683 research outputs found
Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for three years under fully open air conditions.
published or submitted for publicatio
Highly sensitive contact pressure measurements using FBG patch in endotracheal tube cuff
A method for measuring the contact pressure between an endotracheal tube cuff and the trachea was designed and developed by using a fibre Bragg grating (FBG) based optical fibre sensor. The FBG sensor is encased in an epoxy based UV-cured cuboid patch and transduces the transversely loaded pressure into an axial strain that induces wavelength shift of the Bragg reflection. The polymer patch was created by using a PTFE based mould and increases tensile strength and sensitivity of the bare fibre FBG to pressure to 2.10×10-2 nm/kPa. The characteristics of the FBG patch allow for continuous measurement of contact pressure. The measurement of contact pressure was demonstrated by the use of a 3D printed model of a human trachea. The influence of temperature on the measurements is reduced significantly by the use of a second FBG sensor patch that is not in contact with the trachea. Intracuff pressure measurements performed using a commercial manometer agreed well with the FBG contact pressure measurements. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only
Simultaneous temperature and humidity measurements in a mechanical ventilator using an optical fibre sensor
An optical fibre sensor for simultaneous temperature and humidity measurements consisting of one fibre Bragg grating (FBG) to measure temperature and a mesoporous film of bilayers of Poly(allylamine hydrochloride)(PAH) and silica (SiO2) nanoparticles deposited onto the tip of the same fibre to measure humidity is reported. The hygroscopic film was created using the layer-by-layer (LbL) method and the optical reflection spectra were measured up to a maximum of 23 bilayers. The temperature sensitivity of the FBG was 10 pm/°C while the sensitivity to humidity was (-1.4x10-12 W / %RH) using 23 bilayers. The developed sensor was tested in the mechanical ventilator and temperature and humidity of the delivered artificial air was simultaneously measured. Once calibrated, the optical fibre sensor has the potential to control the absolute humidity as an essential part of critical respiratory care. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only
Signature of sterile species in atmospheric neutrino data at neutrino telescopes
The MiniBooNE results have still not been able to comprehensively rule out
the oscillation interpretation of the LSND experiment. So far the so-called
short baseline experiments with energy in the MeV range and baseline of few
meters have been probing the existence of sterile neutrinos. We show how
signatures of these extra sterile states could be obtained in TeV energy range
atmospheric neutrinos travelling distances of thousands of kilometers.
Atmospheric neutrinos in the TeV range would be detected by the upcoming
neutrino telescopes. Of course vacuum oscillations of these neutrinos would be
very small. However, we show that resonant matter effects inside the Earth
could enhance these very tiny oscillations into near-maximal transitions, which
should be hard to miss. We show that imprint of sterile neutrinos could be
unambiguously obtained in this high energy atmospheric neutrino event sample.
Not only would neutrino telescopes tell the presence of sterile neutrinos, it
should also be possible for them to distinguish between the different possible
mass and mixing scenarios with additional sterile states.Comment: 26 pages, 11 figures, Version to appear in JHE
Integrated computational analysis reveals HOX genes cluster as oncogenic drivers in head and neck squamous cell carcinoma
Alterations in homeobox (HOX) gene expression are involved in the progression of several cancer types including head and neck squamous cell carcinoma (HNSCC). However, regulation of the entire HOX cluster in the pathophysiology of HNSCC is still elusive. By using different comprehensive databases, we have identified the significance of differentially expressed HOX genes (DEHGs) in stage stratification and HPV status in the cancer genome atlas (TCGA)-HNSCC datasets. The genetic and epigenetic alterations, druggable genes, their associated functional pathways and their possible association with cancer hallmarks were identified. We have performed extensive analysis to identify the target genes of DEHGs driving HNSCC. The differentially expressed HOX cluster-embedded microRNAs (DEHMs) in HNSCC and their association with HOX-target genes were evaluated to construct a regulatory network of the HOX cluster in HNSCC. Our analysis identified sixteen DEHGs in HNSCC and determined their importance in stage stratification and HPV infection. We found a total of 55 HNSCC driver genes that were identified as targets of DEHGs. The involvement of DEHGs and their targets in cancer-associated signaling mechanisms have confirmed their role in pathophysiology. Further, we found that their oncogenic nature could be targeted by using the novel and approved anti-neoplastic drugs in HNSCC. Construction of the regulatory network depicted the interaction between DEHGs, DEHMs and their targets genes in HNSCC. Hence, aberrantly expressed HOX cluster genes function in a coordinated manner to drive HNSCC. It could provide a broad perspective to carry out the experimental investigation, to understand the underlying oncogenic mechanism and allow the discovery of new clinical biomarkers for HNSCC
Diversity and impact of rare variants in genes encoding the platelet G protein-coupled receptors
Platelet responses to activating agonists are influenced by common
population variants within or near G protein-coupled receptor (GPCR)
genes that affect receptor activity. However, the impact of rare GPCR
gene variants is unknown. We describe the rare single nucleotide variants
(SNVs) in the coding and splice regions of 18 GPCR genes in
7,595 exomes from the 1,000-genomes and Exome Sequencing
Project databases and in 31 cases with inherited platelet function disorders
(IPFDs). In the population databases, the GPCR gene target
regions contained 740 SNVs (318 synonymous, 410 missense, 7 stop
gain and 6 splice region) of which 70 % had global minor allele frequency
(MAF) < 0.05 %. Functional annotation using six computational
algorithms, experimental evidence and structural data identified
156/740 (21 %) SNVs as potentially damaging to GPCR function, most
commonly in regions encoding the transmembrane and C-terminal intracellular
receptor domains. In 31 index cases with IPFDs (Gi-pathway
defect n=15; secretion defect n=11; thromboxane pathway defect
n=3 and complex defect n=2) there were 256 SNVs in the target
regions of 15 stimulatory platelet GPCRs (34 unique; 12 with
MAF< 1 % and 22 with MAF≥ 1 %). These included rare variants predicting
R122H, P258T and V207A substitutions in the P2Y12 receptor
that were annotated as potentially damaging, but only partially explained
the platelet function defects in each case. Our data highlight
that potentially damaging variants in platelet GPCR genes have low
individual frequencies, but are collectively abundant in the population.
Potentially damaging variants are also present in pedigrees with IPFDs
and may contribute to complex laboratory phenotypes
Biomedical application of optical fibre sensors
Optical fibre sensors(OFS), as a result of their unique properties such as small size, no interference with electromagnetic radiation, high sensitivity and the ability to design multiplexed or distributed sensing systems, have found applications ranging from structural health monitoring to biomedical and point of care instrumentation. While the former represents the main commercial application for OFS, there is body of literature concerning the deployment of this versatile sensing platform in healthcare. This paper reviews the different types of OFS and their most recent applications in healthcare. It aims to help clinicians to better understand OFS technology and also provides an overview of the challenges involved in the deployment of developed technology in healthcare. Examples of the application of OFS in healthcare are discussed with particular emphasis on recently (2015–2017) published works to avoid replicating recent review papers. The majority of the work on the development of biomedical OFS stops at the laboratory stage and, with a few exceptions, is not explored in healthcare settings. OFSs have yet to fulfil their great potential in health care and methods of increasing the adoption of medical devices based on optical fibres are discussed. It is important to consider these factors early in the device development process for successful translation of the developed sensors to healthcare practice
Billiards in a general domain with random reflections
We study stochastic billiards on general tables: a particle moves according
to its constant velocity inside some domain until it hits the boundary and bounces randomly inside according to some
reflection law. We assume that the boundary of the domain is locally Lipschitz
and almost everywhere continuously differentiable. The angle of the outgoing
velocity with the inner normal vector has a specified, absolutely continuous
density. We construct the discrete time and the continuous time processes
recording the sequence of hitting points on the boundary and the pair
location/velocity. We mainly focus on the case of bounded domains. Then, we
prove exponential ergodicity of these two Markov processes, we study their
invariant distribution and their normal (Gaussian) fluctuations. Of particular
interest is the case of the cosine reflection law: the stationary distributions
for the two processes are uniform in this case, the discrete time chain is
reversible though the continuous time process is quasi-reversible. Also in this
case, we give a natural construction of a chord "picked at random" in
, and we study the angle of intersection of the process with a
-dimensional manifold contained in .Comment: 50 pages, 10 figures; To appear in: Archive for Rational Mechanics
and Analysis; corrected Theorem 2.8 (induced chords in nonconvex subdomains
Two-dimensional Quantum-Corrected Eternal Black Hole
The one-loop quantum corrections to geometry and thermodynamics of black hole
are studied for the two-dimensional RST model. We chose boundary conditions
corresponding to the eternal black hole being in the thermal equilibrium with
the Hawking radiation. The equations of motion are exactly integrated. The one
of the solutions obtained is the constant curvature space-time with dilaton
being a constant function. Such a solution is absent in the classical theory.
On the other hand, we derive the quantum-corrected metric (\ref{solution})
written in the Schwarzschild like form which is a deformation of the classical
black hole solution \cite{5d}. The space-time singularity occurs to be milder
than in classics and the solution admits two asymptotically flat black hole
space-times lying at "different sides" of the singularity. The thermodynamics
of the classical black hole and its quantum counterpart is formulated. The
thermodynamical quantities (energy, temperature, entropy) are calculated and
occur to be the same for both the classical and quantum-corrected black holes.
So, no quantum corrections to thermodynamics are observed. The possible
relevance of the results obtained to the four-dimensional case is discussed.Comment: Latex, 28 pges; minor corrections in text and abstract made and new
references adde
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