• 농업생명과학연구
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• 제50권3호
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• pp.31-41
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• 2016

본 연구는 산림조성사업에 있어서 가장 큰 비중을 차지하는 인건비와 생산비용을 절감시키고 경사가 험준한 우리나라 산림지형에서 유용하게 이용 가능한 경량 식혈기를 개발하고자 수행하였다. 제작된 1차 시제품은 토양을 굴취하는 스크류(screw) 부분과 동력원인 배터리로 구성되고, 제원은 스크류의 길이 170mm, 상단폭 60mm, 하단폭 47mm, 나선각(Helix angle)은 23°, 그리고 Tip은 송곳형태로 길이 50mm로 설계·제작하였고 무게를 줄이기 위해 1줄 스크류를 채택하였다. 또한, 동력원으로는 회전용 DC Motor(WD-6G2425, WONILL, Korea)로 최대 Torque는 30㎏f-cm, 회전속도는 20~30rpm으로 설정하였다. 감속비는 30:1의 K6G30C 감속기에 무부하 상태로 사용한 결과 48시간 작동하였다. 그리고 배터리는 경량식재기의 개발을 목표로 하기 때문에 무게를 고려하여 리듐배터리를 사용하였으며, 포트묘의 길이가 15cm 내외인 점을 고려하면 스크류의 회전력이 최대 100kgf-cm정도로 설계하였다. 1차 시제품의 성능을 평가하기 위해 조사지에서 굴취시 스크류에 소요되는 회전력을 측정한 결과, 회전력이 가장 큰 곳은 A area(단단한 초지), 그 다음은 F area(경사가 40°인 산지), E area(경사가 30°인 산지)의 순서로 나타났다. 토양의 굴취 회전력은 일반적으로 깊이가 깊어질수록 높아지는 경향을 보이고 있으며, 대체적으로 토양의 깊이 10cm 부근에서 높은 경향을 보였다.

• BMB Reports
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• 제43권4호
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• pp.233-244
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• 2010

Parkinson's disease (PD) is the second most common neurodegenerative disease, and 5-10% of the PD cases are genetically inherited as familial PD (FPD). LRRK2 (leucine-rich repeat kinase 2) was first reported in 2004 as a gene corresponding to PARK8, an autosomal gene whose dominant mutations cause familial PD. LRRK2 contains both active kinase and GTPase domains as well as protein-protein interaction motifs such as LRR (leucine-rich repeat) and WD40. Most pathogenic LRRK2 mutations are located in either the GTPase or kinase domain, implying important roles for the enzymatic activities in PD pathogenic mechanisms. In comparison to other PD causative genes such as parkin and PINK1, LRRK2 exhibits two important features. One is that LRRK2's mutations (especially the G2019S mutation) were observed in sporadic as well as familial PD patients. Another is that, among the various PD-causing genes, pathological characteristics observed in patients carrying LRRK2 mutations are the most similar to patients with sporadic PD. Because of these two observations, LRRK2 has been intensively investigated for its pathogenic mechanism (s) and as a target gene for PD therapeutics. In this review, the general biochemical and molecular features of LRRK2, the recent results of LRRK2 studies and LRRK2's therapeutic potential as a PD target gene will be discussed.

• Animal cells and systems
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• 제13권1호
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• pp.9-15
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• 2009

Eph receptors and their ephrin ligands have been implicated in a variety of cellular processes such as cellular morphogenesis and motility. Our previous studies demonstrated that Odin, one of the Anks family proteins, functions as a scaffolding protein of the EphA8 signaling pathway leading to modulation of cell migration or axonal outgrowth. Here we show that WDR7 is associated with Odin and that it is possibly implicated in the EphA8 signaling pathway. WD40 repeats present in the COOH-terminal region of WDR7 appear to be crucial for its association with Odin, whereas the binding motif of Odin is located in between ankyrin repeats and PTB domain. Co-immunoprecipitation experiments revealed that association of WDR7 with Odin is enhanced by ephrin ligand treatment, possibly through forming large protein complexes including both EphA8 and ephrin-A5. Consistently, immunofluorescence staining experiments suggested that WDR7 constitute a component of the large protein complexes containing Odin, EphA8 and ephrin-A5. Taken together, our results suggest the WDR7-Odin complexes might be involved in the signaling pathway downstream of the EphA8 receptor.

• 한국수산과학회지
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• 제14권4호
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• pp.269-275
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• 1981

연근해 어업용 낚시 6가지형에 대하여 만능실험기로 인장속도를 290mm/min와 780mm/min로 하여 실험한 결과는 다음과 같다. 1) 낚시의 직경은 d, 미늘 기부에서 허리굽이까지의 거리를 w라 하면 낚시의 파단하중은 $B={\alpha}\;wd^2+\beta$ (단, B는 kg, w와 d는 mm)로 나타내며, 인장연도가 290mm/min 일 때의 $\alpha,\;\beta$는 둥근형 낚시 $SR_{p}-F_{1}B,\;SR_{p}-F_{1}S$는 $\alpha_{s}=0.5,\;\beta_{s}=1.6$, 모난형 낚시 $SA_{a}-F_{1}S,\;SA_{a}-F_{1}S_k,\;LA_{a}-F_{1}S_{k}$는 $\alpha_{s}=1.1,\;\beta_{s}=2.0$긴 낚시 $LA_{p}-F_{1}S$는 $\alpha_{s}=0.4,\;\beta_{s}=1.5$정도이다. 2) 인장속도가 780mm/min 일 때 윗식에서 $\alpha,\;\beta$는 둥근형 낚시는 $\alpha_{f}=0.4,\;\beta_{f}=1.4$모난형 낚시는 $\alpha_{f}=1.0$ 일본산은 $\beta_{f}=0.9$, 국산은 $\beta_{f}=-2.5$ 긴 낚시는 $\alpha_{=}0.6,\;\beta_{f}=0.4$ 정도이다. 3) 낚시의 파단변형률은 $40\sim60\%$ 정도이며, 인장속도가 빠를 때의 변형률은 느릴 때에의 $95\%$ 정도이나, 빠를 때의 파단하중은 느릴 때의 $80\%$ 정도이다. 4) 낚시가 파단되는 부위는 인장속도에 관계없이 거의 모두 허리굽이 부분이며 꼭지 기부에서 파단점까지의 거리는 낚시 길이와 거의 같다.

• Journal of Biosystems Engineering
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• 제27권6호
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• pp.479-490
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• 2002

A dynamic model of a power shuttle transmission was developed and its validity was verified using the experimental data obtained from a transmission test bench. A 40㎾, 4WD tractor was also modeled using an application software EASY5 to investigate parameters and their effects on the power shifting performance. For a tractor model, the manual reverse gear was replaced by a power shuttle transmission. The tractor model also included an engine, main-gears for transmission, wheels, differentials and planet gears. Using the tractor model, the effects of the parameters such as modulating pressure and time, engine speed, tractor speed. tractor weight. reverse to forward speed ratio and torsional damper on the transient characteristics at starting and shuttle shifting were investigated by the computer simulation. The transient characteristics were represented by variations in clutch pressure, torque transmitted to input shaft and driving wheels, and power transmission capacity of the clutch. It was found that the modulating pressure and time affected most significantly the torque transmission and shifting time. The input torque, axle torque, power transmission capacity of the clutch and transmission time all increased with increase in engine speed, tractor speed. tractor weight and ratio of reverse to forward speeds. However, the axle torque decreased with tractor speed. Both the axle torque and power transmission capacity of the clutch also decreased with the ratio of reverse to forward speeds.

• Journal of Photoscience
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• 제12권1호
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• pp.1-9
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• 2005

The ubiquitin E3 ligase COP1 (Constitutive Photomorphogenesis 1) is a protein repressor of photomorphogenesis in Arabidopsisplants, and it found in various organisms, including animals. The COP1 protein regulates the stability of many of the light-signaling components that are involved in photomorphogenesis and in the developmental processes. To study the effect of COP1 on flowering in a short day plant, we have cloned a full-length of PnCOP1 (Pharbitis nil COP1) cDNA from Pharbitis nil Choisy cv. Violet, and we examined its transcript levels under various conditions. A full-length PnCOP1 cDNA consists of 2,280 bp nucleotidesthat contain 47 bp of 5'-UTR, 232 bp of 3'-UTR including the poly (A) tail, and 1,998 bp of the coding sequence. The deduced amino acid sequence contains 666 amino acids, giving it a theoretical molecular weight of 75 kD and a isolectric point of 6.2. The PnCOP1 contains three distinct domains, an N-terminal $Zn^2+$-binding RING-finger domain, a coiled-coil structure, and WD40 repeats at the C-terminal, implying that the protein plays a role in protein-protein interactions. The PnCOP1 transcript was detected in the cotyledon, hypocotyls and leaves, but not in root. The levels of the PnCOP1 transcript were reduced in leaves that were a farther distance away from the cotyledons. The expression level of the PnCOP1 gene was inhibited by light, while the expression was increased in the dark. During the floral inductive 16 hour-dark period for Pharbitis nil, the expression was increased and it reached its maximum at the 12th hour of the dark period. The levels of PnCOP1 mRNA were dramatically reduced upon light illumination. These results suggest that PnCOP1 may play an important function in the floral induction of Pharbitis nil.

• 한국임상수의학회지
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• 제24권2호
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• pp.88-93
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• 2007

Malassezia pachydermatis 추출물의 피내접종시 과민반응을 알아보고자 본 실험을 수행하였다. 정상적인 개와 M. pachydermatis 외이염에 이환된 개를 대상으로 M. pachydermatis 추출물의 피내접종을 실시하였다. 전기영동을 통해 M. pachydermatis 분자량 조사를 통해 $43{\sim}63kDa$을 포함하고 있는 추출물을 사용하였다. Malassezia 외이염에 감염된 군에서의 평균 팽진의 직경은 20, 2, 0.2, and $0.02{\mu}g/ml$을 피내로 접종했을 때, 각각 $13.36{\pm}0.67,\;5.33{\pm}0.67,\;5.47{\pm}0.82$와 $5.07{\pm}0.64$을 나타내었으며, 팽진의 두께는 각각 20, 2, 0.2, and $0.02{\mu}g/ml$에서 $6.44{\pm}0.40,\;3.86{\pm}0.35,\;2.64{\pm}0.36$와 $2.60{\pm}0.44$를 나타내었다. 통계학적으로 건강한 군과 외이염에 이환된 군에 있어서 유의한 차이가 인정되었다. (p<0.01). 더구나$20{\mu}g/ml$ 을 주입한 군에서 이 차이는 더욱 두드러져 농도 의존성을 나타내었다. 따라서 M. pachydermatis 유래 항원을 개의 피내에 접종했을 때, 즉시 팽진반응을 유발한다는 것이 확인되었으며 효모균에 대한 과민증은 즉시형 피부과민반응을 보이는 개, 특히 Malassezia otitis에 감염된 개에서 임상증상의 발현에 관여하는 것으로 사료된다. 또한 2, 0.2, $0.02{\mu}g/ml$의 농도에서는 큰 차이를 보이지 않는 것으로 보아 즉시형 과민반응을 나타내기 위해서는 일정한 역치가 있을 것으로 생각되며 이에 대한 추가적인 연구가 필요할 것으로 사료된다.

• Molecules and Cells
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• 제28권6호
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• pp.529-536
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• 2009

Genome sequencing of the pig is being accelerated because of its importance as an evolutionary and biomedical model animal as well as a major livestock animal. However, information on expressed porcine genes is insufficient to allow annotation and use of the genomic information. A series of expressed sequence tags of 5' ends of five full-length enriched cDNA libraries (SUSFLECKs) were functionally characterized. SUSFLECKs were constructed from porcine abdominal fat, induced fat cells, loin muscle, liver, and pituitary gland, and were composed of non-normalized and normalized libraries. A total of 55,658 ESTs that were sequenced once from the 5′ ends of clones were produced and assembled into 17,684 unique sequences with 7,736 contigs and 9,948 singletons. In Gene Ontology analysis, two significant biological process leaf nodes were found: gluconeogenesis and translation elongation. In functional domain analysis based on the Pfam database, the beta transducin repeat domain of WD40 protein was the most frequently occurring domain. Twelve genes, including SLC25A6, EEF1G, EEF1A1, COX1, ACTA1, SLA, and ANXA2, were significantly more abundant in fat tissues than in loin muscle, liver, and pituitary gland in the SUSFLECKs. These characteristics of SUSFLECKs determined by EST analysis can provide important insight to discover the functional pathways in gene networks and to expand our understanding of energy metabolism in the pig.