84 research outputs found

    Probing the cold neutral medium through HI emission morphology with the scattering transform

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    Neutral hydrogen (HI) emission exhibits complex morphology that encodes rich information about the physics of the interstellar medium (ISM). We apply the scattering transform (ST) to characterize HI emission structure via a set of compact and interpretable coefficients, and find a connection between HI emission morphology and HI cold neutral medium (CNM) phase content. Where HI absorption measurements are unavailable, the HI phase structure is typically estimated from the emission via spectral line decomposition. Here we present the first probe of CNM content using measures solely derived from HI emission spatial information. We apply the scattering transform to GALFA-HI data at high Galactic latitudes (|b|>30 deg), and compare the resulting coefficients to CNM fraction measurements derived from archival HI emission and absorption spectra. We quantify the correlation between the ST coefficients and measured CNM fraction (fCNM), and find that HI emission morphology encodes substantial fCNM-correlating information, and that ST-based metrics for small-scale linearity are particularly predictive of fCNM. This is further corroborated by the enhancement of I857/NHII_{857}/N_{HI} ratio with larger ST measures of small-scale linearity. These results are consistent with the picture that regions with higher CNM content are more populated with small-scale filamentary HI structures. Our work illustrates a physical connection between HI morphology and phase content, and suggests that future phase decomposition methods can be improved by making use of both HI spectral and spatial information

    Feasible negotiation procedures for multiple interdependent negotiations

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    Within an agent society, agents utilise their knowledge differently to achieve their individual or joint goals. Agent negotiation provides an effective solution to help agents reach agreements on their future behaviour in the society to guarantee their goals can be achieved successfully. Agents may need to conduct Multiple Interdependent Negotiations (MIN) with different opponents and for different purposes, in order to achieve a goal. By considering the complexity of negotiation environments, interdependencies, opponents and issues in the agent society, conducting MIX efficiently Is a challenging research issue. To the best of the authors\u27 knowledge, most of the state-of-art work primarily focuses on single negotiation scenarios and tries to propose sophisticated negotiation protocols and strategies to help individual agents to succeed in single negotiation. However, very little work has been done while considering interdependencies and tradeoffs among multiple negotiations, so as to help both individual agents as well as the agent society, to increase their welfare. This paper promotes the research on agent negotiation from the single negotiation level to the multiple negotiations level. To effectively conduct MIN in an agent society, this paper proposes three feasible negotiation procedures, which attempt to conduct MIN in a successive way, in a concurrent way, and in a clustered way while considering them in different negotiation situations, respectively. A simulated agent society is built to test the proposed negotiation procedures with rand om experimental settings. According to the experimental results, the successive negotiation procedure produces the highest time efficiency, the concurrent negotiation procedure promises the highest profits and success rates, whilst the clustered negotiation procedure provides a well-balanced solution between negotiation efficiency and effectiveness

    Inhibition of SMYD2 Sensitized Cisplatin to Resistant Cells in NSCLC Through Activating p53 Pathway

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    The protein lysine methyltransferase SMYD2 has recently emerged as a new enzyme modulate gene transcription or signaling pathways, and involved into tumor progression. However, the role of SMYD2 in drug resistant is still not known. Here, we found that inhibition of SMYD2 by specific inhibitor could enhance the cell sensitivity to cisplatin (CDDP), but not paclitaxel, NVB, and VCR in non-small cell lung cancer (NSCLC). Further study showed that SMYD2 and its substrates were overexpressed in NSCLC resistant cells, and the inhibition of SMYD2 or knockdown by specific siRNA could reverse the cell resistance to cisplatin treatment in NSCLC/CDDP cells. In addition, our data indicated that the inhibition or knockdown SMYD2 inhibit tumor sphere formation and reduce cell migration in NSCLC/CDDP cells, but not in NSCLC parental cells. Mechanistically, inhibition of SMYD2 could enhance p53 pathway activity and induce cell apoptosis through regulating its target genes, including p21, GADD45, and Bax. On the contrary, the sensitivity of cells to cisplatin was decreased after knockdown p53 or in p53 deletion NSCLC cells. The synergistically action was further confirmed by in vivo experiments. Taken together, our results demonstrate SMYD2 is involved into cisplatin resistance through regulating p53 pathway, and might become a promising therapeutic target for cisplatin resistance in NSCLC

    Fabrication of long-life quasi-solid-state Na-CO2 battery by formation of Na2C2O4 discharge product

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    Rechargeable Na-CO2 batteries are promising energy-storage devices due to their high energy density, environmental friendliness, and cost effectiveness. However, the insulating nature and irreversibility of the Na2CO3 discharge product cause large polarization and poor cyclicity. Here, we report a reversible quasi-solid-state Na-CO2 battery that is constructed by the synergistic action of a Co-encapsulated N-doped carbon framework catalyst and gel electrolyte to ensure the formation of a highly reversible Na2C2O4 discharge product. Experiments and density functional theory calculations indicate that the electron-agglomeration effect of Co nanoparticles enhances CO2 adsorption and lowers energy barrier, as well as promotes Na2C2O4 generation. A gel electrolyte containing an imidazole organic cation is used to inhibit the decomposition of the thermodynamically unstable Na2C2O4. The fabricated Na-CO2 battery exhibits a high discharge capacity of 3,094 mAh g^-1, a high-rate performance of 1,777 mAh g^-1 at a current density of 0.5 mA cm^-2, and excellent cycling performance of 366 cycles (2,200 h)

    Implicit Neural Representation as a Differentiable Surrogate for Photon Propagation in a Monolithic Neutrino Detector

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    Optical photons are used as signal in a wide variety of particle detectors. Modern neutrino experiments employ hundreds to tens of thousands of photon detectors to observe signal from millions to billions of scintillation photons produced from energy deposition of charged particles. These neutrino detectors are typically large, containing kilotons of target volume, with different optical properties. Modeling individual photon propagation in form of look-up table requires huge computational resources. As the size of a table increases with detector volume for a fixed resolution, this method scales poorly for future larger detectors. Alternative approaches such as fitting a polynomial to the model could address the memory issue, but results in poorer performance. Both look-up table and fitting approaches are prone to discrepancies between the detector simulation and the data collected. We propose a new approach using SIREN, an implicit neural representation with periodic activation functions, to model the look-up table as a 3D scene and reproduces the acceptance map with high accuracy. The number of parameters in our SIREN model is orders of magnitude smaller than the number of voxels in the look-up table. As it models an underlying functional shape, SIREN is scalable to a larger detector. Furthermore, SIREN can successfully learn the spatial gradients of the photon library, providing additional information for downstream applications. Finally, as SIREN is a neural network representation, it is differentiable with respect to its parameters, and therefore tunable via gradient descent. We demonstrate the potential of optimizing SIREN directly on real data, which mitigates the concern of data vs. simulation discrepancies. We further present an application for data reconstruction where SIREN is used to form a likelihood function for photon statistics

    Biomaterial-assisted tumor therapy: A brief review of hydroxyapatite nanoparticles and its composites used in bone tumors therapy

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    Malignant bone tumors can inflict significant damage to affected bones, leaving patients to contend with issues like residual tumor cells, bone defects, and bacterial infections post-surgery. However, hydroxyapatite nanoparticles (nHAp), the principal inorganic constituent of natural bone, possess numerous advantages such as high biocompatibility, bone conduction ability, and a large surface area. Moreover, nHAp’s nanoscale particle size enables it to impede the growth of various tumor cells via diverse pathways. This article presents a comprehensive review of relevant literature spanning the past 2 decades concerning nHAp and bone tumors. The primary goal is to explore the mechanisms responsible for nHAp’s ability to hinder tumor initiation and progression, as well as to investigate the potential of integrating other drugs and components for bone tumor diagnosis and treatment. Lastly, the article discusses future prospects for the development of hydroxyapatite materials as a promising modality for tumor therapy

    3D bioprinted hydrogel/polymer scaffold with factor delivery and mechanical support for growth plate injury repair

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    Introduction: Growth plate injury is a significant challenge in clinical practice, as it could severely affect the limb development of children, leading to limb deformity. Tissue engineering and 3D bioprinting technology have great potential in the repair and regeneration of injured growth plate, but there are still challenges associated with achieving successful repair outcomes.Methods: In this study, GelMA hydrogel containing PLGA microspheres loaded with chondrogenic factor PTH(1–34) was combined with BMSCs and Polycaprolactone (PCL) to develop the PTH(1–34)@PLGA/BMSCs/GelMA-PCL scaffold using bio-3D printing technology.Results: The scaffold exhibited a three-dimensional interconnected porous network structure, good mechanical properties, biocompatibility, and was suitable for cellchondrogenic differentiation. And a rabbit model of growth plate injury was appliedto validate the effect of scaffold on the repair of injured growth plate. The resultsshowed that the scaffold was more effective than injectable hydrogel in promotingcartilage regeneration and reducing bone bridge formation. Moreover, the addition ofPCL to the scaffold provided good mechanical support, significantly reducing limbdeformities after growth plate injury compared with directly injected hydrogel.Discussion: Accordingly, our study demonstrates the feasibility of using 3D printed scaffolds for treating growth plate injuries and could offer a new strategy for the development of growth plate tissue engineering therapy
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