The antioxidant and gap junctional communication（GJC） activities of carotenoids are known to be the two main anticancer mechanisms.Quantitative structure-activity relationship（QSAR） models of the two activities we...The antioxidant and gap junctional communication（GJC） activities of carotenoids are known to be the two main anticancer mechanisms.Quantitative structure-activity relationship（QSAR） models of the two activities were developed using stepwise regression and multilayer perceptron neural network based on the calculated descriptors of quantum chemistry.The results showed that the significant molecular descriptor related to the antioxidant activity of carotenoids was the HOMO-LUMO energy gap（EHL） and the molecular descriptor related to the GJC was the lowest unoccupied molecular orbital energy（ELUMO）.The two models of antioxidant activity both showed good predictive power,but the predictive power of the neural network QSAR model of antioxidant activity was better.In addition,the two GJC models have similar,moderate predictive power.The possible mechanisms of antioxidant activity and GJC of carotenoids were discussed.展开更多
Through lead isotope geochemical mapping in the Yunnan-Guizhou area geochemical steep zones (GSZ) have been established, which clearly reveal the junction relationship of the Cathaysian, Yangtze and Indo-China plates....Through lead isotope geochemical mapping in the Yunnan-Guizhou area geochemical steep zones (GSZ) have been established, which clearly reveal the junction relationship of the Cathaysian, Yangtze and Indo-China plates. GSZ are closey related to gravity Moho gradient zones and lithospheric thickness. The GSZ between the Yangtze and Cathaysian plates is consistent with the Shizong-Mile tectonic belt, where island are basalts are well developed. The Yangtze-Indo-China GSZ is parallel to the Jingdong-Mojiang volcanic belt in rift-island are environments. The evidence of geology, geophysics and geochemistry all indicates that Cathaysia was subducted towards the Yangtze plate and that the Yangtze plate was underthrust beneath the Indo-China, which took place from the Early Carboniferous to the Early Triassic.展开更多
The concept of fault junction is proposed to describe the relationship between the two faults by the authors. The junction relationship between Ganjiang and Tanlu faults is analyzed in this paper, and this has been el...The concept of fault junction is proposed to describe the relationship between the two faults by the authors. The junction relationship between Ganjiang and Tanlu faults is analyzed in this paper, and this has been elucidated through numerical simulation about the tectonic stress field analysis. Numerical simulation of the tectonic stress field conducted for the major mineralization stage of the Jiujiang-Ruichang junction area reveals that the stress field of the junction structure at the major mineralization stage shows a relatively close relationship with the formation of the ore deposits (occurrences).展开更多
基金Supported by the Chinese National Key Technologies R&D Program of 11th Five-year Plan (2006BAD27B06)the Fundamental Research Funds for the Central Universities and Education Foundation of Innovative Engineering Key Project of Education Department (707034)
文摘The antioxidant and gap junctional communication（GJC） activities of carotenoids are known to be the two main anticancer mechanisms.Quantitative structure-activity relationship（QSAR） models of the two activities were developed using stepwise regression and multilayer perceptron neural network based on the calculated descriptors of quantum chemistry.The results showed that the significant molecular descriptor related to the antioxidant activity of carotenoids was the HOMO-LUMO energy gap（EHL） and the molecular descriptor related to the GJC was the lowest unoccupied molecular orbital energy（ELUMO）.The two models of antioxidant activity both showed good predictive power,but the predictive power of the neural network QSAR model of antioxidant activity was better.In addition,the two GJC models have similar,moderate predictive power.The possible mechanisms of antioxidant activity and GJC of carotenoids were discussed.
基金This study was supported by the key project of Chinese Academy of Sciences KZ951-B1-413Project No.973 of the National Commission of Science and Technology(G1999043213).
文摘Through lead isotope geochemical mapping in the Yunnan-Guizhou area geochemical steep zones (GSZ) have been established, which clearly reveal the junction relationship of the Cathaysian, Yangtze and Indo-China plates. GSZ are closey related to gravity Moho gradient zones and lithospheric thickness. The GSZ between the Yangtze and Cathaysian plates is consistent with the Shizong-Mile tectonic belt, where island are basalts are well developed. The Yangtze-Indo-China GSZ is parallel to the Jingdong-Mojiang volcanic belt in rift-island are environments. The evidence of geology, geophysics and geochemistry all indicates that Cathaysia was subducted towards the Yangtze plate and that the Yangtze plate was underthrust beneath the Indo-China, which took place from the Early Carboniferous to the Early Triassic.
文摘The concept of fault junction is proposed to describe the relationship between the two faults by the authors. The junction relationship between Ganjiang and Tanlu faults is analyzed in this paper, and this has been elucidated through numerical simulation about the tectonic stress field analysis. Numerical simulation of the tectonic stress field conducted for the major mineralization stage of the Jiujiang-Ruichang junction area reveals that the stress field of the junction structure at the major mineralization stage shows a relatively close relationship with the formation of the ore deposits (occurrences).
