• Journal of Bio-Environment Control
• /
• v.30 no.4
• /
• pp.401-409
• /
• 2021

This study aimed to estimate the photosynthetic capacity of tomato plants grown in a semi-closed greenhouse using temperature response models of plant photosynthesis by calculating the ribulose 1,5-bisphosphate carboxylase/oxygenase maximum carboxylation rate (V_cmax), maximum electron transport rate (J_max), thermal breakdown (high-temperature inhibition), and leaf respiration to predict the optimal conditions of the CO₂-controlled greenhouse, for maximizing the photosynthetic rate. Gas exchange measurements for the A-C_i curve response to CO₂ level with different light intensities {PAR (Photosynthetically Active Radiation) 200µmol·m^-2·s^-1 to 1500µmol·m^-2·s^-1} and leaf temperatures (20℃ to 35℃) were conducted with a portable infrared gas analyzer system. Arrhenius function, net CO₂ assimilation (A_n), thermal breakdown, and daylight leaf respiration (R_d) were also calculated using the modeling equation. Estimated J_max, A_n, Arrhenius function value, and thermal breakdown decreased in response to increased leaf temperature (> 30℃), and the optimum leaf temperature for the estimated J_max was 30℃. The CO₂ saturation point of the fifth leaf from the apical region was reached at 600ppm for 200 and 400µmol·m^-2·s^-1 of PAR, at 800ppm for 600 and 800µmol·m^-2·s^-1 of PAR, at 1000ppm for 1000µmol of PAR, and at 1500ppm for 1200 and 1500µmol·m^-2·s^-1 of PAR levels. The results suggest that the optimal conditions of CO₂ concentration can be determined, using the photosynthetic model equation, to improve the photosynthetic rates of fruit vegetables grown in greenhouses.

• The Journal of the Acoustical Society of Korea
• /
• v.14 no.2E
• /
• pp.50-56
• /
• 1995

This paper describes an efficient coding method for Korean characters using a three-state transition graph. To our knowledge, this is the first achievement of its kind. This new method, called the Paralle Hangul Dynamic Coding Method(PHDCM), compresses about 3.5 bits per a Korean character, which is more than 1 bit shorter than the conventional codes introduced thus far to achieve extensive code compression. When we ran the method on a MasPar machine, which is on SIMD SM (EFEW-PRAM)., it achieved a 49.314-fold speedup with 64 processors having 10 million Korean characters.

• Archives of Pharmacal Research
• /
• v.8 no.1
• /
• pp.15-20
• /
• 1985

Strong anti-inflammatory saponins Phytolacca americana (Phytolaccaceae) wereobtained from callus mass derived from the stems and also from that derived from the roots of cultivated Phytolacca americana (which were designated as PAS and PAR, respectively). The callus were grown on Linsmair and Skoog's agar medium supplemented with 1ppm OF 2, 4-dichlorophenoxyacetic acid. Phytol accoside B and D were obtained from PAS and phytolaccoside A and B from PAR. The thin layer chromatograms of the crude saponins from PAS and PAR were similar to those of original plants. PAS contained phytolaccoside B as a major component while phytolaccoside E was a major saponin in original plants.

• Journal of Ocean Engineering and Technology
• /
• v.11 no.1
• /
• pp.55-64
• /
• 1997

A wing operating in close proximity to the ground exhibits a reduction in induced drag, which increase the lift/drag ratio. The poert-augmented ram (RAR) phenomenon involves directiing the efflux from forward mounted propulsion ststem under the wings, with the efflux nearly stagnated under the wings. In the present paper, 3 dimentional PAR was numerically studied by solving the Navier-Stokes equations. Pressure distribution and velocity vectors are calculated around the wing surface and the ground. Through the numerical simulation, Cp values and lift/drag ratio are carefully reviewed by changing the height/chord; 0.05, 0.1, 0.3 and 0.8. The shape of model is NACA 0012 with a span/chord ratio of 3.0. According to the numerical results, the relationship between lift/drag and height/chord is fairly reasonable.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.12C
• /
• pp.1175-1187
• /
• 2007

This paper proposes a novel crest factor reduction (CFR) algorithm to be deployed on WCDMA basestation. Generally speaking, it is well described that the reduction of peak-to-average ratio (PAR) yields the possibility of using low cost power amplifier such that the basesation becomes economic However, the simple reduction of PAR could degrade the signal quality measured by either peak code domain error (PCDE) or error vector measurement (EVM), and the level of channel interference constrained by adjacent channel leakage ratio (ACLR). Regarding these imperfections, this paper introduces an effective CFR algorithm in which the function of filter-dependent CFR (FDCFR) incorporated with the histogram-based waterfilling code domain compensation (HBWCDC) carries out. To verify the performance of the proposed CFR technique, substantial simulations including comparative works are conducted with obeying W-CDMA basestation verification specification. To exploit the superiority, the performance of the proposed method is tentatively compared with that associated to the simple memoryless clipping method and the memory-required filter-dependent clipping method.

• Molecules and Cells
• /
• v.38 no.2
• /
• pp.156-162
• /
• 2015

Urokinase plasminogen activator (uPA) and urokinase plasminogen activator receptor (uPAR) play a major role in the infiltrative growth of glioblastoma. Downregulatoion of the uPA and uPAR has been reported to inhibit the growth glioblastoma. Here, we demonstrate that tristetraprolin (TTP) inhibits the growth of U87MG human glioma cells through downregulation of uPA and uPAR. Our results show that expression level of TTP is inversely correlated with those of uPA and uPAR in human glioma cells and tissues. TTP binds to the AU-rich elements within the 3' untranslated regions of uPA and uPAR and overexpression of TTP decreased the expression of uPA and uPAR through enhancing the degradation of their mRNAs. In addition, overexpression of TTP inhibited the growth and invasion of U87MG cells. Our findings implicate that TTP can be used as a promising therapeutic target to treat human glioma.

• Biomolecules & Therapeutics
• /
• v.24 no.5
• /
• pp.529-535
• /
• 2016

Atopic dermatitis (AD) results from gene and environment interactions that lead to a range of immunological abnormalities and breakdown of the skin barrier. Protease-activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is expressed in suprabasal layers of the epidermis. PAR2 is activated by both trypsin and a specific agonist peptide, SLIGKV-$NH_2$ and is involved in both epidermal permeability barrier homeostasis and epithelial inflammation. In this study, we investigated the effect of lobaric acid on inflammation, keratinocyte differentiation, and recovery of the skin barrier in hairless mice. Lobaric acid blocked trypsin-induced and SLIGKV-$NH_2$-induced PAR2 activation resulting in decreased mobilization of intracellular $Ca^{2+}$ in HaCaT keratinocytes. Lobaric acid reduced expression of interleukin-8 induced by SLIGKV-$NH_2$ and thymus and activation regulated chemokine (TARC) induced by tumor necrosis factor-a (TNF-${\alpha}$) and IFN-${\gamma}$ in HaCaT keratinocytes. Lobaric acid also blocked SLIGKV-$NH_2$-induced activation of ERK, which is a downstream signal of PAR2 in normal human keratinocytes (NHEKs). Treatment with SLIGKV-$NH_2$ downregulated expression of involucrin, a differentiation marker protein in HaCaT keratinocytes, and upregulated expression of involucrin, transglutamase1 and filaggrin in NHEKs. However, lobaric acid antagonized the effect of SLIGKV-$NH_2$ in HaCaT keratinocytes and NHEKs. Topical application of lobaric acid accelerated barrier recovery kinetics in a SKH-1 hairless mouse model. These results suggested that lobaric acid is a PAR2 antagonist and could be a possible therapeutic agent for atopic dermatitis.

• Korean Journal of Clinical Laboratory Science
• /
• v.53 no.3
• /
• pp.217-224
• /
• 2021

Fluoroquinolone (FQ) resistant gram-negative pathogens have emerged worldwide, and the recent increase in FQ resistant Escherichia coli is of great concern in Korea. This study investigated FQ resistance determinants and the epidemiological relationship of 56 ciprofloxacin-resistant E. coli isolated from a tertiary hospital in Daejeon, South Korea from June to December 2018. Molecular epidemiology was investigated by multilocus sequence typing (MLST). Polymerase chain reaction (PCR) and sequence analysis were performed to identify chromosomal mutations in the quinolone resistance determining regions (QRDR) of gyrA, gyrB, parC, and parE and to describe the occurrence of the following plasmid-mediated quinolone resistance (PMQR) genes: aac(6)-Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, and qnrS. MLST analysis showed 12 sequence types (STs) and the most prevalent ST was ST131 (31/56, 55.4%), followed by ST1193 (13/56, 23.2%), and ST405 (3/56, 5.4%). In 56 ciprofloxacin-resistant E. coli isolates, Ser83→Leu and Asp87→Asn in gyrA and Ser80→Ile and Glu84→Val in parC (51.8%, 29/56) were the most frequent amino acid substitutions and aac(6)-Ib-cr (33.9%, 19/56) was the most common PMQR gene. These results of FQ resistance determinants were more frequently observed in ST131 compared with other clones. Continuous monitoring of the epidemiological characteristics of ciprofloxacin-resistant E. coli isolates and further investigation of FQ resistance determinants are necessary.

• Journal of Korean Society for Atmospheric Environment
• /
• v.28 no.1
• /
• pp.77-85
• /
• 2012

In this study, emission rates (ER) of biogenic volatile organic compounds (BVOCs) were measured by varying levels of photosynthetically active radiation (PAR). An appropriate plan for ozone reduction according to increasing ecology area ratio in future metropolitan areas was suggested. Several trees were selected as representative tree species in urban areas. Emission rates and composition ratios of monoterpene and isoprene emitted from these trees were estimated and compared. As a result, it was found that emission rates of BVOCs were considerably different depending on tree species. Especially, BVOCs emitted from Platanus orientalis and Quercus mongolica could significantly affect ozone increase in the metropolitan area, because the emission rates were several thousands to ten thousand times higher than those emitted from Zelkova serrata and Prunus serrulata. Furthermore, it was observed that emission rates of BVOCs by species increased maximum up to 10 times when PAR, which has close relations with temperature, rose. It was concluded that tree species such as Zelkova serrata et al., was appropriate for metropolitan areas since the species has low ozone potential and good landscape. Suppose this type of trees are planted on purpose in the urban areas, better ambient air quality will be promised in the future.

• Parasites, Hosts and Diseases
• /
• v.49 no.3
• /
• pp.235-243
• /
• 2011

In order to get a better understanding of the role of protease-activated receptor 2 (PAR2) in type 2 helper T (Th2) cell responses against Trichinella spiralis infection, we analyzed Th2 responses in T. spiralis-infected PAR2 knockout (KO) mice. The levels of the Th2 cell-secreted cytokines, IL-4, IL-5, and IL-13 were markedly reduced in the PAR2 KO mice as compared to the wild type mice following infection with T. spiralis. The serum levels of parasite-specific IgE increased significantly in the wild type mice as the result of T. spiralis infection, but this level was not significantly increased in PAR2 KO mice. The expression level of thymic stromal lymphopoietin, IL-25, and eotaxin gene (the genes were recently known as Th2 response initiators) of mouse intestinal epithelial cells were increased as the result of treatment with T. spiralis excretory-secretory proteins. However, the expression of these chemokine genes was inhibited by protease inhibitor treatments. In conclusion, PAR2 might involve in Th2 responses against T. spiralis infection.