• Title/Summary/Keyword: $K_p$

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Detection of Extracellular Enzyme Activity in Penicillium using Chromogenic Media

  • Yoon, Ji-Hwan;Hong, Seung-Beom;Ko, Seung-Ju;Kim, Seong-Hwan
    • Mycobiology
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    • v.35 no.3
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    • pp.166-169
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    • 2007
  • A total of 106 Penicillium species were tested to examine their ability of degrading cellobiose, pectin and xylan. The activity of ${\beta}$-glucosidase was generally strong in all the Penicillium species tested. P. citrinum, P. charlesii, P. manginii and P. aurantiacum showed the higher ability of producing ${\beta}$-glucosidase than other tested species. Pectinase activity was detected in 24 Penicillium species. P. paracanescens, P. sizovae, P. sartoryi, P. chrysogenum, and P. claviforme showed strong pectinase activity. In xylanase assay, 84 Penicillium species showed activity. Strong xylanase activity was detected from P. megasporum, P. sartoryi, P. chrysogenum, P. glandicola, P. discolor, and P. coprophilum. Overall, most of the Penicillium species tested showed strong ${\beta}$-glucosidase activity. The degree of pectinase and xylanase activity varied depending on Penicillium species.

Effects of Simulated Acid Rain on Mineral Nutrient Movement in Soil (인공산성비 처리가 토양의 무기양분 이동에 미치는 영향)

  • Ryu, Kwan-Shig
    • Korean Journal of Environmental Agriculture
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    • v.17 no.4
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    • pp.362-367
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    • 1998
  • To investigate the effects of simulated acid rain(SAR) on the downward movement of mineral nutrients, SARs of different pH were applied to the soil. SAR of pH 2.0 decreased the soil pH greatly, while SAR of pH 4.0 and 6.0 did not change the soil pH to compare to that of SAR of pH 2.0. Decrease in soil pH was in the order of sandy loam > loam > clay loam. The amoumt of leached exchangeable and soluble bases from the soil due to the penetration of SAR was in the order of Ca >Mg > K. After application of 1200mm SAR of pH 2.0 in to the soil downward mean movements of the exchangeable and soluble bases was in the order of Mg > Ca > K in sandy loam and loam soil and Ca > Mg > K in clay loam soil. Downward movements of the those bases under pH 4.0 into the soil was in the order of Mg > K > Ca in sandy loam and clay loam, and K > Mg > Ca in loam soil. Available phosphorus moved slightly downward with increasing acidity of the SAR.

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Kato's Inequalities for Degenerate Quasilinear Elliptic Operators

  • Horiuchi, Toshio
    • Kyungpook Mathematical Journal
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    • v.48 no.1
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    • pp.15-24
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    • 2008
  • Let $N{\geq}1$ and p > 1. Let ${\Omega}$ be a domain of $\mathbb{R}^N$. In this article we shall establish Kato's inequalities for quasilinear degenerate elliptic operators of the form $A_pu$ = divA(x,$\nabla$u) for $u{\in}K_p({\Omega})$, ), where $K_p({\Omega})$ is an admissible class and $A(x,\xi)\;:\;{\Omega}{\times}\mathbb{R}^N{\rightarrow}\mathbb{R}^N$ is a mapping satisfying some structural conditions. If p = 2 for example, then we have $K_2({\Omega})\;= \;\{u\;{\in}\;L_{loc}^1({\Omega})\;:\;\partial_ju,\;\partial_{j,k}^2u\;{\in}\;L_{loc}^1({\Omega})\;for\;j,k\;=\;1,2,{\cdots},N\}$. Then we shall prove that $A_p{\mid}u{\mid}\;\geq$ (sgn u) $A_pu$ and $A_pu^+\;\geq\;(sgn^+u)^{p-1}\;A_pu$ in D'(${\Omega}$) with $u\;\in\;K_p({\Omega})$. These inequalities are called Kato's inequalities provided that p = 2. The class of operators $A_p$ contains the so-called p-harmonic operators $L_p\;=\;div(\mid{{\nabla}u{\mid}^{p-2}{\nabla}u)$ for $A(x,\xi)={\mid}\xi{\mid}^{p-2}\xi$.

Regulation of Intracellular pH by SHC1 in Saccharomyces cerevisiae (효모에서 SHC1 유전자의 이온 농도 조절에 의한 세포내 pH 항상성 유지)

  • 하승길;전준철;최의열
    • Korean Journal of Microbiology
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    • v.38 no.3
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    • pp.168-172
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    • 2002
  • Budding yeasts maintain an effective system to regulate intracellular pH in response to environmental pH fluctuation. In a previous study we reported that SHC1 plays a role in cell growth at alkaline condition, not at acid pH. We constructed a null mutant deleted an entire open reading frame for SHC1. To test whether the retardation in cell growth was caused by the absence of intracellular pH buffering capacity, we measured intracellular pH with a pH-sensitive fluorescent dye, C.SNARE. The intracellular pH of the mutant cell was much higher than that of wild-type cells, indicating that the mutant cells lack some types of buffering capacity. We also investigated the level of $Na^+ and K^+$ content with atomic mass spectroscopy after alkali shock. Wild-type cell showed a higher level of intracellular K^+$ content, whereas there was no difference in $Na^+$ level. The result suggested that K^+$ is more important in the regulation of intracellular pH in yeasts.

DNA Hypermethylation of Cell Cycle (p15 and p16) and Apoptotic (p14, p53, DAPK and TMS1) Genes in Peripheral Blood of Leukemia Patients

  • Bodoor, Khaldon;Haddad, Yazan;Alkhateeb, Asem;Al-Abbadi, Abdullah;Dowairi, Mohammad;Magableh, Ahmad;Bsoul, Nazzal;Ghabkari, Abdulhameed
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.75-84
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    • 2014
  • Aberrant DNA methylation of tumor suppressor genes has been reported in all major types of leukemia with potential involvement in the inactivation of regulatory cell cycle and apoptosis genes. However, most of the previous reports did not show the extent of concurrent methylation of multiple genes in the four leukemia types. Here, we analyzed six key genes (p14, p15, p16, p53, DAPK and TMS1) for DNA methylation using methylation specific PCR to analyze peripheral blood of 78 leukemia patients (24 CML, 25 CLL, 12 AML, and 17 ALL) and 24 healthy volunteers. In CML, methylation was detected for p15 (11%), p16 (9%), p53 (23%) and DAPK (23%), in CLL, p14 (25%), p15 (19%), p16 (12%), p53 (17%) and DAPK (36%), in AML, p14 (8%), p15 (45%), p53 (9%) and DAPK (17%) and in ALL, p15 (14%), p16 (8%), and p53 (8%). This study highlighted an essential role of DAPK methylation in chronic leukemia in contrast to p15 methylation in the acute cases, whereas TMS1 hypermethylation was absent in all cases. Furthermore, hypermethylation of multiple genes per patient was observed, with obvious selectiveness in the 9p21 chromosomal region genes (p14, p15 and p16). Interestingly, methylation of p15 increased the risk of methylation in p53, and vice versa, by five folds (p=0.03) indicating possible synergistic epigenetic disruption of different phases of the cell cycle or between the cell cycle and apoptosis. The investigation of multiple relationships between methylated genes might shed light on tumor specific inactivation of the cell cycle and apoptotic pathways.

A study on release characteristics and forms of phosphorus in sediments (퇴적물에서의 인의 용출특성과 존재형태에 관한 연구)

  • 김은호;김형석
    • Journal of environmental and Sanitary engineering
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    • v.17 no.1
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    • pp.75-80
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    • 2002
  • This study was carried out to investigate release characteristics of phosphorus with DO, pH and temperature, to suppose its behaviour with time using mathematical model, and to under-stand its forms with pH. Released SRP was in inversely proportional to DO and it did few release in initial aerobic conditions, but it did actively with decreasing DO concentration. Also, its release was increased with increasing pH and temperature. It was found that relation between time and released SRP concentration was zero order reaction. As compared with k values in various pH and temp., they was $k_{15}>k_{25}$ in pH 6 but was $k_{15} in pH 7 and 8. Considering forms of phosphorus with pH, Resdi.-P & NAI-P increased but Ads.-P & Apt.-P decreased with increasing pH.

p-n Heterojunction Composed of n-ZnO/p-Zn-doped InP

  • Shim, Eun-Sub;Kang, Hong-Seong;Kang, Jeong-Seok;Pang, Seong-Sik;Lee, Sang-Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.1
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    • pp.1-3
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    • 2002
  • A p-n junction was obtained by the deposition of an n-type ZnO thin film on a p-type Zn-doped InP substrate. The Zn-doped InP substrate has been made by the diffusion of Zn with sealed ampoule technique. The ZnO deposition process was performed by pulsed laser deposition (PLD). The p-n junction was formed and showed typical I-V characteristics. We will also discuss about the realization of an ultraviolet light-emitting diode (LED). The structure of n-ZnO/p-Zn-doped InP could be a good candidate for the realization of an ultraviolet light-emitting diode or an ultraviolet laser diode.

Effect of pH and Initial Phosphorus Concentration on Phosphorus Removal by Aluminum Salts (알루미늄염에 의한 인 제거 시 pH와 초기 인 농도의 영향)

  • Park, Jeongwon;Kwak, Hyoeun;Min, Sojin;Chung, Hyung-Keun;Park, Pyung-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.2
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    • pp.123-130
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    • 2016
  • Phosphorus (P) removal by aluminum sulfate solution was investigated with varying pH and initial P concentrations. P removal was the highest at around pH 6. The pH range where P removal occurred was slightly wider at higher initial P concentrations. Compared to theoretical calculations, it was confirmed that $AlPO_4$ precipitation was the main reason for P removal at low pH. At high pH, where there should be no $AlPO_4$ precipitates, the P removal by adsorption of amorphous $Al(OH)_3$ precipitates was experimentally observed. The P removal by adding amorphous $Al(OH)_3$ precipitates prepared before the adsorption experiments, however, was lower than that by injecting aluminum sulfate solution because the prepared precipitates became larger, leading to less specific surface area available for adsorption. Ions other than sulfate had little influence on P removal.

The Study of Bfa1pE438K Suggests that Bfa1 Control the MitoticExit Network in Different Mechanisms Depending on DifferentCheckpoint-activating Signals

  • Kim, Junwon;Song, Kiwon
    • Molecules and Cells
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    • v.21 no.2
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    • pp.251-260
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    • 2006
  • During mitosis, genomic integrity is maintained by the proper coordination of anaphase entry and mitotic exit via mitotic checkpoints. In budding yeast, mitotic exit is controlled by a regulatory cascade called the mitotic exit network (MEN). The MEN is regulated by a small GTPase, Tem1p, which in turn is controlled by a two-component GAP, Bfa1p-Bub2p. Recent results suggested that phosphorylation of Bfa1p by the polorelated kinase Cdc5p is also required for triggering mitotic exit, since it decreases the GAP activity of Bfa1p-Bub2p. However, the dispensability of GEF Lte1p for mitotic exit has raised questions about regulation of the MEN by the GTPase activity of Tem1p. We isolated a Bfa1p mutant, $Bfa1p^{E438K}$, whose overexpression only partially induced anaphase arrest. The molecular and biochemical functions of $Bfa1p^{E438K}$ are similar to those of wild type Bfa1p, except for decreased GAP activity. Interestingly, in $BFA1^{E438K}$ cells, the MEN could be regulated with nearly wild type kinetics at physiological temperature, as well as in response to various checkpoint-activating signals, but the cells were more sensitive to spindle damage than wild type. These results suggest that the GAP activity of Bfa1p-Bub2p is responsible for the mitotic arrest caused by spindle damage and Bfa1p overproduction. In addition, the viability of cdc5-2 ${\Delta}bfa1 $ cells was not reduced by $BFA1^{E438K}$, suggesting that Cdc5p also regulates Bfa1p to activate mitotic exit by other mechanism(s), besides phosphorylation.

Association Analysis of Polymorphisms on Dystrobrevin Binding Protein 1(DTNBP1) Gene with Schizophrenia in the Korean Population (한국인에서 Dystrobrevin Binding Protein 1(DTNBP1) 유전자의 다형성과 정신분열병의 연합에 대한 고찰)

  • Moon, Hyun-Il;Lee, Yeon Jung;Park, Byung-Lae;Shin, Hyung Doo;Choi, Ihn-Geun;Han, Sun Ho;Woo, Sung-Il
    • Korean Journal of Biological Psychiatry
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    • v.16 no.3
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    • pp.149-158
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    • 2009
  • Objectives : This study was designed to investigate the association of schizophrenia and P1320, P1325, P1635, P1655, P1763 and SNP A polymorphisms on dystrobrevin binding protein 1(DTNBP1) gene in Korean patients. Methods : We analyzed P1320, P1325, P1635, P1655, P1763 and SNP A polymorphisms on DTNBP1 gene from their DNAs extracted from their blood in 388 Korean schizophrenic patients (male 198, female 190) and 372 control subjects(male 247, female 125). We compared the differences of genotype and allele distributions of the six polymorphisms on DTNBP1 gene between the Korean schizophrenic patient group and the normal control group. Results : There were no statistically significant differences of genotype and allele distributions of the P1320, P1325, P1635, P1655, P1763 and SNP A polymorphisms on DTNBP1 gene between the schizophrenic patient group and the normal control group. Conclusion : The results of this study suggest that P1320, P1325, P1635, P1655, P1763 and SNP A polymorphism on DTNBP1 gene do not have influence on the risk of the schizophnenic in the Korean population.

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