Enzymatic hydrolysis of proteins is a breakdown process of peptide bond in proteins,releasing some peptides with potential biological functions.Previous studies on enzymatic hydrolysis of whey proteins have not identi...Enzymatic hydrolysis of proteins is a breakdown process of peptide bond in proteins,releasing some peptides with potential biological functions.Previous studies on enzymatic hydrolysis of whey proteins have not identified the complete peptide profiles after hydrolysis.In this study,we reconstructed a profile of peptides from whey hydrolysates with two enzymes and different processing conditions.We also developed an ensemble machine learning predictor to classify peptides obtained from whey hydrolysis.A total of 2572 peptides were identified over three process conditions with two enzymes in duplicate.499 peptides were classified and chosen as potential antioxidant peptides from whey proteins.The peptides classified as antioxidants in the hydrolysates had a proportion of 13.1%-24.5%regarding all peptides identified.These results facilitate the selection of promising peptides involved in the antioxidant properties during the enzymatic hydrolysis of whey proteins,aiding the discovery of novel antioxidant peptides.展开更多
A series of granular activated carbons （GACs） were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET speci...A series of granular activated carbons （GACs） were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET specific surface area （SBEr）, total pore volume （Vr） and average pore diameter （da） were measured and cal- culated as well as process parameters such as yield of char （CY） and burn-off （B）. The relationship between the pore structural parameters of the GAC from coal blend （BC-GAC） and the ones of the GACs from corresponding single coals （SC-GACs） was analyzed, in which an index, the relative error （δ）, was presented to define the bias between fitted values and experimental values of these parameters of the BC-GACs. The results show that the BC-GAC keeps qualitatively the pore structural features of the SC-GACs; as concerned as the quantitative relationship, the pore structural parameters of the BC-GAC from coal blend consisting of non-caking coals can be obtained by adding proportionally the pore structural parameters of the SC-GACs with a less than 10%. Meanwhile, for the BC-GAC from coal blend containing weak caking bituminous coal, the δ increases up to 25% and the experimental pore size distribution differs greatly from the fitted one.展开更多
This study aimed to investigate the effect of yam flour substitution (Dioscorea alata L.) and moringa powder in wheat bread on glycemic response. Glycemic index (GI) and glycemic load (GL) of pieces of bread were dete...This study aimed to investigate the effect of yam flour substitution (Dioscorea alata L.) and moringa powder in wheat bread on glycemic response. Glycemic index (GI) and glycemic load (GL) of pieces of bread were determined. A mixture plan design was used to determine the optimal formulation of bread made of yam flour, wheat flour and moringa powder. The mixture of 79.4% soft wheat flour, 20% yam flour and 0.6% moringa leaves powder has a good potential in bread preparation and was used in this study. 100% wheat bread was used as control. Postprandial blood glucose response (glycemic response) was evaluated with the glucose used as a reference food. Blood glucose responses were measured at different intervals for 2 hours. The results indicated that composite bread had low GI and GL values than wheat bread. Values are GI = 80 and GL = 61.2 for wheat bread and GI = 37.78 and GL = 29.65 for the composite bread. This study demonstrated that the inclusion of yam flour of moringa leaves powder in bread production might not pose a threat to blood glucose response compared to wheat bread. These pieces of bread could be included easily in diabetics’ and non-diabetics diet.展开更多
A novel engineering thermoplastic, phenolphthalein poly(ether ether sulfone)(PES C) was blended with a commercial thermotropic liquid crystalline polymer(TLCP), Vectra A950, up to 30 weight percent of TLCP. A rheom...A novel engineering thermoplastic, phenolphthalein poly(ether ether sulfone)(PES C) was blended with a commercial thermotropic liquid crystalline polymer(TLCP), Vectra A950, up to 30 weight percent of TLCP. A rheometrics dynamic spectrometer (RDS Ⅱ) and a CEAST capillary rheometer, a rheoscope 1000 were employed to investigate the melt rheology and extrusion behaviour at both the low and high shearing rates. The morphologies of the blends under different shearing were observed with a scanning electron microscope(SEM) and correlated to the observed rheology. The principal normal stress differences measured with cone and plate geometry give a temperature independent correlation for both blend and PES C when they are plotted against shear stress. But the extrudate swell of the blends showed a strong temperature dependence at each shear stress. The concentration dependence of extrudate swell shows a contrary behaviour to that of the inorganic filled system. A reasonable hypothesis based on the relaxation and disorientation of TLCP during flowing in the capillary and exiting was given to explain it. The melt fracture was checked after extrusion from capillary and was discussed.展开更多
Herbicides are chemical compounds capable of killing or inhibiting the growth of certain plants and they have been frequently detected in natural waters. Advanced treatments, including those using ozone, have been use...Herbicides are chemical compounds capable of killing or inhibiting the growth of certain plants and they have been frequently detected in natural waters. Advanced treatments, including those using ozone, have been used in order to remove herbicides from different types of water with good treatment efficiency. The efficiency of ozonation, an oxidative process, in the removal of persistent compounds is affected by several factors, such as pH and the concentration of the contaminant. The compound metribuzin, the herbicide investigated in this study, is persistent and mobile in the environment with a high potential for transport through soils and thus it can reach the groundwater. In this context, the objective of this study was to evaluate the effect of different pH conditions (2.5, 5.5 and 12.0) and initial concentrations of metribuzin (20, 50 and 100 ppm) on the removal of this herbicide from water using the ozonation process. In order to identify the possible effect of these two variables on the ozonation treatment, the concentration of metribuzin was determined by spectrophotometry UV-vis spectrophotometer. The results were used to evaluate the best conditions for the ozonation treatment. The ozonation conditions which provided the highest metribuzin removal efficiency (86.5% ± 0.3%) were pH 12.0 and an initial metribuzin concentration of 20 ppm. The findings indicate that oxidation with ozone is effective for the removal of metribuzin from aqueous solutions under the conditions studied.展开更多
In this study, the SEBAL (Surface Energy Balance Algorithm for Land) model was used to map the spatio-temporal distribution of actual evapotranspiration in the Yamoussoukro department (Côte d’Ivoire). Like other...In this study, the SEBAL (Surface Energy Balance Algorithm for Land) model was used to map the spatio-temporal distribution of actual evapotranspiration in the Yamoussoukro department (Côte d’Ivoire). Like other regions of the country, the Yamoussoukro district is confronted with the phenomenon of evapotranspiration (ET). This is a very important component that comes into play in the water balance but also in the calculation of the water needs of agricultural crops. Consequently, its estimation is of paramount importance in research related to the rational management of water resources, particularly agricultural water. The objective of this study was to analyze the spatio-temporal distribution of actual evapotranspiration (AET) as a function of land cover and land use. The methodology used is based on the SEBAL model which uses remote sensing (Landsat 8_OLI/TIRS) and climatic data to estimate actual evapotranspiration and analyze the spatio-temporal distribution of AET. The results reveal that the AET varied from 0 to 5.44 mm/day over the period from December 2019 to February 2020 with an average value of 4.92 mm/day. The highest average values occurred for water bodies (4.90 mm/day) and flooded vegetation (4.88 mm/day) while the lowest values occurred in residential areas (2.04 mm/day). Furthermore, the results show that the difference between the SEBAL model and the FAO-Penman-Monteith method is minimal with an average RMSE of 0.36 mm/day for all the satellite images. This study demonstrates the considerable potential of remote sensing for the characterization and estimation of spatial evapotranspiration in the Zatta irrigated rice-growing area.展开更多
The inactivation of bacterial cells through catalyzed oxidation using hydrogen peroxide as the primary oxidant agent is dependent on a series of factors, such as the concentration of the catalyst, the rate of hydroxyl...The inactivation of bacterial cells through catalyzed oxidation using hydrogen peroxide as the primary oxidant agent is dependent on a series of factors, such as the concentration of the catalyst, the rate of hydroxyl radical formation in the controlled decomposition of the oxidant agent, and the concentration and toxicity of hydrogen peroxide. The objective of this study was to develop a mathematical model able to predict the kinetics of the inactivation Escherichia coli and total coliforms cells present in treated domestic sewage through catalytic peroxidation. The catalyst used was iron oxide supported on mineral coal （called CP）, and the effects of the operational conditions, including hydrogen peroxide concentration and dosage of catalyst, were evaluated. The results showed that the disinfection kinetics of the treated domestic sewage is dependent on the concentrations of hydrogen peroxide and catalyst dosage. The kinetic model was shown to be able to predict the behavior of the inactivation kinetics of the bacterium Escherichia coli ATCC-25922 when different concentrations of hydrogen peroxide （75 and 100 mg·L^-1） were used, regardless of the catalyst dosage.展开更多
Human milk is the ideal nutritional support for premature neonates. Considering the need for aggregating nutritional value to human milk provided to such vulnerable group of infants, human milk was concentrated by the...Human milk is the ideal nutritional support for premature neonates. Considering the need for aggregating nutritional value to human milk provided to such vulnerable group of infants, human milk was concentrated by the block freeze concentration technique. The effects of freeze concentration on the physicochemical properties, the efficiency of the process, color parameters, and the density and dynamic viscosity of human milk were assessed. The freeze concentration technology was used to successfully concentrate human milk to a factor equal to 180.48% and 72% of total solid retention in the second stage of freeze concentration. The values observed in the concentrates for the biochemical properties showed that the fraction of concentrated fluid human milk of the second stage (C2) presented elevated amounts of carbohydrates, protein and energy. The elevated caloric value observed in the ice fraction of the first stage (I1) refers to the retention of lipids in it. When added to human milk, C2 and I1 may satisfy the special requisites of nutrients and energy to guarantee the growth and development of preterm neonates.展开更多
Esterification is an important process in the food industry and can be carried out via homogeneous or heterogeneous catalysis.The homogeneous catalyst,despite providing high conversion,can cause corrosion in reactors,...Esterification is an important process in the food industry and can be carried out via homogeneous or heterogeneous catalysis.The homogeneous catalyst,despite providing high conversion,can cause corrosion in reactors,which is not observed with the use of heterogeneous catalysts.However,some of these catalysts require a high process temperature and may lose their catalytic activity with reuse.Thus,catalytic membranes have been proposed as a promising alternative.The combination of catalysis and separation in a single module provides greater conversion,reduction of excess reagents,compact industrial plant,making the process more efficient.Within this context,this work aims to present a literature review on the catalytic membrane for the synthesis of esters,improving the understanding of the production and development.This review examines the materials,catalysts used,and synthetic pathways.A comparison between the methods,as well as limitations and gaps in the literature,are highlighted.展开更多
Fragmentation/disassembly of fiber-like micelles generated by living crystalline-driven self-assembly(CDSA)is usually encountered in aqueous media,which hinders the applications of micelles.Herein,we report the genera...Fragmentation/disassembly of fiber-like micelles generated by living crystalline-driven self-assembly(CDSA)is usually encountered in aqueous media,which hinders the applications of micelles.Herein,we report the generation of uniform fiber-like micelles consisting of a𝜋Л-conjugated oligo(p-phenylenevinylene)core and a crosslinking silica shell with grafted poly(ethylene glycol)(PEG)chains by the combination of living CDSA,silica chemistry and surface grafting-onto strategy.Owing to the presence of crosslinking silica shell and the outmost PEG chains,the resulting micelles exhibit excellent dispersity and colloidal stability in PBS buffer,BSA aqueous solution and upon heating at 80℃ for 2 h without micellar fragmentation/disassembly.The micelles also show negligible cytotoxicity toward both HeLa cervical cancer and HEK239T human embryonic kidney cell lines.Interestingly,micelles with Ln of 156 nm show the“stealth”property with no significant uptake by HeLa cells,whereas some certain amounts of micelles with Ln of 535 nm can penetrate into HeLa cells,showing length-dependent cellular uptake behaviors.These results provide a route to prepare uniform,colloidally stable fiber-like nanostructures with tunable length and functions derived for biomedical applications.展开更多
This paper presents response surface methodology （RSM） as an efficient approach for modeling and optimizing TiO2 nanoparticles preparation via co-precipitation for dye-sensitized solar cell （DSSC） perfor- mance. T...This paper presents response surface methodology （RSM） as an efficient approach for modeling and optimizing TiO2 nanoparticles preparation via co-precipitation for dye-sensitized solar cell （DSSC） perfor- mance. Titanium （IV） bis-（acetylacetonate） di-isopropoxide （DIPBAT）, isopropanol and water were used as precursor, solvent and co-solvent, respectively. Molar ratio of water, aging temperature and calcina- tion temperature as preparation factors with main and interaction effects on particle characteristics and performances were investigated, Particle characteristics in terms of primary and secondary sizes, crys- tal orientation and morphology were determined by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Band gap energy and power conversion efficiency of DSSCs were used for perfor- mance studies. According to analysis of variance （ANOVA） in response surface methodology （RSM）, all three independent parameters were statistically significant and the final model was accurate. The model predicted maximum power conversion efficiency （0.14%） under the optimal condition of molar ratio of DIPBAT-to-isopropanol-to-water of 1 ： 10：500, aging temperature of 36 C and calcination temperature of 400 ℃. A second set of data was adopted to validate the model at optimal conditions and was found to be 0.14 ± 0.015%, which was very close to the predicted value. This study proves the reliability of the model in identi（ving the optimal condition for maximum performance.展开更多
Cultivation of cut flowers is a new agricultural sector in Ethiopia,which currently generates a high amount of income for the country's developments.Despite its significant contribution to economic developme...Cultivation of cut flowers is a new agricultural sector in Ethiopia,which currently generates a high amount of income for the country's developments.Despite its significant contribution to economic developments;many issues were raised from communities and environmentalists concerning its environmental performance.Based on this issue the study assesses cradle to gate of cut flower production in the Wolmera district.The main objective of the study was environmental performance evaluation of flower farms in Wolmera district,Oromia regional state,Ethiopia related to operational activities throughout entire life cycles of cut flower production.In this study,primary and secondary data were collected using ISO 14031 standard structured with LCA tool methodology.Data were collected by inventory using an on-site data collection system from its sources.Based on data collected GHG(CO2,N2O,CH4&NH3)emissions to the atmosphere were evaluated by using an inter-governmental panel on climatic changes(IPCC 2006)for inventory data and eutrophication&acidification estimated from data tested at laboratory levels.Similarly,the study also assesses banned chemicals used in the farms through inventory data assessment,and about 156 chemicals applied in the farms were collected to screen out those banned chemicals used and the two most extremely hazardous chemicals(Impulse&Meltatix)banned by WHO identified in the study.As it understood from a general assessment of all flower farms;all of them haven't EIA document established before construction in the district and production started with having less attention for EHPEA code of conducts in the flower farms which faces the environments for high impacts by emission emitted from flower farms in the district as a whole.展开更多
Zeolites have been little investigated for food applications,despite their chemical composition is similar to clays and clay minerals,which have been extensively analyzed for various applications,including food.Zeolit...Zeolites have been little investigated for food applications,despite their chemical composition is similar to clays and clay minerals,which have been extensively analyzed for various applications,including food.Zeolites can be distinguished from clay materials,since the former have a porous microstructure characterized by intracrystalline cavities and channels,while the latter have a laminar microstructure.The goal of this review paper was to give a comprehensive perspective in terms of the different food applications found so far for zeolites,namely:antimicrobial materials,ethylene scavengers,fillers for food packaging materials,food nanoreactors,food substance sensors,immobilizers and stabilizers of active compounds and enzymes,molecular sieves for the pretreatment of food samples,as well as intelligent food contact materials.The main food applications from zeolites are related to their good properties as adsorbent materials,and these properties can be altered and tuned by ion exchange,surface organo-modification,among others,for a specific designed application.Zeolites for food applications have been investigated primarily as antimicrobial materials,concentrators of target analytes and sensors for food substances.However,the other potential food applications indicated above from zeolites are booming,since they are harmless materials recognized by various organizations.展开更多
Propranolol hydrochloride can be considered a persistent and bioaccumulative pharmaceutical in the environment.This drug and its by-products are potentially toxic and have adverse effects,since these compounds have be...Propranolol hydrochloride can be considered a persistent and bioaccumulative pharmaceutical in the environment.This drug and its by-products are potentially toxic and have adverse effects,since these compounds have been associated with endocrine-disrupting effects,reproductive deficiencies,embryo abnormalities and pericardial oedema.TiO_(2)–La 0.05%–carboxymethyl-β-cyclodextrin(CMCD)nanoparticles were successfully prepared by a simple two-step method,which consists of sonification and functionalization.The characterization analyses reveal that lanthanum is dispersed on the semiconductor surface,probably forming Ti–O–La bonds,which can induce oxygen vacancies and surface defects that effectively restrain the recombination of photogenerated electron/holes pairs.The efficiency of TiO_(2)–La 0.05%–CMCD samples in degradation of propranolol under UV-light irradiation is higher than that of pristine TiO_(2) within 20 min reaction,probably due to complex formation between theβ-blocker and the oligosaccharide,which allows us to propose a photocatalytic mechanism based on the formation of intermediates and competition of these compounds to the radicals and CMCD cavities.展开更多
基金supported and funded by the Gobernación del Cesar-Ministry of Science,Technology,and Innovation through resources for the higher education(grant 736/2015)the Natural Sciences and Engineering Research Council of Canada(NSERC)。
文摘Enzymatic hydrolysis of proteins is a breakdown process of peptide bond in proteins,releasing some peptides with potential biological functions.Previous studies on enzymatic hydrolysis of whey proteins have not identified the complete peptide profiles after hydrolysis.In this study,we reconstructed a profile of peptides from whey hydrolysates with two enzymes and different processing conditions.We also developed an ensemble machine learning predictor to classify peptides obtained from whey hydrolysis.A total of 2572 peptides were identified over three process conditions with two enzymes in duplicate.499 peptides were classified and chosen as potential antioxidant peptides from whey proteins.The peptides classified as antioxidants in the hydrolysates had a proportion of 13.1%-24.5%regarding all peptides identified.These results facilitate the selection of promising peptides involved in the antioxidant properties during the enzymatic hydrolysis of whey proteins,aiding the discovery of novel antioxidant peptides.
基金financially supported by the National High-Tech Research and Development Program of China (No.2008AA05Z308)the National Natural Science Foundation of China (No.20776150)
文摘A series of granular activated carbons （GACs） were prepared by briquetting method from Chinese coals of different ranks and their blends, with coal pitch as the binder. Pore structural parameters including BET specific surface area （SBEr）, total pore volume （Vr） and average pore diameter （da） were measured and cal- culated as well as process parameters such as yield of char （CY） and burn-off （B）. The relationship between the pore structural parameters of the GAC from coal blend （BC-GAC） and the ones of the GACs from corresponding single coals （SC-GACs） was analyzed, in which an index, the relative error （δ）, was presented to define the bias between fitted values and experimental values of these parameters of the BC-GACs. The results show that the BC-GAC keeps qualitatively the pore structural features of the SC-GACs; as concerned as the quantitative relationship, the pore structural parameters of the BC-GAC from coal blend consisting of non-caking coals can be obtained by adding proportionally the pore structural parameters of the SC-GACs with a less than 10%. Meanwhile, for the BC-GAC from coal blend containing weak caking bituminous coal, the δ increases up to 25% and the experimental pore size distribution differs greatly from the fitted one.
文摘This study aimed to investigate the effect of yam flour substitution (Dioscorea alata L.) and moringa powder in wheat bread on glycemic response. Glycemic index (GI) and glycemic load (GL) of pieces of bread were determined. A mixture plan design was used to determine the optimal formulation of bread made of yam flour, wheat flour and moringa powder. The mixture of 79.4% soft wheat flour, 20% yam flour and 0.6% moringa leaves powder has a good potential in bread preparation and was used in this study. 100% wheat bread was used as control. Postprandial blood glucose response (glycemic response) was evaluated with the glucose used as a reference food. Blood glucose responses were measured at different intervals for 2 hours. The results indicated that composite bread had low GI and GL values than wheat bread. Values are GI = 80 and GL = 61.2 for wheat bread and GI = 37.78 and GL = 29.65 for the composite bread. This study demonstrated that the inclusion of yam flour of moringa leaves powder in bread production might not pose a threat to blood glucose response compared to wheat bread. These pieces of bread could be included easily in diabetics’ and non-diabetics diet.
文摘A novel engineering thermoplastic, phenolphthalein poly(ether ether sulfone)(PES C) was blended with a commercial thermotropic liquid crystalline polymer(TLCP), Vectra A950, up to 30 weight percent of TLCP. A rheometrics dynamic spectrometer (RDS Ⅱ) and a CEAST capillary rheometer, a rheoscope 1000 were employed to investigate the melt rheology and extrusion behaviour at both the low and high shearing rates. The morphologies of the blends under different shearing were observed with a scanning electron microscope(SEM) and correlated to the observed rheology. The principal normal stress differences measured with cone and plate geometry give a temperature independent correlation for both blend and PES C when they are plotted against shear stress. But the extrudate swell of the blends showed a strong temperature dependence at each shear stress. The concentration dependence of extrudate swell shows a contrary behaviour to that of the inorganic filled system. A reasonable hypothesis based on the relaxation and disorientation of TLCP during flowing in the capillary and exiting was given to explain it. The melt fracture was checked after extrusion from capillary and was discussed.
文摘Herbicides are chemical compounds capable of killing or inhibiting the growth of certain plants and they have been frequently detected in natural waters. Advanced treatments, including those using ozone, have been used in order to remove herbicides from different types of water with good treatment efficiency. The efficiency of ozonation, an oxidative process, in the removal of persistent compounds is affected by several factors, such as pH and the concentration of the contaminant. The compound metribuzin, the herbicide investigated in this study, is persistent and mobile in the environment with a high potential for transport through soils and thus it can reach the groundwater. In this context, the objective of this study was to evaluate the effect of different pH conditions (2.5, 5.5 and 12.0) and initial concentrations of metribuzin (20, 50 and 100 ppm) on the removal of this herbicide from water using the ozonation process. In order to identify the possible effect of these two variables on the ozonation treatment, the concentration of metribuzin was determined by spectrophotometry UV-vis spectrophotometer. The results were used to evaluate the best conditions for the ozonation treatment. The ozonation conditions which provided the highest metribuzin removal efficiency (86.5% ± 0.3%) were pH 12.0 and an initial metribuzin concentration of 20 ppm. The findings indicate that oxidation with ozone is effective for the removal of metribuzin from aqueous solutions under the conditions studied.
文摘In this study, the SEBAL (Surface Energy Balance Algorithm for Land) model was used to map the spatio-temporal distribution of actual evapotranspiration in the Yamoussoukro department (Côte d’Ivoire). Like other regions of the country, the Yamoussoukro district is confronted with the phenomenon of evapotranspiration (ET). This is a very important component that comes into play in the water balance but also in the calculation of the water needs of agricultural crops. Consequently, its estimation is of paramount importance in research related to the rational management of water resources, particularly agricultural water. The objective of this study was to analyze the spatio-temporal distribution of actual evapotranspiration (AET) as a function of land cover and land use. The methodology used is based on the SEBAL model which uses remote sensing (Landsat 8_OLI/TIRS) and climatic data to estimate actual evapotranspiration and analyze the spatio-temporal distribution of AET. The results reveal that the AET varied from 0 to 5.44 mm/day over the period from December 2019 to February 2020 with an average value of 4.92 mm/day. The highest average values occurred for water bodies (4.90 mm/day) and flooded vegetation (4.88 mm/day) while the lowest values occurred in residential areas (2.04 mm/day). Furthermore, the results show that the difference between the SEBAL model and the FAO-Penman-Monteith method is minimal with an average RMSE of 0.36 mm/day for all the satellite images. This study demonstrates the considerable potential of remote sensing for the characterization and estimation of spatial evapotranspiration in the Zatta irrigated rice-growing area.
文摘The inactivation of bacterial cells through catalyzed oxidation using hydrogen peroxide as the primary oxidant agent is dependent on a series of factors, such as the concentration of the catalyst, the rate of hydroxyl radical formation in the controlled decomposition of the oxidant agent, and the concentration and toxicity of hydrogen peroxide. The objective of this study was to develop a mathematical model able to predict the kinetics of the inactivation Escherichia coli and total coliforms cells present in treated domestic sewage through catalytic peroxidation. The catalyst used was iron oxide supported on mineral coal （called CP）, and the effects of the operational conditions, including hydrogen peroxide concentration and dosage of catalyst, were evaluated. The results showed that the disinfection kinetics of the treated domestic sewage is dependent on the concentrations of hydrogen peroxide and catalyst dosage. The kinetic model was shown to be able to predict the behavior of the inactivation kinetics of the bacterium Escherichia coli ATCC-25922 when different concentrations of hydrogen peroxide （75 and 100 mg·L^-1） were used, regardless of the catalyst dosage.
文摘Human milk is the ideal nutritional support for premature neonates. Considering the need for aggregating nutritional value to human milk provided to such vulnerable group of infants, human milk was concentrated by the block freeze concentration technique. The effects of freeze concentration on the physicochemical properties, the efficiency of the process, color parameters, and the density and dynamic viscosity of human milk were assessed. The freeze concentration technology was used to successfully concentrate human milk to a factor equal to 180.48% and 72% of total solid retention in the second stage of freeze concentration. The values observed in the concentrates for the biochemical properties showed that the fraction of concentrated fluid human milk of the second stage (C2) presented elevated amounts of carbohydrates, protein and energy. The elevated caloric value observed in the ice fraction of the first stage (I1) refers to the retention of lipids in it. When added to human milk, C2 and I1 may satisfy the special requisites of nutrients and energy to guarantee the growth and development of preterm neonates.
基金support from CAPES-Coorde nação de Aperfeiçoamento de Pessoal de Nível Superior(PROEX and PrInt Programs)CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico(307576/2018-3 and 420275/2018-5)and FAPESC-Fundação de AmparoàPesquisa do Estado de Santa Catarina.
文摘Esterification is an important process in the food industry and can be carried out via homogeneous or heterogeneous catalysis.The homogeneous catalyst,despite providing high conversion,can cause corrosion in reactors,which is not observed with the use of heterogeneous catalysts.However,some of these catalysts require a high process temperature and may lose their catalytic activity with reuse.Thus,catalytic membranes have been proposed as a promising alternative.The combination of catalysis and separation in a single module provides greater conversion,reduction of excess reagents,compact industrial plant,making the process more efficient.Within this context,this work aims to present a literature review on the catalytic membrane for the synthesis of esters,improving the understanding of the production and development.This review examines the materials,catalysts used,and synthetic pathways.A comparison between the methods,as well as limitations and gaps in the literature,are highlighted.
基金The authors are thankful for financial support from National Science Foundation for Distinguished Young Scholars(51825304)National Natural Science Foundation of China(52122314,51873229 and 51961145103)+3 种基金the project of Bureau of International Cooperation,CAS(121731KYSB20200006)Youth Innovation Promotion Association of CAS(Y2020062)Shanghai Scientific and Technological Innovation Project(19ZR1468400,19590750400,20JC1415400 and 21520780100)Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-05-E00012).
文摘Fragmentation/disassembly of fiber-like micelles generated by living crystalline-driven self-assembly(CDSA)is usually encountered in aqueous media,which hinders the applications of micelles.Herein,we report the generation of uniform fiber-like micelles consisting of a𝜋Л-conjugated oligo(p-phenylenevinylene)core and a crosslinking silica shell with grafted poly(ethylene glycol)(PEG)chains by the combination of living CDSA,silica chemistry and surface grafting-onto strategy.Owing to the presence of crosslinking silica shell and the outmost PEG chains,the resulting micelles exhibit excellent dispersity and colloidal stability in PBS buffer,BSA aqueous solution and upon heating at 80℃ for 2 h without micellar fragmentation/disassembly.The micelles also show negligible cytotoxicity toward both HeLa cervical cancer and HEK239T human embryonic kidney cell lines.Interestingly,micelles with Ln of 156 nm show the“stealth”property with no significant uptake by HeLa cells,whereas some certain amounts of micelles with Ln of 535 nm can penetrate into HeLa cells,showing length-dependent cellular uptake behaviors.These results provide a route to prepare uniform,colloidally stable fiber-like nanostructures with tunable length and functions derived for biomedical applications.
基金the Malaysian Ministry of Higher Education(MOHE)for providing the financial support through Fundamental Research Grant Scheme(UKM-KK-02FRGS0199-2010)
文摘This paper presents response surface methodology （RSM） as an efficient approach for modeling and optimizing TiO2 nanoparticles preparation via co-precipitation for dye-sensitized solar cell （DSSC） perfor- mance. Titanium （IV） bis-（acetylacetonate） di-isopropoxide （DIPBAT）, isopropanol and water were used as precursor, solvent and co-solvent, respectively. Molar ratio of water, aging temperature and calcina- tion temperature as preparation factors with main and interaction effects on particle characteristics and performances were investigated, Particle characteristics in terms of primary and secondary sizes, crys- tal orientation and morphology were determined by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Band gap energy and power conversion efficiency of DSSCs were used for perfor- mance studies. According to analysis of variance （ANOVA） in response surface methodology （RSM）, all three independent parameters were statistically significant and the final model was accurate. The model predicted maximum power conversion efficiency （0.14%） under the optimal condition of molar ratio of DIPBAT-to-isopropanol-to-water of 1 ： 10：500, aging temperature of 36 C and calcination temperature of 400 ℃. A second set of data was adopted to validate the model at optimal conditions and was found to be 0.14 ± 0.015%, which was very close to the predicted value. This study proves the reliability of the model in identi（ving the optimal condition for maximum performance.
文摘Cultivation of cut flowers is a new agricultural sector in Ethiopia,which currently generates a high amount of income for the country's developments.Despite its significant contribution to economic developments;many issues were raised from communities and environmentalists concerning its environmental performance.Based on this issue the study assesses cradle to gate of cut flower production in the Wolmera district.The main objective of the study was environmental performance evaluation of flower farms in Wolmera district,Oromia regional state,Ethiopia related to operational activities throughout entire life cycles of cut flower production.In this study,primary and secondary data were collected using ISO 14031 standard structured with LCA tool methodology.Data were collected by inventory using an on-site data collection system from its sources.Based on data collected GHG(CO2,N2O,CH4&NH3)emissions to the atmosphere were evaluated by using an inter-governmental panel on climatic changes(IPCC 2006)for inventory data and eutrophication&acidification estimated from data tested at laboratory levels.Similarly,the study also assesses banned chemicals used in the farms through inventory data assessment,and about 156 chemicals applied in the farms were collected to screen out those banned chemicals used and the two most extremely hazardous chemicals(Impulse&Meltatix)banned by WHO identified in the study.As it understood from a general assessment of all flower farms;all of them haven't EIA document established before construction in the district and production started with having less attention for EHPEA code of conducts in the flower farms which faces the environments for high impacts by emission emitted from flower farms in the district as a whole.
文摘Zeolites have been little investigated for food applications,despite their chemical composition is similar to clays and clay minerals,which have been extensively analyzed for various applications,including food.Zeolites can be distinguished from clay materials,since the former have a porous microstructure characterized by intracrystalline cavities and channels,while the latter have a laminar microstructure.The goal of this review paper was to give a comprehensive perspective in terms of the different food applications found so far for zeolites,namely:antimicrobial materials,ethylene scavengers,fillers for food packaging materials,food nanoreactors,food substance sensors,immobilizers and stabilizers of active compounds and enzymes,molecular sieves for the pretreatment of food samples,as well as intelligent food contact materials.The main food applications from zeolites are related to their good properties as adsorbent materials,and these properties can be altered and tuned by ion exchange,surface organo-modification,among others,for a specific designed application.Zeolites for food applications have been investigated primarily as antimicrobial materials,concentrators of target analytes and sensors for food substances.However,the other potential food applications indicated above from zeolites are booming,since they are harmless materials recognized by various organizations.
基金Project supported by the Coordination for the Improvement of Higher Education Personnel (CAPES)。
文摘Propranolol hydrochloride can be considered a persistent and bioaccumulative pharmaceutical in the environment.This drug and its by-products are potentially toxic and have adverse effects,since these compounds have been associated with endocrine-disrupting effects,reproductive deficiencies,embryo abnormalities and pericardial oedema.TiO_(2)–La 0.05%–carboxymethyl-β-cyclodextrin(CMCD)nanoparticles were successfully prepared by a simple two-step method,which consists of sonification and functionalization.The characterization analyses reveal that lanthanum is dispersed on the semiconductor surface,probably forming Ti–O–La bonds,which can induce oxygen vacancies and surface defects that effectively restrain the recombination of photogenerated electron/holes pairs.The efficiency of TiO_(2)–La 0.05%–CMCD samples in degradation of propranolol under UV-light irradiation is higher than that of pristine TiO_(2) within 20 min reaction,probably due to complex formation between theβ-blocker and the oligosaccharide,which allows us to propose a photocatalytic mechanism based on the formation of intermediates and competition of these compounds to the radicals and CMCD cavities.
