全文获取类型
收费全文 | 265110篇 |
免费 | 19502篇 |
国内免费 | 9081篇 |
专业分类
耳鼻咽喉 | 2057篇 |
儿科学 | 4457篇 |
妇产科学 | 3860篇 |
基础医学 | 30581篇 |
口腔科学 | 4000篇 |
临床医学 | 24561篇 |
内科学 | 28611篇 |
皮肤病学 | 2482篇 |
神经病学 | 23762篇 |
特种医学 | 12028篇 |
外国民族医学 | 4篇 |
外科学 | 34314篇 |
综合类 | 39246篇 |
现状与发展 | 26篇 |
一般理论 | 9篇 |
预防医学 | 18484篇 |
眼科学 | 3124篇 |
药学 | 32134篇 |
93篇 | |
中国医学 | 15910篇 |
肿瘤学 | 13950篇 |
出版年
2024年 | 313篇 |
2023年 | 3492篇 |
2022年 | 4969篇 |
2021年 | 10774篇 |
2020年 | 9269篇 |
2019年 | 8662篇 |
2018年 | 8767篇 |
2017年 | 9701篇 |
2016年 | 9902篇 |
2015年 | 9425篇 |
2014年 | 12780篇 |
2013年 | 17910篇 |
2012年 | 14101篇 |
2011年 | 16714篇 |
2010年 | 11863篇 |
2009年 | 11666篇 |
2008年 | 13125篇 |
2007年 | 13973篇 |
2006年 | 13201篇 |
2005年 | 11918篇 |
2004年 | 10120篇 |
2003年 | 9100篇 |
2002年 | 7345篇 |
2001年 | 6536篇 |
2000年 | 5546篇 |
1999年 | 4683篇 |
1998年 | 3743篇 |
1997年 | 3755篇 |
1996年 | 3099篇 |
1995年 | 2864篇 |
1994年 | 2664篇 |
1993年 | 2228篇 |
1992年 | 2069篇 |
1991年 | 1861篇 |
1990年 | 1647篇 |
1989年 | 1385篇 |
1988年 | 1264篇 |
1987年 | 1182篇 |
1986年 | 1107篇 |
1985年 | 1577篇 |
1984年 | 1258篇 |
1983年 | 955篇 |
1982年 | 962篇 |
1981年 | 806篇 |
1980年 | 783篇 |
1979年 | 558篇 |
1978年 | 366篇 |
1977年 | 338篇 |
1976年 | 286篇 |
1975年 | 212篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
《Vaccine》2022,40(16):2370-2378
Porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae (M. hyopneumoniae, Mhp) are two of the most common pathogens involved in the porcine respiratory disease complex (PRDC) resulting in significant economic losses worldwide. Vaccination is the most effective approach to disease prevention. Since PRRSV and Mhp co-infections are very common, an efficient dual vaccine against these pathogens is required for the global swine industry. Compared with traditional vaccines, multi-epitope vaccines have several advantages, they are comparatively easy to produce and construct, are chemically stable, and do not have an infectious potential. In this study, to develop a safe and effective vaccine, B cell and T cell epitopes of PRRSV-GP5, PRRSV-M, Mhp-P46, and Mhp-P65 protein had been screened to construct a recombinant epitope protein rEP-PM that has good hydrophilicity, strong antigenicity, and high surface accessibility, and each epitope is independent and complete. After immunization in mice, rEP-PM could induce the production of high levels of antibodies, and it had good immunoreactivity with anti-rEP-PM, anti-PRRSV, and anti-Mhp antibodies. The anti-rEP-PM antibody specifically recognizes proteins from PRRSV and Mhp. Moreover, rEP-PM induced a Th1-dominant cellular immune response in mice. Our results showed that the rEP-PM protein could be a potential candidate for the development of a safe and effective multi-epitope peptide combined vaccine to control PRRSV and Mhp infections. 相似文献
22.
23.
Anne-Sophie Worm Fenger Markus Harboe Olsen Maria Louise Fabritius Christian Gunge Riberholt Kirsten Møller 《Acta anaesthesiologica Scandinavica》2023,67(2):240-247
Background
Hyperglycaemia is common in patients with acute brain injury admitted to an intensive care unit (ICU). Many studies have found associations between development of hyperglycaemia and increased mortality in hospitalised patients. However, the optimal target for blood glucose control is unknown. We want to conduct a systematic review with meta-analysis and trial sequential analysis to explore the beneficial and harmful effects of restrictive versus liberal glucose control on patient outcomes in adults with severe acute brain injury.Methods
We will systematically search medical databases including CENTRAL, Embase, MEDLINE and trial registries. We will search the following websites for ongoing or unpublished trials: http://www.controlled-trials.com/ , http://www.clinicaltrials.gov/ , www.eudraCT.com , http://centerwatch.com/ , The Cochrane Library's CENTRAL, PubMed, EMBASE, Science Citation Index Expanded and CINAHL. Two authors will independently review and select trials and extract data. We will include randomised trials comparing levels of glucose control in our analyses and observational studies will be included to address potential harms. The primary outcomes are defined as all-cause mortality, functional outcome and health-related quality of life. Secondary outcomes include serious adverse events including hypoglycaemia, length of ICU stay and duration of mechanical ventilation, and explorative outcomes including intracranial pressure and infection. Trial Sequential Analysis will be used to investigate the risk of type I error due to repetitive testing and to further explore imprecision. Quality of trials will be evaluated using the Cochrane Risk of Bias tool, and quality of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.Discussion
The results of the systematic review will be disseminated through peer-reviewed publication. With the review, we hope to inform future randomised clinical trials and improve clinical practice. 相似文献24.
25.
26.
27.
Xiying Fan Glen A. Bjerke Kent Riemondy Li Wang Rui Yi 《Molecular carcinogenesis》2019,58(12):2241-2253
MicroRNAs (miRNAs) play important roles in prostate cancer development. However, it remains unclear how individual miRNAs contribute to the initiation and progression of prostate cancer. Here we show that a basal layer‐enriched miRNA is required for prostate tumorigenesis. We identify miR‐205 as the most highly expressed miRNA and enriched in the basal cells of the prostate. Although miR‐205 is not required for normal prostate development and homeostasis, genetic deletion of miR‐205 in a Pten null tumor model significantly compromises tumor progression and does not promote metastasis. In Pten null basal cells, loss of miR‐205 attenuates pAkt levels and promotes cellular senescence. Furthermore, although overexpression of miR‐205 in prostate cancer cells with luminal phenotypes inhibits cell growth in both human and mouse, miR‐205 has a minimal effect on the growth of a normal human prostate cell line. Taken together, we have provided genetic evidence for a requirement of miR‐205 in the progression of Pten null‐induced prostate cancer. 相似文献
28.
This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.
The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same. 相似文献
29.
30.
《中国现代医生》2020,58(9):144-146+封三
目的探讨MSCT在对比剂外渗的急性腹部创伤性动脉损伤诊断中的应用价值。方法回顾性分析本院2016年1月~2018年12月收治的44例急性创伤性腹部动脉损伤患者及58例腹部非创伤性动脉病变患者影像资料,分析急性腹部创伤性和非创伤性动脉病变所致对比剂外渗的相关性。结果 44例创伤性腹部损伤患者通过MSCT及图像后处理技术共检出59支动脉损伤,其中对比剂外渗34支、非对比剂外渗共25支;58例急性腹部非创伤组共检出58支动脉病变,其中8支存在对比剂外渗。对比剂外渗征象创伤组出现率明显高于非创伤性组(χ~2=24.42,P0.05)。结论与非创伤组相比,急性腹部创伤性动脉损伤对比剂外渗征象较为常见,MSCT可以较好地显示创伤性对比剂外渗的直接及间接征象。 相似文献