全文获取类型
收费全文 | 2044706篇 |
免费 | 144378篇 |
国内免费 | 4217篇 |
专业分类
耳鼻咽喉 | 30171篇 |
儿科学 | 59768篇 |
妇产科学 | 56461篇 |
基础医学 | 288823篇 |
口腔科学 | 62319篇 |
临床医学 | 177395篇 |
内科学 | 395298篇 |
皮肤病学 | 44982篇 |
神经病学 | 161033篇 |
特种医学 | 80809篇 |
外国民族医学 | 501篇 |
外科学 | 319418篇 |
综合类 | 47720篇 |
现状与发展 | 7篇 |
一般理论 | 644篇 |
预防医学 | 143288篇 |
眼科学 | 48725篇 |
药学 | 155751篇 |
7篇 | |
中国医学 | 5197篇 |
肿瘤学 | 114984篇 |
出版年
2018年 | 18842篇 |
2016年 | 16785篇 |
2015年 | 18841篇 |
2014年 | 26174篇 |
2013年 | 39408篇 |
2012年 | 52188篇 |
2011年 | 55432篇 |
2010年 | 32937篇 |
2009年 | 31694篇 |
2008年 | 53215篇 |
2007年 | 56889篇 |
2006年 | 57868篇 |
2005年 | 56166篇 |
2004年 | 55341篇 |
2003年 | 53379篇 |
2002年 | 52386篇 |
2001年 | 101512篇 |
2000年 | 104328篇 |
1999年 | 88112篇 |
1998年 | 23188篇 |
1997年 | 20846篇 |
1996年 | 20233篇 |
1995年 | 19078篇 |
1994年 | 17788篇 |
1993年 | 16637篇 |
1992年 | 67855篇 |
1991年 | 65587篇 |
1990年 | 64194篇 |
1989年 | 62408篇 |
1988年 | 57813篇 |
1987年 | 56716篇 |
1986年 | 53773篇 |
1985年 | 51436篇 |
1984年 | 37921篇 |
1983年 | 32392篇 |
1982年 | 18585篇 |
1981年 | 16818篇 |
1979年 | 35947篇 |
1978年 | 25304篇 |
1977年 | 21998篇 |
1976年 | 19675篇 |
1975年 | 22167篇 |
1974年 | 26441篇 |
1973年 | 25544篇 |
1972年 | 24296篇 |
1971年 | 22772篇 |
1970年 | 21679篇 |
1969年 | 20634篇 |
1968年 | 19225篇 |
1967年 | 17280篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
S F Wong A Lee-Tannock D Amaraddio F Y Chan H D McIntyre 《Ultrasound in obstetrics & gynecology》2006,28(7):934-938
OBJECTIVE: To assess the effect of glucose control on the rate of growth of fetuses in women with pregestational diabetes mellitus (Types 1 and 2). METHODS: All pregestational diabetic women booked at Mater Mothers' Hospital, Brisbane, Australia, between 1 January 1994 and 31 December 2002, were included. Pregnancies with congenital fetal anomalies, multiple pregnancies, and pregnancies terminated prior to 20 weeks' gestation were excluded. Dating scans were performed before 14 weeks' gestation and serial scans were performed at 18, 24, 28, 32 and 36 weeks. Fetal parameters, including biparietal diameter, femur length and abdominal circumference, were recorded. The daily growth rates for biparietal diameter, femur length, and fetal abdominal area were calculated and compared with those in a low-risk (non-diabetic) population. The growth rates in fetuses of women with satisfactory diabetic control (HbA1c < 6.5%) and unsatisfactory control (HbA1c > or = 6.5%) in the three trimesters were compared. RESULTS: A total of 174 diabetic pregnancies were included and a total of 997 ultrasound scans were performed. The growth rates for fetuses of mothers with diabetes mellitus were significantly higher than for those in the low-risk population. The z-scores for biparietal diameter, femur length, and fetal abdominal area were 0.18, 0.59 and 1.44, respectively. Fetuses of diabetic mothers with high HbA1c in the first trimester had significantly greater fetal abdominal area growth rate than those with normal HbA1c (fetal abdominal area z-score of 1.7 vs. 0.75, P = 0.009). Although the fetal abdominal area z-scores in fetuses of diabetic mothers with high HbA1c in the second or third trimesters were also higher than those with normal HbA1c levels, the differences did not reach statistical significance. Maternal obesity did not influence the fetal growth rate. CONCLUSION: The rate of growth of fetuses of diabetic mothers differs from that of the normal population. Growth acceleration persists until the late third trimester. Moreover, periconceptional glucose control appears to have a significant effect on accelerated growth of the fetal abdominal area. 相似文献
62.
63.
64.
Published data devoted to making and characterization of the properties of polymeric wound dressings with proteolytic action
are reviewed. These data are indicative of individual dependence of the physicochemical properties, activity, and stability
of each particular enzyme on the type of polymer matrix and the method of immobilization. In order to obtain wound dressings,
which are active in physiological medium and retain their activity upon sterilization, it is necessary to optimize the composition
and characteristics of a polymer matrix and the enzyme included into its structure.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 8, pp. 24–28, August, 2006. 相似文献
65.
Ohne Zusammenfassung 相似文献
66.
F Pitta T Troosters V S Probst M A Spruit M Decramer R Gosselink 《The European respiratory journal》2006,27(5):1040-1055
Accurate assessment of the amount and intensity of physical activity in daily life is considered very important due to the close relationship between physical activity level, health, disability and mortality. For this reason, assessment of physical activity in daily life has gained interest in recent years, especially in sedentary populations, such as patients with chronic obstructive pulmonary disease (COPD). The present article aims to compare and discuss the two kinds of instruments more commonly used to quantify the amount of physical activity performed by COPD patients in daily life: subjective methods (questionnaires, diaries) and motion sensors (electronic or mechanical methods). Their characteristics are summarised and evidence of their validity, reliability and sensitivity is discussed, when available. Subjective methods have practical value mainly in providing the patients' view on their performance in activities of daily living and functional status. However, care must be taken when using subjective methods to accurately quantify the amount of daily physical activity performed. More accurate information is likely to be available with motion sensors rather than questionnaires. The selection of which motion sensor to use for quantification of physical activity in daily life should depend mainly on the purpose of its use. 相似文献
67.
R H Green C E Brightling S McKenna B Hargadon N Neale D Parker C Ruse I P Hall I D Pavord 《The European respiratory journal》2006,27(6):1144-1151
There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation. 相似文献
68.
C T Gan G P McCann J T Marcus S A van Wolferen J W Twisk A Boonstra P E Postmus A Vonk-Noordegraaf 《The European respiratory journal》2006,28(6):1190-1194
The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function. 相似文献
69.
70.
Severe adverse effects during the use of ovulation inhibitors occur mostly in women who have an elevated risk for the development of certain diseases owing to hereditary or acquired factors. By means of a careful personal or family history analysis as well as specific laboratory examinations, an existing predisposition may frequently be diagnosed and the individual risk associated with the use of oral contraceptive inhibitors may be estimated. The present contribution describes the potential effects of treatment with ovulation inhibitors on women with thrombophilia, cardiovascular disease, diabetes mellitus, dyslipidemia, overweight or underweight, tumors, psychiatric and neurological diseases and autoimmune disease. The hormonal methods and non-hormonal alternatives available for contraception are elucidated according to existing lesions and risk factors and the advantages and disadvantages are discussed. 相似文献