全文获取类型
收费全文 | 542篇 |
免费 | 41篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 11篇 |
妇产科学 | 5篇 |
基础医学 | 73篇 |
口腔科学 | 8篇 |
临床医学 | 60篇 |
内科学 | 108篇 |
皮肤病学 | 4篇 |
神经病学 | 36篇 |
特种医学 | 9篇 |
外科学 | 37篇 |
综合类 | 10篇 |
预防医学 | 50篇 |
眼科学 | 12篇 |
药学 | 108篇 |
1篇 | |
中国医学 | 12篇 |
肿瘤学 | 40篇 |
出版年
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 18篇 |
2020年 | 15篇 |
2019年 | 18篇 |
2018年 | 13篇 |
2017年 | 17篇 |
2016年 | 18篇 |
2015年 | 22篇 |
2014年 | 29篇 |
2013年 | 27篇 |
2012年 | 45篇 |
2011年 | 43篇 |
2010年 | 23篇 |
2009年 | 25篇 |
2008年 | 44篇 |
2007年 | 32篇 |
2006年 | 25篇 |
2005年 | 34篇 |
2004年 | 28篇 |
2003年 | 18篇 |
2002年 | 11篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1927年 | 1篇 |
排序方式: 共有585条查询结果,搜索用时 15 毫秒
41.
42.
43.
Shakila Devi Perumal 《慢性疾病与转化医学(英文)》2021,7(2):107
Pulmonary rehabilitation (PR) is a cornerstone management for chronic obstructive pulmonary disease (COPD). International respiratory societies defined PR is more than “just an exercise program”; it is a comprehensive care delivered by a team of dedicated healthcare professionals with a strong emphasis on long-term health-enhancing Behaviors. However, “Uncertainty” exists with varied reasons for the political and geographical barriers of referral, uptake, attendance, and completion of PR in both primary and secondary care. Besides, COVID-19 pandemic has sparked many global controversies and challenges on pulmonary rehabilitation service delivery. Post-COVID-19 guidelines emphasize on integrated care rehabilitation for patients with COPD. Thus, this concise review intends to understand the gaps in United Kingdom healthcare policies, practices, and PR services resources. To date, there is no clear consensus on PR integrated care model pathway to address the unmet needs, measure the health and social care disparities; adds to the disease burden of COPD. Based on the culmination of evidence, this perspective offers a theoretical framework of PR integrated service model, a pathway to deliver high-value personalized care to patients with COPD. 相似文献
44.
Regional effects of 6-hydroxydopamine (6-OHDA) on free radical scavengers in rat brain 总被引:2,自引:0,他引:2
A S Perumal W K Tordzro M Katz V Jackson-Lewis T B Cooper S Fahn J L Cadet 《Brain research》1989,504(1):139-141
Superoxide dismutase (SOD), catalase, glutathione (GSH), and glutathione peroxidase (GSH-Px) were measured in the caudate-putamen (CPu), the hippocampus (HIP), and the brainstem (BS) of the brains of control animals and of rats treated with one intracerebroventricular infusion of 6-hydroxydopamine (6-OHDA). Injection of 6-OHDA resulted in significant decreases in the activity of SOD in the CPu, the BS, and in the HIP. There were decreases in catalase in the CPu and in the BS, but not in the HIP. GSH was reduced in the CPu and the BS but not changed in the HIP. There were small decreases in the activity of GSH-Px only in the BS. These changes may be secondary to the production of free radicals after the infusion of 6-OHDA in rat brain. 相似文献
45.
46.
The effects of exposure time, drug concentration, and temperature on the activity of ethambutol versus Mycobacterium tuberculosis 总被引:2,自引:0,他引:2
P R Gangadharam P F Pratt V K Perumal M D Iseman 《The American review of respiratory disease》1990,141(6):1478-1482
In a series of dynamic in vitro studies designed to assess the activity of ethambutol (EMB) against Mycobacterium tuberculosis, we made the following observations. Ethambutol showed bactericidal action with 10 micrograms/ml concentration when in constant contact with M. tuberculosis. At a lower concentration, bactericidal action was evident up to 6 days; after that time, this effect was lost owing to the development of drug-resistant mutants. The bactericidal action of ethambutol in this model was similar to that of rifampin and isoniazid. Pulsed exposure for 96 h caused a four-log reduction in cfu counts, but the growth resumed rapidly. The bactericidal action of ethambutol was maximal at 37 degrees C and less at low temperatures. Ethambutol showed little activity against cultures growing at 8 degrees C continuously that were incubated for only 1 h at 37 degrees C. Against cultures growing at 8 degrees C that were brought to 37 degrees C for 6 h, its action was similar to that of rifampin. Ethambutol combined with other drugs showed bactericidal action, although the activity was less than that of the combination isoniazid-streptomycin. 相似文献
47.
Dr Perumal Thiagarajan 《Am J Cardiovasc Drugs》2002,2(4):227-235
The normal hemostatic process is initiated by disruption in the vascular continuity and exposure of the subendothelial components. Platelets adhere to subendothelium-bound von Willebrand factor via glycoprotein (GP) Ib complex. This initial interaction per se and the release of platelet agonists transduce signals that lead to the rise in intracellular Ca2+. The rise in Ca 2+ induces shape change, Prostaglandin synthesis, release of granular contents and conformational changes in platelet Gp IIb-IIIa. Gp IIb-IIIa in activated platelets becomes competent to bind fibrinogen and other adhesive proteins and mediates platelet cohesion (primary hemostatic plug). Furthermore, the activated platelet surface provides an efficient catalytic surface for the coagulation reactions, ultimately resulting in the formation of fibrin (secondary hemostasis). Normally the hemostatic process plays a delicate balance between keeping the blood in the fluid state to maintain flow and rapidly forming an occluding plug following vessel injury. Thrombosis occurs because of alteration in this delicate balance. Consequences of thrombosis are a major cause of morbidity and mortality in industrialized countries. Arterial thrombosis occurs in the setting of previous vessel wall injury mostly because of atherosclerosis, while venous thrombosis occurs in areas of stasis. The recent advances in our understanding of the hemostatic process have led to a better elucidation of the mechanism of action of many antithrombotic drugs and identification of new targets for drug development. The molecular target of the well known antiplatelet drug ticlopidine has been identified. Large numbers of IIb-IIIa inhibitors have been developed based on the crystal structure of a potent antagonist echistatin. The mechanism of action of heparin has been defined at the molecular level. As a result a synthetic pentasaccharide, based on antithrombin-binding domain of heparin, has been developed and tested successfully in clinical trials. New generation direct thrombin inhibitors are being developed based on the crystal structure of thrombin. Factor Xa has a critical position at the convergence of intrinsic and extrinsic pathway ways. The clinical tolerability and the efficacy of low molecular weight heparins led to the concept that inhibition of further thrombin generation, by blocking factor Xa alone, can be an effective way of preventing thrombus growth without inactivating thrombin. A large number of specific factor Xa inhibitors are under development. Some of these drugs have already undergone preliminary clinical trials and appear to be promising. Future clinical trials will determine whether these new drugs will provide better risk-benefit ratio in treatment of thrombotic disorders. 相似文献
48.
Dharmarajan Sriram Ruth Vandana Devakaram Murugesan Dinakaran Perumal Yogeeswari 《Medicinal chemistry research》2010,19(6):524-532
Nine orally active novel artemisinin derivatives were prepared from artemisinin by four-step synthesis, and the compounds
were evaluated in the rodent model using multidrug resistant Plasmodium yoelii nigeriensis. All of the compounds exhibited antimalarial activities with the ED50 ranging from 5.41 mg/kg–12.4 mg/kg. Among them, artemisinin derivative bearing N-(4-hydroxy-3-((4-phenylpiperazin-1-yl)methyl)phenyl)
moiety (5f) was found to be the most active compound and was found to be three times more potent than artemisinin (ED50 16.4 mg/kg). 相似文献
49.
Ramesh Perumal Vijay Shankar Rizwan Basha Dheenadayalan Jayaramaraju Shanmuganathan Rajasekaran 《Journal of Clinical Orthopaedics and Trauma》2018,9(4):322-326
Purpose
Although nail dynamization in femoral and tibial fractures is an effective method of promoting healing, its role beyond twelve weeks is still not clear. It is usually done two to three months following interlocking nailing. This study was done to evaluate the efficacy of late dynamization (after 12 weeks) and factors affecting union.Materials and methods
In this retrospective study, thirty seven patients who underwent dynamization for reamed intramedullary interlocking nails of femur (18) and tibia (20) after twelve weeks from index surgery and with a minimum followup of six months were included. Fracture healing index was calculated using predynamization radiographs. Radiographic union was defined as osseous bridging of three cortices on followup radiographs. Dynamization failure was defined as fractures not showing progressive increase in callus on followup radiographs and those that required secondary intervention.Results
Mean age of patients at time of injury was 35.92 years (range: 16–63) with males (86.8%) predominating. Mean time to dynamization from index surgery was 19.11 weeks (range-12–36). Thirty one fractures (81.5%) went onto union after dynamization of which twelve were femoral and nineteen were tibial fractures. Mean time to union after dynamization was 6 months. Communited fractures (6–21) showed poor results with delayed dynamization compared to other anatomical types which was statistically significant (P?=?0.05). Predynamization FHI of more than 1.18 had 83% sensitivity and 72% specificity in predicting fracture healing after dynamization.Conclusion
Late dynamization is still beneficial in promoting healing in femoral and tibial fractures. Communited fractures showed poor results with dynamization. Predynamization FHI was an important predictor of fracture healing. 相似文献50.
Perumal Yogeeswari Dharmarajan Sriram Ramkumar Kavya Sonali Tiwari 《Biomedicine & Pharmacotherapy》2005,59(9):501-510
Mannich bases of gatifloxacin were synthesized by reacting them with formaldehyde and several isatin derivatives. Their chemical structures have been confirmed by means of their IR, 1H-NMR data and by elemental analysis. The compounds were tested in-vitro against a panel of 58 human tumour cell lines derived from nine neoplastic diseases. Among them compound 1-cyclopropyl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-7[[N4-(3'-sulphadoximino)-1'-(5-bromoisatinyl) methyl]-3-methyl N1-piperazinyl]-3-quinoline carboxylic acid (6) emerged as a potent anticancer agent being more active than standard DNA topoisomerase II inhibitor, etoposide against 30 cancer cell lines. 相似文献