160 research outputs found
Surface Percolation and Growth. An alternative scheme for breaking the diffraction limit in optical patterning
A nanopatterning scheme is presented by which the structure height can be
controlled in the tens of nanometers range and the lateral resolution is a
factor at least three times better than the point spread function of the
writing beam. The method relies on the initiation of the polymerization
mediated by a very inefficient energy transfer from a fluorescent dye molecule
after single photon absorption. The mechanism has the following distinctive
steps: the dye adsorbs on the substrate surface with a higher concentration
than in the bulk, upon illumination it triggers the polymerization, then
isolated islands develop and merge into a uniform structure (percolation),
which subsequently grows until the illumination is interrupted. This
percolation mechanism has a threshold that introduces the needed nonlinearity
for the fabrication of structures beyond the diffraction limit.Comment: 10 pages, 8 figure
Performances of infrared emitters applied to the porous thin materials drying
Drying of solids is one of the oldest and most common unit operations found in diverse processes. In this paper the drying of hygroscopic textile materials is discussed. The authors have previously investigated the drying kinetic of different fabrics dried by a hot air jet. In this paper a comparison between the convective and electric IR drying is made. In particular two fabrics with fibers which show a different hygroscopic behaviour are analysed: wool and cellulose/cotton. Unlike the convective drying, IR drying is weakly affected by the radiation properties and by the hygroscopic behaviour of the two fabrics. This is likely due to a better diffusion of the heat flux, which is constant over the entire drying surface in the case of IR heating, and produces unexpected results on the nondimensional kinetic parameter (characteristic curve). Wool shows a complete different characteristic curve if dried with IR or with convective flow. The better performances have been reached with MW emitter, but it has been observed that this advantage decreases with the distance of the source from the surface to be dried
Detection of Parechovirus (P) and Enterovirus (E) Among Infants Evaluated for Late-Onset Sepsis in the Neonatal Intensive Care Unit (NICU): The VIRIoN-P-E Study
Background:
Limited data exist on the role of human parechoviruses (HPeV) and enteroviruses (EV) as causes of late-onset sepsis (LOS) in the NICU.
Objective:
To determine the frequency of detection of parechoviruses and enteroviruses among infants >72 hr of age who were evaluated for LOS in 2 academic NICUs (Parkland Memorial Hospital [PMH], Dallas -shared bays; Women & Infants Hospital [W&I], RI -single patient rooms)
Design/Methods:
Prospective cohort study of inborn infants hospitalized in the NICU at PMH and WIH from 1/2012 to 1/2013 and were enrolled in the Viral Respiratory Infections in the Neonatal Intensive Care Unit (VIRIoN-I; J Pediatr 2014:165:690). Eligible subjects were infants of all gestational ages (GA) and birth weights (BW) who were >72 hrs of age, remained in the NICU since birth, and underwent evaluation with initiation of antibiotic therapy for suspected LOS. Nasopharyngeal specimens were obtained within 72 hrs of the sepsis evaluation using flexible flocked nylon swabs that were placed in universal transport medium and frozen at -80\ub0C until tested for parechovirus and enterovirus RNA by polymerase chain reaction (PCR) assay (Virology Laboratory, Nationwide Children\u2019s Hospital, Columbus, OH). Demographic, clinical, laboratory, and radiographic data were obtained.
Results:
Of the 100 infants enrolled in the VIRIoN-I study, nasopharyngeal specimens were available from 65 (59, PMH; 6, WIH) for parechovirus and enterovirus PCR testing. These 65 infants (38, male; 27, female; 49, Hispanic; 6, white; 9, Black; 1, unknown) had a mean \ub1SD gestational age of 30 \ub1 5 wks and birth weight of 1619 \ub1 929 g, and received empirical antibiotics for possible LOS. Infants had a total of 94 sepsis evaluations (65, 1 evaluation; 16, 2; 8, 3; 4, 4) at a mean age of 20 days. Reasons for the sepsis evaluations included fever (9), hypothermia (65), apnea (50),feeding intolerance (51), seizure (1), irritabilitiy (5), emesis (20), diarrhea (1), bloody stool (5), rhinorrhea/congestion/cough (6), and lethargy (9). Four infants died. None of the infants had parechovirus or enterovirus detected in nasopharygeal specimens either at the first or subsequent sepsis evaluations.
Conclusion(s):
The burden of disease due to parechovirus and enteroviruses among inborn infants who remain in the NICU since birth appears to be low in those evaluated for LOS. Larger, prospective studies are needed to fully determine their contribution to \u201cculture-negative\u201d sepsis in the NICU.
Publication Number:
3860.53
Prevalencia de enteroparasitosis zoonóticas en mascotas caninas
Las zoonosis enteroparasitarias caninas pueden provocar en la población humana
patologías de gran severidad, siendo los más afectados los niños. La tenencia de
perros como mascotas implica un contacto estrecho con ellos y un factor de riesgo
muy importante para contraer estas enfermedades. Los objetivos del presente trabajo
fueron: Determinar el riesgo de la población pediátrica del departamento de Maipú,
Mendoza, de adquirir infecciones parasitarias zoónoticas caninas a través de investigar
la prevalencia de enteroparásitos zoonóticos en una población de mascotas caninas
de esa zona; y proponer programas de control que interrumpan el ciclo biológico
de entero parásitos caninos para limitar y erradicar estas enfermedades. Para lograr
estos objetivos se realizó un estudio descriptivo exploratorio por muestreo intencionado
no excluyente sobre muestras de materia fecal canina del departamento de
Maipú aportadas voluntariamente por los dueños de los animales y recolectadas por
el equipo de trabajo de este proyecto desde el 16 de febrero hasta el 30 de julio de 2015. A cada dueño de perro
se le entregó una encuesta epidemiológica, para indagar sobre aspectos del núcleo familiar y otros relacionados
con sus mascotas, incluyendo sexo, edad y raza
Estimation of the local instantaneous heat flux inside a pulsating heat pipe for space applications
Imaging the Electrocyte of Torpedo Marmorata by Scanning Force Microscopy
Scanning force microscopy (SFM) and scanning electron microscopy (SEM) were used to examine the tissue structure of the electric organ of Torpedo marmorata in air and in liquid after applying fracturing and cryosectioning techniques and chemical fixation. The electric organ is organized in columns of stacked electrocytes, arranged in a honeycomb pattern. The columns were cut along a plane normal to the cell stack and thin sections were transferred to polylysine coated glass coverslips. The polarity of the electrocytes was made apparent by immunofluorescence microscopy directed to different domains of the acetylcholine receptor (AChR), thus revealing the innervated face of the cell. SFM and SEM both showed cell surfaces to be overlaid by a network of collagen fibers by their characteristic banding pattern with about 64 nm periodicity and about 2.5 nm corrugation amplitude. In liquid, significantly lower structural resolution was achieved by SFM, probably due to sample elasticity
Management of the mother-infant dyad with suspected or confirmed SARS-CoV-2 infection in a highly epidemic context
In the context of SARS-CoV-2 pandemic, the hospital management of mother-infant pairs poses to obstetricians and neonatologists previously unmet challenges. In Lombardy, Northern Italy, 59 maternity wards networked to organise the medical assistance of mothers and neonates with suspected or confirmed SARS-CoV-2 infection. Six "COVID-19 maternity centres" were identified, the architecture and activity of obstetric and neonatal wards of each centre was reorganised, and common assistance protocols for the management of suspected and proven cases were formulated. Here, we present the key features of this reorganization effort, and our current management of the mother-infant dyad before and after birth, including our approach to rooming-in practice, breastfeeding and neonatal follow-up, based on the currently available scientific evidence. Considered the rapid diffusion of COVID-19 all over the world, we believe that preparedness is fundamental to assist mother-infant dyads, minimising the risk of propagation of the infection through maternity and neonatal wards
Prevalence of zoonotic intestinal parasites in a population of canine pets of Maipú, Mendoza
Las zoonosis enteroparasitarias caninas pueden provocar en humanos, sobre todo niños e inmunosuprimidos, patologías severas. El contacto estrecho con mascotas sin controles sanitarios, implica la posibilidad de contraer esas enfermedades. Se estudió prevalencia de enteroparasitosis en canes, de Maipú, Mendo-za, para determinar riesgo de exposición de la población pediátrica a infecciones zoonóticas peligrosas. Conocer la situación epidemiológica propia, permite implementar planes de acción y prevención efectivos y eficaces para esa realidad.
Se propone un programa de control para interrumpir el ciclo biológico de enteroparásitos caninos para limitar y erradicar las enfermedades que producen
Machine Learning Algorithms for Flow Pattern Classification in Pulsating Heat Pipes
Data Availability Statement: Not applicableCopyright: © 2022 by the authors. Owing to their simple construction, cost effectiveness, and high thermal efficiency, pulsating heat pipes (PHPs) are growing in popularity as cooling devices for electronic equipment. While PHPs can be very resilient as passive cooling systems, their operation relies on the establishment and persistence of slug/plug flow as the dominant flow regime. It is, therefore, paramount to predict the flow regime accurately as a function of various operating parameters and design geometry. Flow pattern maps that capture flow regimes as a function of nondimensional numbers (e.g., Froude, Weber, and Bond numbers) have been proposed in the literature. However, the prediction of flow patterns based on deterministic models is a challenging task that relies on the ability of explaining the very complex underlying phenomena or the ability to measure parameters, such as the bubble acceleration, which are very difficult to know beforehand. In contrast, machine learning algorithms require limited a priori knowledge of the system and offer an alternative approach for classifying flow regimes. In this work, experimental data collected for two working fluids (ethanol and FC-72) in a PHP at different gravity and power input levels, were used to train three different classification algorithms (namely K-nearest neighbors, random forest, and multilayer perceptron). The data were previously labeled via visual classification using the experimental results. A comparison of the resulting classification accuracy was carried out via confusion matrices and calculation of accuracy scores. The algorithm presenting the highest classification performance was selected for the development of a flow pattern map, which accurately indicated the flow pattern transition boundaries between slug/plug and annular flows. Results indicate that, once experimental data are available, the proposed machine learning approach could help in reducing the uncertainty in the classification of flow patterns and improve the predictions of the flow regimes.EPSRC grant HyHP (EP/P013112/1); European Space Agency MAP projects TOPDESS; Hexxcell Ltd
Infrared analysis and pressure measurements on a single loop pulsating heat pipe at different gravity levels
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