• The Korean Journal of Physiology and Pharmacology
• /
• v.3 no.1
• /
• pp.1-10
• /
• 1999

We sought to find out the mechanism of vascular relaxation by extracellular $K^+$ concentration $([K^+]_o)$ in the cerebral resistant arteriole from rabbit. Single cells were isolated from the cerebral resistant arteriole, and using voltage-clamp technique barium-sensitive $K^+$ currents were recorded, and their characteristics were observed. Afterwards, the changes in membrane potential and currents through the membrane caused by the change in $[K^+]_o$ was observed. In the smooth muscle cells of cerebral resistant arteriole, ion currents that are blocked by barium, 4-aminopyridine (4-AP), and tetraethylammonium (TEA) exist. Currents that were blocked by barium showed inward rectification. When the $[K^+]_o$ were 6, 20, 60, and 140 mM, the reversal potentials were $-82.7{\pm}1.0,\;-49.5{\pm}1.86,\;-26{\pm}1.14,\;-5.18{\pm}1.17$ mV, respectively, and these values were almost identical to the calculated $K^+$ equilibrium potential. The inhibition of barium-sensitive inward currents by barium depended on the membrane potential. At the membrane potentials of -140, -100, and -60 mV, $K_d$ values were 0.44, 1.19, and 4.82 ${\mu}M,$ respectively. When $[K^+]_o$ was elevatedfrom 6 mM to 15 mM, membrane potential hyperpolarized to -50 mV from -40 mV. Hyperpolarization by $K^+$ was inhibited by barium but not by ouabain. When the membrane potential was held at resting membrane potential and the $[K^+]_o$ was elevated from 6 mM to 15 mM, outward currents increased; when elevated to 25 mM, inward currents increased. Fixing the membrane potential at resting membrane potential and comparing the barium-sensitive outward currents at $[K^+]_o$ of 6 and 15 mM showed that the barium- sensitive outward current increased at 15 mM $K^+.$ From the above results the following were concluded. Barium-sensitive $K^+$?channel activity increased when $[K^+]_o$ is elevated and this leads to an increase in $K^+-outward$ current. Consequently, the membrane potential hyperpolarizes, leading to the relaxation of resistant arteries, and this is thought to contribute to an increase in the local blood flow of brain.

• Korean Journal of Food Science and Technology
• /
• v.27 no.4
• /
• pp.582-592
• /
• 1995

To measure rheological properties of the starch dough, an Extrusion Capillary Viscometer(ECV) cell was self-made and attached to Instron machine(Model 1140). Apparent viscosities of corn and waxy corn starch doughs were measured and their gelatinization degrees were determined by enzymatic analysis. When corn and waxy corn starch doughs with $36{\sim}52%$ moisture content were heated at $60{\sim}100^{\circ}C$, come-up time of the cold point of doughs decreased from 220 sec to 140 sec with increased in the moisture content. In the measurement range of $36{\sim}52%$ moisture content and $60{\sim}100^{\circ}C$ heating temperature, both corn and waxy corn starch doughs showed pseudoplastic flow behaviors. At the same shear rate, both shear stress and viscosity of starch dough decreased as the moisture content increased. At the moisture content above 44%, the shear stress and viscosity of starch dough decreased as the heating temperature increased from $60^{\circ}C\;to\;70^{\circ}C$, but increased as the heating temperature increased from $80^{\circ}C\;to\;100^{\circ}C$. When the moisture content increased and heating temperature, the gelatinization degree of starch dough increased from about 10% to about 62%. The gelatinization degree of waxy corn starch dough was $15{\sim}20%$ higher than that of corn starch dough under the same gelatinization conditions. The effects of moisture content on the viscosity of starch dough were examined by Arrhenius equation. As the moisture content increased, viscosity of starch dough decreased. But the effect of moisture content was greater in the range of $80{\sim}100^{\circ}C$ than in the range of $60{\sim}70^{\circ}C$ heating temperature.

• Journal of Digital Convergence
• /
• v.15 no.12
• /
• pp.489-494
• /
• 2017

In spite of lots of differences in the production process of film animation, the animating method through computer is not much different between game animation and film animation. It is because the principles of film animation are also emphasized for the production of game animation. This study aims to consider the line of action showing the direction of movement and flow of energy among many considerations for the character pose work in case when producing game animation. Starting from the basic theory of drawing, the line of action plays a role of bible in the pose work including cell animation and 3D animation. After examining the theoretical background through preceding researches in order to understand the application of the line of action to the pose work of game characters, the poses of hero characters of a 3D online game 'Over Watch' were collected and then lines were directly drawn to analyze them. And as a result, the pose of characters with simple and clear 'Line of action' was good. This study aimed to consider the expression techniques of character pose in the production of game animation, which is expected to be used as an important reference for game animators at work.

• IMMUNE NETWORK
• /
• v.11 no.2
• /
• pp.114-122
• /
• 2011

Background: The leukocyte common antigen (CD45) is a transmembrane-type protein tyrosine phosphatase that has five isoforms. Methods: We generated seven murine mAbs against human CD45 by injecting cells from different origins, such as human thymocytes, PBMCs, and leukemic cell lines. By using various immunological methods including flow cytometry, immunohistochemistry, and immunoprecipitation, we evaluated the reactivity of those mAbs to CD45 of thymus as well as tonsil lysates. Furthermore, we transiently transfected COS-7 cells with each of gene constructs that express five human CD45 isoforms respectively, and examined the specificities of the mAbs against the transfected isoforms. Results: In case of thymocytes, lymphocytes, and monocytes, all the seven mAbs demonstrated positive reactivities whereas none was reactive to erythrocytes and platelets. The majority of immune cells in formalin-fixed paraffin-embedded thymus and tonsil tissues displayed strong membranous immunoreactivity, and the main antigen was detected near 220 kDa in all cases. Among the mAbs, four mAbs (AP4, DN11, SHL-1, and P6) recognized a region commonly present in all the five isoforms. One mAb, YG27, recognized four isoforms (ABC, AB, BC, and O). Two mAbs, P1 and P14, recognized the isoforms that contain exon A encoded regions (ABC and AB). Conclusion: In this study, we confirmed that AP4, DN11, SHL-1, YG27 and P6, are mAbs reactive with the CD45 antigen whereas P1 and P14 are reactive with the CD45RA antigen.

• Korean Chemical Engineering Research
• /
• v.43 no.2
• /
• pp.236-242
• /
• 2005

Membrane fouling by protein mixtures during microfiltration has been investigated for binary mixtures of bovine serum albumin (BSA), casein, lysozyme, pepsin, and ovalbumin. Filtration experiments were carried out using $0.2{\mu}m$ polycarbonate track-etched (PCTE) membrane in a stirred cell under constant transmembrane pressure (14 kPa) and concentration of hydrogen ion (pH=11) to study the effect of mixture composition on filtrate flux decline. Flux decline data were analyzed using a pore blockage-cake formation model developed recently. It was found that the model is in a good agreement with the experimental data. Fouling parameters such as the rate of pore blockage(${\alpha}$), the initial resistance of the protein deposit ($R_{po}$) and the increasing rate of the protein layer resistance(${\beta}$) were used to evaluate the rate of filtrate flow by membrane fouling in the binary mixture system. Generally, the trend of ${\alpha}$ is comparable with that of filtrate flux decline. It was also found that fast flux decreasing was observed over the binary mixture containing casein. The result is due to high value of the initial resistance of the protein deposit ($R_{po}$) over casein.

• Korean Journal of Crystallography
• /
• v.8 no.2
• /
• pp.127-131
• /
• 1997

The crystal structure of a bromine sorption complex of vacuum-dehydrated Ag+ and Ca2+ exchanged zeolite A(a=12,234(1) Å) has been determined by single-crystal X-ray diffraction methods in the cubic space group Pm3m. The crystal was prepared by flow method using exchange solution in which mole ratio of AgNo3 and Ca(NO3)2 was 1:150 with a total concentration of 0.05M. The crystal was dehydrated at 360℃ and 2 ×10-6 Torr for 2days, followed by exposure to 180 Torr of Br2 vapor for 20min. full-matrix least-squares refinements converged to the final error indices of R1=0.111 and R2=0.101 using 90 reflections for which I>3o(I). About 3.1 Ag+ ions and 4.45 Ca2+ ions lie on the two crystallographically nonequivalent three-fold axes associated with 6-ring oxygens. A total of six bromine molecules are sorbed per unit cell. Each bromine molecule approaches a framework oxide ions axially (Br-Br-O=171(2)', O-Br=3.25(6) Å; and Br-Br=2,61(8) Å by a charge-transfer interaction.

• Clinical and Experimental Reproductive Medicine
• /
• v.38 no.3
• /
• pp.168-173
• /
• 2011

Objective: To examine the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and hyperhomocysteinemia in women with unexplained recurrent miscarriages (RM) and to investigate the association between MTHFR genotype variants and alloimmune activation, proportion of peripheral blood natural killer (pbNK) cells. Methods: A total of 39 patients with a history of two or more unexplained miscarriages were recruited to this study. The controls were women who had a live birth without a history of RM (n=50). The proportion of pbNK cells was measured by flow cytometry. Plasma homocysteine levels and the incidence of the MTHFR variant of the RM and control groups were compared. The proportion of pbNK cells was compared to the MTHFR variants in the RM group. Results: No differences were found between the two groups' mean plasma homocysteine levels ($7.6{\pm}1.5{\mu}mol$/L vs. $7.1{\pm}2.1{\mu}mol$/L) or incidence of the MTHFR genotype variant (CC, 35% vs. 33%; CT, 40% vs. 53%; and TT, 25% vs. 14%). In the RM group, individuals with the TT variant ($7.7{\pm}1.1{\mu}mol$/L) had higher homocysteine levels than those with the CC and CT variants ($7.4{\pm}1.9{\mu}mol$/L and $7.4{\pm}1.2{\mu}mol$/L) and those with the CT variant ($19.2{\pm}8.1%$) had a higher proportion of CD3-/CD56+ pbNK cells than those with the CC and TT variants ($17.7{\pm}6.6%$ and $17.9{\pm}7.0%$), but the results of both comparisons were statistically insignificant. Conclusion: These preliminary results show no difference in plasma homocysteine levels between the RM and control groups or among MTHFR genotype variants in the RM group, which may suggest that the plasma homocysteine level is difficult to use as a predictive marker of RM in the Korean population. A study of a larger number of patients is needed.

• Clinical and Experimental Reproductive Medicine
• /
• v.37 no.3
• /
• pp.181-189
• /
• 2010

The placenta, which is a temporary organ derived from the fetus during pregnancy, is critical to support fetus development via optimal regulation between mother and fetus. Trophoblast as a major cell population of the placenta is one of the earliest to differentiate and shows an extensive proliferation or/and differentiation up to the formation of the placenta. The role of the trophoblast show dynamic changes from early embryo implantation to placentation during pregnancy. Implantation of the blastocyst into the endometrium of the maternal uterus is mediated by invasion of the differentiated trophoblast (e.g. syncytiotrophoblast) from the trophectoderm. During pregnancy, the unique role of the trophoblast is to invasion, eroding, and metastasizing in the placenta as well as to ensure appropriate bidirectional nutrient or waste flow required for growth and maturation of the embryo. The dysfunction of the trophoblast during pregnancy can result in several gynecological diseases including preeclampsia and congenital malformation in neonatal medicine. Therefore, trophoblasts act as a conclusive factor in placental and fetal development. This brief review outlines the classification of trophoblast and its function in the placenta during pregnancy. Also, we introduce the latest research in trophoblast for implantation and the placenta development, and the application potential of trophoblast for infertility and obstetrical diseases.

• The Korean Journal of Mycology
• /
• v.34 no.1
• /
• pp.1-6
• /
• 2006

In order to select a suitable bioreactor type for the submerged cultivation of Ganoderma applanatum, both growth characteristics and polysaccharides production were compared among four different types of bioreactor. These include an external-loop type air-lift bioreactor (ETAB), a balloon type air bubble bioreactor (BTBB), a column type air bubble bioreactor (CTBB) and a stirrer type bioreactor (STB). The mycelial biomass produced from the reactors were in decreasing order: ETAB ($7\;g/{\ell}$) > BTBB ($6.2\;g/{\ell}$) > STB ($6\;g/{\ell}$) > CTBB ($5\;g/{\ell}$). Maximal soluble exopolysaccharides ($1\;g/{\ell}$) and endopolysaccharides (2.7%) were also obtained from ETAB. Thus, the ETAB was most suitable for submerged culture of G applanatum mycelium. Based on the results, ETAB was chosen for further detailed study. The most effective aeration rate for the mycelial growth in ETAB ranged from 0.05 to 0.1 vvm. For the maximal production, the mycelium at the initial growth stage needed low aeration rate to reduce cell damages by fluid flow. However, as the mycelia grew, the culture became viscous and thus needed higher aeration. The molecular weight of exopolysaccharides obtained from the culture grown in ETAB was higher than that from the culture grown in other bioreactors.

• Journal of Life Science
• /
• v.17 no.11
• /
• pp.1596-1600
• /
• 2007

Bee venom is used to treat inflammatory diseases in Korean traditional medicine and has been known to inhibit proliferation and induce apoptosis in cancer cells. However, the molecular mechanisms involved in bee venom-induced apoptosis are still uncharacterized in human lung cancer cells. In the present study, we investigated the effects of bee venom on the apoptosis of A549 human lung epithelial cancer cells. Treatment of bee venom inhibited the cell viability and induced apoptosis in a concentration-dependent manner as measured by hemocytometer counts, fluorescence microscopy and flow cytometry analysis. Bee venom-induced apoptosis in A549 cells was associated with a marked inhibition of anti-apoptotic Bcl-2 expression without significant changes in the levels of Bax and Bcl-xL. Bee venom treatment also inhibited the levels of IAP family members such as cIAP-1 and cIAP-2 and induced the proteolytic activation of caspase-3 and caspase-9. Although further studies are needed, the present results suggest that apoptotic signals evoked by bee vemon in A549 cancer cells may converge caspases activation through a down-regulation of Bcl-2 rather than an up-regulation of Bax. These findings provide important insights into the possible molecular mechanisms of the anti-cancer activity of bee vemon in human cancer cells.