78 research outputs found
Use of dialkyldithiocarbamato complexes of bismuth(III) for the preparation of nano- and microsized Bi2S3 particles and the X-ray crystal structures of [Bi{S2CN(CH3)(C6H13)}(3)] and [Bi{S2CN(CH3)(C6H13)}(3)(C12H8N2)]
A range of bismuth(III) dithiocarbamato complexes were prepared and characterized. The
X-ray crystal structures of the compounds [Bi{S2CN(CH3)(C6H13)}3] (1) and [Bi{S2CN(CH3)-
(C6H13)}3(C12H8N2)] (2) are reported. The preparation of Bi2S3 particulates using a wet
chemical method and involving the thermalysis of Bi(III) dialkyldithiocarbamato complexes
is described. The influence of several experimental parameters on the optical and
morphological properties of the Bi2S3 powders was investigated. Nanosized Bi2S3 colloids
were obtained having long-term stability and showing a blue shift on the optical band edge;
the presence of particles exhibiting quantum size effects is discussed. Morphological welldefined Bi2S3 particles were obtained in which the fiber-type morphology is prevalent.FCT - POCTI/1999/CTM/ 3545
Efficacy of tenofovir disoproxil fumarate therapy in nucleoside-analogue naive Iranian patients treated for chronic hepatitis B
Background: Tenofovir disoproxil fumarate (TDF) is a new effective treatment option for patients with chronic hepatitis B (CHB). Objectives: To evaluate TDF efficacy in nucleos(t)ide analogues (NAs)-naive Iranian patients with CHB. Patients and Methods: The NA-naive patients received TDF for at least six months. The primary endpoint was the proportion of patients achieving a complete virological response (CVR) during the treatment. Multivariate Cox regression analysis determined predictive factors independently associated with the time to CVR. The secondary endpoints were biochemical and serological responses, frequency of virological breakthrough, genotypic resistance development, safety and tolerability. Results: In all, 93 patients (64.5 hepatitis B e antigen HBeAg-negative) were eligible. Of these, 70 patients completed 24 months of treatment. The cumulative CVR rates in HBeAg-negative and HBeAg-positive patients were 87% versus 53% at 24 months, respectively. The multivariate Cox regression model showed only HBeAg positivity at baseline and a high baseline HBV DNA level were independent factors predicting a CVR. No patient achieved hepatitis B surface antigen (HBsAg) and HBeAg loss or seroconversion and no virologic breakthrough occurred. A new amino acid substitution (rtD263E) was observed to develop in 60% of patients with viremia. Conclusions: The cumulative CVR rates showed that patients with HBeAg-negative have better virologic respond than those with HBeAg-positive during the same period. The rtD263E mutation might be associated with partial resistance to TDF. © 2015, Kowsar Corp
Suprasternal innominate artery cannulation for reoperative aortic surgery: A technical note
Suprasternal cannulation of the innominate artery in aortic reoperations may be useful in specific situations. Over a period of 3.5 years, 9 patients (6 males, average age = 49.2 ± 16.1 years) underwent suprasternal cannulation prior to resternotomy. Cannulation was performed using a side graft. All operations were successfully completed. Two patients died after surgery because of coagulopathy and multiorgan failure. There were no complications related to access or technique, and no site complications were detected during follow-up. Suprasternal cannulation of the innominate artery may play a role in selected reoperations. © 2016 The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved
AN EVALUATION OF LANDSLIDE SUSCEPTIBILITY MAPPING USING REMOTE SENSING DATA AND MACHINE LEARNING ALGORITHMS IN IRAN
Landslide is painstaking as one of the most prevalent and devastating forms of mass movement that affects man and his environment. The specific objective of this research paper is to investigate the application and performances of some selected machine learning algorithms (MLA) in landslide susceptibility mapping, in Dodangeh watershed, Iran. A 112 sample point of the past landslide, occurrence or inventory data was generated from the existing and field observations. In addition, fourteen landslide-conditioning parameters were derived from DEM and other topographic databases for the modelling process. These conditioning parameters include total curvature, profile curvature, plan curvature, slope, aspect, altitude, topographic wetness index (TWI), topographic roughness index (TRI), stream transport index (STI), stream power index (SPI), lithology, land use, distance to stream, distance to the fault. Meanwhile, factor analysis was employed to optimize the landslide conditioning parameters and the inventory data, by assessing the multi-collinearity effects and outlier detections respectively. The inventory data is divided into 70% (78) training dataset and 30% (34) test dataset for model validation. The receiver operating characteristics (ROC) curve or area under curve (AUC) value was used for assessing the model's performance. The findings reveal that TRI has 0.89 collinearity effect based on variance-inflated factor (VIF) and based on Gini factor optimization total curvature is not significant in the model development, therefore the two parameters are excluded from the modelling. All the selected MLAs (RF, BRT, and DT) shown promising performances on landslide susceptibility mapping in Dodangeh watershed, Iran. The ROC curve for training and validation for RF are 86% success rate and 83% prediction rate implies the best model performance compared to BRT and DT, with ROC curve of 72% and 70% prediction rate, respectively. In conclusion, RF could be the best algorithm for producing landslide susceptibility map, and such results could be adopted for the decision-making process to support land use planner for improving landslide risk assessment in similar environmental settings
Evaluation of right ventricular function and various models of delayed enhancement with cardiac magnetic resonance imaging in patients with repaired tetralogy of fallot
Background: Tetralogy of Fallot (TOF) is considered as the most frequent cyanotic congenital heart disorder. Right ventricular (RV) dysfunction is possible to be observed in patients with repaired TOF. Delayed enhancement (DE) is one of the recommended findings for RV dysfunction. Objectives: This study aimed at investigating the DE and its probable relationship with RV function through cardiac magnetic resonance (CMR). Patients and Methods: In this cross-sectional study, the values of cardiovascular magnetic resonance of 110 symptomatic patients, who had repaired TOF for 35 years, were gathered. We compared cardiac function indices (CFI) in patients with and without DE. Results: The patients had an average age of 21.93 ± 6.94 years (59.12 were male and 40.94 were female). 93.66 of the subjects showed DE and 6.44 of them did not have DE. 78.61 of the samples had DE of the right ventricular outflow tract (RVOT); whereas, 21.39 showed DE of the other sites. The differences between mean regurgitation fraction, average RV end-diastolic volume (RVEDV), average RV end systolic volume (ESV), and average RV ejection fraction in DE positive and negative patients were statistically significant (P values = 0.01, 0.04, 0.04, and 0.01, respectively.) Conclusion: DE commonly occurs as a complication of surgery to repair TOF and could be used as a factor for impaired RV function and other complications. Using CMR imaging for follow up of these patients could lead to diagnosis of these complications. © 2020, Iranian Journal of Radiology. T
The effect of chemotherapeutic agents on telomere length maintenance in breast cancer cell lines
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