Showing papers by "University of Extremadura published in 1983"
TL;DR: Observations suggest that the ethanol effect in decreasing protein labelling from tracer doses of the radioactive precursor does not reflect variations in the rate of protein synthesis but reflects changes in the specific activity of the precursor.
32 citations
TL;DR: When the whole medial collateral ligament is severed, there is a lateral displacement of the talus, which may be important in the diagnosis and surgical treatment of a torn medialateral ligament.
Abstract: The calcaneotibial and posterior talotibial ligaments slacken and the naviculotibial ligament tightens as the ankle plantarflexes; the reverse occurs in ankle extension. The naviculotibial ligament increases its length and the posterior talotibial ligament relaxes in abduction. The cutting of the posterior talotibial ligament repercutes on other parts of the medial collateral ligament. The cutting of other parts of the medial collateral ligament produces very little change on the posterior talotibial ligament. When the whole medial collateral ligament is severed, there is a lateral displacement of the talus. This may be important in the diagnosis and surgical treatment of a torn medial collateral ligament.
20 citations
TL;DR: Almost complete inhibition of partially purified dinucleoside-tetraphosphatase (EC 3. 6. 1. 17) was observed with 5 microM Zn(II), leaving unaltered the Km value for the enzyme towards diadenosine tetraphosphate.
19 citations
TL;DR: In this paper, the structures of the new compounds were elucidated by chemical and physical methods, and the anomeric configuration of this compound was only suggested, but the structure of the compound was not discussed.
16 citations
TL;DR: Cobalt, copper and cadmium xanthinate tetrahydrates have been prepared in aqueous medium, and characterized on the basis of elemental analysis, IR and 1 HNMR studies as mentioned in this paper.
15 citations
13 citations
TL;DR: In this article, the rotational isomeric states model is applied to calculate dipole moments of polypeptides of the twenty natural α-amino acids in the random coil state.
10 citations
TL;DR: In this article, a fluorimetric method for the determination of Mg(II), based on the formation of a fluorescent 1∶1 chelate with 1,8-dihydroxyanthraquinone, is described.
Abstract: A fluorimetric method for the determination of Mg(II), based on the formation of a fluorescent 1∶1 chelate with 1,8-dihydroxyanthraquinone, is described. With 90% ethanol in ammoniacal medium, the fluorescent complex has excitation maxima at 470, 480 and 495 nm and emission maximum at 600 nm. The logarithm of apparent formation constant of the complex is 4.68. The calibration graph is linear over the range 5–350 ppb Mg(II).
8 citations
TL;DR: The point of view that fatty acids do not act in decreasing protein labelling by perturbing directly the protein synthesis machinery but decreasing the phosphorylation potential is supported.
8 citations
TL;DR: A contaminant compound has been isolated from commercial samples of CTP by ion-exchange chromatography on a Dowex-1 column and has been characterized as cytidine 5'-tetraphosphate from its ultraviolet spectrum, labile and total phosphate content, and periodate consumption.
TL;DR: In this article, a new method for extract-spectrophotometric determination of violet complex isophthaldihydroxamic acid-vanadium extracted into solution of trioctylmethylamethylammonium chloride in ethylacetate was made.
Abstract: The spectrophotometric study of violet complex isophthaldihydroxamic acid-vanadium extracted into solution of trioctylmethylammonium chloride in ethylacetate was made (λmax = 380 nm, ϵ = 7500 lmol−1cm−1; λmax = 510 nm, ϵ = 5510 lmol−1 cm−1; stoichiometries, 1:1 and 1:2, V:reagent) A new method for the extract-spectrophotometric determination of V(V) in the range 14–80 μg of vanadium is proposed
TL;DR: In this article, the thermal behavior of 4-amino-5-nitroso-uracil, 4-AMino-1,3-dimethyl-5,5,nitro-so-URACIL and 4-Amino-3-methyl 5,5-Nitroso URACIL was studied.
Abstract: The silver(I) complexes of 4-amino-5-nitroso-uracil, 4-amino-1-methyl-5-nitroso-uracil, 4-amino-3-methyl-5-nitroso-uracil and 4-amino-1,3-dimethyl-5-nitroso-uracil have been prepared and their thermal behaviour studied. All the isolated compoounds show 1∶1 stoichiometry.
TL;DR: In this paper, a spectrofluorimetric method for the determination of IO−3 between 0.2 and 2.0 ppm with a 0.90 % relative error was proposed.
Abstract: The IO− 3 anion gives a redox reaction, in hydrochloric acid medium, with 1,2,4-trihydroxyanthraquinone-3-carboxylic acid (Pseudopurpurin), which shows adequate analytical fluorescent characteristics. The oxidation product produces a fluorescent emission at 625 nm (wavelength of excitation =515 nm). After studying many variables, as a conclusion, we propose a new spectrofluorimetric method for the determination of IO− 3 between 0.2 and 2.0 ppm with a 0.90 % relative error. The interference levels, stoichiometry and nature of reaction are studies.
TL;DR: In this paper, a kinetic-fluorimetric method for the determination of vanadium(V) (0.03-0.15 μg ml −1 ) is described, based on its oxidation of 1,3,5-triphenyl-δ 2 -pyrazoline.
TL;DR: In this paper, cyclopentane-1,3,dione bis (4-methylthiosemicarbazone) monohydrochloride produces coloured solutions with bromate ions in perchloric acid medium.
Abstract: Cyclopentane-1,3-dione bis (4-methylthiosemicarbazone) monohydrochloride produces coloured solutions with bromate ions in perchloric acid medium. The yellow colour obtained (molar absorptivity 1.8×104 1.mol−1.cm−1 at a wavelength of 400 mm) has been used for the spectrophotometric determination of trace amounts of bromate.
TL;DR: In this paper, the average molar Kerr constants of polypeptides of the twenty natural α-aminoacids in the random coil state were calculated using the Rotational Isomeric States model with the values of energies, dipole moments and optical anisotropies of the repeating units.
Abstract: Calculations of average molar Kerr constants of polypeptides of the twenty natural α-aminoacids in the random coil state are presented. The computation was carried out according to the Rotational Isomeric States model with the values of energies, dipole moments and optical anisotropies of the repeating units reported elsewhere. In the case of homopolypeptides, the ratios /x extrapolated to x→∞ range approximately from −6000 to +5000 in units of 10−27V−2m5mol−1. Results obtained for ten actual proteins and three enzymes in the random coil state are also reported; their values of /x are very sensitive to the kind of aminoacid residues and to the sequence of those residues.
TL;DR: Theoretical values of the mean-squared optical anisotropies (γ2 ), of random-coil polypeptides of the twenty natural α-amino acids by the use of the Rotational Isomeric State model are calculated in this article.
Abstract: Theoretical values of the mean-squared optical anisotropies (γ2 ), of random-coil polypeptides of the twenty natural α-amino- acids are calculated according to the Valence Optical Scheme by the use of the Rotational Isomeric State model. The contribution of each repeat unit to the anisotropic part of the polarizability tensor of the chain [math] was computed by addition of previously optimized bond polarizabilities. Values of (γ2 )1 for single peptide units (identified for this calculation with molecules of the formula CH3 -CO-NH-CH2 R, where R is the side chain of each aminoacid residue) range from 3.5 to 85.7 in units of 10–6 nm6 . The results of (γ2 )x /x in the limit of x → ∞ for homopolypeptides are roughly proportional to (γ2 )1 of the peptide unit. Ten actual proteins and there enzymes are also studied, their values of (γ2 )x /x are almost identical and do not depend on the sequence of aminoacids.
TL;DR: It is concluded that glucanases are synthesized in inactive precursor forms and are converted to the active forms in their secretory pathway.
TL;DR: In this article, the reaction between Cu(II) and pyridine-2-aldehyde guanylhydrazone nitrate (PAG) was investigated by using the techniques of spectrophotometry and polarography.
TL;DR: An analysis of the possible energy barriers to be overcome during processes of association and dissociation of intrinsic membrane proteins within a biological membrane is presented and there arises the possibility of unifying rationalization for the regulation of various membrane-mediated process such catalytic activity, transport processes, hormone responsiveness, and so forth, by physicochemical factors.
TL;DR: Two isozymes of adenylosuccinate synthetase, termed I and II have been separated by chromatography on DEAE-cellulose (DE-52), in Artemia embryos, and the relationship between this enzyme and that from rat liver and other sources is discussed.
Abstract: 1. 1. Two isozymes of adenylosuccinate synthetase, termed I and II have been separated by chromatography on DEAE-cellulose (DE-52), in Artemia embryos. 2. 2. The following data refer to form I and II: apparent molecular weights determined by sucrose gradient centrifugation and chromatography on Sephadex G-100: (I) 96,700, 90,000 and (II) 97,800, 83,000; K m values for their three substrates IMP, GTP and aspartate: (I) 26, 29, 600 and (II) 20, 25, 700 μM; fructose 1,6-biphosphate was a competitive inhibitor towards IMP with a K i value of 22 μM for both isozymes. 3. 3. The relationship between the Artemia enzyme and that from rat liver and other sources, is also discussed in this paper.
TL;DR: A model of the uterus-placenta-fetus system was designed using an electronic device which proportions at its outputs the representative signals of the fetal heart rate (FHR) and uterine contractions (UC).