555 research outputs found

    Method and Device for Removal of Cryoprotectant from Cryopreserved Biological Cells and Tissues

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    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

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    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 ppγGKK+Xpp \to \gamma G_{KK} + X 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

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    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

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    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

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    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

    Gluon Fusion induced Zg and Zgg Productions in the Standard Model at the LHC

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    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

    Same-sign top pair production in an extra-dimension model of flavor at the CERN Large Hadron Collider

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    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.

    Methods and Devices for Cryopreservation of Biological Cells and Tissues

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    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

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    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 MSM_S 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 MSM_S values up to 4.35.64.3\sim 5.6 TeV at 3σ3\sigma level depending on the number of the extra dimensions.Comment: Revised version, published in Phys. Rev.
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