• Title/Summary/Keyword: Low contrast concentration

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Electrochemical Hydrogen Permeation Behaviors of Pre-Strained Fe-Mn-C TWIP Steel With or Without Zn Coating (소성인장변형 몇 아연도금된 Fe-Mn-C계 TWIP 강의 전기화학적 수소투과거동)

  • Sung Jin Kim
    • Corrosion Science and Technology
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    • v.22 no.4
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    • pp.297-303
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    • 2023
  • This study aimed to evaluate hydrogen permeation behaviors of pre-strained twinning-induced plasticity steel with or without Zn coating using electrochemical permeation technique. In contrast to un-strained and 30% strained samples, permeation current density was measured in the 60% strained sample. Tensile pre-straining at 60% involved microstructural modifications, including a high level of dislocation density and stacking fault with a semi-coherent twin boundary, which might provide a high diffusion path for hydrogen atoms. However, reproducibility of measurements of hydrogen permeation current was low due to non-uniform deformation and localized stress concentration. On the other hand, the permeation current was not measured in pre-strained TWIP steel with Zn coating. Instead, numerous blisters with some cracks were observed on the surface of the coating layer. In locally damaged Zn coating under tensile straining, hydrogen atoms could relatively easily permeate through the coating layer. However, they were trapped at the interface between the coating layer and the substrate, which might delay hydrogen penetration into the steel substrate.

The disinfection effect of UV-C and calcium hypochlorite to shrimp farm instruments contaminated with EHP (Enterocytozoon hepatopenaei) (EHP (Enterocytozoon hepatopenaei)에 오염된 사육기구에 대한 UV-C와 차아염소산칼슘의 소독 효과)

  • Ji Min Ryu;Eul Bit Noh;Bo Seong Kim
    • Journal of fish pathology
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    • v.37 no.1
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    • pp.139-145
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    • 2024
  • In this study, nylon mash and silicone tube mainly used as shrimp farm equipment were contaminated with Enterocytozoon hepatopenaei (EHP) which is the cause of Hepatopancreatic microsporidiosis (HPM), and were treated with calcium hypochlorite or UV-C disinfection methods for EHP eradication. As a result, similar with the control group (not disinfected), EHP was detected on the nested PCR until the 10 days in the UV-C single treated group. On the other hand, EHP was not detected from 7 days in calcium hypochlorite single treated group (total concentration 200 ppm as available chlorine), and combination of calcium hypochlorite and UV-C treated group revealed no detection of EHP from 3 days. It is appropriate that treated with UV-C and calcium hypochlorite for 3 days or single treated with calcium hypochlorite for 7 days to eradicate EHP on contaminated instrument used in shrimp farms. In contrast, disinfection effect of only using UV-C is very low.

Effect of Subacute Ruminal Acidosis on Plasma Concentrations of Lipopolysaccharide in Dairy Cattle (젖소에 있어 아급성제1위과산증(SARA)의 강도가 혈장 Lipopolysaccharide (LPS)의 농도에 미치는 효과)

  • Son, Hey In;Baek, Seong Gwang;Moon, Ju Yeon;Ahn, Eui-Young;Lee, Hyun-Jun;Son, Yong Suk
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.33 no.4
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    • pp.313-318
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    • 2013
  • A study was conducted to determine if subacute ruminal acidosis (SARA) induced by feeding high level of non-structural carbohydrates results in increases in lipopolysaccharides (LPS) of peripheral blood in dairy cattle. In this experiment four Holstein steers, two of which having ruminal canulae with indwelling probes placed for measuring long term pH changes, were alloted into two dietary treatments in a cross-over design, where an acidogenic diet (AD) was formulated by including high amount of non-structural carbohydrates (NSC) based on corn silage and corn flake as TMR ingredients. Data for ruminal pH change and plasma LPS concentration were compared against normal diet (ND) which contained grass hay as forage and low NSC ingredients. Feeding AD for more than 14 days to animals brought about a pH change as low as less than 5.8 for more than 4 hours, which made good contrast to ND fed animals. Decreased ruminal pH also had an effect on LPS concentrations which showed significantly higher level for AD compared with ND. Therefore, plasma LPS concentration may be used as an effective indicator to verify acidosis whether it is acute or chronic. Na-bentonite and Propylene glycol, which are frequently included in dairy TMR as additives, helped decrease ruminal pH by buffering and then ultimately alleviates SARA. Therefore, it could also be helpful to lower the occurrence of laminitis which is often caused by increased blood endotoxin (LPS) concentration.

Cotton GhKCH2, a Plant-specific Kinesin, is Low-affinitive and Nucleotide-independent as Binding to Microtubule

  • Xu, Tao;Sun, Xuewei;Jiang, Shiling;Ren, Dongtao;Liu, Guoqin
    • BMB Reports
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    • v.40 no.5
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    • pp.723-730
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    • 2007
  • Kinesin is an ATP-driven microtubule motor protein that plays important roles in control of microtubule dynamics, intracellular transport, cell division and signal transduction. The kinesin superfamily is composed of numerous members that are classified into 14 subfamilies. Animal kinesins have been well characterized. In contrast, plant kinesins have not yet to be characterized adequately. Here, a novel plant-specific kinesin gene, GhKCH2, has been cloned from cotton (Gossypium hirsutum) fibers and biochemically identified by prokaryotic expression, affinity purification, ATPase activity assay and microtubule-binding analysis. The putative motor domain of GhKCH2, $M_{396-734}$ corresponding to amino acids Q396-N734 was fused with 6$\times$His-tag, soluble-expressed in E. coli and affinity-purified in a large amount. The biochemical analysis demonstrated that the basal ATPase activity of $M_{396-734}$ is not activated by $Ca^{2+}$, but stimulated 30-fold max by microtubules. The enzymatic activation is microtubule-concentration-dependent, and the concentration of microtubules that corresponds to half-maximum activation was about 11 ${\mu}M$, much higher than that of other kinesins reported. The cosedimentation assay indicated that $M_{396-734}$ could bind to microtubules in vitro whenever the nucleotide AMP-PNP is present or absent. As a plant-specific microtubule-dependent kinesin with a lower microtubule-affinity and a nucleotide-independent microtubule-binding ability, cotton GhKCH2 might be involved in the function of microtubules during the deposition of cellulose microfibrils in fibers or the formation of cell wall.

Sodium Salicylate Induces the Cyclin-dependent Kinase Inhibitor p21 (Waf1/Cip1) through PI3K-related Protein Kinase-dependent p53 Activation in A549 Cells

  • Kim, Min-Young;Kim, Cho-Hee;Hwang, Jee-Won;Kim, Ji-Hye;Park, Hye-Gyeong;Kang, Ho-Sung
    • Biomedical Science Letters
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    • v.13 no.2
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    • pp.75-81
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    • 2007
  • Sodium salicylate (NaSal), a chemopreventive drug, has been shown to induce apoptosis and cell circle arrest depending on its concentrations in a variety of cancer cells. In A549 cells, low concentration of NaSal (5$\sim$10 mM) induces cell cycle arrest, whereas it induces apoptosis at higher concentration of 20 mM. In the present study, we examined the molecular mechanism for NaSal-induced cell cycle arrest. NaSal induced expression of p53, p21 (Wafl/Cipl), and p27 (Kipl) that play important roles in cell cycle arrest. p53 induction was mediated by its phosphorylation at Ser-15 that could be prevented by the PI3K-related kinase (ATM, ATR and DNA-PK) inhibitors including wortmannin, caffeine and LY294002. In addition, NaSal-induction of p2l (Wafl/Cipl) was detected in P53 (+/+) wild type A549 cells but not in p53 (-/-) mutant H1299 cells, indicating p53-dependent p21 (Wafl/Cipl) induction. In contrast, p27 (Kipl) that is a negative regulate. of cell cycle with p21 (Wafl/Cipl) was observed both in A549 cells and H1299 cells. Thus, 5 mM NaSal appeared to cause cell cycle arrest through inducing the cyclin-dependent kinase inhibitor p21 (Wafl/Cipl) via PI3K-related protein kinase-dependent p53 activation as well as by up-regulating p27 (Kipl) independently of p53 in A549 cells.

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Effect of plant growth regulators on micropropagation of a rare and endangered species, Tsuru-rindo (Tripterospermum japonicum) (멸종위기 식물 덩굴용담의 기내번식에 미치는 생장조절제 효과)

  • Moon, Heung-Kyu;Kim, Sun-Ja;Park, So-Young;Kim, Yong-Wook;Yi, Jae-Seon
    • Journal of Plant Biotechnology
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    • v.36 no.1
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    • pp.13-17
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    • 2009
  • Various plant growth regulators were tested for shoot proliferation of Tripterospermum japonicum, a rare and endangered species. Among the six different media tested, MS medium was the best for the shoot growth. Whereas BA, upto 3 mg/L, significantly increased shoot proliferation rate, it suppressed the rate at higher levels. Neither kinetin nor TDZ was so effective in proliferating shoots as BA. As for rooting, TDZ strongly inhibited it even at very low concentration though spontaneous rooting was frequently observed from the proliferated shoots during culture of lower concentration BA or kinetin. In contrast, shoot elongation was significantly promoted by $GA_3$. More than 90% of the proliferated plantlets could be transplanted via cuttings into pots containing artificial soil mixture where they rooted and resumed normal growth. Most of the plants bloomed to bear fruits in the following year.

Preparation of Lysine-Coated Magnetic Fe2O3 Nanoparticles and Influence on Viability of A549 Lung Cancer Cells

  • Ma, Yu-Hua;Peng, Hai-Ying;Yang, Rui-Xia;Ni, Fang
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8981-8985
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    • 2014
  • Objective: To explore the effect of lysine-coated oxide magnetic nanoparticles (Lys@MNPs) on viability and apoptosis of A549 lung cancer cells. Methods: Transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and Zeta potentiometric analyzer were employed to characterize Lys@MNPs. Then Lys@MNPs and lung cancer A549 cells were co-cultured to study the effect of Lys@MNPs on cell viability and apoptosis. The pathway of Lys@MNPs entering A549 cells was detected by TEM and cell imaging by 1.5 T MRI. Results: Lys@MNPs were 10.2 nm in grain diameter, characterized by small size, positive charge, and superparamagnetism. Under low-dose concentration of Lys@MNPs (< $40{\mu}g/mL$), the survival rate of A549 cells was decreased but remained higher than 95% while under high-dose concentration ($100{\mu}g/mL$), the survival ratewas still higher than 80%, which suggested Lys@MNPs had limited influence on the viability of A549 cells, with good biocompatibility and and no induction of apoptosis. Moreover, high affinity for cytomembranes, was demonstrated presenting good imaging effects. Conclusion: Lys@MNPs can be regarded as a good MRI negative contrast agents, with promising prospects in biomedicine.

Change of Nonvolatile Amines During Fermentation of Anchovy (멸치젓 숙성중 불휘발성아민의 함량 변화)

  • 정종순;이영근;박법규;류병호
    • Journal of Food Hygiene and Safety
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    • v.4 no.1
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    • pp.37-44
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    • 1989
  • The present work was to study the changes of nonvolatile amines and microorganism in fermentation of anchovy during 12 weeks with addition of various concentration of sodium chloride. Changes of histamine occured significantly during fermentation of anchovy with 10, IS, 20% salt and 10% mixed salts (5.0% NaCl+5.0% KCl). A maximum histamine content was observed in anchovy fermented for 6 weeks while the change of histamine content was not with addition of 20% sodium chloride. Tyramine was found at highest contents in the fermented anchovy of 10% mixed salts and increased markedly in all anchovy fermented for 8 weeks. Cadaverine content was higher in fermented for all fermentation periods than in raw. During fermentation cadaverine contents increased significantly in fermented with 10% mixed salts. In contrast with that, fermented anchovy with 20% sodium chloride had very low those content and high sodium chloride concentration had influenced on amine formation. Although the highest content of putrescine was observed in fermented for 8 weeks, those content was not changed significantly during fermantation. The growth of Microflora, Achromobacter, Aeromonas and Pseudomonas were found in the in itial fermantation and Micrococus, Pediococcus, Lactobacillus and Saccharomyces were found during all fermentation periods.

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Semen Quality of the Black Bengal Bucks Used at Commercial Artificial Insemination

  • Dhar, Ajoy Chandra;Talukder, Anup Kumar;Rahman, Mohammad Bozlur;Al-Mamun, Abdullah;Shamsuddin, Mohammed
    • Journal of Embryo Transfer
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    • v.25 no.4
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    • pp.237-245
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    • 2010
  • Only an optimum number of viable spermatozoa in a frozen-thawed insemination dose can ensure conception at artificial insemination (AI). We report here the percentages of normal, abnormal and viable spermatozoa present in the frozen-thawed semen of 20 Black Bengal bucks used for commercial AI. Bucks in this experiment were of 19.3~46.1 months old and 25~42 kg body weight. Four semen straws (0.25 ml) from each buck were collected for evaluation of their kinetic parameters. Scrotal circumference was measured by using a scrotal tape, sperm motility was estimated on eye estimation and sperm concentration was determined by using a haemocytometer. Sperm morphology was studied in paraformaldehyde fixed spermatozoa under differential interference contrast (DIC) microscope. To determine the proportion of live (plasma membrane intact) spermatozoa, semen was stained with SYBR-14 and propidium iodide and examined under fluorescent microscope. Scrotal circumference, post-thaw sperm motility, sperm concentration per insemination dose and proportion of normal spermatozoa were $21.5{\pm}0.7\;cm$, $43.5 {\pm}5.4%$, $83.5{\pm}6.7$ million and $88.3{\pm}4.1%$, respectively. The percentages of spermatozoa with head shape and acrosome abnormalities were lower ($2.7{\pm}1.1$ and $1.4{\pm}1.3$, respectively), whereas higher percentages of abnormalities ($7.0{\pm}1.8$) were observed in mid piece and tail portion. The proportion of live spermatozoa was $28.5{\pm}5.4$. It is concluded that although a good number of morphologically normal spermatozoa are present in the insemination dose, the proportion of live spermatozoa is low, which warrants further improvements of buck semen freezing procedures to ensure good quality at AI.

Anticomplement Activities of Oleanolic Acid Monodesmosides and Bisdesmosides Isolated from Tiarella polyphylla

  • Park, Si-Hyung;Oh, Sei-Ryang;Jung, Keun-Young;Lee, Im-Seon;Ahn, Kyung-Seop;Kim, Jae-Gil;Lee, Jung-Joon;Lee, Hyeong-Kyu
    • Archives of Pharmacal Research
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    • v.22 no.4
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    • pp.428-431
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    • 1999
  • Seven known oleanolic acid glycosides (1-7) were isolated form the MeOH extract of Tiarella polyphylla. The structures were identified to be 3-O-($\beta$-glucopyranosyl) oleanolic acid (1), 3-O-[$\beta$-D-glucopyranosyl-(1 3)-$\beta$-D-glucopyranosyl] oleanolic acid (2), 3-O-D-[$\beta$-D-glucopyranosyl-(1 2)-$\beta$-D-glycopyranosyl] oleanolic acid (3), 3-O-[$\beta$-D-glucopyranosyl-(1 3)-$\beta$-D-glucopyranosyl] oleanolic acid 28-O-$\beta$D-glucopyranosyl ester (4), 3-O-[$\beta$-D-glucopyranosyl-(1 2)-$\beta$-D-glucopyranosyl] oleanolic acid 28-O-$\beta$-D-glucopyranosyl ester (5), 3-O-[a-L-rahmnopyranosyl-(1 3)-$\beta$-D-glucururonopyranosyl] oleanolic acid (6), and 3-O-[$\alpha$-L-rhamnopyranosyl-(1 3)-$\alpha$-D-glucuronopyranosyl] oleanolic acid 28-O-$\alpha$-D-glucopyranosyl ester (7) on the basis of physicochemical and spectral data. These triterpene glycosides were tested for the anti-complement activity and hemolytic activity. Bisdesmosidic saponins, 4, 5, and 7, showed anti-complement activity; in contrast, monodesmosidic saponins, 1-3, and 6, showed direct hemolytic activity. Methyl esterified monodesmosidic saponins showed anti-complement activity at a low concentration and hemolytic activity at a high concentration.

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