젊은 성인에서 흡연에 의한 상완동맥 내피기능의 부전에 관한 연구

이상철,권영주,방덕원,이선해,이보영,김지욱,김영훈,온영근,현민수,김성구 순천향의학연구소 2002 Journal of Soonchunhyang Medical Science Vol.8 No.1

Background and Objectives : Cigarette smoking is a major factor and the most modifiable risk factor for atherosclerosis. Endothelial dysfunction is an early event in atherosclerosis, before the structural change of the systemic arteries. We hypothesized that endothelial dysfunction might be present in the systemic arteries of young adult smokers and that this might be dose-dependent phenomenon. Therefore, we try to certify that smoking is associated with endothelial dysfunction in healthy young adults without other risk factor of atherosclerosis. Subjects and Methods : we studied noninvasively 29 subjects aged 3 to 4 decades without other risk factor of atherosclerosis, they were composed of the two groups, current smokers(n=15) and nonsmokers(n=14). Smoking history varied from 3 to 20 pack years. Using high-resolution ultrasound, vessel diameter and mean flow rate were measured at rest, during reactive hyperemia(with flow-mediated endothelium-dependent dilation), and after sublingual nitroglycerin(NG-induced endothelium-independent vasodilation). Result : Flow mediated endothelium dependent dilation was observed in the control subjects (9.4±3.44%) but was impaired in the smokers(5.8±2.51%)(p=0.004). NG-induced endothelium independent dilation is no difference in all subjects. Conclusion : Cigarette smoking is associated with endothelial dysfunction in healthy young adults.

Ultrastructure of Alternate Spermiogenesis Pathways in Tobacco Budworm, Helicoverpa assulta (Lepidoptera: Noctuidae) I. Morphogenesis of Eupyrene Head

Kwon, Sun-Bang,Huh, Yang-Hun,Yang, He-Young 한국곤충학회 1998 Entomological Research Vol.28 No.4

We examined the ultrastucture of postmeiotic spermiogenesis in the testis of Helicoverpa assulta. Like other Lepidopterian species, tobacco bud worm produces two kinds of sperms-nucleated eupyrene and anucleated apyrene. We emphasized the structural differentiations of the eupyrene head. In elongating spermatids, acrosomes have a long projection and come close to the side of the nucleus. Chromatin scattered inside the nucleus is transformed into a granular structure and then becomes compactly condensed within the inner membrane. Cytoplasm progressively disappears and reticular appendages are attached on the outer membrane. In maturing sperm, acrosomes become very short in length and form narrow channels around the nucleus. An electron - dense nucleus, one centriole, extracellular material, and the ultrastructure of a 9+9+2 flagellum appears in each maturing sperm. Mature sperms are linked by cytoplasmic bridges to form a single clone and almost all of the cytoplasm disappears. In fully mature sperm, reticular and lacinate appendages show up whereas extracellular material disappears.

Effect of Fertilizer Level and Seeding Rate on Yield and Yield Components of Rapeseed in Upland Field

Kwon Byung-Sun,Kim Sang-Kon,Bang Jin-Ki,Choi Seung-Sun,Lim Jung-Mook,Choi Gab-Lim 한국자원식물학회 2005 Plant Resources Vol.8 No.3

In order to select suitable fertilizer level and sowing rate of Dangyo #8^(hybrid) rapeseed at the southern area of Korea, two varieties of Naehanyuchae (Normal) and Dangyo #8(hybrid) rapeseed currently grown for oil production by two fertilizer level with 10-8-8 kg/10a and 15-8-8 kg/10a and three sowing rate with 500 g/10a, 1,000g/10a and 1,500g/10a with relatively high yield was grown at the same condition yield and yield components were observed. Dangyo #8^(hybrid) rapeseed was superior to oil-eed rapeseed for yield at the 15-8-8 kg/10a of fertilizer and 1,500 g/10a of sowing rate. Fertilizer level, N-P^2O^5-K^20 = 15-8-8 kg/10a and sowing rate, 1,500 g/10a showed somewhat higher value in two varieties of Naehanyuchae(Normal) and Dangyo #8^(hybrid).

Ultrastructure of Alternate Spermiogenesis Pathways in Tobacco Budworm, Helicoverpa assulta (Lepidoptera: Noctuidae): II. Morphogenesis of Eupyrene Tail

Kwon, Sun-Bang,Huh, Yang-Hun,Yang, He-Young 한국곤충학회 1999 Entomological Research Vol.29 No.1

We examined the ultrastructure of postmeiotic eupyrene spermiogenesis of Helicoverpa assulta males, emphasing the structural differentiation of mitochondrial derivatives (MDs). As spermatids begin to elongate, nebenkern become divided into two unequal sized MDs. As spermiogenesis progresses, MDs go through dynamic structural differentiation and elongate along most of the length of the spermatid. They are spiral in shape, and run parallel to the axial filament. The manchette is formed around the MDs and cristae exist in the matrix of MDs. Reticular appendage becomes visible on the plasma membrane whereas most of the cytoplasm disappears. Mature sperm consist of electron-dense MDs, reticular appendage, lacinate appendages, and have the 9 + 9 + 2 pattern of microtubules in axial filament. Accessory tubules of axial filament have a high electron density. The manchette and cristae are no longer apparent. Sperm that exist in the vas deferens, after being released from testis, lack lacinate appendages but do retain the reticular appendage, and they acquire a thick crescent shaped coat.

Production and On-column Re-folding of Human Vascular Endothelial Growth Factor 165 in Escherichia coli

Sun Kwon Bang,Young Sik Kim,장병수,박철범,방인석,방선권 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.5

Vascular endothelial growth factors (VEGFs)are a family of proteins that promote angiogenesis and participate in a variety of physiological and pathological processes. In this work, the gene encoding the human VEGF isoform 165 (hVEGF165) was cloned into the expression vector pET32a (+) to construct a fusion expression plasmid that induced the thioredoxin (Trx) gene and transformed into Escherichia coli. The recombinant fusion protein TrxhVEGF165was expressed optimally as inclusion bodies in the case of being cultivated for 4 h at 30oC and 1 mM IPTG concentration. The Trx-hVEGF165 was refolded and purified effectively from urea-solubilized inclusion bodies by the immobilized metal affinity chromatography. Released from the fusion protein by enterokinase cleavage and purified to homogeneity, the recombinant hVEGF165 (rhVEGF165)was biologically active as assessed by the human umbilicalvein endothelial cells (HUVECs) proliferation and the chicken chorioallantoic membrane (CAM) assay. The expression and in vitro refolding of rhVEGF165 resulted in production of an active molecule in a yield of 4.04 mg/L flask cultivation.

복사가열조건에서 표면 거칠기에 따른 액적의 증발 냉각

방창훈,권진순,예용택 한국안전학회 2004 한국안전학회지 Vol.19 No.3

The objective of the present work is to examine evaporation cooling of droplet due to surface roughness under radiative heat input condition. The surface temperatures varied from 80~160℃ on aluminum alloy (AL 2024) and surface roughness was 0.18μm, 1.36μm. The results are as follows; Regardless of surface roughness under radiative heat input condition, as droplet diameter is larger, the in-depth temperature of solid decreases and evaporation time increases. In the case of 0.18μm and 1.36μm of surface roughness, the larger the surface roughness is, the less the evaporation time is and the larger the temperature within the solid is. In the case of Ra = 0.18μm, evaporation time and time averaged heat flux for radiative heat input case is shorter than for the conductive case.

MPEG 압축영역에서 영상 편집의 문제점과 그 해결 방법

방성일,박동권,원치선 한국방송공학회 1998 한국방송공학회 학술대회 Vol.1 No.1

Assembly and Densification of Nanowire Arrays via Shrinkage

Bang, Jaehoon,Choi, Jonghyun,Xia, Fan,Kwon, Sun Sang,Ashraf, Ali,Park, Won Il,Nam, SungWoo American Chemical Society 2014 NANO LETTERS Vol.14 No.6

<P>Chemically synthesized semiconductor nanowires (NWs) have demonstrated substantial promise for nanoelectronics, nanoenergy, and nanobiotechnology, but the lack of an effective and controllable assembly process has limited the wide adoption of NWs in these areas. Here we demonstrate a facile, robust, and controllable approach to assembling and densifying a parallel array of NWs using shrinkable shape memory polymers. Using thermal-induced shrinkage of polystyrene, we were able to successfully assemble and densify NW arrays up to close-packing and, furthermore, achieve tunable density (up to ∼300% amplification of density) by controlling the shrinkage process. We also demonstrate scalable assembly and densification of NWs on a 2.5 × 6 inch scale to explore the manufacturability of the shrink-induced assembly process. Finally, we demonstrate the successful transfer of the shrink-assembled NW arrays onto various 2-dimensional and 3-dimensional substrates without compromising the integrity of NW assembly and density.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2014/nalefd.2014.14.issue-6/nl500709p/production/images/medium/nl-2014-00709p_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl500709p'>ACS Electronic Supporting Info</A></P>

Enhancement of the benzene-sensing performance of Si nanowires through the incorporation of TeO₂ heterointerfaces and Pd-sensitization

Kwon, Yong Jung,Choi, Sun-Woo,Kang, Sung Yong,Choi, Myung Sik,Bang, Jae Hoon,Kim, Sang Sub,Kim, Hyoun Woo Elsevier 2017 Sensors and actuators. B, Chemical Vol.244 No.-

<P><B>Abstract</B></P> <P>We report a novel method to significantly improve the C<SUB>6</SUB>H<SUB>6</SUB>-sensing performance of Si nanowires through the combination of TeO<SUB>2</SUB> branches and Pd sensitization. The morphological investigation revealed that TeO<SUB>2</SUB> branches were densely formed on the stem nanowires (NWs). The sensor responses of the Pd-functionalized branched NWs exhibited superior sensor responses of 55.19 to C<SUB>6</SUB>H<SUB>6</SUB> gas. In particular, Pd nanoparticles enhanced the sensor response to C<SUB>6</SUB>H<SUB>6</SUB> gas most efficiently, increasing the sensor response by 173.5%. Possible mechanisms for the sensing of the Pd-decorated branched nanowires will be associated with resistance modulation along the branch TeO<SUB>2</SUB> nanowires (including catalytic Pd effects), at the networked homojunctions between the branch TeO<SUB>2</SUB> nanowires, at the boundaries of the TeO<SUB>2</SUB> nanograins, and at the Pd/TeO<SUB>2</SUB> heterojunctions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report a novel method to significantly improve the C<SUB>6</SUB>H<SUB>6</SUB>-sensing performance of Si nanowires through the combination of TeO<SUB>2</SUB> branches and Pd sensitization. </LI> <LI> Pd nanoparticles enhance the sensor response most efficiently in regard to C<SUB>6</SUB>H<SUB>6</SUB> gas. </LI> <LI> The sensor responses of the Pd-functionalized branched nanowires exhibited superior sensor responses of 55.19 to C<SUB>6</SUB>H<SUB>6</SUB> gas. </LI> </UL> </P>

표면 거칠기에 따른 액적의 증발 냉각

방창훈,권진순,예용택 한국안전학회 2003 한국안전학회지 Vol.18 No.3

The objective of the present work is to examine evaporation cooling of droplet due to surface roughness on a heated surface. The surface temperatures varied from 80~160℃ on aluminum alloy (AL 2024) and surface roughness was 0.18μm, 1.36μm. The results are as follows; Regardless of surface roughness, as droplet diameter is bigger, the in-depth temperature of solid decreases and evaporation time increases. In the case of same initial temperature on the heated surface, as droplet diameter is smaller and small surface roughness is bigger, evaporation time decreases and time averaged heat flux increases.