• Title/Summary/Keyword: nano technology

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Feeding Effect of an Anabolic Steroid, Nandrolone, on the Male Rat Testis

  • Lee, Dong-Mok;Min, Tae-Sun;Choi, In-Ho;Cheon, Yong-Pil;Chun, Tae-Hoon;Park, Chang-Sik;Lee, Ki-Ho
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.12
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    • pp.1566-1577
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    • 2010
  • Nandrolone, 19-nortestosterone, is a synthetic androgenic-anabolic steroid promoting muscle growth. Nandrolone is also present in pig meat and sera at non-negligible levels. A number of scientific reports have suggested a positive relationship between incidence of infertility and increased meat consumption in humans. The present study was designed to determine out the effect of feeding nandrolone on the testis of the male reproductive tract. Mixtures of food and nandrolone at different concentrations (0.005 ppm and 0.5 ppm) were supplied to pubertal male rats for 6 weeks. Body weight was recorded every week during the entire experimental period. At the end of the treatment, the testis, epididymis, and epididymal fat were collected and weighted. Sperm numbers in the caudal epididymis were counted. Differential gene or protein expression of steroidogenic enzymes in the testes among experimental groups was determined by semi-quantitative real-time PCR or western blotting analysis, respectively. Histological changes of the testis induced by nandrolone treatment were examined by hematoxylin and eosin staining. Immunohistochemical analysis was employed to detect changes in the localization of steroidogenic enzymes in the testes among experimental animals. There were no significant changes on body, testis, epididymis, and epididymal fat weights among experimental groups. A significant increase of caudal sperm number was found in the 0.5 ppm nandrolone-treated group. Histological examination of the testes noted a high frequency of germ cell sloughing in seminiferous tubules of 0.5 ppm nandrolone-treated rats. Even though transcript levels of $3{\beta}$-hydroxysteroid dehydrogenase (HSD) I, $17{\beta}$-HSD4, and $17{\alpha}$-hydroxylase were influenced by nandrolone treatments, protein levels of all molecules examined in the present study were not significantly affected. Immunohistochemical analysis showed no visible changes in the localization of steroidogenic enzymes in the testes among experimental groups. The current study showed that oral intake of nandrolone in male rats for 6 weeks did not cause significant damage to the testis. It is considered that a feeding effect of nandrolone on male fertility would not be remarkable.

Distribution of Phytoplankton Biomass and Nutrient Concentrations in the Barents and Kara Seas during the 1st Korea-Russia Arctic Expedition in August, 2000 (제 1차 한-러 북극해 탐사(2000년 8월) 동안의 바렌츠해와 카라해의 식물플랑크톤 현존량 및 영양염 분포)

  • Kang, Sung-Ho;Chung, Kyung-Ho;Kang, Jae-Shin;Kim, Yea-Dong
    • Ocean and Polar Research
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    • v.25 no.3
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    • pp.315-329
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    • 2003
  • During the 1st Korea-Russia Arctic Expedition from 3 to 26 August, 2000 phytoplankton biomass and nutrient concentration were measured in the Barents and Kara Seas. Total of 57 surface samples were collected f3r the phytoplankton related measurements. Chlorophyll a (chi a) concentraitons were measured to investigate the relations between physico-chemical factors and phytoplankton biomass distribution. Chl a values ranged from 0.14 to $2.34mg\;m^{-3}$ (mean of $0.65{\pm}0.42mg\;m^{-3}$) over the surface stations. The elevated values of the chi a concentrations $(1.49{\sim}2.34mg\;m^{-3})$ were found in the southeastern Barents Sea near the Pechora River. Nanoplanktonic $(<20{\mu}m)$ phytoflagellates were the important contributors for the increase of the chi a. The nano-sized phytoflagellates accounted for more than 80% of the total chi a biomass in the study area. Mean chi a concentration in the Barents Sea $(0.72{\pm}0.57 mg\;m^{-3})$ was higher than in the Kan Sea $(0.52{\pm}0.45mg\;m^{-3})$, but there was no big difference between two areas. Surface temperatures and salinities ranged from 4.1 to $11.7^{\circ}C$ (mean of $8.8{\pm}1.9^{\circ}C$) and from 23.8 to 32.5psu (mean of $30.3{\pm}1.9^{\circ}C$ psu), respectively. The physical factors were not highly correlated with phytoplankton distribution. It is speculated that the insignificant correlation between phytoplankton biomass and physical factor was due to the same current which introduced similar water mass with higher water temperature and lower salinity into the study area. The mean values of major nutrients such as ammonia, nitrite, nitrate, phosphate, and silicate were $0.42{\pm}0.31{\mu}M,\;0.10{\pm}0.03{\mu}M,\;1.44{\pm}1.03{\mu}M,\;0.35{\pm}0.12{\mu}M,\;10.99{\pm}3.45{\pm}M$, respectively. The relations between phytoplankton biomass and nutrient concentration were not close, indicating that the surface nutrient concentrations during the study seem to be controlled by other physical factors such as input of fresh water (i.e. dilution effects).

Study of Particle Emission Contour Construction & Characteristics and Reduction Efficiency of Exhaust-Treatment System of Diesel Engine (승용 디젤 엔진의 후처리 시스템 적용에 따른 나노입자 배출 맵 구축 및 저감특성에 관한 연구)

  • Ko, A-Hyun;Hwang, In-Goo;Myung, Cha-Lee;Park, Sim-Soo;Choi, Hoi-Myung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.8
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    • pp.755-760
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    • 2010
  • In this study, we mainly focused on the PM (Particulate Matter) emission characteristics of a diesel engine. To analyze particle behavior in the tail-pipe, particle emission was measured on the engine-out (downstream of turbocharger), each upstream and downstream both of DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter). Moreover, particle emission contours on each sampling point were constructed. The reduction efficiency of particle number concentration and mass through the DOC and DPF was studied. Parameters such as EGR (Exhaust Gas Recirculation) and the main injection timing were varied in part load conditions and evaluated using the engine-out emissions. The DMS500 (Differential Mobility Spectrometer) was used as a particle measurement instrument that can measure particle concentrations from 5 nm to 1000 nm. Nano-particles of sizes less than 30 nm were reduced by oxidation or coagulated with solid particles in the tail-pipe and DOC. The DPF has a very high filtration efficiency over all operating conditions except during natural regeneration of DPF.

Influences of direction for hexagonal-structure arrays of lens patterns on structural, optical, and electrical properties of InGaN/GaN MQW LEDs

  • Lee, Kwang-Jae;Kim, Hyun-June;Park, Dong-Woo;Jo, Byoung-Gu;Oh, Hye-Min;Hwang, Jeong-Woo;Kim, Jin-Soo;Lee, Jin-Hong;Leem, Jae-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.153-153
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    • 2010
  • Recently, to develop GaN-based light-emitting diodes (LEDs) with better performances, various approaches have been suggested by many research groups. In particular, using the patterned sapphire substrate technique has shown the improvement in both internal quantum efficiency and light extraction properties of GaN-based LEDs. In this paper, we discuss the influences of the direction of the hexagonal-structure arrays of lens-shaped patterns (HSAPs) formed on sapphire substrates on the crystal, optical, and electrical properties of InGaN/GaN multi-quantum-well (MQW) LEDs. The basic direction of the HSAPs is normal (HSAPN) with respect to the primary flat zone of a c-plane sapphire substrate. Another HSAP tilted by 30o (HSAP30) from the HSAPN structure was used to investigate the effects of the pattern direction. The full width at half maximums (FWHMs) of the double-crystal x-ray diffraction (DCXRD) spectrum for the (0002) and (1-102) planes of the HSAPN are 320.4 and 381.6 arcsecs., respectively, which are relatively narrower compared to those of the HSP30. The photoluminescence intensity for the HSAPN structure was ~1.2 times stronger than that for the HSAP30. From the electroluminescence (EL) measurements, the intensity for both structures are almost similar. In addition, the effects of the area of the individual lens pattern consisting of the hexagonal-structure arrays are discussed using the concept of the planar area fraction (PAF) defined as the following equation; PAF = [1-(patterns area/total unit areas)] For the relatively small PAF region up to 0.494, the influences of the HSAP direction on the LED characteristics were significant. However, the direction effects of the HSAP became small with increasing the PAF.

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Effect of Trans-unsaturated Fatty Acid on Serum Lipid Levels in Mice (트랜스형 불포화 지방산이 mice 혈중 지질농도에 미치는 영향)

  • Yu, Sun-Nyoung;Ahn, Jeong-Bin;Park, Eun-Young;Lee, Sun-Jung;Tak, Min-Gi;Kim, Kwang-Youn;Kim, Sang-Hun;Kim, Ki-Dae;Ahn, Soon-Cheol
    • Journal of Life Science
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    • v.22 no.8
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    • pp.1126-1131
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    • 2012
  • The purpose of this study was to investigate the effects of trans-unsaturated fatty acid (TFA), saturated fatty acid (SFA) and general unsaturated fatty acid (USFA) on serum lipid levels in ICR mice. Male ICR 8-week-old mice were divided into six groups; the control group (C) fed with normal diet, the TFA-1 group fed with 10% trans-unsaturated fatty acid, the TFA-2 group fed with 30% trans-unsaturated fatty acid, the TFA-3 group fed with 50% trans-unsaturated fatty acid, the SFA group fed with 50% saturated fatty acid, and USFA group fed with 50% general unsaturated fatty acid. The serum total cholesterol of TFA-3 and SFA was higher than those of other fat groups and C. The serum triglyceride (TG) of TFA-3 and SFA showed the highest levels among all of diet groups. Also the serum HDL cholesterol levels of TFA-3 showed the lowest. LDL cholesterol and atherogenic indices (AI) were remarkedly increased in TFA-3 and SFA, as compared with other fat fed groups and C. Taken together with results, the TFA-3 group showed serum lipid levels similar to the SFA and different from the USFA. These results suggest that intake of high level of trans-unsaturated fatty acid increased serum triglyceride, LDL cholesterol and atherogenic indices, which may affect risk on serum lipid level for lipid metabolism syndrome.

Effect of Fucoidan on Angiogenesis and Gene Expression in Human Umbilical Vein Endothelial Cells (후코이단이 혈관 내피세포의 신생혈관 생성 효과 및 관련 유전자의 발현에 미치는 영향)

  • Park, Ho;Kim, Beom-Su
    • Korean Journal of Clinical Laboratory Science
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    • v.49 no.4
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    • pp.323-328
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    • 2017
  • Angiogenesis is a process including members of the angiogenic factors. In particular, fibroblast growth factor 2 (FGF2) is considered the most potent angiogenic factor because it promotes cell proliferation and tube formation. A recent study reported that fucoidan derived from marine plant potentiated FGF-2 induced tube formation in human endothelial cells. On the other hand, the molecular mechanisms involved in the angiogenic activity of fucoidan and FGF2 are unknown. In this study, a fucoidan treatment promoted angiogenesis induced by FGF2. The effects of fucoidan on FGF2-induced angiogenesis were confirmed by a proliferation assay using a CellTiter96 Aqueous One solution after a treatment with fucoidan and FGF2. The tube formation and wound healing assay for the angiogenic activity were also confirmed. Reverse transcription PCR showed a change in the mRNA of vascular endothelial growth factor-A (VEGF-A), intercellular adhesion molecule-1 (ICAM-1), matrix metallopeptidase9 (MMP9), and the signal transducer and activator of transcription3 (STAT3). In summary, the Fucoidan/FGF2 treatment induced an increase in cell proliferation, improved the tube formation and wound healing activity, and altered the STAT3, VEGF-A, ICAM-1, and MMP9 mRNA expression levels. Further research will be needed to provide a scientific explanation in terms of cell-signaling and confirm the present findings.

Data Qualification of Optical Emission Spectroscopy Spectra in Resist/Nitride/Oxide Etch: Coupon vs. Whole Wafer Etching

  • Kang, Dong-Hyun;Pak, Soo-Kyung;Park, George O.;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.433-433
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    • 2012
  • As the requirement in patterning geometry continuously shrinks down, the termination of etch process at the exact time became crucial for the success in nano patterning technology. By virtue of real-time optical emission spectroscopy (OES), etch end point detection (EPD) technique continuously develops; however, it also faced with difficulty in low open ratio etching, typically in self aligned contact (SAC) and one cylinder contact (OCS), because of very small amount of optical emission from by-product gas species in the bulk plasma glow discharge. In developing etching process, one may observe that coupon test is being performed. It consumes costs and time for preparing the patterned sample wafers every test in priority, so the coupon wafer test instead of the whole patterned wafer is beneficial for testing and developing etch process condition. We also can observe that etch open area is varied with the number of coupons on a dummy wafer. However, this can be a misleading in OES study. If the coupon wafer test are monitored using OES, we can conjecture the endpoint by experienced method, but considering by data, the materials for residual area by being etched open area are needed to consider. In this research, we compare and analysis the OES data for coupon wafer test results for monitoring about the conditions that the areas except the patterns on the coupon wafers for real-time process monitoring. In this research, we compared two cases, first one is etching the coupon wafers attached on the carrier wafer that is covered by the photoresist, and other case is etching the coupon wafers on the chuck. For comparing the emission intensity, we chose the four chemical species (SiF2, N2, CO, CN), and for comparing the etched profile, measured by scanning electron microscope (SEM). In addition, we adopted the Dynamic Time Warping (DTW) algorithm for analyzing the chose OES data patterns, and analysis the covariance and coefficient for statistical method. After the result, coupon wafers are over-etched for without carrier wafer groups, while with carrier wafer groups are under-etched. And the CN emission intensity has significant difference compare with OES raw data. Based on these results, it necessary to reasonable analysis of the OES data to adopt the pre-data processing and algorithms, and the result will influence the reliability for relation of coupon wafer test and whole wafer test.

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A Study on the $SO_2/CO_2/N_2$ Mixed Gas Separation Using Polyetherimide/PEBAX/PEG Composite Hollow Fiber Membrane (Polyetherimide/PEBAX/PEG 복합 중공사막을 이용한 $SO_2/CO_2/N_2$ 혼합기체 분리에 관한 연구)

  • Hyung, Chan-Heui;Park, Chun-Dong;Kim, Kee-Hong;Rhim, Ji-Won;Hwang, Taek-Sung;Lee, Hyung-Keun
    • Membrane Journal
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    • v.22 no.6
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    • pp.404-414
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    • 2012
  • In order to investigate $SO_2$ removal, PEI hollow fiber membranes were produced by a dry-wet phase inversion method. The membrane support layer on surface was coated with PEBAX1657$^{(R)}$ and PEG blending materials. Modules were prepared for the single gas permeation characteristics of composite membrane according to temperature and pressure. As a result, $SO_2$ permeance and $SO_2/N_2$ selectivity were 220~1220 GPU and 100~506 through operating condition, respectively. Moreover, $SO_2/CO_2/N_2$ mixture gas was used to compare the performance of separation properties according to temperature, pressure and retentate flow rate difference. $SO_2$ removal efficiency was increased with pressure and temperature.

Characterization of CdS-quantum dot particles using sedimentation field-flow fractionation (SdFFF) (침강 장-흐름 분획법을 이용한 CdS 양자점 입자의 특성 분석)

  • Choi, Jaeyeong;Kim, Do-Gyun;Jung, Euo Chang;Kwen, HaiDoo;Lee, Seungho
    • Analytical Science and Technology
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    • v.28 no.1
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    • pp.33-39
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    • 2015
  • CdS-QD particles are a nano-sized semiconducting crystal that emits light. Their optical properties show great potential in many areas of applications such as disease-diagnostic reagents, optical technologies, media industries and solar cells. The wavelength of emitting light depends on the particle size and thus the quality control of CdS-QD particle requires accurate determination of the size distribution. In this study, CdS-QD particles were synthesized by a simple ${\gamma}$-ray irradiation method. As a particle stabilizer polyvinyl pyrrolidone (PVP) were added. In order to determine the size and size distribution of the CdS-QD particles, sedimentation field-flow fractionation (SdFFF) was employed. Effects of carious parameters including the the flow rate, external field strength, and field programming conditions were investigated to optimize SdFFF for analysis of CdS-QD particles. The Transmission electron microscopy (TEM) analysis show the primary single particle size was ~4 nm, TEM images indicate that the primarty particles were aggregated to form secondary particles having the mean size of about 159 nm. As the concentration of the stabilizer increases, the particle size tends to decrease. Mean size determined by SdFFF, TEM, and dynamic light scattering (DLS) were 126, 159, and 152 nm, respectively. Results showed SdFFF may become a useful tool for determination of the size and its distribution of various types of inorganic particles.

Spatio-temporal Fluctuation of Phytoplankton Size Fractionation in the Uljin Marine Ranching Area (UMRA), East Sea of Korea (동해 울진 바다목장해역의 크기별 식물플랑크톤 생물량의 시·공간적 분포 특성)

  • Yoon, Yang Ho
    • Korean Journal of Environmental Biology
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    • v.34 no.3
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    • pp.151-160
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    • 2016
  • To understand size fractioned chlorophyll a and material cycles of coastal ecosystem in Uljin marine ranching area (JMRA) of East Sea, 4 times of survey were conducted from April to November 2008. Picoplankton, nanoplankton and netplankton in the surface of UMRA fluctuated with an annual mean of $0.26{\mu}g\;L^{-1}$ between the lowest value of $0.03{\mu}g\;L^{-1}$ and the highest value of $0.87{\mu}g\;L^{-1}$, annual mean $1.32{\mu}g\;L^{-1}$ between $0.11{\mu}g\;L^{-1}$ and $5.60{\mu}g\;L^{-1}$, annual mean $0.45{\mu}g\;L^{-1}$ between no detected (nd) and $4.68{\mu}g\;L^{-1}$, respectively. And the relative ratio of picoplankton, nanoplankton and netplanktons on the phytoplankton biomass was on annual average 12.9%, 65.0% and 22.1%, respectively. The 10 m layer was similar to the surface. The relative ratio of pico- and nano-plankton was higher throughout the year. That is, the material cycle of UMRA consists of a microbial food web rather than traditional food chain at a lower trophic levels. Primary production is deemed to have a higher possibility of being adjusted by top-down dynamics, such as micro-zooplankton grazing pressure rather than nutrients supply.