New therapeutic directions in type II diabetes and its complications: mitochondrial dynamics

As important organelles of energetic and metabolism, changes in the dynamic state of mitochondria affect the homeostasis of cellular metabolism. Mitochondrial dynamics include mitochondrial fusion and mitochondrial fission. The former is coordinated by mitofusin-1 (Mfn1), mitofusin-2 (Mfn2), and optic atrophy 1 (Opa1), and the latter is mediated by dynamin related protein 1 (Drp1), mitochondrial fission 1 (Fis1) and mitochondrial fission factor (MFF). Mitochondrial fusion and fission are generally in dynamic balance and this balance is important to preserve the proper mitochondrial morphology, function and distribution. Diabetic conditions lead to disturbances in mitochondrial dynamics, which in return causes a series of abnormalities in metabolism, including decreased bioenergy production, excessive production of reactive oxygen species (ROS), defective mitophagy and apoptosis, which are ultimately closely linked to multiple chronic complications of diabetes. Multiple researches have shown that the incidence of diabetic complications is connected with increased mitochondrial fission, for example, there is an excessive mitochondrial fission and impaired mitochondrial fusion in diabetic cardiomyocytes, and that the development of cardiac dysfunction induced by diabetes can be attenuated by inhibiting mitochondrial fission. Therefore, targeting the restoration of mitochondrial dynamics would be a promising therapeutic target within type II diabetes (T2D) and its complications. The molecular approaches to mitochondrial dynamics, their impairment in the context of T2D and its complications, and pharmacological approaches targeting mitochondrial dynamics are discussed in this review and promise benefits for the therapy of T2D and its comorbidities

A GIS-based spatial multi-index model for flood risk assessment in the Yangtze River Basin, China

This paper developed a GIS-based spatial multi-index model for large basin-scale flood risk assessment. In terms of the risk definition proposed by the IPCC, the flood risk in the Yangtze River Basin (YRB) was classified into indexes of hazard, vulnerability, and exposure. The model systematically accounts for various flood risk indicators related to the economic, social and ecological environment of the YRB. Using the robust data space analysis and processing capabilities of ArcGIS, these flood risk indicators were superimposed and analyzed to generate an integrated flood risk spatial distribution map for the YRB. The modeling results were verified reasonably well using observation data from the YRB floods in 1998, 2008, and 2016. We found that 24.90% of the study area was at very high and high risk in 1998, and the risk in these areas decreased to 15.95% and 17.61% in 2008 and 2016, respectively. We believe that the GIS-based spatial multi-index model can be applied to other areas where basin-scale flood risk assessment is desired and contribute to further scientific research on flood forecasting and mitigation

Advanced load frequency control design approaches for a power system with penetration of renewable energy sources

Due to the boost of power systems interconnection as well as penetration of renewable energy (RE) power generation, the loads are varying dynamically. So there is a need of control of system frequency. The major objective of this thesis is aimed at advanced load frequency control (LFC) design approaches for a power system with penetration of RE power generation. First of all, the background and motivation of this topic are introduced, followed by the research status summary of three main components used in the proposed control scheme, namely, power system interconnection, LFC and battery energy storage system (BESS). After that, the concept of LFC in a interconnected power system with BESS is coined. Then, different types of battery models are introduced. And based on the I type Thevenin equivalent circuit, BESS model is set up. Subsequently, an adaptive variable droop control strategy is introduced to mitigate the defects of conventional control strategy. After that, every link in LFC including governor, turbine, GRC, generator and load are elaborated. On this basis, the single area LFC model is built. Afterwards, considering the power exchange in tie line, the single area LFC model is expanded to multi-area LFC model. Together with the proposed BESS, the model for LFC in a multi-area power system with BESS is established. Finally, the proposed models are tested based on Matlab/Simulink. The simulation findings show that the suggested control scheme is able to significantly improve the dynamic response of the power system to a sudden load change, and has certain practical engineering significance.Master of Science (Power Engineering

VIRTUAL COMMUNITY TRIALS PLATFORM

With the evolutions of technologies of computer, network, remote sensing and GIS, CyberCity researches are dramatically being improved, and CyberCity applications are becoming more and more important in our world. As the minimum unit for people’s living in a city, community is a primary part of city management. Therefore, virtual community plays a key role in CyberCity. Virtual Community is not only the key node to combine families with the city, but also the indispensable part to construct digital nation in China. In this paper, the architecture and function structure of a proposed virtual community trials platform are presented. Three sub-systems like 3D real-time walkthrough, community services and community managements are included in this platform system. With a virtual community system, residents in a real community may login a specific virtual community via Internet with a computer (or a handheld device) at any site, and then may acquire some information about their real communities. They can order commodities via online E-Commerce, and even acquire some services like education, entertainment and health care, or online work. On the other hand, managers and service providers can provide knight service and manage efficiently with the virtual community system. 1

Floor heave mechanism for gob-side entry retaining with concrete blocks and control method: A case study

The issue of significant floor heave deformation in gob-side entry retaining has long been a challenging problem in the context of longwall mining. This paper studies the floor heave failure mechanism and control method for gob-side entry retaining with concrete blocks in Guizhou Faer Coal Mine in China. Based on Rankine’s earth pressure theory, the effective shear stress equation for the plastic slip of roadway floor is established. The deformation mechanism of floor heave in a retaining roadway with a block wall is revealed in this study. The new comprehensive control method is proposed, encompassing roof pre-splitting blasting for pressure relief, reinforcing cables for roof control, double directions control bolts for concrete block, and pliability cushion yielding pressure. FLAC3D numerical calculation model is established, which shows that the new method can effectively reduce the average vertical stress peak value of the entity coal floor by 34.6% and significantly reduce the pressure source causing the roadway floor heave. Besides, a multi-parameter real-time online monitoring system for mine pressure was designed, and field tests were carried out. The results show that the maximum value of roadway floor heave under the new method is 163 mm, reduced by 66.9%, and the roadway floor heave is effectively controlled. These research findings offer a fresh perspective and new ideas for controlling floor heave in mining operations

Transformation of the Topological Phase and the Edge Modes of Double-Bilayer Bismuthene with Inter-Bilayer Spacing

The transformations of the topological phase and the edge modes of a double-bilayer bismuthene were investigated with first-principles calculations and Green’s function as the inter-bilayer spacing increased from 0 Å to 10 Å. At a critical spacing of 2 Å, a topological phase transition from a topological insulator to a band insulator resulting from a band inversion between the highest valence band and the second lowest conduction band, was observed, and this was understood based on the particular orbital characters of the band inversion involved states. The edge modes of double-bilayer bismuthene survived the phase transition. When d was 2 Å < d < 4 Å, the interaction between the edge modes of two separated bismuthene bilayers induced an anti-crossing gap and resulted in a trivial band connection. At and beyond 4 Å, the two bilayers behavior decoupled entirely. The results demonstrate the transformability of the topological phase and the edge modes with the inter-bilayer spacing in double-bilayer bismuthene, which may be useful for spintronic applications

Molecular characterization of a whirlin-like protein with biomineralization-related functions from the shell of Mytilus coruscus.

Mollusc shells are produced from calcified skeletons and have excellent mechanical properties. Shell matrix proteins (SMPs) have important functions in shell formation. A 16.6 kDa whirlin-like protein (WLP) with a PDZ domain was identified in the shell of Mytilus coruscus as a novel SMP. In this study, the expression, function, and location of WLP were analysed. The WLP gene was highly expressed and specifically located in the adductor muscle and mantle. The expression of recombinant WLP (rWLP) was associated with morphological change, polymorphic change, binding ability, and crystallization rate inhibition of the calcium carbonate crystals in vitro. In addition, an anti-rWLP antibody was prepared, and the results from immunohistochemistry and immunofluorescence analyses revealed the specific location of the WLP in the mantle, adductor muscle, and myostracum layer of the shell, suggesting multiple functions for WLP in biomineralization, muscle-shell attachment, and muscle attraction. Furthermore, results from a pull-down analysis revealed 10 protein partners of WLP in the shell matrices and a possible network of interacting WLPs in the shell. In addition, in this study, one of the WLP partners, actin, was confirmed to have the ability to bind WLP. These results expand the understanding of the functions of PDZ-domain-containing proteins in biomineralization and provide clues for determining the mechanisms of myostracum formation and muscle-shell attachment

Smooth Speed Control of Permanent Magnet Synchronous Machine Using Back Propagation Neural Network

Torque ripple is one of the most critical problems in PMSM system. In this paper, a neural network (NN) torque compensator is combined with a conventional extended state observer (ESO)-based active disturbance rejection controller (ADRC) system to suppress the torque ripple at wide machine operation speed range by generating the optimal current reference. The ESO is able to estimate and reject the low-frequency component in the torque ripple, while the remaining disturbances can be learned and compensated by the neural network. Compared with commonly used schemes, the proposed method does not need to analyze the influence of various sources of the torque ripple, such as the cogging torque, non-sinusoidal back-EMF, parameter variations, and unmodeled disturbances. In addition, the simple structure of the neural network helps reduce the computation time and save computer memory. The effectiveness of the proposed neural network compensator with both the rotor position and mechanical angular velocity as inputs is verified in the experiment under different operation speeds

He-ion Irradiation Effects on the Microstructures and Mechanical Properties of the Ti-Zr-Hf-V-Ta Low-Activation High-Entropy Alloys

High-entropy alloys (HEAs) have shown promising potential applications in advanced reactors due to the outstanding mechanical properties and irradiation tolerance at elevated temperatures. In this work, the novel low-activation Ti2ZrHfxV0.5Ta0.2 HEAs were designed and prepared to explore high-performance HEAs under irradiation. The microstructures and mechanical properties of the Ti2ZrHfxV0.5Ta0.2 HEAs before and after irradiation were investigated. The results showed that the unirradiated Ti2ZrHfxV0.5Ta0.2 HEAs displayed a single-phase BCC structure. The yield strength of the Ti2ZrHfxV0.5Ta0.2 HEAs increased gradually with the increase of Hf content without decreasing the plasticity at room and elevated temperatures. After irradiation, no obvious radiation-induced segregations or precipitations were found in the transmission electron microscope results of the representative Ti2ZrHfV0.5Ta0.2 HEA. The size and number density of the He bubbles in the Ti2ZrHfV0.5Ta0.2 HEA increased with the improvement of fluence at 1023 K. At the fluences of 1 × 1016 and 3 × 1016 ions/cm2, the irradiation hardening fractions of the Ti2ZrHfV0.5Ta0.2 HEA were 17.7% and 34.1%, respectively, which were lower than those of most reported conventional low-activation materials at similar He ion irradiation fluences. The Ti2ZrHfV0.5Ta0.2 HEA showed good comprehensive mechanical properties, structural stability, and irradiation hardening resistance at elevated temperatures, making it a promising structural material candidate for advanced nuclear energy systems

Improved low-frequency disturbance rejection property for position control of PMSM using generalized extended state observer

In the conventional active disturbance rejection (ADR) controller for position control, a classical third-order extended state observer (ESO) is used and thus the system is only able to reject a constant disturbance. Though generalized ESO (GESO) has been reported in speed control systems to enhance the low-frequency disturbance rejection property, its implementation in position control system differs because additional position feedback affects system dynamic performance. In this paper, ADR controller integrating proportional and derivative (PD) feedback control and a fourth-order GESO is developed to improve the low-frequency disturbance rejection property. The effect of using different position feedback is analyzed. To simplify the design process, the position controller is modified to have a comparable structure to the speed controller, allowing design methodologies used in the speed control system to be applied to the position control system. Experimental results are presented to demonstrate the effectiveness of the proposed method.National Research Foundation (NRF)Submitted/Accepted versionThis work was supported in part by the National Research Foundation (NRF) Singapore through its NRF Fellowship under Grant NRF-NRFF12- 2020-0003