The ESR signal of NO bound to hemoglobin was detected during the ischemia-reperfusion of myocardium with low temperature ESR technique, and the synergic effects of NO and oxygen free radicals in the injury of the proc...The ESR signal of NO bound to hemoglobin was detected during the ischemia-reperfusion of myocardium with low temperature ESR technique, and the synergic effects of NO and oxygen free radicals in the injury of the process were studied with this technique. Oxygen free radicals and NO bound to β-subunit of hemoglobin (β-NO complex) could be detected simultaneously in the ischemia-reperfused myocardium. Those signals could not be detected from the normal myocardium even in the presence of L-arginme. However, those signals could be detected and were dose-dependent with L-arginine in the ischemia-reperfused myocardiums and the signal could be suppressed with the inhibitor of NO synthetase, NG-nitro-L-arginine methylester (NAME). Measurement of the activities of lactate dehydrogenase (LDH) and creatine kinase (CK) in the coronary artery effluent of ischemia-reperfused heart showed that L-arginine at lower concentration (<1 mmol/L) could protect the heart from the ischemia-reperfusion injury but at higher concentration aggravate the injury. Addition of NAME to the reperfusion solution could also protect the myocardium. Addition of xanthine (X) ,'xanthine oxidase (XO) or Fe2+/H2O2 to the reperfusion solution increased the production of NO and oxygen free radicals and the ischemia-reperfused injury simultaneously. Addition of superoxide dismutase (SOD) and catalase decreased the production of NO and oxygen free radicals and the ischemia-reperfusion injury.展开更多
Based upon a series of the coal graphite samples collected from China, the jumpy evolution of the EPR response of the high rank coals was found and its geochemical mechanism was further inquired. The results showed th...Based upon a series of the coal graphite samples collected from China, the jumpy evolution of the EPR response of the high rank coals was found and its geochemical mechanism was further inquired. The results showed that the makingup, which is activated notably at about 6.0% maximum vitrinite reflectance, might play a principal role in the development of the macromolecular basic structural units in the coals being in the middle to late stage of high rank coalification and that the homologisation of the chemical bonds in the macro molecular structure might provide a geochemical microenvironment for the realization of the makingup.展开更多
More attention has been paid to hematoporphyrin derivative (HPD), an useful porphyrin photosensitizer used in tumor detection and treatment.Although the photosensitization of Photofrin Ⅱ and YHPD made in China is hig...More attention has been paid to hematoporphyrin derivative (HPD), an useful porphyrin photosensitizer used in tumor detection and treatment.Although the photosensitization of Photofrin Ⅱ and YHPD made in China is higher than that of HPD, the percentages of some of their porphyrin components are greatly different. This raises questions. Which porphyrin component is active? Why is it active? International photochemical and medical scientists have been discussing the chemical structure,展开更多
At first, the ESR dating method in our experiments was applied to measuring the ages of stalagmite-Ⅰ and flowstone samples dated by U-series dating. Based on this, the ages of stalagmite-Ⅱ samples were measured by t...At first, the ESR dating method in our experiments was applied to measuring the ages of stalagmite-Ⅰ and flowstone samples dated by U-series dating. Based on this, the ages of stalagmite-Ⅱ samples were measured by the ESR dating method and determined by the U-series dating method again for the sake of verification. All the measured samples in this work were collected from Shihua Cave, Fangshan, Beijing. The age of the sample can be given展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘The ESR signal of NO bound to hemoglobin was detected during the ischemia-reperfusion of myocardium with low temperature ESR technique, and the synergic effects of NO and oxygen free radicals in the injury of the process were studied with this technique. Oxygen free radicals and NO bound to β-subunit of hemoglobin (β-NO complex) could be detected simultaneously in the ischemia-reperfused myocardium. Those signals could not be detected from the normal myocardium even in the presence of L-arginme. However, those signals could be detected and were dose-dependent with L-arginine in the ischemia-reperfused myocardiums and the signal could be suppressed with the inhibitor of NO synthetase, NG-nitro-L-arginine methylester (NAME). Measurement of the activities of lactate dehydrogenase (LDH) and creatine kinase (CK) in the coronary artery effluent of ischemia-reperfused heart showed that L-arginine at lower concentration (<1 mmol/L) could protect the heart from the ischemia-reperfusion injury but at higher concentration aggravate the injury. Addition of NAME to the reperfusion solution could also protect the myocardium. Addition of xanthine (X) ,'xanthine oxidase (XO) or Fe2+/H2O2 to the reperfusion solution increased the production of NO and oxygen free radicals and the ischemia-reperfused injury simultaneously. Addition of superoxide dismutase (SOD) and catalase decreased the production of NO and oxygen free radicals and the ischemia-reperfusion injury.
文摘Based upon a series of the coal graphite samples collected from China, the jumpy evolution of the EPR response of the high rank coals was found and its geochemical mechanism was further inquired. The results showed that the makingup, which is activated notably at about 6.0% maximum vitrinite reflectance, might play a principal role in the development of the macromolecular basic structural units in the coals being in the middle to late stage of high rank coalification and that the homologisation of the chemical bonds in the macro molecular structure might provide a geochemical microenvironment for the realization of the makingup.
文摘More attention has been paid to hematoporphyrin derivative (HPD), an useful porphyrin photosensitizer used in tumor detection and treatment.Although the photosensitization of Photofrin Ⅱ and YHPD made in China is higher than that of HPD, the percentages of some of their porphyrin components are greatly different. This raises questions. Which porphyrin component is active? Why is it active? International photochemical and medical scientists have been discussing the chemical structure,
文摘At first, the ESR dating method in our experiments was applied to measuring the ages of stalagmite-Ⅰ and flowstone samples dated by U-series dating. Based on this, the ages of stalagmite-Ⅱ samples were measured by the ESR dating method and determined by the U-series dating method again for the sake of verification. All the measured samples in this work were collected from Shihua Cave, Fangshan, Beijing. The age of the sample can be given
