Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.42 (DTA)
 1,693 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The self-assembly behavior of a cationic surfactant (dodecyltrimethylammonium, DTA) with DNA as counterion in mixtures of water and n-alcohols (decanol, octanol, hexanol, butanol, and ethanol) was investigated. The phase diagrams were established and the different regions of the phase diagram characterized with respect to microstructure by (2)H NMR, small-angle X-ray scattering (SAXS), and other techniques. The DNA-DTA surfactant is soluble in all of the studied alcohols, showing increased solubility from decanol down to ethanol. All of the phase diagrams are analogous with respect to the occurrence of liquid crystalline (LC) regions, but the area of the LC region increases as one goes from decanol to ethanol. In all phase diagrams, hexagonal phases (of the reversed type) for the alcohol-rich side and lamellar phases for the other side were detected. For balanced proportions of the components, there is a coexistence of the lamellar and the hexagonal phase, here detected with a double quadrupole splitting in the (2)H NMR spectra. The correctness of the phase diagrams is confirmed by the fact that along the tie-lines the splitting magnitude remains nearly constant. All of the alcohols except for ethanol act as cosurfactants penetrating the DNA-DTA film. Adding salt to the ternary mixtures causes an increase in the unit cell dimension of the lamellar and the hexagonal phases. The phase diagram becomes more complicated when butanol is used for the alcohol phase. Here, there is the occurrence of a new isotropic phase with some properties analogous to those of the disordered sponge (L3) phase obtained for simple surfactant systems.
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PMID:Phase behavior of a DNA-based surfactant mixed with water and n-alcohols. 1692 21

The solid rare-earth (RE=Tb, Eu, Sm, Nd) compounds with 3-hydroxyl-2-naphthalinic acid (L) and phenanthroline (phen) were synthesized in ethanol solution in the present work. Their compositions were determined to be REL4 x phen2 x Na x H2O by the element analysis, infrared and ultraviolet absorption spectra, and DTA-TGA, respectively. The spectral properties of the compounds were studied tentatively, and the coordination mode of carboxyl group was deduced to be bridged style to chelate the rare-earth and sodium ions to form an infinite chain structural complex. The sodium and rare-earth ions are six-coordinated and eight-coordinated geometry respectively.
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PMID:[Synthesis and spectral characterization of rare-earth-3-hydroxyl-2-naphthalinate-phenanthroline compounds]. 1696 Dec 51

The preparation and structural characterization of a novel Ti-O-Ti bonding complex constructed in a dilacunary alpha-Keggin polyoxometalate (POM), [[{Ti(ox)(H2O)}4(mu-O)3](alpha-PW10O37)](7-) (H2ox = oxalic acid) (1a), are described. The water-soluble, crystalline complex with a formula of K6H[1a].0.5KCl.10H2O (1p) was prepared as the bulk sample in 28.0% (0.51 g scale) yield in a 1:4 molar-ratio reaction of the dititanium(IV)-substituted, dimeric form of an alpha-Keggin POM, K10[(alpha-1,2-PW10Ti2O39)2].18H2O, with the titanium(IV) source K2[TiO(ox)2].2H2O in HCl-acidic solution (pH 0.08). Prior to formation of 1p, the KCl-free crystalline compound (1c) obtained was characterized with X-ray crystallography. The compound 1p was unequivocally characterized with complete elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), FTIR, and solution (31P, 183W, and 13C) NMR spectroscopy. The molecular structure of 1a was determined. The POM 1a in the solid state was composed of the four octahedral Ti groups (four guests), i.e., the two Ti-O-Ti groups linked with the mu-O atom, incorporated to the two adjacent, octahedral vacant sites (two hosts) in the dilacunary Keggin POM. The formation of 1a, as well as the recently found POM [{Ti(ox)(H2O)}2(mu-O)](alpha-PW11O39)](5-) (2a), was strongly dependent on the reaction with [TiO(ox)2](2-), i.e., the anionic titanium(IV) complex as the titanium(IV) source. The POM 1a is contrasted to most titanium(IV)-substituted POMs consisting of a combination of a monolacunary site (one host) and an octahedral Ti group (one guest) and also contrasted to 2a as a combination of a monolacunary site (one host) and two octahedral Ti groups or a Ti-O-Ti group (two guests).
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PMID:Novel Ti-O-Ti bonding species constructed in a metal-oxide cluster: reaction products of bis(oxalato)oxotitanate(IV) with the dimeric, 1,2-dititanium(IV)-substituted Keggin polyoxotungstate. 1699 5

Nickel(II) complexes of reduced glutathione (GSH) of general composition Na[Ni(L)(X)]H(2)O, where H(2)L=GSH; X=NO(3)(-), SCN(-), CH(3)CO(2)(-), Cl(-) have been synthesized and characterized by elemental analysis, infrared spectra, electronic spectra, magnetic susceptibility measurements, thermal and X-ray powder diffraction studies. Infrared spectra indicate deprotonation and coordination of cysteinyl sulphur and carboxylate oxygen of glycine residue with nickel ions. It indicates the presence of water molecule in all the complexes which has been supported by TG/DTA. The thermal behavior of complexes shows that water molecule is removed in first step-followed removal of anions and then decomposition of the ligand molecule in subsequent steps. General mechanisms describing the decomposition of the solid complexes are suggested. Kinetic and thermodynamic parameters were computed from the thermal decomposition data. The room temperature magnetic moment values for all the complexes lie in the range of 2.2-2.4BM, indicating departure from spin only values due to second order Zeeman effect. The electronic spectra indicate planar coordination geometry for all the complexes. Crystal data for Na[Ni(L)(CH(3)CO(2)(-))]H(2)O: tetragonal, space group P4/m, a=8.2004A, b=8.2004A, c=16.0226A, V=1077.47A(3), Z=2. Crystal data for Na[Ni(L)(Cl(-))]H(2)O: cubic, space group Pm3, a=16.1055A, b=16.1055A, c=16.1055A, V=4178.38A(3), Z=6. Crystal data for Na[Ni(L)(NO(3)(-))]H(2)O: tetragonal, space group P4/m, a=7.2121A, b=7.2121A, c=12.0200A, V=625.22A(3), Z=2.
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PMID:Nickel(II) complexes of biologically active glutathione: spectroscopic, kinetics of thermal decomposition and XRPD studies. 1703 Jan 48

X-ray, FTIR, and Raman spectra were used to measure the spectral properties of three kinds of zinc phosphate hydrate. Spectral changes with crystalline water were analyzed. The thermal stability of zinc phosphate tetrahydrate was studied by TG-DTA to identify the existent temperature of zinc phosphate hydrate. The results show that the differences in crystalline water among these hydrates results in the variation in both 2theta characteristic values and peaks. The FTIR spectra reflect H--O--H strength information (1 600 cm(-1)) and O--H bond stretching vibrations (3 400-3 500 cm(-1)). Raman spectra show the difference in P--O bond stretching mode at 400-700 cm(-1) and the shape of O--H stretching peak. According to the mass-loss curves, the onset temperature of zinc phosphate tetrahydrate was 95 degrees C. Heating to 145 degrees C was accompanied by the removal of 2H2O and transform into Zn3 (PO4)2 x 2H2O, indicating that Zn3 (PO4)2 x 2H2O was established at this temperature. Zn3 (PO4)2 x H2O can be obtained by heating to 195 degrees C. The third stage of dehydration gave an anhydrous Zn3 (PO4)2 phase.
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PMID:[Spectral properties and thermal stability of zinc phosphate hydrate]. 1705 74

Simultaneous uptake of Ni2+, NH4+, and PO4(3-) by amorphous CaO-Al2O3-SiO2 (C-A-S) compounds was investigated using batch and column methods. Fifteen different C-A-S samples with systematically varied chemical compositions were prepared by coprecipitation from ethanol-water solutions containing Ca(NO3)2.4H2O, Al(NO3)3.9H2O, and Si(OC2H5)4, using NH4OH as the precipitating agent. The resulting precipitates were dried and heated at various temperatures to produce the C-A-S samples, which were then characterized by XRD, FTIR, solid state MAS NMR, DTA-TG, and N2 adsorption. All the C-A-S samples prepared at 600-900 degrees C were amorphous, apart from the CaO-rich samples. Simultaneous uptake of Ni2+, NH4+, and PO4(3-) was determined by a batch method using a solution with an initial concentration of 2 mM. In these experiments, the uptake abilities of the C-A-S samples for Ni2+ and PO4(3-) were high, but were relatively low for NH4+. The uptake abilities for Ni2+ and PO4(3-) increased but that for NH4+ decreased as the silica content in the C-A-S decreased, suggesting that similar uptake mechanisms (ion substitution and/or precipitation) are operating for Ni2+ and PO4(3-), but the uptake mechanism for NH4+ is different (physical adsorption). The column experiments indicate that the order of uptake ability of C-A-S for the three ions is NH4+ << PO4(3-) < Ni2+. Although the silica content of the C-A-S does not have the expected influence on the uptake of these three ions, for NH4+ it plays an important role in the formation of the amorphous phase and also in the suppression of Ca2+ and/or Al3+ release from the C-A-S during the uptake experiments. The optimum uptake properties of the C-A-S can thus be controlled by adjusting the chemical compositions and heating conditions under which the samples are prepared.
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PMID:Simultaneous uptake of Ni2+, NH4+ and PO4(3-) by amorphous CaO-Al2O3-SiO2 compounds. 1706 11

The synthesis of TiO2 and Fe-TiO2 by sol-gel method is demonstrated and characterized. The characterization of TiO2 and Fe-TiO2 is performed with instruments, including TGA/DTA, FTIR, UV-Vis, N2 adsorption and SEM. Dichloromethane is used for the photocatalytic activity test. From the results of dichloromethane photocatalytic degradation, the calcined temperature of TiO2 and the presence of water vapor influence the photocatalytic activity. The optimum doping amount of iron ions is 0.005 mol%, and this can enhance the photocatalytic activity, while too great an amount will make the iron ions become recombination centers for the electron-hole pairs and reduce the photocatalytic activity. UV-Vis diffuse reflectance spectra of Fe-TiO2 show an increase in absorbency in the visible light region with the increase in iron ions doping concentration The intermediate of dichloromethane photodegradation includes CHCl3, CCl4, CH2Cl2 and COCl2. The presence of iron ions may reduce the adsorption of Cl element on the surface of the photocatalyst.
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PMID:Study on photocatalytic degradation of gaseous dichloromethane using pure and iron ion-doped TiO2 prepared by the sol-gel method. 1709 38

The tautomerism of cyameluric acid C6N7O3H3 (1 a), cyamelurates and other heptazine derivatives has recently been studied by several theoretical investigations. In this experimental study we prepared stannyl and silyl derivatives of cyameluric acid (1 a): C6N7O3[Sn(C4H9)3]3 (3 a), C6N7O3[Sn(C2H5)3]3 (3 b), and C6N7O3[Si(CH3)3]3 (4). In order to investigate the structure of 1 a the mono- and dipotassium cyamelurate hydrates K(C6N7O3H2)2 H2O (5) and K2(C6N7O3H)1 H2O (6) were synthesized by UV/Vis-controlled titration of a potassium cyamelurate solution with aqueous hydrochloric acid. Compounds 3-6 were characterized by FTIR and solid-state NMR spectroscopy as well as simultaneous thermal analysis (TGA, DTA). The single crystal X-ray structures of the salts 5 and 6 show that the hydrogen atoms in both anions are localized on the peripheral nitrogen atoms. This indicates-in combination with the solid-state NMR studies-that the most stable tautomer of solid 1 a is the triketo form with C3h symmetry. However, derivatives of both the hydroxyl and the amido tautomers may be formed depending on the substituent atoms: The spectroscopic data and single crystal structures of compounds C6N7O3[Si(CH3)3]3 (4) and the solvate C6N7O3[Sn(C2H5)3]3C2H4Cl2 (3 b') show that the former is derived from the symmetric trihydroxy form of 1 a, while 3 b' crystallizes as a chain-like polymer, which contains the tin atoms as multifunctional building blocks, that is, bridging pentacoordinated Et3SnO2 and Et3SnON units as well as non-bridging four-coordinated Et3SnN units. The cyameluric nucleus is part of the polymeric chains of C6N7O3[Sn(C2H5)3]3C2H4Cl2 (3 b'), by the action of both tautomeric forms of cyameluric acid, the amide and the ester form.
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PMID:The tautomeric forms of cyameluric acid derivatives. 1712 Feb 62

The semiorganic non-linear optical crystal bisthiourea magnesium sulphate (BTMS) was grown by slow evaporation technique using water as solvent. Vibrational spectra were recorded to determine the symmetries of molecular vibrations. The observed Raman and infrared bands were also assigned and discussed. The optical transmission spectral study was carried out to test the transmitting ability of the crystal in the visible range. The second harmonic generation test of BTMS revealed the non-linear nature of the crystal. The TGA/DTA curve was also recorded for the experimental crystal.
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PMID:Crystal growth and vibrational spectroscopic studies of the semiorganic non-linear optical crystal--bisthiourea magnesium sulphate. 1718 29

Selenite adsorption on water-washed manganese nodule leached residues (WMNLR) was studied with the aim of detoxifying industrial effluents before their safe disposal into the environment. WMNLR, a solid waste material, was characterized with the help of XRD, FTIR, TG-DTA, pH(pzc), BET surface area, surface oxygen, surface hydroxyl group, and chemical analyses. The adsorption behavior of WMNLR toward selenite was studied as a function of time, pH, temperature, and concentration of adsorbate and adsorbent. Increased adsorption capacity with rise in temperature indicates that the adsorption process was endothermic in nature. Based on the thermodynamic parameters such as the Gibbs free energy change, standard enthalpy change, and standard entropy change, the adsorption process was found to be spontaneous and endothermic in nature. Adsorption followed second-order kinetics. The adsorption capacity of the material was found to be 54.6 mg g(-1) at 60 mg L(-1) of selenite concentration at pH 5 in 3 h contact time.
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PMID:Studies on selenite adsorption using manganese nodule leached residues. 1720 83


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