Synthesis of thioesters through copper-catalyzed coupling of aldehydeswith thiols in water

Copper-catalyzed C–S bond formation between aldehydes and thiols in the presence of TBHP as an oxidant is described. Functional groups including chloro, trifluoromethyl, bromo, iodo, nitrile, ester and thiophene are all tolerated by the reaction conditions employed. This reaction is performed in water without the use of a surfactant. Both aryl and alkyl aldehydes couple suitably with aryl- and alkyl thiols, affording the corresponding thioesters in moderate to good yields

An Efficient Wireless Recharging Mechanism for Achieving Perpetual Lifetime of Wireless Sensor Networks

[[abstract]]Energy recharging has received much attention in recent years. Several recharging mechanisms were proposed for achieving perpetual lifetime of a given Wireless Sensor Network (WSN). However, most of them require a mobile recharger to visit each sensor and then perform the recharging task, which increases the length of the recharging path. Another common weakness of these works is the requirement for the mobile recharger to stop at the location of each sensor. As a result, it is impossible for recharger to move with a constant speed, leading to inefficient movement. To improve the recharging efficiency, this paper takes “recharging while moving” into consideration when constructing the recharging path. We propose a Recharging Path Construction (RPC) mechanism, which enables the mobile recharger to recharge all sensors using a constant speed, aiming to minimize the length of recharging path and improve the recharging efficiency while achieving the requirement of perpetual network lifetime of a given WSN. Performance studies reveal that the proposed RPC outperforms existing proposals in terms of path length and energy utilization index, as well as visiting cycle.[[notice]]補正完

General properties of fidelity in non-Hermitian quantum systems with PT symmetry

The fidelity susceptibility is a tool for studying quantum phase transitions in the Hermitian condensed matter systems. Recently, it has been generalized with the biorthogonal basis for the non-Hermitian quantum systems. From the general perturbation description with the constrain of parity-time (PT) symmetry, we show that the fidelity $\mathcal{F}$ is always real for the PT-symmetric states. For the PT-broken states, the real part of the fidelity susceptibility equals to one half of the sum of the fidelity susceptibility of the PT-broken and the PT-partner states, $\mathrm{Re}[\mathcal{X}_F] = \frac{1}{2}(\mathcal{X}_F +\bar{\mathcal{X}}_F)$. The negative infinity of the fidelity susceptibility is explored by the perturbation theory when the parameter approaches the exceptional point (EP). Moreover, at the second-order EP where two eigenstates and eigenenergies coalesce, we prove that the real part of the fidelity between PT-symmetric and PT-broken states is $\mathrm{Re}\mathcal{F}=\frac{1}{2}$. We demonstrate these general properties for non-interacting and interacting systems by two examples: the two-legged non-Hermitian Su-Schrieffer-Heeger (SSH) model and the non-Hermitian XXZ spin chain.Comment: 14 pages, 8 figure

Lightly Weighted Automatic Audio Parameter Extraction for the Quality Assessment of Consensus Auditory-Perceptual Evaluation of Voice

The Consensus Auditory-Perceptual Evaluation of Voice is a widely employed tool in clinical voice quality assessment that is significant for streaming communication among clinical professionals and benchmarking for the determination of further treatment. Currently, because the assessment relies on experienced clinicians, it tends to be inconsistent, and thus, difficult to standardize. To address this problem, we propose to leverage lightly weighted automatic audio parameter extraction, to increase the clinical relevance, reduce the complexity, and enhance the interpretability of voice quality assessment. The proposed method utilizes age, sex, and five audio parameters: jitter, absolute jitter, shimmer, harmonic-to-noise ratio (HNR), and zero crossing. A classical machine learning approach is employed. The result reveals that our approach performs similar to state-of-the-art (SOTA) methods, and outperforms the latent representation obtained by using popular audio pre-trained models. This approach provide insights into the feasibility of different feature extraction approaches for voice evaluation. Audio parameters such as jitter and the HNR are proven to be suitable for characterizing voice quality attributes, such as roughness and strain. Conversely, pre-trained models exhibit limitations in effectively addressing noise-related scorings. This study contributes toward more comprehensive and precise voice quality evaluations, achieved by a comprehensively exploring diverse assessment methodologies.Comment: Published in IEEE 42th International Conference on Consumer Electronics (ICCE 2024

5-ALA mediated photodynamic therapy induces autophagic cell death via AMP-activated protein kinase

Photodynamic therapy (PDT) has been developed as an anticancer treatment, which is based on the tumor-specific accumulation of a photosensitizer that induces cell death after irradiation of light with a specific wavelength. Depending on the subcellular localization of the photosensitizer, PDT could trigger various signal transduction cascades and induce cell death such as apoptosis, autophagy, and necrosis. In this study, we report that both AMP-activated protein kinase (AMPK) and mitogen-activated protein kinase (MAPK) signaling cascades are activated following 5-aminolevulinic acid (ALA)-mediated PDT in both PC12 and CL1-0 cells. Although the activities of caspase-9 and -3 are elevated, the caspase inhibitor zVAD-fmk did not protect cells against ALA-PDT-induced cell death. Instead, autophagic cell death was found in PC12 and CL1-0 cells treated with ALA-PDT. Most importantly, we report here for the first time that it is the activation of AMPK, but not MAPKs that plays a crucial role in mediating autophagic cell death induced by ALA-PDT. This novel observation indicates that the AMPK pathway play an important role in ALA-PDT-induced autophagy