The reactions of 2-chloro-1,3,2-dioxaphospholane with various sodium salts of amino acids to afford the pentacoordinated spirophosphoranes containing amino acid were studied by NMR spectra techniques. The results show...The reactions of 2-chloro-1,3,2-dioxaphospholane with various sodium salts of amino acids to afford the pentacoordinated spirophosphoranes containing amino acid were studied by NMR spectra techniques. The results showed that natural alpha-amino acids had greater ability than beta-amino acids to form the pentacoordinated species, which is important in the biosynthesis and prebiotic synthesis of of oligopeptides and proteins.展开更多
Objective:To understand the dietary intake of high-risk population with hypertension in Haikou,and to analyze the relationship between dietary intake and blood pressure,especially the relationship between sodium intak...Objective:To understand the dietary intake of high-risk population with hypertension in Haikou,and to analyze the relationship between dietary intake and blood pressure,especially the relationship between sodium intake and blood pressure,so as to provide a scientific basis for salt reduction.Methods:A multi-stage cluster sampling 2021 was used from July to December to collect 3-4 cscs from each of the four districts in Haikou.A total of 15 cscs were collected,295 permanent residents aged 55-74 were recruited from 15 community service centers,with 20 eligible subjects from each community.The subjects underwent general physical examination,laboratory tests,and a dietary survey using the self-developed Android phone APP“Nutrition Assistant”(registration number:2021SR1547832).SPSS 21.0 was used 2 for t test,x^(2) test and multiple Regression analysis.Result:In Haikou,69.4%of the subjects had energy intake above energy requirement,and 44.8%had fat intake above the acceptable range of macronutrients.There were only differences in energy,carbohydrate,vitamin B 6 and sodium intake(t=-2.174,-1.990,2.333,-5.442,P=0.031,0.048,0.021,<0.001,respectively).There were significant differences in BMI,family history of chronic diseases,systolic blood 2 pressure and diastolic blood pressure(f value or x^(2) value were 4.260,19.045,139.916,36.864,P value were 0.015,<0.001,<0.001,<0.001,respectively).Multiple Regression analysis analysis showed that 24h sodium excretion was significantly correlated with systolic and diastolic blood pressure(t=12.964,P<0.001),systolic and diastolic blood pressure increased by 0.135 mmhg and 0.068 mmhg,respectively.Conclusion:The dietary intake of the middle-aged and elderly people at high risk of hypertension in the Haikou community was unbalanced,and the intake of sodium salt was strongly correlated with blood pressure,it is necessary to continue to promote salt reduction as one of the key ways to prevent and control hypertension.展开更多
Background: The Togolese population, like those around the world, frequently consumes foods high in salt/sodium and low in potassium, thus exposing them to cardiovascular disease (CVD). Nutritional intervention can he...Background: The Togolese population, like those around the world, frequently consumes foods high in salt/sodium and low in potassium, thus exposing them to cardiovascular disease (CVD). Nutritional intervention can help reverse this consumption pattern and reduce related CVD morbidity and mortality. The objective of this study was to measure the effects of a nutrition education intervention on the consumption frequencies of foods rich in sodium and potassium. Methods: The study was a quasi-experimental before- and-after study, conducted from 08 January to 16 April 2023. It involved 200 adults aged 25 - 64 years, randomly selected from two areas: an intervention area and a non-intervention area. Data were collected in two phases at 3-month intervals in both groups. The intervention consisted of nutrition education (awareness raising and cooking demonstrations) on reducing salt/sodium intake and increasing potassium-rich food intake. The kobocollect electronic questionnaire was administered to the respondents to collect data on the frequency of consumption of foods rich in sodium and potassium. Results: The median age of the respondents was 33 years old (30;38) and 56% of the participants were women, 44% and 69% respectively in the control and intervention groups. Most participants lived in rural areas (51%), 52.4% and 49.5% in the control and intervention groups respectively. Overall, 4% (p individuals reduced their frequency of adding salt at mealtime from more than 3 times a week to less than 3 times, i.e., 5.6% in the intervention group and 1.7% in the control group. The proportion of individuals who consumed meals with green leafy vegetable sauces was reduced from more than 3 times a week to less than 3 times, i.e., 7.5% (p < 0.022), or 1% in the intervention group and 4% in the control group. Education level (0.23 [0.10 - 0.50];p - 6.35];p < 0.0006) were associated with reduced salt addition at meals. The same trend was observed for increased consumption of green leafy vegetable sauces (0.95 [0.03 - 0.99];p male (2 [1.08 - 1.84];p Conclusion: This study was able to measure the effects of a nutrition education intervention for adequate sodium and potassium intakes on changing favourable dietary behaviour through a quasi-experimental study. The results show that the continuation of the intervention will contribute to the adoption of favourable behaviours for the reduction of dietary sodium intakes and the optimisation of potassium intakes.展开更多
Background: Food plays an important role in human health. A healthy diet contributes to the improvement of the health of populations. A diet high in sodium/salt and low in potassium has been shown to contribute to car...Background: Food plays an important role in human health. A healthy diet contributes to the improvement of the health of populations. A diet high in sodium/salt and low in potassium has been shown to contribute to cardiovascular disease. The objective of this study was to assess the knowledge, attitudes and practices (KAP) of the inhabitants of Dapaong and its surroundings on dietary intakes of sodium/salt and potassium. Methods: This was a cross-sectional study conducted from 1 November to 15 December 2022 involving 400 adults aged 25 to 44 years. Sampling was done using the probability method and the multistage random sampling technique with proportional allocation. These two methods were applied to select villages, households, and primary targets in each locality according to whether the area of residence was urban or rural. The electronic kobocollect questionnaire was administered to people in households and the interview guide was to resource persons, administrators and community leaders to collect the data. Results: Overall, 80.25% of the respondents had low knowledge of sodium/salt intakes;88.50% had poor attitudes towards the use of foods that provide more sodium/salt and 92.75% had behaviours that were not conducive to reducing excessive salt consumption. With regard to potassium, the same trend was observed in the order of 91%, 72% and 73.75%. Conclusion: The KAP levels of the people studied were not good. The populations are prone to cardiovascular disease. A multisectoral nutritional intervention would be essential to improve the knowledge of the populations on sodium/salt and potassium intakes and therefore favourable to the fight against CVD/NCD.展开更多
Low grade magnesite is one of the main research directions in the future as the raw material for the preparation of magnesia based insulating refractories.Periclase-forsterite(MgO-Mg_(2)SiO_(4)) lightweight insulating...Low grade magnesite is one of the main research directions in the future as the raw material for the preparation of magnesia based insulating refractories.Periclase-forsterite(MgO-Mg_(2)SiO_(4)) lightweight insulating refractories were prepared by the molten salt method with high silica magnesite and tertiary talc ore as raw materials by pretreating them to get light burnt magnesia and talc,and NaCl molten salt as the reaction medium.The effects of the NaCl addition,the sintering temperature,the holding time and the raw material ratio on the sample preparation were studied.The results show that when the NaCl addition is 20% of the mass of light burnt magnesia and talc mixture,the sintering temperature is 1 200 ℃,the holding time is 6 h,and m(light burnt magnesia):m(talc)=5:5,the sample has the optimal comprehensive properties:the bulk density of 1.46 g·cm^(-3) and the apparent porosity of 55.0%.In addition,it is found that self-decomposition of talc and the formation of forsterite can form pores inside the sample.展开更多
Reactive oxygen species(ROS)play a vital role in cell signaling and redox regulation,but when present in excess,lead to numerous pathologies.Detailed quantitative characterization of mitochondrial superoxide anion(O^(...Reactive oxygen species(ROS)play a vital role in cell signaling and redox regulation,but when present in excess,lead to numerous pathologies.Detailed quantitative characterization of mitochondrial superoxide anion(O^(·-)_(2))production in fetal pulmonary artery endothelia cells(PAECs)has never been reported.The aim of this study is to assess mitochondrial O^(·-)_(2)pro-duction in cultured PAECs over time using a novel quantitative optical approach.The rate,the sources,and the dynamics of O^(·-)_(2)production were assessed using targeted metabolic modulators of the mitochondrial electron transport chain(ETC)complexes,specifically an uncoupler and inhibitors of the various ETC complexes,and inhibitors of extra-mitochondrial sources of O^(·-)_(2).After stabilization,the cells were loaded with nanomolar mitochondrial-targeted hydroethidine(Mito-HE,MitoSOX)online during the experiment without washout of the residual dye.Time-lapse fuorescence microscopy was used to monitor the dynamic changes in O^(·-)_(2)fluorescence intensity over time in PAECs.The transient behaviors of the fuorescence time course showed exponential increases in the rate of O^(·-)_(2) production in the presence of the ETC uncoupler or inhibitors.The most dramatic and the fastest increase in O^(·-)_(2)production was observed when the cells were treated with the uncoupling agent,PCP.We also showed that only the complex IV inhibitor,KCN,attenuated the marked surge in O^(·-)_(2)production induced by PCP.The results showed that mitochondrial respiratory complexes I,III and IV are sources of O^(·-)_(2) production in PAECs,and a new observation that ROS production during uncoupling of mitochondrial res-piration is mediated in part via complex IV.This novel method can be applied in other studies that examine ROS production under stress condition and during ROS mediated injuries in vritro.展开更多
Ti( C, N) was synthesized with the starting materials of 76. 9% titania white and 23. 1% carbon black (graphite or activated carbon ), or 40% titania white and 60% amylum, with or without 10% NaBr - KCl, dry mould...Ti( C, N) was synthesized with the starting materials of 76. 9% titania white and 23. 1% carbon black (graphite or activated carbon ), or 40% titania white and 60% amylum, with or without 10% NaBr - KCl, dry moulding and carbon embedded firing at i 300 ℃ and 1 400 ℃ for 3 h, respectively. Phase composition and microstructure of the synthesized Ti (C, N) were analyzed by XRD, SEM and EPMA. Effects of different carbon sources and NaBr-KCl on the synthesis of Ti( C, N) were investigated. The results show that: (1) Ti (C, N) can be synthesized by using carbon black, graphite, activated carbon or amylum as carbon source separately; (2) Additive NaBr - KCl is more favorable for accelerating the carbothermal reduction reaction using carbon black or amylum as carbon source; (3) In the presence of NaBr - KCl, particle size of the synthesized Ti( C, N) is 5 -8μm using carbon black as carbon source fired at 1 300 ℃ for 3 h, while that is only 1 - 3 μm using graphite, activated carbon or amylum fired at 1 400 ℃ for 3 h.展开更多
Owing to the natural abundance and low cost of sodium resources,sodium-ion batteries(SIBs)have drawn considerable attention for state-of-the-art power storage devices over the last few years.To enable advanced SIBs wi...Owing to the natural abundance and low cost of sodium resources,sodium-ion batteries(SIBs)have drawn considerable attention for state-of-the-art power storage devices over the last few years.To enable advanced SIBs with a brighter future,great effort has been made,not only through optimizing the electrode materials,but also with rationally designing various electrolyte systems.Among the available electrolyte systems,organic electrolytes,especially those based on esters as well as ethers,are the most promising ones for practical application in the foreseeable future,due to their numerous inherent advantages.This review is concerned with the recent research progresses on organic electrolytes for SIBs,focusing on etherbased and ester-based ones.展开更多
Background Methanesulfonic acid sodium salt (Dipyrone), an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of t...Background Methanesulfonic acid sodium salt (Dipyrone), an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of this study was to evaluate the potential photoprotective activity of methanesulfonic acid sodium salt in a model of light-induced retinopathy. Methods One hundred mice were assigned randomly into vehicle (V), methanesulfonic acid sodium salt (D), light damage model plus vehicle (MV) and light damage model plus methanesulfonic acid sodium salt (MD) groups (n=25 each). In the MD group, methanesulfonic acid sodium salt (100 mg/kg) was administered by intraperitoneal injection 30 minutes before light exposure. Twenty-four hours after light exposure, hematoxylin and eosin staining and transmission electron microscopy (TEM) were used for histological evaluation. The thickness of the outer plus inner-segment and outer nuclear layer was measured on sections parallel to the vertical meridian of the eye at a distance of 1000 I^m from the optic nerve. Electroretinography (ERG) test was performed to assess the functional change. The morphology of mitochondria was also revealed by TEM. Finally, the expression of cytochrome c (CytC) and the relative apoptotic proteins were detected by Western blotting, and the interaction between mitochondrial proteins was investigated by co-immunoprecipitation. Results The photoreceptor inner and outer segments of the MV group were significantly disorganized than the MD group. The thicknesses of the outer plus inner-segment layers and the outer nuclear layer, and the amplitudes of the a and b waves of the scotopic ERG response markedly decreased in the MV group compared to those in the MD group (P 〈0.05). TEM examination revealed that the mitochondria of the MV group were distinctly swollen and contained disrupted cristae. In contrast, the morphology of mitochondria in the MD group was unaffected. Western blotting analysis showed that CytC, apoptosis proteinase activating factor-1 (Apaf-1), caspase 3, p53, p53-upregulated modulator of apoptosis (PUMA), Bax, and Bad were increased, whereas the anti-apoptotic proteins Bcl-2 and Bcl-XL were significantly decreased in the MV group than the MD group. Co-immunoprecipitation detection revealed that PUMA immunoreactivity precipitated by Bcl-XL decreased, whereas Bax immunoreactivity precipitated by Bcl-XL increased in the MD group compared to those in the MV group. Conclusion Methanesulfonic acid sodium salt is an effective photoprotective agent against light-induced retinopathy through the inhibition of CytC-mediated mitochondrial impairment.展开更多
The introduction of hydroxy group to the 3- or 5-position of 4,4-difluoro-4-bora-3aAa-diazaindacene (BODIPY) results in unexpected tautomerization to BDPONa with interesting structural and photophysical properties. ...The introduction of hydroxy group to the 3- or 5-position of 4,4-difluoro-4-bora-3aAa-diazaindacene (BODIPY) results in unexpected tautomerization to BDPONa with interesting structural and photophysical properties. The core of BDPONa is an anion with sodium cation as counter-ion. BDPONa displays strong fluorescence in organic solvents.展开更多
There are few studies on the mechanism of redox status imbalance and intestinal dysfunction in intrauterine growth restricted(IUGR)newborn piglets.Here,we investigated the mechanism of jejunum dysfunction in weaned pi...There are few studies on the mechanism of redox status imbalance and intestinal dysfunction in intrauterine growth restricted(IUGR)newborn piglets.Here,we investigated the mechanism of jejunum dysfunction in weaned piglets with IUGR and the mechanism through which dimethylglycine sodium salt(DMG-Na)supplementation improving the imbalance of their redox status.In this work,a total of 10 normal birth weight(NBW)newborn piglets and 20 IUGR newborn piglets were obtained.After weaning at 21 d,they were assigned to 3 groups(n=10/group):NBW weaned piglets fed standard basal diets(NBWC);one IUGR weaned piglets fed standard basal diets(IUGRC);another IUGR weaned piglets from the same litter fed standard basal diets plus 0.1%DMG-Na(IUGRD).The piglets in these 3 groups were sacrificed at 49 d of age,and the blood and jejunum samples were collected immediately.The growth performance values in the IUGRC group were lower(P<0.05)than those in the NBWC group.Jejunum histomorphological parameters,inflammatory cytokines,and digestive enzyme activity as well as serum immunoglobulin were lower(P<0.05)in the IUGRC group than those in the NBWC group.Compared with these in the NBWC group,the redox status of serum,jejunum,and mitochondria and the expression levels of jejunum redox status-related,cell adhesion-related,and mitochondrial function-related genes and proteins were suppressed in the IUGRC group(P<0.05).However,compared with those in the IUGRC group,the growth performance values,jejunum histomorphological parameters,inflammatory cytokines,digestive enzyme activity,serum immunoglobulin,redox status of serum,jejunum,and mitochondria,and the expression levels of jejunum redox status-related,cell adhesion-related,and mitochondrial function-related genes and proteins were improved(P<0.05)in the IUGRD group.In conclusion,dietary DMG-Na supplementation alleviates redox status imbalance and intestinal dysfunction in IUGR weaned piglets mainly by activating the sirtuin 1(SIRT1)/peroxisome proliferatoractivated receptorgcoactivator-1a(PGC1a)pathway,thereby improving their unfavorable body state.展开更多
Amidoalkyl naphthols have been synthesized in high yields in the presence of 1-hexanesulphonic acid sodium salt as an inexpensive solid catalyst under solvent-free conditions and microwave-irradiation.This catalyst pr...Amidoalkyl naphthols have been synthesized in high yields in the presence of 1-hexanesulphonic acid sodium salt as an inexpensive solid catalyst under solvent-free conditions and microwave-irradiation.This catalyst provides clean conversion;greater selectivity and easy workup make this protocol practical and economically attractive.展开更多
This study aimed to investigate the mechanism of small intestinal immune dysfunction in intrauterine growth restriction(IUGR)newborn piglets and relieve this dysfunction via dimethylglycine sodium salt(DMG-Na)suppleme...This study aimed to investigate the mechanism of small intestinal immune dysfunction in intrauterine growth restriction(IUGR)newborn piglets and relieve this dysfunction via dimethylglycine sodium salt(DMG-Na)supplementation during the suckling period.Thirty sows(Duroc×[Landrace×Yorkshire])were selected,and 1 male newborn piglet with normal birth weight(NBW)and 1 male newborn piglet with IUGR were obtained from each sow.Among them,10 NBW and 10 IUGR newborns were euthanized without suckling.The other 20 NBW newborns were allocated to the group named NCON,which means NBW newborns fed a basic milk diet(BMD)(n=10),and the group named ND,which means NBW newborns fed BMD supplemented with 0.1%DMG-Na(n=10);the other 20 IUGR newborns were assigned to the group named ICON,which means IUGR newborns fed BMD(n=10),and the group named ID,which means IUGR newborns fed BMD supplemented with 0.1%DMG-Na(n=10).The newborns were fed BMD from 7 to 21 d of age and euthanized at 21 d of age to collect serum and small intestinal samples.The growth performance,small intestinal histological morphology and sub-organelle ultrastructure,serum immunoglobulin,small intestinal digestive enzyme activity,inflammatory cytokine level,and jejunum mRNA and protein expression of the toll-like receptor 4(TLR4)/nucleotide-binding oligomerization domain protein(NOD)/nuclear factor-k B(NF-k B)network deteriorated in the ICON group compared to that in the NCON group.The small intestinal histological morphology and suborganelle ultrastructure,serum immunoglobulin,small intestinal digestive enzyme activity,and inflammatory cytokine level improved(P<0.05)in the ID group compared to those in the ICON group.The jejunum mRNA and protein expression of the TLR4/NOD/NF-k B network improved(P<0.05)in the ID group compared to that in the ICON group.In conclusion,the activity of the TLR4/NOD/NF-k B pathway was inhibited in the IUGR newborns,which in turn led to their jejunum immune dysfunction and reduced their performance.By ingesting DMG-Na,the IUGR newborns activated the TLR4/NOD/NF-k B pathway,thereby improving their unfavorable body state during the suckling period.展开更多
A graft copolymer of polyacrylonitrile (PAN) with sodium salt of partially carboxymethylated tamarind kernel powder (Na-PCMTKP, DS ^-= 0.15) was synthesized by using ceric ammonium nitrate (CAN) as a redox initi...A graft copolymer of polyacrylonitrile (PAN) with sodium salt of partially carboxymethylated tamarind kernel powder (Na-PCMTKP, DS ^-= 0.15) was synthesized by using ceric ammonium nitrate (CAN) as a redox initiator in an aqueous medium. The optimum reaction conditions for affording maximum percentage of grafting were established by successively varying reaction conditions such as concentrations of nitric acid, CAN, monomer (AN) as well as reaction time, temperature and amount of substrate. The influence of these reaction conditions on the grafting yields was discussed. The kinetic scheme of free radical graft copolymerization was proposed and the experimental results were found to agree very well with the proposed kinetic scheme. The graft copolymer (Na-PCMTKP-g-PAN, percentage of grafting G = 413.76% and percentage of grafting efficiency GE = 96.48%) sample synthesized under the established optimized reaction conditions was hydrolyzed by 0.7 mol-L l NaOH solution at 90-95 ℃ to yield the superabsorbent hydrogel, H-Na-PCMTKP-g-PAN. The swelling behavior of the hydrogel was studied by carrying out its absorbency measurements in low conductivity water, 0.15 mol·L^-1 salt (NaCl, CaCl2 and AlCl3) solutions and simulated urine (SU) solution at different timings. FTIR, TGA and SEM techniques were used to characterize the products.展开更多
Photo-induced graft copolymerization of methyl methacrylate(MMA) onto sodium salt of partially carboxymethylated guar gum(Na-PCMGG, DS = 0.291) was carried out in an aqueous medium using ceric ammonium nitrate(CA...Photo-induced graft copolymerization of methyl methacrylate(MMA) onto sodium salt of partially carboxymethylated guar gum(Na-PCMGG, DS = 0.291) was carried out in an aqueous medium using ceric ammonium nitrate(CAN) as photoinitiator to synthesize a novel graft copolymer, Na-PCMGG-g-PMMA, which may find its potential application as a metal adsorbent. The influences of synthesis variables such as concentrations of photoinitiator(CAN), nitric acid and monomer(MMA) as well as reaction time, temperature and amount of substrate on the grafting yields were studied and the reaction conditions for optimum photo-grafting were evaluated. At optimum concentration, the maximum values of the grafting yields achieved were G = 271.61% and GE = 63.89%. The experimental results were found to be in very good agreement with the proposed kinetic scheme. The photo-graft copolymerization of MMA onto Na-PCMGG( DS = 0.291) was also carried out in the presence and absence of ultraviolet radiation for studying the efficiency of the photoinitiator. The influence of carboxymethyl groups introduced onto the guar gum molecules with regard to its behavior towards ultra-violet radiation induced grafting with MMA was also investigated. Photo-grafting process was confirmed and the products were characterized with the help of the spectroscopic(1H-NMR and FTIR) and SEM techniques.展开更多
Anthropogenic activities in the Pearl River Delta (PRD) have caused a deterioration of groundwater quality over the past twenty years as a result of rapid urbanization and industrial development. In this study, the ...Anthropogenic activities in the Pearl River Delta (PRD) have caused a deterioration of groundwater quality over the past twenty years as a result of rapid urbanization and industrial development. In this study, the hydrochemical characteristics, quality, and sources of heavy metals in the groundwater of the PRD were investigated. Twenty-five groundwater samples were collected and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), δ18O,δ~2H, major ions, and heavy metals. The groundwater was slightly acidic and presented TDS values that ranged from 35.5 to 8,779.3 mg.L-1. The concentrations of the major ions followed the order Cl- 〉 HCO3-〉 Na+ 〉 SO24- 〉 NO3 〉 NH4+ 〉 Ca2+ 〉 K+ 〉 Mg2+ 〉 Fe2+/3+ 〉 Al3+. Ca-Mg- HCO3 and Na-K-HCO3 were the predominant types of facies, and the chemical composition of the groundwater was primarily controlled by chemical weathering of the basement rocks, by mixing of freshwater and seawater and by anthropogenic activities. The heavy metal pollution index (HPI) indicated that 64% of the samples were in the low category, 16% were in the medium category and 20% were in the high category, providing further evidence that this groundwater is unsuitable for drinking. Lead, arsenic, and manganese were mainly sourced from landfill leachate; cadmium from landfill leachate and agricultural wastes; mercury from the discharge of leaehate associated with mining activities and agricultural wastes; and chromium primarily from industrial wastes. According to the irrigation water quality indicators, the groundwater in the PRD can be used for irrigation in most farmland without strong negative impacts. However, approximately9 million people in the Guangdong Province are at risk due to the consumption of untreated water. Therefore, we suggest that treating the groundwater to achieve safer levels is necessary.展开更多
The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid)sodium salt(PAASS).Polysulfone and polyethersulfone hollow fiber ultrafiltration membr...The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid)sodium salt(PAASS).Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process.The kinetics of complexation reaction was studied for PAASS with Co^(2+).Results showed that,under a large excess of PAASS,it takes 65,55 and 40 min at pH 5,6 and 7,respectively,to get the equilibrium of complexation.The reaction kinetics can be described by a pseudo-first-order equation.Then,the effects of various parameters on the extraction of Co^(2+)were examined in detail.Results indicated that loading ratio,pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R.Furthermore,a concentration experiment was carried out at pH 7.With increasing volume concentration factor,membrane flux declines slowly,and R value is always about 1.The concentrated retentate was used further for a decomplexation experiment.The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%.After the decomplexation step,a diafiltration experiment was performed at pH 2.5.Cobalt ions can be extracted satisfactorily from the retentate,and a purified PAASS is obtained.展开更多
A post-photochemical cross-linking strategy was successfully demonstrated to enhance the stability of polyelectrolyte poly(allylamine hydrochloride)(PAH)/poly(vinylsulfonic acid sodium salt)(PVS) multilayers. ...A post-photochemical cross-linking strategy was successfully demonstrated to enhance the stability of polyelectrolyte poly(allylamine hydrochloride)(PAH)/poly(vinylsulfonic acid sodium salt)(PVS) multilayers. Con- ventional polyelectrolyte multilayers of PAH/PVS are usually fabricated through electrostatic layer-by-layer(LbL) assembly, resulting in poor stability, especially in basic solutions, which leads to the urgent demand for converting weak electrostatic interactions into covalent bonds to enhance the stability of the multilayers. This stability problem has been ultimately addressed by post-infiltrating a photosensitive cross-linking agent, 4,4'-diazostilbene-2,2'- disulfonie acid disodium salt(DAS), into the LbL assembled films to initiate the photochemical reaction to cross-link the multilayers. The obviously improved stability of the photo-cross-linked multilayers was demonstrated through experiments with basic solution treatments. Compared to the complete decomposition of uncross-linked multilayers in basic solution, over 74.4% of the covalently cross-linked multilayers were retained under the same conditions, even after a longer duration of basic solution treatment.展开更多
Sensitive differentiation of an enantiomer from its mirror image(ie,enantiodifferentiation),a perennial challenge for pharmaceutical production and disease diagnosis,is technically limited by the weak optical activity...Sensitive differentiation of an enantiomer from its mirror image(ie,enantiodifferentiation),a perennial challenge for pharmaceutical production and disease diagnosis,is technically limited by the weak optical activity(OA)of enantiomers,mainly due to their dimensional mismatch with light wavelengths in the ultraviolet(UV)-visible region.Here we use silver chiral nanoparticles(Ag CNPs)with nominally sub-5 nm helical pitch(P)to amplify the OA of(20R,30R,40S)-riboflavin-50-phosphate sodium salts(RP),which have been found to indirectly affect metabolic processes,through the formation of an RP thin film(TF)covering a close-packed array of Ag CNPs.The OA of the RP in the deep-UV region can be amplified up to 80-fold,ascribed to the aggregation of RP in the TFs and the interactions between RP and the atomically chiral lattices at the CNPs'surfaces.The former contribution,not associated with the chiral Ag topographies,plays a dominant role by thickening the RP TFs,so that the observed amplification has no enantioselective dependence on the chirality of the Ag CNPs.This study extends progress in the sensitive detection of bio-enantiomers,which is highly desired for advanced bio-detection in disease diagnosis and production of single-enantiomer pharmaceuticals.展开更多
文摘The reactions of 2-chloro-1,3,2-dioxaphospholane with various sodium salts of amino acids to afford the pentacoordinated spirophosphoranes containing amino acid were studied by NMR spectra techniques. The results showed that natural alpha-amino acids had greater ability than beta-amino acids to form the pentacoordinated species, which is important in the biosynthesis and prebiotic synthesis of of oligopeptides and proteins.
基金National Natural Science Foundation of China(No.81860577)Graduate Innovation and Entrepreneurship Project(No.HYYS2020-02)。
文摘Objective:To understand the dietary intake of high-risk population with hypertension in Haikou,and to analyze the relationship between dietary intake and blood pressure,especially the relationship between sodium intake and blood pressure,so as to provide a scientific basis for salt reduction.Methods:A multi-stage cluster sampling 2021 was used from July to December to collect 3-4 cscs from each of the four districts in Haikou.A total of 15 cscs were collected,295 permanent residents aged 55-74 were recruited from 15 community service centers,with 20 eligible subjects from each community.The subjects underwent general physical examination,laboratory tests,and a dietary survey using the self-developed Android phone APP“Nutrition Assistant”(registration number:2021SR1547832).SPSS 21.0 was used 2 for t test,x^(2) test and multiple Regression analysis.Result:In Haikou,69.4%of the subjects had energy intake above energy requirement,and 44.8%had fat intake above the acceptable range of macronutrients.There were only differences in energy,carbohydrate,vitamin B 6 and sodium intake(t=-2.174,-1.990,2.333,-5.442,P=0.031,0.048,0.021,<0.001,respectively).There were significant differences in BMI,family history of chronic diseases,systolic blood 2 pressure and diastolic blood pressure(f value or x^(2) value were 4.260,19.045,139.916,36.864,P value were 0.015,<0.001,<0.001,<0.001,respectively).Multiple Regression analysis analysis showed that 24h sodium excretion was significantly correlated with systolic and diastolic blood pressure(t=12.964,P<0.001),systolic and diastolic blood pressure increased by 0.135 mmhg and 0.068 mmhg,respectively.Conclusion:The dietary intake of the middle-aged and elderly people at high risk of hypertension in the Haikou community was unbalanced,and the intake of sodium salt was strongly correlated with blood pressure,it is necessary to continue to promote salt reduction as one of the key ways to prevent and control hypertension.
文摘Background: The Togolese population, like those around the world, frequently consumes foods high in salt/sodium and low in potassium, thus exposing them to cardiovascular disease (CVD). Nutritional intervention can help reverse this consumption pattern and reduce related CVD morbidity and mortality. The objective of this study was to measure the effects of a nutrition education intervention on the consumption frequencies of foods rich in sodium and potassium. Methods: The study was a quasi-experimental before- and-after study, conducted from 08 January to 16 April 2023. It involved 200 adults aged 25 - 64 years, randomly selected from two areas: an intervention area and a non-intervention area. Data were collected in two phases at 3-month intervals in both groups. The intervention consisted of nutrition education (awareness raising and cooking demonstrations) on reducing salt/sodium intake and increasing potassium-rich food intake. The kobocollect electronic questionnaire was administered to the respondents to collect data on the frequency of consumption of foods rich in sodium and potassium. Results: The median age of the respondents was 33 years old (30;38) and 56% of the participants were women, 44% and 69% respectively in the control and intervention groups. Most participants lived in rural areas (51%), 52.4% and 49.5% in the control and intervention groups respectively. Overall, 4% (p individuals reduced their frequency of adding salt at mealtime from more than 3 times a week to less than 3 times, i.e., 5.6% in the intervention group and 1.7% in the control group. The proportion of individuals who consumed meals with green leafy vegetable sauces was reduced from more than 3 times a week to less than 3 times, i.e., 7.5% (p < 0.022), or 1% in the intervention group and 4% in the control group. Education level (0.23 [0.10 - 0.50];p - 6.35];p < 0.0006) were associated with reduced salt addition at meals. The same trend was observed for increased consumption of green leafy vegetable sauces (0.95 [0.03 - 0.99];p male (2 [1.08 - 1.84];p Conclusion: This study was able to measure the effects of a nutrition education intervention for adequate sodium and potassium intakes on changing favourable dietary behaviour through a quasi-experimental study. The results show that the continuation of the intervention will contribute to the adoption of favourable behaviours for the reduction of dietary sodium intakes and the optimisation of potassium intakes.
文摘Background: Food plays an important role in human health. A healthy diet contributes to the improvement of the health of populations. A diet high in sodium/salt and low in potassium has been shown to contribute to cardiovascular disease. The objective of this study was to assess the knowledge, attitudes and practices (KAP) of the inhabitants of Dapaong and its surroundings on dietary intakes of sodium/salt and potassium. Methods: This was a cross-sectional study conducted from 1 November to 15 December 2022 involving 400 adults aged 25 to 44 years. Sampling was done using the probability method and the multistage random sampling technique with proportional allocation. These two methods were applied to select villages, households, and primary targets in each locality according to whether the area of residence was urban or rural. The electronic kobocollect questionnaire was administered to people in households and the interview guide was to resource persons, administrators and community leaders to collect the data. Results: Overall, 80.25% of the respondents had low knowledge of sodium/salt intakes;88.50% had poor attitudes towards the use of foods that provide more sodium/salt and 92.75% had behaviours that were not conducive to reducing excessive salt consumption. With regard to potassium, the same trend was observed in the order of 91%, 72% and 73.75%. Conclusion: The KAP levels of the people studied were not good. The populations are prone to cardiovascular disease. A multisectoral nutritional intervention would be essential to improve the knowledge of the populations on sodium/salt and potassium intakes and therefore favourable to the fight against CVD/NCD.
文摘Low grade magnesite is one of the main research directions in the future as the raw material for the preparation of magnesia based insulating refractories.Periclase-forsterite(MgO-Mg_(2)SiO_(4)) lightweight insulating refractories were prepared by the molten salt method with high silica magnesite and tertiary talc ore as raw materials by pretreating them to get light burnt magnesia and talc,and NaCl molten salt as the reaction medium.The effects of the NaCl addition,the sintering temperature,the holding time and the raw material ratio on the sample preparation were studied.The results show that when the NaCl addition is 20% of the mass of light burnt magnesia and talc mixture,the sintering temperature is 1 200 ℃,the holding time is 6 h,and m(light burnt magnesia):m(talc)=5:5,the sample has the optimal comprehensive properties:the bulk density of 1.46 g·cm^(-3) and the apparent porosity of 55.0%.In addition,it is found that self-decomposition of talc and the formation of forsterite can form pores inside the sample.
基金supported by a grant from UWM research growth initiative(101×290)to MR,grants R01 HL057268 and Muma Endowed Chair in Neonatology to GGK,NIH grant P01-GM-066730-12 to AKSC,and NIH grant 1R15HL129209 to SHA.
文摘Reactive oxygen species(ROS)play a vital role in cell signaling and redox regulation,but when present in excess,lead to numerous pathologies.Detailed quantitative characterization of mitochondrial superoxide anion(O^(·-)_(2))production in fetal pulmonary artery endothelia cells(PAECs)has never been reported.The aim of this study is to assess mitochondrial O^(·-)_(2)pro-duction in cultured PAECs over time using a novel quantitative optical approach.The rate,the sources,and the dynamics of O^(·-)_(2)production were assessed using targeted metabolic modulators of the mitochondrial electron transport chain(ETC)complexes,specifically an uncoupler and inhibitors of the various ETC complexes,and inhibitors of extra-mitochondrial sources of O^(·-)_(2).After stabilization,the cells were loaded with nanomolar mitochondrial-targeted hydroethidine(Mito-HE,MitoSOX)online during the experiment without washout of the residual dye.Time-lapse fuorescence microscopy was used to monitor the dynamic changes in O^(·-)_(2)fluorescence intensity over time in PAECs.The transient behaviors of the fuorescence time course showed exponential increases in the rate of O^(·-)_(2) production in the presence of the ETC uncoupler or inhibitors.The most dramatic and the fastest increase in O^(·-)_(2)production was observed when the cells were treated with the uncoupling agent,PCP.We also showed that only the complex IV inhibitor,KCN,attenuated the marked surge in O^(·-)_(2)production induced by PCP.The results showed that mitochondrial respiratory complexes I,III and IV are sources of O^(·-)_(2) production in PAECs,and a new observation that ROS production during uncoupling of mitochondrial res-piration is mediated in part via complex IV.This novel method can be applied in other studies that examine ROS production under stress condition and during ROS mediated injuries in vritro.
基金the Natural Science Foundation of Hubei Province (2007ABA372) and the New Century Excellent Talents in University (NCET- 06-0676).
文摘Ti( C, N) was synthesized with the starting materials of 76. 9% titania white and 23. 1% carbon black (graphite or activated carbon ), or 40% titania white and 60% amylum, with or without 10% NaBr - KCl, dry moulding and carbon embedded firing at i 300 ℃ and 1 400 ℃ for 3 h, respectively. Phase composition and microstructure of the synthesized Ti (C, N) were analyzed by XRD, SEM and EPMA. Effects of different carbon sources and NaBr-KCl on the synthesis of Ti( C, N) were investigated. The results show that: (1) Ti (C, N) can be synthesized by using carbon black, graphite, activated carbon or amylum as carbon source separately; (2) Additive NaBr - KCl is more favorable for accelerating the carbothermal reduction reaction using carbon black or amylum as carbon source; (3) In the presence of NaBr - KCl, particle size of the synthesized Ti( C, N) is 5 -8μm using carbon black as carbon source fired at 1 300 ℃ for 3 h, while that is only 1 - 3 μm using graphite, activated carbon or amylum fired at 1 400 ℃ for 3 h.
基金supported by the Australian Renewable Energy Agency(G00849).
文摘Owing to the natural abundance and low cost of sodium resources,sodium-ion batteries(SIBs)have drawn considerable attention for state-of-the-art power storage devices over the last few years.To enable advanced SIBs with a brighter future,great effort has been made,not only through optimizing the electrode materials,but also with rationally designing various electrolyte systems.Among the available electrolyte systems,organic electrolytes,especially those based on esters as well as ethers,are the most promising ones for practical application in the foreseeable future,due to their numerous inherent advantages.This review is concerned with the recent research progresses on organic electrolytes for SIBs,focusing on etherbased and ester-based ones.
文摘Background Methanesulfonic acid sodium salt (Dipyrone), an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of this study was to evaluate the potential photoprotective activity of methanesulfonic acid sodium salt in a model of light-induced retinopathy. Methods One hundred mice were assigned randomly into vehicle (V), methanesulfonic acid sodium salt (D), light damage model plus vehicle (MV) and light damage model plus methanesulfonic acid sodium salt (MD) groups (n=25 each). In the MD group, methanesulfonic acid sodium salt (100 mg/kg) was administered by intraperitoneal injection 30 minutes before light exposure. Twenty-four hours after light exposure, hematoxylin and eosin staining and transmission electron microscopy (TEM) were used for histological evaluation. The thickness of the outer plus inner-segment and outer nuclear layer was measured on sections parallel to the vertical meridian of the eye at a distance of 1000 I^m from the optic nerve. Electroretinography (ERG) test was performed to assess the functional change. The morphology of mitochondria was also revealed by TEM. Finally, the expression of cytochrome c (CytC) and the relative apoptotic proteins were detected by Western blotting, and the interaction between mitochondrial proteins was investigated by co-immunoprecipitation. Results The photoreceptor inner and outer segments of the MV group were significantly disorganized than the MD group. The thicknesses of the outer plus inner-segment layers and the outer nuclear layer, and the amplitudes of the a and b waves of the scotopic ERG response markedly decreased in the MV group compared to those in the MD group (P 〈0.05). TEM examination revealed that the mitochondria of the MV group were distinctly swollen and contained disrupted cristae. In contrast, the morphology of mitochondria in the MD group was unaffected. Western blotting analysis showed that CytC, apoptosis proteinase activating factor-1 (Apaf-1), caspase 3, p53, p53-upregulated modulator of apoptosis (PUMA), Bax, and Bad were increased, whereas the anti-apoptotic proteins Bcl-2 and Bcl-XL were significantly decreased in the MV group than the MD group. Co-immunoprecipitation detection revealed that PUMA immunoreactivity precipitated by Bcl-XL decreased, whereas Bax immunoreactivity precipitated by Bcl-XL increased in the MD group compared to those in the MV group. Conclusion Methanesulfonic acid sodium salt is an effective photoprotective agent against light-induced retinopathy through the inhibition of CytC-mediated mitochondrial impairment.
基金financially supported by the 973 program (Nos.2013CB933800,2013CB834505)National Natural Science Foundation of China (Nos.21222210,21102155,91027041)the Chinese Academy of Sciences (100 Talents Program)
文摘The introduction of hydroxy group to the 3- or 5-position of 4,4-difluoro-4-bora-3aAa-diazaindacene (BODIPY) results in unexpected tautomerization to BDPONa with interesting structural and photophysical properties. The core of BDPONa is an anion with sodium cation as counter-ion. BDPONa displays strong fluorescence in organic solvents.
基金National Key Research and Development Program of China(No.2018YFD0501101)the National Natural Science Foundation of China(No.31802094).
文摘There are few studies on the mechanism of redox status imbalance and intestinal dysfunction in intrauterine growth restricted(IUGR)newborn piglets.Here,we investigated the mechanism of jejunum dysfunction in weaned piglets with IUGR and the mechanism through which dimethylglycine sodium salt(DMG-Na)supplementation improving the imbalance of their redox status.In this work,a total of 10 normal birth weight(NBW)newborn piglets and 20 IUGR newborn piglets were obtained.After weaning at 21 d,they were assigned to 3 groups(n=10/group):NBW weaned piglets fed standard basal diets(NBWC);one IUGR weaned piglets fed standard basal diets(IUGRC);another IUGR weaned piglets from the same litter fed standard basal diets plus 0.1%DMG-Na(IUGRD).The piglets in these 3 groups were sacrificed at 49 d of age,and the blood and jejunum samples were collected immediately.The growth performance values in the IUGRC group were lower(P<0.05)than those in the NBWC group.Jejunum histomorphological parameters,inflammatory cytokines,and digestive enzyme activity as well as serum immunoglobulin were lower(P<0.05)in the IUGRC group than those in the NBWC group.Compared with these in the NBWC group,the redox status of serum,jejunum,and mitochondria and the expression levels of jejunum redox status-related,cell adhesion-related,and mitochondrial function-related genes and proteins were suppressed in the IUGRC group(P<0.05).However,compared with those in the IUGRC group,the growth performance values,jejunum histomorphological parameters,inflammatory cytokines,digestive enzyme activity,serum immunoglobulin,redox status of serum,jejunum,and mitochondria,and the expression levels of jejunum redox status-related,cell adhesion-related,and mitochondrial function-related genes and proteins were improved(P<0.05)in the IUGRD group.In conclusion,dietary DMG-Na supplementation alleviates redox status imbalance and intestinal dysfunction in IUGR weaned piglets mainly by activating the sirtuin 1(SIRT1)/peroxisome proliferatoractivated receptorgcoactivator-1a(PGC1a)pathway,thereby improving their unfavorable body state.
文摘Amidoalkyl naphthols have been synthesized in high yields in the presence of 1-hexanesulphonic acid sodium salt as an inexpensive solid catalyst under solvent-free conditions and microwave-irradiation.This catalyst provides clean conversion;greater selectivity and easy workup make this protocol practical and economically attractive.
基金National Key Research and Development Program of China(No.2018YFD0501101)the National Natural Science Foundation of China(No.31802094)。
文摘This study aimed to investigate the mechanism of small intestinal immune dysfunction in intrauterine growth restriction(IUGR)newborn piglets and relieve this dysfunction via dimethylglycine sodium salt(DMG-Na)supplementation during the suckling period.Thirty sows(Duroc×[Landrace×Yorkshire])were selected,and 1 male newborn piglet with normal birth weight(NBW)and 1 male newborn piglet with IUGR were obtained from each sow.Among them,10 NBW and 10 IUGR newborns were euthanized without suckling.The other 20 NBW newborns were allocated to the group named NCON,which means NBW newborns fed a basic milk diet(BMD)(n=10),and the group named ND,which means NBW newborns fed BMD supplemented with 0.1%DMG-Na(n=10);the other 20 IUGR newborns were assigned to the group named ICON,which means IUGR newborns fed BMD(n=10),and the group named ID,which means IUGR newborns fed BMD supplemented with 0.1%DMG-Na(n=10).The newborns were fed BMD from 7 to 21 d of age and euthanized at 21 d of age to collect serum and small intestinal samples.The growth performance,small intestinal histological morphology and sub-organelle ultrastructure,serum immunoglobulin,small intestinal digestive enzyme activity,inflammatory cytokine level,and jejunum mRNA and protein expression of the toll-like receptor 4(TLR4)/nucleotide-binding oligomerization domain protein(NOD)/nuclear factor-k B(NF-k B)network deteriorated in the ICON group compared to that in the NCON group.The small intestinal histological morphology and suborganelle ultrastructure,serum immunoglobulin,small intestinal digestive enzyme activity,and inflammatory cytokine level improved(P<0.05)in the ID group compared to those in the ICON group.The jejunum mRNA and protein expression of the TLR4/NOD/NF-k B network improved(P<0.05)in the ID group compared to that in the ICON group.In conclusion,the activity of the TLR4/NOD/NF-k B pathway was inhibited in the IUGR newborns,which in turn led to their jejunum immune dysfunction and reduced their performance.By ingesting DMG-Na,the IUGR newborns activated the TLR4/NOD/NF-k B pathway,thereby improving their unfavorable body state during the suckling period.
文摘A graft copolymer of polyacrylonitrile (PAN) with sodium salt of partially carboxymethylated tamarind kernel powder (Na-PCMTKP, DS ^-= 0.15) was synthesized by using ceric ammonium nitrate (CAN) as a redox initiator in an aqueous medium. The optimum reaction conditions for affording maximum percentage of grafting were established by successively varying reaction conditions such as concentrations of nitric acid, CAN, monomer (AN) as well as reaction time, temperature and amount of substrate. The influence of these reaction conditions on the grafting yields was discussed. The kinetic scheme of free radical graft copolymerization was proposed and the experimental results were found to agree very well with the proposed kinetic scheme. The graft copolymer (Na-PCMTKP-g-PAN, percentage of grafting G = 413.76% and percentage of grafting efficiency GE = 96.48%) sample synthesized under the established optimized reaction conditions was hydrolyzed by 0.7 mol-L l NaOH solution at 90-95 ℃ to yield the superabsorbent hydrogel, H-Na-PCMTKP-g-PAN. The swelling behavior of the hydrogel was studied by carrying out its absorbency measurements in low conductivity water, 0.15 mol·L^-1 salt (NaCl, CaCl2 and AlCl3) solutions and simulated urine (SU) solution at different timings. FTIR, TGA and SEM techniques were used to characterize the products.
文摘Photo-induced graft copolymerization of methyl methacrylate(MMA) onto sodium salt of partially carboxymethylated guar gum(Na-PCMGG, DS = 0.291) was carried out in an aqueous medium using ceric ammonium nitrate(CAN) as photoinitiator to synthesize a novel graft copolymer, Na-PCMGG-g-PMMA, which may find its potential application as a metal adsorbent. The influences of synthesis variables such as concentrations of photoinitiator(CAN), nitric acid and monomer(MMA) as well as reaction time, temperature and amount of substrate on the grafting yields were studied and the reaction conditions for optimum photo-grafting were evaluated. At optimum concentration, the maximum values of the grafting yields achieved were G = 271.61% and GE = 63.89%. The experimental results were found to be in very good agreement with the proposed kinetic scheme. The photo-graft copolymerization of MMA onto Na-PCMGG( DS = 0.291) was also carried out in the presence and absence of ultraviolet radiation for studying the efficiency of the photoinitiator. The influence of carboxymethyl groups introduced onto the guar gum molecules with regard to its behavior towards ultra-violet radiation induced grafting with MMA was also investigated. Photo-grafting process was confirmed and the products were characterized with the help of the spectroscopic(1H-NMR and FTIR) and SEM techniques.
基金This study is supported in part by grants from the National Natural Science Foundation of China ( Grant No. 41103007), the Fundamental Research Funds for the Beijng Jiaotong University (No. C13JB00070) and Beijing Natural Science Foundation (No. 8142031). The authors express that great thanks to the anonymous reviews for their time and efforts.
文摘Anthropogenic activities in the Pearl River Delta (PRD) have caused a deterioration of groundwater quality over the past twenty years as a result of rapid urbanization and industrial development. In this study, the hydrochemical characteristics, quality, and sources of heavy metals in the groundwater of the PRD were investigated. Twenty-five groundwater samples were collected and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), δ18O,δ~2H, major ions, and heavy metals. The groundwater was slightly acidic and presented TDS values that ranged from 35.5 to 8,779.3 mg.L-1. The concentrations of the major ions followed the order Cl- 〉 HCO3-〉 Na+ 〉 SO24- 〉 NO3 〉 NH4+ 〉 Ca2+ 〉 K+ 〉 Mg2+ 〉 Fe2+/3+ 〉 Al3+. Ca-Mg- HCO3 and Na-K-HCO3 were the predominant types of facies, and the chemical composition of the groundwater was primarily controlled by chemical weathering of the basement rocks, by mixing of freshwater and seawater and by anthropogenic activities. The heavy metal pollution index (HPI) indicated that 64% of the samples were in the low category, 16% were in the medium category and 20% were in the high category, providing further evidence that this groundwater is unsuitable for drinking. Lead, arsenic, and manganese were mainly sourced from landfill leachate; cadmium from landfill leachate and agricultural wastes; mercury from the discharge of leaehate associated with mining activities and agricultural wastes; and chromium primarily from industrial wastes. According to the irrigation water quality indicators, the groundwater in the PRD can be used for irrigation in most farmland without strong negative impacts. However, approximately9 million people in the Guangdong Province are at risk due to the consumption of untreated water. Therefore, we suggest that treating the groundwater to achieve safer levels is necessary.
基金supported by the National Natural Science Foundation of China(Grant No.20976040)the financial support from Project Supported by Science and Technology Planning Project of Hunan Province,China(No.2009SK3036).
文摘The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid)sodium salt(PAASS).Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process.The kinetics of complexation reaction was studied for PAASS with Co^(2+).Results showed that,under a large excess of PAASS,it takes 65,55 and 40 min at pH 5,6 and 7,respectively,to get the equilibrium of complexation.The reaction kinetics can be described by a pseudo-first-order equation.Then,the effects of various parameters on the extraction of Co^(2+)were examined in detail.Results indicated that loading ratio,pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R.Furthermore,a concentration experiment was carried out at pH 7.With increasing volume concentration factor,membrane flux declines slowly,and R value is always about 1.The concentrated retentate was used further for a decomplexation experiment.The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%.After the decomplexation step,a diafiltration experiment was performed at pH 2.5.Cobalt ions can be extracted satisfactorily from the retentate,and a purified PAASS is obtained.
基金Supported by the National Natural Science Foundation of China(Nos.51372125, 51302010) and the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20130010120009).
文摘A post-photochemical cross-linking strategy was successfully demonstrated to enhance the stability of polyelectrolyte poly(allylamine hydrochloride)(PAH)/poly(vinylsulfonic acid sodium salt)(PVS) multilayers. Con- ventional polyelectrolyte multilayers of PAH/PVS are usually fabricated through electrostatic layer-by-layer(LbL) assembly, resulting in poor stability, especially in basic solutions, which leads to the urgent demand for converting weak electrostatic interactions into covalent bonds to enhance the stability of the multilayers. This stability problem has been ultimately addressed by post-infiltrating a photosensitive cross-linking agent, 4,4'-diazostilbene-2,2'- disulfonie acid disodium salt(DAS), into the LbL assembled films to initiate the photochemical reaction to cross-link the multilayers. The obviously improved stability of the photo-cross-linked multilayers was demonstrated through experiments with basic solution treatments. Compared to the complete decomposition of uncross-linked multilayers in basic solution, over 74.4% of the covalently cross-linked multilayers were retained under the same conditions, even after a longer duration of basic solution treatment.
基金GRF,Grant/Award Number:12200118National Natural Science Foundation of China,Grant/Award Number:91856127SKLP,Grant/Award Number:1920_P06。
文摘Sensitive differentiation of an enantiomer from its mirror image(ie,enantiodifferentiation),a perennial challenge for pharmaceutical production and disease diagnosis,is technically limited by the weak optical activity(OA)of enantiomers,mainly due to their dimensional mismatch with light wavelengths in the ultraviolet(UV)-visible region.Here we use silver chiral nanoparticles(Ag CNPs)with nominally sub-5 nm helical pitch(P)to amplify the OA of(20R,30R,40S)-riboflavin-50-phosphate sodium salts(RP),which have been found to indirectly affect metabolic processes,through the formation of an RP thin film(TF)covering a close-packed array of Ag CNPs.The OA of the RP in the deep-UV region can be amplified up to 80-fold,ascribed to the aggregation of RP in the TFs and the interactions between RP and the atomically chiral lattices at the CNPs'surfaces.The former contribution,not associated with the chiral Ag topographies,plays a dominant role by thickening the RP TFs,so that the observed amplification has no enantioselective dependence on the chirality of the Ag CNPs.This study extends progress in the sensitive detection of bio-enantiomers,which is highly desired for advanced bio-detection in disease diagnosis and production of single-enantiomer pharmaceuticals.