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Molecular characterization of interactions between lectin - a protein from common edible mushroom (Agaricus bisporus) - and dietary carbohydrates
No full textThis work investigates the molecular interactions between Agaricus bisporus lectin (ABL) and the dietary carbohydrates, glucose and galactose, in comparison to their N-acetylated amino sugar counterparts. Intrinsic fluorescence quenching suggests the presence of binding between ABL and each of the investigated ligands (glucose, galactose, N-acetyl-d-glucosamine and N-acetyl-d-galactosamine), with the former exhibiting the strongest interaction. Molecular docking highlights the likely binding positions, showing the presence of stable interactions between protein and ligands. The conformational difference of a single epimeric hydroxyl group at carbon four of the sugar ring appears to be the main factor in determining binding location, with galactose containing molecules favouring the T-antigen binding site whereas glucose containing molecules favouring another binding location. Fourier transform infrared (FTIR) and circular dichroism (CD) record spectral changes, suggesting that the heterologous interactions affect the secondary structure of the protein molecule. The magnitude of structural alteration in the complex is related to the binding strength. Findings provide a theoretical basis for the potential application of ABL in functional foods and hypoglycaemic nutraceuticals, as well as contributing to the fundamental understanding of the molecular mechanism behind ABL and dietary carbohydrate complexation
Mechanistic insights into α-amylase inhibition, binding affinity and structural changes upon interaction with gallic acid
No full textThe inhibitory mechanism of gallic acid (GA) on α-amylase was investigated through enzymatic inhibition assays, multi-spectroscopy, Job plot analysis and in-silico molecular docking. The results reveal that GA competitively binds to the active site of α-amylase in a 1:1 stoichiometry, dominantly via four hydrogen bonds and one hydrophobic interaction. The α-amylase-GA complex showed an increased thermal stabilisation, accompanied by a rise in α-helical and β-sheet components, resulting in a partial folding of the protein structure. The compact structure prevents substrate binding and inhibits enzyme activity. The self-quenching ability of GA was considered in the intrinsic fluorescence analysis, revealing a distinct loss in fluorescence intensity with a blueshift in the α-amylase-GA complex spectra. This observation suggests a direct interaction between GA and tryptophan amino acid residues, as the residues move to a more hydrophobic environment. Findings in this study provide insights into the interaction mechanism between GA and α-amylase, which will aid in understanding the inhibitory mechanism of their complex forms found in nature
Dynamic Operating Envelope-Based Local Energy Market for Prosumers with Electric Vehicles
No full textThis paper presents a new framework for the management of prosumers with electric vehicles (EVs) and photovoltaic (PV) systems in a local energy market (LEM) using the dynamic operating envelope (DOE) that secures the network operation for prosumers' trading and allows prosumers to manage EVs charge/discharge with PV systems. Prosumers can configure the charge/discharge status of their EVs depending on mobility and determine their net import/export power which will be used to establish DOEs. The proposed framework incorporates a bidding strategy to enable prosumers to participate in the LEM within DOE limits, and peer-to-peer (P2P) energy trading is developed to offer economic benefits to prosumers. The framework's performance is evaluated with a 100% penetration level of EVs and PV systems on the IEEE 55- node low-voltage European test system. The simulation results demonstrate that DOEs can facilitate prosumers in managing their imports/exports for trading without violating voltage and congestion limits. The proposed framework efficiently manages EV charging/discharging with PV systems and enables prosumers to make optimal bids within DOEs, thereby benefiting from P2P trading in the LEM
Efficiently Identifying Unknown COTS RFID Tags for Intelligent Transportation Systems
No full textOver the last decade, the Internet of Things (IoT) technology has advanced significantly in a variety of fields. As a pivotal application of IoT, intelligent transportation systems (ITS) have harvested great attention from the research community. Radio frequency identification (RFID) which is an essential technology in IoT plays a key role in ITS to identify tagged vehicles. Unknown tag identification which aims at identifying the existing unknown tags is crucial to monitor the newly entering vehicles in the RFID-assisted intelligent transportation systems. However, the COTS (commercial-off-the-shelf) RFID tags that harvest energy from the reader can not support the hash function in reality, which hinders the widespread deployment of hash-enabled unknown tag identification protocols. To conquer this tough issue, we propose two approaches to efficiently identify unknown COTS RFID tags. We first propose a Single-Point Selective unknown tag identification approach called SPS, where an analog hash pattern using the EPC (Electronic Product Code) segments is deployed to exclusively identify unknown tags. An unknown tag will be identified when it selects a singleton slot to reply. To improve the time efficiency of SPS, we further propose a Multi-Point Selective unknown tag identification approach called MPS. In MPS, two techniques of batch identification and batch division are developed to reduce the number of empty slots and avoid tag collisions, respectively. Then the parameters are theoretically analyzed to maximize the identification efficiency. The effectiveness of the proposed approaches is validated via both the simulations and COTS RFID device based experiments
Faster and lower dose imaging: evaluating adaptive, constant gantry velocity and angular separation in fast low-dose 4D cone beam CT imaging
No full textBackground: The adoption of four-dimensional cone beam computed tomography (4DCBCT) for image-guided lung cancer radiotherapy is increasing, especially for hypofractionated treatments. However, the drawbacks of 4DCBCT include long scan times (∼240 s), inconsistent image quality, higher imaging dose than necessary, and streaking artifacts. With the emergence of linear accelerators that can acquire 4DCBCT scans in a short period of time (9.2 s) there is a need to examine the impact that these very fast gantry rotations have on 4DCBCT image quality. Purpose: This study investigates the impact of gantry velocity and angular separation between x-ray projections on image quality and its implication for fast low-dose 4DCBCT with emerging systems, such as the Varian Halcyon that provide fast gantry rotation and imaging. Large and uneven angular separation between x-ray projections is known to reduce 4DCBCT image quality through increased streaking artifacts. However, it is not known when angular separation starts degrading image quality. The study assesses the impact of constant and adaptive gantry velocity and determines the level when angular gaps impair image quality using state-of-the-art reconstruction methods. Methods: This study considers fast low-dose 4DCBCT acquisitions (60–80 s, 200-projection scans). To assess the impact of adaptive gantry rotations, the angular position of x-ray projections from adaptive 4DCBCT acquisitions from a 30-patient clinical trial were analyzed (referred to as patient angular gaps). To assess the impact of angular gaps, variable and static angular gaps (20°, 30°, 40°) were introduced into evenly separated 200 projections (ideal angular separation). To simulate fast gantry rotations, which are on emerging linacs, constant gantry velocity acquisitions (9.2 s, 60 s, 120 s, 240 s) were simulated by sampling x-ray projections at constant intervals using the patient breathing traces from the ADAPT clinical trial (ACTRN12618001440213). The 4
Advanced Manufacturing in Industry 5.0: A Survey of Key Enabling Technologies and Future Trends
No full textA revolution in advanced manufacturing has been driven by digital technology in the fourth industrial revolution, also known as Industry 4.0, and has resulted in a substantial increase in profits for the industry. In a new paradigm of Industry 5.0, advanced manufacturing will step further and be capable of offering customized products and a better user experience. A number of key enabling technologies are expected to play crucial roles in assisting Industry 5.0 in meeting higher demands of data acquisition and processing, communications, and collaborative robots in the advanced manufacturing process. The aim of this survey is to provide novel insights into advanced manufacturing in Industry 5.0 by summarizing the latest progress of key enabling technologies such as Artificial Intelligence of Things (AIoT), beyond 5G communications, and collaborative robotics. Finally, key directions for future research to enable this vision to become a reality, such as the industrial metaverse, are outlined
Study on Nonlinear Vibration Stiffness Calculation of Two Ends of Cable Between Struts in a Beam String Structure
No full textPurpose: For fixed or hinged single cables, the vibration equation is well developed. However, the form of boundary constraints between fixed and hinged is used extensively for the single cable in practical engineering, such as the restraint of struts between multi-span cables. As the struts with different lengths and stiffness are placed in the single cable, the mode shape of the multi-span cables is affected significantly. Moreover, with the decrease in the aspect ratio of single-span cable, the effect of the cable bending stiffness cannot be overlooked. The above effects in single and multi-span cables are studied in the proposed model. Methods: The vibration equation of the multi-span cable is developed in two steps. To establish the vibration equation of the single cable with general elastic constraint, the constraints at the ends of the strut are simplified as the compression springs that can bear the pressure. The bending springs that can consider the bending stiffness are also set at both ends simultaneously, then the vibration equation of the single cable with a general elastic constraint can be derived. For a multi-span cable structure, the strut is simplified into the elastic constraints of a single-span cable. By combining the aforementioned vibration equations of single-span cables which have general constraints, the vibration equation of multi-span cables can be established. Results: The vibration frequency equations of m span multi-span cable with constraint stiffness are established, and the objective function optimization algorithm is validated. Conclusion: The analytical solution of the multi-span cable vibration equation in this paper is then validated by the comparison with the multi-span cable vibration model established by the finite element method. The comparison demonstrated that the proposed method is valid and practical
Beyond effective approaches: A rapid review response to designing professional learning
No full textProfessional learning (PL) in education is thought to be a key mechanism for improving classroom instruction and student achievement. Yet despite decades of research into PL, the impact of this investment is not well understood, with reports of limited change in both research and practice. As part of a large-scale investigation focusing on practitioner use of evidence in education, the authors undertook a rapid review to understand what is known about effective PL for K-12 school-based educators. Based on analysis and synthesis of 12 included studies, the review identified eight features of effective PL: collaboration; active learning and reflection; content and pedagogy in context; sustained duration; coaching; external expertise; models and modelling; and, audience and alignment. It also highlighted additional considerations for effective PL, including workplace conditions, PL providers, and online and blended approaches. This paper argues that though there is a consensus around effective PL features, there is a need to go beyond ‘effective approaches’ and consider the broader conditions and methodological limitations that impact improved and sustained change. Overall, this paper has implications for understanding the research landscape around effective PL, and applying an evidence-informed approach to designing PL programmes
Corrosion behavior and mechanical property of Mg-4Li-1Ca alloys under micro-compressive stress
No full textBiomedical materials may suffer from stress-induced corrosion when performing as implant materials at load-bearing sites, bringing about variations in the microstructure, corrosion resistance, and mechanical properties. In this study, the corrosion behavior and mechanical properties of an extruded Mg-4Li-1Ca alloy were investigated under different micro-compressive stresses (0–6 MPa) using a novel homemade loading device. Under 0–3 MPa of micro-compressive stress, the strong basal texture of extruded Mg-4Li-1Ca alloys was weakened and the internal stress gradient stimulated grain boundary migration to induce grain growth. Meanwhile, increased stress resulted in the precipitation of second-phase particles and the accumulation of residual stress, accelerating the corrosion rate due to preferential corrosion. However, with increasing stress, the volume fraction of the second phase increased, becoming the dominant factor controlling the corrosion rate, and residual stress was released for samples under 4.5–6 MPa of micro-compressive stress. Hence, surface corrosion product films rapidly formed and served as effective physical barriers, weakening the microstructural effect on the corrosion behavior. The yield strength of Mg-4Li-1Ca alloy reached 95.48 MPa under 3 MPa of micro-compressive stress owing to the dual effects of precipitation strengthening and shear-band strengthening. The relationships between microstructure, corrosion behavior, and mechanical property provide a theoretical foundation for understanding the degradation characteristics of the Mg-4Li-1Ca alloy under physiological loading and practical application
A repository of COVID-19 related molecular dynamics simulations and utilisation in the context of nsp10-nsp16 antivirals
No full textThe coronavirus disease 2019 (COVID-19) pandemic highlighted the importance of establishing systems and infrastructure to develop vaccines, antiviral drugs, and therapeutic antibodies against emerging pathogens. Typical drug discovery processes involve targeting suitable proteins to effect pathogen replication or to attenuate host responses, by examining either large chemical databases or protein-protein interactions. Following initial screens, molecular dynamics (MD) simulations are critical for gaining further insight into molecular interactions. During the COVID-19 pandemic, many research groups made their simulations widely available, as highlighted by the comprehensive D.E. Shaw Research trajectory database. To investigate protein target sites and evaluate potential lead compounds, we performed over 300 MD simulations relating to COVID-19. We organised our simulations into a repository, which is publicly available at https://epimedlab.org/trajectories/. The trajectories cover a large part of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteome, and the majority of our MD simulations focused on the identification of potential antivirals. For example, we focused on the S-adenosyl-l-methionine binding site of the nsp10-nsp16 complex, a critical component of viral replication, revealing verbascoside as a potential lead. Moreover, we utilised MD trajectories to explore the interface between the spike protein receptor binding domain and human angiotensin-converting enzyme 2 receptor, with the ultimate aim being investigation of new variants in real-time. Overall, MD simulations are a critical component of the in silico drug discovery process and as highlighted throughout the pandemic, data sharing enables accelerated progress. We have organised our extensive collection of COVID-19 related MD trajectories into an easily accessible repository