• Food Science and Preservation
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• v.18 no.4
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• pp.612-619
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• 2011

Cronobacter sakazakii has been isolated from a wide range of environmental sources and from several foods of animal and plant origin. The objective of this study was to determine the resistance of C. sakazakii (ATCC 12868, ATCC 29004, and ATCC 29544) in cold, cold-freeze thaw, cold-acid, and cold starvation-freeze thaw stress. The number of C. sakazakii decreased to 1 log CFU/mL at $5^{\circ}C$ (cold storage) for 10 days. When C. sakazakii was cultivated at a low temperature ($13^{\circ}C$), the population of C sakazakii ATCC 12868 and 29004 increased to $10^9$ CFU/mL, and the population of C. sakazakii ATCC 29544 increased to $10^8$ CFU/mL. For C. sakazakii ATCC 12868 and 29004, the cold-adapted cells ($5^{\circ}C$ 24 hr) decreased by 4 log CFU/mL, and the low-temperature-cultivated cells ($13^{\circ}C$) decreased by 0.5 log CFU/mL. In this study, low-temperature cultivation enhanced the freeze-thaw cross-resistance due to the metabolic changes in the cells. Cold stress ($5^{\circ}C$ 48 hr, $13^{\circ}C$ cultivation) enhanced the cold-acid cross-resistance. The cold-starved cells in the sterilized 0.1% peptone water enhanced the freeze-thaw cross-resistance with significant differences (p<0.05). Therefore, the increased tolerance of the cold-adapted or low-temperature-cultivated C. sakazakii cells to freeze-thaw, acid, or starvation suggests that such environments should be considered when processing minimally processed foods or foods with extended shelf life.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.6
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• pp.445-453
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• 2000

The present investigation tested the hypothesis that the activation of protein kinase G (PKG) leads to a phosphorylation of $Ca^{2+}-activated$ potassium channel $(K_{Ca}\;channel)$ and is involved in the activation of $K_{Ca}$ channel activity in cerebral arterial smooth muscle cells of the rabbit. Single-channel currents were recorded in cell-attached and inside-out patch configurations of patch-clamp techniques. Both molsidomine derivative 3-morpholinosydnonimine-N-ethylcarbamide $(SIN-1,\;50\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate $(8-pCPT-cGMP,\;100\;{\mu}M),$ a membrane-permeable analogue of cGMP, increased the $K_{Ca}$ channel activity in the cell-attached patch configuration, and the effect was removed upon washout of the drugs. In inside-out patches, single-channel current amplitude was not changed by SIN-1 and 8-pCPT-cGMP. Application of ATP $(100\;{\mu}M),$ cGMP $(100\;{\mu}M),$ ATP+cGMP $(100\;{\mu}M\;each),$ PKG $(5\;U/{\mu}l),$ ATP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l),$ or cGMP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ did not increase the channel activity. ATP $(100\;{\mu}M)+cGMP\;(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ added directly to the intracellular phase of inside-out patches increased the channel activity with no changes in the conductance. The heat-inactivated PKG had no effect on the channel activity, and the effect of PKG was inhibited by 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer $(Rp-pCPT-cGMP,\;100\;{\mu}M),$ a potent inhibitor of PKG or protein phosphatase 2A (PP2A, 1 U/ml). In the presence of okadaic acid (OA, 5 nM), PP2A had no effect on the channel activity. The $K_{Ca}$ channel activity spontaneously decayed to the control level upon washout of ATP, cGMP and PKG, and this was prevented by OA (5 nM) in the medium. These results suggest that the PKG-mediated phosphorylations of $K_{Ca}$ channels, or some associated proteins in the membrane patch increase the activity of the $K_{Ca}$ channel, and the activation may be associated with the vasodilating action.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.438-445
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• 2015

The production of GABA was optimized by co-cultivation of immobilized Lactobacillus plantarum K154 (ILK) with Ceriporia lacerata cultures. The mycelial culture of C. lacerata was performed in a defined medium containing 3% glucose, 3% soybean flour, and 0.15% $MgSO_4$ in a submerged condition for 7 days at $25^{\circ}C$, resulting in the production of 29.7 g/L mycelia, 3.1 g/L exopolysaccharides, 2% (w/w) ${\beta}$-glucan, 68.96 unit/mL protease, and 10.37 unit/mL ${\alpha}$-amylase. ILK in C. lacerata culture showed viable cell counts of $3.13{\time}10^9CFU/mL$ for immobilized cells and $1.48{\time}10^8CFU/mL$ for free cells after 1 day. GABA production in the free and immobilized cells was 9.96 mg/mL and 6.30 mg/mL, respectively, after 7 days. A recycling test of ILK in the co-fermentation was consequently performed five times at $30^{\circ}C$ for 15 days, resulting in the highest production of GABA. GABA could also be efficiently overproduced by co-cultivation with the produced polysaccharides, ${\beta}$-glucan, peptides, and probiotics.

• Korean Journal of Optics and Photonics
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• v.27 no.3
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• pp.106-113
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• 2016

In this paper, we deal with the wavefront compensation capability of a silicon carbide (SiC) deformable mirror (DM) with 37 actuators for adaptive optics. The wavefront compensation capability of the SiC DM is predicted by computer simulation and examined by actual experiments with a closed-loop adaptive optics system consistsing of a light source, a phase plate, a SiC DM, a high speed Shack-Hartmann sensor, and a control computer. Distortion of wavefront is caused by the phase plate in the closed-loop adaptive optics system. The distorted wavefront has a peak-to-valley (PV) wavefront error of $0.3{\mu}m{\sim}0.9{\mu}m$ and root-mean-square (RMS) error of $0.06{\mu}m{\sim}0.25{\mu}m$. The high-speed Shack-Hartmann sensor measures the wavefront error of the distortion caused by the phase plate, and the SiC DM compensates for the distorted wavefront. The compensated wavefront has residual errors lower than $0.1{\mu}m$ PV and $0.03{\mu}m$ RMS. Consequently, we conclude that we can compensate for the distorted wavefront using the SiC DM in the closed-loop adaptive optics system with an operating frequency speed of 500 Hz.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.532-542
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• 2007

The purpose of study was to review the transition of dentition according to the evolution of man to know the background of the dental problems like hypodontia and malocclusion. Man is Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Primates, Suborder Haplorrhini, Superfamily Hominoidea, Family Hominidae, Genus Homo, Species Sapiens by taxonomy. The first hominid was Australopithecus which appeared c. 4 millions of years ago and showed bipedalism and distinct dentition. Homos began with H. habilis who appeared c. 2.5 millions of years ago and made stone tools, and then H. erectus and H. neanderthalensis appeared and disappeared until H. sapiens came. The dental formula of primitive mammalians which was I3 C1 P4 M3 changed to I2 C1 P4 M3 of primitive primates, to I2 C1 P3 M3 of Haplorrhini, and to I2 C1 P2 M3 of hominoids. That of H. sapiens is changing to I2 C1 P2 M2.The box type dentition of hominoids changed to the omega type dentition of Australopithecus, and to the parabolic type of H. sapiens. The size of teeth decreased continually, especially the canine and sexual dimorphism. The dentition moved backward and downward to the cranial crown according to the increase of the brain and decrease of the jaws. It was suggested that the change of diet to the starchy foods, food processing, and the development of cooking reduced the necessity of mastication and caused the change of dentition. The future of H. sapiens who is quite a new species in the earth histroy and is now causing the mass extinction of other species is hard to see. It seems that hypodontia and malocclusion are related to the dentition change according to the evolution of man and is likely to increase.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.525-536
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• 2004

The objective of this study was to identify the quantitative traits loci(QTL) for meat quality traits in pigs. Three-generation resource population was constructed from a cross between Korean native boars and Landrace sows. The resource population including founders, $F_1$ and $F_2$ was genotyped for 23 microsatellite markers on chromosome 7. The sex average total length of linkage map on chromosome 7 was estimated 154.6 cM. Meat quality traits including meat pH, meat color, drip loss, shear force, heating loss, crude fat, crude protein, crude ash and water content in muscle were collected from $F_2$ animals. For the QTL mapping, we used $F_2$ QTL Analysis Servlet of QTL express for web-based QTL mapping tools(http://qtl.cap.ed.ac.uk/). The QTLs for CIE-a and CIE-b on SSC7 were significantly detected at 1% and 5% chromosome-wide level, respectively.

• Journal of Oral Medicine and Pain
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• v.26 no.1
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• pp.39-50
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• 2001

In order to investigate the effect of Transforming growth factor ${\beta}1$(below TGF-${\beta}1$) and osteogenic protein-1(below Op-1) onto the myogenic differentiation, C2C12 satellite myoblastic cell line was cultured and treated with both growth factors. At first morphological changes with microscopical examination were examined, and isolated total RNA to analyse mRNA expression of bone marker proteins, muscle regulatory proteins, TGF-${\beta}$ receptor and their ligands by Northern blot analysis. And cellular proliferative inducibility of both growth factors was also tested to C2C12 cells. Incubating the cell with $5ng/m{\ell}$ of TGF-${\beta}1$ until 4 days almost inhibited multinucleated myotube formation expressing muscular regulatory proteins, and induced decreasing Id proteins. However, no osteoblastic phenotypes was induced by TGF-${\beta}1$ in C2C12 cells. The mRNA expression of TGF-${\beta}$ receptors with TGF-${\beta}1$ was conversed after 48 hours cultured. Type I TGF-${\beta}$ receptor was seemed to play a role in negative signalling for inhibition of myogenic differentiation. OP-1 dose dependently induced ALP activity, osteopontine production and bone sialoprotein production at concentrations above $100ng/m{\ell}$ and osteocalcin production at concentrations above $300ng/m{\ell}$. The concentration of OP-1 required to induce these osteoblastic phenotypes was the same as that required to almost completely inhibit myotube formation. Incubation with above $100ng/m{\ell}$ OP-1 suppressed the expression of mRNA for muscular egulatory proteins from 2 days after incubation. Expression of Id-1, 2, 3 mRNA were stimulated by OP-1 at concentration above $300ng/m{\ell}$. When C2C12 cells were treated with both growth factors, TGF-${\beta}1$ potentiated the inhibitory effect of OP-1 on myotube formation and expression of mRNA for myogenin at 12 days. And TGF-${\beta}1$ reduced osteocalcin and bone sialoprotein production induced by OP-1 at 12 days in C2C12 cells. Both growth factor had no mitogenic effect. These results indicate that OP-1 converts the differentiation pathway of C2C12 myoblasts into that of osteoblastic lineage cells and it's not heritable, but TGF-${\beta}1$ does not and has reversible inhibitory activity on the myogenic differentiation. TGF-${\beta}1$ and OP-1 play a role in myogenic differentiation via different mechanism between them.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.4
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• pp.77-84
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• 2006

Surface roughness and wafer-level thickness distribution of the non-cyanide Au bumps were characterized with variations of the electroplating current density and the bath temperature. The Au bumps, electroplated at $3mA/cm^{2}\;and\;5mA/cm^{2}$, exhibited the surface roughness of $80{\sim}100nm$ without depending on the bath temperature of $40^{\circ}C\;and\;60^{\circ}C$. The Au bumps, electroplated with $8mA/cm^{2}$ at $40^{\circ}C\;and60^{\circ}C$, exhibited the surface roughness of 800nm and $80{\sim}100nm$, respectively. Wafer-level thickness deviation of the Au bumps became larger with increasing the current density from $3mA/cm^{2}\;to\;8mA/cm^{2}$. More uniform thickness distribution of the Au bumps was obtained at a bath temperature of $60^{\circ}C$ than that of $40^{\circ}C$.

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.47-55
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• 2007

Using the results of the Piezocone Penetration Test (PCPT) which were executed at the Yangsan-Mulgum site, the applicability of the interpretation methods for estimating the coefficient of consolidation ($C_v$) of soft clay was evaluated. At the same time, laboratory soil tests using the total of 172 undisturbed soft clay samples from the 44 regions of the Yangsan-Mulgum site were performed to study the differency in the coefficient of consolidation ($C_v$) compared to the results of PCPT. The calculated constrained modulus ($M_{\varepsilon}$) and coefficient of consolidation ($C_v$) using the results of consolidation laboratory tests which are based upon the consolidation theory of Terzaghi were compared with the predicted constrained modulus ($M_p$) and coefficient of consolidation ($C_{v-{M_p}}$) from the PCPT. The relationship between the predicted constrained modulus ($M_p$) and the calculated constrained modulus($M_c$) were showed good correlation. The $M_p$ by the Jones & Rust method were showed mostly similar to the calculated constrained modulus ($M_c$). The relationship between the coefficient of consolidation ($C_v$) obtained from the consolidation tests and the calculated coefficient of consolidation ($C_{v-{M_p}}$) were showed a linear relationship. The results of the calculated coefficient of consolidation ($C_{v-{M_p}}$) were about 54% of the value of the coefficient of consolidation ($C_v$) obtained from the consolidation tests.

• Transactions of Materials Processing
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• v.7 no.2
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• pp.158-167
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• 1998

Hot restoration mechanism flow stress and stain of the Al2024 composites reinforced with 1,8,15,36, and $44{\mu}m\;SiC_p$(10 vol. %) were studied by hot torsion tests. The hot restoration mechanism of all the composites was found to be dynamic recrystallization(DRX) at $320^{\circ}C$ while that of the composites reinforced with 1 and $8{\mu}m\;SiC_p$ was found to be dynamic recovery(DRX) at $480^{\circ}C$. It was found that the Al2024 composite with $15{\mu}m\;SiC_p$ showed the highest flow stress(${\sim}$223 MPa) at $320^{\circ}C$ under a strain rate of 1.0/sec. Also the highest flow strain of the composites was obtained at $430^{\circ}C$. The com-posites reinforced with 1 and $8{\mu}m\;SiC_p$ showed lower flow stress and higher flow strain at $480^{\circ}C$ than those of the composites reinforced with 15, 36, and $44\;{\mu}m\;SiC_p$ These result were discussed in relation to the transition of the hot restoration mechanism. $DRX{\leftrightarrow}DRV$. The dependence of flow stress on strain rate and temperature was attempted to fit with the hyperbolic sine equation ($\dot{\varepsilon}=A[sinh({\alpha}{\cdot}{\sigma}_p]^n$ exp(-Q/RT)and Zener-Hollomon parameter($Z=\;\dot{\varepsilon}\;exp(Q/RT))$.