6,671 research outputs found

    Pilomatrix carcinoma of the lacrimal caruncle: a case report.

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    A 45-year-old man presented with a 3-month history of a mass located in the caruncle of his right eye. An incisional biopsy had been performed one month prior by another specialist, and the histopathology report showed basal cell carcinoma. The mass was completely excised with a 2 mm safety margin, and the large conjunctival defect was reconstructed with one sheet of amniotic membrane allograft. A histological diagnosis of pilomatrix carcinoma was established. To prevent recurrence after surgery, we added bevacizumab (25 mg/mL, 1.25 mg/mL per drop) eye drops four times per day for three months. At the one-year follow-up, the patient showed no evidence of local recurrence or distant metastasis after initial excision and remains under close follow-up. Pilomatrix carcinoma should be considered in the differential diagnosis of a caruncular mass

    Parasite motility is critical for virulence of African trypanosomes.

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    African trypanosomes, Trypanosoma brucei spp., are lethal pathogens that cause substantial human suffering and limit economic development in some of the world's most impoverished regions. The name Trypanosoma ("auger cell") derives from the parasite's distinctive motility, which is driven by a single flagellum. However, despite decades of study, a requirement for trypanosome motility in mammalian host infection has not been established. LC1 is a conserved dynein subunit required for flagellar motility. Prior studies with a conditional RNAi-based LC1 mutant, RNAi-K/R, revealed that parasites with defective motility could infect mice. However, RNAi-K/R retained residual expression of wild-type LC1 and residual motility, thus precluding definitive interpretation. To overcome these limitations, here we generate constitutive mutants in which both LC1 alleles are replaced with mutant versions. These double knock-in mutants show reduced motility compared to RNAi-K/R and are viable in culture, but are unable to maintain bloodstream infection in mice. The virulence defect is independent of infection route but dependent on an intact host immune system. By comparing different mutants, we also reveal a critical dependence on the LC1 N-terminus for motility and virulence. Our findings demonstrate that trypanosome motility is critical for establishment and maintenance of bloodstream infection, implicating dynein-dependent flagellar motility as a potential drug target

    Numerical Investigation of Turbulent Hydrogen-Methane-Nitrogen Non-Premixed Jet Flame

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    In this work, the numerical investigation of the two-dimensional axisymmetric turbulent diffusion flame of a composite fuel was performed by using a computational fluid dynamics code to predict flame structure. The composite fuel was an H2/CH4/N2 gas mixture. The amount of H2 and N2 in the fuel mixture varies under constant volumetric fuel flow rate. Fluent, which solves the governing and reaction equations using the finite volume method, was used as the computational fluid dynamics program. The non-premixed model was used for computation of the combustion. The standard k-ε model was used for modeling the turbulent flow. The interaction of the chemistry and turbulence was accounted for by the program with the probability density function model. This model was validated against the experimental data taken from literature. In general, the numerical results of the temperature, velocity, and CO2 concentration distributions were in satisfactory agreement with the experimental results. The numerical results showed that adding H2 to the fuel mixture decreases the flame length and generally increases the maximum temperature of the flame. On the other hand, adding N2 to the mixture decreases both the flame length and maximum flame temperature. The flame length corresponds to the axial position of the peak flame temperature. Keywords: Combustion Modeling; Composite Fuels; Diffusion Flame; H2/CH4/N2 Flame; Flame Length; Emission

    Numerical Investigation of the Effect of Different Conical Turbulators on the Performance of a Liquid Fuelled Boiler

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    The increment in the combustion of fossil fuels for heating and power generation in recent years has led researchers to design more efficient energy conversion systems by increasing the efficiency of the existing systems and by minimizing energy losses. In this study, increasing the efficiency of the liquid fuelled smoke tube boilers used for domestic heating was researched. In this context, turbulators with full conical and frusto-conical geometries placed to smoke tubes of boiler and their effects on flame structure, heat transfer and boiler efficiency were investigated numerically. Calculations were carried out at two dimensional axisymmetric conditions and Fluent was used as the computational fluid dynamics software. In all cases, the standard k-ε model was used for modelling the turbulent flow and the species transport model was used for modelling the combustion. The results obtained by using these turbulators were evaluated for each placement condition of the turbulators. Besides, the temperature and the stream function distribution and the pressure drop in the boiler were investigated according to the type of turbulators. Finally, it was discussed which type of turbulator would be most appropriate at boilers. Keywords: Spray Combustion; Combustion Modelling; Boilers; Conical Turbulator

    The Resident VIEW in Nursing Homes

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    This article presents the Resident VIEW (Voicing Importance, Experience, and Well-Being), a measure designed to learn directly from long-term care residents the extent to which they experience support that matters most to them. The Resident VIEW contains 63 items across eight domains developed through cognitive interviews with residents in different types of residential settings (e.g., nursing homes, assisted living, and adult foster care). Residents rate items on both importance and their experience. In total, 258 nursing home residents living in 32 Oregon nursing homes were selected through a two-stage random sampling design and participated in the study. Results demonstrate that what matters most to residents varies, emphasizing the value of asking residents directly about their preferences. The relationship between importance and experience differed by item. Residents who experienced support rated very important within some domains, reported better quality of life and reported lower levels of depressive symptoms than those who did not experience these things. The interaction between importance and experience, however, did not reach statistical significance, suggesting that positive experiences may provide benefit even in some areas that are not perceived as important by residents. Results underscore the value of incorporating the resident perspective into measure development in long-term care

    The Resident VIEW in Community- Based Care Residential Settings

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    The Resident VIEW is a measure of person-centered care (PCC) from residents’ perspectives and was previously studied in nursing homes. The current study presents descriptive data for the Resident VIEW in community-based care settings including assisted living, residential care (AL/RC), and adult foster homes (AFH). Using a two-stage sampling design, we recruited 31 AL/RC and 119 AFH in Oregon and completed face-to-face structured interviews with 227 and 195 residents, respectively. Residents provided ratings for both the importance of and their experience with 66 items that tapped into PCC practices in eight domains. Results are provided for each item, many of which are significantly associated with greater quality of life, better resident satisfaction, and fewer depressive symptoms, especially in the domains of personalized care and being treated like a person. Incongruence between importance and experience ratings indicate many residents experience unmet needs across multiple domains. The Resident VIEW performed well in different types of settings, providing an important tool for researchers and providers who wish to learn about the PCC experience from residents’ points of view

    Break-up of nano-particle agglomerates by hydrodynamically limited processes

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    When dry nano-particulate powders are first added into a liquid, clusters as large as hundreds of microns can be formed. In this study, high shear impellers, such as the sawtooth Ekatomizer and rotor-stator impellers were used to suspend and break-up these agglomerates in a stirred vessel. The high local energy dissipation rates generated by these impeller could slowly break up clusters to sub-micron sizes by an erosional mechanism. In comparison, single and multiple passes through a valve homogeniser could quickly break the nano-particle clusters to sub-micron sizes; single pass operation had the highest breakage efficiency for a given specific energy input. For both equipment types, the rate of fines generation was found to be controlled by the maximum energy dissipation rate. However, the size of the fine aggregates produced was a constant and was not a function of the energy dissipation rate
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