Polyelectrolyte complexes(PECs)of hyperbranched(HB)and linear polysaccharides are promising as more effective encapsulation agents compared to PECs formed by linear polysaccharides.We investigated the PECs between the...Polyelectrolyte complexes(PECs)of hyperbranched(HB)and linear polysaccharides are promising as more effective encapsulation agents compared to PECs formed by linear polysaccharides.We investigated the PECs between the HB anionic polysaccharide fucoidan(FUC)and the cationic linear polysaccharide chitosan(CS).The FUC had a molecular weight(MW)of 30×106.The PECs were prepared in three solvents(water,0.01 and 0.1 mol/L acetic acid)with CS of MW of 15,110 and 170 kDa,and deacetylation degrees(DDA)of 70%and 97%.The structures of the PECs and the initial FUC were investigated by multi-angle static and dynamic light scattering.As the FUC contained 18 wt%of—OSO3 groups and 5 wt%of uronic acid units,it was a“strong-weak”copolyanion,so the HB macromolecules of the FUC formed nanogel particles in 0.1 mol/L AcOH and open branched structures in water,as confirmed by the Kratky plots.After mixing the solutions of original components,the PEC structures underwent an equilibration period,the duration of which increased with the MW of CS.As the charge stoichiometry was approached,the PECs shrank;the fractal dimension approached unity,indicating the side-by-side packing of adjacent FUC branches with the help of CS.Secondary aggregation in the vicinity of the charge compensation was hardly observed,as it occurred in a very narrow region.The PEC content at theζ-potential inversion depended on solvents’pH and the DDA of CS.In the extreme case of core-shell PECs in 0.1 mol/L AcOH,obtained by mixing FUC nanogels with the solutions of high MW CS of 97%DDA,the protruding tails of CS formed a positively charged shell in the whole range of FUC content(10 wt%<WFUC<90 wt%).Scanning electron microscopy and atomic force microscopy images of dried samples were discussed in relation to the light scattering results.展开更多
Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framewo...Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us.We compare our results with other theoretical studies and experimental data.The couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.展开更多
In this study,water-dispersible graphitic carbon nitride(g-C_(3)N_(4))photocatalysts were successively prepared through the chemically oxidative etching of bulk g-C_(3)N_(4) that was polymerized thermally in different...In this study,water-dispersible graphitic carbon nitride(g-C_(3)N_(4))photocatalysts were successively prepared through the chemically oxidative etching of bulk g-C_(3)N_(4) that was polymerized thermally in different calcination atmospheres such as air,CO_(2),and N_(2).The different calcination atmospheres directly influenced the physicochemical and optical properties of both bulk and water-dispersible g-C_(3)N_(4),changing the photocatalytic degradation behavior of methylene blue(MB)and tetracycline hydrochloride(TCHCl)for water-dispersible g-C_(3)N_(4).The bubble-burst process in the thermal polymerization of thiourea produced defective edges containing C=O groups that preferred substituting the C-NHx groups over bulk g-C_(3)N_(4).In the oxygen-free N_(2) atmosphere among the different calcination atmospheres,more C=O functional groups were generated on the defective edges of bulk g-C_(3)N_(4),resulting in the highest N vacancy of the tri-s-triazine structure.During the successive chemical oxidation,S-or O-containing functional groups were introduced onto water-dispersible g-C_(3)N_(4).The water-dispersible g-C_(3)N_(4) photocatalyst from the oxygen-free N_(2) atmosphere(NTw)contained the most O-and S-functional groups on the g-C_(3)N_(4) surface.Consequently,NTw exhibited the highest photocatalytic activity in the MB and TC-HCl photodegradation because of its slowest recombination process,which was ascribed to the unique surface properties of NTw such as abundant functional groups on the defective edges and N-deficient property.展开更多
In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxide...In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxides/hydroxides composite(FeMg/CER)was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water environment.Characteristics of FeMg/CER were determined by techniques such as Fouriertransform infrared spectroscopy,scanning electron microscopy,and Xray diffraction.The results showed that FeMg/CER material had a high nitrate adsorption capacity of 200 mg NO_(3)^()·g^(1)with a fast equilibrium adsorption time of 30 min at pH 5.In addition,it had good durability of at least 10 times of regeneration,which could be applied to practical water and wastewater treatment.展开更多
Objectives To assess a newly devised procedure of cardiac volume reduction without resection of cardiac muscle and evaluated in experimental settings. Methods Ten beagle dogs underwent a rapid pacing leading to heart ...Objectives To assess a newly devised procedure of cardiac volume reduction without resection of cardiac muscle and evaluated in experimental settings. Methods Ten beagle dogs underwent a rapid pacing leading to heart failure for 3 weeks and received the left ventricular reduction termed overlapping cardiac volume reduction operation (OLCVR) , which consisted of a longitudinal incision in left ventricular (LV) free wall, sutures of the left marginal to the septal wall, and the right marginal to LV free wall. A slope of the linear preload recruitable stroke work relationship ( Mw), with a X - intercept (Vo) were calculated as the precise indicators of left ventricular systolic function. The constant of isovolumic pressure decay (Tau) and a peak filling rate (PFR) were also calculated as the indicators of LV diastolic function. Results LV end- diastolic dimensions was significantly reduced by OLCVR (43 ± 2 to 25 ± 1 ; mm). Fractional shortening was significantly improved by OLCVR (11 ±2 to 30±4;% ). Mw (erg cm^(-3) * 10~3) was also significantly improved (21±2 to 33±3 (p < 0. 001 ) ), whereas Vo, Tau and PFR did not show significant changes. Conclusions The OLCVR significantly increased in the early LV systolic function without detrimental effects on diastolic function. This procedure may become a therapeutic option for end - stage cardiomyopathy.展开更多
This paper presents the determination of the fuel burnup distribution of the Dalat nuclear research reactor(DNRR) using a method of measurements at subcritical conditions. The method is based on the assumption of line...This paper presents the determination of the fuel burnup distribution of the Dalat nuclear research reactor(DNRR) using a method of measurements at subcritical conditions. The method is based on the assumption of linear dependence of the reactivity on the burnup of fuel bundles and the measurements at subcritical conditions.The measurements were taken for seven selected fuel bundles in two different measuring sequences. The measured burnup values have also been compared with the calculations for verifying the method and the measurement procedure. The results obtained with the three detectors have a good agreement with each other with a discrepancy less than 1.0%. The errors of the measured burnup values are within 6%. Comparison between the calculated and measured burnup values shows that the discrepancy of the C/E ratio is within 9% compared to unity. The results indicate that the method of measurements at subcritical conditions could be well applied to determine the relative burnup distribution of the DNRR.展开更多
Background:To date,research has shown an increasing use of the term“ecohealth”in literature,but few researchers have explicitly described how it has been used.We investigated a project on health and environmental sa...Background:To date,research has shown an increasing use of the term“ecohealth”in literature,but few researchers have explicitly described how it has been used.We investigated a project on health and environmental sanitation(the conceptual framework of which included the pillars of ecohealth)to identify the impediments and enablers of ecohealth and investigate how it can move from concept to practice.Methods:A case study approach was used.The interview questions were centred on the nature of interactions and the sharing of information between stakeholders.Results:The analysis identified nine impediments and 15 enablers of ecohealth.Three themes relating to impediments,in particular-integration is not clear,don’t understand,and limited participation-related more directly to the challenges in applying the ecohealth pillars of transdisciplinarity and participation.The themes relating to enablers-awareness and understanding,capacity development,and interactions-facilitated usage of the research results.By extracting information on the environmental,social,economic,and health aspects of environmental sanitation,we found that the issue spanned multiple scales and sectors.Conclusion:The challenge of how to integrate these aspects should be considered at the design stage and throughout the research process.We recommend that ecohealth research teams include a self-investigation of their processes in order to facilitate a comparison of moving from concept to practice,which may offer insights into how to evaluate the process.展开更多
越南建筑师武重义（Vo Trong Nghia）对绿色建筑的实践已经得到越来越多人的肯定，而他这几年也开始涉猎更多空间类型。位于越南连接岘港市和会安古城的城市干道旁的Naman海滨度假村就是由他的建筑事务所主持规划和设计，从客房区到别...越南建筑师武重义（Vo Trong Nghia）对绿色建筑的实践已经得到越来越多人的肯定，而他这几年也开始涉猎更多空间类型。位于越南连接岘港市和会安古城的城市干道旁的Naman海滨度假村就是由他的建筑事务所主持规划和设计，从客房区到别墅区，再到海边休闲吧，每个区域都有着独特的设计个性，它们互不相同却又相互呼应，构成一个和谐的绿色休闲度假空间。展开更多
Complexes of transition metals with histidine play an important role in biochemistry. Walik has studied vanadyl histidine complex by IR at pH=4.5 and suggested that histidine should be coordinated to vanadium atom thr...Complexes of transition metals with histidine play an important role in biochemistry. Walik has studied vanadyl histidine complex by IR at pH=4.5 and suggested that histidine should be coordinated to vanadium atom through amino N and earbexyl O to form a 1:2 complex VO （His）2. Johnson has reported ESR spectra展开更多
基金jointly funded by the Russian Science Foundationthe St.-Petersburg Science Foundation(No.23-23-10005)
文摘Polyelectrolyte complexes(PECs)of hyperbranched(HB)and linear polysaccharides are promising as more effective encapsulation agents compared to PECs formed by linear polysaccharides.We investigated the PECs between the HB anionic polysaccharide fucoidan(FUC)and the cationic linear polysaccharide chitosan(CS).The FUC had a molecular weight(MW)of 30×106.The PECs were prepared in three solvents(water,0.01 and 0.1 mol/L acetic acid)with CS of MW of 15,110 and 170 kDa,and deacetylation degrees(DDA)of 70%and 97%.The structures of the PECs and the initial FUC were investigated by multi-angle static and dynamic light scattering.As the FUC contained 18 wt%of—OSO3 groups and 5 wt%of uronic acid units,it was a“strong-weak”copolyanion,so the HB macromolecules of the FUC formed nanogel particles in 0.1 mol/L AcOH and open branched structures in water,as confirmed by the Kratky plots.After mixing the solutions of original components,the PEC structures underwent an equilibration period,the duration of which increased with the MW of CS.As the charge stoichiometry was approached,the PECs shrank;the fractal dimension approached unity,indicating the side-by-side packing of adjacent FUC branches with the help of CS.Secondary aggregation in the vicinity of the charge compensation was hardly observed,as it occurred in a very narrow region.The PEC content at theζ-potential inversion depended on solvents’pH and the DDA of CS.In the extreme case of core-shell PECs in 0.1 mol/L AcOH,obtained by mixing FUC nanogels with the solutions of high MW CS of 97%DDA,the protruding tails of CS formed a positively charged shell in the whole range of FUC content(10 wt%<WFUC<90 wt%).Scanning electron microscopy and atomic force microscopy images of dried samples were discussed in relation to the light scattering results.
基金Supported by Ho Chi Minh City University of Technology and Education(T2022-26)。
文摘Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us.We compare our results with other theoretical studies and experimental data.The couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.2020R1A4A4079954 and 2021R1A2B5B01001448)。
文摘In this study,water-dispersible graphitic carbon nitride(g-C_(3)N_(4))photocatalysts were successively prepared through the chemically oxidative etching of bulk g-C_(3)N_(4) that was polymerized thermally in different calcination atmospheres such as air,CO_(2),and N_(2).The different calcination atmospheres directly influenced the physicochemical and optical properties of both bulk and water-dispersible g-C_(3)N_(4),changing the photocatalytic degradation behavior of methylene blue(MB)and tetracycline hydrochloride(TCHCl)for water-dispersible g-C_(3)N_(4).The bubble-burst process in the thermal polymerization of thiourea produced defective edges containing C=O groups that preferred substituting the C-NHx groups over bulk g-C_(3)N_(4).In the oxygen-free N_(2) atmosphere among the different calcination atmospheres,more C=O functional groups were generated on the defective edges of bulk g-C_(3)N_(4),resulting in the highest N vacancy of the tri-s-triazine structure.During the successive chemical oxidation,S-or O-containing functional groups were introduced onto water-dispersible g-C_(3)N_(4).The water-dispersible g-C_(3)N_(4) photocatalyst from the oxygen-free N_(2) atmosphere(NTw)contained the most O-and S-functional groups on the g-C_(3)N_(4) surface.Consequently,NTw exhibited the highest photocatalytic activity in the MB and TC-HCl photodegradation because of its slowest recombination process,which was ascribed to the unique surface properties of NTw such as abundant functional groups on the defective edges and N-deficient property.
基金Vietnam National University-Ho Chi Minh City under grant number A2020-16-01.
文摘In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxides/hydroxides composite(FeMg/CER)was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water environment.Characteristics of FeMg/CER were determined by techniques such as Fouriertransform infrared spectroscopy,scanning electron microscopy,and Xray diffraction.The results showed that FeMg/CER material had a high nitrate adsorption capacity of 200 mg NO_(3)^()·g^(1)with a fast equilibrium adsorption time of 30 min at pH 5.In addition,it had good durability of at least 10 times of regeneration,which could be applied to practical water and wastewater treatment.
文摘Objectives To assess a newly devised procedure of cardiac volume reduction without resection of cardiac muscle and evaluated in experimental settings. Methods Ten beagle dogs underwent a rapid pacing leading to heart failure for 3 weeks and received the left ventricular reduction termed overlapping cardiac volume reduction operation (OLCVR) , which consisted of a longitudinal incision in left ventricular (LV) free wall, sutures of the left marginal to the septal wall, and the right marginal to LV free wall. A slope of the linear preload recruitable stroke work relationship ( Mw), with a X - intercept (Vo) were calculated as the precise indicators of left ventricular systolic function. The constant of isovolumic pressure decay (Tau) and a peak filling rate (PFR) were also calculated as the indicators of LV diastolic function. Results LV end- diastolic dimensions was significantly reduced by OLCVR (43 ± 2 to 25 ± 1 ; mm). Fractional shortening was significantly improved by OLCVR (11 ±2 to 30±4;% ). Mw (erg cm^(-3) * 10~3) was also significantly improved (21±2 to 33±3 (p < 0. 001 ) ), whereas Vo, Tau and PFR did not show significant changes. Conclusions The OLCVR significantly increased in the early LV systolic function without detrimental effects on diastolic function. This procedure may become a therapeutic option for end - stage cardiomyopathy.
基金supported by National Foundation for Science and Technology Development(NAFOSTED)of Vietnam under Grant103.04-2016.30
文摘This paper presents the determination of the fuel burnup distribution of the Dalat nuclear research reactor(DNRR) using a method of measurements at subcritical conditions. The method is based on the assumption of linear dependence of the reactivity on the burnup of fuel bundles and the measurements at subcritical conditions.The measurements were taken for seven selected fuel bundles in two different measuring sequences. The measured burnup values have also been compared with the calculations for verifying the method and the measurement procedure. The results obtained with the three detectors have a good agreement with each other with a discrepancy less than 1.0%. The errors of the measured burnup values are within 6%. Comparison between the calculated and measured burnup values shows that the discrepancy of the C/E ratio is within 9% compared to unity. The results indicate that the method of measurements at subcritical conditions could be well applied to determine the relative burnup distribution of the DNRR.
基金the Canadian Community of Practice in Ecohealth and the International Development Research Centre for funding this researchthe Hanoi School of Public Health(Department of Environmental Health),the National Institute for Hygiene and Epidemiology,the Swiss Tropical and Public Health Institute,and the International Livestock Research Institute’s Ecosystem Approaches to Better Management of Zoonotic Infectious Diseases project for their in-kind contributions to this research+1 种基金the research participants from the community and local institutions in the study sites for their insights into the research processand the Public Health Agency of Canada for providing stipend support to VN.
文摘Background:To date,research has shown an increasing use of the term“ecohealth”in literature,but few researchers have explicitly described how it has been used.We investigated a project on health and environmental sanitation(the conceptual framework of which included the pillars of ecohealth)to identify the impediments and enablers of ecohealth and investigate how it can move from concept to practice.Methods:A case study approach was used.The interview questions were centred on the nature of interactions and the sharing of information between stakeholders.Results:The analysis identified nine impediments and 15 enablers of ecohealth.Three themes relating to impediments,in particular-integration is not clear,don’t understand,and limited participation-related more directly to the challenges in applying the ecohealth pillars of transdisciplinarity and participation.The themes relating to enablers-awareness and understanding,capacity development,and interactions-facilitated usage of the research results.By extracting information on the environmental,social,economic,and health aspects of environmental sanitation,we found that the issue spanned multiple scales and sectors.Conclusion:The challenge of how to integrate these aspects should be considered at the design stage and throughout the research process.We recommend that ecohealth research teams include a self-investigation of their processes in order to facilitate a comparison of moving from concept to practice,which may offer insights into how to evaluate the process.
文摘越南建筑师武重义（Vo Trong Nghia）对绿色建筑的实践已经得到越来越多人的肯定，而他这几年也开始涉猎更多空间类型。位于越南连接岘港市和会安古城的城市干道旁的Naman海滨度假村就是由他的建筑事务所主持规划和设计，从客房区到别墅区，再到海边休闲吧，每个区域都有着独特的设计个性，它们互不相同却又相互呼应，构成一个和谐的绿色休闲度假空间。
文摘Complexes of transition metals with histidine play an important role in biochemistry. Walik has studied vanadyl histidine complex by IR at pH=4.5 and suggested that histidine should be coordinated to vanadium atom through amino N and earbexyl O to form a 1:2 complex VO （His）2. Johnson has reported ESR spectra
