Synergistic extraction of cerium（IV） from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester（HEH/EHP, HL） and Di-（2-ethyl hexyl） phosphoric acid（HDEHP, HA） as extractant...Synergistic extraction of cerium（IV） from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester（HEH/EHP, HL） and Di-（2-ethyl hexyl） phosphoric acid（HDEHP, HA） as extractant was investigated.The results indicated that the maximum synergistic enhancement coefficients were obtained at the mole fraction of HEH/EHP=0.6, and cerium（IV） was extracted into organic phase in the form of Ce（SO4）0.5HL2A2.A cation exchange mechanism was proposed for the synergistic extraction of Ce（IV）.The equilibrium constants and thermodynamic functions such as △G, △H, and △S were determined in the extraction of Ce（IV） from sulfuric medium using mixture of HEH/EHP and HDEHP.展开更多
N-methylimidazolium functionalized anion exchange resin in NO3 form （RNO3） was prepared and used for adsorption of Ce（Ⅳ） in nitric acid medimn. The adsorption amount increased with shaking time increasing and the...N-methylimidazolium functionalized anion exchange resin in NO3 form （RNO3） was prepared and used for adsorption of Ce（Ⅳ） in nitric acid medimn. The adsorption amount increased with shaking time increasing and the adsorption equilibrium was obtained within 180 rain. Ce（Ⅳ） was partially reduced to Ce（Ⅲ） and the reduction percent of Ce（Ⅳ） increased with shaking time increasing. But RNO3 was more stable than other resins due to the high resistance to oxidation. A little increase of adsorption amount was found with concentration of HNO3 increasing. However, the reduction percent of Ce（Ⅳ） decreased with the increase of HNO3 concentration. The addition of NaNO3 decreased the adsorption amount of Ce（Ⅳ） on RNO3 due to the competitive anion exchange reaction. Ce（Ⅳ） was adsorbed on RNO3 in the form of Ce（Ⅳ） anion nitrato-complex. RNO3 and Ce（Ⅳ）-loaded RNO3 were characterized by fourier transform infrared （FT-IR） and thermogravimeric analysis （TGA）. Ce（Ⅳ） could be easily separated from RE（Ⅲ） solution by RNO3.展开更多
Tributyl phosphate （TBP） solvent was used for impregnation into Amberlite XAD-16 nonionic polymeric resin beads using the wet method to prepare solvent impregnated resin （SIR）. Undiluted TBP in a ratio to the resi...Tributyl phosphate （TBP） solvent was used for impregnation into Amberlite XAD-16 nonionic polymeric resin beads using the wet method to prepare solvent impregnated resin （SIR）. Undiluted TBP in a ratio to the resin support （volume to mass） of 6.0 at room temperature （RT） in 24 h was impregnated the resin with a mass ratio of 1.944, while the prepared gross sample of SIR at the ratio of solvent to resin of 3.0 was impregnated with a mass ratio of 1.88. Cerium（Ⅳ） oxide concentrate, prepared from crude Egyptian monazite sand, containing 37% cerium, 1.6% thorium and about 40% the other trivalent rare earth oxides, was used to prepare cerium（Ⅳ） nitrate solution for extraction using the prepared SIR. The impregnated resin was satisfactory for Ce（Ⅳ） extraction from nitric acid medium at room temperature. Cerium loading capacity of the impregnated resin reached 95.6% of the calculated theoretical capacity （173 g/kg （Ce/SIR）） under the conditions of 51.57 g/L cerium and 2.48 g/L thorium, 5.0 mol/L free nitric acid, solution to resin ratio of 10.0 and contacting the phases for 5.0 min. The loading capacity reached 98.75% when cerium concentration was increased to 91.43 g/L under the same conditions.展开更多
The relationship between Pb leaching concentration and the solution＇s pH with time was analyzed when cement in its solidified form was leached in an acid medium. The effects of the particle size of the solidified for...The relationship between Pb leaching concentration and the solution＇s pH with time was analyzed when cement in its solidified form was leached in an acid medium. The effects of the particle size of the solidified form, the cement adding method, and the hydration degree on Pb solidification were also investigated. The experimental results indicate that cement is quickly dissolved and hydrated in the acid medium, forming a C-S-H gel or silicic acid sol with good adsorption. When cement-Pb solidified form is leached in an acetate solution, the hydrated product erodes with time, so the Pb concentration increases slightly in the beginning. Then, some of the Pb ions are absorbed by the newly generated silicic acid sol, C-S-H. Others produce Pb（OH）2 precipitation for secondary solidification, leading to a gradual decrease in the Pb concentration in a leaching time of more than two hours. Moreover, the particle size of the solidified form has important effects on the Pb dissolution. When the amount of added cement is low, with a pH of less than 9.5, the solidification affects the sequence of the original cement powder, the cement hydrated powder, and the cement- Pb solidified form. When the added amount of cement increases with a pH of more than 11, the effect of adding methods on solidification decreases, and the solidified form is a little better than others.展开更多
Microbial chain elongation(CE),utilizing anaerobic fermentation for the synthesis of high-value medium chain fatty acids(MCFAs),merges as a promising strategy in resource sustainability.Recently,it has pivoted that th...Microbial chain elongation(CE),utilizing anaerobic fermentation for the synthesis of high-value medium chain fatty acids(MCFAs),merges as a promising strategy in resource sustainability.Recently,it has pivoted that the use of different types of additives or accelerantstowards enhancing the products yield and fermentation quality has got much attention,with carbon-based materials emerging as vital facilitators.Based on bibliometrics insights,this paper firstly commences with a comprehensive review of the past two decades’progress in applying carbon-based materials within anaerobic fermentation contexts.Subsequently,the recent advancements made by different research groups in order to enhance the performance of CE systemperformance are reviewed,with particular focus on the application,impact,and underlying mechanisms of carbon-based materials in expediting MCFAs biosynthesis via CE.Finally,the future research direction is prospected,aiming to inform innovative material design and sophisticated technological applications,as well as provide a reference for improving the efficiency of anaerobic fermentation of MCFAs using carbon-based material,thereby contributing to the broader discourse on enhancing sustainability and efficiency in bio-based processes.展开更多
The electrochemical dissolution process of chalcopyrite and bornite in acid bacteria culture medium was investigated by electrochemical measurements and X-ray photoelectron spectroscopy（XPS） analysis. Bornite was mu...The electrochemical dissolution process of chalcopyrite and bornite in acid bacteria culture medium was investigated by electrochemical measurements and X-ray photoelectron spectroscopy（XPS） analysis. Bornite was much easier to be oxidized rather than to be reduced, and chalcopyrite was difficult to be both oxidized and reduced. The relatively higher copper extraction of bornite dissolution can be attributed to its higher oxidation rate. Covellite（CuS） was detected as the intermediate species during the dissolution processes of both bornite and chalcopyrite. Bornite dissolution was preferred to be a direct oxidation pathway, in which bornite was directly oxidized to covellite（CuS） and cupric ions, and the formed covellite（CuS） may inhibit the further dissolution. Chalcopyrite dissolution was preferred to be a continuous reduction-oxidation pathway, in which chalcopyrite was initially reduced to bornite, then oxidized to covellite（CuS）, and the initial reduction reaction was the rate-limiting step.展开更多
In studies on the extraction chemistry of gold, the extractants of alcohols, ethers, ketones and amines are widely used. The neutral extractants tributylphosphate (TBP) and trioctylphosphine oxide (TPPO) have been wid...In studies on the extraction chemistry of gold, the extractants of alcohols, ethers, ketones and amines are widely used. The neutral extractants tributylphosphate (TBP) and trioctylphosphine oxide (TPPO) have been widely applied. A few experiments on the synthesis of solid complexes of transition metal ions with TPPO have been car-展开更多
Ytterbium purification by an electrolysis reduction in sulfuric acid medium was investigated without nitrogen or argon protection, in which Ru-Ir-Ti alloy nets and mercury were used as anode and cathode, respectively....Ytterbium purification by an electrolysis reduction in sulfuric acid medium was investigated without nitrogen or argon protection, in which Ru-Ir-Ti alloy nets and mercury were used as anode and cathode, respectively. How the conditions such as the acidities of cathode and anode solutions, and the concentration of Yb（ Ⅲ ） to affect the circuit and ratio of Yb（ Ⅱ ）/Yb （ Ⅲ ） in electrolysis reduction were studied.展开更多
Replacing platinum for catalyzing hydrogen evolution reaction （HER） in acidic medium remains great chal- lenges. Herein, we prepared few-layered MoS2 by ball milling as an efficient catalyst for HER in acidic medium...Replacing platinum for catalyzing hydrogen evolution reaction （HER） in acidic medium remains great chal- lenges. Herein, we prepared few-layered MoS2 by ball milling as an efficient catalyst for HER in acidic medium, The activity of as-prepared MoS2 had a strong dependence on the ball milling time, Furthermore, Ketjen Black EC 300J was added into the ball-milled MoS2 followed by a second ball milling, and the resultant MoS2/carbon black hybrid material showed a much higher HER activity than MoS2 and carbon black alone. The enhanced activity of the MoS2/carbon black hybrid material was attributed to the increased abundance of catalytic edge sites of MoS） and excellent electrical coupling to the underlving carbon network.展开更多
Plackett-Burman design and response surface methodology were applied in order to optimize the fermentation medium of (R)-α-hydroxyphenylacetic acid ((R)-HPA) producing Bacillus sp. HZG-19. The factors playing importa...Plackett-Burman design and response surface methodology were applied in order to optimize the fermentation medium of (R)-α-hydroxyphenylacetic acid ((R)-HPA) producing Bacillus sp. HZG-19. The factors playing important roles in the production of (R)-HPA were selected based on Plackett-Burman design. The path of steepest ascent was undertaken to optimize said fermentation medium. Finally, the optimal levels of the factors with the greatest change in regard to product yield were further optimized using Box-Behnken and response surface analysis. The optimal conditions were found to be as follows: casein peptone 30.49 (g × L-1), glycerol 14.09 (g × L-1), KH2PO4 0.1345 (g × L-1), K2HPO4 0.01 (g × L-1), CaCl2 0.1 (g × L-1), MnSO4 0.01 (g × L-1). Under the optimal conditions described above, the yield of (R)-HPA reached 63.30%, which indicated an increase of 14.9%, as compared to the yield obtained before optimization.展开更多
Background:The search for alternatives to antibiotics in pig production has increased the interest in natural resources with antimicrobial properties,such as medium-chain fatty acids(MCFA)as in-feed additives.This stu...Background:The search for alternatives to antibiotics in pig production has increased the interest in natural resources with antimicrobial properties,such as medium-chain fatty acids(MCFA)as in-feed additives.This study evaluated the potential of a novel blend of MCFA salts(DIC)from distilled coconut oil with a lauric acid content to reduce enteropathogens and control intestinal diseases around weaning.Two experimental disease models were implemented in early-weaned piglets,consisting of two oral challenges:Salmonella Typhimurium(1.2×10~8 CFU)or enterotoxigenic Escherichia coli(ETEC)F4(1.5×10~9 CFU).The parameters assessed were:animal performance,clinical signs,pathogen excretion,intestinal fermentation,immune-inflammatory response,and intestinal morphology.Results:The Salmonella challenge promoted an acute course of diarrhea,with most of the parameters responding to the challenge,whereas the ETEC F4 challenge promoted a mild clinical course.A consistent antipathogenic effect of DIC was observed in both trials in the hindgut,with reductions in Salmonella spp.plate counts in the cecum(P=0.03)on d 8 post-inoculation(PI)(Salmonella trial),and of enterobacteria and total coliform counts in the ileum and colon(P<0.10)on d 8 PI(ETEC F4 trial).When analyzing the entire colonic microbiota(16 S rRNA gene sequencing),this additive tended(P=0.13)to reduce the Firmicutes/Bacteroidetes ratio and enriched Fibrobacteres after the Salmonella challenge.In the ETEC F4 challenge,DIC prompted structural changes in the ecosystem with increases in Dialister,and a trend(P=0.14)to increase the Veillonellaceae family.Other parameters such as the intestinal fermentation products or serum pro-inflammatory mediators were not modified by DIC supplementation,nor were the histological parameters.Only the intraepithelial lymphocyte(IEL)counts were lowered by DIC in animals challenged with Salmonella(P=0.07).With ETEC F4,the IEL counts were higher with DIC on d 8 PI(P=0.08).Conclusions:This study confirms the potential activity of this MCFA salts mixture to reduce intestinal colonization by opportunistic pathogens such as Salmonella or E.coli and its ability to modulate colonic microbiota.These changes could explain to some extent the local immune cell response at the ileal level.展开更多
In vivo imaging in the deep near-infrared(NIR)spectral region,that is,beyond 800 nm,has become popular due to its penetration depth.While imaging of the neutral medium/tissue has been repeatedly showcased,imaging of t...In vivo imaging in the deep near-infrared(NIR)spectral region,that is,beyond 800 nm,has become popular due to its penetration depth.While imaging of the neutral medium/tissue has been repeatedly showcased,imaging of the high-acidic medium remains challenging partly because of the high-lying HOMO orbital and hence a high pKa of the electron-donating group of the NIR fluorophores.We devised a novel electron-donating group(D6)with which we further synthesized ECJ.ECJ exhibits an absorption wavelength beyond 900 nm and is fluorescent.Its pKa was found to be lower than zero,rendering it suitable for bioimaging of a highly-acidic medium.Its potential for practical applications was showcased in proof-of-concept in vivo imaging with a mouse model.展开更多
Ludong orogenic belt in China is an importantal continent collision orogenic belt in eastern Asia, between Sino Korean landmass and Yangtze landmass. The host rock of the orogenic belt is metamorphosed medium acidic i...Ludong orogenic belt in China is an importantal continent collision orogenic belt in eastern Asia, between Sino Korean landmass and Yangtze landmass. The host rock of the orogenic belt is metamorphosed medium acidic intrusive complexes, which can be divided into four types, that’s, quartz dioritz, granite dioritz, monzonitic granite and undertint monzonitic granite, principal minerals are plagioclases, potassium feldspars and quartzs, minor minerals are hornblendes, biotites, clinopyxenes and garnets, accessory mineral types and assemblages are very similar, specially, various rocks are mainly fine grained textures. They have the history of regional amphibolite facies metamorphism and deep middle shallow structural layer deformation, and are changed into various gneiss and tectonic system. There are many xenolithes of middle Proterozoic eclogite host rock extrahigh high pressure metamorphic complexes, a small xenolithes of early Proterozoic layered metamorphite system and granulites, and ultrabasic basic rocks of various epoches in the metamorphosed medium acidic intrusive complexes.展开更多
Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoate...Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoates produced are hydrolysed in situ and the corresponding acids are obtained after mostly simple extractive work-up, often without employing organic solvents. Under the same conditions, benzaldehydes are reacted with alkoxycarbonyl bromomethy-lidenephosphorane to produce 3-arylprop-2-ynoic acids (arylpropiolic acids).展开更多
Physico-chemical methods of improved oil recovery make it possible to increase oil production in deposits by injecting surfactants acting on various physical parameters. Oleic acid has an effect on the viscosity of th...Physico-chemical methods of improved oil recovery make it possible to increase oil production in deposits by injecting surfactants acting on various physical parameters. Oleic acid has an effect on the viscosity of the displacement fluid and the flow rate. Therefore, increasing the viscosity of the displacement fluid plays an essential role in improving the improved oil recovery. The physicochemical properties at the interface between petroleum and water are modified by oleic acid, lowering the viscosity of petroleum and increasing the viscosity of water, which facilitated the mobility of petroleum in the porous medium.展开更多
基金support by the High Technology Research and Development Programme (2006AA06Z123) National Key Technology Research and Development Programme (2006BAC02A06) of China
文摘Synergistic extraction of cerium（IV） from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester（HEH/EHP, HL） and Di-（2-ethyl hexyl） phosphoric acid（HDEHP, HA） as extractant was investigated.The results indicated that the maximum synergistic enhancement coefficients were obtained at the mole fraction of HEH/EHP=0.6, and cerium（IV） was extracted into organic phase in the form of Ce（SO4）0.5HL2A2.A cation exchange mechanism was proposed for the synergistic extraction of Ce（IV）.The equilibrium constants and thermodynamic functions such as △G, △H, and △S were determined in the extraction of Ce（IV） from sulfuric medium using mixture of HEH/EHP and HDEHP.
基金supported by the National Natural Science Foundation of China(51174184)National High-Tech R&D Program(2007AA06Z202)+1 种基金Scientific Research Foundation for the Returned Overseas Chinese ScholarsMinistry of Education of China
文摘N-methylimidazolium functionalized anion exchange resin in NO3 form （RNO3） was prepared and used for adsorption of Ce（Ⅳ） in nitric acid medimn. The adsorption amount increased with shaking time increasing and the adsorption equilibrium was obtained within 180 rain. Ce（Ⅳ） was partially reduced to Ce（Ⅲ） and the reduction percent of Ce（Ⅳ） increased with shaking time increasing. But RNO3 was more stable than other resins due to the high resistance to oxidation. A little increase of adsorption amount was found with concentration of HNO3 increasing. However, the reduction percent of Ce（Ⅳ） decreased with the increase of HNO3 concentration. The addition of NaNO3 decreased the adsorption amount of Ce（Ⅳ） on RNO3 due to the competitive anion exchange reaction. Ce（Ⅳ） was adsorbed on RNO3 in the form of Ce（Ⅳ） anion nitrato-complex. RNO3 and Ce（Ⅳ）-loaded RNO3 were characterized by fourier transform infrared （FT-IR） and thermogravimeric analysis （TGA）. Ce（Ⅳ） could be easily separated from RE（Ⅲ） solution by RNO3.
文摘Tributyl phosphate （TBP） solvent was used for impregnation into Amberlite XAD-16 nonionic polymeric resin beads using the wet method to prepare solvent impregnated resin （SIR）. Undiluted TBP in a ratio to the resin support （volume to mass） of 6.0 at room temperature （RT） in 24 h was impregnated the resin with a mass ratio of 1.944, while the prepared gross sample of SIR at the ratio of solvent to resin of 3.0 was impregnated with a mass ratio of 1.88. Cerium（Ⅳ） oxide concentrate, prepared from crude Egyptian monazite sand, containing 37% cerium, 1.6% thorium and about 40% the other trivalent rare earth oxides, was used to prepare cerium（Ⅳ） nitrate solution for extraction using the prepared SIR. The impregnated resin was satisfactory for Ce（Ⅳ） extraction from nitric acid medium at room temperature. Cerium loading capacity of the impregnated resin reached 95.6% of the calculated theoretical capacity （173 g/kg （Ce/SIR）） under the conditions of 51.57 g/L cerium and 2.48 g/L thorium, 5.0 mol/L free nitric acid, solution to resin ratio of 10.0 and contacting the phases for 5.0 min. The loading capacity reached 98.75% when cerium concentration was increased to 91.43 g/L under the same conditions.
基金Found by the National High-tech Research and Development Program of China(No.SS2012AA062204)
文摘The relationship between Pb leaching concentration and the solution＇s pH with time was analyzed when cement in its solidified form was leached in an acid medium. The effects of the particle size of the solidified form, the cement adding method, and the hydration degree on Pb solidification were also investigated. The experimental results indicate that cement is quickly dissolved and hydrated in the acid medium, forming a C-S-H gel or silicic acid sol with good adsorption. When cement-Pb solidified form is leached in an acetate solution, the hydrated product erodes with time, so the Pb concentration increases slightly in the beginning. Then, some of the Pb ions are absorbed by the newly generated silicic acid sol, C-S-H. Others produce Pb（OH）2 precipitation for secondary solidification, leading to a gradual decrease in the Pb concentration in a leaching time of more than two hours. Moreover, the particle size of the solidified form has important effects on the Pb dissolution. When the amount of added cement is low, with a pH of less than 9.5, the solidification affects the sequence of the original cement powder, the cement hydrated powder, and the cement- Pb solidified form. When the added amount of cement increases with a pH of more than 11, the effect of adding methods on solidification decreases, and the solidified form is a little better than others.
基金financially supported by the National Key R&D Program of China(No.2019YFC1906600)the National Natural Science Foundation of China(No.52000132).
文摘Microbial chain elongation(CE),utilizing anaerobic fermentation for the synthesis of high-value medium chain fatty acids(MCFAs),merges as a promising strategy in resource sustainability.Recently,it has pivoted that the use of different types of additives or accelerantstowards enhancing the products yield and fermentation quality has got much attention,with carbon-based materials emerging as vital facilitators.Based on bibliometrics insights,this paper firstly commences with a comprehensive review of the past two decades’progress in applying carbon-based materials within anaerobic fermentation contexts.Subsequently,the recent advancements made by different research groups in order to enhance the performance of CE systemperformance are reviewed,with particular focus on the application,impact,and underlying mechanisms of carbon-based materials in expediting MCFAs biosynthesis via CE.Finally,the future research direction is prospected,aiming to inform innovative material design and sophisticated technological applications,as well as provide a reference for improving the efficiency of anaerobic fermentation of MCFAs using carbon-based material,thereby contributing to the broader discourse on enhancing sustainability and efficiency in bio-based processes.
基金Projects(51374248,51320105006)supported by the National Natural Science Foundation of ChinaProject(NCET-13-0595)supported by the Program for New Century Excellent Talents in University,ChinaProject(CX2014B091)supported by the Hunan Provincial Innovation Foundation for Postgraduate,China
文摘The electrochemical dissolution process of chalcopyrite and bornite in acid bacteria culture medium was investigated by electrochemical measurements and X-ray photoelectron spectroscopy（XPS） analysis. Bornite was much easier to be oxidized rather than to be reduced, and chalcopyrite was difficult to be both oxidized and reduced. The relatively higher copper extraction of bornite dissolution can be attributed to its higher oxidation rate. Covellite（CuS） was detected as the intermediate species during the dissolution processes of both bornite and chalcopyrite. Bornite dissolution was preferred to be a direct oxidation pathway, in which bornite was directly oxidized to covellite（CuS） and cupric ions, and the formed covellite（CuS） may inhibit the further dissolution. Chalcopyrite dissolution was preferred to be a continuous reduction-oxidation pathway, in which chalcopyrite was initially reduced to bornite, then oxidized to covellite（CuS）, and the initial reduction reaction was the rate-limiting step.
基金Project supported by the Science Fund of the Academia Sinica
文摘In studies on the extraction chemistry of gold, the extractants of alcohols, ethers, ketones and amines are widely used. The neutral extractants tributylphosphate (TBP) and trioctylphosphine oxide (TPPO) have been widely applied. A few experiments on the synthesis of solid complexes of transition metal ions with TPPO have been car-
文摘Ytterbium purification by an electrolysis reduction in sulfuric acid medium was investigated without nitrogen or argon protection, in which Ru-Ir-Ti alloy nets and mercury were used as anode and cathode, respectively. How the conditions such as the acidities of cathode and anode solutions, and the concentration of Yb（ Ⅲ ） to affect the circuit and ratio of Yb（ Ⅱ ）/Yb （ Ⅲ ） in electrolysis reduction were studied.
基金the financial support from the Ministry of Science and Technology of China (grants 2012CB215500 and 2013CB933100)the National Natural Science Foundation of China (grants 21573222 and 21103178)
文摘Replacing platinum for catalyzing hydrogen evolution reaction （HER） in acidic medium remains great chal- lenges. Herein, we prepared few-layered MoS2 by ball milling as an efficient catalyst for HER in acidic medium, The activity of as-prepared MoS2 had a strong dependence on the ball milling time, Furthermore, Ketjen Black EC 300J was added into the ball-milled MoS2 followed by a second ball milling, and the resultant MoS2/carbon black hybrid material showed a much higher HER activity than MoS2 and carbon black alone. The enhanced activity of the MoS2/carbon black hybrid material was attributed to the increased abundance of catalytic edge sites of MoS） and excellent electrical coupling to the underlving carbon network.
文摘Plackett-Burman design and response surface methodology were applied in order to optimize the fermentation medium of (R)-α-hydroxyphenylacetic acid ((R)-HPA) producing Bacillus sp. HZG-19. The factors playing important roles in the production of (R)-HPA were selected based on Plackett-Burman design. The path of steepest ascent was undertaken to optimize said fermentation medium. Finally, the optimal levels of the factors with the greatest change in regard to product yield were further optimized using Box-Behnken and response surface analysis. The optimal conditions were found to be as follows: casein peptone 30.49 (g × L-1), glycerol 14.09 (g × L-1), KH2PO4 0.1345 (g × L-1), K2HPO4 0.01 (g × L-1), CaCl2 0.1 (g × L-1), MnSO4 0.01 (g × L-1). Under the optimal conditions described above, the yield of (R)-HPA reached 63.30%, which indicated an increase of 14.9%, as compared to the yield obtained before optimization.
基金funded by the“PORCDIGEST”project(IDI-20140262)funded by the CDTI and the Ministerio de Economía y Competitividad(Spain)support from the pre-doctoral FI grant of the Generalitat de Catalunya(Spain)awarded to Paola López-Colom.
文摘Background:The search for alternatives to antibiotics in pig production has increased the interest in natural resources with antimicrobial properties,such as medium-chain fatty acids(MCFA)as in-feed additives.This study evaluated the potential of a novel blend of MCFA salts(DIC)from distilled coconut oil with a lauric acid content to reduce enteropathogens and control intestinal diseases around weaning.Two experimental disease models were implemented in early-weaned piglets,consisting of two oral challenges:Salmonella Typhimurium(1.2×10~8 CFU)or enterotoxigenic Escherichia coli(ETEC)F4(1.5×10~9 CFU).The parameters assessed were:animal performance,clinical signs,pathogen excretion,intestinal fermentation,immune-inflammatory response,and intestinal morphology.Results:The Salmonella challenge promoted an acute course of diarrhea,with most of the parameters responding to the challenge,whereas the ETEC F4 challenge promoted a mild clinical course.A consistent antipathogenic effect of DIC was observed in both trials in the hindgut,with reductions in Salmonella spp.plate counts in the cecum(P=0.03)on d 8 post-inoculation(PI)(Salmonella trial),and of enterobacteria and total coliform counts in the ileum and colon(P<0.10)on d 8 PI(ETEC F4 trial).When analyzing the entire colonic microbiota(16 S rRNA gene sequencing),this additive tended(P=0.13)to reduce the Firmicutes/Bacteroidetes ratio and enriched Fibrobacteres after the Salmonella challenge.In the ETEC F4 challenge,DIC prompted structural changes in the ecosystem with increases in Dialister,and a trend(P=0.14)to increase the Veillonellaceae family.Other parameters such as the intestinal fermentation products or serum pro-inflammatory mediators were not modified by DIC supplementation,nor were the histological parameters.Only the intraepithelial lymphocyte(IEL)counts were lowered by DIC in animals challenged with Salmonella(P=0.07).With ETEC F4,the IEL counts were higher with DIC on d 8 PI(P=0.08).Conclusions:This study confirms the potential activity of this MCFA salts mixture to reduce intestinal colonization by opportunistic pathogens such as Salmonella or E.coli and its ability to modulate colonic microbiota.These changes could explain to some extent the local immune cell response at the ileal level.
基金supported by the National Key Research and Development Program of China(No.2022YFD17800)the National Natural Science Foundation of China(Nos.22078098,and 22278138)+2 种基金the Shanghai Academic Technology Research Leader(22XD1421000)the Research Funds of Happiness Flower ECNU(2020JK2103)the Open Funding Project of the State Key Laboratory of Bioreactor Engineering.
文摘In vivo imaging in the deep near-infrared(NIR)spectral region,that is,beyond 800 nm,has become popular due to its penetration depth.While imaging of the neutral medium/tissue has been repeatedly showcased,imaging of the high-acidic medium remains challenging partly because of the high-lying HOMO orbital and hence a high pKa of the electron-donating group of the NIR fluorophores.We devised a novel electron-donating group(D6)with which we further synthesized ECJ.ECJ exhibits an absorption wavelength beyond 900 nm and is fluorescent.Its pKa was found to be lower than zero,rendering it suitable for bioimaging of a highly-acidic medium.Its potential for practical applications was showcased in proof-of-concept in vivo imaging with a mouse model.
文摘Ludong orogenic belt in China is an importantal continent collision orogenic belt in eastern Asia, between Sino Korean landmass and Yangtze landmass. The host rock of the orogenic belt is metamorphosed medium acidic intrusive complexes, which can be divided into four types, that’s, quartz dioritz, granite dioritz, monzonitic granite and undertint monzonitic granite, principal minerals are plagioclases, potassium feldspars and quartzs, minor minerals are hornblendes, biotites, clinopyxenes and garnets, accessory mineral types and assemblages are very similar, specially, various rocks are mainly fine grained textures. They have the history of regional amphibolite facies metamorphism and deep middle shallow structural layer deformation, and are changed into various gneiss and tectonic system. There are many xenolithes of middle Proterozoic eclogite host rock extrahigh high pressure metamorphic complexes, a small xenolithes of early Proterozoic layered metamorphite system and granulites, and ultrabasic basic rocks of various epoches in the metamorphosed medium acidic intrusive complexes.
文摘Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoates produced are hydrolysed in situ and the corresponding acids are obtained after mostly simple extractive work-up, often without employing organic solvents. Under the same conditions, benzaldehydes are reacted with alkoxycarbonyl bromomethy-lidenephosphorane to produce 3-arylprop-2-ynoic acids (arylpropiolic acids).
文摘Physico-chemical methods of improved oil recovery make it possible to increase oil production in deposits by injecting surfactants acting on various physical parameters. Oleic acid has an effect on the viscosity of the displacement fluid and the flow rate. Therefore, increasing the viscosity of the displacement fluid plays an essential role in improving the improved oil recovery. The physicochemical properties at the interface between petroleum and water are modified by oleic acid, lowering the viscosity of petroleum and increasing the viscosity of water, which facilitated the mobility of petroleum in the porous medium.
