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Acoustic imaging method is a critical task in various applications since it can locate the sound sources. However, the resolution of the method becomes low at low frequencies. This paper proposes a novel method to realize high-resolution acoustic imaging based on block sparsity constraint. By dividing the focusing area into blocks, the block sparse property of sound sources can be utilized to improve the resolution of the result. In this study, a block orthogonal matching pursuit method is introduced to deal with source localization problem with block sparsity constraint. To evaluate the performance of the proposed method, it is tested through numerical simulations and an experiment. The results of simulations prove that the proposed acoustic imaging method based on block sparsity constraint can localize sound sources accurately and performs better than that based on sparsity constraint. The results of the experiment further validate these findings. [ABSTRACT FROM AUTHOR]

Sound source localization is a critical task in various applications. However, it becomes challenging when the sound sources are not directly visible to the sensors due to obstacles or other environmental factors. This paper proposes a novel approach for locating sound sources in non-line-of-sight environments by combining the equivalent source method (ESM) with the time reversal method (TRM). The ESM is used to compute the frequency responses between the focusing points and the measurement points numerically. These frequency responses are then substituted to the TRM to localize the sound sources. To evaluate the performance of the proposed method, it is tested through numerical simulations and an experiment. The results prove that the ESM can compute the frequency responses accurately, and the combination of TRM and ESM effectively localizes sound sources in non-line-of-sight environments. [ABSTRACT FROM AUTHOR]

Introduction: Diabetes has been recognized as an independent risk factor for periodontitis. Increasing evidences indicate that hyperglycemia aggravates inflammatory response of human periodontal ligament cells (hPDLCs). Carbon monoxide-releasing molecule-3 (CORM-3) is a water-soluble compound that can release carbon monoxide (CO) in a controllable manner. CORM-3 has been shown the anti-inflammatory effect in different cell lineages. Methods: We stimulated periodontal ligament cells with LPS and high glucose. The expression of inflammatory cytokine was detected by ELISA. RT-qPCR, Western blot and immunofluorescence were used to detect the expression of TLR2, TLR4, RAGE and the activation of NF-κB pathway. We performed silencing and overexpression treatment of RAGE targeting the role of RAGE. We performed the immunostaining of paraffin sections of the periodontitis model in diabetes rats. Results: The results showed that CORM-3 significantly inhibited the expression of inflammatory cytokine in hPDLCs stimulated with LPS and high glucose. CORM-3 also inhibited LPS and high glucose-induced expression of RAGE/NF-κB pathway and TLR2/TLR4/NF-κB pathway. Silence of RAGE resulted in significantly decreased expression of proteins above. Overexpression of RAGE significantly enhanced the expression of these factors. CORM-3 abrogated the effect of RAGE partially. In animal model, CORM-3 suppressed the inflammatory response of periodontal tissues in experimental periodontitis of diabetic rats. Discussion: Our research proved CORM-3 reduced the inflammatory response via RAGE/NF-κB pathway and TLR2/TLR4/NF-κB pathway in the process of high glucose exacerbated periodontitis. These findings demonstrated the role of RAGE in the process of high glucose exacerbated periodontitis and suggested that CORM3 be a potential therapeutic strategy for the treatment of diabetes patients with periodontitis. [ABSTRACT FROM AUTHOR]

Transition metal ion doping is an efficient method to enhance the photoelectrochemical (PEC) performance of catalytic composite materials. In this study, Cu−MoS2/CdS composite materials are successfully constructed through two‐step solvothermal and liquid exfoliation methods. CdS nanorods are decorated by fewer layers of MoS2 doped with Cu2+. The properties of the composites materials, such as microstructure, crystal structure and type, element valence state, and energy band structure, are obtained by XRD, XPS, and TEM. The combination of Cu−MoS2 and CdS effectively inhibits the recombination of photo‐generated electrons and holes and improves the photocatalytic properties of the composite materials. The PEC test results show that the Cu−MoS2/CdS composite have a perfect photocurrent density of 77 μA cm−2, which is 12.8 and 2.8 times of those of CdS and MoS2/CdS, respectively. Cu−MoS2/CdS composite has the lowest interfacial resistance and the best interfacial charge transfer capability due to ion doping and the inherent high conductivity of MoS2. At 5 % doping ratio of Cu2+, the photoelectrocatalytic hydrogen evolution rate of Cu−MoS2/CdS reaches 12.78 mmol h−1g−1, which is 60 times of that of CdS. [ABSTRACT FROM AUTHOR]