569 research outputs found
Method and Device for Removal of Cryoprotectant from Cryopreserved Biological Cells and Tissues
Novel methods and devices for removing cryoprotectant from cryoprotectant-containing liquids, and from cells residing therein, are disclosed. In one aspect, the method comprises passing the cryoprotectant-containing liquid through at least one semipermeable hollow fiber membrane contained in a hollow module in a first direction, while passing a liquid which is substantially free of cryoprotectant through the hollow module in a second direction to remove cryoprotectant across a diffusion gradient. In another aspect, a device is described for removing cryoprotectant from a liquid, comprising a hollow module with at least one semipermeable hollow fiber membrane therein for accomplishing such counter-current diffusion removal of cryprotectant. A software program is also provided for predicting optimal flow rates through the device of the invention, thereby allowing optimal cryoprotectant removal regardless of the cryoprotectant used or the material from which the semipermeable hollow fiber membrane is fabricated
Next-to-leading order QCD predictions for graviton and photon associated production in the Large Extra Dimensions model at the LHC
We present the calculations of the complete next-to-leading order(NLO) QCD
corrections to the inclusive total cross sections for the Kaluza-Klein(KK)
graviton and photon associated production process in
the large extra dimensions(LED) model at the LHC. We show that the NLO QCD
corrections in general enhance the total cross sections and reduce the
dependence of the total cross sections on the factorization and renormalization
scales. When jet veto is considered, the NLO corrections reduce the total cross
sections. We also calculate some important differential cross sections for this
process at NLO: the missing transverse momentum distribution, the transverse
momentum distribution and the pseudorapidity distribution of photon.Comment: 28 pages, 14 figures; minor changes, version published in Phys.Rev.
On Newman-Penrose constants of stationary electrovacuum spacetimes
A theorem related to the Newman-Penrose constants is proven. The theorem
states that all the Newman-Penrose constants of asymptotically flat,
stationary, asymptotically algebraically special electrovacuum spacetimes are
zero. Straightforward application of this theorem shows that all the
Newman-Penrose constants of the Kerr-Newman spacetime must vanish.Comment: 11pages, no figures accepted by PR
SNR-Based Teachers-Student Technique for Speech Enhancement
It is very challenging for speech enhancement methods to achieves robust
performance under both high signal-to-noise ratio (SNR) and low SNR
simultaneously. In this paper, we propose a method that integrates an SNR-based
teachers-student technique and time-domain U-Net to deal with this problem.
Specifically, this method consists of multiple teacher models and a student
model. We first train the teacher models under multiple small-range SNRs that
do not coincide with each other so that they can perform speech enhancement
well within the specific SNR range. Then, we choose different teacher models to
supervise the training of the student model according to the SNR of the
training data. Eventually, the student model can perform speech enhancement
under both high SNR and low SNR. To evaluate the proposed method, we
constructed a dataset with an SNR ranging from -20dB to 20dB based on the
public dataset. We experimentally analyzed the effectiveness of the SNR-based
teachers-student technique and compared the proposed method with several
state-of-the-art methods.Comment: Published in 2020 IEEE International Conference on Multimedia and
Expo (ICME 2020
Sub-Band Knowledge Distillation Framework for Speech Enhancement
In single-channel speech enhancement, methods based on full-band spectral
features have been widely studied. However, only a few methods pay attention to
non-full-band spectral features. In this paper, we explore a knowledge
distillation framework based on sub-band spectral mapping for single-channel
speech enhancement. Specifically, we divide the full frequency band into
multiple sub-bands and pre-train an elite-level sub-band enhancement model
(teacher model) for each sub-band. These teacher models are dedicated to
processing their own sub-bands. Next, under the teacher models' guidance, we
train a general sub-band enhancement model (student model) that works for all
sub-bands. Without increasing the number of model parameters and computational
complexity, the student model's performance is further improved. To evaluate
our proposed method, we conducted a large number of experiments on an
open-source data set. The final experimental results show that the guidance
from the elite-level teacher models dramatically improves the student model's
performance, which exceeds the full-band model by employing fewer parameters.Comment: Published in Interspeech 202
Same-sign top pair production in an extra-dimension model of flavor at the CERN Large Hadron Collider
We study the same-sign top pair production mediated by the first Kluza-Klein
(KK) excitation of the gluon in the Randall-Sundrum (RS) model with flavor
violation at the Large Hadron Collider (LHC), in which the nonuniversal
couplings between fermions and KK gauge bosons will lead to observable tree
level flavor-changing neutral current (FCNC) effects. We find that the
same-sign top quarks produced in our case have property of high energy and high
transverse momentum, and lead to an observable signal in the same-sign dilepton
channel even when the mass of the KK gluon reach up to 3 TeV. We further
investigate the potential of the LHC to probe the flavor violating parameters
and find that the LHC can probe their values down to 0.06.Comment: 12 pages, 4 figures; several references added; version appeared in
Phys.Rev.
Gluon Fusion induced Zg and Zgg Productions in the Standard Model at the LHC
We report calculations of the gluon induced Zg and Zgg productions in the
Standard Model at the LHC operating at both 7 TeV and 14 TeV collision energy.
We present total cross sections and differential distributions of the processes
and compare them with the leading and next-to-leading order QCD pp -> Z+1 jet,
Z+2 jets results. Our results show that the gluon induced Zg and Zgg
productions contribute to pp -> Z+1 jet, Z+2 jets at 1% level.Comment: 8 pages, 5 figure
Methods and Devices for Cryopreservation of Biological Cells and Tissues
Novel methods, compositions, and devices for achieving optimal cooling of living cells during cryopreservation are disclosed. In one aspect, the method comprises gradually cooling the cell to a first predetermined temperature, followed by rapidly cooling the cell to a second predetermined temperature. In another aspect, a device is described for achieving a desired cooling rate for a cell, comprising a first container for holding a cell, a second container for holding the first container, and optionally a frame for holding the first container in a spaced apart relationship with the second container. The method of the invention comprises placing cells into the first container, placing the first container in the second container and sealing the second container, and placing the second container in a suitable cooling device. In yet another aspect, novel cryoprotectant compositions are provided comprising conventional cryoprotectant plus one or more high molecular weight cryoprotectants
Signature of Large Extra Dimensions from Z boson pair production at the CERN Large Hadron Collider
We study the Z boson pair production mediated by the Kaluza-Klein (KK)
graviton in large extra dimensions (LED) at the CERN Large Hadron Collider
(LHC). We use the partial wave unitarity to discuss the constraints on the
process energy scale in order to give a self-consistent calculation. We find
that the LED contributions can enhance the Z boson pair production cross
sections significantly when the fundamental scale of the large extra
dimensions is up to several TeV. We also show that the kinematic distributions
of the LED signals are greatly different from the standard model ones and the
LHC can probe the values up to TeV at level
depending on the number of the extra dimensions.Comment: Revised version, published in Phys. Rev.
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