Apple(Malus domestica)fruit generally undergoes a climacteric.During its ripening process,there is a peak in ethylene release and its firmness simultaneously decreases.Although more in-depth research into the mechanis...Apple(Malus domestica)fruit generally undergoes a climacteric.During its ripening process,there is a peak in ethylene release and its firmness simultaneously decreases.Although more in-depth research into the mechanism of climacteric-type fruit ripening is being carried out,some aspects remain unclear.In this study,we compared the transcriptomes of 0-Pre and 15-Post(pre-and post-climacteric fruit),and 15-Post and 15-MCP[fruit treated with 1-MCP(1-methylcyclopropene)].Various transcription factors,such as MADS-box,ERF,NAC,Dof and SHF were identified among the DEGs(differential gene expressions).Furthermore,these transcription factors were selected for further validation analysis by qRT-PCR.Moreover,yeast one hybrid(Y1H),β-glucuronidase(GUS)transactivation assay and dual-luciferase reporter assay showed that MdAGL30,MdAGL104,MdERF008,MdNAC71,MdDof1.2,MdHSFB2a and MdHSFB3 bound to MdACS1 promoter and directly regulated its transcription,thereby regulating ethylene biosynthesis in apple fruit.Our results provide useful information and new insights for research on apple fruit ripening.展开更多
A method was developed for determination of 7 indictors the polychlorinated biphenyls (PCBs) residues in porphyra by gas chromatography (GC) with electron capture detector (ECD). The PCBs were extracted with hexane/me...A method was developed for determination of 7 indictors the polychlorinated biphenyls (PCBs) residues in porphyra by gas chromatography (GC) with electron capture detector (ECD). The PCBs were extracted with hexane/methylene chloride (1:1, v/v) by ultrasonic extraction and the samples were cleaned up by concentrated sulfuric acid and Alumina-N solid phase extraction cartridge. The analytes were quantified by an internal standard method. Under optimal experimental conditions, good linearity was observed in the range of 5 - 200 ng/mL and the correlation coefficients were 0.9994 - 0.9998. The limit of quantitation (LOQ) for target analytes ranged from 6.0 to 10.0 μg/kg. At the spiked levels of 10, 50, 100 μg/kg, the average recoveries ranged from 90.9% to 102% with the relative standard deviations 2.12% - 6.32%. The result showed that the proposed method was rapid, and could be used for the determination of the PCBs in porphyra.展开更多
Selective phenol hydrogenation is a green approach to produce cyclohexanone.It still remains a big challenge to prepare efficient supports of the catalysts for the phenol hydrogenation via a simple and cost-effective ...Selective phenol hydrogenation is a green approach to produce cyclohexanone.It still remains a big challenge to prepare efficient supports of the catalysts for the phenol hydrogenation via a simple and cost-effective approach.Herein,a facile approach was developed,i.e.,direct calcination of activated carbon(AC)under argon at high temperature,to improve its structure and surface properties.The modified AC materials were supported with Pd nanoparticles(NPs)to fabricate the Pd/C catalysts.The as-prepared Pd/C600 catalyst exhibits superior catalytic performance in the phenol hydrogenation,and its turnover frequency(TOF)value is 199.2 h^-1,1.31 times to that of Pd/C-raw.The Pd/C600 catalyst presents both better hydrophobicity and more structural defects,contributing to the improved dispersibility in the reaction solution(phenol-cyclohexane),the better Pd dispersion and the smaller Pd size,which result in the enhancement of the catalytic performance.Furthermore,the as-prepared Pd/C600 catalyst shows a good recyclability.展开更多
Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrog...Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen efficiency.Dietary starch patterns modulation may improve this situation.Methods:Growing barrows(29.7±2.0 kg)were randomly allotted into 5 dietary treatments with LP diets consisting of different purified starches.Treatments included:waxy corn starch(W LP),corn starch+waxy corn starch(C+W LP),corn starch(C LP),pea starch+waxy corn starch(P+W LP)and pea starch(P LP).In the experiment,growth performance,protein deposition,nutrient metabolism,and fecal microbial community of pigs were investigated.In vitro starch digestion was used for predicting the in vivo glucose response.Results:Dietary starch in vitro glucose release profile was determined by starch source and the ratio of amylopectin and amylose.C+W LP treatment showed decreased total nitrogen excretion and plasma citrulline concentration and improved plasma leptin concentration among treatments(P<0.05).Besides,the highest nitrogen apparent biological value,whole-body protein deposition and growth performance and lowest urinary nitrogen excretion were also observed in C+W LP treatment.Compared with the other groups,C+W LP and C LP showed increased plasma pyruvate,IGF-1,and lipase concentrations(P<0.05).The W LP group presented dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin concentrations(P<0.05).Dietary starch patterns did not make an impact on bacterial richness and diversity,but changed the taxonomic and functional structures of the microbial communities.Microbial protein fermentation product(isobutyrate and isovalerate)presented increased in P LP treatments compared with the other treatments(P<0.05).Conclusions:Dietary starch patterns modulation can regulate dietary glucose release profile,nutrient metabolism,protein turnover,and fecal microbial fermentation in pigs.The optimal dietary glucose release profile effectively strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing pigs fed LP diets.展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant No.32002006)China Postdoctoral Science Foundation(Grant No.2020M680984).
文摘Apple(Malus domestica)fruit generally undergoes a climacteric.During its ripening process,there is a peak in ethylene release and its firmness simultaneously decreases.Although more in-depth research into the mechanism of climacteric-type fruit ripening is being carried out,some aspects remain unclear.In this study,we compared the transcriptomes of 0-Pre and 15-Post(pre-and post-climacteric fruit),and 15-Post and 15-MCP[fruit treated with 1-MCP(1-methylcyclopropene)].Various transcription factors,such as MADS-box,ERF,NAC,Dof and SHF were identified among the DEGs(differential gene expressions).Furthermore,these transcription factors were selected for further validation analysis by qRT-PCR.Moreover,yeast one hybrid(Y1H),β-glucuronidase(GUS)transactivation assay and dual-luciferase reporter assay showed that MdAGL30,MdAGL104,MdERF008,MdNAC71,MdDof1.2,MdHSFB2a and MdHSFB3 bound to MdACS1 promoter and directly regulated its transcription,thereby regulating ethylene biosynthesis in apple fruit.Our results provide useful information and new insights for research on apple fruit ripening.
文摘A method was developed for determination of 7 indictors the polychlorinated biphenyls (PCBs) residues in porphyra by gas chromatography (GC) with electron capture detector (ECD). The PCBs were extracted with hexane/methylene chloride (1:1, v/v) by ultrasonic extraction and the samples were cleaned up by concentrated sulfuric acid and Alumina-N solid phase extraction cartridge. The analytes were quantified by an internal standard method. Under optimal experimental conditions, good linearity was observed in the range of 5 - 200 ng/mL and the correlation coefficients were 0.9994 - 0.9998. The limit of quantitation (LOQ) for target analytes ranged from 6.0 to 10.0 μg/kg. At the spiked levels of 10, 50, 100 μg/kg, the average recoveries ranged from 90.9% to 102% with the relative standard deviations 2.12% - 6.32%. The result showed that the proposed method was rapid, and could be used for the determination of the PCBs in porphyra.
基金financial supports from the National Key R&D Program(2016YFB0301503)the National Natural Science Foundation of China(21776127,21921006)+2 种基金the Jiangsu Province Key R&D Program(BE2018009-2)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the State Key Laboratory of Materials-Oriented Chemical Engineering(ZK201902)。
文摘Selective phenol hydrogenation is a green approach to produce cyclohexanone.It still remains a big challenge to prepare efficient supports of the catalysts for the phenol hydrogenation via a simple and cost-effective approach.Herein,a facile approach was developed,i.e.,direct calcination of activated carbon(AC)under argon at high temperature,to improve its structure and surface properties.The modified AC materials were supported with Pd nanoparticles(NPs)to fabricate the Pd/C catalysts.The as-prepared Pd/C600 catalyst exhibits superior catalytic performance in the phenol hydrogenation,and its turnover frequency(TOF)value is 199.2 h^-1,1.31 times to that of Pd/C-raw.The Pd/C600 catalyst presents both better hydrophobicity and more structural defects,contributing to the improved dispersibility in the reaction solution(phenol-cyclohexane),the better Pd dispersion and the smaller Pd size,which result in the enhancement of the catalytic performance.Furthermore,the as-prepared Pd/C600 catalyst shows a good recyclability.
基金financially supported by the Beijing Swine Innovation Team of Modern Agriculture Industry Technological System.
文摘Background:Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein(LP)diets.Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen efficiency.Dietary starch patterns modulation may improve this situation.Methods:Growing barrows(29.7±2.0 kg)were randomly allotted into 5 dietary treatments with LP diets consisting of different purified starches.Treatments included:waxy corn starch(W LP),corn starch+waxy corn starch(C+W LP),corn starch(C LP),pea starch+waxy corn starch(P+W LP)and pea starch(P LP).In the experiment,growth performance,protein deposition,nutrient metabolism,and fecal microbial community of pigs were investigated.In vitro starch digestion was used for predicting the in vivo glucose response.Results:Dietary starch in vitro glucose release profile was determined by starch source and the ratio of amylopectin and amylose.C+W LP treatment showed decreased total nitrogen excretion and plasma citrulline concentration and improved plasma leptin concentration among treatments(P<0.05).Besides,the highest nitrogen apparent biological value,whole-body protein deposition and growth performance and lowest urinary nitrogen excretion were also observed in C+W LP treatment.Compared with the other groups,C+W LP and C LP showed increased plasma pyruvate,IGF-1,and lipase concentrations(P<0.05).The W LP group presented dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin concentrations(P<0.05).Dietary starch patterns did not make an impact on bacterial richness and diversity,but changed the taxonomic and functional structures of the microbial communities.Microbial protein fermentation product(isobutyrate and isovalerate)presented increased in P LP treatments compared with the other treatments(P<0.05).Conclusions:Dietary starch patterns modulation can regulate dietary glucose release profile,nutrient metabolism,protein turnover,and fecal microbial fermentation in pigs.The optimal dietary glucose release profile effectively strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing pigs fed LP diets.
