141 research outputs found
Finite-Time Boundedness of Markov Jump System with Piecewise-Constant Transition Probabilities via Dynamic Output Feedback Control
This paper first investigates the problem of finite-time boundedness of Markovian jump system with piecewise-constant transition probabilities via dynamic output feedback control, which leads to both stochastic jumps and deterministic switches. Based on stochastic Lyapunov functional, the concept of finite-time boundedness, average dwell time, and the coupling relationship among time delays, several sufficient conditions are established for finite-time boundedness and H∞ filtering finite-time boundedness. The system trajectory stays within a prescribed bound. Finally, an example is given to illustrate the efficiency of the proposed method
Wide-range continuous tuning of the thermal conductivity of films via room-temperature ion-gel gating
Solid-state control of the thermal conductivity of materials is of
exceptional interest for novel devices such as thermal diodes and switches.
Here, we demonstrate the ability to continuously tune the thermal conductivity
of nanoscale films of (LSCO) by a factor
of over 5, via a room-temperature electrolyte-gate-induced non-volatile
topotactic phase transformation from perovskite (with ) to
an oxygen-vacancy-ordered brownmillerite phase (with ), accompanied
by a metal-insulator transition. Combining time-domain thermoreflectance and
electronic transport measurements, model analyses based on molecular dynamics
and Boltzmann transport, and structural characterization by X-ray diffraction,
we uncover and deconvolve the effects of these transitions on heat carriers,
including electrons and lattice vibrations. The wide-range continuous
tunability of LSCO thermal conductivity enabled by low-voltage (below 4 V)
room-temperature electrolyte gating opens the door to non-volatile dynamic
control of thermal transport in perovskite-based functional materials, for
thermal regulation and management in device applications
Strong Interplay between Stripe Spin Fluctuations, Nematicity and Superconductivity in FeSe
Elucidating the microscopic origin of nematic order in iron-based
superconducting materials is important because the interactions that drive
nematic order may also mediate the Cooper pairing. Nematic order breaks
fourfold rotational symmetry in the iron plane, which is believed to be driven
by either orbital or spin degrees of freedom. However, as the nematic phase
often develops at a temperature just above or coincides with a stripe magnetic
phase transition, experimentally determining the dominant driving force of
nematic order is difficult. Here, we use neutron scattering to study
structurally the simplest iron-based superconductor FeSe, which displays a
nematic (orthorhombic) phase transition at K, but does not order
antiferromagnetically. Our data reveal substantial stripe spin fluctuations,
which are coupled with orthorhombicity and are enhanced abruptly on cooling to
below . Moreover, a sharp spin resonance develops in the superconducting
state, whose energy (~4 meV) is consistent with an electron boson coupling mode
revealed by scanning tunneling spectroscopy, thereby suggesting a spin
fluctuation-mediated sign-changing pairing symmetry. By normalizing the dynamic
susceptibility into absolute units, we show that the magnetic spectral weight
in FeSe is comparable to that of the iron arsenides. Our findings support
recent theoretical proposals that both nematicity and superconductivity are
driven by spin fluctuations.Comment: 19 pages, 8 figure
The complete chloroplast genome of common walnut (Juglans regia)
Common walnut (Juglans regia L.) is cultivated in temperate regions worldwide for its wood and nuts. The complete chloroplast genome of J. regia was sequenced using the Illumina MiSeq platform. This is the first complete chloroplast sequence for the Juglandaceae, a family that includes numerous species of economic importance. The chloroplast genome of J. regia was 160 367 bp in length, with 36.11% GC content. It contains a pair of inverted repeats (26 035 bp) which were separated by a large single copy (89 872 bp) and a small single copy region (18 425 bp). A total of 137 genes were annotated, which included 86 protein-coding genes, three pseudogenes (two ycf15 and one infA), 40 tRNA genes and eight rRNA genes. The neighbour-joining phylogenetic analysis with the reported chloroplast genomes showed that common walnut chloroplasts are most closely related to those of the Fagaceae family
Altered expression of circadian clock gene, mPer1, in mouse brain and kidney under morphine dependence and withdrawal
Every physiological function in the human body exhibits some form of circadian rhythmicity. Under pathological conditions, however, circadian rhythmicity may be dusrupted. Patients infected with HIV or addicted to drugs of abuse often suffer from sleep disorders and altered circadian rhythms. Early studies in Drosophila suggested that drug seeking behavior might be related to the expression of certain circadian clock genes. Our previous research showed that conditioned place preference with morphine treatment was altered in mice lacking the Period-1 (mPer1) circadian clock gene. Thus, we sought to investigate whether morphine treatment could alter the expression of mPer1, especially in brain regions outside the SCN and in peripheral tissues. Our results using Western blot analysis showed that the mPER1 immunoreactivity exhibited a strong circadian rhythm in the brains of the control (Con), morphine-dependent (MD), and morphine-withdrawal (MW) mice. However, the phase of the circadian rhythm of mPER1 expression in the brains of MD mice significantly differed from that of the Con mice (p < 0.05). In contrast to mPER1 expression in the brain, the circadian rhythm of mPER1 immunoreactivity in the kidneys was abolished after morphine administration, whereas the Con mice maintained robust circadian rhythmicity of mPER1 in the kidney. Therefore, the effect of morphine on the circadian clock gene mPer1 may vary among different organs, resulting in desynchronization of circadian function between the SCN and peripheral organs. Originally published Journal of Circadian Rhythms, Vol. 4, No. 9, Aug 2006
Photometric Variability in the CSTAR Field: Results From the 2008 Data Set
The Chinese Small Telescope ARray (CSTAR) is the first telescope facility
built at Dome A, Antarctica. During the 2008 observing season, the installation
provided long-baseline and high-cadence photometric observations in the i-band
for 18,145 targets within 20 deg2 CSTAR field around the South Celestial Pole
for the purpose of monitoring the astronomical observing quality of Dome A and
detecting various types of photometric variability. Using sensitive and robust
detection methods, we discover 274 potential variables from this data set, 83
of which are new discoveries. We characterize most of them, providing the
periods, amplitudes and classes of variability. The catalog of all these
variables is presented along with the discussion of their statistical
properties.Comment: 38 pages, 11 figures, 4 tables; Accepted for publication in ApJ
Early on‐demand drainage or standard management for acute pancreatitis patients with acute necrotic collections and persistent organ failure: a pilot randomized controlled trial
Background/Purpose
The current standard care for acute pancreatitis with acute necrotic collections (ANC) is to postpone invasive intervention for four weeks when indicated. However, in patients with persistent organ failure (POF), this delayed approach may prolong organ failure. In this study, we aimed to assess the feasibility and safety of earlier drainage for acute pancreatitis patients with ANC and POF.
Methods
A single‐center, randomized controlled trial was conducted. Eligible patients were randomly assigned to either the early on‐demand (EOD) group or the standard management(SM) group. Within 21 days of randomization, early drainage was triggered by unremitted or worsening organ failure in the EOD group. The primary endpoint was a composite of major complications/death during 90‐days follow‐up.
Results
30 patients were randomized. Within 21 days of randomization, 8/15 patients (53%) in the EOD group underwent percutaneous drainage, while 4/15 patients (27%) in the SM group did so (P=0.26). The primary outcome occurred in 3/15 (20%) patients in the EOD group and 7/15(46.7%) in the controls (p=0.25, relative risk 0.43, 95%CI 0.14 to1.35)
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