1,927 research outputs found
Frustration-induced magnetic bimerons in transition metal halide CoX2 (X = Cl, Br) monolayers
With the field of two-dimensional (2D) magnetic materials expanding rapidly,
noncollinear topological magnetic textures in 2D materials are attracting
growing interest recently. As the in-plane counterpart of magnetic skyrmions,
magnetic bimerons have the same topological advantages, but are rarely observed
in experiments. Employing first-principles calculations and Monte Carlo
simulations, we predict that the centrosymmetric transition metal halide CoX2
(X = Cl, Br) monolayers can be promising candidates for observing the
frustration-induced bimerons. These bimerons crystallize into stable triangular
lattice under an appropriate magnetic field. Compared to the skyrmions driven
by the Dzyaloshinskii-Moriya interaction or the long-ranged magnetic
dipole-dipole interactions, these frustration-induced bimerons have much
smaller size and flexible tunability. Furthermore, the biaxial strain provides
an effective method to tune the frustration and thereby to tune the bimeron
lattice. In detail, for CoCl2 monolayer, tensile strain can be applied to
generate bimeron lattice, further shrink bimeron size and increase the density
of bimerons. For CoBr2 monolayer with inherent bimeron lattice state, a unique
orientation rotation of bimeron lattice controlled by compressive strain is
predicted.Comment: 14 pages,6 figure
Enabling Runtime Verification of Causal Discovery Algorithms with Automated Conditional Independence Reasoning (Extended Version)
Causal discovery is a powerful technique for identifying causal relationships
among variables in data. It has been widely used in various applications in
software engineering. Causal discovery extensively involves conditional
independence (CI) tests. Hence, its output quality highly depends on the
performance of CI tests, which can often be unreliable in practice. Moreover,
privacy concerns arise when excessive CI tests are performed.
Despite the distinct nature between unreliable and excessive CI tests, this
paper identifies a unified and principled approach to addressing both of them.
Generally, CI statements, the outputs of CI tests, adhere to Pearl's axioms,
which are a set of well-established integrity constraints on conditional
independence. Hence, we can either detect erroneous CI statements if they
violate Pearl's axioms or prune excessive CI statements if they are logically
entailed by Pearl's axioms. Holistically, both problems boil down to reasoning
about the consistency of CI statements under Pearl's axioms (referred to as CIR
problem).
We propose a runtime verification tool called CICheck, designed to harden
causal discovery algorithms from reliability and privacy perspectives. CICheck
employs a sound and decidable encoding scheme that translates CIR into SMT
problems. To solve the CIR problem efficiently, CICheck introduces a four-stage
decision procedure with three lightweight optimizations that actively prove or
refute consistency, and only resort to costly SMT-based reasoning when
necessary. Based on the decision procedure to CIR, CICheck includes two
variants: ED-CICheck and ED-CICheck, which detect erroneous CI tests (to
enhance reliability) and prune excessive CI tests (to enhance privacy),
respectively. [abridged due to length limit
Ursodeoxycholic Acid Inhibits Glioblastoma Progression via Endoplasmic Reticulum Stress Related Apoptosis and Synergizes with the Proteasome Inhibitor Bortezomib
Ursodeoxycholic acid (UDCA) has demonstrated cancer suppressive potential in several tumors. Here, we investigated the antitumor potential and biochemical mechanism of UDCA on glioblastoma multiforme (GBM), the deadliest form of brain cancer with a median survival of 15 months. Cell viability was assessed using the CCK-8 and colony forming assays. Expression profiles were obtained using RNA sequencing, and PCR and Western blot were used to validate changes in related markers at the RNA and protein levels. Flow cytometry was used to examine cell cycle, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS). UDCA inhibited GBM cell viability in a dose- and time-dependent manner. Flow cytometry demonstrated that cells were arrested in the G1 phase and underwent apoptosis. The RNA sequencing results showed UDCA treatment in part targeted gene expression related to mitochondria and endoplasmic reticulum (ER). UDCA indeed led to decreased MMP, overproduction of ROS, and ER stress. Three critical ER stress sensors ATF6, IRE1α, and PERK were increased in the acute phase. Additionally, combining UDCA with the proteasome inhibitor bortezomib (BTZ) achieved a synergistic effect through enhancing the PERK/ATF4/CHOP pathway and protracting ER stress. UDCA inhibited GBM progression, and the combination with BTZ achieved a synergistic effect via protracted ER stress. Thus, UDCA, alone or with combination of BTZ, shows promise as a possible therapeutic agent for the treatment of GBM.acceptedVersio
Revealing the mystery of the double charm tetraquark in collision
A novel approach is proposed to probe the nature of the double charm
tetraquark through the measurement of production asymmetry between
and in collisions. When comparing two
theoretical pictures, the compact tetraquark and molecular pictures, we find
that the compact tetraquark picture exhibits a significantly larger production
asymmetry and an order of magnitude lower total cross section compared to the
molecular picture, enabling the unambiguous determination of the tetraquark's
internal structure. Additionally, distinctive differences in the transverse
momentum () and rapidity () distributions of
and cross sections emerge, particularly at
and . The difference
between particles and antiparticles in a large rapidity region is attributed to
the behavior of the residual diquarks within the proton. Our work extends
to the exploration of other double heavy tetraquark candidates, offering a
versatile approach to advance our understanding of exotic hadronic states in
particle physics.Comment: 6 pages, 3 figure
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