全文获取类型
收费全文 | 40030篇 |
免费 | 2325篇 |
国内免费 | 712篇 |
专业分类
耳鼻咽喉 | 787篇 |
儿科学 | 1529篇 |
妇产科学 | 1657篇 |
基础医学 | 4415篇 |
口腔科学 | 344篇 |
临床医学 | 3576篇 |
内科学 | 5790篇 |
皮肤病学 | 340篇 |
神经病学 | 3624篇 |
特种医学 | 1310篇 |
外国民族医学 | 4篇 |
外科学 | 4559篇 |
综合类 | 5060篇 |
现状与发展 | 4篇 |
预防医学 | 3158篇 |
眼科学 | 305篇 |
药学 | 3520篇 |
21篇 | |
中国医学 | 922篇 |
肿瘤学 | 2142篇 |
出版年
2023年 | 453篇 |
2022年 | 818篇 |
2021年 | 1309篇 |
2020年 | 1182篇 |
2019年 | 1109篇 |
2018年 | 1081篇 |
2017年 | 1227篇 |
2016年 | 1277篇 |
2015年 | 1220篇 |
2014年 | 2343篇 |
2013年 | 2754篇 |
2012年 | 2091篇 |
2011年 | 2435篇 |
2010年 | 1976篇 |
2009年 | 1916篇 |
2008年 | 1941篇 |
2007年 | 1871篇 |
2006年 | 1709篇 |
2005年 | 1510篇 |
2004年 | 1258篇 |
2003年 | 1175篇 |
2002年 | 924篇 |
2001年 | 857篇 |
2000年 | 805篇 |
1999年 | 681篇 |
1998年 | 585篇 |
1997年 | 570篇 |
1996年 | 516篇 |
1995年 | 456篇 |
1994年 | 442篇 |
1993年 | 405篇 |
1992年 | 386篇 |
1991年 | 356篇 |
1990年 | 383篇 |
1989年 | 295篇 |
1988年 | 230篇 |
1987年 | 226篇 |
1986年 | 237篇 |
1985年 | 327篇 |
1984年 | 281篇 |
1983年 | 177篇 |
1982年 | 234篇 |
1981年 | 177篇 |
1980年 | 166篇 |
1979年 | 143篇 |
1978年 | 126篇 |
1977年 | 107篇 |
1976年 | 75篇 |
1975年 | 63篇 |
1974年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 812 毫秒
1.
2.
Defining con-founders that affect the reliability of diagnostic tests for coronavirus disease 2019 is vital to breaking the chain of infection. The elderly population is a higher risk group for the emerging virus. However, gender seems to exert a critical role in modifying the infection risk among women owing to hormonal changes. The menopause transition is an exceptional period for older women where the protective and immunomodulatory effects of the estrogen hormone are lost. Accordingly, attention should be given to postmenopausal women since they will have an increased risk compared to their pre-menopausal peers. 相似文献
3.
4.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome. 相似文献
5.
《Obstetrics, Gynaecology and Reproductive Medicine》2020,30(6):175-183
Menopause is generally experienced as a biopsychosocial process involving physiological changes, and influenced by a wide range of psychological, social and cultural factors. The loss of ovarian oestrogen production may cause debilitating symptoms, including hot flushes, night sweats, sleep disturbance, vaginal dryness, dyspareunia, bladder dysfunction, loss of libido, and mood changes. Experience of the menopause transition varies widely between individuals, depending on the age of onset, personal health and wellbeing, social context, environment and culture.Hormone Replacement Therapy (HRT) remains the most effective treatment for the management of vasomotor symptoms and vaginal dryness, but has no proven role in the treatment of chronic diseases of ageing. Treatment should be individualized, and for most healthy women aged 50–59 years the risks of HRT are low. An understanding of the pathophysiology of menopausal symptoms and the risks and benefits of both hormonal and non-hormonal treatments assists in the individual management of patients. 相似文献
6.
Platelets are needed to prevent or arrest bleeding and aggregate at the site of injury upon vascular damage. Platelets express receptors for estrogens which might affect the function of the platelets and their hemostatic ability. The aim was to identify possible differences in platelet function related to age, gender, and phases of the menstrual cycle by use of impedance aggregometry with Multiplate. In the first part of the study, platelet function was assessed in 60 healthy individuals (30 men and 30 women) in each of three age groups (20–25, 40–45, and 60–65 years). In the second part of the study, the platelet function was analyzed on four occasions during the menstrual cycle in women without oral contraceptives (OCs) (n = 17) and compared to 19 women on OCs and 18 men of similar age (20–40 years). For the women on OCs, aggregation was analyzed once during the tablet-free week and once late during the period with OCs. The men were sampled once. Women of younger age (<45 years) had significantly higher agonist-induced aggregation response than both men and post-menopausal women (60–65 years). The agonist-induced aggregation response did not differ between phases of the menstrual cycle or OC use. The results suggest that estradiol and/or progesterone affect spontaneous aggregation since it was found to be lowest in the mid-luteal phase. Spontaneous aggregation was significantly lower in women on OCs than in both men and women without OCs. Our findings indicate that fertile age is associated with higher aggregation response capacity of the platelets, possibly to prevent excessive bleeding during menstruation, but this response capacity is not altered during the menstrual cycle or by use of OCs. 相似文献
7.
《Revista brasileira de otorrinolaringologia (English ed.)》2020,86(3):321-326
IntroductionMany studies have been done on proteomics, genomics, epigenetic, immunogenetics in many body fluids. Among these, circulating cell-free DNA (ccfDNA) entered the literature in 1948, but it has not been studied for many years due to technological deficiencies. Following recent advances, geno-metastasis has been mentioned and new research is needed in this area. ccfDNA is known to be an important biomolecule in this regard.ObjectiveThe presence of cell-free DNA in the circulatory system may offer a tremendous opportunity to provide novel biomarkers for thyroid diseases. This experimental study was conducted to determine the amount of ccfDNA in different thyroid diseases, then to evaluate whether the ccfDNA concentration varied between the disease groups and control group.MethodsIn total, we included 121 individuals in the present study. We collected blood samples and then determined the ccfDNA concentration in plasma of collected blood samples from three groups: thyroiditis (n = 33), benign (n = 37), and malignant (n = 30) and from a control group (n = 21).ResultsThe median values of the ccfDNA groups were found as 1610, 1665, 1685 and 576 ng/mL for the thyroiditis, benign, malign, and control groups, respectively. Findings showed that the ccfDNA of the three groups was significantly higher than the control (p < 0.0001). Each group was compared in terms of ccfDNA and the p-values of benign-thyroiditis, benign-malign, and thyroiditis-malign were 0.09, 0.65, and 0.29, respectively.ConclusionsThe clear differences between thyroid diseases and controls suggest that ccfDNA is worthy of attention as a biomarker for further evaluation of different thyroid diseases. Likewise, it might indicate a clear tendency that ccfDNA can also be used to distinguish different thyroid diseases. 相似文献
8.
9.
10.