• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.114-117
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• 2000

일반적으로 LPA에서는 위상을 조정하기 위해 매우 긴 지연선을 필요로 한다. 지연성능은 고전력이나 저전력 모두에서 임의의 길이의 동축선로를 여러번의 과정을 거쳐 적용해봄으로써 구현된다. 그러나 동축선로형 지연선은 부피나 높은 삽입손실 등의 제약이 많이 따른다. 본 논문에서는 마이크로스트립 형태의 지연선 대역통과 여파기를 설계하였고, 실험결과는 지연선여파기가 동축선로를 대신하여 LPA 시스템에 적용이 가능함을 보였다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.3
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• pp.182-189
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• 2020

This study was conducted to evaluate the effect of lactic acid bacteria (LAB) inoculation to domestically-cultivated Italian ryegrass (IRG) on silage fermentation and in vitro ruminal fermentation. There were six treatments based on the LAB inoculants: 1) no addition of LAB (negative control: NC), additions of 2) commercially-available LAB (positive control: PC), 3) Lactobacillus plantarum (LPL), 4) L. paracasei (LPA), 5) L. acidophilus (LA), and 6) L. pentosus (LPT). All treatments were inoculated at a concentration of 10⁶ CFU/g and ensiled for 3, 7, 21, and 42 days in triplicate and analyzed for nutritive values when ensiling was terminated. Day 42 silage from all treatments were also examined for in vitro ruminal fermentation. After 42 days, LAB-inoculated silages had higher (P<0.05) lactic acid concentration compared to the NC. In terms of nutritive values, the silages treated with LPA, LA, and LPT showed higher (P<0.05) crude protein and lower (P<0.05) neutral detergent fiber and acid detergent fiber content compared to the rest of the treatment. In vitro ruminal dry matter degradability was not affected by LAB addition. However, LAB-treated IRG had shown higher (P<0.05) ammonia-N compared with that of the NC. LPA had shown the highest (P<0.05) volatile fatty acid concentration among the LAB examined. In conclusion, the addition of a single strain of LAB appeared to produce a quality IRG silage compared with the NC and the PC. Among the strains examined, LPA seemed to be superior to the others.

• Clinical and Experimental Pediatrics
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• v.59 no.4
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• pp.183-189
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• 2016

Purpose: This study aimed to evaluate the correlation, according to postnatal age, between plasma B-type natriuretic peptide (BNP) levels and echocardiographic parameters for the assessment of patent ductus arteriosus (PDA) in preterm infants with respiratory distress. Methods: We enrolled 42 preterm infants with respiratory distress who underwent serial echocardiographic evaluation with simultaneous plasma BNP measurements until ductal closure. The correlations between BNP levels and the following 4 representative echocardiographic parameters were studied: diameter of the ductus arteriosus (DA), ratio of the left atrial diameter to the aortic diameter (LA/Ao), ratio of the PDA diameter to the infant's left pulmonary artery diameter (PDA/LPA), and the antegrade diastolic flow of LPA (DFLPA). Results: BNP levels were significantly correlated to the magnitude of the ductal shunt, comprising the DA diameter, PDA/LPA ratio, LA/Ao ratio, and antegrade DFLPA for the overall study period. The earliest significant correlation, starting from postnatal day 2, was observed between the LA/Ao ratio and BNP levels. The PDA/LPA ratio and the antegrade DFLPA showed significant correlations with BNP levels postnatal day 3 onward, and with the DA diameter, postnatal day 5 onward. Conclusion: BNP levels and echocardiographic parameters showed a positive correlation, but the significance of the correlations differed according to the postnatal age, especially during the first few days of life.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.1
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• pp.131-142
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• 2017

The function of urban parks as wildlife habitats is becoming increasingly important. The urban park serves as a key area for preserving urban biodiversity. The purpose of this study is to estimate the bird species diversity in 30 parks in Cheonan city and quantitatively analyze the influence of vegetation, park structure and landscape connectivity index. As the results, a total of 27 birds species and 1,509 individuals were found at the sites and the largest number of birds were found in the Cheongsa park with 17 species. The optimal regression model was selected as the explanatory variables for the logged park area (LPA), the tree cover ratio (Co_T) and the patch betweenness centrality (PB). LPA and Co_T mean the internal characteristics of the park, and PB was the external environmental variable meaning landscape connectivity. LPA was the most important factor (73.3%) as bird habitat, and the PB could be interpreted as a factor that should be considered as important (26.7%). It will be possible to consider these environmental variables in the park and green area construction and management.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.81-88
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• 1998

The determination of appropriate parameters and parameter conditions is very important for the optimization of production of target materials. Taguchi's method has been used widely as the basis for development trials and optimization during industrial process design. Reaction variables which influence product yield are easily determined and their effects are revealed by just a few reactions, negating the need for extensive experimental investigation. There are usually some factors that are responsible for variations in process characteristics, so called noise factors. Controlling noise factors is very costly and difficult or impossible. Taguchi's experimental design method was examined to determine the control factor's level that is less sensitive to the changes in environmental conditions and other noise factors without control of noise factors. In this study, optimization of lipase-catalyzed production of lysophosphatidic acid (LPA) which has various physiological functions was performed by Taguchi's method. We obtained LPA yields ($66.5\%$) with low variance (5.32) at 400 RPM, molar ratio of 40 : 3 (mol) (fatty acid: G-3-P), 48 h, and $50^{\circ}C$. Thus, bioactive LPA with a desired fatty acid moiety could be produced with high yields and low variance despite various environmental noise factors.

• Toxicological Research
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• v.22 no.4
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• pp.397-402
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• 2006

Lipid mediator such as lysophosphatidic acid (LPA) plays an important role in inflammation and wound heating, has been recently reported to induce influx of extracellular calcium into erythrocytes. This elevation in intracellular calcium level may cause destruction of membrane asymmetry and procoagulant microvesicle formation. Thus, we investigated if the lipid mediator could induce microvesicle formation as a result of extracellular calcium influx in human erythrocytes. Treatment with lipid mediator to erythrocytes resulted in microvesicle generation In a concentration-, time-dependent manner. Microvesicles formed expressed procoagulant phosphatidylserine (PS) on their surface membrane significantly as well. LPA did not affect the band 3 phosphorylation which is involved in morphological change in erythrocytes. Pretreatment with suramin did not inhibit LPA-induced microvesicle generation, suggesting microvesicle generation was not receptor-dependent pathway. Depletion of intracellular ATP levels in erythrocytes was suggested to be one of the mechanism for these events.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1407-1413
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• 2000

This paper presents a feedforward linear power amplifier (LPA) using error feedback technique to achieve low intermodulation distortions(IMD) of power amplifiers for base stations. Especially, the proposed linear power amplifier is applied to feedforward technique combined with error feedback technique, which has no loss of amplifier gain unlike typical feedback technique. The proposed LPA is designed by using HP ADS ver. 1.3, fabricated. When two-tone signals at 1850 MHz and 1851.25 MHz with -7 dBm/tone from synthesizers are injected into the main power amplifier with gain of 28 dB and P1dB of 1W, the proposed LPA could reduce more than 35 dB.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.168-177
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• 2020

Background: Ginseng has been widely used as a health-promoting tonic. Gintonin present in ginseng acts as a lysophosphatidic acid (LPA) receptor ligand that activates six LPA receptor subtypes. The LPA6 subtype plays a key role in normal hair growth, and mutations in the LPA6 receptor impair normal human hair growth. Currently, human hair loss and alopecia are concerning issues that affect peoples' social and day-to-day lives. Objective: We investigated the in vitro and in vivo effects of a gintonin-enriched fraction (GEF) on mouse hair growth. Methods: Human hair follicle dermal papilla cells (HFDPCs) and six-week-old male C57BL/6 mice were used. The mice were divided into the four groups: control, 1% minoxidil, 0.75% GEF, and 1.5% GEF. The dorsal hair was removed to synchronize the telogen phase. Each group was treated topically, once a day, for 15 days. We analyzed hair growth activity and histological changes. Results: GEF induced transient [Ca²⁺]_i, which stimulated HFDPC proliferation and caused 5-bromo-2'-deoxyuridine (BrdU) incorporation in a concentration-dependent manner. GEF-mediated HFDPC proliferation was blocked by the LPA receptor antagonist and Ca²⁺ chelator. HFDPC treatment with GEF stimulated vascular endothelial growth factor release. Topical application of GEF and minoxidil promoted hair growth in a dose-dependent manner. Histological analysis showed that GEF and minoxidil increased the number of hair follicles and hair weight. Conclusion: Topical application of GEF promotes mouse hair growth through HFDPC proliferation. GEF could be one of the main components of ginseng that promote hair growth and could be used to treat human alopecia.

• Tuberculosis and Respiratory Diseases
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• v.83 no.4
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• pp.289-294
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• 2020

Background: Line probe assay (LPA) is standard diagnostic tool to detect multidrug resistant tuberculosis. Non-interpretable (NI) results in LPA (complete missing or light wild-type 3 and 8 bands with no mutation band in rpoB gene region) poses a diagnostic challenge. Methods: Sputum samples obtained between October 2016 and July 2017 at the Intermediate Reference Laboratory, All India Institute of Medical Sciences Hospital, New Delhi, India were screened. Smear-positive and smear-negative culture-positive specimens were subjected to LPA Genotype MTBDRplus Ver 2.0. Smear-negative with culture-negative and culture contamination were excluded. LPA NI samples were subjected to phenotypic drug susceptibility testing (pDST) using MGIT-960 and sequencing. Results: A total of 1,614 sputum specimens were screened and 1,340 were included for the study (smear-positive [n=1,188] and smear-negative culture-positive [n=152]). LPA demonstrated 1,306 (97.5%) valid results with TUB (Mycobacterium tuberculosis) band, 24 (1.8%) NI, three (0.2%) valid results without TUB band, and seven (0.5%) invalid results. Among the NI results, 22 isolates (91.7%) were found to be rifampicin (RIF) resistant and two (8.3%) were RIF sensitive in the pDST. Sequencing revealed that rpoB mutations were noted in all 22 cases with RIF resistance, whereas the remaining two cases had wild-type strains. Of the 22 cases with rpoB mutations, the most frequent mutation was S531W (n=10, 45.5%), followed by S531F (n=6, 27.2%), L530P (n=2, 9.1%), A532V (n=2, 9.1%), and L533P (n=2, 9.1%). Conclusion: The present study showed that the results of the Genotype MTBDRplus assay were NI in a small proportion of isolates. pDST and rpoB sequencing were useful in elucidating the cause and clinical meaning of the NI results.

• Journal of Ginseng Research
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• v.45 no.3
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• pp.390-400
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• 2021

Background: We recently showed that gintonin, an active ginseng ingredient, exhibits antibrain neurodegenerative disease effects including multiple target mechanisms such as antioxidative stress and antiinflammation via the lysophosphatidic acid (LPA) receptors. Amyotrophic lateral sclerosis (ALS) is a spinal disease characterized by neurodegenerative changes in motor neurons with subsequent skeletal muscle paralysis and death. However, pathophysiological mechanisms of ALS are still elusive, and therapeutic drugs have not yet been developed. We investigate the putative alleviating effects of gintonin in ALS. Methods: The G93A-SOD1 transgenic mouse ALS model was used. Gintonin (50 or 100 mg/kg/day, p.o.) administration started from week seven. We performed histological analyses, immunoblot assays, and behavioral tests. Results: Gintonin extended mouse survival and relieved motor dysfunctions. Histological analyses of spinal cords revealed that gintonin increased the survival of motor neurons, expression of brain-derived neurotrophic factors, choline acetyltransferase, NeuN, and Nissl bodies compared with the vehicle control. Gintonin attenuated elevated spinal NAD(P) quinone oxidoreductase 1 expression and decreased oxidative stress-related ferritin, ionized calcium-binding adapter molecule 1-immunoreactive microglia, S100β-immunoreactive astrocyte, and Olig2-immunoreactive oligodendrocytes compared with the control vehicle. Interestingly, we found that the spinal LPA1 receptor level was decreased, whereas gintonin treatment restored decreased LPA1 receptor expression levels in the G93A-SOD1 transgenic mouse, thereby attenuating neurological symptoms and histological deficits. Conclusion: Gintonin-mediated symptomatic improvements of ALS might be associated with the attenuations of neuronal loss and oxidative stress via the spinal LPA1 receptor regulations. The present results suggest that the spinal LPA1 receptor is engaged in ALS, and gintonin may be useful for relieving ALS symptoms.