• Reproductive and Developmental Biology
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• v.41 no.1
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• pp.1-6
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• 2017

In all mammalian species, progesterone is essential to both the preparation for, and maintenance of, pregnancy. The $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) enzyme predominantly converts progesterone into its biologically inactive form $20{\alpha}$-hydroxyprogesterone, thereby regulating its activity. Thus, to directly assess sexual maturation in the MediKinetics $micropig^{(R)}$, we analyzed the concentration of the steroid hormones progesterone and estradiol during the estrous cycle. Our results show that the progesterone level exhibited by the analyzed $micorpig^{(R)}$ was low at the beginning of the estrous cycle, and then abruptly increased to $30.32{\pm}10.0ng/mL$ and $46.37{\pm}11.0ng/mL$ by days 9 and 11 of the cycle, respectively. It reached the highest level $55.87{\pm}3.5ng/mL$ on day 13 of the estrous cycle, before decreasing to $46.58{\pm}13.1ng/mL$ and $10.0{\pm}7.6ng/mL$ by days 15 and 17 of the cycle, respectively. In contrast, the estradiol level was shown to be highest ($27.13{\pm}11.2ng/mL$) at the initiation of the estrous cycle, after which point it decreased to $13.29{\pm}6.5ng/mL$ and $10.94{\pm}5.9ng/mL$ by days 4 and 5 of the estrous cycle, respectively. By day 17 of the estrous cycle, the estradiol level decreased to $4.13{\pm}7.6ng/mL$. We anticipate that these results will provide useful information to enable the study of human ovulation and reproductive physiology using the MediKinetics $micoripig^{(R)}$ as a model system. We recommend further investigation to elucidate the functional mechanisms underlying the regulation of sexual maturation in the MediKinetics $micropig^{(R)}$.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.11-20
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• 1984

A number of studies on the papillae of cercariae of trematodes reported that the papillar patterns (or chaetotaxy) of cercariae might be an excellent method to attain better understanding of the digenetic trematodes (Richard, 1971 ; Short and Cartrett, 1973; Bayssade-Dufour, 1979) . The present study was aimed to determine the number, distribution pattern and structure of the sensory papillae of Metagonimus yokogawai cercariae, and to elucidate the chaetotaxy of this digenetic trematode. M. yokogawai cercariae were pipetted from a vial in which infected snails (Semisulcospira libertina) had been kept for 3 hours. The snails were collected from an endemic area of M. yokogawai, Boseong river in west-southern part of Korea. Observations of papillae were based on light microscopy of those stained with silver nitrate, and on scanning electron microscopy The results are summarized as follows: 1, All papillae observed were uniciliated. 2. Cilia in anterior tip were shorter than the others in other portions. 3. The body papillae were arranged in essentially symmetrical patterns, Total number of the papillae was 126(63 pairs) in average; anterior tip 40(20 pairs), ventral 20(10 pairs), lateral 42(21 pairs), and caudal 8(4 pairs). 4. The chaetotany of M. yokogawai cercaria was: Ci cycle ($3+3C_{I}V,{\;}2+2C_{I}L,{\;}2+3C_{I}D),{\;}C_{II}{\;}cycle(2C_{II}V,{\;}1C_{II}L,{\;}2C_{II}D),{\;}C_{lll}{\;}cycle{\;}(1+lC_{III}V,{\;}1C_{IlI}L),{\;}C_{IV}{\;}cycle{\;}(1C_{IV}V,{\;}IC_{lV}L){\;}in{\;}cephalic{\;}region:{\;}A_I(1A_{IV}V,{\;}1+2A_{I}L,{\;}1A_{I}D),{\;}A_{II}(1A_{II}V,{\;}1+3A_{II}L,{\;}1A_{II}D),{\;}A_{III}(1A_{III}V,{\;}1+1A_{III}L,{\;}1A_{III}D){\;}and{\;}A_{IV}(1A_{IV}V,{\;}2A_{IV}L)$ in antacetabular region: $1M_{I}V{\;}and{\;}2M_{I}L$ in median: $1+1P_{I}L,{\;}1P_{II}L,{\;}1P_{II}D,{\;}1P_{III}L,{\;}1P_{IV}L{\;}and{\;}1P_{IV}D$ in postacetabular region: 2-2-2-2 in caudal region.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1016-1024
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• 2000

The study was conducted to develop a rapid method for the detection of Listeria monocytogenes in foods via polymerase chain reaction (PCR) technique using hemolysin gene (hlyA) primers. Specificity and sensitivity of PCR, optimal conditions for PCR and application of hlyA gene primers for the detection of L. monocytogenes from milk and beef were investigeted. Each of the 20 L. monocytogenes strains gave a single 713 bp band, but other Listeria sup. and other bacteria did not show any bands. As few as 1 pg of L. monocytogenes DNA or 2.4$\times$10$^4$L. monocytogenes cells could be detected with hlyA gene primers. PCR product was most improved at 20~30 cycle in terms of removal of tailing and sensitivity. Also, the sensitivity was significantly improved by the further 10~15 cycle after 20 cycle PCR amplication. Milk (10 mL) and beef (10 g) samples were inoculated with L. monocytogenes at the concentrations ranging from 0 to 10$^{7}$ CFU/mL or g to determine the best sensitivity of PCR for the rapid detection of L. monocytogenes. PCR assay could detect 2 cells in milk with repeating PCR amplication and 2.6$\times$10$^2$cells in beef sample after 24 hr enrichment growth at 35$^{\circ}C$ in LEB.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.5
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• pp.383-390
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• 2001

We have investigated the L $i_{1+x}$M $n_2$ $O_4$system as a cathode material for lithium rechargeable batteries. To improve the cycle performance of spinel LiM $n_2$ $O_4$ as the cathode of 4V class lithium secondary batteries, spinel phase L $i_{1+x}$M $n_2$ $O_4$(x=0, 0.025, 0.05, 0.075) was prepared at 75$0^{\circ}C$ for 48h. The preparation of L $i_{1+x}$M $n_2$ $O_4$ from L $i_2$ $O_3$ and Mn $O_2$ under air is studied. The compounds were synthesized by using solid-state reaction. Structural refinements were carried out with a Rietveld-refinement program. Electrochemical properties were examined using the Li/L $i_{1+x}$M $n_2$ $O_4$ cells. The capacity of L $i_{1+x}$M $n_2$ $O_4$ decreases with increases lithium content, while the cycle life improves. The initial discharge capacity are 118mAh/g and 116mAh/g for LiM $n_2$ $O_4$ decreases with increases lithium content, while the cycle life improves. The initial discharge capacity are 118mAh/g and 116mAh/g for LiM $n_2$ $O_4$ and L $i_{1.025}$M $n_2$ $O_4$, respectively.pectively.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.415-418
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• 1999

The characteristics of VRLA (valve regulated Iead-acid) battery with the tubular positive plate and gel type electrolyte were examined as a function of active material filling density. The filling density of positive plate was 3.2 g/mL, 3.4 g/mL, and 3.6 g/mL, respectively. These VRLA batteries were cycled with 100% DOD (depth of discharge) at the $C_5/5$ rate, followed by IU-type recharge with $I_{max}=0.2C_{10}/10$ and a final voltage V=2.40 V/cell. The test was performed in a thermostatic room at $25{\pm}1^{\circ}C$. The result indicated that the initial capacity was independent of active material filling density, i.e., the highest initial capacity was 3.4 g/mL of filling density and the lowest was 3.6 g/mL. On aspect of the cycle-life performance of the VRLA battery, the filling density of 3.6 g/mL was similar to that of 3.4 g/mL in the positive plate, and both were higher than that of 3.2 g/mL. Water-loss and degradation of the VRLA battery were decreased according to an increase of the filling density in the positive plate. The optimum filling density of the active material was 3.4~3.6 g/mL.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.444-447
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• 2000

The spinel L $i_{1-x}$ M $n_2$ $O_4$has been synthesized by the solid-state reaction. L $i_{l-x}$M $n_2$ $O_4$which includes a mixture of LiOH . $H_2O$ and Mn $O_2$prepared by preliminary heating at 35$0^{\circ}C$ for 12hr. L $i_{l-x}$M $n_2$ $O_4$fired at temperature range from 75$0^{\circ}C$ for 48hr. The structure and the electrochemical characteristics of spinel to L $i_{1-x}$ M $n_2$ $O_4$which is fabricated by changing sintering condition from starting materials are investigated. The cyclic voltammetric measurement was performed using 3 electrode cells. Electrode specific capacity and cycle life behavior were tested in a 3.0~4.2V range at a constant current density of 0.45mA/c $m^2$. To improve the cycle performance of spinel L $i_{l-x}$M $n_2$ $O_4$as the cathode of 4V class lithium secondary batteries, spinel phases L $i_{1-x}$ M $n_2$ $O_4$were Prepared at various lithium. The results showed that discharge capacity of L $i_{l-x}$M $n_2$ $O_4$varied at lithium quantity decrease with increasing lithium add quantity. The discharge capacities of L $i_{0.925}$M $n_2$ $O_4$and LiM $n_2$ $O_4$revealed 108 and 117mAh/g, respectively.spectively.y.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.349-353
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• 2003

The physiological characteristics of cultures of very high cell mass (e.g. 10g cell mass/L), termed“ultrahigh cell density cultures”is reviewed. A close relationship was found between the length of the optical path (OP) in flat-plate reactors and the optimal cell density of the culture as well as its areal (g m$\^$-2/ day$\^$-1/) productivity. Cell-growth inhibition (GI) unfolds as culture density surpasses a certain threshold. If it is constantly relieved, a 1.0cm OP reactor could produce ca. 50% more than reactors with longer OP, e.g. 5 or 10cm. This unique effect, discovered by Hu et al. [3], is explained in terms of the relationships between the frequency of the light-dark cycle (L-D cycle), cells undergo in their travel between the light and dark volumes in the reactor, and the turnover time of the photosynthetic center (PC). In long OP reactors (5cm and above) the L-D cycle time may be orders of magnitude longer than the PC turnover time, resulting in a light regime in which the cells are exposed along the L-D cycle, to long, wasteful dark periods. In contrast, in reactors with an OP of ca. 1.0 cm, the L-D cycle frequency approaches the PC turnover time resulting in a significant reduction of the wasteful dark exposure time, thereby inducing a surge in photosynthetic efficiency. Presently, the major difficulty in mass cultivation of ultrahigh-density culture (UHDC) concerns cell growth inhibition in the culture, the exact nature of which is awaiting detailed investigation.

• Korean Journal of Mathematics
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• v.21 no.2
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• pp.151-159
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• 2013

An $L(j,k)$-labeling of a graph G is a vertex labeling such that the difference of the labels of any adjacent vertices is at least $j$ and that of any vertices of distance two is at least $k$ for given $j$ and $k$. The minimum span of all L(2, 1)-labelings of G is called the ${\lambda}$-number of G and is denoted by ${\lambda}(G)$. In this paper, we find a lower bound of the ${\lambda}$-number of the Cartesian product $K_m{\Box}C_n$ of the complete graph $K_m$ of order $m$ and the cycle $C_n$ of order $n$. In fact, we show that when $n{\geq}3$, ${\lambda}(K_4{\Box}C_n){\geq}7$ and the equality holds if and only if n is a multiple of 8. Moreover when $m{\geq}5$, ${\lambda}(K_m{\Box}C_n){\geq}2m-1$ and the equality holds if and only if $n$ is even.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1221-1226
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• 2003

High hydrostatic Pressure was applied to Foxtail Millet Yakju to investigate the effects of high pressure on inactivation of microorganisms and enzymes. Total bacteria, lactic acid bacteria and yeast in untreated Yakju were $1.5{\times}$10$^4$,1.9${\times}$10$^4$ and 1.4${\times}$10$^4$ CFU/mL, respectively. Total bacterial count was reduced to 4.1${\times}$l0$^2$ CFU/mL, while lactic acid bacteria and yeast were sterilized completely in Yakju heated at $65^{\circ}C$ for 15 min. Lactic acid bacteria and yeast decreased greatly with the increase of treatment pressure, and were sterilized completely in Yakju treated at more than 300 ㎫ for 10 min/$25^{\circ}C$. Total bacteria were not completely sterilized with pressurization of even 600 ㎫ at room temperature and reduced to 2 log cycle even at $65^{\circ}C$. Total bacteria decreased by 2∼3 log cycle with the increase of treatment time from 10 to 60 min at $25^{\circ}C$/300 ㎫. Pressurization of Yakju caused a partial inactivation of $\alpha$ -amylase and glucosamylase, and the activities of $\alpha$ -amylase and glucoamylase decreased by 18.1% and 21.1%, respectively at $25^{\circ}C$/600 ㎫/10 min. Activities of $\alpha$ -amylase and glucoamylase decreased with the increase of temperature, and 22.2% and 32.1% of the original activity were remained with the treatment at $65^{\circ}C$/300 ㎫/10 min, respectively. Enzyme activities decreased slightly with the increase of treatment time at $65^{\circ}C$/300 ㎫.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.4
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• pp.60-65
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• 2011

Siloxane is an organic silicon compound and is volatilized into the bio gas from anaerobic digestion. It causes failure of gas combustion engines using the bio gas. Siloxane emission characteristics should be identified to provide a proper siloxane control. This study focuses on characterizing siloxane emission in bio gas from an anaerobic digester of food wastewater operating from January to March. The concentrations of total average siloxane and cycle-siloxane D4 were detected to be 9.5 and $4.0mg\;siloxane/m^3$, respectively. The concentrations of cycle-siloxane and linear-siloxane were resulted in D4>D5>D6 and L4>L3>L5>L2, respectively. The total siloxane concentration was the lowest in January and the highest in March.