Search

Ira Katz,1,2 Marine Pichelin,1 Spyridon Montesantos,1 Min-Yeong Kang,3 Bernard Sapoval,3,4 Kaixian Zhu,5 Charles-Philippe Thevenin,5 Robert McCoy,6 Andrew R Martin,7 Georges Caillibotte1 1Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France; 2Department of Mechanical Engineering, Lafayette College, Easton, PA, USA; 3Physique de la Matière Condensée, CNRS, Ecole Polytechnique, Palaiseau, 4Centre de Mathématiques et de leurs Applications, CNRS, UniverSud, Cachan, 5Centre Explor!, Air Liquide Healthcare, Gentilly, France; 6Valley Inspired Products, Inc, Apple Valley, MN, USA; 7Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada Abstract: Oxygen treatment based on intermittent-flow devices with pulse delivery modes available from portable oxygen concentrators (POCs) depends on the characteristics of the delivered pulse such as volume, pulse width (the time of the pulse to be delivered), and pulse delay (the time for the pulse to be initiated from the start of inhalation) as well as a patient’s breathing characteristics, disease state, and respiratory morphology. This article presents a physiological-based analysis of the performance, in terms of blood oxygenation, of a commercial POC at different settings using an in silico model of a COPD patient at rest and during exercise. The analysis encompasses experimental measurements of pulse volume, width, and time delay of the POC at three different settings and two breathing rates related to rest and exercise. These experimental data of device performance are inputs to a physiological-based model of oxygen uptake that takes into account the real dynamic nature of gas exchange to illustrate how device- and patient-specific factors can affect patient oxygenation. This type of physiological analysis that considers the true effectiveness of oxygen transfer to the blood, as opposed to delivery to the nose (or mouth), can be instructive in applying therapies and designing new devices. Keywords: efficiency, respiratory physiology, respiratory disease, pulsed delivery

Abstract In metal additive manufacturing (AM), arc plasma is attracting attention as an alternative heat source to expensive lasers to enable the use of various metal wire materials with a high deposition efficiency. However, the stepwise material deposition and resulting limited number of degrees of freedom limit their potential for high‐throughput and large‐scale production for industrial applications. Herein, a high‐throughput metal 3D printing pen (M3DPen) strategy is proposed based on an arc plasma heat source by harnessing the surface tension of the molten metal for enabling continuous material deposition without a downward flow by gravity. The proposed approach differs from conventional arc‐based metal AM in that it controls the solidification and cooling time between interlayers of a point‐by‐point deposition path, thereby allowing for continuous metal 3D printing of freestanding and overhanging structures at once. The resulting mechanical properties and unique microstructures by continuous metal deposition that occur due to the difference in the thermal conditions of the molten metal under cooling are also investigated. This technology can be applied to a wide range of alloy systems and industrial manufacturing, thereby providing new possibilities for metal 3D printing.

Abstract Background Dimeric human erythropoietin (dHuEPO) peptides are reported to exhibit significantly higher biological activity than the monomeric form of recombinant EPO. The objective of this study was to produce transgenic (tg) mice expressing dHuEPO and to investigate the characteristics of these mice. Methods A dHuEPO-expressing vector under the control of the goat beta-casein promoter, which produced a dimer of human EPO molecules linked by a 2-amino acid peptide linker (Asp-Ile), was constructed and injected into 1-cell fertilized embryos by microinjection. Mice were screened using genomic DNA samples obtained from tail biopsies. Blood samples were obtained by heart puncture using heparinized tubes, and hematologic parameters were assessed. Using the microarray analysis tool, we analyzed differences in gene expression in the spleens of tg and control mice. Results A high rate of spontaneous abortion or death of the offspring was observed in the recipients of dHuEPO embryos. We obtained 3 founder lines (#4, #11, and #47) of tg mice expressing the dHuEPO gene. However, only one founder line showed stable germline integration and transmission, subsequently establishing the only transgenic line (#11). We obtained 2 F1 mice and 3 F2 mice from line #11. The dHuEPO protein could not be obtained because of repeated spontaneous abortions in the tg mice. Tg mice exhibited symptoms such as short lifespan and abnormal blood composition. The red blood cell count, white blood cell count, and hematocrit levels in the tg mice were remarkably higher than those in the control mice. The spleens of the tg mice (F1 and F2 females) were 11- and -21-fold larger than those of the control mice. Microarray analysis revealed 2,672 spleen-derived candidate genes; more genes were downregulated than upregulated (849/764). Reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative real-time PCR (qRT-PCR) were used for validating the results of the microarray analysis of mRNA expression. Conclusions In conclusion, dHuEPO tg mice caused excessive erythrocytosis that led to abnormal blood composition, short lifespan, and abnormal splenomegaly. Further, we identified 2,672 genes associated with splenomegaly by microarray analysis. These results could be useful in the development of dHuEPO-producing tg animals.

Abstract Background The aldo-keto reductase family 1 member C1 (AKR1C1) belongs to a superfamily of NADPH-dependent reductases that convert a wide range of substrates, including carbohydrates, steroid hormones, and endogenous prostaglandins. The 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) is a member of AKR family. The aims of this study were to determine its expression in the ovary and uterus endometrium during the estrous cycle and pregnancy. Methods Rapid amplification of cDNA ends (RACE) experiments were performed to obtain the 5' and 3' ends of the porcine 20alpha-HSD cDNA. Reverse-transcriptase-PCR (RT-PCR), real-time PCR, northern blot analysis, and western blot analysis were performed to examine the expression of porcine 20alpha-HSD. Immunohistochemical analysis was also performed to determine the localization in the ovary. Results The porcine 20alpha-HSD cDNA is 957 bp in length and encodes a protein of 319 amino acids. The cloned cDNA was virtually the same as the porcine AKR1C1 gene (337 amino acids) reported recently, and only differed in the C-terminal region (the AKR1C1 gene has a longer C-terminal region than our sequence). The 20alpha-HSD gene (from now on referred to as AKR1C1) cloned in this paper encodes a deletion of 4 amino acids, compared with the C-terminal region of AKR1C1 genes from other animals. Porcine AKR1C1 mRNA was expressed on day 5, 10, 12, 15 of the cycle and 0-60 of pregnancy in the ovary. The mRNA was also specifically detected in the uterine endometrium on day 30 of pregnancy. Western blot analysis indicated that the pattern of AKR1C1 protein in the ovary during the estrous cycle and uterus during early pregnancy was similar to that of AKR1C1 mRNA expression. The recombinant protein produced in CHO cells was detected at approximately 37 kDa. Immunohistochemical analysis also revealed that pig AKR1C1 protein was localized in the large luteal cells in the early stages of the estrous cycle and before parturition. Conclusions Our study demonstrated that AKR1C1 mRNA and protein are coordinately expressed in the luteal cell of ovary throughout the estrous cycle and in the uterus on day 30 of pregnancy. Thus, the porcine AKR1C1 gene might control important mechanisms during the estrous cycle.

Abstract Nanofluids, which are engineered suspensions of nanoparticles in a solvent such as water, have been found to show enhanced coolant properties such as higher critical heat flux and surface wettability at modest concentrations, which is a useful characteristic in nuclear power plants (NPPs). This study attempted to provide an example of engineering applications in NPPs using nanofluid technology. From these motivations, the conceptual designs of the emergency core cooling systems (ECCSs) assisted by nanofluid injection mechanism were proposed after following a design framework to develop complex engineering systems. We focused on the analysis of functional requirements for integrating the conventional ECCSs and nanofluid injection mechanism without loss of performance and reliability. Three candidates of nanofluid-engineered ECCS proposed in previous researches were investigated by applying axiomatic design (AD) in the manner of reverse engineering and it enabled to identify the compatibility of functional requirements and potential design vulnerabilities. The methods to enhance such vulnerabilities were referred from TRIZ and concretized for the ECCS of the Korean nuclear power plant. The results show a method to decouple the ECCS designs with the installation of a separate nanofluids injection tank adjacent to the safety injection tanks such that a low pH environment for nanofluids can be maintained at atmospheric pressure which is favorable for their injection in passive manner.

Abstract Background IFN-γ is a multifunctional peptide with a potent immune defense function which is also known as a prototypic Th1 cytokine. While screening for genes differentially expressed by Th1 and Th2 cytokines, human thioredoxin was identified as a novel target gene induced by IFN-γ. The mechanism by which thioredoxin is induced by IFN-γ and the signaling pathways involved in its induction were analyzed. In addition, the effects of thioredoxin on immune cell survival and cytokine production were examined by thioredoxin over-expression and recombinant thioredoxin treatment. Results Human thioredoxin was selectively induced by IFN-γ in monocytic and T cell lines. In monocytic cells, the induction of thioredoxin gene expression by IFN-γ was dose-dependent, and both the mRNA and protein levels were increased by 2~3 fold within 4 to 24 h hours of IFN-γ treatment. The thioredoxin induction by IFN-γ was insensitive to cycloheximide treatment, suggesting that it is a primary response gene induced by IFN-γ. Subsequent analysis of the signaling pathways indicated that the Jak/Stat, Akt, and Erk pathways play a role in IFN-γ signaling that leads to thioredoxin gene expression. Thioredoxin was induced by oxidative or radiation stresses, and it protected the immune cells from apoptosis by reducing the levels of reactive oxygen species. Furthermore, thioredoxin modulated the oxidant-induced cytokine balance toward Th1 by counter-regulating the production of IL-4 and IFN-γ in T cells. Conclusion These data suggest that thioredoxin is an IFN-γ-induced factor that may play a role in developing Th1 immunity and in the maintenance of immune homeostasis upon infection, radiation, and oxidative stress.

Objective: This study aimed to identify the occupational factors that influence turnover intention among working women with lower urinary tract symptoms (LUTS)., Methods: This cross-sectional study targeted 410 working women with LUTS from a 2022 survey. Occupational characteristics, including working hours, shift work, bathroom accessibility, sitting time, musculoskeletal strain, job stress, and emotional labor, were assessed through a structured self-reported questionnaire using validated tools. Multiple logistic regression was applied to analyze the association of these factors with turnover intention., Results: Women who worked >52 hours per week had an odds ratio of 2.02 for turnover intention compared to those who worked fewer hours. Higher job stress and emotional labor scores also were associated with increased turnover intention., Conclusions: Women with LUTS have higher turnover intention due to vulnerability to long hours, job stress, and emotional labor., Competing Interests: Conflict of interest: None declared., (Copyright © 2024 American College of Occupational and Environmental Medicine.)

Objectives: Lower urinary tract symptoms (LUTS) are prevalent among women, affecting not only their physical well-being but also their quality of working life. This study aimed to assess the relationship between psychosocial factors at work and LUTS among working women. Additionally, we sought to investigate whether women with psychosocial risk factors at work reported reduced quality of life (QOL) and a higher degree of productivity loss from absenteeism and presenteeism., Methods: An online survey was conducted to collect the demographic characteristics, occupational risk factors, and LUTS among employed Korean women. Shift work, weekly working hours, occupational stress, and emotional labor were surveyed as psychosocial risk factors at work. The association between psychosocial risk factors and LUTS was assessed using adjusted logistic regression. The relationships between psychosocial risk factors and LUTS-related outcomes, such as were examined using a generalized linear model., Results: Of the 1057 participants, 260 (24.6%) and 294 (27.81%) had overactive bladder and urinary incontinence, respectively. Job stress, emotional labor, and night-shift work are significantly associated with a higher prevalence of LUTS, which reduce workers' QOL and labor productivity through absenteeism and presenteeism due to urination symptoms., Conclusions: Psychosocial factors at work, particularly job stress, emotional labor, and night-shift work, were significantly associated with a higher prevalence of LUTS, leading to reduced QOL and labor productivity due to urination symptoms., (© 2024 The Japanese Urological Association.)

This study investigated workplace toilet access related to lower urinary tract symptoms (LUTS) among women in the Korean workforce. A cross-sectional survey was conducted to determine demographic characteristics, occupational risk factors, and urinary tract symptoms among employed Korean women. Occupational risk factors included two survey questions about access to toilets at work. LUTS were assessed using the overactive bladder symptom score (OABSS) and international consultation on incontinence questionnaire-urinary incontinence short form (ICIQ-SF). Health-related productivity losses (HRPL) were estimated using the work productivity and activity impairment questionnaire for urinary symptoms (WPAI-US). Multiple logistic regression was used to determine the association between workplace toilet access and LUTS. In addition, generalised linear regression analysis was performed to assess HRPL according to workplace toilet access. Of the 1057 participants, 260 (24.6%) and 294 (27.81%) had overactive bladder and urinary incontinence, respectively. More than 50% reported poor access to toilet. Multiple logistic regression analysis showed that the lower the access to toilets in the workplace, the higher the incidence of LUTS and the higher HRPL. In conclusion, restricted access to toilets at work are associated with poor urinary health and loss of productivity.

Objectives: To investigate factors associated with individual lifestyle influencing productivity reduction., Methods: Data were collected using a Web-based questionnaire from January 6, 2020, to February 18, 2020. The study included 3890 wage workers across South Korea. Data on drinking, smoking, physical activity, and sleep were collected. This study measured health-related productivity loss (HRPL), using the Work Productivity and Activity Impairment Questionnaire: General Health version., Results: Only nonoptimal sleep time was significantly associated with higher HRPL after adjusting for age, gender, education level, marital status, employment status, income level, weekly working hours, and occupation. This result was most derived from presenteeism than absenteeism. If the sleep disorder was diagnosed by a physician, the HRPL was even greater., Conclusions: This study suggested that sleep is significantly associated with HRPL, particularly in men and manual workers., Competing Interests: Conflict of interest: None declared., (Copyright © 2024 American College of Occupational and Environmental Medicine.)

Public health and clinical medicine should identify and characterize modifiable risk factors for skin cancer in order to facilitate primary prevention. In existing literature, the impact of occupational exposure on skin cancer, including malignant melanoma and non-melanoma skin cancers, has been extensively studied. This review summarizes the available epidemiological evidence on the significance of occupational risk factors and occupations associated with a higher risk in skin cancer. The results of this review suggest that there is sufficient epidemiological evidence to support the relationship between the increased risk of non-melanoma skin cancers and occupational exposure to solar radiation, ultraviolet radiation, ionizing radiation, arsenic and its compounds, and mineral oils. Occupational exposure to pesticides and polychlorinated biphenyls appears to provide sufficient epidemiological evidence for melanoma, and a higher risk of melanoma has been reported among workers in petroleum refining and firefighters. This comprehensive analysis will establish a foundation for subsequent investigations and developing targeted interventions of focused preventive measures against skin cancer among the working population., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Background: Using intelligent monitoring systems can potentially improve the identification and management of ventilator-associated events (VAEs). This single-center retrospective observational study evaluated the impact of implementing intelligent monitoring systems on the clinical outcomes of patients with VAEs in an ICU setting. Method: An intelligent VAE monitoring system was integrated into electronic medical records to continuously collect patient data and alert attending physicians when a ventilated patient met the criteria for a ventilator-associated condition, which was defined as an increase of at least three cm H 2 O in positive end expiratory pressure (PEEP), an increase of at least 0.20 in the fraction of inspired oxygen (FiO 2 ), or the FiO 2 being over baseline for at least two consecutive days. This study covered two phases, consisting of before using the intelligent monitoring system (2021-2022) and during its use (2023-2024). Results: The results showed that patients monitored with the intelligent system experienced earlier VAE detection (4.96 ± 1.86 vs. 7.77 ± 3.35 days, p < 0.001), fewer ventilator-associated condition (VAC) occurrences, and a shorter total duration of VACs. Additionally, the system significantly reduced ventilator days, antibiotic use, and 14-day mortality. Conclusions: Intelligent monitoring systems enhance VAE management, improve clinical outcomes, and provide valuable insights into the future of critical care medicine.

Background: Accurate occupation classification is essential in various fields, including policy development and epidemiological studies. This study aims to develop an occupation classification model based on DistilKoBERT., Methods: This study used data from the 5th and 6th Korean Working Conditions Surveys conducted in 2017 and 2020, respectively. A total of 99,665 survey participants, who were nationally representative of Korean workers, were included. We used natural language responses regarding their job responsibilities and occupational codes based on the Korean Standard Classification of Occupations (7th version, 3-digit codes). The dataset was randomly split into training and test datasets in a ratio of 7:3. The occupation classification model based on DistilKoBERT was fine-tuned using the training dataset, and the model was evaluated using the test dataset. The accuracy, precision, recall, and F1 score were calculated as evaluation metrics., Results: The final model, which classified 28,996 survey participants in the test dataset into 142 occupational codes, exhibited an accuracy of 84.44%. For the evaluation metrics, the precision, recall, and F1 score of the model, calculated by weighting based on the sample size, were 0.83, 0.84, and 0.83, respectively. The model demonstrated high precision in the classification of service and sales workers yet exhibited low precision in the classification of managers. In addition, it displayed high precision in classifying occupations prominently represented in the training dataset., Conclusions: This study developed an occupation classification system based on DistilKoBERT, which demonstrated reasonable performance. Despite further efforts to enhance the classification accuracy, this automated occupation classification model holds promise for advancing epidemiological studies in the fields of occupational safety and health., Competing Interests: Competing interests: The authors declare that they have no competing interests., (Copyright © 2024 Korean Society of Occupational & Environmental Medicine.)

The study examined how neck muscle imbalance and plagiocephaly affect the lying and rolling activities in 118 infants aged 4 to 6 months with postural torticollis. Outcome measures included age, sex, cervical movement, and plagiocephaly severity. Neck muscle function was assessed with the Muscle Function Scale (MFS), and infant motor abilities in lying and rolling were evaluated through the corresponding dimensions of the Gross Motor Function Measure (GMFM). Multiple regression analysis showed that a better MFS score of the affected neck was significantly associated with improved lying and rolling activities in the GMFM ( p  < .01), and importantly, the interaction between the plagiocephaly and the MFS scores of the affected neck muscle in these activities was found to be significant ( p  < .05). These results highlight the need for early intervention in infants with torticollis to address muscle imbalance and plagiocephaly, crucial for early motor development (KCT0008367).

Background: Previous reports showed that age and socioeconomic factors mediated health-related unemployment. However, those studies had limitations controlling for confounding factors. This study examines age and socioeconomic factors contributing to health-related unemployment using propensity score matching (PSM) to control for various confounding variables., Methods: Data were obtained from the Korean National Health and Nutrition Examination Survey (KNHANES) from 2015-2017. We applied a 1:1 PSM to align health factors, and examined the association between health-related unemployment and age or socioeconomic factors through conditional logistic regression. The health-related unemployment group was compared with the employment group., Results: Among the 9,917 participants (5,817 women, 4,100 men), 1,182 (853 women, 329 men) were in the health-related unemployment group. Total 911 pairs (629 women pairs and 282 men pairs) were retained after PSM for health factors. The results of conditional logistic regression showed that older age, low individual and household income levels, low education level, receipt of the Basic Livelihood Security Program benefits and longest-held job characteristics were linked to health-related unemployment, despite having similar health levels., Conclusions: Older age and low socioeconomic status can increase the risk of health-related unemployment, highlighting the presence of age discrimination and socioeconomic inequality. These findings underscore the importance of proactive management strategies aimed at addressing these disparities, which are crucial for reducing the heightened risk of health-related unemployment., Competing Interests: Competing interests: The authors declare that they have no competing interests., (Copyright © 2024 Korean Society of Occupational & Environmental Medicine.)

Background: Traditionally, a venous diameter of less than 3 mm was not considered for creation of AVF. Some studies have reported smaller venous size could be used for operation. AVF created with a smaller vein may have a lower maturation rate. Currently, percutaneous angioplasty is also used to enhance the maturation of AVF. This study aimed to establish whether the BAM procedure could offer comparable results for AVF created with a smaller vein., Methods: From January 2016 to July 2021, 290 patients who received native AVF operation were enrolled in this study. All of the preoperative venous sizes were measured by Duplex ultrasonography under tourniquet enhancement. The study cohort was categorized into two groups based on the pre-operative venous diameter: smaller vein group (SVG, 2.5 < size < 3 mm, 53.1%) and normal vein group (NVG, size ⩾ 3 mm, 46.9%)., Results: The mean age was 64 ± 12.9 years, and 58.6% of patients were male. Hypertension and DM were the most common comorbidities. Most patients underwent operation of radio-cephalic fistula (71.4%). The overall primary maturation rate was 79%. The primary maturation rate was significantly higher in the NVG (86% vs 72.7%, p  = 0.009). However, after the BAM procedure, the secondary maturation rate was similar in both groups (94.1% vs 90.3%, p  = 0.319)., Conclusions: According to our study, the BAM procedure can significantly increase the maturation rate, and the secondary maturation rate was similar in both groups. Thus, more patients can be given the opportunity to undergo creation of an AVF for long-term hemodialysis., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: The microenvironment of pancreatic ductal adenocarcinoma (PDAC) with extensive desmoplastic stroma contributes to aggressive cancer behavior. Angiotensin system inhibitors (ASIs) reduce stromal fibrosis and are a promising therapeutic strategy. The purpose of this study was to examine how ASIs affected the oncological results of patients who had their PDAC removed., Materials and Methods: A retrospective assessment was conducted on the clinicopathological and survival data of patients who received curative resection for PDAC at Severance Hospital between January 2012 and December 2019., Results: A total of 410 participants (228 male and 182 female), with a median follow-up period of 12.8 months, were included in this study. Patients were divided into three groups, based on ASI use and history of hypertension: group 1, normotensive and never used ASI (n=210, 51.2%); group 2, ASI non-users with hypertension (n=50, 12.2%); and group 3, ASI users with hypertension (n=150, 36.6%). The three groups did not differ significantly in terms of age, sex, kind of operation, T and N stages, or adjuvant and neoadjuvant therapy. Moreover, there was no discernible difference in disease-free survival between those who used ASI and those who did not ( p =0.636). The 5-year overall survival (OS) rates in groups 1, 2, and 3 were 52.6%, 32.3%, and 38.0%, respectively. However, the OS rate of ASI users was remarkably higher than that of non-users ( p =0.016)., Conclusion: In patients with resected PDAC, ASI is linked to longer survival rates. Furthermore, for individuals with hypertension, ASI in conjunction with conventional chemotherapy may be an easy and successful treatment option., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2024.)

The optimal indoor environment is associated with comfortable temperatures along with favorable indoor air quality. One of the air pollutants, particulate matter (PM), is potentially harmful to animals and humans. Most farms have monitoring systems to identify other hazardous gases rather than PM due to the sensor cost. In recent decades, the application of environmental monitoring systems based on Internet of Things (IoT) devices that incorporate low-cost sensors has elevated extensively. The current study develops a low-cost air quality monitoring system for swine buildings based on Raspberry Pi single-board computers along with a sensor array. The system collects data using 11 types of environmental variables along with temperature, humidity, CO 2 , light, pressure, and different types of gases, namely PM 1 , PM 2.5 , and PM 10 . The system is designed with a central web server that provides real-time data visualization and data availability through the Internet. It was tested in actual pig barns to ensure stability and functionality. In addition, there was a collocation test conducted by placing the system in two different pig barns to validate the sensor data. The Wilcoxon rank sum test demonstrates that there are no significant differences between the two sensor datasets, as all variables have a p-value greater than 0.05. However, except for carbon monoxide (CO), none of the variables exhibit correlation exceeding 0.5 with PM concentrations. Overall, a scalable, portable, non-complex, low-cost air quality monitoring system was successfully developed within a cost of USD 94.

Background: Hypertension, a major public health problem worldwide, has been linked to lifestyle factors and work conditions, with conflicting evidence on the association between long work hours and risk of hypertension., Methods: We conducted a systematic review and meta-analysis of observational studies to investigate the relationship between working hours and hypertension or blood pressure, assessed the risk of bias and performed subgroup analyses. The protocol was registered with the International Prospective Register of Systematic Reviews., Results: The pooled OR for the association between long working hours and risk of hypertension was 1.09 (95% CI: 0.88 to 1.35) in the 15 studies that used hypertension as the outcome. In the three studies that used blood pressure as the outcome, diastolic blood pressure was higher among those with long working hours compared with those with non-long working hours (1.24 mm Hg, 95% CI: 0.19 to 2.29). In subgroup analysis, the pooled OR for the association between long working hours and risk of hypertension was 1.28 (95% CI: 1.14 to 1.44) and 1.00 (95% CI: 0.64 to 1.56) in women and men, respectively., Conclusions: Although this study could not clearly confirm the relationship between long working hours and hypertension, the subgroup analysis suggests that long working hours may be associated with hypertension, particularly among women. More reliable research is needed to establish causality., Prospero Registration Number: CRD42023406961., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: After the coronavirus disease 2019 pandemic, the widespread adoption of working from home, or teleworking, has prompted extensive research regarding its effects on work productivity and the physical and mental health of employees. In this context, our study aimed to investigate the association between working from home and health-related productivity loss (HRPL)., Methods: An online survey was conducted with a sample of 1,078 workers. HRPL was estimated by the Work Productivity and Activity Impairment Questionnaire: General Health version. Workers that have been working from home in the last 6 months were categorized into the "work from home" group. Generalized linear models were used to compare the mean difference of HRPL between "work from home" and "commuters" group. Stratified analyses were conducted based on various factors including gender, age, income level, occupation, education level, previous diagnosis of chronic disease, presence of preschool children, living in studio apartment, living alone, commuting time, working hours and regular exercise., Results: The overall HRPL was higher in the "work from home" group than in the "commuters" group with a mean difference of 4.05 (95% confidence interval [CI]: 0.09-8.01). In the stratified analyses, significant differences were observed in workers with chronic diseases (mean difference: 8.23, 95% CI: 0.38-16.09), who do not live alone (mean difference: 4.84, 95% CI: 0.35-9.33), and workers that do not exercise regularly (mean difference: 4.96, 95% CI: 0.12-9.80)., Conclusions: Working from home is associated with an increased HRPL in the Korean working population, especially among those with chronic diseases, those who do not live alone, and those who do not exercise regularly., Competing Interests: Competing interests: The authors declare that they have no competing interests., (Copyright © 2024 Korean Society of Occupational & Environmental Medicine.)

Background: The landscape of stroke care has shifted from stand-alone hospitals to cooperative networks among hospitals. Despite the importance of these networks, limited information exists on their characteristics and functional attributes., Methods: We extracted patient-level data on acute stroke care and hospital connectivity by integrating national stroke audit data with reimbursement claims data. We then used this information to transform interhospital transfers into a network framework, where hospitals were designated as nodes and transfers as edges. Using the Louvain algorithm, we grouped densely connected hospitals into distinct stroke care communities. The quality and characteristics in given stroke communities were analysed, and their distinct types were derived using network parameters. The clinical implications of this network model were also explored., Results: Over 6 months, 19 113 patients with acute ischaemic stroke initially presented to 1009 hospitals, with 3114 (16.3%) transferred to 246 stroke care hospitals. These connected hospitals formed 93 communities, with a median of 9 hospitals treating a median of 201 patients. Derived communities demonstrated a modularity of 0.904 , indicating a strong community structure, highly centralised around one or two hubs. Three distinct types of structures were identified: single-hub (n=60), double-hub (n=22) and hubless systems (n=11). The endovascular treatment rate was highest in double-hub systems, followed by single-hub systems, and was almost zero in hubless systems. The hubless communities were characterised by lower patient volumes, fewer hospitals, no hub hospital and no stroke unit., Conclusions: This network analysis could quantify the national stroke care system and point out areas where the organisation and functionality of acute stroke care could be improved., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The present study aimed to analyze several aspects of the working conditions and health status of platform workers in the Republic of Korea, such as ergonomic and emotional hazards. We also compared the health status of the platform workers with that of the general population., Methods: A total of 1,000 platform workers participated in this survey from August 7 to August 17, 2022. The participants included 400 designated drivers, 400 food-delivery drivers, and 200 housekeeping managers. A face-to-face survey with a structured questionnaire was conducted by researchers who had received specific instructions. The focus of the survey extended to the work environment, encompassing factors such as workplace violence, as well as physical, chemical, and ergonomic hazards. Health-related data for the previous year were also collected, covering a range of issues such as hearing problems, skin problems, musculoskeletal symptoms, headaches, injuries, mental health issues, and digestive problems. Subsequently, we compared the health symptom data of the responders with those of the general population in the Republic of Korea., Results: Platform workers, including designated drivers, food-delivery drivers, and housekeeping managers, existed in the blind spot of social insurance, facing frequent exposure to physical and chemical hazards, ergonomic risk factors, and direct or indirect violence. The prevalence of health problems, including musculoskeletal symptoms, general fatigue, and depressive symptoms, in each occupational group was statistically higher than that in the general population after standardization for age and gender., Conclusion: The results revealed unfavorable working environment and inferior occupational health of platform workers compared with those of the general population., (© 2024 The Authors.)

Achieving textbook outcomes (TOs) improves the short-term and long-term performance of a hospital. Our objective was to assess TOs in the laparoscopic liver resection (LLR) of tumors in the PS (posterosuperior) section of the liver and identify the impact of the learning curve. We conducted a retrospective cohort study analyzing patients who underwent LLR for lesions located in the PS segments. Patients were divided into a TO and no-TO group. TOs were defined as negative margins, no transfusion, no readmission, no major complications, no 30-day mortality, and a length of stay ≤ 50th percentile. Patients' outcomes were assessed in two study periods before and after 2015. TOs were achieved in 47.6% ( n = 117). In multivariable analysis, obesity ( p = 0.001), shorter operation time ( p < 0.001), less blood loss ( p < 0.001), normal albumin ( p = 0.003), and minor resection ( p = 0.046) were significantly associated with achieving TOs. Although the 5-year recurrence-free survival rate ( p = 0.096) was not significantly different, the 5-year overall survival rate was significantly greater in the TO group ( p = 0.001). Body mass index > 25 kg/m 2 ( p = 0.020), age > 65 years ( p = 0.049), and achievement of TOs ( p = 0.024) were independently associated with survival. The proportion of patients who achieved a TO was higher after 2015 than before 2015 (52.3% vs. 36.1%; p = 0.022). TOs are important markers not only for assessing hospital and surgeon performance but also as predictors of overall survival. As the number of surgeons who achieve the learning curve increases, the number of patients with TOs will gradually increase with a subsequent improvement in overall survival.

Background: Social jetlag is a circadian misalignment that arises from a discrepancy between activity/sleep schedules on school/work days and free days. This study explored the correlation between social jetlag and self-rated health (SRH) in a representative sample of Korea., Methods: This study included 8259 working population in the Korea National Health and Nutrition Examination Survey, 2016-2018. Social jetlag was calculated as the difference between the midpoint of sleep time on work day and work-free day. Five-point Likert scale of SRH was used to assess subjective health perception on general health conditions. Multiple logistic regression analysis was performed to calculate the odds ratios (ORs) and 95 % confidence interval (CI) for poor SRH in the 1-2 h or longer than 2 h social jetlag groups compared to that in the reference group (less than 1 h), after adjusting for age, sex, marital status, occupation, household income, and weekly working hours., Results: The proportions of those with <1 h, 1-2 h, >2 h of social jetlag were 63.80 %, 25.67 %, and 10.53 %, respectively. The risk of poor SRH increased as social jetlag increased. Greater social jetlag was significantly associated with an increased likelihood of reporting poor SRH. The adjusted ORs for the groups with social jetlag between 1 and <2 h, and >2 h were 1.100 (95 % CI = 0.935-1.295), and 1.503 (95 % CI = 1.097-1.727), respectively. Moreover, the OR trend was statistically significant (p for trend = 0.008)., Conclusion: This study found that social jetlag and poor SRH were significantly related in the Korean working population., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mo-Yeol Kang reports financial support was provided by National Research Foundation of Korea. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: This study investigates the relationship between ergonomic risk exposures and insomnia symptoms, using data representative of Korea's general working population., Methods: Data from the 5th Korean Working Conditions Survey were used for this study. The eligible population (employees) for the current study was 37,026. Insomnia symptoms were estimated using the minimal insomnia symptom scale (MISS) questionnaire. Logistic regression analysis was conducted to explore the association between ergonomic risks and insomnia symptoms., Results: All the investigated ergonomic risks increased odd ratios (ORs) for insomnia symptoms: Tiring or painful positions (OR, 1.64; 95% CI, 1.43-1.88); lifting or moving heavy loads (OR, 2.33; 95% CI, 1.99-2.71); long periods of standing (OR, 1.47; 95% CI, 1.29-1.69); and repetitive hand or arm movements (OR, 1.46; 95% CI, 1.29-1.67). The mediated proportion of musculoskeletal pain was 7.4% (95% CI, 5.81-10.13), and the mediated proportion of feeling of exhaustion was 17.5% (95% CI, 5.81-10.13)., Conclusions: This study provides evidence for the relationship between ergonomic risks and insomnia symptoms, for which musculoskeletal pains and the feeling of exhaustion may be potential mediators., (© 2024. The Author(s).)

Objectives: This study investigated the effects of hot and cold temperature on the renal function of people with chronic diseases, such as diabetes, hypertension, and chronic kidney disease, using large-scale clinical data., Methods: We used retrospective cohort data from the Clinical Data Warehouse of the Seoul St Mary's Hospital, which contains clinical, diagnostic, laboratory, and other information about all patients who have visited the hospital since 1997. We obtained climate data from the Automated Synoptic Observing System of the Korea Meteorological Administration. The heat index was used as a measuring tool to evaluate heat exposure by indexing the actual heat that individuals feel according to temperature and humidity. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. To investigate changes in renal function trends with heat index, this study used generalized additive mixed models., Results: Renal function decreased linearly with increasing heat index after approximately 25°C, which was considered the flexion point of temperature. A linear decrease in the eGFR was observed with the effects of 0 to 5 lag days. Although there was a correlation observed between the decrease in eGFR and temperatures below -10°C, the results did not indicate statistical significance., Conclusions: The results of our study provide scientific evidence that high temperatures affect the renal function of people with chronic diseases. These results can help prevent heat-related morbidity by identifying those who are more likely to develop renal disease and experience worsening renal function., (© The Author(s) [2024]. Published by Oxford University Press on behalf of Journal of Occupational Health.)

Objectives: Marginal part-time workers, working less than 15 hours per week, are a vulnerable working population. We investigated the association between marginal part-time work and depressive symptoms in Korea and European countries to suggest policy implications., Methods: This study used data from the sixth Korean Working Conditions Survey (KWCS) from 2020 to 2021 and European Working Conditions Telephone Survey (EWCTS) in 2021. For the KWCS, 31 789 participants were included in the analysis, and for the EWCTS, 59 070 participants were analyzed. Depressive symptoms were assessed using the World Health Organization Five Well-Being Index (WBI-5). A multiple logistic regression analysis was conducted to assess the association between marginal part-time work and depressive symptoms with KWCS and EWCTS data., Results: In Korea, there was a statistically significant association between depressive symptoms and marginal part-time work. On the other hand, in European countries, the association was not remarkable. Low income and employment instability partially mediated the relationship between marginal part-time work and depressive symptoms in Korea. Conclusions. Korean marginal part-time workers face systemic discrimination related to job insecurity and financial rewards, which appear to contribute to depressive symptoms., (© The Author(s) [2024]. Published by Oxford University Press on behalf of Journal of Occupational Health.)

Objectives: This study explored the association of emotional labor and workplace violence with health-related productivity loss (HRPL)., Methods: We used the initial dataset from a survey known as the Korean Work, Sleep, and Health Study, an ongoing nationwide panel study initiated in 2022. To assess emotional labor, the study included 2386 workers who worked in customer service. The Korean Workplace Violence Scale-13 and the Korean Emotional Labour Scale-11 were used to assess the level of exposure to workplace violence, and the intensity of emotional labor, respectively. The Work Productivity and Activity Impairment Questionnaire was used to measure HRPL, including absenteeism and presenteeism. We examined differences in HRPL based on workplace violence and emotional labor using generalized linear regression models., Results: HRPL increased with an increase in workplace violence and emotional labor scores. Notably, the mean HRPL was highest in the high-risk groups for both workplace violence and emotional labor. The mean HRPL increased as the number of "high-risk" components for workplace violence and emotional labor increased. All the workplace violence and emotional labor components exhibited higher HRPL in the "high-risk" groups compared with the "low-risk" groups., Conclusions: Our study showed that both emotional labor and workplace violence are associated with reduced productivity., (© The Author(s) [2024]. Published by Oxford University Press on behalf of Journal of Occupational Health.)

Objectives: Preventing occupational injuries remains a significant challenge in Korea. A positive safety climate can contribute to reducing workplace injuries. However, the impact of safety climate on preventing occupational injuries among the Korean workforce has not been adequately explored. Therefore, this study aimed to investigate the relationship between the perceived safety climate and occupational injuries within the Korean working population., Methods: This study used baseline data from the Korean Work, Sleep, and Health Study (KWSH). The safety climate was measured using the brief version of the Nordic Safety Climate Questionnaire. Occupational injury was determined by whether injuries or accidents had occurred at workplaces in the past year. Logistic regression analysis was performed to examine the association between the safety climate and occupational injury., Results: Participants who reported an unfavorable workplace safety climate were more likely to experience occupational injuries. Multiple logistic regression analysis revealed that the adjusted odds ratio (OR) for occupational injuries in an unfavorable safety climate was 2.20 (95% confidence interval [CI], 1.38 to 3.51) compared to a favorable safety climate. Specifically, factors such as "not encouraging employees to follow safety rules when on a tight schedule" (OR, 2.02; 95% CI, 1.25 to 3.24) and "not helping each other work safely" (OR, 1.98; 95% CI, 1.17 to 3.25) were significantly associated with occupational injuries., Conclusions: An unfavorable safety climate was associated with increased occupational injuries among Korean workers. Improving the safety climate in the workplace may reduce occupational injuries in Korea.

Background: Knowledge about determinants of workability is crucial for designing interventions to increase the participation of older employees in the workforce and maintain or increase their productivity levels at work., Aims: This study explored the impact of health conditions and job characteristics on poor work ability., Methods: This study used data from the Korean Longitudinal Study of Aging (KLoSA) from 2014 to 2020, which is a nationally representative population-based panel study of Korean citizens aged ≥45 years. The KLoSA survey assessed subjective work ability using work ability score. The participants were asked if they had been diagnosed with any underlying diseases by a physician. The job characteristics were assessed in terms of working conditions and satisfaction. Generalized estimating equations were used to calculate the odds ratios (ORs) and 95% confidence intervals for workers' health-related variables and job characteristics associated with poor work ability., Results: The results showed that workers' health-related factors were associated with poor work ability; poor vision (OR = 1.52) and bad hearing ability (OR = 2.37); low gripping strength (OR = 2.29); poor self-rated health (OR = 3.77) and various diseases such as hypertension, diabetes, cancer, chronic lung disease, liver disease, heart disease, cerebrovascular disease, mental illness, arthritis, prostate disease, gastrointestinal disease and disc disease. Additionally, high physical work demands (OR = 1.51) and low job satisfaction (OR = 4.23) were highly correlated with poor work ability., Conclusions: The findings addressing poor work abilities caused by individuals' health- and job-related factors can help prioritize worker health management and the development of more effective human capital investment strategies at the workplace., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Rationale: A choristoma is a rare and benign neoplasm characterized by the presence of normal tissue in an anomalous anatomical location. In contrast, choristoma tend to occur in other body regions rather than within the spinal canal. Before our findings, only 4 cases of intraspinal choristoma had been recorded. Because its composition is complex and very rare, routine examinations, such as magnetic resonance imaging, are difficult to diagnose, and the possibility of its occurrence is often missed in clinical diagnosis. If there is no specificity in its components, such as in this case, even pathological examinations can only confirm the diagnosis as choristoma after eliminating other possibilities. Therefore, in clinical practice, when encountering patients with intraspinal tumors, it is essential to consider the possibility of choristoma. In this case, the choristoma lack of specific constituent composition sets it apart from previously reported intraspinal choristoma, significantly raising the diagnostic challenge, which offers valuable insights for clinical diagnosis., Patient Concerns: A female patient aged 48 years was admitted to our medical center due to experiencing persistent lower back pain accompanied by radiating pain in both legs for 5 months. Based on the findings from the neurological physical examination and magnetic resonance imaging, the patient was diagnosed with an intradural space-occupying lesion located at the level of the first lumbar vertebral body. We performed an enhanced magnetic resonance neurography examination to further determine the positional relationship between the occupation and nerves in preparation for surgery. Postoperative pathological biopsy showed that the mass was an intraspinal choristoma., Diagnosis: Intradural extramedullary spinal choristoma., Intervention: Occupied lesion is removed surgically., Outcomes: After surgery, all symptoms were significantly relieved, and when the patient was discharged, all symptoms disappeared completely. There was no sign of recurrence after 1 year of follow-up., Lessons: Intraspinal choristomas are not specific and need to be diagnosed by pathologic examination. Early detection of and intervention for intraspinal tumors can mitigate nerve dysfunction., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: We conducted a case-control study to identify high-risk occupations and exposure to occupational hazards for acute myeloid leukemia (AML)., Methods: When patients with AML admitted to the Department of Hematology in the study hospital for the first time are referred to the Department of Occupational and Environmental Medicine, data on occupation are collected by investigators to evaluate work-relatedness. Community-based controls were recruited through an online survey agency, and four controls per case were matched. Occupational information was estimated using structured questionnaires covering 27 specific occupations and 32 exposure agents. Conditional logistic regression analysis was performed by pairing cases and controls., Results: In the analysis of the risk of AML according to occupational classification, a significant association was found in paint manufacturing or painting work (OR = 2.22, 95% CI: 1.03-4.81) and aircrew (OR = 6.00, 95% CI: 1.00-35.91) in males, and in pesticide industry (OR = 6.89, 95% CI: 1.69-28.07) and cokes and steel industry (OR = 2.00, 95% CI: 1.18-22.06) in ≥60 years old. Moreover, the risk of AML increased significantly as the cumulative exposure to thinners increased. In the analyses stratified by sex and age, the association between pesticide exposure and AML was significant in males (OR = 3.28, 95% CI: 1.10-9.77) and in ≥60 years old (OR = 6.22, 95% CI: 1.48-26.08)., Conclusion: This case-control study identified high-risk occupational groups in the Republic of Korea including paint manufacturers and painters, aircrew, and those who are occupationally exposed to pesticides or paint thinners., Competing Interests: The authors declare that they have no competing interests., (© 2023 The Authors.)

Background: This study aimed to examine the impact of chronotype on depressive symptoms and explore the mediating effects of sleep quality, pre-sleep cognitive arousal, and social jetlag in a sample of wage earners., Methods: A total of 3,917 waged workers were surveyed online in July 2022. Logistic regression and mediation analysis were used to assess the relationship between chronotype (morningness, intermediate, and eveningness) and depressive symptoms (Patient Health Questionnaire ≥ 5), and the mediating effects of Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Pre-Sleep Arousal Scale (PSAS). All analyses were adjusted for age, education level, income level, marital status, coffee consumption, alcohol consumption, physical activity, occupation, employment status, and working hours to calculate odds ratios (ORs)., Results: The chronotypes of all the participants were divided into morningness (4.7%), intermediate (93.5%), and eveningness (1.8%). Multiple logistic regression analysis showed an increased risk of depression in the eveningness chronotype (OR: 2.96; 95% confidence interval [CI]: 1.51, 5.86). Regarding the mediation analysis, ISI mediated 28.44% (95% CI: 16.39-40.5), PSQI for 31.25% (95% CI: 19.36, 43.15), and PSAS-Cognitive Score (PSAS-C) for 23.58% (95% CI: 10.66, 36.50) of the association between chronotype and depressive symptoms. However, social jetlag did not significantly mediate this relationship. (percentage mediated = 0.75%, 95% CI: -3.88, 5.39)., Conclusions: Evening chronotypes exhibit an increased risk of depressive symptoms, which ISI, PSQI, and PSAS-C partially mediated. This suggests that interventions to improve sleep quality and maintain adequate sleep habits may effectively prevent and treat depression in employees with an eveningness chronotype., Competing Interests: Competing interests: The authors declare that they have no competing interest., (Copyright © 2023 Korean Society of Occupational & Environmental Medicine.)

For primary prevention, it is important for public health and clinical medicine to identify and characterize modifiable risk factors of stroke. In existing literature, the impact of occupational variables on ischemic and hemorrhagic stroke has been extensively studied. This review summarizes the available data on the significance of occupational variables in stroke. The results of this review suggest that there is sufficient evidence for the relationship between increased risk of stroke and job stress, working in extreme temperatures, long working hours, and/or shift work. The association between long working hours and occupational exposure to noise and chemicals remains inconclusive although several studies have reported this finding. This review will act as a step toward future research and provide information that may serve as a baseline for developing targeted interventions to prevent stroke in the working population.

Background: This study aimed to investigate the bladder cancer risk across workers' industries., Methods: This study was conducted using Korean National Health Insurance claims data. Workers were included in this study to build a retrospective cohort of the entire working population. Workers' industries were divided into 77 industries according to the Korean Standard Industry Classification division category. The standardized incidence ratio was calculated by comparing 77 industries according to the Korean Standard Industry Classification with the educational public officer., Results: Bladder cancer risk was particularly high in the following industrial sectors: passenger land transport, except transport via railways; sea and coastal water transport; restaurants and mobile food service activities; telecommunications; and computer programming, consultancy, and related activities., Conclusions: Our result provides evidence regarding the disparity of bladder cancer incidence among male workers across industries., Competing Interests: Conflict of interest: None declared., (Copyright © 2023 American College of Occupational and Environmental Medicine.)

This study investigated the effects and mechanisms of an online short-term audio-based mindfulness (SAM) intervention program on positive affect and explored how well-being and negative affect influenced these effects and mechanisms. Participants (N = 100) were randomized into an intervention group (n = 50) and a control group (n = 50). Those in the mindfulness group underwent 3 weeks of an online SAM program and completed the online measures four times, while those in the control group completed the measures twice. Participants completed measures including the World Health Organization Well-Being Index, the Freiburg Mindfulness Inventory, and the Positive and Negative Affect Schedule. The effects of measures in both groups were compared. Parallel process latent growth curve modeling analysis was used to explore the longitudinal moderated mediation effects. The results showed that SAM was effective at improving positive affect, mindfulness, well-being, and reducing negative affect. Mindfulness growth speed during the intervention period mediated the relationship between SAM and positive affect improvement speed. The moderation effects of baseline well-being and negative effect on mediation effects were found to be significant. The SAM program was effective for the general public and was more beneficial for those with medium/high well-being and low/medium negative affect., (© 2022 International Association of Applied Psychology.)

Background: The construction workers are vulnerable to fatigue due to high physical workload. This study aimed to investigate the relationship between overwork and heart rate in construction workers and propose a scheme to prevent overwork in advance., Methods: We measured the heart rates of construction workers at a construction site of a residential and commercial complex in Seoul from August to October 2021 and develop an index that monitors overwork in real-time. A total of 66 Korean workers participated in the study, wearing real-time heart rate monitoring equipment. The relative heart rate (RHR) was calculated using the minimum and maximum heart rates, and the maximum acceptable working time (MAWT) was estimated using RHR to calculate the workload. The overwork index (OI) was defined as the cumulative workload evaluated with the MAWT. An appropriate scenario line (PSL) was set as an index that can be compared to the OI to evaluate the degree of overwork in real-time. The excess overwork index (EOI) was evaluated in real-time during work performance using the difference between the OI and the PSL. The EOI value was used to perform receiver operating characteristic (ROC) curve analysis to find the optimal cut-off value for classification of overwork state., Results: Of the 60 participants analyzed, 28 (46.7%) were classified as the overwork group based on their RHR. ROC curve analysis showed that the EOI was a good predictor of overwork, with an area under the curve of 0.824. The optimal cut-off values ranged from 21.8% to 24.0% depending on the method used to determine the cut-off point., Conclusion: The EOI showed promising results as a predictive tool to assess overwork in real-time using heart rate monitoring and calculation through MAWT. Further research is needed to assess physical workload accurately and determine cut-off values across industries., Competing Interests: Competing interests: The authors declare that they have no competing interests., (Copyright © 2023 Korean Society of Occupational & Environmental Medicine.)

Background: Recently, irregular working hours have become controversial issues in Korea. The health impact of irregular working hours on the work-related musculoskeletal pain (MSP) is scarcely researched before. We sought to investigate the association between irregular working hours and work-related MSP among South Korean workers., Methods: This study used data from the sixth Korean Working Conditions Survey in 2020. The prevalence of work-related MSP was analyzed using the χ 2 test. A multiple logistic regression analysis was conducted to assess the association between irregular working hours and work-related MSP. We conducted stratified analysis by gender, weekly working hours, and workers' control over their working hours. We calculated the adjusted odds ratios (ORs) of work-related MSP for irregular working hours combined with weekly working hours., Results: The OR for work-related MSP was significantly higher in the population with irregular working hours than in the population with regular working hours (OR: 1.43, 95% confidence interval [CI]: 1.29-1.58). Irregular and long (> 52 hours/week) working hours have the highest risk of work-related MSP in both genders (in men, OR: 3.48 [95% CI: 2.53-4.78]; in women, OR: 2.41 [95% CI: 1.46-4.00])., Conclusions: Irregular working hours were associated with work-related MSP in Korea. The association was magnified with long working hours. Reform of the Korean Labor Standards Act leading to increase irregular working hours may induce adverse health outcome., Competing Interests: Competing interests: The authors declare that they have no competing interests., (Copyright © 2023 Korean Society of Occupational & Environmental Medicine.)

Background: Due to climate change, days with high temperatures are becoming more frequent. Although the effect of high temperature on the kidneys has been reported in research from Central and South America, Oceania, North America and Europe, evidence from Asia is still lacking. This study aimed to examine the association between short-term exposure to high temperatures and acute kidney injury (AKI) in a nationwide study in South Korea., Methods: We used representative sampling data from the 2002-2015 National Health Insurance Service-National Sample Cohort in South Korea to link the daily mean temperatures and AKI cases that occurred in the summer. We used a bidirectional case-crossover study design with 0-7 lag days before the emergency room visit for AKI. In addition, we stratified the data into six income levels to identify the susceptible population., Results: A total of 1706 participants were included in this study. The odds ratio (OR) per 1°C increase at 0 lag days was 1.051, and the ORs per 1°C increase at a lag of 2 days were both 1.076. The association between exposure to high temperatures and AKI was slightly greater in the low-income group (OR = 1.088; 95% CI: 1.049-1.128) than in the high-income group (OR = 1.065; 95% CI: 1.026-1.105)., Conclusions: In our study, a relationship between exposure to high temperatures and AKI was observed. Precautions should be taken at elevated temperatures to minimize the risk of negative health effects., (© The Author(s) 2022; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)

A systematic review was performed aiming to identify the various occupational risk factors of lower urinary tract symptoms (LUTS) among female workers. A systematic, comprehensive literature search of PubMed, Embase and Cochrane Library databases was conducted to identify studies published until 24 November 2021, evaluating the possible occupational risk factors of LUTS among female workers. Two reviewers assessed all articles retrieved through a computerised search for eligibility using predetermined criteria. Data on the first author, publication year, country, study design, participants, identified occupational risk factors, outcome variables and main results were extracted from the selected articles. The Newcastle-Ottawa Quality Assessment Scale guidelines were adopted to estimate the quality scores. Overall, our search yielded a total of 16 articles suitable for review. The occupational risk factors identified in the studies were strenuous physical demand and activity, prolonged sitting, occupational stress, shift work, limited use of the toilet at work and other occupational environments (eg, an unclean and uncomfortable workplace, dangerous job and probability of accidents, feeling pressed for time and awkward position for long periods). The findings of this review may raise awareness regarding the risk of LUTS among female workers with these factors. From an occupational health perspective, the implementation of tailored prevention strategies based on these occupational factors may prevent female workers from developing LUTS. PROSPERO registration number CRD42022316728., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Social jetlag refers to the discrepancy between social time and the body's internal rhythm, which can lead to unfavorable health outcomes. However, no study has directly explored the relation between social jetlag and chronic kidney disease (CKD). This study aims to investigate the relationship between social jetlag and CKD in a representative population of South Korea. This study included 8259 currently economically active Korean population in the Korea National Health and Nutrition Examination Survey. Social jetlag was calculated as the difference between the midpoint of sleep time on weekdays and free days. The estimated glomerular filtration rate (eGFR) was calculated the by using the serum creatinine value according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Participants with an eGFR less than 60 ml/min/1.73 m 2 were defined as CKD cases. The estimated glomerular filtration rate decreased as social jetlag increased. Multiple logistic regression analysis showed that the adjusted odds ratio (95% confidence interval) of CKD for 1-2 h of social jetlag was 0.926 (0.660-1.299), while the odds ratio for more than 2 h was 2.042 (1.328-3.139) when less than 1 h was used as reference. This study found that social jetlag and risk of CKD were significantly related in the Korean working population., (© 2023. The Author(s).)

Transport in complex networks can describe a variety of natural and human-engineered processes including biological, societal and technological ones. However, how the properties of the source and drain nodes can affect transport subject to random failures, attacks or maintenance optimization in the network remain unknown. In this article, the effects of both the distance between the source and drain nodes and the degree of the source node on the time of transport collapse are studied in scale-free and lattice-based transport networks. These effects are numerically evaluated for two strategies, which employ either transport-based or random link removal. Scale-free networks with small distances are found to result in larger times of collapse. In lattice-based networks, both the dimension and boundary conditions are shown to have a major effect on the time of collapse. We also show that adding a direct link between the source and the drain increases the robustness of scale-free networks when subject to random link removals. Interestingly, the distribution of the times of collapse is then similar to the one of lattice-based networks.

Objectives: Although it is difficult to define the quality of stroke care, acute ischemic stroke (AIS) patients with moderate-to-severe neurological deficits may benefit from thrombectomy-capable hospitals (TCHs) that have a stroke unit, stroke specialists, and a substantial endovascular thrombectomy (EVT) case volume., Methods: From national audit data collected between 2013 and 2016, potential EVT candidates arriving within 24 hours with a baseline National Institutes of Health Stroke Scale score ≥6 were identified. Hospitals were classified as TCHs (≥15 EVT case/y, stroke unit, and stroke specialists), primary stroke hospitals (PSHs) without EVT (PSHs-without-EVT, 0 case/y), and PSHs-with-EVT. Thirty-day and 1-year case-fatality rates (CFRs) were analyzed using random intercept multilevel logistic regression., Results: Out of 35 004 AIS patients, 7954 (22.7%) EVT candidates were included in this study. The average 30-day CFR was 16.3% in PSHs-without-EVT, 14.8% in PSHs-with-EVT, and 11.0% in TCHs. The average 1-year CFR was 37.5% in PSHs-without-EVT, 31.3% in PSHs-with-EVT, and 26.2% in TCHs. In TCHs, a significant reduction was not found in the 30-day CFR (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.76 to 1.12), but was found in the 1-year CFR (OR, 0.84; 95% CI, 0.73 to 0.96)., Conclusions: The 1-year CFR was significantly reduced when EVT candidates were treated at TCHs. TCHs are not defined based solely on the number of EVTs, but also based on the presence of a stroke unit and stroke specialists. This supports the need for TCH certification in Korea and suggests that annual EVT case volume could be used to qualify TCHs.

Background: Social jetlag, which is the mismatch between endogenous rhythm and social timing, is prevalent among the working population. Social jetlag may result in mood changes; however, evidence of relationship between social jetlag and depressive disorders has not been fully verified. Hence, this study aimed to investigate the association between social jetlag and depressive symptoms in a representative working population of South Korea., Methods: This study included 5447 Korean employees in the Korea National Health and Nutrition Examination Survey. Social jetlag was calculated as the difference between the midpoint of sleep time on weekdays and free days. Depressive symptoms were assessed using Patient Health Questionnaire-9. Multiple logistic regression was used to estimate the odds ratio after adjusting for confounding factors. Moreover, social jetlag and continuous depression scores were evaluated using linear regression and generalized additive models., Results: The proportion of the participants who had >2 h of social jetlag was 10.26 %. Depressive symptoms increased as social jetlag increased. Multiple logistic regression analysis showed that the adjusted OR (95 % confidence interval) for 1 to 2 h of social jetlag was 1.355 (0.891-2.059) and for >2 h was 1.859 (1.084-3.187), which <1 h was reference., Limitations: This study used a cross-sectional design and measurements were based on self-reported scales., Conclusion: This study found that social jetlag and depressive symptoms were significantly related in the Korean working population., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objectives: Occupational stress management is particularly important for successful business operations, since occupational stress adversely affects workers' health, eventually lowering their productivity. Therefore, this study aimed to investigate the correlation between occupational stress and health-related productivity loss (HRPL) among Korean workers., Methods: In 2021, 1,078 workers participated in a web-based questionnaire survey. HRPL was measured using the Work Productivity and Activity Impairment Questionnaire, and occupational stress was measured using the Korean Occupational Stress Scale-Short Form. The occupational stress level was divided into tertiles (low, intermediate, and high), and the low occupational stress group was used as the reference group. Using a generalised linear model, differences in labour productivity loss according to the level of occupational stress were tested after adjusting for demographic characteristics such as age, gender, education level, household income, occupation, and underlying medical conditions., Results: Non-parametric regression analysis of HRPL according to occupational stress showed a direct association between occupational stress and HRPL. A statistically significant difference was observed in HRPL between participants with intermediate and high occupational stress and those with low occupational stress., Conclusions: Our results support the hypothesis that high occupational stress is associated with decreased labour productivity.

Objectives: The physical activity paradox suggests that occupational physical activity (OPA), unlike leisure-time physical activity (LTPA), may detrimentally impact health. We explored the relationships of OPA and LTPA with work ability (WA) and health-related productivity loss (HRPL)., Methods: This study included 5,501 workers in Korea who were recruited in 2021 through a web-based cross-sectional questionnaire. The questionnaire was utilized to quantify OPA and LTPA in metabolic equivalents, while WA and HRPL were also measured. Non-parametric regression, using a generalized additive model (GAM), was employed to visualize the relationships of LTPA and OPA with WA and HRPL. Mean differences in WA and HRPL, in relation to OPA and LTPA, were examined using linear regression models. These models were adjusted for covariates including sex, age, body mass index, education level, alcohol consumption, smoking history, insomnia, occupation, hours worked, and income., Results: The GAM and linear regression analyses revealed that higher LTPA corresponded with higher WA and lower HRPL. In contrast, as OPA increased, WA decreased and HRPL increased. However, within the group with high OPA, HRPL was not significantly lower in the high-LTPA subgroup relative to the low-LTPA subgroup (mean difference=1.92%, p=0.343). This pattern was especially pronounced among workers aged 60 years and older, with an increase in HRPL observed with increasing LTPA among the respondents with high OPA., Conclusions: High LTPA levels were associated with elevated WA and diminished HRPL. In contrast, higher levels of OPA were associated with lower WA and higher HRPL.