2,945 research outputs found
Dependence of quantum correlations of twin beams on pump finesse of optical parametric oscillator
The dependence of quantum correlation of twin beams on the pump finesse of an
optical parametric oscillator is studied with a semi-classical analysis. It is
found that the phase-sum correlation of the output signal and idler beams from
an optical parametric oscillator operating above threshold depends on the
finesse of the pump field when the spurious pump phase noise generated inside
the optical cavity and the excess noise of the input pump field are involved in
the Langevin equations. The theoretical calculations can explain the previously
experimental results, quantitatively.Comment: 27 pages, 8 figure
Deep Dyna-Q: Integrating Planning for Task-Completion Dialogue Policy Learning
Training a task-completion dialogue agent via reinforcement learning (RL) is
costly because it requires many interactions with real users. One common
alternative is to use a user simulator. However, a user simulator usually lacks
the language complexity of human interlocutors and the biases in its design may
tend to degrade the agent. To address these issues, we present Deep Dyna-Q,
which to our knowledge is the first deep RL framework that integrates planning
for task-completion dialogue policy learning. We incorporate into the dialogue
agent a model of the environment, referred to as the world model, to mimic real
user response and generate simulated experience. During dialogue policy
learning, the world model is constantly updated with real user experience to
approach real user behavior, and in turn, the dialogue agent is optimized using
both real experience and simulated experience. The effectiveness of our
approach is demonstrated on a movie-ticket booking task in both simulated and
human-in-the-loop settings.Comment: 11 pages, 8 figures, Accepted in ACL 201
[(2-{[3′,6′-Bis(ethylÂamino)-2′,7′-dimethyl-3-oxospiroÂ[1H-isoindole-1,9′-9H-xanthen]-2-yl}ethÂyl)aminoÂmethÂyl]phenol
The title compound, C35H38N4O3, was prepared as a spiroÂlactam ring formation of rhodamine dye for comparison with a ring-opened form. The xanthene ring system is approximately planar. The dihedral angles formed by the spiroÂlactam and phenol rings with the xanthene ring system are 85.7 and 109.4°, respectively. Each of the molÂecules in the crystal structure contains one intraÂmolecular O—H⋯N hydrogen bond, and they form interÂmolecular N—H⋯O hydrogen-bonded chains along the [100] direction. Weak interÂmolecular C—H⋯O hydrogen-bonding contacts connect the infinite chains via crystallographic inversion centres to form a two-dimensional network
Downregulation of CD147 expression alters cytoskeleton architecture and inhibits gelatinase production and SAPK pathway in human hepatocellular carcinoma cells
<p>Abstract</p> <p>Background</p> <p>CD147 plays a critical role in the invasive and metastatic activity of hepatocellular carcinoma (HCC) cells by stimulating the surrounding fibroblasts to express matrix metalloproteinases (MMPs). Tumor cells adhesion to extracellular matrix (ECM) proteins is the first step to the tumor metastasis. MMPs degrade the ECM to promote tumor metastasis. The aim of this study is to investigate the effects of small interfering RNA (siRNA) against CD147 (si-CD147) on hepatocellular carcinoma cells' (SMMC-7721) architecture and functions.</p> <p>Methods</p> <p>Flow cytometry and western blot assays were employed to detect the transfection efficiency of si-CD147. Confocal microscopy was used to determine the effects of si-CD147 on SMMC-7721 cells' cytoskeleton. Invasion assay, gelatin zymography and cell adhesion assay were employed to investigate the effects of si-CD147 on SMMC-7721 cells' invasion, gelatinase production and cell adhesive abilities. Western blot assay was utilized to detect the effects of si-CD147 on focal adhesion kinase (FAK), vinculiln and mitogen-activated protein kinase (MAPK) expression in SMMC-7721 cells.</p> <p>Results</p> <p>Downregulation of CD147 gene induced the alteration of SMMC-7721 cell cytoskeleton including actin, microtubule and vimentin filaments, and inhibited gelatinase production and expression, cells invasion, FAK and vinculin expression. si-CD147 also blocked SMMC-7721 cells adhesion to collagen IV and phosphorylation level of SAPK/JNKs. SAPK/JNKs inhibitor SP600125 inhibited gelatinase production and expression.</p> <p>Conclusion</p> <p>CD147 is required for normal tumor cell architecture and cell invasion. Downregulation of CD147 affects HCC cell structure and function. Moreover, the alteration of cell behavior may be related to SAPK/JNK Pathway. siRNA against CD147 may be a possible new approach for HCC gene therapy.</p
DFTTK: Density Functional Theory Tool Kit for High-throughput Calculations of Thermodynamic Properties at Finite Temperatures
In this work, we present a software package in Python for high-throughput
first-principles calculations of thermodynamic properties at finite
temperatures, which we refer to as DFTTK (Density Functional Theory Tool Kit).
DFTTK is based on the atomate package and integrates our experiences in the
last decades on the development of theoretical methods and computational
software. It includes task submissions on all major operating systems and task
execution on high-performance computing environments. The distribution of the
DFTTK package comes with examples of calculations of phonon density of states,
heat capacity, entropy, enthalpy, and free energy under the quasi-harmonic
phonon scheme for the stoichiometric phases of Al, Ni, Al3Ni, AlNi, AlNi3,
Al3Ni4, and Al3Ni5, and the fcc solution phases treated using the special
quasirandom structures at the compositions of Al3Ni, AlNi, and AlNi3.Comment: 49 pages, 18 figure
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