Electrical-thermal coupling characteristics of pre-insertion resistors in AC filter circuit breaker for UHV grid

The ultra-high voltage (UHV) AC/DC grid can provide a platform for sustainable power worldwide. To improve the bus voltage quality of the UHV AC system, AC filters are frequently switched into the UHV grid through circuit breakers with pre-insertion resistors. The pre-insertion resistors suppress inrush currents and operate over-voltage during switching. In this paper, we establish a macro and micro model of the pre-insertion resistor based on its temperature coefficient and micro-morphology. We simulate and analyze its electric-thermal coupling characteristics under standard closing and short-circuit faults. After the simulation model and physical comparison analysis, we find that under a usual closing surge, the electric field distribution of the pre-insertion resistor is uniform and undergoes a slight rise in temperature. However, under a short circuit fault, the temperature rise is drastic and exceeds the maximum allowable temperature, causing glassy melt in some parts of the resistor. Considering the volume ratio of each component of the resistor, a two-dimensional cross-sectional simulation model of the resistor is established to simulate the electric-thermal characteristics of the microstructure of the resistor, and insinuates that the current is concentrated in the carbon channel. That is mainly due to the uneven distribution of carbon material and may lead the local temperature to exceed the maximum allowable temperature and damage the resistor

Study on sensory properties and efficacy evaluation of whole wheat biscuits supplemented with peony seed oil and chia seed

Abstract Nowadays, peony seed oil (PSO) and chia seed (CS) provide a vast potential in the industries of animal feed, food, nutraceutical, pharmaceuticals, and health. In this paper, study on PSO and CS were added into biscuits, and improvement in the nutraceutical properties of biscuits. The studies indicated that biscuits of acceptable overall quality could be prepared using the content of incorporation of PSO (15 g) and CS (12 g) formulations. The total dietary fiber content was positively correlated with different content of PSO and CS. The body weight of the mice in high dose group was lower than that of control group and other groups, indicating that the components PSO and CS in the biscuits could significantly control the body weight of the mice. From the fourth week, average daily food intake of mice in high dose group was significantly lower compared to control group. However, the grasping power of mice in high dose group increased significantly. With the increase in the content of PSO and CS of biscuits, the DPPH radical scavenging activity increased, too. Thus, the results indicated that whole wheat biscuits supplemented with PSO and CS could be considered as dietary fiber-enriched food, and have antioxidant properties

First-principles study of ground state properties and high pressure behavior of ThO2

The mechanical properties, electronic structure and phonon dispersion of ground state ThO$_{2}$ as well as the structure behavior up to 240 GPa are studied by using first-principles density-functional theory. Our calculated elastic constants indicate that both the ground state fluorite structure and high pressure cotunnite structure of ThO$_{2}$ are mechanically stable. The bulk modulus, shear modulus, and Young's modulus of cotunnite ThO$_{2}$ are all smaller by approximately 25% compared with those of fluorite ThO$_{2}$. The Poisson's ratios of both structures are approximately equal to 0.3 and the hardness of fluorite ThO$_{2}$ is 27.33 GPa. The electronic structure and bonding nature of fluorite ThO$_{2}$ are fully analyzed, which show that the Th-O bond displays a mixed ionic/covalent character. The valence of Th and O ions in fluorite ThO$_{2}$ can be represented as Th$^{3.834+}$ and O$^{0.452-}$. The phase transition from the fluorite to cotunnite structure is calculated to be at the pressure of 26.5 GPa, consistent with recent experimental measurement by Idiri \emph{et al}. \cite{Idiri}. For the cotunnite phase it is further predicted that an isostructural transition takes place in the pressure region of 80 to 130 GPa.Comment: 9 pages, 10 figure

Unveiling the domino effect: a nine-year follow-up on pentalogy of central nervous system induced by a large unruptured cerebral arteriovenous malformation: a case report and literature review

BackgroundThe disruption of intracranial fluid dynamics due to large unruptured cerebral arteriovenous malformation (AVM) commonly triggers a domino effect within the central nervous system. This phenomenon is frequently overlooked in prior clinic and may lead to catastrophic misdiagnoses. Our team has documented the world’s first case of so-called AVM Pentalogy (AVMP) induced by a AVM.Clinical presentation and resultA 30-year-old female was first seen 9 years ago with an occasional fainting, at which time a huge unruptured AVM was discovered. Subsequently, due to progressive symptoms, she sought consultations from several prestigious neurosurgical departments in China, where all consulting neurosurgeons opted for conservation treatment due to perceived surgical risks. During the follow-up period, the patient gradually presented with hydrocephalus, empty sella, secondary Chiari malformation, syringomyelia, and scoliosis (we called as AVMP). When treated in our department, she already displayed numerous symptoms, including severe intracranial hypertension. Our team deduced that the hydrocephalus was the primary driver of her AVMP symptoms, representing the most favorable risk profile for intervention. As expected, a ventriculoperitoneal shunt successfully mitigated all symptoms of AVMP at 21-months post-surgical review.ConclusionDuring the monitoring of unruptured AVM, it is crucial to remain vigilant for the development or progression of AVMP. When any component of AVMP is identified, thorough etiological studies and analysis of cascade reactions are imperative to avert misdiagnosis. When direct AVM intervention is not viable, strategically addressing hydrocephalus as part of the AVMP may serve as the critical therapeutic focus

Increased Drp1 promotes autophagy and ESCC progression by mtDNA stress mediated cGAS-STING pathway.

Background: Mitochondrial dynamics homeostasis is important for cell metabolism, growth, proliferation, and immune responses. The critical GTPase for mitochondrial fission, Drp1 is frequently upregulated in many cancers and is closely implicated in tumorigenesis. However, the mechanism underling Drp1 to influence tumor progression is largely unknown, especially in esophageal squamous cell carcinoma (ESCC). Methods: Immunohistochemistry was used to examine Drp1 and LC3B expression in tissues of ESCC patients. Autophagic vesicles were investigated by transmission electron microscopy. Fluorescent LC3B puncta and mitochondrial nucleoid were observed by fluorescent and confocal microscopy. Mitochondrial function was evaluated by mitochondrial membrane potential, ROS and ATP levels. Xenograft tumor model was performed in BALB/c nude mice to analyze the role of Drp1 on ESCC progression. Results: We found that Drp1 high expression is correlated with poor overall survival of ESCC patients. Drp1 overexpression promotes cell proliferation and xenograft ESCC tumor growth by triggering autophagy. Furthermore, we demonstrated that Drp1 overexpression disturbs mitochondrial function and subsequent induces mitochondrial DNA (mtDNA) released into the cytosol thereby inducing cytosolic mtDNA stress. Mechanistically, cytosolic mtDNA activates the cGAS-STING pathway and facilitates autophagy, which promotes ESCC cancer growth. Moreover, mtDNA digestion with DNase I and autophagy inhibition with chloroquine attenuates the cGAS-STING pathway activation and ESCC cancer growth. Conclusions: Our finding reveals that Drp1 overexpression induces mitochondrial dysfunction and cytosolic mtDNA stress, which subsequently activates the cGAS-STING pathway, triggers autophagy and promotes ESCC progression

Fe3O4–Au and Fe2O3–Au Hybrid Nanorods: Layer-by-Layer Assembly Synthesis and Their Magnetic and Optical Properties

A layer-by-layer technique has been developed to synthesize FeOOH–Au hybrid nanorods that can be transformed into Fe2O3–Au and Fe3O4–Au hybrid nanorods via controllable annealing process. The homogenous deposition of Au nanoparticles onto the surface of FeOOH nanorods can be attributed to the strong electrostatic attraction between metal ions and polyelectrolyte-modified FeOOH nanorods. The annealing atmosphere controls the phase transformation from FeOOH–Au to Fe3O4–Au and α-Fe2O3–Au. Moreover, the magnetic and optical properties of as-synthesized Fe2O3–Au and Fe3O4–Au hybrid nanorods have been investigated

Protective Effect of Quercetin against Oxidative Stress-Induced Cytotoxicity in Rat Pheochromocytoma (PC-12) Cells

Oxidative stress has been implicated in the pathogenesis of many kinds of neurodegenerative disorders, particularly Parkinson’s disease. Quercetin is a bioflavonoid found ubiquitously in fruits and vegetables, and has antioxidative activity. However, the underlying mechanism of the antioxidative effect of quercetin in neurodegenerative diseases has not been well explored. Here, we investigated the antioxidative effect and underlying molecular mechanisms of quercetin on PC-12 cells. We found that PC-12 cells pretreated with quercetin exhibited an increased cell viability and reduced lactate dehydrogenase (LDH) release when exposed to hydrogen peroxide (H2O2). The significantly-alleviated intracellular reactive oxygen species (ROS), malondialdehyde (MDA), and lipoperoxidation of the cell membrane of PC-12 cells induced by H2O2 were observed in the quercetin pretreated group. Furthermore, quercetin pretreatment markedly reduced the apoptosis of PC-12 cells and hippocampal neurons. The inductions of antioxidant enzyme catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in PC-12 cells exposed to H2O2 were significantly reduced by preatment with quercetin. In addition, quercetin pretreatment significantly increased Bcl-2 expression, and reduced Bax, cleaved caspase-3 and p53 expressions. In conclusion, this study demonstrated that quercetin exhibited a protective effect against oxidative stress-induced apoptosis in PC-12 cells. Our findings suggested that quercetin may be developed as a novel therapeutic agent for neurodegenerative diseases induced by oxidative stress

Structure Analysis Research of Transportation Major Curriculum System in Application-Oriented Universities under the Perspective of Engineering Education Accreditation

Engineering education accreditation (EEA) is the internationally accepted engineering education quality guarantee system, and it is the important foundation of international mutual recognition for engineering education and qualifications. First, in contrast to the criteria of EEA, the domestic construction of the transportation major curriculum system is analyzed at the present situation, and the DEMATEL-AISM model to carry out structural analysis research on the transportation major curriculum system in the application-oriented universities is established. Furthermore, the transportation major in Liaocheng University is taken as an example and the adversarial hierarchical topology map of the curriculum system, based on the DEMATEL-AISM model, is created. Finally, a curriculum structure is built which could adapt to the school-running characteristics and talents training goal. Through exploration and practice, the curriculum structure improves the transportation major educational objectives to achieve social fitness and provides a reference for the transportation major curriculum construction in colleges, especially application-oriented universities

Structure Analysis Research of Transportation Major Curriculum System in Application-Oriented Universities under the Perspective of Engineering Education Accreditation

Engineering education accreditation (EEA) is the internationally accepted engineering education quality guarantee system, and it is the important foundation of international mutual recognition for engineering education and qualifications. First, in contrast to the criteria of EEA, the domestic construction of the transportation major curriculum system is analyzed at the present situation, and the DEMATEL-AISM model to carry out structural analysis research on the transportation major curriculum system in the application-oriented universities is established. Furthermore, the transportation major in Liaocheng University is taken as an example and the adversarial hierarchical topology map of the curriculum system, based on the DEMATEL-AISM model, is created. Finally, a curriculum structure is built which could adapt to the school-running characteristics and talents training goal. Through exploration and practice, the curriculum structure improves the transportation major educational objectives to achieve social fitness and provides a reference for the transportation major curriculum construction in colleges, especially application-oriented universities