全文获取类型
收费全文 | 18572篇 |
免费 | 1319篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 153篇 |
儿科学 | 656篇 |
妇产科学 | 573篇 |
基础医学 | 2449篇 |
口腔科学 | 345篇 |
临床医学 | 1956篇 |
内科学 | 3488篇 |
皮肤病学 | 347篇 |
神经病学 | 1381篇 |
特种医学 | 582篇 |
外科学 | 2862篇 |
综合类 | 651篇 |
一般理论 | 9篇 |
预防医学 | 1242篇 |
眼科学 | 499篇 |
药学 | 1135篇 |
2篇 | |
中国医学 | 101篇 |
肿瘤学 | 1587篇 |
出版年
2023年 | 208篇 |
2022年 | 283篇 |
2021年 | 551篇 |
2020年 | 359篇 |
2019年 | 490篇 |
2018年 | 554篇 |
2017年 | 417篇 |
2016年 | 462篇 |
2015年 | 510篇 |
2014年 | 642篇 |
2013年 | 836篇 |
2012年 | 1278篇 |
2011年 | 1384篇 |
2010年 | 763篇 |
2009年 | 721篇 |
2008年 | 1083篇 |
2007年 | 1104篇 |
2006年 | 1039篇 |
2005年 | 1037篇 |
2004年 | 932篇 |
2003年 | 864篇 |
2002年 | 774篇 |
2001年 | 551篇 |
2000年 | 431篇 |
1999年 | 383篇 |
1998年 | 148篇 |
1997年 | 133篇 |
1996年 | 114篇 |
1995年 | 102篇 |
1994年 | 78篇 |
1993年 | 64篇 |
1992年 | 167篇 |
1991年 | 159篇 |
1990年 | 166篇 |
1989年 | 181篇 |
1988年 | 138篇 |
1987年 | 141篇 |
1986年 | 110篇 |
1985年 | 91篇 |
1984年 | 63篇 |
1983年 | 48篇 |
1982年 | 26篇 |
1981年 | 39篇 |
1980年 | 36篇 |
1979年 | 56篇 |
1978年 | 39篇 |
1977年 | 35篇 |
1976年 | 28篇 |
1975年 | 26篇 |
1973年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Stephan Koter Tina U. Cohnert Korbinian B. Hindermayr Jörg Lindenmann Maximilian Brückner Wolfgang K. Oswald Georg Werkgartner Doris Wagner 《Journal of vascular surgery》2019,69(4):1227-1232
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献4.
Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed. 相似文献
5.
6.
7.
Ming-Yeh Yang Ching-Yuan Huang Tina H.T. Chiu Kai-Chih Chang Ming-Nan Lin Liang-Yü Chen Anren Hu 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2019,27(2):494-501
Vitamin D is responsible for multiple metabolic functions in humans. Rickets are the most common disease caused by vitamin D deficiency. It is caused by poor calcium intake resulting in poor serum-ionized calcium. The purpose of this study is to develop a rapid, sensitive, and feasible method to determine the 25-hydroxy-vitamin D3 (25(OH)D3) levels in blood samples for clinical assessment. In this study, gas chromatography coupled mass spectrometry with trimethylsilyl derivatization (TMS-GC-MS) is the most suitable protocol for quantitative analyses of 25(OH)D3. Performance of method was evaluated and compared with liquid chromatography and immunoassay. Method validation has been carried out with plasma specimens. The limit of quantitation of TMS-GC-MS method is 1.5 ppb with good linear correlation. Furthermore, the dietary intake and nutritional status of vegetarian and non-vegetarians in Taiwan were assessed by our validated method. As a result, this vitamin D nutrition survey demonstrates that most Taiwanese people have insufficient vitamin D. Due to dietary habits; the male vegans may have the highest risk of vitamin D deficiency. 相似文献
8.
Chan C. H. Y Ng E. H. Y Chan C. L W 《世界核心医学期刊文摘》2006,2(6):15-15
目的:评价东部身体-智力-精神(EBMS)群体干预对进行体外受精(IVF)的中国妇女焦虑缓解的作用。设计:随机对照研究。机构:三级辅助生殖机构。受试者:227例接受第1个IVF周期治疗的妇女。干预:干预组(n=69)接受4次EBMS群体咨询,而对照组(n=115)无任何干预。主要观察指标:状态-特质焦虑问卷。结果:与对照组相比,干预组在干预后状态焦虑平均分显著下降。每组移植同样数目的卵子,但干预组没有明显更高妊娠率的倾向。 相似文献
9.
INTRODUCTION: The clinical presentation of morphea varies from localized plaques to generalized eruptions. Its cause remains unknown and medical treatments have often proved unsatisfactory. Studies have previously shown that improvement of hypertrophic scars and fibrotic skin can be achieved with the use of a 585 nm pulsed dye laser (PDL). METHODS: A case of plaque-type morphea was treated with 585 nm pulsed dye laser irradiation at an average fluence of 5.0 J/cm2 at bimonthly time intervals. RESULTS: Marked clinical improvement as evidenced by improved pliability and skin coloration was seen after 4 successive PDL treatments. No side effects or complications were encountered. CONCLUSION: Pulsed dye laser therapy is a viable treatment option for morphea. The mechanism of its effect in this condition remains unknown. 相似文献
10.