• Title/Summary/Keyword: Biological signal

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Recent Advances in Nuclear Medicine Imaging Instrumentation (핵의학 영상기기의 최근 진보)

  • Jung, Jin-Ho;Choi, Yong;Hong, Key-Jo;Min, Byung-Jun;Hu, Wei;Kang, Ji-Hoon
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.2
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    • pp.98-111
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    • 2008
  • This review introduces advances in clinical and pre-clinical single photon emission computed tomography (SPECT) and positron emission tomography (PET) providing noninvasive functional images of biological processes. Development of new collimation techniques such as multi-pinhole and slit-slat collimators permits the improvement of system spatial resolution and sensitivity of SPECT. Application specific SPECT systems using smaller and compact solid-state detector have been customized for myocardial perfusion imaging with higher performance. Combined SPECT/CT providing improved diagnostic and functional capabilities has been introduced. Advances in PET and CT instrumentation have been incorporated in the PET/CT design that provide the metabolic information from PET superimposed on the anatomic information from CT. Improvements in the sensitivity of PET have achieved by the fully 3D acquisition with no septa and the extension of axial field-of-view. With the development of faster scintillation crystals and electronics, time-of-flight (TOF) PET is now commercially available allowing the increase in the signal-to-noise ratio by incorporation of TOF information into the PET reconstruction process. Hybrid PET/SPECT/CT systems has become commercially available for molecular imaging in small animal models. The pre-clinical systems have improved spatial resolution using depth-of-interaction measurement and new collimators. The recent works on solid state detector and dual modality nuclear medicine instrumentations incorporating MRI and optical imagers will also be discussed.

Adipocyte-Related Genes and Transcription Factors were Affected by siRNA for Aromatase Gene during 3T3-L1 Differentiation (지방세포 분화중인 3T3-L1 세포에서 아로마테이즈 siRNA 처리에 의한 지방관련 유전자와 전사인자의 발현 조절)

  • Jeong, Dong-Kee
    • Journal of Life Science
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    • v.18 no.11
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    • pp.1600-1605
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    • 2008
  • This study was performed to verify the gene expression of 3T3-L1 using the siRNA of the aromatase gene, which is the estrogen synthesis enzymes. First of all three pairs of siRNA were designed from the CYP19A1 (aromatase) and analyzed the formation of fat cell mechanism by transferring gene to 3T3-L1 and differentiating it. As a result, the expression of leptin gene, which is the main gene causing the obesity, was controlled and the cause of the obesity is related with the insulin specifically. The overexpression of adiponectin and adipsin was observed. This result showed that the formation of the fat was controlled a little without any side effect by obstructing a specific material out of all the signal systems in the fat formation. This study will be an important clue to make it clear that the lack or overexpression of estrogen might be the cause of fat formation mechanism.

Cytogenetic Analysis of Reciprocal Hybrids Reveals a Robertsonian Translocation between Mud Loach ($Misgurnus$ $mizolepis$) and Cyprinid Loach ($M.$ $anguillicaudatus$) (미꾸라지($Misgurnus$ $mizolepis$)와 미꾸리($M.$ $anguillicaudatus$) 및 유도된 종간 잡종의 세포유전학적 연구)

  • Lee, Seung-Ki;Kim, Dong-Soo
    • Korean Journal of Ichthyology
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    • v.24 no.1
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    • pp.1-10
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    • 2012
  • Reciprocal hybrids between the mud loach ($Misgurnus$ $mizolepis$) and cyprinid loach ($M.$ $anguillicaudatus$) were produced by artificial fertilization. The chromosome number of mud loach was 2n=48, consisting of 12M+4SM+32A chromosomes. The cyprinid loach has 2n=50, consisting of 10M+4SM+36A chromosomes. The chromosome numbers of the diploid reciprocal hybrids were 2n=49, consisting of 11M+4SM+34A chromosomes. All the karyotypes documented in this study had the same arm number of 64. There was no evidence of chromosomal polymorphisms or sex-related heteromorphism. The cytogenetic traits of the hybrid genotypes were intermediate between those of the parent species. In all genotypes, the chromosomal NORs localized to the terminal short arms of the same metacentric chromosome pair. These results suggest that Robertsonian translocation occurred between metacentric chromosome 1 of mud loach and acrocentric chromosome of cyprinid loach.

Systems-level mechanisms of action of Panax ginseng: a network pharmacological approach

  • Park, Sa-Yoon;Park, Ji-Hun;Kim, Hyo-Su;Lee, Choong-Yeol;Lee, Hae-Jeung;Kang, Ki Sung;Kim, Chang-Eop
    • Journal of Ginseng Research
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    • v.42 no.1
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    • pp.98-106
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    • 2018
  • Panax ginseng has been used since ancient times based on the traditional Asian medicine theory and clinical experiences, and currently, is one of the most popular herbs in the world. To date, most of the studies concerning P. ginseng have focused on specific mechanisms of action of individual constituents. However, in spite of many studies on the molecular mechanisms of P. ginseng, it still remains unclear how multiple active ingredients of P. ginseng interact with multiple targets simultaneously, giving the multidimensional effects on various conditions and diseases. In order to decipher the systems-level mechanism of multiple ingredients of P. ginseng, a novel approach is needed beyond conventional reductive analysis. We aim to review the systems-level mechanism of P. ginseng by adopting novel analytical framework-network pharmacology. Here, we constructed a compound-target network of P. ginseng using experimentally validated and machine learning-based prediction results. The targets of the network were analyzed in terms of related biological process, pathways, and diseases. The majority of targets were found to be related with primary metabolic process, signal transduction, nitrogen compound metabolic process, blood circulation, immune system process, cell-cell signaling, biosynthetic process, and neurological system process. In pathway enrichment analysis of targets, mainly the terms related with neural activity showed significant enrichment and formed a cluster. Finally, relative degrees analysis for the target-disease association of P. ginseng revealed several categories of related diseases, including respiratory, psychiatric, and cardiovascular diseases.

Identification of Glycine max Genes Expressed in Response to Soybean mosaic virus Infection

  • Jeong, Rae-Dong;Lim, Won-Seok;Kwon, Sang-Wook;Kim, Kook-Hyung
    • The Plant Pathology Journal
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    • v.21 no.1
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    • pp.47-54
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    • 2005
  • Identification of host genes involved in disease progresses and/or defense responses is one of the most critical steps leading to the elucidation of disease resistance mechanisms in plants. Soybean mosaic virus (SMV) is one of the most prevalent pathogen of soybean (Glycine max). Although the soybeans are placed one of many important crops, relatively little is known about defense mechanism. In order to obtain host genes involved in SMV disease progress and host defense especially for virus resistance, two different cloning strategies (DD RT-PCR and Subtractive hybridization) were employed to identify pathogenesis- and defenserelated genes (PRs and DRs) from susceptible (Geumjeong 1) and resistant (Geumjeong 2) cultivars against SMV strain G7H. Using these approaches, we obtained 570 genes that expressed differentially during SMV infection processes. Based upon sequence analyses, differentially expressed host genes were classified into five groups, i.e. metabolism, genetic information processing, environmental information processing, cellular processes and unclassified group. A total of 11 differentially expressed genes including protein kinase, transcription factor, other potential signaling components and resistant-like gene involved in host defense response were selected to further characterize and determine expression profiles of each selected gene. Functional characterization of these genes will likely facilitate the elucidation of defense signal transduction and biological function in SMV-infected soybean plants.

A Double Helix DNA Structure Based on the Block Circulant Matrix (I) (블록순환 행렬에 의한 이중나선 DNA 구조 (I))

  • Lee, Sung-Kook;Park, Ju-Yong;Lee, Moon-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.3
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    • pp.203-211
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    • 2016
  • The genetic code is a key to bio-informatics and to a science of biological self-organizing on the whole. Modern science faces the necessity of understanding and systematically explaining mysterious features of ensembles of molecular structures of the genetic code. This paper is devoted to symmetrical analysis for genetic systems. Mathematical theories of noise-immunity coding and discrete signal processing are based on Jacket matrix methods of representation and analysis of information. Both of the RNA and Jacket Matrix property also have the Element(Block) - wise Inverse Matrices. These matrix methods, which are connected closely with relations of symmetry, are borrowed for a matrix analysis of ensembles of molecular elements of the genetic code. This method is presented for its simplicity and the clarity with which it decomposes a Jacket Matrix in terms of the genetic RNA Codon.

Antidepressant effect of water extract of Taraxacum platycarpum through BDNF, ERK and CREB pathway (BDNF, ERK 및 CREB 경로를 통한 포공영 추출물의 항우울 효과)

  • Gu, Pil Sung;Lee, Jihye;Choi, Yun Hee;Jung, Ji Wook
    • The Korea Journal of Herbology
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    • v.30 no.3
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    • pp.13-17
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    • 2015
  • Objectives : Taraxacum platycarpum H. Dahlstedt has been reported to have several biological properties such as skin hydration and antiinflammation. The purpose of this study was to examine the antidepressive effects of water extract of T. platycarpum (WTP) on an animal model of depression. Methods : In the present study, normal ICR mice (4 weeks) were used, and orally administered with WTP (25, 50 and 100 mg/kg). Depression-like behavior was monitored the forced swimming test (FST) and tail suspension test (TST) in mice. The locomotor activity was evaluated to eliminate the false-positive activity in the open field test (OFT). Fluoxetine, the selective serotonin reuptake inhibitor, as a positive control was intraperitoneally administered at a dose of 15 mg/kg at 30 min before starting the behavioral test. Moreover, we evaluated the effects of WTP on the expression of brain-derived neurotrophic factor (BDNF) and the extracellular signal-regulated kinase (ERK)/ cyclic AMP response-element binding protein (CREB) signaling pathway in the hippocampus using Western blot. Results : The administration of WTP (50 and 100 mg/kg) significantly (P < 0.05, respectively) reduced the immobility time during FST and TST without accompanying changes in locomotor activity by OFT. Furthermore, WTP at dose of 100 mg/kg increased the BDNF expression and the phosphorylation of ERK and CREB in the hippocampus region. Conclusions : These results suggest that WTP has a useful anti-depressant effect through the regulation of BDNF/ERK/CREB signaling pathway.

High-yield Production of Functional Human Lactoferrin in Transgenic Cell Cultures of Siberian Ginseng(Acanthopanax senticosus)

  • Jo, Seung-Hyun;Kwon, Suk-Yoon;Park, Doo-Sang;Yang, Kyoung-Sil;Kim, Jae-Whune;Lee, Ki-Teak;Kwak, Sang-Soo;Lee, Haeng-Soon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.5
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    • pp.442-448
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    • 2006
  • Human lactoferrin (hLf) is an iron-binding glycoprotein that has been considered to play many biological roles in the human, including the stimulation of the immune system, antimicrobial and anti-inflammatory effects, and regulation of iron absorption. We generated transgenic Siberian ginseng (Acanthopanax senticosus) cell cultures producing a functional hLf protein using the signal peptide sequence from the endoplasmic reticulum and driven by an oxidative stress-inducible SWPA2 promoter which is highly expressed in plant cell cultures. The production of hLf increased proportionally to cell growth and showed a maximal level (up to 3.6% of total soluble protein) at the stationary phase in suspension cultures. Full-length hLf protein was identified by immunoblot analysis in transgenic cell cultures of Siberian ginseng. Recombinant hLf (rhLf) was purified from suspension cells of Siberian ginseng by ammonium sulfate precipitation, cation-exchange and gel filtration chromatography. N-terminal sequences of rhLf were identical to native hLf (nhLf). The overall monosaccharide composition of rhLf showed the presence of plant specific xylose while sialic acid is absent. Antibacterial activity of purified rhLf was higher than that of nhLf. Taken together, we anticipate that medicinal Siberian ginseng cultured cells, as demonstrated by this study, will be a biotechnologically useful source for commercial production of functional hLf not requiring further purification.

Analysis of Biocompatible TiO2 Oxide Multilayer by the XPS Depth Profiling

  • Jang, Jae-Myung;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.156-156
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    • 2017
  • In this work, analysis of biocompatible TiO2 oxide multilayer by the XPS depth profiling was researched. the manufacture of the TiO2 barrier-type multilayer was accurately performed in a mixed electrolyte containing HAp, Pd, and Ag nanoparticles. The temperature of the solution was kept at approximatively $32^{\circ}C$ and was regularly rotated by a magnetic stirring rod in order to increase the ionic diffusion rate. The manufactured specimens were carefully analyzed by XPS depth profile to investigate the result of chemical bonding behaviors. From the analysis of chemical states of the TiO2 oxide multilayer using XPS, the peaks are showed with the typical signal of Ti oxide at 459.1 eV and 464.8 eV, due to Ti 2p(3/2) and Ti 2p(1/2), respectively. The Pd-3d peak was split into Pd-3d(5/2) and Pd-3d(3/2)peaks, and shows two bands at 334.7 and 339.9 eV for Pd-3d3 and Pd-3d5, respectively. Also, the peaks of Ag-3d have been investigated. The chemical states consisted of the O-1s, P-2p, and Ti-2p were identified in the forms of PO42- and PO43-. Based on the results of the chemical states, the chemical elements into the TiO2 oxide multilayer were also inferred to be penetrated from the electrolyte during anodic process.The structure characterization of the modified surface were performed by using FE-SEM, and from the result of biological evaluation in simulated body fluid(SBF), the biocompatibility of TiO2 oxide multilayer was effective for bioactive property.

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An Efficient Motion Estimation and Compensation Method for Ultrasound Synthetic Aperture Imaging (초음파 합성구경 영상을 위한 효율적인 움직임 추정 및 보상 기법)

  • 김강식;황재섭;정종섭;송태경
    • Journal of Biomedical Engineering Research
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    • v.23 no.2
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    • pp.87-99
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    • 2002
  • This paper describes a method for overcoming the motion artifacts inherent in synthetic aperture(SA) imaging. based on the investigation results as to the influence of a target motion on synthetic aperture techniques. This method uses a region-based motion compensation approach in which only the axial motion is estimated and compensated for a given region of interest(ROI) under the assumption that the whole ROI moves uniformly The estimated axial motion is calculated with a crosscorrelation(CC) method at the Point where the focused signal has the maximum energy within the ROI. We also presents a method for estimating the axial motion using the autocorrelation(AC) method that is widely used to estimate average Doppler frequency Both computer simulations and in vivo experiments show that the proposed methods can improve greatly the spatial resolution and SNR of ultrasound imaging by implementing the SA techniques for two-way dynamic focusing without motion artifacts. In addition the AC-barred motion compensation method provides almost the same results as the CC-based one, but with a dramatically reduced computational complexity.