• Title/Summary/Keyword: pH-gradient

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Anti-lipid Peroxidative Effect of Extracts and its Fractions Polygonatum odoratum (둥굴레 추출물 및 분획의 과산화지질 생성 저해효과)

  • 김주향;양기숙
    • YAKHAK HOEJI
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    • v.46 no.4
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    • pp.242-246
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    • 2002
  • The rhizoma of Polygonatum odoratum (Liliaceae) promotes the production of body fluid and relives dryness symptoms and has hypoglycemic effect. In order to evaluate the prevention of lipid peroxidative efficacy of P. odoratum, its extracts (Et$_2$O and MeOH ex.) and its fractions ($H_2O$, 20% MeOH, 40% MeOH, 60% MeOH and 100% MeOH fr.) were measured by TBARS assay on rat liver S9 and human erythrocyte ghost membrane. The order of anti-lipid peroxidative effect was as follows: Et$_2$O ex. >40% MeOH fr. >60% MeOH fr.>100% MeOH fr. Based on these results, we conclude that membrane lipid peroxidation is inhibited in vitro by addition of P. odoratum ether extract and its gradient MeOH fractions excepts $H_2O$ fr., and which have significant hepatoprotective activity in $CCl_4$-treated rats.

Sulfate Reduction for Bioremediation of AMD Facilitated by an Indigenous Acid- and Metal-Tolerant Sulfate-Reducer

  • Nguyen, Hai Thi;Nguyen, Huong Lan;Nguyen, Minh Hong;Nguyen, Thao Kim Nu;Dinh, Hang Thuy
    • Journal of Microbiology and Biotechnology
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    • v.30 no.7
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    • pp.1005-1012
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    • 2020
  • Acid mine drainage (AMD) has been a serious environmental issue that threatens soil and aquatic ecosystems. In this study, an acid-tolerant sulfate-reducing bacterium, strain S4, was isolated from the mud of an AMD storage pond in Vietnam via enrichment in anoxic mineral medium at pH 5. Comparative analyses of sequences of the 16S rRNA gene and dsrB gene involved in sulfate reduction revealed that the isolate belonged to the genus Desulfovibrio, and is most closely related to Desulfovibrio oxamicus (with 99% homology in 16S rDNA sequence and 98% homology in dsrB gene sequence). Denaturing gradient gel electrophoresis (DGGE) analyses of dsrB gene showed that strain S4 represented one of the two most abundant groups developed in the enrichment culture. Notably, strain S4 was capable of reducing sulfate in low pH environments (from 2 and above), and resistance to extremely high concentration of heavy metals (Fe 3,000 mg/l, Zn 100 mg/l, Cu 100 mg/l). In a batch incubation experiment in synthetic AMD with pH 3.5, strain S4 showed strong effects in facilitating growth of a neutrophilic, metal sensitive Desulfovibrio sp. strain SR4H, which was not capable of growing alone in such an environment. Thus, it is postulated that under extreme conditions such as an AMD environment, acid- and metal-tolerant sulfate-reducing bacteria (SRB)-like strain S4 would facilitate the growth of other widely distributed SRB by starting to reduce sulfate at low pH, thus increasing pH and lowering the metal concentration in the environment. Owing to such unique physiological characteristics, strain S4 shows great potential for application in sustainable remediation of AMD.

Effects of Daidzein on Testosterone Synthesis and Secretion in Cultured Mouse Leydig Cells

  • Zhang, Liuping;Cui, Sheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.5
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    • pp.618-625
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    • 2009
  • The objective of this work was to study the direct effects of daidzein on steroidogenesis in cultured mouse Leydig cells. Adult mouse Leydig cells were purified by Percoll gradient centrifugation, and the cell purity was determined using a $3{\beta}$-hydroxysteroid dehydrogenase ($3{\beta}$-HSD) staining method. The purified Leydig cells were exposed to different concentrations ($10^{-7}$ M to $10^{-4}$ M) of daidzein for 24 h under basal and human chorionic gonadotropin (hCG)-stimulated conditions. The cell viability and testosterone production were determined, and the related mechanisms of daidzein action were also evaluated using the estrogen receptor antagonist ICI 182,780 and measuring the mRNA levels of steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), and $3{\beta}$-HSD-1 involved in testosterone biosynthesis. The results revealed that daidzein did not influence cell viability. Daidzein increased both basal and hCG-stimulated testosterone production in a dose-dependent manner, and this effect was statistically significant at concentrations of $10^{-5}$ M and $10^{-4}$ M daidzein (p<0.05). ICI 182,780 had no influence on daidzein action. RTPCR results revealed that $10^{-5}$ M and $10^{-4}$ M daidzein did not exert any obvious influence on the mRNA level of P450scc in Leydig cells. However, in the presence of hCG, these concentrations of daidzein significantly increased the StAR and $3{\beta}$-HSD-1 mRNA levels (p<0.05), but in the absence of hCG, only $10^{-5}$ M and $10^{-4}$ M daidzein up-regulated the StAR and $3{\beta}$-HSD-1 mRNA expression (p<0.05), respectively. These results suggest that daidzein has direct effect on Leydig cells. Daidzein-induced increase of testosterone production is probably not mediated by the estrogen receptor but correlates with the increased mRNA levels of StAR and $3{\beta}$-HSD-1.

Effects of Electric Current and Potential on the Electrokinetic Removal of Heavy Metals from an Abandoned Mine Tailings

  • Shin, Hyun-Moo;Lee, Chang-Eun
    • Journal of Environmental Science International
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    • v.13 no.2
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    • pp.149-159
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    • 2004
  • In the removal of heavy metals from the mine deposit using electrokinetic processes, the effects of operation under both constant current and constant potential conditions were estimated. The results of soil pH distributions for DDW-20 V and DDW-100 mA cases after the electrokinetic remediation tests were observed. In the former case, soil pH was not much changed and kept to almost constant value just little higher than initial soil pH of 3.52, except near the cathode, which was about pH 5. While in the latter case, soil pHs of anode and the cathode regions were less than pH 3 and about 6, respectively. The electroosmotic flow to the cathode increased rapidly till 10 hrs and decreased steadily and then maintained to constant rate until the end of operation at constant current condition. Electric potential gradient was continuously increased to as much as 34.375 V/cm. At the steady state, values of the apparent electric conductivity for DDW-20 V and DDW-100 mA were around 40 ${\mu}\textrm{s}$/cm and 30 ${\mu}\textrm{s}$/cm, respectively. In the DDW-100mA test, Cu, Cd, and Zn except Pb showed the tendency of moving toward the cathode. While in the DDW-20 V case, it was observed that Cu, Zn, and Pb except Cd were not moved to any directions. The results of the tests demonstrated that the electrokinetic soil remediation process could be operated better under constant current condition than constant electric potential condition.

Comparison between Human Follicular Fluid and SpermGrad for Sperm Preparation in Asthenozoospermia (무력정자증 환자에서 인간 난포액과 SpermGrad를 이용한 정자처리법의 비교)

  • Chung, Youn Kyung;Lee, Jung Ryeol;Moon, Jeong-Hee;Kim, Hyun-Jun;Han, Sang-Hoon;Jee, Byung-Chul;Ku, Seung-Yup;Suh, Chang-Suk;Kim, Seok-Hyun;Choi, Young-Min;Kim, Jung-Gu;Moon, Shin-Yong
    • Clinical and Experimental Reproductive Medicine
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    • v.33 no.1
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    • pp.53-60
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    • 2006
  • Objective: We tested the usefulness of swim-down technique using human follicular fluid (hFF) in sperm preparation. Methods: Semen samples were obtained from twelve male partners showing asthenozoospermia (sperm motility < 50%) at the time of routine andrologic evaluation in Seoul National University Bundang Hospital. After dividing into two aliquots, each samples were processed either by swim-down using 100% hFF or density gradient using SpermGrad. Sperm quality was assessed by computer-assisted semen analyzer (CASA). Results: Motility, Rapid motility, VCL (curvilinear velocity), ALH (amplitude of lateral head displacement), and hyperactivated sperms were significantly increased, and LIN (mean linearity) was decreased significantly after sperm preparation in both groups. Motility was significantly higher after swim-down using 100% hFF when compared with density gradient using SpermGrad ($81.2{\pm}4.7$ vs. $67.6{\pm}2.3$, p=0.02) The other parameters assessed by CASA were not different between the two methods. Conclusion: Swim-down method with 100% hFF may be a useful method in preparation of sperm from asthenozoospermia.

A 54 kDa cysteine protease purified from the crude extract of Neodiplostomum seoulense adult worms

  • Choi, Min-Ho;Choe, Seong-Choon;Lee, Soon-Hyung
    • Parasites, Hosts and Diseases
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    • v.37 no.1
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    • pp.39-46
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    • 1999
  • As a preliminary study for the explanation of pathobiology of Neodiplostomum seoulense infection. a 54 kDa protease was purified from the crude extract of adult worms by sequential chromatographic methods. The crude extract was subjected to DEAE-Sepharose Fast Flow column, and protein was eluted using 25 mM Tris-HC1 (pH 7.4) containing 0.05. 0.1, 0.2 and 0.4 M NaC1 in stepwise elution. The 0.2 M NaCl fraction was further purified by Q-Sepharose chromatography and protein was eluted using 20 mM sodium acetate (pH 6.4) containing 0.05, 0.1. 0.2 and 0.3 M NaCl, respectively. The 0.1M NaCl fraction showed a single protein band on SDS-PAGE carried out on a 7.5-15% gradient gel. The proteolytic activities of the purified enzyme were specifically inhibited by L-trans-epoxy-succinylleucylamide (4-guanidino) butane (E-64) and iodoacetic acid. The enzyme, cysteine protease. showed the maximum proteolytic activity at pH 6.0 in 0.1 M buffer, and degraded extracellular matrix proteins such as collagen and fibronectin with different activities. It is suggested that the cysteine protease may playa role in the nutrient uptake of N. seoulense from the host intestine.

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MULTIPLICITY RESULTS FOR THE PERIODIC SOLUTIONS OF THE NONLINEAR HAMILTONIAN SYSTEMS

  • Jung, Tacksun;Choi, Q-Heung
    • Journal of the Chungcheong Mathematical Society
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    • v.19 no.2
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    • pp.141-151
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    • 2006
  • We investigate the multiplicity of $2{\pi}$-periodic solutions of the nonlinear Hamiltonian system with almost polynomial and exponential potentials, $\dot{z}=J(G^{\prime}(z)+h(t))$, where $z:R{\rightarrow}R^{2n}$, $\dot{z}=\frac{dz}{dt}$, $J=\(\array{0&-I\\I&o}\)$, I is the identity matrix on $R^n$, $H:R^{2n}{\rightarrow}R$, and $H_z$ is the gradient of H. We look for the weak solutions $z=(p,q){\in}E$ of the nonlinear Hamiltonian system.

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Feasibility study of using Halcyon LINAC for Double-target spine stereotactic body radiation therapy (이중 표적 척추 전이암의 체부정위방사선치료 시 Halcyon LINAC의 치료 유용성 평가)

  • Jeong Hee Ju;An Ye Chan;Park Byung Suk;Park Myung Hwan;Park Yong Chul
    • The Journal of Korean Society for Radiation Therapy
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    • v.34
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    • pp.51-60
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    • 2022
  • Objectives: The purpose is to evaluate dosimetric performance and delivery efficiency of VMAT with Halcyon LINAC for double target spine SBRT Materials and Methods: 12 patients with spine oligometastases were retrospectively studied. Single-isocenter spine SBRT plans was established using Halcyon® with Dual Layer MLC and Truebeam® with High Definition MLC. All patients' plans were created in Eclipse TPS through the identical conditions and optimization. C.I, H.I, G.I (Gradient Index), maximal and volumetric doses to spinal cord and low dose area were evaluated for comparison of both plans. Also, total MU and BOT(Beam On Time) were evaluated. Results: Halcyon plans was no Statistical differences in C.I and H.I. However, the average of G.I was 4.64 for Halcyon, which decreased to 5.5% compared to Truebeam (P<0.001). Halcyon plans demonstrated statistically significant reduced G.I. The average of 50% and 25% isodose volume was 487.56 cc (-3.82%, P<0.001), 1859.45 cc (-4.75%, P<0.001) in Halcyon, respectively. Significantly reduced low dose spill were observed in Halcyon plans. In the evaluation of the spinal cord, the average of Dmean and V10 of Halcyon plans in the sample group with an overlap volume of less than 1 cc was 6.802 Gy (-3.504%, P=0.067), 5.766±1.683 cc (-8.199%, P=0.002), respectively. Halcyon plans demonstrated statistically significant reduced Dmean and V10. For delivery efficiency, MU and BOT(maximum dose rate for each machine), on average, increased in Halcyon plans. However, the average of BOT(800MU/min for each machine) was 648.33 sec for Halcyon (-1.74%, P<0.001). Conclusion: Halcyon plan for double-target spine SBRT demonstrated advantages in the low dose area with a steep dose gradient, while having dosimetrically equivalent target dose distribution and spinal cord protective effect. As a result, Halcyon LINAC produced a dosimetrically improved plan for double-target spine SBRT.

Carrier-Mediated Active Transport Models by Affinity-Switching Strategy

  • Lee, Sung-Kil;Araki, Koji
    • Proceedings of the Membrane Society of Korea Conference
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    • 1996.04a
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    • pp.5-10
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    • 1996
  • Active transport is one of the essential function of biological membrane transport systems, in which substrates are transported from lower to higher concentration side against their concentration gradient. In this article, we describe photo- and pH-induced active transport models by designing the functional carriers based on the affinity-switching strategy.

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Variations of Properties and Microbial Community during Fermentation of Makgeollies by Isolated Yeasts from Traditional Makgeollies (전통막걸리에서 분리한 효모균주를 이용한 막걸리 발효과정 중의 물성 및 미생물 군집의 변화)

  • Jeon, Myong Je;Jang, Min Kyung;Lee, Sol Jee;Park, Sung Hwan;Kim, Mihyang;Sohn, Jae Hak;Lee, Han-Seung;Lee, Dong-Geun;Lee, Sang-Hyeon
    • Journal of Life Science
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    • v.23 no.6
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    • pp.796-803
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    • 2013
  • Property changes and bacterial characterizations by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were investigated during the fermentation of Makgeollies by 5 isolated yeast strains. Changes of pH were large between day 0 (pH 6) and day 2 (pH 3) and showed less variation after then. ANOVA analyses revealed that pHs were statistically different with fermentation times (p<0.001), while strains (p=0.60) did not. Acidities were changed from 0.19 to 1.04% and showed rather high increase from day 2, and fermentation times (p<0.001) and strains (p=0.006) represented statistical differences. All strains showed less than 0.150% at amino-type nitrogen contents except S strain showed 0.442% at day 8, and there were no statistical differences with fermentation times (p=0.4558) and strains (p=0.3513). Saccharinities of C strain were higher from day 4, and fermentation times (p<0.0001) and strains (p=0.007) showed statistical differences. Large variation of alcohol concentrations (%) were observed between day 0 (0%) and day 2 (10%) and showed less variation after day 2, and there was no statistical difference with strains. Dominant prokaryotes were Lactobacillus fermentum and Pediococcus pentosaceus, which producing acids and functional materials. Dominant eukaryote was Saccharomyces cerevisiae, which might be resulted from addition of yeasts.