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ABSTRACT Kim, N.-H.; Hwang, J.H., and Kim, D.H., 2018. Evaluation of Mixing and Stratification in an Estuary of Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 96–100. Coconut Creek (Florida), ISSN 0749-0208. In the estuary, flow structures depend on the relative contributions of the tidal current and the released freshwater, which determine the mixing and the stratification. To understand how artificially discharged freshwater affect the flow structure in an estuary of Korea, flow velocities, temperature, and salinity were measured in the field. During the field campaign, discharged freshwater cyclically forms the stratified layers during ebb tide and relatively well mixed water column during flood tide as in the conventional estuarine process. The gradient Richardson number evaluated such cyclic patterns quantitatively with the field measurement data, which were sampled following the tidal cycle and after the release of freshwater. In the early stage of the freshwater discharge, stratification dominates due to the large density difference, which overcomes the mixing by shear at the interface. As time goes on, the momentum of the released flow weakened and tidal modulation becomes significant and the discharged freshwater advected back and forth along the tidal currents. Different from the conventional mixing during flood, the stratification breaks down not by vertical mixing caused by the shear generated turbulence but by the vertical advection in the front of the gate. [ABSTRACT FROM AUTHOR]

Background: The association between body mass index (BMI) and mortality is not conclusive, especially in East Asian populations. Furthermore, the association has been neither supported by recent data, nor assessed after controlling for weight changes. Methods: We evaluated the relationship between BMI and all-cause or cause-specific mortality, using prospective cohort data by the National Health Insurance Service in Korea, which consisted of more than one million subjects. A total of 153,484 Korean adults over 30 years of age without pre-existing cardiovascular disease or cancer at baseline were followed-up until 2010 (mean follow-up period = 7.91 ± 0.59 years). Study subjects repeatedly measured body weight 3.99 times, on average. Results: During follow-up, 3,937 total deaths occurred; 557 deaths from cardiovascular disease, and 1,224 from cancer. In multiple-adjusted analyses, U-shaped associations were found between BMI and mortality from any cause, cardiovascular disease, and cancer after adjustment for age, sex, smoking status, alcohol consumption, physical activity, socioeconomic status, and weight change. Subjects with a BMI < 23 kg/m2 and ≥ 30 kg/m2 had higher risks of all-cause and cause-specific mortality compared with the reference group (BMI 23–24.9 kg/m2). The lowest risk of all-cause mortality was observed in subjects with a BMI of 25–26.4 kg/m2 (adjusted hazard ratio [HR] 0.86; 95% CI 0.77 to 0.97). In subgroup analyses, including the elderly and those with chronic diseases (diabetes mellitus, hypertension, and chronic kidney disease), subjects with a BMI of 25–29.9 kg/m2 (moderate obesity) had a lower risk of mortality compared with the reference. However, this association has been attenuated in younger individuals, in those with higher socioeconomic status, and those without chronic diseases. Conclusion: Moderate obesity was associated more strongly with a lower risk of mortality than with normal, underweight, and overweight groups in the general population of South Korea. This obesity paradox was prominent in not only the elderly but also individuals with chronic disease. [ABSTRACT FROM AUTHOR]

Objective To investigate the role of NF-AT5, an osmoprotective transcription factor, in synovial hyperplasia and angiogenesis in patients with rheumatoid arthritis (RA). Methods The expression of NF-AT5 in synovial tissue and synoviocytes from RA patients was examined by immunohistochemistry and Western blot analysis, respectively. Messenger RNA (mRNA) in RA synoviocytes and human umbilical vein endothelial cells (HUVECs) transfected with dummy small interfering RNA (siRNA) or NF-AT5 siRNA were profiled using microarray technology. Assays to determine synoviocyte apoptosis and proliferation were performed in the presence of NF-AT5 siRNA. VEGF [ABSTRACT FROM AUTHOR]

Sea surface wind plays an essential role in the simulating and predicting ocean phenomena. However, it is difficult to obtain accurate data with uniform spatiotemporal scale. A high-resolution (10 km) sea surface wind hindcast around the Korean Peninsula (KP) is presented using the weather research and forecasting model focusing on wind speed. The hindcast data for 39 years (1979–2017) are obtained by performing a three-dimensional variational analysis data assimilation, using ERA-Interim as initial and boundary conditions. To evaluate the added value of the hindcasts, the ASCAT-L2 satellite-based gridded data (DASCAT) is employed and regarded as "True" during 2008–2017. Hindcast and DASCAT data are verified using buoy observations from 1997–2017. The added value of the hindcast compared to ERA-Interim is evaluated using a modified Brier skill score method and analyzed for seasonality and wind intensity. Hindcast data primarily adds value to the coastal areas of the KP, particularly over the Yellow Sea in the summer, the East Sea in the winter, and the Korean Strait in all seasons. In case of strong winds (10–25 m·s−1), the hindcast performed better in the East Sea area. The estimation of extreme wind speeds is performed based on the added value and 50-year and 100-year return periods are estimated using a Weibull distribution. The results of this study can provide a reference dataset for climate perspective storm surge and wave simulation studies. [ABSTRACT FROM AUTHOR]

Abstract: We performed a retrospective pooled analysis of 29 patients who had been diagnosed with fulminant type 1 diabetes in Korea and compared the results with 161 patients’ data from a nationwide survey in Japan. Fulminant type 1 diabetic patients in Korea have a similar phenotype compared with Japanese patients. [Copyright &y& Elsevier]

Objective: Thyroid cancer (TC) incidence has increased robustly in Korea. However, the actual cause of death, overall mortality risk, and cause-specific mortality risk in TC patients have not been clearly elucidated., Design: Retrospective cohort study., Methods: We analyzed 4082 TC patients from the Korean National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS, 2002-2013) with a median of 48-month follow-up. We compared these patients with 12 246 controls matched for age, sex, and histories of major cardiovascular disease (CVD) to investigate the cause of death and risks of overall and cause-specific mortality., Results: Overall, 61 deaths (1.5%) occurred in the TC group. The most common cause of death was TC-specific mortality (32.8%), followed by other malignancy-related mortality (31.1%) and CVD mortality (13.1%). The overall mortality risk was comparable between the TC and control groups (unadjusted hazard ratio (HR): 1.17; 95% confidence interval (CI): 0.87-1.58); the adjusted HR remained at 1.25 (95% CI: 0.90-1.74) after multivariate adjustment for body mass index (BMI), socioeconomic status (SES), smoking, alcohol consumption, and histories of hypertension, diabetes mellitus, and dyslipidemia. In addition, there was not enough evidence against the surmise that the CVD mortality risk was similar between the TC and control groups, with an HR of 0.50 (95% CI: 0.22-1.16) after adjustment for CVD risk factors., Conclusions: Excellent overall survival was observed in TC patients. The most common cause of death was TC-specific mortality, suggesting the importance of thyroid cancer treatment. The overall and cause-specific mortality risks, particularly CVD mortality risk, did not differ between TC patients and the general population.

Purpose: To investigate whether allelic polymorphism of haptoglobin (Hp) is associated with premature rupture of membrane (PROM), the Hp phenotypes of pregnant women with PROM were analyzed., Patients and Methods: The Hp phenotypes of 221 pregnant Korean women (187 control and 34 PROM patients) were determined by benzidine/hydrogen peroxide staining, following native polyacrylamide gel electrophoresis of hemoglobin-mixed sera. The Hp allele frequencies were calculated from the data of Hp phenotypes, and overall association with PROM was evaluated using Pearson Chi-Square test., Results: The polymorphic distribution of the patients cohort who underwent a normal delivery (control group) was similar to that of healthy Koreans. In contrast, however, patients with PROM showed significantly higher occurrence of the Hp 1-1 phenotype than control group (23.5% vs 8.0%). Hp 2-2 phenotype was lower in PROM cohort (38.2%) than in the control group (48.7%). The Hp(1) allele frequency in PROM group was significantly higher than that in the control group (0.426 vs 0.297, p = 0.034) with odds ratio of 1.762 (95% CI: 1.038 - 2.991)., Conclusion: These findings suggest that pregnant Korean women who possess Hp(1) allele (expressed as Hp 1-1 phenotype) have higher incidence of PROM than women with Hp(2) allele (expressed as Hp 2-2 phenotype). This is the first study that evaluated the significance of Hp polymorphism with respect to the development of PROM.

Background: The presence of antibody to the hepatitis B core antigen (anti-HBc) IgG in serum usually means a past infection of the hepatitis B virus (HBV). The clinical characteristics of patients with hepatocellular carcinoma (HCC), who have only a marker for past HBV infection, were investigated., Methods: A total of 565 HCC patients were classified according to their markers for HBV and the hepatitis C virus (HCV). The clinical features and the survival rate of hepatitis B surface antigen (HBsAg)(-)/anti-HBc(+) patients were compared to those of HBsAg(+) patients., Results: Four hundred and three patients were positive for HBsAg (B group, 71.3%), 64 were positive for anti-HCV (11.3%), and 90 were negative for both HBsAg and anti-HCV (N group, 15.9%). In the N group, 71 were positive for anti-HBc (PB group, 12.6% of total patients). The clinical characteristics of the PB group were different from those of the B group: age at diagnosis (60.6 +/- 9.6 vs 53.3 +/- 10.6 years, P < 0.001), habitual drinking (59.2% vs 23.6%, P < 0.001), family history of liver disease (9.9% vs 38.9%, P < 0.005), detection with periodic screening (28.2% vs 50.4%, P < 0.001), and elevated alpha-fetoprotein (53.5% vs 76.2%, P < 0.001). In both the PB group and the B group, liver cirrhosis was accompanied by a similar high prevalence (74.6% vs 89.1%). However, there was no significant difference in the cumulative survival rate., Conclusions: The prevalence of HBsAg(-)/anti-HBc(+) HCC is not rare or more common than that of anti-HCV(+) HCC in Korea, a high HBV endemic area. Although some differences in clinical characteristics may imply a different pathogenesis, chronic HBV infection or habitual drinking may be major contributing factors in the development of HCC in these patients.

Interleukin-1B and IL-1 receptor antagonist gene polymorphisms are associated with an increased risk of gastric cancer (GC) in Caucasian populations. However, recent studies could not find any association between IL-1B-511T polymorphism and the risk of GC in Asians. We tested for an association between IL-1 loci polymorphisms with increased gastric mucosal levels of IL-1beta and an increased risk of developing GC in a Korean population. Polymorphisms of IL-1A-889, IL-1B-31, IL-1B-511 and IL-1RN were genotyped in 434 controls and 234 patients with GC. Mucosal IL-1beta cytokine was measured using an ELISA. The frequencies of IL-1A, IL-1B-511, IL-1B-31 and IL-1RN were not statistically different between controls and all patients with GC. After subclassification of GC, only patients with intestinal-type GC showed a higher frequency of IL-1B-31T homozygotes (OR = 2.2; 95% CI = 1.1-4.3) compared with controls. Risk was also significantly increased in these patients for IL-1B-31T homozygotes compared with patients with diffuse-type GC (OR = 3.4; 95% CI = 1.5-7.7). As in Caucasian populations, linkage disequilibrium between IL-1B-31 and IL-1B-511 was nearly complete, but the pattern of haplotype related to the risk of GC (IL-1B-31T/IL-1B-511C) was opposite (IL-1B-511T/IL-1B-31C). Mucosal IL-1beta levels in H. pylori-infected GC patients were higher in patients homozygous for IL-1B-31T compared with IL-1B-31C/T and IL-1B-31C/C. Thus, the combined effects of H. pylori infection and IL-1B-31T/IL-1B-511C polymorphisms with enhanced mucosal IL-1beta production contributed to the development of intestinal-type GC in this Korean population., ((c) 2004 Wiley-Liss, Inc.)