The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-i...The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-instar larvae of American white moth (Hyphantria cunea (Drury)) for determination of the activities of the protective enzyme system inside larvae’s body. The physiological and biochemical effects of the transgenic poplars on the larvae were studied. The results showed that the two kinds of transgenic poplars had similar effects on the protective enzyme system in the midgut of larvae. The activities of superoxide dismutase, catalase, and peroxidase in midgut of the larvae increased gradually, reached the highest value at a certain time, and then decreased suddenly. For the larvae that were fed with the leaves of Bt transgenic poplar, the peak value of superoxide dismutase and catalase presented at the time of 24-h feeding, while the peak of peroxidase took place at the time of 12-h feeding. The activities of these protective enzymes for the larvae that were fed with leaves of CpTI transgenic poplar peaked 12 h later than that of those fed with leaves of Bt transgenic poplar. The comparison of activities of the protective enzymes was also carried out between the larvae with different levels of intoxication. It was found that the activities of protective enzyme of the seriously intoxicant larvae were higher than that of the lightly intoxicant larvae. This difference was more obvious in the group treated with CpTI transgenic poplar.展开更多
A study was conducted to determine the responses of soil enzymes （invertase, polyphenol oxidase, catalase, and dehydrogenase） to long-term CO2 enrichment at the Research Station of Changbai Mountain Forest Ecosystem...A study was conducted to determine the responses of soil enzymes （invertase, polyphenol oxidase, catalase, and dehydrogenase） to long-term CO2 enrichment at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences （42°24＇N, 128°28＇E; 738 m in elevation） in the northeast China during 1999-2006. Three treatments of the CO2 enrichment, designed as 500 μmol·mol-1 CO2 open-top chamber （OTC）, ambient control chamber and unchambered field （approx. 370 μmol·mol^-1CO2）, were conducted with Pinus koraiensis and Pinus sylvestriformis tree species. Soil sampling was made and analyzed separately in spring, summer and autumn in 2006 after the soil enzymes were exposed to elevated CO2 concentration （500 μmol·mol^-1） for eight growing seasons. Results showed that, at elevated CO2 concentration （500 μmol·mol^-1）, the activities of invertase （except for the summer samples of P. koraiensis） presented a remarkable decline in all growing seasons, while the activities of dehydrogenase had an increase but only part of the results was remarkable; the activities of polyphenol oxidase in P. sylvestriformis rhizosphere showed a remarkable decrease; the catalase activities increased in spring, while in turn were decline in other seasons. This study also revealed that the soil enzyme activities are significantly correlated with the tree species under the CO2 enhancement.展开更多
A study was conducted to test wettability changes of the wheat straw treated with different methods for the preparation of wheat straw particle board. The wheat straws were separately sprayed with two chemicals （0.6%...A study was conducted to test wettability changes of the wheat straw treated with different methods for the preparation of wheat straw particle board. The wheat straws were separately sprayed with two chemicals （0.6% NaOH, 0.3% H2O2） and three enzymes （lipase, xylanase, cellulase）. The contact angle between water and the surface of wheat straw was measured and the spreading-penetration parameters （K-values） were also calculated with wetting model. The surfaces of treated wheat straw and control sample were scanned by means of Micro-FTIR, and their peaks arrangements were analyzed. The surface morphologies of treated wheat straw and control sample were also observed by SEM. Chemical etching was found on the exterior surfaces of the straws treated separately with 0.6% NaOH and 0.3% H2O2; furthermore, the spreading-penetration parameters （K-values） of the distilled water on the exterior surfaces of the treated wheat straw along the grain were higher than that of control. The wettability of exterior surfaces of the wheat straws treated separately with lipase, xylanase and cellulose were improved after treating for seven days, and among the three enzymes treatments, the lipase treatment showed best result. The lipase treatment and NaOH treatment were determined as better methods for improving the wettability of wheat straw surfaces. However, in the economic aspect, NaOH treatment was more practical and easier in the pretreatment for the manufacture of straw particle board.展开更多
This study investigates the effects of cold-acclimation in conferring chilling tolerance in seedlings of the mulberry(Morus alba) variety ‘Qiuyu’. Changes in photosynthesis and antioxidant enzymes in chilling acclim...This study investigates the effects of cold-acclimation in conferring chilling tolerance in seedlings of the mulberry(Morus alba) variety ‘Qiuyu’. Changes in photosynthesis and antioxidant enzymes in chilling acclimatized(CA), and non-acclimatized(NA) seedlings were recorded during chilling stress(3 °C) and a recovery period(25 °C) each for 3 days. The results showed that CA plants had higher net photosynthetic rates(P_n), stomatal conductance(G_s), and maximum photochemical efficiency of photosystem Ⅱ(F_v/F_m) in response to chilling stress compared to NA. The seedlings maintained the same trends during the recovery stage. The responses of Q_A reduction degree (1-q_P) and prime electronic transfer rates(F_o) were lower in acclimatized than in non-acclimatized seedlings. Low-temperature acclimation and chilling stress also caused an increase in leaf proline and soluble sugar contents. Leaf malondialdehyde levels were significantly lower while ascorbate peroxidase(APX) activity was significantly higher in acclimatized seedlings, suggesting that elevated osmolytes and APX confer resistance to chilling temperatures. In this study on the response of mulberry seedlings to chilling stress, we also looked at the recovery process. The response to chilling determines whether mulberry leaves can survive under cold temperatures, while the recovery process determines whether photosynthesis can recover as soon as possible to avoid any secondary damage.展开更多
Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Mothoda Totally 100 young male army members newly recruited from Sichuan province （4...Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Mothoda Totally 100 young male army members newly recruited from Sichuan province （400 meters above sea level） were enrolled. They were randomly divided into two groups： 50 in aminophylline group （A group） and 50 in control group （ C group）. A group and C group orally took aminophylline and placebo respectively for 10 days, 7 days before entering Lhasa （3 658 meters above sea level） by air and 3 days after it. Several parameters were measured at three time points： before drug taken, 7 days after drug taken, and 3 days after ascending high altitude. These parameters included serum levels of nitric oxide （NO）, superoxide dismutase （SOD）, catalase （CAT）, hydrogen dioxide （H2O2）, lactic acid （LA）, as well as arterial oxygen saturation （SO2）, arterial oxygen partial pressure （PaO2）, and arterial carbon dioxide partial pressure （PaCO2）. Statistical analysis was conducted to compare the difference between two groups with Stata 7.0 software system. Results There were no statistical differences between groups in hypoxia and oxidation indicators before and after drug taken in plain area. Three days after ascending high altitude, the serum levels of SOD, CAT, H202, LA, PaCO2 increased in both groups, yet to a much larger degree in C group than A group （P 〈0. 01 ） ; and NO, SO2 , PaO2 decreased more markedly in C group （ P 〈 0. 05 for NO, P 〈 0. 0001 for SO2 and PaO2 ）. Conclusion Aminophylline has significant anti-hypoxia and anti-oxidation effects at high altitude.展开更多
The present study aimed to evaluate the effects of chrysoeriol from Cardiospermum halicacabum in streptozotocin induced Wistar rats.Thirty rats were categorized as control,diabetic control supplemented with 0,20 mg/kg...The present study aimed to evaluate the effects of chrysoeriol from Cardiospermum halicacabum in streptozotocin induced Wistar rats.Thirty rats were categorized as control,diabetic control supplemented with 0,20 mg/kg chrysoeriol and 600μg/kg BW of glibenclamide for 45-day trial period.Our results indicated that the inclusion of chrysoeriol(20 mg/kg)showed a significant reduction in plasma glucose,hemoglobin and glycosylated hemoglobin level with a rising of plasma insulin sensitivity.Further,downregulated enzymes including glucose 6-phosphatase,fructose 1,6-bisphosphatase,and glycogen phosphorylase as well upregulated enzymes such as hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,and hepatic glycogen content.There was a diminish action found in liver glycogen synthase of tested rat with a rise in gamma-glutamyl transpeptidase,towards normal levels upon treatment with chrysoeriol.The histopathological study confirmed that renewal of the beta cells of pancreatic of chrysoeriol and glibenclamide treated rats.In addition,the molecular docking of chrysoeriol against glycolytic enzymes including hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,using Argus software shows chrysoeriol had greatest ligand binding energy as equivalent to glibenclamide,as a standard drug.Thus,chrysoeriol found to be non-toxic with potential regulation on glycemic control and upregulation of the carbohydrate metabolic enzymes.展开更多
A pulsed electric field(PEF) was applied to unpasteurized sake at constant temperatures, at which α-amylase was not inactivated. We adjusted the input energy to be identical for the temperatures by changing the numbe...A pulsed electric field(PEF) was applied to unpasteurized sake at constant temperatures, at which α-amylase was not inactivated. We adjusted the input energy to be identical for the temperatures by changing the number of PEF application, because the current significantly increased with the temperature, even the amplitude of the applied voltage was identical. As a result, the α-amylase was seemed to be inactivated by PEF application, not due to thermal effect.The glucoamylase was significantly inactivated by PEF. Moreover, the acid carboxypeptidase was inactivated by PEF at 4 °C but significantly activated at 25 °C. These results show that the sensitivity of enzyme to PEF application differs depending on the types of enzyme and treatment temperature. On the other hand, the colony number of bacteria was remarkably decreased, but the amount of the volatile flavor compounds was not decreased by PEF application.展开更多
To exam ine the effect of digestive attributes such as digestive enzymes and pH on changes in phenolic compound content and antioxidant activity during digestion,the bioavailability of green tea infusion was investiga...To exam ine the effect of digestive attributes such as digestive enzymes and pH on changes in phenolic compound content and antioxidant activity during digestion,the bioavailability of green tea infusion was investigated using a simulated in vitro gastrointestinal digestion model.The total polyphenol content(TPC)decreased to 65%–70%throughout the mimicked normal digestion(MD)compared to the initial value.The total flavonoid content(TFC)decreased to approximately 25%after starting the gastric stage(pH 1.2);however,it regained to approximately 60%in the intestinal stage(pH 6.8).The mimicked digestive condition without digestive enzymes(WOE),which followed only the pH conditions of MD,showed significantly lower TPC and TFC values than MD.The percentage of antioxidant activity based on the initial values indexed by DPPH,ABTS,and FRAP gradually declined from approximately 60%at the gastric stage to approximately 40%at the final digestion stage.Meanwhile,the percentage of residual MIC was around 50%at the gastric stage.However,it gradually increased at the intestinal stage.The significantly lower antioxidant activity showed for WOE than MD throughout the simulated digestion.This study demonstrated that digestive enzymes and pH play a crucial role in the bioavailability of green tea infusion.展开更多
Whole grain cereals are important dietary sources for management of metabolic diseases due to the bioactive components they contain.Hence,this study investigated enzymes(pancreatic lipase,-amylase,-glucosidase,xanthin...Whole grain cereals are important dietary sources for management of metabolic diseases due to the bioactive components they contain.Hence,this study investigated enzymes(pancreatic lipase,-amylase,-glucosidase,xanthine oxidase and angiotensin 1-converting enzyme)inhibitory property,antioxidant activity and phenolics profile of raw and roasted red sorghum(Sorghum bicolor)grains in vitro.Extracts of flours of raw and roasted(150◦C and 180◦C,for 20 min)grains were assayed for enzymes inhibitory and antioxidant activities using spectrophotometric methods;while their phenolic constituents were characterized using HPLC-DAD.The raw grains exhibited strong enzymes inhibitory and antioxidant activities,and contained phenolic acids(gallic,chlorogenic,caffeic,ellagic and p-coumaric acids)and flavonoids(quercetin,luteolin and apigenin).However,whereas the enzymes inhibitory activity and levels of the phenolic compounds in the grains decreased significantly(p<0.05)with increasing roasting temperature,the antioxidant activity increased.Hence,roasting at high temperature may not be recommended for the optimum retention of the enzymes inhibitory property and phenolic compounds of red sorghum grains.展开更多
To study the effect of jasmonates(JAs)on the resistance of economic forest plants to insects,R osa rugosa‘Plena'leaves were treated with 1 mmol/L jasmonic acid(JA),methyl jasmonate(MeJA)and Z-jasmone,then the con...To study the effect of jasmonates(JAs)on the resistance of economic forest plants to insects,R osa rugosa‘Plena'leaves were treated with 1 mmol/L jasmonic acid(JA),methyl jasmonate(MeJA)and Z-jasmone,then the content of tannin and total phenol in leaves and the feeding area of Monolepta hieroglyphica adults on leaves were measured.Changes in the activities of detoxification enzymes in adult M.hieroglyphica that had fed on leaves treated with JAs were also studied.Tannin and total phenol levels in leaves increased significantly after treatment with JAs,and tannin level was 1.36–1.55-fold higher than in the control after treatment with 1 mmol/L MeJA.The total content of phenol in leaves treated with 1.0 mmol/L Z-jasmone increased by 1.33–2.20-fold compared with those of the control.The activities of detoxification enzymes in adults were inhibited to differing degrees:activity of alkaline phosphatase(AKP)first increased,then decreased;the activities of acid phosphatase(ACP),glutathione S-transferases(GSTs)and carboxylesterase(CarE)following treatment with 1 mmol/L MeJA were significantly reduced and were 22%–31%,11%–26%,and 11%–31%lower than those of the control,respectively.Moreover,the feeding area of adult M.hieroglyphica on the leaves treated with JAs was significantly reduced(P<0.05).The feeding area of economic forest R.rugosa‘Plena'leaves treated with 1 mmol/L MeJA decreased by 17%–43%compared with that of the control.Moreover,the decrease in the adult M.hieroglyphica feeding area was highly positively correlated with the content of tannin and positively correlated with the contents of total phenol of economic forest R.rugosa‘Plena'leaves.The reduced feeding area of adult M.hieroglyphica was highly negatively correlated with the activities of AKP and ACP and negatively correlated with those of the GSTs.In conclusion,the use of 1 mmol/L MeJA can noticeably decrease the deleterious effects of adult M.hieroglyphica.展开更多
The inhibitory effect of methanol extracts of Brachystegia eurycoma and Detarium microcarpum seeds flours on some key enzymes[α-amylase,α-glucosidase and aldose reductase(AR)]linked to the pathology and complication...The inhibitory effect of methanol extracts of Brachystegia eurycoma and Detarium microcarpum seeds flours on some key enzymes[α-amylase,α-glucosidase and aldose reductase(AR)]linked to the pathology and complications of type 2 diabetes(T2D);and their antioxidant properties were evaluated.The antioxidant properties evaluated were DPPH•and ABTS•^+scavenging abilities,reducing power,and antioxidant phytochemicals(total phenolics,tannins,total flavonoids and total saponins).Extracts of both flours inhibitedα-amylase,α-glucosidase and AR in a dose-dependent manner.The half-maximal inhibitory concentrations(IC50)of B.eurycoma onα-amylase,α-glucosidase,AR and lipid peroxidation were lower than those of D.microcarpum,indicating that it had stronger inhibitory potency than D.microcarpum.B.eurycoma also had significantly(P<0.05)higher DPPH•and ABTS•^+scavenging abilities,and reducing power than D.microcarpum.The antioxidant phytochemicals(total phenolics,tannins,total flavonoids and total saponins)were also significantly(P<0.05)higher in B.eurycoma than D.microcarpum.The inhibitory effect of B.eurycoma and D.microcarpum extracts onα-amylase,α-glucosidase and AR activities may be attributed to the combined action of their polyphenols and total saponins,and this may be a possible mechanism of action providing support for their use in managing hyperglycemia and the complications of T2D.展开更多
Objective The increasing recognition of the role for oxidative stress in hepatic disorders has led to extensive investigation on the protection by exogenous antioxidants against hepatic injury.In this study,we choose ...Objective The increasing recognition of the role for oxidative stress in hepatic disorders has led to extensive investigation on the protection by exogenous antioxidants against hepatic injury.In this study,we choose two typical polyphenol,quercetin and rutin,to investigate the mechanism of induction of cellular antioxidants and phase 2 enzymes in human HepG2 cells.Methods The HepG2 cells were treated with various concentrations of quercetin and rutin for 6 h and 24 h.The activities of NAD(P)H:quinone oxidoreductase(NQO1)in HepG2 cells were measured by 2,6-dichloroindophenol reduction method.The content of superoxide dismutase(SOD)was determined with the method of chemical colorimetry.The protein expressions of NQO1 and NF-E2-related factor 2(Nrf2)in HepG2 cells were detected by Western blotting.Results Incubation of HepG2 cells with quercetin and rutin resulted in a marked concentration-and time-dependent induction of a number of cellular antioxidants and phase 2 enzymes,including NQO1,SOD.Quercetin and rutin treatment of HepG2 cells also caused increase in protein expressions of NQO1 and Nrf2.Conclusions This study demonstrates that a series of phase 2 enzymes in HepG2 cells can be induced by quercetin and rutin in a concentration-and time-dependent fashion by upregulation the protein expression of nrf2.展开更多
Stoichiometric and silicon-rich(Si-rich) SiC films were deposited by microwave electron cyclotron resonance(MWECR) plasma enhanced RF magnetron sputtering method.As-deposited films were oxidized at 800℃,900 ℃,and 10...Stoichiometric and silicon-rich(Si-rich) SiC films were deposited by microwave electron cyclotron resonance(MWECR) plasma enhanced RF magnetron sputtering method.As-deposited films were oxidized at 800℃,900 ℃,and 1000 ℃in air for 60 min.The chemical composition and structure of the films were analyzed by x-ray photoelectron spectroscopy(XPS),Raman spectroscopy and Fourier transform infrared spectroscopy(FT-IR).The surface morphology of the films before and after the high temperature oxidation was measured by atomic force microscopy.The mechanical property of the films was measured by a nano-indenter.The anti-oxidation temperature of the Si-rich SiC film is 100 ℃ higher than that of the stoichiometric SiC film.The oxidation layer thickness of the Si-rich SiC film is thinner than that of the stoichiometric SiC film in depth direction.The large amount of extra silicon in the Si-rich SiC film plays an important role in the improvement of its high temperature anti-oxidation property.展开更多
Microbial fuel cells(MFCs)are a well-known technology used for bioelectricity production from the decomposition of organic waste via electroactive microbes.Fat,oil,and grease(FOG)as a new substrate in the anode and mi...Microbial fuel cells(MFCs)are a well-known technology used for bioelectricity production from the decomposition of organic waste via electroactive microbes.Fat,oil,and grease(FOG)as a new substrate in the anode and microalgae in the cathode were added to accelerate the electrogenesis.The effect of FOG concentrations(0.1%,0.5%,1%,and 1.5%)on the anode chamber was investigated.The FOG degradation,volatile fatty acid(VFAs)production,and soluble chemical oxygen demand along with voltage output kinetics were analyzed.Moreover,the microbial community analysis and active functional enzymes were also evaluated.The maximum power and current density were observed at 0.5%FOG which accounts for 96 mW m^(-2)(8-folds enhancement)and 560 mA m^(-2)(3.7-folds enhancement),respectively.The daily voltage output enhanced upto 2.3-folds with 77.08%coulombic efficiency under 0.5%FOG,which was the highest among all the reactors.The 0.5%FOG was degraded>85%,followed by a 1%FOG-loaded reactor.The chief enzymes inβ-oxidation and electrogenesis were acetyl-CoA C-acetyltransferase,riboflavin synthase,and riboflavin kinase.The identified enzymes symbolize the presence of Clostridium sp.(>15%)and Pseudomonas(>10%)which served as electrochemical active bacteria(EAB).The major metabolic pathways involved in electrogenesis and FOG degradation were fatty acid biosynthesis and glycerophospholipid metabolism.Utilization of lipidic-waste(such as FOG)in MFCs could be a potential approach for simultaneous biowaste utilization and bioenergy generation.展开更多
Ciprofloxacin(CIP)is an antibiotic used to treat infections caused by bacteria.In this experiment,key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4 was researched under CIP stress.The results ...Ciprofloxacin(CIP)is an antibiotic used to treat infections caused by bacteria.In this experiment,key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4 was researched under CIP stress.The results showed that the activities of hexokinase,pyruvate kinase,β-galactosidase and Na^(+),K^(+)-ATPase after 1/2 minimum bacteriostatic concentration(MIC)CIP treatment were significantly decreased(P<0.01).Gas chromatography-mass spectrometry was used to analysis the changes of main metabolites in the cells and principal component analysis and partial least square model were constructed.The results indicated that CIP could cause changes in intracellular fatty acids,carbohydrates and amino acids,and the mechanism of amino acid metabolism under CIP stress was significantly inhibited.L.plantarum DNZ-4 made stress response to CIP by regulating the ratio of saturated fatty acids and unsaturated fats.This experiment revealed the changes of growth and metabolism mechanism of L.plantarum DNZ-4 under CIP stress,which help to provide technical means for the development of effective probiotics preparation products.展开更多
The conversion of biomass into sugar platform compounds is very important for the biorefinery industry.Pretreatment is essential to the biomass of the sugar platform,however,the lignin obtained by pretreatment,as a ke...The conversion of biomass into sugar platform compounds is very important for the biorefinery industry.Pretreatment is essential to the biomass of the sugar platform,however,the lignin obtained by pretreatment,as a key part of lignocellulose,generally has a passive effect on the enzymatic hydrolysis of cellulose into sugars.In this study,p-TsOH(p-toluenesulfonic acid),DES(Deep eutectic solvent)and CAOSA(cooking with active oxygen and solid alkali)pretreatment ways were used to fraction lignin from bamboo biomass.After CAOSA treatment,the hydrolysis efficiency of the pulp was 95.57%.Moreover,the effect of different treatment methods on lignin properties was studied and the promotion effect of lignin was investigated by adding it to the cellulose enzymatic hydrolysis system.In this work,the results showed that CAOSA-extracted lignin with lower D(1.31-1.25)had a better adsorption effect on the enzyme protein.p-TsOH-extracted lignin with a larger S/G ratio enhanced the inhibition of enzymatic hydrolysis.In addition,the presence of-COOHs in lignin could reduce its inhibitory effect on cellulose saccharification.展开更多
Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with ...Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics.They were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic activities.The Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic activities.They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change.The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic process.ACVPs were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic performance.The enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic process.This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.展开更多
文摘The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-instar larvae of American white moth (Hyphantria cunea (Drury)) for determination of the activities of the protective enzyme system inside larvae’s body. The physiological and biochemical effects of the transgenic poplars on the larvae were studied. The results showed that the two kinds of transgenic poplars had similar effects on the protective enzyme system in the midgut of larvae. The activities of superoxide dismutase, catalase, and peroxidase in midgut of the larvae increased gradually, reached the highest value at a certain time, and then decreased suddenly. For the larvae that were fed with the leaves of Bt transgenic poplar, the peak value of superoxide dismutase and catalase presented at the time of 24-h feeding, while the peak of peroxidase took place at the time of 12-h feeding. The activities of these protective enzymes for the larvae that were fed with leaves of CpTI transgenic poplar peaked 12 h later than that of those fed with leaves of Bt transgenic poplar. The comparison of activities of the protective enzymes was also carried out between the larvae with different levels of intoxication. It was found that the activities of protective enzyme of the seriously intoxicant larvae were higher than that of the lightly intoxicant larvae. This difference was more obvious in the group treated with CpTI transgenic poplar.
基金This research was supported by National Basic Research Program of China (No.2002CB412502)Project of Key Pro-gram of the National Science Foundation of China (No.90411020)Natural Science Foundation of China (No.30400051)
文摘A study was conducted to determine the responses of soil enzymes （invertase, polyphenol oxidase, catalase, and dehydrogenase） to long-term CO2 enrichment at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences （42°24＇N, 128°28＇E; 738 m in elevation） in the northeast China during 1999-2006. Three treatments of the CO2 enrichment, designed as 500 μmol·mol-1 CO2 open-top chamber （OTC）, ambient control chamber and unchambered field （approx. 370 μmol·mol^-1CO2）, were conducted with Pinus koraiensis and Pinus sylvestriformis tree species. Soil sampling was made and analyzed separately in spring, summer and autumn in 2006 after the soil enzymes were exposed to elevated CO2 concentration （500 μmol·mol^-1） for eight growing seasons. Results showed that, at elevated CO2 concentration （500 μmol·mol^-1）, the activities of invertase （except for the summer samples of P. koraiensis） presented a remarkable decline in all growing seasons, while the activities of dehydrogenase had an increase but only part of the results was remarkable; the activities of polyphenol oxidase in P. sylvestriformis rhizosphere showed a remarkable decrease; the catalase activities increased in spring, while in turn were decline in other seasons. This study also revealed that the soil enzyme activities are significantly correlated with the tree species under the CO2 enhancement.
基金funded by theScientific Research Foundation of the Bureau of Science and Technologyof Heilongjiang Province (LC07C27)
文摘A study was conducted to test wettability changes of the wheat straw treated with different methods for the preparation of wheat straw particle board. The wheat straws were separately sprayed with two chemicals （0.6% NaOH, 0.3% H2O2） and three enzymes （lipase, xylanase, cellulase）. The contact angle between water and the surface of wheat straw was measured and the spreading-penetration parameters （K-values） were also calculated with wetting model. The surfaces of treated wheat straw and control sample were scanned by means of Micro-FTIR, and their peaks arrangements were analyzed. The surface morphologies of treated wheat straw and control sample were also observed by SEM. Chemical etching was found on the exterior surfaces of the straws treated separately with 0.6% NaOH and 0.3% H2O2; furthermore, the spreading-penetration parameters （K-values） of the distilled water on the exterior surfaces of the treated wheat straw along the grain were higher than that of control. The wettability of exterior surfaces of the wheat straws treated separately with lipase, xylanase and cellulose were improved after treating for seven days, and among the three enzymes treatments, the lipase treatment showed best result. The lipase treatment and NaOH treatment were determined as better methods for improving the wettability of wheat straw surfaces. However, in the economic aspect, NaOH treatment was more practical and easier in the pretreatment for the manufacture of straw particle board.
基金financially supported by the National Natural Science Foundation(31500323 41501583 31370426)
文摘This study investigates the effects of cold-acclimation in conferring chilling tolerance in seedlings of the mulberry(Morus alba) variety ‘Qiuyu’. Changes in photosynthesis and antioxidant enzymes in chilling acclimatized(CA), and non-acclimatized(NA) seedlings were recorded during chilling stress(3 °C) and a recovery period(25 °C) each for 3 days. The results showed that CA plants had higher net photosynthetic rates(P_n), stomatal conductance(G_s), and maximum photochemical efficiency of photosystem Ⅱ(F_v/F_m) in response to chilling stress compared to NA. The seedlings maintained the same trends during the recovery stage. The responses of Q_A reduction degree (1-q_P) and prime electronic transfer rates(F_o) were lower in acclimatized than in non-acclimatized seedlings. Low-temperature acclimation and chilling stress also caused an increase in leaf proline and soluble sugar contents. Leaf malondialdehyde levels were significantly lower while ascorbate peroxidase(APX) activity was significantly higher in acclimatized seedlings, suggesting that elevated osmolytes and APX confer resistance to chilling temperatures. In this study on the response of mulberry seedlings to chilling stress, we also looked at the recovery process. The response to chilling determines whether mulberry leaves can survive under cold temperatures, while the recovery process determines whether photosynthesis can recover as soon as possible to avoid any secondary damage.
文摘Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Mothoda Totally 100 young male army members newly recruited from Sichuan province （400 meters above sea level） were enrolled. They were randomly divided into two groups： 50 in aminophylline group （A group） and 50 in control group （ C group）. A group and C group orally took aminophylline and placebo respectively for 10 days, 7 days before entering Lhasa （3 658 meters above sea level） by air and 3 days after it. Several parameters were measured at three time points： before drug taken, 7 days after drug taken, and 3 days after ascending high altitude. These parameters included serum levels of nitric oxide （NO）, superoxide dismutase （SOD）, catalase （CAT）, hydrogen dioxide （H2O2）, lactic acid （LA）, as well as arterial oxygen saturation （SO2）, arterial oxygen partial pressure （PaO2）, and arterial carbon dioxide partial pressure （PaCO2）. Statistical analysis was conducted to compare the difference between two groups with Stata 7.0 software system. Results There were no statistical differences between groups in hypoxia and oxidation indicators before and after drug taken in plain area. Three days after ascending high altitude, the serum levels of SOD, CAT, H202, LA, PaCO2 increased in both groups, yet to a much larger degree in C group than A group （P 〈0. 01 ） ; and NO, SO2 , PaO2 decreased more markedly in C group （ P 〈 0. 05 for NO, P 〈 0. 0001 for SO2 and PaO2 ）. Conclusion Aminophylline has significant anti-hypoxia and anti-oxidation effects at high altitude.
文摘The present study aimed to evaluate the effects of chrysoeriol from Cardiospermum halicacabum in streptozotocin induced Wistar rats.Thirty rats were categorized as control,diabetic control supplemented with 0,20 mg/kg chrysoeriol and 600μg/kg BW of glibenclamide for 45-day trial period.Our results indicated that the inclusion of chrysoeriol(20 mg/kg)showed a significant reduction in plasma glucose,hemoglobin and glycosylated hemoglobin level with a rising of plasma insulin sensitivity.Further,downregulated enzymes including glucose 6-phosphatase,fructose 1,6-bisphosphatase,and glycogen phosphorylase as well upregulated enzymes such as hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,and hepatic glycogen content.There was a diminish action found in liver glycogen synthase of tested rat with a rise in gamma-glutamyl transpeptidase,towards normal levels upon treatment with chrysoeriol.The histopathological study confirmed that renewal of the beta cells of pancreatic of chrysoeriol and glibenclamide treated rats.In addition,the molecular docking of chrysoeriol against glycolytic enzymes including hexokinase,glucose-6-phosphate dehydrogenase,pyruvate kinase,using Argus software shows chrysoeriol had greatest ligand binding energy as equivalent to glibenclamide,as a standard drug.Thus,chrysoeriol found to be non-toxic with potential regulation on glycemic control and upregulation of the carbohydrate metabolic enzymes.
基金the support by a Grantin-Aid for Scientific Research (A) from the Japan Society for the Promotion of Science, Grant Number 15H02231
文摘A pulsed electric field(PEF) was applied to unpasteurized sake at constant temperatures, at which α-amylase was not inactivated. We adjusted the input energy to be identical for the temperatures by changing the number of PEF application, because the current significantly increased with the temperature, even the amplitude of the applied voltage was identical. As a result, the α-amylase was seemed to be inactivated by PEF application, not due to thermal effect.The glucoamylase was significantly inactivated by PEF. Moreover, the acid carboxypeptidase was inactivated by PEF at 4 °C but significantly activated at 25 °C. These results show that the sensitivity of enzyme to PEF application differs depending on the types of enzyme and treatment temperature. On the other hand, the colony number of bacteria was remarkably decreased, but the amount of the volatile flavor compounds was not decreased by PEF application.
基金supported by funding received from the Tojuro Iijima Foundation for Food Science and Technologythe International Kyowa Scholarship Foundation。
文摘To exam ine the effect of digestive attributes such as digestive enzymes and pH on changes in phenolic compound content and antioxidant activity during digestion,the bioavailability of green tea infusion was investigated using a simulated in vitro gastrointestinal digestion model.The total polyphenol content(TPC)decreased to 65%–70%throughout the mimicked normal digestion(MD)compared to the initial value.The total flavonoid content(TFC)decreased to approximately 25%after starting the gastric stage(pH 1.2);however,it regained to approximately 60%in the intestinal stage(pH 6.8).The mimicked digestive condition without digestive enzymes(WOE),which followed only the pH conditions of MD,showed significantly lower TPC and TFC values than MD.The percentage of antioxidant activity based on the initial values indexed by DPPH,ABTS,and FRAP gradually declined from approximately 60%at the gastric stage to approximately 40%at the final digestion stage.Meanwhile,the percentage of residual MIC was around 50%at the gastric stage.However,it gradually increased at the intestinal stage.The significantly lower antioxidant activity showed for WOE than MD throughout the simulated digestion.This study demonstrated that digestive enzymes and pH play a crucial role in the bioavailability of green tea infusion.
文摘Whole grain cereals are important dietary sources for management of metabolic diseases due to the bioactive components they contain.Hence,this study investigated enzymes(pancreatic lipase,-amylase,-glucosidase,xanthine oxidase and angiotensin 1-converting enzyme)inhibitory property,antioxidant activity and phenolics profile of raw and roasted red sorghum(Sorghum bicolor)grains in vitro.Extracts of flours of raw and roasted(150◦C and 180◦C,for 20 min)grains were assayed for enzymes inhibitory and antioxidant activities using spectrophotometric methods;while their phenolic constituents were characterized using HPLC-DAD.The raw grains exhibited strong enzymes inhibitory and antioxidant activities,and contained phenolic acids(gallic,chlorogenic,caffeic,ellagic and p-coumaric acids)and flavonoids(quercetin,luteolin and apigenin).However,whereas the enzymes inhibitory activity and levels of the phenolic compounds in the grains decreased significantly(p<0.05)with increasing roasting temperature,the antioxidant activity increased.Hence,roasting at high temperature may not be recommended for the optimum retention of the enzymes inhibitory property and phenolic compounds of red sorghum grains.
基金financially by the National Natural Science Foundation of China(No.31800546)the National Key R&D Program of China(No.2018YFC1200400)the Fundamental Research Funds for the Central Universities(No.2572016CA11)。
文摘To study the effect of jasmonates(JAs)on the resistance of economic forest plants to insects,R osa rugosa‘Plena'leaves were treated with 1 mmol/L jasmonic acid(JA),methyl jasmonate(MeJA)and Z-jasmone,then the content of tannin and total phenol in leaves and the feeding area of Monolepta hieroglyphica adults on leaves were measured.Changes in the activities of detoxification enzymes in adult M.hieroglyphica that had fed on leaves treated with JAs were also studied.Tannin and total phenol levels in leaves increased significantly after treatment with JAs,and tannin level was 1.36–1.55-fold higher than in the control after treatment with 1 mmol/L MeJA.The total content of phenol in leaves treated with 1.0 mmol/L Z-jasmone increased by 1.33–2.20-fold compared with those of the control.The activities of detoxification enzymes in adults were inhibited to differing degrees:activity of alkaline phosphatase(AKP)first increased,then decreased;the activities of acid phosphatase(ACP),glutathione S-transferases(GSTs)and carboxylesterase(CarE)following treatment with 1 mmol/L MeJA were significantly reduced and were 22%–31%,11%–26%,and 11%–31%lower than those of the control,respectively.Moreover,the feeding area of adult M.hieroglyphica on the leaves treated with JAs was significantly reduced(P<0.05).The feeding area of economic forest R.rugosa‘Plena'leaves treated with 1 mmol/L MeJA decreased by 17%–43%compared with that of the control.Moreover,the decrease in the adult M.hieroglyphica feeding area was highly positively correlated with the content of tannin and positively correlated with the contents of total phenol of economic forest R.rugosa‘Plena'leaves.The reduced feeding area of adult M.hieroglyphica was highly negatively correlated with the activities of AKP and ACP and negatively correlated with those of the GSTs.In conclusion,the use of 1 mmol/L MeJA can noticeably decrease the deleterious effects of adult M.hieroglyphica.
文摘The inhibitory effect of methanol extracts of Brachystegia eurycoma and Detarium microcarpum seeds flours on some key enzymes[α-amylase,α-glucosidase and aldose reductase(AR)]linked to the pathology and complications of type 2 diabetes(T2D);and their antioxidant properties were evaluated.The antioxidant properties evaluated were DPPH•and ABTS•^+scavenging abilities,reducing power,and antioxidant phytochemicals(total phenolics,tannins,total flavonoids and total saponins).Extracts of both flours inhibitedα-amylase,α-glucosidase and AR in a dose-dependent manner.The half-maximal inhibitory concentrations(IC50)of B.eurycoma onα-amylase,α-glucosidase,AR and lipid peroxidation were lower than those of D.microcarpum,indicating that it had stronger inhibitory potency than D.microcarpum.B.eurycoma also had significantly(P<0.05)higher DPPH•and ABTS•^+scavenging abilities,and reducing power than D.microcarpum.The antioxidant phytochemicals(total phenolics,tannins,total flavonoids and total saponins)were also significantly(P<0.05)higher in B.eurycoma than D.microcarpum.The inhibitory effect of B.eurycoma and D.microcarpum extracts onα-amylase,α-glucosidase and AR activities may be attributed to the combined action of their polyphenols and total saponins,and this may be a possible mechanism of action providing support for their use in managing hyperglycemia and the complications of T2D.
文摘Objective The increasing recognition of the role for oxidative stress in hepatic disorders has led to extensive investigation on the protection by exogenous antioxidants against hepatic injury.In this study,we choose two typical polyphenol,quercetin and rutin,to investigate the mechanism of induction of cellular antioxidants and phase 2 enzymes in human HepG2 cells.Methods The HepG2 cells were treated with various concentrations of quercetin and rutin for 6 h and 24 h.The activities of NAD(P)H:quinone oxidoreductase(NQO1)in HepG2 cells were measured by 2,6-dichloroindophenol reduction method.The content of superoxide dismutase(SOD)was determined with the method of chemical colorimetry.The protein expressions of NQO1 and NF-E2-related factor 2(Nrf2)in HepG2 cells were detected by Western blotting.Results Incubation of HepG2 cells with quercetin and rutin resulted in a marked concentration-and time-dependent induction of a number of cellular antioxidants and phase 2 enzymes,including NQO1,SOD.Quercetin and rutin treatment of HepG2 cells also caused increase in protein expressions of NQO1 and Nrf2.Conclusions This study demonstrates that a series of phase 2 enzymes in HepG2 cells can be induced by quercetin and rutin in a concentration-and time-dependent fashion by upregulation the protein expression of nrf2.
文摘Stoichiometric and silicon-rich(Si-rich) SiC films were deposited by microwave electron cyclotron resonance(MWECR) plasma enhanced RF magnetron sputtering method.As-deposited films were oxidized at 800℃,900 ℃,and 1000 ℃in air for 60 min.The chemical composition and structure of the films were analyzed by x-ray photoelectron spectroscopy(XPS),Raman spectroscopy and Fourier transform infrared spectroscopy(FT-IR).The surface morphology of the films before and after the high temperature oxidation was measured by atomic force microscopy.The mechanical property of the films was measured by a nano-indenter.The anti-oxidation temperature of the Si-rich SiC film is 100 ℃ higher than that of the stoichiometric SiC film.The oxidation layer thickness of the Si-rich SiC film is thinner than that of the stoichiometric SiC film in depth direction.The large amount of extra silicon in the Si-rich SiC film plays an important role in the improvement of its high temperature anti-oxidation property.
基金the Deanship of Scientific Research at Najran University for funding this work,under the Research Groups Funding program grant code(NU/RG/SERC/12/23)。
文摘Microbial fuel cells(MFCs)are a well-known technology used for bioelectricity production from the decomposition of organic waste via electroactive microbes.Fat,oil,and grease(FOG)as a new substrate in the anode and microalgae in the cathode were added to accelerate the electrogenesis.The effect of FOG concentrations(0.1%,0.5%,1%,and 1.5%)on the anode chamber was investigated.The FOG degradation,volatile fatty acid(VFAs)production,and soluble chemical oxygen demand along with voltage output kinetics were analyzed.Moreover,the microbial community analysis and active functional enzymes were also evaluated.The maximum power and current density were observed at 0.5%FOG which accounts for 96 mW m^(-2)(8-folds enhancement)and 560 mA m^(-2)(3.7-folds enhancement),respectively.The daily voltage output enhanced upto 2.3-folds with 77.08%coulombic efficiency under 0.5%FOG,which was the highest among all the reactors.The 0.5%FOG was degraded>85%,followed by a 1%FOG-loaded reactor.The chief enzymes inβ-oxidation and electrogenesis were acetyl-CoA C-acetyltransferase,riboflavin synthase,and riboflavin kinase.The identified enzymes symbolize the presence of Clostridium sp.(>15%)and Pseudomonas(>10%)which served as electrochemical active bacteria(EAB).The major metabolic pathways involved in electrogenesis and FOG degradation were fatty acid biosynthesis and glycerophospholipid metabolism.Utilization of lipidic-waste(such as FOG)in MFCs could be a potential approach for simultaneous biowaste utilization and bioenergy generation.
基金supported by the National Natural Science Foundation of China(Grant No.31671874)National Key Research and Development Project(2018YFD0502404)+3 种基金Natural Science Foundation of Heilongjiang Province of China(Grant No.C2018022)Academic Backbone Plan of Northeast Agricultural University(Grant No.18XG27)Research Fund for Key Laboratory of Dairy Science,Ministry of Education,Heilongjiang Province,China(2015KLDSOF-07)the Project of Young Innovative Talents of Colleges and Universities(UNPYSCT-2016149)。
文摘Ciprofloxacin(CIP)is an antibiotic used to treat infections caused by bacteria.In this experiment,key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4 was researched under CIP stress.The results showed that the activities of hexokinase,pyruvate kinase,β-galactosidase and Na^(+),K^(+)-ATPase after 1/2 minimum bacteriostatic concentration(MIC)CIP treatment were significantly decreased(P<0.01).Gas chromatography-mass spectrometry was used to analysis the changes of main metabolites in the cells and principal component analysis and partial least square model were constructed.The results indicated that CIP could cause changes in intracellular fatty acids,carbohydrates and amino acids,and the mechanism of amino acid metabolism under CIP stress was significantly inhibited.L.plantarum DNZ-4 made stress response to CIP by regulating the ratio of saturated fatty acids and unsaturated fats.This experiment revealed the changes of growth and metabolism mechanism of L.plantarum DNZ-4 under CIP stress,which help to provide technical means for the development of effective probiotics preparation products.
基金financially supported by the National Key R&D Program of China(No.2021YFC2101604)National Natural Science Foundation of China(No.22278339,21978248)Fujian Provincial Key Science and Technology Program of China(No.2022YZ037013)。
文摘The conversion of biomass into sugar platform compounds is very important for the biorefinery industry.Pretreatment is essential to the biomass of the sugar platform,however,the lignin obtained by pretreatment,as a key part of lignocellulose,generally has a passive effect on the enzymatic hydrolysis of cellulose into sugars.In this study,p-TsOH(p-toluenesulfonic acid),DES(Deep eutectic solvent)and CAOSA(cooking with active oxygen and solid alkali)pretreatment ways were used to fraction lignin from bamboo biomass.After CAOSA treatment,the hydrolysis efficiency of the pulp was 95.57%.Moreover,the effect of different treatment methods on lignin properties was studied and the promotion effect of lignin was investigated by adding it to the cellulose enzymatic hydrolysis system.In this work,the results showed that CAOSA-extracted lignin with lower D(1.31-1.25)had a better adsorption effect on the enzyme protein.p-TsOH-extracted lignin with a larger S/G ratio enhanced the inhibition of enzymatic hydrolysis.In addition,the presence of-COOHs in lignin could reduce its inhibitory effect on cellulose saccharification.
基金supported by National Natural Science Foundation of China(52208272,41706080 and 51702328)the Basic Scientific Fund for National Public Research Institutes of China(2020S02 and 2019Y03)+3 种基金the Basic Frontier Science Research Program of Chinese Academy of Sciences(ZDBS-LY-DQC025)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20210201)the Strategic Leading Science&Technology Program of the Chinese Academy of Sciences(XDA13040403)the Key Research and Development Program of Shandong Province(Major Scientific and Technological Innovation Project)(2019JZZY020711).
文摘Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics.They were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic activities.The Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic activities.They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change.The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic process.ACVPs were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic performance.The enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic process.This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.
