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How to reduce the cogging torque of the integrated propeller motor is an important means to improve its noise performance because cogging torque is one of the key factors causing torque ripple. We proposed a method to reduce the cogging torque by optimizing the size of the Halbach array's auxiliary pole. First, an analytical model for the airgap magnetic field of Halbach array based on different dimensions (including the circumference ratio and the radial thickness) of the auxiliary pole is given. Then the finite element method is used to verify the analytical model. On the basis, we calculated the cogging torque of different size of auxiliary poles as sample data by combining different circumference ratio and radial thickness. Furthermore, using the two-variable single-objective neural network genetic optimization algorithm based on Backpropagation (BP), we obtain the optimal size of the auxiliary pole. Finally, comparing the motor cogging torque and torque ripple before and after optimization indicated that the cogging torque and torque ripple are effectively reduced after optimizing the size of the auxiliary pole. [ABSTRACT FROM AUTHOR]

Permanent magnet couplings (PMCs) are widely used in underwater propulsion because it can solve the deep-sea sealing problem effectively. In this paper, a new type of conical permanent magnet coupling (CPMC) is proposed, which is able to match the tail shape of the underwater vehicle and make full use of the tail space to increase pull-out torque capability. Based on the three-dimensional finite element method (3D-FEM), the electromagnetic characteristics of an initial model for CPMC are analyzed. In order to facilitate the design and optimization of CPMC, an equivalent three-dimensional (3D) analytical method for the pull-out torque calculation is presented, and its accuracy is verified by comparison with the 3D finite element results. Finally, the influence of design parameters such as half-cone angle, pole pair, pole arc coefficient and permanent magnet thickness on maximum pull-out torque and torque density of CPMC is analyzed, and a preliminary optimization model is obtained. [ABSTRACT FROM AUTHOR]

This study introduces a novel approach for synthesizing Benzoxazine-centered Polychiral Polyheterocycles (BPCPHCs) via an innovative asymmetric carbene-alkyne metathesis-triggered cascade. Overcoming challenges associated with intricate stereochemistry and multiple chiral centers, the catalytic asymmetric Carbene Alkyne Metathesis-mediated Cascade (CAMC) is employed using dirhodium catalyst/Brønsted acid co-catalysis, ensuring precise stereo control as validated by X-ray crystallography. Systematic substrate scope evaluation establishes exceptional diastereo- and enantioselectivities, creating a unique library of BPCPHCs. Pharmacological exploration identifies twelve BPCPHCs as potent Nav ion channel blockers, notably compound 8 g. In vivo studies demonstrate that intrathecal injection of 8 g effectively reverses mechanical hyperalgesia associated with chemotherapy-induced peripheral neuropathy (CIPN), suggesting a promising therapeutic avenue. Electrophysiological investigations unveil the inhibitory effects of 8 g on Nav1.7 currents. Molecular docking, dynamics simulations and surface plasmon resonance (SPR) assay provide insights into the stable complex formation and favorable binding free energy of 8 g with C5aR1. This research represents a significant advancement in asymmetric CAMC for BPCPHCs and unveils BPCPHC 8 g as a promising, uniquely acting pain blocker, establishing a C5aR1-Nav1.7 connection in the context of CIPN., (© 2024 Wiley-VCH GmbH.)

N -(Anthrancen-9-ylmethyl) isoserines are useful drug intermediates but short for efficient synthesis. We herein report the synthesis of N -(anthrancen-9-ylmethyl) isoserines via a Rh 2 (Ph 3 COO) 3 (OAc) and chiral phosphoric acid (CPA) synergistically catalyzed multicomponent reaction (MCR) of N -alkyl imines, alcohols, and diazoesters. The method representing the first example of N -alkyl imines-involved MCR is featured by high atom-economy, high diastereo- and enantioselectivities, and broad substrate scope. DFT calculations on the mechanism of the MCR reveals that the hydrophobic interactions and π-π stackings between N -(anthrancen-9-ylmethyl) imines and Rh 2 (Ph 3 COO) 3 (OAc)/CPA cocatalyst is essential to the reactivity and stereocontrol. The synthetic applications of the MCR products include the semisynthesis of paclitaxel, its alkyne-tagged derivative, and β -lactam as an anticancer agent overcoming paclitaxel-resistance. We expect this work to shed light on the development of new N -alkyl imines-involved reactions and on the synthesis of drugs with isoserines as intermediates.

The blockade of A 2A adenosine receptor (A 2A AR) activates immunostimulatory response through regulating signaling in tumor microenvironment. Thus, A 2A AR has been proposed as a promising target for cancer immunotherapy. In this work, we designed a new series of benzo[4,5]imidazo[1,2- a ]pyrazin-1-amine derivatives bearing an amide substitution at 3-position to obtain potent antitumor antagonist in vivo . The structure-activity relationship studies were performed by molecular modeling and radioactive assay. The in vitro anticancer activities were evaluated by 3',5'-cyclic adenosine monophosphate (cAMP) functional and T cell activation assay. The most potent compound 12o·2HCl showed much higher affinity toward A 2A AR ( K i = 0.08 nM) and exhibited more significant in vitro immunostimulatory anticancer activity than clinical antagonist AZD4635. More importantly, 12o·2HCl significantly inhibited the growth of triple-negative breast cancer by reversing immunosuppressive tumor microenvironment in the xenograft mouse model without severe toxicity at the testing dose. These results make 12o·2HCl a promising immunotherapy anticancer drug candidate.