• Title/Summary/Keyword: M-N interaction

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EFFECTS OF ETHANOLON NMDA-MEDIATED INTRACELLULAR FREE $Ca^{2+}$ CONCENTRATION IN DISSOCIATED BRAIN CELLS

  • Chung, In-Kyo;Kim, Dong-Soo;Chung, Yong-Za;Kim, Inn-Se;Cho, Goon-Jae;Park, Chang-Hwa;Kim, Bong-Sun;Jang, Hye-Ock;Il Yun
    • Journal of Photoscience
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    • v.6 no.4
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    • pp.187-191
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    • 1999
  • Using fluorescent probe fura-2 acetoxymethyl ester, we studied effects of N-Methyl-D-aspartate (NMDA) on free intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]$_{i}$) and interaction of ethanol with NMDA-mediated response in freshly dissociated brain cells from newborn rats. Twenty five micromolar NMDA significantly increased ($Ca^{2+}$), and this increasing effect could be prevented or reversed by the NMDA antagonists $Mg^{2}$(1.0 mM) and 2-amino-5-phosphonovalerate (AP5, 100 ${\mu}$M). Ethanol at concentrations from 2.5 to 100 mM inhibited NMDA-mediated calcium current in a concentration-dependent manner. Maximal inhibition of NMDA-mediated calcium current by ethanol was 82% at 50 mM. The ethanol inhibition at 100 mM was not significantly different from the inhibition at 50 mM.

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Influence of oxyfluorination on activated carbon nanofibers for CO2 storage

  • Bai, Byong-Chol;Kim, Jong-Gu;Im, Ji-Sun;Jung, Sang-Chul;Lee, Young-Seak
    • Carbon letters
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    • v.12 no.4
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    • pp.236-242
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    • 2011
  • The oxyfluorination effects of activated carbon nanofibers (OFACFs) were investigated for $CO_2$ storage. Electrospun CFs were prepared from a polyacrylonitrile/N,N-dimethylformamide solution via electrospinning and heat treatment. The electrospun CFs were chemically activated in order to generate the pore structure, and then oxyfluorination was used to modify the surface. The samples were labeled CF (electrospun CF), ACF (activated CF), OFACF-1 ($O_2:F_2$ = 7:3), OFACF-2 ($O_2:F_2$ = 5:5) and OFACF-3 ($O_2:F_2$ = 3:7). The functional group of OFACFs was investigated using X-ray photoelectron spectroscopy analysis. The C-F bonds formed on surface of ACFs. The intensities of the C-O peaks increased after oxyfluorination and increased the oxygen content in the reaction gas. The specific surface area, pore volume and pore size of OFACFs were calculated by the Brunauer-Emmett-Teller and density functional theory equation. Through the $N_2$ adsorption isotherm, the specific surface area and pore volume slightly decreased as a result of oxyfluorination treatment. Nevertheless, the $CO_2$ adsorption efficiency of oxyfluorinated ACF improved around 16 wt% due to the semi-ionic interaction effect of surface modificated oxygen functional groups and $CO_2$ molecules.

Distributions of Dissolved Pb and Cd in the Surface Water of East Sea, Korea (동해 표층수중 용존 Pb, Cd의 분포 특성)

  • Yoon, Sang Chol;Yoon, Yi Yong
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.18 no.2
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    • pp.64-73
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    • 2015
  • The distributions of Pb and Cd concentrations in the surface seawater of the East Sea were investigated during the R/V Lavrentyev cruise (July 2009) in which four transects from Russia shore to South were conducted to collect 26 surface water samples. The total dissolved concentrations of Pb and Cd were measured using ICP-MS (Perkin Elmer, DRC-e). In the coastal area, their concentrations of Russia shore (Pb, 0.08; Cd, 0.10 nM) were comparable for Cd but on the other hand, 6 times lower for Pb than Korea shore (Pb, 0.49; Cd, 0.11 nM). In the subregion, their concentrations of Warm region (Pb, 0.22; Cd, 0.01 nM) were about 1.7 times higher for Pb but 0.4 lower for Cd than Cold region (Pb, 0.13; Cd, 0.14 nM). The distributions of Pb and Cd concentrations were divided by lowest level at $10^{\circ}C$ of water temperature. Below $10^{\circ}C$, Pb and Cd concentrations increased when surface water temperatures decreased. Above $10^{\circ}C$, their concentrations increased with temperature, which showed highest concentrations in the Ulleung basin, directly influenced by flux from East Korean Warm Current and neighboring countrys (Korea and Japan). Specially, in the case of Pb, the concentrations decrease remarkablely with temperatures decrease from D10 directly influenced by flux from East Korean Warm Current, which shows highest Pb level. By comparing with other sea areas (Western Mediterranean, East Pacific), Pb concentrations in the East Sea were a little higher. The influence of East Korean Warm Current and neighboring countrys (Korea and Japan) may be relatively important. Therefore, the distribution of Cd may primarily be influenced by mixing of different water masses while the distribution of Pb may mainly be influenced by flux from East Korean Warm Current and atmospheric inputs. River inputs and interaction with particulate materials may also some roles for the distribution of these elements.

Fabrication and Characterization of Pyrolyzed Carbon for Use as an Electrode Material in Electrochemical Biosensor (전기화학 바이오센서의 전극물질로 응용을 위한 열분해 탄소의 제작 및 특성 연구)

  • Lee, Jung-A.;Hwang, Seong-Pil;Kwak, Ju-Hyoun;Park, Se-Il;Lee, Seung-Seob;Lee, Kwang-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.10
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    • pp.986-992
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    • 2007
  • This paper presents the fabrication and characterization of carbon films pyrolyzed with various photoresists for bioMEMS applications. To verify the usefulness of pyrolyzed carbon films as an electrode material in an electrochemical biosensor developed by the authors, interactions between avidin and biotin on the pyrolyzed carbon film were studied via electrochemical impedance spectroscopy based on electrostatic interactions between avidin and negatively-charged ferricyanide. The pyrolyzed carbon films were characterized using a surface profiler, a precision semiconductor parameter analyzer, a nanoindentor, scanning electron microscopy, and atomic force microscopy. Amine conjugated biotin was immobilized on the electrode using EDC/NHS as crosslinkers after $O_2$ plasma treatment to enhance functional groups on the carbon electrode pyrolyzed at $1000^{\circ}C$ with AZ9260. The detection of avidin binding with different concentrations in a range of 0.75 nM to $7.5\;{\mu}M$ to the pyrolyzed carbon electrode modified with biotin was carried out by measuring the electrochemical impedance change. The results show that avidin binds to the biotin on the electrode not by non-specific interaction but by specific interaction, and that EIS successfully detects this binding event. Pyrolyzed carbon films are a promising material for miniaturization, integration, and low-cost fabrication in electrochemical biosensors.

Reproductive Performance of Three Iranian Sheep Breeds

  • Kiyanzad, M.R.;Panandam, J.M.;Emamjomeh Kashan, N.;Jelan, Z.A.;Dahlan, I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.1
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    • pp.11-14
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    • 2003
  • To evaluate the ewe reproductive performances of three Iranian local sheep breeds, namely Moghani, Chal and Zel, 27 rams and 473 ewes were used as the foundation flock in a crossbreeding program. The three breeds were crossed amongst themselves reciprocally. Ram breed and ewe breed showed a two-way interaction on apparent fertility. The Zel ewes showed higher fertility than the Chal and Moghani ewes (94.4 vs 77.3 and 84.6%). Prolificacy among main and individual mating groups were not significantly different (p>0.05). Zel ewes were 22.3 and 14.8% more reproductive (p<0.05) than Chal and Moghani ewes, respectively. Zel and Moghani ewes showed higher (p<0.05) ewe productivity than Chal ewes. Ram breed had a significant (p<0.05) effect on ewe efficiency. The Zel rams were not completely successful to mate with Chal ewes, this caused a to way-interaction between ram and ewe breeds. The Zel ewes mated with Chal and Moghani rams showed 26.1 and 28.5% more efficiency than those mated with Zel rams. This observation strongly supports the use of crossbreeding to improve the efficiency of the Zel ewes. With decreasing lamb mortality, through supplemented feeding of lambs in pre-weaning period, and increasing litter weight, through crossbreeding, it should be possible to improve the efficiency of Zel ewes even better than Chal and Moghani ewes. Small body size of Zel ewes that needs the lower maintenance requirements would be a well advantageous to using Zel ewes as the dam herd to produce commercial lambs in north area of Iran.

Aurora-A kinase-inactive mutants disrupt the interaction with Ajuba and cause defects in mitotic spindle formation and G2/M phase arrest in HeLa cells

  • Bai, Meirong;Ni, Jun;Shen, Suqin;Huang, Qiang;Wu, Jiaxue;Le, Yichen;Yu, Long
    • BMB Reports
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    • v.47 no.11
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    • pp.631-636
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    • 2014
  • Aurora-A is a centrosome-localized serine/threonine kinase that is overexpressed in multiple human cancers. We previously reported an intramolecular inhibitory regulation of Aurora-A between its N-terminal regulatory domain (Nt, amino acids [aa] 1-128) and the C-terminal catalytic domain (Cd, aa 129-403). Here, we demonstrate that although both Aurora-A mutants (AurA-K250G and AurA-D294G/Y295G) lacked interactions between the Nt and Cd, they also failed to interact with Ajuba, an essential activator of Aurora-A, leading to loss of kinase activity. Additionally, overexpression of either of the mutants resulted in centrosome amplification and mitotic spindle formation defects. Both mutants were also able to cause G2/M arrest and apoptosis. These results indicate that both K250 and D294/Y295 are critical for direct interaction between Aurora-A and Ajuba and the function of the Aurora-A complex in cell cycle progression.

Effects of Experimental Haemonchus contortus Infection on Red Blood Cells and White Blood Cells of Growing Goats

  • Howlader, M.M.R.;Capitan, S.S.;Eduardo, S.L.;Roxas, N.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.6
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    • pp.679-682
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    • 1997
  • A uniform group of 12 upgraded growing goats aged between 6.0 and 7.5 months were used in this study. They were divided into three groups of $T_1$, $T_2$ and $T_3$. Four animals were randomly allocated to each group. They were infected orally with three levels (0 larva, 5,000 larvae and 10,000 larvae) of infective Haemonchus contortus larvae. Before infection, all animals were housed in individual pens with concrete floors. They were provided with a uniform management. Total red blood cells (RBC) and total white blood cells (WBC) were measured by hemacytometric method. Results showed significant interaction effect of H. contortus infection and duration of infection on red blood cell counts. The RBC counts of animals in treatment groups 2 and 3 showed significantly lower values over the control group from the second fortnight to the end of the study. The overall mean RBC values of groups 1, 2 and 3 were 11.73, 9.70 and $9.12million/mm^3$ blood, respectively. H. contortus infection did not significantly influence the total leukocyte counts. Worm infection and duration of infection interaction was also absent on WBC counts. However, the time or duration of infection significantly influenced the WBC counts. Fecal egg counts showed patent infections in the infected animals which also indicated by postmortem worm counts.

The antinociceptive effect of artemisinin on the inflammatory pain and role of GABAergic and opioidergic systems

  • Dehkordi, Faraz Mahdian;Kaboutari, Jahangir;Zendehdel, Morteza;Javdani, Moosa
    • The Korean Journal of Pain
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    • v.32 no.3
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    • pp.160-167
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    • 2019
  • Background: Pain is a complex mechanism which involves different systems, including the opioidergic and GABAergic systems. Due to the side effects of chemical analgesic agents, attention toward natural agents have been increased. Artemisinin is an herbal compound with widespread modern and traditional therapeutic indications, which its interaction with the GABAergic system and antinoniceptive effects on neuropathic pain have shown. Therefore, this study was designed to evaluate the antinociceptive effects of artemisinin during inflammatory pain and interaction with the GABAergic and opioidergic systems by using a writhing response test. Methods: On the whole, 198 adult male albino mice were used in 4 experiments, including 9 groups (n = 6) each with three replicates, by intraperitoneal (i.p.) administration of artemisinin (2.5, 5, and 10 mg/kg), naloxone (2 mg/kg), bicuculline (2 mg/kg), saclofen (2 mg/kg), indomethacin (5 mg/kg), and ethanol (10 mL/kg). Writhing test responses were induced by i.p. injection of 10 mL/kg of 0.6% acetic acid, and the percentage of writhing inhibition was recorded. Results: Results showed significant dose dependent anti-nociceptive effects from artemisinin which, at a 10 mg/kg dose, was statistically similar to indomethacin. Neither saclofen nor naloxone had antinociceptive effects and did not antagonize antinociceptive effects of artemisinin, whereas bicuculline significantly inhibited the antinocicptive effect of artemisinin. Conclusions: It seems that antinocicptive effects of artemisinin are mediated by $GABA_A$ receptors.

Edge perturbation on electronic properties of boron nitride nanoribbons

  • K.L. Wong;K.W. Lai;M.W. Chuan;Y. Wong;A. Hamzah;S. Rusli;N.E. Alias;S. Mohamed Sultan;C.S. Lim;M.L.P. Tan
    • Advances in nano research
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    • v.15 no.5
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    • pp.385-399
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    • 2023
  • Hexagonal boron nitride (h-BN), commonly referred to as Boron Nitride Nanoribbons (BNNRs), is an electrical insulator characterized by high thermal stability and a wide bandgap semiconductor property. This study delves into the electronic properties of two BNNR configurations: Armchair BNNRs (ABNNRs) and Zigzag BNNRs (ZBNNRs). Utilizing the nearest-neighbour tight-binding approach and numerical methods, the electronic properties of BNNRs were simulated. A simplifying assumption, the Hamiltonian matrix is used to compute the electronic properties by considering the self-interaction energy of a unit cell and the interaction energy between the unit cells. The edge perturbation is applied to the selected atoms of ABNNRs and ZBNNRs to simulate the electronic properties changes. This simulation work is done by generating a custom script using numerical computational methods in MATLAB software. When benchmarked against a reference study, our results aligned closely in terms of band structure and bandgap energy for ABNNRs. However, variations were observed in the peak values of the continuous curves for the local density of states. This discrepancy can be attributed to the use of numerical methods in our study, in contrast to the semi-analytical approach adopted in the reference work.

Application of Arbuscular Mycorrhizal Fungi during the Acclimatization of Alpinia purpurata to Induce Tolerance to Meloidogyne arenaria

  • da Silva Campos, Maryluce Albuquerque;da Silva, Fabio Sergio Barbosa;Yano-Melo, Adriana Mayumi;de Melo, Natoniel Franklin;Maia, Leonor Costa
    • The Plant Pathology Journal
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    • v.33 no.3
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    • pp.329-336
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    • 2017
  • An experiment was conducted to evaluate the tolerance of micropropagated and mycorrhized alpinia plants to the parasite Meloidogyne arenaria. The experimental design was completely randomized with a factorial arrangement of four inoculation treatments with arbuscular mycorrhizal fungi (AMF) (Gigaspora albida, Claroideoglomus etunicatum, Acaulospora longula, and a non-inoculated control) in the presence or absence of M. arenaria with five replicates. The following characteristics were evaluated after 270 days of mycorrhization and 170 days of M. arenaria inoculation: height, number of leaves and tillers, fresh mass of aerial and subterranean parts, dry mass of aerial parts, foliar area, nutritional content, mycorrhizal colonization, AMF sporulation, and the number of galls, egg masses, and eggs. The results indicated a significant interaction between the treatments for AMF spore density, total mycorrhizal colonization, and nutrient content (Zn, Na, and N), while the remaining parameters were influenced by either AMF or nematodes. Plants inoculated with A. longula or C. etunicatum exhibited greater growth than the control. Lower N content was observed in plants inoculated with AMF, while Zn and Na were found in larger quantities in plants inoculated with C. etunicatum. Fewer galls were observed on mycorrhized plants, and egg mass production and the number of eggs were lower in plants inoculated with G. albida. Plants inoculated with A. longula showed a higher percentage of total mycorrhizal colonization in the presence of the nematode. Therefore, the association of micropropagated alpinia plants and A. longula enhanced tolerance to parasitism by M. arenaria.