• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.254-263
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• 2016

Many studies on the prognosis of avulsed teeth were published but follow-up studies on Korean children and adolescents are insufficient. The aim of this study was to identify clinical factors determining the healing and prognosis of permanent incisors that were replanted after avulsion injury. This study included 184 permanent teeth in 142 patients aged 6-14 years. The clinical and radiographic data of the patients were analyzed from electronic medical records. Immature teeth had a higher probability of pulp revascularization than mature teeth. When extra-alveolar time was longer than 60 minutes, the incidence of inflammatory root resorption (IRR) was higher in immature teeth than mature teeth. However, the incidence of replacement root resorption (RR) was higher in mature teeth than immature teeth under the same condition. The incidence of IRR was increased when pulp was extirpated more than 20 days after replantation. IRR had a more significant influence on the decrease of survival expectation than RR. There was no significant correlation between the root development stage and survival expectation. However, when RR occurred, immature teeth survived shorter than mature teeth. Long term follow-up results from this study are expected to be used as fundamental data for the treatment guidelines and evaluation of the prognosis of replanted teeth.

• The Journal of Korean Association of Computer Education
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• v.16 no.2
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• pp.61-68
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• 2013

SNS is a social networking service that helps people to have a two-way communication, manage their personal relationships and share information. The domestic and international SNS markets have attained a steady growth, and their growth is being more accelerated recently. Under these circumstances, immature students are more likely to show negative cyber behavior. This study attempted to analyze the relationship between the use of SNS, motives of SNS use, the use of active SNS functions, SNS-dependency and views in SNS and negative SNS behaviors among elementary and middle school students. For this, negative cycber behaviors are classified into four stages depending on the severity, for each of which distribution of factors is investigated and the combination of factors to determine each stage is obtained through association rule analysis. As a result, it is found that 85% of the students rarely show negative cyber behaviors, stealing personal information and contacting with strangers are the most frequent negative behaviors, and students with a great dependency on SNS are highly probable to show negative behaviors.

• Reproductive and Developmental Biology
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• v.30 no.1
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• pp.7-11
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• 2006

This study was conducted to examine the effects of hormone and sodium pyruvate on in vitro maturation of canine oocytes. Canine oocytes were collected from the ovaries of dogs and cultured in NCSU-37 medium with hormones and sodium pyruvate for 72 hr. Oocytes matured to the metaphase II (MII) stage were observed only from estradiol $17{\beta}\;(E_2)$, and the presence of gonadotropin did not improve the nuclear maturation. No oocytes were developed to the MII stage when $E_2$ was added to medium during the first 6 and 24 hrs of culture period. The presence of $E_2$ during the whole culture period enhanced the nuclear maturation to the MII stage (6.0%, P<0.05). High concentration of sodium pyruvate (2.5 mM) slightly enhanced the nuclear maturation to the metapahse I (HMI) stage, but not the MII stage. the result of the present study shows that the presence of $ E_2$ during the whole culture period of 72 hr enhances the maturation of canine oocytes to the M stage, but sodium pyruvate does not affect the nuclear maturation of the canine oocytes.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.189-196
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• 1985

In order to observe the protein composltlOns of soluble extracts of P. westermani, and their changes during early developmental stages, the crude saline extracts of 4, 6, 8, 10 and 12 week-old worms which were harvested from experimentally infected dogs were analysed by disc-PAGE. The results were as follows: 1. A total of 15 bands were identified from electrophoregrams of respective developmental stages. Of them, 5 bands were recognized throughout the developmental stages. 2. The number and protein amount of identified bands changed according to the worm development from 4 weeks to 12 weeks. However, tLe bar::ding patterns of 4 and 6 week-old worms and 8 and 10 week-old worms were similar each other. 3. Of 15 identified bands, Band 1 was recognized only in 12 week-old worms whereas Bands 3, 4, 8, 9, 10, 11 and 15 gradually lowered their amount according to dcvelor:ment to disappear in 12 week-old. In addition, Band 5 became a major band in 12 week-old while Band 6 turned to a minor band at the same age. The possible relations of changing patterns of protein bands with worm development were discussed.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.287-296
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• 2014

Chicken eggs undergo various physiological changes during egg maturation. To study genes associated with the egg maturation in pre-ovulation (immature) and post-ovulation (mature), we compared gene expression patterns between in the immature egg and mature egg using RNA sequencing data. Mature and immature eggs were obtained from a Heuksaek Jaerae-jong of Korean native chicken. Total RNAs obtained from the eggs were sequenced by Illumina HiSeq 2000 platform, and the generated sequence reads were mapped to Galgal4 reference sequence assembly using Tuxedo Protocol. From the comparison of the RNA sequencing data, 315 genes were differentially expressed between mature and immature eggs, and 46 genes were only detected in immature egg. Further gene ontology (GO) analysis was performed for the differentially expressed genes using DAVID, showing that 29 and 28 GO terms were independently clustered from mature and immature, respectively. From those clustered GO terms, genes related to germ cell development, sex differentiation and defense response to bacterium were mainly expressed in the immature egg, while genes related to regulation of apoptosis, steroid metabolic process and lipid homeostasis were mainly detected in the mature egg. Our results could contribute to understand egg maturation before and after ovulation, and develop genetic markers for improving egg quality and productivity.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.1-14
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• 2003

This study was conducted to investigate that the immature and mature oocytes of porcine can be cryopreserved by vitrification. Oocytes were centrifuged to polarize the cytoplasmic lipid droplets. The lipids were removed from cytoplasm by micromanipulation. Delipated oocytes were centrifuged after being preincubated with cytochalasin B(CB) fer 10 min, and lipid droplets were removed. Centrifuged oocytes were treated with CB and centrifuged to polorize lipid droplets but not delipated and control oocytes is not-treatment. Oocytes of three types were vitrified in electron microscope(EM) grids. The results of survival, maturation and cleavage rates were as follows. 1 The survival rates of immature oocytes were 15.1%, 0% and 0% in the Delipated, Centrifuged and Control after vitrification, respectively, and its rate of Delipated wassignificantly higher than Centrifuged and Control(P<.01). 2. The survival rates of mature oocytes were 12.21%, 0% and 0% in the Delipated, Centrifuged and Control after vitrification, respectively, and its rate of Delipated was significantly higher than Centrifuged and Control(P<.01). 3 The maturation rates of immature oocytes were 37.5% and 68.9% for metaphase II in the Delipated after vitrification and Non-vitrification, respectively, and its rate of Non-vitrification was significantly higher than Delipated after vitrification(P<.01). 4. The cleavage rates of immature oocytes were 12.5%, 0%, 0% and 56.1% in the Delipated, Centrifuged, Control after vitrification and Non-vitrification, respectively. It's rate of Delipated was higher than Centrifuged and Control, but there were no significant difference, and its rate of Non-vitrification was significantly higher than Delipated, Centrifuged and Control(P<.05). 5 The cleavage rates of mature oocytes were 25.0%, 0%, 0% and 67.9% in the Delipated, Centrifuged, Control after vitrification and Non-vitrification, respectively. It's rate of Delipated was higher than Centrifuged and Control, but there were no significant difference, and its rate of Non-vitrification was significantly higher than Delipated, Centrifuged and Control(P<.05).

• Development and Reproduction
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• v.7 no.1
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• pp.23-28
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• 2003

The seasonal reproductive cycle of the female honeycomb grouper, Epinephelus merra, inhabiting Chuuk was examined by histological observations of the ovaries. The gonadosomatic index (GSI) began to increase in February and peaked in March. Histological observations revealed many oocytes laden with yolk in the ovaries from March to April. From June to January, the ovaries were occupied by immature oocytes. These results suggest that the reproductive season of E. merra in Chuuk is from March through April.

• Environmental and Resource Economics Review
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• v.7 no.1
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• pp.165-183
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• 1997

생명공학은 기술의 특성상 보건 의료, 농업, 자원 환경, 에너지 등 광범위한 산업에 응용될 수 있는 고부가가치형, 두뇌기술집약형, 탈공해형, 자원 및 에너지절약형 기술이라는 특징을 지니고 있어 21세기 미래산업을 선도할 것으로 기대되고 있다. 본 연구의 목적은 생명공학기술이 1980년과 1990년 사이의 산업구조에 어떠한 변화를 초래하였는지를 알아보는 것이다. 생명공학의 산업경제적 파급효과를 분석해 보기 위해 한국은행에서 발행한 산업연관표를 이용하여 생명공학 관련산업의 지원에 따른 국내 제반산업의 생산변화율을 측정하였다. 정부의 지원이나 금리 및 세제의 혜택을 통해 생명공학 산업 관련 비용이 감소하게 되면 이에 따른 가격변화가 국내 산업발전과 고용의 증가를 갖는 것으로 믿어진다. 고정계수 아닌 변화계수를 특징으로 하는 본 모형의 접근방법은 생명공학에 대한 재정지원 및 세제 인센티브 등을 외생변수로 처리하여 산업구조 변화의 추이와 고용유발 등을 예측하였다. 본 논문의 가설은 생명공학의 영역이 점차 증대되어 나아가기 때문에 1980년의 제반산업의 영향은 1990년의 영향보다는 적어야 한다. 즉 생명공학 관련비용 하락이 전체산업에 미치는 1980년의 생산율 증가보다 1990년의 생산율 증가가 커야 할 것이다. 본 가설에 대한 검증의 과정에서 얻은 통계치를 통해 생명공학산업이 한국 산업 전체에 미치는 영향이 10년 동안에 그 차이가 거의 없어 미성숙 단계에 있다는 결론을 짓게 되었다. 따라서 생명공학 분야의 계속적인 발전을 위해서는 선진국 수준의 독자적 기술개발을 통한 국제 경쟁력을 강화해야 하는데 이를 위한 정부 및 민간기업 투자확대와 연구개발 지원체제의 확대가 요망되고 있다.

• Journal of Mushroom
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• v.2 no.3
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• pp.145-148
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• 2004

This study was carried out to screen the fruiting body formation-specific genes from the medicinal mushroom Cordyceps militaris. A cDNA synthesized using total RNA from 4 stages of mushroom development, mycelium, primordium, immature fruiting body and mature fruiting body. Differential expression gene screening was performed by DD-PCR(Differential Display Arbitrary Primer PCR) with cDNA, we sequenced partial 6 genes using pGEM cloning vector. The DNA Sequence of the six DD-PCR products derived from differentially expressed genes was compared to that in the GenBank database by using the NCBI BLAST search to identify similarities to known sequences. Sequence analysis showed that six of DD-PCR products have unknown sequence.

• Korean Journal of Ichthyology
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• v.27 no.4
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• pp.263-274
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• 2015

Change in morphological and biological characteristics of Japanese eel, Anguilla japonica, by maturation were determined by examination of 182 individuals collected in Korea waters from September to December 2014. Eels were classified into four stages based on the silvering index. The proportion of silver eels collected from streams and estuaries (34.6%) was higher than that from the freshwater reservoirs (3.8%). The sex ratio between female and male was 1:0.11 (n=182). Mean total length and weight were positively related to the silvering process. The ratios of head and pectoral lengths to total length and the ratio of horizontal and vertical orbital diameters to head length were significantly different between the maturation stages. However the ratio of pre-dorsal and pre-anal lengths to total length were not significantly different between the maturation stages. The gonado-somatic index was the single character that could identify the whole four stages among the indices examined: gonado-somatic index (GSI), condition factor (K), gut index (GI) and eye index (EI) but hepato-somatic index (HSI). One pseudo-silver eel collected. looked like a late silver eel in the S2 stage according to its external body color and morphology, but most of other characteristics suggested that it might be in Y1 (yellow eel) or Y2 stage (late yellow eel).