1,050 research outputs found
On quasi modules at infinity for vertex algebras
A theory of quasi modules at infinity for (weak) quantum vertex algebras
including vertex algebras was previously developed in \cite{li-infinity}. In
this current paper, quasi modules at infinity for vertex algebras are
revisited. Among the main results, we extend some technical results, to fill in
a gap in the proof of a theorem therein, and we obtain a commutator formula for
general quasi modules at infinity and establish a version of the converse of
the aforementioned theorem.Comment: 18 page
Anomalous hybridization of spectral winding topology in quantized steady-state responses
Quantized response is one distinguishing feature of a topological system. In
non-Hermitian systems, the spectral winding topology yields quantized
steady-state response. By considering two weakly coupled non-Hermitian chains,
we discover that the spectral winding topology of one chain can be probed by a
steady-state response defined solely on the other chain, even when other
important properties, e.g., {energetics} and entanglement entropy, indicate
that eigen-solutions are effectively {not hybridized} between the two chains.
This intriguing phenomenon, as carefully investigated in a large parameter
space with a varying system size, not only offers a new angle to understand
interchain signal propagation in a non-Hermitian setting but also reveals
unexpected physics of spectral winding topology vs quantized response.Comment: 10 pages, 9 figures, comments are welcom
System identification of rubber-bearing isolators based on experimental tests
Rubber-bearing isolation systems have been used in buildings and bridges. These base isolation systems will become more popular in the future due to their ability to reduce significantly the structural responses induced by earthquakes and other dynamic loads. To ensure the integrity and safety of these base isolation systems, a structural health monitoring system is needed. One important problem in the structural health monitoring is the identification of the system and the detection of damages. This problem is more challenging for the rubberbearing isolation systems because of their nonlinear behavior. In this paper, experimental studies have been conducted for the system identification of nonlinear hysteretic rubberbearings. Experimental tests of a rubber-bearing isolator under El Centro and Kobe earthquakes have been performed. The Bouc-Wen models with 3, 5 and 6 unknown parameters, respectively, have been investigated to represent the hysteretic behavior of rubber-bearing isolators. The extended Kalman filter (EKF) approach has been used to identify the nonlinear parameters of the Bouc-Wen models for the rubber-bearing isolators. Our experimental studies demonstrate that the Bouc-Wen models are capable of describing the nonlinear behavior of rubber-bearing isolators, and that the EKF approach is effective in identifying nonlinear hysteretic parameters
TetraÂaquaÂbisÂ[5-(3-pyridÂyl)tetraÂzolido-κN 5]zinc(II) tetraÂhydrate
The title compound, [Zn(C6H4N5)2(H2O)4]·4H2O, was synthesized by the hydroÂthermal reaction of Zn(CH3COO)2·2H2O with 3-(2H-tetraÂzol-5-yl)pyridine. The ZnII ion is located on an inversion center and is coordinated by two pyridine N atoms from two 5-(3-pyridÂyl)tetraÂzolide ligands and four coordinated water molÂecules in a slightly distorted octaÂhedral geometry. The dihedral angle between the pyridine and tetraÂzole rings is 9.920 (7)°. In the crystal, molÂecules are linked into a three-dimensional network by interÂmolecular O—H⋯O and O—H⋯N hydrogen bonds involving the tetraÂzole group N atoms, the aqua ligands and solvent water molÂecules
Biphenyl-3,3′-dicarbÂoxyÂlic acid
The asymmetric unit of the title compound, C14H10O4, contains one half molÂecule, the complete molÂecule being generated by a twofold axis. The two benzene rings form a dihedral angle of 43.11 (5)°. InterÂmolecular O—H⋯O hydrogen bonds link the molÂecules into one-dimensional zigzag chains. These chains are further connected into two-dimensional supraÂmolecular layers by weak π–π stacking interÂactions between neighbouring benzene rings, with centroid–centroid distances of 3.7648 (8) Å
OnionNet-2: A Convolutional Neural Network Model for Predicting Protein-Ligand Binding Affinity based on Residue-Atom Contacting Shells
One key task in virtual screening is to accurately predict the binding
affinity () of protein-ligand complexes. Recently, deep learning
(DL) has significantly increased the predicting accuracy of scoring functions
due to the extraordinary ability of DL to extract useful features from raw
data. Nevertheless, more efforts still need to be paid in many aspects, for the
aim of increasing prediction accuracy and decreasing computational cost. In
this study, we proposed a simple scoring function (called OnionNet-2) based on
convolutional neural network to predict . The protein-ligand
interactions are characterized by the number of contacts between protein
residues and ligand atoms in multiple distance shells. Compared to published
models, the efficacy of OnionNet-2 is demonstrated to be the best for two
widely used datasets CASF-2016 and CASF-2013 benchmarks. The OnionNet-2 model
was further verified by non-experimental decoy structures from docking program
and the CSAR NRC-HiQ data set (a high-quality data set provided by CSAR), which
showed great success. Thus, our study provides a simple but efficient scoring
function for predicting protein-ligand binding free energy.Comment: 7 pages, 4 figures, 1 tabl
Rapamycin sensitizes T-ALL cells to dexamethasone-induced apoptosis
<p>Abstract</p> <p>Background</p> <p>Glucocorticoid (GC) resistance is frequently seen in acute lymphoblastic leukemia of T-cell lineage (T-ALL). In this study we investigate the potential and mechanism of using rapamycin to restore the sensitivity of GC-resistant T-ALL cells to dexamethasone (Dex) treatment.</p> <p>Methods</p> <p>Cell proliferation was detected by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay. Fluorescence-activated cell sorting (FACS) analysis was used to analyze apoptosis and cell cycles. Western blot analysis was performed to test the expression of the downstream effector proteins of mammalian target of rapamycin (mTOR), the cell cycle regulatory proteins, and apoptosis associated proteins.</p> <p>Results</p> <p>10 nM rapamycin markedly increased GC sensitivity in GC-resistant T-ALL cells and this effect was mediated, at least in part, by inhibition of mTOR signaling pathway. Cell cycle arrest was associated with modulation of G<sub>1</sub>-S phase regulators. Both rapamycin and Dex can induce up-regulation of cyclin-dependent kinase (CDK) inhibitors of p21 and p27 and co-treatment of rapamycin with Dex resulted in a synergistic induction of their expressions. Rapamycin did not obviously affect the expression of cyclin A, whereas Dex induced cyclin A expression. Rapamycin prevented Dex-induced expression of cyclin A. Rapamycin had a stronger inhibition of cyclin D1 expression than Dex. Rapamycin enhanced GC-induced apoptosis and this was not achieved by modulation of glucocorticoid receptor (GR) expression, but synergistically up-regulation of pro-apoptotic proteins like caspase-3, Bax, and Bim, and down-regulation of anti-apoptotic protein of Mcl-1.</p> <p>Conclusion</p> <p>Our data suggests that rapamycin can effectively reverse GC resistance in T-ALL and this effect is achieved by inducing cell cycles arrested at G<sub>0</sub>/G<sub>1 </sub>phase and activating the intrinsic apoptotic program. Therefore, combination of mTOR inhibitor rapamycin with GC containing protocol might be an attracting new therapeutic approach for GC resistant T-ALL patients.</p
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