全文获取类型
收费全文 | 63709篇 |
免费 | 4768篇 |
国内免费 | 337篇 |
专业分类
耳鼻咽喉 | 637篇 |
儿科学 | 1613篇 |
妇产科学 | 1543篇 |
基础医学 | 7867篇 |
口腔科学 | 1546篇 |
临床医学 | 6432篇 |
内科学 | 14515篇 |
皮肤病学 | 809篇 |
神经病学 | 5036篇 |
特种医学 | 2106篇 |
外国民族医学 | 2篇 |
外科学 | 9787篇 |
综合类 | 1020篇 |
现状与发展 | 1篇 |
一般理论 | 103篇 |
预防医学 | 5267篇 |
眼科学 | 1860篇 |
药学 | 4440篇 |
中国医学 | 139篇 |
肿瘤学 | 4091篇 |
出版年
2023年 | 303篇 |
2022年 | 464篇 |
2021年 | 1161篇 |
2020年 | 728篇 |
2019年 | 1011篇 |
2018年 | 1267篇 |
2017年 | 857篇 |
2016年 | 984篇 |
2015年 | 1153篇 |
2014年 | 1812篇 |
2013年 | 2851篇 |
2012年 | 3777篇 |
2011年 | 4128篇 |
2010年 | 2377篇 |
2009年 | 2233篇 |
2008年 | 4027篇 |
2007年 | 4203篇 |
2006年 | 4028篇 |
2005年 | 4121篇 |
2004年 | 3853篇 |
2003年 | 3458篇 |
2002年 | 3422篇 |
2001年 | 738篇 |
2000年 | 631篇 |
1999年 | 729篇 |
1998年 | 762篇 |
1997年 | 632篇 |
1996年 | 508篇 |
1995年 | 504篇 |
1994年 | 475篇 |
1993年 | 455篇 |
1992年 | 535篇 |
1991年 | 512篇 |
1990年 | 424篇 |
1989年 | 459篇 |
1988年 | 412篇 |
1987年 | 386篇 |
1986年 | 363篇 |
1985年 | 431篇 |
1984年 | 435篇 |
1983年 | 398篇 |
1982年 | 537篇 |
1981年 | 449篇 |
1980年 | 494篇 |
1979年 | 305篇 |
1978年 | 324篇 |
1977年 | 327篇 |
1976年 | 268篇 |
1975年 | 291篇 |
1974年 | 246篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
Measuring health care workers’ perceptions of what constitutes a compassionate organisation culture and working environment: Findings from a quantitative feasibility survey
下载免费PDF全文
![点击此处可从《Journal of nursing management》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Robert McSherry PhD RGN DipN B.Sc. MSc PGCE RT FHEC FFNRRCSI NTF Paddy Pearce RGN B.Sc. MSc 《Journal of nursing management》2018,26(2):127-139
912.
913.
George E. Badham Scott J. Dos Santos 《Minimally invasive therapy & allied technologies》2017,26(4):200-206
Aims: To investigate the thermal spread achieved in porcine liver when using an optimised radiofrequency ablation protocol and correlate findings with the effects seen in ex vivo great saphenous vein (GSV), in order to justify clinical use with the new treatment protocol.Material and methods: Porcine liver and GSV sections were treated with radiofrequency-induced thermotherapy (RFiTT) using the following settings: 20 W at 1?s/cm (linear endovenous energy density; LEED 20 J/cm), 18 W at 1?s/cm (LEED 18 J/cm), 18 W at 3?s/cm (LEED 54 J/cm), 6 W interrupted pull-back 6?s stationary every 0.5?cm (LEED 72 J/cm). Thermal spread in the liver was measured via digital imaging. GSV sections were sent to an independent laboratory for histological analysis. Previous work suggests a thermal spread of?>0.65?mm in liver correlates with transmural thermoablation of a GSV.Results: Parameters giving a LEED of 72 J/cm produced the best results, with a clear transmural effect in the GSV and maximal thermal spread of 1.65?mm, without excessive thermal damage or carbonisation in the ablation tract.Conclusions: Our porcine liver model correlated well with histological findings and was representative of the thermoablative effects observed in the GSV wall treated with RFiTT. Clinical investigations are now being carried out to investigate the efficacy of this protocol in the clinical setting. 相似文献
914.
915.
916.
917.
918.
919.
George R. Hoffmann Andrew V. Moczula Amanda M. Laterza Lindsey K. MacNeil Jason P. Tartaglione 《Environmental and molecular mutagenesis》2013,54(6):384-396
The assay for trp5 gene conversion and ilv1‐92 reversion in Saccharomyces cerevisiae strain D7 was used to characterize the induction of an adaptive response by hydrogen peroxide (H2O2). Effects of a small priming dose on the genotoxic effects of a larger challenge dose were measured in exponential cultures and in early stationary phase. An adaptive response, indicated by smaller convertant and revertant frequencies after the priming dose, occurred at lower priming and challenge doses in young, well‐aerated cultures. Closely spaced priming doses from 0.000975 to 2 mM, followed by a 1 mM challenge, showed that the induction of the adaptive response is biphasic. In exponential cultures it was maximal with a priming dose of 0.125–0.25 mM. Very small priming doses were insufficient to induce the adaptive response, whereas higher doses contributed to damage. A significant adaptive response was detected when the challenge dose was administered 10–20 min after the priming exposure. It was fully expressed within 45 min, and the yeast began to return to the nonadapted state after 4–6 hr. Because of the similarity of the biphasic induction to hormetic curves and the proposal that adaptive responses are a manifestation of hormesis, we evaluated whether the low doses of H2O2 that induce the adaptive response show a clear hormetic response without a subsequent challenge dose. Hormesis was not evident, but there was an apparent threshold for genotoxicity at or slightly below 0.125 mM. The results are discussed with respect to linear, threshold, and hormesis dose–response models. Environ. Mol. Mutagen. 54:384–396, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
920.
George Kosmadakis Enrique Da Costa Correia Odette Carceles Frederic Somda Didier Aguilera 《Renal failure》2014,36(4):638-650
Despite the significant technical evolution of the blood purification methods, cardiovascular morbidity and mortality in dialysis patients is still several times higher than that observed in the general population. Vitamins are playing a crucial role in multiple key metabolic pathways. Due to multiple factors, dialysis patients present very often hypo- or hypervitaminosis for a broad range of vitamins. Dialysis in the context of renal replacement therapy is associated with a non-physiological potassium-sparing dietetic regime. Additionally, there is a non-selective intradialytic loss of micro- and macronutrients, deranged intracellular kinetics and gastrointestinal malabsorption due to uratemia. Frequent treatment with antibiotics due to infections associated with the acquired uremia-related immunosuppression may derange the vitamin-producing intestinal microflora. Certain agents prescribed in the context of renal failure or other conditions may reduce the absorption of vitamins from the gastrointestinal tract. These factors may deplete a dialysis patient from vitamins, especially the ones with antioxidant activity that may be associated with cardioprotective properties. In other cases, vitamins metabolized and excreted by the kidneys may be accumulated and exert toxic effects. The scope of this paper is to describe the main issues on vitamin therapy in dialysis patients in view of the ever contradictory opinions and practices. 相似文献