• Korean Journal of Animal Reproduction
• /
• v.20 no.4
• /
• pp.467-472
• /
• 1997

This study was conducted to determine the optimal DC voltage for NT of in vivo donor embryo nuclei and investigate the effect of donor embryo guality on fusion and in vitro development of NT embryos . Recpient oocytes were enucleated 25~27h after IVM and further cuitured for 18~20h prior to fusion for oocyte aging. Donor embryos of molura stage were recovered from superovulated heifers and classified l into good and low quality group. Their nuclei were transferred in to the emucleated oocytes 42~44h post-IVM and fused 43-45h post-IVM with a single 0.75kV /cm or 1.0kV /cm DC voltage for 70${\mu}\textrm{A}$sec. The fusion rate of oocytes was not different between two DC voltages. However, the cleavage and M + B developmnent was more high at 1.0kV /cm DC voltage and the proportion of M+B was 19.0% at 0.75kV /cm DC and 29.4% at 1.0kV /cm DC voltage. Donor embryo qualtiy did not greatly affect the fusion and cleavage of NT oocytes, but none of NT embryos derived from low embryo quatity reached the morula stage. The results indicate that the most suitable DC v voltage for electrofusion of in vivo donor muclei was a single 1.0kV /cm DC voltage and donor embryo quality was an important factor affecting the development in vitro of NT embryos.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.2
• /
• pp.75-79
• /
• 2017

Honeycomb-shaped Ag-grid transparent conductive electrodes (TCEs) were fabricated using two different processes, high density plasma etching and lift-off, and the optical and electrical properties were compared according to the fabrication method. For the fabrication of the Ag-grid TCEs by plasma etching, etch characteristics of the Ag thin film in $10CF_4/5Ar$ inductively coupled plasma (ICP) discharges were studied. The Ag etch rate increased as the power increased at relatively low ICP source power or rf chuck power conditions, and then decreased at higher powers due to either decrease in $Ar^+$ ion energy or $Ar^+$ ion-assisted removal of the reactive F radicals. The Ag-grid TCEs fabricated by the $10CF_4/5Ar$ ICP etching process showed better grid pattern transfer efficiency without any distortion or breakage in the grid pattern and higher optical transmittance values of average 83.3 % (pixel size $30{\mu}m/line$ width $5{\mu}m$) and 71 % (pixel size $26{\mu}m/line$ width $8{\mu}m$) in the visible range of spectrum, respectively. On the other hand, the Ag-grid TCEs fabricated by the lift-off process showed lower sheet resistance values of $2.163{\Omega}/{\square}$ (pixel size $26{\mu}m/line$ width $18{\mu}m$) and $4.932{\Omega}/{\square}$ (pixel size $30{\mu}m/line$ width $5{\mu}m$), respectively.

• Journal of Aquaculture
• /
• v.18 no.1
• /
• pp.45-51
• /
• 2005

The optimum salinity and the effects of rapid salinity change on oxygen consumption and ammonia nitrogen excretion were examined in River Puffer Takifugu obscrus (total length 9.5$\pm$0.9 cm, total weight 18.7$\pm$5.4 g). Fish examined at the different transfer medium salinity (2, 12, 22 and 32 psu) after 2 months of acclimation period at each salinities. The routine metabolic rates of River puffer are shown as parabola equation, $Y=-0.0873X^2+0.6384X-0.690$ for oxygen consumption and $Y=-2.1667X^2+7.1672X+31.999$ for ammonia nitrogen excretion with the salinity medium at 2, 12. 22 and 32 psu. The oxygen consumption and ammonia nitrogen excretion of River puffer trans-ferred to the low salinity medium (2 and 12 psu) showed significantly difference in each salinities rearing groups than to salinity of 22 and 32 psu. Fish has a diurnal rhythm in relate to feeding, it was showed that the peak of oxygen consumption appeared at 3 hours after feeding and the ammonia nitrogen excretion rate reached maximum 4 hours after feeding. These results may indicate that the optimum salinity for rearing of River puffer is 22 psu based on growth and feed conversion ratio. The rapid change of medium salinity had no effects on the oxygen consumption and nitrogen excretion in River puffer based on this experiment.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.4
• /
• pp.331-341
• /
• 2013

In a solar domestic hot water (SDHW) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (TST) as hot water. In this study, a computational fluid dynamics (CFD) model was developed to predict the solar thermal energy storage in a hybrid-type TST equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a TST, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the TST. The developed model was validated by the good agreement between the CFD results and the experimental results performed with the hybrid-type TST in SDHW settings.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.31 no.9_10
• /
• pp.1475-1486
• /
• 2007

This study aims to develop knitted ware design to meet desire to express diversity in the modern fashion design so that we designed knitted ware by applying african geometric pattern and color to suggest new knitted ware design. We collect data about african texture pattern through technical books, publications, internet, and preceding research and visit and investigate the African museum. We investigate knitted Jacquard texture through preceding research and collect sample and data which is insufficient in the data source. The conclusions in this study are summarized as follows: First, African textile pattern is formulated with animism based on their religious view of art for a basis and African regards nature like animal and plant as a motive and interprets nature in the so that they can create symbolized geometric features that constitute African texture pattern. Those patterns is composed of extremely geometric figures so that they we fit to apply for color jacquad knit design. Second, color knitted jacquad can be distinguished by knitting method and status of knitting as 7 kinds of techniques such as Nomal, Bird'eye, Floating, Tubular, Ladder's back, Blister, Transfer Jacquard, and as a result of preceding research and knitting texture directly, jacquard technique makes different texture under same condition like consistent spinning rate and same crochet hook. Third, Bird'eye Jacquard used generally to make knitted ware and Ladder's back Jacquard, Tubular Jacquard used to make knitted ware light are fit to apply them to 7GG and 12GG machines. We design a cloak as a outer garment, a coat shaped like one-piece dress and a coat with hood by using Tubular Jacquard which can make thick texture and design a jacket, a skirt and a one-piece dress by using Bird'eye Jacquard. we make a light and flimsy one-piece dress by using Ladder's back Jacquard. Fourth, we apply the contrast of $4{\sim}6$ color and line and the contrast of texture and raw material to jacquard in order to emphasize texture property and visual property.

• Journal of Plant Biotechnology
• /
• v.34 no.3
• /
• pp.223-227
• /
• 2007

Plant regeneration system from leaf and root segments of Lycoris chejuensis via bulblet formation was established. Surface-sterilized leaf and root segments were cultured on the B5 medium containing 2,4-D. After 12 weeks of culture onto B5 medium containing 2,4-D, white globular structures and white calluses were formed on the cut surface of the explants. The highest frequency of globular structures and calluses formation from leaf explants was 32.1% when leaf explants were cultured onto B5 medium supplemented with 1 mg/L of 2,4-D. However, the higher concentration of 2,4-D (over than 3 mg/L) resulted in decrease of the frequency. In comparison to leaf explants, root segments showed the highest frequency at a rate of 36.1% when root explants were cultured onto B5 medium supplemented with 3 mg/L of 2,4-D. These structures and calluses were sub-cultured and proliferated onto the same culture medium. Upon transfer to B5 basal medium, white globular structures were developed into bulblets and normal plantlets. After 4 weeks of incubation in the light, plantlets were successfully rooted over the frequency of approximately 90%. Rooted plantlets were successfully transferred to potting soil and acclimatized in the growth chamber. The plant regeneration system of Lycoris chejuensis established in this study, might be applied to mass proliferation, conservation of genetic resources and genetic transformation for molecular breeding.

• Reproductive and Developmental Biology
• /
• v.34 no.3
• /
• pp.181-184
• /
• 2010

Osmolarity of culture media is one of the most important factors affecting in vitro development. This study was conducted to investigate the DNA methylation status of Pre-1 and satellite sequence in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaG or 0.05M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. Previous our studies have reported that pNT embryos cultured in both hypertonic media showed significantly higher blastocyst formation rate than that of control. The DNA methylation status of the satellite sequences in blastocyst was characterized using bisulfite-sequencing technology. The satellite region had a similar methylation pattern of in vivo blastocyst among two culture groups excepting the control group. Each level of methylation is that the satellite DNA moderately methylated (43.10% of PZM-3; 56.12% of NaCl; 55.06% of sucrose; 60.00% of in vivo embryos). As a result of the sequence of PRE-1, CpG methylation pattern was similar to three groups, including in vivo group. In case of the satellite DNA region, the osmolarity conditions were affected CpG DNA methylation status while PRE-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. These results indicate that the modification of osmolarity in a culture media may influence to spatially change of DNA methylation of repetitive sequence for pNT embryo development.

• Journal of the Korean Ceramic Society
• /
• v.42 no.4
• /
• pp.251-259
• /
• 2005

In order to characterize the influence of the reaction-site density on the cathodic polarization property of LSCF, we chose the porosity of LSCF as a main controlling variable, which is supposed to be closely related with active sites for the cathode reaction. To control the porosity of cathodes, we changed the mixing ratio of fine and coarse LSCF powders. The porosity and pore perimeter of cathodes were quantitatively analyzed by image analysis. The electrochemical half cell test for the cathodic polarization was performed via 3-probe AC-impedance spectroscopy. According to the investigation, the reduction of oxygen at LSCF cathode was mainly controlled by following two rate determining steps; i) surface diffusion and/or ionic conduction of ionized oxygen through bulk LSCF phase, ii) charge transfer of oxygen ion at cathode/electrolyte interface. Moreover, the overall cathode polarization was diminished as the cathode porosity increased due to the increase of the active reaction sites in cathode layer.

• Journal of Korean Neurosurgical Society
• /
• v.61 no.4
• /
• pp.478-484
• /
• 2018

Objective : Cerebrovascular disease (CVD) was the third most common cause of death in South Korea in 2014. Evidence from abroad suggests that comprehensive stroke centers play an important role in improving the mortality rate of stroke. However, surgical treatment for CVD is currently slightly neglected by national policy, and there is still regional imbalance in this regard. For this reason, we conducted a survey on the necessity of, and the requirements for, establishing regional comprehensive cerebrovascular surgery centers (CCVSCs). Methods : This investigation was performed using the questionnaire survey method. The questionnaire was consisted with two sections. The first concerned the respondent's opinion regarding the current status of demand and the regional imbalance of cerebrovascular surgery in South Korea. The second section asked about the requirements for establishing regional CCVSCs. We sent the questionnaire to 100 board members of the Korean Society of Cerebrovascular Surgeons. Results : Most experts agreed that cerebrovascular surgery patients were concentrated in large hospitals in the capital area, and 83.6% of respondents agreed that it was necessary to alleviate the regional imbalance of cerebrovascular surgery. With regards to personnel, over 90% of respondents answered that at least two neuro-vascular surgeons and two neuro-interventionists are necessary to establish a CCVSC. Regarding facilities, almost all respondents stated that each CCVSC would require a neuro-intensive care unit and hybrid operating room. The survey asked the respondents about 13 specific neurovascular surgical procedures and whether they were necessary for a regional CCVSC. In the questions about the necessity of cerebrovascular surgical equipment, all seven pieces of equipment were considered essential by all respondents. A further five pieces of equipment were considered necessary on site: computed tomographic angiography, magnetic resonance angiography, conventional angiography, surgical microscope, and surgical navigation. Our results may provide a basis for future policy regarding treatment of cerebrovascular disease, including surgery. Conclusion : Raising the comprehensiveness of treatment at a regional level would lower the national disease burden. Policies should be drafted regarding comprehensive treatment including surgery for cerebrovascular disease, and related support plans should be implemented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.678-681
• /
• 2003

In this paper, we aims to develop a microcontroll er-based portable pulse oximeter using Compact Flash Interface. First, portable pulse oxineter system is designed to record 2 channel of biosignals simultaneously, including 1 channel of SpO$_2$ and 1 channel of pulse rate. It is very small and portable. Besides, the system makes it possible to measure a patients condition without an additional medical equipment. We tried to solve the problems generated by a patient's motion. That is, we added an analog circuit to a traditional pulse oximeter in order to eliminate the change of the base line. And we used 2D sector algorithm. As present, SpO$_2$ modules are completed. But there are still many further development needed in order to enhance the function. Especially, compact flash interface remains the most to complete. Second, ECG monitoring system uses almost same as present 3-lead ECG system. But we focus on the analog part, especially in filter. The proposed filter is composed of two parts. One is a filter to remove the power-line interface. The other is a filter to remove the baseline drift. A filter to remove the power-line and the baseline drift is necessarily used in the ECG system. The implemented filter have three features; minimizing the distortion in DC component, removing the harmonic component of power-line frequency. Using compact flash interface, we can easily transfer a patient's personal information and the measured signal data to a network based server environment. That means, it is possible to implement a patient's monitoring system with low cost.