ESTUDO COMPARATIVO DA POSIÇÃO ÂNTERO POSTERIOR DOS PRIMEIROS MOLARES INFERIORES NO TRATAMENTO ORTODÔNTICO, UTILIZANDO AS TÉCNICAS STRAIGHT-WIRE E EDGEWISE, EM CASOS DE MÁ OCLUSÃO DE CLASSE I DE ANGLE, COM EXTRAÇÃO DE PRIMEIROS PRÉ-MOLARES

Este estudo avaliou o posicionamento ântero posterior dos primeiros molares inferiores, durante o tratamento ortodôntico, utilizando o arco lingual inferior como acessório de ancoragem na técnica Straight-Wire, em comparação aos casos tratados pela técnica Edgewise, sem a utilização do arco lingual. Dois grupos foram selecionados, ambos apresentando má oclusão de Classe I de Angle7, tratados com extração dos primeiros pré-molares superiores e inferiores. Foi utilizada uma amostra de 255 telerradiografias em norma lateral, obtidas de pacientes brasileiros, de ambos os sexos, com média de idade de 13 anos e 6 meses e com diferentes padrões de crescimento facial. Embasado na análise e discussão dos resultados, concluiu-se que: 1) do início do tratamento ao fim da fase de nivelamento, a perda de ancoragem coronária do primeiro molar inferior foi maior nos casos tratados com a técnica Straight-Wire; 2) do fim da fase de nivelamento ao fim do tratamento, a perda de ancoragem coronária e radicular do primeiro molar inferior foi maior na técnica Edgewise; 3) do início ao fim tratamento a perda de ancoragem radicular foi maior nos pacientes tratados com a técnica Edgewise; e 4) o deslocamento ântero-posterior dos incisivos inferiores não apresentou diferença estatisticamente significante para ambas as técnicas, em todas as etapas observadas.(AU)

ESTUDO COMPARATIVO DA POSIÇÃO ÂNTERO POSTERIOR DOS PRIMEIROS MOLARES INFERIORES NO TRATAMENTO ORTODÔNTICO, UTILIZANDO AS TÉCNICAS STRAIGHT-WIRE E EDGEWISE, EM CASOS DE MÁ OCLUSÃO DE CLASSE I DE ANGLE, COM EXTRAÇÃO DE PRIMEIROS PRÉ-MOLARES

Este estudo avaliou o posicionamento ântero posterior dos primeiros molares inferiores, durante o tratamento ortodôntico, utilizando o arco lingual inferior como acessório de ancoragem na técnica Straight-Wire, em comparação aos casos tratados pela técnica Edgewise, sem a utilização do arco lingual. Dois grupos foram selecionados, ambos apresentando má oclusão de Classe I de Angle7, tratados com extração dos primeiros pré-molares superiores e inferiores. Foi utilizada uma amostra de 255 telerradiografias em norma lateral, obtidas de pacientes brasileiros, de ambos os sexos, com média de idade de 13 anos e 6 meses e com diferentes padrões de crescimento facial. Embasado na análise e discussão dos resultados, concluiu-se que: 1) do início do tratamento ao fim da fase de nivelamento, a perda de ancoragem coronária do primeiro molar inferior foi maior nos casos tratados com a técnica Straight-Wire; 2) do fim da fase de nivelamento ao fim do tratamento, a perda de ancoragem coronária e radicular do primeiro molar inferior foi maior na técnica Edgewise; 3) do início ao fim tratamento a perda de ancoragem radicular foi maior nos pacientes tratados com a técnica Edgewise; e 4) o deslocamento ântero-posterior dos incisivos inferiores não apresentou diferença estatisticamente significante para ambas as técnicas, em todas as etapas observadas.(AU)

Interacting helical faces of subunits a and c in the F1Fo ATP synthase of Escherichia coli defined by disulfide cross-linking

Subunits a and c of Fo are thought to cooperatively catalyze proton translocation during ATP synthesis by the Escherichia coli F1Fo ATP synthase. Optimizing mutations in subunit a at residues A217, I221, and L224 improves the partial function of the cA24D/cD61G double mutant and, on this basis, these three residues were proposed to lie on one face of a transmembrane helix of subunit a, which then interacted with the transmembrane helix of subunit c anchoring the essential aspartyl group. To test this model, in the present work Cys residues were introduced into the second transmembrane helix of subunit c and the predicted fourth transmembrane helix of subunit a. After treating the membrane vesicles of these mutants with Cu(1,10-phenanthroline)2SO4 at 0°, 10°, or 20°C, strong a–c dimer formation was observed at all three temperatures in membranes of 7 of the 65 double mutants constructed, i.e., in the aS207C/cI55C, aN214C/cA62C, aN214C/cM65C, aI221C/cG69C, aI223C/cL72C, aL224C/cY73C, and aI225C/cY73C double mutant proteins. The pattern of cross-linking aligns the helices in a parallel fashion over a span of 19 residues with the aN214C residue lying close to the cA62C and cM65C residues in the middle of the membrane. Lesser a–c dimer formation was observed in nine other double mutants after treatment at 20°C in a pattern generally supporting that indicated by the seven landmark residues cited above. Cross-link formation was not observed between helix-1 of subunit c and helix-4 of subunit a in 19 additional combinations of doubly Cys-substituted proteins. These results provide direct chemical evidence that helix-2 of subunit c and helix-4 of subunit a pack close enough to each other in the membrane to interact during function. The proximity of helices supports the possibility of an interaction between Arg210 in helix-4 of subunit a and Asp61 in helix-2 of subunit c during proton translocation, as has been suggested previously.

Libya’s new unity government faces the mother of all rebuilding jobs

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Legalidade das formas de processo e gestão processual ou as duas faces de Janus

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Neural fate of seen and unseen faces in visuospatial neglect: A combined event-related functional MRI and event-related potential study

To compare neural activity produced by visual events that escape or reach conscious awareness, we used event-related MRI and evoked potentials in a patient who had neglect and extinction after focal right parietal damage, but intact visual fields. This neurological disorder entails a loss of awareness for stimuli in the field contralateral to a brain lesion when stimuli are simultaneously presented on the ipsilateral side, even though early visual areas may be intact, and single contralateral stimuli may still be perceived. Functional MRI and event-related potential study were performed during a task where faces or shapes appeared in the right, left, or both fields. Unilateral stimuli produced normal responses in V1 and extrastriate areas. In bilateral events, left faces that were not perceived still activated right V1 and inferior temporal cortex and evoked nonsignificantly reduced N1 potentials, with preserved face-specific negative potentials at 170 ms. When left faces were perceived, the same stimuli produced greater activity in a distributed network of areas including right V1 and cuneus, bilateral fusiform gyri, and left parietal cortex. Also, effective connectivity between visual, parietal, and frontal areas increased during perception of faces. These results suggest that activity can occur in V1 and ventral temporal cortex without awareness, whereas coupling with dorsal parietal and frontal areas may be critical for such activity to afford conscious perception.

Partial molar volume, surface area, and hydration changes for equilibrium unfolding and formation of aggregation transition state: High-pressure and cosolute studies on recombinant human IFN-γ

The equilibrium dissociation of recombinant human IFN-γ was monitored as a function of pressure and sucrose concentration. The partial molar volume change for dissociation was −209 ± 13 ml/mol of dimer. The specific molar surface area change for dissociation was 12.7 ± 1.6 nm2/molecule of dimer. The first-order aggregation rate of recombinant human IFN-γ in 0.45 M guanidine hydrochloride was studied as a function of sucrose concentration and pressure. Aggregation proceeded through a transition-state species, N*. Sucrose reduced aggregation rate by shifting the equilibrium between native state (N) and N* toward the more compact N. Pressure increased aggregation rate through increased solvation of the protein, which exposes more surface area, thus shifting the equilibrium away from N toward N*. The changes in partial molar volume and specific molar surface area between the N* and N were −41 ± 9 ml/mol of dimer and 3.5 ± 0.2 nm2/molecule, respectively. Thus, the structural change required for the formation of the transition state for aggregation is small relative to the difference between N and the dissociated state. Changes in waters of hydration were estimated from both specific molar surface area and partial molar volume data. From partial molar volume data, estimates were 25 and 128 mol H2O/mol dimer for formation of the aggregation transition state and for dissociation, respectively. From surface area data, estimates were 27 and 98 mol H2O/mol dimer. Osmotic stress theory yielded values ≈4-fold larger for both transitions.