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p. 180-188
Received: 30 April 2006; in revised form: 8 February 2007 / Accepted: 12 February 2007 / Published: 7 March 2007
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| Download PDF Full-text (144 KB) Abstract: One of the room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazoliumchloride ([BMIM]Cl) was chosen to prepare the concentrated solutions of Polyacrylonitrile(PAN). The rheological behaviors of the solutions were measured with rotational rheometryunder different conditions, including temperatures, concentration, and molecular weight ofPAN. The solutions exhibited shear-thinning behaviors, similar to that of PAN/DMFsolutions. The viscosities decreased with the increasing of shear rates. However, theviscosity decreased sharply at high shear rates when the concentration was up to 16wt%. Thedependence of the viscosity on temperature was analyzed through the determination of theapparent activation energy. Unusually, the viscosity of solutions of higher concentration islower than that of lower concentration. Similarly, the viscosity of low molecular weightPAN was higher than high molecular weight PAN at high shear rates. The dynamicrheological measurement indicates the loss modulus is much higher than storage modulus.The trend of complex viscosity is similar with the result of static rheological measurement.The interaction between PAN and ionic liquid [BMIM]Cl was discussed.
p. 189-203
Received: 14 January 2007 / Accepted: 2 March 2007 / Published: 9 March 2007
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| Download PDF Full-text (110 KB) Abstract: The aim of the paper is to present the results obtained by utilization of an originalapproach called Molecular Descriptors Family on Structure-Property (MDF-SPR) andStructure-Activity Relationships (MDF-SAR) applied on classes of chemical compoundsand its usefulness as precursors of models elaboration of new compounds with betterproperties and/or activities and low production costs. The MDF-SPR/MDF-SARmethodology integrates the complex information obtained from compound’s structure inunitary efficient models in order to explain properties/activities. The methodology has beenapplied on a number of thirty sets of chemical compounds. The best subsets of moleculardescriptors family members able to estimate and predict property/activity of interest wereidentified and were statistically and visually analyzed. The MDF-SPR/MDF-SAR modelswere validated through internal and/or external validation methods. The estimation andprediction abilities of the MDF-SPR/MDF-SAR models were compared with previousreported models by applying of correlated correlation analysis, which revealed that theMDF-SPR/MDF-SAR methodology is reliable. The MDF-SPR/MDF-SAR methodologyopens a new pathway in understanding the relationships between compound’s structure andproperty/activity, in property/activity prediction, and in discovery, investigation andcharacterization of new chemical compounds, more competitive as costs andproperty/activity, being a method less expensive comparative with experimental methods.
p. 204-213
Received: 14 December 2006 / Accepted: 26 February 2007 / Published: 9 March 2007
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| Download PDF Full-text (149 KB) Abstract: The expression of mitochondrial voltage-dependent anion channels (VDAC) mayunderlie the protective effects of Limonium sinense (Girard) Ktze root extracts (LSE) againstcarbon tetrachloride-induced liver damage. Pretreatment of mice with 100 mg/kg, 200mg/kg or 400 mg/kg LSE significantly blocked the carbon tetrachloride-induced increase inboth serum aspartate aminotransferase (sAST) and serum alanine aminotransferase (sALT)levels. Ultrastructural observations by electron microscope confirmed hepatoprotection,showing decreased nuclear condensation, ameliorated mitochondrial fragmentation of thecristae and less lipid deposition. Pretreatment with LSE prevented the decrease of thedisruption of mitochondrial membrane potential (15.3%) observed in the liver of the carbontetrachloride-insulted mice, further demonstrating the mitochondrial protection. In addition,LSE treatment (100-400 mg/kg) significantly increased both transcription and translation ofVDAC. The above data suggests that LSE mitigates the damage to liver mitochondriainduced by carbon tetrachloride, possibly through regulation of mitochondrial VDAC, one ofthe most important proteins in the mitochondrial outer membrane.
p. 214-228
Received: 13 February 2007 / Accepted: 5 March 2007 / Published: 13 March 2007
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| Download PDF Full-text (4170 KB) Abstract: Article describes the synthesis of fifteen β-hydroxy-β-arylalkanoic acids byReformatsky reaction using the 1-ethoxyethyl-2-bromoalkanoates, aromatic or cycloalkylketones or aromatic aldehydes. The short survey of previously reported synthetic proceduresfor title compounds, is given. The majority of obtained compounds exert antiproliferativeactivity in vitro toward human: HeLa, Fem-X cells, K562, and LS174 cells, having IC50 values from 62.20 to 205 μM. The most active compound is 3-OH-2,2-di-Me-3-(4-biphenylyl)-butanoic acid, having the IC50 value 62.20 μM toward HeLa cells. Sevenexamined compounds did not affect proliferation of healthy human blood peripheralmononuclear cells (PBMC and PBMC PHA), IC50 > 300 μM. The preliminary QSARresults show that estimated lipophilicity of compounds influences their antiproliferativeactivity in the first place. The ability of dehydration, and the spatial arrangement ofhydrophobic portion, HBD and HBA in molecules are has almost equal importance aslipophilicity.
p. 229-240
Received: 16 December 2006 / Accepted: 5 March 2007 / Published: 13 March 2007
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| Download PDF Full-text (298 KB) Abstract: This study was made to explore the effects of acetazolamide on tumor growth,metastasis and the possible mechanisms. The mice bearing with Lewis lung carcinomaswere taken as the animal model. The effects of acetazolamide were compared with thecombination treatment of NaHCO3 on tumor growth, metastasis and carbonic anhydraseactivity in lung and tumor tissues using imidazole-Tris technique. And also the possible roleof AQP1 in tumor tissues was investigated by Western blot and immuno-histochemicalanalysis. Results showed that acetazolamide alone could sharply reduce the number of lungmetastasis and primary tumor growth, and appeared in a dose-dependent manner.Acetazolamide significantly inhibited carbonic anhydrase activity in tumor tissue. After theaddition of NaHCO3 , the suppression of acetazolamide on tumor growth, number ofmetastasis and carbonic anhydrase activity in primary tumor tissue could not be alteredsignificantly, but the inhibitory rate of metastasis in lung and carbonic anhydrase activity inlung tissue appeared to show a reversal trend in the dose dependency from the acetazolamidetreatment alone. The exactly mechanisms need to be clarified in future. Western blot andimmunohistochemical analysis demonstrated that AQP1 expression in the tumor tissue washigher than both tissue of normal and treated with acetazolamide treatment alone.Combination with NaHCO3 could not synergistically inhibit the expression of AQP1 withacetazolamide. The results suggested that the mechanism of acetazolamide on anti-tumor especially on its anti-metastasis actions might partly involve either inhibiting the carbonic anhydrase activity or reducing AQP1 water channel protein expression, whatever if treated with or without NaHCO3 .
p. 241-258
Received: 14 February 2007 / Accepted: 1 March 2007 / Published: 16 March 2007
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| Download PDF Full-text (811 KB) Abstract: 9, 10-bis(3,5-dihydroxyphenyl)anthracene (BDHA) and 2,2′,4,4′-tetrahydroxybenzophenone (THB) are crystallized with bipyridine bases 4,4 ́-bipyridyl(bipy), 1,2-bis(4-pyridyl)ethane (bipy-eta), 1,2-di(4-pyridyl)ethylene (dipy-ete), 1,3-di(4-pyridyl)propane (dipy-pra), 4,4 ́-dipyridyl sulfide (dipy-sul), and 4,4 ́-dipyridyl disulfide(dipy-dis) to afford molecular complexes (BDHA)·(bipy)2 1, (BDHA)·(bipy-eta)2 2,(BDHA)0.5 ·(dipy-pra)·CH3 CH2 OH 3, (BDHA)0.5 ·(dipy-sul)·H2 O 4, (BDHA)0.5 ·(dipy-dis)·CH3 CH2 OH 5 and (THB)·(dipy-ete)2 ·H2 O 6. The crystal structures of 1–6 have beendetermined by single-crystal X-ray diffraction. All these molecular complexes exhibitpolymeric supramolecular structures via O–H···N or O–H···O hydrogen-bonding. 1 and 2form infinitely rectangular macrocycles linked with one another, whose sizes are ca.12.477 å× 4.802 å and ca.14.575 å × 4.809 å, respectively. 3, 5 and 6 form the one-dimensionalzigzag chain structure. 4 forms a ladder structure, and two dipy-sul molecules were includedin a frame.
p. 259-272
Received: 23 January 2007 / Accepted: 2 March 2007 / Published: 30 March 2007
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| Download PDF Full-text (212 KB) Abstract: The SPASIBA force field parameters have been obtained for Fe3+ /Fe2+ -Oxygeninteractions occuring between non-heminic iron and hydroxyl groups of polyphenols foundin tannins. These parameters were derived from normal modes analyses based on quantumchemical calculations using the Density Functional Theory (DFT). Four models involvingcomplexation of iron with water ([Fe(H2 O)6 ]3+ , [Fe(H2 O)6]2+ ) and with cathechol molecules([Fe(cat)2 (H2 O)2 ]-1 , [Fe(cat)2 (H2 O)2 ]-2 ) were studied using the Density Functional Theoryand the B3LYP hybrid functional under high spin states of iron.
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