Search

Magnesium (Mg) has many unique properties. The present review highlights the basic properties of Mg and its application in energy processes such as photocatalysis, electrocatalysis, energy storage, solar harvesting, hydrogen storage, plasmonic, and sensing.

Objective: We evaluated the effects of microclimate temperature on the subjective and objective sleep quality of healthy young adults. For this purpose, we maintained a constant ambient temperature and manipulated the mattress temperature to change the microclimate.Methods: We enrolled 34 healthy young adults (12 males and 22 females; mean age: 24.06±2.70 years). Data from 26 individuals were analyzed (8 males and 18 females; mean age: 23.46±2.40 years). Nocturnal polysomnography (nPSG) was performed and self-reported questionnaires were completed at an ambient temperature of 27°C and mattress temperature of 28°C, 30°C, or 32°C.Results: The subjective sleep satisfaction was lower at a mattress temperature of 32°C than at 28°C. The subjective sleep latency was longer at 32°C than at 30°C. The number of respondents that selected sleep environment (including temperature) as the cause of sleep dissatisfaction was greater at higher temperatures. Participants felt that the mattress temperature was the least cool when they woke up at 32° than 30°C. Furthermore, they reported that the sleep latency at 32°C was longer than the other temperatures compared to usual sleep, and that they had more frequent awakenings at 32°C than at 28°C. The nPSG results showed that the proportion of rapid eye movement (REM) sleep was lower at 28°C than at 30°C.Conclusion: A high microclimate temperature caused by a high mattress temperature was associated with poor subjective sleep quality. Mattress temperature was also related to the objective proportion of REM sleep; however, the results are inconsistent with previous findings. Additional large-scale studies that evaluate a wider temperature range are required.

A piezoelectric energy generating device that produces electricity using plasmon-enhanced solar radiation pressure (SRP) is developed. The SRP is greatly enhanced on the operational region of the device with a unique crater-like structure, and direct current is generated successfully on the device. By optimizing the material and thickness of top electrode, a maximum power density of 396 µW cm−2 is obtained. In addition, by using Raman measurements, finite-difference time-domain simulation, and COMSOL Multiphysics analysis, it is confirmed that the SRP is greatly amplified on the operational region with the nanoscale surface roughness due to resonance between the incident light and surface plasmons. By increasing the rotational speed of an optical chopper used to measure the change in the output characteristics of the device, and comparing this with the simulated result, it is found that the constant charge produced by the piezoelectric effect arose due to the superposition of charge phases in the device.

Epigenetic dysregulation characterized by aberrant DNA hypermethylation is a hallmark of cancer, and it can be targeted by hypomethylating agents (HMAs). Recently, we described the superior therapeutic efficacy of a novel HMA, namely, NTX-301, when used as a monotherapy and in combination with venetoclax in the treatment of acute myeloid leukemia. Following a previous study, we further explored the therapeutic properties of NTX-301 based on experimental investigations and integrative data analyses. Comprehensive sensitivity profiling revealed that NTX-301 primarily exerted anticancer effects against blood cancers and exhibited improved potency against a wide range of solid cancers. Subsequent assays showed that the superior efficacy of NTX-301 depended on its strong effects on cell cycle arrest, apoptosis, and differentiation. Due to its superior efficacy, low doses of NTX-301 achieved sufficiently substantial tumor regression in vivo. Multiomics analyses revealed the mechanisms of action (MoAs) of NTX-301 and linked these MoAs to markers of sensitivity to NTX-301 and to the demethylation activity of NTX-301 with high concordance. In conclusion, our findings provide a rationale for currently ongoing clinical trials of NTX-301 and will help guide the development of novel therapeutic options for cancer patients.

Over the last years, the development of highly active and durable Pt-based electrocatalysts has been identified as the main target for a large-scale industrial application of fuel cells. In this work, we make a significant step ahead in this direction by preparing a high-performance electrocatalyst and suggesting new structure-activity design concepts which could shape the future of oxygen reduction reaction (ORR) catalyst design. For this, we present a new one-dimensional nanowire catalyst consisting of a L1

Nanowires have garnered considerable attention in photonics and optoelectronics due to their unique features. Owing to the large surface area and significant potential of usage as a resonator and waveguide in photonic integrated circuits (PICs), nanowires have been applied in many research areas in nanophotonics. To enhance the properties of light emitting materials, the hybrid of nanowires and 2D materials has been deployed in many papers. This paper summarises recent studies on the application of various types of nanowires in photonics and optoelectronics, as well as the combination of nanowires and 2D materials. This review article introduces nanowires that act as resonators or/and waveguides to increase the performance of 2D materials used in PICs for light enhancement and guiding. Moreover, the review lays out the hybrid of nanowires and 2D materials that have been studied in the field of optoelectronics. The hybridization of nanowires and 2D materials for photonics and optoelectronics is discussed in this review for the outlook of future studies.

Introduction Shift work is known to be associated with sleep disturbance and circadian misalignment and may contribute to alterations in the brain implicated in emotion dysregulation. In this study, we examined 1) neural correlates of emotion dysregulation, including emotional reactivity and regulation in shift workers and 2) relationships between neural correlates of emotion dysregulation, sleep disturbance, and circadian misalignment. Methods Fifty-six rotating shift workers (SW, 42 females, 30.80 ± 6.94 years old) who had non-standard shift schedules and 52 healthy controls (HC, 36 females, 31.69 ± 7.86 years old) who did not work as shift schedules participated in this study. Both SW and HC completed self-reported measures of sleep and mood problems, and wrote sleep diary and wore actigraphy to assess sleep quality and circadian rhythms. They also underwent one night polysomnography and were scanned while they were performing the emotion regulation task. We analyzed group differences in mood, sleep, circadian rhythms, and neural bases of emotional reactivity and regulation, and examined relationships between these variables. Results SW showed significant differences in actigraphy-estimated sleep (i.e., lower sleep efficiency) and circadian rhythms (e.g., greater motor activity [M10] and lower interdaily stability) compared to HC. SW also exhibited increased anterior insula (AI) activation in response to negative pictures, but reduced activation in the dorsomedial prefrontal cortex (dMPFC) and AI-dMPFC functional connectivity during emotion regulation compared to HC. AI activation and AI-dMPFC functional connectivity were significantly associated with sleep disturbance (i.e., sleep diary-estimated sleep onset latency) and circadian misalignment (e.g., M10 and interdaily stability). Furthermore, a mediation analysis revealed that shift work was associated with increased motor activity during the most active 10-hour period, which then contributed to increased AI activation in response to negative pictures. Conclusion Our findings suggest that shift work may contribute to sleep disturbance and circadian misalignment, and neural alterations associated with emotional reactivity and regulation. Furthermore, the mediation result suggests that increased motor activity along with misaligned circadian rhythm may serve as a pathway, through shift work contributes to heightened emotional reactivity to negative information. Support (if any) National Research Foundation (No. 2022R1A2C2008417, NRF-2022R1A2C1008209) and Korea Institute for Advancement of Technology (No. 20009210).

Resistive switching memory has been studied actively for next-generation computing. Several binary oxides, such as HfO2 and Ta2O5, are widely adapted as resistive switching layers; however, there are several limitations to obtaining an energy- and area-efficient operation with sufficient reliability. Rare-earth oxide materials exhibit interesting resistive switching properties because of their reactivities with active anion species. In this study, atomic-layer-deposited GdOx films were investigated as an active switching layer for resistive switching memory. Post-deposition annealing of as-grown GdOx films enhanced the tunability of the resistance states, which can be useful for the multilevel operation of nonvolatile memory and neuromorphic computing applications. The effects of the crystallization and hygroscopic nature of the GdOx film are investigated for elucidating the change in the resistive switching characteristics and its underlying mechanism.

Yunjee Hwang,1 Kyung Hwa Lee,2,3 Nambeom Kim,4 Jooyoung Lee,5 Ha Young Lee,2 Jeong Eun Jeon,2 Yu Jin Lee,2 Seog Ju Kim5 1Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea; 2Department of Psychiatry and Center for Sleep and Chronobiology, Seoul National University, College of Medicine and Hospital, Seoul, Republic of Korea; 3Division of Child and Adolescent Psychiatry, Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea; 4Department of Biomedical Engineering Research Center, Gachon University, Incheon, Republic of Korea; 5Department of Psychiatry, Sungkyunkwan University College of Medicine, Samsung Medical Center, Seoul, Republic of KoreaCorrespondence: Yu Jin Lee, Department of Psychiatry and Center for Sleep and Chronobiology, Seoul National University, College of Medicine and Hospital, Seoul, Republic of Korea, Email ewpsyche@snu.ac.kr Seog Ju Kim, Department of Psychiatry, Sungkyunkwan University College of Medicine, Samsung Medical Center, Seoul, Republic of Korea, Email ksj7126@skku.eduPurpose: Sounds play important roles in promoting and disrupting sleep. How our brain processes sleep-related sounds and individual differences in processing sleep-related sounds must be determined to understand the role of sound in sleep. We investigated neural responses to sleep-related sounds and their associations with cognitive appraisals of sleep.Participants and Methods: Forty-four healthy adults heard sleep-related and neutral sounds during functional magnetic resonance imaging using a 3T scanner. They also completed the Dysfunctional Beliefs and Attitudes about Sleep (DBAS) questionnaire, which was used to assess cognitive appraisals of sleep. We conducted a voxel-wise whole-brain analysis to compare brain activation in response to sleep-related and neutral sounds. We also examined the association between the DBAS score and brain activity in response to sleep-related sounds (vs neutral sounds) using region of interest (ROI) and whole-brain correlation analyses. The ROIs included the anterior cingulate cortex (ACC), anterior insula (AI), and amygdala.Results: The whole-brain analysis revealed increased activation in the temporal regions and decreased activation in the ACC in response to sleep-related sounds compared to neutral sounds. The ROI and whole-brain correlation analyses showed that higher DBAS scores, indicating a negative appraisal of sleep, were significantly correlated with increased activation of the ACC, right medial prefrontal cortex, and brainstem in response to sleep-related sounds.Conclusion: These results indicate that the temporal cortex and ACC, which are implicated in affective sound processing, may play important roles in the processing of sleep-related sounds. The positive association between the neural responses to sleep-related sounds and DBAS scores suggest that negative and dysfunctional appraisals of sleep may be an important factor in individual differences in the processing of sleep-related sounds.Keywords: anterior cingulate cortex, appraisal, functional magnetic resonance imaging, sleep-related sounds

Introduction Obstructive sleep apnea (OSA), which is associated with a high mortality, is a heterogeneous disease that is affected by various pathophysiology. Although the severity of OSA is divided based on apnea-hypopnea index (AHI), AHI alone did not sufficiently represent these pathologies. The objective of this study is to categorize OSA using PSG data and compare the characteristics of each group including mortality. Methods 7,247 subjects were recruited at the Center for Sleep and Chronobiology, Seoul National University Hospital from June 2004 to December 2021. Demographic data, polysomnography, Sleep scale including Epworth sleepiness scale, Pittsburgh sleep quality index, Beck depression inventory, and Beck anxiety inventory were performed. After categorizing OSA using K-mean cluster analysis, Kaplan-Meir survival analysis and Cox proportional hazard regression analysis were used to evaluate all-cause mortality and hazard ratios. Results Three clusters were identified; Cluster 1 was associated with moderate OSA (mean AHI=19.28/h), high sleep efficiency and low arousal, Cluster 2 with moderate OSA (mean AHI=24.81/h), low sleep efficiency and high arousal, Cluster 3 with the most severe OSA (mean AHI=64.76/h), obese, and decreased O2 saturation. Conventional classification of OSA showed no difference in mortality between group, whereas Cluster 1 and Cluster 3 showed significant higher all-cause mortality compared to not-OSA group (Cluster 1, Log rank p=0.008; Cluster 3 Log rank p< 0.001). The risk of mortality was also significantly increased in cluster 1 (HR 2.048, 95% CI 1.265-3.317, p=0.004) and cluster 3 (HR 3.686, 95% CI 1.871-7.262, p< 0.001). These results were also observed after adjustment for sex, age, BMI and comorbid disease (Cluster 1, HR 2.053, 95% CI 1.197-3.518, p=0.009; Cluster 4, HR 2.640, 95% CI 1.230-5.666, p=0.012). Conclusion Phenotyping of OSA considered multiple variables is more appropriate to predict mortality than conventional classification based on AHI. In addition to evaluate patient with severe OSA, patients with moderate OSA who shows relatively good sleep and low arousal should be cautiously evaluated and monitored. Support (if any) This study was supported by the Technology Innovation Infrastructure program through the Korea Institute for Advancement of Technology funded by the Ministry of Trade, Industry and Energy.(study no.: P0014279, 20009210, Dr. Yu Jin Lee)

Introduction Physiological hyperarousal is suggested as a core feature of insomnia and resting-state functional magnetic resonance imaging (rs-fMRI) studies have examined the neurobiological basis of the hyperarousal theory. However, few have investigated the associations between rs-fMRI and the biomarkers of physiological hyperarousal. We aimed to investigate (1) the differences in the resting-state functional connectivity (RSFC) between chronic insomnia disorder (CID) patients and good sleepers (GS), and (2) the relationships between altered RSFC and the hyperarousal biomarkers including electroencephalogram (EEG) and heart rate variability (HRV). Methods Fifty CID patients (37 females, 45.8±12.7 years old) and 52 GS (32 females, 37.0±13.2 years old) completed self-report questionnaires, and underwent nocturnal polysomnography and rs-fMRI. We analyzed RSFC in the amygdala (AMYG) and anterior insula (AI), which were core regions of the salience network probably associated with hyperarousal. We also analyzed EEG relative beta power at central derivations and frequency domain HRV parameters (e.g., low frequency and high frequency) in ECG lead ll during sleep. We then tested differences in the RSFC between CID and GS and examined the correlations between RSFC, EEG beta power, and HRV. Results Compared with GS, CID showed more negative RSFC between the right AMYG and left supramarginal gyrus (SMG), but less positive RSFC between the left AI and bilateral lateral prefrontal cortex (LPFC). The right AMYG-left SMG RSFC was positively correlated with EEG beta power in non-rapid eye movement (NREM) stage 3 sleep measured on central regions (C3: r=-0.336, p=0.012; C4: r=-0.314, p=0.024). We did not find any significant correlations between RSFC and HRV parameters. Conclusion Decreased RSFC between the AMYG and SMG in insomnia patients may reflect a difficulty in the cortical top-down regulation of the amygdala, indicating hyperarousal during daytime. We also found a significant correlation between the AMYG-SMG RSFC and EEG beta power. This result suggests that altered AMYG connectivity during daytime is associated with cortical hyperarousal during sleep. Overall, our study may provide neurobiological evidence for the 24-hour hyperarousal theory of insomnia. Support (if any) The Korea Institute for Advancement of Technology funded by the Ministry of Trade, Industry and Energy (study no.: P0014279, 20009210).

Metal oxide semiconductors with branched structures, such as branched nanowires (b-NWs), have promising properties for being used in gas sensors. In this work, we synthesized Pt-decorated Bi2O3-branched SnO2 nanowires (NWs). NO2 sensing studies revealed the superior capacity of a Pt-decorated Bi2O3-branched SnO2 NWs gas sensor relative to pristine and branched SnO2 gas sensors, and it worked at near room temperature (50 °C). The increased sensing capacity was related to the synergistic effects of Pt decoration and Bi2O3 branching, particularly the morphology of the gas sensor with branched structures, the promising effects of Pt as a noble metal with good catalytic activity, and the generation of homo- and heterojunctions in the Pt-decorated Bi2O3-branched SnO2 NWs gas sensor. The results obtained in this work are useful for design and development of NO2 gas sensors using a simple strategy, which can be easily extended to various metal oxides.

Osteoporosis is a disease in which bone mineral density decreases due to abnormal activity of osteoclasts, and is commonly found in post-menopausal women who have decreased levels of female hormones. Sphingosylphosphorylcholine (SPC) is an important biological lipid that can be converted to sphingosine-1-phosphate (S1P) by autotaxin. S1P is known to be involved in osteoclast activation by stimulating osteoblasts, but bone regulation by SPC is not well understood. In this study, we found that SPC strongly inhibits RANKL-induced osteoclast differentiation. SPC-induced inhibitory effects on osteoclast differentiation were not affected by several antagonists of S1P receptors or pertussis toxin, suggesting cell surface receptor independency. However, SPC inhibited RANKL-induced calcineurin activation and subsequent NFATc1 activity, leading to decrease of the expression of Trap and Ctsk. Moreover, we found that bone loss in an experimental osteoporosis mouse model was recovered by SPC injection. SPC also blocked ovariectomy-induced body weight increase and Nfatc1 gene expression in mice. We also found that SPC inhibits RANKL-induced osteoclast differentiation in human macrophages. Since currently available treatments for osteoporosis, such as administration of female hormones or hormone receptor modulators, show serious side effects, SPC has potential as a new agent for osteoporosis treatment.

The oxygen reduction reaction (ORR) activity of platinum (Pt)-based catalyst is not satisfactory in high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) operating with a phosphoric ...

In this study, reduced graphene oxide (RGO) nanosheets were synthesized and then functionalized with Pt nanoparticles (NPs) for gas sensing studies at room temperature. Pt-functionalized RGOs (Pt-RGOs) were irradiated by a 2 MeV electron beam with different doses of 100 and 500 kGy (Pt-RGO-100 and Pt-RGO-500) to study the role of electron beam irradiation (EBI) on properties and NO2 gas sensing characteristics. Different characterization techniques verified the generation of structural defects after EBI. Additionally, NO2 sensing tests at room temperature revealed that the Pt-RGO-100 sensor had the highest response to NO2 gas as well as the shortest response time. We surmise that the improved sensing signal with respect to NO2 gas for Pt-RGO-100 sensor was related to the role of oxygen functional groups. However, decreases in the response for Pt-RGO-500 sensor were related to the creation of reactive oxygen gases that could be adsorbed on the active defects of the RGO by the interaction of electron beams with oxygen species in the ambient air, leading to a decrease of the effective defect sites and decreases of the sensing response. This work suggests progress towards an improved performance of RGO-based gas sensors that can work at low temperature, by using EBI as a clean tool applied at room temperature with Pt-functionalization.

Herein, an oxygen reduction reaction (ORR) catalyst consisting of CoN-decorated Pt nanoparticles (NPs) on thin two-dimensional (2D) nanosheet-structured Co-N-doped porous carbon is prepared by util...

Polycrystalline alloy electrodes of Pt with alkaline earth metals (Ca, Sr, and Ba) have been shown to exhibit enhanced electrocatalytic performance for oxygen reduction reaction (ORR) relative to P...

Composites of different semiconductors are found to show much improved electronic conductivity and decreased charge transfer resistance. In this work, this hypothesis is tested by preparing composi...

We analyzed the extracellular proteome of colistin-resistant Korean Acinetobacter baumannii (KAB) strains to identify proteome profiles that can be used to characterize extensively drug-resistant KAB strains. Four colistin-resistant KAB strains with colistin resistance associated with point mutations in pmrB and pmrC genes were analyzed. Analysis of the extracellular proteome of these strains revealed the presence of 506 induced common proteins, which were hence considered as the core extracellular proteome. Class C ADC-30 and class D OXA-23 β-lactamases were abundantly induced in these strains. Porins (CarO and CarO-like porin), outer membrane proteins (OmpH and BamABDE), transport protein (AdeK), receptor (TonB), and several proteins of unknown function were among the specifically induced proteins. Based on the sequence homology analysis of proteins from the core proteome and those of other A. baumannii strains and pathogenic bacterial species as well as further in silico screening, we propose that CarO-like porin is an A. baumannii-specific protein and that two tryptic peptides that originate from CarO-like porin detected by tandem mass spectrometry are peptide makers of this protein.

Hepatocellular carcinoma is a malignant disease with improved hepatic regeneration and survival, and is activated by human telomere transferase (hTERT). hTERT is expressed during early fetal development and switched off in most adult tissues, but it becomes reactivated in HCC. The exact mechanism regulating these expression changes remains unknown during HCC progress. We evaluated the relationship between hTERT expression and human kruppel-related 3 (HKR3) and cell cycle-related factors in HCC cell lines. Following transfection for hTERT knockdown and HKR3 overexpression, proteomic and transcriptomic analyses related to hTERT were performed using liquid chromatography/mass spectrometry (LC/MS) and RNA sequencing (RNAseq) in HCC cell lines. The expression levels of hTERT, HKR3, and cell cycle-related factors were measured using western blotting, and tumor growth were evaluated via cell proliferation and cell cycle assays. Transcriptomic and proteomic analyses showed that HKR3, hTERT and cyclin-dependent kinase inhibitor 2A (CDKN2A) were correlated. Up-regulation of HKR3 expression decreased hTERT and cyclin activation and suppressed the G1/S phase of the cell cycle through CDKN2A activation. Our results suggest that HKR3 induced regulation of cell cycle through hTERT inhibition and CDKN2A activation. Our results will facilitate further exploration of the pathways regulating human telomerase activity in HCC cell lines.