• Title/Summary/Keyword: Biomedical technology

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Comparison Study on Low Energy Physics Model of GEANT4 (GEANT4 저 에너지 전자기 물리 모델에 대한 비교 연구)

  • Park, So-Hyun;Jung, Won-Gyun;Suh, Tae-Suk
    • Journal of Radiation Protection and Research
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    • v.35 no.3
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    • pp.124-134
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    • 2010
  • The Geant4 simulation toolkit provides improved or renewed physics model according to the version. The latest Geant4.9.3 which has been recoded by developers applies inserted Livermore data and renewed physics model to the low energy electromagnetic physics model. And also, Geant4.9.3 improved the physics factors by modified code. In this study, the stopping power and CSDA(Continuously Slowing Down Approximation) range data of electron or particles were acquired in various material and then, these data were compared with NIST(National Institute of Standards and Technology) data. Through comparison between data of Geant4 simulation and NIST, the improvement of physics model on low energy electromagnetic of Geant4.9.3 was evaluated by comparing the Geant4.9.2.

Distribution of Allergen Reactivity in Serum of Allergy Patients

  • Jung, An Na;Jun, Jin Hyun;Hur, Sung Ho;Seong, Hee Kyung
    • Biomedical Science Letters
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    • v.19 no.4
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    • pp.315-329
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    • 2013
  • This study was conducted to evaluate the distribution, frequency, sensitization rate, and types of specific allergen in allergic patients. We analyzed allergens of 12,882 allergic patient's serum referred for Medical Laboratory using MAST Allergy Screen Test (Inhalation/food panel) from April, 2010 to March, 2011. Allergen reactivity were not detected in 833/12,882 (6.5%) allergic patients and the other allergic patients had two or more types of allergens of food and inhalant, respectively. In the distribution of the allergen food 73.4% (9,450/12,882 patients) was much higher than the pollen 26.6% (3,432/12,882 patients). The sensitization rate to each allergen showed garlic 26.7%, egg white 21.5% of food allergens, mugwort 24.9%, ragweed short 19.6% of pollen allergens, Candida albicans 10.5%, Alternaria spp. 7.9% of fungus allergens, and showed high sensitized rate to Dermatophagoides farinae 90.2%, Dermatophagoides pteronyssinus 77.8%, house dust 57% of indoor allergens, respectively. The specific allergens of food allergen, fungus allergen, and indoor allergen were more frequent in young child than adult, but pollen allergens were frequent in adult than young child. In seasonal distribution, the food allergen were frequent in summer and autumn, the pollen allergen in autumn, fungus allergen in spring and in winter, and indoor allergen in autumn and in winter. In conclusion, the mite of Dermatophagoides farinae and Dermatophagoides pteronyssinus, and house dust showed the highest sensitization rate in specific allergen of allergic patients. The allergens showed difference feature according to the age, region, and types of allergen.

Analysis of Hyaluronic Acid Microneedle Characteristics as Its Shapes (히알루론산 마이크로니들 형태에 따른 특성 분석)

  • Ryu, Jong Hoon;Shin, Hyun Young;Lee, Jeong-Gun;Tae, Ki-Sik;Kim, Minseok S.
    • Journal of Biomedical Engineering Research
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    • v.39 no.1
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    • pp.30-35
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    • 2018
  • Conventional drug delivery methods mainly include subcutaneous injection and oral administration. Subcutaneous injection has the advantages of delivering the correct concentration, but it might cause pain and trauma to patients. Although oral administrations do not accompany pain as the subcutaneous injection, unexpected side effects may occur because they undergo digestion process and it is not easy for many drugs to be exposed to targeted sites with proper concentration. While dissolving microneedles have been extensively studied to overcome the limitations of conventional subcutaneous injection, the effects on microneedle shapes for drug release have not been fully explored. In this study, the characteristics of hyaluronic acid microneedles for cone and quadrangular pyramidal shapes were examined by the size, volume, contact surface area, skin permeability, and dissolution rate. As a result, the cone shapes of hyaluronic acid microneedles had high skin permeability, and the quadrangular pyramid of shapes hyaluronic acid microneedles showed a fast dissolution rate, given by the large contact area on the skin. Based on the results, we could confirm that the shape of a dissolving microneedles can affect skin permeability and the drug delivery rate.

Extraction Method of Significant Clinical Tests Based on Data Discretization and Rough Set Approximation Techniques: Application to Differential Diagnosis of Cholecystitis and Cholelithiasis Diseases (데이터 이산화와 러프 근사화 기술에 기반한 중요 임상검사항목의 추출방법: 담낭 및 담석증 질환의 감별진단에의 응용)

  • Son, Chang-Sik;Kim, Min-Soo;Seo, Suk-Tae;Cho, Yun-Kyeong;Kim, Yoon-Nyun
    • Journal of Biomedical Engineering Research
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    • v.32 no.2
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    • pp.134-143
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    • 2011
  • The selection of meaningful clinical tests and its reference values from a high-dimensional clinical data with imbalanced class distribution, one class is represented by a large number of examples while the other is represented by only a few, is an important issue for differential diagnosis between similar diseases, but difficult. For this purpose, this study introduces methods based on the concepts of both discernibility matrix and function in rough set theory (RST) with two discretization approaches, equal width and frequency discretization. Here these discretization approaches are used to define the reference values for clinical tests, and the discernibility matrix and function are used to extract a subset of significant clinical tests from the translated nominal attribute values. To show its applicability in the differential diagnosis problem, we have applied it to extract the significant clinical tests and its reference values between normal (N = 351) and abnormal group (N = 101) with either cholecystitis or cholelithiasis disease. In addition, we investigated not only the selected significant clinical tests and the variations of its reference values, but also the average predictive accuracies on four evaluation criteria, i.e., accuracy, sensitivity, specificity, and geometric mean, during l0-fold cross validation. From the experimental results, we confirmed that two discretization approaches based rough set approximation methods with relative frequency give better results than those with absolute frequency, in the evaluation criteria (i.e., average geometric mean). Thus it shows that the prediction model using relative frequency can be used effectively in classification and prediction problems of the clinical data with imbalanced class distribution.

Compare correlation differnces in blood in blood flow velocity parameters and blood flow velocity the radial artery and a piece of paper as a maker (요골동맥과 첨지를 이용하여 혈류속도 파라미터와 혈류속도 사이의 상관관계 비교)

  • Heo, Sun-Oh;Jeong, Jin-Hyeong;Lee, Sang-Sik
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.2
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    • pp.187-193
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    • 2015
  • In this study, regressive models were employed to predict the blood velocity by using independent variables which measured by 3 sensors, such as electrocardiogram (ECG), photo-plethysmogram (PPG), pulse diagnosis sensor, without ultrasound device at high cost. In experiment, the high predictable model was induced to estimate the blood velocity correctly by comparing correlation values and significance probabilities between independent variables and blood velocities. Results showed that the model induced by two or three independent variables had a higher predictability than those by a single independent variable.

Effect on Improvement of Muscle Strength Imbalance according to Load Deviation Pattern of Left and Right Arms in Upper Limbs (상지 좌우 운동부하 편차방식이 근력 불균형 개선에 미치는 영향)

  • Kang, Seung-Rok;Seo, Shin-Bae;Jeong, Gu-Young;Bae, Jong-Jin;Yu, Chang-Ho;Yu, Mi;Moon, Dong-An;Jeong, Jang-Sik;Kwon, Tae-Kyu
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.9
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    • pp.1026-1034
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    • 2012
  • The purpose of this study was to verify the validation of effect on improvement of muscle strength unbalance according to exercise load deviation during rowing exercise. We performed evaluation of muscular activity and joint torque before the test. We recruited twenty subjects who one side's muscle strength is bigger in more 20% than other side. Subjects divided two groups. One is dominant left side and the other was dominant right side. Subjects performed rowing exercise in electric load deviation rowing equipment (Robo.gym, Humonic Co., Ltd., Daegu, Korea). Exercise performed four sets a day including 25 times a set, and three days a week. Measurements consist of evaluation of muscular activity and joint torque. Exercise load deviation adapted that different value of muscle strength in both arms multiplied 1RM% and added 1RM 50%. The results in adapted load deviation showed that the differences of maximal peak torque in 22.75% were getting increase significantly during exercise in 5.72%. This interpreted that rowing exercise with loading deviation types could provide muscle strength and muscular endurance exercise in same time for balance. Our study found out that loading deviation could provide muscle strength and muscular endurance exercise for improving muscle unbalance.

Review : Effectiveness of transcranial direct current stimulation in rodent models of Alzheimer's disease (알츠하이머병 쥐 모델에서 경두개 직류 전기자극의 효용성 검토)

  • Kim, Ji-Eun;Park, Ye-Eun;Jeong, Jin-Hyoung;Lee, Sang-Sik
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.5
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    • pp.403-412
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    • 2021
  • Alzheimer's disease (AD) is the most common cause of dementia, showing progressive neurodegeneration. Although oral medications for symptomatic improvement still take a huge part of treatment, there are several limitations caused by pharmacology-based real world clinic. In this respect, non-pharmacologic treatment for AD is rising to prominence. Transcranial direct current stimulation (tDCS) is a one of the non-invasive neuromodulation technique, using low-voltage direct current. In terms of safety, tDCS already has been proven through numerous previous reports. This review focused on behavioral, neurophysiologic and histopathologic improvement by applying tDCS in AD rodent models, thereby suggesting reliable background evidence for human-based tDCS study.

OAS1 and OAS3 negatively regulate the expression of chemokines and interferon-responsive genes in human macrophages

  • Lee, Wook-Bin;Choi, Won Young;Lee, Dong-Hyun;Shim, Hyeran;KimHa, Jeongsil;Kim, Young-Joon
    • BMB Reports
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    • v.52 no.2
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    • pp.133-138
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    • 2019
  • Upon viral infection, the 2', 5'-oligoadenylate synthetase (OAS)-ribonuclease L (RNaseL) system works to cleave viral RNA, thereby blocking viral replication. However, it is unclear whether OAS proteins have a role in regulating gene expression. Here, we show that OAS1 and OAS3 act as negative regulators of the expression of chemokines and interferon-responsive genes in human macrophages. Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (Cas9) technology was used to engineer human myeloid cell lines in which the OAS1 or OAS3 gene was deleted. Neither OAS1 nor OAS3 was exclusively responsible for the degradation of rRNA in macrophages stimulated with poly(I:C), a synthetic surrogate for viral double-stranded (ds)RNA. An mRNA sequencing analysis revealed that genes related to type I interferon signaling and chemokine activity were increased in $OAS1^{-/-}$ and $OAS3^{-/-}$ macrophages treated with intracellular poly(I:C). Indeed, retinoic-acid-inducible gene (RIG)-I- and interferon-induced helicase C domain-containing protein (IFIH1 or MDA5)-mediated induction of chemokines and interferon-stimulated genes was regulated by OAS3, but Toll-like receptor 3 (TLR3)- and TLR4-mediated induction of those genes was modulated by OAS1 in macrophages. However, stimulation of these cells with type I interferons had no effect on OAS1- or OAS3-mediated chemokine secretion. These data suggest that OAS1 and OAS3 negatively regulate the expression of chemokines and interferon-responsive genes in human macrophages.

The Effects of Moral Sensitivity, Biomedical Ethics Awareness on Attitudes toward Withdrawal of Life-Sustaining Treatment of Nursing Students (간호대학생의 도덕적 민감성, 생명의료윤리의식이 연명치료중단에 대한 태도에 미치는 영향)

  • Jang, Young-Mi;Ahn, EunKyong
    • Journal of Industrial Convergence
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    • v.17 no.2
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    • pp.53-61
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    • 2019
  • This study was conducted to explore the effects of Moral Sensitivity(MS), Biomedical Ethics Awareness(BEA) on Attitudes toward Withdrawal of Life-Sustaining Treatment(AWLST) of nursing students. The data were collected from May 1, 2018 to May 20, 2018 for 302 nursing students. The collected data were analyzed using SPSS 22.0. The average degree of MS was 3.45, BEA was 3.69, and AWLST was 3.36. MS was positively correlated with BEA(r=.149, p=.010) and AWLST(r=.223, p<.001). BEA was negatively correlated with AWLST(r=-.129 p=.025). Models including MS(${\beta}=.2.47$, p<.001) and BEA(${\beta}=-.166$, p=.003) explained 7% of variance in the AWLST. It is necessary to provide education that consider the MS, BEA and AWLST level of nursing students to help them establish an acceptable view of AWLST.

NEUROD1 Intrinsically Initiates Differentiation of Induced Pluripotent Stem Cells into Neural Progenitor Cells

  • Choi, Won-Young;Hwang, Ji-Hyun;Cho, Ann-Na;Lee, Andrew J.;Jung, Inkyung;Cho, Seung-Woo;Kim, Lark Kyun;Kim, Young-Joon
    • Molecules and Cells
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    • v.43 no.12
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    • pp.1011-1022
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    • 2020
  • Cell type specification is a delicate biological event in which every step is under tight regulation. From a molecular point of view, cell fate commitment begins with chromatin alteration, which kickstarts lineage-determining factors to initiate a series of genes required for cell specification. Several important neuronal differentiation factors have been identified from ectopic over-expression studies. However, there is scarce information on which DNA regions are modified during induced pluripotent stem cell (iPSC) to neuronal progenitor cell (NPC) differentiation, the cis regulatory factors that attach to these accessible regions, or the genes that are initially expressed. In this study, we identified the DNA accessible regions of iPSCs and NPCs via the Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq). We identified which chromatin regions were modified after neuronal differentiation and found that the enhancer regions had more active histone modification changes than the promoters. Through motif enrichment analysis, we found that NEUROD1 controls iPSC differentiation to NPC by binding to the accessible regions of enhancers in cooperation with other factors such as the Hox proteins. Finally, by using Hi-C data, we categorized the genes that directly interacted with the enhancers under the control of NEUROD1 during iPSC to NPC differentiation.