• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.250-254
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• 1997

The internal invertase of Rhodosporidium toruloids mating type a cells was purified to a single band on SDS-PAGE from cell-free extract by acid precipitation, ion exchange chromatogaphy andgel filtration. The determined molecular weight of he purified enzyme was about 95,000 by gel filtration and 100,000 daltons on SDS-polyacryamide gel electrophoresis. This enzyme didn't show any activity change by several metal ions except 15.4% decrease by {TEX}$Mn^{2+}${/TEX} and was strongly inhibited by 2-mercaptoethanol and SDS. The invertase maintained its activity at high level until 70℃, but inactivated at 80℃ almost completely. The optimal temperature and pH of the enzyme were about 60℃ and pH 5.0, respectively. The stable pH range of invertase was narrow from pH 3.0 to 6.0. The Km value and isoelectric point of enzyme were 3.4×{TEX}$10^{3}${/TEX} M, pH 4.4, respectively.

• Korean journal of dermatology
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• v.56 no.9
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• pp.548-551
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• 2018

Biologics are the most advanced treatment for psoriasis. Ustekinumab, one of the biologics for psoriasis, is a human monoclonal antibody that binds to the p40 subunit of interleukin-12 and interleukin-23. A 41-year-old woman with a 17-year history of plaque psoriasis and psoriatic arthritis presented with worsening lesions. The patient had previously been treated with a number of topical and systemic medications and narrow band ultraviolet B. However, none of the treatments consistently controlled her disease. Thus, treatment with ustekinumab 45 mg via subcutaneous injection was initiated. Approximately 7 days after the first treatment, she experienced a flare with generalized pustules in her whole body. The condition was controlled with systemic steroid treatment. The patient was subsequently treated with adalimumab, and improvement in her plaque and pustular lesions was noted. Herein, we report a case of psoriasis that flared up after ustekinumab therapy, which was accompanied by a morphological change from plaque to pustular lesions.

• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.343-348
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• 2012

This paper described an off-axis five-mirror-anastigmatic telescope. It is composed of three aspheric surfaces and one spherical surface while the third mirror and fifth mirror have the same parameters at the same place. This configuration is useful for having wide field of view. The strip full field of view for the near infrared telescope is $20^{\circ}{\times}0.2^{\circ}$. The entrance pupil is located in front of the first mirror. There is an intermediate image between the second mirror and the third mirror. The entrance pupil diameter is 100 mm and the effective focal length is 250 mm. The spectral range is $0.85-1.75{\mu}m$. The pixel pitch is $15{\mu}m$. The image quality is near the diffraction limit. Some methods were used to restrain the stray light such as a field stop near the intermediate image, the baffle, the narrow-band pass filter and a stop in front of the focal plane.

• Current Optics and Photonics
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• v.4 no.4
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• pp.373-379
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• 2020

In this study, we investigate terahertz (THz) generation by a photoconductive antenna with electrodes in the shape of split-ring resonators. According to our theoretical investigation based on a lumped-circuit model, the inductance of this electrode structure leads to resonant behavior of the photo-induced current. Hence, near the resonance frequency the spectral components generated by a resonant photoconductive antenna can be greater than those produced by a non-resonant one. For experimental verification, a resonant photoconductive antenna, which possesses a resonance mode at 0.6 THz, and a non-resonant photoconductive antenna with stripe-shaped electrodes were fabricated on a semi-insulating GaAs substrate. The THz generation by both of the photoconductive antennas demonstrated a good agreement with the theoretically expected results. The observed relationship between the resonant electrodes of the photoconductive antenna and the generated THz spectrum can be further employed to design a narrow-band THz source with an on-demand frequency.

• Korean Journal of Materials Research
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• v.31 no.9
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• pp.496-501
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• 2021

Metal halide perovskite nanocrystals, due to their high absorption coefficient, high diffusion length, and photoluminescence quantum yield, have received significant attention in the fields of optoelectronic applications such as highly efficient photovoltaic cells and narrow-line-width light emitting diodes. Their energy band structure can be controlled via chemical exchange of the halide anion or monovalent cations in the perovskite nanocrystals. Recently, it has been demonstrated that chemical exfoliation of the halide perovskite crystal structure can be achieved by addition of organic ligands such as n-octylamine during the synthetic process. In this study, we systematically investigated the quantum confinement effect of methylammonium lead bromide (CH₃NH₃PbBr₃, MAPbBr₃) nanocrystals by precise control of the crystal thickness via chemical exfoliation using n-octylammonium bromide (OABr). We found that the crystalline thickness consistently decreases with increasing amounts of OABr, which has a larger ionic radius than that of CH₃NH₃⁺ ions. In particular, a significant quantum confinement effect is observed when the amounts of OABr are higher than 60 %, which exhibited a blue-shifted PL emission (~ 100 nm) as well as an increase of energy bandgap (~ 1.53 eV).

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.826-841
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• 2018

The military satellite communication of ROK military, ANASIS is designed for analog data such as voice and streaming data. ANASIS cannot fully support ALL-IP communications due to its long propagation delay. The next generation satellite communication system is being designed to overcome the limitation. Next generation satellite communications system considers both high-speed and low-speed networks to support various operating environment. The low-speed satellite supports both broadband and narrow-band communication. This network works as the infrastructure for of wide-area internetworking over multiple AS's in the terrestrial network. It requires minimum satellite frequency and minimum power and works without PEP and router. In this paper, we propose a network operation structure to enable the inter-operation between high and low-speed satellite networks. In addition, we propose a data link protocol for low speed satellite networks.

• Korean Journal of Materials Research
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• v.29 no.8
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• pp.477-482
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• 2019

The magnetic properties and electronic structures of the B20 crystal structure MnGe and MnSi were investigated using the density functional theory with local density approximation. The low symmetry of the B20 crystal structure plays a very important role to make electromagnetic characteristics of these materials. The important result of the calculations is that it can be observed the appearance of a pair of gaps in the density of states near the Fermi level in both compounds. These features are results from d-band splitting by the low symmetry of the crystal field from B20 crystal structure. It can be seen that there is half-metallic characteristics from the density of states in both compounds. The calculation shows that the value of magnetic moment of MnGe is 5 times bigger than that of MnSi even though they have same crystal structure. The electronic structures of paramagnetic case have a very narrow indirect gap just above the Fermi level in both compounds. These gaps acquire some significance in establishing the stability of the ferromagnetic states within the local density approximation. Calculation shows that the Mn 3d character dominates the density of states near the Fermi level in both materials.

• Computers and Concrete
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• v.24 no.2
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• pp.95-102
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• 2019

Current article proposes a cheap prototype of an embedded wireless sensor to monitor concrete structures. The prototype can measure temperature and relative humidity concurrently at a controlled through smartphone time interval. It implements a maturity method to estimate in-place concrete strength, which is considered as an alternative for traditional shock impulse method and compression tests used in Kazakhstan. The prototype was tested and adequately performed in the laboratory and field conditions. Tests aimed to study the effect of internal and ambient temperature and relative humidity on the concrete strength gain. According to test results revealed that all parameters influence the strength gain to some extent. For a better understanding of how strongly parameters influence the strength as well as each other, proposed a multicolored cross-correlation matrix technique. The technique is based on the determination coefficients. It is able to show the value of significance of correlation, its positivity or negativity, as well as the degree of inter-influence of parameters. The prototype testing also recognized the inconvenience of Bluetooth control due to weakness of signal and inability to access several prototypes simultaneously. Therefore, further improvement of the prototype presume to include the replacement of Bluetooth by Narrow Band IoT standard.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.46.3-46.3
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• 2019

We present our observational and theoretical investigation of Raman-scattered features in symbiotic stars (SySts). SySts are long interacting binaries, consisting of a hot compact star and an evolved giant, whose interaction via accretion process is at the origin of a tangled network of gas and dust nebulae. These systems are ideal objects to study a variety of important astrophysical problems, and have also been proposed as possible progenitors of type Ia supernova. In this talk, we emphasize that Raman-scattered features are exclusive spectroscopic tools to probe the stellar wind accretion processes in SySts. We studied mass transfer and mass loss processes in SySts using high resolution spectra obtained with 1.8m telescope at Mt. Bohyun and the 6.5m Magellan-Clay telescope combining with the theoretical modeling of radiative transfer of Raman-scattered features. We also note that there are a much smaller number of SySts known in our Galaxy, implying the necessity of systematic search programs. In view of the fact that Raman O VI features at $6830{\AA}$ are found in only bona fide SySts, we will carry out a photometric search of objects with Raman O VI features using a narrow band filter centered at $6830{\AA}$ in Local group galaxies.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.44.4-44.4
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• 2019

The supernova remnant Cassiopeia A (Cas A) provides a unique opportunity to observe the fine details of the explosion of core-collapse supernova (SN). Previous optical and near-infrared (NIR) observations of Cas A have shown that the spatial distribution of the metal-enriched SN ejecta is very complicated, indicating that the SN explosion should have been asymmetric and turbulent, especially near the core. Recently, we obtained a long-exposure (~10 hr) image of Cas A by using the UKIRT 3.6-m telescope with a narrow-band filter centered at [Fe II] 1.644 um emission. This 'deep [Fe II] image' provides an unprecedented panoramic view of Cas A, revealing the distribution of dense SN ejecta over the entire remnant. We have carried out NIR multi-object spectroscopic observations of the dense ejecta knots in the northeastern (NE) and eastern (E) outer regions of the remnant using the MMIRS attached on the MMT 6.5-m telescope. A total of 67 ejecta knots are detected. By analyzing their spectra, we have found that the knots in the NE area show strong [S II]/[S III] and [Fe II] lines but little or no [P II] line, while those in the E outer region show strong [Fe II] lines but weak [S II]/[S III] lines. In this talk, we present the preliminary results of our NIR spectroscopic observations and discuss the implications.