Publications by authors named "SangJun Choi"

Objectives: Information systems focusing on occupational carcinogen exposure, whether categorized by industry or occupation, play a pivotal role in the prevention of occupational cancers. Recently, the Korean CARcinogen EXposure (K-CAREX) system was developed to assess carcinogen exposure by industry. However, corresponding information categorized by occupation has yet to be developed.

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Introduction: Cigarette smoke exposure is known to induce inflammation, leading to elevated levels of inflammatory markers such as white blood cell (WBC) count and C-reactive protein (CRP). Despite extensive research on this relationship, longitudinal studies are limited. We aimed to explore the association between cigarette smoke exposure and WBC count and CRP levels by restructuring community cohort data.

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We propose helical topological superconductivity away from the Fermi surface in three-dimensional time-reversal-symmetric odd-parity multiband superconductors. In these systems, pairing between electrons originating from different bands is responsible for the corresponding topological phase transition. Consequently, a pair of helical topological Dirac surface states emerges at finite excitation energies.

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Article Synopsis
  • The study developed a Korean construction job exposure matrix (KoConJEM) to assess exposure risks in 60 occupations identified by the construction workers mutual aid association.
  • Experts evaluated exposure to 26 hazardous agents, calculating risk scores and using a heatmap and web-based dashboard for comparison.
  • Key findings highlighted awkward posture, heat/cold, heavy lifting, and noise as common exposure risks, with KoConJEM serving as a valuable tool for epidemiological studies on construction workers' health risks.
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Objectives: Industry- and occupation-based carcinogen exposure matrices play a pivotal role in preventing occupational cancer. While the Korean CARcinogen EXposure (K-CAREX) has been developed in recent years to assess exposure prevalence and intensity by industry, the feasibility of constructing an occupation-based exposure matrix remains unexplored. Hence, the objective of this study is to explore the potential of combining the nationwide work environment measurement database (WEMD) and the special health examination database (SHED) to develop a comprehensive occupation-based exposure matrix.

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Josephson tunnel junctions exhibit a supercurrent typically proportional to the sine of the superconducting phase difference ϕ. In general, a term proportional to cos(ϕ) is also present, alongside microscopic electronic retardation effects. We show that voltage pulses sharply varying in time prompt a significant impact of the cos(ϕ) term.

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Introduction: Cigarette smoke increases peripheral white blood cell (WBC) count. However, the dose-dependent association between smoking and C-reactive protein (CRP), an important inflammatory marker, has been reported as inconsistent.

Aims And Methods: Here, we evaluated the associations between smoking and CRP using both smoking questionnaires and urine cotinine as exposure markers.

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Background: Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure.

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Objectives: Peak exposure to extremely low-frequency magnetic fields (ELF-MF) among semiconductor workers was characterized by type of factory, operation, and job.

Methods: A portable EMDEX meter was used to monitor the ELF-MF exposure of 117 semiconductor workers who are involved in wafer fabrication (fab) and assembly operations. ELF-MF measurements were logged every 3 s and categorized by process and job or activity during working hours.

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Background: The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database.

Methods: We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process.

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Background: Occupational cancer is a global health issue. The Korean CARcinogen EXposure (K-CAREX), a database of CARcinogen EXposure, was developed for the Korean labor force to estimate the number of workers exposed to carcinogens by industry. The present study aimed to estimate the intensity of exposure to carcinogens by industry, in order to supply complementary information about CARcinogen EXposure intensity to the K-CAREX.

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Van der Waals heterostructures with two-dimensional magnets offer a magnetic junction with an atomically sharp and clean interface. This attribute ensures that the magnetic layers maintain their intrinsic spin-polarized electronic states and spin-flipping scattering processes at a minimum level, a trait that can expand spintronic device functionalities. Here, using a van der Waals assembly of ferromagnetic FeGeTe with non-magnetic hexagonal boron nitride and WSe layers, we demonstrate electrically tunable, highly transparent spin injection and detection across the van der Waals interfaces.

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Background: Gender equality in the workplace remains a challenge. This study aimed to investigate the gender gap of human resources in the field of occupational safety and health (OSH) in Korea.

Methods: Several national statistical data that can confirm the gender distribution of personnel in the OSH sector were reviewed.

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Objectives: The purpose of this study is to investigate health managers' exposure to workplace violence (WPV) at construction sites and to review the statistical characteristics of experts in the safety and health fields using a gender-based analysis.

Methods: A preliminary survey of health managers at construction sites was conducted from March to April 2020 via the Health Managers Council in Construction Industry online community (https://band.us/band/62438722).

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Deep theoretical understanding of the electrical response of Josephson junctions is indispensable regarding both recent discoveries of new kinds of superconductivity and technological advances such as superconducting quantum computers. Here, we study the microscopic theory of the dc current-biased I-V characteristics of Josephson tunnel junctions. We derive an analytical formula of the I-V characteristics of generic junctions.

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The association between lung injury and exposure to humidifier disinfectant (HD) containing a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) has been controversial in South Korea. This study conducts a literature review in order to evaluate the likelihood of CMIT/MIT reaching the lower part of the respiratory tract and causing lung injury. A literature review focused on the inhalation risk of HD containing a mixture of CMIT and MIT.

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This study aimed to identify the major industries and jobs with the highest proportion of workers' compensation (WC) claims for COVID-19, characterize COVID-19 WC claims in terms of their demographic properties and disease severity, and identify factors influencing the approval of COVID-19 WC claims as occupational disease. A total of 488 workers who submitted COVID-19-related claims to the Korea Workers' Compensation and Welfare Service (KWCWS) from January 2020 to July 2021 were analyzed. A Fisher's exact test was employed to associate the severity of COVID-19 infection with demographic properties.

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Objective: Exposure to ultraviolet (UV) radiation from sunlight induces the production of essential vitamin D, whereas overexposure to sunlight leads to skin cancer. Sunlight exposure has been measured using questionnaires, dosimeters, and vitamin D levels. Several studies have measured vitamin D in the working population; however, these studies were limited to certain occupations such as farmers and construction workers.

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Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database.

Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016.

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Article Synopsis
  • - The study investigates the risk of benzene exposure among workers at a Korean semiconductor manufacturing company by analyzing relevant patents.
  • - A systematic patent search identified 75 documents from 1994 to 2010, revealing that benzene was potentially used in various semiconductor manufacturing processes such as chemical vapor deposition and etching.
  • - The findings suggest that workers involved in specific manufacturing processes, such as chemical vapor deposition and immersion lithography, may have been exposed to benzene between 1996 and 2010.
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This study aimed to evaluate the exposure levels and variation in airborne endotoxin and heavy metals such as aluminum, chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), zinc, and lead (Pb) in the three different South Korean subway environments (driver room, station office, and underground tunnel) and identify subway characteristics influencing endotoxin and heavy metals levels. Air samples were collected and analyzed using the kinetic Limulus Amebocyte Lysate assay and inductively coupled plasma mass spectrometers. The geometric mean was determined for endotoxin levels (0.

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Electron-phonon scatterings in solid-state systems are pivotal processes in determining many key physical quantities such as charge carrier mobilities and thermal conductivities. Here, we report direct probing of phonon mode specific electron-phonon scatterings in layered semiconducting transition metal dichalcogenides WSe, MoSe, WS, and MoS through inelastic electron tunneling spectroscopy measurements, quantum transport simulations, and density functional calculation. We experimentally and theoretically characterize momentum-conserving single- and two-phonon electron-phonon scatterings involving up to as many as eight individual phonon modes in mono- and bilayer films, among which transverse, longitudinal acoustic and optical, and flexural optical phonons play significant roles in quantum charge flows.

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Background: A job-exposure matrix (JEM) is an important surrogate indicator to evaluate past exposure levels. Although a Korean asbestos JEM has been constructed previously, this JEM includes only a few industrial and occupational groups. This study aimed to reconstruct the JEM by integrating the latest organized data to improve its utility.

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Objective: To prevent occupational cancers, carcinogen exposure surveillance systems have been developed in many countries. This study aimed to develop a carcinogen exposure database specific to South Korea.

Methods: Twenty known human carcinogens were selected for this study.

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There is currently no governmental body in South Korea resembling the type of poison center (PC) recommended by the World Health Organization (WHO). All Organization for Economic Cooperation and Development (OECD) member countries except for South Korea maintain such a PC tasked with both preventing poisoning accidents and supporting the prompt treatment of poisoned patients. Such a PC could very possibly have allowed the country to more promptly recognize the widespread wave of humidifier disinfectant (HD) associated health effects, including fatal lung injury and death, that lasted started roughly in 2000 and continued through 2011.

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