In the studying of the stereospecific hydroxylation of different Δ5-steroids with performic acid, followed by hydrolysis with CH3OH/KOH, we found 19-substituting groups considerably affected the reaction and we put f...In the studying of the stereospecific hydroxylation of different Δ5-steroids with performic acid, followed by hydrolysis with CH3OH/KOH, we found 19-substituting groups considerably affected the reaction and we put forward the mechanism.展开更多
Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gil...Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins(cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP(12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts(89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results: Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level(P > 0.10) except that average daily feed intake was increased by CSM diets(P = 0.03). Gilts offered reduced protein diets had lower muscle p H45min(P 〈 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency(P 〈 0.01). CSM diets increased N intake(P = 0.04),but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine(P 〈 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased(P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle(P 〈 0.05).Conclusion: These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids(FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.展开更多
Background: As a organic acid, benzoic acid has become one of the most important alternatives for antibiotics,and its beneficial effect on performance in animals has been proven for a decade. However, knowledge of th...Background: As a organic acid, benzoic acid has become one of the most important alternatives for antibiotics,and its beneficial effect on performance in animals has been proven for a decade. However, knowledge of the effects of benzoic acid on jejunal digestive physiology, especially the antioxidant capacity and mucosal glucagon-like peptide2(GLP-2) concentrations is lacking.Methods: A total of 20 barrows [Duroc ×(Yorkshire × Landrace)] with an average body weight(BW) of 18.75 ± 0.2 kg were used in a 14-d trial to determine the potential mechanisms of benzoic acid supplementation on the performance,nutrient digestibility and jejunal digestive physiology in young pigs. All pigs were randomly allotted to 1 of 2 diets supplemented with 0 or 5000 mg/kg benzoic acid.Results: Relative to the control, benzoic acid supplementation increased the average daily feed intake(ADFI), and average daily gain(ADG) in young pigs(P 〈 0.05), improved the apparent total tract digestibility of dry matter(DM),crude protein(CP), ether extract(EE), gross energy(GE) and crude ash(P 〈 0.05), and enhanced the activities of trypsin,lipase and amylase in the jejunum(P 〈 0.05). Similarly, relative to the control, supplementing benzoic acid in the diet resulted in a trend to reduce the p H values of the digesta(P = 0.06), decreased crypt depth and increased the villus height to crypt depth ratio(P 〈 0.05) in the jejunum of pigs. Finally, benzoic acid supplementation increased the mR NA expression and concentration of glucagon-like peptide 2 and the activities of glutathione peroxidase and superoxide dismutase in the jejunal mucosa of young pigs(P 〈 0.05).Conclusions: In conclusion, supplementation with 5000 mg/kg benzoic acid improved the performance of young pigs through promoting nutrient digestion, improving jejunal antioxidant capacity, and maintaining the jejunal morphology in young pigs.展开更多
A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and t...A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.展开更多
Formic acid(FA) dehydrogenation has attracted a lot of attentions since it is a convenient method for H_2 production. In this work, we designed a self-supporting fuel cell system, in which H_2 from FA is supplied in...Formic acid(FA) dehydrogenation has attracted a lot of attentions since it is a convenient method for H_2 production. In this work, we designed a self-supporting fuel cell system, in which H_2 from FA is supplied into the fuel cell, and the exhaust heat from the fuel cell supported the FA dehydrogenation. In order to realize the system, we synthesized a highly active and selective homogeneous catalyst Ir Cp*Cl_2 bpym for FA dehydrogenation. The turnover frequency(TOF) of the catalyst for FA dehydrogenation is as high as7150 h^(-1)at 50°C, and is up to 144,000 h^(-1)at 90°C. The catalyst also shows excellent catalytic stability for FA dehydrogenation after several cycles of test. The conversion ratio of FA can achieve 93.2%, and no carbon monoxide is detected in the evolved gas. Therefore, the evolved gas could be applied in the proton exchange membrane fuel cell(PEMFC) directly. This is a potential technology for hydrogen storage and generation. The power density of the PEMFC driven by the evolved gas could approximate to that using pure hydrogen.展开更多
文摘In the studying of the stereospecific hydroxylation of different Δ5-steroids with performic acid, followed by hydrolysis with CH3OH/KOH, we found 19-substituting groups considerably affected the reaction and we put forward the mechanism.
基金financially supported by the National Key Basic Research Program of China (2012CB124702, 2013CB127302)National Natural Science Foundation of China (31272452)the National Key Technology R&D Program of China (2011BAD26B01)
文摘Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins(cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP(12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts(89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results: Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level(P > 0.10) except that average daily feed intake was increased by CSM diets(P = 0.03). Gilts offered reduced protein diets had lower muscle p H45min(P 〈 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency(P 〈 0.01). CSM diets increased N intake(P = 0.04),but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine(P 〈 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased(P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle(P 〈 0.05).Conclusion: These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids(FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.
基金financially supported by a China Pig Modern Industrial Technology System Grant (CARS-36)
文摘Background: As a organic acid, benzoic acid has become one of the most important alternatives for antibiotics,and its beneficial effect on performance in animals has been proven for a decade. However, knowledge of the effects of benzoic acid on jejunal digestive physiology, especially the antioxidant capacity and mucosal glucagon-like peptide2(GLP-2) concentrations is lacking.Methods: A total of 20 barrows [Duroc ×(Yorkshire × Landrace)] with an average body weight(BW) of 18.75 ± 0.2 kg were used in a 14-d trial to determine the potential mechanisms of benzoic acid supplementation on the performance,nutrient digestibility and jejunal digestive physiology in young pigs. All pigs were randomly allotted to 1 of 2 diets supplemented with 0 or 5000 mg/kg benzoic acid.Results: Relative to the control, benzoic acid supplementation increased the average daily feed intake(ADFI), and average daily gain(ADG) in young pigs(P 〈 0.05), improved the apparent total tract digestibility of dry matter(DM),crude protein(CP), ether extract(EE), gross energy(GE) and crude ash(P 〈 0.05), and enhanced the activities of trypsin,lipase and amylase in the jejunum(P 〈 0.05). Similarly, relative to the control, supplementing benzoic acid in the diet resulted in a trend to reduce the p H values of the digesta(P = 0.06), decreased crypt depth and increased the villus height to crypt depth ratio(P 〈 0.05) in the jejunum of pigs. Finally, benzoic acid supplementation increased the mR NA expression and concentration of glucagon-like peptide 2 and the activities of glutathione peroxidase and superoxide dismutase in the jejunal mucosa of young pigs(P 〈 0.05).Conclusions: In conclusion, supplementation with 5000 mg/kg benzoic acid improved the performance of young pigs through promoting nutrient digestion, improving jejunal antioxidant capacity, and maintaining the jejunal morphology in young pigs.
文摘A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.
基金financial support granted by Ministry of Science and Technology of China(Nos.2016YFE0105700,2016YFA0200700)the National Natural Science Foundation of China(Nos.21373264,21573275)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20150362)Suzhou Institute of Nano-tech and Nano-bionics(No.Y3AAA11004)Thousand Youth Talents Plan(No.Y3BQA11001)
文摘Formic acid(FA) dehydrogenation has attracted a lot of attentions since it is a convenient method for H_2 production. In this work, we designed a self-supporting fuel cell system, in which H_2 from FA is supplied into the fuel cell, and the exhaust heat from the fuel cell supported the FA dehydrogenation. In order to realize the system, we synthesized a highly active and selective homogeneous catalyst Ir Cp*Cl_2 bpym for FA dehydrogenation. The turnover frequency(TOF) of the catalyst for FA dehydrogenation is as high as7150 h^(-1)at 50°C, and is up to 144,000 h^(-1)at 90°C. The catalyst also shows excellent catalytic stability for FA dehydrogenation after several cycles of test. The conversion ratio of FA can achieve 93.2%, and no carbon monoxide is detected in the evolved gas. Therefore, the evolved gas could be applied in the proton exchange membrane fuel cell(PEMFC) directly. This is a potential technology for hydrogen storage and generation. The power density of the PEMFC driven by the evolved gas could approximate to that using pure hydrogen.