• Title/Summary/Keyword: Structural modification

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Synthesis and Application of Magnetoplasmonic Nanoparticles (마그네토플라즈모닉 나노 자성 입자의 합성과 응용)

  • Park, Sejeong;Hwang, Siyeong;Jung, Seonghwan;Gwak, Juyong;Lee, Jaebeom
    • Journal of Powder Materials
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    • v.28 no.5
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    • pp.429-434
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    • 2021
  • Magnetic nanoparticles have a significant impact on the development of basic sciences and nanomedical, electronic, optical, and biotech industries. The development of magnetic structures with size homogeneity, magnetization, and particle dispersibility due to high-quality process development can broaden their utilization for separation analysis, structural color optics using surface modification, and energy/catalysts. In addition, magnetic nanoparticles simultaneously exhibit two properties: magnetic and plasmon resonance, which can be self-assembled and can improve signal sensitivity through plasmon resonance. This paper reports typical examples of the synthesis and properties of various magnetic nanoparticles, especially magnetoplasmonic nanoparticles developed in our laboratory over the past decade, and their optical, electrochemical, energy/catalytic, and bio-applications. In addition, the future value of magnetoplasmonic nanoparticles can be reevaluated by comparing them with that reported in the literature.

Results Of Mathematical Modeling Of Organizational And Technological Solutions Of Effective Use Of Available Resource Of Modern Roofs

  • Arutiunian, Iryna;Mishuk, Katerina;Dankevych, Natalia;Yukhymenko, Artem;Anin, Victor;Poltavets, Maryna;Sharapova, Tetiana
    • International Journal of Computer Science & Network Security
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    • v.21 no.1
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    • pp.49-54
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    • 2021
  • Relative to the outer surface of the mastic coating, the reliability of the available waterproofing resource is determined by the ability to stabilize the structural characteristics in difficult climatic conditions. Organic components of mastic as a result of solar radiation, elevated temperatures and their alternating change, atmospheric oxidants, especially in industrial areas, have a tendency to self-polymerization and loss of low molecular weight components. This is the gradual loss of deformability and the transition to brittleness with its tendency to crack as the reasons for the gradual transition from normal to emergency operating condition.The presented mechanism of functioning of the coating surface indicates the expediency of increasing its components, able to stabilize the structure and prevent changes in deformability.Durability, hydrophobicity, water displacement, water absorption are accepted as estimating indicators. The main dependences of the influence of the lost additional components of mastic on the operational properties of the formed coating characterize the ability to provide successful resistance to environmental influences and longer stability. As a result, mastic acquires additional service life.

Synthetic Computed Tomography Generation while Preserving Metallic Markers for Three-Dimensional Intracavitary Radiotherapy: Preliminary Study

  • Jin, Hyeongmin;Kang, Seonghee;Kang, Hyun-Cheol;Choi, Chang Heon
    • Progress in Medical Physics
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    • v.32 no.4
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    • pp.172-178
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    • 2021
  • Purpose: This study aimed to develop a deep learning architecture combining two task models to generate synthetic computed tomography (sCT) images from low-tesla magnetic resonance (MR) images to improve metallic marker visibility. Methods: Twenty-three patients with cervical cancer treated with intracavitary radiotherapy (ICR) were retrospectively enrolled, and images were acquired using both a computed tomography (CT) scanner and a low-tesla MR machine. The CT images were aligned to the corresponding MR images using a deformable registration, and the metallic dummy source markers were delineated using threshold-based segmentation followed by manual modification. The deformed CT (dCT), MR, and segmentation mask pairs were used for training and testing. The sCT generation model has a cascaded three-dimensional (3D) U-Net-based architecture that converts MR images to CT images and segments the metallic marker. The performance of the model was evaluated with intensity-based comparison metrics. Results: The proposed model with segmentation loss outperformed the 3D U-Net in terms of errors between the sCT and dCT. The structural similarity score difference was not significant. Conclusions: Our study shows the two-task-based deep learning models for generating the sCT images using low-tesla MR images for 3D ICR. This approach will be useful to the MR-only workflow in high-dose-rate brachytherapy.

Impacts of label quality on performance of steel fatigue crack recognition using deep learning-based image segmentation

  • Hsu, Shun-Hsiang;Chang, Ting-Wei;Chang, Chia-Ming
    • Smart Structures and Systems
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    • v.29 no.1
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    • pp.207-220
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    • 2022
  • Structural health monitoring (SHM) plays a vital role in the maintenance and operation of constructions. In recent years, autonomous inspection has received considerable attention because conventional monitoring methods are inefficient and expensive to some extent. To develop autonomous inspection, a potential approach of crack identification is needed to locate defects. Therefore, this study exploits two deep learning-based segmentation models, DeepLabv3+ and Mask R-CNN, for crack segmentation because these two segmentation models can outperform other similar models on public datasets. Additionally, impacts of label quality on model performance are explored to obtain an empirical guideline on the preparation of image datasets. The influence of image cropping and label refining are also investigated, and different strategies are applied to the dataset, resulting in six alternated datasets. By conducting experiments with these datasets, the highest mean Intersection-over-Union (mIoU), 75%, is achieved by Mask R-CNN. The rise in the percentage of annotations by image cropping improves model performance while the label refining has opposite effects on the two models. As the label refining results in fewer error annotations of cracks, this modification enhances the performance of DeepLabv3+. Instead, the performance of Mask R-CNN decreases because fragmented annotations may mistake an instance as multiple instances. To sum up, both DeepLabv3+ and Mask R-CNN are capable of crack identification, and an empirical guideline on the data preparation is presented to strengthen identification successfulness via image cropping and label refining.

Causal Relationship between e-Service Quality, Online Trust and Purchase Intentions on Lazada Group, An Asia's Leading E-commerce Platform

  • RUANGUTTAMANUN, Chutima;PEEMANEE, Jindarat
    • Journal of Distribution Science
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    • v.20 no.1
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    • pp.13-26
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    • 2022
  • Purpose: The Covid-19 pandemic has accelerated and triggered changes in online shopping especially in an emerging market. This paper develops a modification of SERVQUAL model to examine the relationship between individual dimensions of e-service quality, online trust and purchase intentions in singular online shopping platform. Research design, data and methodology: Data from an online survey of 385 Lazada's shoppers were used to test the research model. The structural equation modeling technique was performed to test the research model. Results: The analytical results revealed that five dimensions of e-service quality were positively correlated with one another whereas some dimensions were negatively correlated with purchase intentions. The results of this study provide new insight into the literature as well as practical implications for marketers especially in Thai online market. Conclusion: This study develops the instrument dimensions of e-service quality through modifying the SERVQUAL model to examine the e-commerce context and to testify how these individual dimensions are interlinked with one another. It also suggests that responsiveness has two-sided affects that in responses which are too prompt and insistent could make the customer feel uncomfortable and perhaps ending up with no interaction and transaction.

Effects of Positive Characteristics of SNS on Use Satisfaction and Using Reluctant Intention: A Path Model for the Role of Trust and Value

  • Yang, Hoe-Chang;Kim, Hwa-Kyung
    • The Journal of Economics, Marketing and Management
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    • v.5 no.3
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    • pp.21-29
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    • 2017
  • This study was conducted to examine the effects of interactivity, entertainment and ease of use, which are positive characteristics of SNS, on SNS using satisfaction and using reluctant intention and the roles of perceived values and trust among users in the relationships among these variables, in order to find a clue to contribution to positive use and development of SNS. For this study, a survey was performed targeting normal people in Seoul and the metropolitan area and a total of 224 effective questionnaires were acquired. Then frequency analysis, descriptive statistic analysis, correlation analysis and structural equation path analysis were carried out. As a result of analysis, interactivity and ease of use increased SNS using satisfaction and decreased using reluctant intention via trust and users' perceived values respectively. The result of analyzing the modification model showed that interactivity and entertainment directly increased SNS using satisfaction. These findings imply that SNS providers fully need to reflect the needs of consumers for interactivity, entertainment and ease of use for improving consumers' perceived values and trust. It is also concluded that consumers can enjoy positive SNS activities by increasing trust with SNS users through a positive understanding of interactivity and participation.

Methods on improvements of the poor oral bioavailability of ginsenosides: Pre-processing, structural modification, drug combination, and micro- or nano- delivery system

  • Qi-rui Hu;Huan Hong;Zhi-hong Zhang;Hua Feng;Ting Luo;Jing Li;Ze-yuan Deng;Fang Chen
    • Journal of Ginseng Research
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    • v.47 no.6
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    • pp.694-705
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    • 2023
  • Panax ginseng Meyer is a traditional Chinese medicine that is widely used as tonic in Asia. The main pharmacologically active components of ginseng are the dammarane-type ginsenosides, which have been shown to have anti-cancer, anti-inflammatory, immunoregulatory, neuroprotective, and metabolic regulatory activities. Moreover, some of ginsenosides (eg, Rh2 and Rg3) have been developed into nutraceuticals. However, the utilization of ginsenosides in clinic is restrictive due to poor permeability in cells and low bioavailability in human body. Obviously, the dammarane skeleton and glycosyls of ginsenosides are responsible for these limitations. Therefore, improving the oral bioavailability of ginsenosides has become a pressing issue. Here, based on the structures of ginsenosides, we summarized the understanding of the factors affecting the oral bioavailability of ginsenosides, introduced the methods to enhance the oral bioavailability and proposed the future perspectives on improving the oral bioavailability of ginsenosides.

Design of web-stiffened lipped channel beams experiencing distortional global interaction by direct strength method

  • Hashmi S.S. Ahmed;G. Khushbu;M. Anbarasu;Ather Khan
    • Structural Engineering and Mechanics
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    • v.90 no.2
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    • pp.117-125
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    • 2024
  • This article presents the behaviour and design of cold-formed steel (CFS) web-stiffened lipped channel beams that primarily fail owing to the buckling interaction of distortional and global buckling modes. The incorporation of an intermediate stiffener in the web of the lipped channel improved the buckling performance leads to distortional buckling at intermediate length beams. The prediction of the strength of members that fail in individual buckling modes can be easily determined using the current DSM equations. However, it is difficult to estimate the strength of members undergoing buckling interactions. Special attention is required to predict the strength of the members undergoing strong buckling interactions. In the present study, the geometric dimensions of the web stiffened lipped channel beam sections were chosen such that they have almost equal distortional and global buckling stresses to have strong interactions. A validated numerical model was used to perform a parametric study and obtain design strength data for CFS web-stiffened lipped channel beams. Based on the obtained numerical data, an assessment of the current DSM equations and the equations proposed in the literature (for lipped channel CFS sections) is performed. Suitable modifications were also proposed in this work, which resulted in a higher level of design accuracy to predict the flexural strength of CFS web stiffened lipped channel beams undergoing distortional and global mode interaction. Furthermore, reliability analysis was performed to confirm the reliability of the proposed modification.

A Comprehensive Review of Recent Advances in the Enrichment and Mass Spectrometric Analysis of Glycoproteins and Glycopeptides in Complex Biological Matrices

  • Mohamed A. Gab-Allah;Jeongkwon Kim
    • Mass Spectrometry Letters
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    • v.15 no.1
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    • pp.1-25
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    • 2024
  • Protein glycosylation, a highly significant and ubiquitous post-translational modification (PTM) in eukaryotic cells, has attracted considerable research interest due to its pivotal role in a wide array of essential biological processes. Conducting a comprehensive analysis of glycoproteins is imperative for understanding glycoprotein bio-functions and identifying glycosylated biomarkers. However, the complexity and heterogeneity of glycan structures, coupled with the low abundance and poor ionization efficiencies of glycopeptides have all contributed to making the analysis and subsequent identification of glycans and glycopeptides much more challenging than any other biopolymers. Nevertheless, the significant advancements in enrichment techniques, chromatographic separation, and mass spectrometric methodologies represent promising avenues for mitigating these challenges. Numerous substrates and multifunctional materials are being designed for glycopeptide enrichment, proving valuable in glycomics and glycoproteomics. Mass spectrometry (MS) is pivotal for probing protein glycosylation, offering sensitivity and structural insight into glycopeptides and glycans. Additionally, enhanced MS-based glycopeptide characterization employs various separation techniques like liquid chromatography, capillary electrophoresis, and ion mobility. In this review, we highlight recent advances in enrichment methods and MS-based separation techniques for analyzing different types of protein glycosylation. This review also discusses various approaches employed for glycan release that facilitate the investigation of the glycosylation sites of the identified glycoproteins. Furthermore, numerous bioinformatics tools aiding in accurately characterizing glycan and glycopeptides are covered.

Synthesis of Fluorophores with Aggregation-induced Emission Characteristics using Fluorescein Derivatives

  • Chae Yun Jeong;Jongho Jeon
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.9 no.2
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    • pp.57-61
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    • 2023
  • In this research, novel AIE (Aggregation-Induced Emission) fluorophores were synthesized by ingeniously attaching a variety of substituents, including allyl, benzyl, and propargyl groups, to the hydroxy and carboxylate groups of fluorescein. The findings revealed a fascinating trend: the fluorescence intensity of these compounds varied progressively with the solvent ratio. This intriguing behavior is attributed to the superior aggregation of the synthesized materials in aqueous environments compared to organic solvents, resulting in markedly enhanced fluorescence. Moreover, the optical characteristics of these materials were found to be significantly influenced by the specific type of substituent grafted onto the fluorescein backbone. Notably, the fluorescence intensity was observed to escalate in the sequence of methoxy triethylene glycol, azidoethyl, allyl, propargyl, and benzyl group in the solution of H2O:DMSO (=99:1). The implications of this study can be vast, particularly in the realm of fundamental research areas like molecular imaging and sensor technology. These innovative AIE fluorophores offer a promising platform for advanced applications, leveraging their unique fluorescence behavior dictated by the nature of the substituent and the solvent environment.