• 생태와환경
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• 제38권2호통권112호
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• pp.137-145
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• 2005

전통적인 스크린 방법으로는 자연계에 존재하는 99% 이상의 미생물 자원을 확보하지 못했다. 자연생태계의 핵산을 직접 클로닝하는 전략은 배양 가능한 미생물의 유전적인 정보보다 더 광범위한 유전적인 정보를 전체의 미생물 메타지놈에서 확보하기 위한 계획을 세웠다. 그 결과 유용한 유전자를 탐색하는 한 방법으로 다양한 환경에서 메타지놈 DNA 라이브러리를 구축하는 방법이었다. 본 연구는 국내 중부권에 위치한 대청호로부터 시료를 수집하였고, T-RFLP 방법을 사용하여 미생물 군집의 다양성을 분석하였다. 핵산의 추출은 SDS를 사용한 freeing-thawing 방법을 사용하였으며, 추출한 핵산은 $UltraClean^{TM}kit$ (MoBio, USA)을 사용하여 정제하였다. 메타지놈 라이브러리는 제작은 정제한DNA와 pBACe3.6 vector를 EcoRI, BamHI, 그리고 SacII 등의 제한효소로 partial digestion하였고, 이들을 ligation한 다음 Escherichia coli DH10B에 형질전화 시켜 제작하였다. 메타지놈 라이브러는 14 Mb 정도 확보하였는데, 평균 insert size는 약 13 ${\sim}$ 15 kb이었다. Colony hybridization으로 메타지놈 라이브러리로부터 1, 2-dichloroethane (1, 2-DCE) hydrolytic dehalogenation의 분해에 관련된 유전자를 확인하였다. 1, 2-DCE dehalogenas효소는 기질에 대한 높은 활성을 나타내었다. 1, 2-dichloroethane dehalogenase 유전자의 클론을 만들었고, 염기서열을 분석하였다. 이들 결과로 보아 대청호로부터 제작한 메타지놈에서 dhlA 유전자를 확인한 균주는 1, 2-DCE 분해에 탁월한 능력을 나타내었다.

• 한국양식학회지
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• 제6권1호
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• pp.1-12
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• 1993

일본 북해도의 망주만에서 방류양식된 가리비, Patinopecten yessoensis를 재료로 하여, 전자현미경적 및 조직화학적 관찰을 토대로 혈구의 미세구조에 따른 형태학적 동정 및 생리학적 기능을 연구한 결과는 다음과 같다. 가리비의 체내에 분포하는 혈구는 3종류로 구분되었다. I형 : 세포의 외형은 타원형으로 세포질의 전자밀도가 비교적 낮다. 타원형의 핵은 가끔 2핵으로 분엽하며 그 주변부에 소관상의 골면소포체와 액포가 발달하나, 유리 리보솜의 양은 적다. II형 : 세포의 외형은 장타원형으로 세포질은 전자밀도가 높다. 핵은 타원형으로 분엽하지 않으며 그 주변부에 소양상의 골면소포체와 유리 리보솜이 발달하나, 액포는 존재하지않는다. III형 : 세포의 외형은 원형으로 전자밀도는 3종의 혈구중 가장 높다. 핵은 차축상으로 염색질결절이 많으며 세포질에는 조면소포체가 현저하게 발달하나, 액포는 존재하지 않는다. 이들 혈구에 대한 미세구조 및 식작용에 관한 조직화학적 실험을 통하여 그 기능을 검토한 결과, I형은 주로 세균 등의 외래 물질 및 내인성 노화세포의 식작용에, II형은 영양물질의 운반에 관여하며, 특히, III형혈구는 체액성 방어기구과 관련한 모종의 단백질 생산분비 기능을 가지는 것으로 판단되었다

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1541-1545
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• 2006

The polymorphism of insulin-like growth factor I receptor (IGFIR) gene in 12 pig breeds (total n = 593) was detected by PCR-SacII-restriction fragment length polymorphism and allele A (379 bp) or allele B (235 bp and 144 bp) observed. In the studied breeds, it was found that European pigs principally carried allele A, while Chinese native pig breeds principally carried allele B. In addition, the role of pig IGFIR was investigated in 156 Wanbai pigs and 212 Large Yorkshire pigs. Growth related variables including body weight at birth, 2-, 4- and 6-mo of age and backfat thickness and lean percentage estimated by ultrasonography at 6-mo of age were recorded in analyzing the association between IGFIR gene polymorphism and growth traits. AA-genotype pigs exhibited greater (p<0.05) body weights (BW) at birth, 2- and 6-mo of age, but not at 4-mo of age, than those of the BB-genotype in Wanbai and Yorkshire breeds. Moreover, in the Yorkshire breed, AA-genotype pigs had less backfat thickness (p<0.05) and greater lean percentage (p<0.01) than the BB genotype. Based on these results, it is necessary to do more studies on IGFIR before introducing the IGFIR locus into breeding programs.

• 한국식물병리학회지
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• 제10권3호
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• pp.235-239
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• 1994

Viral RNA was extracted from purified Chinese cabbage strain of turnip mosaic virus (TuMV-Ca) from infected leaves of turnip. Polyadenylated genomic viral RNA was recovered by oligo (dT) cellulose column chromatography and used as a template for the synthesis of complementary DNA (cDNA). Recombinant plasmids contained cDNA ranged from about 900 bp to 2, 450 bp were synthesized. Among the selected 41 transformants, pTUCA31 and pTUCA35 had over 2 Kbp cDNA insert. Restriction endonuclease patterns of the clones examined were very similar among them. Clones pTUCA23 and pTUCA31 were overlapped with pTUA35. The longest clone pTUCA35, encoding 3'-end, showed that it contained two sites for EcoRI, and one site for BamHI, ClaI, HincII, SacI and XbaI, respectively. The restriction mapping indicated that the clone pTUCA35 contained partial nuclear inclusion body gene, complete coding region of the coat protein and 3' untranslated region of TuMV-Ca genomic RNA.

• 대한수학교육학회지:수학교육학연구
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• 제9권2호
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• pp.419-438
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• 1999

This paper explored the impact of dynamic geometry software such as CabriII, GSP on student's understanding deductive justification, on the assumption that proof in school mathematics should be used in the broader, psychological sense of justification rather than in the narrow sense of deductive, formal proof. The following results have been drawn: Dynamic geometry provided positive impact on interacting between empirical justification and deductive justification, especially on understanding the necessity of deductive justification. And teacher in the computer environment played crucial role in reducing on difficulties in connecting empirical justification to deductive justification. At the beginning of the research, however, it was not the case. However, once students got intocul-de-sac in empirical justification and understood the need of deductive justification, they tried to justify deductively. Compared with current paper-and-pencil environment that many students fail to learn the basic knowledge on proof, dynamic geometry software will give more positive ffect for learning. Dynamic geometry software may promote interaction between empirical justification and edeductive justification and give a feedback to students about results of their own actions. At present, there is some very helpful computer software. However the presence of good dynamic geometry software can not be the solution in itself. Since learning on proof is a function of various factors such as curriculum organization, evaluation method, the role of teacher and student. Most of all, the meaning of proof need to be reconceptualized in the future research.

• 원예과학기술지
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• 제35권3호
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• pp.323-332
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• 2017

Homology-specific transcriptional and post-transcriptional silencing, an intrinsic mechanism of gene regulation in most eukaryotes, can be induced by anti-sense, co-suppression, or hairpin-based double-stranded RNA. Hairpin-based RNA interference (RNAi) has been applied to analyze gene function and genetically modify crops. However, RNAi vector construction usually requires high-cost cloning steps and large amounts of time, or involves methods that are protected by intellectual property rights. We describe a more effective method for generating intron-spliced RNAi constructs. To produce intron-spliced hairpin RNA, an RNAi cassette was ligated with the first intron and splicing sequences of the Brassica rapa ssp. pekinensis histone deacetylase 1 gene. This method requires a single ligation of the PCR-amplified target gene to SpeI-NcoI and SacI-BglII enzyme sites to create a gene-specific silencing construct. We named the resulting binary vector system pKHi and verified its functionality by constructing a vector to silence DIHYDROFLAVONOL 4-REDUCTASE (DFR), transforming it into tobacco plants, and confirming DFR gene-silencing via PCR, RT-qPCR, and analysis of the accumulation of small interfering RNAs. Reduction of anthocyanin biosynthesis was also confirmed by analyzing flower color of the transgenic tobacco plants. This study demonstrates that small interfering RNAs generated through the pKHi vector system can efficiently silence target genes and could be used in developing genetically modified crops.

• Clinical and Experimental Reproductive Medicine
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• 제31권3호
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• pp.169-176
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• 2004

Objective: This study was performed to evaluate and compare the embryonic developmental capacity and pregnancy rates in conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) with ejaculated sperm or testicular sperm cycles. Materials and Methods: Fertilization was examined in the following morning after IVF (group I), ICSI (group II) or TESE-ICSI cycles (group III). Fertilized oocytes were co-cultured with Vero cells until embryo transfer (ET). On day 2 and $5{\sim}7$, grades of embryos (<4- or $\geq$4-cell) and blastocysts (BG1, 2, 3 or early) were evaluated. Clinical pregnancy rate was determined by detecting G-sac with transvaginal ultrasonogram. We analyzed the results by $X^2$ and Student's t-test and considered statistically significant when P value was less than 0.05. Results: Fertilization rate was significantly higher (p<0.05) in group I ($79.0{\pm}21.2%$) than in group II and III ($56.8{\pm}21.6%$ and $36.7{\pm}25.3%$). Cleavage and blastulation rate of group I ($95.8{\pm}13.8%$ and $59.5{\pm}25.3%$) were significantly higher (p<0.05) than those of group III ($83.4{\pm}18.6%$ and $40.4{\pm}36.5%$). Clinical pregnancy rate was significantly higher (p<0.05) in group I and II (40.7% and 41.7%) than that in group III (12.5%). No differences were found in the rates of multiple pregnancy and abortion among three groups. Embryonic implantation rate was higher in group I ($15.1{\pm}20.2%$, p<0.05) and II ($14.7{\pm}20.6%$, NS) than that in group III ($5.1{\pm}15.6%$). However, embryonic implantation rate was increased in ET with blastocyst(s) among three groups. Conclusions: Fertilized oocytes obtained from TESE-ICSI were harder to be successfully cultured to blastocyst stage for 5$\sim$7 days than that from IVF cycles. However, all blastocyst(s) ET increased the embryonic implantation rate equally in IVF, ICSI and TESE-ICSI cycles.

• Journal of Korean Neurosurgical Society
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• 제29권9호
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• pp.1188-1194
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• 2000

Objective : Internal carotid-posterior communicating artery(IC-PC) aneurysms can be clipped easily without any special preparations. Occasionally, however, it is difficult to clip the low-lying IC-PC aneurysms without some kinds of additional procedures. Clinical Material and Methods : We experienced four cases of low-lying IC-PC aneurysms, which the intradural anterior clinoidectomy and/or anterior petroclinoid fold(APF) resection was essential to expose the proximal side of the aneurysmal neck and/or proximal control. One patient harbored two low-lying IC-PC aneurysms bilaterally. The patients were divided into two groups according to the necessity of anterior clinoidectomy : Group I(n=4) that needed an intradural clinoidectomy and/or APF resection and Group II(n=29) that had IC-PC aneurysms, easily clipped without any special preparation. Also, various radiometric parameters were measured through the preoperative angiograms. Results : The incidence of such aneurysms was 12% among a total of thirty-three surgically treated IC-PC aneurysms during lasr 3 years. Among four cases, three cases presented with subarachnoid hemorrhage and all aneurysmal sac projected to postero-inferior direction. In our study, We initially considered the necessity of intraoperative anterior clinoid process(ACP) removal and/or resection of APF in cases of shorter distance less than 5.6mm between the proximal aneurysmal sac and tip of the ACP(p<0.001), and the proximal portion of aneurysmal neck has located below the interclinoid line(p=0.001). Conclusion : Through a careful preoperative evaluation, some radiometric parameters can be used to determine whether the ACP should be removed in clipping of the low-lying IC-PC aneurysms. Unlike to total removal of the ACP, the intradural partial anterior clinolidectomy and/or APF resection, which are more familiar to surgeons, reduce the risks of the premature rupture, operative time, and also contribute a more precise clip placement with proximal control than the extradural clinoidectomy.

• The Korean Journal of Pain
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• 제13권1호
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• pp.84-88
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• 2000

Background: An increase in the maximum level of sensory blockade (MLSB) following an epidural top-up in combined spinal epidural anesthesia (CSE) may be achieved by a volume effect as the volume of local anesthetic compresses the dural sac, by a local anesthetic effect, or by a combination of both effects. This study was conducted to investigate the contribution of each of these effects. Methods: Sixty patients scheduled for lower limb surgery under CSE were randomly allocated to one of three groups of twenty patients each. Using the needle-through needle technique, all patients received a subarachnoid dose of 10 mg hyperbaric 0.5% bupivacaine. At 30 min after subarachnoid injection, an epidural top-up with saline 10 ml (group II) or 0.5% bupivacaine 10 ml (group III) was administered; patients in group I received no epidural top-up. The level of sensory blockade was assessed at 5, 10, 15, 20, 25, 30 min after subarachnoid injection and at 5, 10, 15, 20, 25, 30 min after epidural top-up. Results: There was no significant difference in the MLSB and the onset time of MLSB among group I-III. Conclusions: We concluded that the epidural top-up with saline 10 ml or 0.5% bupivacaine 10 ml which injected at 30 min after subarachnoid injection did not significantly increase the level of subarachnoid block in lower extremity surgical patients.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2082-2089
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• 2015

Avian beta-defensin 9 (AvBD9) is a small cationic peptide consisting of 41 amino acids that plays a crucial rule in innate immunity and acquired immunity in chickens. Owing to its wide antibacterial spectrum, lack of a residue, and failure to induce bacterial drug resistance, AvBD9 is expected to become a substitute for conventional antibiotics in the livestock and poultry industries. Using the preferred codon of Pichia pastoris, the mature AvBD9 peptide was designed and synthesized, based on the sequence from GenBank. The P. pastoris constitutive expression vector pGHKα was used to construct a pGHKα-AvBD9 recombinant plasmid. Restriction enzyme digestion was performed using SacI and BglII to remove the ampicillin resistance gene, and the plasmid was electrotransformed into P. pastoris GS115. High-expression strains with G418 resistance were screened, and the culture supernatant was analyzed by Tricine-SDS-PAGE and western blot assay to identify target bands of about 6 kDa. A concentrate of the supernatant containing AvBD9 was used for determination of antimicrobial activity. The supernatant concentrate was effective against Escherichia coli, Salmonella paratyphi, Salmonella pullorum, Pseudomonas aeruginosa, Enterococcus faecalis, and Enterobacter cloacae. The fermentation product of P. pastoris carrying the recombinant AvBD9 plasmid was adjusted to 1.0 × 10⁸ CFU/ml and added to the drinking water of white feather broilers at different concentrations. The daily average weight gain and immune organ indices in broilers older than 7 days were significantly improved by the AvBD9 treatment.