A major concern from the scientific community has been raised since evidence of Bisphenol A(BP-A)can leach out from the products where they are incorporated as well as its endocrine disrupting effects observed in anim...A major concern from the scientific community has been raised since evidence of Bisphenol A(BP-A)can leach out from the products where they are incorporated as well as its endocrine disrupting effects observed in animals and humans.BP-A and several related chemicals such as Bisphenol AP(BP-AP),Bisphenol B(BPeB),Bisphenol S(BPeS),Bisphenol AF(BP-AF),Bisphenol(BPeP),Bisphenol Z(BP-Z)were analyzed in this study.BP-A and BP-S were the only bisphenols detected in the samples analyzed in this study.The median(range;mean)concentrations of BP-A found in this study was 321 ng/g(11-200932;4893 ng/g).The analysis was carried out by sonicating 0.1 g of a cryo-milled sample aliquot in methanol followed by UPLC-MS/MS determination.High concentrations of BP-A were found in several products labeled as BP-A free such as nursing bottles which are particularly problematic from the children's exposure point of view.This study presents the first reliable bisphenols in children's toys and baby products commercialized in the Middle East.There is,however,a need to continue monitoring these compounds,especially in low-cost toys,and the so-called BP-A-free products,which appear to have high levels of target contaminants and can pose an exposure risk for infants and children in the region.展开更多
In this work,noise removal in digital images is investigated.The importance of this problem lies in the fact that removal of noise is a necessary pre-processing step for other image processing tasks such as edge detec...In this work,noise removal in digital images is investigated.The importance of this problem lies in the fact that removal of noise is a necessary pre-processing step for other image processing tasks such as edge detection,image segmentation,image compression,classification problems,image registration etc.A number of different approaches have been proposed in the literature.In this work,a non-linear PDE-based algorithm is developed based on the ideas proposed by Lysaker,Osher and Tai[IEEE Trans.Image Process.,13(2004),1345-1357].This algorithm consists of two steps:flow field smoothing of the normal vectors,followed by image reconstruction.We propose a finite-difference based additive operator-splitting method that allows for much larger time-steps.This results in an efficient method for noise-removal that is shown to have good visual results.The energy is studied as an objective measure of the algorithm performance.展开更多
基金Foundation for the Advancement of Sciences(KFAS)for funding the project Chemical Safety of Children's Toys and Baby Products Sold in the State of Kuwait:A Preliminary Assessment(PR17-41BO-01).
文摘A major concern from the scientific community has been raised since evidence of Bisphenol A(BP-A)can leach out from the products where they are incorporated as well as its endocrine disrupting effects observed in animals and humans.BP-A and several related chemicals such as Bisphenol AP(BP-AP),Bisphenol B(BPeB),Bisphenol S(BPeS),Bisphenol AF(BP-AF),Bisphenol(BPeP),Bisphenol Z(BP-Z)were analyzed in this study.BP-A and BP-S were the only bisphenols detected in the samples analyzed in this study.The median(range;mean)concentrations of BP-A found in this study was 321 ng/g(11-200932;4893 ng/g).The analysis was carried out by sonicating 0.1 g of a cryo-milled sample aliquot in methanol followed by UPLC-MS/MS determination.High concentrations of BP-A were found in several products labeled as BP-A free such as nursing bottles which are particularly problematic from the children's exposure point of view.This study presents the first reliable bisphenols in children's toys and baby products commercialized in the Middle East.There is,however,a need to continue monitoring these compounds,especially in low-cost toys,and the so-called BP-A-free products,which appear to have high levels of target contaminants and can pose an exposure risk for infants and children in the region.
文摘In this work,noise removal in digital images is investigated.The importance of this problem lies in the fact that removal of noise is a necessary pre-processing step for other image processing tasks such as edge detection,image segmentation,image compression,classification problems,image registration etc.A number of different approaches have been proposed in the literature.In this work,a non-linear PDE-based algorithm is developed based on the ideas proposed by Lysaker,Osher and Tai[IEEE Trans.Image Process.,13(2004),1345-1357].This algorithm consists of two steps:flow field smoothing of the normal vectors,followed by image reconstruction.We propose a finite-difference based additive operator-splitting method that allows for much larger time-steps.This results in an efficient method for noise-removal that is shown to have good visual results.The energy is studied as an objective measure of the algorithm performance.
