全文获取类型
收费全文 | 2467篇 |
免费 | 167篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 83篇 |
妇产科学 | 80篇 |
基础医学 | 447篇 |
口腔科学 | 82篇 |
临床医学 | 198篇 |
内科学 | 513篇 |
皮肤病学 | 53篇 |
神经病学 | 246篇 |
特种医学 | 52篇 |
外科学 | 307篇 |
综合类 | 16篇 |
预防医学 | 151篇 |
眼科学 | 34篇 |
药学 | 124篇 |
肿瘤学 | 238篇 |
出版年
2023年 | 18篇 |
2022年 | 47篇 |
2021年 | 72篇 |
2020年 | 37篇 |
2019年 | 47篇 |
2018年 | 44篇 |
2017年 | 39篇 |
2016年 | 58篇 |
2015年 | 50篇 |
2014年 | 72篇 |
2013年 | 119篇 |
2012年 | 153篇 |
2011年 | 172篇 |
2010年 | 88篇 |
2009年 | 89篇 |
2008年 | 163篇 |
2007年 | 156篇 |
2006年 | 147篇 |
2005年 | 132篇 |
2004年 | 121篇 |
2003年 | 93篇 |
2002年 | 101篇 |
2001年 | 68篇 |
2000年 | 64篇 |
1999年 | 66篇 |
1998年 | 27篇 |
1997年 | 14篇 |
1996年 | 15篇 |
1995年 | 10篇 |
1994年 | 17篇 |
1992年 | 25篇 |
1991年 | 23篇 |
1990年 | 18篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1986年 | 19篇 |
1985年 | 18篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 11篇 |
1975年 | 10篇 |
1974年 | 21篇 |
1973年 | 14篇 |
1972年 | 10篇 |
1970年 | 9篇 |
1969年 | 15篇 |
排序方式: 共有2643条查询结果,搜索用时 31 毫秒
41.
Pagona Lagiou Chung-Cheng Hsieh Evangelia Samoli Areti Lagiou Biao Xu Guo-Pei Yu Sagano Onoyama Lucy Chie Lars J. Vatten Hans-Olov Adami Dimitrios Trichopoulos Michelle A. Williams 《Annals of epidemiology》2013,23(11):669-673
PurposePlacental weight has been associated with mammographic pattern and coronary heart disease in the adult offspring, but the mechanisms are unknown. We evaluated the associations of maternal and cord blood hormones with placental weight in normal pregnancies.MethodsProspective study of 167 normal singleton pregnancies in Boston, USA and 256 in Shanghai, China. Maternal hormone levels at the 27th gestational week were available for all pregnancies. Cord blood measurements were available for 86 pregnancies in Boston and 104 in Shanghai. Pearson partial correlation coefficients of log-transformed hormone levels with placental weight were calculated.ResultsMaternal levels of estriol, testosterone, and progesterone (P < .05) were positively associated with placental weight. There was no such evidence for adiponectin, prolactin, and insulin-like growth factor (IGF)-I. Cord blood steroids tended to be inversely associated with placental weight, the results being statistically significant for testosterone (P < .05). There was a marginally significant positive association of cord blood IGF-I with placental weight. Reported results were adjusted for study center.ConclusionsPlacental weight appears to be positively correlated with maternal steroids. Its correlation with cord blood steroids, however, appears inverse, compatible with negative feedback mechanisms. There is also a suggestion for placental weight to be positively associated with cord blood IGF-I. 相似文献
42.
Nefta-Eleftheria P. Votsi Antonios D. Mazaris Athanasios S. Kallimanis Evangelia G. Drakou John D. Pantis 《International journal of environmental health research》2014,24(2):176-187
Human health and well-being presuppose environmental quality. Several studies have documented the indicative role of land use types in environmental quality. However, the exact role of land use composition on disease distribution has remained scientifically vague. We assessed the congruence of diseases’ distribution with land use composition, focusing on high environmental quality areas, defined as tranquil areas with view to indicating places offering well-being. Landscape composition is linked to the presence of diseases across 51 prefectures of Greece. Agricultural and natural land use types proved to be the main drivers of disease distribution. Tranquility demonstrated a strong negative correlation with population density, thus could be considered as a quantitative spatial index of life-quality. We concluded that the landscape context affects the dominance of diseases’ patterns. Special emphasis should be put on the role of tranquil areas in human health and the relative environmental health policies. 相似文献
43.
Phototherapy as a first‐line treatment for early‐stage mycosis fungoides: The results of a large retrospective analysis 下载免费PDF全文
44.
45.
Theohari Irini Alexandrou Paraskevi Giannopoulou Ioanna Papadimitriou Christos Nakopoulou Lydia 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2013,121(9):797-805
Reduced Axin expression has been associated with an aggressive behavior in lung and esophageal squamous cell carcinomas. Its role in breast cancer has not been defined. The aim of our study was to investigate the expression pattern of Axin protein in invasive breast carcinomas, in relation to the behavior and prognosis of the disease. Immunohistochemistry was performed for the detection of Axin expression in 232 breast cancer tissues. Univariate and multivariate statistical analyses were used to assess the relation of Axin expression with classic clinicopathological parameters, patients' survival and various biologic markers Human Epidermal Factor‐2 (HER‐2), Ki‐67, topoIIα, glycogen synthase kinase‐3β (GSK‐3β)]. Preserved cytoplasmic Axin expression was positively correlated to lymph node invasion, HER‐2 and GSK‐3β and inversely to Ki‐67 and topoIIα. Nuclear Axin was positively associated with tumor size. Stromal Axin showed a parallel association with lymph node status and HER‐2. In the subgroup of lobular breast carcinomas, preserved Axin was found to exert an unfavorable impact on patients' overall survival. Our findings indicate, for the first time, that in invasive breast cancer preserved Axin expression is associated with a more aggressive phenotype and that in the discrete subtype of lobular breast carcinomas Axin negatively influences patients' overall survival. 相似文献
46.
47.
48.
Andriana I. Papaioannou Evangelia Fouka Despina Papakosta Spyridon Papiris Stelios Loukides 《Clinical and experimental allergy》2021,51(2):221-227
During the last decades, new treatments targeting disease mechanisms referred as biologics have been introduced in the therapy of asthma and currently, five monoclonal antibodies have been approved. Although these therapeutic agents have been formulated to target specific asthma endotypes, it is often difficult for the treating physician to identify which patient is the best candidate for each one of these specific treatments especially in the clinical scenario of a patient in whom clinical characteristics overlap between different endotypes, allowing the selection of more than one biologic agent. As no head-to-head comparisons between these biologics have been attempted, there is no evidence on the superiority of one biologic agent over the other. Furthermore, a physician's first therapeutic decision, no matter how carefully has been made, may often result in suboptimal clinical response and drug discontinuation, indicating the need for switching to a different biologic. In this short review, we discuss the available evidence regarding the switching between biologics in patients with severe asthma and we propose a simple algorithm on switching possibilities in case that the physicians’ initial choice is proven not to be the best. 相似文献
49.
Eleftherios Dimitros Nikolaos Koutlianos Maria Anifanti Efstathios Pagourelias Evangelia Kouidi Asterios Deligiannis 《Sport Sciences for Health》2012,8(2-3):101-107
The identification of left ventricular hypertrophy (LVH) through electrocardiographic voltage criteria has been widely studied in patients. However, their validity in “athlete’s heart” remains quite unknown. The aim of this study was to evaluate the most common electrocardiographic indices indicative of LVH compared to the known echocardiographic ones in athletes. The study group comprised 150 male adult competitive athletes (group A) and 50 sedentary participants (group B). Thirteen accepted electrocardiographic voltage criteria indicative of LVH were calculated and correlated with the common echocardiographic indices of left ventricular mass (LVM). Nine of the 13 ECG voltage criteria were significantly increased in athletes compared to controls. Statistically, the Sokolow–Lyon index, which is the most commonly used voltage index was found to be affected by the body mass index (10.7 %, p < 0.05), the group (7.3 %, p < 0.05) and systolic blood pressure (4.5 %, p < 0.05) in total variance of 16.6 % (p < 0.05). No electrocardiographic voltage criterion was significantly correlated with any echocardiographic index, except for the Cornell index that was correlated with end-diastolic volume index (r = 0.29, p < 0.05) and the Sokolow index (V6) with LVMI (r = 0.26, p < 0.05) in group A. We suggested that ECG voltage indices should not be considered valid when assessing LVH in athletes. Thus, the echocardiographic study is preferable in studying training-induced structural cardiac changes. 相似文献
50.
Clinical association between chronic periodontitis and the leukocyte extravasation inhibitors developmental endothelial locus‐1 and pentraxin‐3 下载免费PDF全文
Matthias Folwaczny Evangelia Karnesi Tamara Berger Ekaterini Paschos 《European journal of oral sciences》2017,125(4):258-264
This clinical study aimed to determine whether periodontal disease is associated with expression of developmental endothelial locus‐1 (Del‐1) and pentraxin‐3 (PTX‐3), endogenous inhibitors of leukocyte extravasation in humans. Expression of DEL1, PTX3, interleukin‐17A (IL17A), and lymphocyte function‐associated antigen‐1 (LFA1) was determined, using RT‐PCR and melting curve analysis, in biopsies of gingival tissues from 95 patients: 42 with moderate periodontitis; 40 with severe periodontitis; and 13 healthy controls. Relative expression of DEL1 and PTX3 was statistically significantly weaker in patients with periodontitis than in the control subjects. On the contrary, both IL17A and LFA1 showed statistically significant stronger expression in patients with periodontitis than in healthy controls. Correlation analysis, performed using Spearman's test, showed that expression of DEL1 was statistically significantly linked to periodontitis (ρ = ?0.103) and to age (ρ = ?0.134), but not to the gender of the patient, and that expression of PTX3 was significantly correlated with periodontitis (ρ = ?0.354). Expression of neutrophil extravasation inhibitors DEL1 and PTX3 show significant, but weak, association with the clinical manifestation of chronic periodontitis. 相似文献