We have developed a prognostic index model for survival data based on an ensemble of artificial neural networks that optimizes directly on the concordance index. Approximations of the c-index are avoided with the use of a genetic algorithm, which does not require gradient information. The model is compared with Cox proportional hazards (COX) and three support vector machine (SVM) models by Van ...

BACKGROUND Regression models for survival data have traditionally been based on the Cox regression model. However, its validity relies heavily on assumption of proportional hazards. Another restriction of the Cox model is insufficiency in dealing with time-varying covariate effects, since the regression coefficients are assumed constant. These weaknesses have generated interest in alternative a...

Cerebral malaria (CM) is a severe complication of malaria, in which cytokine production can produce immunopathological consequences. Cytokines can up-regulate prostaglandin synthesis via an increase in cyclooxygenase (COX) enzyme activity. We investigated the expression of COX enzymes, COX-1 and COX-2, in the brain by use of murine models of CM and of malaria without cerebral involvement. Altho...

a group of regioisomeric 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives possessing a cox-2 so2me pharmacophore at the para position of the c-2 or c-4 phenyl ring, in conjunction with a c-4 or c-2 phenyl (4-h) or substituted-phenyl ring (4-f,4-cl,4-br,4-ome,4-me, 4-no2), were designed for evaluation as selective cyclooxygenase-2 (cox-2) inhibitors. these target 5-oxo-1,4,5,6,7,8 hexahydroquino...

Compounds combining dual inhibitory action against FAAH and cyclooxygenase (COX) may be potentially useful analgesics. Here, we describe a novel flurbiprofen analogue, N-(3-bromopyridin-2-yl)-2-(2-fluoro-(1,1'-biphenyl)-4-yl)propanamide (Flu-AM4). The compound is competitive, reversible inhibitor of with Ki value 13 nM which inhibits COX activity in substrate-selective manner. Molecular modelli...

This paper proposes an analytical approximation to price exotic options within a stochastic volatility framework. Assuming a general mean reverting process for the underlying asset and a square-root process for the volatility, we derive an approximation for option prices using a Taylor expansion around two average defined volatilities. The moments of the average volatilities are computed analyt...

Design of selective cyclooxygenase-2 (COX-2) inhibitors is still a challenging task because of active site similarities between COX isoenzymes. To help with this issue, we tried to generate a 3D-QSAR (3 dimensional quantitative structure activity relationship) model that might reflect the essential features of COX-2 active sites. Compounds in a series of resveratrol derivatives inhibitors with ...

background: the incidence of restenosis in patients suffering from coronary artery disease after undergoing angioplasty is of paramount importance. accordingly, this study aimed to investigate factors affecting the time of the first incidence of restenosis in patients undergone angioplasty in the city of zanjan, iran.   methods: this retrospective cohort study was conducted on 421 patients who ...