Desordenes orales potencialmente malignos-Lo que el odontólogo debe conocer / Oral potentially malignant disorders-What the dentist should know

RESUMEN Objetivo: El objetivo de este estudio es actualizar los conocimientos sobre Desordenes Orales Potencialmente Malignos, dando énfasis a datos epidemiológicos, apariencia clínica, sintomatología, diagnóstico diferencial y manejo terapéutico, así como también resaltar el rol del odontólogo general en el examen clínico. Material y métodos: Fue realizada una búsqueda de la literatura en las bases de datos científicas "Medline", "Pubmed" y "SciELO", utilizando las palabras clave "Leukoplakia", "Erythroplasia", "Cheilitis", "Nevus, Pigmented", "Oral Submucous Fibrosis", "Lichen Planus". La búsqueda fue orientada hacia artículos de revisión, estudios clínicos y reportes de caso, priorizando los artículos publicados en los últimos 5 años y sin hacer distinciones por el idioma. Resultados: Como resultado de la búsqueda se obtuvieron 165 artículos, los cuales fueron revisados cuidadosamente para conservar solo aquellos que se dedicaran a describir, comparar o tratar desordenes con potencial de malignidad, incluyendo datos de relevancia como epidemiología, apariencia clínica, sintomatología, diagnóstico diferencial y manejo terapéutico. De esta manera, el estudio se limitó a 41 artículos. Conclusiones: Al adoptar medidas preventivas, así como un meticuloso examen clínico sobre tejidos blandos, se puede facilitar la detección temprana de Desordenes Orales Potencialmente Malignos. La eliminación de lesiones sospechosas o un control de las condiciones cancerígenas puede evitar en gran mayoría el desarrollo de tumores malignos.

SUMMARY Objective: The objective of this study is to update scientific knowledge about OPMDs, emphasizing epidemiological data, clinical appearance, symptomatology, differential diagnosis and therapeutic management, as well as highlighting the role of the general dentist in the clinical examination. Material and methods: A literature search was carried out, making use of the keywords "Leukoplakia", "Erythroplasia", "Cheilitis", "Nevus, Pigmented", "Oral Submucous Fibrosis" and "Lichen Planus". Prioritizing articles published in the last 5 years on the scientific databases "Medline", "Pubmed" and "SciELO". Results: As a result of the search, 165 articles were obtained, which were carefully reviewed to preserve only those that were dedicated to describe, compare or treat lesions with malignant potential, including relevant data such as epidemiology, clinical appearance, symptomatology, differential diagnosis and management. therapeutic. In this way, the study was limited to 41 articles. Conclusions: By taking preventive measures, as well as through a clinical examination of soft tissues, early detection of potentially malignant disorders can be facilitated. The removal of suspicious lesions or a control of their carcinogenic conditions can largely prevent the development of malignant tumors.

An international comparability study on quantification of mRNA gene expression ratios: CCQM-P103.1.

Measurement of RNA can be used to study and monitor a range of infectious and non-communicable diseases, with profiling of multiple gene expression mRNA transcripts being increasingly applied to cancer stratification and prognosis. An international comparison study (Consultative Committee for Amount of Substance (CCQM)-P103.1) was performed in order to evaluate the comparability of measurements of RNA copy number ratio for multiple gene targets between two samples. Six exogenous synthetic targets comprising of External RNA Control Consortium (ERCC) standards were measured alongside transcripts for three endogenous gene targets present in the background of human cell line RNA. The study was carried out under the auspices of the Nucleic Acids (formerly Bioanalysis) Working Group of the CCQM. It was coordinated by LGC (United Kingdom) with the support of National Institute of Standards and Technology (USA) and results were submitted from thirteen National Metrology Institutes and Designated Institutes. The majority of laboratories performed RNA measurements using RT-qPCR, with datasets also being submitted by two laboratories based on reverse transcription digital polymerase chain reaction and one laboratory using a next-generation sequencing method. In RT-qPCR analysis, the RNA copy number ratios between the two samples were quantified using either a standard curve or a relative quantification approach. In general, good agreement was observed between the reported results of ERCC RNA copy number ratio measurements. Measurements of the RNA copy number ratios for endogenous genes between the two samples were also consistent between the majority of laboratories. Some differences in the reported values and confidence intervals ('measurement uncertainties') were noted which may be attributable to choice of measurement method or quantification approach. This highlights the need for standardised practices for the calculation of fold change ratios and uncertainties in the area of gene expression profiling.

On the Performance of Optimally Tuned Range-Separated Hybrid Functionals for X-ray Absorption Modeling.

We investigate the performance of optimally tuned range-separated hybrid functionals (OT-RSH) for modeling X-ray absorption spectra (XAS) of a benchmark set of simple molecules (water, ammonia, methane, hydrogen peroxide, hydrazine, and ethane), using time-dependent density functional theory (TDDFT). Spectra were simulated within the Path Integral based Reflection Principle methodology. Relative intensities, peak positions, and widths were compared with available experimental data. We show that the OT-RSH approach outperforms empirically parametrized functionals in terms of relative peak positions and intensities. Furthermore, we investigate the effect of geometry specific tuning where the range separation parameter is optimized for each geometry. Finally, we propose a simple correction scheme allowing for calculations of XAS on the absolute energy scale using the OT-RSH approach combined with ΔSCF/TDDFT-based calculations of core ionization energies.

[Systematic review of epidemiological studies on interpersonal discrimination and mental health]. / Revisão sistemática dos estudos epidemiológicos sobre discriminação interpessoal e saúde mental.

The article describes epidemiological studies on the relationship between interpersonal discrimination and mental health outcomes, updating previous literature reviews on the topic. The review included 34 papers published in PubMed from 2000 to 2010, 68% of which were based on convenience samples and 82% with a cross-sectional design. Positive and statistically significant associations were observed between discrimination and adverse mental health outcomes, particularly substance use, depression, and alcohol-related disorders. Only one third of the studies explicitly adopted a specific theoretical framework to interpret the examined relationships. Mirroring previous reviews, discrimination was positively and consistently associated with adverse mental health outcomes. However, future studies should employ robust designs for causal inference, use discrimination instruments with good psychometric properties, and adopt theoretical frameworks to interpret their findings.

Revisão sistemática dos estudos epidemiológicos sobre discriminação interpessoal e saúde mental / Systematic review of epidemiological studies on interpersonal discrimination and mental health / Revisión sistemática de estudios epidemiológicos sobre la discriminación interpersonal y salud mental

Foram caracterizados estudos epidemiológicos que avaliaram a relação entre discriminação interpessoal e condições de saúde mental, atualizando revisões prévias sobre o tema. Identificaram-se 34 artigos publicados entre 2000 e 2010 no PubMed, dos quais 68% utilizaram amostras de conveniência e 82% o delineamento transversal. Observaram-se associações positivas e estatisticamente significativas entre discriminação e condições adversas de saúde mental, especialmente uso de substâncias, depressão e transtornos associados ao uso de álcool. Somente um terço dos estudos explicitou um referencial teórico para interpretar as relações examinadas. Similarmente às revisões anteriores, pode-se afirmar que as experiências discriminatórias se associam positiva e consistentemente com desfechos adversos de saúde mental. Entretanto, investigações futuras deverão empregar delineamentos mais robustos para a inferência causal, utilizar instrumentos de discriminação com boas propriedades psicométricas e adotar referencial teórico específico para interpretar os resultados produzidos.

The article describes epidemiological studies on the relationship between interpersonal discrimination and mental health outcomes, updating previous literature reviews on the topic. The review included 34 papers published in PubMed from 2000 to 2010, 68% of which were based on convenience samples and 82% with a cross-sectional design. Positive and statistically significant associations were observed between discrimination and adverse mental health outcomes, particularly substance use, depression, and alcohol-related disorders. Only one third of the studies explicitly adopted a specific theoretical framework to interpret the examined relationships. Mirroring previous reviews, discrimination was positively and consistently associated with adverse mental health outcomes. However, future studies should employ robust designs for causal inference, use discrimination instruments with good psychometric properties, and adopt theoretical frameworks to interpret their findings.

Fueron caracterizados los estudios epidemiológicos que evaluaron la relación entre la discriminación interpersonal y salud mental, actualizando revisiones previas sobre el tema. Se identificaron 34 artículos publicados entre 2000 y 2010 a través del PubMed, de los cuales el 68% utilizaron muestras de conveniencia y el 82% fueron estudios transversales. Se observaron asociaciones positivas y estadísticamente significativas entre la discriminación y condiciones adversas de salud mental, especialmente consumo de substancias, depresión y los trastornos asociados al consumo de alcohol. Sólo un tercio de los estudios explicitó un marco teórico para interpretar las relaciones examinadas. Al igual que en las revisiones anteriores, se puede afirmar que las experiencias discriminatorias se asocian positiva y consistentemente con resultados adversos de salud mental. Sin embargo, investigaciones futuras deberán emplear diseños más robustos para la inferencia causal, utilizar instrumentos de discriminación con buenas propiedades psicométricas y adoptar un marco teórico específico para interpretar los resultados producidos.

Insights into the ultraviolet spectrum of liquid water from model calculations: the different roles of donor and acceptor hydrogen bonds in water pentamers.

With a view toward a better understanding of changes in the peak position and shape of the first absorption band of water with condensation or temperature, results from electronic structure calculations using high level wavefunction based and time-dependent density functional methods are reported for water pentamers. Excitation energies, oscillator strengths, and redistributions of electron density are determined for the quasitetrahedral water pentamer in its C(2v) equilibrium geometry and for many pentamer configurations sampled from molecular simulation of liquid water. Excitations associated with surface molecules are removed in order to focus on those states associated with the central molecule, which are the most representative of the liquid environment. The effect of hydrogen bonding on the lowest excited state associated with the central molecule is studied by adding acceptor or donor hydrogen bonds to tetramer and trimer substructures of the C(2v) pentamer, and by sampling liquid-like configurations having increasing number of acceptor or donor hydrogen bonds of the central molecule. Our results provide clear evidence that the blueshift of excitation energies upon condensation is essentially determined by acceptor hydrogen bonds, and the magnitudes of these shifts are determined by the number of such, whereas donor hydrogen bonds do not induce significant shifts in excitation energies. This qualitatively different role of donor and acceptor hydrogen bonds is understood in terms of the different roles of the 1b(1) monomer molecular orbitals, which establishes an intimate connection between the valence hole and excitation energy shifts. Since the valence hole of the lowest excitation associated with the central molecule is found to be well localized in all liquid-like hydrogen bonding environments, with an average radius of gyration of ~1.6 Å that is much lower than the nearest neighbor O-O distance, a clear and unambiguous connection between hydrogen bonding environments and excitation energy shifts can be established. Based on these results, it is concluded that peak position of the first absorption band is mainly determined by the relative distribution of single and double acceptor hydrogen bonding environments, whereas the shape of the first absorption band is mainly determined by the relative distribution of acceptor and broken acceptor hydrogen bonding environments. The temperature dependence of the peak position and shape of the first absorption band can be readily understood in terms of changes to these relative populations.

Blood pressure and interpersonal discrimination: systematic review of epidemiologic studies.

The relationship between blood pressure and discrimination has been recently investigated, and there are conflicting debates in literature devoted to the topic. The objective of this study was to update previous literature reviews on discrimination and blood pressure. A bibliographic search was conducted in PubMed between January/2000 and December/2010, including epidemiological studies, assessing the relationship between interpersonal discrimination and blood pressure/hypertension. The 22 studies included originated from the United States; 96% of them used the cross-sectional design with convenience sample, comprising, in 59% of the studies, exclusively Black participants. The Everyday Discrimination Scale and the Perceived Racism Scale were the most frequently used instruments, emphasizing lifetime or chronic/everyday racial/ethnic discrimination. In the 22 studies assessed, the association between discrimination and blood pressure/hypertension was assessed 50 times. Twenty results (40%) showed no association between them, and only 15 (30%) revealed global positive associations, of which 67% were statistically significant. Eight negative associations were also observed, suggesting that higher exposure to discrimination would be associated with lower blood pressure/hypertension. The studies did not consistently support the hypothesis that discrimination is associated with higher blood pressure. These findings can be partially attributed to the limitations of the studies, especially those related to the measurement of discrimination and of factors that might modify its association with outcomes. To establish discrimination as an epidemiological risk factor, more rigorous methodological strategies should be used, and the theoretical frameworks that postulate causal relationships between discrimination and blood pressure should be reviewed.

Pressão arterial e discriminação interpessoal: revisão sistemática de estudos epidemiológicos / Blood pressure and interpersonal discrimination: systematic review of epidemiologic studies

A relação entre pressão arterial e discriminação tem sido investigada recentemente, havendo intensos debates na literatura sobre o tema. Este trabalho objetivou atualizar as revisões de literatura sobre discriminação e pressão arterial ou hipertensão. Foi conduzida pesquisa no PubMed, entre janeiro/2000 e dezembro/2010, incluindo estudos epidemiológicos, que avaliaram a discriminação interpessoal e sua relação com pressão arterial/hipertensão. Os 22 estudos identificados originaram-se dos Estados Unidos; 96% deles empregaram o delineamento transversal, com amostras de conveniência e compostas, em 59% dos casos, exclusivamente por negros. Os instrumentos mais utilizados para aferir discriminação foram Everyday Discrimination Scale e Perceived Racism Scale, enfatizando a discriminação étnico-racial, ocorrida ao longo da vida ou cotidianamente. Nos 22 estudos avaliados, a relação entre discriminação e os desfechos foi analisada 50 vezes. Em 20 (40%) resultados, não foi encontrada qualquer associação e, em apenas 15 (30%), observaram-se associações positivas globais, sendo 67% destas estatisticamente significativas. Foram também observadas oito associações inversas, sugerindo que maior exposição à discriminação estaria associada com menor pressão arterial/hipertensão. Os estudos não permitiram apoiar consistentemente a hipótese de que a discriminação está associada à maior pressão arterial. Isto pode ser atribuído, em parte, às limitações dos estudos, relacionadas à mensuração da discriminação e de eventos que podem modificar sua associação com os desfechos. Para consolidar a discriminação como um fator de risco epidemiológico, é necessário utilizar estratégias metodológicas mais rigorosas e revisar os marcos teóricos que propõem relações de causa e efeito entre discriminação e pressão arterial.

The relationship between blood pressure and discrimination has been recently investigated, and there are conflicting debates in literature devoted to the topic. The objective of this study was to update previous literature reviews on discrimination and blood pressure. A bibliographic search was conducted in PubMed between January/2000 and December/2010, including epidemiological studies, assessing the relationship between interpersonal discrimination and blood pressure/hypertension. The 22 studies included originated from the United States; 96% of them used the cross-sectional design with convenience sample, comprising, in 59% of the studies, exclusively Black participants. The Everyday Discrimination Scale and the Perceived Racism Scale were the most frequently used instruments, emphasizing lifetime or chronic/everyday racial/ethnic discrimination. In the 22 studies assessed, the association between discrimination and blood pressure/hypertension was assessed 50 times. Twenty results (40%) showed no association between them, and only 15 (30%) revealed global positive associations, of which 67% were statistically significant. Eight negative associations were also observed, suggesting that higher exposure to discrimination would be associated with lower blood pressure/hypertension. The studies did not consistently support the hypothesis that discrimination is associated with higher blood pressure. These findings can be partially attributed to the limitations of the studies, especially those related to the measurement of discrimination and of factors that might modify its association with outcomes. To establish discrimination as an epidemiological risk factor, more rigorous methodological strategies should be used, and the theoretical frameworks that postulate causal relationships between discrimination and blood pressure should be reviewed.

How does dielectric solvation affect the size of an ion?

The effect of solvation by a continuum dielectric on the size of an ion is examined using electronic structure calculations. Various measures correlated with size are considered, including the root-mean-square radius of the electronic charge density, the amount of solute charge penetrating outside the cavity, the electronic radial distribution function, the nucleus-electron potential energy, and the electron-electron potential energy. Calculations are made on several representative ionic solutes, and it is found that every measure indicates that the application of a dielectric makes the cations larger and the anions smaller. These counterintuitive trends are examined, and a plausible explanation is offered for the observed behavior.

Insights into the ultraviolet spectrum of liquid water from model calculations.

With a view toward a better molecular level understanding of the effects of hydrogen bonding on the ultraviolet absorption spectrum of liquid water, benchmark electronic structure calculations using high level wave function based methods and systematically enlarged basis sets are reported for excitation energies and oscillator strengths of valence excited states in the equilibrium water monomer and dimer and in a selection of liquid-like dimer structures. Analysis of the electron density redistribution associated with the two lowest valence excitations of the water dimer shows that these are usually localized on one or the other monomer, although valence hole delocalization can occur for certain relative orientations of the water molecules. The lowest excited state is mostly associated with the hydrogen bond donor and the significantly higher energy second excited state mostly with the acceptor. The magnitude of the lowest excitation energies is strongly dependent on where the valence hole is created, and only to a lesser degree on the perturbation of the excited electron density distribution by the neighboring water molecule. These results suggest that the lowest excitation energies in clusters and liquid water can be associated with broken acceptor hydrogen bonds, which provide energetically favorable locations for the formation of a valence hole. Higher valence excited states of the dimer typically involve delocalization of the valence hole and/or delocalization of the excited electron and/or charge transfer. Two of the higher valence excited states that involve delocalized valence holes always have particularly large oscillator strengths. Due to the pervasive delocalization and charge transfer, it is suggested that most condensed phase water valence excitations intimately involve more than one water molecule and, as a consequence, will not be adequately described by models based on perturbation of free water monomer states. The benchmark calculations are further used to evaluate a series of representative semilocal, global hybrid, and range separated hybrid functionals used in efficient time-dependent density functional methods. It is shown that such an evaluation is only meaningful when comparison is made at or near the complete basis set limit of the wave function based reference method. A functional is found that quantitatively describes the two lowest excitations of water dimer and also provides a semiquantitative description of the higher energy valence excited states. This functional is recommended for use in further studies on the absorption spectrum of large water clusters and of condensed phase water.

Esterilização em Ortodontia: eficácia do esterilizador com esferas de vidro / Sterilization in Orthodontics: effectiveness of glass bead sterilizers

OBJETIVO: avaliar a efetividade do esterilizador com esferas de vidro Steri® 350, quanto ao controle de infecção das partes ativas dos alicates ortodônticos. METODOLOGIA: foram utilizados nove alicates ortodônticos, previamente esterilizados em autoclave à temperatura de 121ºC, durante 20 minutos. Posteriormente, as partes ativas dos alicates foram contaminadas com Bacillus stearothermophilus. Logo após, as pontas dos alicates foram colocadas no Steri® 350, durante os períodos de 3, 5, 10, 15, 20, 30 e 40 segundos, em temperatura de 255ºC, para avaliar a eficácia da esterilização. RESULTADOS E CONCLUSÕES: o esterilizador com esferas de vidro mostrou-se eficaz no controle do crescimento de Bacillus stearothermophilus nas partes ativas dos alicates ortodônticos, a partir de 10 segundos de exposição à temperatura de 255ºC.

AIM: The aim of this research was to evaluate the efficiency of Steri® 350glass bead sterilizer, on the infection control of the active part of the orthodontic pliers. METHODS: Nine orthodontic pliers were sterilized in the steam autoclave at 121ºC in 20 minutes and subsequently the active part of each plier was dipped in a culture for Bacillus stearothermophilus. Later, the active part of each plier was putted into the Steri® 350 in the following periods: 3, 5, 10, 15, 20, 30, and 40 seconds at 255ºC to evaluate the efficiency of this method in the infection control. RESULTS AND CONCLUSIONS: This sterilization method has been effective to control the presence of Bacillus stearothermophilus on the active part of orthodontic pliers at 255ºC in 10 seconds.

Electronically excited water aggregates and the adiabatic band gap of water.

The authors report results for the electronic properties of the S(1) singlet excited state of H(3)O(+)[OH(H(2)O)((n-2))](-) aggregates, where n=2-5 is the number of water molecules. The energy of the excited state was defined relative to the ground state of neutral water clusters. Results for ionized aggregates are also reported. The results are based on configuration interaction with single excitations geometry optimizations followed by density functional theory and time dependent density functional theory calculations. Emphasis was placed on the relationship between electronic properties of the aggregates and the adiabatic band gap of liquid water. The authors' predictions for the adiabatic energy gap of water clusters are in the 6.01-6.55 eV range. These values are approximately 0.9-0.4 eV below the experimental adiabatic band gap of liquid water (6.9 eV). Comparison with experimental information for water is reported for several properties of interest including vertical and adiabatic ionization energies, excitation energies, photoemission thresholds, and conduction band edge. The results provide a description, at the molecular level, for the electronic properties of water aggregates that is consistent with the current picture for the band gap of bulk water [J. V. Coe, Int. Rev. Phys. Chem. 20, 33 (2001)].

Análisis de la eficacia de agentes químicos de desinfección en materiales elastoméricos / Analysis of the efficacy of disinfective chemical agents on elastomeric materials

El objetivo de este estudio fue evaluar la eficacia de agentes de desinfección indicados para polisulfuros (mercaptanos), poliéteres y siliconas por condensación y por adición. Fueron confeccionadas noventa muestras de cada material, siendo treinta de ellas contaminadas con Streptococcus mutans o Staphylococcus aureus o Candida albicans. De cada solución microbiana fueron retiradas diez muestras del polisulfeto y de ambas las siliconas, que fueron inmersas por diez minutos en glutaraldehído al 2 por ciento y otras diez inmersas en agua destilada estéril (control negativo). Después de un nuevo lavado en agua destilada, las muestras fueron transferidas a medios de cultivo estériles. Las diez muestras restantes no fueron sometidas al agente de desinfección y fueron transferidas a medios asociados a agentes antimicrobianos específicos (control positivo). La turbidez de los medios de cultivo fue evaluada como indicativo del crecimiento microbiano siguiéndose a la incubación por 24 h a 37O C y se realizó la dilución y sembrado en placas de Petri para contar las colonias. Para el poliéter fue ejecutado el mismo procedimiento, pero el agente de desinfección usado fue el hipoclorito de sodio a 1. No hubo turbidez comprobatoria del crecimiento microbiano en ninguno de los medios de cultivo que contenían los especimenes sometidos a los agentes de desinfección. Se concluyó que el glutaraldehído al 2 por ciento es un agente de desinfección eficaz para el polisulfuro y para las siliconas por adición y por condensación, así como el hipoclorito a 1 por ciento es eficaz para el poliéter, para los microorganismos evaluados

The aim of this in vitro study was to evaluate the disinfection efficacy of elastomeric impression materials such as polysulfides, polyethers, condensation and addition silicones. Ninety samples of each material were made and every thirty samples contaminated with Streptococcus mutans or Staphylococcus aureus or Candida albicans. From each microbial solution there were taken ten samples of polysulfide and of both silicones which were immersed for ten minutes in a 2% glutaraldehyde solution and other ten immersed in sterile distilled water (negative control). After being washed again in distilled water, the samples were transferred to sterile culture medium. The last ten samples were not submitted to any disinfection agent and were transferred to mediums associated with specific anti-microbial agents (positive control). The turbidity of the culture mediums was evaluated as an indication of the microbial growth after a period of 24-hour incubation at 37oC and the dilution and seeding in Petri dishes were done to count the colonies. The same procedure was done for the polyether, but the disinfection agent used was 1% sodium hypoclorite. There was no proved turbidity of the microbial growth in any of the culture mediums which had samples submitted to the disinfection agents tested. It was concluded that the 2% glutaraldehyde is an effective disinfection agent to polysulfides and to both condensation and addition silicones, as well as 1% sodium hypoclorite is effective to polyether, for the tested microorganisms.

O objetivo deste estudo in vitro foi avaliar a eficácia de agentes de desinfecção indicados para polissulfetos, poliéteres e siliconas de condensação e adição. Foram confeccionadas noventa amostras de cada material, sendo cada trinta contaminadas com Streptococcus mutans, Staphylococcus aureus ou Candida albicans. De cada solução microbiana foram retiradas dez amostras do polissulfeto e de ambas as siliconas, que foram imersas por dez minutos no glutaraldeído a 2% e outras dez imersas em água destilada estéril (controle negativo). Após nova lavagem em água destilada, as amostras foram transferidas para meios de cultura estéreis. As dez amostras restantes não foram submetidas ao agente de desinfecção e foram transferidas para meios associados a agentes antimicrobianos específicos (controle positivo). A turbidez dos meios de cultura foi avaliada como indicativo de crescimento microbiano após incubação por 24 h a 37O C e realizou-se a diluição e semeadura nas placas de Petri para contagem de colônias. Para o poliéter foi executado o mesmo procedimento, porém o agente de desinfecção empregado foi o hipoclorito de sódio a 1%. Não houve turvação comprobatória de crescimento bacteriano em nenhum dos meios da cultura que continham corpos de prova submetidos aos agentes de desinfecção. Concluiu-se que o glutaraldeído a 2% é um agente de desinfecção eficaz para o polissulfeto e para as siliconas por adição e por condensação, assim como o hipoclorito a 1% é eficaz para o poliéter, para os microorganismos testados.

Measurement of thermophysical properties of ceramics by the flash method

The flash method, proposed by Parker, Butler, Jenkins and Abbott from the U.S. Navy Radiological Defense Laboratory in 1961, is the most popular method for measuring the thermal diffusivity of solids. In this method, the front surface of a small sample is subjected to a very short burst of radiant thermal energy. The resulting temperature rise on the opposite surface of the sample is measured and the thermal diffusivity is computed from the temperature rise versus time data. Also, the specific heat can be computed from the measured data, thus allowing for the calculation of the thermal conductivity. Several theoretical models are available for the flash method, which include adiabatic boundary conditions, heat losses, surface coating effects, among other aspects. In this paper, tests were made for the identification of thermo-physical properties of a Ceramic block. The Netzsch Nanoflash LFA 447/1 of LTTC/COPPE/UFRJ was used for the measurements.

Development of a certified reference material: ethanol in water - a practical case

O presente trabalho descreve o desenvolvimento de um material de referência certificado (MRC) referente a soluções de etanol em água em cinco concentrações diferentes, abordando todas as etapas necessárias para o desenvolvimento de um MRC, conforme prescreve as ISO GUIDE 30, 31, 32, 33, 34 e 35. O desenvolvimento deste MRC originou-se nas determinações da Portaria Inmetro n° 006 de 2002, que assegura que todos os etilômetros a serem utilizados no Brasil deverão ter os seus modelos aprovados, e as verificações realizadas a partir de ensaios com soluções de etanol em água. Após um treinamento, em fevereiro de 2003, no The Federal Institute for Material Research and Testing - BAM, que é um instituto metrológico alemão designado, a Dquim iniciou o processo de desenvolvimento deste MRC, o qual foi concluído em agosto de 2004. No Inmetro desenvolveu-se inicialmente o procedimento de preparo individual, onde as soluções do MRC são preparadas em garrafas de 0,5 L. Atualmente está se estudando, no Inmetro, o desenvolvimento do procedimento em batelada, o que corresponde ao preparo das soluções do MRC em garrafas de 5,0 L, com seqüente distribuição em garrafas de 0,5 L. Pode-se considerar que o processo de desenvolvimento deste material de referência certificado está num período contínuo, onde melhorias estão sendo viabilizadas, como a utilização da técnica de DSC para a determinação da pureza do etanol, e a finalização do desenvolvimento do procedimento em batelada, que será um importante passo para a agilização no processo de preparo destas soluções. Desta forma, o desenvolvimento deste MRC contribui de forma significativa, para confiabilidade nas medições realizadas com etilômetros, tendo incerteza de medição declarada. Outro ponto importante é que a partir deste desenvolvimento, possibilita-se a sociedade um MRC que pode ter aplicações variadas, não se restringindo somente a ensaios com etilômetros.

Pseudartrose da diáfise umeral: tratamento cirúrgico pela técnica da haste intramedular bloqueada / Pseudarthrosis of the humeral shaft: surgical treatment with locked intramedullary nail

Objetivo: Avaliar os resultados clínico e radiográfico do tratamento cirúrgico pela técnica de haste intramedular bloqueada, em pacientes com pseudartrose diafisária de úmero. Casuística e métodos: Vinte e cinco pacientes com diagnóstico inicial de fratura diafisária do úmero tratados, primariamente, por diversos métodos, evoluíram para pseudartrose. Desses, 12 eram do sexo masculino e 13 do feminino, com idade variando de 22 a 82 anos. Os mesmos foram operados de seis a 47 meses após o acidente inicial. O tempo de seguimento variou de seis a 48 meses, com média de 27 meses. Os pacientes foram submetidos a exames clínico e radiográfico para avaliação do tratamento. Resultados: A consolidação óssea foi obtida em 19 pacientes, ou seja, em 76 por cento dos casos. Dos seis restantes, quatro obtiveram o que se denominou "consolidação clínica". Quanto à função do ombro, houve apenas dois resultados considerados maus. Conclusões: Considerando o alto número de consolidações ósseas obtidas, aliado ao de "consolidações clínicas", e o baixo índice de complicações, os autores afirmam ser este método válido no tratamento dessa entidade.

Luxação cervical unifacetária. Tratamento através da abordagem por via posterior da coluna cervical e osteossíntese com placas e parafusos: técnica de Roy-Camille / Unilateral facet cervical dislocation. Treatment by posterior approach of the cervical spine and osteosynthesis with plates and screws: Roy-Camille technique

Os autores relacionam 25 pacientes, operados de julho de 1981 a março de 1998, com luxação cervical unifacetária (LCU), de origem traumática, tratados pelo método de Roy-Camille, que consiste em abordagem por via posterior da coluna cervical, redução da luxação e osteossíntese com placas a parafusos, fixos aos maciços articulares. A causa mais freqüente foi o acidente automobilístico (13 casos), seguido de quedas de alturas variáveis (dois casos), mergulho em águas rasas (dois casos) a trauma indireto (dois casos). Do ponto de vista neurológico, 20 pacientes (80 por cento) apresentaram algum grau de comprometimento, tendo havido regressão completa do quadro em 16. A intervenção cirúrgica alcançou o objetivo na totalidade dos casos.

Diagnóstico ultra-sonográfico das lesöes dos ligamentos cruzados do joelho / Ultrasound diagnosis of cruciate ligament lesions of the knee

Os autores utilizaram a ultra-sonografia, como método complementar, no diagnóstico de lesoes dos ligamentos cruzados do joelho. Foram analisados 11 pacientes do sexo masculino, com idade média de 30,7 anos, dos quais 9 apresentavam lesao isolada do ligamento cruzado anterior e 2, lesoes associadas dos ligamentos cruzados anterior e posterior. Todos foram submetidos a reconstruçao ligamentar (com enxerto autólogo do tendao patelar), sendo, nessa ocasiao, confirmado o diagnóstico da ultra-sonografia. Apesar de a casuística nao ser estatisticamente significativa, trata-se de exame opicional, nos casos de diagnóstico duvidoso, quando a ressonância magnética nao puder ser solicitada. Outras vantagens sao a fácil aplicabilidade e a possibilidade do exame dinâmico.

Artrodese do punho com placa de compressäo dinâmica / Wrist arthrodesis with dynamic compression plate

Foram avaliados sete casos de artrodese de punho (cinco seqüelas de trauma e dois tumores de células gigantes da metáfise distal do rádio), com fixaçao interna, com placa de compressao dinâmica, segundo a técnica AO. Em cinco casos, a fusao incluiu o rádio, ossos do carpo e III metacarpiano; e, em dois, houve a centralizaçao da ulna em substituiçao ao rádio. O seguimento pós-operatório variou de 6 a 20 meses; a consolidaçao foi obtida, em todos os casos, aos 3 meses de seguimento pós-operatório. A única complicaçao observada foi a formaçao de hematoma na ferida operatória (três casos), que foi facilmente sanada. Todos os pacientes ficaram satisfeitos com os resultados obtidos.