In response to the high demand of the operation reliability by implementing real-time monitoring and system health management, a robust fault estimation and fault-tolerant control approach is ...proposed for Takagi-Sugeno fuzzy systems in this study, by integrating the augmented system method, unknown input fuzzy observer design, linear matrix inequality optimization, and signal compensation techniques. Specifically, a fuzzy augmented system method is used to construct an augmented plant with the concerned faults and system states being the augmented states. An unknown input fuzzy observer technique is thus utilized to estimate the augmented states and decouple unknown inputs that can be decoupled. A linear matrix inequality approach is further addressed to ensure the global stability of the estimation error dynamics and attenuate the influences from the unknown inputs that cannot be decoupled. As a result, the robust estimates of the concerned faults and system states can be obtained simultaneously. Based on the fault estimates, a signal compensation scheme is developed to remove the effects of the faults on the system dynamics and outputs, leading to a stable dynamic satisfying the expected performance. Finally, the effectiveness of the proposed Takagi-Sugeno model based fault estimation and signal compensation algorithms is demonstrated by a case study on a 4.8-MW wind turbine benchmark system.
Robust fault estimation plays an important role in real-time monitoring, diagnosis, and fault-tolerance control. Accordingly, this paper aims to develop an effective fault estimation technique to ...simultaneously estimate the system states and the concerned faults, while minimizing the influences from process/sensor disturbances. Specifically, an augmented system is constructed by forming an augmented state vector composed of the system states and the concerned faults. Next, an unknown input observer (UIO) is designed for the augmented system by decoupling the partial disturbances and attenuating the disturbances that cannot be decoupled, leading to a simultaneous estimate of the system states and the concerned faults. In order to be close to the practical engineering situations, the process disturbances in this study are assumed not to be completely decoupled. In the first part of this paper, the existence condition of such an UIO is proposed to facilitate the fault estimation for linear systems subjected to process disturbances. In the second part, robust fault estimation techniques are addressed for Lipschitz nonlinear systems subjected to both process and sensor disturbances. The proposed technique is finally illustrated by the simulation studies of a three-shaft gas turbine engine and a single-link flexible joint robot.
A position offset-based multiparameter estimation for permanent magnet synchronous machines (PMSMs) under variable speed control is proposed in this paper, which does not need the aid from nominal ...parameter values of the PMSM and could estimate the rotor permanent magnet (PM) flux linkage and winding resistance separately. For the estimation of rotor PM flux linkage, two sets of PMSM data corresponding to two position offsets are measured while the dq -axis reference currents are set to constants so as to ensure that the estimated machine parameters will not vary during the data measurement. Afterwards, the winding resistance will be estimated from measured PMSM data without addition of position offsets, in which the estimation and compensation of distorted voltage due to inverter nonlinearity are also taken into account. The conventional quantum genetic algorithm is used for aiding the calculation of proposed estimation, which is finally tested on an interior PMSM and shows very good performance in the estimation of rotor PM flux linkage and winding resistance. Thus, it could be used for the condition monitoring of stator winding and rotor PMs of PMSMs.
Summary
Vitamin D receptor (VDR) mediates various biochemical activities between the cytoplasm and the nucleus in the cell. The nucleotide‐binding, oligomerization domain (NOD)‐like receptor family, ...pyrin domain containing 3 (NLRP3) protein is involved in the T helper type 2 (Th2) response. This study tests a hypothesis that VDR interacts with NLRP3 to restrict the Th2‐biased response. In this study, VDR–/– mice and WT (WT) mice were used. Th2 cell differentiation between VDR–/– mice and WT mice was observed. We observed that CD4+ T cell activation was higher in VDR–/– mice. The VDR–/–CD4+ T cells were prone to Th2 polarization. VDR–/– mice produced more immunoglobulin (Ig)E. VDR bound NLRP3 to prevent Th2 differentiation by restricting IL4 gene transcription. Th2 biased inflammation spontaneously developed in the intestine of VDR–/– mice. In conclusion, VDR binds NLRP3 to restrict IL4 gene transcription and prevent biased Th2 polarization.
VDR expression is lower in CD4+ T cells of FA patients; VDR is negatively correlated with Th2 cytokines in CD4+ T cells of FA patients
Earlier, mapping of the 9p23-24 amplicon in esophageal cancer cell lines led us to the positional cloning of gene amplified in squamous cell carcinoma 1 (GASC1), which encodes a nuclear protein with ...a Jumonji C domain that catalyzes lysine (K) demethylation of histones. However, the transforming roles of GASC1 in breast cancer remain to be determined. In this study, we identified GASC1 as one of the amplified genes for the 9p23-24 region in breast cancer, particularly in basal-like subtypes. The levels of GASC1 transcript expression were significantly higher in aggressive, basal-like breast cancers compared with nonbasal-like breast cancers. Our in vitro assays demonstrated that GASC1 induces transformed phenotypes, including growth factor-independent proliferation, anchorage-independent growth, altered morphogenesis in Matrigel, and mammosphere forming ability, when overexpressed in immortalized, nontransformed mammary epithelial MCF10A cells. Additionally, GASC1 demethylase activity regulates the expression of genes critical for stem cell self-renewal, including NOTCH1, and may be linked to the stem cell phenotypes in breast cancer. Thus, GASC1 is a driving oncogene in the 9p23-24 amplicon in human breast cancer and targeted inhibition of GASC1 histone demethylase in cancer could provide potential new avenues for therapeutic development.
The caspase family is well characterized as playing a crucial role in modulation of programmed cell death (PCD), which is a genetically regulated, evolutionarily conserved process with numerous links ...to many human diseases, most notably cancer. In this review, we focus on summarizing the intricate relationships between some members of the caspase family and their key apoptotic mediators, involving tumour necrosis factor receptors, the Bcl‐2 family, cytochrome c, Apaf‐1 and IAPs in cancer initiation and progression. We elucidate new emerging types of cross‐talk between several caspases and autophagy‐related genes (Atgs) in cancer. Moreover, we focus on presenting several PCD‐modulating agents that may target caspases‐3, ‐8 and ‐9, and their substrates PARP‐1 and Beclin‐1, which may help us harness caspase‐modulated PCD pathways for future drug discovery.
In this paper, novel variable flux reluctance machines (VFRMs) with different rotor pole numbers, which employ a doubly salient structure together with field windings identically located in the ...stator for each phase, are investigated and compared. Different from other doubly salient machines, such as switched reluctance machines (SRM) and doubly fed doubly salient machines (DFDSM), the equation for determining the stator/rotor pole numbers, i.e., N r = N s ±2 k , is no longer limited in VFRMs. More feasible selections of rotor pole numbers can be used if the stator/rotor pole numbers can satisfy N r ≠ kN ph . Thus, for a 6-stator pole machine not only the rotor pole number can be selected as even numbers, such as 4- and 8-rotor poles, which are commonly used for SRM and DFDSM, but odd numbers, such as 5- and 7- rotor poles, are also feasible. The benefits of using 5- and 7-rotor poles are the cancellation of even-order harmonics together with the third-order harmonic in the flux-linkage and back-EMF. Hence, more sinusoidal back-EMF can be obtained to produce a lower torque ripple. The cancellation in 5- and 7-rotor pole machines is because the flux generated by field and armature windings can pass through the adjacent stator poles to form a shorter flux path, which can further increase their average torque. To validate the analysis, four prototype machines with different rotor pole numbers are manufactured and tested.
Abstract
Recent observations of Her X-1 with NuSTAR (as well as with INTEGRAL, Swift, and Astrosat) have provided evidence that the nearly 20 yr-long decay of the cyclotron line energy since ∼1994 ...has ended and that a stable value has replaced the decay. Using the observations of the Hard X-ray Modulation Telescope (Insight-HXMT) performed between 2017 July and 2020 February, we analyze the spectra of Her X-1 in its main-on state, focusing on tracing the evolution of cyclotron line energy. While our analysis of eight main-on observations with Insight-HXMT (two in coordination with NuSTAR) shows significant differences with the results of NuSTAR, two earlier findings are confirmed: the positive correlation between the cyclotron line energy and the X-ray flux (source luminosity) and the constancy of the flux-normalized cyclotron line energy during 2017–2020—albeit with significant uncertainty about the absolute value.
This paper proposes an integrated field and armature current control strategy for a variable flux reluctance machine (VFRM) with an open-winding topology. By using an open-winding inverter, the field ...and armature currents can be injected into a single coil as a sinusoidal current biased by the dc offset rather than the separated field and armature windings. The integrated current control can reduce the copper loss to half and extend the operating speed range owing to the reduction in the winding resistance. In order to utilize the zero-sequence current as a field current, a zero-vector modification technique is proposed, in which the switching-on time of the zero vectors is modified to generate the constant zero-sequence voltage between two inverters. The proposed scheme is implemented in a synchronous dq0-axis frame with space vector modulation. For the validation of the proposed method, a machine model of the VFRM is developed and implemented in MATLAB/Simulink. The simulation and experimental results verify that the proposed strategy can effectively reduce the copper loss and extend the operating speed range.
Background
The overproduction of IgE plays a critical role in the pathogenesis of allergy; the mechanism is unclear. Histone‐acetyltransferase (HAT) activities are required in gene transcription of a ...large number of molecules in the immune system of the body.
Objectives
This study tests a hypothesis that HAT Tat‐interactive protein 60 (Tip60) plays an important role in the initiation of IgE‐mediated allergy.
Methods
The effects of Tip60 on regulating IgE expression were assessed with B cells. An intestinal allergy mouse model was developed to assess the role of Tip60 in the induction of IgE‐mediated allergic inflammation.
Results
High levels of Tip60 were observed in the peripheral B cells of patients with FA. Tat‐interactive protein 60 (Tip60) was required in the expression of IgE and IgG1 in B cells by inducing the chromatin remolding at the gene locus, in which histone acetylation, signal transducer and activator of transcription 6 (STAT6), and nuclear factor‐κB at the locus of Iε promoter were markedly increased. Blocking Tip60 significantly attenuated the allergic inflammation in the mouse intestinal mucosa.
Conclusions
Tat‐interactive protein 60 (Tip60) plays an important role in the induction of IgE in B cells. Blocking Tip60 inhibits the allergic inflammation in the intestine, suggesting Tip60 inhibitor may be a potential anti‐allergy drug.
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