• Investigative Magnetic Resonance Imaging
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• v.20 no.1
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• pp.36-43
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• 2016

Visualization of the tissue loss tangent property can provide distinct contrast and offer new information related to tissue electrical properties. A method for non-invasive imaging of the electrical loss tangent of tissue using magnetic resonance imaging (MRI) was demonstrated, and the effect of loss tangent was observed through simulations assuming a hyperthermia procedure. For measurement of tissue loss tangent, radiofrequency field maps ($B_1{^+}$ complex map) were acquired using a double-angle actual flip angle imaging MRI sequence. The conductivity and permittivity were estimated from the complex valued $B_1{^+}$ map using Helmholtz equations. Phantom and ex-vivo experiments were then performed. Electromagnetic simulations of hyperthermia were carried out for observation of temperature elevation with respect to loss tangent. Non-invasive imaging of tissue loss tangent via complex valued $B_1{^+}$ mapping using MRI was successfully conducted. Simulation results indicated that loss tangent is a dominant factor in temperature elevation in the high frequency range during hyperthermia. Knowledge of the tissue loss tangent value can be a useful marker for thermotherapy applications.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.488-493
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• 2010

Therapeutic manipulation of angiogenesis, the formation of new vascular sprouts from existing capillaries, is one of the promising strategies for treatment of human diseases such as cancer, arthritis, and cardiovascular disorder. In the present study, we examined the effects and molecular mechanism of tissue inhibitor of metalloproteinases-2 (TIMP-2) and endostatin on fibroblast growth factor-2 (FGF-2)-stimulated endothelial cell proliferation, migration and adhesion in vitro, and angiogenesis in vivo. TIMP-2 and endostatin showed potent anti-angiogenic activity in vitro and in vivo. These effects appear to be mediated through different angiogenic signaling pathways. Collectively, our findings demonstrate that TIMP-2 and endostatin strongly inhibit FGF-2-induced angiogenic responses, and the establishment of fast and reproducible evaluation system in vitro and in vivo for the development of anti-angiogenic biomaterials and therapeutics.

• Radiation Oncology Journal
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• v.12 no.2
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• pp.219-223
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• 1994

This paper describes the basic data measurements for total body irradiation with 6 Mv photon beam including compensators design. The technique uses bilateral opposing fields with tissue compensators for the head, neck, lungs, and legs from the hip to toes. In vivo dosimetry was carried out for determining absorbed dose at various regions in 7 patients using diode detectors(MULTIDOSE,k Model 9310, MULTIDATA Co., USA). As a results, the dose uniformity of${\pm}3.5{\%}$(generally, within${\pm}10{\%}$can be achieved with out total body irradiation technique.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.63-66
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• 1993

Localized NMR spectra were obtained from phantom by OSIRIS technique. The selected volume, which can be controlled by frequency and its bandwidth, was 0.125cc out of 25cc and free of contamination from outer volume. With this technique NMR spectrum of a living tissue can be obtained without biopsy. i.e. in vivo state in which the metabolism of tissue may be quite different from in in vitro state. It is expected of this technique to be useful in the study of metabolism of living tissue as well as in diagnosis of deseases.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.2102-2102
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• 2001

Near infrared, diffuse reflectance spectroscopy has shown significant potential for in vitro and in vivo assessment of metabolic status. However, the complexity of living samples can lead to ambiguous results. This presentation will focus on methods that provide controls for scattering and absorption estimation in tissue. For robust estimations, normalization procedures will be shown which can greatly improve interpretability of results. Normalization based on time, location and spectral property will be shown with data from models, tissue phantoms and in vivo measurements. In particular, interpretation of NIR spectra associated with major respiratory constituents will be examined. Measurement of constituents such as hemoglobin, myoglobin, tissue edema, and lactate will be shown. Results suggest that NIR may provide a valuable tool for physiological monitoring in critical care research and practice.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1613-1617
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• 2006

Optimum analytical conditions for cyclic voltammetry (CV) and square wave (SW) stripping voltammetry were determined using mercury-mixed carbon nanotube paste electrode (PE). The results approached the microgram working ranges of SW: 10.0-80.0 $ugL^{-1}$ and CV: 100-700 $ugL^{-1}$ Cd (II); working conditions of 300-Hz frequency, 100 mV amplitude, 1.6 V accumulation potential, 400 sec accumulation time, and 40 mV increment potential. First, analysis was performed through direct assay of cadmium ions deep into the fishs brain core and plant tissue in real time with a preconcentration time of 400 sec. The relative standard deviation of 10.0 $mgL^{-1}$ Cd (II) observed was 0.064 (n = 12) at optimum conditions. The low detection limit (S/N) was set at 0.6 $ugL^{-1}$ ($5.33{\times}10^{-9}$ M). The methods can be used in direct analysis in vivo or in real-time monitoring of plant tissue.

• Advances in Traditional Medicine
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• v.8 no.3
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• pp.295-301
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• 2008

The methanolic root extract of tissue cultured Pluchea indica (L.) Less. was tested for its antibacterial potentiality against 102 different strains of bacteria belonging to both Gram positive and Gram negative groups. The bacteria could be arranged according to their decreasing order of sensitivity as follows: Staphylococcus aureus, Vibrio cholerae, Bacillus spp. Vibrio parahaemolyticus, shigellae, Salmonella spp., and Escherichia coli. The extract was found to be bacteriostatic in nature against Salmonella typhimurium NCTC 74. When administered to Swiss strain of white mice at the doses of 0.5 and 1.0 mg/kg body weight, the extract could significantly protect the animals challenged with 50 MLD of S. typhimurium NCTC 74. According to the chi-square test, the in vivo data is highly significant (P < 0.001).

• Journal of Life Science
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• v.32 no.4
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• pp.318-324
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• 2022

PPARγ and C/EBPα are master adipogenic transcription factors (TFs) required for adipose tissue development. They control the induction of many adipocyte genes and the early phase of adipogenesis in the embryonic development of adipose tissue. Adipose tissue continues to expand after birth, which, as a late phase of adipogenesis, requires the lipogenesis of adipocytes. In particular, the liver and adipose tissues are major sites for de novo lipogenesis (DNL), where carbohydrates are primarily converted to fatty acids. Furthermore, fatty acids are esterified with glycerol-3-phosphate to produce triglyceride, a major source of lipid droplets in adipocytes. Hepatic DNL has been actively studied, but the DNL of adipocytes in vivo remains not fully understood. Thus, an understanding of lipogenesis and adipose expansion may provide therapeutic opportunities for obesity, type 2 diabetes, and metabolic diseases. In adipocytes, DNL gene expression is transcriptionally regulated by lipogenesis coactivators, as well as by lipogenic TFs such as ChREBP and SREBP1a. Recent in vivo studies have revealed new insights into the lipogenesis gene expression and adipose expansion. Future detailed molecular mechanism studies will determine how nutrients and metabolism regulate DNL and adipose expansion. This review will summarize recent updates of DNL in adipocytes and adipose expansion in terms of transcriptional regulation.

• Animal cells and systems
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• v.5 no.2
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• pp.91-99
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• 2001

Vertebrates regenerate tissues in three ways: proliferation of cells that maintain some or all of their differentiated structure and function, redifferentiation of mature cells followed by proliferation and redifferentiation into the same cell type or transdetermination to another cell type, and activation of restricted lineage stem cells, which have the ability to transdetermine to different lineages under the appropriate conditions. The behavior of the cells during regeneration is regulated by growth factors and extracellular matrix molecules. Some non-regenerating tissues are now known to harbor stem cells which, though they form scar tissue in vivo, are capable of producing new tissue-specific cells in vitro, suggesting that the injury environment inhibits latent regenerative capacity. Regenerative medicine seeks to restore tissues via transplantation of stem cell derivatives, implantation of bioartificial tissues, or stimulation of regeneration in vivo. These approaches have been partly successful, but several research issues must be addressed before regenerative medicine becomes a clinical reality.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1857-1863
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• 2013

Most of biomaterials come in direct contact with the body, making standardized methods of evaluation and validation of biocompatibility an important aspect to biomaterial development. However, biomaterial validation guidelines have not been fully established, until now. This study was to compare the in vitro behavior of osteoblasts cultured on nanomaterial $TiO_2$ surfaces to osteoblast behavior on culture plates. Comparisons were also made to cells grown in conditioned media (CM) that creates an environment similar to the in vivo environment. Comparisons were made between the different growth conditions for osteoblast adhesion, proliferation, differentiation, and functionality. We found that the in vivo-like system of growing cells in concentrated CM provided a good validation method for biomaterial development and in vivo implant therapy. The $TiO_2$ materials were biocompatible, showing similar behavior to that observed in vivo. This study provided valuable information that would aid in the creation of guidelines into standardization and evaluation of biocompatibility in $TiO_2$ biomaterials.