全文获取类型
收费全文 | 1445671篇 |
免费 | 124957篇 |
国内免费 | 14115篇 |
专业分类
耳鼻咽喉 | 17665篇 |
儿科学 | 44380篇 |
妇产科学 | 38742篇 |
基础医学 | 196079篇 |
口腔科学 | 38215篇 |
临床医学 | 135195篇 |
内科学 | 294290篇 |
皮肤病学 | 33182篇 |
神经病学 | 116047篇 |
特种医学 | 59572篇 |
外国民族医学 | 344篇 |
外科学 | 221860篇 |
综合类 | 49993篇 |
现状与发展 | 26篇 |
一般理论 | 417篇 |
预防医学 | 113087篇 |
眼科学 | 31451篇 |
药学 | 105545篇 |
116篇 | |
中国医学 | 8134篇 |
肿瘤学 | 80403篇 |
出版年
2021年 | 12816篇 |
2019年 | 12996篇 |
2018年 | 17383篇 |
2017年 | 14195篇 |
2016年 | 16129篇 |
2015年 | 19344篇 |
2014年 | 26272篇 |
2013年 | 35574篇 |
2012年 | 44813篇 |
2011年 | 48307篇 |
2010年 | 30159篇 |
2009年 | 28461篇 |
2008年 | 42598篇 |
2007年 | 45021篇 |
2006年 | 46173篇 |
2005年 | 44760篇 |
2004年 | 40980篇 |
2003年 | 39816篇 |
2002年 | 37161篇 |
2001年 | 68729篇 |
2000年 | 70615篇 |
1999年 | 59365篇 |
1998年 | 18046篇 |
1997年 | 16241篇 |
1996年 | 16705篇 |
1995年 | 17560篇 |
1994年 | 16253篇 |
1993年 | 14861篇 |
1992年 | 48112篇 |
1991年 | 46658篇 |
1990年 | 44736篇 |
1989年 | 42487篇 |
1988年 | 39331篇 |
1987年 | 38603篇 |
1986年 | 36243篇 |
1985年 | 34989篇 |
1984年 | 26532篇 |
1983年 | 22212篇 |
1982年 | 13910篇 |
1981年 | 12506篇 |
1979年 | 23601篇 |
1978年 | 17069篇 |
1977年 | 14369篇 |
1976年 | 13177篇 |
1975年 | 13735篇 |
1974年 | 16118篇 |
1973年 | 15409篇 |
1972年 | 14186篇 |
1971年 | 13042篇 |
1970年 | 11874篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
慢性疼痛是一种复杂的身心疾病,包括躯体痛觉异常、认知障碍、负性情绪等多个方面的改变,同时伴随着神经系统的功能以及结构的改变。本文将对慢性疼痛与下行疼痛调节通路、疼痛情感-认知调控网络以及中脑边缘奖赏网络的相关性,以及针刺镇痛的中枢机制相关研究文献进行综述,旨在探讨下行疼痛调节通路、疼痛情感-认知调控网络以及中脑边缘奖赏网络在慢痛发生机制中的作用,为临床治疗慢性疼痛类疾病提供更优势的治疗方案。 相似文献
13.
14.
Moskaleva P. V. Shnayder N. A. Dmitrenko D. V. Shilkina O. S. Neznanov N. G. Nasyrova R. F. 《Neuroscience and behavioral physiology》2022,52(3):462-469
Neuroscience and Behavioral Physiology - The question of the involvement of impairments to the metabolism of melatonin and its precursors (tryptophan and serotonin) in the development of... 相似文献
15.
Andreas Lundin Martin Annborn Ola Borgquist Joachim Düring Johan Undén Christian Rylander 《Acta anaesthesiologica Scandinavica》2023,67(5):655-662
Patients admitted to intensive care after cardiac arrest are at risk of circulatory shock and early mortality due to cardiovascular failure. The aim of this study was to evaluate the ability of the veno-arterial pCO2 difference (∆pCO2; central venous CO2 – arterial CO2) and lactate to predict early mortality in postcardiac arrest patients. This was a pre-planned prospective observational sub-study of the target temperature management 2 trial. The sub-study patients were included at five Swedish sites. Repeated measurements of ∆pCO2 and lactate were conducted at 4, 8, 12, 16, 24, 48, and 72 h after randomization. We assessed the association between each marker and 96-h mortality and their prognostic value for 96-h mortality. One hundred sixty-three patients were included in the analysis. Mortality at 96 h was 17%. During the initial 24 h, there was no difference in ∆pCO2 levels between 96-h survivors and non-survivors. ∆pCO2 measured at 4 h was associated with an increased risk of death within 96 h (adjusted odds ratio: 1.15; 95% confidence interval [CI]: 1.02–1.29; p = .018). Lactate levels were associated with poor outcome over multiple measurements. The area under the receiving operating curve to predict death within 96 h was 0.59 (95% CI: 0.48–0.74) and 0.82 (95% CI: 0.72–0.92) for ∆pCO2 and lactate, respectively. Our results do not support the use of ∆pCO2 to identify patients with early mortality in the postresuscitation phase. In contrast, non-survivors demonstrated higher lactate levels in the initial phase and lactate identified patients with early mortality with moderate accuracy. 相似文献
16.
目的 评价美国国家电器制造协会(National Electrical Manufactures Association, NEMA)最新标准(NU 2-2018)在正电子发射型计算机断层显像/电子计算机断层显像(positron emission tomography/computed tomography, PET/CT)设备性能检测中的作用。 方法 依据最新的NEMA NU 2-2018标准,检测西门子Biograph Vision PET/CT的空间分辨率、灵敏度、散射分数、计数丢失、随机符合、飞行时间分辨率、计数丢失率和随机符合校正精度、图像质量、衰减和散射校正精度及PET与CT配准精度指标。 结果 距视野中心1 cm处横向和轴向空间分辨率分别为3.75 mm和3.76 mm;在视野中心和轴向10 cm处的灵敏度分别为16.83 kcps/MBq和16.67 kcps/MBq;放射性浓度为27.37 kBq/mL时,最大等效噪声计数率为258.26 kcps,散射分数为38.58%;系统时间分辨率为209.82 ps;图像质量模型的对比度恢复系数范围为88.9%~96.2%,背景变异系数范围为2.05%~6.80%,平均肺插件残余误差为2.43%;计数丢失和随机符合校正最大误差为3.9%;距离床板末端 5 cm 和 100 cm处,在距视野中心Y轴1 cm处,PET和CT的配准精度分别为0.46 mm和1.07 mm,在距视野中心X轴20 cm处,PET和CT的配准精度分别为1.06 mm和1.45 mm,在距视野中心Y轴20 cm处PET和CT的配准精度分别为0.85 mm和1.15 mm。 结论 NEMA NU 2-2018标准检测条件更加接近临床,能更好地反映PET/CT设备的系统性能。 相似文献
17.
18.
Gordon K. B. Saburov V. O. Koryakin S. N. Gulidov I. A. Fatkhudinov T. Kh. Arutyunyan I. V. Kaprin A. D. Solov’ev A. N. 《Bulletin of experimental biology and medicine》2022,173(2):281-285
Bulletin of Experimental Biology and Medicine - Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a... 相似文献
19.
20.
Mursheda Begum Grant Lewison Xiang Wang Philip D. Dunne Tim Maughan Richard Sullivan Mark Lawler 《International journal of cancer. Journal international du cancer》2023,152(3):470-479
The purpose of this study was to provide an evidence base for colorectal cancer research activity that might influence policy, mainly at the national level. Improvements in healthcare delivery have lengthened life expectancy, but within a situation of increased cancer incidence. The disease burden of CRC has risen significantly, particularly in Africa, Asia and Latin America. Research is key to its control and reduction, but few studies have delineated the volume and funding of global research on CRC. We identified research papers in the Web of Science (WoS) from 2007 to 2021, and determined the contributions of the leading countries, the research domains studied, and their sources of funding. We identified 62 716 papers, representing 5.7% of all cancer papers. This percentage was somewhat disproportionate to the disease burden (7.7% in 2015), especially in Eastern Europe. International collaboration increased over the time period in almost all countries except in China. Genetics, surgery and prognosis were the leading research domains. However, research on palliative care and quality-of-life in CRC was lacking. In Western Europe, the main funding source was the charity sector, particularly in the UK, but in most other countries government played the leading role, especially in China and the USA. There was little support from industry. Several Asian countries provided minimal contestable funding, which may have reduced the impact of their CRC research. Certain countries must perform more CRC research overall, especially in domains such as screening, palliative care and quality-of-life. The private-non-profit sector should be an alternative source of support. 相似文献