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  1. Article ; Online: Effect of Zinc Oxide Incorporation on the Antibacterial, Physicochemical, and Mechanical Properties of Pit and Fissure Sealants.

    Choi, Ji-Won / Yang, Song-Yi

    Polymers

    2023  Volume 15, Issue 3

    Abstract: This study aimed to evaluate the antibacterial, physicochemical, and mechanical properties of pit and fissure sealants containing different weight percentages of zinc oxide nanoparticles (ZnO NPs). The following amounts of ZnO NPs were added to a ... ...

    Abstract This study aimed to evaluate the antibacterial, physicochemical, and mechanical properties of pit and fissure sealants containing different weight percentages of zinc oxide nanoparticles (ZnO NPs). The following amounts of ZnO NPs were added to a commercially available pit and fissure sealant (BeautiSealant, Shofu, Japan) to prepare the experimental materials: 0 wt.% (commercial control (CC)), 0.5 wt.% (ZnO 0.5), 1 wt.% (ZnO 1.0), 2 wt.% (ZnO 2.0), and 4 wt.% (ZnO 4.0). The antibacterial effect against
    Language English
    Publishing date 2023-01-19
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527146-5
    ISSN 2073-4360 ; 2073-4360
    ISSN (online) 2073-4360
    ISSN 2073-4360
    DOI 10.3390/polym15030529
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Suppression of the phenolic SOA formation in the presence of electrolytic inorganic seed.

    Choi, Jiwon / Jang, Myoseon

    The Science of the total environment

    2022  Volume 851, Issue Pt 1, Page(s) 158082

    Abstract: Phenolic compounds are largely attributed to wildfire gases and rapidly react with atmospheric oxidants to form persistent phenoxy free radicals, which influence atmospheric chemistry and secondary organic aerosol (SOA) formation. In this study, phenol ... ...

    Abstract Phenolic compounds are largely attributed to wildfire gases and rapidly react with atmospheric oxidants to form persistent phenoxy free radicals, which influence atmospheric chemistry and secondary organic aerosol (SOA) formation. In this study, phenol or o-cresol was photochemically oxidized under various conditions (NO
    MeSH term(s) Aerosols/analysis ; Air Pollutants/chemistry ; Catechols ; Cresols ; Free Radicals ; Oxidants ; Oxidation-Reduction ; Ozone ; Peroxides ; Phenol
    Chemical Substances Aerosols ; Air Pollutants ; Catechols ; Cresols ; Free Radicals ; Oxidants ; Peroxides ; Phenol (339NCG44TV) ; Ozone (66H7ZZK23N) ; 2-cresol (YW84DH5I7U)
    Language English
    Publishing date 2022-08-17
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2022.158082
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Suppression of the phenolic SOA formation in the presence of electrolytic inorganic seed

    Choi, Jiwon / Jang, Myoseon

    Science of the total environment. 2022 Dec. 10, v. 851

    2022  

    Abstract: Phenolic compounds are largely attributed to wildfire gases and rapidly react with atmospheric oxidants to form persistent phenoxy free radicals, which influence atmospheric chemistry and secondary organic aerosol (SOA) formation. In this study, phenol ... ...

    Abstract Phenolic compounds are largely attributed to wildfire gases and rapidly react with atmospheric oxidants to form persistent phenoxy free radicals, which influence atmospheric chemistry and secondary organic aerosol (SOA) formation. In this study, phenol or o-cresol was photochemically oxidized under various conditions (NOₓ levels, humidity, and seed conditions) in an outdoor photochemical reactor. Unexpectedly, SOA growth of both phenols was suppressed in the presence of salted aqueous aerosol compared to non-seed SOA. This discovery is different from the typical SOA formation of aromatic or biogenic hydrocarbons, which show noticeably higher SOA yields via organic aqueous reactions. Phenol, o-cresol, and their phenolic products (e.g., catechols) are absorbed in aqueous aerosol and form phenoxy radicals via heterogeneous reactions under sunlight. The resulting phenoxy radicals are redistributed between the gas and particle phases. Gaseous phenoxy radicals quickly react with ozone to form phenyl peroxide radicals and regenerated through a NOₓ cycle to retard phenol oxidation and SOA formation. The explicit oxidation mechanisms of phenol or o-cresol in the absence of aqueous phase were derived including the Master Chemical Mechanism (MCM v3.3.1) and the path for peroxy radical adducts originating from the addition of an OH radical to phenols to form low volatility products (e.g., multi-hydroxy aromatics). The resulting gas mechanisms of phenol or o-cresol were, then, applied to the Unified Partitioning Aerosol Phase Reaction (UNIPAR) model to predict SOA formation via multiphase partitioning of organics and aerosol-phase oligomerization. The model well simulated chamber-generated phenolic SOA in absence of wet-inorganic seed, but significantly overestimated SOA mass in presence of wet seed. This study suggests that heterogeneous chemistry to form phenoxy radicals needs to be included to improve SOA prediction from phenols. The suppression of atmospheric oxidation due to phenoxy radicals in wet inorganic aerosol can explain the low SOA formation during wildfire episodes.
    Keywords aerosols ; atmospheric chemistry ; environment ; humidity ; models ; o-cresol ; oligomerization ; oxidation ; ozone ; phenol ; photochemistry ; prediction ; solar radiation ; wildfires
    Language English
    Dates of publication 2022-1210
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2022.158082
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Icariin Supplementation Suppresses the Markers of Ferroptosis and Attenuates the Progression of Nonalcoholic Steatohepatitis in Mice Fed a Methionine Choline-Deficient Diet.

    Choi, Jiwon / Choi, Hyewon / Chung, Jayong

    International journal of molecular sciences

    2023  Volume 24, Issue 15

    Abstract: Icariin, a flavonoid abundant in the herb Epimedium, exhibits anti-ferroptotic activity. However, its impact on nonalcoholic steatohepatitis (NASH) development remains unclear. This study aimed to investigate the potential role of icariin in mitigating ... ...

    Abstract Icariin, a flavonoid abundant in the herb Epimedium, exhibits anti-ferroptotic activity. However, its impact on nonalcoholic steatohepatitis (NASH) development remains unclear. This study aimed to investigate the potential role of icariin in mitigating methionine choline-deficient (MCD) diet-induced NASH in C57BL/6J mice. The results showed that icariin treatment significantly reduced serum alanine aminotrasferase and aspartate aminotransferase activities while improving steatosis, inflammation, ballooning, and fibrosis in the liver tissues of mice fed the MCD diet. These improvements were accompanied by a substantial reduction in the hepatic iron contents and levels of malondialdehyde and 4-hydroxynonenal, as well as an increase in the activities of catalase and superoxide dismutase. Notably, icariin treatment suppressed the hepatic protein levels of ferroptosis markers such as acyl-CoA synthetase long-chain family member 4 and arachidonate 12-lipoxygenase, which were induced by the MCD diet. Furthermore, transmission electron microscopy confirmed the restoration of morphological changes in the mitochondria, a hallmark characteristic of ferroptosis, by icariin. Additionally, icariin treatment significantly increased the protein levels of Nrf2, a cystine/glutamate transporter (xCT), and glutathione peroxidase 4 (GPX4). In conclusion, our study suggests that icariin has the potential to attenuate NASH, possibly by suppressing ferroptosis via the Nrf2-xCT/GPX4 pathway.
    MeSH term(s) Mice ; Animals ; Non-alcoholic Fatty Liver Disease/etiology ; Non-alcoholic Fatty Liver Disease/complications ; Choline/metabolism ; Methionine/metabolism ; Ferroptosis ; NF-E2-Related Factor 2/metabolism ; Choline Deficiency/complications ; Choline Deficiency/metabolism ; Mice, Inbred C57BL ; Liver/metabolism ; Flavonoids/pharmacology ; Flavonoids/metabolism ; Racemethionine/metabolism ; Diet ; Dietary Supplements
    Chemical Substances Choline (N91BDP6H0X) ; Methionine (AE28F7PNPL) ; icariin (VNM47R2QSQ) ; NF-E2-Related Factor 2 ; Flavonoids ; Racemethionine (73JWT2K6T3)
    Language English
    Publishing date 2023-08-07
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms241512510
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Body distribution and ecotoxicological effect of nanoplastics in freshwater fish, Zacco platypus.

    Choi, Jiwon / Choi, Yeowool / Kim, Sang Don

    Chemosphere

    2023  Volume 341, Page(s) 140107

    Abstract: The increased consumption of plastics worldwide, has led to the emergence of nanoplastics as important environmental pollutants. Despite the presence of nanoplastics in aquatic environments, their effects on ecosystems remain largely unexplored due to ... ...

    Abstract The increased consumption of plastics worldwide, has led to the emergence of nanoplastics as important environmental pollutants. Despite the presence of nanoplastics in aquatic environments, their effects on ecosystems remain largely unexplored due to the analysis complexity. This study investigated the organ accumulation and toxic effects of 50 nm polystyrene nanoplastics (PS-NPs) in Zacco platypus (Z. platypus; also known as pale chub fish) using pyrolyzer-gas chromatography-mass spectrometry (Pyr-GC/MS). PS-NPs accumulated in Z. platypus' brain, digestive tract, branchia, and liver, causing changes at cellular level. Over a 14-day exposure, the accumulated PS-NPs led to observable changes in fish behavior (e.g., Total traveled distance and maximum velocity). In addition, the oxidative stress in each organ of Z. platypus increased as the exposure concentration of PS-NPs increased. This study shows that accumulation of nanoplastics in fish, resulting in behavioral changes and biochemical toxicity. As the pattern of change magnifies with exposure time and concentration, from a long-term perspective, the influence of nanoplastics on aquatic ecosystems become evident. This underscores the urgency for continuous research into the potential risks of nanoplastics in aquatic ecosystems.
    MeSH term(s) Animals ; Microplastics/toxicity ; Platypus ; Ecosystem ; Fishes ; Fresh Water ; Polystyrenes/toxicity
    Chemical Substances Microplastics ; Polystyrenes
    Language English
    Publishing date 2023-09-06
    Publishing country England
    Document type Journal Article
    ZDB-ID 120089-6
    ISSN 1879-1298 ; 0045-6535 ; 0366-7111
    ISSN (online) 1879-1298
    ISSN 0045-6535 ; 0366-7111
    DOI 10.1016/j.chemosphere.2023.140107
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Co-treatment with vactosertib, a novel, orally bioavailable activin receptor-like kinase 5 inhibitor, suppresses radiotherapy-induced epithelial-to-mesenchymal transition, cancer cell stemness, and lung metastasis of breast cancer

    Choi Jiwon / Park Jiyoung / Cho Ilyoung / Sheen Yhunyhong

    Radiology and Oncology, Vol 56, Iss 2, Pp 185-

    2022  Volume 197

    Abstract: Acquired metastasis and invasion of cancer cells during radiotherapy are in part due to induction of epithelial-to-mesenchymal transition (EMT) and cancer stem cell (CSC) properties, which are mediated by TGF-β signaling. Here we evaluated the anti- ... ...

    Abstract Acquired metastasis and invasion of cancer cells during radiotherapy are in part due to induction of epithelial-to-mesenchymal transition (EMT) and cancer stem cell (CSC) properties, which are mediated by TGF-β signaling. Here we evaluated the anti-metastatic therapeutic potential of vactosertib, an orally bioavailable TGF-β type I receptor (activin receptor-like kinase 5, ALK5) inhibitor, via suppression of radiation-induced EMT and CSC properties, oxidative stress generation, and breast to lung metastasis in a breast cancer mouse model and breast cancer cell lines.
    Keywords vactosertib ; transforming growth factor-β (tgf-β) ; radiotherapy ; epithelial-to-mesenchymal transition ; cancer stem cell ; breast cancer ; Medical physics. Medical radiology. Nuclear medicine ; R895-920
    Language English
    Publishing date 2022-04-01T00:00:00Z
    Publisher Sciendo
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Design of an interactive system for access cavity assessment: A novel feedback tool for preclinical endodontics.

    Choi, Seongwon / Choi, Jiwon / Peters, Ove A / Peters, Christine I

    European journal of dental education : official journal of the Association for Dental Education in Europe

    2023  Volume 27, Issue 4, Page(s) 1031–1039

    Abstract: Introduction: A software program was developed to provide visual, guided feedback to students for access cavity preparations in preclinical learning. The specific aim of the study was to investigate students' overall experiences with the new learning ... ...

    Abstract Introduction: A software program was developed to provide visual, guided feedback to students for access cavity preparations in preclinical learning. The specific aim of the study was to investigate students' overall experiences with the new learning method and compare their experiences with traditional teaching.
    Materials and methods: A workflow based on freely available software was designed to interactively register three-dimensional models of molars with access cavities, and to metrically compare these to instructor-prepared standard cavities. Third-year students practicing molar endodontics access cavity preparation in the preclinical course were then surveyed. A total of 44/79 students completed self-administered questionnaires prior and after the use of the feedback software to gauge their learning experience.
    Results: The results of the post-training questionnaire illustrated that all surveyed students agreed/strongly agreed that the software assisted their learning in access cavity preparation. In addition, 86 and 89%, respectively, of students agreed that the use of the software improved their skills of access cavity preparation and felt more confident about their access cavity preparation skills after using the software package, 3D Dental Align.
    Discussion: The presented software solution permitted setting and comparing access cavity preparations by students against a standard access prepared by an instructor. The process of data acquisition and registration was fast and straightforward. Student feedback was very positive and suggested the integration of this type of experiential learning into the preclinical curriculum.
    Conclusion: This feasibility study demonstrated the utility of the new technology to assist dental students' access cavity preparation learning.
    MeSH term(s) Humans ; Feedback ; Educational Measurement/methods ; Students, Dental ; Education, Dental/methods ; Software ; Endodontics/education
    Language English
    Publishing date 2023-01-29
    Publishing country England
    Document type Journal Article
    ZDB-ID 1386587-0
    ISSN 1600-0579 ; 1396-5883
    ISSN (online) 1600-0579
    ISSN 1396-5883
    DOI 10.1111/eje.12895
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: MRA Toolbox v. 1.0: a web-based toolbox for predicting mixture toxicity of chemical substances in chemical products.

    Kim, Jongwoon / Seo, Myungwon / Choi, Jiwon / Na, Minju

    Scientific reports

    2022  Volume 12, Issue 1, Page(s) 8880

    Abstract: The chemical risk assessment paradigm is shifting from "substance-based" to "product/mixture-based" and from "animal testing" to "alternative testing" under chemical regulations. Organisms and the environment may be exposed to mixtures rather than a ... ...

    Abstract The chemical risk assessment paradigm is shifting from "substance-based" to "product/mixture-based" and from "animal testing" to "alternative testing" under chemical regulations. Organisms and the environment may be exposed to mixtures rather than a single substance. Conducting toxicity tests for all possible combinations is impractical due to the enormous combinatorial complexity. This study highlights the development and application case studies of Mixture Risk Assessment Toolbox, a novel web-based platform that supports mixture risk assessment through the use of different prediction models and public databases. This integrated framework provides new functional values for assessors to easily screen and compare the toxicity of mixture products using different computational techniques and find strategic solutions to reduce the mixture toxicity in the product development process. The toolbox ( https://www.mratoolbox.org ) includes four additive toxicity models: two conventional (Concentration Addition; and Independent Action) and two advanced (Generalized Concentration Addition; and Quantitative Structure-Activity Relationship-based Two-Stage Prediction) models. We demonstrated the multiple functions of the toolbox using three cases: (i) how it can be used to calculate the mixture toxicity, (ii) those for which safety data sheet (SDS) only indicating representative toxicity values (EC
    MeSH term(s) Animals ; Internet ; Lethal Dose 50 ; Quantitative Structure-Activity Relationship ; Risk Assessment/methods ; Toxicity Tests
    Language English
    Publishing date 2022-05-25
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-022-13028-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Co-treatment with vactosertib, a novel, orally bioavailable activin receptor-like kinase 5 inhibitor, suppresses radiotherapy-induced epithelial-to-mesenchymal transition, cancer cell stemness, and lung metastasis of breast cancer.

    Choi, Jiwon / Park, Jiyoung / Cho, Ilyoung / Sheen, Yhunyhong

    Radiology and oncology

    2022  Volume 56, Issue 2, Page(s) 185–197

    Abstract: Background: Acquired metastasis and invasion of cancer cells during radiotherapy are in part due to induction of epithelial-to-mesenchymal transition (EMT) and cancer stem cell (CSC) properties, which are mediated by TGF-β signaling. Here we evaluated ... ...

    Abstract Background: Acquired metastasis and invasion of cancer cells during radiotherapy are in part due to induction of epithelial-to-mesenchymal transition (EMT) and cancer stem cell (CSC) properties, which are mediated by TGF-β signaling. Here we evaluated the anti-metastatic therapeutic potential of vactosertib, an orally bioavailable TGF-β type I receptor (activin receptor-like kinase 5, ALK5) inhibitor, via suppression of radiation-induced EMT and CSC properties, oxidative stress generation, and breast to lung metastasis in a breast cancer mouse model and breast cancer cell lines.
    Materials and methods: Co-treatment of vactosertib with radiation was investigated in the 4T1-Luc allografted BALB/c syngeneic mouse model and in 4T1-Luc and MDA-MB-231 cells. The anti-metastatic therapeutic potential of vactosertib in breast cancer was investigated using fluorescence immunohistochemistry, real-time quantitative reverse transcription-polymerase chain reaction, western blotting, wound healing assay, mammosphere formation assay, and lung metastasis analysis
    Results: Radiation induced TGF-β signaling, EMT markers (Vimentin, Fibronectin, Snail, Slug, Twist, and N-cadherin), CSC properties (expression of pluripotent stem cell regulators, mammosphere forming ability), reactive oxygen species markers (NOX4, 4-HNE), and motility of breast cancer cells
    Conclusions: These results indicate that inhibition of TGF-β signaling with vactosertib in breast cancer patients undergoing radiotherapy would be an attractive strategy for the prevention of cancer metastasis and recurrence.
    MeSH term(s) Aniline Compounds ; Animals ; Breast Neoplasms/drug therapy ; Breast Neoplasms/metabolism ; Breast Neoplasms/radiotherapy ; Cell Line, Tumor ; Epithelial-Mesenchymal Transition ; Female ; Humans ; Lung Neoplasms/drug therapy ; Lung Neoplasms/radiotherapy ; Mice ; Protein Kinase Inhibitors/pharmacology ; Receptor, Transforming Growth Factor-beta Type I ; Transforming Growth Factor beta ; Triazoles
    Chemical Substances Aniline Compounds ; Protein Kinase Inhibitors ; Transforming Growth Factor beta ; Triazoles ; vactosertib (6T4O391P5Y) ; Receptor, Transforming Growth Factor-beta Type I (EC 2.7.11.30)
    Language English
    Publishing date 2022-04-07
    Publishing country Poland
    Document type Journal Article
    ZDB-ID 1128829-2
    ISSN 1581-3207 ; 0485-893X ; 1318-2099
    ISSN (online) 1581-3207
    ISSN 0485-893X ; 1318-2099
    DOI 10.2478/raon-2022-0012
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Book ; Online: Dual roles of inorganic aqueous phase on SOA growth from benzene and phenol

    Choi, Jiwon / Jang, Myoseon / Blau, Spencer

    eISSN:

    2023  

    Abstract: Benzene, emitted from automobile exhaust and biomass burning, is ubiquitous in ambient air. Benzene is a precursor hydrocarbon (HC) that forms secondary organic aerosols (SOA), but its SOA formation mechanism is not well studied. To accurately predict ... ...

    Abstract Benzene, emitted from automobile exhaust and biomass burning, is ubiquitous in ambient air. Benzene is a precursor hydrocarbon (HC) that forms secondary organic aerosols (SOA), but its SOA formation mechanism is not well studied. To accurately predict the formation of benzene SOA, it is important to understand the gas mechanisms of phenol, which is one of the major products formed from the atmospheric oxidation of benzene. Our chamber study found that wet-inorganic aerosol retarded the gas oxidation or phenol or benzene, and thus their SOA formation. To explain this unusual effect, it is hypothesized that a persistent phenoxy radical (PPR) effectively forms via a heterogeneous reaction of phenol and phenol-related products in the presence of wet-inorganic aerosol. These PPR species are capable of catalytically consuming ozone during a NO x cycle and negatively influencing SOA growth. In this study, explicit gas mechanisms were derived to produce the oxygenated products from the atmospheric oxidation of phenol and benzene. Gas mechanisms include the existing Master Chemical Mechanism (MCM v3.3.1); the reaction path for peroxy radical adducts originating from the addition of an OH radical to phenols forming low-volatility products (e.g., multi-hydroxy aromatics); and the mechanisms to form heterogeneous production of PPR. The simulated gas products were classified into volatility-reactivity based lumping species and incorporated into the UNIfied Partitioning Aerosol Reaction (UNIPAR) model that predicts SOA formation via multiphase reactions of phenol or benzene. The predictability of the UNIPAR model was examined using chamber data, which were generated for the photooxidation of phenol or benzene under various experimental conditions (NO x levels, humidity, and inorganic seed types). The SOA formation from both phenol and benzene still increased in the presence of wet inorganic seed because of the oligomerization of reactive organic species in aqueous phase. However, model simulations show a significant ...
    Subject code 660
    Language English
    Publishing date 2023-11-07
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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