Search results for "thing"
showing 10 items of 908 documents
mPEG-PLGA Nanoparticles Labelled with Loaded or Conjugated Rhodamine-B for Potential Nose-to-Brain Delivery
2021
Nowdays, neurodegenerative diseases represent a great challenge from both the therapeutic and diagnostic points of view. Indeed, several physiological barriers of the body, including the blood brain barrier (BBB), nasal, dermal, and intestinal barriers, interpose between the development of new drugs and their effective administration to reach the target organ or target cells at therapeutic concentrations. Currently, the nose-to-brain delivery with nanoformulations specifically designed for intranasal administration is a strategy widely investigated with the goal to reach the brain while bypassing the BBB. To produce nanosystems suitable to study both in vitro and/or in vivo cells traffickin…
The Phenomenology of Space and Time: Husserl, Sartre, Derrida
2016
The notions of space and time have been a subject of philosophical discussion since antiquity. In modern philosophy, Newton’s concepts of absolute space and absolute time was subject to criticism by empiricists like Berkeley and Hume, who prepared the ground for Einstein and the ideas behind his theories of relativity. In this article, I will consider the concept of space-time from a phenomenological point of view, with particular reference to Jean-Paul Sartre and Jacques Derrida. Sartre presents a phenomenological notion of space as nothingness, and I argue that this notion corresponds closely to Einstein's view, and can be extended to include the notion of time, and hence of space-time. I…
Lacunar fractal photon sieves
2007
We present a new family of diffractive lenses whose structure is based on the combination of two concepts: photon sieve and fractal zone plates with variable lacunarity. The focusing properties of different members of this family are examined. It is shown that the sieves provide a smoothing effect on the higher order foci of a conventional lacunar fractal zone plate. However, the characteristic self-similar axial response of the fractal zone plates is always preserved.
Implications of the Semigeostrophic Nature of Rossby Waves for Rossby Wave Packet Detection
2015
Abstract Upper-tropospheric Rossby wave packets have received increased attention recently. In most previous studies wave packets have been detected by computing the envelope of the meridional wind field using either complex demodulation or a Hilbert transform. The latter requires fewer choices to be made and appears, therefore, preferable. However, the Hilbert transform is fraught with a significant problem, namely, a tendency that fragments a single wave packet into several parts. The problem arises because Rossby wave packets show substantial deviations from the almost-plane wave paradigm, a feature that is well represented by semigeostrophic dynamics. As a consequence, higher harmonics …
On cosmic quantum tunneling from “nothing”
2015
We extend to a general Λ-Eriedmann-Lemaitre-Robertson-Walker (ΛFLRW) a previous result by Vilenkin and others according to which a closed de Sitter universe could be created from "nothing". More specifically, our main result is that only the closed ΛFLRW universe (but not the open and flat ones) could be created from a corresponding instanton, that is, from the corresponding solution with signature +4 of the Einstein field equations. Before getting this result the suitable corresponding instantons are calculated. The result is in accordance with previous results by another authors obtained by different methods.
Design of a Close Power Loop Test Bench for Contra-Rotating Propellers
2020
The aim of the research is to develop an azimuthing contra-rotating propeller for commercial applications with a power of 2000 kW. The thruster system is designed especially to be installed on high speed crafts (HSCs) for passenger transport with a cruising speed of about 35–40 knots. The topic is very useful because the azimuth thruster solutions currently do not find commercial applications in naval units for passenger transport. The latter are heavy, not very efficient from a hydrodynamic point of view and suitable for maximum cruising speed of about 18–20 knots. The study is interesting because among the advantages that these solutions provide are the possibility of transmitting very hi…
Smoothing of structure in the fusion and quasielastic barrier distributions for the20Ne+208Pb system
2012
We present simultaneously measured barrier distributions for the ${}^{20}$Ne $+$ ${}^{208}$Pb system derived from large-angle quasielastic scattering and fusion, in the latter case by means of the detection of fission fragments. Both distributions turned out to be smooth, in spectacular disagreement with the results of standard coupled-channels calculations. Namely, they do not posses the strong structure expected from coupled-channels calculations, even if apparently they take into account explicitly all relevant strong couplings. This points to the importance of weak channels, i.e., transfer reactions and scattering connected with noncollective excitations.
Total decay and transition rates from LQCD
2018
We present a new technique for extracting total transition rates into final states with any number of hadrons from lattice QCD. The method involves constructing a finite-volume Euclidean four-point function whose corresponding infinite-volume spectral function gives access to the decay and transition rates into all allowed final states. The inverse problem of calculating the spectral function is solved via the Backus-Gilbert method, which automatically includes a smoothing procedure. This smoothing is in fact required so that an infinite-volume limit of the spectral function exists. Using a numerical toy example we find that reasonable precision can be achieved with realistic lattice data. …
Inspiratory inhibition and rebound activation elicited by intermittent electrical bulbar stimulation in various states of pulmonary afferent vagal ex…
1975
In anesthetized rabbits spirogram and diaphragmatic activity were examined during electrical stimulation of regions of the medulla oblongata. The volleys were triggered by the animal's own respiration. 1. One volley of 120 msec duration at 100 pulses p.s., applied during inspiratory, caused an immediate and transient inhibition of the diaphragmatic activity. After the end of the volley and inspiratory rebound appeared: the tidal volume was increased and the inspiration was prolonged by some 150 msec. The respiratory rate decreased. 2. Continuous low or high frequency electrical stimulation of pulmonary stretch afferents caused an inspiratory or an expiratory effect respectively. In both con…
The bulbar respiratory centre in the rabbit. I. Changes of respiratory parameters caused by intermittent electrical bulbar stimulation during inspira…
1976
In anesthetized rabbits, spirogram and diaphragmatic activity were examined during electrical stimulation of the bulbar lateral reticular formation. The activity of bulbar respiratory neurons was recorded contra-or ipsilaterally to the stimulation site. One volley of repetitive stimuli per breath was delivered during either inspiration or expiration. 1. Each volley of about 120 ms duration at 100 pulses per second, delivered early ininspiration, caused an immediate and transient inhibition of the diaphragmatic activity. An inspiratory, rebound comprising lengthening of inspiration and increase in tidal volume occurred. a) “Inspiratory” and “expiratory-inspiratory” phase-spanning neurons exh…