Daegu Gyeongbuk Institute of Science and Technology
DGIST Library Institutional RepositoryNot a member yet
12664 research outputs found
Sort by
비강 외 후각수용체의 길항제 선별 및 그 기능 규명
No full textOdorant receptor, antagonists, screeningList of Contents
Abstract i
List of contents ii
Ⅰ. Introduction 1
ⅠI. MATERIALS AND METHOD 4
IIⅠ. RESULTS
3.1 Establishment of a Stable Cell Line Expressing OR5V1 9
3.2 Primary Screening for OR5V1 Antagonists 11
3.3 Secondary Screening for OR5V1 Antagonists 16
3.4 Antagonists Inhibit OR5V1 Function in Primary Cells 19
3.5 Effects of Antagonists on Different Types of Agonists in OR5V1. 22
3.6 Agonist Identification from Secondary screening 25
ⅠV. DISCUSSION 28
V REFERENCES 30MasterdCollectio
An algebraic C 2-equivariant Bézout theorem
Get PDFOne interpretation of Bézout’s theorem, nonequivariantly, is as a calculation of the Euler class of a sum of line bundles over complex projective space, expressing it in terms of the rank of the bundle and its degree. We generalize this calculation to the C2 –equivariant context, using the calculation of the cohomology of C2 –complex projective spaces from an earlier paper, which used ordinary C2 –cohomology with Burnside ring coefficients and an extended grading necessary to define the Euler class. We express the Euler class in terms of the equivariant rank of the bundle and the degrees of the bundle and its fixed subbundles. We do similar calculations using constant Z coefficients and Borel cohomology and compare the results. © 2024 MSP (Mathematical Sciences Publishers).TRUEsciescopu
Reducing carrier recombination loss by suppressing Sn loss and defect formation via Ag doping in Cu2ZnSn(S,Se)4 solar cells
No full textIn this study, we analyzed the effect of the position of Ag in the stacked precursor structure of CZTSSe solar cells. Five precursor structures were designed by adding a 5-nm-thick Ag layer to soda-lime glass (SLG)/Mo/Zn/Cu/Sn at various positions, and CZTSSe devices were fabricated through a sulfo-selenization process. The SLG/Mo/Ag/Zn/Cu/Sn precursor structure device (C2) showed the best efficiency. This improvement is attributed to Ag promoting grain growth by forming a Cu-Sn alloy at a low temperature and suppressing the formation of defects and defect clusters. Conversely, the SLG/Mo/Zn/Ag/Cu/Sn precursor structure device (C3) hindered Cu-Zn interdiffusion, degrading the performance. C2 exhibited a small difference between the bandgap energy (Eg) and the photoluminescence, a high activation energy (EA)/Eg, and a long carrier lifetime, indicating reduced defect and carrier recombination loss. This study suggests that the location of Ag plays an important role in optimizing the CZTSSe efficiency. Additionally, a precursor containing Ag has been shown to suppress Sn loss during the sulfo-selenization process and improve device performance through liquid-assisted grain growth. This study shows that the location of Ag plays an important role in suppressing the carrier recombination loss of CZTSSe devices. © 2024 The Royal Society of Chemistry.FALSEsciescopu
Effects of fatty acid esters on mechanical, thermal, microbial, and moisture barrier properties of carboxymethyl cellulose-based edible films
Get PDFFatty acid esters being biodegradable and environment friendly has been a sought-after class of molecule for various food grade applications. This work involves the incorporation of fatty acid esters namely cetyl-caprylate and cetyl-caprate in edible Carboxymethyl cellulose -based films. The esters were enzymatically synthesized by esterification of caprylic acid and capric acid respectively with cetyl alcohol at a molar ratio of 1:1, using Candida antarctica lipase B which was immobilized (10 % w/w) at 65 °C. Carboxymethyl cellulose films were prepared. To it, glycerol and by emulsification, cetyl-caprylate or cetyl-caprate esters were amalgamated. Film characterizations involved analysis of surface morphology, mechanical properties, and thermal properties. It was further characterized by X-Ray diffraction analysis, water vapor permeability, and moisture uptake. Barrier property carboxymethyl cellulose films showed significant improvement due to the incorporation of cetyl-caprylate or cetyl-caprate esters. However, when the film's melting point was measured, it was seen that glycerol influenced the thermal properties more prominently than cetyl-caprylate and cetyl-caprate esters. Thus, the addition of an optimized amount of glycerol and cetyl-caprylate or cetyl-caprate esters to the carboxymethyl cellulose films is required for improved mechanical strength and better thermal properties. Further, an antimicrobial well diffusion assay of both the esters established the antimicrobial property of the same, which thereby recommends the addition of the wax esters even more. © 2024 The Author(s)TRUEscopu
A FMRFamide-like neuropeptide FLP-12 signaling regulates head locomotive behaviors in Caenorhabditis elegans
Get PDFNeuropeptides play a critical role in regulating behaviors across organisms, but the precise mechanisms by which neuropeptides orchestrate complex behavioral programs are not fully understood. Here, we show that the FMRFamide-like neuropeptide FLP-12 signaling from the SMB head motor neurons modulates head locomotive behaviors, including stomatal oscillation in Caenorhabditis elegans. lim-4 mutants, in which the SMB neurons are not properly specified, exhibited various head and body locomotive defects, including stomatal oscillation. Chronic activation or inhibition of neuropeptidergic signaling in the SMB motor neurons resulted in a decrease or increase in stomatal oscillation, respectively. The flp-12 neuropeptide gene is expressed and acts in the SMB neurons to regulate head and body locomotion, including stomatal oscillation. Moreover, the frpr-8 G protein-couple receptor (GPCR) and gpa-7 Gα genes are expressed in the AVD command interneurons to relay the FLP-12 signal to mediate stomatal oscillation. Finally, heterologous expression of FRPR-8 either Xenopus oocytes or HEK293T cells conferred FLP-12 induced responses. Taken together, these results indicate that the C. elegans FMRFamide neuropeptide FLP-12 acts as a modulator of stomatal oscillation via the FRPR-8 GPCR and the GPA-7 G-protein. © 2024 The AuthorsTRUEsciescopuskc
저주파 기록으로부터 고주파 신경 스파이크 재구성 기계 학습 알고리즘에서의 노이즈 제거 성능 분석 연구
No full textBMI, reconstruction models, denoising, data complexityWith the increasing advancements of machine learning in biomedical applications, data complexity, and noise distortions become necessary subsidizations to consider. A reconstruction-based algorithm can reconstruct a high-frequency neuronal signal from its low-frequency component, which can be subsampled during transmission to reduce data complexity. The model, due to its use in in-vitro and in-vivo data, has an elevated chance of distortions due to the introduction of noise. This model, when exploited with increased noise, showcased an unpredicted ability to reduce the noise band of the expected signal.
Here, we will evaluate the performance and information retainability of this algorithm with respect to conventional denoising algorithms to explore this additional ability. The evaluation will compare the variations in the performance metrics related to spike information retention of the output high-frequency neuronal data with elevated noise levels.
Keywords: BMI, reconstruction models, denoising, data complexity|뇌-기계 인터페이스의 (Brain Machine Interface, BMI) 데이터 rehabilitation과 분석을 위해서 신뢰성 있고 왜곡이 적으며 데이터 복잡도가 낮은 데이터 처리 방법이 필요합니다. 이는 데이터 처리, 해석 또는 분석에 대한 기계 학습 인터페이스를 활용함으로써 가능합니다. 저주파 수신 신호의 고주파 신경 스파이크 신호를 예측할 수 있는 변환 기반의‘Spk-Recon’이라는 독특한 알고리즘이 개발되었으며, 이는 저장 데이터 용량을 줄이는 목적으로 작동 할 수 있는 능력을 갖추고 있어 보편화된 LFP 신호와 함께 사용될 수 있으며, BMI 기술에 대한 새로운 신호 처리 방법이 될 수 있습니다. 본 논문에서 실제적데이터 기록에 적용하는 이 알고리즘의 견고성을 확인하기 위해 높은 백색 소음의 추가에 의한 이 알고리즘의 노이즈 제거 성능을 평가하였습니다. 이 알고리즘은 낮은 노이즈 밴드에서 고주파 신호를 예측하는 개념으로 설계되어 있어, 주파수 대역폭이 좁기 때문에, 근본적인 노이즈 제거 특성을 갖추고 있습니다. 이러한 개념에 기반하여 Spk-Recon의 다양한 백색 노이즈 수준에 따른 노이즈 제거 성능을 다른 일반적으로 사용되는 노이즈 제거 방법과 비교하였습니다.
우리는 Spk-Recon 및 일반적으로 사용되는 wavelet denoising 방법, discrete wavelet transform 및 stationary wavelet transform 방법들을 이용하여 in vitro 및 in vivo 데이터의 노이즈 평가를 수행하였습니다. 알고리즘의 성능은 노이즈 수준의 상승에 따른 스파이크 정보의 보존에 대해 비교하였습니다. Spk-Recon은 Jaccard 지수에 따른 일관된 고도로 유사한 스파이크 타임스탬프의 재구성을 갖추었습니다. Spk-Recon에 의해 보존된 스파이크 모양 정보는 wavelet 노이즈 제거 결과보다 크게 오류가 적었습니다. 스파이크 분류의 성능 측면에서, Spk-Recon은 일관되게 높은 스파이크 클러스터링 정확도를 보였습니다. 동시에 Spk-Recon 알고리즘은 데이터 압축이 가능하여, 저장 데이터 용량 감소의 장점이 있습니다. Wavelet denoised 신호와의 비교를 통해 Spk-Recon의 결과는 그 신뢰성을 입증하고 재활 등의 BMI 시스템에 충분히 활용될 가능성을 보입니다.
핵심어: 뇌-기계 인터페이스, 노이즈, 낮은 데이터 처리, 기계 학습Ⅰ. Introduction 1
1.1 Background 1
1.2 Motivation 4
1.3Denoising 5
II. Methodology 7
2.1 Process flow 7
2.3 Evaluation parameters 13
III. Result and Discussion 18
3.1 Comparison of the resultant signal data 18
3.2 Effect of denoising on spike detection performance 20
3.2.1 Recall (hit rate) 20
3.2.2 Precision 21
3.2.3 Jaccard index 22
3.3 Effect of denoising on spike shape retention and sorting performance 23
3.3.1 NRMSE of average waveform 23
3.3.2 Silhouette score 26
3.3.3 Percentage of negative Silhouette score 27
3.3.4 Clustering accuracy 28
3.4 Effect of denoising on Spike Detection for in vivo data 29
IV. Conclusion 32
4.1 Summary 32
V. Appendix 34
5.1 Python script for training Spk-Recon 34
5.2 Python script to validate Spk-Recon 38
5.3 Python function to detect spikes 40
5.4 Python function to detect spikes and get the timestamps 40
5.5 Python function to calculate Hit Rate 41
5.6 Python function to calculate Precision 42
5.7 Python function to calculate Jaccard Index 42
5.8 Python function to calculate NRMSE 43
5.9 Python function to calculate Silhouette score, error percentage and clustering accuracy 44
References 47
요 약 문 51MasterdCollectio
A Loop-Break Decision Feedback Equalizer for DAC/ADC-DSP-Based Wireline Transceivers
No full textThis paper presents a novel digital decision feedback equalizer (DFE) design that can relax the feedback timing constraints for analog-to-digital converter (ADC)-based high-speed wireline receivers. The proposed technique breaks the loop-unrolled DFE (LU-DFE) chain by computing multiple LU-DFE chains in parallel with all possible seed symbols, and selecting the appropriate output by the post-processing selection logic. The proposed loop-break DFE (LB-DFE) is functionally equivalent to the conventional DFE with any other implementation techniques such as LU-DFE, look-ahead DFE (LA-DFE), or direct DFE. With topographical synthesis in 28nm CMOS process, the proposed LB-DFE achieved up to 54% of DFE area saving as compared to LA-DFE with look-ahead factor (LF) of 16 for 112Gb/s PAM-4 with 875MHz DSP clock speed. The implementation feasibility and functionality are verified using ZCU111 RFSoC platform at 6Gb/s (3GS/s ADC conversion rate) with a channel exhibiting 25dB loss at 1.5GHz, demonstrating the same bit error rate (BER) performance between the LB-DFE and the LA-DFE. Equipment-based measurements using arbitrary waveform generator (AWG) and real-time oscilloscope transmitting/receiving 40GBaud PAM-4 (80Gb/s) to/from the differential cables with software 21-tap feed-forward equalizer (FFE) and LB-DFE on PC was also conducted. © 2024 IEEE.FALSEsciescopu
Control of optical imaging depth using ultrasound-induced microbubbles for deep optical microscopy
No full textControl of the ultrasound-induced gas bubble for deep optical microscopy can enable selective deep optical imaging. Changing the ultrasound operating frequency may be a solution for controlling the thickness of the bubble cloud. © 2024 The Author(s
Unraveling Polymorphic Crystal Structures of Li4SiS4 for All-Solid-State Batteries: Enhanced Ionic Conductivity via Aliovalent Sb Substitution
No full textSafety concerns regarding organic-based liquid electrolytes in Li-ion batteries have led to extensive research on lithium-ion conductors. Despite cost-effectiveness, thio-silicate Li4SiS4 has been overlooked owing to unclear crystallographic information. This study clarifies the crystal structures and electrochemical properties of two Li4SiS4 polymorphs and their aliovalent substitution series, i.e., Li4-xSi1-xSbxS4. Our findings indicate that the polymorphs differ primarily in their SiS4 tetrahedra stacking configurations, with the high-temperature phase being more orderly than the low-temperature phase. However, they exhibit similar ionic-transport properties, indicating that the tetrahedra stacking minimally affects Li-ion mobility. We found that the dense packing of Li in these structures restricts ion movement, necessitating the creation of Li vacancies through the aliovalent substitution of Sb5+ for Si4+ to enhance Li mobility. The substitution series Li4-xSi1-xSbxS4 with x = 0.15 exhibited a 10-fold conductivity increase, signifying the influence of Li vacancies on ionic transport. Cyclic voltammetry confirmed the suitability of Li3.85Si0.85Sb0.15S4 as a solid electrolyte for all-solid-state batteries. This study suggests that the ionic conductivity in Li4SiS4 depends more on Li-ion concentration than on SiS4 tetrahedra stacking, providing strategic insights for developing more efficient solid-state battery materials. © 2024 American Chemical SocietyFALSEsciescopu
Therapeutic targeting of differentiation-state dependent metabolic vulnerabilities in diffuse midline glioma
Get PDFH3K27M diffuse midline gliomas (DMG), including diffuse intrinsic pontine gliomas (DIPG), exhibit cellular heterogeneity comprising less-differentiated oligodendrocyte precursors (OPC)-like stem cells and more differentiated astrocyte (AC)-like cells. Here, we establish in vitro models that recapitulate DMG-OPC-like and AC-like phenotypes and perform transcriptomics, metabolomics, and bioenergetic profiling to identify metabolic programs in the different cellular states. We then define strategies to target metabolic vulnerabilities within specific tumor populations. We show that AC-like cells exhibit a mesenchymal phenotype and are sensitized to ferroptotic cell death. In contrast, OPC-like cells upregulate cholesterol biosynthesis, have diminished mitochondrial oxidative phosphorylation (OXPHOS), and are accordingly more sensitive to statins and OXPHOS inhibitors. Additionally, statins and OXPHOS inhibitors show efficacy and extend survival in preclinical orthotopic models established with stem-like H3K27M DMG cells. Together, this study demonstrates that cellular subtypes within DMGs harbor distinct metabolic vulnerabilities that can be uniquely and selectively targeted for therapeutic gain. © The Author(s) 2024.TRUEsciescopu