全文获取类型
收费全文 | 181511篇 |
免费 | 16203篇 |
国内免费 | 10444篇 |
专业分类
耳鼻咽喉 | 1566篇 |
儿科学 | 2401篇 |
妇产科学 | 3461篇 |
基础医学 | 19522篇 |
口腔科学 | 3644篇 |
临床医学 | 23331篇 |
内科学 | 27584篇 |
皮肤病学 | 2041篇 |
神经病学 | 9003篇 |
特种医学 | 6157篇 |
外国民族医学 | 79篇 |
外科学 | 18307篇 |
综合类 | 29154篇 |
现状与发展 | 35篇 |
一般理论 | 19篇 |
预防医学 | 12919篇 |
眼科学 | 5076篇 |
药学 | 19198篇 |
147篇 | |
中国医学 | 9878篇 |
肿瘤学 | 14636篇 |
出版年
2024年 | 556篇 |
2023年 | 2656篇 |
2022年 | 6317篇 |
2021年 | 8384篇 |
2020年 | 6194篇 |
2019年 | 5387篇 |
2018年 | 5879篇 |
2017年 | 5360篇 |
2016年 | 4928篇 |
2015年 | 7781篇 |
2014年 | 9856篇 |
2013年 | 9538篇 |
2012年 | 14000篇 |
2011年 | 15206篇 |
2010年 | 10000篇 |
2009年 | 8241篇 |
2008年 | 10441篇 |
2007年 | 10405篇 |
2006年 | 10021篇 |
2005年 | 9391篇 |
2004年 | 6606篇 |
2003年 | 6042篇 |
2002年 | 5080篇 |
2001年 | 4246篇 |
2000年 | 4080篇 |
1999年 | 3932篇 |
1998年 | 2171篇 |
1997年 | 2033篇 |
1996年 | 1614篇 |
1995年 | 1534篇 |
1994年 | 1369篇 |
1993年 | 809篇 |
1992年 | 1270篇 |
1991年 | 1102篇 |
1990年 | 945篇 |
1989年 | 803篇 |
1988年 | 743篇 |
1987年 | 613篇 |
1986年 | 496篇 |
1985年 | 387篇 |
1984年 | 230篇 |
1983年 | 208篇 |
1982年 | 112篇 |
1981年 | 113篇 |
1980年 | 82篇 |
1979年 | 155篇 |
1978年 | 111篇 |
1977年 | 85篇 |
1974年 | 95篇 |
1972年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Ming-Yeh Yang Ching-Yuan Huang Tina H.T. Chiu Kai-Chih Chang Ming-Nan Lin Liang-Yü Chen Anren Hu 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2019,27(2):494-501
Vitamin D is responsible for multiple metabolic functions in humans. Rickets are the most common disease caused by vitamin D deficiency. It is caused by poor calcium intake resulting in poor serum-ionized calcium. The purpose of this study is to develop a rapid, sensitive, and feasible method to determine the 25-hydroxy-vitamin D3 (25(OH)D3) levels in blood samples for clinical assessment. In this study, gas chromatography coupled mass spectrometry with trimethylsilyl derivatization (TMS-GC-MS) is the most suitable protocol for quantitative analyses of 25(OH)D3. Performance of method was evaluated and compared with liquid chromatography and immunoassay. Method validation has been carried out with plasma specimens. The limit of quantitation of TMS-GC-MS method is 1.5 ppb with good linear correlation. Furthermore, the dietary intake and nutritional status of vegetarian and non-vegetarians in Taiwan were assessed by our validated method. As a result, this vitamin D nutrition survey demonstrates that most Taiwanese people have insufficient vitamin D. Due to dietary habits; the male vegans may have the highest risk of vitamin D deficiency. 相似文献
52.
53.
OBJECTIVES: To assess the effectiveness and safety of additional bedtime H2‐receptor antagonists (H2RAs) in suppressing nocturnal gastric acid breakthrough (NAB) via a systematic review. METHODS: Eligible trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 2, 2004), MEDLINE (January 1966–June 2004), EMBASE (January 1980–June 2004) and CINAHL (January 1982–June 2004). Additional hand‐searching was conducted on the proceedings of correlated conferences, eight important Chinese journals and references of all included trials. All randomized controlled trials evaluating H2RAs for the control of NAB were eligible for inclusion. The systematic review was conducted using methods recommended by The Cochrane Collaboration. RESULTS: Only two randomized crossover studies, comprising 32 participants, met the inclusion criteria. Because the design, dosage and duration of the treatments were different between the studies, it was not possible to conduct meta‐analysis. There were no consistent conclusions found between the two included studies in evaluating H2RAs for the control of NAB. CONCLUSIONS: No implications for practice at this stage can be concluded. Appropriately designed large‐scale randomized controlled trials with long‐term follow up are needed to determine the effects of additional bedtime H2RAs in suppressing NAB. 相似文献
54.
55.
网络环境下医学专题检索服务的深化 总被引:3,自引:2,他引:1
分析网络环境下图书馆定题服务的现状和价值,提出跟踪服务的方式,进行分阶段的、具体的定题服务,并实例分析分阶段定题服务的优势。 相似文献
56.
57.
阿格雷(Peter Agre)博士,美国杜克大学医学院细胞生物学系教授,约翰斯霍普金斯大学医学院生物化学系客座教授。阿格雷教授其研究成果在于分离出了长期以来所搜寻的特定输送水分子的通道。这一发现开启了针对细菌、植物和哺乳动物水通道的系列生化、生理和遗传研究之门,从而使得研究人员可以仔细跟踪水分子通过细胞膜的过程,并了解为何只有水分子而不是其他小分子能够通过细胞膜,阿格雷博士也因此获得了2003年诺贝尔化学奖。 相似文献
58.
The spine, pelvic bones and long bones of the lower extremities are common sites for insufficiency fractures. Cases of sternum insufficiency fractures have been rarely reported in an elderly patient. Insufficiency fracture tends to occur in bones with decreased mechanical strength. It tends to occur in elderly patients, especially in postmenopausal women, with underlying diseases. We describe a case of sternum insufficiency fracture in a patient with rheumatoid arthritis and systemic lupus erythematosus on long-term corticosteroid therapy diagnosed in an emergency setting. Sternum insufficiency fracture is a rare cause of chest pain. This case serves to remind the emergency physician to remain vigilant for other noncardiac and nontraumatic causes of chest pain. If diagnosed accurately, these patients can be discharged and treated as outpatients. 相似文献
59.
目的观察前置胎盘孕妇的恐惧心理反应,做好前置胎盘孕妇的心理护理。方法由孕妇自行填写CES-D和SA2量表,进行统计学分析。结果70.2%的前置胎盘孕妇具有恐惧心理。结论在妊娠过程应提高孕妇认知水平,加强心理护理,有助于她们顺利渡过妊娠期。 相似文献
60.
快速供肝切取与修整的外科技巧 总被引:12,自引:2,他引:10
目的总结肝脏移植供肝的快速切取和修整经验。方法分析2004年共186例快速供肝的切取和修整的资料。快速切取技术采用原位腹主动脉、肠系膜上静脉灌注附加下腔静脉引流,快速切取供肝,4℃UW液中保存和修整肝脏。结果供肝热缺血时间为3~10min,平均4.5min;冷缺血时间平均为3-16h,平均7h。供肝的修整时间为26~90min,平均46min。供肝修整时发现肝动脉解剖变异20例。结论快速供肝切取法要求术者技术娴熟、动作迅速和准确,可最大限度地减少供肝热缺血时间。快速切取法能保证供肝的质量和确保供肝切取的成功。 相似文献