• Molecules and Cells
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• v.42 no.11
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• pp.783-793
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• 2019

When endoplasmic reticulum (ER) functions are perturbed, the ER induces several signaling pathways called unfolded protein response to reestablish ER homeostasis through three ER transmembrane proteins: inositol-requiring enzyme 1 (IRE1), PKR-like ER kinase (PERK), and activating transcription factor 6 (ATF6). Although it is important to measure the activity of ATF6 that can indicate the status of the ER, no specific cell-based reporter assay is currently available. Here, we report a new cell-based method for monitoring ER stress based on the cleavage of $ATF6{\alpha}$ by sequential actions of proteases at the Golgi apparatus during ER stress. A new expressing vector was constructed by using fusion gene of GAL4 DNA binding domain (GAL4DBD) and activation domain derived from herpes simplex virus VP16 protein (VP16AD) followed by a human $ATF6{\alpha}$ N-terminal deletion variant. During ER stress, the GAL4DBD-VP16AD(GV)-$hATF6{\alpha}$ deletion variant was cleaved to liberate active transcription activator encompassing GV-$hATF6{\alpha}$ fragment which could translocate into the nucleus. The translocated GV-$hATF6{\alpha}$ fragment strongly induced the expression of firefly luciferase in HeLa Luciferase Reporter cell line containing a stably integrated 5X GAL4 site-luciferase gene. The established double stable reporter cell line HLR-GV-$hATF6{\alpha}$(333) represents an innovative tool to investigate regulated intramembrane proteolysis of $ATF6{\alpha}$. It can substitute active pATF6(N) binding motif-based reporter cell lines.

• Food Science and Preservation
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• v.16 no.2
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• pp.166-171
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• 2009

The effects of vacuum precooling(VP) on the shelf-life of polyethylene film(PE) packaged King oyster mushrooms(Pleurotus eryngii) during storage at $-1^{\circ}C$ were investigated. VP was conducted below $0^{\circ}C$ in a $-1^{\circ}C$ cold chamber of 40 minutes, and mushrooms were stored for 30 days in batches of 1kg. The weight loss of the VP-treated mushroom was slightly lower than that of control. The $O_2$ concentrations of VP-treated mushroos, within 4 days of storage, were 2.44-14.50 %/kg-package/hr, thus higher than control values(2.01-8.19%/kg-package/hr). $CO_2$ generation of VP-treated mushrooms, again within 4 days of storage, was 0.47%/kg-package/hr, thus lower than that of controls(0.58%/kg-package/hr). The $CO_2/O_2$ ratio peaked on day 4 of storage in the control group, tbut no such peak was observed in VP-treated mushrooms. In the VP-treated fungi, lightness was higher, and redness and yellowness lower, than in controls, at all storage times.. In VP-treated mushrooms, strength, hardness and chewiness were significantly higher than in controls, but there were no significant differemces in springiness or cohesiveness. Softening and breakdown of under-cap wrinkles were observed in control mushrooms stored for 30 days, but occurred to a lesser extent in VP-treated fungi. Stipe reticulum tissue vessels in the 30 day-stored VP-treated mushrooms were relatively well-defined and clear, but were softer and diffuse in the control fungi. The results thus confirmed that VP after harvest enhanced mushroom shelf-life and PE packaging prolonged storage time. The data will have industrial applications.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.1
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• pp.87-94
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• 1992

The purpose of this study was to evaluate the effect of scatter radiation to dental x-ray film with long time-exposure in the different structures of the tooth, by using pinhole camera. For this study, pinhole camera, skull with tooth, and pocket dosimeter were used. The radiation with 70 and 90kVp and exposure time (minimum: 2.5 min., maximum 10 hrs.) was projected to the film in the pinhole camera. And density of the obtained x-ray film was measured with densitometer. In the intra-oral film taking, the amount of exposure of the scatter radiation affecting the thyroid gland area was measured with the dosimeter at the thyroid gland. The density of radiographs was compared in radiation projected with or without the metal cone of dental machine. The effect of the back scatter radiation to the film was also evaluated when the lead foil was removed. The obtained results were as follows: 1. A pinhole camera was a valuable device for locating the source of x-ray. 2. The scatter radiation affected the dental x-ray film when the radiation source was exposed. more than 5 hours'. In that case, the density of the scatter radiation could be observed visually. 3. The scatter radiation caused by short exposure of dental radiation didn't affect the diagnostic quality of the dental x-ray film. 4. The differences of densities between the tooth and the soft tissue according to exposure time showed 0.16 in 5 hours' exposure & 0.17 in 10 hours' exposure at 70 kVp & 0.12 in 5 hours' exposure & 0.13 in 10 hours' exposure at the 90kVp. 5. The differences of densities between the tooth and the soft tissue according to kVp showed no difference between 5 hours' exposure of tooth at 70 kVp and soft tissue at 90 kVp, but showed 0.05 high density in tooth when 10 hours' exposure at 90 kVp. 6. No difference of density was on radiographs taken with or without dental machine cone. 7. Back scatter radiation was recorded image of radiographs for only 3 min. 8. The amounts of the scatter radiation exposed to the thyroid gland in intraoral film taking were 1.12 mr in upper anterior, 0.55 mr in upper posterior, 2.75 mr in lower anterior, and 1.92 mr in lower posterior teeth.

• Journal of radiological science and technology
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• v.11 no.1
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• pp.3-16
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• 1988

Author has made an experiment on absolute speeds of 18 screenfilm combinations that have been on sale in Korea, with various beam qualities. At this time, the beam qualities were 60kVp with the ANSI extremity phantom, 80kVp with the ANSI chest phantom and 85kVp with 20 mm aluminium filter under scatter free condition. The obtained results were as follows; 1. When three independent measurements were performed, the percent standard deviations of mAs quantities of 1.0 + fog were decreased by the hardening of the beam quality, and the decreasing tendency was somewhat great in the blue systems. 2. Generally, the increasing tendency of absolute speeds was distinct by the hardening of the beam quality in the green systems. Conclusively, the green systems were more strongly dependent upon the beam quality rather than the blue systems. Therefore, the relative speed of green systems to blue systems were great under the same condition. 3. Differences in the green systems were kept almost constant even though the beam qualities were changed. 4. They were shown the mutual relationship of absolute speed and relative speed rather than independent.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.127-132
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• 2010

The purpose of this study is to measure scattered ray which is occurred except for Z-axis range of the detector in MDCT's iso-center and present the basic data about the standard for reduction of scattered ray. The development of MDCT brings out the enlargement of beam thickness to the patient's Z-axis, which distributes to the increase in exposure dose according to the rise of scattered ray. Also MDCT brings out the increase of scattered ray about 4times more than SDCT. To evaluate scattered ray according to the change of beam thickness on MDCT, we measured scattered ray of MDCT's Z-axis beam thickness by using one 16-slice CTs and two 64-slice CTs. We used the ionization chamber 60ml 2026C as the equipment of measurement. In our results, we found out that the change of scattered ray according to the beam thickness in the same kVp has increase of scattered ray. Secondly we found out the increase of scattered ray according to the increase of kVp. Lastly we found out the decrease of scattered ray according to the increase of the distance from the ionization chamber.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.1
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• pp.113-124
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• 1990

For the study of the influence of kilovoltage and exposure time on radiographic density and contrast, we measured radiographic density of aluminum step wedge which composed of contiguous 8 steps wedges of 2-16㎜ thickness with densitometer. Aluminum step wedge was radiographed on Kodak ultraspeed DF-58 and Ektaspeed EP-21 film with range of 60-90 kVp and 5-60 impulse and subject contrast of aluminum step wedge with constant radiographic density and image contrast percentage without radiographic density was evaluated. Then we evaluated the film quality of teeth and their surrounding structure according to the change of kVp and exposure time by score rating method. The obtained results were as follows: 1. Radiographic density was related to the change of kilovoltage, especially in increased exposure time. 2. With constant radiographic density, subject contrast of thin aluminum step wedges was greater in low kilovolt age than high kilovoltage, but kilovolt age had not great influence on subject contrast of thick aluminum step wedge. On the other hand, radiographic density difference between 2mm and 16mm aluminum step wedge was decreased according to in- creasing kilovoltage. 3. Without constant radiographic density, image contrast percentage was decreased with increasing kilovoltage, but was not related with the change of exposure time. 4. Radiographic contrast of teeth and their surrounding structure which was taken with the range of 60-90 kVp and 6-30 impulse had not great influence on film quality.

• Journal of the Korean Vacuum Society
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• v.19 no.2
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• pp.81-90
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• 2010

We introduce a novel and versatile approach for preparing self-assembled nanoporous multilayered films with antireflective properties. Protonated polystyrene-block-poly (4-vinylpyrine) (PS-b-P4VP) and anionic polystyrene-block-poly (acrylic acid) (PS-b-PAA) block copolymer micelles (BCM) were used as building blocks for the layer-by-layer assembly of BCM multilayer films. BCM film growth is governed by electrostatic and hydrogen-bonding interactions between the oppositely BCMs. Both film porosity and film thickness are dependent upon the charge density of the micelles, with the porosity of the film controlled by the solution pH and the molecular weight (Mw) of the constituents. PS7K-b-P4VP28K/PS2K-b-PAA8K films prepared at pH 4 (for PS7K-b-P4VP28K) and pH 6 (for PS2K-b-PAA8K) are highly nanoporous and antireflective. In contrast, PS7K-b-P4VP28K/PS2K-b-PAA8K films assembled at pH 4/4 show a relatively dense surface morphology due to the decreased charge density of PS2K-b-PAA8K. Films formed from BCMs with increased PS block and decreased hydrophilic block (P4VP or PAA) size (e.g., PS36K-b-P4VP12K/PS16K-b-PAA4K at pH 4/4) were also nanoporous. Furthermore, we demonstrate that the nanostructured electrochemical sensors based on patterning methods show the electrochemical activities. Anionic poly(styrene sulfonate) (PSS) layers were selectively and uniformly deposited onto the catalase (CAT)-coated surface using the micro-contact printing method. The pH-induced charge reversal of catalase can provide the selective deposition of consecutive PE multilayers onto patterned PSS layers by causing the electrostatic repulsion between next PE layer and catalase. Based on this patterning method, the hybrid patterned multilayers composed of platinum nanoparticles (PtNP) and catalase were prepared and then their electrochemical properties were investigated from sensing $H_2O_2$ and NO gas. This study was based on the papers reported by our group. (J. Am. Chem. Soc. 128, 9935 (2006); Adv. Mater. 19, 4364 (2007); Electro. Mater. Lett. 3, 163 (2007)).

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.207-213
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• 2009

Rabbit hemorrhagic disease (RHD) is caused by RHD virus (RHDV) and is one of the most fatal diseases of rabbits. Acute death of rabbits occurred in a farm located in the Gyeonggi province of South Korea. The virus was isolated and confirmed as RHDV based on reverse transcription polymerase chain reaction and hemagglutination assay (HA), and the isolate was designated as KV0801. The nucleotide sequence of the complete VP60 gene of KV0801 was determined and the corresponding amino acid sequence was deduced. Molecular analysis showed that the KV0801 isolate can be classified as a pandemic antigenic variant strain, RHDVa. The VP60 nucleotide sequence and deduced amino acid homology between KV0801 and other Korean isolate, RHF89, which was isolated in 1988, were 92.1 and 94.3%, respectively. The pathogenicity of the KV0801 isolate at an HA titer ranging from 16,384 to 0.16 HA units was evaluated in five-month-old SFP rabbits. The rabbits inoculated with KV0801 isolate containing more than 1.63 HA units died within six days of inoculation. These results suggest that a highly pathogenic RHDVa is circulating in the rabbit populations of Korea.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2613-2615
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• 2001

청각시스템의 저전력 및 가격의 저렴화를 위해 달팽이관의 BM(Basilar Membrain)모델을 아날로그 VLSI 마이크로 파워 공정으로 구현하고 있다. 본 논문에서는 소리의 주파수 정보 추출기능을 하는 직렬 연결된 트리구조(TSBF : Tree-structured Cascaded Bandpass Filter)의 16채널의 아날로그 중간대역통과 필터회로를 CMOS VLSI 공정을 이용하여 설계하였다. 특히 큰 입력 신호에 대해서도 파형왜곡 없이 선형적인 특성을 가지는 트랜스 컨턱터를 이용하여 필터를 구현하였다. 필터는 저대역통과필터와 출력이득의 감쇄를 줄이기 위해서 중간대역통과필터를 이용하여 전체 시스템을 설계했다. 본 논문에서 기존의 150mVp-p 입력신호 범위의 트랜스 컨턱터를 Substrate 입력을 가지는 트랜스 컨턱터를 이용하여 입력신호 범위를 1Vp-p 까지 늘였다.

• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.84-89
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• 2012

The purpose of this study was to compare radiation dose and image quality between low-dose (LDP) and standard-dose protocol (SDP). LDP (120 kVp, 30 mAs, 2-mm thickness) and SDP (120 kVp, 180 mAs, 1.2-mm thickness) images obtained from 61 subjects were retrospectively evaluated at level of carina bifurcation, using multi-detector CT (Brilliance 16, Philips Medical Systems). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated at ascending aorta and infraspinatus muscle, from CT number and back-ground noise. Radiation dose from two protocols measured at 5-point using acrylic-phantom, and CT number and noise measured at 4-point using water-phantom. All statistical analysis were performed using SPSS 19.0 program. LDP images showed significantly more noise and a significantly lower SNR and CNR than did SDP images at ascending aorta and infraspinatus muscle. Noise, SNR and CNR were significantly correlated with body mass index (p<0.001). Radiation dose, SNR and CNR from phantom were significant differences between two protocols. LDP showed a significant reduction of radiation dose with a significant change in SNR and CNR compared with SDP. Therefore, exposure dose on LDP in clinical applications needs resetting highly more considering image quality.