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  1. Article ; Online: Hierarchical channel morphology in O-rings after two cycling exposures to 70 MPa hydrogen gas: a case study of sealing failure.

    Lee, Chang Hoon / Jung, Jae Kap / Kim, Kyung Sook / Kim, Chang Jong

    Scientific reports

    2024  Volume 14, Issue 1, Page(s) 5319

    Abstract: ... material show no significant changes when exposed to 70 MPa hydrogen gas. However, in the micrometre range ...

    Abstract This study investigates the impact of high-pressure hydrogen gas exposure on the structural and morphological characteristics of O-ring materials. O-ring specimens undergo two cycles of sealing under 70 MPa hydrogen gas, and their resulting variations are examined using advanced characterization techniques, including powder X-ray diffraction (PXRD), small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Our findings reveal that the lattice parameters of the O-ring material show no significant changes when exposed to 70 MPa hydrogen gas. However, in the micrometre range, the formation of a hierarchical channel morphology becomes evident. This morphology is accompanied by the separation of carbon black filler from the rubber matrix, contributing to mechanical weakening of the O-ring. These observations can be attributed to the pressure gradient that develops between the inner and outer radii of the O-ring, resulting from compression forces acting perpendicularly to the radial direction due to clamp locking.
    Language English
    Publishing date 2024-03-04
    Publishing country England
    Document type Journal Article
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-024-55101-w
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Hydrogenation of High-Density Polyethylene during Decompression of Pressurized Hydrogen at 90 MPa: A Molecular Perspective.

    Kim, Mina / Lee, Chang Hoon

    Polymers

    2023  Volume 15, Issue 13

    Abstract: To investigate changes in the physical and chemical properties of high-density polyethylene (HDPE ... The results showed that both physical and chemical changes occurred in HDPE upon a rapid release of hydrogen ...

    Abstract To investigate changes in the physical and chemical properties of high-density polyethylene (HDPE) upon the rapid release of hydrogen gas at a pressure of 90 MPa, several characterization techniques have been employed, including optical microscopy, scanning electron microscopy, X-ray diffraction, differential scanning thermal analysis, and attenuated total reflectance Fourier-transform infrared spectroscopy. The results showed that both physical and chemical changes occurred in HDPE upon a rapid release of hydrogen gas. Physically, a partial hexagonal phase was formed within the amorphous region, and the overall crystallinity of HDPE decreased. Chemically, hydrogenation occurred, leading to the addition of hydrogen atoms to the polymer chains. Oxidation also occurred, for example, the formation of ester -C=O groups. Crosslinking and an increase in -CH
    Language English
    Publishing date 2023-06-29
    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/polym15132880
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Hydrogenation of High-Density Polyethylene during Decompression of Pressurized Hydrogen at 90 MPa

    Mina Kim / Chang Hoon Lee

    Polymers, Vol 15, Iss 2880, p

    A Molecular Perspective

    2023  Volume 2880

    Abstract: To investigate changes in the physical and chemical properties of high-density polyethylene (HDPE ... The results showed that both physical and chemical changes occurred in HDPE upon a rapid release of hydrogen ... an increase in -CH 3 end termination were also observed. These changes suggest that structural transformation ...

    Abstract To investigate changes in the physical and chemical properties of high-density polyethylene (HDPE) upon the rapid release of hydrogen gas at a pressure of 90 MPa, several characterization techniques have been employed, including optical microscopy, scanning electron microscopy, X-ray diffraction, differential scanning thermal analysis, and attenuated total reflectance Fourier-transform infrared spectroscopy. The results showed that both physical and chemical changes occurred in HDPE upon a rapid release of hydrogen gas. Physically, a partial hexagonal phase was formed within the amorphous region, and the overall crystallinity of HDPE decreased. Chemically, hydrogenation occurred, leading to the addition of hydrogen atoms to the polymer chains. Oxidation also occurred, for example, the formation of ester -C=O groups. Crosslinking and an increase in -CH 3 end termination were also observed. These changes suggest that structural transformation and chemical modification of HDPE occurred upon the rapid release of hydrogen gas.
    Keywords hydrogenation ; partial hexagonal phase ; 90 MPa hydrogen pressure ; Organic chemistry ; QD241-441
    Subject code 660
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: ChatGPT Vision for Radiological Interpretation: An Investigation Using Medical School Radiology Examinations.

    Kim, Hyungjin / Kim, Paul / Joo, Ijin / Kim, Jung Hoon / Park, Chang Min / Yoon, Soon Ho

    Korean journal of radiology

    2024  Volume 25, Issue 4, Page(s) 403–406

    MeSH term(s) Humans ; Schools, Medical ; Radiography ; Radiology
    Language English
    Publishing date 2024-03-25
    Publishing country Korea (South)
    Document type Journal Article
    ZDB-ID 2046981-0
    ISSN 2005-8330 ; 1229-6929
    ISSN (online) 2005-8330
    ISSN 1229-6929
    DOI 10.3348/kjr.2024.0017
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Effects of physical activity level on quality of life, stress, and dietary behavior in people living with HIV/AIDS: A pilot study.

    Kim, Sung-Hoon / Joo, Chang-Hwa

    Medicine

    2023  Volume 102, Issue 14, Page(s) e33460

    Abstract: The aim of this study was to analyze the daily physical activity and the relationship between the physical activity levels and psychological variables of Koreans with HIV. Twenty-two people with HIV participated in this study. The participants completed ... ...

    Abstract The aim of this study was to analyze the daily physical activity and the relationship between the physical activity levels and psychological variables of Koreans with HIV. Twenty-two people with HIV participated in this study. The participants completed questionnaires, and we assessed the daily physical activity for 2 weeks. The daily physical activity level of most of the participants was low-intensity; high-intensity activities were only performed for approximately 1 minute. The participants had unhealthy dietary habits, such as eating 2 meals a day, eating irregularly, and skipping breakfast. Psychological well-being and environmental satisfaction were higher in the high-intensity group than in the medium- and low-intensity groups (P < .05). The overall stress level among the groups was statistically significantly different (P < .05), and the stress level was lower in the high-intensity group than in the low- and medium-intensity groups. Restraint eating was higher in the low-intensity group than in the medium- and high-intensity groups (P < .05). However, among the groups, the external eating variable was highest in the high-intensity group (P < .05). Daily physical activity during positively affects the physical and mental well-being of people living with HIV.
    MeSH term(s) Humans ; Pilot Projects ; Quality of Life ; Feeding Behavior/psychology ; Surveys and Questionnaires ; Exercise ; Diet ; HIV Infections
    Language English
    Publishing date 2023-04-07
    Publishing country United States
    Document type Journal Article
    ZDB-ID 80184-7
    ISSN 1536-5964 ; 0025-7974
    ISSN (online) 1536-5964
    ISSN 0025-7974
    DOI 10.1097/MD.0000000000033460
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: A novel strategy for treatment of bladder cancer: Antibody-drug conjugates.

    Kim, Jung Hoon / Chang, In Ho

    Investigative and clinical urology

    2022  Volume 63, Issue 4, Page(s) 373–384

    Abstract: In the past, there was no second-line chemotherapeutic agent suitable for use when urothelial carcinoma (UC) progressed to platinum-resistant UC. However, recently, several new treatment options, such as immune checkpoint inhibitors or targeted therapy ... ...

    Abstract In the past, there was no second-line chemotherapeutic agent suitable for use when urothelial carcinoma (UC) progressed to platinum-resistant UC. However, recently, several new treatment options, such as immune checkpoint inhibitors or targeted therapy have shifted the treatment paradigm regarding second-line therapeutic modalities. A novel class of therapeutic agents includes an antibody-drug conjugate (ADC). ADCs consist of three characteristics: a monoclonal antibody, linker, and payload. The specificity of the monoclonal antibody facilitates the delivery of a linked cytotoxic drug directly into the target tumor cell. Although various ADCs have been developed and approved for use in treating several solid tumors, almost all ADCs for the treatment of UC are still in the testing phase. Here, we review the key points about ADCs and summarize the novel ADCs that are approved or are involved in ongoing studies in UC.
    MeSH term(s) Antibodies, Monoclonal/therapeutic use ; Antineoplastic Agents/therapeutic use ; Carcinoma, Transitional Cell/drug therapy ; Humans ; Immunoconjugates/pharmacology ; Immunoconjugates/therapeutic use ; Urinary Bladder Neoplasms/drug therapy
    Chemical Substances Antibodies, Monoclonal ; Antineoplastic Agents ; Immunoconjugates
    Language English
    Publishing date 2022-05-30
    Publishing country Korea (South)
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't
    ZDB-ID 2923014-7
    ISSN 2466-054X ; 2466-0493
    ISSN (online) 2466-054X
    ISSN 2466-0493
    DOI 10.4111/icu.20220061
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Conference proceedings: Secondary Trigeminal Neuralgia Caused by Meningiomas Involving the Meckel’s Cave and Microsurgical Decompression

    Byeon, Yukyeng / Lee, Chaejin / Song, Sang Woo / Kim, Young-Hoon / Hong, Chang-Ki / Kim, Jeong Hoon

    Journal of Neurological Surgery Part B: Skull Base

    2024  Volume 85, Issue S 01

    Event/congress 33rd Annual Meeting North American Skull Base Society, Atlanta Marriott Marquis Atlanta, Georgia, United States, 2024-02-16
    Language English
    Publishing date 2024-02-01
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article ; Conference proceedings
    ZDB-ID 2654269-9
    ISSN 2193-634X ; 2193-6331
    ISSN (online) 2193-634X
    ISSN 2193-6331
    DOI 10.1055/s-0044-1780139
    Database Thieme publisher's database

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  8. Article ; Conference proceedings: Endoscopic Endonasal Approach for Retroclival Meningiomas: Insights from a Single Institutional Case Series

    Lee, Chaejin / Song, Sang Woo / Kim, Young-Hoon / Kim, Jeong Hoon / Hong, Chang Ki

    Journal of Neurological Surgery Part B: Skull Base

    2024  Volume 85, Issue S 01

    Event/congress 33rd Annual Meeting North American Skull Base Society, Atlanta Marriott Marquis Atlanta, Georgia, United States, 2024-02-16
    Language English
    Publishing date 2024-02-01
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article ; Conference proceedings
    ZDB-ID 2654269-9
    ISSN 2193-634X ; 2193-6331
    ISSN (online) 2193-634X
    ISSN 2193-6331
    DOI 10.1055/s-0044-1780140
    Database Thieme publisher's database

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  9. Article ; Conference proceedings: Tailored Reconstruction Strategy for the Prevention of Cerebrospinal Fluid (CSF) Leakage AFTER Endoscopic Endonasal Transclival Approach

    Kim, Young-Hoon / Hong, Chang-Ki

    Journal of Neurological Surgery Part B: Skull Base

    2023  Volume 84, Issue S 01

    Event/congress 32nd Annual Meeting North American Skull Base Society, JW Marriott Tampa Water Street, Tampa, Florida, United States, 2023-02-17
    Language English
    Publishing date 2023-02-01
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article ; Conference proceedings
    ZDB-ID 2654269-9
    ISSN 2193-634X ; 2193-6331
    ISSN (online) 2193-634X
    ISSN 2193-6331
    DOI 10.1055/s-0043-1762429
    Database Thieme publisher's database

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  10. Article: Are Electronic Cigarettes Harmful? Mucin May Be the Key.

    Rha, Min-Seok / Kim, Chang-Hoon

    Clinical and experimental otorhinolaryngology

    2021  Volume 14, Issue 3, Page(s) 249–250

    Language English
    Publishing date 2021-08-01
    Publishing country Korea (South)
    Document type Editorial
    ZDB-ID 2491719-9
    ISSN 2005-0720 ; 1976-8710
    ISSN (online) 2005-0720
    ISSN 1976-8710
    DOI 10.21053/ceo.2021.00906
    Database MEDical Literature Analysis and Retrieval System OnLINE

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