全文获取类型
收费全文 | 1777835篇 |
免费 | 149060篇 |
国内免费 | 4703篇 |
专业分类
耳鼻咽喉 | 23784篇 |
儿科学 | 57840篇 |
妇产科学 | 48175篇 |
基础医学 | 242966篇 |
口腔科学 | 53314篇 |
临床医学 | 174494篇 |
内科学 | 353622篇 |
皮肤病学 | 41569篇 |
神经病学 | 141485篇 |
特种医学 | 66856篇 |
外国民族医学 | 242篇 |
外科学 | 272399篇 |
综合类 | 39038篇 |
现状与发展 | 42篇 |
一般理论 | 531篇 |
预防医学 | 136156篇 |
眼科学 | 42119篇 |
药学 | 124344篇 |
7篇 | |
中国医学 | 4483篇 |
肿瘤学 | 108132篇 |
出版年
2021年 | 14980篇 |
2019年 | 15103篇 |
2018年 | 25824篇 |
2017年 | 21630篇 |
2016年 | 23490篇 |
2015年 | 25879篇 |
2014年 | 35197篇 |
2013年 | 48459篇 |
2012年 | 55684篇 |
2011年 | 58206篇 |
2010年 | 38646篇 |
2009年 | 38602篇 |
2008年 | 54339篇 |
2007年 | 56709篇 |
2006年 | 58205篇 |
2005年 | 54156篇 |
2004年 | 51850篇 |
2003年 | 49014篇 |
2002年 | 47154篇 |
2001年 | 93354篇 |
2000年 | 94610篇 |
1999年 | 78434篇 |
1998年 | 21550篇 |
1997年 | 18931篇 |
1996年 | 19098篇 |
1995年 | 18179篇 |
1994年 | 16222篇 |
1993年 | 14863篇 |
1992年 | 58005篇 |
1991年 | 55796篇 |
1990年 | 53408篇 |
1989年 | 51176篇 |
1988年 | 46564篇 |
1987年 | 45256篇 |
1986年 | 42520篇 |
1985年 | 40227篇 |
1984年 | 29557篇 |
1983年 | 25170篇 |
1982年 | 14071篇 |
1981年 | 12563篇 |
1979年 | 25578篇 |
1978年 | 17688篇 |
1977年 | 15011篇 |
1976年 | 13944篇 |
1975年 | 14619篇 |
1974年 | 17697篇 |
1973年 | 16991篇 |
1972年 | 15744篇 |
1971年 | 14498篇 |
1970年 | 13486篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
There are an estimated 200 million users of an illicit drug in the world today. In addition, an estimated 40 million people are infected with the human immunodeficiency virus (HIV) and an estimated 180 million people are infected with the hepatitis C virus (HCV). Both the use of an illicit drug and the co-occurrence of infections are associated with a multitude of medical and health consequences including hormonal and metabolic disorders. Thus, the National Institute on Drug Abuse (NIDA), a part of the National Institutes of Health (NIH) hosted a workshop on hormonal and metabolic disorders of HIV among substance abusers. A number of clinicians and scientists participated and discussed a wide range of issues concerning hormones, nutrition and metabolic complications in HIV and substance abuse. Their observations and the recommendations they made for future research are presented in these proceedings. The readers are encouraged to contact the NIH staff (JK, FV) for technical guidance and programmatic priorities on the subject and directly contact the individual authors for collaborations. 相似文献
94.
95.
96.
J Finsterer E-W Kues S Brunner 《The European journal of contraception & reproductive health care》2006,11(3):237-240
OBJECTIVES: Pseudotumour cerebri has been previously recognized as a neurological side effect of combined oral contraceptives but has not been diagnosed with a delay of 3 years after initiation of combined oral contraceptives. CASE REPORT: A 19-year-old obese woman developed visual impairment and headache, 4 months after starting combined oral contraceptives. Three years later symptoms deteriorated and she presented with prominent tendon-jerks and congested optical-discs. Normal CSF drained with high pressure from the spinal tap. Pseudotumour cerebri was diagnosed. Headache and visual impairment resolved within 3 weeks after discontinuation of combined oral contraceptives. CONCLUSIONS: Combined oral contraceptives-induced pseudotumour cerebri may remain undetected for years. Young, obese women with visual impairment and headache under combined oral contraceptives should undergo immediate neurological and ophthalmological investigation. 相似文献
97.
A Gyang S Mirando 《The European journal of contraception & reproductive health care》2006,11(4):319-321
A 41-year-old Chinese lady had a Gr?fenberg ring in utero for 15 years. During that period of time, she had one normal vaginal delivery a year after insertion, followed by an ectopic pregnancy 12 years later. We discuss the possible mechanism of action of the Gr?fenberg ring and sequelae of its prolonged presence in the uterus. 相似文献
98.
Postpartum fatigue is a normal condition that most women experience. Breastfeeding is often associated in women's minds as contributing to the feeling of overall perceived fatigue, and many women indicate that they have ceased breastfeeding because of fatigue. However, the relationship between feeding choice and perceived fatigue has never been established. Two hundred and fifty-three women participated in a study examining whether perceived fatigue differed for bottle-feeding and breastfeeding women at 3 different times during the postpartum period (2-4 days, 6 weeks, and 12 weeks postpartum). Results showed no significant differences for these 2 groups, suggesting that perceived fatigue during the postpartum period is not dependent on feeding choice. Additional analyses examining other variables with a potential effect were nonsignificant. Because perceived physical fatigue does not appear to be dependent on feeding choice, women should be prepared for the feeling of perceived fatigue during the postpartum period while at the same time be reassured that feeding choice is not correlated. 相似文献
99.
100.
Caterina Proto Daniela Romualdi Rosa Maria Cento Rosario S Spada Giuseppina Di Mento Raffaele Ferri Antonio Lanzone 《Gynecological endocrinology》2006,22(4):213-218
BACKGROUND: In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimer's disease (AD). Indeed, previous studies have documented that glucagon-like peptide 1 (GLP-1) possesses neurotropic properties and can reduce amyloid-beta peptide levels in the brain in vivo. Moreover, the concentrations of neuropeptide Y (NPY) seem to be altered in the cerebrospinal fluid of patients with AD and in subjects with major depression. Finally, among the modifications induced by aging, a dysregulation of the ghrelin-growth hormone (GH) system has been reported. METHODS: We investigated the plasma concentrations of these neuropeptides in 14 subjects with AD. Data obtained from these patients were compared with data from an age- and weight-matched healthy group. RESULTS: No significant differences were found between the two groups in relation to plasma levels of GLP-1, NPY, ghrelin and GH. Peripheral NPY concentrations were positively correlated with ghrelin levels in both groups, and with plasma GLP-1 concentration only in controls. CONCLUSION: On the basis of our results, peripheral levels of these neuropeptides seem not to serve as biochemical markers of AD. 相似文献