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2篇 您的检索式:作者名="Helena Barroca"
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1A comparative study on emergent pollutants photo-assisted degradation using ruthenium modified titanate nanotubes and nanowires as catalysts显示文摘Several methods have been used to tailor nanomaterials structure and properties.Sometimes,slight changes in the structure outcomes expressive improvements in the optical and photocatalytic properties of semiconductor nanoparticles.In this context,the influence of the metal doping and the morphology on a catalyst performance was studied in this work.Here,ruthenium doped titanate nanotubes(RuTNT)were synthesised for the first time using an amorphous Ru-containing precursor.Afterwards,the photocatalytic performance of this sample was compared to the one obtained for ruthenium titanate nanowires(RuTNW),recently reported.Two samples,RuTNW and RuTNT,were produced using the same Ru-containing precursor but distinct hydrothermal methodologies.The powders were structural,morphological and optical characterized by X-ray diffraction and fluorescence,transmission electron microscopy,Raman,X-ray photoelectron and photoluminescence spectroscopies.Distinct variations on the structural and optical properties of the RuTNT and RuTNW nanoparticles,due to ruthenium incorporation were observed.Their potential use as photocatalysts was evaluated on the hydroxyl radical photo-assisted production.Both samples were catalytic for this reaction,presenting better performances than the pristine counterparts,being RuTNT the best photocatalyst.Subsequently,the degradation of two emergent pollutants,caffeine and sulfamethazine,was studied.RuTNT demonstrated to be better photocatalyst than RuTNW for caffeine but identical performances were obtained for sulfamethazine.For both catalysts,the degradation mechanism of the pollutants was explored through the identification and quantification of the intermediate compounds produced and several differences were found.This indicates the importance of the structural and morphological aspects of a material on its catalytic performance.Beatriz Barrocas M.Conceicao Oliveira Helena I.S.Nogueira Sara Fateixa Olinda C.Monteiro 2020Journal of Environmental Sciences2020,32,6:0
2Exosomal glypican-1 is elevated in pancreatic cancer precursors and can signal genetic predisposition in the absence of endoscopic ultrasound abnormalities显示文摘BACKGROUND Individuals within specific risk groups for pancreatic ductal adenocarcinoma(PDAC)[mucinous cystic lesions(MCLs),hereditary risk(HR),and new-late onset diabetes mellitus(NLOD)]represent an opportunity for early cancer detection.Endoscopic ultrasound(EUS)is a premium image modality for PDAC screening and precursor lesion characterization.While no specific biomarker is currently clinically available for this purpose,glypican-1(GPC1)is overexpressed in the circulating exosomes(crExos)of patients with PDAC compared with healthy subjects or those harboring benign pancreatic diseases.AIM To evaluate the capacity of GPC1+crExos to identify individuals at higher risk within these specific groups,all characterized by EUS.METHODS This cross-sectional study with a prospective unicentric cohort included 88 subjects:40 patients with MCL,20 individuals with HR,and 20 patients with NLOD.A control group(CG)was submitted to EUS for other reasons than pancreatic pathology,with normal pancreas and absence of hereditary risk factors(n=8).The inclusion period was between October 2016 and January 2019,and the study was approved by the Ethics Committee of Centro Hospitalar Universitário de São João,Porto,Portugal.All patients provided written informed consent.EUS and blood tests for quantification of GPC1+crExos by flow cytometry and carbohydrate antigen 19-9(CA 19-9)levels by ELISA were performed in all subjects.EUS-guided tissue acquisition was done whenever necessary.For statistical analysis,SPSS®27.0(IBM Corp.,Armonk,NY,United States)version was used.All graphs were created using GraphPad Prism 7.00(GraphPad Software,San Diego,CA,United States).RESULTS Half of MCLs harbored worrisome features(WF)or high-risk stigmata(HRS).Pancreatic abnormalities were detected by EUS in 10.0%and 35.0%in HR and NLOD individuals,respectively,all considered non-malignant and“harmless.”Median levels of GPC1+crExos were statistically different:MCL[99.4%,interquartile range(IQR):94.9%-99.8%],HR(82.0%,IQR:28.9%-98.2%),NLOD(12.6%,IQR:5.2%-63.4%),and CG(16.2%,IQR:6.6%-20.1%)(P<0.0001).Median levels of CA 19-9 were within the normal range in all groups(standard clinical cut-off of 37 U/mL).Within HR,individuals with a positive history of cancer had higher median levels of GPC1+crExos(97.9%;IQR:61.7%-99.5%),compared to those without(59.7%;IQR:26.3%-96.4%),despite no statistical significance(P=0.21).Pancreatic cysts with WF/HRS were statistically associated with higher median levels of GPC1+crExos(99.6%;IQR:97.6%-99.8%)compared to those without(96.5%;IQR:81.3%-99.5%)(P=0.011),presenting an area under the receiver operating characteristic curve value of 0.723(sensitivity 75.0%and specificity 67.7%,using a cutoff of 98.5%;P=0.012).CONCLUSION GPC1+crExos may act as biomarker to support the diagnosis and stratification of PDAC precursor lesions,and in signaling individuals with genetic predisposition in the absence of EUS abnormalities.Pedro Moutinho-Ribeiro Ines A Batista Sofia T Quintas Bárbara Adem Marco Silva Rui Morais Armando Peixoto Rosa Coelho Pedro Costa-Moreira Renato Medas Susana Lopes Filipe Vilas-Boas Manuela Baptista Diogo Dias-Silva Ana L Esteves Filipa Martins Joanne Lopes Helena Barroca Fátima Carneiro Guilherme Macedo Sonia A Melo 2022World Journal of Gastroenterology2022,28,31:0
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