DGIST 전자도서관

Effectiveness of a Mobile Wellness Program for Nurses with Rotating Shifts during COVID-19 Pandemic: A Pilot Cluster-Randomized Trial

2022-01International Journal of Environmental Research and Public Health, v.19, no.2, pp.1014

Nurses with rotating shifts, including night shifts, have suffered from low physical activity during the COVID-19 pandemic and lower sleep quality due to the disruption of their circadian rhythm. This study aimed to develop and examine the effectiveness of a mobile wellness program on daily steps, sleep quality, exercise self-efficacy, intrinsic motivation for exercise, self-rated fatigue, and wellness. A cluster randomized controlled trial design was used to examine the effectiveness of the mobile wellness program for nurses with rotating shifts. Sixty nurses from one university hospital participated and were allocated to an intervention group and a control group. The intervention group received a 12-week mobile wellness program to improve their physical activity and sleep quality, and the control group was only given a Fitbit to self-monitor their health behaviors. There were significant differences between the two groups in daily steps (p = 0.000), three components (subjective sleep quality, sleep disturbance, daytime dysfunction) of the PSQI, exercise self-efficacy, intrinsic motivation for exercise, and wellness. In conclusion, this study provides meaningful information that the mobile wellness program using Fitbit, online exercise using Zoom, online health coaching on a Korean mobile platform, and motivational text messages effectively promoted physical activity and sleep quality for nurses with rotating shifts during the COVID-19 pandemic.

Reparo: A Fast RAID Recovery Scheme for Ultra-large SSDs

2021-08ACM Transactions on Storage, v.17, no.3, pp.1 - 24

A recent ultra-large SSD (e.g., a 32-TB SSD) provides many benefits in building cost-efficient enterprise storage systems. Owing to its large capacity, however, when such SSDs fail in a RAID storage system, a long rebuild overhead is inevitable for RAID reconstruction that requires a huge amount of data copies among SSDs. Motivated by modern SSD failure characteristics, we propose a new recovery scheme, called reparo, for a RAID storage system with ultra-large SSDs. Unlike existing RAID recovery schemes, reparo repairs a failed SSD at the NAND die granularity without replacing it with a new SSD, thus avoiding most of the inter-SSD data copies during a RAID recovery step. When a NAND die of an SSD fails, reparo exploits a multi-core processor of the SSD controller in identifying failed LBAs from the failed NAND die and recovering data from the failed LBAs. Furthermore, reparo ensures no negative post-recovery impact on the performance and lifetime of the repaired SSD. Experimental results using 32-TB enterprise SSDs show that reparo can recover from a NAND die failure about 57 times faster than the existing rebuild method while little degradation on the SSD performance and lifetime is observed after recovery. © 2021 Association for Computing Machinery.

Emergence of microfluidics for next generation biomedical devices

2022-05Biosensors and Bioelectronics: X, v.10, pp.100106

The attention in lab-on-a-chip devices with their potent application in medical engineering has prolonged swiftly over the last ten years. Travelling through the technology development, innovative microfluidics devices shown enormous potential to lift the lab-on-a-chip biomedical research in traditions that are not imaginable using conventional techniques. The advances in the arena of microfluidics have prompted high-tech uprisings in numerous biomedical disciplines, including diagnostics, single-cell analysis, micro- and nano device fabrication, organ-in-chip platforms, and med-tech applications. The speedy development is motivated by the cumulative cooperation among central nanomaterials advances and innovative microfluidic aptitudes in the range of biomedical applications. Microfluidic gadgets presently undertake a significant part in numerous organic, synthetic, and designing applications, that have multiple approaches to create the vital channel and highlight measurements. In this review, the critical assessments on the frontiers of microfluidic platforms are carried out towards advancements in the microfluidic capabilities for the new-edge biomedical applications. It has been exhibited that microfluidics offers a scope of benefits contrasted with customary strategies, including further developed controllability and consistency specified by nanomaterial attributes. Herein, authors have discussed how innumerable nanomaterials empower the manufacture of microfluidic systems with advanced optical, mechanical, electrical chemical, and bio-interfacial properties ranging from the basics of microfluidics, various factors, types, and fabrication procedure to biomedical applications. A comprehensive investigation in the state-of-the-art usage of microfluidics in biomedical field is steered exemplarily to understand the significant advantages. Moreover, our assessment provides an interdisciplinary overview of modern microfabrication strategies that can be adopted for academic and industrial interests.

LRRTM3 regulates activity-dependent synchronization of synapse properties in topographically connected hippocampal neural circuits

2022-01Proceedings of the National Academy of Sciences of the United States of America, v.119, no.3, pp.e2110196119

Synaptic cell-adhesion molecules (CAMs) organize the architecture and properties of neural circuits. However, whether synaptic CAMs are involved in activity-dependent remodeling of specific neural circuits is incompletely understood. Leucine-rich repeat transmembrane protein 3 (LRRTM3) is required for the excitatory synapse development of hippocampal dentate gyrus (DG) granule neurons. Here, we report that <jats:italic>Lrrtm3</jats:italic>-deficient mice exhibit selective reductions in excitatory synapse density and synaptic strength in projections involving the medial entorhinal cortex (MEC) and DG granule neurons, accompanied by increased neurotransmitter release and decreased excitability of granule neurons. LRRTM3 deletion significantly reduced excitatory synaptic innervation of hippocampal mossy fibers (Mf) of DG granule neurons onto thorny excrescences in hippocampal CA3 neurons. Moreover, LRRTM3 loss in DG neurons significantly decreased mossy fiber long-term potentiation (Mf-LTP). Remarkably, silencing MEC–DG circuits protected against the decrease in the excitatory synaptic inputs onto DG and CA3 neurons, excitability of DG granule neurons, and Mf-LTP in <jats:italic>Lrrtm3</jats:italic>-deficient mice. These results suggest that LRRTM3 may be a critical factor in activity-dependent synchronization of the topography of MEC–DG–CA3 excitatory synaptic connections. Collectively, our data propose that LRRTM3 shapes the target-specific structural and functional properties of specific hippocampal circuits.

An electroceutical approach enhances myelination via upregulation of lipid biosynthesis in the dorsal root ganglion

2022-01Biofabrication, v.14, no.1

As the myelin sheath is crucial for neuronal saltatory conduction, loss of myelin in the peripheral nervous system (PNS) leads to demyelinating neuropathies causing muscular atrophy, numbness, foot deformities and paralysis. Unfortunately, few interventions are available for such neuropathies, because previous pharmaceuticals have shown severe side effects and failed in clinical trials. Therefore, exploring new strategies to enhance PNS myelination is critical to provide solution for such intractable diseases. This study aimed to investigate the effectiveness of electrical stimulation (ES) to enhance myelination in the mouse dorsal root ganglion (DRG)-an ex vivo model of the PNS. Mouse embryonic DRGs were extracted at E13 and seeded onto Matrigel-coated surfaces. After sufficient growth and differentiation, screening was carried out by applying ES in the 1-100 Hz range at the beginning of the myelination process. DRG myelination was evaluated via immunostaining at the intermediate (19 days in vitro (DIV)) and mature (30 DIV) stages. Further biochemical analyses were carried out by utilizing ribonucleic acid sequencing, quantitative polymerase chain reaction and biochemical assays at both intermediate and mature myelination stages. Imaging of DRG myelin lipids was carried out via time-of-flight secondary ion mass spectrometry (ToF-SIMS). With screening ES conditions, optimal condition was identified at 20 Hz, which enhanced the percentage of myelinated neurons and average myelin length not only at intermediate (129% and 61%) but also at mature (72% and 17%) myelination stages. Further biochemical analyses elucidated that ES promoted lipid biosynthesis in the DRG. ToF-SIMS imaging showed higher abundance of the structural lipids, cholesterol and sphingomyelin, in the myelin membrane. Therefore, promotion of lipid biosynthesis and higher abundance of myelin lipids led to ES-mediated myelination enhancement. Given that myelin lipid deficiency is culpable for most demyelinating PNS neuropathies, the results might pave a new way to treat such diseases via electroceuticals.

Hypo-trimethylation of Histone H3 Lysine 4 and Hyper-tri/dimethylation of Histone H3 Lysine 27 as Epigenetic Markers of Poor Prognosis in Patients with Primary Central Nervous System Lymphoma

ACCEPTCancer Research and Treatment

Purpose This study aimed to investigate the methylation status of major histone modification sites in primary central nervous system lymphoma (PCNSL) samples and examine their prognostic roles in patients with PCNSL. Materials and Method Between 2007 and 2020, 87 patients were histopathologically diagnosed with PCNSL. We performed immunohistochemical staining of the formalin-fixed paraffin-embedded samples of PCNSL for major histone modification sites, such as H3K4, H3K9, H3K27, H3K14, and H3K36. After detection of meaningful methylation sites, we examined histone modification enzymes that induce methylation or demethylation at each site using immunohistochemical staining. The meaningful immunoreactivity was validated by western blotting using fresh tissue of PCNSL. Results More frequent recurrences were found in hypomethylation of H3K4me3 (p=0.004) and hypermethylation of H3K27me2 (p<0.001) and H3K27me3 (p=0.002). These factors were also statistically related to short PFS and OS in the univariate and multivariate analyses. Next, histone modification enzymes inducing the demethylation of H3K4 (lysine-specific demethylase (LSD)-1/2 and Jumonji AT-rich interactive domain 1A (JARID1A-D)) and methylation of H3K27 (enhancer of zeste homolog (EZH)-1/2) were immunohistochemically stained. Among them, the immunoreactivity of JARID1A inversely associated with the methylation status of H3K4me3 (R2=-1.431), and immunoreactivity of EZH2 was directly associated with the methylation status of H3K27me2 (R2=0.667) and H3K27me3 (R2=0.604). These results were validated by western blotting in fresh PCNSL samples. Conclusion Our study suggests that hypomethylation of H3K4me3 and hypermethylation of H3K27me2 and H3K27me3 could be associated with poor outcomes in patients with PCNSL and that these relationships are modified by JARID1A and EZH2.© Korean Cancer Association

Relationship between Resting-State Alpha Coherence and Cognitive Control in Individuals with Internet Gaming Disorder: A Multimodal Approach Based on Resting-State Electroencephalography and Event-Related Potentials

2021-12Brain Sciences, v.11, no.12

The human brain is constantly active, even at rest. Alpha coherence is an electroencephalography (EEG) rhythm that regulates functional connectivity between different brain regions. However, the relationships between resting-state alpha coherence and N2/P3 components associated with response inhibition and cognitive processes have not been investigated in addictive disorders. The present study investigated the relationships between alpha coherence during the resting state and N2/P3 components of event-related potentials during the Go/Nogo task in healthy controls (HCs) and patients with Internet gaming disorder (IGD). A total of 64 young adults (HC: n = 31; IGD: n = 33) participated in this study. Alpha coherence values at left fronto-central and bilateral centro-temporal electrode sites were significantly correlated with P3 latency in HCs, whereas inverse correlations were observed in patients with IGD. Furthermore, significant differences were observed in the correlation values between the groups. Our results suggest that patients with IGD lack dynamic interactions of functional connectivity between the fronto-centro-temporal regions during the resting state and the event-related potential (ERP) index during cognitive tasks. The findings of this study may have important implications for understanding the neurophysiological mechanisms linking resting-state EEG and task-related ERPs underlying IGD.

Nanoarchitectonics of Metal-Free Porous Polyketone as Photocatalytic Assemblies for Artificial Photosynthesis

2022-01ACS Applied Materials and Interfaces, v.14, no.1, pp.771 - 783

The main component of natural gas is methane, whose combustion contributes to global warming. As such, sustainable, energy efficient, nonfossil-based methane production is needed to satisfy current energy demands and chemical feedstocks. In this article, we have constructed a metal-free porous polyketone (TPA-DPA PPK) with donor-acceptor (D-A) groups with an extensive pi-conjugation by facile Friedel-Crafts acylation reaction between triphenylamine (TPA) and pyridine-2,6-dicarbonyl dichloride (DPA). TPA-DPA PPK is a metal-free catalyst for visible-light driven CO2 photoreduction to CH4, which can be used as a solar fuel in the absence of any cocatalyst and sacrificial agent. CH4 production (152.65 ppm g(-1)) is similar to 5 times greater than that of g-C3N4 under the same test conditions. Charge-density difference plots from excited-state time-dependent density functional theory (TD-DFT) calculations indicate a depletion and accumulation of charge density among the donor/acceptor functional groups upon photoexcitation. Most notably, binding energies from DFT demonstrate that H2O is more strongly bound with the pyridinic nitrogen group than CO2, which shed insight into mechanistic pathways for photocatalytic CO2 reduction.

Enhanced location tracking in sensor fusion-assisted virtual reality micro-manipulation environments

2021-12PLoS ONE, v.16, no.12

Virtual reality (VR) technology plays a significant role in many biomedical applications. These VR scenarios increase the valuable experience of tasks requiring great accuracy with human subjects. Unfortunately, commercial VR controllers have large positioning errors in a micro-manipulation task. Here, we propose a VR-based framework along with a sensor fusion algorithm to improve the microposition tracking performance of a microsurgical tool. To the best of our knowledge, this is the first application of Kalman filter in a millimeter scale VR environment, by using the position data between the VR controller and an inertial measuring device. This study builds and tests two cases: (1) without sensor fusion tracking and (2) location tracking with active sensor fusion. The static and dynamic experiments demonstrate that the Kalman filter can provide greater precision during micro-manipulation in small scale VR scenarios. © 2021 Prada et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Two-point coupling method to independently control coupling efficiency at different wavelengths

2022-01Optics Letters, v.47, no.1, pp.106 - 109

To efficiently access light waves confined in a high-quality-factor (Q) microcavity over a wide spectral range, it is necessary to independently control coupling efficiency at different wavelengths. Here we suggest an approach to add a degree of freedom to control the coupling efficiency based on a two-point coupling geometry. By changing the phase difference between two paths connecting two coupling points, various combinations of coupling efficiencies at multiple wavelengths can be achieved. An analytic model describing the coupling property is derived and confirmed by experimental results. It is also shown that the coupling property can be modified by adjusting the effective refractive index difference between a waveguide and a resonator. © 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Ambient Mass Spectrometry Imaging of Small Molecules from Cells and Tissues

2022.0Methods in molecular biology (Clifton, N.J.), v.2437, pp.41 - 59

New methods to analyze cells and tissues in ambient condition without any harsh chemical fixation or physical freezing and drying are summarized in this report. The first approach, an atmospheric pressure mass spectrometry imaging method, is based on laser ablation in atmospheric pressure assisted by atmospheric plasma and nanomaterials such as nanoparticles and graphene to enhance laser ablation. The second one is based on secondary ion mass spectrometry (SIMS) imaging of live cells in solution capped with single-layer graphene to preserve intact and hydrated biological samples even under ultrahigh vacuum for SIMS bio-imaging in solution. © 2022, The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.

Unraveling highly efficient nanomaterial photocatalyst for pollutant removal: a comprehensive review and future progress

2022-03Materials Today Chemistry, v.23

The presence of pollutants in the environment harms the living organism. Photocatalytic technology has been considered as one of the efficient methods for pollutant removal. Photocatalysis is a process that converts abundantly available photonic energy into useful chemical energy. Nanostructured photocatalysts have gained attention in various applications such as removal of organic pollutants, reduction of the level of contaminations arising out of heavy metals, purification of water, and evolution of hydrogen as they possess multiple benefits such as improved light-harvesting efficiency, low charge recombination, and accelerated surface reactions. The foremost goal of such photocatalysis-based technologies is to synthesize an efficient photocatalyst material with high catalytic efficiency and energy harvesting capability in light spectra such as ultra-violet (UV) or visible regions. This article provides an extensive review of different photocatalytic materials that are activated in UV or visible light irradiation for pollutant removal. Special attention is paid to metal oxides, chalcogenides, chalcohalides, perovskites, carbon-based materials, and metal-organic frameworks (MOFs), which are considered active photocatalyst materials. This review article summarizes the recent achievements in the photocatalytic removal of harmful contaminants using a wide range of materials from the most explored inorganic compounds to novel heterostructures as well as hybrid inorganic-organic structures. Moreover, the influence of different factors, including material morphology, surface area, optical properties, and material doping on photocatalytic activity is discussed in detail in this article. Finally, the prospects in new catalyst design, preparation, and modification are proposed to overcome the significant problems existing in the field of modern photocatalysis. © 2021 Published by Elsevier Ltd.