• The Korean Journal of Physiology
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• v.23 no.1
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• pp.43-49
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• 1989

Effects of atrial natriuretic peptide (ANP) on the development of hypertension in 2-kidney, 1-clip (2-K, 1-C) rats were examined. In one group of rats, ANP infusion (500 ng/hr, iv) started immediately after clipping the renal artery. Another group of rats with one kidney-clipped was without ANP infusion and served as a control. Blood pressure was measured on days 4, 7, and 10 following clipping the renal artery. Upon the last blood pressure measurement finished, blood sample was collected by decapitation to measure plasma renin activity (PRA), and both kidneys were taken to weigh and to measure renin content. The ANP-infused group showed an attenuation of increases in blood pressure compared to the non-infused control group. PRA was lower in the ANP-infused group than in the non-infused group. Cortical renal renin content (RRC) of the clipped kidneys was not different between ANP-infused and non-infused groups. The clipped kidneys showed a higher RRC and weighed less than the non-clipped contralateral kidneys within each group. In contrast, sham-clipped rats did not show significant changes in any of the parameters examined regardless of whether ANP was infused or not. These results demonstrate that chronic ANP infusion does not prevent but does attenuate the development of hypertension in 2-K, 1-C rats. It is suggested that ANP plays a role in the long-term regulation of blood pressure, at least in part, by antagonizing the renin-angiotensin-system.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.285-294
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• 2011

The abatement of methane emission from ruminants is an important global issue due to its contribution to greenhouse gas with carbon dioxide. Methane is generated in the rumen by methanogens (archaea) that utilize metabolic hydrogen ($H_2$) to reduce carbon dioxide, and is a significant electron sink in the rumen ecosystem. Therefore, the competition for hydrogen used for methanogenesis with alternative reductions of rumen microbes should be an effective option to reduce rumen methanogenesis. Some methanogens parasitically survive on the surface of ciliate protozoa, so that defaunation or decrease in protozoa number might contribute to abate methanogenesis. The most important issue for mitigation of rumen methanogenesis with manipulators is to secure safety for animals and their products and the environment. In this respect, prophylactic effects of probiotics, prebiotics and miscellaneous compounds to mitigate rumen methanogenesis have been developed instead of antibiotics, ionophores such as monensin, and lasalocid in Japan. Nitrate suppresses rumen methanogenesis by its reducing reaction in the rumen. However, excess intake of nitrate causes intoxication due to nitrite accumulation, which induces methemoglobinemia. The nitrite accumulation is attributed to a relatively higher rate of nitrate reduction to nitrite than nitrite to ammonia via nitroxyl and hydroxylamine. The in vitro and in vivo trials have been conducted to clarify the prophylactic effects of L-cysteine, some strains of lactic acid bacteria and yeast and/or ${\beta}$1-4 galactooligosaccharide on nitrate-nitrite intoxication and methanogenesis. The administration of nitrate with ${\beta}$1-4 galacto-oligosaccharide, Candida kefyr, and Lactococcus lactis subsp. lactis were suggested to possibly control rumen methanogenesis and prevent nitrite formation in the rumen. For prebiotics, nisin which is a bacteriocin produced by Lactococcus lactis subsp. lactis has been demonstrated to abate rumen methanogenesis in the same manner as monensin. A protein resistant anti-microbe (PRA) has been isolated from Lactobacillus plantarum as a manipulator to mitigate rumen methanogenesis. Recently, hydrogen peroxide was identified as a part of the manipulating effect of PRA on rumen methanogenesis. The suppressing effects of secondary metabolites from plants such as saponin and tannin on rumen methanogenesis have been examined. Especially, yucca schidigera extract, sarsaponin (steroidal glycosides), can suppress rumen methanogenesis thereby improving protein utilization efficiency. The cashew nutshell liquid (CNSL), or cashew shell oil, which is a natural resin found in the honeycomb structure of the cashew nutshell has been found to mitigate rumen methanogenesis. In an attempt to seek manipulators in the section on methane belching from ruminants, the arrangement of an inventory of mitigation technologies available for the Clean Development Mechanism (CDM) and Joint Implementation (JI) in the Kyoto mechanism has been advancing to target ruminant livestock in Asian and Pacific regions.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.117-124
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• 2015

Purpose: The purpose of this study was to compare the accommodative function of young adult in their 20s wearing monovision, modified monovision, and aspheric multifocal contact lenses at near task. Methods: Thirty young adults ($23.53{\pm}2.37years$) were fitted with monovision, modified monovision (the application of single vision contact lenses and center-near low addition aspheric multifocal contact lenses), and aspheric center-near multifocal contact lenses. After wearing these modalities during a week for adaption, and after watching visual display at computer for inducing accommodative pressure for 1 hour. The following assessments of accommodative function were made: contrast visual acuity (VA) at distance and near; accommodative response; near accommodative facility; and negative relative accommodation (NRA)/positive relative accommodation (PRA). All measurements were carried out binocularly. Results: In binocular distance VA with contrast of 10%, monovision was the worst among the four modalities (p=0.005). In accommodative response at 1 m (1.00 D), monovision was the lowest (p<0.05) and accommodative response at 40 cm (2.50 D) with monovision was lower than that of modified monovision and multifocal contact lens (p<0.05). We also found that there were no significant differences in accommodative facility and NRA/PRA among the four modalities. Conclusions: In young adult (20s), monovision with low add reduced the accommodative response at near task, however, modified monovision and multifocal lens with center-near type did not affect accommodative relaxation.

• Journal of Periodontal and Implant Science
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• v.54 no.2
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• pp.75-84
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• 2024

Purpose: This study investigated the relationship between the number of days that hospital visits were postponed and changes in clinical parameters due to the spread of coronavirus disease 2019 (COVID-19), after the Japanese government declared a state of emergency in April 2020. Methods: Regarding the status of postponement of appointments, we analyzed the patients who had visited the Nihon University Hospital at Matsudo for more than 1 year for supportive periodontal therapy (SPT) and classified them into low-, moderate- and high-risk subgroups according to the periodontal risk assessment (PRA). Clinical parameters for periodontal disease such as probing depth (PD), full-mouth bleeding score (FMBS), full-mouth plaque score, periodontal inflamed surface area (PISA), and periodontal epithelial surface area (PESA) were analyzed in 2 periods, from October 2019 to March 2020 and after April 2020. Correlation coefficients between days of deferral and the degree of changes in clinical parameters were calculated. Results: The mean age of the 749 patients was 67.56±10.85 years, and 63.82% were female. Out of 749 patients, 33.24% deferred their SPT appointments after April 2020. The average total of postponement days was 109.49±88.84. The number of postponement days was positively correlated with changes in average PD (rs=0.474) and PESA (rs=0.443) in the high-risk subgroup of FMBS, and average PD (rs=0.293) and PESA (rs=0.253) in the highrisk subgroup of tooth number (TN). Patients belonging to the high-risk subgroups for both FMBS and TN had a positive correlation between postponement days and PISA (rs=0.56). Conclusions: The findings, the spread of COVID-19 appears to have extended the visit interval for some SPT patients. Moreover, longer visit intervals were correlated with the worsening of some clinical parameters for SPT patients with high PRA.

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.60-60
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• 2015

Hybrid histidine kinase is a part of two-component system that is required for various stress responses and pathogenesis of pathogenic fungi. In the present study, Tco1, a homologue of human pathogen Cryptococcus neoformans Tco1 encoding a hybrid histidine kinase, was identified in corn smut pathogen Ustilago maydis by bioinformatic analysis. To explore the role of Tco1 in the virulence of U. maydis, mutants in which the tco1 gene was partially deleted were constructed by allelic exchange. The U. maydis tco1 mutants did show unaltered growth rate on axenic medium but were unable to produce conjugation tubes and develop fuzzy filaments, resulting in impaired mating of compatible strains. The expression levels of prf1, pra1, and mfa1 which are involved in the pheromone pathway significantly decreased in the tco1 mutants. In inoculation tests to host, the tco1 mutants showed significantly reduced ability in the production of anthocyanin pigments and tumor development on maize leaves. Overall, the combined results indicated that Tco1 plays important roles in sexual development and virulence of U. maydis by regulating the expression of the genes involved in the pheromone pathway.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1166-1179
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• 2013

In wireless sensor network (WSN) environments, environmental noises are generated by, for example, small passing animals, crickets chirping or foliage blowing and will interfere target detection if the noises are higher than the sensor threshold value. For accurate tracking by acoustic WSNs, these environmental noises should be filtered out before initiating track. This paper presents the effect of environmental noises on target tracking and proposes a new algorithm for the noise mitigation in acoustic WSNs. We find that our noise mitigation algorithm works well even for targets with sensing range shorter than the sensor separation as well as with longer sensing ranges. It is also found that noise duration at each sensor affects the performance of the algorithm. A detection algorithm is also presented to account for the Doppler effect which is an important consideration for tracking higher-speed ground targets. For tracking, we use the weighted sensor position centroid to represent the target position measurement and use the Kalman filter (KF) for tracking.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.170-175
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• 2004

The purpose of this study was to monitor bacteria present in raw water and to investigate the effect of ozone, UV and combined ozone/UV processes for inactivating bacteria. Both polymerase chain reaction (PCR)-fragment length polymorphic analysis (PRA) and PCR-sequence analysis (PSA) were applied for the simultaneous analysis of numerous bacteria species present in each tested water, such as drinking water (DRW), drinking water source (DRWS) and sewage effluent water (SEW). According to the result, the number of detected bacteria species was zero in DRW, 58 in DRWS and 13 in SEW. After treatment of the each process, the ozone/UV process was the most successful for inactivating almost all bacteria. However, it was found that Flavobacterium sp., Pseudomonas sp. and Beta proteobacterium sp. had strong resistant to all tested processes, requiring further detailed study.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.81-81
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• 1997

We previously demonstrated an enhancer-like positive regulatory element within a 259-bp sequence (-2352 to-2094 bp) of the human CYP1A2 gene in HepG2 cells. Three protein binding sites were identified by DNase I footprint analyses within the 259-bp sequence: protected region A PRA ( -2283 to-2243 bp), PRB (-2218 to-2187 bp), and PRC (-2124 to-2098 bp) (I. Chung and E. Bresnick, Mol. Pharmacol. 47, 677-685, 1995). In the present study, the functional significance of those protected regions was examined. Transfection experiments with deletion and substitution mutants defined the PRB and PRC as containing positive and negative regulatory elements, respectively. Human breast carcinoma MCF-7 cells were cotransfected with a hepatocyte nuclear factor-1 (HNF-1) expression vector and CYP1A2 promoter-or thymidine kinase promoter-luciferase remoter gene constructs. HNF-1, which contributes to the liver specificity of genes, enhanced reporter gene activity in a PRC sequence-dependent manner. These results suggested that PRC could exist bound to a repressor which was displaceable by other transcription factors such as HNF-1. Results obtained by transfection of HepG2 hepatoma cells with various PRB substitution mutant-luciferase gene fusion constructs indicated that the entire sequence of PRB was necessary for promoter activity. Consequently, the regulation of CYP1A3 expression is very complex, requiring a number of both positive and negative regulatory factors.

• Journal of the Korean Society of Systems Engineering
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• v.12 no.2
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• pp.91-99
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• 2016

The safety of nuclear power plants has received much attention; this safety largely depends on the continuous availability of electrical energy source during all modes of nuclear power plant operation. A station blackout (SBO) describes the loss of the off-site electric power, the failure of the emergency diesel generators, and the unavailability of the alternate AC (AAC) power. Consequently, all systems that are AC powered such as the safety injection, shutdown cooling, component cooling water, and essential service water systems are unavailable. The aim of this study is to investigate the deficiencies of the existing alternatives for coping with an extended SBO for APR1400 design. The method is analyzing the existing deficiencies and proposing an optimal solution for the NPP design during the extended SBO. This study, established a new passive system, called passive decay heat removal system (PDHRS), using systems engineering approach.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.128-129
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• 2008

The annealing effects of $SiO_2/Si_3N_4$ stacked tunneling dielectrics were investigated. I-V characteristics of band gap engineered tunneling gate stacks consisted of $Si_3N_4/SiO_2/Si_3N_4$(NON), $SiO_2/Si_3N_4/SiO_2$(ONO) dielectrics were evaluated and compared with $SiO_2$ single layer using the MOS(Metal-Oxide-Semiconductor) capacitor structure. The leakage currents of engineered tunneling barriers (ONO, NON stacks) are lower than that of the conventional $SiO_2$ single layer at low electrical field. Meanwhile, the engineered tunneling barriers have larger tunneling current at high electrical field and improved electrical characteristics by annealing processes than $SiO_2$ layer.