全文获取类型
| 收费全文 | 835603篇 |
| 免费 | 61463篇 |
| 国内免费 | 9116篇 |
专业分类
| 耳鼻咽喉 | 10424篇 |
| 儿科学 | 24724篇 |
| 妇产科学 | 19616篇 |
| 基础医学 | 127679篇 |
| 口腔科学 | 22772篇 |
| 临床医学 | 79269篇 |
| 内科学 | 155714篇 |
| 皮肤病学 | 17800篇 |
| 神经病学 | 57275篇 |
| 特种医学 | 30355篇 |
| 外国民族医学 | 143篇 |
| 外科学 | 119248篇 |
| 综合类 | 33096篇 |
| 现状与发展 | 33篇 |
| 一般理论 | 168篇 |
| 预防医学 | 59153篇 |
| 眼科学 | 20003篇 |
| 药学 | 66952篇 |
| 71篇 | |
| 中国医学 | 7779篇 |
| 肿瘤学 | 53908篇 |
出版年
| 2022年 | 6441篇 |
| 2021年 | 10454篇 |
| 2020年 | 7142篇 |
| 2019年 | 8926篇 |
| 2018年 | 11862篇 |
| 2017年 | 9639篇 |
| 2016年 | 10099篇 |
| 2015年 | 12393篇 |
| 2014年 | 16187篇 |
| 2013年 | 20851篇 |
| 2012年 | 28465篇 |
| 2011年 | 30278篇 |
| 2010年 | 18003篇 |
| 2009年 | 16223篇 |
| 2008年 | 25627篇 |
| 2007年 | 27559篇 |
| 2006年 | 27755篇 |
| 2005年 | 26174篇 |
| 2004年 | 23883篇 |
| 2003年 | 22591篇 |
| 2002年 | 21742篇 |
| 2001年 | 41974篇 |
| 2000年 | 42762篇 |
| 1999年 | 36095篇 |
| 1998年 | 10716篇 |
| 1997年 | 9103篇 |
| 1996年 | 8681篇 |
| 1995年 | 8116篇 |
| 1994年 | 7370篇 |
| 1993年 | 6545篇 |
| 1992年 | 25352篇 |
| 1991年 | 24988篇 |
| 1990年 | 24208篇 |
| 1989年 | 23819篇 |
| 1988年 | 21565篇 |
| 1987年 | 20771篇 |
| 1986年 | 19645篇 |
| 1985年 | 18276篇 |
| 1984年 | 13302篇 |
| 1983年 | 11219篇 |
| 1979年 | 11793篇 |
| 1978年 | 8197篇 |
| 1977年 | 6883篇 |
| 1976年 | 6656篇 |
| 1975年 | 7327篇 |
| 1974年 | 8568篇 |
| 1973年 | 8229篇 |
| 1972年 | 7724篇 |
| 1971年 | 7180篇 |
| 1970年 | 6936篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
91.
目的 通过UHPLC-Q-TOF-MS代谢组学探讨艾灸关元穴对老年大鼠肾代谢物的影响，进而为艾灸关元穴的作用机制提供参考。方法 将8月龄SD雄性大鼠设为成年对照组（8只），21月龄SD雄性大鼠随机分为老年对照组（8只）、老年金匮肾气丸组（7只）、老年艾灸组（8只）。老年金匮肾气丸组每日按体重给药，老年艾灸组每日艾灸关元穴15 min，均每周5天。实验持续13周后检测大鼠肾组织线粒体呼吸耗氧速率、琥珀酸脱氢酶（SDH）活性以及血清肾功能指标，观察肾脏病理变化，结合UHPLC-Q-TOF-MS技术对大鼠的肾组织进行代谢轮廓分析，筛选代谢差异物并进行鉴定。结果 与老年对照组比较，老年艾灸组大鼠肾线粒体的呼吸耗氧速率和SDH酶的活力显著提高（P<0.01）。代谢组学结果显示，肾组织中筛选出13个共同差异化合物，分别是丁酸十二烷基酯、亚油酰胺、5-甲基四氢叶酸、PC（16∶0/22∶5（7Z，10Z，13Z，16Z，19Z））、6，8-二羟基嘌呤、1，2，3-丙烷三羧酸、3-（4-甲氧基苯基）-2-氧代丙酸、吲哚-3-乙酰甘氨酸、亚麻油酸、9，10-环氧十八烷酸、二十二碳五烯酸（22n-6）、牛磺胆酸、LysoPS （18∶0/0∶0）。结论 艾灸关元穴可通过调控老年大鼠的牛磺酸和亚牛磺酸代谢、α-亚麻酸代谢、亚油酸代谢、甘油磷脂代谢来调节肾的能量代谢。 相似文献
92.
周天保 《中华移植杂志(电子版)》2019,13(3):252-254
目前，国内外肝移植学界对肝移植术后急性排斥反应(AR)的机制阐释为T细胞介导的细胞免疫应答，但为获得长期生存仍需长期乃至终身服用免疫抑制剂。即使如此，临床上AR仍时有发生，并导致相当一部分受者移植肝功能丧失，更重要的是受者术后还受到感染、肿瘤和其他一系列不良反应及沉重经济负担的影响。因此，为肝移植AR机制提出新的理论解释，更全面深入阐明肝移植免疫排斥反应的内在机制，进而依据新的机制研制出新型免疫抑制剂已势在必行。本文就B细胞介导的体液免疫应答在肝移植AR中的作用作一综述。 相似文献
93.
Joseph F. Levy Rahul Khairnar Alexander V. Louie Timothy N. Showalter C. Daniel Mullins Mark V. Mishra 《Practical radiation oncology》2019,9(2):e172-e179
Purpose
A hydrogel rectal spacer (HRS) is a medical device that is approved by the U.S. Food and Drug Administration to increase the separation between the prostate and rectum. We conducted a cost-effectiveness analysis of HRS use for reduction in radiation therapy (RT) toxicities in patients with prostate cancer (PC) undergoing external beam RT (EBRT).Methods and Materials
A multistate Markov model was constructed from the U.S. payer perspective to examine the cost-effectiveness of HRS in men with localized PC receiving EBRT (EBRT alone vs EBRT + HRS). The subgroups analyzed included site of HRS placement (hospital outpatient, physician office, ambulatory surgery center) and proportion of patients with good baseline erectile function (EF). Data on EF, gastrointestinal and genitourinary toxicities incidence, and potential risks associated with HRS implantation were obtained from a recently published randomized clinical trial. Health utilities and costs were derived from the literature and the 2018 Physician Fee Schedule and were discounted 3% annually. Quality-adjusted life years (QALYs) and costs were modeled for a 5-year period from receipt of RT. Probabilistic sensitivity analysis and value-based threshold analyses were conducted.Results
The per-patient 5-year incremental cost for spacers administered in a hospital outpatient setting was $3578, and the incremental effectiveness was 0.0371 QALYs. The incremental cost-effectiveness ratio was $96,440/QALY for patients with PC undergoing HRS insertion in a hospital and $39,286/QALY for patients undergoing HRS insertion in an ambulatory facility. For men with good baseline EF, the incremental cost-effectiveness ratio was $35,548/QALY and $9627/QALY in hospital outpatient and ambulatory facility settings, respectively.Conclusions
Based on the current Medicare Physician Fee Schedule, HRS is cost-effective at a willingness to pay threshold of $100,000. These results contain substantial uncertainty, suggesting more evidence is needed to refine future decision-making. 相似文献94.
95.
Michael W. Manning Yi-Ju Li Dean Linder John C. Haney Yi-Hung Wu Mihai V. Podgoreanu Madhav Swaminathan Jacob N. Schroder Carmelo A. Milano Ian J. Welsby Mark Stafford-Smith Kamrouz Ghadimi 《Journal of cardiothoracic and vascular anesthesia》2021,35(5):1310-1318
- Download : Download high-res image (215KB)
- Download : Download full-size image
96.
Xiaojie Wu Leyan Zhang Jiadi Zhou Luying Liu Qiang Fu Aili Fu Xiaoying Feng Rui Xin Hongrui Liu Yong Gao Jiangnan Xue 《Current problems in cancer》2019,43(1):18-26
Aim
Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an immune inhibitory receptor which is expressed within most types of hematopoietic cells and negatively regulates immune responses. Recently, we found LAIR-1 expression to be present within tumors of nonhematopoietic lineages. However, the roles of LAIR-1 in hepatocellular carcinoma (HCC) have yet to be examined. The purpose of this study was to investigate the expression of LAIR-1 in HCC tissue and assess its clinical significance at this site.Materials and methods
Expression levels of LAIR-1 within HCC samples collected from 90 patients and compared with that of slides of normal liver tissue collected from 9 non-HCC patients were measured by immunohistochemistry using tissue microarrays. A semiquantitative score was assigned, as was based on staining intensity and percent of positive cells and a Spearman Rank correlation test was used to assess any potential significant correlations between LAIR-1 expression and clinicopathological factors. Overall survival analysis was performed using the Kaplan-Meier and Log Rank statistical test.Results
LAIR-1 expression was detected in cancer tissue and adjacent tumor tissue, but not in normal liver tissue. The percent of LAIR-1-positive expression in cancer tissue of HCC samples was 97.78% (88/90) while that in adjacent tumor tissue was 96.67% (87/90). Significantly greater expression levels of LAIR-1 were obtained from cancer tissue (Mean?±?SD?=?5.722?±?2.145) than that in adjacent tumor tissue (4.141?±?1.486). In addition, LAIR-1 expression was found to be significantly correlated with pathological grade of HCC, T stage, and age. Expression levels of LAIR-1 were related with worse overall survival rates of HCC patients, especially in HCC patients with hepatic cirrhosis.Conclusion
Results of this study show that LAIR-1 is expressed in HCC tissues and that high levels of LAIR-1 expression are associated with the poor cancer differentiation. In addition, overexpression of LAIR-1 was significantly associated with worse overall survival in the patients with HCC. These data suggest that LAIR-1 may be an independent predictor for clinical outcomes in patients with HCC. 相似文献97.
98.
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
99.
目的 运用网状Meta分析方法评价针灸联合关节松动术治疗肩周炎的疗效。方法 运用计算机检索Web of Science、PubMed、Cochrane Library、EMbase、维普（VIP）、中国知网（CNKI）、万方（Wanfang）、中国生物医学文献数据库（CBM），搜寻有关针灸联合关节松动术治疗肩周炎的随机对照试验。所有研究人员均独立纳排文献、提录资料、风险评估，对符合质量标准的RCT研究采用Stata16.0和Review Manager 5.4软件进行分析。结果 共检索出6561篇文献，最终纳入37项研究，涉及10种针灸联合关节松动术方法。总样本量2890例，其中试验组1432例，对照组1458例。网状Meta分析所得结果表明：①在总有效率方面，最好的3种治疗方法为内热针联合组、温针联合组、动筋针联合组；②在降低VAS评分方面，最好的3种治疗方法为内热针联合组、动筋针联合组、针刀联合组。结论 针灸联合关节松动术治疗肩周炎疗效总体优于单独使用，且内热针联合组具有最佳的疗效。 相似文献
100.