全文获取类型
收费全文 | 7502篇 |
免费 | 558篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 100篇 |
儿科学 | 252篇 |
妇产科学 | 164篇 |
基础医学 | 906篇 |
口腔科学 | 75篇 |
临床医学 | 1005篇 |
内科学 | 1324篇 |
皮肤病学 | 112篇 |
神经病学 | 721篇 |
特种医学 | 183篇 |
外科学 | 810篇 |
综合类 | 75篇 |
一般理论 | 3篇 |
预防医学 | 1080篇 |
眼科学 | 217篇 |
药学 | 481篇 |
中国医学 | 5篇 |
肿瘤学 | 562篇 |
出版年
2023年 | 64篇 |
2022年 | 90篇 |
2021年 | 268篇 |
2020年 | 170篇 |
2019年 | 202篇 |
2018年 | 262篇 |
2017年 | 205篇 |
2016年 | 197篇 |
2015年 | 236篇 |
2014年 | 314篇 |
2013年 | 441篇 |
2012年 | 622篇 |
2011年 | 655篇 |
2010年 | 365篇 |
2009年 | 322篇 |
2008年 | 500篇 |
2007年 | 481篇 |
2006年 | 442篇 |
2005年 | 479篇 |
2004年 | 423篇 |
2003年 | 376篇 |
2002年 | 326篇 |
2001年 | 53篇 |
2000年 | 40篇 |
1999年 | 44篇 |
1998年 | 44篇 |
1997年 | 53篇 |
1996年 | 28篇 |
1995年 | 23篇 |
1994年 | 16篇 |
1993年 | 8篇 |
1992年 | 18篇 |
1991年 | 20篇 |
1990年 | 18篇 |
1989年 | 11篇 |
1988年 | 17篇 |
1987年 | 8篇 |
1986年 | 24篇 |
1985年 | 18篇 |
1984年 | 16篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1981年 | 14篇 |
1980年 | 10篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1975年 | 9篇 |
1970年 | 10篇 |
排序方式: 共有8075条查询结果,搜索用时 31 毫秒
81.
82.
Mutaz Dana 《Hemoglobin》2018,42(2):138-140
The major hemoglobin (Hb) during fetal life is fetal Hb (Hb F). It is mostly replaced by adult Hbs before birth and during the first year of life. In adults, where Hb F comprises <2.0% of the total Hb, it is not homogenously distributed among the red blood cells (RBCs) but is concentrated in a few RBCs, termed F-cells. Interestingly, for reasons that are unclear, Hb F increases in the maternal circulation during pregnancy. This increased Hb F could have two potential origins that are not mutually exclusive: A) maternal origin, due to inducing environment of Hb F in the maternal erythroid precursors; B) fetal origin, due to fetal cells crossing the placenta and entering the maternal circulation. The question we present herein is whether the observed increased Hb F in the maternal circulation during pregnancy is, at least partially, derived from the fetal origin. Peripheral blood was obtained from normal neonates (1–3 days old), adult men and pregnant and non pregnant women. The RBCs were stained for Hb F and carbonic anhydrase (CA) using a fetal cell count kit and analyzed by flow cytometry. Fetal and adult F-cells were distinguished by their expression of Hb F and CA. Fetal F-cells were Hb F++/CA?, while adult F-cells were Hb F+/CA+. Comparing pregnant and non pregnant women samples (n?=?10), we found six samples of pregnant women with 0.2–1.7% fetal cells, but none in the non pregnant group. These results support the possibility that at least part of the increase in Hb F during pregnancy is due to fetal cells entering the maternal circulation. 相似文献
83.
84.
Dana M. Hartl Guillaume Landry François Bidault Stéphane Hans Morbize Julieron Gérard Mamelle François Janot Daniel F. Brasnu 《European archives of oto-rhino-laryngology》2013,270(1):287-291
Treatment choice for laryngeal cancer may be influenced by the diagnosis of thyroid cartilage invasion on preoperative computed tomography (CT). Our objective was to determine the predictive value of CT for thyroid cartilage invasion in early- to mid-stage laryngeal cancer. Retrospective study (1992–2008) of laryngeal squamous cell carcinoma treated with open partial laryngectomy and resection of at least part of the thyroid cartilage. Previous laser surgery, radiation therapy, chemotherapy and second primaries were excluded. CT prediction of thyroid cartilage invasion was determined by specialized radiologists. Tumor characteristics and pathologic thyroid cartilage invasion were compared to the radiologic assessment. 236 patients were treated by vertical (20 %), supracricoid (67 %) or supraglottic partial laryngectomy (13 %) for tumors staged cT1 (26 %), cT2 (55 %), and cT3 (19 %). The thyroid cartilage was invaded on pathology in 19 cases (8 %). CT’s sensitivity was 10.5 %, specificity 94 %, positive predictive value 13 %, and negative predictive value 92 %. CT correctly predicted thyroid cartilage invasion in only two cases for an overall accuracy of 87 %. Among the false-positive CT’s, tumors involving the anterior commissure were significantly over-represented (61.5 % vs. 27 %, p = .004). Tumors with decreased vocal fold (VF) mobility were significantly over-represented in the group of false-negatives (41 vs. 13 %, p = .0035). Preoperative CT was not effective in predicting thyroid cartilage invasion in these early- to mid-stage lesions, overestimating cartilage invasion for AC lesions and underestimating invasion for lesions with decreased VF mobility. 相似文献
85.
86.
87.
Maria Adriana Neag rei Otto Mitre Adrian Catinean Anca Dana Buzoianu 《World journal of gastroenterology : WJG》2021,27(43):7446-7461
Viral B and C hepatitis are a major current health issue, both diseases having a chronic damaging effect on the liver and its functions. Chronic liver disease can lead to even more severe and life-threatening conditions, such as liver cirrhosis and hepatocellular carcinoma. Recent years have uncovered an important interplay between the liver and the gut microbiome: the gut-liver axis. Hepatitis B and C infections often cause alterations in the gut microbiota by lowering the levels of ‘protective’ gut microorganisms and, by doing so, hinder the microbiota ability to boost the immune response. Treatments aimed at restoring the gut microbiota balance may provide a valuable addition to current practice therapies and may help limit the chronic changes observed in the liver of hepatitis B and C patients. This review aims to summarize the current knowledge on the anato-functional axis between the gut and liver and to highlight the influence that hepatitis B and C viruses have on the microbiota balance, as well as the influence of treatments aimed at restoring the gut microbiota on infected livers and disease progression. 相似文献
88.
89.
Play has long been recognised as a vehicle by which significant developmental advances occur during early childhood. Children use play to explore their relationships, their psychosocial skills, and their environment, and through their experiences, they begin to adopt specific capacities and values that have an impact on future socio-emotional and academic outcomes. To understand more fully the factors that contribute to well-being in early childhood, we explored footage of a full ‘day in the life’ of a 5-year-old boy in transition to kindergarten, and we conducted interviews with him, his parents, and teacher. We identified agentive and communitarian strivings to be significant sources of his thriving and primary elements of many episodes of play during his filmed day. Previous research indicates that the development of strong agentive and communitarian skills and values is related to positive psychosocial outcomes. The current case study explores our participant's agentive and communitarian behaviours as exemplified through episodes of play, and the ways in which these skills and values are encouraged and supported by his caregivers. Implications regarding the role of parents and educators in the facilitation of agentive and communitarian skills are discussed. 相似文献
90.
James M. Shultz Dana Rose Garfin Zelde Espinel Ricardo Araya Maria A. Oquendo Milton L. Wainberg Roberto Chaskel Silvia L. Gaviria Anna E. Ordóñez Maria Espinola Fiona E. Wilson Natalia Muñoz García Ángela Milena Gómez Ceballos Yanira Garcia-Barcena Helen Verdeli Yuval Neria 《Current psychiatry reports》2014,16(10):1-16
While conflict-induced forced migration is a global phenomenon, the situation in Colombia, South America, is distinctive. Colombia has ranked either first or second in the number of internally displaced persons for 10 years, a consequence of decades of armed conflict compounded by high prevalence of drug trafficking. The displacement trajectory for displaced persons in Colombia proceeds through a sequence of stages: (1) pre-expulsion threats and vulnerability, (2) expulsion, (3) migration, (4) initial adaptation to relocation, (5) protracted resettlement (the end point for most forced migrants), and, rarely, (6) return to the community of origin. Trauma signature analysis, an evidence-based method that elucidates the physical and psychological consequences associated with exposures to harm and loss during disasters and complex emergencies, was used to identify the psychological risk factors and potentially traumatic events experienced by conflict-displaced persons in Colombia, stratified across the phases of displacement. Trauma and loss are experienced differentially throughout the pathway of displacement. 相似文献