全文获取类型
收费全文 | 478篇 |
免费 | 43篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 13篇 |
妇产科学 | 15篇 |
基础医学 | 57篇 |
口腔科学 | 10篇 |
临床医学 | 42篇 |
内科学 | 169篇 |
皮肤病学 | 7篇 |
神经病学 | 25篇 |
特种医学 | 25篇 |
外科学 | 53篇 |
综合类 | 18篇 |
预防医学 | 23篇 |
眼科学 | 2篇 |
药学 | 33篇 |
中国医学 | 2篇 |
肿瘤学 | 28篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 19篇 |
2020年 | 7篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 10篇 |
2016年 | 16篇 |
2015年 | 15篇 |
2014年 | 18篇 |
2013年 | 20篇 |
2012年 | 26篇 |
2011年 | 37篇 |
2010年 | 18篇 |
2009年 | 22篇 |
2008年 | 17篇 |
2007年 | 27篇 |
2006年 | 19篇 |
2005年 | 25篇 |
2004年 | 14篇 |
2003年 | 20篇 |
2002年 | 28篇 |
2001年 | 10篇 |
2000年 | 12篇 |
1999年 | 14篇 |
1998年 | 5篇 |
1997年 | 13篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有523条查询结果,搜索用时 125 毫秒
51.
J M Old S N Khan I Verma S Fucharoen M Kleanthous P Ioannou N Kotea C Fisher S Riazuddin R Saxena P Winichagoon K Kyriacou F Al-Quobaili B Khan 《Hemoglobin》2001,25(4):397-407
The spectrum of the beta-thalassemia mutations of Thailand, Pakistan, India, Sri Lanka, Mauritius and Syria has been further characterized by a multi-center study of 1,235 transfusion-dependent patients, and the mutations discovered used to assess the fidelity of a simple diagnostic strategy. A total of 44 beta-thalassemia mutations were identified either by allele-specific oligonucleotide hybridization, amplification with allele-specific primers, or DNA sequencing of amplified product. The results confirm and extend earlier findings for Thailand, Pakistan, India, Mauritius and Syria. This is the first detailed report of the spectrum of mutations for Sri Lanka. Two novel mutations were identified, codon 55 (-A) and IVS-I-129 (A-->C), both found in Sri Lankan patients. Two beta-thalassemia mutations were found to coexist in one beta-globin gene: Sri Lankan patients homozygous for the beta0 codon 16 (-C) frameshift were also homozygous for the beta+ codon 10 (C-->A) mutation. Studies of Sri Lankan, Pakistani, and Indian carriers suggest the codon 10 (C-->A) mutation is just a rare polymorphism on an ancestral allele, on which the beta0 codon 16 (-C) mutation has arisen. Each country was found to have only a few common mutations accounting for 70% or more of the beta-thalassemia alleles. A panel of primers to diagnose the majority of the mutations by the amplification refractory mutation system was developed, enabling a simple molecular diagnostic strategy to be introduced for each country participating in the multi-center study. 相似文献
52.
Vergoulas Georgios; Eleftheriadis Theodoros; Avdelidou Aphroditi; Ioannou Konstantinos; Miserlis Gregorios; Solonaki Fillio; Papagiannis Andreas; Takoudas Dimitrios 《Nephrology, dialysis, transplantation》2005,20(2):473
Sir, Currently administered immunosuppression schemes usually includecyclosporin. Cyclosporin has brought about a revolution in patientprognosis and in renal graft survival, but, unfortunately, ithas many side effects [1,2]. While physicians are attentiveto the more serious and life threatening of these side effects, 相似文献
53.
Petros Ioannou Aggeliki Andrianaki Tonia Akoumianaki Irene Kyrmizi Nathaniel Albert David Perlin George Samonis Dimitrios P. Kontoyiannis Georgios Chamilos 《Antimicrobial agents and chemotherapy》2016,60(3):1226-1233
The modest in vitro activity of echinocandins against Aspergillus implies that host-related factors augment the action of these antifungal agents in vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against various Aspergillus species under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P = 0. 0005). Importantly, the enhanced activity of caspofungin against Aspergillus spp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinating Aspergillus hyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin with Aspergillus hyphae (P < 0.0001). Collectively, we found a novel synergistic interaction between albumin and caspofungin, with albumin acting as a potential carrier molecule to facilitate antifungal drug delivery to Aspergillus hyphae. 相似文献
54.
The molecular basis of most beta-thalassemia syndromes has been defined, while the spectrum of mutations causing delta-thalassemia is not well characterized. In an attempt to identify such mutations, the region encompassing the delta-globin gene from three Greek Cypriot families suspected of having delta-thalassemia was amplified by polymerase chain reaction (PCR), and DNA sequence determined using an automated fluorescence-based sequencer. Four novel mutations were identified: a G----T change at codon 27 that results in an alanine to serine change; a C----T change at codon 116 converting arginine to cysteine; a T----C change at codon 141 converting leucine to proline; and an AG----GG change at the consensus 3'-acceptor site in IVS-2. While the latter is clearly a thalassemic mutation, the low hemoglobin A2 in the first three may be due to either decreased production or instability of the altered delta-globin chain. All four mutations may be detected by PCR amplification of genomic DNA followed by restriction enzyme digestion. Two mutations abolish restriction sites while two create new cleavage sites. Screening for molecular defects that cause delta-thalassemia or unstable delta-globin by PCR amplification and restriction enzyme digestion will lead to correct diagnosis of beta/delta-thalassemia compound heterozygotes and improved genetic counseling. 相似文献
55.
56.
Multicenter study of the molecular basis of thalassemia intermedia in different ethnic populations 总被引:2,自引:0,他引:2
Verma IC Kleanthous M Saxena R Fucharoen S Winichagoon P Raizuddin S Khan SN Akbari MT Izadyar M Kotea N Old JM Ioannou PA Khan B 《Hemoglobin》2007,31(4):439-452
We studied 325 thalassemia intermedia patients from Iran, India, Pakistan, Thailand, Mauritius and Cyprus to examine factors which influence the phenotype. The beta-thalassemia (thal) mutations were determined for 219 beta-thal/beta-thal and 106 beta-thal/Hb E [beta26(B8)Glu-->Lys, GAG-->AAG] thalassemia intermedia patients. Thirty-one different mutations were identified, and their combination gave rise to more than 44 different genotypes, of which 14 (31.8%) had the beta(0)/beta(0), 21 (47.7%) the beta(0)/beta(+) and nine (20.5%) the beta(+)/beta(+) types. Thus, the beta(+)-thal mutations were present in 68.2% of patients. alpha-Thalassemia mutations were present in frequencies higher than in the general population of all ethnic groups studied, as 45% of the patients carried alpha-thal mutations. Correlation of alpha-thal mutations with beta-globin mutations showed that the alpha-thal mutations were mainly co-inherited with the beta(+)-thal mutations. The XmnI (G)gamma polymorphic site at -158 (C-->T) was positive (T) in nine (8.8%) of 102 patients of the beta(+)/beta(+) genotype, and the percentage of both XmnI (G)gamma polymorphism [+/-] (T/C) and [+/+] (T/T) genotypes increased to 42.9 and 87.3, respectively, in the beta(0)/beta(+) and beta(0)/beta(0) patients. This polymorphism was found in the majority of beta(+)-thal/Hb E compound heterozygote patients (88.6%), and beta(0)-thal/Hb E patients (84.8%), suggesting that it could be linked to the Hb E chromosome. Therefore, the XmnI (G)gamma polymorphism at -158 (C-->T) was associated with beta(0)-thal mutations as well as the Hb E chromosome. The present study demonstrates that in cases of thalassemia intermedia with beta(+) mutations, the common ameliorating factor is the presence of alpha-thal mutations, while in cases with beta(0) mutations, the common ameliorating factor is the presence of the XmnI (G)gamma polymorphism at -158 (C-->T). 相似文献
57.
BACKGROUND AND AIMS: Earlier studies have suggested that patients with hemochromatosis have poor post-transplantation survival. We aimed to compare patients with hemochromatosis to those with other causes of liver disease with regard to post-transplantation survival. METHODS: We compared the post-transplant survival of patients with and without hemochromatosis using data provided by the United Network for Organ Sharing on 50,306 adult, cadaveric liver transplantations performed in the United States between January 1, 1990, and July 18, 2006. RESULTS: During 1990-1996, the post-transplantation survival of patients with hemochromatosis (n = 177) at 1 year (79.1%), 3 years (71.8%), and 5 years (64.6%) was lower than the average 1-year (86.4%), 3-year (79.5%), and 5-year (73.8%) survival of all other transplant recipients (hazard ratio for death, 1.38; 95% confidence interval [CI], 1.12-1.71). In contrast, during 1997-2006, patients with hemochromatosis (n = 217) had excellent 1-year (86.1%), 3-year (80.8%), and 5-year (77.3%) post-transplantation survival, which was not different from the 1-year (88.4%), 3-year (80.3%), and 5-year (74.0%) post-transplantation survival of all other transplant recipients (hazard ratio for death, 0.89; 95% CI, 0.65-1.22). Adjustment for donor and recipient characteristics did not substantially change these results. Compared with recipients without hemochromatosis, those with hemochromatosis were more likely to die of cardiovascular diseases and less likely to die as a result of graft failure. CONCLUSIONS: The post-transplantation survival of patients with hemochromatosis, which was previously reported to be poor, has been excellent in the United States during the past 10 years. 相似文献
58.
Zarogiannis S Hatzoglou C Stefanidis I Ioannou M Paraskeva E Gourgoulianis K Molyvdas PA 《Clinical and experimental pharmacology & physiology》2007,34(1-2):129-131
1. Pleural permeability may contribute to pleural fluid turnover. The transmesothelial resistance (R(TM)), is an established surrogate of mesothelial permeability. The aim of the present study was to compare the electrophysiological properties of costal and diaphragmatic parietal pleura. 2. Specimens of the parietal pleura were isolated from 12 adult sheep from the chest wall and the diaphragm. Electrophysiological measurements were conducted with the Ussing system. Specimens of the parietal pleura of both types (diaphragmatic and costal) were compared histologically and total protein content measurements were also made. 3. The R(TM) of the diaphragmatic parietal pleura was significantly higher than that of the costal parietal pleura throughout the experiment. The diaphragmatic parietal pleura contains more cuboidal cells than the costal parietal pleura and its protein content was higher, however this difference was not statistically significant. 4. The costal parietal pleura consists of a more 'leaky' mesothelium than the diaphragmatic pleura. The morphological differences between the two types of parietal pleura may underline the electrophysiological findings. 相似文献
59.
George N Ioannou 《Liver transplantation》2006,12(11):1594-1606
This study aimed to develop and validate a comprehensive model that predicts survival after liver transplantation based on pretransplant donor and recipient characteristics. Complete data were available from the United Network for Organ Sharing for 20,301 persons who underwent liver transplantation in the United States between 1994 and 2003. Proportional-hazards regression was used to identify the donor and recipient characteristics that best predicted survival and incorporate these characteristics in a multivariate model. A data-splitting approach was used to compare survival predicted by the model to the observed survival in samples not used in the derivation of the model. A model was derived using 4 donor characteristics (age, cold ischemia time, gender, and race/ethnicity) and 9 recipient characteristics (age, body max index, model for end-stage liver disease score, United Network for Organ Sharing priority status, gender, race/ethnicity, diabetes mellitus, cause of liver disease, and serum albumin) that adequately predicted survival after liver transplantation in patients without hepatitis C virus, and a slightly different model was used for patients with hepatitis C virus. The models illustrate that variations in both pretransplant donor and recipient characteristics have a large effect on posttransplant survival. In conclusion, the models presented here can be used to derive scores that are proportional to the excess risk of graft loss after liver transplantation for potential donors, recipients, or donor/recipient combinations. The models may be used to inform liver transplant candidates and their doctors what posttransplant survival would be expected when a given donor is offered and may be particularly helpful for marginal or high-risk donors. 相似文献
60.
Recurrent varicose veins after surgery: a new appraisal of a common and complex problem in vascular surgery. 总被引:3,自引:0,他引:3
T Kostas C V Ioannou E Touloupakis E Daskalaki A D Giannoukas D Tsetis A N Katsamouris 《European journal of vascular and endovascular surgery》2004,27(3):275-282
OBJECTIVE: To assess the true incidence, the reflux patterns and the mechanisms responsible for recurrent varicose vein disease according to current definitions and guidelines. PATIENTS AND METHODS: Ninety-three patients (69 female, 24 male, mean age: 48 years) were prospectively evaluated pre- and postoperatively (1 month and 5 years), using clinical and colour duplex examination of both lower limbs. The CEAP score and its modification for recurrence (REVAS) were used for classification. RESULTS: In 113 operated lower limbs, 28 (25%) were found to have a recurrence, 20 of which were symptomatic (20/28, 72%). However, in this group, the mean severity score decreased significantly from 6.5 (SD 3.1) to 5.2 (SD 2.8) (p<0.001, paired t-test). The correlation between the type and cause of recurrence revealed: (1) true recurrent varices in eight limbs (8/28, 29%), primarily caused by neovascularisation, (2) new varicose veins as a consequence of disease progression in seven limbs (7/28, 25%), (3) residual veins in three limbs (3/28, 11%) mainly due to tactical errors (e.g. failure to strip the GSV), (4) complex patterns in 10 limbs (10/28, 36%). In the limbs with recurrence, 42 sources of venous reflux were identified: (1) 19 new sites of venous reflux were due to disease progression (15% of the operated limbs), (2) 13 were caused by neovascularisation (11.5% of the operated limbs), (3) six resulted from tactical failures (5.3% of the operated limbs) and (4) four were due to technical failures (3.5% of the operated limbs). CONCLUSIONS: This study shows that the recurrence of varicose veins after surgery is not uncommon. However, the clinical condition of most affected limbs remains improved. Progression of the disease and neovascularisation are responsible for more than half of the recurrences. Rigorous evaluation of patients and assiduous surgical technique might reduce recurrence due to technical and tactical failures. 相似文献