[Objective] This study was conducted to evaluate the effect of 1-methylcy- clopropene （1-MCP） on fruit firmness, and the activity of the enzymes involved in ethylene metabolism and membrane lipid peroxidation. [Meth...[Objective] This study was conducted to evaluate the effect of 1-methylcy- clopropene （1-MCP） on fruit firmness, and the activity of the enzymes involved in ethylene metabolism and membrane lipid peroxidation. [Method] The nearly ripe fruits of the papaya cultivar Risheng were randomly assigned to one of four groups. Two groups were treated under hypobaric and hypoxic （HH） atmosphere condition for six hours, and immediately soaked in deionized water （HH alone）, or fumigated with 2.0 mg/L 1-MCP （HH＋I-MCP） for 24 h. The other two groups untreated under HH condition were also soaked in deionized water （negative control）, or fumigated with 2.0 mg/L 1-MCP （1-MCP alone） for 24 h. After that, the fruits of all the four treatments were stored at room temperature （23＋1） ℃. Cell membrane permeability, fruit firmness, respiration rate, ethylene release rate, SOD activity, POD activity, CAT activity, MAD content and LOX activity were measured once every three days during storage. [Result] Treatment with 1-MCP delayed the occurrence of the peaks of respiration rate and ethylene release rate, significantly reduced the accumulation of malondialdehyde （MDA）, and inhibited the decrease in papaya fruit firmness. Compared with the control, 1-MCP treatment significantly increased the SOD （su- peroxide dismutase）, POD （peroxidase） and CAT （catalase） activity, reduced the ac- tivity of lipoxygenase （LOX）, a product of lipid peroxidatlon in membranes, and in- hibited ethylene biosynthesis, thus delaying the aging process and prolonging the storage life of papaya fruits. [Conclusion] The results will provide a theoretical basis for analvzina the key factors controllinq postharvest maturity and aging of papaya fruits.展开更多
A novel adsorbent based on iron oxide dispersed over activated carbon （AC） were prepared, and used for phosphate removal from aqueous solutions. The influence of pre-oxidation treatment on the physical, chemical and...A novel adsorbent based on iron oxide dispersed over activated carbon （AC） were prepared, and used for phosphate removal from aqueous solutions. The influence of pre-oxidation treatment on the physical, chemical and phosphate adsorption properties of iron-containing AC were determined. Two series of ACs, non-oxidized and oxidized carbon modified by iron （denoted as AC-Fe and AC/O- Fe）, resulted in a maximum impregnated iron of 4.03% and 7.56%, respectively. AC/O-Fe showed 34.0%46.6% higher phosphate removal efficiency than the AC-Fe did. This was first attributed to the moderate pre-oxidation of raw AC by nitric acid, achieved by dosing Fe（II） after a pre-oxidation, to obtain higher iron loading, which is favorable for phosphate adsorption. Additionally, the in-situ formed active site on the surface of carbon, which was derived from the oxidation of Fe（II） by nitric acid dominated the remarkably high efficiency with respect to the removal of phosphate. The activation energy for adsorption was calculated to be 10.53 and 18.88 kJ/mol for AC-Fe and AC/O- Fe, respectively. The results showed that the surface mass transfer and intra-parficle diffusion were simultaneously occurring during the process and contribute to the adsorption mechanism.展开更多
AIM: To investigate oxidative stress and lipid peroxi-dation in hepatic steatosis and the underlying implica-tions in pathological mechanisms of non-alcoholic fatty liver disease (NAFLD). METHODS: F_2-isoprostanes (i...AIM: To investigate oxidative stress and lipid peroxi-dation in hepatic steatosis and the underlying implica-tions in pathological mechanisms of non-alcoholic fatty liver disease (NAFLD). METHODS: F_2-isoprostanes (iPF2α-) in blood and liver samples from steatotic (n = 9) and control (n = 7) rats were measured as in vivo marker of lipid peroxida-tion by a mass spectrometric approach. The lipid pro-fi le and endogenous antioxidant status (SOD and CAT) in the rats were also analyzed. RESULTS: Signifi cantly higher levels of iPF2α-(mean 3.47 vs 2.40 pmol/mg tissue, P = 0.004) and lower activities of SOD (mean 1.26 U vs 1.40 U, P < 0.001) and CAT (mean 1026.36 U/mg vs 1149.68 U/mg pro-tein, without signifi cance) were observed in the livers of steatotic rats. Plasma total iPF2α-was signifi cantly correlated with the abnormalities of blood lipids as well as alanine aminotransferase (ALT) levels in the rats with simple steatosis, whereas no similar tendencies were observed in the control rats. CONCLUSION: Enhancement of hepatic oxidative imbalance occurring at the steatotic stage of NAFLD suggests a possibility that manifestation of the local ⅢⅢⅢoxidative damage precedes that of systemic oxidative imbalance. Predominant metabolic features of the in-creased lipid peroxidation further suggest a close asso-ciation of the oxidative imbalance and the dyslipidemia with functional deterioration of the steatotic liver. The fi ndings need to be further evaluated, especially in hu-man studies.展开更多
The aim of the present experiments was to discern if the “entanglement”-like photon emissions from pairs of cell cultures or human brains separated by significant distances but sharing the same circling magnetic fie...The aim of the present experiments was to discern if the “entanglement”-like photon emissions from pairs of cell cultures or human brains separated by significant distances but sharing the same circling magnetic field could be demonstrated with a classic chemiluminescent reaction produced by hydrogen peroxide and hypochlorite. Simultaneous injection of the same amount of peroxide into a local dish (above a photomultiplier tube) and a dish 10 m away in a closed chamber produced a “doubling” of the durations of the photon spikes only when the two reactions were placed in the center of separate spaces around each of which magnetic fields were generated as accelerating group velocities containing decreasing phase modulations followed by decelerating group velocities embedded with increasing phase modulations. The duration of this “entanglement” was about 8 min. These results suggest that separate distances behave as if they were “the same space” if they are exposed to the same precise temporal configuration of magnetic fields with specific angular velocities.展开更多
文摘[Objective] This study was conducted to evaluate the effect of 1-methylcy- clopropene （1-MCP） on fruit firmness, and the activity of the enzymes involved in ethylene metabolism and membrane lipid peroxidation. [Method] The nearly ripe fruits of the papaya cultivar Risheng were randomly assigned to one of four groups. Two groups were treated under hypobaric and hypoxic （HH） atmosphere condition for six hours, and immediately soaked in deionized water （HH alone）, or fumigated with 2.0 mg/L 1-MCP （HH＋I-MCP） for 24 h. The other two groups untreated under HH condition were also soaked in deionized water （negative control）, or fumigated with 2.0 mg/L 1-MCP （1-MCP alone） for 24 h. After that, the fruits of all the four treatments were stored at room temperature （23＋1） ℃. Cell membrane permeability, fruit firmness, respiration rate, ethylene release rate, SOD activity, POD activity, CAT activity, MAD content and LOX activity were measured once every three days during storage. [Result] Treatment with 1-MCP delayed the occurrence of the peaks of respiration rate and ethylene release rate, significantly reduced the accumulation of malondialdehyde （MDA）, and inhibited the decrease in papaya fruit firmness. Compared with the control, 1-MCP treatment significantly increased the SOD （su- peroxide dismutase）, POD （peroxidase） and CAT （catalase） activity, reduced the ac- tivity of lipoxygenase （LOX）, a product of lipid peroxidatlon in membranes, and in- hibited ethylene biosynthesis, thus delaying the aging process and prolonging the storage life of papaya fruits. [Conclusion] The results will provide a theoretical basis for analvzina the key factors controllinq postharvest maturity and aging of papaya fruits.
基金supported by the Major Science and Technology Program forWater Pollution Control and Treatment(No.2012ZX07102-004)
文摘A novel adsorbent based on iron oxide dispersed over activated carbon （AC） were prepared, and used for phosphate removal from aqueous solutions. The influence of pre-oxidation treatment on the physical, chemical and phosphate adsorption properties of iron-containing AC were determined. Two series of ACs, non-oxidized and oxidized carbon modified by iron （denoted as AC-Fe and AC/O- Fe）, resulted in a maximum impregnated iron of 4.03% and 7.56%, respectively. AC/O-Fe showed 34.0%46.6% higher phosphate removal efficiency than the AC-Fe did. This was first attributed to the moderate pre-oxidation of raw AC by nitric acid, achieved by dosing Fe（II） after a pre-oxidation, to obtain higher iron loading, which is favorable for phosphate adsorption. Additionally, the in-situ formed active site on the surface of carbon, which was derived from the oxidation of Fe（II） by nitric acid dominated the remarkably high efficiency with respect to the removal of phosphate. The activation energy for adsorption was calculated to be 10.53 and 18.88 kJ/mol for AC-Fe and AC/O- Fe, respectively. The results showed that the surface mass transfer and intra-parficle diffusion were simultaneously occurring during the process and contribute to the adsorption mechanism.
基金the Science and Technology Commission of Shanghai Municipality, No. 05PJ14044 No. 06DZ19002
文摘AIM: To investigate oxidative stress and lipid peroxi-dation in hepatic steatosis and the underlying implica-tions in pathological mechanisms of non-alcoholic fatty liver disease (NAFLD). METHODS: F_2-isoprostanes (iPF2α-) in blood and liver samples from steatotic (n = 9) and control (n = 7) rats were measured as in vivo marker of lipid peroxida-tion by a mass spectrometric approach. The lipid pro-fi le and endogenous antioxidant status (SOD and CAT) in the rats were also analyzed. RESULTS: Signifi cantly higher levels of iPF2α-(mean 3.47 vs 2.40 pmol/mg tissue, P = 0.004) and lower activities of SOD (mean 1.26 U vs 1.40 U, P < 0.001) and CAT (mean 1026.36 U/mg vs 1149.68 U/mg pro-tein, without signifi cance) were observed in the livers of steatotic rats. Plasma total iPF2α-was signifi cantly correlated with the abnormalities of blood lipids as well as alanine aminotransferase (ALT) levels in the rats with simple steatosis, whereas no similar tendencies were observed in the control rats. CONCLUSION: Enhancement of hepatic oxidative imbalance occurring at the steatotic stage of NAFLD suggests a possibility that manifestation of the local ⅢⅢⅢoxidative damage precedes that of systemic oxidative imbalance. Predominant metabolic features of the in-creased lipid peroxidation further suggest a close asso-ciation of the oxidative imbalance and the dyslipidemia with functional deterioration of the steatotic liver. The fi ndings need to be further evaluated, especially in hu-man studies.
文摘The aim of the present experiments was to discern if the “entanglement”-like photon emissions from pairs of cell cultures or human brains separated by significant distances but sharing the same circling magnetic field could be demonstrated with a classic chemiluminescent reaction produced by hydrogen peroxide and hypochlorite. Simultaneous injection of the same amount of peroxide into a local dish (above a photomultiplier tube) and a dish 10 m away in a closed chamber produced a “doubling” of the durations of the photon spikes only when the two reactions were placed in the center of separate spaces around each of which magnetic fields were generated as accelerating group velocities containing decreasing phase modulations followed by decelerating group velocities embedded with increasing phase modulations. The duration of this “entanglement” was about 8 min. These results suggest that separate distances behave as if they were “the same space” if they are exposed to the same precise temporal configuration of magnetic fields with specific angular velocities.
