The unique photocatalytic mechanism of S-scheme heterojunction can be used to study new and efficient photocatalysts.By carefully selecting semiconductors for S-scheme heterojunction photo-catalysts,it is possible to ...The unique photocatalytic mechanism of S-scheme heterojunction can be used to study new and efficient photocatalysts.By carefully selecting semiconductors for S-scheme heterojunction photo-catalysts,it is possible to reduce the rate of photogenerated carrier recombination and increase the conversion efficiency of light into energy.Chalcogenides are a group of compounds that include sulfides and selenides(e.g.,CdS,ZnS,Bi_(2)S_(3),MoS_(2),ZnSe,CdSe,and CuSe).Chalcogenides have at-tracted considerable attention as heterojunction photocatalysts owing to their narrow bandgap,wide light absorption range,and excellent photoreduction properties.This paper presents a thor-ough analysis of S-scheme heterojunction photocatalysts based on chalcogenides.Following an introduction to the fundamental characteristics and benefits of S-scheme heterojunction photocata-lysts,various chalcogenide-based S-scheme heterojunction photocatalyst synthesis techniques are summarized.These photocatalysts are used in numerous significant photocatalytic reactions,in-cluding the reduction of carbon dioxide,synthesis of hydrogen peroxide,conversion of organic matter,generation of hydrogen from water,nitrogen fixation,degradation of organic pollutants,and sterilization.In addition,cutting-edge characterization techniques,including in situ characterization techniques,are discussed to validate the steady and transient states of photocatalysts with an S-scheme heterojunction.Finally,the design and challenges of chalcogenide-based S-scheme het-erojunction photocatalysts are explored and recommended in light of state-of-the-art research.展开更多
To improve β-Bi2O3 photocatalysis,we couple β-Bi2O3 with BiO I to form β-Bi2O3/BiO I heterojunctions through an in-situ treatment with hydriodic acid. The prepared heterojunctions are characterized with X-ray diffr...To improve β-Bi2O3 photocatalysis,we couple β-Bi2O3 with BiO I to form β-Bi2O3/BiO I heterojunctions through an in-situ treatment with hydriodic acid. The prepared heterojunctions are characterized with X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,ultra violet-diffuse reflectance spectroscopy,and X-ray photoelectron spectroscopy. Upon visible-light irradiation(λ 420 nm),the β-Bi2O3/BiO I heterojunctions,especially with the molar ratio of HI to β-Bi2O3 at 0.4,exhibit much higher photocatalytic activity than pure β-Bi2O3 and BiO I for the degradation of methyl orange. The efficient separation of photogenerated electron-hole pairs across the interface of the heterojunction between β-Bi2O3 and BiO I would be responsible for the enhanced photocatalytic performances.展开更多
Objective: Application of magnetic nanoparticles as gene carrier in gene therapy has developed quickly. This study was designed to investigate the preparation of superparamagnetic dextran-coated iron oxide nanoparticl...Objective: Application of magnetic nanoparticles as gene carrier in gene therapy has developed quickly. This study was designed to investigate the preparation of superparamagnetic dextran-coated iron oxide nanoparticles (SDION) and the feasibility of SDION used as a novel gene carrier for plasmid DNA in vitro. Methods: SDION were prepared by chemical coprecipitation and separated by gel filtration on Sephacryl S-300HR, characterized by TEM, laser scattering system and Vibrating Sample Magnetometer Signal Processor. The green fluorescent protein (pGFP-C2) plasmid DNA was used as target gene. SDION-pGFP-C2 conjugate compounds were produced by means of oxidoreduction reaction. The connection ratio of SDION and pGFP-C2 DNA was analyzed and evaluated by agarose electrophoresis and the concentration of pGFP-C2 in supernatant was measured. Using liposome as control, the transfection efficiency of SDION and liposome was respectively evaluated under fluorescence microscope in vitro. Results: The diameter of SDION ranges from 3 nm to 8 nm, the effective diameter was 59.2 nm and the saturation magnetization was 0.23 emu/g. After SDION were reasonably oxidized, SDION could connect with pGFP-C2 to a high degree. The transfection efficiency of SDION as gene carrier was higher than that of liposome. Conclusion: The successes in connecting SDION with pGFP-C2 plasmid by means of oxidoreduction reaction and in transferring pGFP-C2 gene into human bladder cancer BIU-87 cells in vitro provided the experimental evidence for the feasibility of SDION used as a novel gene carrier.展开更多
A strain capable of phenol degradation, hetemtrophic nitrification and aerobic denitrification was isolated from activated sludge of coking-plant wastewater ponds under aerobic condition. Based on its morphology, phys...A strain capable of phenol degradation, hetemtrophic nitrification and aerobic denitrification was isolated from activated sludge of coking-plant wastewater ponds under aerobic condition. Based on its morphology, physiology, biochemical analysis and phylogenetic characteristics, the isolate was identified as Diaphorobacter sp. PD-7. Biodegradation tests of phenol showed that the maximum phenol degradation occurred at the late phase of exponential growth stages, with 1400 mg·L^-1 phenol completely degraded within 85 h. Diaphorobacter sp. PD-7 accumulated a vast quantity of phenol hydroxylase in this physiological phase, ensuring that the cells quickly utilize phenol as a sole carbon and energy source. The kinetic behavior ofDiaphorobacter sp. PD-7 in batch cultures was investigated over a wide range of initial phenol concentrations (0-1400mg·L^-1) by using the Haldane model, which adequately describes the dynamic behavior of phenol biodegradation by strain Diaphombacter sp. PD-7. At initial phenol concentration of 1400mg· L^-l, batch experiments (0.25 L flask) of nitrogen removal under aerobic condition gave almost entirely removal of 120.69mg· L^- 1 ammonium nitrogen within 75 h, while nitrate nitrogen removal reached 91% within 65 h. Moreover, hydroxylamine oxidase, periplasmic nitrate reductase and nitrite reductase were successfully expressed in the isolate.展开更多
The structures and isomerization of magnesium fluorosilylenoid H2SiFMgF were investigated by ab initio molecular orbital theory. Four equilibrium structures and three isomeric transition states were located and fully ...The structures and isomerization of magnesium fluorosilylenoid H2SiFMgF were investigated by ab initio molecular orbital theory. Four equilibrium structures and three isomeric transition states were located and fully optimized at the B3LYP/6-31G(d,p) and G3MP2B3 levels, respectively. Based on the B3LYP/6- 31G(d,p) optimized geometries, harmonic frequencies of various structures were obtained and 29Si chemical shifts were calculated. The solvent effects were investigated by means of the polarizable continuum model using THF as a solvent at B3LYP/6-31G(d,p) level. Isomerization paths for isomers were confirmed by intrinsic reaction coordinate calculations. The calculated results show that tetrahedral structure has the lowest energy and is the most stable; tetrahedral, three-membered ring, and p-complex structures are suggested to be the experimentally detectable ones; and a-complex structure has the highest energy and will not exist.展开更多
Purpose: The purpose of this study was to investigate the effects of obesity and high-intensity acute exercise on oxidant-antioxidant status,neurotrophic factor expression, and blood-brain barrier(BBB) disruption.Meth...Purpose: The purpose of this study was to investigate the effects of obesity and high-intensity acute exercise on oxidant-antioxidant status,neurotrophic factor expression, and blood-brain barrier(BBB) disruption.Methods: Twenty-four healthy, untrained men(12 non-obese(mean 14.9% body fat) and 12 obese subjects(mean 29.8% body fat)) performed20 min of continuous submaximal aerobic exercise at 85% maximal oxygen consumption. Blood sampling was performed to examine the oxidant-antioxidant status(reactive oxygen species(ROS) and superoxide dismutase(SOD)), neurotrophic factors(brain-derived neurotrophic factor(BDNF) and nerve growth factor(NGF)), and BBB disruption(S100β and neuron-specific enolase) before and after acute exercise.Results: The obese group showed significantly higher pre-exercise serum ROS levels and significantly lower pre-exercise serum SOD levels than the non-obese group(p < 0.05). Serum ROS, SOD, BDNF, NGF, and S100β levels were significantly increased post-exercise compared with pre-exercise levels in both the non-obese and the obese groups(p < 0.05). The obese group showed significantly higher serum ROS, BDNF, NGF,and S100β levels post-exercise compared to the non-obese group(p < 0.05).Conclusion: Our study suggests that episodic vigorous exercise can increase oxidative stress and blood neurotrophic factor levels and induce disruption of the BBB. Moreover, high levels of neurotrophic factor in the blood after exercise in the obese group may be due to BBB disruption,and it is assumed that oxidative stress was the main cause of this BBB disruption.展开更多
Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory (B3LYP) and two post- Hartree-Fock approaches (MP2, CCSD...Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory (B3LYP) and two post- Hartree-Fock approaches (MP2, CCSD(T)), several stable isomers for new three pnictogen dianionic Sb4^2-, Bi4^2-, and (SbBi)2^2- species were determined. For two homoatomic Sb4^2- and Bi4^2- species, there are three stable isomers: square (D4h), roof-shaped (C2v-1), and C2v-2 structure with the square isomer being the ground state. For the heteroatomic dian- ionic (SbBi)2^2- species, there are also three stable isomers: rhombus (D2h), roof-shaped (C1), and C2v structures with the rhombic isomer being the ground state. The calculated NICS values show that nucleus-independent chemical shifts (NICS) values of roof-shaped isomers for Sb4^2-, Bi4^2-, and (SbBi)2^2- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters. The aromaticity for the two stable roof-shaped and square isomers are preliminarily explained and discussed with MO analysis.展开更多
Laccases are blue copper oxidases (E.C. 1.10.3.2 benzenediol:oxygen oxidoreductase) that catalyze the one-electron oxidation of phenolics, aromatic amines and other electron-rich substrates with the concomitant red...Laccases are blue copper oxidases (E.C. 1.10.3.2 benzenediol:oxygen oxidoreductase) that catalyze the one-electron oxidation of phenolics, aromatic amines and other electron-rich substrates with the concomitant reduction of 02 to H20. They are currently seen as highly interesting industrial enzymes because of their broad substrate specificity. The Phanerochaete flavido-alba laccase is expressed and secreted as a soluble active enzyme by Aspergillus niger (rLac-LPFA). rLac-LPFA is easily purified to homogeneity. Metal ions like HgCI2, KC12, FeSO4 and MgSO4 at a concentration of 2 mM have inhibiting effect on recombinant and native laccase, whereas, CuSO4 and MnSO4 moderately increase both enzyme activities. Two potential inhibitors (sodium azide and EDTA) inhibited enzyme activity, whereas, urea and SDS have no effect on enzyme activity. The Km and V,,ax values for recombinant laccase are 0.65 mM and 300 U/mg respectively for 2,6-DMP as substrate.展开更多
In ultrasonic extraction technology, optimization of technical parameters often considers extraction medium only, without including ultrasonic parameters. This paper focuses on controlling the ultrasonic extraction pr...In ultrasonic extraction technology, optimization of technical parameters often considers extraction medium only, without including ultrasonic parameters. This paper focuses on controlling the ultrasonic extraction process of puerarin, investigating the influence of ultrasonic parameters on extraction rate, and empirically analyzing the main components of Pueraria, i.e., isoflavone compounds. A method is presented combining orthogonal experi- mental design with a support vector machine and a predictive model is established for optimization of technical parameters. From the analysis with the predictive model, appropriate process parameters are achieved for higher extraction rate. With these parameters in the ultrasonic extraction of puerarin, the experimental result is satisfactory. This method is of significance to the study of extracfing root-stock plant medicines.展开更多
For the investigation of anti-infection immune response of Pseudosciaena crocea, 160 healthy fish samples were categorized into infected and control groups. Each individual fish in the infected group was injected intr...For the investigation of anti-infection immune response of Pseudosciaena crocea, 160 healthy fish samples were categorized into infected and control groups. Each individual fish in the infected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension of Vibrio alginolyticus in density of 2×107 CFU/ml, while each individual in the control group was injected i.p. with 0.2 ml sterile saline solution (0.85%). It was observed that the artificial injection of V. alginolyticus significantly increased the number of erythrocytes, leucocytes, lymphocytes in peripheral blood as well as peripheral serum antibacterial activity and antibody titer of large yellow croaker, and significantly reduced the number of peripheral blood granulocytes as compared with those in the control group. No significant difference in acid phosphytase and superoxide dismutase activity of serum was detected between the two groups. It is suggested that non-specific immune factors including leucocytes and anti-bacteria substance in peripheral blood played important role at the initial stage of infection, and specific immune factors such as antibody then played important role in response to anti-infection at the latter stage.展开更多
The present study was conducted to evaluate the feasibility of replacing fish meal(FM) with bioactive peptides(BPs) in diet of white shrimp(Litopenaeus vannamei). The changes in growth performance, body composition, n...The present study was conducted to evaluate the feasibility of replacing fish meal(FM) with bioactive peptides(BPs) in diet of white shrimp(Litopenaeus vannamei). The changes in growth performance, body composition, non-specific immunity, and water quality were examined after the shrimp were fed four diets, in which 0%(control), 33.3%, 66.7% and 100% of FM was replaced by BPs, respectively. The groups were designated as Con, 1/3BPs, 2/3BPs, and 3/3BPs. A total of 720 shrimp with an initial body weight of 1.46 ± 0.78 g were fed the experimental diets for 56 days. The results revealed that: 1) the weight gain rate(WGR) in 1/3BPs, 2/3BPs, and 3/3BPs was significantly higher than that in Con(P < 0.05), while no significant difference was found on survival rate and feed conversion ratio(FCR); 2) the whole-body crude protein(CP) and crude lipids(CL) were significantly different among groups, while there was no significant difference between crude ash and phosphorus contents; 3) the levels of acid phosphatase(ACP), lysozyme(LZM), superoxide dismutase(SOD), phenol oxidase(PO) and bactericidal activity increased significantly with the inclusion of BPs; 4) in terms of water quality, no significant difference was found in p H and dissolved oxygen among diets during the whole experimental period. Moreover, even though nitrite and ammonium levels tended to increase with time, there was no significant difference among groups. The results indicated that BPs is an applicable alternative of protein source, which can substitute FM in the diets of L. vannamei; it is able to effectively promote growth performance and improve immunity. Moreover, BPs in the diets had no negative impact on water quality.展开更多
文摘The unique photocatalytic mechanism of S-scheme heterojunction can be used to study new and efficient photocatalysts.By carefully selecting semiconductors for S-scheme heterojunction photo-catalysts,it is possible to reduce the rate of photogenerated carrier recombination and increase the conversion efficiency of light into energy.Chalcogenides are a group of compounds that include sulfides and selenides(e.g.,CdS,ZnS,Bi_(2)S_(3),MoS_(2),ZnSe,CdSe,and CuSe).Chalcogenides have at-tracted considerable attention as heterojunction photocatalysts owing to their narrow bandgap,wide light absorption range,and excellent photoreduction properties.This paper presents a thor-ough analysis of S-scheme heterojunction photocatalysts based on chalcogenides.Following an introduction to the fundamental characteristics and benefits of S-scheme heterojunction photocata-lysts,various chalcogenide-based S-scheme heterojunction photocatalyst synthesis techniques are summarized.These photocatalysts are used in numerous significant photocatalytic reactions,in-cluding the reduction of carbon dioxide,synthesis of hydrogen peroxide,conversion of organic matter,generation of hydrogen from water,nitrogen fixation,degradation of organic pollutants,and sterilization.In addition,cutting-edge characterization techniques,including in situ characterization techniques,are discussed to validate the steady and transient states of photocatalysts with an S-scheme heterojunction.Finally,the design and challenges of chalcogenide-based S-scheme het-erojunction photocatalysts are explored and recommended in light of state-of-the-art research.
基金supported by the National Natural Science Foundation of China(21273281)the National Basic Research Program of China(973 Program2013CB632405)~~
文摘To improve β-Bi2O3 photocatalysis,we couple β-Bi2O3 with BiO I to form β-Bi2O3/BiO I heterojunctions through an in-situ treatment with hydriodic acid. The prepared heterojunctions are characterized with X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,ultra violet-diffuse reflectance spectroscopy,and X-ray photoelectron spectroscopy. Upon visible-light irradiation(λ 420 nm),the β-Bi2O3/BiO I heterojunctions,especially with the molar ratio of HI to β-Bi2O3 at 0.4,exhibit much higher photocatalytic activity than pure β-Bi2O3 and BiO I for the degradation of methyl orange. The efficient separation of photogenerated electron-hole pairs across the interface of the heterojunction between β-Bi2O3 and BiO I would be responsible for the enhanced photocatalytic performances.
基金This project was supported by a grant from the National Natural Science Foundation of China (No. 30271300).
文摘Objective: Application of magnetic nanoparticles as gene carrier in gene therapy has developed quickly. This study was designed to investigate the preparation of superparamagnetic dextran-coated iron oxide nanoparticles (SDION) and the feasibility of SDION used as a novel gene carrier for plasmid DNA in vitro. Methods: SDION were prepared by chemical coprecipitation and separated by gel filtration on Sephacryl S-300HR, characterized by TEM, laser scattering system and Vibrating Sample Magnetometer Signal Processor. The green fluorescent protein (pGFP-C2) plasmid DNA was used as target gene. SDION-pGFP-C2 conjugate compounds were produced by means of oxidoreduction reaction. The connection ratio of SDION and pGFP-C2 DNA was analyzed and evaluated by agarose electrophoresis and the concentration of pGFP-C2 in supernatant was measured. Using liposome as control, the transfection efficiency of SDION and liposome was respectively evaluated under fluorescence microscope in vitro. Results: The diameter of SDION ranges from 3 nm to 8 nm, the effective diameter was 59.2 nm and the saturation magnetization was 0.23 emu/g. After SDION were reasonably oxidized, SDION could connect with pGFP-C2 to a high degree. The transfection efficiency of SDION as gene carrier was higher than that of liposome. Conclusion: The successes in connecting SDION with pGFP-C2 plasmid by means of oxidoreduction reaction and in transferring pGFP-C2 gene into human bladder cancer BIU-87 cells in vitro provided the experimental evidence for the feasibility of SDION used as a novel gene carrier.
基金the National Natural Science Foundation of China(51378330 and51408396)the Natural Science Foundation of Shanxi Province(2013021023-3)
文摘A strain capable of phenol degradation, hetemtrophic nitrification and aerobic denitrification was isolated from activated sludge of coking-plant wastewater ponds under aerobic condition. Based on its morphology, physiology, biochemical analysis and phylogenetic characteristics, the isolate was identified as Diaphorobacter sp. PD-7. Biodegradation tests of phenol showed that the maximum phenol degradation occurred at the late phase of exponential growth stages, with 1400 mg·L^-1 phenol completely degraded within 85 h. Diaphorobacter sp. PD-7 accumulated a vast quantity of phenol hydroxylase in this physiological phase, ensuring that the cells quickly utilize phenol as a sole carbon and energy source. The kinetic behavior ofDiaphorobacter sp. PD-7 in batch cultures was investigated over a wide range of initial phenol concentrations (0-1400mg·L^-1) by using the Haldane model, which adequately describes the dynamic behavior of phenol biodegradation by strain Diaphombacter sp. PD-7. At initial phenol concentration of 1400mg· L^-l, batch experiments (0.25 L flask) of nitrogen removal under aerobic condition gave almost entirely removal of 120.69mg· L^- 1 ammonium nitrogen within 75 h, while nitrate nitrogen removal reached 91% within 65 h. Moreover, hydroxylamine oxidase, periplasmic nitrate reductase and nitrite reductase were successfully expressed in the isolate.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20574043) and the Natural Science Foundation of Shandong Province (No.Z2007B02).
文摘The structures and isomerization of magnesium fluorosilylenoid H2SiFMgF were investigated by ab initio molecular orbital theory. Four equilibrium structures and three isomeric transition states were located and fully optimized at the B3LYP/6-31G(d,p) and G3MP2B3 levels, respectively. Based on the B3LYP/6- 31G(d,p) optimized geometries, harmonic frequencies of various structures were obtained and 29Si chemical shifts were calculated. The solvent effects were investigated by means of the polarizable continuum model using THF as a solvent at B3LYP/6-31G(d,p) level. Isomerization paths for isomers were confirmed by intrinsic reaction coordinate calculations. The calculated results show that tetrahedral structure has the lowest energy and is the most stable; tetrahedral, three-membered ring, and p-complex structures are suggested to be the experimentally detectable ones; and a-complex structure has the highest energy and will not exist.
基金supported by the Dong-A University (Busan, Korea) research fund
文摘Purpose: The purpose of this study was to investigate the effects of obesity and high-intensity acute exercise on oxidant-antioxidant status,neurotrophic factor expression, and blood-brain barrier(BBB) disruption.Methods: Twenty-four healthy, untrained men(12 non-obese(mean 14.9% body fat) and 12 obese subjects(mean 29.8% body fat)) performed20 min of continuous submaximal aerobic exercise at 85% maximal oxygen consumption. Blood sampling was performed to examine the oxidant-antioxidant status(reactive oxygen species(ROS) and superoxide dismutase(SOD)), neurotrophic factors(brain-derived neurotrophic factor(BDNF) and nerve growth factor(NGF)), and BBB disruption(S100β and neuron-specific enolase) before and after acute exercise.Results: The obese group showed significantly higher pre-exercise serum ROS levels and significantly lower pre-exercise serum SOD levels than the non-obese group(p < 0.05). Serum ROS, SOD, BDNF, NGF, and S100β levels were significantly increased post-exercise compared with pre-exercise levels in both the non-obese and the obese groups(p < 0.05). The obese group showed significantly higher serum ROS, BDNF, NGF,and S100β levels post-exercise compared to the non-obese group(p < 0.05).Conclusion: Our study suggests that episodic vigorous exercise can increase oxidative stress and blood neurotrophic factor levels and induce disruption of the BBB. Moreover, high levels of neurotrophic factor in the blood after exercise in the obese group may be due to BBB disruption,and it is assumed that oxidative stress was the main cause of this BBB disruption.
文摘Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory (B3LYP) and two post- Hartree-Fock approaches (MP2, CCSD(T)), several stable isomers for new three pnictogen dianionic Sb4^2-, Bi4^2-, and (SbBi)2^2- species were determined. For two homoatomic Sb4^2- and Bi4^2- species, there are three stable isomers: square (D4h), roof-shaped (C2v-1), and C2v-2 structure with the square isomer being the ground state. For the heteroatomic dian- ionic (SbBi)2^2- species, there are also three stable isomers: rhombus (D2h), roof-shaped (C1), and C2v structures with the rhombic isomer being the ground state. The calculated NICS values show that nucleus-independent chemical shifts (NICS) values of roof-shaped isomers for Sb4^2-, Bi4^2-, and (SbBi)2^2- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters. The aromaticity for the two stable roof-shaped and square isomers are preliminarily explained and discussed with MO analysis.
文摘Laccases are blue copper oxidases (E.C. 1.10.3.2 benzenediol:oxygen oxidoreductase) that catalyze the one-electron oxidation of phenolics, aromatic amines and other electron-rich substrates with the concomitant reduction of 02 to H20. They are currently seen as highly interesting industrial enzymes because of their broad substrate specificity. The Phanerochaete flavido-alba laccase is expressed and secreted as a soluble active enzyme by Aspergillus niger (rLac-LPFA). rLac-LPFA is easily purified to homogeneity. Metal ions like HgCI2, KC12, FeSO4 and MgSO4 at a concentration of 2 mM have inhibiting effect on recombinant and native laccase, whereas, CuSO4 and MnSO4 moderately increase both enzyme activities. Two potential inhibitors (sodium azide and EDTA) inhibited enzyme activity, whereas, urea and SDS have no effect on enzyme activity. The Km and V,,ax values for recombinant laccase are 0.65 mM and 300 U/mg respectively for 2,6-DMP as substrate.
基金Supported by the National Natural Science Foundation of China(21146009,21376014)
文摘In ultrasonic extraction technology, optimization of technical parameters often considers extraction medium only, without including ultrasonic parameters. This paper focuses on controlling the ultrasonic extraction process of puerarin, investigating the influence of ultrasonic parameters on extraction rate, and empirically analyzing the main components of Pueraria, i.e., isoflavone compounds. A method is presented combining orthogonal experi- mental design with a support vector machine and a predictive model is established for optimization of technical parameters. From the analysis with the predictive model, appropriate process parameters are achieved for higher extraction rate. With these parameters in the ultrasonic extraction of puerarin, the experimental result is satisfactory. This method is of significance to the study of extracfing root-stock plant medicines.
基金Supported by the National High Technology Research and Development Program of China (863 program, No. 2007AA09Z115)Technology Program of Xiamen (No. 3502Z73019)
文摘For the investigation of anti-infection immune response of Pseudosciaena crocea, 160 healthy fish samples were categorized into infected and control groups. Each individual fish in the infected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension of Vibrio alginolyticus in density of 2×107 CFU/ml, while each individual in the control group was injected i.p. with 0.2 ml sterile saline solution (0.85%). It was observed that the artificial injection of V. alginolyticus significantly increased the number of erythrocytes, leucocytes, lymphocytes in peripheral blood as well as peripheral serum antibacterial activity and antibody titer of large yellow croaker, and significantly reduced the number of peripheral blood granulocytes as compared with those in the control group. No significant difference in acid phosphytase and superoxide dismutase activity of serum was detected between the two groups. It is suggested that non-specific immune factors including leucocytes and anti-bacteria substance in peripheral blood played important role at the initial stage of infection, and specific immune factors such as antibody then played important role in response to anti-infection at the latter stage.
基金supported by the Science-Technology Supporting Project of the National Twelfth Five-YearPlan of China (No. 2012BAD25B01)
文摘The present study was conducted to evaluate the feasibility of replacing fish meal(FM) with bioactive peptides(BPs) in diet of white shrimp(Litopenaeus vannamei). The changes in growth performance, body composition, non-specific immunity, and water quality were examined after the shrimp were fed four diets, in which 0%(control), 33.3%, 66.7% and 100% of FM was replaced by BPs, respectively. The groups were designated as Con, 1/3BPs, 2/3BPs, and 3/3BPs. A total of 720 shrimp with an initial body weight of 1.46 ± 0.78 g were fed the experimental diets for 56 days. The results revealed that: 1) the weight gain rate(WGR) in 1/3BPs, 2/3BPs, and 3/3BPs was significantly higher than that in Con(P < 0.05), while no significant difference was found on survival rate and feed conversion ratio(FCR); 2) the whole-body crude protein(CP) and crude lipids(CL) were significantly different among groups, while there was no significant difference between crude ash and phosphorus contents; 3) the levels of acid phosphatase(ACP), lysozyme(LZM), superoxide dismutase(SOD), phenol oxidase(PO) and bactericidal activity increased significantly with the inclusion of BPs; 4) in terms of water quality, no significant difference was found in p H and dissolved oxygen among diets during the whole experimental period. Moreover, even though nitrite and ammonium levels tended to increase with time, there was no significant difference among groups. The results indicated that BPs is an applicable alternative of protein source, which can substitute FM in the diets of L. vannamei; it is able to effectively promote growth performance and improve immunity. Moreover, BPs in the diets had no negative impact on water quality.