2,521 research outputs found
Recovery of baseline renal function after treatment for prolonged in-stent artery thrombosis, in a COVID-19 positive patient: a case report
Objective: Acute renal in-stent thrombosis is common, especially after complex endovascular treatments, or in case of risk factors such as Covid-19 infection. Irreversible renal damage occurred when the renal artery was occluded for more than 3 hours. In this case, we present a case of renal function recovery after
thromboaspiration of a renal stent thrombosis for more than 72 hours.
Case presentation: A 88-year-old man who tested positive for COVID-19 presented to the emergency room with dyspnea and anuria. He referred a previous complex endovascular intervention with the triple chimney technique (ChEVAR). More than 72 hours passed between the onset of symptoms to the diagnosis of acute renal intra-stent thrombosis. He underwent urgent thromboaspiration with neurovascular devices returning to his baseline renal function.
Conclusion: Despite the prolonged ischemia, renal revascularization with thromboaspiration restored renal function and rescued the remaining renal parenchym
Dynamic instabilities in resonant tunneling induced by a magnetic field
We show that the addition of a magnetic field parallel to the current induces
self sustained intrinsic current oscillations in an asymmetric double barrier
structure. The oscillations are attributed to the nonlinear dynamic coupling of
the current to the charge trapped in the well, and the effect of the external
field over the local density of states across the system. Our results show that
the system bifurcates as the field is increased, and may transit to chaos at
large enough fields.Comment: 4 pages, 3 figures, accepted in Phys. Rev. Letter
Molecular Gas, Dust and Star Formation in Galaxies: II. Dust properties and scalings in \sim\ 1600 nearby galaxies
We aim to characterize the relationship between dust properties. We also aim
to provide equations to estimate accurate dust properties from limited
observational datasets.
We assemble a sample of 1,630 nearby (z<0.1) galaxies-over a large range of
Mstar, SFR - with multi-wavelength observations available from wise, iras,
planck and/or SCUBA. The characterization of dust emission comes from SED
fitting using Draine & Li dust models, which we parametrize using two
components (warm and cold ). The subsample of these galaxies with global
measurements of CO and/or HI are used to explore the molecular and/or atomic
gas content of the galaxies.
The total Lir, Mdust and dust temperature of the cold component (Tc) form a
plane that we refer to as the dust plane. A galaxy's sSFR drives its position
on the dust plane: starburst galaxies show higher Lir, Mdust and Tc compared to
Main Sequence and passive galaxies. Starburst galaxies also show higher
specific Mdust (Mdust/Mstar) and specific Mgas (Mgas/Mstar). The Mdust is more
closely correlated with the total Mgas (atomic plus molecular) than with the
individual components. Our multi wavelength data allows us to define several
equations to estimate Lir, Mdust and Tc from one or two monochromatic
luminosities in the infrared and/or sub-millimeter.
We estimate the dust mass and infrared luminosity from a single monochromatic
luminosity within the R-J tail of the dust emission, with errors of 0.12 and
0.20dex, respectively. These errors are reduced to 0.05 and 0.10 dex,
respectively, if the Tc is used. The Mdust is correlated with the total Mism
(Mism \propto Mdust^0.7). For galaxies with Mstar 8.5<log(Mstar/Msun) < 11.9,
the conversion factor \alpha_850mum shows a large scatter (rms=0.29dex). The SF
mode of a galaxy shows a correlation with both the Mgass and Mdust: high
Mdust/Mstar galaxies are gas-rich and show the highest SFRs.Comment: 24 pages, 28 figures, 6 tables, Accepted for publication in A&
A mesoscopic ring as a XNOR gate: An exact result
We describe XNOR gate response in a mesoscopic ring threaded by a magnetic
flux . The ring is attached symmetrically to two semi-infinite
one-dimensional metallic electrodes and two gate voltages, viz, and
, are applied in one arm of the ring which are treated as the inputs of
the XNOR gate. The calculations are based on the tight-binding model and the
Green's function method, which numerically compute the conductance-energy and
current-voltage characteristics as functions of the ring-to-electrode coupling
strength, magnetic flux and gate voltages. Our theoretical study shows that,
for a particular value of () (, the elementary
flux-quantum), a high output current (1) (in the logical sense) appears if both
the two inputs to the gate are the same, while if one but not both inputs are
high (1), a low output current (0) results. It clearly exhibits the XNOR gate
behavior and this aspect may be utilized in designing an electronic logic gate.Comment: 8 pages, 5 figure
Aharonov-Bohm Effect for Parallel and T-shaped Double Quantum Dots
We investigate the Aharonov-Bohm (AB) effect for the double quantum dots in
the Kondo regime using the slave-boson mean-field approximation. In contrast to
the non-interacting case, where the AB oscillation generally has the period of
4 when the two-subring structure is formed via the interdot tunneling
, we find that the AB oscillation has the period of 2 in the Kondo
regime. Such effects appear for the double quantum dots close to the T-shaped
geometry even in the charge-fluctuation regime. These results follow from the
fact that the Kondo resonance is always fixed to the Fermi level irrespective
of the detailed structure of the bare dot-levels.Comment: 3 pages, 4 figures; minor change
International health and Hispanic culture
This research project focuses on the interrelations between health and culture in the Hispanic countries and their impact on individuals and communities. The research explores medical diseases and conditions, people\u27s traditions, beliefs, and perceptions related to concerns related to health issues, home remedies, behavior change, family and community, doctor-patient relationship, and social aspects of public health (ethnicity, gender, poverty). Students will have the opportunity to travel to the Dominican Republic with the researchers and participate in service learning activities to help Hispanic communities and collect data for this research project. CI students will lead the following research topics in the Dominican Republic: 1) self-medication, low-income population accessibility to medicines, and the governmental pharmacy system (Boticas Populares) (Caleb Addis); 2) domestic violence as a public health concern (Aliyah Anjarwalla); 3) how chronic diseases are promoted, prevented and controlled (Deepti Athavale); 4) hepatitis A as a public health concern (Thomas Cotton); 5) challenges/barriers of people with disabilities to access physical therapy services (Breci Davis) ; 6) cultural and socio-economic determinants of childhood obesity (Michelle Fuentes); 7)medical equipment maintenance at public health care settings: advantages and disadvantages of donated equipment (Hannah Haire); 8) challenges and opportunities for the implementation of the HIV Vertical Transmission Prevention Program (Ashley Jamison); and 9) a behavioral theory analysis of drug abuse (Katherine Orellana)
Posible declinaci\uf3n poblacional de la mariposa Papilio polyxenes americus Kollar (Lepidoptera: Papilionidae) en el valle intra-andino de M\ue9rida, Venezuela
Orellana A, Erazo M. 2002. Possible population decline of the
swallowtail Papilio polyxenes americus Kollar (Lepidoptera:
Papilionidae) in the intra-Andean valley of M\ue9rida, Venezuela.
Entomotropica 17(2):189-190. Since the second half of the 90's, the
swallowtail butterfly, Papilio polyxenes americus Kollar, 1859, a
formerly common species, has become scarce or may even be disappearing
from the Chama river basin of Andean M\ue9rida, Venezuela. No
concrete explanations are given for the fact, but it is presumed that
it may be linked to human activities, especially the use of pesticides.Orellana A, Erazo M. 2002. Posible declinaci\uf3n poblacional de la
mariposa Papilio polyxenes americus Kollar (Lepidoptera:
Papilionidae) en el valle intra-andino de M\ue9rida, Venezuela.
Entomotropica 17(2):189-190. A partir de la segunda mitad de los
a\uf1os 1990 Papilio polyxenes americus Kollar, 1850, anteriormente
com\ufan, parece estar desapareciendo de la zona media del r\uedo
Chama, en el estado andino de M\ue9rida, Venezuela. Esto se sustenta
en observaciones no sistem\ue1ticas, pero continuas. No se ofrecen
explicaciones concretas para esta disminuci\uf3n, pero pudiera estar
vinculada a actividades humanas, especialmente el uso de plaguicidas
Transport through a quantum wire with a side quantum-dot array
A noninteracting quantum-dot array side-coupled to a quantum wire is studied.
Transport through the quantum wire is investigated by using a noninteracting
Anderson tunneling Hamiltonian. The conductance at zero temperature develops an
oscillating band with resonances and antiresonances due to constructive and
destructive interference in the ballistic channel, respectively. Moreover, we
have found an odd-even parity in the system, whose conductance vanishes for an
odd number of quantum dots while becomes for an even number. We
established an explicit relation between this odd-even parity, and the
positions of the resonances and antiresonances of the conductivity with the
spectrum of the isolated QD arrayComment: 5 pages, 4 figures, submitted to PR
Physics and chemistry of hydrogen in the vacancies of semiconductors
Hydrogen is well known to cause electrical passivation of lattice vacancies in semiconductors. This effect follows from the chemical passivation of the dangling bonds. Recently it was found that H in the carbon vacancy of SiC forms a three-center bond with two silicon neighbors in the vacancy, and gives rise to a new electrically active state. In this paper we examine hydrogen in the anion vacancies of BN, AlN, and GaN. We find that three-center bonding of H is quite common and follows clear trends in terms of the second-neighbor distance in the lattice, the typical (two-center) hydrogen-host-atom bond length, the electronegativity difference between host atoms and hydrogen, as well as the charge state of the vacancy. Three-center bonding limits the number of H atoms a nitrogen vacancy can capture to two, and prevents electric passivation in GaAs as well
Optimal treatment allocations in space and time for on-line control of an emerging infectious disease
A key component in controlling the spread of an epidemic is deciding where, whenand to whom to apply an intervention.We develop a framework for using data to informthese decisionsin realtime.We formalize a treatment allocation strategy as a sequence of functions, oneper treatment period, that map up-to-date information on the spread of an infectious diseaseto a subset of locations where treatment should be allocated. An optimal allocation strategyoptimizes some cumulative outcome, e.g. the number of uninfected locations, the geographicfootprint of the disease or the cost of the epidemic. Estimation of an optimal allocation strategyfor an emerging infectious disease is challenging because spatial proximity induces interferencebetween locations, the number of possible allocations is exponential in the number oflocations, and because disease dynamics and intervention effectiveness are unknown at outbreak.We derive a Bayesian on-line estimator of the optimal allocation strategy that combinessimulation–optimization with Thompson sampling.The estimator proposed performs favourablyin simulation experiments. This work is motivated by and illustrated using data on the spread ofwhite nose syndrome, which is a highly fatal infectious disease devastating bat populations inNorth America
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