全文获取类型
收费全文 | 3101篇 |
免费 | 194篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 188篇 |
妇产科学 | 55篇 |
基础医学 | 421篇 |
口腔科学 | 108篇 |
临床医学 | 241篇 |
内科学 | 726篇 |
皮肤病学 | 51篇 |
神经病学 | 137篇 |
特种医学 | 497篇 |
外科学 | 365篇 |
综合类 | 33篇 |
预防医学 | 168篇 |
眼科学 | 28篇 |
药学 | 123篇 |
中国医学 | 10篇 |
肿瘤学 | 120篇 |
出版年
2022年 | 19篇 |
2021年 | 53篇 |
2020年 | 34篇 |
2019年 | 37篇 |
2018年 | 68篇 |
2017年 | 40篇 |
2016年 | 50篇 |
2015年 | 61篇 |
2014年 | 55篇 |
2013年 | 119篇 |
2012年 | 111篇 |
2011年 | 118篇 |
2010年 | 146篇 |
2009年 | 111篇 |
2008年 | 110篇 |
2007年 | 107篇 |
2006年 | 97篇 |
2005年 | 89篇 |
2004年 | 81篇 |
2003年 | 82篇 |
2002年 | 73篇 |
2001年 | 65篇 |
2000年 | 89篇 |
1999年 | 66篇 |
1998年 | 148篇 |
1997年 | 129篇 |
1996年 | 134篇 |
1995年 | 96篇 |
1994年 | 78篇 |
1993年 | 86篇 |
1992年 | 44篇 |
1991年 | 49篇 |
1990年 | 29篇 |
1989年 | 72篇 |
1988年 | 55篇 |
1987年 | 57篇 |
1986年 | 52篇 |
1985年 | 53篇 |
1984年 | 32篇 |
1983年 | 35篇 |
1982年 | 36篇 |
1981年 | 21篇 |
1980年 | 37篇 |
1979年 | 14篇 |
1978年 | 18篇 |
1977年 | 20篇 |
1976年 | 24篇 |
1975年 | 29篇 |
1969年 | 8篇 |
1966年 | 10篇 |
排序方式: 共有3318条查询结果,搜索用时 15 毫秒
1.
2.
B. Bogin P. Smith A.B. Orden M.I. Varela Silva J. Loucky 《American journal of human biology》2002,14(6):753-761
Maya families from Guatemala migrated to the United States in record numbers from the late 1970s to the early 1990s. Births to Maya immigrant women have created a sizable number of Maya American children. The height and sitting height of 5 to 12 years children (n = 431) were measured in 1999 and 2000. Leg length was estimated and the sitting height ratio was calculated. These data were compared with a sample of Maya children living in Guatemala measured in 1998 (n = 1,347). Maya American children are currently 11.54 cm taller and 6.83 cm longer‐legged, on average, than Maya children living in Guatemala. Consequently, the Maya Americans have a significantly lower average sitting height ratio (i.e., relatively longer legs in proportion to length of the head and trunk) than do the Maya in Guatemala. These results add support to the hypothesis that both the height and body proportions of human populations are sensitive indicators of the quality of the environment for growth. Am. J. Hum. Biol. 14:753–761, 2002. © 2002 Wiley‐Liss, Inc. 相似文献
3.
4.
JA HYEON KU CHEOL KWAK SEUNG-JUNE OH EUNSIK LEE SANG EUN LEE JAE-SEUNG PAICK 《International journal of urology》2004,11(7):489-493
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population. 相似文献
5.
6.
7.
S Varela J Mendez C González de la Cuesta I Iglesias C González M Menéndez 《Journal of investigational allergology & clinical immunology》2003,13(2):124-130
A retrospective study was performed to describe the features of the pollinosis caused by Betula in the area of Ourense, Spain. The pollen count was carried out with a Lanzoni volumetric Hirts spore trap (1993-2000). The Betula pollen represented 5% over the annual total (annual mean quantity: 965 grains). It was present in the air from March to mid-May. The highest peaks took place in April (maximum values mean: 131 grains/m3). The medical records of 222 patients (mean age 25.66 years) diagnosed with pollinosis (1998-2000), who lived at less than 30 km. from the spore trap, were reviewed. In all of them, the skin-prick test (SPT) was carried out with pollen allergens. The percentages of positive SPT were: Lolium perenne, 91.89% (16.6% monosensitized); Plantago lanceolata, 71.17% (1.26% monosensitized); Betula alba, 41.89% (10.75% monosensitized); Platanus hybrida, 34.95%; Olea europea, 10.36%; and Parietaria judaica, 6.3%. The mean age of Betula monosensitized patients was 44.7 years. The majority of them had symptoms in March-April, 40% had asthma symptoms, 80% had lived in Central Europe, and 30% of them presented an oral allergy syndrome to fruits. There were 41.93% of the patients with positive SPT to Betula pollen who had asthma symptoms, in comparison with 23.25% of the patients with negative SPT to Betula (p = 0.0034). There were 20.28% of the patients with positive SPT to Betula pollen, who had lived in Central Europe, in comparison with 4.27% of the patients with negative SPT to Betula, p: 0.00049. The relative risk of sensitization was 2.05. CONCLUSIONS: Betula pollen was the second cause of clinical pollinosis in our patients, after grass, being responsible of the symptoms in the early spring, in a small number of the patients in their forties. The presence of asthma was higher in Betula sensitized patients, and the residence in Central Europe was a sensitization risk factor. 相似文献
8.
9.
10.