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Differential-based biosensor array for fluorescence-chemometric discrimination and the quantification of subtle chloropropanols by cross-reactive serum albumin scaffolding
No full textFood contamination is a serious concern because of a high level of chemicals in food causes severe health issues. Safeguarding the public from the risk of adulterated foods has become a challenging mission. Chloropropanols are of importance to food safety and food security because they are common chemical food contaminants and believed to be carcinogenic to humans. In chemical sensing, chloropropanols are challenging analytes owing to the lacking diversity of functional groups and difficulty in targeting the hydroxyl group in aqueous environments. Moreover, because of their small molecular size, the compositions of chloropropanols remain challenging for achieving chromatographic determination. Herein, to simulate human smell and taste sensations, serum albumins, which are protein-based receptors, were introduced as low-selective receptors for differential sensing. Utilizing serum albumins, a fluorophore (PRODAN), and an additive (ascorbic acid), a differential-based optical biosensor array was developed to detect and differentiate chloropropanols. By integrating the sensor array with linear discriminant analysis (LDA), four chloropropanols were effectively differentiated based on their isomerism properties and the number of the hydroxyl groups, even at ultra-low concentration (5 nM). This concentration is far below the maximum tolerable level of 0.18 μM for chloropropanols. The sensing array was then employed for chloropropanols differentiation and quantification in the complex mixtures (e.g., synthetic soy and dark soy sauces). Leave-one-out cross-validation (LOOCV) analysis demonstrated 100% accurate classification for all tests. These results signify our differential sensing array as a practical and powerful tool to speedily identify, differentiate, and even quantify chloropropanols in food matrices. © 2020 Elsevier B.V
Development of small molecule inhibitors targeting TGF-β ligand and receptor: Structures, mechanism, preclinical studies and clinical usage
No full textTransforming growth factor-β (TGF-β) is a member of a superfamily of pleiotropic proteins that regulate multiple cellular processes such as growth, development and differentiation. Following binding to type I and II TGF-β serine/threonine kinase receptors, TGF-β activates downstream signaling cascades involving both SMAD-dependent and -independent pathways. Aberrant TGF-β signaling is associated with a variety of diseases, such as fibrosis, cardiovascular disease and cancer. Hence, the TGF-β signaling pathway is recognized as a potential drug target. Various organic molecules have been designed and developed as TGF-β signaling pathway inhibitors and they function by either down-regulating the expression of TGF-β or by inhibiting the kinase activities of the TGF-β receptors. In this review, we discuss the current status of research regarding organic molecules as TGF-β inhibitors, focusing on the biological functions and the binding poses of compounds that are in the market or in the clinical or pre-clinical phases of development. © 2020 Elsevier Masson SA
Comparison of sunlight-driven photocatalytic activity of semiconductor metal oxides of tin oxide and cadmium oxide nanoparticles
No full textThis study is aimed to investigate the photocatalytic efficiencies of two different metal oxide nanoparticles (NPs), SnO2 and CdO formed by the simple chemical precipitation route. The synthesized metal oxide NPs were examined by several techniques in order to understand the morphological (FESEM), structural (XRD), functional (FTIR), and optical (UV-vis) characteristics. The analysis of results confirmed the successful formation of SnO2 and CdO NPs along with their desired chemical compositions and electronic band structures. Further testing of their photocatalytic efficiency with the use of methylene blue (MB) degradation in the presence of sunlight confirmed their catalytic efficiency. Within the two NPs, the SnO2 has a little higher activity as compared to the CdO NPs and this can be attributed to the increased surface area by means of the formation of nanospheres for the SnO2 ones, while the rod-shaped agglomerated structure with less surface area delaying the rate of degradation. Further from the analysis, it can be confirmed for the superior photocatalytic activity of SnO2 particles having spherical shape against the rod-shaped CdO NPs. © 2020 Elsevier Gmb
Increase of Input Resistance of a Normal-Mode Helical Antenna (NMHA) in Human Body Application
No full textIn recent years, the development of healthcare monitoring devices requires high performance and compact in-body sensor antennas. A normal-mode helical antenna (NMHA) is one of the most suitable candidates that meets the criteria, especially with the ability to achieve high efficiency when the antenna structure is in self-resonant mode. It was reported that when the antenna was placed in a human body, the antenna efficiency was decreased due to the increase of its input resistance (Rin). However, the reason for Rin increase was not clarified. In this paper, the increase of Rin is ensured through experiments and the physical reasons are validated through electromagnetic simulations. In the simulation, the Rin is calculated by placing the NMHA inside a human’s stomach, skin and fat. The dependency of Rin to conductivity (σ) is significant. Through current distribution calculation, it is verified that the reason of the increase in Rin is due to the decrease of antenna current. The effects of Rin to bandwidth (BW) and electrical field are also numerically clarified. Furthermore, by using the fabricated human body phantom, the measured Rin and bandwidth are also obtained. From the good agreement between the measured and simulated results, the condition of Rin increment is clarified. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
A Lookup Table Model Predictive Direct Torque Control of Permanent-Magnet Synchronous Generator Based on Vienna Rectifier
No full textThis paper presents the development and implementation of a lookup table model predictive direct torque control (LUT-MPDTC) for a permanent-magnet synchronous generator controlled using a Vienna rectifier. Using a machine model in the stator synchronous reference frame, the feasibility of direct torque control-based model predictive control for the Vienna rectifier is demonstrated. To reduce the computational burden of the MPDTC, a lookup table (LUT) is proposed based on the stator current position and dc-link voltages. The LUT simplifies the complexity of the MPDTC by reducing the number of switching vectors from eight to five, while maintaining the stabilization of the neutral point voltage. The performance and effectiveness of the proposed method are evaluated via MATLAB/Simulink and further validated experimentally using a Texas Instrument-based TMS320F28335 development board. The simulation and experimental results show that the proposed LUT-MPDTC can successfully improve the torque and stator flux ripples as compared to the classical DTC. © 2013 IEEE
H2 Gas Sensor Based on Pd/ZnO Nanostructures Deposited on Tapered Optical Fiber
No full textA novel H2 sensor using tapered optical fiber coated with Pd/ZnO nanostructures have been developed. The ZnO nanostructures was synthesized and deposited onto tapered optical fiber via chemical bath deposition (CBD) method. The ZnO was characterized by FESEM, XRD and EDX to confirm the material properties. It was discovered that the sensor is sensitive towards different concentrations of H2 in synthetic air at 180° C of operating temperature. By varying the deposition time of ZnO coating, different thickness of ZnO layer can be obtained. It was observed that with 280 nm thickness, the maximum absorbance response can be achieved. Further investigation with sensor sample of as-prepared and annealed was carried out to study its sensing performance towards H2. The absorbance response of 280 nm thickness of annealed Pd/ZnO has increased 64% as compared to as-prepared Pd/ZnO upon 1% H2 exposure in the synthetic air when measured in the visible to near infra-red optical wavelength. It can be concluded that the Pd/ZnO optical fiber sensor with thickness around 280 nm provided better sensitivity in sensing H2 at 180°C as compared to other thicknesses investigated. © 2001-2012 IEEE
The development of a novel transforming growth factor-β (TGF-β) inhibitor that disrupts ligand-receptor interactions
No full textTransforming growth factor-β (TGF-β) plays an important role in regulating epithelial to mesenchymal transition (EMT) and the TGF-β signaling pathway is a potential target for therapeutic intervention in the development of many diseases, such as fibrosis and cancer. Most currently available inhibitors of TGF-β signaling function as TGF-β receptor I (TβR-I) kinase inhibitors, however, such kinase inhibitors often lack specificity. In the present study, we targeted the extracellular protein binding domain of the TGF-β receptor II (TβR-II) to interfere with the protein-protein interactions (PPIs) between TGF-β and its receptors. One compound, CJJ300, inhibited TGF-β signaling by disrupting the formation of the TGF-β-TβR-I-TβR-II signaling complex. Treatment of A549 cells with CJJ300 resulted in the inhibition of downstream signaling events such as the phosphorylation of key factors along the TGF-β pathway and the induction of EMT markers. Concomitant with these effects, CJJ300 significantly inhibited cell migration. The present study describes for the first time a designed molecule that can regulate TGF-β-induced signaling and EMT by interfering with the PPIs required for the formation of the TGF-β signaling complex. Therefore, CJJ300 can be an important lead compound with which to study TGF-β signaling and to design more potent TGF-β signaling antagonists. © 2020 Elsevier Masson SA
Cellular Localization of gdnf in Adult Zebrafish Brain
No full textGlial cell line-derived neurotrophic factor (GDNF) was initially described as important for dopaminergic neuronal survival and is involved in many other essential functions in the central nervous system. Characterization of GDNF phenotype in mammals is well described; however, studies in non-mammalian vertebrate models are scarce. Here, we characterized the anatomical distribution of gdnf -expressing cells in adult zebrafish brain by means of combined in situ hybridization (ISH) and immunohistochemistry. Our results revealed that gdnf was widely dispersed in the brain. gdnf transcripts were co-localized with radial glial cells along the ventricular area of the telencephalon and in the hypothalamus. Interestingly, Sox2 positive cells expressed gdnf in the neuronal layer but not in the ventricular zone of the telencephalon. A subset of GABAergic precursor cells labeled with dlx6a-1.4kbdlx5a/6a: green fluorescence protein (GFP) in the pallium, parvocellular preoptic nucleus, and the anterior and dorsal zones of the periventricular hypothalamus also showed expression with gdnf mRNA. In addition, gdnf signals were detected in subsets of dopaminergic neurons, including those in the ventral diencephalon, similar to what is seen in mammalian brain. Our work extends our knowledge of gdnf action sites and suggests a potential role for gdnf in adult brain neurogenesis and regeneration. © 2020 by the authors
Effects of Submarine-Cable Types and Parameters on Performance of a Future-Scheduled Offshore Wind Farm Connected to Taiwan Power System
No full textSubmarine cables are indispensable for offshore wind farms (OWFs) connected to a power grid. The submarine cable can cause certain degrees of impact on the system performance due to its different lengths, characteristics, electrical parameters, etc. This paper employs the power-system simulation software of Power System Simulator for Engineering (PSS/E) for modeling a future-scheduled OWF, i.e., a large-scale doubly-fed induction generator-based OWF of 200 MW, connected to Jang-Bin distribution substation of Taiwan Power System through five feeders, five circuit breakers, two step-up power transformers, a commercial submarine cable, and an underground cable. This paper simulates and compares the electrical quantities of the studied OWF with different operating capacities under various lengths of three types of commercial submarine cable. The transient surge peak voltages at the common bus of the OWF and the bus of Jang-Bin distribution substation subject to the switching of one of the five circuit breakers of the studied OWF under different lengths of the three types of commercial submarine cable are also compared using the power-system simulation software of ATPDraw in Alternative Transients Program (ATP) version of Electromagnetic Transients Program (EMTP). © 1972-2012 IEEE
Sex Differences in Mate Preferences Across 45 Countries: A Large-Scale Replication
No full textConsiderable research has examined human mate preferences across cultures, finding universal sex differences in preferences for attractiveness and resources as well as sources of systematic cultural variation. Two competing perspectives—an evolutionary psychological perspective and a biosocial role perspective—offer alternative explanations for these findings. However, the original data on which each perspective relies are decades old, and the literature is fraught with conflicting methods, analyses, results, and conclusions. Using a new 45-country sample (N = 14,399), we attempted to replicate classic studies and test both the evolutionary and biosocial role perspectives. Support for universal sex differences in preferences remains robust: Men, more than women, prefer attractive, young mates, and women, more than men, prefer older mates with financial prospects. Cross-culturally, both sexes have mates closer to their own ages as gender equality increases. Beyond age of partner, neither pathogen prevalence nor gender equality robustly predicted sex differences or preferences across countries. © The Author(s) 2020