Factors that Affect Customers Satisfaction: An Empirical Study of Export-Import Service Consultant Companies in Vietnam

LE, Thai Thanh Dat,HO, Thi Thanh Ngan,LE, Nguyen Truc Quyen,HUYNH, Thi Khanh Tuyen,NGUYEN, Minh Tri,LUU, Thi Mai Anh,HOANG, Thi Phuong Thao,NGUYEN, Trong Luan Korea Distribution Science Association 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.6

The purpose of the study is to analyze the significant impacts of expectations, performance, complaints, and fairness that affect consumer satisfaction. The methodology involves reviewing and referencing relevant literature carefully, then proposing a model for customer satisfaction. This study is empirically based on a survey with 50 respondents who work in the field of import and export in the region stretching from the north to the south of Vietnam. The sampling method used in this study is the in-depth interview method. The results show that: (1) expectation has a specific impact on customer satisfaction, (2) performance has a positive impact on customer satisfaction, and (3) complaint which is an intermediary factor between expectation, performance, and fairness has an impact on satisfaction, (4) fairness has a positive effect on satisfaction, in addition, fairness is an extremely important feature when customers choose an import-export service. Research implies that increasing expectations, performance, and fairness results in an improved customer experience and satisfaction when they use the service. It is suggested that the complaint factor continue to be studied and looked into because it still has some effect on satisfaction and is an intermediate variable that changes how the other factors relate to each other.

Engineered horseradish peroxidase-catalyzed hydrogels with high tissue adhesiveness for biomedical applications

Thai Thanh Hoang Thi,이윤기,Phuong Le Thi,박기동 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.78 No.-

Adhesive hydrogels offer considerable potential in biomedical applications because of the excellentintegration between materials and tissues. Horseradish peroxidase (HRP)-catalyzed hydrogelation, withadvantages that include ease of handling, simplicity in material design, high biocompatibility, andprocessability, is becoming a promising candidate to be engineered as an adhesive hydrogel. This reviewsummarizes recent development of HRP-mediated hydrogelation towards the bioadhesivefield, andother applications requiring the tissue adhesion of hydrogels. From the viewpoint of adhesive hydrogeldesignation, the basic chemistry of the adhesive mechanism, combinations of interactions, and currentlycommercial bioglues are summarized. The review recapitulated the adhesive hydrogel applications, theclinical translation ability, the controlling hydrogelation kinetics, the related physicochemicalcharacteristics, cytotoxicity, and animal studies. Looking to the future, to make more substantialcontributions to the bioadhesivefield, or to various biomedical applications, higher adhesion should becontinuously improved, and greater emphasis should be placed on clinical trials.

Oxidized Alginate Supplemented Gelatin Hydrogels for the In Situ Formation of Wound Dressing with High Antibacterial Activity

Thai Thanh Hoang Thi,이윤기,Phuong Le Thi,박기동 한국고분자학회 2019 Macromolecular Research Vol.27 No.8

The development of antibacterial wound dressing with easily removable characteristic and highly exudate absorption is becoming a major requirement in the treatment of chronic wounds. In this study, the in situ forming gelatin/oxidized alginate-tyramine hydrogels (GH/OATA) were designed to overcome the current limitations. These hybrid hydrogels were quickly and controllably formed from several seconds to a few minutes by horseradish peroxidase/H2O2. The hybrid hydrogels at the optimal composition of GH/OATA 50/50 v/v showed the unique feature including stiffness being similar to skin, high swelling ratio due to the hydrophilic property of oxidized alginate, low adhesive strength allowing for the easy dressing removal without pain. In addition, the hybrid hydrogels could release the H2O2 amount sustainably to kill bacteria. Furthermore, 3D culture of human dermal fibroblasts inside hybrid hydrogels achieved more than 80% cell proliferation which implies the cell-compatibility.

Self-antibacterial chitosan/Aloe barbadensis Miller hydrogels releasing nitrite for biomedical applications

Thai Thanh Hoang Thi,Binh D.T. Trinh,Phuong Le Thi,Dieu Linh Tran,박기동,Dai Hai Nguyen 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-

Because of the toxic glutaraldehyde, the chitosan-glutaraldehyde hydrogels are seriously limited inbiomedical applications. In this study, exploiting bioactive compounds of Aloe barbadensis Miller, the chitosan/Aloe barbadensis Miller-glutaraldehyde (CS/AV-GDA) hydrogels were fabricated with 4-fold lowerglutaraldehyde concentration without compromising hydrogel characteristics. The gelation time wascontrolled from a few seconds to several hours. The elastic modulus was varied from 483 to 99940 Pa. The CS/AV-GDA hydrogels could release the natural nitrite amount from 24.0 to 89.6 lM within the firsthour for antibacterial activity, then continuously deliver a few lM every next hour for cell activities. Theantibacterial test against Escherichia coli and Staphylococcus aureus revealed that the CS/AV-GDA hydrogelscould kill the planktonic bacteria 5-fold more highly than control and prevent bacteria attachmenton hydrogel surface effectively. Although the CS/AV-GDA hydrogels consumed only 0.25% glutaraldehydeconcentration, their antibacterial capacities were comparable to chitosan-only hydrogels with 2% glutaraldehyde. For cytotoxicity tests, the CS/AV-GDA hydrogels using 0.25% glutaraldehyde concentrationinduce the human dermal fibroblasts proliferation significantly. All CS/AV-GDA hydrogels with glutaraldehydecrosslinker less than 1% showed non-cytotoxicity. As a result, the new CS/AV-GDA hydrogelsmight become an attractive candidate for medicine regeneration and tissue engineering.

Catechol-rich gelatin hydrogels <i>in situ</i> hybridizations with silver nanoparticle for enhanced antibacterial activity

Le Thi, Phuong,Lee, Yunki,Hoang Thi, Thai Thanh,Park, Kyung Min,Park, Ki Dong Elsevier 2018 Materials science & engineering. C, Materials for Vol.92 No.-

<P><B>Abstract</B></P> <P>Recently, the interest in antimicrobial hydrogels with impregnated antibacterial agents has significantly increased because of their ability to combat infection in biomedical applications, including wound management, tissue engineering, and biomaterial surface coating. Among these antibacterial reagents, silver nanoparticles (AgNP) show good antibacterial activity against both gram-negative and gram-positive bacteria, including highly multi-resistant strains. However, the entrapment of AgNP within a hydrogel matrix is often associated with toxicity issues because of the use of chemical reductants (<I>e.g.</I>, commonly sodium borohydride), burst leaching, or unwanted agglomeration of AgNP in the absence of surfactants or stabilizers. In this study, we present catechol-rich gelatin hydrogels with <I>in situ</I> hybridization of AgNP for enhanced antimicrobial activities. AgNP were formed through a redox reaction between silver ions and the catechol moieties of a gelatin derivative polymer, without the addition of any chemical reductants. The AgNP with an average size of 20 nm were entrapped within hydrogel matrices and showed sustained release from the hydrogel matrix (8.7% for 14 days). The resulting hydrogels could kill both gram-negative and gram-positive bacteria, depending on the amount of AgNP released from the hydrogels and did not have a significant influence on mammalian cell viability. We believe that our catechol-rich hydrogels <I>in situ</I> hybridizations with AgNP have great potential for biomedical applications, such as wound management and surface coating, because of their excellent antibacterial activities and biocompatibility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Silver nanoparticles incorporation (AgNP) impart the antimicrobial properties to injectable gelatin hydrogel. </LI> <LI> AgNP was <I>in situ</I> synthesized within the hydrogel matrix, with controllable size and sustained release. </LI> <LI> The nanocomposite hydrogels significantly inhibited bacterial growth without affecting viability of mammalian cells. </LI> <LI> These <I>in situ</I> forming GHD/AgNP hydrogels are potential for a wide range of biomedical applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A simple method using catecholic chemistry to prepare an injectable nanocomposite hydrogel with excellent antimicrobial activities. Silver nanoparticles (AgNP) were <I>in situ</I> synthesized within the gelatin hydrogel matrix, during the hydrogelation without use of toxic reductants. The hydrogels inhibited bacterial growth while not affected the viability of mammalian cells. This injectable hydrogel is easy to fabricate <I>in vivo</I> with promising potential for biomedical applications, where advantageous antibacterial activities are required to reduce the infection rates, for example wound dressing, tissue adhesives, biomaterial surface coatings …</P> <P>[DISPLAY OMISSION]</P>

In Situ Forming and Nitric Oxide-Releasing Hydrogels with Highly Antibacterial Activities for Biomedical Applications

( Le Thi Phuong ),( Thai Thanh Hoang Thi ),박기동 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Nitric oxide (NO), an essential signaling molecule, participates in a broad range of physiological processes, such as cardiovascular homeostasis, neuronal transmission, immunomodulation, and tumor growth. Recently, NO releasing materials have emerged as potential therapies to inhibit drug-resistance bacteria without causing undesirable effects. Herein, we developed an injectable gelatin-based hydrogels (GH) to controllably release NO by incorporating the NO donor S-nitrosothiolated gelatin (GelSNO). The hydrogels were rapidly formed via HRP/H₂O₂-mediated crosslinking reaction. The NO release behaviors were controlled by varying the GelSNO concentration. The killing effect against both E. coli and S. aureus as well as the cytotoxicity against human dermal fibroblasts of hydrogels were also evaluated.

Collagen Gel Embedded 3D Electrospun Scaffold Induce Myoblasts Elongation and Differentiation

고웅현,Thai Le Phuong Anh,이준호,박석희,신현정 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.바이오공학 No.-

Influence of MoS2 deposition time on the photocatalytic activity of MoS2/ V, N co-doped TiO2 heterostructure thin film in the visible light region

Hang Nguyen Thai Phung,Nguyen Duc Truong,Phuong Ai Duong,Le Vu Tuan Hung 한국물리학회 2018 Current Applied Physics Vol.18 No.6

Electron-hole separation and a narrow band-gap are essential steps to obtain efficient photocatalysis, towards which the use of co-catalysts or co-doped-TiO2 photocatalysts has become a widely used strategy. In this article, the combination of MoS2 and co-doping of V, N is the goal to achieve high performance photocatalysts. We synthesized MoS2/V, N co-doped TiO2 heterostructure thin film by solgel and chemical bath deposition methods. Herein, we investigated the influence of deposition time of MoS2 layer on visible-photocatalytic activity of the obtained samples. The thin films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UVevis spectroscopy techniques. Visible-photocatalytic activity of these samples were evaluated on the removal of methylene blue (MB) under visible light irradiation. The results show that the aforementioned heterostructure thin films have better photocatalytic activities than those of TiO2, MoS2 and V, N codoped TiO2 counterparts in visible light region. The mechanism for increasing visible-photocatalytic property of the heterostructure thin films is discussed in detail. We find that MoS2/V, N co-doped TiO2 heterostructure thin film at MoS2 deposition time of 45-min shows the highest photocatalytic performance in the visible light region with MB photodegradation rate about 99% for 150 min and the degradation rate constant is 2.06 times higher than that of V and N co-doped TiO2 counterpart.

Nitric oxide-releasing injectable hydrogels with high antibacterial activity through in situ formation of peroxynitrite

Hoang Thi, Thai Thanh,Lee, Yunki,Le Thi, Phuong,Park, Ki Dong Elsevier 2018 ACTA BIOMATERIALIA Vol.67 No.-

<P><B>Abstract</B></P> <P>Nitric oxide (NO) is an endogenous molecule with many critical biological functions that depend on its concentration. At high levels, NO provides broad-spectrum antibacterial effects through both its pathogen inhibition and killing abilities. However, its short half-life has been a great challenge to its clinical application in pharmaceutical forms. In this study, we incorporated the NO donor S-nitrosothiolated gelatin (GelSNO) into injectable gelatin-based hydrogels (GHs) to controllably release NO. Under catalysis by horseradish peroxidase, H<SUB>2</SUB>O<SUB>2</SUB> oxidizes phenol moieties functionalized on gelatin to quickly form phenol-phenol crosslinks that encapsulate GelSNO. Through thermal, visible light, and oxidizing agent-driven mechanisms, NO is released from the GH/GelSNO hydrogels. By varying the GelSNO concentration, the release of NO was controllable in a wide range, 0.054–2.050 μmol/mL, for up to 14 days. In addition, NO release was fine-tunable as a function of H<SUB>2</SUB>O<SUB>2</SUB> concentration. Notably, the in situ formation of peroxynitrite (ONOO<SUP>−</SUP>) that produces potent antibacterial effects originated from H<SUB>2</SUB>O<SUB>2</SUB> residues and nitrous acid formed by NO and oxygen in aqueous solution. The Kirby-Bauer method indicated that there was an inhibition zone against both <I>Escherichia coli</I> and <I>Staphylococcus aureus</I> incubated with GH/GelSNO hydrogels. The AlarmaBlue assay showed that <I>E. coli</I> and <I>S. aureus</I> were completely killed at NO concentrations of 0.39 and 0.58 μmol/mL. Cytotoxicity tests of GH/GelSNO hydrogels on human dermal fibroblasts at the indicated bactericidal NO concentrations induced no cell toxicity. In summary, GH/GelSNO hydrogels may provide a new platform for topical delivery of NO in treating wound infections and for various biomedical applications.</P> <P><B>Statement of Significance</B></P> <P>NO is an effective antibacterial agent even in cases of antibiotic-resistant bacteria. Moreover, its intermediate, peroxynitrite, has been reported to have a much higher ability to kill bacteria. In this study, we utilized injectable GH/GelSNO hydrogels formed by HRP/H<SUB>2</SUB>O<SUB>2</SUB> reaction not only to control NO release but also to generate peroxynitrite in situ from released NO and H<SUB>2</SUB>O<SUB>2</SUB> residues. The GH/GelSNO hydrogels showed significant antibacterial ability on both gram-positive and negative bacteria, while no cytotoxicity was induced on human dermal fibroblasts. In addition, their tunable chemico-physical properties and controllable NO release within a wide range but narrow scale will make the hydrogels useful in various biomedical applications.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Engineered horseradish peroxidase-catalyzed hydrogels with high tissue adhesiveness for biomedical applications

Hoang Thi, Thai Thanh,Lee, Yunki,Le Thi, Phuong,Park, Ki Dong Elsevier 2019 Journal of industrial and engineering chemistry Vol.78 No.-

<P><B>Abstract</B></P> <P>Adhesive hydrogels offer considerable potential in biomedical applications because of the excellent integration between materials and tissues. Horseradish peroxidase (HRP)-catalyzed hydrogelation, with advantages that include ease of handling, simplicity in material design, high biocompatibility, and processability, is becoming a promising candidate to be engineered as an adhesive hydrogel. This review summarizes recent development of HRP-mediated hydrogelation towards the bioadhesive field, and other applications requiring the tissue adhesion of hydrogels. From the viewpoint of adhesive hydrogel designation, the basic chemistry of the adhesive mechanism, combinations of interactions, and currently commercial bioglues are summarized. The review recapitulated the adhesive hydrogel applications, the clinical translation ability, the controlling hydrogelation kinetics, the related physicochemical characteristics, cytotoxicity, and animal studies. Looking to the future, to make more substantial contributions to the bioadhesive field, or to various biomedical applications, higher adhesion should be continuously improved, and greater emphasis should be placed on clinical trials.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>