Sound Absorption by Acoustic Microlattice with Optimized Pore Configuration

Sound absorption or dissipation principally involves joint interactions between sound waves, material morphology and the air medium. How these elements work most efficiently for sound absorption remains elusive to date. In this paper, we suggest a fundamental relation concisely cross-linking the three elements, which reveals that optimal sound absorption efficiency occurs when the pore size of the material is twice the thickness of the viscous boundary layer of the acoustic air medium. The study is validated by microlattice materials comprising of well-controlled regular structures that absorb sound in a tunable manner. Optimized material morphology in terms of pore size and porosity is determined to provide a robust guidance for optimizing sound absorbing materials.Comment: 14 pages, 7 figure

Combined PD-1 blockade and GITR triggering induce a potent antitumor immunity in murine cancer models and synergizes with chemotherapeutic drugs

BACKGROUND: The coinhibitory receptor Programmed Death-1 (PD-1) inhibits effector functions of activated T cells and prevents autoimmunity, however, cancer hijack this pathway to escape from immune attack. The costimulatory receptor glucocorticoid-induced TNFR related protein (GITR) is up-regulated on activated T cells and increases their proliferation, activation and cytokine production. We hypothesize that concomitant PD-1 blockade and GITR triggering would synergistically improve the effector functions of tumor-infiltrating T cells and increase the antitumor immunity. In present study, we evaluated the antitumor effects and mechanisms of combined PD-1 blockade and GITR triggering in a clinically highly relevant murine ID8 ovarian cancer model. METHODS: Mice with 7 days-established peritoneal ID8 ovarian cancer were treated intraperitoneally (i.p.) with either control, anti-PD-1, anti-GITR or anti-PD-1/GITR monoclonal antibody (mAb) and their survival was evaluated; the phenotype and function of tumor-associated immune cells in peritoneal cavity of treated mice was analyzed by flow cytometry, and systemic antigen-specific immune response was evaluated by ELISA and cytotoxicity assay. RESULTS: Combined anti-PD-1/GITR mAb treatment remarkably inhibited peritoneal ID8 tumor growth with 20% of mice tumor free 90 days after tumor challenge while treatment with either anti-PD-1 or anti-GITR mAb alone exhibited little antitumor effect. The durable antitumor effect was associated with a memory immune response and conferred by CD4(+) cells and CD8(+) T cells. The treatment of anti-PD-1/GITR mAb increased the frequencies of interferon-γ-producing effector T cells and decreased immunosuppressive regulatory T cells and myeloid-derived suppressor cells, shifting an immunosuppressive tumor milieu to an immunostimulatory state in peritoneal cavity. In addition, combined treatment of anti-PD-1/GITR mAb mounted an antigen-specific immune response as evidenced by antigen-specific IFN-γ production and cytolytic activity of spleen cells from treated mice. More importantly, combined treatment of anti-PD-1/GITR mAb and chemotherapeutic drugs (cisplatin or paclitaxel) further increased the antitumor efficacy with 80% of mice obtaining tumor-free long-term survival in murine ID8 ovarian cancer and 4 T1 breast cancer models. CONCLUSIONS: Combined anti-PD-1/GITR mAb treatment induces a potent antitumor immunity, which can be further promoted by chemotherapeutic drugs. A combined strategy of anti-PD-1/GITR mAb plus cisplatin or paclitaxel should be considered translation into clinic

Studies of intermediates and regulation in SNARE-mediated membrane fusion

At the synapse, neurotransmitters are released via Ca2+-triggered exocytotic fusion of synaptic vesicles with the presynaptic plasma membrane. The whole process is controlled by various proteins. SNAREs have been recognized as the key components that drive membrane fusion. In addition, many other proteins, such as Munc18/nSec1, Mun13, synaptotagmin, complexin, etc. are characterized to regulate synaptic transmission temporally and spatially.;The in vitro bulk fluorescence assay was applied to examine the kinetics of membrane fusion of liposomes mediated by recombinant neuronal SNAREs and led to the demonstration of hemifusion as an intermediate in the pathway. In order to monitor the fusion process in more sophisticated level, we developed the Single-liposome FRET assay and combined site-directed spin labeling (SDSL) and electron paramagnetic resonance (EPR) techniques to study the function of two SNARE regulators, synaptotagmin and complexin.;The EPR and fluorescence assay were also applied for the study of the SNAREs mediating the trafficking in yeast. It was found that supermolecular SNARE assembly precedes hemifusion, which was subsequently followed by distal leaflet mixing and formation of the cis-SNARE complex

Dynamic Performance of High-Speed Railway Overhead Contact Line Interacting With Pantograph Considering Local Dropper Defect

The local dropper defect is the most common fault in the early service stage of the overhead contact line (OCL) system. The plastic deformation and loose of a dropper may cause the variation of the contact line height, which has a direct effect on the contact performance of the pantograph-OCL system. This paper proposes a methodology to model the OCL with local dropper defect using a nonlinear finite element approach. Employing a developed TCUD (Target Configuration under Dead Load) method, which takes the vertical defective dropper position in the contact line as additional constraints, the local dropper defect is exactly added in the initial configuration of the OCL model. Several simulations of pantograph-OCL interaction are run with different positions of the defective dropper. The effect of local dropper defect on the pantograph-OCL contact forces is analysed. The results show that the increase of the defect degree causes the increment of the contact force peak around the defective dropper point. The defect on the first or last dropper within a span is the most detrimental to the current collection quality, as it directly causes the increase of maximum contact force, which challenges the safe operation of the pantograph-OCL system, and should be strictly restricted. The PSD (Power Spectral Density) analysis of contact force indicates that the dropper defect distorts the frequency characteristics of the contact force. The energy of contact forces decreases at the dropper-interval related frequencies due to the presence of dropper defect. Similarly, a significant `break' of the dropper-interval frequency component can be observed in the time-frequency representation of the contact force. This phenomenon has the potential to be used to identify and locate the defective dropper from the measured contact force.acceptedVersion© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

Unraveling Feature Extraction Mechanisms in Neural Networks

The underlying mechanism of neural networks in capturing precise knowledge has been the subject of consistent research efforts. In this work, we propose a theoretical approach based on Neural Tangent Kernels (NTKs) to investigate such mechanisms. Specifically, considering the infinite network width, we hypothesize the learning dynamics of target models may intuitively unravel the features they acquire from training data, deepening our insights into their internal mechanisms. We apply our approach to several fundamental models and reveal how these models leverage statistical features during gradient descent and how they are integrated into final decisions. We also discovered that the choice of activation function can affect feature extraction. For instance, the use of the \textit{ReLU} activation function could potentially introduce a bias in features, providing a plausible explanation for its replacement with alternative functions in recent pre-trained language models. Additionally, we find that while self-attention and CNN models may exhibit limitations in learning n-grams, multiplication-based models seem to excel in this area. We verify these theoretical findings through experiments and find that they can be applied to analyze language modeling tasks, which can be regarded as a special variant of classification. Our contributions offer insights into the roles and capacities of fundamental components within large language models, thereby aiding the broader understanding of these complex systems.Comment: Accepted by EMNLP 202

Regenerative medicine in China: demands, capacity, and regulation

Abstract Regenerative medicine (RM) is an emerging interdisciplinary field of research. Its clinical application focuses on the repair, replacement, and regeneration of cells, tissues, and organs by approaches including cell reprogramming, stem cell transplantation, tissue engineering, activating factors, and clone treatment. RM has become a hot point of research in China and other countries. China’s main and local governments have attached great importance to RM and given strong support in relevant policies and funding. About 3.5 billion RMB has been invested in this field. Since 1999, China has established about 30 RM centers and cooperates with many advanced countries in RM research and benefits from their cooperation. However, China needs to develop standards, regulations, and management practices suitable for the healthy development of RM. In this review, we focus on its great demand, capacity, and relative regulations.</jats:p

Directed Self-Assembly of Block Copolymers Based on the Heterogeneous Nucleation Process

By introducing the heterogeneous nucleation concept to directed self-assembly of block copolymers, the ordering of dynamical process and defect pattern design in thin films of binary blend, AB diblock/C homopolymer (AB/C), are investigated by the time-dependent Ginzburg-Landau theory and simulated by the cell dynamics simulations. The detailed annealing process of a few isolated defects occurring in AB/C blend under triangular and hexagonal confinements is presented, and it indicates that angle-matched confinement of triangular and hexagonal potential well is favorable conditions for generating defect-free ordered structures. Meanwhile, we gave a model which composed of many double-spot potentials with controllable position and orientation to investigate the relationship between defect spacing and mismatched angle, and we found the relationship is similar to hard crystals. Additionally, as an example, the design of defect pattern of “NXU” for abbreviation of Ningxia University is proposed and tested. In this chapter, the feasibility of directed self-assembly of block copolymers based on the heterogeneous nucleation process is systematically confirmed

Domain Consistency Regularization for Unsupervised Multi-source Domain Adaptive Classification

Deep learning-based multi-source unsupervised domain adaptation (MUDA) has been actively studied in recent years. Compared with single-source unsupervised domain adaptation (SUDA), domain shift in MUDA exists not only between the source and target domains but also among multiple source domains. Most existing MUDA algorithms focus on extracting domain-invariant representations among all domains whereas the task-specific decision boundaries among classes are largely neglected. In this paper, we propose an end-to-end trainable network that exploits domain Consistency Regularization for unsupervised Multi-source domain Adaptive classification (CRMA). CRMA aligns not only the distributions of each pair of source and target domains but also that of all domains. For each pair of source and target domains, we employ an intra-domain consistency to regularize a pair of domain-specific classifiers to achieve intra-domain alignment. In addition, we design an inter-domain consistency that targets joint inter-domain alignment among all domains. To address different similarities between multiple source domains and the target domain, we design an authorization strategy that assigns different authorities to domain-specific classifiers adaptively for optimal pseudo label prediction and self-training. Extensive experiments show that CRMA tackles unsupervised domain adaptation effectively under a multi-source setup and achieves superior adaptation consistently across multiple MUDA datasets

Effects of salt stress and nitrogen application on growth and ion accumulation of Suaeda salsa plants

Suaeda&nbsp;salsa&nbsp;is a typical pioneer species which can grow well in high&nbsp;salt&nbsp;environmental conditions. The objective&nbsp;of&nbsp;this study is to evaluate the&nbsp;effect&nbsp;of&nbsp;different levels&nbsp;of&nbsp;salinity (5.25, 10.5 and 21g NaCl per kg soil) and nutrient supply (0, 0.3, 0.6 and 1.2g urea per kg soil)&nbsp;on&nbsp;plant&nbsp;morphology, biomass,&nbsp;accumulation&nbsp;of&nbsp;ions&nbsp;and C/N ratio in leaves&nbsp;of&nbsp;S.&nbsp;salsa. The results showed that the&nbsp;plant&nbsp;height, number&nbsp;of&nbsp;branches, length&nbsp;of&nbsp;branches and diameter&nbsp;of&nbsp;shoot were significantly affected by&nbsp;salt&nbsp;stress, and the&nbsp;nitrogen&nbsp;released the negative&nbsp;effects&nbsp;of&nbsp;salt. The&nbsp;nitrogen&nbsp;treatment increased the biomass&nbsp;ofleaf, shoot and root. Leaf water content was significantly affected by the interaction&nbsp;of&nbsp;salt&nbsp;stress&nbsp;andnitrogen&nbsp;treatment. The content&nbsp;of&nbsp;Na&nbsp;+&nbsp;and Cl-&nbsp;increased significantly as increasing&nbsp;of&nbsp;salt, the content&nbsp;ofK+, Ca2+, Mg2+&nbsp;and SO&nbsp;42-&nbsp;decreased simultaneously to keep&nbsp;ion&nbsp;balance. The C/N ratio decreased significantly as increasing&nbsp;of&nbsp;nitrogen&nbsp;treatment. The content&nbsp;of&nbsp;proline increased significantly with the increasing&nbsp;of&nbsp;salt&nbsp;and&nbsp;nitrogen&nbsp;treatments. The results together indicated that at different&nbsp;saltenvironment, different amount&nbsp;of&nbsp;nitrogen&nbsp;supply can be used to improve the population&nbsp;growth&nbsp;of&nbsp;S.salsa&nbsp;plants, and the restoration&nbsp;of&nbsp;degraded wetland could be accelerated by nutrient supply reasonably.&nbsp