• Parasites, Hosts and Diseases
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• 제53권1호
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• pp.65-75
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• 2015

Clonorchis sinensis habitating in the bile duct of mammals causes clonorchiasis endemic in East Asian countries. Parkin is a RING-between-RING protein and has E3-ubiquitin ligase activity catalyzing ubiquitination and degradation of substrate proteins. A cDNA clone of C. sinensis was predicted to encode a polypeptide homologous to parkin (CsParkin) including 5 domains (Ubl, RING0, RING1, IBR, and RING2). The cysteine and histidine residues binding to $Zn^{2+}$ were all conserved and participated in formation of tertiary structural RINGs. Conserved residues were also an E2-binding site in RING1 domain and a catalytic cysteine residue in the RING2 domain. Native CsParkin was determined to have an estimated molecular weight of 45.7 kDa from C. sinensis adults by immunoblotting. CsParkin revealed E3-ubiquitin ligase activity and higher expression in metacercariae than in adults. CsParkin was localized in the locomotive and male reproductive organs of C. sinensis adults, and extensively in metacercariae. Parkin has been found to participate in regulating mitochondrial function and energy metabolism in mammalian cells. From these results, it is suggested that CsParkin play roles in energy metabolism of the locomotive organs, and possibly in protein metabolism of the reproductive organs of C. sinensis.

• 대한물리의학회지
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• 제8권1호
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• pp.1-9
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• 2013

PURPOSE: This study compared the effects of dual motor task training and simple task training on the balance of subacute stroke patients. METHODS: A total of 23 subacute stroke patients participated in the study. The subjects were allocated randomly to two groups: an experimental group and a control group. Both groups received conventional treatment for 50 minutes, 5 times per week for 6 weeks. In addition, the experimental group stacked blocks, moved catch cups, and moved rings while standing and gait. To evaluate the effects of the exercises, subjects were evaluated by using the balance system and the timed get up and go test(TUG) for balance measurement. The data was analyzed using a paired t-test and independent t-test to determine the statistical significance. RESULTS: The experimental group showed a significant decrease on the medial-lateral and anterior-posterior stability index compared to the control group (p<.05) for the simple task and a significant decrease on the medial-lateral and anterior-posterior stability index compared to the control group for the dual task. In addition, the experimental group showed a significant increase in TUG time compared to the control group (p<.05). CONCLUSION: These results support the perceived benefits of dual motor task training to augment the balance of subacute stroke patients. Therefore, dual motor task training is recommended for subacute stroke patients.

• Tribology and Lubricants
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• 제30권5호
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• pp.303-310
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• 2014

In order to reduce friction and improve reliability, researchers have applied various surface texturing methods to highly sliding machine elements such as mechanical seals and piston rings. Despite extensive theoretical research on surface texturing, previous numerical results are only applicable to isothermal and iso-viscous conditions. Because the lubricant flow pattern of textured bearing surfaces is much more complicated than that for non-textured bearings, the Navier?Stokes equation is more suitable than the Reynolds equation for the former. This study carries out a thermohydrodynamic (THD) lubrication analysis to investigate the lubrication characteristics of a single micro-dimpled parallel thrust bearing cell. The analysis involves using the continuity, Navier?Stokes, energy, temperature?viscosity relation, and heat conduction equations with the commercial computational fluid dynamics (CFD) code FLUENT. This study discretizes these equations using the finite volume method and solves them using the SIMPLE algorithm. The results include finding the streamlines, pressure and temperature distributions, and variations in the friction force and leakage for various dimple radii and depths. Increasing the dimple radius and decreasing the depth causes a recirculation flow to form because of a strong vortex, and the oil temperature greatly increases compared with the non-textured case. The present numerical scheme and results are applicable to THD analysis of various surface-textured sliding bearings and can lead to further study.

• 한국물환경학회지
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• 제24권6호
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• pp.682-689
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• 2008

The purpose of this study was to find out the variation between molecular size distribution (MSD) of natural organic matter (NOM) in raw waters after different water treatment processes like conventional process (coagulation, flocculation, filtration) followed by advanced oxidation process (ozonation, GAC adsorption). The MSD of NOM of Suji pilot plant were determined by Liquid Chromatography-Organic Carbon Detection (LC-OCD) which is a kine of high-performance size-exclusion chromatography (HPSEC) with nondispersive infrared (NDIR) detector and $UV_{254}$ detector. Five distinct fractions were generally separated from water samples with the Toyopearl HW-50S column, using 28 mmol phosphate buffer at pH 6.58 as an eluent. Large and intermediate humic fractions were the most dominant fractions in surface water. High molecular weight (HMW) matter was clearly easier to remove in coagulation and clarification than low molecular weight (LMW) matter. Water treatment processes removed the two largest fractions almost completely shifting the MSD towards smaller molecular size in DW. No more distinct variation of MSD was observed by ozone process after sand filtration but the SUVA value were obviously reduced during increase of the ozone doses. UVD results and HS-Diagram demonstrate that ozone induce not the variation of molecular size of humic substance but change the bond structure from aromatic rings or double bonds to single bond. Granular activated carbon (GAC) filtration removed 8~9% of organic compounds and showed better adsorption property for small MSD than large one.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.

• Journal of the Korean Wood Science and Technology
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• 제39권5호
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• pp.406-419
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• 2011

This study was carried out to offer basic information on the wood anatomy of domestic yellow-poplar (Liriodendron tulipifera L.), a new plantation species selected by Korea Forest Service as one of the promising hardwood and bioenergy sources of the future, through comparison of stem wood with root wood in the qualitative and quantitative features. In the qualitative anatomical features, growth rings were distinct in stem wood but relatively less distinct in root wood. And stem wood appeared to have pores in radial multiples of 2 to 5, sometimes clusters but root wood to have pores in radial multiples of 2 to 3, rarely clusters. And numbers of bars in scalariform perforation plates were somewhat numerous in vessel elements of root wood than in those of stem wood. Interestingly, on the other hand, more extraneous materials in the wood rays of tap root than in those of lateral root and stem were confirmed in the chemical composition analyses. In the quantitative anatomical features, pore densities were significantly greater but vessel elements were considerably narrower in stem wood than in root wood. Vessel elements and wood fibers of root wood were considerably longer than those of stem wood. Rays were somewhat more numerous in stem wood than in root wood, and only ray heights of stem wood were more or less greater in cell numbers but both ray heights and widths of stem wood were lower in dimension than those of root wood. The anatomical differences between stem wood and root wood were thought to be associated with different growth environments between the stem above ground and the root below ground.

• Mass Spectrometry Letters
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• 제4권2호
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• pp.30-33
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• 2013

Chalcones are naturally occurring, biologically active molecules generating interest from a wide range of research applications including synthetic methodology development, biological activity investigation and studying fragmentation patterns. In this article, a series of chalcones has been synthesized and their fragmentation behavior was studied using modern ambient ionization technique Direct Analysis in Real Time (DART). DART ion source connected with an ion trap mass spectrometer was used for the fragmentation of various substituted chalcones. The chalcones were introduced to the DART source using a glass capillary without sample preparation step. All the chalcones showed prominent molecular ion peaks $[M]^{{\cdot}+}$ corresponding to the structures. Multistage mass spectral data $MS^n$ ($MS^2$ and $MS^3$) were collected for all the chalcones studied. The chalcones with substitutions at 3, 4 or 5 positions gave product ion peaks with the loss of a phenyl radical ($Ph^{\cdot}$) by radical initiated ${\alpha}$-cleavage, while substitution at 2 position of chalcone in the A-ring gave a product ion peak with the loss of substituted styryl radical (PhCH = $CH^{\cdot}$). In case of the chalcones with the substituent at 4 positions in A and B rings gave both types of fragmentation patterns. In conclusion, chalcones can be easily characterized using modern DART interface in very short time and efficiently without any cumbersome sample pretreatment.

• 천문학회보
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• 제42권1호
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• pp.58.3-58.3
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• 2017

In a ${\Lambda}CDM$ universe, galaxies are believed to evolve by mergers and accretions. The debris resulting from such processes remains as diffuse, low-surface brightness structures, such as outer disks, stellar halos, and faint companions. These structures will give us fruitful insight into the recent mass assembly history of galaxies, but it is challenging to observe them due to their low surface brightness. In order to explore the structural properties of outskirts of nearby galaxies, we conduct deep wide-field imaging survey with KMTNet. Here we present a progress report of data reduction for the images of NGC 1291, a lenticular barred galaxy with outer rings. To achieve accurate flat fielding, we use dark sky flat and remove the sky gradient of each exposure with a polynomial fit. As a result, we are able to reach 1 sigma depth of ${\mu}_R{\sim}29.6\;mag\;arcsec^{-2}$. We expect to investigate the surface brightness profile of NGC 1291 in 1-D profile, and color-gradient in the outer part of the galaxy using the B- and R-band images.

• 한국인터넷방송통신학회논문지
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• 제14권1호
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• pp.7-13
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• 2014

본 논문에서는 위성통신 시스템에 사용 가능한 새로운 구조의 도파관 저역통과 여파기를 제안하였다. 제안된 저역통과 여파기는 고차모드의 간섭이 없는 광대역 특성과 저지대역에서의 충분한 감쇠 그리고 도파관의 소형화와 경량화를 위하여 evanescent-mode 리지 구조를 사용하여 설계 하였고, 도파관 내에 리지를 둘러싸는 직사각형 링을 삽입하여 반사손실과 격리도를 향상시켰다. 또한 매칭을 위해 여파기의 입출력 포트 단은 임피던스 스텝 구조를 사용하여 설계하였다. 제작된 저역통과 여파기는 통과 대역 주파수인 7.25 ~ 8.4 GHz에서 반사손실이 19.5 dB이상, 삽입손실은 1.41 dB이하로 측정 되었으며 억제 대역 주파수인 12.25 ~ 14.5 GHz에서의 격리도는 67.2 dB이상을 만족하였다.

• 한국인터넷방송통신학회논문지
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• 제17권5호
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• pp.187-192
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• 2017

마이크로스트립 콤 어레이 안테나에 대한 CSRR-메타물질의 영향을 연구하였다. 마이크로스트립 콤 어레이 안테나는 12개의 방사체로 구성되었고 24GHz ISM 대역에서 16.09dBi의 이득과 0.24GHz 대역폭을 갖도록 설계하였다. 설계된 안테나는 안테나 면에 수직한 방사빔과 16.09dBi의 동일편파 이득, -10.86dBi의 교차편파 이득을 갖고 있었다. CSRR-메타물질은 0.24GHz이던 마이크로스트립 콤 어레이 안테나의 임피던스 대역폭을 3.6GHz로 대폭 증가시켰으나 동일편파 이득이 10.8dBi로 되고 교차편파 이득이 14.1dBi로 되어 동일편파와 교차편파가 혼재했으며 안테나 이득을 1.99dB 만큼 저하시켰다. 한편, CSRR 링의 스플릿 방향에 따른 연구에서 링의 스플릿 방향을 위로하거나 아래로 했을 때는 거의 같은 특성을 보였다. 그러나 링의 스플릿 방향을 위와 아래로 교번하여 배치하였을 때는 동일편파 이득이 -1.29dBi로 감소하고 교차편파 이득이 13.9dBi로 증가하여 교차편파가 주가 되는 파로 변환되었다.