Unraveling the Potential of Vinyl Ether as an Ethylene Surrogate in Heteroarene C─H Functionalization via the Spin-Center Shift.

Despite the simplicity and abundance of ethylene, its practical application presents significant hurdles due to its nature as a highly flammable gas. Herein, a strategic use of easily handled vinyl ether is reported as a latent ethylene surrogate achieved via a spin-center shift (SCS) pathway, enabling the successful three-component reaction that bridges heteroarenes and various coupling partners, including sulfinates, thiols, and phosphine oxides. Through a photoredox catalytic process, α-oxy radicals are generated by combining various radicals with phenyl vinyl ether, which are subsequently added to N-heteroarenes. Subsequently, the radical-mediated SCS pathway serves as the driving force for C─O bond cleavage, effectively engaging the phenoxy group as a leaving group. In addition, by broadening the utility of the method, a valuable synthon is provided for efficient C─H vinylation of N-heteroarenes following sulfonyl group elimination. This approach not only enriches the toolbox of synthetic methodology but also provides a more streamlined alternative, circumventing the challenges associated with direct ethylene gas usage. The versatility of the method, particularly evident in late-stage functionalizations of medicinally relevant molecules and peptides, underscores its capability to produce invaluable three-component compounds and vinylated N-heteroarene derivatives.

Association Between Flexible Work Arrangement and Sleep Problems Among Paid Workers: Using 6th Korean Working Conditions Survey.

Background: As social distancing persists and interest in work-life balance grows, more companies are adopting flexible work policies. While there have been studies on sleep disorders associated with different types of work, such as shift work, research exploring the relationship between flexible work schedules and sleep disorders is still limited, particularly among Korean workers. Methods: We performed a secondary analysis of the 6th Korean Working Conditions Survey, focusing on 31,243 paid workers out of a total of 50,538 participants. We defined flexible workers as those who set their own working hours. Sleep disorders were divided into three categories: 'difficulty falling asleep,' 'frequent waking during sleep,' and 'waking up feeling exhausted and fatigued.' Using scores derived from three specific symptoms, the Minimal Insomnia Symptoms Scale (MISS) was calculated to assess the prevalence of insomnia. We used chi-square tests to analyze demographic and job-related differences. A multivariate logistic regression analysis was employed to identify any relationship between flexible work schedules and sleep disorders. Results: Significant differences were found between flexible and non-flexible workers regarding age, income level, education level, and job type. Flexible workers reported sleep-related symptoms significantly more often. The odds ratio for insomnia was 1.40 (95% CI 1.21-1.61). For males, the odds ratio was 1.68 (1.36-2.08). Conclusion: This study establishes a correlation between flexible work schedules and sleep disorders among Korean salaried workers. Potential causes could include changes in circadian rhythm, increased work demands, and extended working hours. To precisely determine causality and associated diseases, further research is required.

Global carrier frequency and predicted genetic prevalence of patients with pathogenic sequence variants in autosomal recessive genetic neuromuscular diseases.

Genetic neuromuscular diseases are clinically and genetically heterogeneous genetic disorders that primarily affect the peripheral nerves, muscles, and neuromuscular junctions. This study aimed to identify pathogenic variants, calculate carrier frequency, and predict the genetic prevalence of autosomal recessive neuromuscular diseases (AR-NMDs). We selected 268 AR-NMD genes and analyzed their genetic variants sourced from the gnomAD database. After identifying the pathogenic variants using an algorithm, we calculated the carrier frequency and predicted the genetic prevalence of AR-NMDs. In total, 10,887 pathogenic variants were identified, including 3848 literature verified and 7039 manually verified variants. In the global population, the carrier frequency of AR-NMDs is 32.9%, with variations across subpopulations ranging from 22.4% in the Finnish population to 36.2% in the non-Finnish European population. The predicted genetic prevalence of AR-NMDs was estimated to be 24.3 cases per 100,000 individuals worldwide, with variations across subpopulations ranging from 26.5 to 41.4 cases per 100,000 individuals in the Latino/Admixed American and the Ashkenazi Jewish populations, respectively. The AR-NMD gene with the highest carrier frequency was GAA (1.3%) and the variant with the highest allele frequency was c.-32-13 T>G in GAA with 0.0033 in the global population. Our study revealed a higher-than-expected frequency of AR-NMD carriers, constituting approximately one-third of the global population, highlighting ethnic heterogeneity in genetic susceptibility.

Beyond working hours: the association between long working hours, the use of work-related communication devices outside regular working hours, and anxiety symptoms.

OBJECTIVES: The present study aimed to identify and compare the associations between long working hours and use of work-related communication devices outside regular working hours and anxiety symptoms, thereby providing insight into redefining working hours. METHODS: Based on the cross-sectional data from the sixth Korean Working Conditions Survey (KWCS), specifically the responses from 46 055 workers, the use of work-related communication devices outside of regular working hours, long working hours, and anxiety symptoms were assessed. To investigate the associations between using work-related communication devices outside regular working hours or long working hours with anxiety symptoms, odds ratios (ORs) and 95% CIs were calculated using multiple logistic regression models. RESULTS: Among 46 055 participants, 25 659 (55.7%) used work-related communication devices outside working hours, 8145 (17.7%) worked long hours, and 2664 (5.8%) experienced anxiety symptoms. Compared with the reference group, those who used work-related communication devices outside regular working hours without working long hours, had higher OR of anxiety symptoms (OR: 2.18; 95% CI, 1.97-2.41) than those who worked long hours without using work-related communication devices during off-hours (OR: 1.32; 95% CI, 1.09-1.59). Furthermore, the group that both worked long hours and used work-related communication devices outside working hours exhibited the highest OR of anxiety symptoms (OR: 2.57; 95% CI, 2.24-2.97). CONCLUSIONS: Using work-related communication devices outside regular working hours is associated with a higher risk of anxiety symptoms compared with long working hours. This result suggests that using work-related devices outside regular working hours, in addition to regular work time, should be considered when redefining working hours.

HIF-1α inhibition by MO-2097, a novel chiral-free benzofuran targeting hnRNPA2B1.

INTRODUCTION: Hypoxia-inducible factor 1 (HIF-1) is a transcriptional activator mediating adaptive responses to hypoxia. It is up-regulated in the tumor microenvironment and recognized as an effective anticancer drug target. Previously, we discovered that the natural compound moracin-O and its synthetic derivative MO-460 inhibited HIF-1α via hnRNPA2B1. OBJECTIVES: This study aimed to develop novel HIF-1 inhibitors for cancer chemotherapy by harnessing the potential of the natural products moracins-O and P. METHODS: In an ongoing search for novel HIF-1 inhibitors, a series of nature-inspired benzofurans with modifications on the chiral rings of moracins-O and P were synthesized. They showed improved chemical tractability and were evaluated for their inhibitory activity on HIF-1α accumulation under hypoxic conditions in HeLa CCL2 cells. The most potent derivative's chemical-based toxicities, binding affinities, and in vivo anti-tumorigenic effects were evaluated. Further, we examined whether our compound, MO-2097, exhibited anticancer effects in three-dimensional cultured organoids. RESULTS: Herein, we identified a novel synthetic chiral-free compound, MO-2097, with reduced structural complexity and increased efficiency. MO-2097 exhibited inhibitory effects on hypoxia-induced HIF-1α accumulation in HeLa CCL2 cells via inhibition of hnRNPA2B1 protein, whose binding affinities were confirmed by isothermal titration calorimetry analysis. In addition, MO-2097 demonstrated in vivo efficacy and biocompatibility in a BALB/c mice xenograft model. The immunohistochemistry staining of MO-2097-treated tissues showed decreased expression of HIF-1α and increased levels of apoptosis marker cleaved caspase 3, confirming in vivo efficacy. Furthermore, we confirmed that MO-2097 works effectively in cancer patient-based organoid models. CONCLUSION: MO-2097 represents a promising new generation of chemotherapeutic agents targeting HIF-1α inhibition via hnRNPA2B1, requiring further investigation.

The relationship between exposure to environmental noise and risk of atopic dermatitis, asthma, and allergic rhinitis.

BACKGROUND: Noise is defined as unwanted sound. It may induce negative emotions and mental health problems and may even lead to increased suicide risk. However, the impact of noise exposure on environmental diseases and disease severity is not well understood. This study aimed to elucidate the association between night-time noise exposure and the prevalence of environmental diseases in South Korea. METHODS: We conducted an analysis of the Environmental Disease Database provide by the National Health Insurance Service (NHIS) from 2013 to 2017. After spatially interpolating the noise data provided by the National Noise Information System (NNIS), night-time noise values in the district level were obtained by calculating the mean noise values at the administrative district level. The linear regression analyses were performed to test the association between the age-standardized prevalence ratio (SPR) and the night-time noise exposure in the district level. RESULTS: In areas with high night-time noise exposure (≥55 dB), the SPR for atopic dermatitis and allergic rhinitis were 1.0515 (95 % confidence interval [CI]:1.0508-1.0521) and 1.0202 (95 % CI:1.0201-1.0204), respectively, which were higher than those in the general population. The SPR for environmental diseases, including atopic dermatitis, asthma, and allergic rhinitis, was 1.0104 (95 % CI:1.0103-1.0105). Additionally, a significant linear association was observed between the level of nocturnal noise exposure and the total hospitalization period for atopic dermatitis (ß = 399.3, p < 0.01). CONCLUSION: We provide evidence of a significant association between night-time environmental noise and environmental diseases, particularly atopic dermatitis and allergic rhinitis. Furthermore, we observed a significant linear association between night-time noise exposure and the severity of atopic dermatitis.

Association between lone work and self-rated health status: using the 5th Korean Working Conditions Survey.

Background: Lone workers are generally defined as individuals who work alone without supervision, including self-employed people. While lone workers are considered a vulnerable group in some countries, there is a lack of research on their health status in domestic studies. Globally, the number of lone workers has been increasing, and this trend has been further accelerated since the coronavirus disease 2019 (COVID-19) pandemic with the rise of remote work. Methods: The study analyzed data from 44,281 participants, excluding unpaid family workers, soldiers, and those with missing data. Lone workers were defined as individuals who reported having no colleagues with the same job at their current workplace. Self-rated health status was categorized as "good" or "poor." Results: This study found a statistically significant higher number of lone workers among women compare to men. The largest occupational category for lone workers was service and sales workers, followed by agriculture and fisheries workers. A majority of non-lone workers reported working 40 hours or less per week, while the majority of lone workers reported working 53 hours or more per week. In addition, lone workers had significantly poorer health status evaluations compared to non-lone workers (odds ratio: 1.297; 95% confidence interval: 1.165-1.444). Conclusions: Further research is needed to investigate the causal relationship between lone work and health, using data collected after the COVID-19 pandemic.

Research Note: Distribution of nanospheres in the cuticle layer of the eggshell in major poultry species.

Mineralized eggshell is a unique and protective structure in an avian egg. Among different eggshell layers, the cuticle layer is an outermost layer and plays a critical role in protection against bacterial infection. Although the importance of nanosphere in the cuticle layer on the antimicrobial function has been widely accepted, the detailed nanostructure of the cuticle layer in the major poultry species has not been investigated. In the current study, eggs from Japanese quail, commercial layer chickens, mixed breed turkeys, and White Pekin ducks were collected. To investigate the nanostructure throughout the cuticle layer, images of the cross-sectional cuticle layer were taken using a scanning electron microscope (SEM). Unlike the cuticle layer in ducks showing deformed bunched nanospheres, clearly separated nanospheres were present throughout the cuticle layer in quail, chickens, and turkeys. The average size of the nanosphere was the biggest in turkeys and similar between quail and chickens. Most importantly, the size of nanospheres was increased as they ascended from the bottom of the cuticle layer in quail, showing a positive correlation between the size and distance of the nanospheres. However, different sizes of nanospheres were randomly distributed throughout the cuticle layer in chickens and turkeys, showing a weak correlation in chickens and no correlation in turkeys between the size and distance of nanospheres. These new findings in different nanostructures of the cuticle layers in quail, chickens, turkeys, and ducks will serve as a new foundation to better relate their structures with functions.

Fourier holographic endoscopy for imaging continuously moving objects.

Coherent fiber bundles are widely used for endoscopy, but conventional approaches require distal optics to form an object image and acquire pixelated information owing to the geometry of the fiber cores. Recently, holographic recording of a reflection matrix enables a bare fiber bundle to perform pixelation-free microscopic imaging as well as allows a flexible mode operation, because the random core-to-core phase retardations due to any fiber bending and twisting could be removed in situ from the recorded matrix. Despite its flexibility, the method is not suitable for a moving object because the fiber probe should remain stationary during the matrix recording to avoid the alteration of the phase retardations. Here, we acquire a reflection matrix of a Fourier holographic endoscope equipped with a fiber bundle and explore the effect of fiber bending on the recorded matrix. By removing the motion effect, we develop a method that can resolve the perturbation of the reflection matrix caused by a continuously moving fiber bundle. Thus, we demonstrate high-resolution endoscopic imaging through a fiber bundle, even when the fiber probe changes its shape along with the moving objects. The proposed method can be used for minimally invasive monitoring of behaving animals.

Cancer risk in Vietnam war veterans from the Korean Vietnam war veterans' health study cohort.

Introduction: During the Vietnam War, several unknown chemicals, such as Agent Orange, were used in Vietnam by the military. Therefore, there have been continuous health concerns among the Vietnamese population and veterans exposed to these hazardous chemicals. This study aimed to investigate the risk of all cancers and also organ-specific cancers among Korean veterans of the Vietnam War. Methods: This study used a national representative cohort that included all Korean Vietnam War veterans as the interest group, with 1:4 age-sex-region-matched general Korean citizens as the reference group, from 2002 to 2018. Age-standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated for all cancers and for 31 organ-specific cancer categories based on the medical facility visit data. Results: An increased SIR of 1.07 (95% CI, 1.06-1.08) was observed for all cancers among the veterans. There was a significantly increased risk of cancer among 22/31 organspecific cancers, with 18 cancer categories showing a significantly higher risk than all cancers. The highest risk was observed for "malignant neoplasms of other parts of the central nervous system" (SIR, 1.71; 95% CI, 1.51-1.92). Discussion: This study evaluated the risk of cancer among Korean Vietnam War veterans. Further studies are warranted to investigate various health determinants in the veterans as well as the Vietnamese population.

Building an annotated corpus for automatic metadata extraction from multilingual journal article references.

Bibliographic references containing citation information of academic literature play an important role as a medium connecting earlier and recent studies. As references contain machine-readable metadata such as author name, title, or publication year, they have been widely used in the field of citation information services including search services for scholarly information and research trend analysis. Many institutions around the world manually extract and continuously accumulate reference metadata to provide various scholarly services. However, manually collection of reference metadata every year continues to be a burden because of the associated cost and time consumption. With the accumulation of a large volume of academic literature, several tools, including GROBID and CERMINE, that automatically extract reference metadata have been released. However, these tools have some limitations. For example, they are only applicable to references written in English, the types of extractable metadata are limited for each tool, and the performance of the tools is insufficient to replace the manual extraction of reference metadata. Therefore, in this study, we focused on constructing a high-quality corpus to automatically extract metadata from multilingual journal article references. Using our constructed corpus, we trained and evaluated a BERT-based transfer-learning model. Furthermore, we compared the performance of the BERT-based model with that of the existing model, GROBID. Currently, our corpus contains 3,815,987 multilingual references, mainly in English and Korean, with labels for 13 different metadata types. According to our experiment, the BERT-based model trained using our corpus showed excellent performance in extracting metadata not only from journal references written in English but also in other languages, particularly Korean. This corpus is available at http://doi.org/10.23057/47.

C4-Selective C-H Borylation of Pyridinium Derivatives Driven by Electron Donor-Acceptor Complexes.

The photoinduced C4-selective C-H borylation of pyridines was achieved using electron donor-acceptor complexes derived from a Lewis base and N-amidopyridinium salts under external oxidant- and photocatalyst-free conditions. Notably, the nucleophilic character of phosphite-ligated boryl radicals enables addition of a radical to position C4 of pyridinium salts to afford C4-borylated heteroarenes that are otherwise difficult to obtain. This approach provides a versatile platform for the installation of both phosphite- and amine-coordinated boron groups on a series of pyridines under mild conditions, demonstrating excellent C4-positional selectivity for the pyridine scaffolds.

Standards for recognition and approval rate of occupational cerebro-cardiovascular diseases in Korea.

Background: Although working hours have decreased in Korea, they are still high compared to that of other countries. In Korea, cardiovascular and cerebrovascular diseases (CCVDs) related to overwork in Korea continually occur, and the social burden from overwork is estimated to be high. This study investigated the amendment of regulations affecting the approval rate of occupational CCVDs. Methods: The change in approval rate of occupational CCVDs and related regulations were investigated using the Act and public notice on the standards for recognition of occupational CCVDs and the yearbooks of the Ministry of Employment and Labor. The CCVD mortality was estimated using data on the number of deaths according to the cause of death, the number of employed people, and resident registration population aged 15-64 years. The cumulative mortality of CCVDs was estimated using the Kaplan-Meier method. Results: Since the establishment of the standards for recognition in Korea in 1982, the scope of occupational diseases has been expanded to include intracerebral hemorrhage, subarachnoid hemorrhage, cerebral infarction, myocardial infarction, and aortic dissection. In 2013, the concept of working hours was introduced in chronic overwork. The approval rate of occupational CCVDs was 44.7% in 2006, which decreased to 12.9% in 2011. After the improvement of related regulations, the approval rate increased to 41.3% in 2018. From 2000 to 2017, the CCVD mortality of both the unemployed and employed tended to decrease, and their cumulative CCVD mortalities were 549.3 and 319.7 per 100,000 people, respectively. Conclusions: CCVDs are recognized as occupational diseases in Korea. The amendments to the standards for recognition, the introduction of the Occupational Disease Adjudication Committee, the principle of presumption, and the reduction of working hours have changed the approval rate of occupational CCVDs. A strategic approach is needed to further reduce the incidence of CCVDs.

The value of the peroneus brevis tendon cross-sectional area in early diagnosing of peroneus brevis tendinitis: The peroneus brevis tendon cross-sectional area.

A thickened peroneus brevis tendon has been considered to be an important morphologic parameter of peroneus brevis tendinitis (PBT). Previous researchers have found that the peroneus brevis tendon thickness (PBTT) is correlated with inflammation of the peroneus brevis tendon. However, inflammatory hypertrophic change is different from simple thickness. Thus, we devised the peroneus brevis tendon cross-sectional area (PBTCSA) as a new diagnostic parameter to analyze the hypertrophy of the whole PBT. We assumed that the PBTCSA is a major morphologic parameter useful for early PBT diagnosis. Peroneus brevis tendon images were collected from 22 patients with PBT and from 22 normal subjects who underwent ankle-magnetic resonance imaging and revealed no evidence of PBT. The T1-weighted axial ankle-magnetic resonance imaging images were evaluated at the ankle level from all participants. The PBTT was measured as the thickest point at the transverse image of the peroneus brevis tendon. The PBTCSA was measured as the cross-sectional ligament whole area of the peroneus brevis tendon that was most hypertrophied in the axial A-MR images. The average PBTT was 2.22 ± 0.29 mm in the normal group and 2.85 ± 0.36 mm in the PBT group. The average PBTCSA was 6.98 ± 1.54 mm2 in the normal group and 13.11 ± 2.45 mm2 in the PBT group. PBT patients had significantly greater PBTT (P < .001) and PBTCSA (P < .001) than the normal group did. A receiver operating characteristic curve analysis revealed that the most suitable cutoff value of the PBTT was 2.51 mm, with 81.8% sensitivity and 81.8% specificity, and an AUC for the score was 0.93. The most suitable cutoff value of the PBTCSA was 10.08 mm2, with 90.9% sensitivity and 90.9% specificity, and AUC for the score was 0.98. Even though the PBTT and PBTCSA were both significantly associated with PBT, the PBTCSA was a more sensitive diagnostic parameter.

Cohort Profile: Gachon Regional Occupational Cohort Study (GROCS).

Background/Aims: The Gachon Regional Occupational Cohort Study (GROCS) is a large-scale longitudinal study of occupational safety and health data (covering Work Environment Monitoring, Workers' Health Surveillance, and Occupational Health Service) conducted by the Gachon University Gil Medical Center (GUGMC) in Incheon, Republic of Korea. We conducted GROCS to identify the health effects of workers' occupational risks, behavior, socioeconomic status, and life style. Methods: The GROCS includes data from Work Environment Monitoring, Workers' Health Surveillance, and Occupational Health Service. The baseline year for all data collection was 2018. Work Environment Monitoring was conducted in 240 companies located in Incheon. General Health Examination and Special Health Examination were performed on 32,725 and 9,504 workers, respectively. Occupational Health Services were provided to 16,883 workers in 171 companies. These data have been collected and operated at an external data management institution and were provided as a retrospective cohort after removing personal identification information. Results: In 2018, the total number of companies was 2,854, among which which 488 special Health Examination, 171 Work Environment Monitoring, and 240 Occupational Health Service. The proportion of companies undergoing Special Health Examination was 17.1%, the proportion of companies undergoing Work Environment Monitoring was 8.4%, and the proportion of Companies undergoing Occupational Health Service was 6.0%. Conclusion: GROCS expects researchers to utilize its useful and reliable resource for occupational health and surveillance with for academic or political purposes to lead to improved workers' health and working environment.

Flexible-type ultrathin holographic endoscope for microscopic imaging of unstained biological tissues.

Ultrathin lensless fibre endoscopes offer minimally invasive investigation, but they mostly operate as a rigid type due to the need for prior calibration of a fibre probe. Furthermore, most implementations work in fluorescence mode rather than label-free imaging mode, making them unsuitable for general medical diagnosis. Herein, we report a fully flexible ultrathin fibre endoscope taking 3D holographic images of unstained tissues with 0.85-µm spatial resolution. Using a bare fibre bundle as thin as 200-µm diameter, we design a lensless Fourier holographic imaging configuration to selectively detect weak reflections from biological tissues, a critical step for label-free endoscopic reflectance imaging. A unique algorithm is developed for calibration-free holographic image reconstruction, allowing us to image through a narrow and curved passage regardless of fibre bending. We demonstrate endoscopic reflectance imaging of unstained rat intestine tissues that are completely invisible to conventional endoscopes. The proposed endoscope will expedite a more accurate and earlier diagnosis than before with minimal complications.

Plant phenotype relationship corpus for biomedical relationships between plants and phenotypes.

Medicinal plants have demonstrated therapeutic potential for applicability for a wide range of observable characteristics in the human body, known as "phenotype," and have been considered favorably in clinical treatment. With an ever increasing interest in plants, many researchers have attempted to extract meaningful information by identifying relationships between plants and phenotypes from the existing literature. Although natural language processing (NLP) aims to extract useful information from unstructured textual data, there is no appropriate corpus available to train and evaluate the NLP model for plants and phenotypes. Therefore, in the present study, we have presented the plant-phenotype relationship (PPR) corpus, a high-quality resource that supports the development of various NLP fields; it includes information derived from 600 PubMed abstracts corresponding to 5,668 plant and 11,282 phenotype entities, and demonstrates a total of 9,709 relationships. We have also described benchmark results through named entity recognition and relation extraction systems to verify the quality of our data and to show the significant performance of NLP tasks in the PPR test set.

Comparison of compensatory lumbar movement in participants with and without non-specific chronic low back pain: A cross-sectional study.

BACKGROUND: Many studies have compared muscle length and muscle activity for low back pain. However, compensatory movement for non-specific low back pain has not yet been studied sufficiently. OBJECTIVE: The purpose of this study was to compare the length of the hip flexor, lumbar extensor endurance and the muscle activity of the erector spinae and gluteus maximus during hip extension, and the compensatory movement of the lumbar in people with or without nonspecific chronic low back pain. METHODS: In this case-control study, 16 participants with non-specific chronic LBP and 17 without LBP were included. Hip flexor length was assessed by the modified Thomas test. Lumbar extensor endurance was assessed by the modified Biering-Sorensen test. Muscle activity of the erector spinae and gluteus maximus during hip extension was measured using a Delsys-Trigno wireless EMG system. Compensatory lumbar movements during hip extension were measured using a digital inclinometer. RESULTS: Muscle activity of the erector spinae and compensatory lumbar movements were significantly higher in the LBP group. (p< 0.05). Hip flexor length, muscle activity of the gluteus maximus and endurance of the lumbar extensor were significantly differences in the LBP group (p< 0.05). CONCLUSIONS: Shortened hip flexors, low gluteus maximus activity, and high erector spinae activity during hip extension, lumbar extensor weak endurance, lumbar compensatory movement are potential factors for non-specific LBP.

Analysis of self-reported mental health problems among the self-employed compared with paid workers in the Republic of Korea.

Background: As self-employed workers are vulnerable to health problems, this study aimed to analyze mental health problems and sleep disturbances among self-employed workers compared with paid workers in Korea. Methods: A total of 34,750 workers (23,938 paid workers and 10,812 self-employed workers) were analyzed from the fifth Korean Working Condition Survey, which included 50,205 households collected by stratified sampling in 2017. To compare mental health problems and sleep disturbance among self-employed workers and paid workers, multivariate logistic regression analyses were performed. Results: The odds ratio in self-employed workers compared with paid workers was 1.25 (95% confidence interval [CI]: 1.09-1.42) for anxiety, 1.11 (95% CI: 1.04-1.17) for overall fatigue, 1.11 (95% CI: 1.04-1.20) for difficulty falling asleep, 1.10 (95% CI: 1.02-1.18) for difficulty maintaining sleep and 1.24 (95% CI: 1.16-1.32) for extreme fatigue after waking up. Conclusions: Self-employed workers in Korea have a higher risk of self-reported mental health problems and sleep disturbances than paid workers. Further studies with a longitudinal design and structured evaluation are required to investigate the causal relationship between health problems and self-employment.

Cohort Profile: The Korean Vietnam War Veterans' Health Study Cohort (KOVECO).

During the Vietnam War, many troops and citizen were exposed to large amounts of Agent Orange (AO), and the hazardous effects of AO are continuously being researched and reported. The Korean Vietnam War Veterans' Health Study Cohort (KOVECO) is a retrospective cohort to demonstrate the health status of the Korean Vietnam War veterans and their second-generation offsprings. The KOVECO is a collaboration of data from the Ministry of Patriots and Veterans Affairs and the National Health Insurance Sharing Service from 2002 to 2018. The study participants were all Korean Vietnam War veterans and their second-generation offsprings, and the references were the general population in which gender and region were matched with the participants. As of 2002, 191,272 Vietnam War veterans (1,000,320 comparisons) and 1,963,402 s-generations (1,173,061 references) were included in the cohort. The KOVECO consists of personal information, medical facility visit information, and general health examination information. The KOVECO could act as a health surveillance system, which would be able to detect long-term health effects caused by exposure to AO and provide a direction for policy making through academic research.