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Search Results: 1 - 10 of 297482 matches for " Jo?o Batista Gadelha de;Gonzaga-Silva "
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Identification of mechanisms involved in the relaxation of rabbit cavernous smooth muscle by a new nitric oxide donor ruthenium compound
Cerqueira, Joo Batista Gadelha de;Gonzaga-Silva, Lúcio Flávio;Silva, Francisco Ordelei Nascimento da;Cerqueira, Joo Victor Medeiros de;Oliveira, Ricardo Reges Maia;Moraes, Maria Elisabete Amaral de;Nascimento, Nilberto Robson Falc?o do;
International braz j urol , 2012, DOI: 10.1590/S1677-55382012000500015
Abstract: purpose: the aim of this study was to evaluate the relaxation in vitro of cavernous smooth muscle induced by a new no donor of the complex nitrosil-ruthenium, named trans-[ru(nh3)4(caffeine)(no)]c13 (rut-caf) and sodium nitroprusside (snp). materials and methods: the tissues, immersed in isolated bath systems, were pre-contracted with phenilephrine (pe) (1 μm) and then concentration-response curves (10-12 - 10-4 m) were obtained. to clarify the mechanism of action involved, it was added to the baths odq (10 μm, 30 μm), oxyhemoglobin (10 μm), l-cysteine (100 μm), hydroxicobalamine (100 μm), glibenclamide, iberotoxin and apamine. tissue samples were frozen in liquid nitrogen to measure the amount of cgmp and camp produced. results: the substances provoked significant relaxation of the cavernous smooth muscle. both rut-caf and snp determined dose-dependent relaxation with similar potency (pec50) and maximum effect (emax). the substances showed activity through activation of the soluble guanylyl cyclase (sgc), because the relaxations were inhibited by odq. oxyhemoglobin significantly diminished the relaxation effect of the substances. l-cysteine failed to modify the relaxations caused by the agents. hydroxicobalamine significantly diminished the relaxation effect of rut-caf. glibenclamide significantly increased the efficacy of rut-caf (pec50 4.09 x 7.09). there were no alterations of potency or maximum effect of the substances with the addition of the other ion channel blockers. rut-caf induced production of significant amounts of cgmp and camp during the relaxation process. conclusions: in conclusion, rut-caf causes relaxation of smooth muscle of corpus cavernosum by means of activation of sgc with intracellular production of cgmp and camp; and also by release of no in the intracellular environment. rut-caf releases the no free radical and it does not act directly on the potassium ion channels.
Locally advanced penile carcinoma: classic emasculation or testis-sparing surgery?
Gonzaga-Silva, Lúcio Flávio;Lima, George R. M.;Tavares, José M.;Pinheiro, Vladmir O.;Magalh?es, George A.;Tomas, Manoel E.;Nogueira, Cleto D.;Lima, Marcos V. A.;
International braz j urol , 2012, DOI: 10.1590/1677-553820133806750
Molybdenite as a Rhenium Carrier: First Results of a Spectroscopic Approach Using Synchrotron Radiation  [PDF]
Teresa Pereira da Silva, Maria-Ondina Figueiredo, Daniel de Oliveira, Joo Pedro Veiga, Maria Joo Batista
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2013, DOI: 10.4236/jmmce.2013.15032
Abstract: The chemical and physical properties of rhenium render it a highly demanded metal for advanced applications in important industrial fields. This very scarce element occurs mainly in ores of porphyry copper-molybdenum deposits associated with the mineral molybdenite, MoS2, but it has also been found in granite pegmatites and quartz veins as well as in volcanic gases. Molybdenite is a typical polytype mineral which crystal structure is based on the stacking of [S-Mo-S] with molybdenum in prismatic coordination by sulphide anions; however, it is not yet clearly established if rhenium ions replace Mo4+ cations in a disordered way or else, if such replacement gives rise to dispersed nanodomains of a rhenium-rich phase. As a contribution to clarify this question, an X-ray absorption spectroscopy (XANES) study using synchrotron radiation was performed at the Re L3-edge of rhenium-containing molybdenite samples. Obtained results are described and discussed supporting the generally accepted structural perspective that rhenium is mainly carried by molybdenite through the isomorphous replacement of Mo, rather than by the formation of dispersed Re-specific nanophase(s).
Towards the Recovery of By-Product Metals from Mine Wastes: An X-Ray Absorption Spectroscopy Study on the Binding State of Rhenium in Debris from a Centennial Iberian Pyrite Belt Mine  [PDF]
Maria-Ondina Figueiredo, Teresa Pereira da Silva, Joo Pedro Veiga, Daniel de Oliveira, Maria Joo Batista
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2014, DOI: 10.4236/jmmce.2014.22018
Abstract: Rhenium is a very scarce element, occurring in the Earth's crust mainly carried by molybdenite (MoS2). Due to a very low availability comparative to actual industrial demand, rhenium is nowadays one of the most expensive mineral commodities and an increased interest is focused on ex- ploring residues resulting from a long-term mining, particularly of sulphide ore deposits. It is therefore noteworthy to assign the presence of rhenium (in a concentration up to 3 ppm) in the waste materials from the old sulphur factory at the abandoned mine of Sao Domingos (Iberian Pyrite Belt, Southeast Portugal), exploited since the Roman occupation of Iberia. Aiming at a potential sustainable recovery of rhenium as a by-product, X-ray near-edge absorption spectroscopy (XANES) was applied to clarify the Re-binding and mode of occurrence by comparing Re L3-edge XANES spectra obtained from mine waste samples (previously fully characterized by X-ray laboratory techniques) with similar spectra collected from Re-rich molybdenites (Mo1-xRexS2) and from Re-O model compounds configuring various valences and coordination environments of rhenium ions. Obtained results are commented, ruling out a possible Re-S binding and rather conforming with the binding of rhenium to oxygen in the analysed mine waste materials.
Carlos Henrique Pereira Mello,Luiz Gonzaga Mariano de Souza,Joo Batista Turrioni,Danielle Fernandes Campos
Engevista , 2012,
Abstract: This work proposes a tool, called continuous audit, whose objective is to improve the internalaudit process through the registration of the quality management system (QMS) nonconformities basedin ISO 9001 standard in real time and to increase the employees’ participation in the process of QMSevaluation. This tool was developed starting from the combination among visual management, CEDACand quality audit. This work relates, through a retrospective action-research in a thermal products company,a research made 10 years ago that results in a dissertation. The verification of its adequateness shows thata reduction of the number of nonconformities of the analyzed requirements was obtained. The researchallowed concluding that the proposal tool support a larger employees’ participation in the evaluation andimprovement of QMS and that it beholds the features of a communication instrument based on visualmanagement.
Experimental model of human corpus cavernosum smooth muscle relaxation
Regadas, Rommel P.;Moraes, Maria E. A.;Mesquita, Francisco J. C.;Cerqueira, Joao B. G.;Gonzaga-Silva, Lucio F.;
International braz j urol , 2010, DOI: 10.1590/S1677-55382010000400012
Abstract: purpose: to describe a technique for en bloc harvesting of the corpus cavernosum, cavernous artery and urethra from transplant organ donors and contraction-relaxation experiments with corpus cavernosum smooth muscle. materials and methods: the corpus cavernosum was dissected to the point of attachment with the crus penis. a 3 cm segment (corpus cavernosum and urethra) was isolated and placed in ice-cold sterile transportation buffer. under magnification, the cavernous artery was dissected. thus, 2 cm fragments of cavernous artery and corpus cavernosum were obtained. strips measuring 3 x 3 x 8 mm3 were then mounted vertically in an isolated organ bath device. contractions were measured isometrically with a narco-biosystems force displacement transducer (model f-60, narco-biosystems, houston, tx, usa) and recorded on a 4-channel narco-biosystems desk model polygraph. results: phenylephrine (1μm) was used to induce tonic contractions in the corpus cavernosum (3 - 5 g tension) and cavernous artery (0.5 - 1g tension) until reaching a plateau. after precontraction, smooth muscle relaxants were used to produce relaxation-response curves (10-12m to 10-4 m). sodium nitroprusside was used as a relaxation control. conclusion: the harvesting technique and the smooth muscle contraction-relaxation model described in this study were shown to be useful instruments in the search for new drugs for the treatment of human erectile dysfunction.
The genus Habenaria (Orchidaceae) in the Brazilian Amazon
Batista, Joo A. N.;Silva, Joo Batista F. da;Bianchetti, Luciano de Bem;
Brazilian Journal of Botany , 2008, DOI: 10.1590/S0100-84042008000100011
Abstract: a survey of habenaria in the amazon region in northern brazil was undertaken. forty species are recognized for the region. the majority of the species occur in savannah vegetation and the vegetation types with the highest number of species are the inland savannahs on terra firme (19 spp.), the savannahs of roraima (16 spp.) and the coastal savannahs of pará and amapá (15 spp.). only four species grow in forest and three in the amazonian caatinga. nine of these species are restricted in brazil to the amazon region, four species from forest formations and three from highlands at the border with venezuela. only one species, h. sylvicultrix lindl. ex kraenzl., is possibly endemic to northern brazil. when compared to other regions, the greatest similarity is found with the "cerrado" of the centralwestern region (28 spp. in common) and the guianas (26 spp.). only five species are common with the atlantic forest. five species are recorded for the first time or confirmed in brazil: h. avicula schltr., h. dentifera schweinf., h. huberi carnevali & morillo, h. lehmanniana kraenzl. and h. seticauda lindl. new synonyms are proposed and habenaria marupaana schltr. is included under the synonymy of h. amambayensis schltr., h. platydactyla kraenzl. under h. schwackei barb. rodr., h. mitomorpha kraenzl. under h. subfiliformis cogn., and h. pratensis (salzm. ex lindl.) rchb. f. var. parviflora cogn. under h. spathulifera cogn.
Sorption, solubility and residual monomers of a dental adhesive cured by different light-curing units
Moreira, Francine do Couto Lima;Antoniosi Filho, Nelson Roberto;Souza, Joo Batista de;Lopes, Lawrence Gonzaga;
Brazilian Dental Journal , 2010, DOI: 10.1590/S0103-64402010000500010
Abstract: the aim of this study was to assess polymerization ability of three light-curing units by evaluating the influence of the light source, curing regimen and permeant (water or ethanol) on sorption, solubility and amount of residual monomers of a dental adhesive. specimens of adper single bond 2 were fabricated using a stainless steel circular matrix (8 mm x 1 mm). one quartz-tungsten-halogen (qth) lamp and two light-emitting diode (led) device at three different curing regimes (l1 = 12 j; l2 = 24 j; l3 = 24 j) were used to cure the specimens. specimens were stored in two types of permeants - deionized water or 75% ethanol - for two storage times (g1 =7 days; g2 = 30 days). the specimens underwent water sorption and solubility tests, according to iso 4049:2000 standard. after storage, residual monomers were identified and quantified by high performance liquid chromatography (hplc). for sorption, l1 showed the highest values and qth, the lowest. for solubility, in ethanol-stored groups, l1 had also the highest values, and qth, the lowest, and findings were significantly different from the other curing regimens. l1 leached significantly more monomers than the others, and qth had the lowest results. in conclusion, the type of light source, the curing regimen and the permeant affected sorption, solubility and amount of residual monomers of the adhesive under study.
Influence of pulse-delay curing on sorption and solubility of a composite resin
Lopes, Lawrence Gonzaga;Jardim Filho, Alfeu da Veiga;Souza, Joo Batista de;Rabelo, Denilson;Franco, Eduardo Batista;Freitas, Gersinei Carlos de;
Journal of Applied Oral Science , 2009, DOI: 10.1590/S1678-77572009000100006
Abstract: the purpose of this study was to evaluate the sorption and solubility of a composite resin (tph3; dentsply) cured with halogen light due to different storage media and curing modes. the methodology was based on the iso 4049 standard. two independent groups were established according to the storage time (7 days-g1; 60 days-g2). a stainless steel mould (2 mm x 8 mm ?) was used. the selected curing modes were: i (conventional - c): 40s - 600 mw/cm2; ii (pulse i - pd): 3 s - 200 mw/cm2 + 2 min (delay) + 39 s - 600 mw/cm2; iii (pulse ii): 10 s - 200 mw/cm2 + 2 min (delay) + 37 s - 600 mw/cm2; iv (pulse iii): 3 s- 600 mw/cm2 + 2 min (delay) + 37 s -600 mw/cm2. the media used were: distilled water, 75% ethanol and 100% chlorophorm. five repetitions were made for each group. the specimens were placed in a desiccator at 37oc for 24 h and, after that, at 23oc for 1 h to be weighed until a constant mass (m1) was obtained. the discs were immersed separately into the 3 media for 7 days (g1) and 60 days (g2), and thereafter reweighed (m2). the reconditioning in the desiccator was done until a constant mass (m3) was obtained. sorption and solubility were calculated and the data of g1 and the sorption data of g2 were subjected to two-way anova and tukey's tests (p=0.05). the solubility data of g2 were analyzed by kruskal-wallis test (p=0.05). for g1 and g2, no statistically significant differences were found in sorption among curing techniques (p>0.05). the solubility values were negative, which means that there was mass gain. regarding the storage media, in g2 chlorophorm had the highest sorption values. it may be concluded that the curing modes (c and pd i, ii and iii) did not affect the sorption of the tested composite resin. however, different storage media influenced sorption behavior. the solubility test demonstrated negative data, masking the real solubility.
Effect of light sources and curing mode techniques on sorption, solubility and biaxial flexural strength of a composite resin
Carvalho, Andreia Assis;Moreira, Francine do Couto Lima;Fonseca, Rodrigo Borges;Soares, Carlos José;Franco, Eduardo Batista;Souza, Joo Batista de;Lopes, Lawrence Gonzaga;
Journal of Applied Oral Science , 2012, DOI: 10.1590/S1678-77572012000200021
Abstract: adequate polymerization plays an important role on the longevity of the composite resin restorations. objectives: the aim of this study was to evaluate the effect of light-curing units, curing mode techniques and storage media on sorption, solubility and biaxial flexural strength (bfs) of a composite resin. material and methods: two hundred and forty specimens were made of one composite resin (esthet-x) in a stainless steel mold (2 mm x 8 mm ?), and divided into 24 groups (n=10) established according to the 4 study factors: light-curing units: quartz tungsten halogen (qth) lamp and light-emitting diodes (led); energy densities: 16 j/cm2 and 20 j/cm2; curing modes: conventional (cm) and pulse-delay (pd); and permeants: deionized water and 75% ethanol for 28 days. sorption and solubility tests were performed according to iso 4049:2000 specifications. all specimens were then tested for bfs according to astm f394-78 specification. data were analyzed by three-way anova followed by tukey, kruskal-wallis and mann-whitney tests (α=0.05). results: in general, no significant differences were found regarding sorption, solubility or bfs means for the light-curing units and curing modes (p>0.05). only led unit using 16 j/cm2 and pd using 10 s produced higher sorption and solubility values than qth. otherwise, using cm (16 j/cm2), led produced lower values of bfs than qth (p<0.05). 75% ethanol permeant produced higher values of sorption and solubility and lower values of bfs than water (p<0.05). conclusion: ethanol storage media produced more damage on composite resin than water. in general the led and qth curing units using 16 and 20 j/cm2 by cm and pd curing modes produced no influence on the sorption, solubility or bfs of the tested resin.
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