• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.459-463
• /
• 1997

In this paper, we present the elimination of ECG artifact from the polysomnographic EEG and EOG. The idea of this method is that the ECG synchronized EEG segment is detected from ECG and regard samples of that segment a missing signal. After this, we used two interpolation methods to recover the missing segment. One is the Lagrange Polynomial Interpolation Method and the other is the Least Square Error AR Interpolation method. We tested those methods by applying to simulated signals. AR methods works well enough to reject the artifact about 10% of the main artifact level. We practically applied to real EEG and EOG signals. We also developed the algorithm to detect whether the artifact level is high or not. If the artifact level is high, then the interpolations are applied.

• Applied Biological Chemistry
• /
• v.32 no.1
• /
• pp.64-72
• /
• 1989

Near full length cDNA clones encoding the rice seed storage protein, prolamine, were isolated and divided into two homology classes based on cross-hybridization and DNA sequencing analysis. These cDNA clones contain a single open reading frame encoding a putative rice prolamine precursor(M.W.=17,200) possessing atypical 14 amino acid signal peptide. Clones of these two homology classes diverge mainly by insertions/deletions of short nucleotide stretches and point mutations. The deduced primary structures of both types of prolamine polypeptides are devoid of any major tandem repetitive sequences, a feature prevalent in other cereal prolamines. No significant homology teas detected between the rice prolamine and other cereal prolamines, indicating that the rice gene evolved from a different ancestor that gave rise to other cereal prolamine genes. Developing wheat and rice endosperms were examined using ultrathin sections prepared from tissues harvested at various days after flowering. By immunocytochemical localization techniques, wheat prolamines are localized within vesicles from Golgi apparatus and in homogeneous regions of protein bodies. The involvement of the goli apparatus in the packaging of wheat prolamines into protein bodies indicates a pathway which differs from the mode of other cereal prolamines and resembles the mechanism employed for the storage of rice glutelin and legume globulins.

• Biomolecules & Therapeutics
• /
• v.20 no.4
• /
• pp.399-405
• /
• 2012

Silver nanoparticles (AgNPs) are widely used nanoparticles and they are mainly used in antibacterial and personal care products. In this study, we evaluated the effect of AgNPs on cell death induction in the murine dendritic cell line DC2.4. DC2.4 cells exposed to AgNPs showed a marked decrease in cell viability and an induction of lactate dehydrogenase (LDH) leakage in a time- and dose-dependent manner. In addition, AgNPs promoted reactive oxygen species (ROS)-dependent apoptosis and AgNP-induced ROS triggered a decrease in mitochondrial membrane potential. The activation of the intracellular signal transduction pathway was also observed in cells cultured with AgNPs. Taken together, our data demonstrate that AgNPs are able to induce a cytotoxic effect in DCs through ROS generation. This study provides important information about the safety of AgNPs that may help in guiding the development of nanotechnology applications.

• Molecules and Cells
• /
• v.39 no.1
• /
• pp.6-19
• /
• 2016

Redox signalling comprises the biology of molecular signal transduction mediated by reactive oxygen (or nitrogen) species. By specific and reversible oxidation of redoxsensitive cysteines, many biological processes sense and respond to signals from the intracellular redox environment. Redox signals are therefore important regulators of cellular homeostasis. Recently, it has become apparent that the cellular redox state oscillates in vivo and in vitro, with a period of about one day (circadian). Circadian timekeeping allows cells and organisms to adapt their biology to resonate with the 24-hour cycle of day/night. The importance of this innate biological timekeeping is illustrated by the association of clock disruption with the early onset of several diseases (e.g. type II diabetes, stroke and several forms of cancer). Circadian regulation of cellular redox balance suggests potentially two distinct roles for redox signalling in relation to the cellular clock: one where it is regulated by the clock, and one where it regulates the clock. Here, we introduce the concepts of redox signalling and cellular timekeeping, and then critically appraise the evidence for the reciprocal regulation between cellular redox state and the circadian clock. We conclude there is a substantial body of evidence supporting circadian regulation of cellular redox state, but that it would be premature to conclude that the converse is also true. We therefore propose some approaches that might yield more insight into redox control of cellular timekeeping.

• Journal of Plant Biology
• /
• v.39 no.4
• /
• pp.295-300
• /
• 1996

The physiological effects of oligogalacturonic acid (OGA:D. P. 6-7), a product of acid hydrolysis of polygalacturonic acid (PGA), on ethylene biosynthesis in mung bean (Vigna radiata W.) hypocotyl segments was studied. Among PGA, OGA and monogalacturomic acid (MGA), only OGA stimulated ethylene production in mung bean hypocotyl segments, and the most effective concentraton of OGA was 50$\mu\textrm{g}$/mL. Time course data indicated that this stimulatiion effect of OGA appeared after 90 min incubation period and continued until 24 h. When indol-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) were treated with OGA to investigate the mechanism of OGA on ethylene production, they did not show synergistic effects on ethylene production. The stimulation of ethylene production by OGA was due to the increase of in vivo ACC synthase activity, but OGA treatment had no effect of in vivo ACC oxidase activity. The effect of aminoethoxy vinyl glycine (AVG) and Co2+, the inhibitor of ethylene synthesis, was siminished a little by the OGA, but the treatment of Ca2+, known to increase ACC, with OGA did not increase the ethylene production, this effect seems to be specific for Ca2+ because other divalent cation, Mg2+, did not show the inhibition of OGA-indyuced ethylene production. It is possible that the OGA adopts a different signal transduction pathway to the ethylene bioxynthesis.

• Microbiology and Biotechnology Letters
• /
• v.50 no.1
• /
• pp.1-14
• /
• 2022

Bacteria communicate with each other through an intricate communication mechanism known as quorum sensing (QS). QS regulates different behavioral aspects in bacteria, such as biofilm formation, sporulation, virulence gene expression, antibiotic production, and bioluminescence. Several different chemical signals and signal detection systems play vital roles in promoting highly efficient intra- and interspecies communication. Gram-negative bacteria coordinate gene regulation through the production of acyl homoserine lactones (AHLs). Gram-positive bacteria do not code for AHL production, while some gram-negative bacteria have an incomplete AHL-QS system. Despite this fact, these microbes can detect AHLs owing to the presence of LuxR solo receptors. Various studies have reported the role of AHLs in interspecies signaling. Moreover, as bacteria live in a polymicrobial community, the production of extracellular compounds to compete for resources is imperative. Thus, AHL-mediated signaling and inhibition are considered to affect virulence in bacteria. In the current review, we focus on the synthesis and regulation mechanisms of AHLs and highlight their role in interspecies bacterial signaling. Exploring interspecies bacterial signaling will further help us understand host-pathogen interactions, thereby contributing to the development of therapeutic strategies intended to target chronic polymicrobial infections.

• Korean Journal of Biological Psychiatry
• /
• v.30 no.1
• /
• pp.1-6
• /
• 2023

Many psychiatric disorders are associated with brain functional dysfunctions and neuronal degeneration. According to the research so far, enhanced brain plasticity reduces neurodegeneration and recovers neuronal damage. Brain-derived neurotrophic factor (BDNF) is one of the most extensively studied neurotrophins in the mammalian brain that plays major roles in neuronal survival, development, growth, and maintenance of neurons in brain circuits related to emotion and cognitive function. Also, BDNF plays an important role in brain plasticity, influencing dendritic spines in the hippocampus neurogenesis. Changes in neurogenesis and dendritic density can improve psychiatric symptoms and cognitive functions. BDNF has potent effects on brain plasticity through biochemical mechanisms, cellular signal pathways, and epigenetic changes. There are pharmacological and non-pharmacological interventions to increase the expression of BDNF and enhance brain plasticity. Non-pharmacological interventions such as physical exercise, nutritional change, environmental enrichment, and neuromodulation have biological mechanisms that increase the expression of BDNF and brain plasticity. Non-pharmacological interventions are cost-effective and safe ways to improve psychiatric symptoms.

• Journal of Biomedical Engineering Research
• /
• v.28 no.6
• /
• pp.768-776
• /
• 2007

A new type of the fluid circulation blood pressure simulator was proposed to enhance the blood pressure simulator used for the development and evaluation of automatic sphygmomanometers. Various pressure waveform of fluid flowing in the pipe was reproduced by operating the proportional control valve after applying a pressure on the fluid in pressurized oil tank. After that, appropriate fluid was supplied by operating the proportional control valve, which enabled to reproduce various pressure wave of the fluid flowing in the tube. To accomplish this work, the mathematical model was carefully reviewed in cooperating with the proposed simulator. After modeling the driving signal as input signal and the pressure in internal tube as output signal, the simulation on system parameters such as internal volume, cross-section of orifice and supply pressure, which are sensitive to dynamic characteristic of system, was accomplished. System parameters affecting the dynamic characteristic were analyzed in the frequency bandwidth and also reflected to the design of the plant. The performance evaluator of fluid dynamic characteristic using proportional control signal was fabricated on the basis of obtained simulation result. An experimental apparatus was set-up and measurements on the dynamic characteristic, nonlinearity, and rising and falling response was carried out to verify the characteristic of the fluid dynamic model. Controller was designed and thereafter, simulation was performed to control the output signal with respect to the reference input in the fluid dynamic model using the proposed proportional control valve. Hybrid controller combined with an proportional controller and feed-forward controller was fabricated after applying a disturbance observer to the control plant. Comparison of the simulations between the conventional proportional controller and the proposed hybrid simulator indicated that even though the former showed good control performance.

• Journal of Biomedical Engineering Research
• /
• v.34 no.3
• /
• pp.105-110
• /
• 2013

Respiratory signal is one of the important physiological information indicating the status and function of the body. Recent studies have provided the possibility of being able to estimate the respiratory signal by using a change of PWV(pulse width variability), PRV(pulse rate variability) and PAV(pulse amplitude variability) in the PPG (photoplethysmography) signal during daily life. But, it is not clear whether the respiratory monitoring is possible even during sleep. Therefore, in this paper, we estimated the respiration from PWV, PRV and PAV of PPG signals during sleep. In addition, respiration rates of the estimated respiration signal were calculated through a time-frequency analysis, and errors between respiration rates calculated from each parameter and from reference signal were evaluated in terms of 1 sec, 10 sec and 1 min. As a result, it showed the errors in PWV(1s: $36.38{\pm}37.69$ mHz, 10s: $36.53{\pm}38.16$ mHz, 60s: $30.35{\pm}38.72$ mHz), in PRV(1s: $1.45{\pm}1.38$ mHz, 10s: $1.44{\pm}1.37$ mHz, 60s: $0.45{\pm}0.56$ mHz), and in PAV(1s: $1.05{\pm}0.81$ mHz, 10s: $1.05{\pm}0.79$ mHz, 60s: $0.56{\pm}0.93$ mHz). The errors in PRV and PAV are lower than that of PWV. Finally, we concluded that PRV and PAV are more effective than PWV in monitoring the respiration in daily life as well as during sleep.

• Journal of Biomedical Engineering Research
• /
• v.26 no.6
• /
• pp.399-406
• /
• 2005

In these days, HIS(Hospital Information System) raise the quality of medical services by effective management of medical records. As computing environment was developed, it is possible to search information quickly. But, standard medical data exchange is not completed between medical clinic and another organ so far. In case of patient transfer, past medical record was not efficiently transmitted. It be feasible treatment delay or medical accident. It is trouble that medical records is transferred by a person and communicate with each other. Extensible Markup Language (XML) is a simple, very flexible text format derived from SGML. Originally designed to meet the challenges of large-scale electronic publishing, XML is also playing an increasingly important role in the exchange of a wide variety of data on the Web and elsewhere. Form in system of company product, relative organs that handle bio-signal data is each other dissimilar and integration and to transmit to supplement bottleneck this research uses XML. In this study, it is discussed about sharing of medical data using XML web technology to standard medical record between hospital and relative organization The data structure model was designed to manage bio-signal data and patient record. We experimented about data transmission and all-in-one between different systems (one make use of MS-SQL database system and the other manage existent bio-signal data in itself form in file in this research). In order to search and refer medical record, the web-based system was implemented. The system that can be shared medical data was tested to estimate the merits of XML. Implemented XML schema confirms data transmission between different data system and integration result.