Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultu...Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.展开更多
The paper deals with some questions of important aspects of food safety and application of principles of food physics in the food sector. Food production and processing of quality food and safe food are today of prima...The paper deals with some questions of important aspects of food safety and application of principles of food physics in the food sector. Food production and processing of quality food and safe food are today of primary importance. Food production is based on the principles of Good Agricultural Practice （GAP）, Good Manufactoring Practice （GMP） and Good Hygiene Practice （GHP）. Recently, the industrial food processing is focused dominantly on the quality, and one of the basic requirements of the quality is the safety. There are different methods and techniques to produce safe food. The up-to-date food technologies and quality measurements （quality control and quality assurance） involve the application of different physical methods, e.g., high pressure, pulsing electrical field, nondestructive techniques, e.g., nuclear magnetic resonance （NMR）, near infrared reflectance, near infrared transmittance （NIR-NIT）, photo acoustic spectroscopy （PAS） and instrumental neutron activation analysis （INAA） for chemical composition determination, radiation techniques, nanofiltration and reverse osmosis （RO） as well. Using ionizing radiation （nuclear methods） and non-ionizing radiation technologies, it is possible to fulfill a lot of expectations： decrease of microbial contamination, improve of sensory properties, increase of storability, etc..展开更多
In this paper, globally-averaged, thermospheric total mass density, derived from the orbits of -5000 objects at 250, 400, and 550 km that were tracked from 1967 to 2006, has been used to quantitatively study the annua...In this paper, globally-averaged, thermospheric total mass density, derived from the orbits of -5000 objects at 250, 400, and 550 km that were tracked from 1967 to 2006, has been used to quantitatively study the annual asymmetry of thermospheric mass density and its mechanism（s）. The results show that thermospheric mass density had a significant annual asymmetry, which changed from year to year. The annual asymmetry at the three altitudes varied synchronously and its absolute value increased with altitudes. The results suggest that there is an annual asymmetry in solar EUV radiation that is caused by the difference in the Sun-Earth distance between the two solstices and the random variation of solar activity within a year. This change in radiation results in an annual change in the thermospheric temperature and thus the scale height of the neutral gas, and is the main cause of the annual asymmetry of thermospheric mass density. The annual asymmetry of mass density increases with altitude because of the accumulating effect of the changes in neutral temperature and scale height in the vertical direction.展开更多
The determination of the effective minimum detectable activity （MDA） of radionuclides by a detection system plays an im- portant role in environmental radiation monitoring. In this study, the responses of an NaI（TI...The determination of the effective minimum detectable activity （MDA） of radionuclides by a detection system plays an im- portant role in environmental radiation monitoring. In this study, the responses of an NaI（TI） airborne γ ray spectrometry （AGRS） system to different radionuclides （137Cs and 131I） were investigated using the Monte Carlo technique. The MDA values were determined under different conditions according to the counting spectra obtained from the Monte Carlo simulation. The equivalent mass thickness method was applied to the Monte Carlo modeling for monitoring ground radiation to reduce sta- tistical uncertainty. The secondary source method was used to monitor both air and ground radiation. A quadratic relationship was found between the MDA and activity concentration. An exponential relationship was found between the MDA and altitude The MDA of a specific radionuclide from external detectors was found to be superior to that obtained from internal detectors under the same conditions. The MDA values in an NaI（Tl） AGRS system under different conditions can be estimated based on the results of this study.展开更多
Nitrogen oxides(NOx) from flue gas can be removed efficiently by activated carbon continuously irradiated by microwave,which,however,needs high temperature and consumes excessive carbon. If catalyst is added into acti...Nitrogen oxides(NOx) from flue gas can be removed efficiently by activated carbon continuously irradiated by microwave,which,however,needs high temperature and consumes excessive carbon. If catalyst is added into activated carbon,then reaction temperature can be reduced and selectivity of reaction enhanced. The effects on flue gas denitrification by adding different catalysts to microwave reactor were studied in this paper. It was found that the addition of catalyst could reduce the microwave power required by the same removal efficiency obviously;the difference of removal efficiency was different due to different catalysts,and the Cu-based catalyst has more catalytic action efficiency. Reaction temperature decreased by about 200℃ and removal efficiency increased by 25% after adding Cu-based catalyst. In addition,characteristic analysis for activated carbon conducted by X-ray diffraction confirmed that active component of catalyst existed on the surface of activated carbon.展开更多
基金in part by Natural Sciences Foundation of China (No. 39870239)by the Sasagawa Fellowship,Japan.
文摘Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.
文摘The paper deals with some questions of important aspects of food safety and application of principles of food physics in the food sector. Food production and processing of quality food and safe food are today of primary importance. Food production is based on the principles of Good Agricultural Practice （GAP）, Good Manufactoring Practice （GMP） and Good Hygiene Practice （GHP）. Recently, the industrial food processing is focused dominantly on the quality, and one of the basic requirements of the quality is the safety. There are different methods and techniques to produce safe food. The up-to-date food technologies and quality measurements （quality control and quality assurance） involve the application of different physical methods, e.g., high pressure, pulsing electrical field, nondestructive techniques, e.g., nuclear magnetic resonance （NMR）, near infrared reflectance, near infrared transmittance （NIR-NIT）, photo acoustic spectroscopy （PAS） and instrumental neutron activation analysis （INAA） for chemical composition determination, radiation techniques, nanofiltration and reverse osmosis （RO） as well. Using ionizing radiation （nuclear methods） and non-ionizing radiation technologies, it is possible to fulfill a lot of expectations： decrease of microbial contamination, improve of sensory properties, increase of storability, etc..
基金supported by the Chinese Academy of Sciences(Grant No.KZZD-EW-01-2)the National Natural Science Foundation of China(Grant Nos.41229001,41331069,41174139)+1 种基金the Specialized Research Fund for State Key Laboratoriessupported by the US National Science Foundation
文摘In this paper, globally-averaged, thermospheric total mass density, derived from the orbits of -5000 objects at 250, 400, and 550 km that were tracked from 1967 to 2006, has been used to quantitatively study the annual asymmetry of thermospheric mass density and its mechanism（s）. The results show that thermospheric mass density had a significant annual asymmetry, which changed from year to year. The annual asymmetry at the three altitudes varied synchronously and its absolute value increased with altitudes. The results suggest that there is an annual asymmetry in solar EUV radiation that is caused by the difference in the Sun-Earth distance between the two solstices and the random variation of solar activity within a year. This change in radiation results in an annual change in the thermospheric temperature and thus the scale height of the neutral gas, and is the main cause of the annual asymmetry of thermospheric mass density. The annual asymmetry of mass density increases with altitude because of the accumulating effect of the changes in neutral temperature and scale height in the vertical direction.
基金supported by the National Defense Basic Scientific Research Project(Grant No.B2520133077)National High-tech R&D Program of China("863"Program)(Grant No.2012AA061803)
文摘The determination of the effective minimum detectable activity （MDA） of radionuclides by a detection system plays an im- portant role in environmental radiation monitoring. In this study, the responses of an NaI（TI） airborne γ ray spectrometry （AGRS） system to different radionuclides （137Cs and 131I） were investigated using the Monte Carlo technique. The MDA values were determined under different conditions according to the counting spectra obtained from the Monte Carlo simulation. The equivalent mass thickness method was applied to the Monte Carlo modeling for monitoring ground radiation to reduce sta- tistical uncertainty. The secondary source method was used to monitor both air and ground radiation. A quadratic relationship was found between the MDA and activity concentration. An exponential relationship was found between the MDA and altitude The MDA of a specific radionuclide from external detectors was found to be superior to that obtained from internal detectors under the same conditions. The MDA values in an NaI（Tl） AGRS system under different conditions can be estimated based on the results of this study.
基金supported by the National Natural Science Foundation of China (Grant No.50976035)
文摘Nitrogen oxides(NOx) from flue gas can be removed efficiently by activated carbon continuously irradiated by microwave,which,however,needs high temperature and consumes excessive carbon. If catalyst is added into activated carbon,then reaction temperature can be reduced and selectivity of reaction enhanced. The effects on flue gas denitrification by adding different catalysts to microwave reactor were studied in this paper. It was found that the addition of catalyst could reduce the microwave power required by the same removal efficiency obviously;the difference of removal efficiency was different due to different catalysts,and the Cu-based catalyst has more catalytic action efficiency. Reaction temperature decreased by about 200℃ and removal efficiency increased by 25% after adding Cu-based catalyst. In addition,characteristic analysis for activated carbon conducted by X-ray diffraction confirmed that active component of catalyst existed on the surface of activated carbon.
