全文获取类型
收费全文 | 1086820篇 |
免费 | 86489篇 |
国内免费 | 2895篇 |
专业分类
耳鼻咽喉 | 15229篇 |
儿科学 | 30678篇 |
妇产科学 | 29379篇 |
基础医学 | 153467篇 |
口腔科学 | 29651篇 |
临床医学 | 97986篇 |
内科学 | 212011篇 |
皮肤病学 | 20150篇 |
神经病学 | 91732篇 |
特种医学 | 42799篇 |
外国民族医学 | 182篇 |
外科学 | 169848篇 |
综合类 | 27821篇 |
现状与发展 | 2篇 |
一般理论 | 566篇 |
预防医学 | 86400篇 |
眼科学 | 26309篇 |
药学 | 79943篇 |
6篇 | |
中国医学 | 1918篇 |
肿瘤学 | 60127篇 |
出版年
2021年 | 9837篇 |
2019年 | 9986篇 |
2018年 | 12640篇 |
2017年 | 9777篇 |
2016年 | 10939篇 |
2015年 | 12942篇 |
2014年 | 18778篇 |
2013年 | 27353篇 |
2012年 | 38676篇 |
2011年 | 40581篇 |
2010年 | 23243篇 |
2009年 | 21476篇 |
2008年 | 37330篇 |
2007年 | 40042篇 |
2006年 | 39810篇 |
2005年 | 39454篇 |
2004年 | 37935篇 |
2003年 | 36133篇 |
2002年 | 34349篇 |
2001年 | 37803篇 |
2000年 | 37980篇 |
1999年 | 33019篇 |
1998年 | 11942篇 |
1997年 | 10810篇 |
1996年 | 10435篇 |
1995年 | 9890篇 |
1994年 | 9273篇 |
1992年 | 27836篇 |
1991年 | 27200篇 |
1990年 | 26552篇 |
1989年 | 25626篇 |
1988年 | 24135篇 |
1987年 | 23773篇 |
1986年 | 22659篇 |
1985年 | 22013篇 |
1984年 | 17511篇 |
1983年 | 15041篇 |
1982年 | 10079篇 |
1981年 | 9368篇 |
1979年 | 17400篇 |
1978年 | 12783篇 |
1977年 | 10762篇 |
1976年 | 9869篇 |
1975年 | 10555篇 |
1974年 | 13074篇 |
1973年 | 12503篇 |
1972年 | 11845篇 |
1971年 | 10941篇 |
1970年 | 10444篇 |
1969年 | 10074篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
Peter Stone MD FRNZCOG FRCOG David Cook FRNZCOG MRCOG John Hutton PhD FRNZCOG FRCOG Gordon Purdie BSc Henry Murray MD FRNZCOG MRCOG Lauren Harcourt MPP BA 《The Australian & New Zealand journal of obstetrics & gynaecology》1995,35(1):32-37
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects. 相似文献
74.
Juin Fok-Seang Linda C. Smith-Thomas Sally Meiners Elizabeth Muir Jian-Sheng Du Elizabeth Housden Alan R. Johnson Andreas Faissner Herbert M. Geller Roger J. Keynes John H. Rogers James W. Fawcett 《Brain research》1995,689(2):207
The adult mammalian central nervous system (CNS) lacks the capacity to support axonal regeneration. There is increasing evidence to suggest that astrocytes, the major glial population in the CNS, may possess both axon-growth promoting and axon-growth inhibitory properties and the latter may contribute to the poor regenerative capacity of the CNS. In order to examine the molecular differences between axon-growth permissive and axon-growth inhibitory astrocytes, a panel of astrocyte cell lines exhibiting a range of axon-growth promoting properties was generated and analysed. No clear correlation was found between the axon-growth promoting properties of these astrocyte cell lines with: (i) the expression of known neurite-outgrowth promoting molecules such as laminin, fibronectin andN-cadherin; (ii) the expression of known inhibitory molecules such tenascin and chondroitin sulphate proteoglycan; (iii) plasminogen activator and plasminogen activator inhibitor activity; and (iv) growth cone collapsing activity. EM studies on aggregates formed from astrocyte cell lines, however, revealed the presence of an abundance of extracellular matrix material associated with the more inhibitory astrocyte cell lines. When matrix deposited by astrocyte cell lines was assessed for axon-growth promoting activity, matrix from permissive lines was found to be a good substrate, whereas matrix from the inhibitory astrocyte lines was a poor substrate for neuritic growth. Our findings, taken together, suggest that the functional differences between the permissive and the inhibitory astrocyte cell lines reside largely with the ECM. 相似文献
75.
David A. Hughes Graham C. Smith Joyce E. Davidson Anna V. Murphy T. James Beattie 《Pediatric nephrology (Berlin, Germany)》1996,10(4):445-447
. Neutrophil-mediated tissue damage has been implicated in the pathogenesis of diarrhoea-associated haemolytic uraemic syndrome
(D+ HUS). This study evaluates priming and activation of the neutrophil oxidative burst in D+ HUS using chemiluminescent techniques.
Peripheral blood neutrophils from 11 children with acute D+ HUS were examined. No difference was found in the oxidative burst
of neutrophils from patients and controls. Serum elastase levels were measured in 8 patients and found to be significantly
elevated. Although elastase results suggest neutrophil activation, chemiluminescence studies do not confirm this in the peripheral
blood neutrophil. This does not support a significant role for circulating agents in priming and activating the peripheral
blood neutrophil.
Received August 17, 1995; received in revised form and accepted November 27, 1995 相似文献
76.
77.
David A. Rothenberger M.D. 《Diseases of the colon and rectum》1997,40(5):632-635
78.
Abstract Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment. 相似文献
79.
80.