Dual-Segment Three-Phase PMSM With Dual Inverters for Leakage Current and Common-Mode EMI Reduction

In a motor drive system, the inverter working in discrete and impulse states generates a common-mode voltage (CMV) at the terminal of the stator winding neutral point. The high-frequency CMV can induce a leakage current and a common-mode (CM) electromagnetic interference (EMI), which are potential threats to personal safety and system stability. The conventional single three-phase inverter is found to be powerless in eliminating the CMV, while the two paralleled inverters can effectively eliminate the CMV theoretically, but the three coupled inductors (CIs) should be added to the motor drive system which reduces the power density and efficiency of the system. A novel method, which associates a specially designed dual-segment three-phase motor with the CMV elimination modulation algorithm, can be utilized to cancel the extra CIs without degrading the function of the leakage current and the CM EMI suppression. The design of the dual-segment three-phase permanent magnet synchronous machine is introduced, with identical back electromotive forces for two groups of windings but with little magnetic coupling between them. Simulation and experimental results are provided to verify the validity of the proposed method in CM-related reduction and CI cancellation. Compared with the zero-CM pulsewidth modulation for paralleled inverters proposed in a previous work, the proposed dual-segment three-phase motor drive can achieve a better power density by removing the CIs

A Novel Zero-Sequence Current Elimination PWM Scheme for an Open-Winding PMSM With Common DC Bus

This paper introduces a novel pulse width modulation (PWM) scheme for an OW-PMSM driven by dual two-level three-phase inverter with common dc bus which can effectively deal with the inherent zero-sequence current (ZSC) problem. Based on conventional symmetrical unipolar double frequency SPWM scheme with appropriate phase-shift, the common mode voltage (CMV) of two inverters can keep the same and cancel out each other to eliminate the modulated zero sequence voltage (ZSV) disturbance source. In this case, the double frequency effect can be retained to reduce the ac side current ripple and suppress both the corresponding motor vibration and acoustic noise which is advantageous to improve the synthetic performance of motor. The DC bus voltage utilization of the novel PWM scheme is proved to reach the maximum value as same as the conventional modulated ZSV elimination scheme. Meanwhile, a zero-sequence controller is designed to suppress ZSC by further adjusting the two CMVs to counteract other zero-sequence disturbance sources. To verify the analysis, the proposed PWM technique associated with the control method is implemented in an OW-PMSM experimental setup to validate the superiority of proposed method

A Variant of TNFR2-Fc Fusion Protein Exhibits Improved Efficacy in Treating Experimental Rheumatoid Arthritis

Etanercept, a TNF receptor 2-Fc fusion protein, is currently being used for the treatment of rheumatoid arthritis (RA). However, 25% to 38% of patients show no response which is suspected to be partially due to insufficient affinity of this protein to TNFα. By using computational protein design, we found that residue W89 and E92 of TNFR2 were critical for ligand binding. Among several mutants tested, W89Y/E92N displayed 1.49-fold higher neutralizing activity to TNFα, as compared to that of Etanercept. Surface plasmon resonance (SPR) based binding assay revealed that the equilibrium dissociation constant of W89Y/E92N to TNFα was 3.65-fold higher than that of Etanercept. In a rat model of collagen-induced arthritis (CIA), W89Y/E92N showed a significantly better ability than Etanercept in reducing paw swelling and improvement of arthritic joint histopathologically. These data demonstrate that W89Y/E92N is potentially a better candidate with improved efficacy in treating RA and other autoimmune diseases

IgA Anti-β2-Glycoprotein I Autoantibodies Are Associated with an Increased Risk of Thromboembolic Events in Patients with Systemic Lupus Erythematosus

The clinical utility of testing for antiphospholipid antibodies (aPL) of IgA isotype remains controversial.To address this issue, we reasoned that if IgA aPL contribute to the clinical manifestations of the antiphospholipid syndrome, then an association with thromboembolic events should manifest in patients whose only aPL is of IgA isotype. We performed a retrospective chart review of 56 patients (31 with systemic lupus erythematosus [SLE] and 25 without SLE) whose only positive aPL was IgA anti-beta2-glycoprotein I (isolated IgA anti-beta2GPI) and compared their clinical features with 56 individually matched control patients without any aPL. Patients with isolated IgA anti-beta2GPI had a significantly increased number of thromboembolic events, as compared to controls. When patients were stratified into those with and without SLE, the association between isolated IgA anti-beta2GPI and thromboembolic events persisted for patients with SLE, but was lost for those without SLE. Titers of IgA anti-beta2GPI were significantly higher in SLE patients who suffered a thromboembolic event. Among patients with isolated IgA anti-beta2GPI, there was an increased prevalence of diseases or morbidities involving organs of mucosal immunity (i.e., gastrointestinal system, pulmonary system, and skin).The presence of isolated IgA anti-beta2GPI is associated with an increased risk of thromboembolic events, especially among patients with SLE. IgA anti-beta2GPI is associated with an increased prevalence of morbidities involving organs of mucosal immunity

Key Points of Ridge Cultivation of Lane Late Navel Orange

Ridge cultivation can effectively enhance soil permeability, promote root development and improve fruit quality. Based on the characteristics of Lane Late navel orange, this paper summarizes the technical points related to ridge cultivation and compares the effects of ridge cultivation and conventional cultivation on the growth, so as to provide guidance for better production practices

Representative joint histopathology of the groups with CIA administered with W89Y/E92N and Etanercept.

<p>Tissue sections from each group were stained with hematoxylin and eosin (HE). (A) None-immune group. (B) Untreated group treated with normal saline. (C) W89Y/E92N 1mg/kg treated group. (D) Etanercept 1mg/kg treated group. (E) W89Y/E92N 3mg/kg treated group. (F) Etanercept 3mg/kg treated group. (G) W89Y/E92N 9mg/kg treated group. (H) Etanercept 9mg/kg treated group. Scale shown on the right-hand side of (H) is equivalent to 0.1 mm.</p

The neutralizing activity of Etanercept and its variants on TNFα-induced cytotoxicity in mouse L929 cells.

a<p>1 unit is the dose of Etanercept that neutralised the cytotoxic activity of 1 IU TNFα on mouse L929 cells. Values are means of a triplicate experiment.</p

Paw-swelling.

<p>(A) Comparison of 1mg/kg Etanercept treated vs. the same dose of W89Y/E92N. (B) Comparison of 3mg/kg Etanercept treated vs. the same dose of W89Y/E92N. (C) Comparison of 9mg/kg Etanercept treated vs. the same dose of W89Y/E92N. Arrows indicate the time of treatment. *, **, a significant reduction of paw swelling of W89Y/E92N treatment compared to the groups given Etanercept (P<0.05; P<0.01 student t test). There were 10 rats per group. Black triangle, untreated group; Black diamond, 1mg/kg Etanercept treated group; White diamond, 1mg/kg W89Y/E92N treated group; Black square, 3 mg/kg Etanercept treated group; White square, 3mg/kg W89Y/E92N treated group; Black circle, 9 mg/kg Etanercept treated group; White circle, 9mg/kg W89Y/E92N treated group.</p