• Journal of the Optical Society of Korea
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• v.19 no.3
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• pp.228-236
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• 2015

Fluorescence recovery after photobleaching (FRAP) is a well-established method commonly used to measure the diffusion of fluorescent solutes and biomolecules in living cells or tissues. Here a fiber-optic-based FRAP (f-FRAP) system was developed, and validated using macromolecules in water and agarose gels of different concentrations. We applied f-FRAP to measure the site-specific diffusion of fluorescein (NaFluo) in peritoneal membranes (PMs) on the liver, cecum, and kidney of a living rat during peritoneal dialysis. Diffusion of fluorescein in PM varied in a time-dependent manner according to the type of organ ($D_{PM\;on\;Liver}/D_{NaFluo}=0.199{\pm}0.085$, $D_{PM\;on\;Cecum}/D_{NaFluo}=0.292{\pm}0.151$, $D_{PM\;on\;Kidney}/D_{NaFluo}=0.218{\pm}0.110$). The proposed method allows direct quantitative measurement of the three-dimensional diffusion in local PM in vivo, which was previously inaccessible by peritoneal function test methods such as peritoneal equilibration test (PET) and standardized PM assessment (SPA). f-FRAP is promising for local and dynamic assessments of peritoneal pathophysiology and the mass transport properties of PMs, presumed to be affected by variation of tissue structures over different organs and functional changes of the PM with years of peritoneal dialysis.

• Korean Journal of Radiology
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• v.22 no.10
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• pp.1690-1696
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• 2021

Objective: To describe the anatomic locations and imaging features of posterior lung herniation in unilateral pulmonary agenesis and aplasia, focusing on radiograph-CT/MRI correlation. Materials and Methods: A total of 10 patients (seven with pulmonary agenesis and three with pulmonary aplasia, male: female = 1:9, mean age 7.3 years, age range from 1 month to 20 years) were included. Chest radiographs (n = 9), CT (n = 9), and MRI (n = 1) were reviewed to assess the type of lung underdevelopment, presence of anterior and posterior lung herniation, bronchus origin, supplying artery, and draining vein of the herniated lung. Results: Pulmonary agenesis/aplasia more commonly affected the left lung (n = 7) than the right lung (n = 3). Anterior lung herniation was observed in nine of the 10 patients. Posterior lung herniation was observed in seven patients with left pulmonary agenesis/aplasia. Two patients showed posterior lung herniation crossing the midline but not beyond the aorta, and five patients showed the posteriorly herniated right lower lobe crossing the midline to extend into the left hemithorax farther beyond the descending thoracic aorta through the space between the esophagus and the aorta. This anatomical configuration resulted in a characteristic radiographic finding of a radiolucent area with a convex lateral border and a vertical medial border in the left lower lung zone, revealing a tongue-like projection on CT and MRI. Conclusion: Posterior lung herniation occurs in unilateral left lung agenesis/aplasia. Approximately 70% of the cases of posterior lung herniation reveal a unique radiolucent tongue-like projection in the left lower lung zone on imaging studies, which is caused by the extension of the posteriorly herniated right lung farther beyond the descending aorta.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.4
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• pp.922-937
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• 2024

Maritime activities are on the rise, there is a growing demand for high-quality communication services that can cover larger areas. However, the transmission of high data rates to maritime users is challenging due to path loss from land base stations, which limits the transmission power. To overcome this challenge, researchers have been exploring the use of buoys in a marine environment as relays for communication technology. This paper proposes a simulation-based approach to investigate the impact of various beamwidths on communication performance when using a buoy as a relay. The objective is to determine the optimal beamwidth that yields the highest data rate for the target location. The approach is based on an offshore wave model where the direction of the buoy changes according to the height of the wave. The study investigates the performance of the relay in the downlink situation using receive beamforming, and the capacity at the user in the three-hop situation is verified using an amplify-and-forward (AF) relay that uses transmit beamforming to the user. The simulation results suggest that the beamwidth of the relay should be adjusted according to the wave conditions to optimize the data rate and relay position that satisfies a data rate superior to the direct path to the target position. Using a buoy as a relay can be a promising solution for enhancing maritime communications, and the simulation-based approach proposed in this paper can provide insights into how to optimize beamwidth for effective communication system design and implementation. In conclusion, the study results suggest that the use of buoys as relays for maritime communication is a feasible solution for expanding coverage and enhancing communication quality. The proposed simulation-based approach provides a useful tool for identifying relay beamwidths for achieving higher data rates in different wave conditions. These findings have significant implications for the design and deployment of communication systems in maritime environments.

• Journal of Pharmacopuncture
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• v.7 no.3
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• pp.73-76
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• 2004

We report the new threadlike structures outside the blood vessels of mice. For this, we developed an in-situ searching method of the structure by vital staining with the dye of acridine orange and using a fluorescent stereomicroscope designed specifically for this purpose. We consider that the newly found threadlike structure might be rediscovery of the extra-vascular Bonghan duct which was reported in 1963 by Bonghan Kim.

• Macromolecular Research
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• v.9 no.4
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• pp.185-196
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• 2001

The self-assembly of block copolymers can lead to a variety of ordered structures on a nanometer scale. In this article, the self-assembling behaviors of triblock copolymers in the melt and the selective solvent are described with the results obtained from the computer simulations. With the advances of computing power, computer simulations using molecular dynamics and Monte Carlo techniques make it possible to study very complicated phenomena observed in the self-assembly of triblock copolymer. 13king full advantage of the computer simulation based on well-defined model, the effects of various structural and thermodynamic parameters such as the copolymer composition, the block sequence, the pairwise interaction energies, and temperature on the self-assembly are discussed in some detail. Some simulation results are compared with experimental ones End analyzed by comparing them with the theoretical treatment.

• Journal of Dairy Science and Biotechnology
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• v.32 no.1
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• pp.31-36
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• 2014

Thermal pasteurization has been effectively used for decades as a method to extend the shelf life of milk and to inactivate any pathogenic bacteria that it may contain; however, it can negatively affect the nutritional properties of milk. In recent years, the food industry has sought new, less aggressive technologies that affect food freshness and its nutritive and health benefits less significantly. Various means have been used to extend the shelf life of dairy foods, such as high-pressure processing, irradiation, ohmic heating, and pulsed electric field (PEF) technologies. Of these, PEF technologies are potential alternatives to traditional thermal milk pasteurization, owing to their advantages in minimizing sensory and nutritional damage. In this review, we have primarily focused on the feasibility of applying PEF technologies to the sterilization of dairy products and briefly discussed whether they should be adopted for use in the dairy beverage industry in the future.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.979-982
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• 2006

Two knockout vectors, in which the truncated Kluyveromyces lactis URAS gene is flanked by a direct repeat, were developed for Saccharomyces cerevisiae. Each vector was designed to harbor 5'- and 3'-end homology regions for integration. Two knockout fragments were devised to integrate into the correct locus in a complementary manner to disrupt a gene of interest and. concomitantly to make functional Kl URA3 for transfomant selection. The use of dual complementary knockout cassettes was expected to dramatically reduce integration into unwanted loci in the genome. The knockout system developed in this study was successfully used for disruption of the GAL1 gene in S. cerevisiae.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.156-157
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• 2000

The amplification method using evanescent wave coupling has a long history and has been widely used as a new lasing method, especially, in the waveguide optics$^{(1)}$ . In particular, it has been observed experimentally that when the light wave propagating in a dielectric medium is totally reflected at the planar interface between the dielectric and a pumped active medium, the reflectance may be greater than unity, i.e., amplification is possible$^{(2)}$ . There were several attempts by other authors to explain this enhanced internal reflection (EIR) classically$^{(3)}$ . They commonly introduced a complex refractive index for the active medium with its imaginary part being negative, and this scheme was also used to describe an amplification process in a waveguide having active-cladding region$^{(4)}$ . However these theories are phenomenological, using macroscopic constants, and therefore a microscopic theory is needed to understand EIR in a fundamental level. (omitted)

• BMB Reports
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• v.41 no.5
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• pp.345-352
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• 2008

The cerebral microvessels possess barrier characteristics which are tightly sealed excluding many toxic substances and protecting neural tissues. The specialized blood-neural barriers as well as the cerebral microvascular barrier are recognized in the retina, inner ear, spinal cord, and cerebrospinal fluid. Microvascular endothelial cells in the brain closely interact with other components such as astrocytes, pericytes, perivascular microglia and neurons to form functional 'neurovascular unit'. Communication between endothelial cells and other surrounding cells enhances the barrier functions, consequently resulting in maintenance and elaboration of proper brain homeostasis. Furthermore, the disruption of the neurovascular unit is closely involved in cerebrovascular disorders. In this review, we focus on the location and function of these various blood-neural barriers, and the importance of the cell-to-cell communication for development and maintenance of the barrier integrity at the neurovascular unit. We also demonstrate the close relation between the alteration of the blood-neural barriers and cerebrovascular disorders.

• Investigative Magnetic Resonance Imaging
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• v.20 no.4
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• pp.250-253
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• 2016

Acute Japanese encephalitis (JE) is an endemic viral infectious disease in various parts of Far East and Southeast Asian countries including Korea. Bilateral thalami are the most common involving sites in JE. Other areas including the basal ganglia, substantia nigra, red nucleus, pons, cerebral cortex and cerebellum may be also involved. We report an extremely unusual brain diffusion-weighted MR imaging (DWI) findings in a 53-year-old man with serologically proven JE involving unilateral deep gray matter and temporal lobe, which shows multifocal high signal intensities in left thalamus, left substantia nigra, left caudate nucleus and left medial temporal cortex on T2-weighted image and DWI with iso-intensity on apparent diffusion coefficient (ADC) map.