Studied on the law and interaction of hydrological cycle and social water circulation on the earth,it is pointed out that the water environment,water resources and water cycle are the unity of water movement.The roots...Studied on the law and interaction of hydrological cycle and social water circulation on the earth,it is pointed out that the water environment,water resources and water cycle are the unity of water movement.The roots of contemporary crisis are also analyzed.The strategy of water environment recovery and social water healthy cycle is proposed and applied in many cities,which has achieved good results.展开更多
In this short review we describe implications of age-related changes of protein and DNA oxidation as a public mechanism of biological aging. Oxidatively modified protein and DNA have been demonstrated to increase with...In this short review we describe implications of age-related changes of protein and DNA oxidation as a public mechanism of biological aging. Oxidatively modified protein and DNA have been demonstrated to increase with advancing age in rodents. Half-life of proteins is extended and DNA repair activity declines in old animals. Dietary restriction initiated late in life can shorten the half-life of proteins to levels of young animals, thus contributing to reduce level of altered proteins in old animals by the regimen. Regular exercise reduced oxidatively modified proteins in the brain with improved cognitive functions. It attenuated oxidative stress in the liver, i.e., ameliorating activation of nuclear factor κB, increasing reduced glutathione, and decreasing oxidized guanine base in nuclear and mitochondrial DNA. These findings suggest that regular exercise has systemic effects in reducing oxidative stress. Thus, life-styles such as diet and exercise may extend health span, by up-regulating overall anti-oxidant capacities that include proteins involved in protein turnover and DNA repair, resulting in reduction of damaged proteins and DNA that potentially promote physiological and pathological aging.展开更多
In the field of adiabatic correction for complex reactions,a simple one-stage kinetic model was used to estimate the real reaction kinetics.However,this assumption simplified the real process,inevitably generated inac...In the field of adiabatic correction for complex reactions,a simple one-stage kinetic model was used to estimate the real reaction kinetics.However,this assumption simplified the real process,inevitably generated inaccurate or even unsafe results.Therefore,it was necessary to find a new correction method for complex reactions.In this work,esterification of acetic anhydride by methanol was chosen as an object reaction of study.The reaction was studied under different conditions by Reaction Calorimeter(RC1).Then,Thermal Safety Software(TSS)was used to establish the kinetic model and estimate the parameters,where,activation energies for three stages were67.09,81.02,73.77 kJ?mol^(-1)respectively,and corresponding frequency factors in logarithmic form were 16.05,19.59,15.72 s^(-1).In addition,two adiabatic tests were performed by Vent Sizing Package2(VSP2).For accurate correction of VSP2 tests,a new correction method based on Enhanced Fisher method was proposed.Combined with kinetics,adiabatic correction of esterification reaction was achieved.Through this research,accurate kinetic parameters for a three-step kinetic model of the esterification reaction were acquired.Furthermore,the correlation coefficients between simulated curves and corrected curves were 0.976 and 0.968,which proved the accuracy of proposed new adiabatic correction method.Based on this new method,conservative corrected results were able to be acquired and be applied in safety assessment.展开更多
Objective： To study whether the range of knee flexion （ROF） is affected by geometrical mismatch of the femoral component and the resultant change in the pos- terior condylar offset （PCO） after high-flexion poster...Objective： To study whether the range of knee flexion （ROF） is affected by geometrical mismatch of the femoral component and the resultant change in the pos- terior condylar offset （PCO） after high-flexion posterior-sta- bilized total knee arthroplasty （TKA）. Methods： One hundred osteoarthritic patients （50 males and 50 females） underwent femoral osteotomy by the ante- rior referencing technique. The PCO for each patient was measured from lateral radiographs before, during and 2 years after TKA. The thickness of the joint cartilage was mea- sured by magnetic resonance imaging before TKA and added onto the radiographic measurement. The relationship between changes in the PCO and improvements in the ROF before, during and 2 years after TKA were statistically analyzed. Results： Compared with the preoperative value, the PCO was reduced by （3.45±3.28） mm after TKA, with a significantly larger reduction observed in female patients than male patients （P〈0.05）. When examining the subject popu- lation as a whole, there was a significant positive correla- tion between PCO and ROF improvement during TKA （P〈 0.05）, but this improvement was not maintained 2 years after TKA （P〉0.05）. However, when male and female patients were analyzed separately, there was a significant positive correlation between PCO change and ROF improvement for both sexes at both time points （all P〈0.05）. Conclusions： Restoration of PCO plays an important role in the optimization of knee flexion even after posteriorstabilized TKA. Femoral components based on Caucasian anatomic characteristics could not match the native anatomy of distal femurs in Chinese population especially female Chinese. Rotated resection of distal femur with anterior referencing technique usually leads to a decreased PCO and therefore reduces maximal obtainable flexion.展开更多
文摘Studied on the law and interaction of hydrological cycle and social water circulation on the earth,it is pointed out that the water environment,water resources and water cycle are the unity of water movement.The roots of contemporary crisis are also analyzed.The strategy of water environment recovery and social water healthy cycle is proposed and applied in many cities,which has achieved good results.
文摘In this short review we describe implications of age-related changes of protein and DNA oxidation as a public mechanism of biological aging. Oxidatively modified protein and DNA have been demonstrated to increase with advancing age in rodents. Half-life of proteins is extended and DNA repair activity declines in old animals. Dietary restriction initiated late in life can shorten the half-life of proteins to levels of young animals, thus contributing to reduce level of altered proteins in old animals by the regimen. Regular exercise reduced oxidatively modified proteins in the brain with improved cognitive functions. It attenuated oxidative stress in the liver, i.e., ameliorating activation of nuclear factor κB, increasing reduced glutathione, and decreasing oxidized guanine base in nuclear and mitochondrial DNA. These findings suggest that regular exercise has systemic effects in reducing oxidative stress. Thus, life-styles such as diet and exercise may extend health span, by up-regulating overall anti-oxidant capacities that include proteins involved in protein turnover and DNA repair, resulting in reduction of damaged proteins and DNA that potentially promote physiological and pathological aging.
文摘In the field of adiabatic correction for complex reactions,a simple one-stage kinetic model was used to estimate the real reaction kinetics.However,this assumption simplified the real process,inevitably generated inaccurate or even unsafe results.Therefore,it was necessary to find a new correction method for complex reactions.In this work,esterification of acetic anhydride by methanol was chosen as an object reaction of study.The reaction was studied under different conditions by Reaction Calorimeter(RC1).Then,Thermal Safety Software(TSS)was used to establish the kinetic model and estimate the parameters,where,activation energies for three stages were67.09,81.02,73.77 kJ?mol^(-1)respectively,and corresponding frequency factors in logarithmic form were 16.05,19.59,15.72 s^(-1).In addition,two adiabatic tests were performed by Vent Sizing Package2(VSP2).For accurate correction of VSP2 tests,a new correction method based on Enhanced Fisher method was proposed.Combined with kinetics,adiabatic correction of esterification reaction was achieved.Through this research,accurate kinetic parameters for a three-step kinetic model of the esterification reaction were acquired.Furthermore,the correlation coefficients between simulated curves and corrected curves were 0.976 and 0.968,which proved the accuracy of proposed new adiabatic correction method.Based on this new method,conservative corrected results were able to be acquired and be applied in safety assessment.
文摘Objective： To study whether the range of knee flexion （ROF） is affected by geometrical mismatch of the femoral component and the resultant change in the pos- terior condylar offset （PCO） after high-flexion posterior-sta- bilized total knee arthroplasty （TKA）. Methods： One hundred osteoarthritic patients （50 males and 50 females） underwent femoral osteotomy by the ante- rior referencing technique. The PCO for each patient was measured from lateral radiographs before, during and 2 years after TKA. The thickness of the joint cartilage was mea- sured by magnetic resonance imaging before TKA and added onto the radiographic measurement. The relationship between changes in the PCO and improvements in the ROF before, during and 2 years after TKA were statistically analyzed. Results： Compared with the preoperative value, the PCO was reduced by （3.45±3.28） mm after TKA, with a significantly larger reduction observed in female patients than male patients （P〈0.05）. When examining the subject popu- lation as a whole, there was a significant positive correla- tion between PCO and ROF improvement during TKA （P〈 0.05）, but this improvement was not maintained 2 years after TKA （P〉0.05）. However, when male and female patients were analyzed separately, there was a significant positive correlation between PCO change and ROF improvement for both sexes at both time points （all P〈0.05）. Conclusions： Restoration of PCO plays an important role in the optimization of knee flexion even after posteriorstabilized TKA. Femoral components based on Caucasian anatomic characteristics could not match the native anatomy of distal femurs in Chinese population especially female Chinese. Rotated resection of distal femur with anterior referencing technique usually leads to a decreased PCO and therefore reduces maximal obtainable flexion.
