全文获取类型
收费全文 | 53064篇 |
免费 | 3357篇 |
国内免费 | 1696篇 |
专业分类
耳鼻咽喉 | 664篇 |
儿科学 | 1126篇 |
妇产科学 | 681篇 |
基础医学 | 4864篇 |
口腔科学 | 1023篇 |
临床医学 | 4993篇 |
内科学 | 7495篇 |
皮肤病学 | 2309篇 |
神经病学 | 3165篇 |
特种医学 | 1697篇 |
外国民族医学 | 1篇 |
外科学 | 2198篇 |
综合类 | 7322篇 |
现状与发展 | 3篇 |
一般理论 | 1篇 |
预防医学 | 8104篇 |
眼科学 | 583篇 |
药学 | 7660篇 |
34篇 | |
中国医学 | 3020篇 |
肿瘤学 | 1174篇 |
出版年
2024年 | 88篇 |
2023年 | 580篇 |
2022年 | 1350篇 |
2021年 | 1900篇 |
2020年 | 1581篇 |
2019年 | 1434篇 |
2018年 | 1461篇 |
2017年 | 1521篇 |
2016年 | 1570篇 |
2015年 | 1672篇 |
2014年 | 3125篇 |
2013年 | 3604篇 |
2012年 | 3300篇 |
2011年 | 3718篇 |
2010年 | 2881篇 |
2009年 | 2595篇 |
2008年 | 2620篇 |
2007年 | 2720篇 |
2006年 | 2268篇 |
2005年 | 2090篇 |
2004年 | 1750篇 |
2003年 | 1521篇 |
2002年 | 1254篇 |
2001年 | 1207篇 |
2000年 | 989篇 |
1999年 | 917篇 |
1998年 | 758篇 |
1997年 | 735篇 |
1996年 | 666篇 |
1995年 | 638篇 |
1994年 | 595篇 |
1993年 | 462篇 |
1992年 | 498篇 |
1991年 | 466篇 |
1990年 | 373篇 |
1989年 | 396篇 |
1988年 | 365篇 |
1987年 | 336篇 |
1986年 | 268篇 |
1985年 | 325篇 |
1984年 | 246篇 |
1983年 | 204篇 |
1982年 | 219篇 |
1981年 | 170篇 |
1980年 | 139篇 |
1979年 | 119篇 |
1978年 | 93篇 |
1977年 | 83篇 |
1976年 | 61篇 |
1975年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Incidence of childhood diabetes mellitus in Yorkshire, northern England, is associated with nitrate in drinking water: an ecological analysis 总被引:7,自引:1,他引:6
R. C. Parslow P. A. McKinney G. R. Law A. Staines R. Williams H. J. Bodansky 《Diabetologia》1997,40(5):550-556
Summary The relationship between the incidence of childhood-onset insulin-dependent diabetes mellitus and levels of nitrate in drinking
water in the former Yorkshire Regional Health Authority was investigated by means of an ecological analysis. A population-based
register contributed 1797 0–16-year-olds diagnosed with diabetes between 1978 and 1994. Nitrate data were based on 9330 samples
of drinking water tested between 1990 and 1995 in 148 water supply zones, for which 1991 census small area statistics were
taken on population density, ethnicity and socio-economic status. Diabetes incidence was positively associated with raised
mean nitrate levels with a standardised incidence ratio of 115 in zones with greater than 14.85 mg · l–1 (χ2 = 26.81, 1 df, p < 0.001). Significant negative trends were found between standardised incidence ratios and proportion of non-whites in the
population (χ2 = 33.57, 1 df, p < 0.001), childhood population density (χ2 = 30.81, 1 df, p < 0.001) and the Townsend deprivation score (χ2 = 33.89, 1 df, p < 0.001). Poisson regression modelling, adjusting for the other factors, showed a significant increase in relative incidence
rate ratio from a baseline of 1 at nitrate levels below 3.22 mg · l–1 to 1.27 (95 % confidence interval 1.09,1.48) for mean nitrate levels above 14.85 mg · l–1. An association between higher nitrate levels in domestic drinking water and incidence of childhood diabetes has been demonstrated.
This was not explained by the ethnic composition of the population, population density or socioeconomic status. Nitrate in
drinking water may be a precursor of chemicals which are toxic to the pancreas. [Diabetologia (1997) 40: 550–556]
Received: 24 October 1996 and in revised form: 20 December 1996 相似文献
83.
M V Shestakova N A Mukhin I I Dedov V N Titov V A Warshavsky 《Journal of internal medicine》1992,231(3):213-217
The acute effects of protein loading (1.5 g kg-1) on glomerular filtration rate (GFR) and urinary albumin excretion (UAE) were investigated in 23 type-I diabetic patients with no clinical nephropathy, and in 7 healthy subjects (controls). The results were compared with renal morphology data. In controls and in 14 diabetic patients (group 1) GFR increased by 27 and 37%, respectively, corresponding to normal renal reserve, but in 9 patients (group 2) GFR decreased by 20%, indicating the absence of a renal reserve. Microalbuminuria was found in none of the patients in group 1 and in 50% of patients in group 2. Two hours after the load UAE increased in all groups, but the increase was most marked in group 2, despite the fall in GFR. The two groups of patients did not differ with regard to the duration and control of diabetes, but differed markedly in terms of baseline GFR (131 vs. 195 ml min-1, P less than 0.01, in groups 1 and 2, respectively). Renal morphology showed minimal non-specific glomerular injury in group 1, and signs of glomerulosclerosis in group 2. We conclude that the impaired renal response to protein load precedes other subclinical manifestations of diabetic renal injury, and may be useful in the diagnosis of latent diabetic nephropathy. 相似文献
84.
本文采用中和试验、沉降反应和解离试验对135例已知血型人精液中ABH血型物质的分泌强度进行了检验,并将其分为强、中、弱三型。这对区别个人血型物质含量及性犯罪的法医学鉴定均有重要意义。并证明了AB型人精液中A、B血型物质含量不均等现象,并且绝大多数人B型物质高于A型物质。 相似文献
85.
Spatial Learning Deficits in Mice with a Targeted Glucocorticoid Receptor Gene Disruption 总被引:5,自引:0,他引:5
Melly S. Oitzl E. Ron de Kloet Marian Joëls Wolfgang Schmid Timothy J. Cole 《The European journal of neuroscience》1997,9(11):2284-2296
Previous studies in rats using the Morris water maze suggested that the processing of spatial information is modulated by corticosteroid hormones through mineralocorticoid and glucocorticoid receptors in the hippocampus. Mineralocorticoid receptors appear to be involved in the modulation of explorative behaviour, while additional activation of glucocorticoid receptors facilitates the storage of information. In the present study we used the water maze task to examine spatial learning and memory in mice homozygous and heterozygous for a targeted disruption of the glucocorticoid receptor gene. Compared with wild-type controls, homozygous and heterozygous mice were impaired in the processing of spatial but not visual information. Homozygous mutants performed variably during training, without specific platform-directed search strategies. The spatial learning disability was partly compensated for by increased motor activity. The deficits were indicative of a dysfunction of glucocorticoid receptors as well as of mineralocorticoid receptors. Although the heterozygous mice performed similarly to wild-type mice with respect to latency to find the platform, their strategy was more similar to that of the homozygous mice. Glucocorticoid receptor-related long-term spatial memory was impaired. The increased behavioural reactivity of the heterozygous mice in the open field points to a more prominent mineralocorticoid receptor-mediated function. The findings indicate that (i) the glucocorticoid receptor is of critical importance for the control of spatial behavioural functions, and (ii) mineralocorticoid receptor-mediated effects on this behaviour require interaction with functional glucocorticoid receptors. Until the development of site-specific, inducible glucocorticoid receptor mutants, glucocorticoid receptor-knockout mice present the only animal model for the study of corticosteroid-mediated effects in the complete absence of a functional receptor. 相似文献
86.
The cold pressor test: Vascular and myocardial response patterns and their stability 总被引:2,自引:0,他引:2
PATRICE G. SAAB MARIA M. LLABRE BARRY E. HURWITZ NEIL SCHNEIDERMAN WILLIAM WOHLGEMUTH LYNN A. DUREL CLIFFORD MASSIE JOACHIM NAGEL 《Psychophysiology》1993,30(4):366-373
The purposes of the present study were to compare the cardiovascular response patterns evoked by three versions of the cold pressor test (either forehead stimulation or hand or foot immersion) and to determine the reproducibility of the responses over a 2-week interval. Blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, and systolic time intervals were obtained during rest and during the cold pressor test in 42 young men. Across conditions, the pressor response was supported by peripheral resistance increases with concomitant stroke volume decreases. Although the response panerns were generally similar across sites, exceptions were apparent for heart rate. Forehead stimulation was characterized by no significant change in heart rate, whereas limb (hand or foot) immersion was associated with significant heart rate acceleration. The responses elicited by the three cold pressor test conditions were reliable and showed little evidence of attenuation over the test-retest interval. 相似文献
87.
宣肺清热颗粒剂稳定性研究 总被引:1,自引:0,他引:1
目的:研究宣肺清热颗粒剂中橙皮甙热稳定性变化,为该颗粒剂有效期的确定、制剂生产、贮存条什提供实验参考依据。方法:采用加速实验法对橙皮甙热稳定性进行研究,用甲醇超声提取样品,HPLC进行含量测定。根据Arrhenius公式处理数据。结果:Arrhenius公式得室温下的速度常数K298=3.38×10-5/h,得出常温下该颗粒剂以橙皮甙为指标的有效期为3.6年。结论:宣肺清热颗粒剂稳定性好,初步符合中药稳定性要求。 相似文献
88.
Michael J Radcliffe George T Lewith Philip Prescott Martin K Church Stephen T Holgate 《Clinical and experimental allergy》2006,36(12):1488-1493
BACKGROUND: In the investigation of seasonal allergic rhinoconjunctivitis (SAR), quantitative skin and conjunctival allergen challenge tests are used to measure individual allergen sensitivity. These tests are reproducible and relate well to prevalence but their relationship to symptom severity is less well established. OBJECTIVE: We wished to determine if quantitative skin prick tests (QSPT) and conjunctival provocation tests (CPTs) using a single grass pollen allergen extract are reproducible and predict symptom severity in SAR. METHODS: We retrospectively analysed data from 91 participants in a previously published randomized placebo controlled study of low dosage allergen immunotherapy who were randomized to receive placebo treatment. We examined the relationship between pre-seasonal QSPT, CPT and SAR symptoms. RESULTS: We found a high level of reproducibility when repeated measures were compared for both the QSPT (P < 0.001) and the CPT (P < 0.001) and moderate correlation (0.49) between the standard skin prick test (SPT) and the QSPT (P < 0.001). We found weak negative correlation (-0.27) between the QSPT and the CPT (P < 0.001). We found no correlation between seasonal symptom, use of rescue medication or quality of life (QOL) scores and pre-seasonal QSPT or CPT. Conclusion In the assessment of seasonal rhinoconjunctivitis, quantitative skin and conjunctival allergen challenge tests are strongly reproducible, although there is no correlation between these tests and seasonal symptom, use of rescue medication or QOL scores. 相似文献
89.
Postictal Language Dysfunction in Patients with Right or Bilateral Hemispheric Language Localization 总被引:2,自引:1,他引:1
Summary: Purpose : As shown previously, when temporal lobe complex partial seizures (TLCPS) originate from the language dominant hemisphere, patients cannot read a test phrase correctly within 60 s of the end of the ictal discharge. We wished to assess whether postictal language testing results discordant with this pattern identified patients with non-left (right hemisphere or mixed) language dominance.
Methods : Since 1988, all patients undergoing video/EEG monitoring at our institution have been given a test phrase to read aloud as soon as a seizure is detected. Inclusion criteria for this study were (a) postictal language testing within 60 s of seizure end for at least one TLCPS, (b) >90% seizure reduction after anterior temporal lobectomy with 2-year minimum follow- follow- up, and (c) language localization by either intracarotid amobarbital test (IAT) or direct electrical stimulation of left hemisphere cortex.
Results : Two hundred twenty-four seizures in 64 patients were analyzed. Discordant postictal language patterns were noted in 10 of 11 patients with IAT documented non-left language dominance and in 15 of 53 with left dominance (p = 0.006; sensitivity 90.9%, specificity 71.7%).
Conclusions : Postictal language testing accurately identifies patients with non-left language dominance and may be useful in selecting appropriate patients for IAT. 相似文献
Methods : Since 1988, all patients undergoing video/EEG monitoring at our institution have been given a test phrase to read aloud as soon as a seizure is detected. Inclusion criteria for this study were (a) postictal language testing within 60 s of seizure end for at least one TLCPS, (b) >90% seizure reduction after anterior temporal lobectomy with 2-year minimum follow- follow- up, and (c) language localization by either intracarotid amobarbital test (IAT) or direct electrical stimulation of left hemisphere cortex.
Results : Two hundred twenty-four seizures in 64 patients were analyzed. Discordant postictal language patterns were noted in 10 of 11 patients with IAT documented non-left language dominance and in 15 of 53 with left dominance (p = 0.006; sensitivity 90.9%, specificity 71.7%).
Conclusions : Postictal language testing accurately identifies patients with non-left language dominance and may be useful in selecting appropriate patients for IAT. 相似文献
90.
T. Eger L. Zller H.-P. Müller S. Hoffmann D. Lobinsky 《European journal of oral sciences》1996,104(2):112-117
Actinobacillus actinomycetemcomitans has been implicated in the pathogenesis of several forms of early onset and refractory adult periodontitis. Early diagnosis of colonization of the oral cavity might be of importance in order to initiate preventive measures. The aim of the present study was to determine the potential diagnostic value of oral mucosal and salivary tests to identify, among healthy young men with no or minor periodontal disease, individuals colonized by A. actinomycetemcomitans. Two hundred and one male recruits. 18–25 yr of age, took part in the present study. Mean values of periodontal parameters suggested only minor periodontal disease. Of the sites, 64.8±17.6% (mean ± SD) had a periodonta) probing depth (PPD) of 1 or 2 mm. only 1.6±2.9% deep sites of 5 mm were detected. More than 1000 subgingival and extracrevicular samples were selectively cultivated for A. actinomycetemcomitans. The organism was isolated in 55 subjects (21%). The odds for presence of at least 1 deep site of 5 mm was increased by a factor 1.99 if A. actinomycetemcomitans could be recovered. In identifying subjects colonized by A. actinomycetemcomitans. diagnostic test parameters sensitivity and predictive value for a negative test were 74.5±5.9% and 91.1±2.3%', respectively, for both saliva and dorsum of tongue samples. In contrast, pooled subgingival plaque from mesial surfaces of 1st molars was only 34.5±6.4% sensitive: the negative predictive value was 80.2±3.0%. The results point to a high diagnostic value of oral mucosal and especially saliva samples to identify young adult individuals colonized by A. actinomycetemcomitans. 相似文献