• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.193-198
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• 2022

Contrast enhanced magnetic resonance imaging using gadolinium-based contrast agent (GBCA) is a very useful in vivo technique to visualize the inner ear pathology including endolymphatic hydrops. Although systemic intravenous (IV) administration can visualize the perilymph space, the visualization was possible by indirect passage of contrast agent through blood-perilymph barrier. All animal experimental procedures were performed under anesthesia with 5% isoflurane. Lipopolysaccharide (LPS) was instilled into the left tympanic cavity through the tympanic membrane using a sterile 27gauge needle to induce hydrops model. Tucker-Davis Technologies system was used to measure Auditory Brainstem Responses (ABRs). For intracerebroven-tricular (ICV) administration, 25 µmol of GADOVIST (Bayer, Berlin, Germany) was used and diluted GADOVIST injection was 10 µl. MR imaging was acquired with a 9.4 Tesla MRI scanner. Transmit-receive volume coil with 40 mm inner diameter and 75 mm out diameter was used. ICV administration well demonstrated the strong enhancement along the cerebrospinal fluid (CSF) microcirculation pathway including CSF fluid in the subarachnoid space and CSF space of the inner ear structures. On the other hand, IV administration showed no contrast enhancement along the CSF microcirculation pathway and showed weak enhancement in the inner ear structures. In case of rat hydrops model, ICV administration showed that the reduced contrast enhancement in the perilymph space of the hydrops induced inner ear compared to the contrast enhancement in the perilymph space of the normal inner ear. New systemic ICV administration method provide contrast enhancement of GBCA in the inner ear through CSF microcirculation pathway.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1521_1522
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• 2009

Chemotaxis is the directed movement of cells in gradients of signaling molecules, an essential biological process that underlies morhpogenesis during development, and the recruitment of immune cells to sites of infection. Especially, bacterial chemotaxis has utilized as an important prelude to study metabolism, prey-predator relationship, symbiosis, other ecological interactions in microbial communities. Recently, novel analytical formats integrated with microfluidics were introduced to investigate the chemotaxis of the cells with the precise control of chemical gradient and small volume of cells. In this study, we present a method to detect bacterial chemotaxis by direct fluidic contacting. The developed fluidic-handling method is driven by capillary force, hydrophobic barrier and a cohesion force between fluids. We have investigated the chemotactic response of E Coli. and Pseudomonas aeruginosa to three kinds of chemoeffectors such as HEPES buffer, peptone and chloroform.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2286-2300
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• 2011

We synthesized eight G8 molecular transporters (MTs) based on 4 different monosaccharide scaffolds, and studied their biological properties with a special focus on possible mitochondrial targeting and tissue selectivity. The mitochondrial affinity of these MTs was found to be clearly related to the scaffold stereochemistry and also tenuously with the lipophilicity. It may be suggested that in the practical delivery strategy of drugs for the brain and mitochondrial diseases the BBB permeability and mitochondrial affinity should be considered as key parameters, and that an enhanced mitochondrial affinity appears possible by further research on the structure-property relationship of guanidine-rich molecular transporters.

• Applied Microscopy
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• v.13 no.1
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• pp.31-40
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• 1983

Ultrathin sections of intact mycelia, released protoplast and fused protoplast of Micromonospora rosaria were observed by electron microscopy Intact mycelia showed a typical gram-positive bacterial cell wall structure and mesosomes. Released protoplasts had no cell wall components and fibrous nuclear region was distinguished from cytoplsmic region clearly. Protoplasts which treated with sucrose supplemented buffer were stable. But those treated with buffer without sucrose were extensively damaged, forming mom braneous vesicles. It was surmised that those vesicles originated from the damaged cytoplasmic membrane. High frequency of fusion was achieved by 50%(w/v). polyethylene-glycol 1,000 Fusion bodies in different stage of fusion were observed. Cell membrane barrier was stepwise relieved.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.433-436
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• 2005

Chitosans were obtained with varying deacetylation times using the ${\beta}$-chitin isolated from Todarodes pacificus, and their deacetylation degrees and average molecular weights were determined. Films prepared with the squid chitosans were characterized by estimating their tensile strengths, percent elongations, water vapor permeabilities, degree of swelling, and temperatures of glass transition and thermal decomposition. The results suggest that the squid chitosan films were comparable to common crustacean chitosan films in regard of mechanical, moisture barrier, and thermal properties, although further, multilateral investigations are necessary to make a more definitive conclusion.

• Animal Bioscience
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• v.34 no.3_spc
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• pp.345-353
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• 2021

Phytobiotics, also known as phytochemicals or phytogenics, have a wide variety of biological activities and have recently emerged as alternatives to synthetic antibiotic growth promoters. Numerous studies have reported the growth-promoting effects of phytobiotics in chickens, but their precise mechanism of action is yet to be elucidated. Phytobiotics are traditionally known for their antioxidant activity. However, extensive investigations have shown that these compounds also have anti-inflammatory, antimicrobial, and transcription-modulating effects. Phytobiotics are non-nutritive constituents, and their bioavailability is low. Nonetheless, their beneficial effects have been observed in several tissues or organs. The health benefits of the ingestion of phytobiotics are attributed to their antioxidant activity. However, several studies have revealed that not all these benefits could be explained by the antioxidant effects alone. In this review, I focused on the bioavailability of phytobiotics and the possible mechanisms underlying their overall effects on intestinal barrier functions, inflammatory status, gut microbiota, systemic inflammation, and metabolism, rather than the specific effects of each compound. I also discuss the possible mechanisms by which phytobiotics contribute to growth promotion in chickens.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.154-155
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• 1998

Taurine, 2-aminoethanesulfonic acid is widely distributed in animal tissues and has a variety of biological activities. A recent worldwide study demonstrated beneficial effects of taurine on aging and age-associated disorders. In general, taurine levels in the brain decrease when an animal is subjected to pathologic conditions such as ischemia-anoxia and seizure. But taurine levels tend to increase in the brain in hypertention. In the present study, the blood-brain barrier BBB) transport of [$^3$H]taurine was compared between spontaneously hypertensive rats (SHR) and normotensive Sprague-Dawley rats (SD) using Internal artery carotid perfusion (ICAP) at a rate of 4$m\ell$/min for 10, 15 and 30 second. Calculated V$\_$D/, volume of distribution in brain, and PS, the permeability surface area product of [$^3$H]taurine through the BBB in SHR was a little lower than that in SD. PS for 15s is more higher than that of other seconds in both of them. It could be followed by taurine efflux back into blood after 15s. We also obtained pharmacokinetic parameters using intravenous injection of plasma volume marker, [$\^$14/C]sucrose and [$^3$H] taurine. PS value of [$^3$H]taurine in SHR (16.1 ${\pm}$ 2.9 ${\times}$ 10$\^$-3/ $m\ell$/min/g) was significantly higher than that in SD (7.4 ${\pm}$ 0.8 ${\times}$ 10$\^$-3/ $m\ell$/min/g). There is also significant difference for %ID/g in brain between SHR (0.195 ${\pm}$ 0.031) and SD (0.058 ${\pm}$ 0.003).

• Journal of Ginseng Research
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• v.39 no.2
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• pp.135-140
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• 2015

Background: A leaf cuticle has different structures and functions as a barrier to water loss and as protection from various environmental stressors. Methods: Leaves of Panax ginseng were examined by scanning electron microscopy and transmission electron microscopy to investigate the characteristics and development of the epicuticular structure. Results: Along the epidermal wall surface, the uniformly protuberant fine structure was on the adaxial surface of the cuticle. This epicuticular structure was highly wrinkled and radially extended to the marginal region of epidermal cells. The cuticle at the protuberant positions maintained the same thickness. The density of the wall matrix under the structures was also similar to that of the other wall region. By contrast, none of this structure was distributed on the abaxial surface, except in the region of the stoma. During the early developmental phase of the epicuticular structure, small vesicles appeared on wallecuticle interface in the peripheral wall of epidermal cells. Some electron-opaque vesicles adjacent to the cuticle were fused and formed the cuticle layer, whereas electron-translucent vesicles contacted each other and progressively increased in size within the epidermal wall. Conclusion: The outwardly projected cuticle and epidermal cell wall (i.e., an epicuticular wrinkle) acts as a major barrier to block out sunlight in ginseng leaves. The small vesicles in the peripheral region of epidermal cells may suppress the cuticle and parts of epidermal wall, push it upward, and consequently contribute to the formation of the epicuticular structure.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.519-526
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• 2021

Background: This study aimed to investigate the effect of cold plasma treatment on the improvement of seed germination and surface sterilization of ginseng seeds. Methods: Dehisced ginseng (Panax ginseng) seeds were exposed to dielectric barrier discharge (DBD) plasma operated in argon (Ar) or an argon/oxygen mixture (Ar/O₂), and the resulting germination and surface sterilization were compared with those of an untreated control group. Bacterial and fungal detection assays were performed for plasma-treated ginseng seeds after serial dilution of surface-washed suspensions. The microbial colonies (fungi and bacteria) were classified according to their phenotypical morphologies and identified by molecular analysis. Furthermore, the effect of cold plasma treatment on the in vitro antifungal activity and suppression of Cylindrocarpon destructans in 4-year-old ginseng root discs was investigated. Results: Seeds treated with plasma in Ar or Ar/O₂ exhibited a higher germination rate (%) compared with the untreated controls. Furthermore, the plasma treatment exhibited bactericidal and fungicidal effects on the seed surface, and the latter effect was stronger than the former. In addition, plasma treatment exhibited in vitro antifungal activity against C. destructans and reduced the disease severity (%) of root rot in 4-year-old ginseng root discs. The results demonstrate the stimulatory effect of plasma treatment on seed germination, surface sterilization, and root rot disease suppression in ginseng. Conclusion: The results of this study indicate that the cold plasma treatment can suppress the microbial community on the seed surface root rot in ginseng.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.83-92
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• 2023

The bullet shape of the plasma jet using the atmospheric-pressure dielectric barrier discharge method changes depending on the applied fluid rate and the intensity of the electric field. This changes appear as a difference in spectral distribution due to a difference in density of the DBD plasma jet. It is an important factor in utilizing the plasma device that difference between the occurrence of active species and the intensity through the analysis of the spectrum of the generated plasma jet. In this paper, a plasma jet generator of the atmospheric pressure volume DBD method using Ar gas was make a prototype in accordance with the proposed design method. The characteristics jet fluid rate analysis of Ar gas was accomplished through simulation to determine the dependence of flow rate for the generation of plasma jets, and the characteristics of plasma jets using spectrometers were analyzed in the prototype system to generate optimal plasma jet bullet shapes through MFC flow control. Through the design method of the proposed system, the method of establishing the optimal plasma jet characteristics in the device and the results of active species on the EOS were verified.