Serum response factor (SRF) is a ubiquitously expressed transcription factor that binds a 10-bp element known as the CArG box, located in the proximal regulatory region of hundreds of target genes. SRF activates target genes in a cell- and context-dependent manner by assembling unique combinations of cofactors over CArG elements. One particularly strong SRF cofactor, myocardin (MYOCD), acts as a component of a molecular switch for smooth muscle cell (SMC) differentiation by activating cytoskeletal and contractile genes harboring SRF-binding CArG elements. Here we report that the human ACTG2 promoter, containing four conserved CArG elements, displays SMC-specific basal activity and is highly induced in the presence of MYOCD. Stable transfection of a non-SMC cell type with Myocd elicits elevations in endogenous Actg2 mRNA. Gel shift and luciferase assays reveal a strong bias for MYOCD-dependent transactivation through CArG2 of the human ACTG2 promoter. Substitution of CArG2 with other CArGs, including a consensus CArG element, fails to reconstitute full MYOCD-dependent ACTG2 promoter stimulation. Mutation of an adjacent binding site for NKX3.1 reduces MYOCD-dependent transactivation of the ACTG2 promoter. Co-immunoprecipitation, glutathione S-transferase pulldown, and luciferase assays show a physical and functional association between MYOCD and NKX3.1; no such functional relationship is evident with the related NKX2.5 transcription factor despite its interaction with MYOCD. These results demonstrate the ability of MYOCD to discriminate among several juxtaposed CArG elements, presumably through its novel partnership with NKX3.1, to optimally transactivate the human ACTG2 promoter.
Four wholly aromatic Poly (amide-sulfonamide) s (PASAs) were synthesized by the solution polycondensation from m-chlorosulfonyl benzoyl chloride and aromatic diamines in tetramethylene sulfone and substituted 2-Piucoline as the acid acceptor. The chemical structures of PASAs were characterized by FTIR, 1 HNMR. Thermal properties of PASAs were investigated by TGA.
Benzaldehyde 1, 2-propanediol acetal was synthesized from benzaldehyde and 1, 2-propanediol in the presence of ionic liquid [HMIM]HSO 4 . The effect of the amount of catalyst, reaction time, reaction temperature, and the molar ratio of raw materials agent on the product yield was investigated respectively. Experimental results demonstrate that ionic liquid [HMIM]HSO 4 is a good catalyst for preparation of benzaldehyde 1, 2-propanediol acetal. Results showed the optimal reaction conditions are as follows: the mole ratio of benzaldehyde to 1, 2-propanediol is 1：1.3, the amount of catalyst is 3.0g, the reaction temperature is 343K, and the reaction time is 4h. The achieved yield of acetal is 78. 7%.
A low expense chloro-monomer, 1-(4'-chloro-1-benzoyl)-3-(4'-1-choro-benzene sulfonyl)-benzene(CBCBSB), was synthesized by the Friedel-Crafts reaction of m-chlorosu1fonyl benzoyl chloride with chlorobenzene. A novel poly (aryl ether sulfone ketone)s (PAESK) containing m-sulfonylbenzoyl linkages in the main chains were prepared by copolycondensation of CBCBSB with hydroquinone in N, N-Dimethylacetamide (DMAc). The structure of PAESK was confirmed by FT-IR, 1H-NMR and characterized by XRD. thermogravimetry (TG) and Differential Scanning Calorimeter (DSC) were carried out to demonstrate its good melt processability. The polymer exhibited the better solubility in chloroform, N-methyl-2-pyrrlidone(NMP), dimethylacetamide(DMAC), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) and excellent mechanical performance.
A method based on OEMD (Orthogonal Empirical Mode Decomposition) and the theory of time-frequency entropy was applied to detect different rail fastener conditions. The original vertical vibration acceleration response of rail under different fastening conditions was obtained from outdoor experiment. The OEMD method was used to get orthogonal IMFs (Intrinsic Mode Functions) of the original vibration signal. The Hilbert time-frequency spectrum was then obtained based on the orthogonal IMFs and corresponding entropy was calculated and compared. The results show that the method is available to detect different rail fastener conditions.
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