200 research outputs found
On the maxima of suprema of dependent Gaussian models
In this paper, we study the asymptotic distribution of the maxima of suprema
of dependent Gaussian processes with trend. For different scales of the time
horizon we obtain different normalizing functions for the convergence of the
maxima. The obtained results not only have potential applications in estimating
the delay of certain Gaussian fork-join queueing systems but also provide
interesting insights to the extreme value theory for triangular arrays of
random variables with row-wise dependence.Comment: 21 page
Jahn-Teller distortion driven ferromagnetism in a perovskite fluoride monolayer
The Jahn-Teller distortion and the resulting orbital order usually cause some
fascinating correlated electronic behaviors, and generally lead to
antiferromagnetism in perovskite bulks. Here we demonstrate that the
Jahn-Teller distortion present in the perovskite fluoride KCrF bulk can be
retained to the two-dimensional limit, resulting in a staggered orbital order
and ferromagnetism in the perovskite monolayer. Octahedral tilt and rotation
distortion also appear in the ground-state structure of the perovskite
monolayer, which have minor effects on the electronic and magnetic properties
with respect to the Jahn-Teller distortion. In addition, in the prototype phase
without structural distortion, the partial occupation of the orbitals
leads to a ferromagnetic metallic state. This work facilitates the design of
two-dimensional ferromagnets and functional properties based on Jahn-Teller
distortion and orbital orderComment: 8 pages, 5 figures, 1 tabl
Anti-PD-L1/TGF-βR fusion protein (SHR-1701) overcomes disrupted lymphocyte recovery-induced resistance to PD-1/PD-L1 inhibitors in lung cancer
Background
Second-generation programmed cell death-protein 1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors, such as bintrafusp alfa (M7824), SHR-1701, and YM101, have been developed to simultaneously block PD-1/PD-L1 and transforming growth factor-beta/transforming growth factor-beta receptor (TGF-β/TGF-βR). Consequently, it is necessary to identify predictive factors of lung cancer patients who are not only resistant to PD-1/PD-L1 inhibitors but also sensitive to bifunctional drugs. The purpose of this study was to search for such predictors.
Methods
Multivariable Cox regression was used to study the association between the clinical outcome of treatment with PD-1/PD-L1 inhibitors and lymphocyte recovery after lymphopenia in lung cancer patients. Murine CMT167 lung cancer cells were engineered to express the firefly luciferase gene and implanted orthotopically in the lung of syngeneic mice. Bioluminescence imaging, flow cytometry, and immunohistochemistry were employed to determine response to immunotherapy and function of tumor-infiltrating immune cells.
Results
For lung cancer patients treated with anti-PD-1/PD-L1 antibodies, poor lymphocyte recovery was associated with a shorter progression-free survival (PFS; P < 0.001), an accumulation of regulatory T cells (Tregs), and an elimination of CD8+ T cells in the peripheral blood. Levels of CD8+ T cells and Treg cells were also imbalanced in the tumors and peripheral immune organs of mice with poor lymphocyte recovery after chemotherapy. Moreover, these mice failed to respond to anti-PD-1 antibodies but remained sensitive to the anti-PD-L1/TGF-βR fusion protein (SHR-1701). Consistently, SHR-1701 but not anti-PD-1 antibodies, markedly enhanced IFN-γ production and Ki-67 expression in peripheral CD8+ T cells from patients with impaired lymphocyte recovery.
Conclusions
Lung cancer patients with poor lymphocyte recovery and suffering from persistent lymphopenia after previous chemotherapy are resistant to anti-PD-1/PD-L1 antibodies but might be sensitive to second-generation agents such as SHR-1701.publishedVersio
MeV Astrophysical Spectroscopic Surveyor (MASS): A Compton Telescope Mission Concept
We propose a future mission concept, the MeV Astrophysical Spectroscopic
Surveyor (MASS), which is a large area Compton telescope using 3D position
sensitive cadmium zinc telluride (CZT) detectors optimized for emission line
detection. The payload consists of two layers of CZT detectors in a misaligned
chessboard layout, with a total geometric area of 4096 cm for on-axis
observations. The detectors can be operated at room-temperature with an energy
resolution of 0.6\% at 0.662 MeV. The in-orbit background is estimated with a
mass model. At energies around 1 MeV, a line sensitivity of about
photons cm s can be obtained with a 1 Ms observation. The main
science objectives of MASS include nucleosynthesis in astrophysics and high
energy astrophysics related to compact objects and transient sources. The
payload CZT detectors weigh roughly 40 kg, suggesting that it can be integrated
into a micro- or mini-satellite. We have constructed a pathfinder, named as
MASS-Cube, to have a direct test of the technique with 4 detector units in
space in the near future.Comment: accepted for publication in Experimental Astronom
Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst
The recently discovered neutron star transient Swift J0243.6+6124 has been
monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT).
Based on the obtained data, we investigate the broadband spectrum of the source
throughout the outburst. We estimate the broadband flux of the source and
search for possible cyclotron line in the broadband spectrum. No evidence of
line-like features is, however, found up to . In the absence of
any cyclotron line in its energy spectrum, we estimate the magnetic field of
the source based on the observed spin evolution of the neutron star by applying
two accretion torque models. In both cases, we get consistent results with
, and peak luminosity of which makes the source the first Galactic ultraluminous
X-ray source hosting a neutron star.Comment: publishe
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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