2,225 research outputs found
Solar system tests for realistic models with nonminimal torsion-matter coupling
In the previous paper, we have constructed two 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 CDM. 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)]
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 octaÂhedral geometry. Two pyrazolyl-3,5-dicarboxylÂate 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 molÂecules on the MnII ion are disordered in a 50:50 fashion
Synthesis and Cytotoxic Analysis of Some Disodium 3β,6β-Dihydroxysterol Disulfates
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
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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