Telomeres are protective structures at the ends of eukaryotic chromosomes. The loss of telomeres through cell division and oxidative stress is related to cellular aging, organismal growth and disease. In this way, tel...Telomeres are protective structures at the ends of eukaryotic chromosomes. The loss of telomeres through cell division and oxidative stress is related to cellular aging, organismal growth and disease. In this way, telomeres link molecular and cellular mechanisms with organismal processes, and may explain variation in a number of important life-history traits. Here, we discuss how telomere biology relates to the study of physiological ecology and life history evolution. We emphasize current knowledge on how telomeres may relate to growth, survival and lifespan in natural populations. We finish by examining interest- ing new connections between telomeres and the glucocorticoid stress response. Glucocorticoids are often employed as indices of physiological condition, and there is evidence that the glucocorticoid stress response is adaptive. We suggest that one way that glucocorticoids impact organismal survival is through elevated oxidative stress and telomere loss. Future work needs to establish and explore the link between the glucocorticoid stress response and telomere shortening in natural populations. If a link is found, it provides an explanatory mechanism by which environmental perturbation impacts life history trajectories [Current Zoology 56 （6）： 714-727, 2010].展开更多
We investigated the role of GA3, uniconazole-P and IAA on tension wood formation, in particular the vessel features, in Fraxinu smandshurica seedlings. Ninety seedlings were used and treated with applications of GA3 a...We investigated the role of GA3, uniconazole-P and IAA on tension wood formation, in particular the vessel features, in Fraxinu smandshurica seedlings. Ninety seedlings were used and treated with applications of GA3 and/or IAA to the apical bud of the stem using a micropipette. Applications of GA3 or GA3 plus IAA with uniconazole-P strongly increased cell number of tension wood in comparison to that of no-uniconazole-P-applied, indicated that GA3 is more efficient than IAA on xylem cell production. Wood quality was also regulated by relative concentration ratio of GA3 to lAA, because of the vessel elements differentiation, density and size were controlled by GA3 and/or IAA on the different levels. These results suggested that the relative concentration ratio of GA3 to IAA and interactions of them are essential in regulating both wood quality and wood quantity, and tension wood formation in this species.展开更多
Objective:To probe into the intervening action of polysaccharides of Zhu Zi Shen(Rhizoma Panacis Majoris)(PZZS) on oxidative stress and hemodynamics in rats with adriamycin-induced chronic congestive heart failure(CHF...Objective:To probe into the intervening action of polysaccharides of Zhu Zi Shen(Rhizoma Panacis Majoris)(PZZS) on oxidative stress and hemodynamics in rats with adriamycin-induced chronic congestive heart failure(CHF).Methods:After SD rats were successfully modeled with adriamycin,they were randomly divided into a normal control group,a model group,a PZZS group,and a captopril group,and were administrated respectively.At the end of experiment,the hemodynamic function,whole heart weight index,and the blood CK,SOD,MDA,NO,NOS were detected;and the myocardial morphological examinations were carried out.Results:Compared with the normal control group,the arterial systolic pressure(SBP),diastolic pressure(DBP),mean arterial pressure(MAP),heart rate(HR),left ventricular systolic peak(LVSP),and left ventricular pressure change rate(dp/dtmax) significantly decreased,and left ventricular end diastolic pressure(LVEDP),whole heart weight index,the blood CK,MDA,NO,NOS significantly increased in the model group.PZZS significantly improved the hemodynamic function,lowered the MDA and NO levels,and decreased the CK and NOS activities in the CHF rats.Conclusion:PZZS can improve the hemodynamic function,and alleviate the oxidative stress reaction in the CHF rat.展开更多
Within the framework of the dynamical cluster decay model （DCM）, the in evaporation cross-sections （σ1n） of cold fusion reactions （Pb and Bi targets） are calculated for ZCN = 104-113 superheavy nuclei. The calc...Within the framework of the dynamical cluster decay model （DCM）, the in evaporation cross-sections （σ1n） of cold fusion reactions （Pb and Bi targets） are calculated for ZCN = 104-113 superheavy nuclei. The calculations are carried out in the fixed range of excitation energy ECN = 15 ± 1 MeV, so that the comparative analysis of reaction dynamics can be worked out. First of all, the fission barriers （Bf ） and neutron separation energies （S1n） are estimated to account the decreasing cross-sections of cold fusion reactions. In addition to this, the importance of hot optimum orientations of β24-deformed nuclei over cold one is explored at fixed angular momentum and neck-length parameters. The hot optimum orientations support all the target-projectile （t,p） combinations, which are explored experimentally in the cold fusion reactions. Some new target-projectile combinations are also predicted for future exploration. Further, the In cross-sections are addressed for ZCN = 104-113 superheavy nuclei at comparable excitation energies which show the decent agrement with experimental data upto ZCN = 109 nuclei. Finally, to understand the dynamics of higher-Z superheavy nuclei, the cross-sections are also calculated at maximum available energies around the Coulomb barrier and the effect of non-sticking moment of inertia （INS） is also investigated at these energies.展开更多
According to the principle of thermal activation process, the energy state of a material under the action of stress is a function of local stress. A generalized Butler-Volmer relationship for the electrode reaction on...According to the principle of thermal activation process, the energy state of a material under the action of stress is a function of local stress. A generalized Butler-Volmer relationship for the electrode reaction on the surface of a curved electrode is derived,which takes account of the effects of local stress and the radius of mean curvature. From this relationship, the overpotential is found to be proportional to hydrostatic stress and the activation volume under the condition of open circuit. The conditions for the deposition of the material made solely from solute atoms and the formation of surface pits and porous structures are obtained,using the generalized Butler-Volmer relationship.展开更多
文摘Telomeres are protective structures at the ends of eukaryotic chromosomes. The loss of telomeres through cell division and oxidative stress is related to cellular aging, organismal growth and disease. In this way, telomeres link molecular and cellular mechanisms with organismal processes, and may explain variation in a number of important life-history traits. Here, we discuss how telomere biology relates to the study of physiological ecology and life history evolution. We emphasize current knowledge on how telomeres may relate to growth, survival and lifespan in natural populations. We finish by examining interest- ing new connections between telomeres and the glucocorticoid stress response. Glucocorticoids are often employed as indices of physiological condition, and there is evidence that the glucocorticoid stress response is adaptive. We suggest that one way that glucocorticoids impact organismal survival is through elevated oxidative stress and telomere loss. Future work needs to establish and explore the link between the glucocorticoid stress response and telomere shortening in natural populations. If a link is found, it provides an explanatory mechanism by which environmental perturbation impacts life history trajectories [Current Zoology 56 （6）： 714-727, 2010].
文摘We investigated the role of GA3, uniconazole-P and IAA on tension wood formation, in particular the vessel features, in Fraxinu smandshurica seedlings. Ninety seedlings were used and treated with applications of GA3 and/or IAA to the apical bud of the stem using a micropipette. Applications of GA3 or GA3 plus IAA with uniconazole-P strongly increased cell number of tension wood in comparison to that of no-uniconazole-P-applied, indicated that GA3 is more efficient than IAA on xylem cell production. Wood quality was also regulated by relative concentration ratio of GA3 to lAA, because of the vessel elements differentiation, density and size were controlled by GA3 and/or IAA on the different levels. These results suggested that the relative concentration ratio of GA3 to IAA and interactions of them are essential in regulating both wood quality and wood quantity, and tension wood formation in this species.
文摘Objective:To probe into the intervening action of polysaccharides of Zhu Zi Shen(Rhizoma Panacis Majoris)(PZZS) on oxidative stress and hemodynamics in rats with adriamycin-induced chronic congestive heart failure(CHF).Methods:After SD rats were successfully modeled with adriamycin,they were randomly divided into a normal control group,a model group,a PZZS group,and a captopril group,and were administrated respectively.At the end of experiment,the hemodynamic function,whole heart weight index,and the blood CK,SOD,MDA,NO,NOS were detected;and the myocardial morphological examinations were carried out.Results:Compared with the normal control group,the arterial systolic pressure(SBP),diastolic pressure(DBP),mean arterial pressure(MAP),heart rate(HR),left ventricular systolic peak(LVSP),and left ventricular pressure change rate(dp/dtmax) significantly decreased,and left ventricular end diastolic pressure(LVEDP),whole heart weight index,the blood CK,MDA,NO,NOS significantly increased in the model group.PZZS significantly improved the hemodynamic function,lowered the MDA and NO levels,and decreased the CK and NOS activities in the CHF rats.Conclusion:PZZS can improve the hemodynamic function,and alleviate the oxidative stress reaction in the CHF rat.
基金Supported by the Council of Scientific and Industrial Research(CSIR),in the Form of Research Project Grant No.03(1341)/15/EMR-Ⅱ and to DST,New DelhiINSPIRE-Fellowship Grant No.DST/INSPIRE/03/2015/000199
文摘Within the framework of the dynamical cluster decay model （DCM）, the in evaporation cross-sections （σ1n） of cold fusion reactions （Pb and Bi targets） are calculated for ZCN = 104-113 superheavy nuclei. The calculations are carried out in the fixed range of excitation energy ECN = 15 ± 1 MeV, so that the comparative analysis of reaction dynamics can be worked out. First of all, the fission barriers （Bf ） and neutron separation energies （S1n） are estimated to account the decreasing cross-sections of cold fusion reactions. In addition to this, the importance of hot optimum orientations of β24-deformed nuclei over cold one is explored at fixed angular momentum and neck-length parameters. The hot optimum orientations support all the target-projectile （t,p） combinations, which are explored experimentally in the cold fusion reactions. Some new target-projectile combinations are also predicted for future exploration. Further, the In cross-sections are addressed for ZCN = 104-113 superheavy nuclei at comparable excitation energies which show the decent agrement with experimental data upto ZCN = 109 nuclei. Finally, to understand the dynamics of higher-Z superheavy nuclei, the cross-sections are also calculated at maximum available energies around the Coulomb barrier and the effect of non-sticking moment of inertia （INS） is also investigated at these energies.
文摘According to the principle of thermal activation process, the energy state of a material under the action of stress is a function of local stress. A generalized Butler-Volmer relationship for the electrode reaction on the surface of a curved electrode is derived,which takes account of the effects of local stress and the radius of mean curvature. From this relationship, the overpotential is found to be proportional to hydrostatic stress and the activation volume under the condition of open circuit. The conditions for the deposition of the material made solely from solute atoms and the formation of surface pits and porous structures are obtained,using the generalized Butler-Volmer relationship.
