Efficacy of a gas permeable contact lens to induce peripheral myopic defocus

Purpose. The purpose of this work was to evaluate the potential of a novel custom-designed rigid gas permeable (RGP) contact lens to modify the relative peripheral refractive error in a sample of myopic patients. Methods. Fifty-two right eyes of 52 myopic patients (mean [TSD] age, 21 [T2] years) with spherical refractive errors ranging from j0.75 to j8.00 diopters (D) and refractive astigmatism of 1.00 D or less were fitted with a novel experimental RGP (ExpRGP) lens designed to create myopic defocus in the peripheral retina. A standard RGP (StdRGP) lens was used as a control in the same eye. The relative peripheral refractive error was measured without the lens and with each of two lenses (StdRGP and ExpRGP) using an open-field autorefractometer from 30 degrees nasal to 30 degrees temporal, in 5-degree steps. The effectiveness of the lens design was evaluated as the amount of relative peripheral refractive error difference induced by the ExpRGP compared with no lens and with StdRGP conditions at 30 degrees in the nasal and temporal (averaged) peripheral visual fields. Results. Experimental RGP lens induced a significant change in relative peripheral refractive error compared with the nolens condition (baseline), beyond the 10 degrees of eccentricity to the nasal and temporal side of the visual field (p G 0.05). The maximum effect was achieved at 30 degrees. Wearing the ExpRGP lens, 60% of the eyes had peripheral myopia exceeding j1.00 D, whereas none of the eyes presented with this feature at baseline. There was no significant correlation (r = 0.04; p = 0.756) between the degree of myopia induced at 30 degrees of eccentricity of the visual field with the ExpRGP lens and the baseline refractive error. Conclusions. Custom-designed RGP contact lenses can generate a significant degree of relative peripheral myopia in myopic patients regardless of their baselin spherical equivalent refractive error.

Symptoms and signs in rigid gas permeable lens wearers during adaptation period

Objectives: To evaluate neophyte contact lens wearers’ fitting to rigid gas permeable (RGP) contact lenses in terms of wearing time, tear volume, stability, corneal staining, and subjective ratings, over a 1-month period of time. Methods: Twenty-two young healthy subjects were enrolled for wearing RGP on a daily wear basis. The participants included in this study never wore contact lenses and showed a value under 10 in McMonnies Questionnaire. Contact Lens Dry Eye Questionnaire, Visual Analog Scales, Schirmer test, tear film break-up time (BUT), and corneal staining grading were performed. Follow-up visits were scheduled at 1, 7, 15, and 28 days. Results: Six subjects dropped out due to discomfort from the study before 1 month (27% of discontinuation rate). Successful RGP wearers (16 participants) achieved high levels of subjective vision and reported comfort scores of approximately 9 of 10 between 10 and 15 days. They reported wearing their lenses for an average of 10.1262.43 hr after 1 month of wear. Conversely, unsuccessful wearers discontinued wearing the lenses after the first 10 to 15 days, showing comfort scores and wearing time significantly lower compared with the first day of wear. Schirmer test showed a signifi- cant increase at 10 days (P,0.001), and the BUT trends decreased after the first week of wear in unsuccessful group. Conclusions: Symptomatology related with dryness and discomfort, detected during the first 10 days of the adaptation, may help the clinician to predict those participants who will potentially fail to adapt to RGP lens wear.

Analysis of a Local HIV-1 Epidemic in Portugal Highlights Established Transmission of non-B and -G Subtypes

Existing data supports Portugal as the Western Europe country with highest HIV-1 subtype diversity. However, detailed phylogenetic studies of Portuguese HIV-1 epidemics are still scarce. Thus, our main goal was to analyze the phylodynamics of a local HIV-1 infection in the Portuguese region of Minho. Molecular epidemiological analysis was applied to data from 289 HIV-1 infected individuals followed in the reference Hospital of the province of Minho, Portugal, in which isolated viruses had been sequenced between 2000 and 2012. Viruses of the G (29.1%) and B (27.0%) subtypes were the most frequent, followed by recombinant forms (17.6%), C (14.5%), F1 (7.3%) and A1 (4.2%) subtypes. Multinomial logistic regression revealed that the odds of being infected with A1 and F1 subtype increased over the years when compared with B, G, C or recombinant viruses. As expected, polyphyletic patterns suggesting multiple and old introductions of subtypes B and G were found. However, transmission clusters of non-B and -G viruses among native individuals were also found with the dates of the most recent common ancestor estimated to the early 2000s. Our study supports that the HIV-1 subtype diversity in the Portuguese region of Minho is high and has been increasing in a manner that is apparently driven by factors other than immigration and international travel. Infections with A1 and F1 viruses in the region of Minho are becoming established and were mainly found in sexually transmitted clusters, reinforcing the need for more efficacious control measures targeting this infection route.

Layer-by-layer technique to developing functional nanolaminate films with antifungal activity

The layer-by-layer (LbL) deposition method was used to build up alternating layers (five) of different polyelectrolyte solutions (alginate, zein-carvacrol nanocapsules, chitosan and chitosan-carvacrol emulsions) on an aminolysed/charged polyethylene terephthalate (A/C PET) film. These nanolaminated films were characterised by contact angle measurements and through the determination of water vapour (WVTR) and oxygen (O2TR) transmission rates. The effect of active nanolaminated films against the Alternaria sp. and Rhizopus stolonifer was also evaluated. This procedure allowed developing optically transparent nanolaminated films with tuneable water vapour and gas properties and antifungal activity. The water and oxygen transmission rate values for the multilayer films were lower than those previously reported for the neat alginate or chitosan films. The presence of carvacrol and zein nanocapsules significantly decreased the water transmission rate (up to 40 %) of the nanolaminated films. However, the O2TR behaved differently and was only improved (up to 45 %) when carvacrol was encapsulated, i.e. nanolaminated films prepared by alternating alginate with nanocapsules of zein-carvacrol layers showed better oxygen barrier properties than those prepared as an emulsion of chitosan and carvacrol. These films containing zein-carvacrol nanocapsules also showed the highest antifungal activity (30 %), which did not significantly differ from those obtained with the highest amount of carvacrol, probably due to the controlled release of the active agent (carvacrol) from the zein-carvacrol nanocapsules. Thus, this work shows that nanolaminated films prepared with alternating layers of alginate and zein-carvacrol nanocapsules can be considered to improve the shelf-life of foodstuffs.

Avaliação da equivalência semântica e consistência interna da Game Addiction Scale (GAS): versão em português

Objetivo Avaliar a equivalência semântica e a consistência interna da Game Addiction Scale (GAS): versão em português. Métodos O procedimento constituiu-se das seguintes etapas: a) revisão da literatura; b) tradução do instrumento original; c) retrotradução; d) revisão técnica e avaliação da compreensão verbal, realizada por profissionais da área da saúde; e) avaliação da compreensão verbal do instrumento, por uma amostra de estudantes; f) análise da consistência interna (alfa de Cronbach). Os participantes, com exceção dos especialistas, foram selecionados por conveniência. A participação dos sujeitos foi diferente em cada fase: tradutores (n = 2), retrotradução (n = 1), revisão técnica (n = 2), especialistas (n = 12), pré-teste com estudantes universitários (n = 40) e mensuração com estudantes universitários (n = 100). Resultados Poucas alterações semânticas de expressões e termos foram realizadas para adaptar-se à cultura-alvo. O nível de compreensão verbal dos participantes (especialistas e estudantes) foi superior a 90% e a análise do alfa de Cronbach correspondeu a 0,92 para todo o instrumento. Conclusão A Escala de Dependência de Jogos Eletrônicos (ESDEJE) foi submetida a tradução e adaptação para o idioma português (do Brasil), apresentando consistência interna adequada. Ademais, sugere-se a realização do processo de validação referente à equivalência de mensuração e reprodutibilidade do instrumento.

Transmission and progression to disease of Mycobacterium tuberculosis phylogenetic lineages in The Netherlands

The aim of this study was to determine if mycobacterial lineages affect infection risk, clustering, and disease progression among Mycobacterium tuberculosis cases in The Netherlands. Multivariate negative binomial regression models adjusted for patient-related factors and stratified by patient ethnicity were used to determine the association between phylogenetic lineages and infectivity (mean number of positive contacts around each patient) and clustering (as defined by number of secondary cases within 2 years after diagnosis of an index case sharing the same fingerprint) indices. An estimate of progression to disease by each risk factor was calculated as a bootstrapped risk ratio of the clustering index by the infectivity index. Compared to the Euro-American reference, Mycobacterium africanum showed significantly lower infectivity and clustering indices in the foreign-born population, while Mycobacterium bovis showed significantly lower infectivity and clustering indices in the native population. Significantly lower infectivity was also observed for the East African Indian lineage in the foreign-born population. Smear positivity was a significant risk factor for increased infectivity and increased clustering. Estimates of progression to disease were significantly associated with age, sputum-smear status, and behavioral risk factors, such as alcohol and intravenous drug abuse, but not with phylogenetic lineages. In conclusion, we found evidence of a bacteriological factor influencing indicators of a strain's transmissibility, namely, a decreased ability to infect and a lower clustering index in ancient phylogenetic lineages compared to their modern counterparts. Confirmation of these findings via follow-up studies using tuberculin skin test conversion data should have important implications on M. tuberculosis control efforts.

Gas exchange during exercise in different evolutional stages of chronic Chagas' heart disease

OBJECTIVE: To compare gas exchange at rest and during exercise in patients with chronic Chagas' heart disease grouped according to the Los Andes clinical/hemodynamic classification. METHODS: We studied 15 healthy volunteers and 52 patients grouped according to the Los Andes clinical/hemodynamic classification as follows: 17 patients in group IA (normal electrocardiogram/echocardiogram), 9 patients in group IB (normal electrocardiogram and abnormal echocardiogram), 14 patients in group II (abnormal electrocardiogram/echocardiogram, without congestive heart failure), and 12 patients in group III (abnormal electrocardiogram/echocardiogram with congestive heart failure). The following variables were analyzed: oxygen consumption (V O2), carbon dioxide production (V CO2), gas exchange rate (R), inspiratory current volume (V IC), expiratory current volume (V EC), respiratory frequency, minute volume (V E), heart rate (HR), maximum load, O2 pulse, and ventilatory anaerobic threshold (AT). RESULTS: When compared with the healthy group, patients in groups II and III showed significant changes in the following variables: V O2peak, V CO2peak, V ICpeak, V ECpeak, E, HR, and maximum load. Group IA showed significantly better results for these same variables as compared with group III. CONCLUSION: The functional capacity of patients in the initial phase of chronic Chagas' heart disease is higher than that of patients in an advanced phase and shows a decrease that follows the loss in cardiac-hemodynamic performance.

Contribution to an efficient transmission of information to the textile fashion consumer and the influence in sustainable attitudes

The concepts involved in sustainable textile fashion, demanding good knowledge about raw materials, processes, end use properties and circuits amongst others, are able to determine the way the textile product is designed and the behavior of the consumer, regarding life style and buying decisions. The textile product`s life integrates raw materials, their processing, distribution, use by the consumer and destination of the product after useful lifetime, this is, his complete life cycle. It is very important to recognize the power of the consumer to influence parameters related to sustainability, namely when he decides how, when and why he buys and afterwards by the attitudes taken during and after use. The conscious act of consumption involves ethical, ecological and technical knowledge in which the concern is overall lifecycle of the fashion product and not exclusively aesthetic and symbolic values strongly related with its ephemeral nature. The present work proposes the classification of textile products by means of an innovative label aiming to establish a rating related to the Life of Fashion Products, by using parameters considered with especial impact in lifecycle, as textile fibers, processing conditions, generated wastes, commercialization circuits, durability and cleaning procedures. This label for sustainable fashion products aims to assist the stakeholders with informed attitudes and correct decisions in order to promote the objectives of sustainable fashion near designers, consumers and industrial experts.

Anaerobic oxidation of methane associated with sulfate reduction in a natural freshwater gas source

The occurrence of anaerobic oxidation of methane (AOM) and trace methane oxidation (TMO) was investigated in a freshwater natural gas source. Sediment samples were taken and analyzed for potential electron acceptors coupled to AOM. Long-term incubations with 13C-labeled CH4 (13CH4) and different electron acceptors showed that both AOM and TMO occurred. In most conditions, 13C-labeled CO2 (13CO2) simultaneously increased with methane formation, which is typical for TMO. In the presence of nitrate, neither methane formation nor methane oxidation occurred. Net AOM was measured only with sulfate as electron acceptor. Here, sulfide production occurred simultaneously with 13CO2 production and no methanogenesis occurred, excluding TMO as a possible source for 13CO2 production from 13CH4. Archaeal 16S rRNA gene analysis showed the highest presence of ANME-2a/b (ANaerobic MEthane oxidizing archaea) and AAA (AOM Associated Archaea) sequences in the incubations with methane and sulfate as compared with only methane addition. Higher abundance of ANME-2a/b in incubations with methane and sulfate as compared with only sulfate addition was shown by qPCR analysis. Bacterial 16S rRNA gene analysis showed the presence of sulfate-reducing bacteria belonging to SEEP-SRB1. This is the first report that explicitly shows that AOM is associated with sulfate reduction in an enrichment culture of ANME-2a/b and AAA methanotrophs and SEEP-SRB1 sulfate reducers from a low-saline environment.

Integración de la industria del gas natural en el Mercosur. Un modelo de redes

El objetivo de este trabajo es identificar la política óptima (considerando producción, transporte y regulación) para la integración de la industria de gas natural en el Mercosur. Se analizarán factores que promueven o limitan la integración en la región. Utilizando un modelo matemático de flujo de redes, se minimizará el costo total (producción y transporte) para la región en su conjunto, satisfaciendo las restricciones de producción, capacidad de transporte y equilibrio (oferta igual a demanda) en cada nodo. El costo total (CT) de la producción y transporte de gas natural (considerando nodos para cada país en la región) es la función objetivo. El proceso de optimización consiste en identificar el nivel de gas natural producido y transportado que minimiza el costo total del sistema para la región. El modelo es estático, no considerando una optimización dinámica con relación a las reservas remanentes. Restricciones Consideramos cuatro restricciones en operación, a saber: 1. Equilibrio en los nodos: esta ecuación establece el equilibrio entre la oferta y la demanda de gas natural en cada nodo. La oferta incluye la producción local y las importaciones. Por su parte, la demanda incluye el consumo doméstico más las exportaciones. 2. Capacidad de producción en cada cuenca: esta restricción establece que las cantidades producidas en cada cuenca debería ser menor o igual a su capacidad de producción. Ello también permite la existencia de una utilización no plena de la capacidad. La capacidad máxima de producción en cada cuenca está determinada sobre la base de una medida de política para cada país a través de la cual el horizonte de consumo de las reservas probadas está establecido. Dada esta relación, el límite sobre la producción de cada año está fijado. En otras palabras, el nivel de producción no está basado ni en la capacidad instalada de producción ni en los precios, sino en la política de agotamiento decidida sobre las reservas probadas en el año de calibración del modelo. Esto permite diferentes escenarios para el análisis. Para las simulaciones se tomó el ratio de reservas a producción en el año de calibración del modelo. 3. Capacidad de transporte: el gas transportado a través de un gasoducto (los operativos y aquellos que están en plan de construcción), en general, y el gas transportado desde cada cuenca a cada mercado, en particular, debería ser menor o igual a la capacidad del gasoducto. 4. Nivel no negativo de gas natural producido: esto evita la existencia de soluciones inconsistentes no sólo desde un punto de vista económico sino también técnico. Referencias Banco Interamericano de Desarrollo BID (2001). Integración Energética en el Mercosur Ampliado, Washington DC. Beato, Paulina and Juan Benavides (2004). Gas Market Integration in the Southern Cone. Inter-American Development Bank. Washington, D.C. Conrad, Jon M. (1999). Resource Economics. Cambridge University Press. United States of America. Dasgupta, P.S. and G. M. Heal (1979). Economic Theory and Exhaustible Resources. Cambridge University Press. United States of America. Dos Santos, Edmilson M, Victorio E. Oxilia Dávalos, and Murilo T. Werneck Fagá (2006). “Natural Gas Integration in Latin America: Forward or Backwards?”. Revue de l’Energie, Nº 571, mai-juin. Fagundes de Almeida, E.L. y Trebat, N. (2004). “Drivers and barriers to cross-border gas trade in the southern cone”. Oil, Gas & Energy Law Intelligence, Vol. 2, Nº 3, Julio. Givogri, Pablo (2007). “Condiciones de abastecimiento y precios de la industria del gas de Argentina en los próximos años”. Fundación Mediterránea. Julio. Córdoba, Argentina. Kozulj, Roberto (2004). “La industria del gas natural en América del Sur: situación y posibilidades de la integración de los mercados”. Serie Recursos Naturales e Infraestructura. Nº 77. CEPAL. Santiago de Chile, Chile. Diciembre.

Untersuchung des Flüssigkeitseintrages auf die Temperaturverteilung in Gas-/Feststoff-Wirbelschichten

Liquid separation efficiency, liquid penetration, modeling, arrays of temperature, distribution, fluidized bed, two-phase-nozzle

Analysis of energy efficiency of gas driven heat pumps

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2011

Full-wave field interactions of nonuniform transmission lines

Transmission-line supertheory, generalized transmission-line theory, radiation

Erweiterung der Transmission-Line-Methode auf die Biegewelle zur Simulation von Crashsensorsignalen

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2011