全文获取类型
收费全文 | 1346篇 |
免费 | 89篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 45篇 |
妇产科学 | 67篇 |
基础医学 | 204篇 |
口腔科学 | 29篇 |
临床医学 | 120篇 |
内科学 | 274篇 |
皮肤病学 | 26篇 |
神经病学 | 178篇 |
特种医学 | 35篇 |
外科学 | 135篇 |
综合类 | 1篇 |
一般理论 | 2篇 |
预防医学 | 68篇 |
眼科学 | 20篇 |
药学 | 91篇 |
中国医学 | 2篇 |
肿瘤学 | 145篇 |
出版年
2024年 | 4篇 |
2023年 | 39篇 |
2022年 | 65篇 |
2021年 | 86篇 |
2020年 | 65篇 |
2019年 | 68篇 |
2018年 | 81篇 |
2017年 | 45篇 |
2016年 | 65篇 |
2015年 | 64篇 |
2014年 | 65篇 |
2013年 | 72篇 |
2012年 | 98篇 |
2011年 | 112篇 |
2010年 | 61篇 |
2009年 | 44篇 |
2008年 | 86篇 |
2007年 | 60篇 |
2006年 | 63篇 |
2005年 | 58篇 |
2004年 | 56篇 |
2003年 | 34篇 |
2002年 | 37篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1976年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有1452条查询结果,搜索用时 15 毫秒
1.
2.
Aldo Becciolini Manuela Balzi Paola Faraoni Elena Tisti Giorgia Zappoli Thyrion Valentino Giach Luca Bandettini Christopher S. Potten 《Acta oncologica (Stockholm, Sweden)》1998,37(1):65-71
Cell kinetics parameters have been analysed in colonic mucosa at different distances from a tumour in patients with colon carcinoma. Total cell number (TCN), H thymidine labelling index (TLI), mitotic index (MI), Goblet cell index (GCI) and the distribution of labelled cells along the crypt column (cell position frequency plot) were determined in well-aligned crypts. Total cell number, GCI and the labelled cell position frequency plots were similar in different samples from the same individual. A negative linear correlation between TCN and TLI was observed. The analysis of the cell position plots showed two patterns 1) with a high concentration in the bottom fifth of the crypt and 2) with frequent labelled cells at high positions. Whereas a negative correlation between overall TLI and the percent contribution to the TLI of the lowermost fifth was seen, the correlation was positive for the next 3 fifths and labelling was absent in the last part of the crypt. 相似文献
3.
BACKGROUND AND PURPOSE: To appraise the potential benefit of a conformal technique with non-coplanar fields to minimise lung irradiation in the radiation treatment of breast. PATIENTS AND METHODS: A comparative study was carried out at planning level for six patients selected for their inadequate sparing of healthy lung tissue with the reference tangential technique. Plans were designed for the conventional tangential technique, for an alternative conformal approach with three beams and for the newly proposed technique with two non-coplanar beams. RESULTS: In average for the new technique compared to the reference, mean lung dose dropped from approximately 16 to 10.5 Gy, V(20 Gy) from 29.5 to 18.2% and the dose delivered to 1/3 (1/4) of the lung volume dropped from 28.5% (67.3%) to 8.7% (13.4%). For PTV, the volume receiving at least 90% of the prescribed dose resulted 97.4% for the new and 97.3% for the reference. Conformity index improved significantly from 2.58 for the reference to 1.84 for the new technique. CONCLUSIONS: For a subgroup population of breast cancer patients, where conventional techniques failed to achieve high conformal avoidance, a treatment modality with non-coplanar beams was developed and clinically tested for six patients. It resulted dosimetrically adequate, particularly when the risk of toxicity is relevant. 相似文献
4.
Jason Doran Nabil Seyidov Samir Mehdiyev Giorgia Gon Esther Kissling Trent Herdman Javahir Suleymanova Ana Paula Couthino Rehse Richard Pebody Mark A. Katz Gahraman Hagverdiyev 《Influenza and other respiratory viruses》2022,16(4):626
IntroductionWe evaluated uptake and factors associated with COVID‐19 vaccination among health workers (HWs) in Azerbaijan.ResultsAmong 1575 HWs, 73% had received at least one dose, and 67% received two doses; all received CoronaVac. Factors associated with vaccination uptake included no previous COVID‐19 infection, older age, belief in the vaccine''s safety, previous vaccination for influenza, having patient‐facing roles and good or excellent health by self‐assessment.ConclusionThese findings could inform strategies to increase vaccination uptake as the campaign continues. 相似文献
5.
6.
7.
8.
Giorgia Del Favero Silvio Sosa Mark Poli Aurelia Tubaro Orfeo Sbaizero Paola Lorenzon 《Toxicology letters》2014
Palytoxins (PLTXs) are known seafood contaminants and their entrance into the food chain raises concern about possible effects on human health. The increasing number of analogs being identified in edible marine organisms complicates the estimation of the real hazard associated with the presence of PLTX-like compounds. So far, 42-OH-PLTX is one of the few congeners available, and the study of its toxicity represents an important step toward a better comprehension of the mechanism of action of this family of compounds. From this perspective, the aim of this work was to investigate the in vivo and in vitro effect of 42-OH-PLTX on skeletal muscle, one of the most sensitive targets for PLTXs. Our results demonstrate that 42-OH-PLTX causes damage at the skeletal muscle level with a cytotoxic potency similar to that of PLTX. 42-OH-PLTX induces cytotoxicity and cell swelling in a Na+-dependent manner similar to the parent compound. However, the limited Ca2+-dependence of the toxic insult induced by 42-OH-PLTX suggests a specific mechanism of action for this analog. Our results also suggest an impaired response to the physiological agonist acetylcholine and altered cell elasticity. 相似文献
9.
Elena Della Vecchia Alberto Modenese Tom Loney Martina Muscatello Marilia Silva Paulo Giorgia Rossi Fabriziomaria Gobba 《La Medicina del lavoro》2020,111(4):269
Background:The eye is an important sensory organ occupationally exposed to ionizing radiation (IR) in healthcare workers (HCWs) engaged in medical imaging (MI). New evidence highlights the possible induction of cataract at IR exposure levels to be much lower than expected in the past.Objective:Conduct an updated review on the current evidence on cataract risk in healthcare workers exposed to IR.Methods:Published scientific studies on cataract risk in IR exposed healthcare workers were collected through a systematic search of two biomedical databases (MEDLINE and Scopus). Data from included studies was extracted and summarized. Study quality was also assessed.Results:All 21 eligible studies reported an increased prevalence of cataract, especially posterior subcapsular cataract, in IR exposed HCWs with a higher prevalence in interventional cardiology staff.Discussion:Our review synthesizes the latest evidence to support the hypothesis of a significantly increased risk of occupational cataract in healthcare workers operating MI and exposed to IR, especially in interventional cardiologists. Data also support a dose-response relationship between IR exposure and the prevalence of opacities, especially posterior subcapsular opacities.Conclusions:Findings highlight the need for effective control measures including appropriate training, adherence to protective procedures, and a constant use of shields and eye personal protective equipment in healthcare workers with optical exposure to IR. Periodic health surveillance programs, possibly including lens evaluation, are also important to monitor cataract risk in these MI operators.Key words: Healthcare workers, ionizing radiation, cataract, radiation, radiology, radiologist work-related injury, occupational injury, occupational exposure, interventional radiology, radiation protection, radiation-induced cataract, interventional fluoroscopy, dosimetry, radiation workers, dosimeter, radiation effects 相似文献