全文获取类型
收费全文 | 639篇 |
免费 | 55篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 68篇 |
妇产科学 | 8篇 |
基础医学 | 55篇 |
口腔科学 | 15篇 |
临床医学 | 47篇 |
内科学 | 135篇 |
皮肤病学 | 55篇 |
神经病学 | 27篇 |
特种医学 | 64篇 |
外科学 | 59篇 |
综合类 | 59篇 |
预防医学 | 34篇 |
眼科学 | 2篇 |
药学 | 35篇 |
中国医学 | 1篇 |
肿瘤学 | 54篇 |
出版年
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 12篇 |
2017年 | 5篇 |
2016年 | 10篇 |
2015年 | 24篇 |
2014年 | 24篇 |
2013年 | 22篇 |
2012年 | 36篇 |
2011年 | 25篇 |
2010年 | 25篇 |
2009年 | 24篇 |
2008年 | 29篇 |
2007年 | 32篇 |
2006年 | 31篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 11篇 |
1998年 | 34篇 |
1997年 | 39篇 |
1996年 | 32篇 |
1995年 | 18篇 |
1994年 | 13篇 |
1993年 | 18篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 16篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 3篇 |
1985年 | 15篇 |
1984年 | 3篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1973年 | 4篇 |
1971年 | 3篇 |
1970年 | 6篇 |
1965年 | 3篇 |
排序方式: 共有723条查询结果,搜索用时 15 毫秒
31.
32.
Toretsky JA Jenson J Sun CC Eskenazi AE Campbell A Hunger SP Caires A Frantz C Hill JL Stamberg J 《American journal of clinical oncology》2003,26(3):300-306
Thymic carcinoma is a rare epithelial neoplasm of the thymus. The presence of a specific chromosomal abnormality may augment diagnosis and therapeutic stratification. We report a 15-year-old boy diagnosed with thymic carcinoma who presented with a large anterior mediastinal mass, pleural effusion, and bone metastasis. The pleural fluid, cytology, bony lesions, and bone marrow were examined and chromosomal studies were performed. Histologic and immunohistochemical studies confirmed a poorly differentiated squamous cell type of thymic carcinoma. The karyotype of the pleural fluid at the time of diagnosis revealed a complex three-way translocation t(11;15;19)(p15;q12;p13.3). The constitutional karyotype was 46,XY. Five months after diagnosis, a bone marrow aspirate demonstrated tetraploidy with all translocation chromosomes in duplicate, as well as an unbalanced rearrangement involving chromosome 1: 92,XXYY,t(11;15;19)(p15;q12;p13.3)x2[15]/92,XXYY,idem,add(1)(qter)[5]. Despite aggressive multiagent chemotherapy, the patient's condition progressed with bone marrow disease and he died 6 months after diagnosis. Several case reports of a similar chromosomal abnormality have been reported for thymic carcinoma in young patients with poor outcome. This karyotypic abnormality appears to mark a cohort of patients with thymic carcinoma who have a poor prognosis despite aggressive chemotherapy. 相似文献
33.
34.
Robert E. Hunger Claude Carnaud Irne Garcia Pierre Vassalli Christoph Mueller 《European journal of immunology》1997,27(1):255-261
The non-obese diabetic (NOD) mouse represents a relevant animal model of autoimmunity for insulin-dependent diabetes mellitus. The pathogenic role of tumor necrosis factor (TNF) in insulitis and β cell destruction observed in these mice remains controversial, since injections of TNF or of anti-TNF antibodies have been reported to exert protection or acceleration of diabetes, depending on the timing of administration. In this study, we demonstrate that, in contrast to the non-transgenic littermates, NOD mice with permanent neutralization of TNF by high blood levels of soluble TNF receptor p55-human FcIgG3-fusion molecules resulting from the expression of a transgene are protected from spontaneous diabetes. They are also protected from accelerated forms of disease caused by transfer of NOD spleen cells or cyclophosphamide injections. This protection is associated with a marked decrease in the severity and incidence of insulitis and in the expression of the adhesion molecules MAdCAM-1 and ICAM-1 on the venules of pancreatic islets. These data suggest a central role for TNF-α in the mediation of insulitis and of the subsequent destruction of insulin-secreting β-cells observed in NOD mice. They may be relevant to cell-mediated autoimmune diseases in general, in which treatment with soluble TNF receptors might be beneficial. 相似文献
35.
Objective: To identify risk factors for development of dehydration in under five year olds with acute watery diarrhoea.Design: Hospital based unmatched case-control study.Setting: Diarrhoea Treatment Unit, Government Medical College Hospital, Nagpur, India.Participants: The study included 387 cases of diarrhoea having severe or moderate dehydration and 387 controls suffering from diarrhoea with mild or no dehydration.Risk factors: The study included infancy, female sex, religion, residing in urban slums or rural area, under nutrition, cessation of breast feeding during diarrhoeal episode, fluid intake decreased/stopped during diarrhoea, ORS not received, home available fluids (HAF) not received, both ORS and HAF not received, non-washing of hands by mother before preparation of food, after defaecation, after disposal of faeces, history of measles in the previous six months, frequency of stools >8/d, frequency of vomiting more than twice per day and temperature more than 99°F, as risk factors for development of dehydration.Statistical analysis: Univariate analysis included OR, 95% CI for OR and Chi-square test. Multivariate analysis was carried out by unconditional multiple logistic regression (MLR).Results: This study identified the significance of infancy, religion, severe undernutrition, non-washing of hands by mother before preparation of food, frequency of stool >8/d, frequency of vomiting >2/d, history of measles in previous six months, withdrawal of breast feeding during diarrhoea, withdrawal of fluids during diarrhoea and not giving ORS, HAF or both during diarrhoea, in the outcome of development of moderate or severe dehydration.Conclusions: Timely intervention in the preventable risk factors included in this study may prevent the development of moderate or severe dehydration in the children suffering form acute watery diarrhoea. 相似文献
36.
目的 建立一种快速、灵敏的高效液相色谱-串联质谱(HPLC-MS/MS)方法以测定人血浆中对乙酰氨基酚浓度,并应用于两种对乙酰氨基酚制剂的人体药代动力学和生物等效性研究。方法 以替硝唑为内标,200μL血浆样品经5倍于其体积的乙酸乙酯液液萃取,再经Waters XBridge? C18柱等度洗脱分离后导入串联质谱,以正离子多反应监测模式进行定量分析,对乙酰氨基酚和内标的选择性反应离子对分别是m/z 152→110和248→121。方法经验证后应用于19名健康受试者单剂量空腹口服两种对乙酰氨基酚制剂500mg后药代动力学和生物等效性的研究。结果 血浆中对乙酰氨基酚在0.1~8.0 μg·mL-1范围内线性良好(r2 > 0.99),最低检测限为 0.1 μg·mL-1,提取回收率为91.0%~98.7%,日内和日间准确度分别为98.8%~111.3% (精密度:CV ? 9.03%)和94.9%~102.6% (精密度:CV ? 10.68%)。生物等效性试验中,受试制剂与参比制剂的主要药代动力学参数Cmax、AUC0-t和AUC0-∞ 几何均值比的90%置信区间分别为83.50%~105.79%,94.25%~101.54%和93.24%~101.02%,均落在生物等效可接受标准80.00%~125.00%范围内。结论 所建立测定人血浆中对乙酰氨基酚浓度的HPLC-MS/MS法具有快速灵敏、回收率高、选择性好的特点,适用于对乙酰氨基酚片人体药代动力学和生物等效性研究。受试制剂与参比制剂在人体内吸收速度和程度相似,两种制剂生物等效。 相似文献
37.
38.
背景:阿德福韦双酯(ADV) 是一种有效治疗野生型和耐拉米夫定乙肝病毒(HBV)的核苷酸类药物。在使用核苷酸类药物治疗慢性乙肝时,当治疗时间为 48、96、144周时,耐ADV变异体出现的累积发生率分别为0、 0.8-3%和0-5.9%。目的:研究67例对拉米夫定耐药且接受ADV治疗的慢性乙肝患者耐ADV病毒变异体的表型和基因型特点。方法:HBV DNA含量采用实时定量PCR技术。ADV变异体检测采用基质辅助激光解吸电离/飞行时间质谱为基础的基因分型 相似文献
39.
40.