Alfredo Ribeiro‐da‐Silva, José Manuel Castro‐Lopes, Antonio Coimbra,
In the cervical enlargement of the rat spinal cord, fluoride-resistant acid phosphatase (FRAP) occurs in most of the small dark sinuous primary afferent central terminals (C1-terminals) of type I-synaptic glomeruli of lamina II and is lacking in the large light roundish primary afferent CII-terminals of type II-glomeruli. Reactive C1-terminals are heterogeneously distributed across the dorsoventral thickness of lamina II, with maximal frequency in the zone heavily stained for FRAP in light micrographs, ...
Tópico(s): Receptor Mechanisms and Signaling
1986 - Elsevier BV | Brain Research
Manuel A.V. Ribeiro da Silva, Manuel J.S. Monte, José R. Ribeiro,
The Knudsen mass-loss effusion technique was used to measure the vapour pressures at different temperatures of the following crystalline dicarboxylic acids: succinic acid, between T = 360.11 K and T = 375.14 K; methylsuccinic acid, between T = 343.12 K and T = 360.11 K; 2,2-dimethylsuccinic acid, between T = 350.11 K, and T = 365.11 K; 2-methylglutaric acid, between T = 338.38 K and T = 347.63 K; and 2,2-dimethylglutaric acid between T = 342.18 K and T = 352.66 K. From the temperature dependence of the vapour pressure, ...
Tópico(s): thermodynamics and calorimetric analyses
2001 - Elsevier BV | The Journal of Chemical Thermodynamics
Manuel A.V. Ribeiro da Silva, Manuel J.S. Monte, José R. Ribeiro,
The Knudsen mass-loss effusion technique was used to measure the vapour pressures of five crystalline dicarboxylic acids as a function of temperature. From the temperature dependence of the vapour pressure, the standard molar enthalpies of sublimation were derived by using the Clausius–Clapeyron equation and the standard molar entropies of sublimation were calculated. The standard molar enthalpies and entropies of sublimation atT = 298.15 K were also calculated by using the estimated value of the ...
Tópico(s): Phase Equilibria and Thermodynamics
1999 - Elsevier BV | The Journal of Chemical Thermodynamics
Manuel A.V. Ribeiro da Silva, José M.S. Fonseca, Rui P.B.M. Carvalho, Manuel J.S. Monte,
Tópico(s): Phase Equilibria and Thermodynamics
2004 - Elsevier BV | The Journal of Chemical Thermodynamics
Produção Nacional
Revisado por pares
Marcelo Luís Gomes Ribeiro, José Humberto Vilar da Silva, Manuel de Oliveira Dantas, Fernando Guilherme Perazzo Costa, Sérgio Felix de Oliveira, José Jordão Filho, Edson Lindolfo da Silva,
O experimento objetivou estimar as exigências de lisina total e a relação lisina: proteína em codornas, na fase de produção. Foram utilizadas 320 codornas, resultado do cruzamento entre a codorna japonesa e a européia de 60 a 144 dias de idade, com peso vivo médio de 178+12 g, alimentadas com rações contendo 20 e 23% de proteína bruta (PB) e, 0,80; 0,95; 1,10; 1,25 e 1,40% de lisina. O delineamento experimental foi o inteiramente ao acaso em esquema fatorial 2x5 (dois níveis de PB x cinco níveis de ...
Tópico(s): Bird parasitology and diseases
2003 - Sociedade Brasileira de Zootecnia | Revista Brasileira de Zootecnia
Manuel A. V. Ribeiro da Silva, Manuel J.S. Monte, José R. Ribeiro,
The Knudsen mass-loss effusion technique was used to measure the vapor pressures at different temperatures of the following crystalline dicarboxylic acids: methylmalonic acid, between 341.13 K and 354.74 K, dimethylmalonic acid, between 347.18 K and 363.26 K, ethylmalonic acid, between 347.52 K and 362.34 K and butylmalonic acid, between 348.20 K and 362.18 K. From the temperature dependence of the vapor pressure, the standard molar enthalpies of sublimation were derived by the Clausius−Clapeyron ...
Tópico(s): Thermal and Kinetic Analysis
2000 - American Chemical Society | Journal of Chemical & Engineering Data
Manuel A. V. Ribeiro da Silva, José R. B. Gomes, Ana I.M.C. Lobo Ferreira,
The standard (p° = 0.1 MPa) molar enthalpies of formation of 2-, 3-, and 4-chloroaniline were derived from the standard molar energies of combustion, in oxygen, at T = 298.15 K, measured by rotating bomb combustion calorimetry. The Calvet high-temperature vacuum sublimation technique was used to measure the enthalpies of vaporization or sublimation of the three isomers. These two thermodynamic parameters yielded the standard molar enthalpies of formation of the three isomers of chloroaniline, in the ...
Tópico(s): Free Radicals and Antioxidants
2005 - American Chemical Society | The Journal of Physical Chemistry B
Ana L. C. Lagoa, Hermı́nio P. Diogo, M. Pilar Dias, Manuel E. Minas da Piedade, Luı́sa M.P.F. Amaral, Manuel A.V. Ribeiro da Silva, José A. Martinho Simões, Rita C. Guedes, Benedito J. Costa Cabral, Karsten Schwarz, Matthias Epple,
The standard molar enthalpies of formation of chloro-, bromo-, and iodoacetic acids in the crystalline state, at 298.15 K, were determined as deltafH(o)m(C2H3O2Cl, cr alpha)=-(509.74+/- 0.49) kJ x mol(-1), deltafH(o)m(C2H3O2Br, cr I)-(466.98 +/- 1.08) kJ x mol(-1), and deltafH(o)m (C2H3O2I, cr)=-(415.44 +/- 1.53) kJ x mol(-1), respectively, by rotating-bomb combustion calorimetry. Vapor pressure versus temperature measurements by the Knudsen effusion method led to deltasubH(o)m(C2H3O2Cl)=(82.19 +/- 0.92) kJ ...
Tópico(s): Free Radicals and Antioxidants
2001 - Wiley | Chemistry - A European Journal
Produção Nacional
Revisado por pares
Antônia Suely Guimarães-e-Silva, Soraia de Oliveira Silva, Rosa Cristina Ribeiro da Silva, Valéria Cristina Soares Pinheiro, José Manuel Macário Rebêlo, Maria Norma Melo,
The aims of the study were to determine the blood feeding preferences of sandflies and to identify species of Leishmania that infected phlebotomines in Caxias, Maranhão, Brazil, an area that is highly endemic for leishmaniasis. Sandflies were captured in light traps located in the peridomiciliary environments of randomly selected houses in urban and rural settings between 1800 and 0600 hours on new moon days between March 2013 and February 2015. DNA extracts from 982 engorged female sandflies were ...
Tópico(s): Trypanosoma species research and implications
2017 - Public Library of Science | PLoS ONE
Luzia Teixeira, Andreia Marques, Carla Sofia Meireles, Ana R. Seabra, Diana Rodrigues, Pedro Madureira, Augusto Faustino, Carolina Silva, Adília Ribeiro, Paula Ferreira, José Manuel Correia da Costa, Nuno Canada, Manuel Vilanova,
Summary Activation of B cells occurring in hosts infected with protozoan parasites has been implicated either in protective or parasite‐evasion immune‐mediated mechanisms. Intraperitoneal inoculation of Neospora caninum tachyzoites into BALB/c mice induces an acute response characterized by a rapid increase in the numbers of CD69‐expressing peritoneal and splenic B cells. This early B‐cell stimulatory effect preceded an increase in the numbers of total and immunoglobulin‐secreting splenic B cells ...
Tópico(s): Parasitic Infections and Diagnostics
2005 - Wiley | Immunology
Manuel A.V. Ribeiro da Silva, Ana Filipa L.O.M. Santos, José R. B. Gomes, Marı́a Victoria Roux, Manuel Temprado, Pilar Jiménez, Rafael Notario,
The relative stabilities of 2,2'- and 3,3'-bithiophenes were evaluated by experimental thermochemistry and the results compared with data obtained from state of the art calculations, which were also extended to 2,3'-bithiophene. The standard (p degrees = 0.1 MPa) molar enthalpies of formation of crystalline 2,2'-bithiophene and 3,3'-bithiophene were calculated from the standard molar energies of combustion, in oxygen, to yield CO(2) (g) and H(2)SO(4) x 115 H(2)O, measured by rotating-bomb combustion ...
Tópico(s): Chemistry and Chemical Engineering
2009 - American Chemical Society | The Journal of Physical Chemistry A
Ana Filipa L.O.M. Santos, José R. B. Gomes, Manuel A. V. Ribeiro da Silva,
A combined experimental and computational study on the thermochemistry of 2- and 3-acetylpyrroles was performed. The enthalpies of combustion and sublimation were measured by static bomb combustion calorimetry and Knudsen effusion mass-loss technique, respectively, and the standard (p° = 0.1 MPa) molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, were determined. Additionally, the gas-phase enthalpies of formation were estimated by G3(MP2)//B3LYP calculations, using several gas-phase ...
Tópico(s): Chemical and Physical Properties in Aqueous Solutions
2009 - American Chemical Society | The Journal of Physical Chemistry A
José R. B. Gomes, Manuel A. V. Ribeiro da Silva,
Density functional theory has been used to investigate gas-phase thermodynamic properties of phenol and dichlorophenols. Molecular geometries, energies, and vibrational frequencies were computed at the B3LYP and BP86 levels of theory. At T = 298.15 K, calculated standard enthalpies of formation are in excellent agreement with experimental data. The average deviation between calculated and experimental values is of about 2.3 kJ/mol, and in some cases, theoretical values fall within experimental uncertainty. ...
Tópico(s): Chemical Thermodynamics and Molecular Structure
2003 - American Chemical Society | The Journal of Physical Chemistry A
José R. B. Gomes, Manuel A. V. Ribeiro da Silva,
A computational study on the thermodynamic properties of 13 β-diketones is presented. The B3LYP//6-311+G(2d,2p)//B3LYP/6-31G(d) theoretical approach was employed to compute the O−H and C−H bond dissociation enthalpies and enthalpy of tautomerization and to estimate standard gas-phase enthalpies of formation for the radicals and for the parent molecules. The gas-phase enthalpies of formation for the neutral molecules are in excellent agreement with available experimental data, supporting the estimates ...
Tópico(s): Thermal and Kinetic Analysis
2006 - American Chemical Society | The Journal of Physical Chemistry A
Hermı́nio P. Diogo, Manuel E. Minas da Piedade, Anabela C. Fernandes, José A. Martinho Simões, Manuel A.V. Ribeiro da Silva, Manuel J.S. Monte,
The enthalpy of sublimation of diphenylacetylene at 298.15 K, ΔgcrH⊖m(C2(C6H5)2] = 95.1 ± 1.1 kJmol−1, was derived from vapour pressure-temperature data, obtained with two different Knudsen effusion apparatus, and from heat capacity measurements obtained by differential scanning calorimetry. The molybdenum-diphenylacetylene bond dissociation enthalpy in Mo(η5-C5H5)2[C2(C6H5)2] was reevaluated as 115 ± 26 kJ mol−1, on the basis of the new value for ΔcrgH⊖m[C2(C6H5)2].
Tópico(s): Thermal and Kinetic Analysis
1993 - Elsevier BV | Thermochimica Acta
José R. B. Gomes, Manuel A.V. Ribeiro da Silva,
Gas-phase standard enthalpies of formation, S−H bond dissociation enthalpies, and gas-phase acidities, at T = 298.15 K, for a large number of small sulfur-containing molecules were calculated by means of B3LYP, CBS-Q, G3MP2B3, and G3 approaches. The computed values are compared with available experimental results for these quantities. It is shown that the DFT approach is well-suited to predict S−H bond dissociation enthalpies and gas-phase acidities but fails completely in the estimation of enthalpies ...
Tópico(s): Advanced Chemical Physics Studies
2004 - American Chemical Society | The Journal of Physical Chemistry A
José R. B. Gomes, Manuel A. V. Ribeiro da Silva,
Abstract Density Functional Theory was used to investigate several gas‐phase thermodynamic parameters of the o ‐, m ‐, and p ‐aminophenol isomers. Within the DFT approach, the B3LYP method and the 6‐31G(d) and 6‐311+G(2d,2p) basis sets were used to compute standard enthalpies of formation. Calculated data are in excellent agreement with the experimental work of Nuñez et al. [J Chem Thermodyn 1996, 18, 575–579] but differs significantly from the values of Sabbah et al. [Can J Chem 1996, 74, 500–507]. In this ...
Tópico(s): Advanced Chemical Physics Studies
2004 - Wiley | International Journal of Quantum Chemistry
Luı́s Rodrigues, José Manuel Pereira, Amélia Ferreira da Silva, Humberto Ribeiro,
There is an expectation that the introduction of artificial intelligence (AI) will bring about profound changes in the current paradigm of the audit profession, ensuring better reliability and security in the analysis of financial statements. This paper reports the results of a questionnaire survey to ascertain the perceptions of certified auditors, from two Portuguese districts, regarding the impact of artificial intelligence on the audit profession. Findings reveal that the respondents believe ...
Tópico(s): Explainable Artificial Intelligence (XAI)
2022 - Lectito Journals | Journal of Information Systems Engineering & Management
I.M. Soares-da-Silva, José A. Ribeiro, Carla Valongo, Ricardo Mouro Pinto, Manuel Vilanova, Reiner Bleher, Jorge Machado,
The haemocytes in bivalve mussels are involved in many processes such as lesion repair, shell repair, elimination of small particles and toxic substances. In Anodonta cygnea there are two categories of haemolymph cells, the granulocytes and hyalinocytes. Two groups of cells were identified by flow cytometry and morphological studies: one with larger size and granularity representing 75%, and another group of cells (25%) which were approximately half the size. The cytochemical reactions showed peroxidase ...
Tópico(s): Marine Biology and Environmental Chemistry
2002 - Elsevier BV | Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology
Jorge C. G. Calado, A.R. Dias, José A. Martinho Simões, Manuel A. V. Ribeiro da Silva,
Bond-enthalpy contribution values D(Mo–Me)= 149·5 kJ mol–1 and D(W–Me)= 197·8 kJ mol–1 have been derived from the standard enthalpies of formation ΔH°f[Mo(η-C5H5)2Me2, c]=(283·8 ± 3·8) kJ mol–1 and ΔH°f[W(η-C5H5)2Me2, c]=(295·6 ± 3·5) kJ mol–1 obtained from measurements of the reaction enthalpies of Mo(η-C5H5)2Me2(c) and W(η-C5H5)2Me2(c) in an aqueous solution of hydrochloric acid.
Tópico(s): Carbon dioxide utilization in catalysis
1978 - Royal Society of Chemistry | Journal of the Chemical Society Chemical Communications
Manuel A.V. Ribeiro da Silva, Joana I.T.A. Cabral, José R. B. Gomes,
In order to understand the influence of the methyl group in the stability of the indole unit, the standard (p∘=0.1MPa) molar enthalpies of formation of 1-, 2-, and 3-methylindoles, in the gaseous phase, were determined at T = 298.15 K. For that, combustion calorimetry was used to determine the massic energies of combustion and consequently the standard molar enthalpies of formation in the condensed phase, and Calvet microcalorimetry was employed to measure the standard molar enthalpy of phase transition ( ...
Tópico(s): Phase Equilibria and Thermodynamics
2009 - Elsevier BV | The Journal of Chemical Thermodynamics
Manuel A.V. Ribeiro da Silva, Joana I.T.A. Cabral, José R. B. Gomes,
Static bomb calorimetry, Calvet microcalorimetry and the Knudsen effusion technique were used to determine the standard molar enthalpy of formation in the gas phase, at T = 298.15 K, of the indole and indoline heterocyclic compounds. The values obtained were 164.3 ± 1.3 kJ·mol−1 and 120.0 ± 2.9 kJ·mol−1, respectively. Several different computational approaches and different working reactions were used to estimate the gas-phase enthalpies of formation for indole and indoline. The computational approaches ...
Tópico(s): Free Radicals and Antioxidants
2008 - American Chemical Society | The Journal of Physical Chemistry A
Manuel A.V. Ribeiro da Silva, Luı́sa M.P.F. Amaral, José R. B. Gomes,
The standard (p° = 0.1 MPa) molar enthalpies of formation, , of crystalline 2-, 3- and 4-chlorobenzophenone and 4,4‘-dichlorobenzophenone were derived from the standard molar energies of combustion, , in oxygen, to yield CO2(g), N2(g), and HCl·600H2O(l), at T = 298.15 K, measured by rotating bomb combustion calorimetry. The Calvet high-temperature vacuum sublimation technique was used to measure the enthalpy of sublimation, , of the compound 2-chlorobenzophenone. For the other three compounds, the standard ...
Tópico(s): Thermal and Kinetic Analysis
2007 - American Chemical Society | The Journal of Physical Chemistry B
Manuel A. V. Ribeiro da Silva, Luı́sa M.P.F. Amaral, José R. B. Gomes,
The standard (p0 = 0.1 MPa) molar enthalpies of formation, Δf , for liquid 2,4,6-trichloropyrimidine and for crystalline 2-chloropyrimidine, 2,4- and 4,6-dichloropyrimidine, and 2,4,5,6-tetrachloropyrimidine compounds were determined at T = 298.15 K by rotating-bomb combustion calorimetry. The standard molar enthalpies of vaporization or sublimation, , of these compounds at T = 298.15 K were determined by Calvet microcalorimetry. The experimental standard molar enthalpies of formation of those compounds, in ...
Tópico(s): Analytical Chemistry and Chromatography
2007 - American Chemical Society | The Journal of Physical Chemistry B
Manuel A. V. Ribeiro da Silva, Luı́sa M.P.F. Amaral, José R. B. Gomes,
The standard (po = 0.1 MPa) molar enthalpies of formation of 2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-dichloroanilines were derived from the standard molar energies of combustion, in oxygen, to yield CO2(g), N2(g) and HCl·600H2O(l), at T = 298.15 K, measured by rotating bomb combustion calorimetry. The Calvet high-temperature vacuum sublimation technique was used to measure the enthalpies of sublimation of the six isomers. These two thermodynamic parameters yielded the standard molar enthalpies of formation ...
Tópico(s): Free Radicals and Antioxidants
2006 - American Chemical Society | The Journal of Physical Chemistry A
José R. B. Gomes, María D.M.C. Ribeiro da Silva, Manuel A.V. Ribeiro da Silva,
In this work, the gas-phase homolytic N−H bond dissociation enthalpy (BDE) was investigated for a large series of molecules containing at least one N−H bond by means of accurate density-functional theory calculations. The molecules studied belong to different classes of compounds, namely, amines, amides and anilines, amino acids, phenoxazines, indolamines, and other compounds of general interest, such as anti-inflammatory drugs. To achieve these purposes, the (RO)B3LYP/6-311+G(2d,2p)//(U)B3LYP/6-31G* ...
Tópico(s): Chemical Thermodynamics and Molecular Structure
2004 - American Chemical Society | The Journal of Physical Chemistry A
Produção Nacional
Revisado por pares
Renata Silva Diniz, Jane Sélia dos Reis Coimbra, Álvaro Vianna Novaes de Carvalho Teixeira, Angélica Ribeiro da Costa, Igor José Boggione Santos, Gustavo Costa Bressan, Antonio Manuel da Cruz Rodrigues, Luiza Helena Meller da Silva,
The study of protein interactions has generated great interest in the food industry. Therefore, research on new supramolecular structures shows promise. Supramolecular structures of the whey proteins α-lactalbumin and glycomacropeptide were produced under varying heat treatments (25 to 75°C) and acidic conditions (pH3.5 to 6.5). Isothermal titration calorimetry experiments showed protein interactions and demonstrated that this is an enthalpically driven process. Supramolecular protein structures in ...
Tópico(s): Surfactants and Colloidal Systems
2014 - Elsevier BV | Food Research International
Manuel A.V. Ribeiro da Silva, María D.M.C. Ribeiro da Silva, Luı́sa M.P.F. Amaral, José Elguero, Pilar Jiménez, Marı́a Victoria Roux, Juan Z. Dávalos, Manuel Temprado, Pilar Cabildo, Rosa M. Claramunt, Otília Mó, Manuel Yáñez,
The standard (p∘ = 0.1 MPa) molar enthalpy of formation for gaseous 2-phenylbenzimidazole (2-PhBIM) and 2-benzylbenzimidazole (2-BzBIM) were derived from the standard molar enthalpies of combustion, at T = 298.15 K, measured by static bomb calorimetry, and the standard molar enthalpy of sublimation, at T = 298.15 K, measured by Calvet microcalorimetry in the case of 2-phenylbenzimidazole or derived from the variation of the vapour pressures, determined by the Knudsen effusion technique, with temperatures ...
Tópico(s): thermodynamics and calorimetric analyses
2005 - Elsevier BV | The Journal of Chemical Thermodynamics
José R. B. Gomes, María D.M.C. Ribeiro da Silva, Manuel A.V. Ribeiro da Silva,
DFT calculations have been performed to investigate the effect of several different substituents on the N–O bond dissociation enthalpies of 2-substituted-quinoxaline-1,4-dioxides. Further, the influence of electron and proton affinities and also of N–O bond dissociation enthalpies on the antitumor activity of selected compounds is analyzed. In agreement with experimental data, the calculations suggest that Tirapazamine is more active than Quindoxin due to a much easier reduction and protonation ...
Tópico(s): Chemical Reaction Mechanisms
2006 - Elsevier BV | Chemical Physics Letters
Manuel A.V. Ribeiro da Silva, Ana I.M.C. Lobo Ferreira, José R. B. Gomes,
The standard (p° = 0.1 MPa) molar enthalpies of formation in the condensed phase of all the fluoroanilines, with the exception of the 2,3,5-trifluoroaniline compound, were derived from the standard molar energies of combustion in oxygen at T = 298.15 K, measured by rotating bomb combustion calorimetry. Calvet high-temperature vacuum sublimation experiments were performed to measure their enthalpies of vaporization or sublimation. These experiments allowed the determination of the standard molar enthalpies ...
Tópico(s): Thermal and Kinetic Analysis
2007 - American Chemical Society | The Journal of Physical Chemistry B