The crystal structure of the title compound {[Mn(phen)2(OAc)(H2O)]ClO4}2H2O (phen = 1,10-phenanthroline) has been synthesized and determined by X-ray diffraction. The crystal is of triclinic, space group P?with a = 12...The crystal structure of the title compound {[Mn(phen)2(OAc)(H2O)]ClO4}2H2O (phen = 1,10-phenanthroline) has been synthesized and determined by X-ray diffraction. The crystal is of triclinic, space group P?with a = 12.7955(4), b = 15.0544(4), c = 16.2183(4) , ?= 64.479(1), b =67.526(1), g = 83.582(1), C52H40Cl2Mn2N8O15, Mr = 1197.70, V = 2600.1(1) ?, Dc = 1.530 g/cm3, F(000) = 1224, = 0.666 cm-1 and Z = 2. The final refinement gave R = 0.0691 and wR = 0.1821 for 6131 observed reflections with I > 2s(I). The cell of the complex contains two uniform mono-manganese molecules [Mn(phen)2(OAc)(H2O)]ClO4 and a solvate water molecule. Four nitrogen atoms from two chelating phenanthroline ligands and one oxygen atom from acetate ligate to the MnⅡ ion, forming a distorted octahedral geometry together with one coordinated water molecule. One ClO4- anion and one water molecule exist outside the cation [Mn(phen)2(OAc)- (H2O)]+ as a counter ion and solvate molecule, respectively.展开更多
Atomic force microscopy (AFM) was employed to quantitatively detect the interaction between a transcription factor, ZmDREBIA, and its target DNA sequence (DRE).The specificity of the interaction was revealed by compar...Atomic force microscopy (AFM) was employed to quantitatively detect the interaction between a transcription factor, ZmDREBIA, and its target DNA sequence (DRE).The specificity of the interaction was revealed by comparing the binding probability of ZmDREBIA to DRE element with core sequence ACCGAC and to the ERE element with core sequence AGCCGCC. Moreover, the single-molecular unbinding force between ZmDREBIA and DRE element was determined using Poisson statistical method to be 99±9 pN.The results indicated that AFM could serve as a sensitive and reliable technique to probe the interaction properties of the transcription factor and DNA element at single-molecular level, thus indicating that AFM is advantageous over the traditional methods, such as the electrophoretic mobility shift assay, regarding to the functional analysis of transcription factors.展开更多
The authors present a semi-definite relaxation algorithm for the scheduling problem with controllable times on a single machine. Their approach shows how to relate this problem with the maximum vertex-cover problem wi...The authors present a semi-definite relaxation algorithm for the scheduling problem with controllable times on a single machine. Their approach shows how to relate this problem with the maximum vertex-cover problem with kernel constraints (MKVC).The established relationship enables to transfer the approximate solutions of MKVCinto the approximate solutions for the scheduling problem. Then, they show how to obtain an integer approximate solution for MKVC based on the semi-definite relaxation and randomized rounding technique.展开更多
基金This work was supported by the State Key Basic Research and Development Plan (G1998010100) and NNSFC (No. 30170229 29973047 and 39970177)
文摘The crystal structure of the title compound {[Mn(phen)2(OAc)(H2O)]ClO4}2H2O (phen = 1,10-phenanthroline) has been synthesized and determined by X-ray diffraction. The crystal is of triclinic, space group P?with a = 12.7955(4), b = 15.0544(4), c = 16.2183(4) , ?= 64.479(1), b =67.526(1), g = 83.582(1), C52H40Cl2Mn2N8O15, Mr = 1197.70, V = 2600.1(1) ?, Dc = 1.530 g/cm3, F(000) = 1224, = 0.666 cm-1 and Z = 2. The final refinement gave R = 0.0691 and wR = 0.1821 for 6131 observed reflections with I > 2s(I). The cell of the complex contains two uniform mono-manganese molecules [Mn(phen)2(OAc)(H2O)]ClO4 and a solvate water molecule. Four nitrogen atoms from two chelating phenanthroline ligands and one oxygen atom from acetate ligate to the MnⅡ ion, forming a distorted octahedral geometry together with one coordinated water molecule. One ClO4- anion and one water molecule exist outside the cation [Mn(phen)2(OAc)- (H2O)]+ as a counter ion and solvate molecule, respectively.
文摘Atomic force microscopy (AFM) was employed to quantitatively detect the interaction between a transcription factor, ZmDREBIA, and its target DNA sequence (DRE).The specificity of the interaction was revealed by comparing the binding probability of ZmDREBIA to DRE element with core sequence ACCGAC and to the ERE element with core sequence AGCCGCC. Moreover, the single-molecular unbinding force between ZmDREBIA and DRE element was determined using Poisson statistical method to be 99±9 pN.The results indicated that AFM could serve as a sensitive and reliable technique to probe the interaction properties of the transcription factor and DNA element at single-molecular level, thus indicating that AFM is advantageous over the traditional methods, such as the electrophoretic mobility shift assay, regarding to the functional analysis of transcription factors.
文摘The authors present a semi-definite relaxation algorithm for the scheduling problem with controllable times on a single machine. Their approach shows how to relate this problem with the maximum vertex-cover problem with kernel constraints (MKVC).The established relationship enables to transfer the approximate solutions of MKVCinto the approximate solutions for the scheduling problem. Then, they show how to obtain an integer approximate solution for MKVC based on the semi-definite relaxation and randomized rounding technique.
