Fully Metal-Coated Scanning Near-Field Optical Microscopy Probes with Spiral Corrugations for Superfocusing under Arbitrarily Oriented Linearly Polarised Excitation

We study the effect of a spiral corrugation on the outer surface of a fully metal-coated scanning near-field optical microscopy (SNOM) probe using the finite element method. The introduction of a novel form of asymmetry, devoid of any preferential spatial direction and covering the whole angular range of the originally axisymmetric tip, allows attaining strong field localization for a linearly polarised mode with arbitrary orientation. Compared to previously proposed asymmetric structures which require linearly polarised excitation properly oriented with respect to the asymmetry, such a configuration enables significant simplification in mode injection. In fact, not only is the need for the delicate procedure to generate radially polarised beams overcome, but also the relative alignment between the linearly polarised beam and the tip modification is no longer critical

In vitro comparison of five nebulizers during noninvasive ventilation: Analysis of inhaled and lost doses

Background: Few studies on performance comparison of nebulizer systems coupled with a single-limb circuit bilevel ventilator are available. Most of these data compared the aerosol drug delivery for only two different systems. Using an adult lung bench model of noninvasive ventilation, we compared inhaled and lost doses of three nebulizer systems coupled with a single-limb circuit bilevel ventilator, as well as the influence of the nebulizer position. Method: Three vibrating mesh nebulizers (Aeroneb® Pro, Aeroneb® Solo, and NIVO®), one jet nebulizer (Sidestream®), and one ultrasonic nebulizer (Servo Ultra Nebulizer 145®) coupled with a bilevel ventilator were tested. They were charged with amikacin solution (500mg/4mL) and operated at two different positions: before and after the exhalation port (starting from the lung). The inhaled dose, the expiratory wasted dose, and the estimated lost dose were assessed by the residual gravimetric method. Results: The doses varied widely among the nebulizer types and position. When the nebulizer was positioned before the exhalation port, the vibrating mesh nebulizer delivered the highest inhaled dose (p<0.001), the jet nebulizer the highest expiratory wasted dose (p<0.001), and the ultrasonic device the highest total lost dose (p<0.001). When the nebulizer was positioned after the exhalation port, the vibrating mesh nebulizers delivered the highest inhaled (p<0.001) and expiratory wasted doses (p<0.001), and the ultrasonic device the highest total lost dose (p<0.001). The most efficient nebulizers were NIVO and Aeroneb Solo when placed before the exhalation port. Conclusions: In a single-limb circuit bilevel ventilator, vibrating mesh nebulizers positioned between the exhalation port and lung model are more efficient for drug delivery compared with jet or ultrasonic nebulizers. In this position, the improved efficiency of vibrating mesh nebulizers was due to an increase in the inhaled dose and a reduction in the exhaled wasted dose compared with placement between the ventilator and the expiratory port. Because of the high total lost dose, the ultrasonic device should not be recommended. Nebulizer placement before the exhalation port increased the inhaled dose and decreased the expiratory wasted dose, except for the jet nebulizer

Transcription Factors in Mature B Cells During Aging

The purpose of this chapter is to give an overview of the age-related changes in the expression and function of the major transcription factors regulating mature B cells. We also summarize our recent work and show that the age-related defects in Ig class switch are directly related to the decrease in the transcription factor E47 which controls the expression of activation-induced cytidine deaminase (AID), the enzyme needed for class-switch recombination (CSR) and somatic hypermutation (SHM). The age-associated effects on the expression and function of the transcription factors NF-kB and Pax-5 are also described. Blimp-1 seems not to be modified by aging, and only one report has shown age effects on Bach2. For other transcription factors relevant for mature B cell functions, such as IRF4, Notch2, and HoxC4, no effects of aging have been reported so far. The defects presented herein for aged B cells should allow the discovery of mechanisms to improve humoral immune responses in both humans and mice in the near future

Un enfoque de contrato social para la sostenibilidad

This paper asks whether it is possible to derive a concern for future generations (‘‘sustainability’’) from an account of the firm as a social contract (SC) among its stakeholders. Two aspects of a leading SC model of the firm limit its usefulness for an analysis of sustainability. First, the stakeholders provide investments to the firm over time. Second, the relationship between contemporaries and future generations is marked by asymmetries of power and knowledge that need to be considered while reconstructing the SC today. I discuss three reformulations of the SC that are all, in principle, capable of introducing within the SC a concern for future generations. The first describes the contractors as heads of families. The second envisages a grand meeting of stakeholders of all generations. The third, which I find most defensible, views the SC as an ahistorical agreement reached behind a thick veil of ignorance. This agreement is based on John Rawls’s norm of reciprocity, whereby the stakeholders adopt today the decision they wish all previous (and future) generations had made regarding the rate of consumption of natural resources and emission of pollutants