Assessment of fractional flow reserve in intermediate coronary stenosis using optical coherence tomography-based machine learning.

Objectives: This study aimed to evaluate and compare the diagnostic accuracy of machine learning (ML)- fractional flow reserve (FFR) based on optical coherence tomography (OCT) with wire-based FFR irrespective of the coronary territory. Background: ML techniques for assessing hemodynamics features including FFR in coronary artery disease have been developed based on various imaging modalities. However, there is no study using OCT-based ML models for all coronary artery territories. Methods: OCT and FFR data were obtained for 356 individual coronary lesions in 130 patients. The training and testing groups were divided in a ratio of 4:1. The ML-FFR was derived for the testing group and compared with the wire-based FFR in terms of the diagnosis of ischemia (FFR ≤ 0.80). Results: The mean age of the subjects was 62.6 years. The numbers of the left anterior descending, left circumflex, and right coronary arteries were 130 (36.5%), 110 (30.9%), and 116 (32.6%), respectively. Using seven major features, the ML-FFR showed strong correlation (r = 0.8782, P < 0.001) with the wire-based FFR. The ML-FFR predicted wire-based FFR ≤ 0.80 in the test set with sensitivity of 98.3%, specificity of 61.5%, and overall accuracy of 91.7% (area under the curve: 0.948). External validation showed good correlation (r = 0.7884, P < 0.001) and accuracy of 83.2% (area under the curve: 0.912). Conclusion: OCT-based ML-FFR showed good diagnostic performance in predicting FFR irrespective of the coronary territory. Because the study was a small-size study, the results should be warranted the performance in further large-scale research.

Fusion Assessment of Oblique Lumbar Interbody Fusion Using Demineralized Bone Matrix: A 2-Year Prospective Study.

OBJECTIVE: Although several studies have reported successful fusion rates after oblique lumbar interbody fusion (OLIF) using allografts or dimerized bone matrix (DBM) instead of autografts, whether OLIF can achieve satisfactory solid fusion without the use of autografts remains unclear. This study investigated the real fusion rates after OLIF using allografts and DBM, which were evaluated using both dynamic radiographs and computed tomography scans. METHODS: We enrolled 79 consecutive patients who underwent minimally invasive OLIF followed by percutaneous pedicle screw fixation. All patients were treated with OLIF between L2 and L5 and underwent radiographic and clinical follow-ups at 12, 18, and 24 months after surgery. Radiographic assessment of fusion was performed using the modified BrantigaSteffee-Fraser (mBSF) scale, which was categorized as follows: grades I (radiographic pseudoarthrosis), II (indeterminate fusion), and III (solid radiographic fusion). Other radiologic and clinical outcomes were evaluated using the following parameters: vertebral slippage distance, disc height, subsidence, Oswestry Disability Index (ODI), and visual analogue scale (VAS). RESULTS: Clinical outcomes demonstrated significant improvements in the VAS scores for back pain, leg pain, and ODI after surgery. Subsidence was present in 34 cases (35.4%) at 12 months postoperatively, which increased to 47.9% and reached 50.0% at 1.5 years and 2 years after surgery, respectively. The solid fusion rate after OLIF was 32.3% at 1 year, increased to 58.3% at 1.5 years, and reached 72.9% at 2 years. Radiographic pseudoarthrosis was 24.0% at 1 year, which decreased to 6.3% at 1.5 years and 3.1% at 2 years. CONCLUSION: OLIF is a safe and effective surgical procedure for the treatment of degenerative lumbar diseases. The mBSF scale, which simultaneously evaluates both dynamic angles and bone bridge formation, offers great reliability for the radiological assessment of fusion. Moreover, OLIF using allografts and DBM, which is performed on one or 2 levels at L2-5, can achieve satisfactory fusion rates within 2 years after surgery.

Analysis of the Influence of Geographical Environment on Chinese Ethnic Folk Dance, Taking the Development of Dance Curriculum in Huaihua No. 1 Middle School as an Example.

Among the treasures of Chinese art, ethnic dance is an important part. As a key form of expression of national art and emotion, dance has strong regional and gender characteristics for those affected by different ethnic groups and regions. The unique characteristics of the region are the driving force for the masses of all ethnic groups in China to continuously promote the prosperity and development of ethnic and folk dances living alone in different living conditions and living environments. In the analysis of ethnic and folk dances, environmental elements have a profound impact on the rapid development of dance. The main reason for folk dance is the relationship between the costumes of the dance, the connotation of the dance, and the laws of nature, resulting in the derivation of the environment. The article will also focus on a more in-depth discussion and analysis of the characteristics of Chinese folk dance. Scientific research on the regionality of ethnic dance plays a vital role in understanding and inheriting ethnic and folk dances.

Assessment of Sinkholes Investigations in Jangseong-Gun Area, South Korea, and Recommendations for Similar Studies.

This paper reviews the site investigation field data and access work performed between 2016 and 2019 in the study area located close to Gun-dong mine. The research was aimed at defining the cause of sinkholes and their relationship with the underlying karstic limestone bedrock and nearby mining activities. Only a limited number of small sinkholes appeared in 2014, 2016, and 2018 in the agricultural land close to the limestone mine. The previously open pit mine started its underground operations in 2007. Since then, the mine has developed, and is now comprised of, large underground excavations at several levels below the surface. The studies carried out concluded that the appearance of sinkholes may be related to a general lowering of the groundwater table because of nearby agricultural and mining activities and also due to over-extraction of water due to increased urban use. Whilst these are the best determinations, this paper identifies missing elements of the previous investigations mentioned above, some issues with the interpretation of poorly prepared borehole logs and the improper preservation of borehole cores. The authors make recommendations for a systematic approach for implementation of an investigation strategy. This paper concludes that the appearance of sinkholes is a natural phenomenon, developing over geological time. However, human intervention contributes to sinkhole formation, which in urban areas may result in human, property, and economic losses. A better understanding, based on a methodical approach and suitable technologies, can determine the causes of sinkholes and can lead to the formulation of solutions and the implementation of economically and socially acceptable mitigation measures.

Educational and economic returns to cognitive ability in low- and middle-income countries: A systematic review.

There is growing interest to use early cognitive ability to predict schooling and employment outcomes in low- and middle-income countries (LMICs). Rather than using educational attainment and school enrollment as predictors of future economic growth or of improving an individual's earning potential, mounting evidence suggests that cognitive ability may be a better predictor. The relationship between cognitive ability, education, and employment are essential to predict future development in LMICs. We performed a systematic literature review and meta-analysis of the evidence regarding the relationship between cognitive ability and educational outcomes, and between cognitive ability and economic outcomes across LMICs. We searched peer-reviewed studies since 2000 that quantitatively measured these relationships. Based on an initial search of 3,766 records, we identified 14 studies, including 8 studies that examined the cognition-education link and 8 studies that assessed cognition-employment returns in LMICs. Identified studies showed that higher cognitive ability increased the probability of school enrollment, academic achievement, and educational attainment across LMICs. A meta-analysis of returns to wages from cognitive ability suggested that a standard deviation increase in cognitive test scores was associated with a 4.5% (95% CI 2.6%-9.6%) increase in wages. Investments into early cognitive development could play a critical role in improving educational and economic outcomes in LMICs. Further research should focus particularly in low-income countries with the least evidence, and examine the impact on education and economic outcomes by cognitive domains to provide more robust evidence for policy makers to take action.

Assessment of life factors affecting the experience of depressive symptoms in adolescents: a secondary analysis using the Korea Youth Risk Behavior Survey.

BACKGROUND: Adolescents may experience several changes in their lifestyle, such as social activity and school life, which makes them vulnerable to developing a depressive disorder. Therefore, the present study aimed to identify the factors affecting the experience of depressive symptoms during adolescence. METHODS: We conducted a secondary analysis using the 2019 Korean Youth Risk Behavior Web-based survey data, including a total of 57,303 middle and high school students selected from among 400 schools. Factors such as dietary habits, physical activity levels, time spent studying, duration of internet use, and other health risk behaviors were included in the analysis. Logistic regression analysis was performed to identify factors that predict the risk of experiencing depressive symptoms. RESULTS: The perceived stress of Korean adolescents showed a tendency to increase with age, and high school seniors and girls were more likely to report depressive symptoms. Perceived health status, academic performance, time spent studying, physical activity, duration of internet use, and effort to control weight were associated with individual experiences of depressive symptoms. CONCLUSION: We identified factors that influence the experience of depressive symptoms in adolescents. Our results suggest the possibility that the purpose of students' physical activities and their leisure activity preferences may be related to their emotional status. We suggest that activities that are appropriate to the culture and lifestyle of adolescents should be recommended to reduce the occurrence of depressive symptoms.

Performance assessment of ASTA MicroIDSys, a new matrix assisted laser desorption ionization-time of flight mass spectrometry system, for identification of viridans group streptococci.

The performance of the ASTA MicroIDSys system (ASTA), a new matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) system, was evaluated for the identification of viridans group streptococci (VGS) and compared with the results obtained with the Bruker Biotyper system (Bruker Daltonics). A total of 106 Streptococcus reference strains belonging to 24 species from the bacterial strain bank was analyzed using the two MALDI-TOF MS systems. Of the 106 reference strains tested, ASTA MicroIDSys and Bruker Biotyper correctly identified 84.9% and 81.1% at the species level, 100% and 97.2% at the group level and 100% and 98.1% at the genus level, respectively. The difference between the two systems was not statistically significant (P = 0.289). Out of 24 species, 13 species were accurately identified to the species level with 100% accurate identification rates with both systems. The accurate identification rates at the species level of ASTA MicroIDSys and Bruker Biotyper were 100% and 87.5% for the S. anginosus group; 78.4% and 73.5% for the S. mitis group; 91.7% and 91.7% for the S. mutans group; and 100% and 100% for the S. salivarius group, respectively. The ASTA MicroIDSys showed an identification performance equivalent to that of the Bruker Biotyper for VGS. Therefore, it would be useful for the identification of VGS strains in clinical microbiology laboratories.

Analysis of Characteristics and Mortality in Cardiac Arrest Patients by Hospital Level: a Nationwide Population-based Study.

BACKGROUND: Survival and post-cardiac arrest care vary considerably by hospital, region, and country. In the current study, we aimed to analyze mortality in patients who underwent cardiac arrest by hospital level, and to reveal differences in patient characteristics and hospital factors, including post-cardiac arrest care, hospital costs, and adherence to changes in resuscitation guidelines. METHODS: We enrolled adult patients (≥ 20 years) who suffered non-traumatic cardiac arrest from 2006 to 2015. Patient demographics, insurance type, admission route, comorbidities, treatments, and hospital costs were extracted from the National Health Insurance Service database. We categorized patients into tertiary hospital, general hospital, and hospital groups according to the level of the hospital where they were treated. We analyzed the patients' characteristics, hospital factors, and mortalities among the three groups. We also analyzed post-cardiac arrest care before and after the 2010 guideline changes. The primary end-point was 30 days and 1 year mortality rates. RESULTS: The tertiary hospital, general hospital, and hospital groups represented 32.6%, 49.6%, and 17.8% of 337,042 patients, respectively. The tertiary and general hospital groups were younger, had a lower proportion of medical aid coverage, and fewer comorbidities, compared to the hospital group. Post-cardiac arrest care, such as percutaneous coronary intervention, targeted temperature management, and extracorporeal membrane oxygenation, were provided more frequently in the tertiary and general hospital groups. After adjusting for age, sex, insurance type, urbanization level, admission route, comorbidities, defibrillation, resuscitation medications, angiography, and guideline changes, the tertiary and general hospital groups showed lower 1-year mortality (tertiary hospital vs. general hospital vs. hospital, adjusted odds ratios, 0.538 vs. 0.604 vs. 1; P < 0.001). After 2010 guideline changes, a marked decline in atropine use and an increase in post-cardiac arrest care were observed in the tertiary and general hospital groups. CONCLUSION: The tertiary and general hospital groups showed lower 30 days and 1 year mortality rates than the hospital group, after adjusting for patient characteristics and hospital factors. Higher-level hospitals provided more post-cardiac arrest care, which led to high hospital costs, and showed good adherence to the guideline change after 2010.

A structural equation model of successful aging in Korean older women: using selection-optimization-compensation (SOC) strategies.

The purpose of this study was to test a hypothetical model of successful aging based on the selection-optimization-compensation (SOC) model in Korean older women. The obtained results confirm that SOC strategies, subjective health status, and family support exert significant direct effects on the successful aging of older women, while depression and social support have indirect effects. Successful aging can be achieved by improving SOC strategies and social factors for older women. It is necessary to develop social services that replace the support traditionally received from the family in response to recent changes in family values in Korea.

The Effects of Social Networks of the Older Adults with Limited Instrumental Activities of Daily Living on Unmet Medical Needs.

This study was conducted to identify the effects of social networks on unmet medical needs among older adults with limited instrumental activities of daily living (IADL) who live in a community. This study analyzed data from 2281 older adults with limited IADL from the 2017 National Survey of Older Koreans. Data were analyzed using descriptive statistics, X2 tests, t-tests, and logistic regression analysis. About 73.0% of the subjects were female and 15.8% of the subjects had experienced unmet medical needs. The predictors of unmet medical needs according to gender are as follows: annual household income, participation in social activities, and physical support for male subjects and annual household income, number of chronic diseases, living alone in a household, living with others in a household, frequency of contacting close friends, and emotional support for female subjects. The findings of this study will be utilized as a basis for establishing relevant measures to enable older adults to receive proper medical services by heightening the understanding of the gap between medical service use and the medical needs of older adults with limited IADL.

Complementing conventional infectious disease surveillance with national health insurance claims data in the Republic of Korea.

Surveillance remains an important tool for timely outbreak detection and response. Many countries, including Korea, have established national infectious disease surveillance systems with clinical notification. We aimed to evaluate the National Health Insurance Claims-based Surveillance (NHICS) compared to conventional passive report-based National Infectious Diseases Surveillance (NIDS). Reported to claimed cases ratios (R/C ratio) were evaluated from monthly notifiable disease cases captured by NIDS and NHICS. The relationships between 26 infectious diseases and each surveillance system were analysed using Pearson's correlation analysis and linear regression. There was an overall increase in R/C ratio from 2010-2017 (0.37 to 0.78). In 22 infectious diseases, there was a correlation between NIDS and NHICS. Moreover, claim-based surveillance showed less fluctuating disease incidence rates than report-based surveillance for specific infectious diseases, such as varicella, mumps, and scarlet fever. However, for infectious diseases with episodic outbreaks or low incidence, it was difficult to assess NHICS usefulness. Claim-based surveillance is less affected by limitations of conventional report-based surveillance systems, such as reporting rate. Given delays in claim systems, a claim-based surveillance is expected to be complementary to conventional systems for the detection of various infectious diseases with the advancement of bio-information technology.

Antineuroinflammatory Activities and Neurotoxicological Assessment of Curcumin Loaded Solid Lipid Nanoparticles on LPS-Stimulated BV-2 Microglia Cell Models.

Curcumin, which is a potential antineuroinflammatory and neuroprotective compound, exhibits poor bioavailability in brain cells due to its difficulty in crossing the blood⁻brain barrier and its rapid metabolism during circulation, which decreases its efficacy in treating chronic neuroinflammatory diseases in the central nervous system. The bioavailability and potential of curcumin can be improved by using a nanodelivery system, which includes solid lipid nanoparticles. Curcumin-loaded solid lipid nanoparticles (SLCN) were efficiently developed to have a particle size of about 86 nm and do not exhibit any toxicity in the endothelial brain cells. Furthermore, the curcumin-loaded solid lipid nanoparticles (SLCN) were studied to assess their efficacy in BV-2 microglial cells against LPS-induced neuroinflammation. The SLCN showed a higher inhibition of nitric oxide (NO) production compared to conventional curcumin in a dose-dependent manner. Similarly, the mRNA and proinflammatory cytokine levels were also reduced in a dose-dependent manner when compared to those with free curcumin. Thus, SLCN could be a potential delivery system for curcumin to treat microglia-mediated neuroinflammation.

Relationships between hand-grip strength, socioeconomic status, and depressive symptoms in community-dwelling older adults.

BACKGROUND: Depressive symptoms have been found to be associated with decreased hand-grip strength (HGS) and low socioeconomic status (SES) in older adults. We aimed to investigate the potential moderating effect of SES on the association between HGS and depressive symptoms and the potential mediating effect of HGS on the association between SES and depressive symptoms using a nationally representative sample of older adults. METHOD: Data from 3169 community-dwelling adults aged 60 years or older were acquired from the Korea National Health and Nutrition Examination Survey conducted in 2014 and 2016. HGS was measured using a digital hand-grip dynamometer. Depressive symptoms were evaluated using the 9-item version of the Patient Health Questionnaire-9 (PHQ-9). SES was assessed using equivalent monthly household income and education level. RESULTS: Older adults in the lowest tertile of HGS measures were more likely to have experienced depressive symptoms compared to those in the highest tertile (odds ratio = 1.95, 95% confidence interval = 1.25-2.74). A significant moderating effect of household income level was observed on the association between HGS and PHQ-9 score (P = 0.014). Older adults with a low income had a stronger inverse correlation between HGS and PHQ-9 score compared to those with a high income (low income: beta =  -0.162, P < 0.001; high income: beta = -0.119, P = 0.036). HGS partially mediated the association between low income and depressive symptoms. CONCLUSION: Our findings indicate that there may be a stronger relationship between low HGS and depressive symptoms in socioeconomically deprived older people. Further research on muscle strength and income level in older adults is required regarding depression risk assessment.

One-year clinical outcomes of ticagrelor compared with clopidogrel after percutaneous coronary intervention in patients with acute myocardial infarction: From Korean Health Insurance Review and Assessment Data.

BACKGROUND: Ticagrelor has been widely accepted in clinical practice for treatment of acute myocardial infarction (AMI), however its clinical safety and efficacy have not been revealed sufficiently in Asian populations. METHODS AND RESULTS: Among a total 20,270 patients (age <75 years) with AMI undergoing percutaneous coronary intervention who received dual antiplatelet therapy for at least 30 days, clinical outcomes at 1 year were assessed from the database of Health Insurance Review and Assessment Service in Korea between 2013 and 2014. Ticagrelor showed a significant effect on reduction of all-cause death [stabilized inverse probability of treatment weighted (sIPTW)-adjusted odds ratio (aOR) 0.57, 95% confidence interval (CI) 0.42-0.77, p<0.001]. Stroke was also reduced by using ticagrelor (sIPTW-aOR 0.58, 95% CI 0.41-0.82, p=0.002). Bleeding risk was not increased by ticagrelor use. There were nearly 30% of patients who switched from ticagrelor to different P2Y12 inhibitors. Switching P2Y12 inhibitors was associated with clinical adverse events including MI, stroke, and bleeding. CONCLUSIONS: Among patients aged younger than 75 years, ticagrelor was associated with lower incidence of all-cause mortality. Stroke risk was also reduced in patients with a prescription for ticagrelor without an increase in bleeding risk.

Epidemiological Impact of the Korean National Immunization Program on Varicella Incidence.

The number of reported varicella cases is continuously increasing in Korea; however, associated medical utilization is declining. The ratio between varicella insurance claims and reports of passive infectious disease surveillance has gradually increased to > 80% since the second half of 2017. The recent increase in reported varicella cases is influenced by improved reporting. We calculated the varicella incidence and cumulative incidence in each birth cohort according to age. The cumulative incidence rate among children aged < 6 years in the birth cohort born after the National Immunization Program introduced the varicella vaccine was about 60% lower than among children born before.

Cost-effective 400-Gbps micro-intradyne coherent receiver using optical butt-coupling and FPCB wirings.

We present a cost-effective and bandwidth-enhanced 64-Gbaud micro-intradyne coherent receiver based on hybrid integration of InP waveguide-photodetector (WG-PD) and silica planar lightwave circuit (PLC). InP waveguide-photodetector (WG-PD) arrays are simply chip-to-chip bonded and optically butt-coupled to a silica-based dual-polarization optical hybrid chip. Multiple flexible printed circuit boards are adapted for electrical RF and DC wirings, which provide low-cost integration and good RF performance of the receiver. A 3-dB bandwidth of the fabricated coherent receiver is extended to ~36 GHz by optimization of bondwire inductance between the WG-PD array and the transimpedance amplifier (TIA), even when commercial TIAs with a typical bandwidth of ~29 GHz are used. Through optimization of the silica hybrid integrated coherent receiver, 64-Gbaud DP-16QAM signal transmission over 1050-km standard single-mode fiber is successfully demonstrated below a bit error rate of 2 × 10-3. This is the threshold for a soft decision-based forward error correction, at the optical signal to noise ratio of 23.8 dB.

Relationship of depression, chronic disease, self-rated health, and gender with health care utilization among community-living elderly.

BACKGROUND: We investigated the interactive effects of depressive symptoms and chronic diseases on health care utilization among elderly people and explored the potential moderating effect of gender and the mediating effect of self-rated health (SRH) on the association between depressive symptoms and health care utilization. METHOD: We analyzed data from 5223 people aged 60 years or older living in the community from the Korea Welfare Panel Study in 2015. Depressive symptoms were measured using an 11-item version of the Center for Epidemiologic Studies Depression (CES-D-11) Scale and morbidity within 28 disease categories was assessed. Health care utilization was evaluated as the number of outpatient visits (OV), number of hospitalizations (NH), and number of days spent in the hospital (DH) during past year. Hierarchical moderated regression analyses were applied to investigate the interactive effects. We also adopted the mediation analysis method by Hayes and Preacher. RESULTS: A significant interactive effect of CES-D-11 score and chronic disease on OV was found. A positive correlation between CES-D-11 score and OV was only observed in those with chronic disease. Gender had a moderating effect on the association of depression symptoms with OV, NH, and DH among elderly people with chronic disease. SRH had mediating effects on the association of CES-D-11 with OV, NH, and DH only among those with chronic disease. LIMITATIONS: The severity or multimorbidity of chronic diseases, which could affect health care utilization among elderly were not considered. CONCLUSIONS: We elucidated the complex aspects of the relationship between depressive symptoms and chronic disease and their interactive effects on health care utilization among elderly people, and identified important roles of gender and SRH.

Impact of the Health Insurance Coverage Policy on Oral Anticoagulant Prescription among Patients with Atrial Fibrillation in Korea from 2014 to 2016.

BACKGROUND: To evaluate oral anticoagulant (OAC) utilization in patients with atrial fibrillation after the changes in the health insurance coverage policy in July 2015. METHODS: We used the Health Insurance Review and Assessment Service-National Patient Samples (HIRA-NPS) between 2014 and 2016. The HIRA-NPS, including approximately 1.4 million individuals, is a stratified random sample of 3% of the entire Korean population using 16 age groups and 2 sex groups. The HIRA-NPS comprises personal and medical information such as surgical or medical treatment provided, diagnoses, age, sex, region of medical institution, and clinician characteristics. The studied drugs included non-vitamin K antagonist OACs (NOACs) such as apixaban, dabigatran, edoxaban, and rivaroxaban, and were compared with warfarin. We analyzed drug utilization pattern under three aspects: person, time, and place. RESULTS: The number of patients with atrial fibrillation who were prescribed OACs was 3,114, 3,954, and 4,828; and the proportions of prescribed NOACs to total OACs were 5.1%, 36.2%, and 60.8% in 2014, 2015, and 2016, respectively. The growth rate of OACs prescription increased from 61.4 patients/quarter before June 2015 to 147.7 patients/quarter thereafter. These changes were predominantly in elderly individuals aged more than 70 years. The proportion of NOACs to OACs showed significant regional difference. CONCLUSION: The change of health insurance coverage policy substantially influenced OACs prescription pattern in whole Korean region. But the impact has been significantly different among regions and age groups, which provides the evidence for developing standard clinical practice guideline on OACs use.