Breakdown modes of capacitively coupled plasma I: transitions from glow discharge to multipactor

In this work, a one-dimensional direct implicit particle-in-cell/Monte Carlo collision (PIC/MCC) code is used to study the capacitive discharge driven under 60 MHz rf power in the background gas of pure argon. The electron-induced secondary electron emission (ESEE) model suitable for SiO$_2$ electrode is taken into account. Several discharge modes are found in the transition region between the higher-pressure glow discharge and the abnormal multipactor discharge in this simulation. In a nerrow voltage range of hundreds of volts, the abnormal multipactor will transform to normal multipactor with the contining decrease of pressure. The characteristic of the three sustainale discharges are given and anaysed, and their fomation porcess are discussed. These new discharges have higher electron energy and electron flux at the boundary and are mainly sustained by higher electrode-induced SEE coefficient and high frequency. The appearence of the two multipactor modes in 60 MHz range might broaden the theory of gas discharge and expand the application of capacitive discharges.Comment: 17pages,12 figure

Bis{(E)-4-bromo-2-[(2-chloro-3-pyrid­yl)imino­meth­yl]phenolato-κ2 N,O}copper(II)

In the title complex, [Cu(C12H7BrClN2O)2], the CuII center is tetra­coordinated by two phenolate O and two azomethine N atoms from two independent bidentate 4-bromo-2-[(2-chloro-3-pyrid­yl)imino­meth­yl]phenolate (L) ligands. In the crystal structure, the CuII atom has a distorted square-planar coordination environment. The inter­planar dihedral angles between the benzene and pyridine rings in the individual ligands are 63.83 (4) and 54.43 (3)°, indicating the pyridine ring to have considerably weaker steric hindrance

CIF-PT: Bridging Speech and Text Representations for Spoken Language Understanding via Continuous Integrate-and-Fire Pre-Training

Speech or text representation generated by pre-trained models contains modal-specific information that could be combined for benefiting spoken language understanding (SLU) tasks. In this work, we propose a novel pre-training paradigm termed Continuous Integrate-and-Fire Pre-Training (CIF-PT). It relies on a simple but effective frame-to-token alignment: continuous integrate-and-fire (CIF) to bridge the representations between speech and text. It jointly performs speech-to-text training and language model distillation through CIF as the pre-training (PT). Evaluated on SLU benchmark SLURP dataset, CIF-PT outperforms the state-of-the-art model by 1.94% of accuracy and 2.71% of SLU-F1 on the tasks of intent classification and slot filling, respectively. We also observe the cross-modal representation extracted by CIF-PT obtains better performance than other neural interfaces for the tasks of SLU, including the dominant speech representation learned from self-supervised pre-training.Comment: Accepted by ACL 2023 Finding

Protective Effect of Anthocyanins Extract from Blueberry on TNBS-Induced IBD Model of Mice

This study was carried out to evaluate the protective effect of anthocyanins extract of blueberry on trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) model of mice. The study employed female C57BL/6 mice (n = 50), and colitis was induced by intracolonic injection of 0.5 mg of TNBS dissolved in 50% ethanol–phosphate buffered solution. The mice were divided into five groups (n = 10): vehicle, TNBS control and anthocyanins groups that received different doses of anthocyanins extract (10, 20 and 40 mg kg−1) daily for 6 days. Both increase in body weight and diarrhea symptoms were monitored each day. After 6 days, the animals were killed, and the following parameters were assessed: colon length, morphological score, histological score and biochemical assay (NO, myeloperoxidase (MPO), interleukin (IL)-12, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ). The results showed that the anthocyanins extract of blueberry rendered strong protection against TNBS-induced colonic damage at a dosage of 40 mg kg−1. When compared with the control, anthocyanins extract significantly prevented loss of body weight and ameliorated the scores of diarrhea, morphology and histology. Treatment with anthocyanins extract restored IL-10 excretion, as well as caused reduction in the levels of NO, MPO, IL-12, TNF-α and IFN-γ. Our research revealed the protective effect of anthocyanins extract from blueberry on TNBS-induced experimental colitis in mice, as well as examined whether high levels of dietary blueberries would lower the risk or have protective effects on human IBD, which may require further investigation

GMPC: Geometric Model Predictive Control for Wheeled Mobile Robot Trajectory Tracking

The configuration of most robotic systems lies in continuous transformation groups. However, in mobile robot trajectory tracking, many recent works still naively utilize optimization methods for elements in vector space without considering the manifold constraint of the robot configuration. In this letter, we propose a geometric model predictive control (MPC) framework for wheeled mobile robot trajectory tracking. We first derive the error dynamics of the wheeled mobile robot trajectory tracking by considering its manifold constraint and kinematic constraint simultaneously. After that, we utilize the relationship between the Lie group and Lie algebra to convexify the tracking control problem, which enables us to solve the problem efficiently. Thanks to the Lie group formulation, our method tracks the trajectory more smoothly than existing nonlinear MPC. Simulations and physical experiments verify the effectiveness of our proposed methods. Our pure Python-based simulation platform is publicly available to benefit further research in the community

N-acetylcysteine decreases malignant characteristics of glioblastoma cells by inhibiting Notch2 signaling

Background: Glioblastomas multiforme (GBM) is the most devastating primary intracranial malignancy lacking effective clinical treatments. Notch2 has been established to be a prognostic marker and probably involved in GBM malignant progression. N-acetylcysteine (NAC), a precursor of intracellular glutathione (GSH), has been widely implicated in prevention and therapy of several cancers. However, the role of NAC in GBM remains unclear and the property of NAC independent of its antioxidation is largely unknown. Methods: The mRNA and protein levels of Notch family and other related factors were detected by RT-PCR and western blot, respectively. In addition, intracellular reactive oxygen species (ROS) was measured by flow cytometry-based DCFH-DA. Moreover, cell viability was assessed by CCK8 and cell cycle was analyzed by flow cytometry-based PI staining. The level of apoptosis was checked by flow cytometry-based Annexin V/PI. Cell migration and invasion were evaluated by wound healing and transwell invasion assays. At last, U87 Xenograft model was established to confirm whether NAC could restrain the growth of tumor. Results: Our data showed that NAC could decrease the protein level of Notch2. Meanwhile, NAC had a decreasing effect on the mRNA and protein levels of its downstream targets Hes1 and Hey1. These effects caused by NAC were independent of cellular GSH and ROS levels. The mechanism of NAC-mediated Notch2 reduction was elucidated by promoting Notch2 degradation through Itch-dependent lysosome pathway. Furthermore, NAC could prevent proliferation, migration, and invasion and might induce apoptosis in GBM cells via targeting Notch2. Significantly, NAC could suppress the growth of tumor in vivo. Conclusions: NAC could facilitate Notch2 degradation through lysosomal pathway in an antioxidant-independent manner, thus attenuating Notch2 malignant signaling in GBM cells. The remarkable ability of NAC to inhibit cancer cell proliferation and tumor growth may implicate a novel application of NAC on GBM therapy