182 research outputs found

    Sensorless Control of a Ferrite PM Assisted-Synchronous Reluctance Machines by Using Sliding Mode Observer and High Frequency Signal Injection

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    This paper presents sensorless control of ferrite permanent magnet-assisted synchronous reluctance machines (FPMA-SynRM) over wide speed range by using sliding mode observer (SMO) and high frequency signal injection. The basic equation of sliding mode observer will be derived based on dynamic model of PMSynRM. In the study, the equivalent of EMF-based SMO is proposed to estimate rotor position at medium and high speed range. The principles of high frequency signal injection, digital signal processing and rotor polarity identification is also analysed. Finally, the theoretical analysis have been verified with the experiments and the results obtained show that the resolution of estimated position signal can meet requirements of some industrial drive applications

    Empirical research on the evaluation model and method of sustainability of the open source ecosystem

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    The development of open source brings new thinking and production modes to software engineering and computer science, and establishes a software development method and ecological environment in which groups participate. Regardless of investors, developers, participants, and managers, they are most concerned about whether the Open Source Ecosystem can be sustainable to ensure that the ecosystem they choose will serve users for a long time. Moreover, the most important quality of the software ecosystem is sustainability, and it is also a research area in Symmetry. Therefore, it is significant to assess the sustainability of the Open Source Ecosystem. However, the current measurement of the sustainability of the Open Source Ecosystem lacks universal measurement indicators, as well as a method and a model. Therefore, this paper constructs an Evaluation Indicators System, which consists of three levels: The target level, the guideline level and the evaluation level, and takes openness, stability, activity, and extensibility as measurement indicators. On this basis, a weight calculation method, based on information contribution values and a Sustainability Assessment Model, is proposed. The models and methods are used to analyze the factors affecting the sustainability of Stack Overflow (SO) ecosystem. Through the analysis, we find that every indicator in the SO ecosystem is partaking in different development trends. The development trend of a single indicator does not represent the sustainable development trend of the whole ecosystem. It is necessary to consider all of the indicators to judge that ecosystem’s sustainability. The research on the sustainability of the Open Source Ecosystem is helpful for judging software health, measuring development efficiency and adjusting organizational structure. It also provides a reference for researchers who study the sustainability of software engineering

    Wheel Running Improves Motor Function and Spinal Cord Plasticity in Mice With Genetic Absence of the Corticospinal Tract

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    Our previous studies showed that mutant mice with congenital absence of the corticospinal tract (CST) undergo spontaneous remodeling of motor networks to partially compensate for absent CST function. Here, we asked whether voluntary wheel running could further improve locomotor plasticity in CST-deficient mice. Adult mutant mice were randomly allocated to a “runners” group with free access to a wheel, or a “non-runners” group with no access to a wheel. In comparison with non-runners, there was a significant motor improvement including fine movement, grip strength, decreased footslip errors in runners after 8-week training, which was supported by the elevated amplitude of electromyography recording and increased neuromuscular junctions in the biceps. In runners, terminal ramifications of monoaminergic and rubrospinal descending axons were significantly increased in spinal segments after 12 weeks of exercise compared to non-runners. 5-ethynyl-2′-deoxyuridine (EDU) labeling showed that proliferating cells, 90% of which were Olig2-positive oligodendrocyte progenitors, were 4.8-fold more abundant in runners than in non-runners. In 8-week runners, RNAseq analysis of spinal samples identified 404 genes up-regulated and 398 genes down-regulated, and 69 differently expressed genes involved in signal transduction, among which the NF-κB, PI3K-Akt and cyclic AMP (cAMP) signaling were three top pathways. Twelve-week training induced a significant elevation of postsynaptic density protein 95 (PSD95), synaptophysin 38 and myelin basic protein (MBP), but not of brain derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and insulin like growth factor-1 (IGF-1). Thus, locomotor training activates multiple signaling pathways, contributes to neural plasticity and functional improvement, and might palliate locomotor deficits in patients

    Basalt-polypropylene fiber reinforced concrete for durable and sustainable pipe production. Part 1: experimental program

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    This is the peer reviewed version of the following article: [ Deng, Z, Liu, X, Chen, P, et al. Basalt-polypropylene fiber reinforced concrete for durable and sustainable pipe production. Part 1: Experimental program. Structural Concrete. 2022; 23: 311– 327. https://doi.org/10.1002/suco.202000759], which has been published in final form at https://onlinelibrary.wiley.com/doi/abs/10.1002/suco.202000759. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.An experimental program consisting in producing and testing reinforced concrete pipes (RCPs) under the three-edge bearing tests considering different types of reinforcement was carried out. Four types of RCPs were produced, these reinforced with: (1) polypropylene macrofibers; (2) basalt microfibers; (3) combination of both (hybrid reinforcement); and (4) plain concrete. The analysis of the crack patterns and both service and ultimate mechanical responses allowed concluding that the use of fibers do not lead to an effective increase of the first cracking load; however, both types of fibers allowed a better crack width control respect to the standard RCP. In this regard, basalt microfiber reinforced concrete led to a better response caused by concentrated loads (jacketing) whilst polypropylene macrofibers increased the concrete pipe performance in terms of bearing capacity and flexural crack control. The hybrid fiber reinforced concrete was found to be the most suitable alternative for increasing the load bearing capacity and the crack width control for service loads. These incipient experimental results permit to conclude that this type of hybrid basalt-polypropylene fiber reinforced concretes are an interesting alternative to traditional steel-cage RCPs.This work is supported by the National Key Research and Development Program of China (2018YFC1504802), Natural Science Foundation Project of Chongqing, Chongqing Science and Technology Commission (cstc2018jscxmszdX0071), Postgraduate Research Innovation Project of Chongqing (CYS19005, CYS18026). In addition, Prof. Albert de la Fuente also wants to express his gratitude to the Spanish Ministry of Science and Innovation for the financial support received under the scope of the project CREEF (PID2019-108978RB-C32).Peer ReviewedPostprint (author's final draft

    Sensitive Detection of Silver Ions Based on Chiroplasmonic Assemblies of Nanoparticles

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100155/1/adom201300148.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/100155/2/adom201300148-sup-0001-S1.pd

    Molybdenum disulfide nanoflowers mediated anti-inflammation macrophage modulation for spinal cord injury treatment

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    Spinal cord injury (SCI) can cause locomotor dysfunctions and sensory deficits. Evidence shows that functional nanodrugs can regulate macrophage polarization and promote anti-inflammatory cytokine expression, which is feasible in SCI immunotherapeutic treatments. Molybdenum disulfide (MoS2) nanomaterials have garnered great attention as potential carriers for therapeutic payload. Herein, we synthesize MoS2@PEG (MoS2 = molybdenum disulfide, PEG = poly (ethylene glycol)) nanoflowers as an effective carrier for loading etanercept (ET) to treat SCI. We characterize drug loading and release properties of MoS2@PEG in vitro and demonstrate that ET-loading MoS2@PEG obviously inhibits the expression of M1-related pro-inflammatory markers (TNF-α, CD86 and iNOS), while promoting M2-related anti-inflammatory markers (Agr1, CD206 and IL-10) levels. In vivo, the mouse model of SCI shows that long-circulating ET-MoS2@PEG nanodrugs can effectively extravasate into the injured spinal cord up to 96 h after SCI, and promote macrophages towards M2 type polarization. As a result, the ET-loading MoS2@PEG administration in mice can protect survival motor neurons, thus, reducing injured areas at central lesion sites, and significantly improving locomotor recovery. This study demonstrates the anti-inflammatory and neuroprotective activities of ET-MoS2@PEG and promising utility of MoS2 nanomaterial-mediated drug delivery

    Application of Industrial Standard Methods for Detection of Horse- and Donkey-Derived Ingredients for Detecting Mule Meat

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    Both horse- and donkey-derived ingredients have been detected in mule meat by real-time polymerase chain reaction (PCR) as described in China’s industry standards for detection of horse (SN/T 3730.5-2013) and donkey (SN/T 3730.4-2013) ingredients in food and feed, respectively. This contradicts the theory of strict maternal inheritance of mitochondrial DNA (mtDNA). Therefore, in this study, 3 horse meat samples, 3 donkey meat samples and 3 mule meat samples were detected by mitochondrial gene and nuclear gene sequencing based on PCR and the China’s industry standard methods for horse and donkey ingredients, respectively, and the results of the SN/T 3730.4-2013 method for mule meat were analyzed. According to the results of mitochondrial gene and nuclear gene sequencing, all 3 mule meat samples were derived from mules. Both donkey and horse ingredients were detected in the 3 mule meat samples by the SN/T 3730.4-2013 and SN/T 3730.5-2013 methods. The cycle threshold (Ct) of the SN/T 3730.5-2013 method for horse ingredient was in the range of ≤ 20.00, and that of the SN/T 3730.4-2013 method for donkey ingredient were in the range of 25.00-35.00. The sequencing results of PCR products using the primers described in the SN/T 3730.4-2013 method showed that the 3 mule meat samples had no homology with horse or donkey meat. This might be because the SN/T 3730.4-2013 target sequence appeared in the form of nuclear mitochondrial DNA segments in low repeat numbers in the mule nuclear genome, and some base insertions and deletions occurred. The possibility that mule ingredient may be present should be considered when the Ct value of the SN/T 3730.4-2013 is ≤ 20.00, while the Ct value of the SN/T 3730.5-2013 is in the range of 25.00-35.00 for horse and donkey ingredients in known samples of single animal-derived ingredients, respectively

    Characteristics of enzymolysis of silkworm pupa protein after tri-frequency ultrasonic pretreatment: kinetics, thermodynamics, structure and antioxidant changes

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    As a by-product of the sericulture industry, the utilization rate of silkworm pupa resources is currently not high. Proteins are converted into bioactive peptides through enzymatic hydrolysis. Not only can it solve the utilization problem, but it also creates more valuable nutritional additives. Silkworm pupa protein (SPP) was pretreated with tri-frequency ultrasonic (22/28/40 kHz). Effects of ultrasonic pretreatment on enzymolysis kinetics, enzymolysis thermodynamics, hydrolysate structure as well as hydrolysate antioxidant of SPP were investigated. Ultrasonic pretreatment significantly increased the hydrolysis efficiency, showing a 6.369% decrease in km and a 16.746% increase in kA after ultrasonic action (p < 0.05). The SPP enzymolysis reaction followed a second-order rate kinetics model. Evaluation of enzymolysis thermodynamics revealed that Ultrasonic pretreatment markedly enhanced the SPP enzymolysis, leading to a 21.943% decrease in Ea. Besides, Ultrasonic pretreatment significantly increased SPP hydrolysate’s surface hydrophobicity, thermal stability, crystallinity, and antioxidant activities (DPPH radical scavenging activity, Fe2+ chelation ability, and reducing power). This study indicated that tri-frequency ultrasonic pretreatment could be an efficient approach to enhancing the enzymolysis and improving the functional properties of SPP. Therefore, tri-frequency ultrasound technology can be applied industrially to enhance enzyme reaction process

    Uncovering the Functional Link Between SHANK3 Deletions and Deficiency in Neurodevelopment Using iPSC-Derived Human Neurons

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    SHANK3 mutations, including de novo deletions, have been associated with autism spectrum disorders (ASD). However, the effects of SHANK3 loss of function on neurodevelopment remain poorly understood. Here we generated human induced pluripotent stem cells (iPSC) in vitro, followed by neuro-differentiation and lentivirus-mediated shRNA expression to evaluate how SHANK3 knockdown affects the in vitro neurodevelopmental process at multiple time points (up to 4 weeks). We found that SHANK3 knockdown impaired both early stage of neuronal development and mature neuronal function, as demonstrated by a reduction in neuronal soma size, growth cone area, neurite length and branch numbers. Notably, electrophysiology analyses showed defects in excitatory and inhibitory synaptic transmission. Furthermore, transcriptome analyses revealed that multiple biological pathways related to neuron projection, motility and regulation of neurogenesis were disrupted in cells with SHANK3 knockdown. In conclusion, utilizing a human iPSC-based neural induction model, this study presented combined morphological, electrophysiological and transcription evidence that support that SHANK3 as an intrinsic, cell autonomous factor that controls cellular function development in human neurons
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