2,225 research outputs found

    Solar system tests for realistic f(T)f(T) models with nonminimal torsion-matter coupling

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    In the previous paper, we have constructed two f(T)f(T) models with nonminimal torsion-matter coupling extension, which are successful in describing the evolution history of the Universe including the radiation-dominated era, the matter-dominated era, and the present accelerating expansion. Meantime, the significant advantage of these models is that they could avoid the cosmological constant problem of Λ\LambdaCDM. However, the nonminimal coupling between matter and torsion will affect the tests of Solar system. In this paper, we study the effects of Solar system in these models, including the gravitation redshift, geodetic effect and perihelion preccesion. We find that Model I can pass all three of the Solar system tests. For Model II, the parameter is constrained by the measure of the perihelion precession of Mercury.Comment: 10 page

    catena-Poly[hexaaqua-1κO,2κO,3κ4 O-(μ4-3,5-dicarboxylatopyrazol-1-ido-3′:1:2:3κ6 O 5:N 1,O 5′:N 2,O 3:O 3′)(μ2-3,5-dicarboxylatopyrazol-1-ido-1:2κ4 N 2,O 3:N 1,O 5)-1,2-dicopper(II)-3-manganese(II)]

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    In the title compound, [Cu2Mn(C5HN2O4)2(H2O)6]n, the CuII ion is coordinated by two N atoms, two O atoms and one water O atom in a distorted square-pyramidal geometry. The MnII ion is coordinated by two O atoms and four water O atoms in a distorted octa­hedral geometry. Two pyrazolyl-3,5-dicarboxyl­ate anions chelate to two copper ions, forming a dinuclear unit, which further connects the MnII ions into chains extending along [100]. Both independent coordinated water mol­ecules on the MnII ion are disordered in a 50:50 fashion

    Synthesis and Cytotoxic Analysis of Some Disodium 3β,6β-Dihydroxysterol Disulfates

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    Disodium 3β,6β-dihydroxy-5α-cholestane disulfate (1) was synthesized in 4 steps with a high overall yield from cholesterol. First, cholesterol (4a) was converted to cholest-4-en-3,6-dione (5a) via oxidation with pyridinium chlorochromate (PCC) and then 5a was reduced by NaBH4 in the presence of NiCl2 to produce cholest-3β,6β-diol (6a). The reaction of 6a with the triethylamine-sulfur trioxide complex generated diammonium 3β,6β-dihydroxy-5α-cholestane disulfate (7a) and the treatment of 7a by cation exchange resin 732 (sodium form)(Na+) yielded the target steroid 1. Disodium 24-ethyl-3β,6β-dihydroxycholest-22-ene disulfate (2) and disodium 24-ethyl-3β,6β-dihydroxycholestane disulfate (3) were synthesized using a similar method. The cytotoxicity of these compounds against Sk-Hep-1 (human liver carcinoma cell line), H-292 (human lung carcinoma cell line), PC-3 (human prostate carcinoma cell line) and Hey-1B (human ovarian carcinoma cell line) cells was investigated. Our results indicate that presence of a cholesterol-type side chain at position 17 is necessary for their biological activity

    Synthesis and Cytotoxic Analysis of Some Disodium 3β,6β-Dihydroxysterol Disulfates

    Get PDF
    Disodium 3β,6β-dihydroxy-5α-cholestane disulfate (1) was synthesized in 4 steps with a high overall yield from cholesterol. First, cholesterol (4a) was converted to cholest-4-en-3,6-dione (5a) via oxidation with pyridinium chlorochromate (PCC) and then 5a was reduced by NaBH4 in the presence of NiCl2 to produce cholest-3β,6β-diol (6a). The reaction of 6a with the triethylamine-sulfur trioxide complex generated diammonium 3β,6β-dihydroxy-5α-cholestane disulfate (7a) and the treatment of 7a by cation exchange resin 732 (sodium form)(Na+) yielded the target steroid 1. Disodium 24-ethyl-3β,6β-dihydroxycholest-22-ene disulfate (2) and disodium 24-ethyl-3β,6β-dihydroxycholestane disulfate (3) were synthesized using a similar method. The cytotoxicity of these compounds against Sk-Hep-1 (human liver carcinoma cell line), H-292 (human lung carcinoma cell line), PC-3 (human prostate carcinoma cell line) and Hey-1B (human ovarian carcinoma cell line) cells was investigated. Our results indicate that presence of a cholesterol-type side chain at position 17 is necessary for their biological activity
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