全文获取类型
收费全文 | 872篇 |
免费 | 176篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 23篇 |
妇产科学 | 3篇 |
基础医学 | 167篇 |
口腔科学 | 15篇 |
临床医学 | 78篇 |
内科学 | 133篇 |
皮肤病学 | 6篇 |
神经病学 | 44篇 |
特种医学 | 194篇 |
外科学 | 82篇 |
综合类 | 78篇 |
预防医学 | 122篇 |
眼科学 | 4篇 |
药学 | 73篇 |
中国医学 | 1篇 |
肿瘤学 | 21篇 |
出版年
2021年 | 7篇 |
2018年 | 14篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 38篇 |
2012年 | 34篇 |
2011年 | 20篇 |
2010年 | 20篇 |
2009年 | 26篇 |
2008年 | 24篇 |
2007年 | 22篇 |
2006年 | 24篇 |
2005年 | 29篇 |
2004年 | 36篇 |
2003年 | 31篇 |
2002年 | 23篇 |
2001年 | 25篇 |
2000年 | 27篇 |
1999年 | 27篇 |
1998年 | 23篇 |
1997年 | 25篇 |
1996年 | 20篇 |
1995年 | 12篇 |
1994年 | 24篇 |
1993年 | 10篇 |
1992年 | 28篇 |
1991年 | 18篇 |
1990年 | 17篇 |
1989年 | 18篇 |
1988年 | 24篇 |
1987年 | 30篇 |
1986年 | 29篇 |
1985年 | 27篇 |
1984年 | 19篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 8篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1977年 | 19篇 |
1976年 | 20篇 |
1975年 | 20篇 |
1974年 | 14篇 |
1973年 | 21篇 |
1971年 | 17篇 |
1970年 | 8篇 |
1969年 | 10篇 |
1968年 | 15篇 |
1967年 | 10篇 |
排序方式: 共有1049条查询结果,搜索用时 15 毫秒
11.
Rats of 18 genotypes derived from the Roman selected strains were tested for inhibition of feeding due to novelty (hyponeophagia) in the absence or presence of 1 mg/kg diazepam. The resulting data from three behavioral indices were subjected to the Hayman [(1954). Biometrics10:235–244], variance/covariance, Mendelian cross, and single-test cross analyses. Additive genetic variation, directional dominance for high neophobia, and some nonallelic interaction were detected. The genetic architecture of the separate behavioral indices, and its modification in the drugged subjects, was discussed in relation to evolutionary adaptation and the anxiolytic and appetite-enhancing actions of the drug.This work was jointly funded by the Science and Engineering Research Council and Imperial Chemical Industries Pharmaceuticals Ltd. through an award to R.A.S. 相似文献
12.
Franois Trudeau Roy J. Shephard Stephane Bouchard Louis Laurencelle 《American journal of human biology》2003,15(2):187-191
This study evaluated intraindividual child–adult and interindividual child–parent relationships of body mass index (BMI) using data from the Trois‐Rivières semilongitudinal study of growth and development. Intraindividual correlations between age 12 and 35 years were substantial (r2 = 36% of variance in women, 30% of variance in men). Interindividual child–parent correlations for mothers and fathers age 36.6 ± 0.4 and 39.5 ± 0.4 years, respectively, were very low to low for daughters age 12 years (r = 0.09, NS and 0.34, P < 0.001 vs. father and mother, respectively) but all very low for sons age 12 years (r = 0.07, NS and 0.16, NS vs. father and mother, respectively). A multiple regression analysis predicted adult BMI from the individual's BMI at 10, 11, 12 years plus the maternal and paternal BMIs as calculated from self‐reported heights and weights. The BMI at age 12 years was a better predictor of adult BMI than the parental BMI in both men and women (P < 0.001) and multivariate analysis revealed that this index at age 12 years was the sole significant predictor of adult BMI for both men and women. The results from our study do not support the hypothesis that parental BMI is a stronger predictor of adult BMI than childhood BMI. However, useful information for the prediction and prevention of adult overweight can be obtained from the BMI at age 12 years. Our results suggest that environmental influences may be the major factor in the present obesity epidemic. Am. J. Hum. Biol. 15:187–191, 2003. © 2003 Wiley‐Liss, Inc. 相似文献
13.
14.
V. Rogiers A. Callaerts A. Vercruysse M. Akrawi E. Shephard I. Phillips 《Pharmacy World & Science》1992,14(3):127-131
Male Wistar rats werein vivo exposed for 2 weeks to 100 g/ml sodium valproate by subcutaneous implantation of osmotic pumps and hepatocytes were isolated. As anin vitro model co-cultures of rat hepatocytes with epithelial cells were daily treated with valproate (25, 50, 100, 200g/ml) for 2 weeks. In both models the cytochrome P-450 content and the enzymatic activities of 7-ethoxycoumarinO-deethylase, aldrin epoxidase and glutathioneS-transferase were determined in valproate-treated hepatocytes, in controls and in phenobarbital-induced cells. It appeared that in both systems the cytochrome P-450 content and the 7-ethoxycoumarinO-deethylase activity increased significantly after valproate treatment. On the other hand, the activities of aldrin epoxidase and glutathioneS-transferase decreased. A cDNA probe, encoding rat P450IIB2 was used to determine whether mRNAs encoding the P450IIB subfamily were induced by valproate. It became clear that the inducing effect of valproate was even more pronouncedin vitro thanin vivo. 相似文献
15.
16.
Anne EG Lenferink Joanne Magoon Christiane Cantin Maureen D O'Connor-McCourt 《Breast cancer research : BCR》2004,6(5):R514
Introduction
This report describes the isolation and characterization of three new murine mammary epithelial cell lines derived from mammary tumors from MMTV (mouse mammary tumor virus)/activated Neu + TβRII-AS (transforming growth factor [TGF]-β type II receptor antisense RNA) bigenic mice (BRI-JM01 and BRI-JM05 cell lines) and MMTV/activated Neu transgenic mice (BRI-JM04 cell line). 相似文献17.
J M Furman J A Goebel M A Hamid J Hanson V Honrubia R Peterka T Schumann N T Shephard C W Stockwell C Wall 《Otolaryngology--head and neck surgery》2000,122(1):23-30
Standardization of rotational chair testing across laboratories has not been achieved because of differences in test protocol and analysis algorithms. The Interlaboratory Rotational Chair Study Group was formed to investigate these differences. Its first study demonstrated significant variability in calculated results using actual patient data files. No estimation of accuracy could be made, however, because the "true" values of response parameters were unknown. In this study we used simulated "patient" data files to further explore the differences among analysis algorithms. We found a high degree of agreement and accuracy across laboratories using automated analysis of high signal-to-noise/low-artifact data for gain, phase, and asymmetry. Variability increased significantly for the lower signal-to-noise ratio/higher artifact files. Operator intervention generally improved accuracy and decreased variability, but there were cases in which operator intervention reduced accuracy. 相似文献
18.
19.
Geoffrey Wright MASc Philip Randell MTDE Roy J. Shephard MD PhD 《Archives of environmental & occupational health》2013,68(6):349-354
Eighty milliliters of carbon monoxide (CO) or 80 ml of air was administered doubleblind to 50 adults (32 men, 18 women). Blood carboxyhemoglobin (COHb) levels increased by 3.4% in those receiving CO. Brake reaction time, night vision, glare vision, glare recovery, hand-steadiness, and depth perception all showed small and individually insignificant deterioration in the group receiving CO; grouping data in a nonparametric analysis, the performance difference became significant (P < .005). During operation of a driving simulator, the CO-exposed group showed a highly significant deficit in “careful driving” skills (P < .005), with a statistically insignificant facilitation of emergency-type movements. Since a 3.4% increase of COHb level is sufficient to prejudice safe driving, there is a need to revise the permitted eight-hour industrial CO exposure level of 50 ppm. 相似文献
20.
The "early-labeled" peak (ELP) of 14CO excretion following injection of glycine-2-14C was used to study erythropoiesis in a patient with sideroblastic anemia and in four subjects with myeloproliferative disorders. The ELP was greatly enlarged in all patients, as compared with a normal volunteer. The contour of the peaks from the hematologically abnormal subjects suggested the presence of increased erythroid heme degradation. In the patient with sideroblastic anemia, all hours of the early peak were significantly reduced after transfusion. This was interpreted to mean that even the earliest or "nonerythroid" phase of the peak is influenced by erythropoietic activity, at least under conditions of erythropoietic stress. 相似文献