ROLE OF CHOLINERGIC AND ADRENERGIC PATHWAYS OF THE MEDIAL SEPTAL AREA IN THE WATER-INTAKE AND PRESSOR-RESPONSE TO CENTRAL ANGIOTENSIN-II AND CARBACHOL IN RATS

In the present study, we investigated the effect of previous injection of either prazosin (alpha 1-adrenergic antagonist) or atropine (muscarinic cholinergic antagonist) into the medial septal area (MSA) on the presser and dipsogenic responses induced by intracerebroventricular (ICV) injection of carbachol (cholinergic agonist) and angiotensin II (ANGII) in rats. The presser and dipsogenic responses to ICV carbachol (7 nmol) were reduced after previous treatment of the MSA with atropine (0.5 to 5 nmol), but not prazosin (20 and 40 nmol). The dipsogenic response to ICV ANGII (25 ng) was reduced after prazosin (40 nmol) into the MSA. The presser response to ICV ANGII was not changed either by previous treatment of the MSA with prazosin or atropine. The present results suggest a dissociation among the pathways subserving the control of dipsogenic and presser responses to central cholinergic or angiotensinergic activation.

TiO2 films organofunctionalized with 2-aminothiazole ligand and adsorbed Pd(II) ions applied in the photocatalytic degradation of phenol in an aqueous medium

This paper describes the preparation of thin titanium films via sol-gel route and their subsequent chemical modification by anchoring with 2-aminothiazole ligand and Pd(II) ion sorption, aiming to maximize the photocatalytic activity. The material was characterized by diffuse reflectance infrared Fourier transform spectroscopy, ultraviolet and visible spectrometry, X-ray diffractometry, and scanning electronic microscopy. The amount of palladium adsorbed on the film's surface, determined by graphite furnace atomic absorption spectrometry, showed a value of 2.69 x 10(16) atoms CM-2. The photocatalytic tests indicated that the functionalization with 2-aminothiazole and the adsorption of palladium (II) were determinants in the semiconductor's enhanced photocatalytic activity. (c) 2007 Elsevier B.V. All rights reserved.

Study of alternative schemes for the parameterization step of the continuation power flow method based on physical parameters, part II: Performance evaluation

New parameterization schemes have been proposed by the authors in Part I of this paper. In this part these new options for the parameterization of power flow equations are tested, namely, the total power losses (real and reactive), the power at the slack bus (real or reactive), the reactive power at generation buses, and the transmission line power losses (real and reactive). These different parameterization schemes can be used to obtain the maximum loading point without ill-conditioning problems, once the singularity of Jacobian matrix is avoided. The results obtained with the new approach for the IEEE test systems (14, 30, 57, and 118 buses) show that the characteristics of the conventional method are not only preserved but also improved. In addition, it is shown that the proposed method and the conventional one can be switched during the tracing of PV curves to determine, with few iterations, all points of the PV curve. Several tests were also carried out to compare the performance of the proposed parameterization schemes for the continuation power flow method with the use of both the secant and tangent predictors.

THE ROLE OF ANGIOTENSIN AT1 RECEPTORS IN THE DIURETIC, NATRIURETIC, KALIURETIC AND BLOOD-PRESSURE RESPONSES INDUCED BY ANGIOTENSIN-II ACTIVATION OF THE MEDIAN PREOPTIC NUCLEUS IN CONSCIOUS RATS

We determined the effects of two classical angiotensin II (ANG II) antagonists, [Sar(1), Ala(8)]-ANG II and [Sar(1), Thr(8)]-ANG II, and losartan (a nonpeptide and selective antagonist for the AT 1 angiotensin receptors) on diuresis, natriuresis, kaliuresis and arterial blood pressure induced by ANG II administration into the median preoptic nucleus (MnPO) of male Holtzman rats weighing 250-300 g. Urine was collected in rats submitted to a water load (5% body weight) by gastric gavage, followed by a second water load (5% body weight) 1 h later. The volume of the drug solutions injected was 0.5 mu l over 10-15 s. Pre-treatment with [Sar(1), Ala(8)]-ANG II (12 rats) and [Sar(1), Thr(8)]-ANG II (9 rats), at the dose of 60 ng reduced (13.7 +/- 1.0 vs 11.0 +/- 1.0 and 10.7 +/- 1.2, respectively), whereas losartan (14 rats) at the dose of 160 ng totally blocked (13.7 +/- 1.0 vs 7.6 +/- 1.5) the urine excretion induced by injection of 12 ng of ANG II (14 rats). [Sar(1), Ala(8)]-ANG II impaired Na+ excretion (193 +/- 16 vs 120 +/- 19): whereas [Sar(1), Thr(8)]-ANG II and losartan blocked Na+ excretion (193 +/- 16 vs 77 +/- 15 and 100 +/- 12, respectively) induced by ANG II. Similar effects induced by ANG II on K+ excretion were observed with [Sar(1), Ala(8)]-ANG II, [Sar(1), Thr(8)]-ANG II, and losartan pretreatment (133 +/- 18 vs 108 +/- 11, 80 +/- 12, and 82 +/- 15, respectively). The same doses as above of [Sar(1), Ala(8)]-ANG II (8 rats), [Sar(1), Thr(8)]-ANG II (8 rats). and losartan (9 rats) blocked the increase in the arterial blood pressure induced by 12 ng of ANG II (12 rats) (32 +/- 4 ru 4 +/- 2, 3.5 +/- 1, and 2 +/- 1: respectively. The results indicate that the AT1 receptor subtype participates in the increases of diuresis, natriuresis. kaliuresis and arterial blood pressure induced by the administration of ANG II into the MnPO.

Fluorescence study of the interaction between metal ions and methyl methacrylate methacrylic acid copolymers in aqueous solutions: thallium(I), calcium(II), and terbium(III)

The binding of the cations thallium(I), calcium(II) and terbium(III) to methyl methacrylate-methacrylic acid copolymers with different fractions of acid groups (x) has been studied in aqueous solution at, various pH values using the fluorescence of covalently bonded 9-vinyl anthracene as a probe. In all cases, the extent of binding increases as a function of the charge of the polymer with either increasing fraction of carboxylic acids or of pH. However, differences are observed in the behavior of the three cations, With Tl(I), quenching of the anthracene group fluorescence is observed. indicating that the thallium(I) approaches the probe and suggesting that the alkylanthracene is probably in a relatively polar region. Binding constants have been determined from anthracene quenching data and from studies with the fluorescent-probe sodium pyrenetetrasulfonate, Good agreement is obtained between the two methods, and values for the binding constants increase from 250 to 950 M-1 as x increases from 0.39 to 1. It is suggested that the cation is held in the polyelectrolyte domain, partly by Debye-Huckel effects and partly by more specific interactions. Stronger binding is found with calcium(II) and terbium(III), and in this case increases in fluorescence intensity are observed on complexation due to the anthracene group being in a more hydrophobic region, probably as a result of conformational changes in the polymer chain. In the former case the stoichiometry of the interaction was determined from the fluorescence data to involve two carboxylate groups bound per calcium. Association constants were found using murexide as an indicator of free calcium to vary from 8400 to 37 000 M-1 as x increases from 0.39 to 1. It is suggested that in this case specific calcium(II)-carboxylate interactions contribute to the binding. With terbium(III), a greater increase in the probe fluorescence intensity was observed than with calcium, and it is suggested that the interaction with the polymer is even stronger, leading to a more pronounced conformational change in the polymer. It is proposed that the terbium(III) interacts with sis carboxylic groups on the polymer chain, with three being coordinated and three attracted by electrostatic interactions.

Thermal decomposition of crystalline Ni-II-Cr-III layered double hydroxide: A structural study of the segregation process

A structural study of the thermal evolution of Ni0.69Cr0.31(OH)(2)(CO3)(0.155)(.)nH(2)O into NiO and tetragonal NiCr2O4 is reported. The characteristic structural parameters of the two coexisting crystalline phases, as well as their relative abundance, were determined by Rietveld refinement of powder x-ray diffraction (PXRD) patterns. The results of the simulations allowed us to elucidate the mechanism of the demixing process of the oxides. It is demonstrated that nucleation of a metastable nickel chromite within the common oxygen framework of the parent Cr-III-doped bunsenite is the initial step of the cationic redistribution. The role that trivalent cations play in the segregation of crystalline spinels is also discussed.

Cycloaddition reaction of the azido-bridged cyclometallated complex [Pd(dmba)N-3](2) with CS2. Crystal and molecular structure of DI(mu, N,S-1,2,3,4-thiatriazole-5-thiolate) bis[(N,N-dimethylbenzyl-amine-C-2,N)palladium(II)]

The 1,3-dipolar cycloaddition of carbon disulfide to the coordinated azide in the cyclometallated compound [Pd(dmba)(N-3)](2) (1), dmba = N,N-dimethylbenzylamine, was investigated. The compound obtained di(mu, N,S-1,2,3,4-thiatriazole-5-thiolate)-bis[(N,N-dimethylbenzylamine-C-2,N)palladium(II)] (2), was characterized by IR spectroscopy and X-ray diffraction. Complex (2) is dimeric with the two [Pd(N,N-dimethylbenzylamine)] moieties being connected by the two vicinal bridging N,S-1,2,3,4-thiatriazole-5-thiolate anions in a square-planar coordination for the palladium atoms.

An investigation of the thermal behavior of heterobimetallic species containing copper(II) and tetracyanopalladate(II)

Synthesis, characterization and thermal behavior of four compounds that have the general formula [Cu{Pd(CN)(4)}(L)(x)](n), in which en = 1,2-diaminoethane and pn = 1,3-diaminopropane (L = en, x = 1 (I); L = pn, x = 1 (II); L = en, x = 2 (III); L = pn, x = 2 (IV)) were described in this work. The complexes were studied by elemental analysis, infrared spectroscopy (IR), differential thermal analysis (DTA) and thermogravimetry (TG) and the residues of the thermal decomposition were characterized by X-ray powder diffraction and found as a mixture of CuO and PdO. The stoichiometry of the compounds was established via thermogravimetric and elemental analyses and their structures were proposed as coordination polymers based on their infrared spectra. The following thermal stability sequence was found: IV < I=II < III.

A rapid procedure for the isolation of the Lys-49 myotoxin II from Bothrops moojeni (caissaca) venom: Biochemical characterization, crystallization, myotoxic and edematogenic activity

A, M. Soares, V, M, Rodrigues, M. I. Homsi-Brandeburgo, M. H. Toyama, F, R, Lombardi, K. Arni and J. R, Giglio. A rapid procedure for the isolation of the Lys-49 myotoxin II from Bothrops moojeni (caissaca) venom: Biochemical characterization, crystallization, myotoxic and edematogenic activity. Toxicon 36, 503-514, 1998.-Bothrops moojeni snake venom was fractionated on a CM-Sepharose column which was previously equilibrated with 0.05 M ammonium bicarbonate buffer at pH 8.0 and subsequently eluted with an ammonium bicarbonate concentration gradient from 0.05 to 0.5 M at constant pH (8.0) and temperature (25 degrees C). The fraction which eluted last (M-VI) showed, after direct lyophilization, a single band by polyacrylamide gel electrophoresis (PAGE) and SDS-PAGE, indicating an approximate M,. of 14 000 and 77 000, in the presence and absence of dithiothreitol, respectively. Its amino acid composition revealed a high level of hydrophobic and basic amino acids as well as 13 half-cystine residues. Its isoelectric point and extinction coefficient (E-1.0cm(1.0mg/ml) at 278 nm and pH 7.0) were 8.2 and 1.170, respectively. M-VI was devoid of phospholipase A(2) (PLA(2)) activity on egg yolk, as well as of hemorrhagic, anticoagulant and coagulant activities, but could induce drastic necrosis on skeletal muscle fibres as well as rapid and transient edema on the rat paw. Its N-terminal sequence: SLFELGKMILQETGKNPAKSYGVYGCNCGVGGRGKPKDATDRCCYVHKCCYK.... revealed high homology with other Lys 49 PLA(2)-like myotoxins from other bothropic venoms. Orthorhombic crystals of M-VI? which diffracted to a maximal resolution of 1.6 Angstrom. were obtained and indicated the presence of a dimer in the asymmetrical unit. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

Comparative study of the Frankel (FR-2) and bionator appliances in the treatment of Class II malocclusion

The purpose of this investigation was to compare the dentoalveolar and skeletal cephalometric changes produced by the Frankel (FR-2) and bionator appliances in persons with Class 11 malocclusion. Lateral cephalograms were available for 66 patients of both sexes, who were divided into 3 groups of 22. The control group included untreated Class 11 children, with an initial mean age of 8 years 7 months; they were followed without treatment for 13 months. The FR-2 appliance group had an initial mean age of 9 years; those children were treated for a mean period of 17 months. The bionator group initially had a mean age of 10 years 8 months; on average, they were treated for 16 months. The results demonstrated no significant changes in maxillary growth during the evaluation period. Both appliances showed statistically significant increases in mandibular growth and mandibular protrusion, with greater increases in patients treated in the bionator group. Both experimental groups showed an improvement in the maxillomandibular relationship. There were no significant changes in growth direction, while the bionator group had a greater increase in posterior facial height. Both appliances produced similar labial tipping and protrusion of the lower incisors, lingual inclination, retrusion of the upper incisors, and a significant increase in mandibular posterior dentoalveolar height. The major treatment effects of bionator and FR-2 appliances were dentoalveolar, with a smaller, but significant, skeletal effect.

Thermal behavior of the Ti(IV), Zr(IV) and Pb(II) complexes with 5-nitro-8-hydroxyquinoline

Ti(IV), Zr(IV) and Pb(II) complexes with 5-nitro-8-hydroxyquinoline (5-NQ) were obtained by precipitation in acetone/ammonium solution medium. The compounds TiO(C9H5N2O3)(2).0.5H(2)O, ZrO(C9H5N2O3)(2)2H(2)O and Pb(C9H5N2O3)(2) were characterized by Elemental Analysis, X-ray Diffratometry and Infrared Absorption Spectrometry and their thermal behavior followed by TG/DTA. This present study intends to show the variations in the thermal behavior of the compounds and in the composition and/or structure of final oxide residues, in different atmospheres and heating rates.