Fundamento e desenho do teste randomizado PAINT

FUNDAMENTO: Descrevemos as bases teóricas e o formato do "Estudo PAINT - Intervenção percutânea com stents com eluição de paclitaxel ou sirolimus em polímero biodegradável comparados com stents sem recobrimento no tratamento de lesões coronárias de novo". OBJETIVO: Avaliar duas novas formulações de stents com eluição de paclitaxel ou sirolimus em comparação com um stent de estrutura metálica idêntica, porém sem recobrimento polimérico ou eluição de droga. MÉTODOS: O PAINT é um estudo randomizado, multicêntrico, de 3 braços, conduzido em centros terciários brasileiros, que incluiu 275 pacientes alocados para tratamento com os stents InfinniumR (paclitaxel), the SupralimusR (sirolimus) ou Milennium MatrixR (sem recobrimento) na proporção 2:2:1 ratio. Os pacientes apresentavam lesões coronarianas de novo em vasos nativos com um diâmetro entre 2,5 e 3,5 mm, passíveis de tratamento com um único stent com comprimento de 29 mm ou menos. O objetivo primário era comparar a perda tardia aos nove meses de ambos stents com paclitaxel- ou sirolimus versus a perda luminal dos stents convencionais de controle. Objetivos secundários importantes incluíam a comparação angiográfica entre os dois tipos de stents farmacológicos, bem como a análise da ocorrência de eventos clínicos adversos. RESULTADOS E CONCLUSÕES: O estudo PAINT apresenta um formato peculiar e único que permitiu a avaliação da segurança e eficácia de duas novas formulações de stents farmacológicos, com carreador polimérico biodegradável, e liberação de paclitaxel ou sirolimus, os quais foram comparados contra um stent metálico convencional (objetivo primário). Uma vez que os stents farmacológicos diferiram entre sí somente pela droga, mas eram idênticos nas suas outras características, os estudo também permitiu a comparação do efeito anti-restenótico entre sirolimus e paclitaxel (objetivo secundário).

Acute hypersensitivity pneumonitis in a paint quality controller : a case report

Introduction: Isocyanates are sensitizing chemicals used in various industries such as polyurethane foam production or paint-related purposes. Acting as haptens recognized by T-lymphocytes, they can cause allergic asthma and rarely hypersensitivity pneumonitis (HP). We aim to present a case report of acute HP due to hexamethylene diisocyanate (HDI) in a paint quality controller, a profession not generally considered at a high risk for work-related Isocyanates exposure. Case report: A 30-yr-old otherwise healthy female, light smoker working as a paint quality controller developed shortness of breath, malaise, sweating and chills at workplace six hours after handling a HDI-based hardener. Upon admission to emergency department, symptoms had progressed to severe respiratory failure. HR computer tomography (HRCT) showed bilateral ground-glass attenuation without pleural effusion. Rapid clinical and radiological improvement occurred under facial oxygen supply and systemic steroid therapy. Occupational medicine investigations revealed regular handling of HDI using latex gloves without respiratory protection. Assessment at workplace showed insufficient air renewal (1.5 times per hour), inadequate local aspiration and HDI exposure at levels of 1-4.25 ppb/m3 (Swiss Occupation Exposure Limit 5 ppb/m3). Biological monitoring after identical work procedure executed by a co-worker showed HDI exposure (5.1 micrograms hexamethylene diamine/g creatinine). Resumption of work was disadvised because of the life-threatening event. Discussion: The diagnosis of occupational HP is highly supported by classical findings on imagery and typical symptoms occurring within approved latency interval, associated with rapid clinical improvement. Although neither broncho-alveolar lavage nor specific IgG diagnosis (en route) were performed during the acute episode, various blood tests managed to rule out evidence of an infection or autoimmune disease. Other causes of HP seem unlikely as the patient did not have any recurrence of symptoms since absence from work. Workplace evaluation provided significant information on HDI exposure and allowed substantial recommendations to diminish Isocyanate exposure for the 20 still healthy laboratory co-workers. Although the entryways (air or skin) and precise mechanism of toxicity remain unclear, the present case clearly shows that Isocyanates may trigger acute HP in susceptible workers in a profession not generally considered at a high risk.

Paint on whiteboard desktop

Es un proyecto para la creación de una herramienta aplicable al uso de pizarras digitales. Pintar sobre el escritorio o aplicaciones abiertas.

Experimental and computational study on the synthesis and characterization of self-assembling meso/macroporous materials in highly concentrated emulsions

Report for the scientific sojourn carried out at Massachusetts General Hospital Cancer Center-Harvard Medical School, Estats Units, from 2010 to 2011. The project aims to study the aggregation behavior of amphiphilic molecules in the continuous phase of highly concentrated emulsions, which can be used as templates for the synthesis of meso/macroporous materials. At this stage of the project, we have investigated the self-assembly of diblock and triblock surfactants under the effect of a confined geometry being surrounded by the droplets of the dispersed phase. These droplets limit the growth of the aggregates, deeply modify their orientation and hence alter their spatial arrangement as compared to the self-assembly taking place far enough from any boundary surface, that is in the bulk. By performing Monte Carlo simulations, we have showed that the interface between the dispersed and continuous phases as well as its shape has a significant impact on the structural order of the resulting aggregates and hence on the potential applications of highly concentrated emulsions as reaction media, drug delivery systems, or templates for meso/macroporous materials. Due to the combined effect of symmetry breaking and morphological frustration, very intriguing structures, such as square columnar liquid crystals, twisted X-shaped aggregates, and helical phases of cylindrical aggregates, never observed in the bulk for the same model surfactant, have been found. The presence of other more conventional structures, such as micelles and cubic and hexagonal liquid crystals, formed at low and high amphiphilic concentrations, respectively, further enhance the interest on this already rich aggregation behavior.

Acute life-threatening extrinsic allergic alveolitis in a paint controller.

BACKGROUND: Occupational diisocyanate-induced extrinsic allergic alveolitis (EAA) is a rare and probably underestimated diagnosis. Two acute occupational EAA cases have been described in this context, but neither of them concerned hexamethylene diisocyanate (HDI) exposure. AIMS: To investigate the cause of a life-threatening EAA arising at work in a healthy 30-year-old female paint quality controller. METHODS: Occupational medical assessment, workplace evaluation, airborne and biological monitoring and immunodermatological tests. RESULTS: Diagnosis of EAA relied on congruent clinical and radiological information, confirmed occupational HDI exposure and positive IgG antibodies and patch tests. The patient worked in a small laboratory for 7 years, only occasionally using HDI-containing hardeners. While working with HDI for 6 h, she developed breathlessness, rapidly progressing to severe respiratory failure. Workplace HDI airborne exposure values ranged from undetectable levels to 4.25 p.p.b. Biological monitoring of urinary hexamethylene diamine in co-workers ranged from <1.0 to 15.4 μg/g creatinine. Patch tests 8 months later showed delayed skin reaction to HDI at 48 h. Subsequent skin biopsy showed spongiotic dermatitis with infiltration of CD4(+) and CD8(+) T cells. CONCLUSIONS: We believe this is the first reported case of acute life-threatening EAA following exposure to HDI. Low concentrations of airborne HDI and relatively high urinary hexamethylene diamine suggest significant skin absorption of HDI could have significantly contributed to the development of this acute occupational EAA.

Asphalt Emulsions for Highway Construction, HR-216, 1985

A 5.8 mile section of Dubuque County (Iowa) Road D-53 was selected for this project, the objective of which were to: 1. identify a cost effective asphalt emulsion bound macadam typical cross section; 2. determine the effectiveness of engineering fabric placed under macadam roadbeds; and 3. evalaute the use of emulsions in surface seal coats. A number of conclusions were reached: 1. The minus #200 sieve material for the macadam stone should be held to a minimum. For the emulsion used on this project, the minus #200 material had less than 4 percent to achieve satisfactory coating of the macadam stone. 2. The placement of the emulsion treated macadam required no additional equipment or time than the plain macadam placement. 3. Emulsion treating the macadam stone for the shoulder base appears unnecessary. 4. The emulsion treated macadam base beneath an asphaltic concrete wearing surface yielded a higher structural rating than the plain macadam beneath a comparable ashaltic concrete surface. 5. The performance of the fabric between the subgrade and the macadam base to prevent soil intrusion into the base could not be determined by the non-destructive testing conducted. 6. When no choke stone is used over the macadam base, allowance for ac mix overrun should be made. 7. Use of an emulsion instead of a cutback asphalt saved money and energy. However, the poor performance of the seal coat negated any real savings.

Soil Tracking Paint Test, MLR-89-13, 1989

A new paint testing device was built to determine the resistance of paints to darkening due to road grime being tracked onto them. The device consists of a tire rotating on a sample drum. Soil was applied to the tire and then tracked onto paint samples which were attached to the drum. A colorimeter was used to measure the lightness of the paints after being tracked. Lightness is measured from 0 (absolute black) to 100 (absolute white). Four experiments were run to determine the optimum time length to track a sample, the reproducibility, the effects of different soils, and the maximum acceptable level for darkening of a paint. The following conclusions were reached: 1) the optimum tracking time was 10 minutes; 2) the reproducibility had a standard deviation of 1.5 lightness units; 3) different soils did not have a large effect on the amount of darkening on the paints; 4) a maximum acceptable darkness could not be established based on the limited amount of data; and 5) a correlation exists between the paints which were darkening in the field and the paints which were turning the darkest on the tracking wheel.

Survey of D.O.T.'s Traffic Paint Costs in 1979, HR-515, 1980

This report presents the results of a survey on the use of yellow versus white traffic paint. It was found that in most states the white paint was less expensive than the yellow. A substantial savings could be realized if an all white traffic marking system was permitted by the Federal Highway Administration. Paint costs from each state are presented, as well as by each region.

Asphalt Emulsions for Highway Construction (Emulsion Seal Coat), HR-1028, 1980

For the past several year Kossuth County has had a scheduled maintenance program of bituminous seal coating. This program has been used to maintain the 467 miles of asphaltic concrete surfaced roads in Kossuth County. Since most of the experience that Kossuth County had in seal coating was with cutback asphalt, it was decided to include the use of emulsified asphalt in Kossuth County's 1980 seal coat program. Federal Demonstration Project Funds were requested from the Federal Highway Administration to study the use of emulsified asphalt and funding was granted under Demonstration Project No. 55,:Asphalt Emulsions for Highway Construction." Items studied were design and construction procedure cost of alternate material, energy consumption and environmental considerations. A construction contract was awarded to Everds Brothers, Inc. of Algona, Iowa, on July 1, 1980. There were four bidders on the 54.5 miles of seal coating that was let. A map showing the location of the seal coating projects is shown in Appendix A, and a copy of the contract is shown in Appendix B. The contractor started the project on July 11, 1980 and completed the project on August 1, 1980. Construction inspection and follow-up inspections of the project were conducted by personnel of the Kossuth County Engineer's Office and testing of the materials, friction testing and road rater testing were conducted by the Material's Department of the Iowa Department of Transportation.

Highly concentrated bitumen emulsions. A state of the art, review of experimental results

Les emulsions concentrades o altament concentrades de betum són un camp molt poc estudiat avui en dia. El treball és un estat de l'art de tots els papers que hi ha sobre aquest tema desde el mètode tradicional fins el HIPR (High Internal Phase Ratio).

Scale-up model obtained from the rheological analysis of highly concentrated emulsions prepared at three scales

We examine the scale invariants in the preparation of highly concentrated w/o emulsions at different scales and in varying conditions. The emulsions are characterized using rheological parameters, owing to their highly elastic behavior. We first construct and validate empirical models to describe the rheological properties. These models yield a reasonable prediction of experimental data. We then build an empirical scale-up model, to predict the preparation and composition conditions that have to be kept constant at each scale to prepare the same emulsion. For this purpose, three preparation scales with geometric similarity are used. The parameter N¿D^α, as a function of the stirring rate N, the scale (D, impeller diameter) and the exponent α (calculated empirically from the regression of all the experiments in the three scales), is defined as the scale invariant that needs to be optimized, once the dispersed phase of the emulsion, the surfactant concentration, and the dispersed phase addition time are set. As far as we know, no other study has obtained a scale invariant factor N¿Dα for the preparation of highly concentrated emulsions prepared at three different scales, which covers all three scales, different addition times and surfactant concentrations. The power law exponent obtained seems to indicate that the scale-up criterion for this system is the power input per unit volume (P/V).

Phase behavior and rheological analysis of reverse liquid crystals and W/I2, W/H2 gel emulsions using an amphiphilic block copolymer.

This article reports the phase behavior determi- nation of a system forming reverse liquid crystals and the formation of novel disperse systems in the two-phase region. The studied system is formed by water, cyclohexane, and Pluronic L-121, an amphiphilic block copolymer considered of special interest due to its aggregation and structural proper- ties. This system forms reverse cubic (I2) and reverse hexagonal (H2) phases at high polymer concentrations. These reverse phases are of particular interest since in the two-phase region, stable high internal phase reverse emulsions can be formed. The characterization of the I2 and H2 phases and of the derived gel emulsions was performed with small-angle X-ray scattering (SAXS) and rheometry, and the influence of temperature and water content was studied. TheH2 phase experimented a thermal transition to an I2 phase when temperature was increased, which presented an Fd3m structure. All samples showed a strong shear thinning behavior from low shear rates. The elasticmodulus (G0) in the I2 phase was around 1 order of magnitude higher than in theH2 phase. G0 was predominantly higher than the viscousmodulus (G00). In the gel emulsions,G0 was nearly frequency-independent, indicating their gel type nature. Contrarily to water-in-oil (W/O) normal emulsions, in W/I2 and W/H2 gel emulsions, G0, the complex viscosity (|η*|), and the yield stress (τ0) decreased with increasing water content, since the highly viscous microstructure of the con- tinuous phase was responsible for the high viscosity and elastic behavior of the emulsions, instead of the volumefraction of dispersed phase and droplet size. A rheological analysis, in which the cooperative flow theory, the soft glass rheology model, and the slip plane model were analyzed and compared, was performed to obtain one single model that could describe the non-Maxwellian behavior of both reverse phases and highly concentrated emulsions and to characterize their microstructure with the rheological properties.