L（ s, t）-labeling is a variation of graph coloring which is motivated by a special kind of the channel assignment problem. Let s and t be any two nonnegative integers. An L （s, t）-labeling of a graph G is an assig...L（ s, t）-labeling is a variation of graph coloring which is motivated by a special kind of the channel assignment problem. Let s and t be any two nonnegative integers. An L （s, t）-labeling of a graph G is an assignment of integers to the vertices of G such that adjacent vertices receive integers which differ by at least s, and vertices that are at distance of two receive integers which differ by at least t. Given an L（s, t） -labeling f of a graph G, the L（s, t） edge span of f, βst （ G, f） = max { ｜f（u） -f（v）｜： （ u, v） ∈ E（G） } is defined. The L（ s, t） edge span of G, βst（G）, is minβst（G,f）, where the minimum runs over all L（s, t）-labelings f of G. Let T be any tree with a maximum degree of △≥2. It is proved that if 2s≥t≥0, then βst（T） =（ [△/2 ] - 1）t ＋s; if 0≤2s 〈 t and △ is even, then βst（T） = [ （△ - 1） t/2 ] ; and if 0 ≤2s 〈 t and △ is odd, then βst（T） = （△ - 1） t/2 ＋ s. Thus, the L（s, t） edge spans of the Cartesian product of two paths and of the square lattice are completely determined.展开更多
Genistein, a potent antioxidant compound, protects dopaminergic neurons in a mouse model of Parkinson＇s disease. However, the mecha- nism underlying this action remains unknown. This study investigated human SH-SYSY ...Genistein, a potent antioxidant compound, protects dopaminergic neurons in a mouse model of Parkinson＇s disease. However, the mecha- nism underlying this action remains unknown. This study investigated human SH-SYSY cells overexpressing the A53T mutant of α-synuclein. Four groups of cells were assayed： a control group （without any treatment）, a genistein group （incubated with 20 μM genistein）, a rote- none group （treated with 50 μM rotenone）, and a rotenone ＋ genistein group （incubated with 20 μM genistein and then treated with 50μM rotenone）. A lactate dehydrogenase release test confirmed the protective effect of genistein, and genistein remarkably reversed mitochondrial oxidative injury caused by rotenone. Western blot assays showed that BCL-2 and Beclin ! levels were markedly higher in the genistein group than in the rotenone group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling revealed that genistein inhibited rotenone-induced apoptosis in SH-SYSY cells. Compared with the control group, the expression of NFE2L2 and HMOX1 was significantly increased in the genistein ＋ rotenone group. However, after treatment with estrogen receptor and NFE2L2 channel blockers （ICI-182780 and ML385, respectively）, genistein could not elevate NFE2L2 and HMOX1 expression. ICI-182780 effectively prevented genistein-mediated phosphorylation of NFE2L2 and remarkably suppressed phosphorylation of AKT, a protein downstream of the estrogen receptor. These findings confirm that genistein has neuroprotective effects in a cell model of Parkinson＇s dis- ease. Genistein can reduce oxidative stress damage and cell apoptosis by activating estrogen receptors and NFE2L2 channels.展开更多
A black hole is essentially a relativistic as well as a quantum object. Therefore the information paradox of black holes is a consequence of the clash between these two most fundamental theories of modern physics. It ...A black hole is essentially a relativistic as well as a quantum object. Therefore the information paradox of black holes is a consequence of the clash between these two most fundamental theories of modern physics. It is logical to conclude that a resolution of the problem requires some form of a quantum gravity theory. The present work proposes such a resolution using set theory and pointless spacetime geometry.展开更多
基金The National Natural Science Foundation of China(No10671033)Southeast University Science Foundation ( NoXJ0607230)
文摘L（ s, t）-labeling is a variation of graph coloring which is motivated by a special kind of the channel assignment problem. Let s and t be any two nonnegative integers. An L （s, t）-labeling of a graph G is an assignment of integers to the vertices of G such that adjacent vertices receive integers which differ by at least s, and vertices that are at distance of two receive integers which differ by at least t. Given an L（s, t） -labeling f of a graph G, the L（s, t） edge span of f, βst （ G, f） = max { ｜f（u） -f（v）｜： （ u, v） ∈ E（G） } is defined. The L（ s, t） edge span of G, βst（G）, is minβst（G,f）, where the minimum runs over all L（s, t）-labelings f of G. Let T be any tree with a maximum degree of △≥2. It is proved that if 2s≥t≥0, then βst（T） =（ [△/2 ] - 1）t ＋s; if 0≤2s 〈 t and △ is even, then βst（T） = [ （△ - 1） t/2 ] ; and if 0 ≤2s 〈 t and △ is odd, then βst（T） = （△ - 1） t/2 ＋ s. Thus, the L（s, t） edge spans of the Cartesian product of two paths and of the square lattice are completely determined.
基金supported by a grant from the National Key Research and Development Plan of China,No.2016YFC1101500the National Natural Science Foundation of China,No.11672332,11102235,8167050417+1 种基金the Key Science and Technology Support Foundation of Tianjin City of China,No.17YFZCSY00620the Natural Science Foundation of Tianjin City of China,No.15JCYBJC28600,17JCZDJC35400
文摘Genistein, a potent antioxidant compound, protects dopaminergic neurons in a mouse model of Parkinson＇s disease. However, the mecha- nism underlying this action remains unknown. This study investigated human SH-SYSY cells overexpressing the A53T mutant of α-synuclein. Four groups of cells were assayed： a control group （without any treatment）, a genistein group （incubated with 20 μM genistein）, a rote- none group （treated with 50 μM rotenone）, and a rotenone ＋ genistein group （incubated with 20 μM genistein and then treated with 50μM rotenone）. A lactate dehydrogenase release test confirmed the protective effect of genistein, and genistein remarkably reversed mitochondrial oxidative injury caused by rotenone. Western blot assays showed that BCL-2 and Beclin ! levels were markedly higher in the genistein group than in the rotenone group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling revealed that genistein inhibited rotenone-induced apoptosis in SH-SYSY cells. Compared with the control group, the expression of NFE2L2 and HMOX1 was significantly increased in the genistein ＋ rotenone group. However, after treatment with estrogen receptor and NFE2L2 channel blockers （ICI-182780 and ML385, respectively）, genistein could not elevate NFE2L2 and HMOX1 expression. ICI-182780 effectively prevented genistein-mediated phosphorylation of NFE2L2 and remarkably suppressed phosphorylation of AKT, a protein downstream of the estrogen receptor. These findings confirm that genistein has neuroprotective effects in a cell model of Parkinson＇s dis- ease. Genistein can reduce oxidative stress damage and cell apoptosis by activating estrogen receptors and NFE2L2 channels.
文摘A black hole is essentially a relativistic as well as a quantum object. Therefore the information paradox of black holes is a consequence of the clash between these two most fundamental theories of modern physics. It is logical to conclude that a resolution of the problem requires some form of a quantum gravity theory. The present work proposes such a resolution using set theory and pointless spacetime geometry.
