Showing papers by "Universidade Federal de Minas Gerais published in 1981"
TL;DR: In this paper, a new type effective field approach is used to derive the thermodynamic properties of the transverse Ising model and the lines of critical points in the Ω-T plane are derived and the critical transverse fields are obtained analytically, for lattices with coordination numbers z = 2, 4 and 6.
Abstract: A new type effective field approach is used to derive the thermodynamical properties of the transverse Ising model. The method is based on an exact formal identity for the two-state transverse Ising model and utilizes an exponential operator technique. The lines of critical points in the Ω-T plane are derived and the critical transverse fields ΩC are obtained analytically, for lattices with coordination numbers z = 2, 4 and 6. This simple method yields results which represent a remarkable improvement on the usual mean field approximation. Our results are also compared with those from series expansion method.
173 citations
TL;DR: By centrifuging heparinised human blood through a discontinuous Ficoll-Hypaque density gradient, it is possible to separate simultaneously mononuclear cells, neutrophils, and eosinophils.
86 citations
TL;DR: The data suggest that brain involvement is common in hepatosplenic schistosomiasis mansoni, and the possible paths by which the eggs of S. mansoni reach the nervous system are discussed.
Abstract: The brains of 46 patients with hepatosplenic schistosomiasis mansoni were studied. Eggs of Schistosoma mansoni were found in 12 brains (26 per cent). The parasite location, brain reaction, clinical features and the possible paths by which the eggs of S. mansoni reach the nervous system are discussed. Our data and those of the literature suggest that brain involvement is common in hepatosplenic schistosomiasis mansoni.
70 citations
TL;DR: Simple 1:1 adducts of the antitumor complex, Rh 2 (acetate) 4, have been prepared with Adenine and Adenosine, and the binding site assigned as N 7 of the purine ring indicates unequivocally the same binding site for DNA.
37 citations
TL;DR: A thrombin-like enzyme has been purified from the venom of Lachesis muta noctivaga (41-fold purification and 43% yield) and in vitro the activity for human fibrinogen-fibrin conversion was equivalent to 1650 ± 12 NIHThrombin units/mg protein enzyme.
35 citations
TL;DR: Raw and pasteurized milks used for cheesemaking were surveyed in a dairy plant, Juiz de Fora, MG, Brazil from 1978 to 1979 and detection of S. aureus was based on methods used for raw milk plus use of Baird-Parker/CAP method.
29 citations
TL;DR: Serum samples from 30 patients who had had Chagas' disease demonstrated either by serological tests or blood culture were examined for circulating antigens of Trypanosoma cruzi by an enzyme-linked immunosorbent assay (ELISA), suggesting that parasite antIGens were present in the sera.
29 citations
TL;DR: In this article, the authors show that the temperature dependence of the SeO4-4 EPR frequencies and the asymmetric broadening of the EPR lines in the incommensurate phase of K2SeO4 can be explained by an incomensurate spatial modulation of the g tensors which corresponds to the “broad” phase soliton limit.
26 citations
TL;DR: In this paper, 1,8-Dihydroxy-3-methyl-6-methoxyanthraquinone (physcion) and two derivatives, 7-( trans -3methyl-1-butenyl)-physcions (vismiaquinone) and 7-(3methyl 2-oxobutyl)-PHyscion(vismIAquinone B), were isolated respectively from Vismia cayennensis and V. japurensis.
24 citations
TL;DR: The potential for Staphylococcus aureus survival, growth and enterotoxigenesis in Minas cheese was studied in this paper, where 20 lots of cheese were made with raw and pasteurized milk and with and without starter culture.
TL;DR: Stimulation of the salivary glands by purified scorpion toxin (tityustoxin) evoked flow of saliva and sodium, potassium and kallikrein secretion, which may be a suitable tool to study the physiology and pharmacology of the Salivary gland.
TL;DR: In this paper, the Longuet-Higgins recurrence relations for the dynamical J-T problem are equivalent to a system of two ordinary linear first order differential equations, which are very simple.
TL;DR: The trunk wood of Qualea labouriauana contains (2 R )-5,7,4′-trihydroxy-3′-methoxy-6,8-dimethylflavanone, ( 2 R ) -5, 7, 4′ -trihydrox-8-methylflanone, the biosynthetically interesting 2,2′-dihydroxy-4,6, 4.6′,6′-tetramethoxy -3, 3′-dimethylbenzophenone.
TL;DR: The failure to observe a starter culture effect upon staphylococcal counts in whey may be due to the short time between starting the cheesemaking process and sampling of whey, insufficient amount of lactic acid produced by the starter culture and the detrimental effect of the processing temperature upon the starter bacteria.
TL;DR: Findings may indicate that the salivary secretion in the edentates is regulated by the parasympathetic rather than by the sympathetic nervous system.
Abstract: The intraglandular distribution of adrenergic and cholinergic nerve fibers was studied histochemically in the parotid, mandibular, and sublingual glands of six species of edentates belonging to the three families that comprise the order; namely, the Dasypodidae (armadillos), the Myrmecophagidae (anteaters), and the Bradipodidae (sloths). The following histochemical techniques were used: (a) acetylcholinesterase reaction for the demonstration of cholinergic fibers; (b) formaldehyde- and glyoxylic acid-induced fluorescence for the demonstration of adrenergic fibers. In addition, norepinephrine (NE) was assayed fluorimetrically in the mandibular and parotid glands of the armadillo. A network of acetylcholinesterase-positive nerve fibers surrounds the intra- and interlobular ducts and endpieces of all glands; it is of low density in the mandibular and sublingual gland of the sloth, of high density in the sublingual gland of the anteater and of moderate density in the remaining glands. A vascular cholinergic innervation occurs in all salivary glands. Although present around the vessels, adrenergic new fibers were virtually absent from the parenchyma of all glands, even after in vitro incubation of glandular tissue with NE, or after administration of NE to armadillos previously treated with a monoamine oxidase (MAO) inhibitor. Consistent with this fact, the amount of NE present in the parotid and mandibular gland of the armadillo was extremely low. These findings may indicate that the salivary secretion in the edentates is regulated by the parasympathetic rather than by the sympathetic nervous system.
TL;DR: The authors determined the true hosts of six species of ectoparasites in Caratinga county, Minas Gerais, Brazil, being four species of mites and two species of fleas.
Abstract: Os autores determinaram os hospedeiros reais para seis especies de ectoparasitos na regiao de Caratinga, Minas Gerais, sendo quatro especies de acaros e duas de pulgas, utilizando-se do indice de infestacao e do coeficiente de associacao interespecifico hospedeiro/ parasito.
TL;DR: It seems that the morphological, quantitative and karyometric astrocyte changes in schistosomiasis may be the result of the same factors as those previously described for liver cirrhosis and experimental portacaval shunt.
Abstract: A morphological, quantitative and karyometric study of astrocytes of the cerebral cortex in patients with liver cirrhosis, hepatosplenic schistosomiasis mansoni and controls is reported. Cell proliferation was commonly seen but there was no significant increase in number of astrocytes in either cirrhosis and schistosomiasis groups. A highly significant increase in astrocyte nuclear volume in cirrhosis and schistosomiasis in relation to controls was observed. The astrocyte average nuclear volume in the cirrhotics was also significantly increased in relation to the schistosomiasis group. From the present data and those reported by other investigators it may be concluded that under normal conditions the astrocyte population is continually reforming and it proliferates in liver cirrhosis and hepatosplenic schistosomiasis. It seems that the morphological, quantitative and karyometric astrocyte changes in schistosomiasis may be the result of the same factors as those previously described for liver cirrhosis and experimental portacaval shunt.
01 May 1981
TL;DR: A decomposition scheme especially suitable for solving sectorial economic equilibrium models is presented, and a dynamic and nonconvex case as it arises with one producer in a situation of marginal cost pricing and a spatial price equilibrium model representing the competitive behavior of many producers and distribution agents.
Abstract: A decomposition scheme especially suitable for solving sectorial economic equilibrium models is presented. The approach can be classified as "projection/feasible directions," but unlike the adaptive demand procedures, we project onto the space of production (or distribution) variables as opposed to projecting the whole problem onto the space of demand variables. The advantage is to work implicitly with a differentiable master program; yet the subprograms are easily solved by duality techniques. Some computational experiments related to two typical situations are also presented: 1) a dynamic and nonconvex case as it arises with one producer (a public power utility) in a situation of marginal cost pricing and 2) a spatial price equilibrium model representing the competitive behavior of many producers and distribution agents.
TL;DR: There was a significant correlation between decreased rates of brain metabolism and the elevation of serum total and unbound bilirubin.
Abstract: Bilirubin in different concentrations was injected in newborn guinea-pigs and the following parameters were determined: serum total and unbound bilirubin, whole brain bilirubin content and oxygen consumption, NADH-cytochrome c reductase and ATPase activities in brain mitochondria. The results showed a significant correlation between decreased rates of brain metabolism and the elevation of serum total and unbound bilirubin.
TL;DR: The formation and structure of four different Cu(II)-clupeine Z complexes have been studied using potentiometric and spectroscopic (ir and visible absorption, and CD) measurements as mentioned in this paper.
Abstract: The formation and structure of four different Cu(II)–clupeine Z complexes have been studied using potentiometric and spectroscopic (ir and visible absorption, and CD) measurements. The results thus obtained indicate the presence of up to 8 binding sites in the pH range from 6.5 to 10.5. The spectroscopic evidence suggests that the strongest site available contains the α-amino terminal and the adjacent peptide nitrogen, which bind to copper from pH 5 to 6.5 to form the first complex. The stability constant of this first complex has a value of (9.5 ± 0.9) × 103 mol−1 1. From pH 6.5 to 8.5, two intervening guanidinium nitrogens of arginine residues occupy the two other corners of the coordination square, giving rise to the second complex. The other sites potentially available from pH 6.5 to 10.5 are formed by two amino nitrogens of arginine residues and two contiguous peptide nitrogens. The first intervene up to pH 8.5, forming the third complex, and the latter from this pH to 10.5, forming the fourth complex. Although the ligands intervening at sites 2–8 appear to be the same, the sites are by no means equivalent. The spectroscopic data enable one to distinguish three different types of binding sites.
Abstract: The word of the age of Innocence is New York upper-class leisured society. There is a “younger set” that, surprisingly enough to us moderns, yields to its older relatives in matters of how to think and behave. The families that make up the characters in the time they lived, ‘the early seventies’, i.e. the last quarter of the nineteenth century, the 1870’s, and also because of the social environment in which they moved and found the meanings of their lives.
TL;DR: In this article, the preparation and properties of eighteen stable adducts of organotin halides with both aliphatic and aromatic sulphoxides are reported for the first time, whereas the others have only been partially studied before.
TL;DR: The morphologic and morphometric data indicate that the parotid salivary gland of Gyr Zebu reaches anatomic maturity at about 13 months of age, an age which correlates with the onset of spermatogenesis in this species.
Abstract: Histologic and morphometric alterations in the parotid salivary gland of 14 male Gyr Zebu were carried out coupled with a histochemical study of the mucosubstance of this gland. Animals ranging in age from 1–2 months to 17–21 months were utilized. The gland was found to represent a compound tubular gland which is entirely serous in older animals, but with mucous endpieces in younger animals. The morphologic and morphometric data indicate that this gland reaches anatomic maturity at about 13 months of age, an age which correlates with the onset of spermatogenesis in this species. The histochemical nature of secretions is discussed for various components of the gland.
TL;DR: In this article, a solution of the dynamical J-T problem in terms of Neumann series is given, whose coefficients are determined by simple recurrence relations, and it is conjectured that the solutions of this sequence converge as m → ∞ and give the correct eigenvalues.
Journal Article•
TL;DR: A retrospective study of primary intracranial tumors found in 19.760 consecutive autopsies and 72.972 consecutive biopsies during a period of over 41 years found gliomas constituted the largest group of primary tumors, most of which were found in the cerebral hemispheres, particularly in the frontal lobes.
Abstract: A retrospective study of primary intracranial tumors found in 19.760 consecutive autopsies and 72.972 consecutive biopsies during a period of over 41 years was carried out. Two hundred and five neoplasms comprising 69,7% of the primary intracranial tumors were located in the supratentorial compartment whereas 84 tumors (28,6%) were infratentorial in site. Gliomas constituted the largest group of primary tumors comprising 60,9% of the intracranial primary neoplasms. Most of gliomas were found in the cerebral hemispheres, particularly in the frontal lobes. Of the total number of gliomas 40,2% were astrocytomas, 29,6% glioblastomas, 10,6% ependymomas, 10,1% medulloblasto-mas, 5% oligodendrogliomas and 2,2% choroid plexus papillomas. Meningiomas constituted the second most common primary intracranial tumors being found in 56 cases (19%), most of them in parasagittal region, sphenoid ridge and anterior fossa. In the sella region there were 39 neoplasms including 21 pituitary adenomas, seven meningiomas, five craniopharyngiomas, four epidermoid cysts and two teratomas. Six capillary hemangioblastomas of the cerebellum and two chordomas of the clivus were also found. Sixty-five tumors occurred in patients under 15 years of age, 53,3% of them infratentorial in location - 36% in the cerebellum, 9,3% in the brainstem and 8% in the fourth ventricle. The majority of these tumors were astrocytomas, medulloblastomas and ependymomas. The present data are discussed in relation to other pathological series found in the literature.
TL;DR: In this paper, five complexes were prepared containing VOSO4 and the ligands 4-aminopyridine (4-APY), 3-amino-polymorphic acid (3-APEY), 2-amina-polymyline (2-AMY), 4-AMO-poly(4)-poly(3)-polycyclic acid(4-AMP) and aniline (AN), and they were tested with orthophenanthroline (o-phen) and dipyridyl (dipy).
Abstract: Five complexes were prepared containing VOSO4 and the ligands 4-aminopyridine (4-APY), 3-aminopyridine (3-APY), 2-aminopyridine (2-APY), 2-aminopyrimidine (2-APYM), and aniline (AN). Complexes of 4-APY and AN did not react with orthophenanthroline (o-phen) and dipyridyl (dipy); the others did react, however, giving similar products. Spectroscopic evidence shows that bonding occurs preferably through an endocyclic nitrogen whenever the ligand possesses more than one type of nitrogen atom.