全文获取类型
收费全文 | 243784篇 |
免费 | 21190篇 |
国内免费 | 14280篇 |
专业分类
耳鼻咽喉 | 2198篇 |
儿科学 | 3048篇 |
妇产科学 | 4884篇 |
基础医学 | 28385篇 |
口腔科学 | 4235篇 |
临床医学 | 31143篇 |
内科学 | 40129篇 |
皮肤病学 | 2825篇 |
神经病学 | 13624篇 |
特种医学 | 8581篇 |
外国民族医学 | 96篇 |
外科学 | 27040篇 |
综合类 | 34417篇 |
现状与发展 | 48篇 |
一般理论 | 45篇 |
预防医学 | 15183篇 |
眼科学 | 6733篇 |
药学 | 24344篇 |
169篇 | |
中国医学 | 11199篇 |
肿瘤学 | 20928篇 |
出版年
2024年 | 2410篇 |
2023年 | 3586篇 |
2022年 | 8711篇 |
2021年 | 11457篇 |
2020年 | 8626篇 |
2019年 | 7637篇 |
2018年 | 8036篇 |
2017年 | 7050篇 |
2016年 | 6735篇 |
2015年 | 10105篇 |
2014年 | 12693篇 |
2013年 | 11896篇 |
2012年 | 17569篇 |
2011年 | 19212篇 |
2010年 | 11714篇 |
2009年 | 9373篇 |
2008年 | 12756篇 |
2007年 | 12803篇 |
2006年 | 12359篇 |
2005年 | 12436篇 |
2004年 | 8596篇 |
2003年 | 7637篇 |
2002年 | 6608篇 |
2001年 | 5990篇 |
2000年 | 6104篇 |
1999年 | 6403篇 |
1998年 | 3650篇 |
1997年 | 3670篇 |
1996年 | 2791篇 |
1995年 | 2581篇 |
1994年 | 2230篇 |
1993年 | 1496篇 |
1992年 | 2289篇 |
1991年 | 1995篇 |
1990年 | 1664篇 |
1989年 | 1454篇 |
1988年 | 1264篇 |
1987年 | 1177篇 |
1986年 | 941篇 |
1985年 | 748篇 |
1984年 | 491篇 |
1983年 | 381篇 |
1982年 | 225篇 |
1981年 | 201篇 |
1980年 | 191篇 |
1979年 | 244篇 |
1978年 | 141篇 |
1977年 | 112篇 |
1976年 | 97篇 |
1974年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Anti‐viral therapy is associated with improved survival but is underutilised in patients with hepatitis B virus‐related hepatocellular carcinoma: real‐world east and west experience 下载免费PDF全文
V. L. Chen M.‐L. Yeh A. K. Le M. Jun W. K. Saeed J. D. Yang C.‐F. Huang H. Y. Lee P.‐C. Tsai M.‐H. Lee N. Giama N. G. Kim P. P. Nguyen H. Dang H. A. Ali N. Zhang J.‐F. Huang C.‐Y. Dai W.‐L. Chuang L. R. Roberts D. W. Jun Y.‐S. Lim M.‐L. Yu M. H. Nguyen 《Alimentary pharmacology & therapeutics》2018,48(1):44-54
42.
Zhiming Chen Gang Wang Minhao Xie Heyun Huang Erming Wu Yang Wang 《Journal of labelled compounds & radiopharmaceuticals》2018,61(2):107-111
We have developed a new set of lyophilized kits, composed of 3 different kits, for the instant preparation of no‐carrier‐added 131I‐MIBG in the clinic. We here discussed the formulation of the kits, optimization of radiolabelling, quality control of radiolabeled 131I‐MIBG, and studies of animal biodistribution. The no‐carrier‐added (nca) 131I‐MIBG injection could be prepared within 30 minutes in the clinic with the help of the lyophilized kits. The radiochemical purity and specific activity (SA) could achieve above 98% and 6700 MBq/mg, respectively. 相似文献
43.
Kuan Chen Junbin He Zhimin Hu Wei Song Liyan Yu Kai Li 《Journal of Asian natural products research》2018,20(7):615-623
AbstractGlycosylation is an effective approach to improve the druggability of natural products by increasing their water solubility. In this work, we report the glycosylation of oleanane-type triterpenoids by a recombinant microbial glycosyltransferase YjiC1. A preliminary screening test indicated YjiC1 exhibited robust capabilities for O-glycosylation of triterpenoids, based on LC/MS analysis. Among the products, two new compounds (2a and 3a), together with a known one (1a), were isolated and characterized. These products exhibited improved water solubility, and 3a showed moderate anti-HIV activities at 100 μM. This reaction provides a facile and efficient approach to synthesize the glucosides of triterpenoids. 相似文献
44.
Tian Yue Ke-Bo Xie Zhen Tan Ri-Dao Chen Da-Wei Chen Ji-Mei Liu 《Journal of Asian natural products research》2018,20(7):605-614
AbstractGlucuronidation is an important and popular metabolic reaction in vivo of drugs. The further evaluation of biological activity and toxicity of glucuronides is necessary in the course of the drug research and development. However, the synthesis of glucuronides is limited by the lack of efficient approach. Herein, we have developed a new glucuronide synthesis method using plant uridine diphosphate-dependent glucuronosyltransferases (UGTs), UGT88D4, UGT88D7, and EpGT8, enabling the convenient preparation for corresponding O-glucuronide metabolites (1a, 2a, 3a, and 3b) in milligram scale of two neurological active agents, IMM-H004 (1) and FLZ (2). Their structures were characterized by spectroscopic data analyses. 相似文献
45.
Ji-Wu Huang Fang-You Chen Chuang-Jun Li Jing-Zhi Yang Jie Ma Xiao-Guang Chen 《Journal of Asian natural products research》2018,20(4):337-343
Two new saponins, notoginsenosides Ng1 (1) and Ng2 (2), together with seven known compounds (3–9), were isolated from the leaves of Panax notoginseng. Their structures were elucidated by UV, IR, HRESIMS, and NMR experiments. Compounds 6 and 7 showed moderate cytotoxic activities against HCT-116, with IC50 values of 4.98 and 0.64 μmol/L, respectively. 相似文献
46.
Hui Chen Yu-Jie Li Xiao-Fei Li Yan-Jun Sun Hong-Wei Li Fang-Yi Su 《Journal of Asian natural products research》2018,20(1):92-100
A new homoisoflavanone, (3R)-5-hydroxy-7-methoxyl-3-(2′-hydroxy-4′- methoxybenzyl)-chroman-4-one (1), together with six known analogs, were isolated from the rhizomes of Polygonatum sibiricum. Their structures were elucidated on the basis of extensive spectroscopic analysis. All compounds were tested for their estrogenic activity using the MCF-7 estrogenresponsive human breast cancer cell lines. At a dose of 0.1 μmol/L, compounds 1–7 exhibited significant proliferative effects on MCF-7 cells compared with E2. The molecular docking study results indicated that the activity of compounds 3, 5, 6, and 7 may be the binding with ERR. 相似文献
47.
48.
Yang Zhang Bowen Deng Yida Cui Xue Chen Jiayi Bi Guogang Zhang 《Journal of natural medicines》2018,72(4):946-953
Two new secoiridoid glucosides, ilexpublignoside (1), pubzenoside (2), and a new lignan, ilexlignan B (3), along with seven known compounds (4–10) were isolated from the roots of Ilex pubescens for the first time. Their chemical structures were elucidated on the basis of extensive spectroscopic methods, including IR, UV, HR-ESI–MS, CD, NMR experiments, as well as comparison with the reported data. 相似文献
49.
目的 掌握广西辖区内糖厂密封放射源的使用分布情况,评价密封放射源对周围环境、职业人员、公众成员产生的辐射影响,为今后糖厂放射源的使用管理提供科学依据。方法 按监测规范合理布点,利用γ辐射剂量率仪对广西区内所有使用密封放射源的糖厂开展辐射环境现场测量,根据监测结果进行估算,并结合个人剂量监测结果进行分析。结果 密封放射源使用场所周围辐射剂量率高于环境本底水平,职业人员、公众成员会受到一定的辐射剂量。结论 职业人员及公众成员年有效剂量结果符合相关要求。 相似文献
50.
Deverick J Anderson Luke F Chen David J Weber Rebekah W Moehring Sarah S Lewis Patricia F Triplett Michael Blocker Paul Becherer J Conrad Schwab Lauren P Knelson Yuliya Lokhnygina William A Rutalo Hajimori Kanamori Marina F Gergen Daniel J Sexton for the CDC Prevention Epicenters Program 《中华医院感染学杂志》2018,(12)
中文:背景患者入院后可从不当消毒的环境表面获得多药耐药菌和艰难梭菌。本文确定了3种强化的终末消毒(入住同一病房的两名患者之间的消毒)策略,对感染耐甲氧西林金黄色葡萄球菌(MRSA)、耐万古霉素肠球菌(VRE)、艰难梭菌(CD)和多重耐药不动杆菌的影响。方法本文在美国东南部的9家医院开展了一项务实的、集群-随机、交叉研究。凡曾有感染或定植目标细菌感染患者居住过的病房,患者出院后随机采取4种消毒策略中的一种方法进行终末消毒:对照(季胺盐类消毒剂消毒,但凡遇到CD采用含氯消毒剂);UV(季胺盐类+UV-C消毒,但凡遇到CD采用含氯消毒剂+UV-C);含氯消毒剂;含氯消毒剂+UV-C。凡入住目标病房的患者被列为暴露人群。这4种终末消毒方法分别在每家医院连续实施7个月的周期。本文随机设计这几种消毒策略在每家医院内的实施顺序(1:1:1:1)。主要产出的结果是,观察暴露患者中目标细菌的感染的发生或定植情况,以及ITT人群中暴露患者CD感染发生率。本研究ClinicalTrials.gov注册编号:NCT01579370。结果共有31 226名患者暴露,其中21 395(69%)符合标准,包括4 916名对照组,5 178名UV组,5 438名含氯消毒剂组,以及5 863名含氯消毒剂+UV组。在对照组中,22 426个暴露日中有115名患者发生目标细菌的感染(51.3/10000暴露日)。在标准清洁策略的基础上增加UV消毒的暴露患者,其目标细菌感染的发生率明显较低(n=76;33.9/10 000暴露日;RR:0.70,95%CI:0.50~0.988;P=0.036)。含氯消毒剂组(n=101;41.6/10 000暴露日;RR:0.85,95%CI:0.69~1.04;P=0.116),或含氯消毒剂+UV组患者(n=131;45.6/10 000暴露日;RR:0.91,95%CI:0.76~1.09;P=0.303)的目标细菌的感染率,其差异无统计学意义。同样,在含氯消毒剂的基础上增加UV消毒,暴露患者中CD感染率也没有发生改变((n=38 vs 36;30.4 vs 31.6/10 000暴露日;RR:1.0,95%CI:0.57-1.75;P=0.997)。解释污染的医疗机构环境是获得病原微生物的重要来源;强化终末消毒可以降低这一风险。 相似文献