• Title/Summary/Keyword: Biomedical Model

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Infection with Citrobacter rodentium in μMT Knockout Mice

  • Jo, Minjeong;Hwang, Soonjae;Rhee, Ki-Jong
    • Biomedical Science Letters
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    • v.24 no.1
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    • pp.1-8
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    • 2018
  • ${\mu}MT$ knockout mice are genetically deficient in the transmembrane domain of mu chain of the immunoglobulin M (IgM) heavy chain, resulting in the absence of mature B cells. ${\mu}MT$ knockout mice is an in vivo model system used to clarify the role of B cells in various diseases. Enteropathogenic Escherichia coli (EPEC) induces acute and chronic diarrheal disease, especially in children of developing countries. The formation of attaching and effacing (A/E) lesion is a prominent pathogenic factor in the intestinal epithelium of EPEC infection. The A/E lesion is modulated by genes located on the pathogenic island locus of enterocyte effacement (LEE) which encode a type III secretion system (T3SS) and A/E lesion-related effector proteins. Citrobacter rodentium is a murine pathogen utilized in studying the pathogenic mechanisms of EPEC in human infections. Citrobacter rodentium produce A/E lesion to attach to intestinal epithelium, thus providing a murine model pathogen to study EPEC. Several studies have investigated the pathogenesis of Citrobacter rodentium in the ${\mu}MT$ knockout mice. In this review, we introduce the ${\mu}MT$ murine model in the context of C. rodentium pathogenesis and describe in detail the role of B cells and antibodies in this disease.

Assesment of Heart Rate Variability by Integral Pulse Frequency Modulation Model (IPFM 모델의 해석을 통한 심박변이도 해석)

  • Park, Sang-Eun;Kim, Jeong-Hwan;Jeung, Gyeo-Wun;Kim, Kyeong-Seop
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.5
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    • pp.799-804
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    • 2015
  • This study aims at the new analysis of heart beat fluctuations by applying physiological Heart Rate Variability Model with representing the cardiac control system in sympathetic and parasympathetic-coupling oscillator constants, Cs and Cp. To find the effects of coupling constants on the beat-to-beat fluctuations, Integral Pulse Frequency Modulation (IPFM) model is adopted to generate the time series data of ECG R-peaks and represent them by poincaré scattergram plot in the time domain and HRV in the frequency domain, respectively. The actual poincaré plots and HRV spectrum are also analyzed by acquiring the experimental data from the subjects exposed to the emotional-stress invoking environment and the function of the coupling constants are verified in terms of antagonism in sympathetic and parasympathetic activity.

A Study on the Prediction of Drug Efficacy by Using Molecular Structure (분자구조 유사도를 활용한 약물 효능 예측 알고리즘 연구)

  • Jeong, Hwayoung;Song, Changhyeon;Cho, Hyeyoun;Key, Jaehong
    • Journal of Biomedical Engineering Research
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    • v.43 no.4
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    • pp.230-240
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    • 2022
  • Drug regeneration technology is an efficient strategy than the existing new drug development process, which requires large costs and time by using drugs that have already been proven safe. In this study, we recognize the importance of the new drug regeneration aspect of new drug development and research in predicting functional similarities through the basic molecular structure that forms drugs. We test four string-based algorithms by using SMILES data and searching for their similarities. And by using the ATC codes, pair them with functional similarities, which we compare and validate to select the optimal model. We confirmed that the higher the molecular structure similarity, the higher the ATC code matching rate. We suggest the possibility of additional potency of random drugs, which can be predicted through data that give information on drugs with high molecular similarities. This model has the advantage of being a great combination with additional data, so we look forward to using this model in future research.

A Physical Ear Model for Evaluating Hybrid-acoustic Sensor Characteristics of Fully Implantable Middle-ear Hearing Aid (완전 이식형 인공중이의 하이브리드 음향센서 특성 평가를 위한 귀 물리모델)

  • Shin, Dong Ho;Moon, Ha Jun;Kim, Myoung Nam;Cho, Jin-Ho
    • Journal of Korea Multimedia Society
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    • v.22 no.8
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    • pp.923-929
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    • 2019
  • In this paper, biomimetic based physical ear model proposed for measuring the characteristics of a hybrid-acoustic sensor for fully implantable middle-ear hearing aid. The proposed physical ear model consists of the external ear, middle-ear, and cochlea. The physical ear model was implemented based on the anatomical structure and CT images of the human ear. To confirm the characteristics of the ear model, the vibrational characteristics of the stapes was measured after applying sound pressure to the tympanic membrane. The measured results were compared with the vibrational characteristics of the human temporal bone specified by ASTM F2504-05. Through the comparison results, the feasibility of the proposed ear model was confirmed. Then, after attaching the hybrid-acoustic sensor to the ear model, the output characteristics of the ECM and acceleration sensor were measured according to the sound pressure. The measured results were compared with previous studies using human temporal bone, and the usefulness of the proposed physical ear model was verified through the analysis results.

Characterization of Thickness and Electrical Properties of Ni-Cr Thin Films via Terahertz Time-domain Spectroscopy

  • Sunghun Kim;Inhee Maeng;Hyeon Sang Bark;Jungsup Byun;Jae Hun, Na;Seho Kim;Myeong Suk Yim;Byung-Youl Cha;Youngbin Ji;Seung Jae Oh
    • Current Optics and Photonics
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    • v.7 no.5
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    • pp.569-573
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    • 2023
  • We utilized terahertz time-domain spectroscopy (THz-TDS) to measure the thickness and electrical properties of nickel-chromium (Ni-Cr) films. This technique not only aligns well with traditional methods, such as haze-meter and transmission-densitometer measurements, but it also reveals the electrical properties and thickness of films down to a few tens of nanometers. The complex conductivity of the Ni-Cr thin films was extracted using the Tinkham formula. The experimental values closely aligned with the Drude model, indicating the reliability of our Ni-Cr film's electrical and optical constants. The thickness of Ni-Cr was estimated using the complex conductivity. These findings emphasize the potential of THz-TDS in quality control of metallic nanofilms, pointing toward an efficient and nondestructive test (NDT) for such analyses.

A CoMFA Study of Quinazoline-based Anticancer Agents

  • Balupuri, Anand;Balasubramanian, Pavithra K.;Cho, Seung Joo
    • Journal of Integrative Natural Science
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    • v.8 no.3
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    • pp.214-220
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    • 2015
  • Cancer has emerged as one of the leading cause of deaths worldwide. A three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis was performed on a series of quinazoline-based anticancer agents. Purpose of the study is to understand the structural basis for their inhibitory activity. Comparative molecular field analysis (CoMFA) technique was employed to develop 3D-QSAR model. Ligand-based alignment scheme was used to generate a reliable CoMFA model. The model produced statistically significant results with a cross-validated correlation coefficient ($q^2$) of 0.589 and a non-cross-validated correlation coefficient ($r^2$) of 0.928. Model was further validated by bootstrapping and progressive scrambling analysis. This study could assist in the design of novel and more potent anticancer agents.

Partial Least Squares-discriminant Analysis for the Prediction of Hemodynamic Changes Using Near Infrared Spectroscopy

  • Seo, Youngwook;Lee, Seungduk;Koh, Dalkwon;Kim, Beop-Min
    • Journal of the Optical Society of Korea
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    • v.16 no.1
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    • pp.57-62
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    • 2012
  • Using continuous wave near-infrared spectroscopy, we measured time-resolved concentration changes of oxy-hemoglobin and deoxy-hemoglobin from the primary motor cortex following finger tapping tasks. These data were processed using partial least squares-discriminant analysis (PLS-DA) to develop a prediction model for a brain-computer interface. The tasks were composed of a series of finger tapping for 15 sec and relaxation for 45 sec. The location of the motor cortex was confirmed by the anti-phasic behavior of the oxy- and deoxy-hemoglobin changes. The results were compared with those obtained using the hidden Markov model (HMM) which has been known to produce the best prediction model. Our data imply that PLS-DA makes better judgments in determining the onset of the events than HMM.

Development of PC-Based Client/Server Puretone Audiometer supporting Multiple Subject Concurrently (다수 피검자를 동시 검사할 수 있는 PC 기반 클라이언트/서버 순음청력검사 시스템 개발)

  • Song, Bok-Deuk;Kang, Deok-Hun;Lee, Wan-Jik;Shin, Bum-Joo;Kim, Jin-Dong;Kong, Soo-Keun;Lee, Il-Woo;Jeon, Gye-Rok;Wang, Soo-Geun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.6
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    • pp.2225-2233
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    • 2010
  • Current puretone audiometer takes an operation model, so called face-to-face model, in which model an audiometrist assesses only one subject at a time. Such model results in high cost and long waiting time when there exist many patients. In order to solve such a disadvantage of face-to-face model, we have developed PC-based audiometer supporting client/server model, in which model one audiometrist is able to measure several subjects concurrently. This model has an architecture like that several PCs for subjects are connected to an audiometrist's PC through LAN and each assessment process of subjects are displayed onto audiometrist's monitor in real time. And if necessary, it makes possible for audometrist to adjust the assessment progress of particular subject like as a face to face model.

Biological Pathway Extension Using Microarray Gene Expression Data

  • Chung, Tae-Su;Kim, Ji-Hun;Kim, Kee-Won;Kim, Ju-Han
    • Genomics & Informatics
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    • v.6 no.4
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    • pp.202-209
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    • 2008
  • Biological pathways are known as collections of knowledge of certain biological processes. Although knowledge about a pathway is quite significant to further analysis, it covers only tiny portion of genes that exists. In this paper, we suggest a model to extend each individual pathway using a microarray expression data based on the known knowledge about the pathway. We take the Rosetta compendium dataset to extend pathways of Saccharomyces cerevisiae obtained from KEGG (Kyoto Encyclopedia of genes and genomes) database. Before applying our model, we verify the underlying assumption that microarray data reflect the interactive knowledge from pathway, and we evaluate our scoring system by introducing performance function. In the last step, we validate proposed candidates with the help of another type of biological information. We introduced a pathway extending model using its intrinsic structure and microarray expression data. The model provides the suitable candidate genes for each single biological pathway to extend it.

Survival Prediction of Rats with Hemorrhagic Shocks Using Support Vector Machine (지원벡터기계를 이용한 출혈을 일으킨 흰쥐에서의 생존 예측)

  • Jang, K.H.;Choi, J.L.;Yoo, T.K.;Kwon, M.K.;Kim, D.W.
    • Journal of Biomedical Engineering Research
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    • v.33 no.1
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    • pp.1-7
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    • 2012
  • Hemorrhagic shock is a common cause of death in emergency rooms. Early diagnosis of hemorrhagic shock makes it possible for physicians to treat patients successfully. Therefore, the purpose of this study was to select an optimal survival prediction model using physiological parameters for the two analyzed periods: two and five minutes before and after the bleeding end. We obtained heart rates, mean arterial pressures, respiration rates and temperatures from 45 rats. These physiological parameters were used for the training and testing data sets of survival prediction models using an artificial neural network (ANN) and support vector machine (SVM). We applied a 5-fold cross validation method to avoid over-fitting and to select the optimal survival prediction model. In conclusion, SVM model showed slightly better accuracy than ANN model for survival prediction during the entire analysis period.