
口腔科学 | 1752篇 |
临床医学 | 7171篇 |
内科学 | 15194篇 |
皮肤病学 | 1168篇 |
神经病学 | 8186篇 |
特种医学 | 1383篇 |
外国民族医学 | 15篇 |
外科学 | 5400篇 |
综合类 | 14369篇 |
现状与发展 | 22篇 |
预防医学 | 5024篇 |
眼科学 | 1038篇 |
药学 | 11068篇 |
13篇 | |
中国医学 | 2665篇 |
肿瘤学 | 5769篇 |
出版年
2024年 | 188篇 |
2023年 | 943篇 |
2022年 | 2329篇 |
2021年 | 3171篇 |
2020年 | 2559篇 |
2019年 | 2156篇 |
2018年 | 2152篇 |
2017年 | 2453篇 |
2016年 | 2819篇 |
2015年 | 3199篇 |
2014年 | 5336篇 |
2013年 | 6006篇 |
2012年 | 5651篇 |
2011年 | 6327篇 |
2010年 | 5014篇 |
2009年 | 4924篇 |
2008年 | 5040篇 |
2007年 | 4882篇 |
2006年 | 4362篇 |
2005年 | 4073篇 |
2004年 | 3378篇 |
2003年 | 2867篇 |
2002年 | 2198篇 |
2001年 | 1883篇 |
2000年 | 1623篇 |
1999年 | 1390篇 |
1998年 | 1306篇 |
1997年 | 1131篇 |
1996年 | 964篇 |
1995年 | 774篇 |
1994年 | 745篇 |
1993年 | 625篇 |
1992年 | 534篇 |
1991年 | 503篇 |
1990年 | 420篇 |
1989年 | 332篇 |
1988年 | 321篇 |
1987年 | 299篇 |
1986年 | 264篇 |
1985年 | 374篇 |
1984年 | 330篇 |
1983年 | 219篇 |
1982年 | 254篇 |
1981年 | 197篇 |
1980年 | 171篇 |
1979年 | 115篇 |
1978年 | 95篇 |
1977年 | 83篇 |
1976年 | 78篇 |
1975年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
1. Evidence that vegetarian dietary patterns lower blood pressure (BP) comes from both population studies and randomized controlled trials in normotensive and hypertensive subjects. 2. The effect has been shown most clearly in those who keep to a strict lacto-ovo vegetarian diet characterized by a relatively low intake of saturated fat, a high polyunsaturated/saturated fat ratio, and a high intake of fruit, vegetables and other fibre containing products. Randomized controlled dietary trials suggest the effects are independent of dietary sodium, additive to that of calorie restriction, and not due to the absence of meat protein per se. Indeed, recent population studies suggest an inverse relationship between dietary protein and BP. 4. Dietary fats, fibre, potassium, magnesium and calcium do not independently seem to account for the effects. A possible role for complex carbohydrate in conjunction with the other dietary factors has yet to be fully explored. 相似文献
82.
83.
A. MacDonald 《Journal of human nutrition and dietetics》1994,7(2):105-114
This article is a report of a meeting of dietitians held on 15 September 1992 in Birmingham to discuss the recommendations of a 'Medical Research Council Working Party on the Dietary Management of Phenylketonuria'. (Contributions on the day of the meeting came from Judith Houghton, Eleanor Weetch, Isabel Smith, Sheena Laing, Ruth Watling, John Walter, Rodney Pollitt.) 相似文献
84.
D. M. F. Edwards C. Pellizzoni H. P. Breuel A. Berardi M. G. Castelli E. Frigerio I. Poggesi M. Rocchetti A. Dubini M. Strolin Benedetti 《Biopharmaceutics & drug disposition》1995,16(6):443-460
The pharmacokinetics of reboxetine, a new antidepressant agent, were found to be close to linear in a crossover study comparing administration of single 2, 3, 4 and 5 mg capsule doses in 15 healthy male volunteers, and in the same study the capsules were bioequivalent to the proposed therapeutic tablet formulation (4mg). Kinetic analysis was based on HPLC assay of reboxetine in plasma and urine collected up to 72 h after each administration. Plasma levels indicated a rapid absorption (tmax?2h) and an elimination half-life of about 13 h. Clearance and volume of distribution were modest (ratios to bioavailability: CL/F?29 mL min?1; Vz/F?32L); urinary excretion was ~9% of dose, corresponding to a renal clearance of only 3 mL min?1 (a value consistent with the rate of glomerular filtration of unbound drug). In vitro, binding to plasma proteins, estimated from radioactivity levels following dialysis of 14C-labelled reboxetine, appeared to be dominated by α1-acid glycoprotein without marked saturation up to plasma concentrations of over 500 ng mL?1 (2.8–3.1% unbound with human plasma from three additional volunteers; 1.8–2.0% for 2gL?1 orosomucoid α1-acid glycoprotein, and 46.4–47.4% for 40 gL?1 albumin), whilst the mean Cmax in the current study was much lower (164 ng mL?1 after a 5 mg dose). 相似文献
85.
86.
A protein C deficient woman, with a past history of recurrent thrombosis and purpura fulminans, was successfully treated with protein C concentrate in the peripartum period. © 1992 Wiley-Liss, Inc. 相似文献
87.
目的探讨温度、抗凝剂(EDTA-K2)对血嗜酸性粒细胞阳离子蛋白(ECP)水平的影响。方法采用固相双位点酶放大化学发光法,分别对22例健康体检者在两种不同温度(25℃和37℃)的血清标本,以及在相同温度(37℃)下,加抗凝剂和不加抗凝剂的血标本进行ECP水平测定。结果25℃组和37℃组血清ECP水平分别为8.92±6.45μg/L(x±s)和19.87±12.16μg/L(x±s),两组有显著性差异(P<0.01);37℃温度下加抗凝剂和不加抗凝剂血标本的ECP水平分别为5.26±2.60μg/L(x±s)和19.87±12.16μg/L(x±s),两组也有显著性差异(P<0.001)。结论温度和抗凝剂(EDTA-K2)对血标本的ECP水平测定有不同程度的影响。 相似文献
88.
Barbara Porton Adriana Ferreira Lynn E DeLisi Hung Teh Kao 《Neuropsychopharmacology》2004,55(2):118-125
BACKGROUND: Synapsin III plays a role in neuronal plasticity and maps to chromosome 22q12-13, a region suggested to be linked to schizophrenia. To determine if synapsin III plays a role in this disease, we searched for polymorphisms in this gene in patients with schizophrenia and controls. METHODS: The synapsin III gene was initially sequenced from 10 individuals with schizophrenia to identify polymorphisms. Association analysis was then performed using 118 individuals with schizophrenia and 330 population controls. Synapsin III expression was studied by immunoblot analyses, and phosphorylation sites were mapped by sequencing trypsin-digested synapsin III fragments phosphorylated with phosphorus-32. RESULTS: A rare, missense polymorphism, S470N, was identified in the synapsin III gene and appeared more frequently in individuals with schizophrenia than in controls (p =.0048). The site affected by the polymorphism, Ser470, was determined to be a substrate for mitogen-activated protein kinase, a downstream effector of neurotrophin action. Phosphorylation at Ser470 was increased during neonatal development and in response to neurotrophin-3 in cultured hippocampal neurons. CONCLUSIONS: Our observations suggest an association of a rare polymorphism in synapsin III with schizophrenia, but further studies will be required to clarify its role in this disease. 相似文献
89.
Jasper E Visser Bastiaan R Bloem Bart P C van de Warrenburg 《Movement disorders》2007,22(7):1024-1026
Progressive myoclonic ataxia, also referred to as Ramsay Hunt syndrome, is characterized by a combination of myoclonus and cerebellar ataxia, infrequently accompanied by tonic-clonic seizures. Its differential diagnosis overlaps with progressive myoclonic epilepsy, a syndrome with myoclonus, tonic-clonic seizures, progressive ataxia and dementia. In patients with progressive myoclonic epilepsy, specific diseases can frequently be recognized, but the diagnostic yield in progressive myoclonic ataxia is much lower. We describe a patient who presented with multifocal myoclonus in his thirties and who later developed cerebellar ataxia and focal dystonia. His father was similarly affected. Genetic studies revealed a mutation in the protein kinase C gamma (PRKCG) gene, known to cause spinocerebellar ataxia type 14 (SCA-14). This case illustrates that both myoclonus and dystonia are part of the clinical spectrum in SCA-14 and that myoclonus can even be the presenting symptom. We suggest that SCA-14 should be considered in the differential diagnosis of progressive myoclonic ataxia. 相似文献
90.
目的探讨多发伤患者外周血降钙素原(procalcitonin,PCT)与C反应蛋白(C reac- tive protein,CRP)的动态变化及其临床意义。方法将96例多发伤患者按照ISS、输血量的多少、有无MODS、感染、脓毒血症及预后情况进行分类,分别检测不同类别患者外周血PCT、CRP浓度。结果与对照组相比,多发伤患者PCT和CRP均明显升高,其峰值分别出现在伤后2 d (PCT),5,7 d(CRP)。发生MODS、感染及脓毒血症时,PCT和CRP均明显升高。此外,PCT还与患者ISS评分、预后和输血量具有相关性。结论联合检测PCT、CRP有助于多发伤患者伤情的诊治及预后判断,其中PCT较CRP更具有敏感性。 相似文献