• Title/Summary/Keyword: Experimental research

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On the Secretion and Functions of Equine Chorionic Gonadotropin (말의 융모성 성선자극 호르몬의 분비와 기능)

  • Min, K.S.
    • Korean Journal of Animal Reproduction
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    • v.24 no.2
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    • pp.125-142
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    • 2000
  • 13). Analysis of a purified preparation of eCG revealed that its $\beta$ -subunit consists of 149 amino acids, which was confirmed by the molecular cloning of its cDNA. There seem to be at least four to six, or even as many as 11, O-glycosylation sites on the extended C-tenninal region of the eCG $\beta$-subunit. Interestingly, eCG is a unique member of this family, as it appear to be a single molecule that possesses both LH- and FSH-like activities. Using the cDNA prepared from mRNA extracted from equine placental and pituitary tissues, we cloned the cDNA of eCG $\alpha$- and $\beta$ -subunits and eFSH $\beta$ -subunit. The mRNA expression of each subunit seems to be independently regulated, which may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. Thus, eCG is a distinct molecule from the view points of its biological function and glycoresidue structures. Recombinant eCGs including the mutants which lack oligosaccharides will be useful tools for analyzing the structure-function relationships of gonadotropins in the horse as well as other species. Similar experiments will also clarify the proposed structure and biological functions for the glycoprotein hormones. These experimental are now possible, and hopefully a resolution of the existing controversy will be forthcoming in the near future.

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Effects of Dietary Probiotic on Performance, Noxious Gas Emission and Microflora Population on the Cecum in Broiler (복합 생균제 첨가가 육계 생산성, 유해가스 발생량 및 맹장내 균총에 미치는 영향)

  • Ko, Y.D.;Sin, J.H.;Kim, S.C.;Kim, Y.M.;Park, K.D.;Kim, J.H.
    • Journal of Animal Science and Technology
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    • v.45 no.4
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    • pp.559-568
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    • 2003
  • This study was carried out to investigate the effect of probiotics on the performance, nutrients digestibility, noxious gas emission and microflora population on the cecum of broilers. A total of 120 broilers, consisted of 4 treatments X 3 replicates X 10 broilers per replicates, were fed the experimental diets containing 0, 0.1, 0.3 and 0.5% probiotics for 5 weeks. Broilers fed the diets containing 0.1 and 0.3% probiotic had higher (p<0.05) body weight gain and feed conversion than those of the others from the 3rd to 4th week. Broilers fed 0.3% probiotic had higher (p<0.05) body weight gain and feed conversion than those of the other levels from the 5th to 6th week. Broilers fed the diets containing 0.1% and 0.3% probiotic had higher (p<0.05) body weight gain and feed conversion than those of the others from the 2nd to 6th week. Dry matter digestibility was significantly (p<0.05) improved with 0.3% probiotic. Emission of ammonia and sulfate hydrogen gas was significantly (p<0.05) decreased at 6th week. However, there was no (p<0.05) difference at the levels of 0, 0.1, 0.3 and 0.5% at the 4th weeks. There was an increase in the lactobacillus sp, but there was a decrease in the microflora population of coliforms in the cecum of broiler with 0.1% and 0.3% probiotics. These results indicated that the compound probiotics of 0.1${\sim}$0.3% were effective in the body weight gain, feed conversion, nutrients digestibility, noxious gas emission and microflora population on the cecum in broilers.

Evaluation of the Shear Strength and Stiffness of Frozen Soil with a Low Water Content (함수비가 낮은 동결토의 전단강도 및 강성 평가)

  • Kim, Sang Yeob;Lee, Jong-Sub;Kim, Young Seok;Byun, Yong-Hoon
    • The Journal of Engineering Geology
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    • v.25 no.1
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    • pp.93-102
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    • 2015
  • The characteristics of frozen soils are one of most important factors for foundation design in cold region. The objective of this study is to evaluate the shear strength and stiffness of frozen soils according to the confining conditions during the freezing and shearing phase. A direct shear box is constructed for the frozen specimens and bender elements are mounted on the wall of the shear box to measure shear wave velocities. Specimens are prepared by mixing sand and silt with a silt fraction of 30% in weight and the degree of saturation of 10%, giving a relative density of 60% for all tests. The temperature of the specimens in the freezer is allowed to fall below -5℃, and then direct shear tests are performed. A series of vertical stresses are applied during the freezing and shearing phase. Shear stress, vertical displacement, and shear wave along the horizontal displacement are measured. Experimental results show that in all the tests, shear strength increases with increasing vertical stress applied during the freezing and shearing phases. The magnitude of the increase in shear strength with increasing vertical stress during shearing under fixed vertical stress in the frozen state is smaller than the magnitude of the increase in vertical stress during freezing and shearing. In addition, the change in shear wave velocities varies with the position of the bender elements. In the case of shear waves passing through the shear plane, the shear wave velocities decrease with increasing horizontal displacement. This study provides an evaluation of the properties of shear strength and stiffness of frozen soils under varied confining condition.

Effect of $K^+-channel$ Blockers on the $A_1-adenosine$ Receptor-Coupled Regulation of Electrically-Evoked Norepinephrine Release in the Rat Hippocampus (흰쥐 해마에서 Norepinephrine 유리를 조절하는 $A_1-adenosine$ 수용체의 역할에 미치는 $K^+$ 통로 차단제의 영향)

  • Choi, Bong-Kyu;Kim, Sang-Hoon
    • The Korean Journal of Pharmacology
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    • v.32 no.3
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    • pp.301-309
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    • 1996
  • Since it has been reported that the depolarization-induced NE release is inhibited by activation of presynaptic $A_1-adenosine$ heteroreceptor in hippocampus, a large body of experimental data on the post-receptor mechanism of this process has been accumulated. But, the post-receptor mechanism of presynaptic $A_1-adenosine$ receptor on the NE release has not been clearly elucidated yet. Therefore, it was attempted to clarify the participation of $K^+-channel$ in the post-receptor mechanisms of the $A_1-adenosine$ receptor-mediated control of NE release in this study. Slices from rat hippocampus were equilibrated with $^3H-norepinephrine$ and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 $VCm^{-1}$, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium-outflow was investigated. Adenosine, in concentrations ranging from $1{\sim}30\;{\mu}M$, decreased the NE release in a dose-dependent manner, without affecting the basal rate of release. 4AP $(1{\sim}30{\mu}M)$, a specific A-type $K^+-channel$ blocker, increased the evoked NE release in a dose-related fashion, and the basal rate of release is increased by 10 and $30{\mu}M$. TEA $(1{\sim}10{\mu}\;M)$, a nonspecific $K^+-channel$ blocker, increased the evoked NE release in a dose-dependent manner without affecting basal release. The adenosine effects were significantly inhibites by 3 ${\mu}M$ 4AP and 10 mM TEA treatment. 4AP $(30{\mu}M)-$ and TEA (10 mM)-induced increments of evoked NE release were completely abolished in $Ca^{++} free, but these were recoverd in low $Ca^{++} medium. And the effects of $K^+-channel$ blockers in low $Ca^{++} medium were inhibites and abolishes by $Mg^{++} (4 mM) adding and TTX $(0.3{\mu}M)$ adding medium, respectively. These results suggest that the decrement of the evoked NE-release by $A_1-adenosine$ receptor is mediated by 4AP and TEA sensitive $K^+-channel$.

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Study of Absorbed Dose and Effective Dose for Prostate Cancer Image Guided Radiation Therapy using kV Cone Beam Computed Tomography (kV Cone Beam Computed Tomography (CBCT)를 이용한 전립선암 영상유도방사선치료 시 흡수선량 및 유효선량에 관한 고찰)

  • Na, Jong-Eok;Lee, Do-Geun;Kim, Jin-Soo;Baek, Geum-Mun;Kwon, Kyung-Tae
    • The Journal of Korean Society for Radiation Therapy
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    • v.21 no.2
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    • pp.67-74
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    • 2009
  • Purpose: To evaluate the results of absorbed and effective doses using two different modes, standard mode (A-mode) and low-dose mode (B-mode) settings for prostate cancer IGRT from CBCT. Materials and Methods: This experimental study was obtained using Clinac iX integrated with On Board Imager (OBI) System and CBCT. CT images were obtained using a GE Light Speed scanner. Absorbed dose to organs from ICRP recommendations and effective doses to body was performed using A-mode and B-mode CBCT. Measurements were performed using a Anderson rando phantom with TLD-100 (Thermoluminescent dosimeters). TLD-100 were widely used to estimate absorbed dose and effective dose from CBCT with TLD System 4000 HAWSHAW. TLD-100 were calibrated to know sensitivity values using photon beam. The measurements were repeated three times for prostate center. Then, Evaluations of effective dose and absorbed dose were performed among the A-mode and B-mode CBCT. Results: The prostate absorbed dose from A-mode and B mode CBCT were 5.5 cGy 1.1 cGy per scan. Respectively Effective doses to body from A mode and B-mode CBCT were 19.1 mSv, 4.4 mSv per scan. Effective dose from A-mode CBCT were approximately 4 times lower than B-mode CBCT. Conclusion: We have shown that it is possible to reduce the effective dose considerably by low dose mode(B-mode) or lower mAs CBCT settings for prostate cancer IGRT. Therefore, we should try to select B-mode or low condition setting to decrease extra patient dose during the IGRT for prostate cancer as possible.

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Clinical and Cytogenetic Analysis of Children with Maternal Chromosomal Balanced Translocation (모체의 염색체 균형전좌를 가진 환아들의 임상적 세포 유전학적 관찰)

  • Lim, Han Hyuk;Jeong, Hee Jeong;Park, Kyung Duk;Kim, Sook Ja
    • Clinical and Experimental Pediatrics
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    • v.48 no.7
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    • pp.701-705
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    • 2005
  • Purpose : Parents' genetic information plays an important role in their children's genetic expression. Human chromosome has 23-paternal chromosomes and 23-maternal chromosomes. Parental chromosomal translocation can induce clinical problems in their children because of imbalance in genetic information. We intent to analyze the cytogenentic and clinical features about children with maternal balanced translocation between chromosome 15 and 18. Methods : We detected by one family's FISH study of chromosome 15. We have evaluated children born to clinically normal parents about peripheral bood analysis, endocrine, metabolic, radiologic study, electroencephalogram and social & intelligence scale. and We analysis their clinical manifestation by hospital records. Results : Patient's father and elder sister are normal clinically and genetically. Her mother's chromosome show balanced translocation, 46, XX, t(15;18)(p11.2;p11.3). One child has 46, XX, der(18) t(15;18)(p11.2;p11.3), mental retardation, growth retardation, speech & social developmental delay, recurrent infection and mild mitochondria dysfunction. Her young brother has 46, XY, der(15) t(15;18) (p11.2;p11.3), mental retardation, aggressive behavior, obesity and speech developmental delay. Conclusion : In this study we observed the children with developmental delay, dysmorphic facial features, mental retardation, growth retardation associated with growth hormone deficiency and aggressive behavior due to unbalanced translocation between chromosome 15 and 18.

Investigation of Automated Neonatal Hearing Screening for Early Detection of Childhood Hearing Impairment (소아 난청의 조기진단을 위한 신생아 청력 선별검사에 대한 평가)

  • Seo, Jeong Il;Yoo, Si Uk;Gong, Sung Hyeon;Hwang, Gwang Su;Lee, Hyeon Jung;Kim, Joong Pyo;Choi, Hyeon;Lee, Bo Young;Mok, Ji Sun
    • Clinical and Experimental Pediatrics
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    • v.48 no.7
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    • pp.706-710
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    • 2005
  • Purpose : Early diagnosis of congenital hearing loss through the neonatal hearing screening test minimizes language defect. This research intends to identify frequency of congenital hearing loss in infants through neonatal hearing screening test with the aim of communicating the importance of hearing test for infants. Methods : From May 20, 2003 to May 19, 2004, infants were subjected to Automated Auditory Brainstem Response test during one month of birth to conduct the test with 35 dB sound. Infants who passed the 1st round of hearing test, were classified into 'pass' group whereas those who did not were classified into 'refer' group. Infants who did not 'pass' in the hearing test conducted within one month of birth were subjected to re-test one month later, and if classified as 'refer' during the re-test, they were subjected to the diagnosis for validation of hearing loss by requesting test to the hearing loss clinic. Results : There was no difference among the 'pass' and 'refer' group in terms of form of childbirth, weight at birth and gestational age. In the 1st test, total of 45 infants were classified into 'refer' group. Six among 35 who were subjected to re-test(17%) did not pass the re-test, and all were diagnosed with congenital hearing loss. This corresponds to 0.35%(3.5 per 1,000) among total number of 1,718 subjects. Conclusion : In our study the congenital hearing loss tends to be considerably more frequently than congenital metabolic disorder. Accordingly, newly born infants are strongly recommended to undergo neonatal hearing screening test.

Isolation rate of 4 type virus of acute gastroenteritis in full-term neonates during neonatal period (신생아기 급성 장염의 4종 바이러스 양성률)

  • Moon, Soo Kyoung;Lee, Jae In;Yoon, Hye Sun;Ahn, Young Min
    • Clinical and Experimental Pediatrics
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    • v.50 no.9
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    • pp.855-861
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    • 2007
  • Purpose : The most common causes of acute viral gastroenteritis in newborn period are rotavirus, astrovirus, norovirus and enteric adenovirus. This study was designed to investigate the clinical characteristics, clinical symptoms, isolation rate and distribution of these viruses in full-term neonates during neonatal period. We also studied the influence on the viral isolation rate by postnatal care place and feeding type. Methods : We evaluated 112 healthy full-term neonates who were admitted to Eulji hospital, presenting with symptoms of acute viral gastroenteritis from September 2004 to August 2005. Epidemiologic, clinical and laboratory data were reviewed. Enzyme-linked immunosorbent assay (ELISA) for rotavirus, astrovirus and norovirus and RT-PCR for enteric adenovirus were performed in study subjects.Results : The mean age at the admission was $11.4{\pm}5.4days$, mean weight loss was $5.9{\pm}5.1%$, mean hospitalization duration was $6.3{\pm}3.4days$. Moderate and severe weight loss were expressed in 51.7% and metabolic acidosis was in 13.4%. The percent of living in postnatal care facility (PCF) was 74.1 % and the percent of mixed feeding was 64.3%. Isolation rate of virus was 33%. The most prevalent virus was rotavirus (59.5%), followed by astrovirus (29.7%) and norovirus (10.8%). There was no differences in virus isolation rate by postnatal care place and by feeding type. The rotavirus was main virus in both home group and PCF group. But astrovirus was more detected in PCF and norovirus was more detected in home (P<0.05). According to monthly distribution of virus, acute viral gastroenteritis in newborn period was concentrated in September to December. Conclusion : The isolation rate of 4 type viruses was 33% and rotavirus was the leading cause of acute gastroenteritis during neonatal period. There was no differences in clinical characteristics on each viral groups.

Combustion Characteristic Study of LNG Flame in an Oxygen Enriched Environment (산소부화 조건에 따른 LNG 연소특성 연구)

  • Kim, Hey-Suk;Shin, Mi-Soo;Jang, Dong-Soon;Lee, Dae-Geun
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.1
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    • pp.23-30
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    • 2007
  • The ultimate objective of this study is to develop oxygen-enriched combustion techniques applicable to the system of practical industrial boiler. To this end the combustion characteristics of lab-scale LNG combustor were investigated as a first step using the method of numerical simulation by analyzing the flame characteristics and pollutant emission behaviour as a function of oxygen enrichment level. Several useful conclusions could be drawn based on this study. First of all, the increase of oxygen enrichment level instead of air caused long and thin flame called laminar flame feature. This was in good agreement with experimental results appeared in open literature and explained by the effect of the decrease of turbulent mixing due to the decrease of absolute amount of oxidizer flow rate by the absence of the nitrogen species. Further, as expected, oxygen enrichment increased the flame temperatures to a significant level together with concentrations of $CO_2$ and $H_2O$ species because of the elimination of the heat sink and dilution effects by the presence of $N_2$ inert gas. However, the increased flame temperature with $O_2$ enriched air showed the high possibility of the generation of thermal $NO_x$ if nitrogen species were present. In order to remedy the problem caused by the oxygen-enriched combustion, the appropriate amount of recirculation $CO_2$ gas was desirable to enhance the turbulent mixing and thereby flame stability and further optimum determination of operational conditions were necessary. For example, the adjustment of burner with swirl angle of $30\sim45^{\circ}$ increased the combustion efficiency of LNG fuel and simultaneously dropped the $NO_x$ formation.

Effects of Chromium Picolinate on Growth Performance, Carcass Characteristics and Plasma Components in Holstein Bulls (홀스타인 수소에 있어서 Chromium Picolinate의 첨가가 성장성적, 혈액성상 및 도체품질에 미치는 영향)

  • Hong, Z.S.;Jin, M.G.;Jin, R.H.;Han, S.Y.;Lee, H.G.;Lee, H.J.;Choi, Y.J.
    • Journal of Animal Science and Technology
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    • v.44 no.4
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    • pp.419-426
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    • 2002
  • We conducted two experiments to evaluate the effects of chromium picolinate(CrP) on growth performance, carcass characteristics and plasma components in Holstein bulls. In trial Ⅰ, eight finishing Holstein bulls(300${\pm}$6.99Kg) were allocated to 2 treatments(control and 0.05% CrP) with 4 replication for 10-months. In results, growth performance was not affected by CrP addition. The plasma insulin concentration in 0.05% CrP group was about 2 times higher than the control group of Holstein bulls. The levels of plasma NEFA were significantly decreased to 59.00 mEq/dl with 0.05% CrP treatment(P<0.05), but the levels of plasma glucose and PUN were not altered by 0.05% CrP treatment. The grade of carcass was not different between control and 0.05% CrP group, but back fat thickness in 0.05% CrP group was increased in 22.33% compared with control group. In trial 2, fifteen growing- finishing Holstein bulls(160${\pm}$4.63Kg) were allocated to 3 treatments(control, 0.025% CrP and 0.05% CrP) with 5 replication for 14-months. During the overall experimental period, growth performance was not affected by CrP levels. The levels of hormone and metabolites were not affected by CrP supplementa- tion. The carcass characteristics were not different between control and treatment. These results show that the CrP may have no effects for beef cattle production because of degradation of CrP conjugation in the rumen. However treatment of short term provide a possibility the effects of development for lipogenesis.