• Journal of the Economic Geographical Society of Korea
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• v.23 no.2
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• pp.166-181
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• 2020

This paper attempts to compare and analyze the intensity, trend, and regional gap of income inequality, capitalizing upon the Age-Period-Cohort model which considers age, time and cohort effects, with the 1998-2018 Korea Labor Panel (KLIPS) survey data for respondents living in the Capital and Non-Capital Regions. The main analysis results are as follows. First, in the case of both cohort and age effects, those in their 50~60s, including the so-called baby boomers and '386 generation' living in the Capital Region, have relatively lower income inequality effect compared to that of other age groups and cohorts in the Non-Capital Region. Second, the micro-individual characteristics cannot be ignored to account for a regional gap in income inequality, but rather the effects of structural and institutional omitted variables and the social discrimination effects of individual characteristics variables are more significant in explaining it. Overall, intra-and inter-cohort income inequalities appear to overlap.

• Journal of the Korean Vacuum Society
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• v.9 no.3
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• pp.249-253
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• 2000

We have analyzed electrical characteristics of the amorphous $MgTiO_3$thin films deposited by pulsed laser deposition (PLD) technique with the temperature of 400~$500^{\circ}C$. The electrical characteristics of $MgTiO_3$films heavily depend on the deposition temperature. We speculate that the density of anomalous positive charge (APC) substantially increases as the deposition temperature lowers, causing the HF C-V curves shift to the direction of the negative gate voltage. We further observed that both the degree of C-V shift as a function of the deposition temperature and the density of APC were minimized by the use of $SiO_2$with thickness of approximately 100 $\AA$ between $MgTiO_3$films and the Si substrate.

• Biomolecules & Therapeutics
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• v.28 no.1
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• pp.110-118
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• 2020

Migration presents a substantial social and public health issue. However, it is unclear whether diabetes is worse among Asian migrants than natives of South Korea over time. This longitudinal study investigated the nationwide population, including 2,680,495 adults aged 20 years and older (987,214 Asian migrants and 1,693,281 natives), who received health check-ups, using the Korean National Health Insurance Service data (2009-2015). Joinpoint regression was used to estimate the annual percentage change of diabetes, and multivariable logistic regression was used to examine differences in incident type 2 diabetes between Asian migrants and natives adjusting for age, sex, economic status, body mass index, smoking status, any alcohol use, and physical activity. The age-adjusted prevalence of diabetes increased among native men (from 8.8% in 2009 to 9.7% in 2015, APC=1.64, p<0.05) compared to Asian migrant men, and the age-adjusted prevalence of diabetes increased among native women (from 6.0% in 2009 to 6.7% in 2015, APC=1.88, p<0.05) compared to Asian migrant women. In the multivariate analyses, Asian migrants were less likely to get type 2 diabetes than natives (odds ratio, 0.82; 95% CI, 0.78 to 0.86) between the first and last health check-ups. However, the odds ratio for developing type 2 diabetes was 1.15 (95% CI, 1.10 to 1.20) among low-income levels compared to high-income levels, regardless of whether they were Asian migrants or natives. The results could help to establish a new strategy for prevention, treatment, and management of diabetes among the Asian population.

• Journal of Cancer Prevention
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• v.21 no.2
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• pp.95-103
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• 2016

Background: Excess energy supply induces chronic low-grade inflammation in association with oxidative stress in various tissues including intestinal epithelium. The objective of this study was to investigate the effect of high-fat diet (HFD) on intestinal cell membrane integrity and intestinal tumorigenesis in $Apc^{Min/+}$ mice. Methods: Mice were fed with either normal diet (ND) or HFD for 12 weeks. The number of intestinal tumors were counted and biomarkers of endotoxemia, oxidative stress, and inflammation were determined. Changes in intestinal integrity was measured by fluorescein isothiocyanate (FITC)-dextran penetration and membrane gap junction protein expression. Results: HFD group had significantly higher number of tumors compared to ND group (P < 0.05). Blood total antioxidant capacity was lower in HFD group, while colonic 8-hydroxy-2'-deoxyguanosine level, a marker of oxidative damage, was higher in HFD group compared to that of ND group (P < 0.05). The penetration of FITC-dextran was substantially increased in HFD group (P < 0.05) while the expressions of membrane gap junction proteins including zonula occludens-1, claudin-1, and occludin were lower in HFD group (P < 0.05) compared to those in ND group. Serum concentration of lipopolysaccharide (LPS) receptor (CD14) and colonic toll-like receptor 4 (a LPS receptor) mRNA expression were significantly higher in HFD group than in ND group (P < 0.05), suggesting that significant endotoxemia may occur in HFD group due to the increased membrane permeability. Serum interleukin-6 concentration and myeloperoxidase activity were also higher in HFD group compared to those of ND group (P < 0.05). Conclusions: HFD increases oxidative stress disrupting intestinal gap junction proteins, thereby accelerating membrane permeability endotoxemia, inflammation, and intestinal tumorigenesis.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.950-966
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• 2021

This study investigated the effects of lemon extract powder and vinegar powder on the physicochemical and microbiological characteristics of pork sausages naturally cured using white kimchi powder during storage for 30 days. Six batches were included: control (0.01% sodium nitrite and 0.05% sodium ascorbate); treatment 1 (0.3% white kimchi powder and 0.5% lemon extract powder); treatment 2 (0.3% white kimchi powder and 1.0% lemon extract powder); treatment 3 (0.3% white kimchi powder and 0.5% vinegar powder); treatment 4 (0.3% white kimchi powder and 1.0% vinegar powder); and treatment 5 (0.3% white kimchi powder, 0.5% lemon extract powder, and 0.5% vinegar powder). Treatment 2 had significantly lower pH values and higher cooking loss than the other batches (p<0.05). Treatments 1, 2, and 5 had similar (p>0.05) CIE a^* as the control, while treatments 3 and 4 showed significantly lower values (p<0.05). The residual nitrite content in naturally cured products was lower than the control (p<0.05), while treatments 1 and 2 showed significantly higher nitrosyl hemochrome content and curing efficiency (p<0.05). TBARS values were similar for all treatments and the control (p>0.05). Treatments 1 and 2 showed significantly reduced aerobic plate counts (APC; p<0.05) than the control and other treatments. However, across all batches, TBARS values and APC significantly increased during storage (p<0.05). Our results suggest that lemon extract powder, rather than vinegar powder, may offer a promising alternative for supplementing the functions of nitrite in naturally cured sausages.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.4
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• pp.311-315
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• 2021

Objective: As clinicians and patients await consensus on intraovarian platelet-rich plasma (PRP) treatment, this project evaluated contemporary research trends in the literature. Methods: A PubMed/NLM search aggregated all ovarian PRP-related publications (n=54) to evaluate their scope, abstract utility, submission-to-publication interval, journal selected, article processing charge (APC), free reader access to full-text manuscripts, number and nationality of authors, and inclusion of international collaborators. The NIH Clinical Trials database was also audited. Results: Published output on intraovarian PRP has increased consistently since 2016, especially among investigators in Greece, Iran, USA, and Turkey. Between 2013 and 2021, 42 articles met the relevancy criteria, of which 40.5% reported clinical studies, small series, or case reports, 33% described experimental animal models, and 23.8% were opinion/review papers. Only two works included a placebo control group. The submission-to-publication interval (mean±standard deviation) was 130±96 days, there were 5.9±3.2 authors per project, and journals invoiced US $1,613±1,466 (range, $0-$3,860) for APCs. Conclusion: There was no correlation between APC and time to publish (Pearson's r=-0.01). Abstract content was inconsistent; sample size and patient age were often missing, yet free full-text "open access" was available for most publications (59.5%). The NIH Clinical Trials portal lists eight registered studies on "ovarian rejuvenation," of which two are actively recruiting patients, while four have been terminated or have an uncertain status. Two studies have concluded, with results from one posted to the NIH website. PRP and its derivatives for ovarian treatment show early promise, but require further investigation. Research is accelerating and should be encouraged, particularly placebo-controlled randomized clinical trials.

• Journal of Preventive Medicine and Public Health
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• v.52 no.3
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• pp.188-194
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• 2019

Objectives: Outbreaks of scarlet fever in Mexico in 1999, Hong Kong and mainland China in 2011, and England in 2014-2016 have received global attention, and the number of notified cases in Korean children, including in Jeju Province, has also increased since 2010. To identify relevant hypotheses regarding this emerging outbreak, an age-period-cohort (APC) analysis of scarlet fever incidence was conducted among children in Jeju Province, Korea. Methods: This study analyzed data from the nationwide insurance claims database administered by the Korean National Health Insurance Service. The inclusion criteria were children aged ${\leq}14years$ residing in Jeju Province, Korea who received any form of healthcare for scarlet fever from 2002 to 2016. The age and year variables were categorized into 5 groups, respectively. After calculating the crude incidence rate (CIR) for age and calendar year groups, the intrinsic estimator (IE) method was applied to conduct the APC analysis. Results: In total, 2345 cases were identified from 2002 to 2016. Scarlet fever was most common in the 0-2 age group, and boys presented more cases than girls. Since the CIR decreased with age between 2002 and 2016, the age and period effect decreased in all observed years. The IE coefficients suggesting a cohort effect shifted from negative to positive in 2009. Conclusions: The results suggest that the recent outbreak of scarlet fever among children in Jeju Province might be explained through the cohort effect. As children born after 2009 showed a higher risk of scarlet fever, further descriptive epidemiological studies are needed.

• Korean Journal of Materials Research
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• v.29 no.10
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• pp.623-630
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• 2019

Because of their excellent stability and highly specific surface area, carbon based materials have received attention as electrode materials of electrical double-layer capacitors(EDLCs). Biomass based carbon materials have been studied for electrode materials of EDLCs; these materials have low capacitance and high-rate performance. We fabricated tofu based porous activated carbon by polymer dissolution reaction and KOH activation. The activated porous carbon(APC-15), which has an optimum condition of 15 wt%, has a high specific surface area($1,296.1m^2\;g^{-1}$), an increased average pore diameter(2.3194 nm), and a high mesopore distribution(32.4 %), as well as increased surface functional groups. In addition, APC has a high specific capacitance($195F\;g^{-1}$) at low current density of $0.1A\;g^{-1}$ and excellent specific capacitance($164F\;g^{-1}$) at high current density of $2.0A\;g^{-1}$. Due to the increased specific surface area, volume ratio of mesopores, and surface functional groups, the specific capacitance and high-rate performance increased. Consequently, the tofu based activated porous carbon can be proposed as an electrode material for high-performance EDLCs.

• Journal of the Korean Dietetic Association
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• v.27 no.1
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• pp.45-58
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• 2021

This study evaluated the sanitation management standards for vegetable preparation processes without a cooking stage. The aerobic plate counts (APC), coliform counts, and Escherichia coli of the samples at each production step were analyzed, and microbial growth of the samples stored at different temperatures was measured. The validation was judged in accordance with the microbial criteria stipulated by the British PHLS. After washing and disinfection, the APCs of the two samples decreased to 3~4 log CFU/g in both seasons. Compared to the purchasing stage, the decrease in coliform counts was approximately 0~3 log CFU/g in both seasons; E. coli was not detected. The initial APC and coliform levels of two vegetable samples were 4~5 log CFU/g in both seasons, with an increase of 1 log CFU/g taking more than 6 h at 25℃ and 2 h at 35℃. More than 10 h at 25℃ and 6 h at 35℃ were required to increase the E. coli O157:H7 count by 1~2 log CFU/g for two seasoned samples. In conclusion, washing and disinfection effects and changes in microbial growth during room temperature storage were similar in the two vegetables. Despite the low sanitizing effect of the two vegetables, when cut vegetables were stored under the critical limit within 2 h at two different room temperatures, seasoned lettuce and chicory were at the 'satisfactory' or 'acceptable' levels of PHLS regardless of the storage temperatures. The validation of sanitation management standards applied to vegetable preparation with the no-cook step was approved.

• Health Policy and Management
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• v.31 no.2
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• pp.225-231
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• 2021

Unmet healthcare is an important indicator to measure accessibility of healthcare services. To examine the latest status of unmet healthcare needs in South Korea, the four different data which is composed of nationally representative sample of South Korean population were used; the Korea Health and Nutrition Examination Survey (KNAHANES, 2007-2019), the Community Health Survey (CHS, 2008-2019), the Korea Health Panel Survey (KHP, 2011-2017), and the Korean Welfare Panel Study (KOWEPS, 2006-2019). The proportion of individuals reporting unmet healthcare needs were 5.8% (KNHANES), 5.3% (CHS), and 11.6% (KHP). Annual percentage change (APC) which identifies trend for the follow-up period was -9.5%, -8.0%, and -6.5%, respectively. The proportion of individuals reporting unmet healthcare needs due to cost were 1.1% (KNAHANES), 0.7% (CHS), 2.4% (KHP), and 0.4% (KOWEPS). The APC was -10.5%, -14.2%, -12.2%, and -19.6%, respectively. Compared to last year, the rate of unmet healthcare needs has declined in general. However, the low-income and the elderly population were reporting the highest rate of unmet health care needs, and the disparity between lowest and highest groups were remained. These results suggest that adequate benefit coverage is needed for low-income and elderly population.