全文获取类型
收费全文 | 854篇 |
免费 | 50篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 20篇 |
妇产科学 | 13篇 |
基础医学 | 91篇 |
口腔科学 | 6篇 |
临床医学 | 59篇 |
内科学 | 222篇 |
皮肤病学 | 8篇 |
神经病学 | 53篇 |
特种医学 | 40篇 |
外科学 | 187篇 |
综合类 | 14篇 |
预防医学 | 49篇 |
眼科学 | 26篇 |
药学 | 26篇 |
中国医学 | 2篇 |
肿瘤学 | 89篇 |
出版年
2023年 | 6篇 |
2022年 | 22篇 |
2021年 | 38篇 |
2020年 | 18篇 |
2019年 | 32篇 |
2018年 | 34篇 |
2017年 | 15篇 |
2016年 | 19篇 |
2015年 | 34篇 |
2014年 | 43篇 |
2013年 | 45篇 |
2012年 | 78篇 |
2011年 | 87篇 |
2010年 | 58篇 |
2009年 | 44篇 |
2008年 | 61篇 |
2007年 | 60篇 |
2006年 | 47篇 |
2005年 | 39篇 |
2004年 | 33篇 |
2003年 | 38篇 |
2002年 | 25篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1976年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有906条查询结果,搜索用时 359 毫秒
21.
Sofosbuvir and simeprevir without ribavirin effectively treat hepatitis C virus genotype 1 infection after liver transplantation in a two‐center experience
下载免费PDF全文
![点击此处可从《Clinical transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
22.
Nizar Al-Zoubi Faten Odah Wasfy Obeidat Ahmad Al-Jaberi Ioannis Partheniadis Ioannis Nikolakakis 《Journal of pharmaceutical sciences》2018,107(9):2385-2398
Solid dispersions of spironolactone with Soluplus® and polyvinylpyrrolidone were prepared by spray drying according to a mixture experimental design and evaluated for moisture content, particle size, drug solubility, crystallinity (powder X-ray diffraction and differential scanning calorimetry), and physicochemical interactions (Fourier-transform infrared spectroscopy, Raman). In vitro dissolution was evaluated for the spray dried product itself and after compression into tablets, and prediction models were derived using multiple linear regression analysis. The spray dried products consisted of amorphous drug, indicated by the absence of crystalline powder X-ray diffraction peaks. Amorphization and interactions impacted changes in the Fourier-transform infrared spectroscopy spectra in the ranges 2900-3000 cm?1 (C-H) and 1600-1800 cm?1 (C=O) and caused merging at 1690 cm?1 (C=O of lactone) and 1670 cm?1 (C=O of thioacetyl group). In the Raman spectra, amorphization and interactions resulted in disappearance of peak at 1690 cm?1 (C=O) and merging of peaks at 582 and 600 cm?1 (C-S). Hydrogen bonding between the thioacetyl group of the drug with the hydroxyl groups of Soluplus® caused marked suppression of the peak at 1190 cm?1 (R-C(=O)-S vibration). Amorphization and interactions resulted in improved solubility and dissolution which was greatest for drug/Soluplus® ratio 1:4 and was also demonstrated in the corresponding tablets. 相似文献
23.
Rana Obaidat Nizar Al-Shar'i Bassam Tashtoush Tamara Athamneh 《Pharmaceutical development and technology》2018,23(10):986-997
AbstractLevodopa is a promising candidate for administration via the transdermal route because it exhibits a short plasma half-life and has a small window of absorption in the upper section of the small intestine. The aim of this study was to prepare stable levodopa transdermal patches. Both xanthan gum and Carbopol 971 polymers were selected with ethylcellulose constituting the backing layer of the prepared patches. The effect of adding β-cyclodextrin on the prepared patches was investigated. The uniformity in thickness, weight and content of the studied patches was acceptable. Physicochemical characterization revealed that there was no interaction between levodopa and the applied polymer. The results proved that levodopa precipitated as an amorphous form in carbopol patches. Controlled drug release was achieved for all the tested patches over a 6?h period. However, increased permeation was achieved for the carbopol patches. Although cyclodextrin did not enhance levodopa permeation, the stability study confirmed that levodopa stability was enhanced when complexed with β-cyclodextrin. The cumulative amount of drug released from carbopol patches is slightly higher than that of xanthan patches. The optimal stability was achieved in the carbopol/levodopa:β-cyclodextrin patch. The levodopa-β-cyclodextrin complex was successfully characterized using X-ray diffraction, NMR analysis and molecular dynamics simulations. In conclusion, carbopol/levodopa:β-cyclodextrin patches can be considered as a promising stable and effective transdermal drug-delivery system. 相似文献
24.
Karem. H Alzoubi Omar. F Khabour Sayer I Al-azzam Murad H Tashtoush Nizar M Mhaidat 《Current Neuropharmacology》2014,12(2):186-192
Chronic administration of L-methionine leads to memory impairment, which is attributed to increase in the level of oxidative stress in the brain. On the other hand, metformin is a commonly used antidiabetic drug with strong antioxidant properties. In the current study, we tested if chronic metformin administration prevents memory impairment induced by administration of L-methionine. In addition, a number of molecules related to the action of metformin on cognitive functions were examined. Both metformin and L-methionine were administered to animals by oral gavage. Testing of spatial learning and memory was carried out using radial arm water maze (RAWM). Additionally, hippocampal levels or activities of catalase, thiobarbituric acid reactive substances (TBARs), glutathione peroxidase (GPx), glutathione (GSH), oxidized glutathione (GSSG) and GSH/GSSG ratio were determined. Results showed that chronic L-methionine administration resulted in both short- and long- term memory impairment, whereas metformin treatment prevented such effect. Additionally, L-methionine treatment induced significant elevation in GSSG and TBARs, along with reduction in GSH/GSSG ratio and activities of catalase, and GPx. These effects were shown to be restored by metformin treatment. In conclusion, L-methionine induced memory impairment, and treatment with metformin prevented this impairment probably by normalizing oxidative stress in the hippocampus. 相似文献
25.
Y. Raja Rampersaud Stephen J. Lewis J. Roderick Davey Rajiv Gandhi Nizar N. Mahomed 《The spine journal》2014,14(2):234-243
Background contextIt is well accepted that total hip and knee arthroplasty (THA/TKA) for osteoarthritis (OA) is associated with reliable and sustained improvements in postoperative health-related quality of life (HRQoL). Although several studies have demonstrated comparable outcomes with THA/TKA after surgical intervention for lumbar spinal stenosis (LSS), the sustainability of the outcome after LSS surgery compared with THA/TKA remains uncertain.PurposeThe primary purpose of this study is to assess whether improvements in HRQoL after surgical management of focal lumbar spinal stenosis (FLSS) with or without spondylolisthesis are sustainable over the long term compared with that of THA/TKA for OA.Study designSingle-center, retrospective, longitudinal matched cohort study of prospectively collected outcomes, with a minimum of 5-year follow-up (FU).Patient samplePatients who had primary one- to two-level spinal decompression with or without instrumented fusion for FLSS and THA/TKA for primary OA.Outcome measuresPostoperative change from baseline to last FU in Short-Form 36 physical component summary (PCS) and mental component summary (MCS) scores among groups was used as the primary outcome measure.MethodsAn age, sex-matched inception cohort of primary one- to two-level spinal decompression with or without instrumented fusion for FLSS (n=99) was compared with a cohort of primary THA (n=99) and TKA (n=99) for OA and followed for a minimum of 5 years. Linear regression was used for the primary analysis.ResultsMean (percent) FUs in months were 80.5+16.04 (79%), 94.6+16.62 (92%), and 80.6+16.84 (85%) for the FLSS, THA, and TKA cohorts, respectively, with a range of 5 to 10 years for all three cohorts. The number of patients who have undergone revision including those lost to FU for the FLSS, THA, and TKA cohorts were n=20 (20.2%, same site [n=7] and adjacent segment [n=13]) requiring 27 operations, n=3 (3%, same site) requiring 5 operations, and n=8 (8.1%, same site) requiring 12 operations, respectively (p<.01). The average time to first revision was 56/65/43 months, respectively. Mean postoperative PCS (p<.0001) and MCS (p<.02) scores improved significantly and were durable for all groups at the last FU. The mean changes from baseline PCS/MCS scores to last FU were 8.5/6.4, 12.3/7.0, and 8.3/4.9 for FLSS, THA, and TKA, respectively. Adjusting for baseline age, sex, body mass index, PCS score, and MCS score, there was a strong trend in favor of greater sustained change in the PCS score of THA over FLSS (p=.07) and TKA (p=.08). No difference was noted for change in PCS score between FLSS and TKA (p=.95). No differences were noted for change in MCS score among all three cohorts (p>.1).ConclusionsSignificant improvements in HRQoL after surgical treatment of FLSS with or without spondylolisthesis and hip and knee OA are sustained for a mean of 7 to 8 years, with a minimum of 5-year FU. Despite a higher revision rate, patients undergoing surgery for FLSS can expect a comparable long-term average improvement in HRQoL from baseline compared with their peers undergoing TKA and to a lesser extent THA. 相似文献
26.
Alterations of the arginine metabolome in asthma 总被引:1,自引:0,他引:1
Lara A Khatri SB Wang Z Comhair SA Xu W Dweik RA Bodine M Levison BS Hammel J Bleecker E Busse W Calhoun WJ Castro M Chung KF Curran-Everett D Gaston B Israel E Jarjour N Moore W Peters SP Teague WG Wenzel S Hazen SL Erzurum SC;National Heart Lung Blood Institute's Severe Asthma Research Program 《American journal of respiratory and critical care medicine》2008,178(7):673-681
27.
28.
Ziadé Nelly Hmamouchi Ihsane el Kibbi Lina Abdulateef Nizar Halabi Hussein Abutiban Fatemah Hamdi Wafa el Rakawi Manal Eissa Mervat Masri Basel 《Clinical rheumatology》2020,39(11):3205-3213
Clinical Rheumatology - To evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on rheumatology practice. A cross-sectional web survey was designed by the members of the Arab... 相似文献
29.
30.