• Clinical and Experimental Reproductive Medicine
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• v.8 no.1
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• pp.23-34
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• 1981

In order to study twin pregnancies, a retrospective survey was carried out in Yonsei University, Severance Hospital. Twin deliveries during 1967-1976 numbered altogether 264, and their relative frequency was 1.30%. Clinical palpation in addition to auscultation and roentgenologic technique had been used in the twin diagnosis. The diagnosis was made prior to delivery in 93.18% of the cases. The deliveries took place in the 37.26th (S.D. 3.95) gestational weeks on an average. The mean weights of the infants were-A (first baby) 2416.03g. (S.D. 802.61), and B (second baby) 2299.81g. (S.D. 190.31). The most common manner of twin delivery was spontaneous vaginal delivery. Cesarean section was done in 14.39%, of which the most common indication was hypotonic uterine dysfunction (34.21 %). Low one minute Apgar scores occured more often in B twins than among A twins. Breech delivery gave low one minute Apgar scores more often than did spontaneous vertex delivery in both twins. Full term twins and infants weighing more than 2500g. had fewer low one minute Apgar scores than the preterm infants and those with low birth weight. Perinatal mortality (PNM) in the total series was 14.77% (A 12.50% and B17.05%). The most common cause of perinatal mortality was prematurity in 44.87%. The worst outcome was recorded for the age groups 15-19 and ${\geqq}$40, in which perinatal mortality were 50.00%, respectively. The perinatal mortality of both A and B infants was lowest in the group diagnosed early during antenatal care before delivery. On the basis of our findings, we wish to emphasize particularly the importance of the early diagnosis of twins.

• Journal of the Korean Society for Heat Treatment
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• v.14 no.3
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• pp.155-159
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• 2001

The thermal shock resistance has been investigated and compared in three hot-work tool steels. The resistance to thermal shock is first of all a matter of good toughness and ductility. Therefore, a proper hot-work tool steel should be characterized by high fracture strength and high temperature toughness. In this study, new test method is proposed to measure the thermal shock resistance. New method is basically based on Uddeholm' thermal shock test but some modification has been properly applied. Based on these results, some critical temperature($T_{fractures}$) at which fracture occur can be measured to characterize the thermal resistance of the materials. The specific values of ${\Delta}T$, the temperature difference between holding temperature and $T_{fractures}$, has been successfully used as a measure of the thermal shock resistance in this study, the results showed that the thermal shock method used in this study was properly modified.

• Journal of The Korean Astronomical Society
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• v.14 no.2
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• pp.55-71
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• 1981

On the basis of observational constraints, particularly the relationship between metal abundance and cumulative stellar mass, a simple two-zone disk-halo model for the chemical evolution of our Galaxy was investigated, assuming different chemical processes in the disk and halo and the infall rates of the halo gas defined by the halo evolution. The main results of the present model calculations are: (i) The halo formation requires more than 80% of the initial galactic mass and it takes a period of $2{\sim}3{\times}10^9$ yrs. (ii) The halo evolution is divided into two phases, a fast collapse phase ($t=2{\sim}3{\times}10^8$ yrs) during which period most of the halo stars $({\sim}95%)$ are formed and a later slow collapse phase which is characterized by the chemical enrichment due to the inflow of external matter to the halo. (iii) The disk evolution is also divided into two phases, an active disk formation phase with a time-dependent initial mass function (IMF) up to $t{\approx}6{\times}10^9$ yrs and a later steady slow formation phase with a constant IMF. It is found that at the very early time $t{\approx}5{\times}10^8$ yrs, the metal abundance in the disk is rapidly increased to ${\sim}1/3$ of the present value but the total stellar mass only to ${\sim}10%$ of the present value, finally reaching about 80% of the present values toward the end of the active formation phase.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.611-622
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• 2006

Fatty acid compositions and physicochemical properties of feta cheese made from bovine milk were studied. Nutritional compositions of feta cheese were fat 22.79%, protein 10.57% with moisture content of 59.87%. The log cfu/g of lactic acid bacteria in bovine feta cheese decreased from 10.25 to 7.95 and pH also changed from pH 6.22 to pH 5.55 during storage at 4℃ for 14 d aging. The color of feta cheese turned into more whitish (L-value, 100.1) with a red (a-value, 4.6) and gray (b-value,－4.1) color after 14day's aging. For the texture profile analysis of bovine feta cheese, resilience was increased significantly (p<0.01) throughout the aging periods and adhesiveness was rapidly increased right after progressing of aging at both temperatures, but no difference was found between the aging periods. Hardness, fracturability, gumminess and chewiness were gradually increased at 0℃, but no statistical significances were found. Springiness and cohesiveness were not changed at both temperatures. In organoleptic evaluations, organoleptic intensities in sweetness, milky taste and saltiness were significantly enhanced over those of the control cheese at the level of p<0.01, and masticatory texture at p<0.05 with the progress of aging to 14d. Organoleptic preferences were significantly (p<0.01) enhanced except smell, color, mouth feel, and masticatory texture with the aging. In the fatty acid compositions of feta cheese analyzed by gas chromatography, the content of SFA (52.61%) was slight higher than that of USFA (47.39%) composed with MUFA (28.98%) and PUFA (18.41%). Among the nutritionally important fatty acids; ω6 (9.27%) and ω3 (0.55%) fatty acids, CLA (0.12%), arachidonic acid (0.19%) and DHA (0.12%) were also found in bovine feta cheese.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.14-22
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• 1992

A series of new N-[1-(benzotriazol-1-yl)aryl]arylamine derivatives were synthesized and their antifungal activities $(pI_{50})$ in vitro against Pyricularia oryzae, Fusarium oxysporum f. sp. sesami, Valsa ceratosperma and Botrytis cinerea were dertermined by the agar medium dilution method. From the results of the quantitative structure-activity relationships $(QSAR_S)$ analysis, $hydrophobicity({\pi})$, $electronic({\Sigma\sigma})$ and molar $refractivity({\Sigma}M_R)$ parameter of X & Y-substituents on the phenyl group were also shown to be important factor in determining the variation in the antifungal activity. 4-Bromo group substituents (1d & 2b) were the most effective compounds and the $half-life(T_{1/2})$ on the hydrolysis of X(1) at netural pH was about 1.5 day. Molecular orbital(MO) functions of substrate compound, linear free energy relationships$(LFER_S)$ on the antifungal reactivity arid the results of molecular design were also discussed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.5
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• pp.17-35
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• 2011

The purpose of this study is to offer the raw data for management and conservation of national park by systematic and objective surveying and analysing the flora distributed in the Hwarang district, Gyeongju national park. The results are as follows. The vascular plants in this site were summarized as 396 taxa: 95 families, 272 genera, 351 species, 2 subspecies, 38 varieties and 5 forma. The rare plants designated by Korea Forest Service were 5 taxa: Exochorda serratifolia S.Moore, Potentilla discolor Bunge, Prunus yedoensis Matsum, Lysimachia coreana Nakai and Inula salicina var. asiatica Kitam.. The korean endemic plants were 6 taxa: Populus tomentiglandulosa T.B.Lee, Clematis trichotoma Nakai, Lespedeza maritima Nakai, Lysimachia coreana Nakai, Forsythia koreana (Rehder) Nakai and Weigela subsessilis (Nakai) L.H.Bailey. The specific plants by floristic region were 30 taxa: Asplenium sarelii Hk., Salix chaenomeloides Kimura, Lysimachia barystachys Bunge, Achillea alpina L., Celtis aurantiaca Nakai, Vitex negundo var. incisa (Lam.) C.B.Clarke and so forth. The plants with approval for delivering oversea were 6 taxa: Clematis trichotoma Nakai, Exochorda serratifolia S.Moore, Glycine soja Siebold & Zucc., Lespedeza maritima Nakai, Lysimachia coreana Nakai and Weigela subsessilis (Nakai) L.H.Bailey. The naturalized plants were 49 taxa: Bilderdykia dumetora (L.) Holub, Descurainia pinnata Britton, Oxalis corymbosa DC., Bidens frondosa L., Panicum dichotomiflorum Michx. and so forth. The invasive alien plants were 2 taxa: Ambrosia artemisiifolia L. and Aster pilosus Willd. In future, if we will survey the flora of whole Gyeongju national park, we will offer the help to establishing the conservation plan of ecosystem in Gyeongju national park.

• Bulletin of the Korean Chemical Society
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• v.14 no.6
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• pp.713-717
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• 1993

The crystal structure of the potassium salt of penicillin V has been studied by the X-ray crystallographic methods. Crystal data are as follows; potassium 3,3-dimethyl-7-oxo-6-phenoxyacetoamido-4-thia-1- azabicyclo[3.2.0]-heptane-2${\alpha}$-carboxylate, $K^+{\cdot}C_{16}H_{18}N_2O_5S^-$, $M_r$= 388.5, triclinic, Pl, a= 9.371 (1), b= 12.497 (2), c= 15.313 (2) ${\AA},\;{\alpha}= 93.74\;(2),\;{\beta}=99.32\;(1),\;{\gamma}=90.17\;(1)^{\circ},\;V=1765.7\;(2)\;{\AA}^3$, Z=4, $D_m=1.461\;gcm^{-1},\;{\lambda}(Cu\;K{\alpha})=1.5418\;{\AA},\;{\mu}=40.1\;cm^{-1}$, F(000)=808, T=296 K. The structure was solved by the heavy atom and difference Fourier methods with intensity data measured on an automated four-circle diffractometer. The structure was refined by the full-matrix least-squares method to a final R= 0.081 for 3563 observed $[I_0{\geq}2{\sigam}(I_0)]$ reflections. The four independent molecules assume different overall conformations with systematically different orientations of the phenyl groups although the penam moieties have the same closed conformations. There are intramolecular hydrogen bonds between the exocyclic amide nitrogen and phenoxy oxygen atoms. The penam moiety is conformationally very restricted although the carboxyl and exocyclic amide groups apparently have certain rotational degrees of freedom but the phenyl group is flexible about the ether bond despite the presence of the intramolecular N-H${\cdots}$O hydrogen bond. There are complicated pseudo symmetric relationships in the crystal lattice. The penam moieties are related by pseudo 20.5 screw axes and the phenyl groups by pseudo centers of symmetry. The potassium ions, related by both pseudo symmetries, form an infinite zigzag planar chain parallel to the b axis. Each potassium ion is coordinated to seven oxygen atoms in a severely distorted pentagonal bipyramid configuration, forming the infinite hydrophilic channels which in turn form the molecular stacks. Between these stacks, there are only lipophilic interactions involving the phenyl groups.

• Culinary science and hospitality research
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• v.17 no.1
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• pp.226-237
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• 2011

This study investigates the effects of chajogi (perilla frutescens) extracts on quality of vinaigrette dressing during storage. Vinaigrette dressing(VD) samples prepared with chajogi(perilla frutescens) extracts were divided into control(0% chajogi extracts) and the groups added chajogi extracts. VD samples prepared with chajogi extracts were divided into $T_1$(VD with 0.4% chajogi extracts), $T_2$(VD with 0.8% chajogi extracts) and $T_1$(VD with 1.2% chajogi extracts). The pH values during storage at 25 and $50^{\circ}C$ for 120 days in all samples ranged from 2.38 to 2.83 and form 3.21 to 3.36, respectively. As for total acidity, it decreased in all samples during storage while there wasn't significant difference in the samples of different storage temperature(25 and $50^{\circ}C$). L(lightness) value scores of all samples added with chajogi extracts during storage went higher and a(redness) and b(yellowness) value scores became lower. Escerichia coli forms were not detected in all samples. Antioxidant capacity by peroxide value of T1, T2 and T3 sample showed higher than that of the control sample. Crude Fat contents of the control sample during storage at $25^{\circ}C$ were the highest as compared to those of the other samples.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1131-1138
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• 2004

The objective of this study was to investigate the effects of different sources of Ca and P on urine and ileal digesta pH, and ammonia ($NH_{3}$), methane ($CH_{4}$), and odor emission. In experiment 1, eight pigs (commercial three-way cross; initial BW 67$\pm$3 kg) were arranged in a repeated 4$\times$4 Latin Square design. All pigs were equipped with a T-cannula in the distal ileum. Four corn-soybean meal based diets were formulated. Diet 1 was the control in which dicalcium phosphate (DCP) and limestone ($CaCO_{3}$) were used as the sources of inorganic P and Ca. In Diets 2 and 3, ${H_{3}}{PO_{4}}$, monocalcium phosphate (MCP), and $CaSO_{4}$replaced DCP and $CaCO_{3}$ as the inorganic sources of P and Ca. Diet 4 was similar to Diet 1 except that it was fortified with HCl to provide an acid load similar to that of diet 2. Urine and ileal digesta pH were determined in pigs fed each of these diets. In Exp. 1, urine pH decreased (p<0.05) in animals consuming diets containing ${H_{3}}{PO_{4}}$-$CaSO_{4}$ (5.85$\pm$0.38) and MCP-$CaSO_{4}$(5.73$\pm$0.30) compared with the DCP-$CaCO_{3}$ diet (6.89$\pm$0.24). In the pigs consuming ${H_{3}}{PO_{4}}$-$CaSO_{4}$, ileal digesta pH decreased compared with the control (5.52$\pm$0.28 vs. 6.66$\pm$0.17; p<0.05). Based on the results of Exp. 1, a total of four trials were performed in environmental chambers for determining how $NH_{3}$, $NH_{4}$, and odor were affected by the different dietary Ca and P sources (Exp. 2). In Exp. 2, pigs fed the ${H_{3}}{PO_{4}}$-$CaSO_{4}$ diet had decreased (30%) $NH_{3}$ emissions compared with the control (p<0.05). Also, a combination of MCP-$CaCO_{3}$-$CaCl_{12}$ decreased $NH_{3}$ emission by 15% (p<0.05). Emission of $CH_{4}$ was decreased only with the ${H_{3}}{PO_{4}}$-$CaSO_{4}$ diet with 14% (p<0.05). Odorant emission of phenolics and volatile fatty acids increased roughly three-fold with the DCP-$CaSO_{4}$ diet but was not affected by other test diets. In conclusion, acidogenic Ca and P sources in swine diets can decrease the urinary pH and reduce $NH_{3}$ and $CH_{4}$ emission from swine facilities.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.922-925
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• 2015

This study was conducted to estimate the genetic parameters for pork belly traits and muscles in Yorkshire pigs. Each pork belly was cut into nine parts perpendicular to the thoracic vertebrae (6th to 14th). Traits of belly muscles including the deep pectoral, latissimus dorsi, cutaneous trunci, rectus abdominis, external and internal abdominal oblique from 382 purebred pigs were recorded and analyzed using SAS Package (9.1) and Derivative-free restricted maximum likelihood methods. Heritability estimates for belly traits ranged from 0.27 to 0.49, while they were 0.12 to 0.66 for belly muscles. Moderate to high heritability estimates were noted in belly weight (0.33), belly length (0.28), and belly width (0.49). In belly muscles, the latissimus dorsi and deep pectoral, which are located only in the 6th to 9th vertebrae sections, were found to have heritability estimates ranging from 0.21 to 0.29 and 0.23 to 0.35, respectively. Strong heritability estimates were observed in the 7th to 13th sections of cutaneous trunci muscle ranging from 0.42 to 0.66. Genetic correlations of latissimus dorsi m. with belly length were positive (0.50), while cutaneous trunci m. with belly weight also revealed a positive relationship that ranged from 0.35 to 0.47. The estimated genetic parameters indicate that belly weight can be improved by genetic selection. Differences in the levels of heritability occurred among various parameters of Yorkshire pork belly, which should be considered when performing selection to improve pork belly quality. Moreover, these results can provide valuable information that can be used as the basis for further investigations to improve pork belly.