• Journal of Environmental Science International
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• v.33 no.3
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• pp.205-215
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• 2024

Antibiotics are substances produced by microorganisms that kill or inhibit and are essential for infectious diseases management. This study aimed to provide basic data for overcoming antibiotic resistance in the marine bacterium LJ-18. The API 20NE and API 50CH kits were used to identify this microorganism. Morphological, physiological, and biochemical properties were investigated using MacFaddin's manuals. Subsequently, isolated LJ-18 was found to belong to a genus of Streptomyces that forms mycelia. LJ-18 also grew well at 28-32℃ on modified Bennett's agar. To isolate and purify the antibacterial compound, LJ-18 culture was divided into ethyl acetate and distilled water fractions. Considerable antimicrobial activity against various pathogenic microorganisms, including methicillin-resistant Staphylococcus aureus (MRSA), was confirmed in the C₁₈ ODS open column fractions. Peak 2 compound was obtained using reversed-phase HPLC. As a result, this compound had a significant antimicrobial activity against various pathogenic microorganisms. In particular, it showed strong activity against MRSA, Mycobacterium smegmatis, Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus.

• Proceedings of the Korea Information Processing Society Conference
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• 2024.05a
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• pp.450-452
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• 2024

본 논문에서는 다양한 합병증의 원인인 형태 이상 적혈구로 인한 질환 진단의 정확도 및 오진율 감소를 위해 말초 혈액 도말 검사를 통한 혈액의 병리학적 이미지를 토대로 형태 이상 적혈구를 검출 및 계수하는 시스템을 구현하였다. 본 시스템은 혈액 분석 검사에 주로 사용되는 자동 혈구 분석기의 비용 및 인력, 시간의 부담을 줄이고, 수기법의 검출 소요시간 및 검사자의 주관적 진단 등 문제점을 개선시켜 단시간 내에 대량 분석을 할 수 있는 객관적인 진단 기구로 활용되어 정밀 의료 분야에 큰 기여를 할 수 있을 것으로 기대한다.

• Membrane Journal
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• v.31 no.4
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• pp.241-252
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• 2021

Rapid industrialization with growing population leads to environmental water pollution. Demand in generation of clean water from waste water is ever increasing by scarcity of rain water due to change in weather pattern. Colorimetric detection of heavy metal present in clean water is very simple and effective technique. In this review membrane based colorimetric detection of mercury (II) ions are discussed in details. Membrane such as cellulose, polycaprolactone, chitosan, polysulfone etc., are used as support for metal ion detection. Nanofiber based materials have wide range of applications in energy, environment and biomedical research. Membranes made up of nanofiber consist up plenty of functional groups available in the polymer along with large surface area and high porosity. As a result, it is easy for surface modification and grafting of ligand on the fiber surface enhanced nanoparticles attachment.

• Membrane Journal
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• v.31 no.2
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• pp.153-159
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• 2021

In recent years, polymer membranes, which are actively used in various industrial fields, have the advantage of being able to impart unique properties through the control of chemical structures and physical properties in the film-fabrication process, as well as through fabricating blend membranes mixed with various materials. In this study, the solubility parameter, which can be used as an index of miscibility with other materials, was calculated using molecular dynamics using a silkworm (Bombyx mori) silk polymer which has a wide potential to be used as an eco-friendly natural material. When the solubility parameter of polyvinylalcohol (PVA), which is also environmentally friendly and biocompatible, was calculated by molecular dynamics and compared with each other, it was confirmed that the two polymer materials had similar solubility parameter values. In conclusion, it was theoretically proved that the two polymers could blend well with each other, which was confirmed through experiments.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.52-60
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• 2022

Purpose: For now, cognitive load is assessed based on survey-based methods, which can be difficult to track the amount of cognitive load in real-time. In this study, we investigated the difference in electrophysiological activation due to different levels of cognitive load not only at sensor-level but also at source-level using electroencephalogram that might be potentially used for quantitative cognitive load evaluation. Materials and Methods: In this study, ten healthy subjects (mean age 24.3 ± 2.1, three female) participated the experiment. All participants performed 4 sessions of n-back task in different difficulties: 0-, 1-, 2-, and 3-back during electroencephalogram recording. For sensor-level analysis, we calculated the event-related potential and event-related spectral perturbation while low resolution brain electromagnetic tomography (LORETA) to estimate the source activation. Each result was compared between different workload conditions using statistical analysis. Results: Statistical results revealed that the accuracy of the task performance was significantly different between different cognitive loads (p = 0.018). The post-hoc analysis confirmed that the accuracy of the 3-back task was significantly decreased compared to 1-back condition (p = 0.018), but not with 2-back condition (p = 0.180). ERP results showed that P300 target amplitude between 1-back and 3-back had a marginal difference in Cz (p = 0.059) and Pz(p = 0.093). A significant inhibition in Cz high-beta activation (p = 0.017) and decrease in source activation of right parahippocampal gyrus was found in 3-back condition compared to 1-back condition (p < 0.05). Conclusion: In this study, we compared the sensor- and source-level differences in electroencephalogram between different levels of cognitive load, that were found to be in line with the previous reports related to cognitive load evaluation. We expect that the outcome of the current study can be used as a feature to establish a quantitative cognitive load assessment system.

• Science of Emotion and Sensibility
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• v.26 no.3
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• pp.149-160
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• 2023

This study develops a time-varying system-based noncontact fabric sensor that can measure cerebral blood-flow signals to explore the possibility of brain blood-signal detection and emotional evaluation. The textile sensor was implemented as a coil-type sensor by combining 30 silver threads of 40 deniers and then embroidering it with the computer machine. For the cerebral blood-flow measurement experiment, subjects were asked to attach a coil-type sensor to the carotid artery area, wear an electrocardiogram (ECG) electrode and a respiration (RSP) measurement belt. In addition, Doppler ultrasonography was performed using an ultrasonic diagnostic device to measure the speed of blood flow. The subject was asked to wear Meta Quest 2, measure the blood-flow change signal when viewing the manipulated image visual stimulus, and fill out an emotional-evaluation questionnaire. The measurement results show that the textile-sensor-measured signal also changes with a change in the blood-flow rate signal measured using the Doppler ultrasonography. These findings verify that the cerebral blood-flow signal can be measured using a coil-type textile sensor. In addition, the HRV extracted from ECG and PLL signals (textile sensor signals) are calculated and compared for emotional evaluation. The comparison results show that for the change in the ratio because of the activation of the sympathetic and parasympathetic nervous systems due to visual stimulation, the values calculated using the textile sensor and ECG signals tend to be similar. In conclusion, a the proposed time-varying system-based coil-type textile sensor can be used to study changes in the cerebral blood flow and monitor emotions.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.4
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• pp.801-816
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• 2014

This paper is a theoretically grounded empirical study aimed at shedding light on the Triple Helix of University-Industry-Government (U-I-G) relations in biotechnology cluster of Singapore. It questions the issue about the gap between theoretical consideration of the Triple Helix of U-I-G relations and the actual reality in biotechnology cluster, and the experience of Singapore was investigated. In terms of evolutionary perspective, biotechnology cluster in Singapore has gone through ongoing processes from a certain stage to other, and within the processes the Triple Helix nexus has been found. Analysis of the empirical study reveals significant findings: first, the government policies play a critical role in the operation of U-I-G relations rather than universities; second, therefore, the binding force of U-I-G relationships is based on the government policies being comprehensive including researchers immigration, student scholarship for local students, and tax and non-tax incentives for firms, rather than focusing on a targeted policy; third, the role of government starts from an initial stage, and it's role is ongoing processes by supporting infrastructure, human sources and continuous nourishment enabling the triple helix of U-I-G relations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1236-1241
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• 2016

Cancer has been the most frequent in Korea, and pathogenesis and progression of cancer have been known to be occurred through various causes and stages. Recently, the research of chromosomal and genetic disorder and the research about prognostic factor to predict occurrence, recurrence and progress of chromosomal and genetic disorder have been performed actively. In this paper, we analyzed DNA methylation data downloaded from TCGA (The Cancer Genome Atlas), open database, to research bladder cancer which is the most frequent among urinary system cancers. Using three level of methylation data which had the most preprocessing, 59 candidate CpG island were extracted from 480,000 CpG island, and then we analyzed extracted CpG island applying data mining technique. As a result, cg12840719 CpG island were analyzed significant, and in Cox's regression we can find the CpG island with high relative risk in comparison with other CpG island. Shown in the result of classification analysis, the CpG island which have high correlation with bladder cancer are cg03146993, cg07323648, cg12840719, cg14676825 and classification accuracy is about 76%. Also we found out that positive predictive value, the probability which predicts cancer in case of cancer was 72.4%. Through the verification of candidate CpG island from the result, we can utilize this method for diagnosing and treating cancer.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.452-459
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• 2023

Acoustic tweezers represent an exceptionally versatile and adaptable collection of instruments that harness the intrinsic power of sound waves to manipulate a wide spectrum of bioparticles, ranging from minuscule extracellular vesicles at the nanoscale to more substantial multicellular organisms measuring in millimeters. This field of research has witnessed remarkable progress over the course of the past few decades, primarily in the domain of Single Beam Acoustic Tweezers (SBAT) which utilizes a single element transducer for its operation. Initially conceived as a method for particle trapping, SBAT has since evolved into an advanced platform capable of achieving precise translation of cells and organisms. Recent groundbreaking advancements have significantly enhanced the capabilities of SBAT, unlocking new functionalities such as particle/cell separation and controlled deformation of single cells. These advancements have propelled SBAT to the forefront of bioparticle/cell manipulation, gathering attention within the scientific community. This review explores the core principles of SBAT and how sound waves affect bioparticles/cells. We aim to build a strong conceptual foundation for understanding advancements in this field by detailing its principles and methodologies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.1-15
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• 2015

Tissue engineering is an emerging, innovative technology to improve or replace the biological functions of damaged tissues and organs. Scaffolds are important materials for tissue engineering as they support cell attachment, migration, and differentiation. Marine sponges naturally contain scaffolds formed by extracellular matrix proteins (collagen and sponging) and strengthened by a siliceous or calcium carbonate skeleton. Coral skeletons are also derived naturally formed by essential calcium carbonate in the form of aragonite, and are similar to human bone. In addition, collagen extracted from jellyfish is a biosafe alternative to bovine and porcine collagen and gained attention as a potential source for tissue engineering. Moreover, cuttlefish bone is an excellent calcium source and can be used to generate bio-synthetic calcium phosphate. It has become a natural candidate for biomimetic scaffolds. This review describes the use of natural products derived from marine invertebrates for applications in bone tissue engineering based on studies from 2008 to 2014.