• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.49-54
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• 2005

An experiment was conducted to investigate whether dietary yeast (Saccharomyces cerevisiae, SC) and its' structural components, i.e., yeast cell-extract (YE) and yeast cell-wall (CW) could influence growth performance, ileal morphology and serum lipids of male broiler chickens. There were four dietary treatments, each consisting of 6 replicates (10 birds per replicate). Chickens were fed a corn-soybean meal base control diet and diets containing SC ($0.5\%$), YE ($0.25\%$) and CW ($0.25\%$), respectively for 5-wk-experimental period. Dietary SC, YE and CW versus the control diet did not affect growth performance of male broiler chickens. Ileal morphology as to villus height, crypt depth and villus:crypt ratio of birds fed on the control diet was not significant from those fed on diets rich in SC, YE and CW, respectively. Dietary SC significantly lowered (P<0.05) serum total cholesterol by on average $19.7\%$ as compared to the control group. In addition, chickens fed on diets with either YE or CW lowered serum cholesterol by on average 15.3 and $12.5\%$, respectively as compared to the control albeit that the former only reached statistical significance. In conclusion, our study observed the hypocholesterolemic effect of SC in male broiler chickens. Moreover, YE, i.e., an extract of intracellular components of SC contains active molecules that are responsible far lowering serum cholesterol concentrations, but their identification at the molecular level needs to be assessed.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.61-66
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• 1970

This study examined the morphology and physical and chemical characteristics of the Changpyeong series developed on gently sloping to rolling relief on dissected old paddiplains and terraces. This soil has dark brown silty clay loam A horizons, very thick dark red to red silty clay or clay Bt horizons, and C horizons of old alluvial materials frequently with strongly weathered round cobbles and pebbles. It is strongly acid with a low organic matter content, relatively low in cation exchange capacity, but with relatively high base-status based on amount of extractable cations. There is no obvious changes in particle size distribution with depth and textural B horizons probably have not been formed by podzolization but formed by mechanical movement of clay. This soil is classified as Typic Hapludalfs in USDA 7th approximation and Brunic Luvisols in FAO classification system.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.14-15
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• 2010

Recently there has been growing interest in topological insulators or the quantum spin Hall (QSH) phase, which are insulating materials with bulk band gaps but have metallic edge states that are formed topologically and robust against any non-magnetic impurity [1]. In a three-dimensional material, the two-dimensional surface states correspond to the edge states (topological metal) and their intriguing nature in terms of electronic and spin structures have been experimentally observed in bulk Bi1-xSbx single crystals [2,3,4]. However, if we want to know the transport properties of these topological metals, high purity samples as well as very low temperature will be needed because of the contribution from bulk states or impurity effects. In a recent report, it was also shown that an intriguing coupling between the surface and bulk states will occur [5]. A simple solution to this bothersome problem is to prepare a topological metal on an ultrathin film, in which the surface-to-bulk ratio is drastically increased. Therefore in the present study, we have investigated if there is a method to make an ultrathin Bi1-xSbx film on a semiconductor substrate. From reflection high-energy electron diffraction observation, it was found that single crystal Bi1-xSbx films (0${\sim}30\;{\AA}A$ can be prepared on Si(111)-$7{\times}7$. The transport properties of such films were characterized by in situ monolithic micro four-point probes [6]. The temperature dependence of the resistivity for the x=0.1 samples was insulating when the film thickness was $240\;{\AA}A$. However, it became metallic as the thickness was reduced down to $30\;{\AA}A$, indicating surface-state dominant electrical conduction. Figure 1 shows the Fermi surface of $40\;{\AA}A$ thick Bi0.92Sb0.08 (a) and Bi0.84Sb0.16 (b) films mapped by angle-resolved photoemission spectroscopy. The basic features of the electronic structure of these surface states were shown to be the same as those found on bulk surfaces, meaning that topological metals can be prepared at the surface of an ultrathin film. The details will be given in the presentation.

• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.13-26
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• 1968

To establish the most efficient method of nitrogen and phosphorus fertilization in paddy rice a series of internationally coordinated research using $N^{15}\;P^{32}$ isotopes were carried out from the year 1962 through 1967, supervised by the Joint FAO/IAEA Division of Atomic Energy in Agriculture under the auspicies of FAO, UN. In Korea College of Agriculture, Seoul National University had been participated in the Coordinated Research Programme from the year 1963 through the last year, arid the results obtained through the six years' researches are summarized as follows: 1. In the application of superphosphate broadcasting or placement at the surface of paddy as basal dressing was most efficient. 2. Split or late application of superphosphate did not affect the grain yield of the rice, but its efficiency in the rice plant uptake was less than in the case of basal dressing of whole amounts. 3. The contents of available soil phoshorus of the experimental sites in Korea were above 60 ppm, and the efficiency of phosphorus utilization of the rice from the fertilizer was approximately 10 per cent. The grain yield response of the rice to phosphorus application in Korea was rather small comparing to those of other countries. 4. The nitrogen uptake of the rice plants from the fertilizer was most efficient when the fertilizer was applied at the time of ear prime growth. However, the most efficient utilization of nitrogen did not necessarily accompany the maximum yield of the rice and basic application of adequate amount of nitrogen was required to secure proper number of panicles. 5. In the application of nitrogenous fertilizer shallow placement at 5 cm depth was most efficient. The effect of split application of nitrogen was not so noticeable. It seemed due to the fact that total application amount of nitrogen, 60 kg N/ha, was smaller than that of usual dosage in Korea. 6. The efficiency of nitrogen utilization of the rice from the fertilizer was about 40 percent in Korea, and the yield reponse of the rice plant to nitrogen application was remarkable comparing to those of other countries, showing the marked differences in the fertilizer efficiency and grain yield according to the application method. 7. The nitrogen uptake of the rice plant was not likely affected by the time and the rate of phosphorus application whereas the efficiency of phosphorus utilization was affected to some degree by the method of nitrogen application.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.989-998
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• 2004

The objectives of this work was to investigate the effects of feeding type of concentrates during growing period and slaughter age on growth performance, feed efficiency and carcass characteristics in growing-fattening Holstein steers. Treatments were two concentrates feeding types(ad libitum or restricted 1.9% of BW) and three slaughter ages(at 19, 22 or 25 mo). Body weight at slaughter was numerically higher(approx. 8.3%) for the restricted than the ad libitum feeding groups. TDN intake rate was higher(8.4%) for the restricted than the ad libitum feeding groups. One mo slaughter delay increased TDN intake by 4%. Despite the lack of significances, higher back fat thickness and rib-eye area appeared in the restricted feeding or the late slaughter groups compared with the ad libitum feeding or the early slaughter groups. Marbling score(mean 2.46) numerically increased when the steers were restrictively fed concentrates compared with the ad libitum feeding groups. In addition, significant increases in the marbling score were associated with the slaughter age delay. In economic analysis, increases in total income were associated with the restricted feeding and the slaughter age delay. Whereas the highest monthly income appeared in the restricted feeding-and-slaughter at 22 mo group. In conclusion, the optimal feeding system may be 1) the restricted concentrates feeding(1.9% of BW) during growing period and 2) the late slaughter age(22${\sim}$25 mo of age) in growing-fattening Holstein steers fed rice straw.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.279-287
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• 2005

This study was carried out to investigate resumption of ovarian cyclicity and effect of BCS on estrous response by treatment of $PGF_2a+PGF_2a+CIDR$ program on day 40 postpartum in lactating dairy cow. First $PGF_2a$ was given on day 40 postpartum, second $PGF_2a$ was given 14 days apart to cows not-responded to 1st $PGF_2a$ and then CIDR was inserted for 7 days after 5 days in cows not-responded to 2nd $PGF_2a$. The $42.9\%$ of the cows showed more than 1 ng/mL milk progesterone concentration within 10 to 30 days postpartum. About $19\%$ of the cows exhibited more than 1 ng/mL milk pro-gesterone concentration between 31 to 50 days postpartum. However $38.1\%$ of the cows have not shown more than 1 ng/mL milk progesterone up to 50 days postpartum. Estrous response to the treatment of 1 st $PGF_2a$ and 2nd $PGF_2a$ was $47.5\%$ and $52.4\%$, respectively. Combination of 1 st $PGF_2a$ and 2nd $PGF_2a$ was $75\%$ and combination of 1st $PGF_2a$+2nd $PGF_2a$+CIDR was $87.5\%$. Estrous response to the treatment of $PGF_2a+PGF_2a$ program was $61.5\%$ in cows with less than 2.50 BCS and $81.5\%$ in cows with 2.75${\~}$3.50 BCS. Estrous response to the treatment of CIDR was $40\%$ in cows with less than 2.50 BCS and $80\%$ in cows with 2.75${\~}$3.50 BCS. Estrous response to the treatment of PPC on day 40 postpartum was $76.9\%$ in cows with less than 2.50 BCS and $96.3\%$ in cows with 2.75${\~}$3.50 BCS.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.56-62
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• 2015

Various pretreatment methods were evaluated to prevent tissue softening of heated onion. Changes in onion tissue firmness during heating were explained by 3-mechanism model consisting of texture hardening at low temperature ($60-80^{\circ}C$) and substrate softening at high temperature. Preheating of onion in a $Ca^{2+}$-containing solution significantly improved its texture after high-temperature heating. The improvement of firmness by preheating at low temperature was related to the formation of strong cross-linking between carboxyl groups and $Ca^{2+}$ by the action of pectin methylesterase in onion. The highest firmness was obtained by pre-heating at $70^{\circ}C$ for 120 min in 0.5% calcium solution. This result was supported by chemical analysis showing that the amount of bound calcium was the highest at $70^{\circ}C$. Further investigation should be carried out to establish the optimal conditions to prevent the softening of various vegetables.

• Clinical and Experimental Pediatrics
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• v.50 no.2
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• pp.157-162
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• 2007

Purpose : The purpose of this study was to analyze the epidemiology, causative organism, clinical manifestation and prognosis of bacterial meningitis for children after the introduction of Haemophilus influenzae type b (Hib) vaccine in Daejeon and Chungcheong area. Methods : We analyzed retrospectively 53 medical records who had been diagnosed with bacterial meningitis at 10 general or university hospitals in Daejeon and Chungcheong area. All patients aged 1 month-14 years admitted between January 2001 through December 2005. Results : During the 5-year study period, 40 of all cases were positive for bacterial growth. Of the 40 cases that were CSF culture-proven bacterial meningitis, Streptococcus peumoniae was the most common bacteria for 17 (32.1%) of all cases, followed by H. influenzae for 10 (18.9%), Neisseria meningitidis for 3 (5.7%). In this study, the most common clinical manifestation is fever, accompanied by all cases. CSF leukocyte count was more than $100/mm^3$ in 45 (84.1%) cases. CSF glucose concentration was less than 50 mg/dL in 42 (79.2%) cases and protein concentration was more than 45 mg/dL in 49 (92.5%) cases. 45 of all cases made a recovery after treatment and were discharged. Most common complication after treatment is subdural effusion (19.0%) and hearing disturbance (9.4%). Conclusion : The most common organism of culture-proven bacterial meningitis in the children beyond neonatal period was S. pneumoniae. Continued surveillance studies were demanded to know the altered incidence of bacterial meningitis, because we expect the incidence of S. pneumoniae meninigitis will be on the decrease after more active innoculation of pneumococcal protein conjugate vaccine.

• Food Science of Animal Resources
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• v.32 no.2
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• pp.190-197
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• 2012

This study was performed to evaluate the extraction method (Yacon ethanol extracts; YEE, Yacon pressed extracts; YPE) and various levels (0.05-1.0%) of Yacon (Polymnia sonchifolia) on antioxidant and antimicrobial activities. In linoleic acid emulsion of YPE, there were higher iron chelation activity and antioxidant activity than those of YEE (p<0.05). A 1,1- diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity and reducing power of both extracts showed a higher rate at 0.5% level. Ground pork patties, which contain 0.5% YEE and YPE, were manufactured and BHT (0.01%) was used as a reference. Physicochemical properties and microbial counts of ground pork patties, containing a different type of Yacon, were evaluated during the 14 d of storage at $4^{\circ}C$. A pH level, and lightness (Hunter L), as well as the yellowness (Hunter b) values of treatments were not different from those of the control (p>0.05), but increased during storage, at $4^{\circ}C$. Lightness values of ground pork patties, with Yacon extracts, showed the highest. TBARS value of ground pork patties that contains Yacon increased with increased storage at $4^{\circ}C$ (p<0.05), and pork patties with YPE or YEE retarded the lipid oxidation, during refrigerated storage, as compared to that of the CTL. Thus, YPE could be used as a potential possibility to inhibit the lipid oxidation of processed meats, during the refrigerated storage.

• Applied Microscopy
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• v.15 no.2
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• pp.31-68
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• 1985

Authors are trying to unveil the ultrastructural organization of olfactory bulb, which has been summerized under light microscopic level or communicated only in some detail in different view point until now. For the critical point of view, since the phylogenetical approach will give the ultimate value in the correlative study between structural and functional bases (Brodal, 1969), the present study was carried out light and electron microscopic analyses of the structures of the neurons and synaptic organizations in olfactory bulbs from different animals in phylogenetical scale. We selected each one species from five animal classes: the house rabbit(Oryctolagus cuniculus var. domesticus [Gmelin]) from Mammalia, the domestic fowl (Gallus gallus domesticus Brisson) from Aves, the viper (Agkistrodon hylys [G.P. Pallas]) from Reptilia, a frog (Bombiana orientalis Boulenger) from Amphibia and the crussian carp (Carassius carassius [Linne]) from Pisces. For light microscopic study, samples were fixed in 10% formalin and paraffin sections were stained with hematoxylin-eosin. For the electron microscopic study, the tissues were fixed by perfusion through the heart or immersion with 1% paraform-aldehyde-glutaraldehyde mixture (phosphate buffer, pH 7.4), and final tissue block trimmed under dissecting microscope were osmicated (1% OsO4), they were embedded in Araldite or Epon 812, and ultrathin sections were made by LKB-V ultratome following the inspection of semi-thin sections stained with toluidine blue-borax solution. Ultra-thin sections contrasted with uranyl acetate and lead citrate were observed with JEM 100CX electron microscope. We have summerized our morphological analyses as follows: 1. The olfactory bulb of rabbit, viper and frog shows the eight layers of fila olfactoria, glomerular, external granular, external plexiform, mitral cell, internal plexiform, internal granular, medullary but domestic fowl shows the five layers of glomerular, fibrillar, mitral, granular and medullary and the three layers of fibrilla, glomerular and medullary in crussian carp. The sharpness of demarcation between the layers shows deferential tendency according to phylogenetical order. 2. Mitral cells of vertebrate have large triangular or oval shape with spherical nuclei which contain not so much chromatin. The cytoplasm contains numerous cell organelles, of which Nissl's bodies or granular endoplasmic reticula arranged as parallel strands. Development of granular endoplasmic reticula were declined as the phylogentical grade is going lower. 3. Tufted cells of all animal are mostly spindle or polygonal contour and contain oval nuclei which located in periphery of cytoplasm. The nuclei of rabbit, fowl, viper and frog has relatively space chromatin, but a nucleus of crussian carp contain irregularly aggregated chromatin in karyoplasm. Their cytoplasmic volume and cell organelle contents are in between those of mitral cell and granular cell. They contain moderate amount of mitochondria, granular endoplasmic reticula, a few Golgi complex, polysomes, lysosome, etc. 4. Granule of cells of all the vertebrate amimals studied exhibit similar features; cells and their dense nuclei show spherical or oval contour, and they have the thin rim of cytoplasm which contain only a few cell organelles. 5. In rabbit, the soma of mitral cells were in contact with boutons with two types of synaptic vesicles, that is, round and flat vesicles, especially flat vesicles in boutons were showing reciprocal synapses. However, in domestic fowls, vipers, frogs and crussian carps, there were found boutons showing only spherical synaptic vesicles. 6. The boutons containing round synaptic vesicles were made contact with the some of tufted cell of olfactory bulb in the rabbits, fowls, vipers and frogs, but no synaptic boutons were observed in soma of tufted cells in crussian carps. In the frogs, there were observed dendrites were contact with the soma of tufted cells. 7. In the neuropils of plexiform, granular and glomerular layers olfactory bulbs in the vertebrate, the synapses were axo-large dendrites, axo-median and small dendrites, dendrodendritic, and axo-axonal contacts. However, in the neuropil of crussian carps, synapses were observed only in glomerular layer.