• Journal of Pharmaceutical Investigation
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• v.40 no.2
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• pp.91-100
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• 2010

The objective of this work is to study transdermal delivery of donepezil hydrochloride (DH) using iontophoresis and to evaluate various factors which affect the transdermal transport. After the flux study using 4 kinds of hydrogel, hydrogel containing 8% poly(ethylene oxide) (PEO) was chosen as the hydrogel for further studies. Under experimental condition, DH was stable. We have studied the effect of polarity, current density, drug concentration and current profile on transdermal flux and compared the results. In vitro flux study was performed at $33^{\circ}C$, using side-by-side diffusion cell and full thickness hairless mouse skin. DH is positively charged at pH 7.4, and anodal delivery was much larger than cathodal and passive delivery at all current densities studied (0.2, 0.4 and 0.6 mA/$cm^2$). Cathodal delivery showed higher flux than passive flux. Flux increased as the concentration of DH in hydrogel increased. Pulsatile application of current showed smaller flux value than the application of continuous current. Based on these results, we have evaluated the possibility of delivering enough amount of DH to reach the therapeutic level. The maximum cumulative amount of DH transported for 12 hours was 455 ${\mu}g/cm^2{\cdot}hr$ when the amount of DH in the hydrogel was 3 mg/mL and the current density was 0.4 mA/$cm^2$. If the patch size is 10 $cm^2$, then we can deliver 4.6 mg for 12 hours. Because the daily dosage of DH is 5 mg, it seems possible to deliver clinically effective amount of DH using iontophoresis. This study also provides some information about the role of electrorepulsion and electroosmosis during the transport through skin.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.1
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• pp.47-53
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• 2004

양방향 2차로 도로에서는 보다 효율적으로 운영하고 도로의 안전성을 도모하기 위하여 오르막 차로 및 양보차로 추월차로 등의 부가차로를 설치하고 있다. 이러한 부가차로 효율성의 비교 분석을 통한 연구에 의하여 기존의 도로를 효율적으로 운영하는 방안이 제시되어야 된다. 본 연구에서는 이러한 부가차로 중 추월차로 및 양보차로가 포함된 구간을 조사하여 기하구조에 따른 교통류 특성을 분석하고 각 구간별로 서비스 수준분석을 실시하였다. 그 결과는 다음과 같다. (1) 각 기하구조별로 지점속도와 통행속도를 분석한 결과 지점속도는 통행속도보다 조사지점의 기하구조에 의한 영향을 많이 받아 변동이 심한 것을 알 수 있었으며, 통행속도는 그 기하구조에 따른 교통류의 특성을 잘 반영하고 있음을 알 수 있었다. (2) 차량별 지점속도의 비교 분석에서는 현재 차량성능의 진보로 인하여 조사구간의 설계속도에 반해 중차량 및 버스-트럭, 승용에 대한 차량별 속도차이가 거의 없는 것으로 분석되었다. 기존의 중차량에 대한 보정은 현장제한속도에 대하여 감안되어야 된다고 판단된다. (3) 모의실험모형과 현장조사에 의한 교통류특성을 비교해 보았을 때, 시뮬레이션은 도로의 전구간에 대한 결과는 잘 반영하고 있으나 짧은 구간에 대하여 교통류의 연속성을 파악하기에는 부족하다고 판단된다. (4) 추월가능 구간과 양보차로구간의 효율성을 비교해 보면, 추월율에서 양보차로구간이 추월가능구간보다 22.5%나 높게 나왔으며 총지체비교에서는 추월가능구간보다 5.56sec/h의 지체감소를 보이고 있다. 서비스 수준분석에서는 같은 C의 수준을 보이고 있으나 양보차로의 영향으로 양보차로 후구간의 서비스 수준이 A까지 상향되었다. 따라서 대향교통류의 영향을 받는 추월차로의 확보보다는 효율성이 좋은 양보차로구간의 보급이 많아야 되겠다.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.264-274
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• 2008

Seasonal variations of cyanobacterial toxins (microcystins) in Yeongehun reservoir were studied from March to December, 2007. High level of microcystins production was shown during the late autumn and winter seasons. Total microcystins concentration increased sharply when the dominant species changed from Anabaena sp. to Microcystis aeruginosa. Microcystins-RR and -YR were the main components of the microcystins, whereas microcystin-LR was detected in small quantities. Especially, large amounts of microcystin-LR were detected when standing crops of M. aeruginosa increased exponentially. Total microcystins concentration showed a negative correlation with water temperature. However, total microcystins were lowly correlated with other environmental factors except for water temperature. As a result, this study clearly demonstrated that M. aeruginosa was the main producer of microcystins in Yeongchun reservoir.

• Journal of Biomedical Engineering Research
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• v.26 no.3
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• pp.151-155
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• 2005

Interspinous spacers have been developed as an alternative surgical treatment for laminectomy or fusion with pedicle screws and rods for the treatment of lumbar spinal stenosis. However, its biomedical efficacies are well not known. In this study, we evaluated kinematic behaviors of the surgical and the adjacent levels before and after inserting interspinous spacers. Three porcine lumbar spines were prepared. On each specimen, an interspinous spacer was inserted at the L4-L5. Flexion-extension moments (0, 2.5, 5.0, 7.5, 10Nm) were applied. A stereophotogrammetric set-up with DLT algorithm was used to assess the three-dimensional motions of the specimen where three markers $({\square}0.8mm)$ were attached to each vertebra. Results showed that extension motion decreased by $15-24\%$ at the surgical level (L4-L5) after insertion of interspinous spacer. At the adjacent levels, the range of motion remained unchanged. In flexion, no significant changes in motion were observed regardless of levels. Therefore, our experimental results demonstrated the interspinous spacer is very effective in limiting the extension motion that may cause narrowing of the spinal canal and vertebral foramen while maintaining kinematic behaviors at the adjacent levels. Further, these results suggested that the use of interspinous spacer may be able to prevent lower back pain at the surgical level and to lower the incidence of degenerative changes at the adjacent levels.

• Journal of Biosystems Engineering
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• v.14 no.4
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• pp.272-281
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• 1989

It is desirable for the vertical wind tunnel which can build uniform air flow across the vertical duct to be used for the purpose of the investigation of the aerodynamic properties of grains. This study was conducted to examine how the air velocity profile in the vertical duct is influenced by the various alternations of the elements of the wind tunnel, and to prepare design guidance of the vertical wind tunnel which can be used for investigating aerodynamic properties of grains. In addition, several tests were conducted to locate the test section which can be applicable for determining the terminal velocity of grain. The following conclusions were obtained from the study: 1. The size and the location of the outlet of the plenum chamber should be determined such that the outlet air flow is less affected by the air flow and the back pressure by the side wall of the chamber. 2. The honeycomb was not helpful for attaining uniform air flow in case that the air flow profile at the bottom of the vertical duct is serverely different from the ideal one. 3. Even though considerable pressure drop was resulted from the screens installed within the vertical duct, the screens were helpful for attaining uniform air flow in the duct. 4. It is desirable for the test section to be located at the position that not only the air flow of the duct is not disturbed by the distorted back pressure in the plenum chamber, but also less boundary layer is developed.

• Applied Microscopy
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• v.12 no.2
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• pp.35-44
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• 1982

The fat bodies of cabbage worm (Pieris rapae) and silk worm (Bomyx mori) during metamorphosis was comparatively studied by electron microscope. 1. Cell oranelles: Golgi apparatus were not observed in both species. It is observed that RER of cabbage worms initiate to degenerate in prepupa stage with complete degeneration at adult stage, while that of silk worms shows similar degenerative pattern. However, mitochondria of cabbage worms are transformed into autophagic vacuole from prepupa stage until adult stage whereas those of silk worm shows a decrease in number in prepupa stage but maintains a certain level until adult stage. 2. Storage substance in cell: Lipid droplets in cabbage worms were observed to increase in numbers during larval stage but afterward decrease in number with an enlargement in size. However immediately after their pupal stage, they almost disappear. On the contrary lipid droplets in silk worms show rather increase in number until adult stage. Protein storage granules in bothspecies were arised from autophagic vacuoles(lysosome) . Fat cells of cabbage worm in adult stage turn out to be residual bodies which last until final stage, but those of silk worm rapidly decrease. Glycogen particles in both species reach maximum at last larval instar and thee gradually decrease thereafter. 3. Fat body sheath: The average width of fat body sheath was measured to be $0.2{\mu}m$ and $0.6{\mu}m$ and surface of fat cells adjacent to fat body sheath in silk worm is heavily infolded.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.288-294
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• 1994

Seedling vigor of introgressive hybrids between birdsfoot refoil 'MO-20"(Lotus corniculatus) used as the maternal parent and tetraploid(2n=4x=24)accession PI302921 narrowleaf trefoil(Lotus corniculatus L.), and parents were compared in terms of dry matter accumulation , net photosynthetic rate, dark respiration rate, and growth analysis. The hybrids showed better seedling vigor than PI302921 as they had lower dark respiration rate and higher relative growth rate (RGR) than PI302921. Hybrids grew faster than MO-20, but there was not significant difference between them. Net photosynthesis per unit area increased during three weeks after emergence without difference among the entries, then decreased sharply with leaf age and shading marking much differences among entries Dark respiration rate was very high just after emergence, after which it decreased rapidly until it reached a stable level at 1 week through 3 weeks of age, and then dropped again. In general, dark respiration, photosynthesis, and seedling growth of the hybrid was similar to those if MO-20. Although there are some reports about interspecific hybrids of Lotus species, it still remains as a new area for genetic improvement of seedling vigor of L. corniculatus.atus.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.6
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• pp.369-374
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• 2005

Nitrogen ion implantation in Nimonic 80A using plasma immersion ion implantation (PIII) was investigated at a pulse voltage of -60 kV and ion dose of $3{\times}10^{17}{\sharp}/cm^2$, $6{\times}10^{17}{\sharp}/cm^2$, $12{\times}10^{17}{\sharp}/cm^2$. PIII is an effective technology to improve the surface hardness and wear resistance of materials. And also this technology is not limited by the shape and size of materials. PIII would be a promising technique in the future. Surface hardness and wear resistance of the $N^+$ ion implanted Nimonic 80A were increased with the increase in the incident ion dose. The surface hardness of the untreated Nimonic 80A is 420 Hv, the hardness of implanted Nimonic 80A is 1050 Hv at $N^+$ ion dose of $12{\times}10^{17}{\sharp}/cm^2$. The wear loss of the untreated is 82.5 mg, the wear loss of the implanted is 0.004g at $N^+$ ion dose of $12{\times}10^{17}{\sharp}/cm^2$. The $Cr_2N$ is detected on the surface of the implanted Nimonic 80A by XRD analysis.

• Journal of Embryo Transfer
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• v.27 no.4
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• pp.265-270
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• 2012

In canine, oocytes are ovulated at the GV (germinal vesicle) stage and they have to fulfill maturation phase before reaching metaphase II stage. The efficiency of in vitro maturation is still very low. Therefore, the aim of this study was to investigate the effect of in vitro maturation on nuclear changes of immature canine oocytes recovered from different reproductive stages ovaries and different culture conditions. The oocytes were cultured in TCM-199 with supplement at 5% $CO_2$ and $38.5^{\circ}C$ for 72 h. The nuclear maturation of canine oocytes was evaluated with Hoechst 33342 stain under fluorescence microscope (Fig. 1). The results of this study detected differences in in vitro maturation rate between oocytes recovered from follicle status and non-follicle status ovaries. However, these differences were not significant as indicated in Table 1 and Fig. 2. In regard to the effect of culture condition with supplements, we did not found significant differences compared with control group (Table 2, Table 3). One of the reasons for this data could be the conditions that ovaries were exposed during slaughtering process or the long distant transportation of the ovaries. Although these data have not shown clearly significant differences results compared with control, furthermore the different reproductive status ovaries was beneficial for maturation of oocytes in vitro and can be a basic part of knowledge to improve in vitro maturation of canine oocytes.

• Archives of design research
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• v.12 no.1
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• pp.51-60
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• 1999

Since the appearance of moving images, the expansion of mass media such as 1V or VCR has made the pace and range of spreading information to people faster and widely popular. Recendy, the development of digital image technique has resulted in solving the problem -great defect- of the display quality of analogue system; special effects by means of computer graphics have risen to a higher quality level; showed the new direction of digital image; and popular wi1h people all c:Ner the world. This paper reestablishes the notion of image up to now, and analyses the technical differences between analogue system and digital system on the basis of the SpecifIC property and skill of digital image editing; it also studies the special effects which can be applied to the image editing software. Moreover, in researdting 1V advertising, the special effects by digital system in use in 1his country today complies with the statistics in their own field. The special effects in 1V advertising is performed at a higher standard by a professional production. Accordingly, with the help of technology of digital moving image, the special effects are expected to continue developing into a level of high quality