全文获取类型
收费全文 | 3858篇 |
免费 | 277篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 30篇 |
妇产科学 | 44篇 |
基础医学 | 495篇 |
口腔科学 | 51篇 |
临床医学 | 408篇 |
内科学 | 481篇 |
皮肤病学 | 31篇 |
神经病学 | 167篇 |
特种医学 | 148篇 |
外科学 | 173篇 |
综合类 | 704篇 |
预防医学 | 625篇 |
眼科学 | 14篇 |
药学 | 454篇 |
1篇 | |
中国医学 | 274篇 |
肿瘤学 | 69篇 |
出版年
2023年 | 86篇 |
2022年 | 138篇 |
2021年 | 177篇 |
2020年 | 148篇 |
2019年 | 217篇 |
2018年 | 173篇 |
2017年 | 134篇 |
2016年 | 129篇 |
2015年 | 130篇 |
2014年 | 299篇 |
2013年 | 276篇 |
2012年 | 249篇 |
2011年 | 279篇 |
2010年 | 237篇 |
2009年 | 217篇 |
2008年 | 174篇 |
2007年 | 173篇 |
2006年 | 139篇 |
2005年 | 98篇 |
2004年 | 82篇 |
2003年 | 71篇 |
2002年 | 69篇 |
2001年 | 48篇 |
2000年 | 37篇 |
1999年 | 32篇 |
1998年 | 27篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 25篇 |
1994年 | 19篇 |
1993年 | 16篇 |
1992年 | 22篇 |
1991年 | 13篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1985年 | 19篇 |
1984年 | 18篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 17篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 14篇 |
1976年 | 9篇 |
1974年 | 6篇 |
1973年 | 10篇 |
1972年 | 10篇 |
1971年 | 10篇 |
排序方式: 共有4184条查询结果,搜索用时 296 毫秒
1.
B.B. Damian T.C.S. Bonetti D.D.G. Horovitz 《Brazilian journal of medical and biological research》2015,48(1):25-33
Preimplantation genetic diagnosis (PGD) was originally developed to diagnose
embryo-related genetic abnormalities for couples who present a high risk of a
specific inherited disorder. Because this technology involves embryo selection, the
medical, bioethical, and legal implications of the technique have been debated,
particularly when it is used to select features that are not related to serious
diseases. Although several initiatives have attempted to achieve regulatory
harmonization, the diversity of healthcare services available and the presence of
cultural differences have hampered attempts to achieve this goal. Thus, in different
countries, the provision of PGD and regulatory frameworks reflect the perceptions of
scientific groups, legislators, and society regarding this technology. In Brazil,
several texts have been analyzed by the National Congress to regulate the use of
assisted reproduction technologies. Legislative debates, however, are not conclusive,
and limited information has been published on how PGD is specifically regulated. The
country requires the development of new regulatory standards to ensure adequate
access to this technology and to guarantee its safe practice. This study examined
official documents published on PGD regulation in Brazil and demonstrated how little
direct oversight of PGD currently exists. It provides relevant information to
encourage reflection on a particular regulation model in a Brazilian context, and
should serve as part of the basis to enable further reform of the clinical practice
of PGD in the country. 相似文献
2.
《Bulletin du cancer》2019,106(4):389-394
3.
4.
The presence of pesticides in the Israeli food supply is well documented but little is known about the risks posed by children's diets for potential exposures. We investigated potential exposures to food-borne pesticides in a sample of 301 urban Israeli children (2008–10). Data from a food frequency questionnaire, 24 hour food recall, and Israel's national pesticide monitoring program were used to estimate uptake factors for 26 compounds in 27 fruits and vegetables. A pilot risk assessment was performed and the findings were compared with the Israel Ministry of Health's 2012 pesticide risk assessment for the general population. The surveyed children had higher potential exposures than the general population for over one third of the compounds, and uptake factors exceeded the Acceptable Daily Intake in ten compounds. Methamidophos, exceeded the ADI at the 25th percentile and fenamiphos, iprodione, and oxydemethon methyl, exceeded the ADI at the 50 percentile. ADIs for several compounds were exceeded even though the residues detected were below the statutory limit. Improved monitoring, enforcement, and revision of the Maximum Residue Limit for certain food/pesticide pairs are indicated as is the need to incorporate data on children's actual food consumption in national risk assessments. 相似文献
5.
《Vaccine》2016,34(45):5436-5441
Influenza is a viral infection that affects much of the global population each year. Vaccination remains the most effective tool for preventing the disease. Live attenuated influenza vaccine (LAIV) has been used since the 1950s to protect humans against seasonal influenza. LAIVs developed by the Institute of Experimental Medicine (IEM), Saint Petersburg, Russia, have been successfully used in Russia since 1987.In 2006, the World Health Organization (WHO) announced a Global action plan for influenza vaccines (GAP). WHO, recognizing potential advantages of LAIV over the inactivated influenza vaccine in a pandemic situation, included LAIV in the GAP.BioDiem Ltd., a vaccine development company based in Melbourne, Australia which held the rights for the Russian LAIV, licensed this technology to WHO in 2009. WHO was permitted to grant sub-licenses to vaccine manufacturers in newly industrialized and developing countries to use the Russian LAIV for the development, manufacture, use and sale of pandemic and seasonal LAIVs. To date, WHO has granted sub-licenses to vaccine manufacturers in China (Changchun BCHT Biotechnology Co., Ltd.), India (Serum Institute of India Pvt. Ltd.) and Thailand (Government Pharmaceutical Organization). In parallel, in 2009, IEM signed an agreement with WHO, under which IEM committed to supply pandemic and seasonal candidate vaccine viruses to the sub-licensees.This paper describes the progress made by collaborators from China, India, Russia and Thailand in developing preventive measures, including LAIV against pandemic influenza. 相似文献
6.
Elisa Giani Andrea Enzo Scaramuzza Gian Vincenzo Zuccotti 《World journal of diabetes》2015,6(8):999-1004
Technologies for diabetes management, such as continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) systems, have improved remarkably over the last decades. These developments are impacting the capacity to achieve recommended hemoglobin A1c levels and assisting in preventing the development and progression of micro- and macro vascular complications. While improvements in metabolic control and decreases in risk of severe and moderate hypoglycemia have been described with use of these technologies, large epidemiological international studies show that many patients are still unable to meet their glycemic goals, even when these technologies are used. This editorial will review the impact of technology on glycemic control, hypoglycemia and quality of life in children and youth with type 1 diabetes. Technologies reviewed include CSII, CGM systems and sensor-augmented insulin pumps. In addition, the usefulness of advanced functions such as bolus profiles, bolus calculators and threshold-suspend features will be also discussed. Moreover, the current editorial will explore the challenges of using these technologies. Indeed, despite the evidence currently available of the potential benefits of using advanced technologies in diabetes management, many patients still report barriers to using them. Finally this article will highlight the importance of future studies tailored toward overcome these barriers to optimizing glycemic control and avoiding severe hypoglycemia. 相似文献
7.
8.
小红参滴丸的制备工艺研究 总被引:2,自引:0,他引:2
目的 :研究小红参滴丸的最佳成型工艺条件。方法 :采用正交试验法 ,考察了提取物与基质配比、滴制温度、滴头口径大小等因素TLC定性鉴别。结果 :药物提取物 :基质 (1:1.4 ) ,滴制温度 85℃ ,滴头口径 1/ 2mm (内径 /外径 )。滴速 (8± 2 )滴 /min ,滴距 8cm ,冷却剂温度 (4± 2 )℃ ,柱高 6 0cm进行滴制 ,滴丸的成型率最高。结论 :证明此工艺可行 ,成品得率高 ,符合滴丸剂的质量标准。 相似文献
9.
体外培养的小鼠骨髓基质细胞对血细胞集落形成的支持 总被引:2,自引:0,他引:2
为探讨骨髓基质细胞在液体条件下支持造血的能力,对小鼠骨髓有核细胞体外培养,在液体培养基中形成基质细胞贴壁层,更换培养液,再种植骨髓有核细胞。结果在贴壁的基质细胞上形成了细胞集落。按细胞形态特征分为两类:一类为基质细胞集落,仅为偶见。另一类为造血细胞集落,数量较多,并且集落通过一定的结构与贴壁的基质细胞连接。结果提示,造血细胞集落的形成,需要有与骨髓基质细胞接触的微环境,并可对基质细胞的生长发育有一定的反作用。本文提出了造血细胞集落的液体培养法。 相似文献
10.
从高原部队医院实际出发,阐述了适应新形势谋求新发展应处理好的七个关系:即继承与创新的关系;坚持“姓军为兵的服务方向与对外有偿服务的关系;基础建设与人才建设的关系;日常医疗保障与科研的关系;发挥自身特色与学习借鉴的关系;硬件建设与软件建设的关系;科技研究与成果转化的关系。 相似文献