全文获取类型
收费全文 | 174527篇 |
免费 | 804篇 |
专业分类
耳鼻咽喉 | 1172篇 |
儿科学 | 6607篇 |
妇产科学 | 3005篇 |
基础医学 | 16351篇 |
口腔科学 | 1539篇 |
临床医学 | 12253篇 |
内科学 | 30517篇 |
皮肤病学 | 652篇 |
神经病学 | 16345篇 |
特种医学 | 8889篇 |
外科学 | 28693篇 |
综合类 | 2307篇 |
预防医学 | 18008篇 |
眼科学 | 2725篇 |
药学 | 9374篇 |
中国医学 | 623篇 |
肿瘤学 | 16271篇 |
出版年
2018年 | 21917篇 |
2017年 | 17361篇 |
2016年 | 19509篇 |
2015年 | 885篇 |
2014年 | 772篇 |
2013年 | 724篇 |
2012年 | 6885篇 |
2011年 | 20921篇 |
2010年 | 18765篇 |
2009年 | 11470篇 |
2008年 | 19416篇 |
2007年 | 21623篇 |
2006年 | 466篇 |
2005年 | 2095篇 |
2004年 | 3302篇 |
2003年 | 4269篇 |
2002年 | 2424篇 |
2001年 | 257篇 |
2000年 | 400篇 |
1999年 | 150篇 |
1998年 | 191篇 |
1997年 | 196篇 |
1996年 | 83篇 |
1995年 | 95篇 |
1994年 | 93篇 |
1993年 | 57篇 |
1992年 | 34篇 |
1991年 | 84篇 |
1990年 | 121篇 |
1989年 | 73篇 |
1988年 | 50篇 |
1987年 | 37篇 |
1986年 | 21篇 |
1985年 | 28篇 |
1984年 | 18篇 |
1983年 | 20篇 |
1982年 | 24篇 |
1980年 | 39篇 |
1974年 | 19篇 |
1970年 | 19篇 |
1969年 | 20篇 |
1968年 | 17篇 |
1939年 | 20篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 22篇 |
1934年 | 30篇 |
1933年 | 14篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
Hernia - To find out the current status of the internet use of patients who undergo surgery for repair of their hernias. The patients who were diagnosed with abdominal wall hernia and scheduled for... 相似文献
3.
Jing-wei Liang Ting-jian Zhang Zuo-jing Li Zai-xing Chen Xin-li Yan Fan-hao Meng 《Medicinal chemistry research》2016,25(6):1115-1124
Aconitine compounds are found in Aconitum Ouwu head, Chuan Wu, Aconitum, and other Ranunculaceae aconitum plants, which are not only active ingredient but also toxic component. In present study, 20 antitumor target proteins of different types were selected from Protein Data Bank (http://www.rcsb.org), for the purpose of finding potential antitumor targets of aconitum alkaloids, top ranked proteins were screened by molecular docking method, using the docking module in Sybyl-X 1.1 and Molecular Operating Environment (MOE) 2008, and screening result was verified by protein–ligand interaction fingerprint (PLIF) in MOE. Mesaconitine showed a C-shaped conformation when docking into heat-shock protein 90 (HSP90), which was similar with ANSA ring of geldanamycin. And the PLIF indicated that they shared many common amino acid residues interacted with HSP90; equally, Yunaconitine was found having similar conformation with the inhibitor of poly ADP-ribose polymerase-1 (PARP-1). 相似文献
4.
The t(9;22) translocation that causes chronic myeloid leukemia (CML) drives both transformation and the progression process that eventually results in the disease changing to acute leukemia. Constitutively activated Bcr-Abl signaling in CML creates high levels of reactive oxygen species (ROS) that produce 8-oxo-guanine in DNA; this is mutagenic and causes chronic phase (CP) progression to blast phase (BP). We modeled three types of mutations involved in this progression: mutations that result in myeloid progenitor cells proliferating independently of external growth factors; mutations causing failure of myeloid progenitor cells to differentiate; and mutations that enable these cells to survive independently of attachment to marrow stroma. We further modeled tyrosine kinase inhibitors (TKI) as restoring myeloid cell apoptosis and preventing ROS-driven mutagenesis, and mutations that cause TKI resistance. We suggest that the unusually low rate of resistance to TKI arises because these drugs deplete ROS, which in turn decrease mutation rates. 相似文献
5.
Introduction
Stimulant medications are approved to treat attention deficit hyperactivity disorder (ADHD) in children over the age of 6 years. Fatal ingestion of stimulants by children has been reported, although most ingestions do not result in severe toxicity. Lisdexamfetamine dimesylate, a once daily long-acting stimulant, is a prodrug requiring conversion to its active form, dextroamphetamine, in the bloodstream. Based on its unique pharmacokinetics, peak levels of d-amphetamine are delayed. We describe a case of accidental ingestion of lisdexamfetamine dimesylate in an infant.Case Report
A previously healthy 10-month-old infant was admitted to the hospital with a 5-h history of tachycardia, hypertension, dyskinesia, and altered mental status of unknown etiology. Confirmatory urine testing, from a specimen collected approximately 16 h after the onset of symptoms, revealed an urine amphetamine concentration of 22,312 ng/mL (positive cutoff 200 ng/mL). The serum amphetamine concentration, from a specimen collected approximately 37 h after the onset of symptoms, was 68 ng/mL (positive cutoff 20 ng/mL). Urine and serum were both negative for methamphetamine, methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA, Ecstasy), and methylenedioxyethamphetamine (MDEA). During the hospitalization, it was discovered that the infant had access to lisdexamfetamine dimesylate prior to the onset of symptoms.Conclusion
Amphetamine ingestions in young children are uncommon but do occur. Clinicians should be aware of signs and symptoms of amphetamine toxicity and consider ingestion when a pediatric patient presents with symptoms of a sympathetic toxidrome even when ingestion is denied.6.
7.
8.
Raimund Geene Antje Richter-Kornweitz Petra Strehmel Susanne Borkowski 《Pr?vention und Gesundheitsf?rderung》2016,11(4):230-236
Background
The German law to strengthen health promotion and prevention (Prevention Law, PraevG 2015) along with the Federal Recommendations Framework recognize daycare centers for children as a central setting for health promotion. However, concrete regulations and strategies to support implementation are currently lacking.Objective
The objective of this article is to discuss how day-care centers for children can be established as a central setting for health promotion in practice.Methods
The new legal regulations for the setting approach and the agreements with daycare centers of the national prevention conference are presented, the field-specific challenges for health care promotion in daycare enters are compared, the current situation is analyzed, and the needs for action are identified based on the evaluation of the health objective and the federal health report.Results
The Prevention Law (PraevG 2015) has substantially improved the situation to initiate health promotion activities in daycare centers for children. Educational frameworks offer a number of points for further contact regarding health promotion activities. While a large number of health promotion activities already exist, they mainly tend to be isolated projects offered by various health insurance funds rather than a coordinated approach.Conclusion
New opportunities should be used to focus on quality development and coordination of the existing programs with due consideration of field-specific requirements. A comprehensive strategy to promote and guide coordinated efforts for activities is needed to replace the current trend of isolated programs.9.
M. Teresa Boquete Valeria Spagnuolo J. Ángel Fernández Jesús R. Aboal Ivana Imperatore Simonetta Giordano 《Ecotoxicology (London, England)》2016,25(10):1812-1821
In this study, we used amplified fragment length polymorphism analysis to investigate the genetic structure of the terrestrial moss Pseudoscleropodium purum (Hedw.) M. Fleish. naturally exposed to different levels of atmospheric deposition of heavy metals. We also determined the heavy metal concentrations in samples of this moss to evaluate whether there was a relationship between atmospheric pollution and population genetic diversity. A low level of genetic diversity and a limited gene flow among populations were observed which is in accordance to the prevalence of asexual reproduction in this species. In addition, no significant correlation was found between metal content and gene diversity in P. purum, probably because of the common history of the sampled populations and/or to the lack of a drastic reduction of the size of the population; nonetheless, a clear genetic structure was evident in relation to the existing pollution gradient. Thus, based on the results of the principal coordinate analysis and Bayesian analysis of the genotypes, the mixed structure of the second most polluted population would suggest an ongoing differentiation of metal-tolerant genotypes in the most polluted sites of the sampling area. 相似文献
10.
An increasing number of newly discovered drugs are poorly water-soluble and the use of natural and synthetic lipids to improve the oral bioavailability of these drugs by utilizing the digestion pathway in-vivo has proved an effective formulation strategy. The mechanisms responsible for lipid digestion and drug solubilisation during gastrointestinal transit have been explored in detail, but the implications of drug precipitation beyond the potential adverse effect on bioavailability have received attention only in recent years. Specifically, these implications are that different solid forms of drug on precipitation may affect the total amount of drug absorbed in-vivo through their different physico-chemical properties, and the possibility that the dynamic environment of the small intestine may afford re-dissolution of precipitated drug if present in a high-energy form. This review describes the events that lead to drug precipitation during the dispersion and digestion of lipid based formulations, common methods used to inhibit precipitation, as well as conventional and newly emerging characterization techniques for studying the solid state form of the precipitated drug. Moreover, selected case studies are discussed where drug precipitation has ensued from the digestion of lipid based formulations, as well as the apparent link between drug ionisability and altered solid forms on precipitation, culminating in a discussion about the importance of the solid form on precipitation with relevance to the total drug absorbed. 相似文献