Encapsulation of Peanut Allergens with Bimetallic Metal-Phenolic Networks (MPNs) for Therapeutic Applications

The efficacy and safety of oral immunotherapy for food allergy is still an ongoing challenge. Plant-derived polyphenols have been shown to exhibit immunomodulatory action through their anti-inflammatory and antioxidant properties. This thesis explored a synthesis of dual-functional pH-responsive metal-phenolic networks (MPNs) encapsulated peanut allergens using plant phenolics as an immunomodulating “adjuvant”. The compatibility of ferric/ferrous (Fe3+/Fe2+) and zinc ion (Zn2+) with plant-derived phenolics, tannic acid (TA) and catechin hydrate (CTC), was investigated for the formation of stable MPN film and encapsulation of peanut crude protein. Using bovine serum albumin (BSA) as a template biomolecule, it was demonstrated that the concentration/molar ratio between different metal ions and between metal ions and phenolics, order of reagent addition, synthesis methods and pH change during the synthesis influenced the final colour, size, and overall surface charge of the particles. The optimum condition for each tested MPN system with the protein template tested varied significantly. In the two bimetallic systems, Fe3+ showed the strongest interaction with the other coordinating ions, and with phenolics, followed by Fe2+ and then Zn2+. The morphological and elemental analysis of the BSA-Fe2+/Zn2+-CTC MPN confirmed the spherical particles presented in clusters and that a significantly higher Fe2+ than Zn2+ presented in the bimetallic MPN system. The selected bimetallic Fe2+/Zn2+-CTC MPN was implemented in the encapsulation of peanut crude protein with mixed molecular weight (MW) proteins and the major allergen, Ara h 1. More negatively charged nanoparticles were observed for the crude protein capsules compared to Ara h 1 capsules. The pH-responsive controlled release of the crude peanut-MPN capsules under the simulated gastric condition revealed that protein-MPN capsules with final pH of 6.3 were more stable than those with pH 3.9. The former had small amounts of residues remaining intact, whilst the latter dissociated completely after 2 hr digestion. The MPN capsules disassembled immediately after being exposed to the acidic condition and the dissociation rate was faster at pH 2 than pH 3. The released peanut protein was still immunoreactive. The pH-responsive peanut-MPN capsules using the bimetallic system with immunomodulating plant polyphenols could be a prospective allergen delivery system for oral immunotherapy

SYNTHESIS OF BIOTINYLATED FERROCENE, AND ITS APPLICATION AS A REDOX PROBE FOR ELECTROCHEMICAL IMMUNOSENSOR

The coupling compound of Biotin (Vitamin H) and redox molecule ferrocene throughcovalent bonding was studied. Synthesis and structure identification of Biotinylated 1 - (- 2-aminoethyl) ferrocene were performed by 1H-NMR, 13C-NMR and MS. The ultimate goal of thispaper is to develop derivatives of ferroceneservingas an electrochemical probe that wouldenhance the performance of immunosensor.An immunosensor based on polypyrrole-streptavidinlayer as platform for immobilization of biotinylatedferrocene and antibodies was developed. Themeasurement of redox signal of ferrocene was analyzed by differential pulse voltammetry(DPV) method and underlined a variation of redox properties upon the antigen interaction. Theintroduction of the redox biotinylatedferrocene into streptavidin-polypyrrole layer affords a goodsensitivity of the biosensor with a detection limit of 0.16 pg.mL-1

Factores que afectan el ciclo de vida del producto en las empresas electrónicas: evidencia de un país emergente

Introduction:This paper is the product of the study “Factors affecting product life cycle in electronic enterprises – Evidence from an emerging country” developed at the Electric Power University and National Economics University between 2020 and 2022. Problem:The electronic manufacturing industry is increasingly developing in emerging markets and integrating into the global economy. The life cycle of electronic products is shorter and requires management.Objective:The paper aims to study factors that affect the product life cycle in Vietnamese electronic enterprises. The study helps managers in cost management. Methodology:The paper used a survey of non-probability sampling, and applied regression analysis to examine Vietnamese electronic enterprises. The analysis is done by SPSS and Smart PLS software. Results:The research results indicate that technology, consumer trends, and R&D are factors affecting product life cycle and post-sale service, and disposal has no impact on electronic products’ life cycle. This could be explained by the fact that electronic products are constantly updating and their life cycle is short, that post-sales service does not play a key role, and that waste treatment after sales is not taken seriously by manufacturers, customers, or other related parties. Conclusion:The results give some meaningful insights for electronics or other enterprises in Vietnam to use effective management of product life cycle. Originality:The results of this paper provide practical insights into the management of product life cycle and cost management of product life cycle for researchers and managers.Limitations:The research model should be expanded and the sample size increased to get an overview and greater insight.Introducción: Este artículo es producto del estudio “Factores que afectan el ciclo de vida del producto en empresas electrónicas – Evidencia de un país emergente” desarrollado en la Electric Power University y la National Economics University entre 2020 y 2022.Problema: La industria de fabricación electrónica se está desarrollando cada vez más en los mercados emer-gentes y se está integrando a la economía global. El ciclo de vida de los productos electrónicos es más corto y requiere gestión. Objetivo: El documento tiene como objetivo estudiar los factores que afectan el ciclo de vida del producto en las empresas electrónicas vietnamitas. El estudio ayuda a los gerentes en la gestión de costos. Metodología: El documento utilizó una encuesta de muestreo no probabilístico y aplicó un análisis de regresión para examinar las empresas electrónicas vietnamitas. El análisis se realiza mediante el software SPSS y Smart PLS. Resultados: Los resultados de la investigación indican que la tecnología, las tendencias de consumo y la I+D son factores que afectan el ciclo de vida del producto y el servicio postventa, y que el desecho no tiene impacto en el ciclo de vida de los productos electrónicos. Esto podría explicarse por el hecho de que los productos electrónicos se actualizan constantemente y su ciclo de vida es corto, que el servicio posventa no juega un papel clave y que el tratamiento de residuos posventa no es tomado en serio por los fabricantes, clientes u otras partes relacionadas. Conclusión: Los resultados brindan algunas ideas significativas para la electrónica u otras empresas en Vietnam para utilizar una gestión eficaz del ciclo de vida del producto. Originalidad: los resultados de este documento brindan información práctica sobre la gestión del ciclo de vida del producto y la gestión de costos del ciclo de vida del producto para investigadores y gerentes.Limitaciones: el modelo de investigación debe ampliarse y aumentar el tamaño de la muestra para obtener una visión general y una mayor comprensión

SỰ LAN TRUYỀN SÓNG ĐIỆN TỪ TRONG SIÊU VẬT LIỆU HYPERBOLIC VỚI ĐỘ THẤM ĐIỆN MÔI GẦN BẰNG KHÔNG

In this paper, we investigated hyperbolic metamaterials based on a structure containing metallic nanowires embedded in a dielectric matrix with the utility environment theory method. Hyperbolic metamaterials with near-zero permittivity may exist simultaneously in type I and type II. The propagation of transverse electromagnetic waves in these two types of metamaterial was considered. The diverging incident light beam seems to convert into a well-collimated beam and transfers all its energy in the direction perpendicular to the surface of the hyperbolic metamaterial of type I in the region of special values ​​of the incidence angle from –5 to 5°. In the hyperbolic metamaterial of type II, the light wave entirely transmits through the material layers, while the transmittance remains constant in the range of incident angle values ​​from –40 to 40°. The radius of the metal nanowires and the material thickness also affect the characteristics of electromagnetic wave propagation.Trong bài báo này, chúng tôi nghiên cứu siêu vật liệu hyperbolic trên cơ sở cấu trúc chứa sợi kim loại kích thước nanomet nhúng trong nền điện môi bằng phương pháp lý thuyết môi trường hiệu dụng. Kết quả nghiên cứu cho thấy siêu vật liệu hyperbolic với độ thấm điện môi gần bằng 0 (ENZ) có thể tồn tại cùng lúc ở loại I và loại II. Điểm đặc biệt lan truyền sóng điện từ phân cực từ ngang được nghiên cứu trong hai loại siêu vật liệu này. Chùm ánh sáng đến phân kỳ dường như chuyển thành chùm sáng chuẩn trực tốt và chuyển toàn bộ năng lượng theo hướng vuông góc với bề mặt siêu vật liệu hyperbolic loại I trong vùng giá trị đặc biệt của góc tới từ –5 đến 5°. Trong siêu vật liệu hyperbolic loại II, sóng ánh sáng truyền hoàn toàn qua lớp cấu trúc vật liệu; đồng thời, giá trị hệ số truyền qua không đổi trong vùng giá trị góc tới từ –40 đến 40°. Sự thay đổi bán kính sợi kim loại trong cấu trúc và độ dày của lớp siêu vật liệu có ảnh hưởng đến đặc tính lan truyền sóng điện từ

Survey on Vietnamese teachers’ perspectives and perceived support during COVID-19

The COVID-19 pandemic has caused unprecedented damage to the educational system worldwide. Besides the measurable economic impacts in the short-term and long-term, there is intangible destruction within educational institutions. In particular, teachers – the most critical intellectual resources of any schools – have to face various types of financial, physical, and mental struggles due to COVID-19. To capture the current context of more than one million Vietnamese teachers during COVID-19, we distributed an e- survey to more than 2,500 randomly selected teachers from two major teacher communities on Facebook from 6th to 11th April 2020. From over 373 responses, we excluded the observations which violated our cross-check questions and retained 294 observations for further analysis. This dataset includes: (i) Demographics of participants; (ii) Teachers' perspectives regarding the operation of teaching activities during the pandemic; (iii) Teachers' received support from their schools, government bodies, other stakeholders such as teacher unions, and parents' associations; and (iv) teachers' evaluation of school readiness toward digital transformation. Further, the dataset was supplemented with an additional question on the teachers' primary source of professional development activities during the pandemic

The Impact of TikTok UGC Videos on Online Purchase Intention: Mediating Role of Cognitive States

Background: User-Generated Content (UGC) videos have received considerable attention in recent years thanks to their great potential for buyers and sellers. However, the effect of this content on consumer behavior remains unclear, especially in the context of developing countries (e.g., Vietnam). By applying the Stimulus-Organism-Response model (S-O-R model), this paper examines the effect of UGC videos on online purchase intention. Moreover, the mediating role of cognitive responses, consisting of perceived credibility, perceived diagnosticity, and mental imagery, is also examined to offer valuable insights to businesses, enabling them to leverage and effectively promote the trends of UGC videos. Method: A convenience sampling method was employed to collect the data. A total of 318 valid respondents participated in this survey. The data was analyzed with the Partial Least Squares Structural Equation Modeling method (PLS-SEM). Results: The findings show that UGC videos have a direct impact on online purchase intention. This paper also verified that cognitive states mediate the relationship between stimuli and subsequent behavioral intentions. Conclusion: Our research findings enrich the literature on consumer’s online purchase intentions by applying the S-O-R framework by highlighting the role of cognitive responses, and improving generalizability by contributing additional consumer behavior findings in developing Asian nations. Moreover, this paper offers businesses insights into the formation of customers\u27 purchase intentions while watching UGC videos. Based on that, this paper raises practical recommendations regarding promoting the UGC video trend and creating UGC videos effectively to improve the cognitive states perceived by customers, including credibility, diagnostic value, and mental imagery

EMBRYONIC MOSAICISM BY MICROINJECTION

Cytoplasmic microinjection (CI) of the CRISPR/Cas9 system enabled the induction of site-specific mutations in porcine zygotes and resulting pigs. However, mosaicism is a serious problem for genetically modified pigs. In the present study, we investigated suitable timing and concentration of CRISPR/Cas9 components for introduction into oocytes/zygotes by CI, to reduce mosaicism in the resulting blastocysts. First, we introduced 20 ng/μl of Cas9 protein and guide RNA (gRNA), targeting the α-1,3-galactosyltransferase (GalT) gene in oocytes before in vitro fertilization (IVF), in zygotes after IVF, or in oocytes/zygotes before and after IVF, twice. CI treatment had no detrimental effects on blastocyst formation rates. The highest value of the rate of mutant blastocysts was observed in zygotes injected after IVF. Next, we injected Cas9 protein and gRNA into zygotes after IVF at a concentration of 20 ng/μl each (20 ng/μl group) or 100 ng/μl each (100 ng/μl group). The ratio of the number of blastocysts that carried mutations to the total number of blastocysts examined in the 100 ng/μl group was significantly higher (P < 0.05) than that in the 20 ng/μl group. Although no blastocysts from the 20 ng/μl group carried a biallelic mutation, 16.7% of blastocysts from the 100 ng/μl group carried a biallelic mutation. In conclusion, increasing the concentration of Cas9 protein and gRNA is effective in generating biallelic mutant blastocysts. To reduce mosaicism, however, further optimization of the timing of CI, and the concentration of CRISPR/Cas9 components, is needed

Influence of damping coefficient into engine rubber mounting system on vehicle ride comfort

This study presents a method to improve vehicle ride comfort using additional damping coefficient values for an internal combustion engine (ICE) rubber mounting system. To analyze the effect of the adding damping coefficient values into the rubber mounting system on vehicle ride comfort, a full-vehicle vibration model with 10 degrees of freedom is established under the combination of road surface roughness and ICE excitations. The damping coefficient values are added into ICE rubber mounting system which are respectively analyzed and evaluated according to the international standard ISO 2631-1 (1997). The study results do not only evaluate the influence of the adding damping coefficients on vehicle ride comfort but also suggest the optimal design solution for ICE mounting system to improve vehicle ride comfort