This paper proposes a novel scheme for the identification of the whole flux linkage map of permanent magnet synchronous machines, by which the map of dq -axis flux linkages at different load or ...saturation conditions can be identified by the minimization of a proposed estimation model. The proposed method works on a conventional three-phase inverter based vector control system and the immune clonal based quantum genetic algorithm is employed for the global searching of minimal point. Besides, it is also noteworthy that the influence of uncertain inverter nonlinearity and circuit resistance are cancelled during the modeling process. The proposed method is subsequently tested on two PMSMs and shows quite good performance compared with the finite element prediction results.
Adipocyte differentiation of bone marrow mesenchymal stem/stromal cells (BMSCs) instead of osteoblast formation contributes to age- and menopause-related marrow adiposity and osteoporosis. Vascular ...calcification often occurs with osteoporosis, a contradictory association called "calcification paradox". Here we show that extracellular vesicles derived from aged bone matrix (AB-EVs) during bone resorption favor BMSC adipogenesis rather than osteogenesis and augment calcification of vascular smooth muscle cells. Intravenous or intramedullary injection of AB-EVs promotes bone-fat imbalance and exacerbates Vitamin D3 (VD3)-induced vascular calcification in young or old mice. Alendronate (ALE), a bone resorption inhibitor, down-regulates AB-EVs release and attenuates aging- and ovariectomy-induced bone-fat imbalance. In the VD3-treated aged mice, ALE suppresses the ovariectomy-induced aggravation of vascular calcification. MiR-483-5p and miR-2861 are enriched in AB-EVs and essential for the AB-EVs-induced bone-fat imbalance and exacerbation of vascular calcification. Our study uncovers the role of AB-EVs as a messenger for calcification paradox by transferring miR-483-5p and miR-2861.
Multifunctional catalysts in operation: A novel class of trifunctional thiourea catalysts containing natural amino acid residues have been prepared (see scheme), and found to be very effective ...towards the asymmetric addition of 3‐alkyl‐oxindoles to 1,1‐bis(benzenesulfonyl)ethylene. This synthetic protocol has led to the enantioselective synthesis of 3‐alkyl‐3‐aryl‐disubstituted oxindoles and indolines with an all‐carbon quaternary stereogenic center.
In this article, a low noise and simple initial position estimation and startup method based on high-frequency rotating sinusoidal voltage injection is proposed for interior permanent magnet ...synchronous machine. Different from the conventional method that uses negative sequence current and closed-loop position observer, the proposed method simply compares the three-phase high-frequency current amplitudes calculated by discrete Fourier transform to detect the rotor sector. The initial position can be obtained within only half of the injection cycle without parameter tuning. Thus, it is fast and simple compared to the conventional method. Both discrete and continuous rotor positions can be obtained and used for startup. Furthermore, to mitigate the acoustic noise during starting, a multifrequency injection strategy is introduced to reduce the noise emission caused by high-frequency voltage injection. Experiments are carried out to verify the effectiveness of the proposed method.
In photoswitches that undergo fluorescence switching upon ultraviolet irradiation, photoluminescence and photoisomerization often occur simultaneously, leading to unstable fluorescence properties. ...Here, we successfully demonstrated reversible solid‐state triple fluorescence switching through “Pump–Trigger” multiphoton manipulation. A novel fluorescence photoswitch, BOSA‐SP, achieved green, yellow, and red fluorescence under excitation by pump light and isomerization induced by trigger light. The energy ranges of photoexcitation and photoisomerization did not overlap, enabling appropriate selection of the multiphoton light for “pump” and “trigger” photoswitching, respectively. Additionally, the large free volume of the spiropyran (SP) moiety in the solid state promoted reversible photoisomerization. Switching between “pump” and “trigger” light is useful for three‐color tunable switching cell imaging, which can be exploited in programmable fluorescence switching. Furthermore, we exploited reversible dual‐fluorescence switching in a single molecular system to successfully achieve two‐color super‐resolution imaging.
Stable and programmable triple fluorescence switching in the solid state was demonstrated through an alternative “Pump–Trigger” optical manipulation strategy employing a spiropyran‐functionalized distyrylanthracene derivative. The unique switching ability enabled innovative multicolor, tunable, switching cell imaging and two‐color super‐resolution imaging in a single‐molecule system.
The study of grain boundary phase transitions is an emerging field until recently dominated by experiments. The major bottleneck in the exploration of this phenomenon with atomistic modeling has been ...the lack of a robust computational tool that can predict interface structure. Here we develop a computational tool based on evolutionary algorithms that performs efficient grand-canonical grain boundary structure search and we design a clustering analysis that automatically identifies different grain boundary phases. Its application to a model system of symmetric tilt boundaries in Cu uncovers an unexpected rich polymorphism in the grain boundary structures. We find new ground and metastable states by exploring structures with different atomic densities. Our results demonstrate that the grain boundaries within the entire misorientation range have multiple phases and exhibit structural transitions, suggesting that phase behavior of interfaces is likely a general phenomenon.
Iron homeostasis disturbance has been implicated in Alzheimer's disease (AD), and excess iron exacerbates oxidative damage and cognitive defects. Ferroptosis is a nonapoptotic form of cell death ...dependent upon intracellular iron. However, the involvement of ferroptosis in the pathogenesis of AD remains elusive. Here, we report that ferroportin1 (Fpn), the only identified mammalian nonheme iron exporter, was downregulated in the brains of APPswe/PS1dE9 mice as an Alzheimer's mouse model and Alzheimer's patients. Genetic deletion of Fpn in principal neurons of the neocortex and hippocampus by breeding Fpn
mice with NEX-Cre mice led to AD-like hippocampal atrophy and memory deficits. Interestingly, the canonical morphological and molecular characteristics of ferroptosis were observed in both Fpn
and AD mice. Gene set enrichment analysis (GSEA) of ferroptosis-related RNA-seq data showed that the differentially expressed genes were highly enriched in gene sets associated with AD. Furthermore, administration of specific inhibitors of ferroptosis effectively reduced the neuronal death and memory impairments induced by Aβ aggregation in vitro and in vivo. In addition, restoring Fpn ameliorated ferroptosis and memory impairment in APPswe/PS1dE9 mice. Our study demonstrates the critical role of Fpn and ferroptosis in the progression of AD, thus provides promising therapeutic approaches for this disease.
In this article, a method of simultaneous sensorless rotor position and torque estimation is proposed for interior permanent magnet synchronous machines at standstill and low speed. The proposed ...method estimates the torque using high-frequency inductances identified from the current variations due to high-frequency square wave voltage injections in the estimated dq -axes, which are simultaneously used for sensorless rotor position estimation. The proposed method is not dependent on the fundamental model and has taken the cross-coupling effect into consideration, allowing for low cost and fast torque estimation at standstill and low speed. Both simulations and experiments are carried out to verify the effectiveness of the proposed method.
MicroRNAs have been implicated in diverse physiological and pathological processes. We previously reported that aberrant microRNA‐124 (miR‐124)/non‐receptor–type protein phosphatase 1 (PTPN1) ...signaling plays an important role in the synaptic disorders associated with Alzheimer's disease (AD). In this study, we further investigated the potential role of miR‐124/PTPN1 in the tau pathology of AD. We first treated the mice with intra‐hippocampal stereotactic injections. Then, we used quantitative real‐time reverse transcription PCR (qRT‐PCR) to detect the expression of microRNAs. Western blotting was used to measure the level of PTPN1, the level of tau protein, the phosphorylation of tau at AD‐related sites, and alterations in the activity of glycogen synthase kinase 3β (GSK‐3β) and protein phosphatase 2 (PP2A). Immunohistochemistry was also used to detect changes in tau phosphorylation levels at AD‐related sites and somadendritic aggregation. Soluble and insoluble tau protein was separated by 70% formic acid (FA) extraction to examine tau solubility. Finally, behavioral experiments (including the Morris water maze, fear conditioning, and elevated plus maze) were performed to examine learning and memory ability and emotion‐related behavior. We found that artificially replicating the abnormalities in miR‐124/PTPN1 signaling induced AD‐like tau pathology in the hippocampus of wild‐type mice, including hyperphosphorylation at multiple sites, insolubility and somadendritic aggregation, as well as learning/memory deficits. We also found that disruption of miR‐124/PTPN1 signaling was caused by the loss of RE1‐silencing transcription factor protein, which can be initiated by Aβ insults or oxidative stress, as observed in the brains of P301S mice. Correcting the deregulation of miR‐124/PTPN1 signaling rescued the tau pathology and learning/memory impairments in the P301S mice. We also found that miR‐124/PTPN1 abnormalities induced activation of glycogen synthase kinase 3 (GSK‐3) and inactivation of protein phosphatase 2A (PP2A) by promoting tyrosine phosphorylation, implicating an imbalance in tau kinase/phosphatase. Thus, targeting the miR‐124/PTPN1 signaling pathway is a promising therapeutic strategy for AD.
Disruption of miRNA signals had been implicated in Alzheimer's disease (AD). We previously reported that aberrant miR‐124/PTPN1 signaling induces the synaptic disorders in AD. In this study, we further investigated the potential role of miR‐124/PTPN1 in the tau pathology of AD. We found that artificially replicated disturbance of miR‐124/PTPN1 results in the tau pathology while correcting this abnormality rescued the tau pathology and learning/memory impairments in the P301S mice. Our study extends the critical role of miR‐124/PTPN1 in the pathogenesis and provides the potential therapeutic target for AD.
Aberrant regulation of microRNAs (miRNAs) has been implicated in the pathogenesis of Alzheimer's disease (AD), but most abnormally expressed miRNAs found in AD are not regulated by synaptic activity. ...Here we report that dysfunction of miR-135a-5p/Rock2/Add1 results in memory/synaptic disorder in a mouse model of AD. miR-135a-5p levels are significantly reduced in excitatory hippocampal neurons of AD model mice. This decrease is tau dependent and mediated by Foxd3. Inhibition of miR-135a-5p leads to synaptic disorder and memory impairments. Furthermore, excess Rock2 levels caused by loss of miR-135a-5p plays an important role in the synaptic disorder of AD via phosphorylation of Ser726 on adducin 1 (Add1). Blocking the phosphorylation of Ser726 on Add1 with a membrane-permeable peptide effectively rescues the memory impairments in AD mice. Taken together, these findings demonstrate that synaptic-related miR-135a-5p mediates synaptic/memory deficits in AD via the Rock2/Add1 signaling pathway, illuminating a potential therapeutic strategy for AD.
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