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Purpose: This study analyzed the current status of and correlations between Korean medical students’ experiences and perspectives surrounding patient-centered medical education (PCME).Methods: A structured PCME questionnaire composed of three categories, understanding patients within social and cultural contexts, understanding patients’ individual health contexts through communication, and placement of patients at the center of medical education, was used. The students were stratified into pre-medical (Pre-med), medical (Med), and policlinic (PK) groups because of curriculum differences by grade. The χ2 test was applied to analyze the association between students’ experiences with and perspectives on PCME. A Cramer’s V of 0.200 was considered a large effect size for any association between experiences with and perspectives on PCME.Results: Among the respondents, 50.6% answered that they did not know about patient-centered medicine before the survey. With increasing school years went up from Pre-med to PK, fewer students agreed that PCME should be added to pre-clinical medicine curricula (p

Dispersed MoxW(1−x)S2 catalysts were obtained in situ in the hydrocracking (HCK) of vacuum residue (VR) at 693 K at 9.5 MPa H2 with the same metal loading of 0.113 mmol with varying Mo:W ratios. The intrinsic activities of the catalysts were compared based on the H2 consumption rate per the surface site number, i.e. TOFs. The Mo0.75W0.25S2 catalyst showed a superior activity with a high TOFs of 0.6012 s−1 over those of monometallic sulfides of MoS2 (0.4764 s−1) or WS2 (0.2550 s−1). Transmission electron microscopy (TEM) analysis identified that the morphology and average particle size of the MoWS2 catalyst maintains even after three times of recycles. Moreover, extended X-ray absorption fine structure (EXAFS) analysis confirmed homogeneous distribution of Mo and W species in the MoWS2 phase.

In this letter, a noninverting buck–boost converter with state-based current control is proposed for Li-ion battery management. Unlike conventional multimode control in buck–boost converters, our control scheme utilizes a state controller with a single-level error current and a state checking clock to define the operation mode at every cycle. The state-based buck–boost converter enables seamless mode transition and stable output regulation with fixed interleaving patterns even when input and output voltages are similar, ensuring robust mode change with inherent hysteresis. The prototype IC was fabricated in a 0.18- μ m BCD process and achieved 90.9% efficiency with 1.1-A maximum load current capability at 1-MHz switching frequency.

Unsupported bimetallic sulfide catalysts were obtained in situ using Mo(CO)6 and Co octoate as precursors to investigate the promotional effect of Co on the MoS2 catalyst in the hydrocracking (HCK) of vacuum residue (VR). Transmission electron microscopy (TEM) and X-ray absorption fine structure spectroscopy were used to obtain structural properties of the catalysts. The bimetallic CoMoS2 catalyst exhibited high catalytic activity in the VR HCK with respect to the H2 consumption rate and asphaltene conversion as compared with monometallic sulfides such as Co9S8 or MoS2 with the same catalyst loading of 0.113 mmol at 673 K and 9.5 MPa H2. Higher hydrodesulfurization activity was also observed for the CoMoS2 catalyst. Moreover, extended X-ray absorption fine structure and TEM analysis identified the formation of a Co–Mo–S phase in monoslab particles of average particle size 6.7 nm and the maintenance of the morphology during five times of recycle tests. These results thus suggest that the unsupported CoMoS2 catalyst has a promotional effect on VR HCK.

OBJECTIVE : This study aimed to investigate the relationship between long working hours and chronic kidney disease (CKD) according to diabetic status. METHODS : 12,703 full-time employees without diabetes and 2,136 with diabetes were included in this study. Participants were grouped according to working hours: ≤40, 41-52, and > 52 h/week. Multiple logistic regression was used to evaluate the association between working hours and CKD prevalence. RESULTS : Participants with diabetes who worked 41-52 h/week showed 1.85 times higher odds of CKD (95% CI 1.15-2.96; P = 0.0112) compared with those who worked ≤40 h/week after adjusting for covariates. An interaction between diabetes and long working hours was observed (P for interaction = 0.0212) in the model. CONCLUSION : Long working hours are associated with CKD in participants with diabetes. An interaction between long working hours and diabetes leading to CKD development may exist.

STUDY OBJECTIVES: To evaluate whether obstructive sleep apnea (OSA) and its severity are related to dyslipidemia and alanine transaminase elevation as a marker of nonalcoholic fatty liver disease in children. METHODS: The data collected from polysomnography, laboratory measurements (lipid profile and liver enzyme), and body mass index in children aged 0–18 years who visited the pediatric department between 2012 and 2018 were retrospectively analyzed. RESULTS: There were a total of 273 participants in the study (ages 0–6 years, 7–12 years, and 13–18 years: 61.9%, 26.4%, and 11.7%, respectively). In the ages 7–12 and 13–18 years groups, obesity was strongly associated with OSA severity (Cramer’s V = 0.498, P < .001). High-density lipoprotein cholesterol levels were significantly lower in the OSA group than in the non-OSA group, irrespective of the presence of obesity. In addition, high-density lipoprotein cholesterol levels were significantly different between the OSA severity groups after adjusting for body mass index (P = .000). In participants who were obese, moderate and severe OSA were associated with alanine transaminase elevation (P = .023 and P = .045, respectively). CONCLUSIONS: This study suggests that OSA may be an independent risk factor for dyslipidemia and that OSA and obesity have a synergistic effect on alanine transaminase elevation. Early diagnosis and treatment of OSA from childhood, especially in obese children, will reduce metabolic complications. CITATION: Kang EK, Jang MJ, Kim KD, Ahn YM. The association of obstructive sleep apnea with dyslipidemia in Korean children and adolescents: a single-center, cross-sectional study. J Clin Sleep Med. 2021;17(8):1599–1605.

Different morphologies of oil-dispersed MoS2 catalysts were obtained by a ligand stabilization method using Mo(CO)6 as a Mo precursor and trioctylphosphine oxide (TOPO) as a coordinating agent to identify the active site of MoS2 in the hydrocracking (HCK) of vacuum residue (VR). Transmission electron microscopy (TEM) and extended X-ray absorption fine structure (EXAFS) spectroscopy were used to obtain structural properties of the dispersed catalyst. It was observed that the MoS2 forms a nanoscaled monolayer from 5 to 10 nm in size. The effect of the oil-dispersed MoS2 catalysts having different morphology on the slurry phase HCK of VR was investigated at 673 K and 9.5 MPa H2. The turnover frequency (TOF) of the dispersed MoS2 catalysts in the VR HCK was found to show a good correlation with the rim-site Mo dispersion of the MoS2 slabs based on the same metal loading of 0.113 mmol at 673 K and 9.5 MPa H2.

Kyung Rae Ko,1 Sangcheol Lee,2 Seo Yoon Oh,3 Ki-duk Kim,4 Sin Hyung Park,4,* Soonchul Lee2,* 1Department of Orthopaedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; 2Department of Orthopaedic Surgery, CHA Bundang Medical Center, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea; 3University of California, Berkeley, CA 94720, USA; 4Department of Orthopaedic Surgery, Bucheon Hospital, Soonchunhyang University School of Medicine, Bucheon-si, Gyeonggi-do, Republic of Korea*These authors contributed equally to this workCorrespondence: Soonchul LeeDepartment of Orthopaedic Surgery, CHA Bundang Medical Center, CHA University, 59 Yatap-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, Republic of KoreaTel +82 31-780-5289Fax +82 31-708-3578Email Lsceline78@gmail.comSin Hyung ParkDepartment of Orthopaedic Surgery, Bucheon Hospital, Soonchunhyang University School of Medicine, 170 Jomaru-Ro, Bucheon-si, Gyeonggi-do, Republic of KoreaTel +82 32-621-5114Fax +82 32-708-3578Email Sh0803@schmc.ac.krBackground: Factors determining bisphosphonate compliance are not fully understood. We examined fluctuations in oral bisphosphonate dosing intervals to gauge therapeutic compliance in patients with osteoporosis.Materials and Methods: Hospital data accruing between 2010 and 2017 were accessed to retrospectively study patients ≥ 50 years old (N=1873), each prescribed bisphosphonate at initial diagnosis of osteoporosis. The medication possession ratio (MPR), calculated as total days supplied divided by length of follow-up, served to measure therapeutic compliance. We compared MPRs of various prescription patterns (daily, weekly, monthly, and switch [ie, ≥ 1 change in pattern] groups). We also analyzed the impact of age, sex, fracture history, surgical history, and comorbidities. Multiple regression analysis was ultimately performed, using MPR as a dependent variable.Results: In our cohort (mean follow-up=5.7± 2.4 years), once weekly dosing was the most common prescription pattern (1223/1873, 65.3%), as opposed to monthly (366/1873, 19.5%) or daily (164/1873, 8.8%) dosing. A total of 120 patients (6.4%) comprising the switch group changed dosing patterns during the study period. MPR was significantly higher in the switch group (32.8± 22.7) than in the other three groups (daily, 21.9± 25.9; weekly, 22.7± 27.3; monthly, 23.2± 27.7). In multiple regression analysis, younger age (P< 0.001), female sex (P=0.004), and switching of prescription pattern (decrease or increase frequency) were factors significantly associated with higher MPR, signaling better compliance.Conclusion: Better bisphosphonate compliance was associated with physician-modified dosing patterns. We therefore recommend adjustments of prescription intervals in poorly compliant patients requiring long-term treatment.Keywords: bisphosphonate, compliance, medication possession ratio, MPR

As internet-of-things (IoT) devices continue to be installed everywhere, the concept of disposable IoT is emerging owing to better cost-efficiency and ease of maintenance without battery recharging. Lasting several years, IoTs powered with standard alkaline batteries can be a promising solution due to the long shelf life, low cost, and high reliability of these batteries as compared to the Li-ion type. As shown in the top portion of Fig. 11.8.1, a single alkaline cell has a maximum voltage of 1.5V, but it can decay down to 0.9V [1]. To power an IoT device operating with $\mathrm{V}_{\mathrm{DD}}=2\mathrm{V}$ , a variety of design options can be considered, such as the battery configuration and the power conversion topology, as shown in Fig. 11.8.1 (bottom). The first approach is step-down conversion [2], [3] from multi-cell batteries (3×BATs) connected in series. In this configuration, cell-balancing must be carefully considered; otherwise, the energy of the BATs cannot be fully utilized if any weak cells exist among them. Considering the power conversion stage, the input RMS current $\mathrm{I}_{\mathrm{IN},\mathrm{RMS}}$ becomes much higher than the average current $\mathrm{I}_{\mathrm{IN},\mathrm{AVG}}$ due to the inherently discontinuous $\mathrm{I}_{\mathrm{IN}}$ supplied from batteries, resulting in a significant power loss in the series combination of the direct current resistance $(\mathrm{R}_{\mathrm{DCR}, \mathrm{BAT}})$ of batteries which in the case of 3 batteries in series is $3\times \mathrm{R}_{\mathrm{DCR}, \mathrm{BAT}}$ (-300m $\Omega$ ). Regarding step-up conversion [4], [5] with parallel-connected batteries, most of the energy imbalances are compelled to be uselessly wasted via reverse currents $\mathrm{I}_{\mathrm{B}}$ ‘ The $\mathrm{I}_{\mathrm{B}}$ also can cause explosion or leakage of corrosive substances. Furthermore, the inductor current $\mathrm{I}_{\mathrm{L}}$ is likely to be high, caused by the discontinuous $\mathrm{I}_{\mathrm{D}}$ delivered to the output; this significantly contributes to the power loss with a large $\mathrm{R}_{\mathrm{DCR},\mathrm{IND}}$ of the inductor. In summary, the battery cell imbalance and the discontinuous input/output (I/O) current of converter are perhaps the major issues that prevent the full utilization of alkaline batteries in IoT applications.

The effects of Co, Ni, or Mo precursors having different oil solubility and oxidation state on the slurry phase hydrocracking (HCK) of vacuum residue (VR) was investigated at 673 K and 9.5 MPa H2. X-ray diffraction and extended X-ray absorption fine structure spectroscopy were used to obtain structural properties of the dispersed catalyst. Under standard operating condition, the metal precursors were found to form nanoscaled dispersed particles of MoS2, Co9S8, and Ni3S2, with the following VR HCK performances in the order MoS2 > Co9S8 ≫ Ni3S2, based on the same metal loading of 0.113 mmol. Among the oil-soluble Mo precursors such as Mo-hexacarbonyl, -octoate, and -naphthenate, it was observed that Mo-octoate having an intermediate oxidation state forms the smallest particles of 5.8 nm in size and shows the best activity in the VR HCK.

The effects of tetralin as an H-donor on the reactivity of asphaltenes in a petroleum pitch were investigated under thermal cracking or catalytic hydrocracking conditions at 693 K and 10.0 MPa N2 or H2. Reaction temperatures, pressures, and tetralin contents were varied to examine the reactivity of asphaltenes. Thermal cracking of the petroleum pitch led to a considerable amount of coke formation, close to 53.7 wt%, but the addition of tetralin reduced the coke formation down to 23.6 wt%. The coke formation was considerably reduced to 10.3 wt% in the catalytic hydrocracking condition, and was not formed in the presence of tetralin. Kinetic studies on the catalytic hydrocracking of petroleum pitch in the absence or presence of tetralin demonstrated that the addition of tetralin, showing an increase in the hydrogen transfer capacity, contribute to the marked performance of hydrocracking of the petroleum pitch in the presence of dispersed MoS2 catalyst.

The effects of various organic solvents having different H-donor index, asphaltene solubility, and alkyl-substitution on the upgrading of vacuum residue (VR) were investigated under thermal cracking or catalytic hydrocracking conditions at 673 K and 10.0 MPa N2 or H2. Molecular dynamics simulations were also adopted to verify physical interaction between asphaltene species with H-donor solvents. Thermal cracking led to a considerable amount of coke formation, close to 29.8 wt.%, but the addition of H-donors reduced the coke formation down to 23.4, 19.0, 12.4, and 4.1 wt.% in the presence of naphthalene, 1-methyl naphthalene(1-MN), decalin, and tetralin, respectively. The coke formation was considerably reduced to 7.2 wt.% in the hydrocracking condition, and further down to 2.9 and 1.2 wt.% in the presence of naphthalene and tetralin, respectively. It was demonstrated that H-donors retaining the H transfer capability coupled with the solubility of asphaltene contributed to the marked performance of VR hydrocracking in the presence of dispersed MoS2 catalyst.