RESUMEN
Transmission of SARS-CoV-2 between passengers on airplanes is a significant concern and reducing the transmission of SARS-CoV-2 or other viruses aboard aircraft could save lives. Solving the Airplane Seating Assignment Problem (ASAP) produces seating arrangements that minimize transmission risks between passengers aboard an aircraft, but the chosen risk model affects the optimal seating arrangement. We analyze previous risk models and introduce two new risk models, masked and unmasked, based on previous experiments performed aboard real aircraft to test aerosol dispersion of SARS-CoV-2 sized particles. We make recommendations on when each risk model is applicable and the types of seating arrangements that are optimal for each risk model.
RESUMEN
The elderly are at much higher risk for developing pneumonia than younger individuals. Pneumonia is a leading cause of death and is the third most common reason for hospitalization in the elderly. One reason that elderly people may be more susceptible to pneumonia is a breakdown in the lung's first line of defense, mucociliary clearance. Cilia beat in a coordinated manner to propel out invading microorganisms and particles. Ciliary beat frequency (CBF) is known to slow with aging, however, little is known about the mechanism(s) involved. We compared the CBF in BALB/c and C57BL/6 mice aged 2, 12, and 24 mo and found that CBF diminishes with age. Cilia in the mice at age 12 and 24 mo retained their ability to be stimulated by the ß2 agonist procaterol. To help determine the mechanism of ciliary slowing, we measured protein kinase C alpha and epsilon (PKCα and PKCε) activity. There were no activity differences in PKCα between the mice aged 2, 12, or 24 mo. However, we demonstrated a significantly higher PKCε activity in the mice at 12 and 24 mo than the in the mice 2 mo of age. The increase in activity is likely due to a nearly threefold increase in PKCε protein in the lung during aging. To strengthen the connection between activation of PKCε and ciliary slowing, we treated tracheas of mice at 2 mo with the PKCε agonist 8-[2-(2-pentylcyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA). We noted a similar decrease in baseline CBF, and the cilia remained sensitive to stimulation with ß2 agonists. The mechanisms for the slowing of baseline CBF have not been previously determined. In this mouse model of aging we were able to show that decreases in CBF are related to an increase in PKCε activity.
Asunto(s)
Envejecimiento/fisiología , Pulmón/fisiopatología , Depuración Mucociliar/fisiología , Neumonía/enzimología , Proteína Quinasa C-epsilon/metabolismo , Agonistas de Receptores Adrenérgicos beta 2/farmacología , Factores de Edad , Animales , Caprilatos/farmacología , Cilios/enzimología , Cilios/fisiología , Células Epiteliales/fisiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Modelos Animales , Procaterol/farmacología , Proteína Quinasa C-alfa/metabolismoAsunto(s)
Dolor en el Pecho/etiología , Histoplasmosis/diagnóstico , Enfermedades Pulmonares Fúngicas/diagnóstico , Adulto , Asia Sudoriental/etnología , Biopsia , Diagnóstico Diferencial , Histoplasmosis/diagnóstico por imagen , Histoplasmosis/etnología , Histoplasmosis/patología , Humanos , Enfermedades Pulmonares Fúngicas/diagnóstico por imagen , Enfermedades Pulmonares Fúngicas/etnología , Enfermedades Pulmonares Fúngicas/patología , Masculino , Radiografía Torácica , Tomografía Computarizada por Rayos XRESUMEN
The article reports on low-temperature high-rate sputtering of hydrophilic transparent TiO2thin films using dc dual magnetron (DM) sputtering in Ar + O2mixture on unheated glass substrates. The DM was operated in a bipolar asymmetric mode and was equipped with Ti(99.5) targets of 50 mm in diameter. The substrate surface temperature Tsurfmeasured by a thermostrip was less than 180 °C for all experiments. The effect of the repetition frequency frwas investigated in detail. It was found that the increase of frfrom 100 to 350 kHz leads to (a) an improvement of the efficiency of the deposition process that results in a significant increase of the deposition rate aDof sputtered TiO2films and (b) a decrease of peak pulse voltage and sustaining of the magnetron discharge at higher target power densities. It was demonstrated that several hundreds nm thick hydrophilic TiO2films can be sputtered on unheated glass substrates at aD = 80 nm/min, Tsurf < 180 °C when high value of fr = 350 kHz was used. Properties of a thin hydrophilic TiO2film deposited on a polycarbonate substrate are given.
RESUMEN
5-Phenylisothiazole undergoes phototransposition via the electrocyclic ring closure-heteroatom migration pathway and by the N(2)-C(3) interchange reaction pathway. The latter route is enhanced by the addition of triethylamine (TEA) to the reaction medium and by increasing the polarity of the solvent. In addition to phototransposition, 5-phenylisothiazole also undergoes photocleavage to 2-cyano-1-phenylethenethiol which was trapped by reaction with benzyl bromide to yield 2-cyano-1-phenylethen-1-ylbenzyl thioether. 3-Phenylisothiazole also phototransposes by both reaction pathways, but the product distribution is not affected by the addition of TEA or by changing the solvent polarity.
Asunto(s)
Tiazoles/química , Etilaminas , Indicadores y Reactivos , Cinética , Estructura Molecular , Fotólisis , Relación Estructura-ActividadAsunto(s)
Fracturas Óseas/diagnóstico , Esternón/lesiones , Adulto , Anciano , Femenino , Fracturas Óseas/terapia , Humanos , Masculino , Persona de Mediana EdadAsunto(s)
Amoníaco , Hepatopatías/diagnóstico , Pruebas de Función Hepática/métodos , Proteínas , HumanosRESUMEN
Brief heating of Bacillus Licheniformis cell walls at 100 degrees C in aqueous buffers of pH3.0-4.0 removes some polymers but not others from the mucopeptides. For example, relatively undegraded teichuronic acid can be extracted at 100 degrees C in 20min at pH3.0 whereas the teichoic acids are not removed. Similar specificity can be shown with walls from three other species of micro-organism.