291 research outputs found
Ischemia Reperfusion Injury: The New Frontier for Wound Healing & HBOT
This session will introduce the attendee to the impact of oxygen free radicals on wound healing. Ischemia reperfusion injury (IRI) and oxygen free radicals are defined and the basic chemistry surrounding reactive oxygen species (ROS) will be discussed. Detailed analysis of the inflammatory phase of wound healing and the role of oxygen free radicals in inflammation are presented
Gigahertz Peaked Spectrum sources from the Jodrell Bank-VLA Astrometric Survey
Observations with MERLIN at 408 MHz have been used to establish the
low-frequency part of the spectra of more than a hundred compact radio sources
taken from the part of the Jodrell Bank--VLA Astrometric Survey limited by 35
deg. < \delta < 75 deg. These sources were selected from JVAS and other
catalogues to have convex spectra between 1.4 and 8.4 GHz, characteristic of
Gigahertz Peaked Spectrum (GPS) sources. We have confirmed convex shapes of the
spectra of 76 objects (one half of our initial candidates) thereby yielding the
largest genuine sample of GPS sources compiled so far. Seven of 17 identified
quasars in the sample have large (z\ga 2) redshifts.Comment: 18 pages, 2 figures, minor corrections. To appear in: A&A Suppl. vol.
135 (March 1999
Cooperatively enhanced precision of hybrid light-matter sensors
We consider a hybrid system of matter and light as a sensing device and quantify the role of cooperative effects. The latter generically enhance the precision with which modifications of the effective light-matter coupling constant can be measured. In particular, considering a fundamental model of N qubits coupled to a single electromagnetic mode, we demonstrate that the ultimate bound for the precision shows double-Heisenberg scaling: Delta theta proportional to 1/(Nn), with N and n the number of qubits and photons, respectively. Moreover, even using classical states and measuring only one subsystem, a Heisenberg-times-shot-noise scaling, i.e., 1/(N root n) or 1/(n root N), is reached. As an application, we show that a Bose-Einstein condensate trapped in a double-well optical lattice within an optical cavity can in principle be used to detect the gravitational acceleration g with the relative precision of Delta g/g similar to 10(-4) Hz(-1/2). The analytical approach presented in this study takes into account the leakage of photons through the cavity mirrors, and allows one to determine the sensitivity when g is inferred via measurements on atoms or photons
Cooperatively-enhanced precision of hybrid light-matter sensors
We consider a hybrid system of matter and light as a sensing device and
quantify the role of cooperative effects. The latter generically enhance the
precision with which modifications of the effective light-matter coupling
constant can be measured. In particular, considering a fundamental model of
qubits coupled to a single electromagnetic mode, we show that the ultimate
bound for the precision shows double-Heisenberg scaling:
, with and being the number of qubits and
photons, respectively. Moreover, even using classical states and measuring only
one subsystem, a Heisenberg-times-shot-noise scaling, i.e. or
, is reached. As an application, we show that a Bose-Einstein
condensate trapped in a double-well potential within an optical cavity can
detect the gravitational acceleration with the relative precision of
. The analytical approach presented in
this study takes into account the leakage of photons through the cavity
mirrors, and allows to determine the sensitivity when is inferred via
measurements on atoms or photons.Comment: 13 pages, 3 figure
Investigation of methods to produce a uniform cloud of fuel particles in a flame tube
The combustion of a uniform, quiescent cloud of 30-micron fuel particles in a flame tube was proposed as a space-based, low-gravity experiment. The subject is the normal- and low-gravity testing of several methods to produce such a cloud, including telescoping propeller fans, air pumps, axial and quadrature acoustical speakers, and combinations of these devices. When operated in steady state, none of the methods produced an acceptably uniform cloud (+ or - 5 percent of the mean concentration), and voids in the cloud were clearly visible. In some cases, severe particle agglomeration was observed; however, these clusters could be broken apart by a short acoustic burst from an axially in-line speaker. Analyses and experiments reported elsewhere suggest that transient, acoustic mixing methods can enhance cloud uniformity while minimizing particle agglomeration
Editorial: Vagus nerve-mediated drive in supporting homeostasis: optimizing global health through monitoring and stimulating vagal function
Epigenetics encompasses the changes in gene expression triggered by environmental cues that occur without altering the underlying DNA sequences. Although epigenetics involves a limited number of identified mechanisms so far (DNA methylation, histone modifications and noncoding RNAs), the field of Epigenetics is spreading rapidly over integrated physiopathology (Jeffries, 2020). The importance of epigenetics has been acknowledged in cancer (Sun et al., 2022), sepsis (Binnie et al., 2020), autoimmune/inflammatory diseases (Surace and Hedrich, 2019), addiction (Hamilton and Nestler, 2019), aging (Pal and Tyler, 2016; PĂ©rez et al., 2022), neurodegenerative diseases (Berson et al., 2018; Zhang et al., 2022) and even in neurodevelopmental (Esposito et al., 2018; Wu et al., 2020) and psychiatric diseases (Abdolmaleky et al., 2023). Likewise, a broad and expanding set of therapies in clinics have been potentialized by tuning the vagal complex of brainstem, i.e., the key neural node of homeostasis, via non-invasive Vagus Nerve Stimulation (VNS) (Hilz, 2022). Moreover, Heart Rate Variability (HRV), a physiologically validated and easily accessible read-out of the vagal tone (Lewis et al., 2012), is acknowledged as a polyvalent prognostic tool (Gidron et al., 2018; Mol et al., 2021). This is not surprising, since Epigenome is considered as a âmediator for host-microbiome crosstalkâ (Peery et al., 2021) and since vagus nerve represents the fastest pathway of the Microbiota-Gut-brain Axis (FĂŒlling et al., 2019). However, except for regulating neuro-inflammation (Chen et al., 2022), the mechanisms through which VNS influences peripheral and central nervous system plasticity are not well described yet, limiting therapeutic optimization (Morrison et al., 2020; Keute and Gharabaghi, 2021). Therefore, as the vagal complex (i.e., peripheral and brainstem components) is definitely prone to bring about epigenetic modulations, notably through neuro-endocrine stimuli (Gil et al., 2013), we questioned the epigenetic role of vagus nerve, in order to promote noninvasive VNS, guided by HRV monitoring, as a universal therapy to stay healthy
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