全文获取类型
收费全文 | 1100405篇 |
免费 | 87851篇 |
国内免费 | 2919篇 |
专业分类
耳鼻咽喉 | 15247篇 |
儿科学 | 30928篇 |
妇产科学 | 29944篇 |
基础医学 | 155537篇 |
口腔科学 | 29950篇 |
临床医学 | 99765篇 |
内科学 | 214511篇 |
皮肤病学 | 20358篇 |
神经病学 | 92984篇 |
特种医学 | 43143篇 |
外国民族医学 | 182篇 |
外科学 | 171571篇 |
综合类 | 28128篇 |
现状与发展 | 2篇 |
一般理论 | 581篇 |
预防医学 | 87859篇 |
眼科学 | 26480篇 |
药学 | 81209篇 |
6篇 | |
中国医学 | 1946篇 |
肿瘤学 | 60844篇 |
出版年
2021年 | 10003篇 |
2019年 | 10164篇 |
2018年 | 12860篇 |
2017年 | 9917篇 |
2016年 | 11108篇 |
2015年 | 13149篇 |
2014年 | 19046篇 |
2013年 | 27809篇 |
2012年 | 39322篇 |
2011年 | 41225篇 |
2010年 | 23605篇 |
2009年 | 21808篇 |
2008年 | 37862篇 |
2007年 | 40701篇 |
2006年 | 40413篇 |
2005年 | 39947篇 |
2004年 | 38527篇 |
2003年 | 36667篇 |
2002年 | 34865篇 |
2001年 | 38299篇 |
2000年 | 38461篇 |
1999年 | 33468篇 |
1998年 | 12111篇 |
1997年 | 10963篇 |
1996年 | 10571篇 |
1995年 | 10030篇 |
1994年 | 9384篇 |
1992年 | 28183篇 |
1991年 | 27522篇 |
1990年 | 26853篇 |
1989年 | 25962篇 |
1988年 | 24422篇 |
1987年 | 24024篇 |
1986年 | 22948篇 |
1985年 | 22214篇 |
1984年 | 17683篇 |
1983年 | 15258篇 |
1982年 | 10195篇 |
1981年 | 9465篇 |
1979年 | 17558篇 |
1978年 | 12903篇 |
1977年 | 10864篇 |
1976年 | 9972篇 |
1975年 | 10645篇 |
1974年 | 13167篇 |
1973年 | 12629篇 |
1972年 | 11948篇 |
1971年 | 11053篇 |
1970年 | 10550篇 |
1969年 | 10163篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
M D Silverstein D A Albert N M Hadler M W Ropes 《Journal of clinical epidemiology》1988,41(7):623-633
132.
133.
134.
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
135.
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
136.
Pharmacokinetics and pharmacodynamics of benazepril hydrochloride in patients with major proteinuria
Ch. Schweizer G. Kaiser W. Dieterle J. Mann 《European journal of clinical pharmacology》1993,44(5):463-466
Summary We have investigated whether the pharmacokinetics and pharmacodynamics of the ACE inhibitor benazepril hydrochloride are altered with proteinuria by studying 8 patients with major proteinuria of different causes who were given a single dose of 10 mg p.o.The maximum plasma concentration of benazepril was found between 0.5 and 2 h after dosing (median 1 h). Its elimination was almost complete within 6 h. Peak plasma levels of benazeprilat, the active metabolite of benazepril, were observed between 1 and 6 h (median 2.5 h). The elimination of benazeprilat from plasma was biphasic, with mean initial and terminal half-lives of 3.0 and 17.3 h, respectively. On average, the pharmacokinetic parameters of benazepril and benazeprilat in the patients did not differ from those in a historical control group of healthy volunteers, but intersubject variability in the AUC and half-lives of benazeprilat was greater in the patients.Plasma ACE was completely inhibited from 1.5 to 6 h after dosing, and at 48 h the mean inhibition was still 42 %. Plasma renin showed substantial intersubject variation. Mean supine blood pressure (systolic/diastolic) was reduced from baseline by a maximum of 18/13 mm Hg at 6 h. Proteinuria was diminished after benazepril in 7 patients.In conclusion, the results of this study suggest that proteinuria in the nephrotic range does not require a change in benazepril dosage. 相似文献
137.
P. A. Milligan P. E. McGill C. W. Howden A. W. Kelman B. Whiting 《European journal of clinical pharmacology》1993,45(6):507-512
Summary A randomised crossover study was performed in subjects with rheumatoid arthritis (or other arthropathies) to investigate if any alteration in the steady pharmacokinetics of the NSAID piroxicam (a drug which is extensively metabolised via cytochrome P450) or its major metabolites occurred as a result of coadministering either cimetidine or nizatidine.Twelve females and 2 males with mean age, weight, and albumin concentrations of 58 years, 61 kg, and 40 g·L–1 respectively, completed the study. Comparisons were made between the following parameters: plasma piroxicam AUCs [AUC0-24(P)], plasma 5-hydroxypiroxicam AUCs [AUC0-24(5-OHP)], the ratio of these i.e. AUC0-24(5-OHP):AUC0-24(p), the % piroxicam daily dose excreted in urine as 5-hydroxypiroxicam (before and after glucuronidase incubation); and the mean of the steady state trough piroxicam, and 5-hydroxypiroxicam concentrations (obtained during each study phase in addition to the wash-out period).A statistically significant difference as a result of initiating either cimetidine or nizatidine was obtained only for the ratio AUC0-23(5-OHP):AUC0-24(P). This was indicative of a weak potential to inhibit piroxicam hydroxylation.No clinically significant alteration in the steady state pharmacokinetics of piroxicam occurred in these subjects as a result of cimetidine or nizatidine coadministration. Consequently it is unlikely that any adverse events would arise from these combinations. 相似文献
138.
Sarah A. Taylor Jacqueline Benedetti David Schuller Stephen P. Richman Goronwy O. Broun Alexander Hantel 《Investigational new drugs》1993,11(2-3):227-229
Summary Twenty-two patients with recurrent or metastatic squamous cell carcinoma of the head and neck were treated with piroxantrone 150 mg/m2 intravenously every 21 days. There were no objective responses. The 95% upper confidence bound for response is 15%. Primary toxicity was hematologic. 相似文献
139.
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
140.