Zeolite Membrane-Based Low-Temperature Dehydrogenation of a Liquid Organic Hydrogen Carrier: A Key Step in the Development of a Hydrogen Economy.

Methylcyclohexane (MCH) dehydrogenation is an equilibrium-limited reaction that requires high temperatures (>300 °C) for complete conversion. However, high-temperature operation can degrade catalytic activity and produce unwanted side products. Thus, a hybrid zeolite membrane (Z) is prepared on the inner surface of a tubular support and used it as a wall in a membrane reactor (MR) configuration. Pt/C catalysts is packed diluted with quartz sand inside the Z-coated tube and applied the MR for MCH dehydrogenation at low temperatures (190-250 °C). Z showed a remarkable H2-permselectivity in the presence of both toluene and MCH, yielding separation factors over 350. The Z-based MR achieved higher MCH conversion (75.3% ± 0.8% at 220 °C) than the conventional packed-bed reactor (56.4% ± 0.3%) and the equilibrium state (53.2%), owing to the selective removal of H2 through Z. In summary, the hybrid zeolite MR enhances MCH dehydrogenation at low temperatures by overcoming thermodynamic limitations and improves the catalytic performance and product selectivity of the reaction.

Changes in the Equity of the Long-Term Care System in Korea Based on Coulter Index Differences for the Years 2000, 2008, and 2015.

In this study, we examined the adequacy of supply and demand under private expansion of the long-term care (LTC) infrastructure after the introduction of long-term care insurance (LTCI) for the older people in Korea. We used Coulter's coefficient of inequality (Coulter index) to analyze the equity of LTC services by region. In addition, we analyzed the trend of equity changes through equity analysis for three time points: 2000, 2008, and 2015. We found that the level of inequity in LTC service infrastructure in Korea is lower in 2015 compared with 2000, but the differences among regions are high. The adjustment factors in 2015 showed prominent shortages of facilities in urban areas and oversupply in suburban areas. Based on these results, we propose an LTC service infrastructure that meets the demand and improves service access according to regional characteristics.

How do medical students actually think while solving problems in three different types of clinical assessments in Korea: Clinical performance examination (CPX), multimedia case-based assessment (CBA), and modified essay question (MEQ).

PURPOSE: This study aimed to explore students' cognitive patterns while solving clinical problems in three different types of assessments - clinical performance examination (CPX), multimedia case-based assessment (CBA), and modified essay question (MEQ) - and thus, to understand how different types of assessments can afford different thinking. METHODS: A total of six test-performance cases from two fourth-year medical students were used for a cross-case study. Data were collected through one-on-one interviews using a stimulated recall protocol where students were: 1) shown videos of themselves taking each assessment and 2) asked to elaborate on what they were thinking. The unit of analysis was the smallest phrases or sentences, from the participants' narratives, representing a meaningful cognitive occurrence. The narrative data were reorganized chronologically and then analyzed according to a frame of hypothetico-deductive reasoning as clinical reasoning. RESULTS: Both participants demonstrated similar patterns in their proportional frequencies of clinical reasoning on the same clinical assessment. The results also revealed that the three different assessment types may afford different aspects of clinical reasoning. For example, the CPX highly promoted the participants' reasoning related to inquiry strategy, while the MEQ highly promoted hypothesis generation. Similarly, the participants' data analysis and synthesis were more afforded by the CBA than the other types. CONCLUSION: This study discovered that different assessment design affords different thinking in problem-solving. This finding can contribute to leveraging ways of improving current clinical assessments. Importantly, the research method used in this study can be utilized as an alternative way of examining the validity of clinical assessments.

Prevalence of treated epilepsy in Korea based on national health insurance data.

The Korean national health security system covers the entire population and all medical facilities. We aimed to estimate epilepsy prevalence, anticonvulsant utilization pattern and the cost. We identified prevalent epilepsy patients by the prescription of anticonvulsants under the diagnostic codes suggesting seizure or epilepsy from 2007 Korean National Health Insurance databases. The information of demography, residential area, the kind of medical security service reflecting economic status, anticonvulsants, and the costs was extracted. The overall prevalence of treated epilepsy patients was 2.41/1,000, and higher for men than women. The age-specific prevalence was the lowest in those in their thirties and forties. Epilepsy was more prevalent among lower-income individuals receiving medical aid. The regional prevalence was the highest in Jeju Island and lowest in Ulsan city. New anticonvulsants were more frequently used than old anticonvulsants in the younger age group. The total annual cost of epilepsy or seizure reached 0.46% of total medical expenditure and 0.27% of total expenditure on health. This is the first nationwide epidemiological report issued on epilepsy in Korea. Epilepsy prevalence in Korea is comparable to those in developed countries. Economic status and geography affect the prevalence of epilepsy.