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Remote Sensing of Partial Discharge in Gas-insulated Switchgear (GIS) Using a 3 × 3 Optical Interferometer
No full textGas-insulated switchgear (GIS) is a kind of electric switch widely used in high-voltage applications where partial discharge (PD) frequently occurs, leading to degradation of the equipment. In this study, we present a novel method for detecting the PD occurring in a GIS chamber by using a 3 × 3 optical interferometer. The proposed system can remotely measure sub-nanometer displacements, enabling the detection of PD-induced surface vibration or displacement on the GIS housing. The correlation between PD intensity and the induced surface displacement was analyzed experimentally. The results showed that as PD intensity increased, the spectral components of the displacement signal were intensified within a 1–5.5 kHz range. After band-pass filtering there, it was observed that the displacement amplitude increased proportionally with PD intensity. The proposed method is expected to offer a remote and realtime alternative for GIS condition monitoring and increase operator safety and system reliability.TRUEsciescopuskc
Single-cell RNA sequencing of baseline PBMCs predicts ICI efficacy and irAE severity in patients with NSCLC
Get PDFBackground Immune checkpoint inhibitors (ICIs) have transformed treatment and have provided significant clinical benefits and durable responses for patients with advanced non-small cell lung cancer (NSCLC). However, only a small percentage of patients respond to ICI treatment, and immune-related adverse events (irAEs) leading to treatment discontinuation remain challenging. Despite the recognized need for biomarkers to predict both the efficacy of ICIs and the risk of irAEs, such biomarkers are yet to be clearly identified.Methods In this study, we performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) from 33 patients with NSCLC before ICIs treatment. To validate our findings, we reanalyzed public scRNA-seq data, conducted a cytometric bead array (CBA), and supported our findings with T-cell receptor sequencing.Results While the immune response was more pronounced in patients with a favorable prognosis, the hypoxic pathway was more prominent in patients with primary resistance. Lymphocytes such as CD8 T cells, CD4 T cells, and natural killer cells were primarily involved in these pathways, with PRF1 and GZMB expression showing strong associations with favorable prognosis. In contrast, irAEs were mainly linked to myeloid cells, such as monocytes and macrophages. As irAE severity increased, inflammation and the TNF-NFKB1 pathway were more prominent. Specifically, increased expression of IL1B, CXCL8, and CXCL2 in monocytes and TNF in macrophages was closely associated with severe irAE through involvement in these pathways. Notably, the increase of PRF1 and GZMB expression showed a close association with both a favorable prognosis and a reduced severity of irAE, which was validated through CBA analysis. Moreover, the expression of these key markers varied according to prognosis and irAE severity regardless of patient background, such as programmed death-ligand 1 expression levels, tumor histology, or prior treatment regimens.Results While the immune response was more pronounced in patients with a favorable prognosis, the hypoxic pathway was more prominent in patients with primary resistance. Lymphocytes such as CD8 T cells, CD4 T cells, and natural killer cells were primarily involved in these pathways, with PRF1 and GZMB expression showing strong associations with favorable prognosis. In contrast, irAEs were mainly linked to myeloid cells, such as monocytes and macrophages. As irAE severity increased, inflammation and the TNF-NFKB1 pathway were more prominent. Specifically, increased expression of IL1B, CXCL8, and CXCL2 in monocytes and TNF in macrophages was closely associated with severe irAE through involvement in these pathways. Notably, the increase of PRF1 and GZMB expression showed a close association with both a favorable prognosis and a reduced severity of irAE, which was validated through CBA analysis. Moreover, the expression of these key markers varied according to prognosis and irAE severity regardless of patient background, such as programmed death-ligand 1 expression levels, tumor histology, or prior treatment regimens.Conclusions This study identified biological pathways and key biomarkers associated with ICI prognosis and irAE severity using PBMC samples before treatment. These findings provide a foundation for improved therapeutic strategies that enhance clinical outcomes while minimizing ICI treatment-associated risks.TRUEsciescopu
Albumin Variant expression in yeast and its application to therapeutics
No full textTherapeutic proteins are used to treat a variety of diseases due to their low side effects and low immunogenicity. However, many therapeutic protein candidates suffer from short half-lives, due to degradation by proteases and removal by kidney filtration. To address this issue, various studies have been conducted to increase the half-life by conjugating human serum albumin (HSA). Previous studies have successfully conjugated therapeutic proteins to albumin using the SpyTag/SpyCatcher (ST/SC) system, leading to the development of Albucatcher, a novel conjugation platform that increases the half-life while maintaining activity. However, despite its many advantages, the resulting Albucatcher Ver.1 required multiple steps to fabricate, which left challenges to overcome, including time, effort, and reduced yield. Albucatcher Ver.2 aims to effectively reduce the multiple steps required to conjugate albumin with SpyCatcher (SC) by creating an albumin genetically conjugated with SpyCatcher and introducing it into yeast. We have confirmed that Albucatcher Ver.2 successfully forms a Uox-albumin conjugate (Uox-HSA) with Urate Oxidase (Uox), the model protein used for previous conjugation, and maintains the same activity.MasterAbstract i․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
List of contents ii․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
List of figures v․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
List of schemes v․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
I. INTRODUCTION 1․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
II. HSA and its variant Expression in Yeast Eukaryotic protein expression system
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1. Introduction ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 4
2. Experimental Materials & Methods ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 5
2.1. Materials ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 5
2.2. Construction of Plasmid ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 5
2.2.1. Point-mutation of pYD1 plasmid (Nco1 Insertion) ․․․․․․․․․․․ 5
2.2.2. pYD1-HSA Subcloning (For Display) ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 6
2.3. Yeast protein Expression and Display ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 6
2.4. Displayed HSA check with Fluorescent microscope ․․․․․․․․․․․․․․․ 7
3. Results and Discussion ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 7
3.1. Yeast Protein Display check with Fluorescent microscope
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4. Conclusion 9․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
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III. Half-life extended HSA Variants (K573P), SpyCatcher inserted Albumin
(Albucatcher ver.2) expression and Albucatcher ver.2 Conjugation with Uricase
Oxidase (Uox) Therapeutic protein 10․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
1. Introduction ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 10
2. Experimental Materials & Methods ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 12
2.1. Materials ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 12
2.2. Construction of Plasmid ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 12
2.2.1. Construction of pYD1-HSA (For Secretion) ․․․․․․․․․․․․․․․․․ 13
2.2.2. Half-life extended Albumin variant (K573P) ․․․․․․․․․․․․․․․․․ 13
2.2.3. Expression efficacy increasing sequence insertion ․․․․․ 13
2.2.4. Insert the SpyCatcher sequence to the N terminus and C
terminus of pYD1-HSA Plasmid ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 14
2.2.5. Introduce a linker sequence between HSA and SC ․․․ 15
2.2.6. Twin-strep-tag Insertion for Protein purification ․․․․․․ 15
2.3. Computational protein structure prediction using Alphafold 3
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2.4. Yeast protein expression and purification ․․․․․․․․․․․․․․․․․․․․․․․․ 17
2.5. Characterization of Expressed HSA-WT ․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 17
2.6. Conjugation of Albucatcher ver.2 with Uox-ST ․․․․․․․․․․․․․․․ 18
2.7. SEC separation and Uox-HSA purification from mixed protein
sample ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․ 18
2.8. Emzymatic Activity Assay of Uox-ST and Uox-HSA Conjugate
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3. Results and Discussion 19․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
3.1. HSA-WT and HSA Variant Expression, Purification and
Characterization 19․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
3.2. Uox-ST Expression and Purification 20․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
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3.3. Uox-ST and Albucatcher ver.2 Conjugation and Purification
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3.4. In Vitro Uox-ST and Uox-HSA Activity Assay 24․․․․․․․․․․․․․․․․․․․․․
4. Conclusions 25․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
Summary 26․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
Reference 27․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
Acknowledgment 29․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․
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Energy- and Area-Efficient CMOS Neuron and Max Pooling Circuit for RRAM-Based CNN Accelerators
No full textThis study proposes an energy-and area-efficient CMOS neuron and analog max pooling circuit for RRAM-based convolutional neural network (CNN) accelerators. The proposed max pooling circuit implements a 2 x 2 max pooling operation with a simple analog circuit in the current domain. The current-mode max pooling is performed before the current-to-voltage and voltage-to-digital conversions, thus reducing the number of circuits required for the conversions in the conventional CNN accelerators. Consequently, the 2 x 2 pooling circuit reduces the energy and area of the accelerator to a quarter. In addition to the max pooling circuit, the neuron circuit improves energy efficiency. The proposed neuron circuit implements the ReLU activation function along with digital conversion by modifying the operating principle of a conventional single-slope analog-to-digital converter. By implementing the ReLU function and digital conversion, the neuron achieves high energy efficiency by applying a high-speed asynchronous operation. A prototype chip, which included the neuron and current-mode max pooling circuit, was fabricated using a 130 nm standard CMOS process. The measurement results of the chip demonstrate its energy efficiency of 5.5 TOPS/W. Additionally, a simulation for image recognition demonstrates that a CNN accelerator employing the proposed neuron and max pooling circuit achieves 96.2 and 82.7% classification accuracies for the MNIST and Fashion-MNIST datasets, respectively.TRUEsciescopu
A Time-Series Deep Learning Approach for EEG-Based Sleep Stage Classification
No full text수면단계분류는수면의질평가및수면장애의조기진단에필수적인과정으로,기 존에는 전문가의 수작업에 의존해 많은 시간과 비용이 소요된다. 그래서 본 연구에서는 다양한 머신러닝 및 딥러닝 기법을 활용하여 수면 단계를 자동으로 분류하고자 한다. 연령에따른모델성능분석결과,전반적으로 LightGBM이가장높은정확도를보였 으나, 나이에 따라 성능의 차이가 나타났다. 이는 연령 증가에 따른 수면 구조의 변화와 EEG 특성 차이에서 기인한 것으로 해석된다. 수면 시간 흐름에 따른 성능 분석에서는, 과거 데이터를 활용한 시계열 기반 모델이 그렇지 않은 모델에 비해 더 나은 성능을 보였다. 그러나 개인 간 성능 편차가 크게 나타났으며, 특히 수면 단계의 변화가 잦은 피험자일수록예측정확도가낮은경향을보였다.이는수면단계간지속시간의차이와 개인별 생리적 특성이 모델 성능에 영향을 미친다는 점을 시사한다. 본 연구는 두 가지의 방법을 통해 수면의 단계를 분류하였다. 첫번째 연구에서 우리 는 연령에 따라서 그룹을 나누어 모델을 학습하는 것이 그렇지 않은 모델에 비해서 더 좋은 성능을 보이는 것을 입증했다. 또한 두번째 연구에서 우리는 시간에 대한 정보를 학습한 모델이 그렇지 않은 것에 비해 성능의 향상을 보이는 것을 확인했다. 이 연구를 통해 수면의 단계를 분류하는 학습에서 나이 및 시간에 대한 정보를 고려하는 것은 필요 함을 제시하였다. 하지만 여러 한계점들이 여전히 해결해야 할 과제로 남아 있고, 향후 연구에서는 이러한 한계를 해결하기 위한 추가 연구가 필요하다.MasterI. Introduction 1
1.1 Sleep Background 2
1.2 Related Work 4
1.3 Study Objective 5
II. Material and Methods 6
2.1 Dataset 6
2.2 Preprocessing 7
2.2.1 Power Spectral Density (PSD) 7
2.2.2 Hjorth parameter 8
2.2.3 Sample Entropy 9
2.2.4 Spectral Edge Frequency (SEF) 10
2.2.5 Evaluation method 10
III. Study 1: Age-specific classification 12
3.1 Introduction 12
3.1.1 EEG signal and aging 12
3.1.2 Related Work 13
3.2 Methods 14
3.2.1 Models for age-specific classification 14
3.3 Results 17
3.3.1 Model setting 18
3.3.2 Results of three methods 18
3.3.3 Results of age group 20
3.3.4 Performance compared by other researches 21
3.4 Conclusion 22
IV. Study 2: Time-series classification 25
4.1 Introduction 25
4.1.1 Sleep stage progression over time 25
4.1.2 Related Work 26
4.2 Methods 26
4.3 Results 27
4.3.1 Model setting 28
4.3.2 Results over time input values 29
4.3.3 Results subject-wise 30
4.3.4 Performance compared by other researches 32
4.4 Conclusion 34
IV. Conclusion 36
References 38
Abbreviations 45
Acknowledgements 46
Curriculum Vitae 4
NADH-dependent CO2 reductase on graphite for capacitive electrocatalytic interfacing mediated by solid-binding peptide
No full textNAD+/NADH-dependent CO2 reductase (CR) adapted from Candida methylica (E.C. 1.17.1.9) was introduced with a non-native graphite-specific peptide (Gr; IMVTESSDYSSY) as molecular binder to modify the native enzyme (CR-WT) with peptide insertion at N, C and NC terminus (CR-GrN, CR-GrC and CR-GrNC) to assess the influence of site-specific fusion on electrode binding. Graphite surface-binding activity relative to the electrode topography was evaluated for both native and synthetic CRs to establish the enzyme-electrode interfacing potentiality for efficient electron channelling. Impact of site-specific peptide fusion and amino-acids positioning was assessed for the active site binding availability and adsorption/desorption capability towards competent CO2-based redox catalysis. Solid-binding peptide and graphite surface interactive ability on direct electron transfer was studied with structural, enzymatic and electrochemical characterizations for efficient CO2 electrosynthesis. Overall, enzymatic CO2 reduction to formate based on interactive potentiality of enzyme-electrode complex with peptide modifications and graphite surface towards possibility of bioelectronics upscaling was depicted. © 2024 Elsevier LtdFALSEsciescopu
Alteration of prefrontal functional connectivity in preclinical Alzheimer's disease: an fNIRS study
No full textBackground: Early detection of Alzheimer's disease (AD) is vital for delaying its progression through timely intervention. The preclinical stage, the longest phase of AD, often goes undetected due to a lack of noticeable symptoms. Developing an accessible and quantitative screening method for AD is essential for enabling appropriate interventions during this stage. Methods: Functional near-infrared spectroscopy was used to investigate prefrontal functional connectivity in preclinical AD subjects. A total of 99 participants, including healthy controls and preclinical subjects who were amyloid beta (Aβ) positive (n = 45), were recruited. We designed a mixed phonemic and semantic verbal fluency task for the experimental protocol. Functional connectivity was then analyzed as z-values in the left, right, and interhemispheric prefrontal regions during a verbal fluency task. Finally, we assessed the correlation between the participants' z-values and clinical indices. Results: The preclinical AD group exhibited increased interhemispheric functional connectivity derived from oxygenated and deoxygenated hemoglobin during verbal tasks involving the first phonemic letter. Additionally, significant right and left functional connectivity differences were observed in the healthy control group during verbal tasks with the letter and categories, but not in the preclinical AD group. Lastly, the difference in interhemispheric functional connectivity of oxygenated hemoglobin between the first and second verbal trials was significantly greater in the preclinical AD group. These interhemispheric functional connectivity values were significantly correlated with Aβ results from positron emission tomography. Conclusion: The initial increase and subsequent reduction of interhemispheric functional connectivity in the preclinical AD group across task repetitions suggests that task-related prefrontal network alterations may occur during the preclinical phase of AD and shows its potential as a biomarker for screening preclinical AD. Copyright © 2025 Kim, Lee, Choi, Kim, Gwak, Lee and Kim.TRUEsciescopu
Rapid Equipment-Free Nucleic Acid Extraction Using a Silica-Based Pipet Tip Column
No full textNucleic acid extraction from clinical specimens is essential for accurate molecular diagnostic assays. However, conventional extraction methods are often slow, equipment-dependent, and require trained personnel, limiting the point-of-care applicability. We introduce a novel silica-based pipet tip column that enables rapid nucleic acid extraction from clinical samples in less than 3 min. The pipet tip column has a large surface area for effective nucleic acid extraction using chaotropic salts. The integrated disposable 1 mL syringe eliminates the need for a pipet. Sample application is achieved by simply pushing and pulling the syringe, requiring no external power or specialized equipment. The pipet tip column performance was validated using standard influenza A and B, severe acute respiratory syndrome coronavirus-2, and Staphylococcus aureus samples, achieving high performance even at low concentrations (1 PFU/mL or 1 TCID50/mL). Our approach demonstrated a 90-110% nucleic acid recovery rate, comparable to that of traditional methods. Pipette tip-column nucleic acid extraction was successful for nasopharyngeal and saliva samples, including those in loop-mediated isothermal amplification assays. The pipet tip column provides a rapid, cost-effective, reliable, and portable solution for on-site molecular diagnostics. Additionally, nonexpert users can perform nucleic acid extraction without sample transportation or storage, reducing contamination risks and operational costs.TRUEsciescopu
Femtosecond laser direct writing of Fiber Bragg Grating with high-speed and high-resolution scanning technique
No full textWe employed two fabrication methods, a laser scanning system and a phase mask, to produce Fiber Bragg Gratings (FBGs). A micro-scanning adapter was used to enable high-speed and high-resolution laser focusing inside the optical fiber via a scanner and an objective lens. By continuously moving the fiber-fixed stage while adjusting the scanner repetition speed, micropatterns with various periods were generated. This approach allowed for the detection of FBG signals at multiple wavelengths. Laser direct writing, utilizing a high-speed and high-resolution laser scanning system, facilitated FBG production without the need to remove the fiber coating. This method provided a straightforward way to control the FBG wavelength, signal intensity, and bandwidth by adjusting the scanner and stage movement speeds. The use of femtosecond lasers for FBG fabrication offers the additional advantage of reduced material dependence, enabling FBG production in various optical fibers without requiring additional processing steps compared to conventional methods. © 2024 The AuthorsTRUEscopu
