• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.993-994
• /
• 2008

Electrochromic (EC) devices are capable of reversibly changing their optical properties upon charge injection and extraction induced by the external voltage. The characteristics of the EC device, such as low power consumption, high coloration efficiency, and memory effects under open circuit status, make them suitable for use in a variety of applications including smart windows and electronic papers. Coloration due to reduction or oxidation of redox chromophores can be used for EC devices (e-paper), but the switching time is slow (second level). Recently, with increasing demand for the low cost, lightweight flat panel display with paper-like readability (electronic paper), an EC display technology based on dye-modified $TiO_2$ nanoparticle electrode was developed. A well known organic dye molecule, viologen, was adsorbed on the surface of a mesoporous $TiO_2$ nanoparticle film to form the EC electrode. On the other hand, ZnO is a wide bandgap II-VI semiconductor which has been applied in many fields such as UV lasers, field effect transistors and transparent conductors. The bandgap of the bulk ZnO is about 3.37 eV, which is close to that of the $TiO_2$ (3.4 eV). As a traditional transparent conductor, ZnO has excellent electron transport properties, even in ZnO nanoparticle films. In the past few years, one-dimension (1D) nanostructures of ZnO have attracted extensive research interest. In particular, 1D ZnO nanowires renders much better electron transportation capability by providing a direct conduction path for electron transport and greatly reducing the number of grain boundaries. These unique advantages make ZnO nanowires a promising matrix electrode for EC dye molecule loading. ZnO nanowires grow vertically from the substrate and form a dense array (Fig. 1). The ZnO nanowires show regular hexagonal cross section and the average diameter of the ZnO nanowires is about 100 nm. The cross-section image of the ZnO nanowires array (Fig. 1) indicates that the length of the ZnO nanowires is about $6\;{\mu}m$. From one on/off cycle of the ZnO EC cell (Fig. 2). We can see that, the switching time of a ZnO nanowire electrode EC cell with an active area of $1\;{\times}\;1\;cm^2$ is 170 ms and 142 ms for coloration and bleaching, respectively. The coloration and bleaching time is faster compared to the $TiO_2$ mesoporous EC devices with both coloration and bleaching time of about 250 ms for a device with an active area of $2.5\;cm^2$. With further optimization, it is possible that the response time can reach ten(s) of millisecond, i.e. capable of displaying video. Fig. 3 shows a prototype with two different transmittance states. It can be seen that good contrast was obtained. The retention was at least a few hours for these prototypes. Being an oxide, ZnO is oxidation resistant, i.e. it is more durable for field emission cathode. ZnO nanotetropods were also applied to realize the first prototype triode field emission device, making use of scattered surface-conduction electrons for field emission (Fig. 4). The device has a high efficiency (field emitted electron to total electron ratio) of about 60%. With this high efficiency, we were able to fabricate some prototype displays (Fig. 5 showing some alphanumerical symbols). ZnO tetrapods have four legs, which guarantees that there is one leg always pointing upward, even using screen printing method to fabricate the cathode.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권6호
• /
• pp.774-780
• /
• 2011

Inadequate supply of glucose or glucogenic substrates to the body tissues can affect metabolism of absorbed acetogenic metabolites from the gut and therefore, influence feed intake in ruminants. This study investigated the effect of energy supplementation on rumen kinetics in the gut, and the acetate clearance rate in the body tissues of sheep fed low quality basal roughage. A basal diet consisting of urea-treated mixture of wheaten chaff and barley straw (3:1 DM) containing 22.2 g N/kg DM was used. Four Merino cross wethers weighing $45{\pm}4.38\;kg$ fitted with permanent rumen and abomasal cannulae were allocated to four treatments in a $4{\times}4$ LSD. The treatments were basal diet ($E_0$), or basal diet supplemented with sucrose (112.5 g/d) administered intraruminally ($E_R$), abomasally ($E_A$), or via both routes (50:50) ($E_{RA}$). There was no difference (p>0.05) in the rumen liquid kinetics parameters between the four dietary treatments. However, there was a trend of animals supplemented with sucrose wholly or partly through the abomasum having lower faecal DM and therefore poor pellet formation, and low pH. Although the glucogenic potential of the fermentation products absorbed from the rumen was increased (p<0.001) by intra-ruminal supplementation with sucrose ($E_R$ and $E_{RA}$), there was no significant difference (p<0.05) in acetate clearance rate between the four dietary treatments.

• 한국임상수의학회지
• /
• 제7권2호
• /
• pp.511-515
• /
• 1990

소에 있어서 효율적인 쌍자생산 방법을 검토하기 위하여 이분수정란의 이식, 저단위 FSH에 의한 다배란 유도후의 인공수정, 인공수정후의 수정란이식, 수정란 2개의 양측 및 단측 자각에의 이식 등의 방범을 적용하여 본 실험을 수행하였다. 각 실험군의 60일 수태율은 각각 34.8%, 65.0%(평균), 66.7%, 62.5%, 57.1%였으며 쌍태임신율은 8.7%, 15.0%(평균), 16.7%, 18.7%, 21.4%였다. 위의 결과에서 볼 때 저단위 FSH 투여법(Group B1)과 수정란 2개의 단측 자궁각 이식방법에 있어 쌍태율이 높게 나타나는 경향이 있었으나 실용적 측면에서는 낮은 수준이었다.

• 방사성폐기물학회지
• /
• 제6권4호
• /
• pp.297-306
• /
• 2008

본 연구는 방사성 폐기물 처분장의 지하수 화학 조건을 조절하는 수리지구화학 특성을 규명할 목적으로 수행되었다. 이를 위해 처분장 주변의 관측공 중 12개의 관측공이 선정되었으며, 이들 시료를 심도별로 총 46 지점에서 채취하였다. 또한 지표수 3점과 해수 1점의 시료도 채취하였다. 채취된 시료는 양/음이온 분석이 수행되었으며, 물과 용질의 기원을 규명할 추적자로서 산소-수소, 삼중수소, 탄소, 황 동위원소도 분석되었다. 산소-수소 동위원소 분석 결과 지표수와 지하수는 모두 강우 기원임을 보여주었으며, 삼중수소 농도는 깊이가 깊어짐에 따라 감소하고는 있으나 높은 삼중수소 농도는 최근에 충진된 물임을 나타내고 있었다. 양/음이온 분석 결과를 통한 수질 유형 분석에서는 연구 지역 지하수는 Ca-Na-$HCO_3$ 유형과 Na-Cl-$SO_4$ 유형이 대표적이었으며, 상관 분석 결과 이들 이온은 해염, 물-암석 반응의 영향을 받은 것으로 판단된다. 특히 연구 지역에서 Na 비율이 높은 이유는 양이온 교환 반응에 의해 이루어지고 있음을 보여 주었다. 연구 지역의 산화-환원 조건의 경우에는 심도가 깊어짐에 따라 낮은 DO와 Eh 값을 나타내어 환원 환경이 형성되었음을 나타내며, 높은 Fe와 Mn의 농도는 Fe와 Mn 산화물의 환원 반응이 산화-환원 조건을 조절하고 있음을 보여주었다.

• Clinical and Experimental Reproductive Medicine
• /
• 제25권2호
• /
• pp.115-122
• /
• 1998

The maintenance of a viable pregnancy has long been viewed as an immunological paradox. The deveolping embryo and trophoblast are immunologically foreign to the maternal immune system due to their maternally inherited genes products and tissue-specific differentiation antigens (Hill & Anderson, 1988). Therefore, speculation has arisen that spontaneous abortion may be caused by impaired maternal immune tolerance to the semiallogenic conceptus (Hill, 1990). Loss of recall antigen has been reported in immunosuppressed transplant recipients and is associated with graft survival (Muluk et al., 1991; Schulik et al., 1994). Progesterone $(10^{-5}M)$ has immunosuppressive capabilities (Szekeres-Bartho et al., 1985). Previous study showed that fertile women, but not women with unexplained recurrent abortion (URA), lose their immune response to recall antigens when pregnant (Bermas & Hill, 1997). Therefore, we hypothesized that immunosuppressive doses of progesterone may affect proliferative response of lymphocytes to trophoblast antigen and alloantigen. Proliferative responses using $^3H$-thymidine ($^3H$-TdR) incorporation of peripheral blood mononuclear cells (PBMCs) to the irradiated allogeneic periperal blood mononuclear cells as alloantigen, trophoblast extract and Flu as recall antigen, and PHA as mitogen were serially checked in 9 women who had experienced unexplained recurrent miscarriage. Progesterone vaginal suppositories (100mg b.i.d; Utrogestan, Organon) beginning 3 days after ovulation were given to 9 women with unexplained RSA who had prior evidence of Th1 immunity to trophoblast. We checked proliferation responses to conception cycle before and after progesterone supplementation once a week through the first 7 weeks of pregnancy. All patients of alloantigen and PHA had a positive proliferation response that occmed in the baseline phase. But 4 out of 9 patients (44.4%) of trophoblast antigen and Flu antigen had a positive proliferative response. The suppression of proliferation response to each antigen were started after proliferative phase and during pregnancy cycles. Our data demonstrated that since in vivo progesterone treated PBMCs suppressed more T-lymphocyte activation and $^3H$-TdR incorporation compare to PBMCs, which are not influenced by progesterone. This data suggested that it might be influenced by immunosuppressive effect of progesterone. In conclusion, progesterone may play an important immunological role in regulating local immune response in the fetal-placental unit. Furthermore, in the 9 women given progesterone during a conception cycle, Only two (22%) repeat pregnancy losses occured in these 9 women despite loss of antigen responsiveness (one chemical pregnancy loss and one loss at 8 weeks of growth which was karyotyped as a Trisomy 4). These finding suggested that pregnancy loss due to fetal aneuploidy is not associated with immunological phenomena.

• 대한유전성대사질환학회지
• /
• 제2권1호
• /
• pp.77-79
• /
• 2002

The urea cycle, consisting of a series of six enzymatic reactions, plays key roles to prevent the accumulation of toxic nitrogenous compound and synthesize arginine de novo. Five well characterized diseases have been described, resulting from an enzymatic defect in the biosynthesis of one of the normally expressed enzyme. This presentation will focus on two representative diseases; ornithine transcarbamylase(OTC) deficiency and citrullinemia(argininosuccinate synthetase deficiency). OTC deficiency is one of the most common inborn error of urea cycle, which is inherited in X-linked manner. We identified 17 different mutations in 20 unrelated Korean patients with OTC deficiency; L9X, R26P, R26X, T44I, R92X, G100R, R141Q, G195R, M205T, H214Y, D249G, R277W, F281S, 853 del C, R320X, V323M and 10 bp del at nt. 796-805. These mutations occur at well conserved nucleotide sequences across species or CpG hot spot. The L9X and R26X lead to the disruption of leader sequences, required for directing mitochondrial localization of the OTC precursor. Their phenotypes are severe, and neonatal onset. The G100R, R277W and V323M mutations were uniquely identified in patients with late onset OTC deficiency. The other genotypes are associated with neonatal onset. Out of 20 patients with OTC deficiency, only 6 patients are alive; two were liver transplanted, and normal in growth and development at 2, 4 years after transplantation respectively. Citrullinemia is an autosomal recessive disease, caused by the mutations in the argininosuccinate synthetase(ASS) gene. We identified in 3 major mutations in 11 unrelated Korean patients with citrullinemia; G324S, $IVS6^{-2}$ A to G, and 67 bp ins at nt 1125-1126. Among these, the 67 base pair insertion mutation is novel. The allele frequency of each mutation is; G324S(45%), IVS6-2 A to G(32%), and 67 base pair insertion(14%). All patients are diagnosed at neonatal or infantile age. Interestingly, two patients presented with stroke like episode. Out of 11 patients, 5 patients died. Among 6 patients alive, one patient was successfully liver transplanted.

• ALGAE
• /
• 제27권4호
• /
• pp.295-301
• /
• 2012

Carbon concentrating mechanisms play a vital role in photosynthesis in microalgae and cyanobacteria especially in the proper functioning of Rubisco and assimilation of carbon via the Calvin cycle. This study evaluates the role of carbon dioxide on carbon concentrating mechanism (CCM) in a cynaobacteria, Spirulina platensis and a microalga, Chlorella sp. 786. The study organisms were grown in both atmospheric (control sample, 0.035%) and high (exposed sample, 10%) $CO_2$ concentrations. Second dimension (2D) electrophoresis revealed a huge difference in the protein profiles of both organisms suggesting the induction of CCM related proteins in the sample maintained at atmospheric $CO_2$ concentration and the repression of CCM related proteins in the sample maintained at 10% $CO_2$. Liquid chromatography-mass spectroscopy analysis revealed the presence of two important $C_i$ transporter proteins in the control sample of S. platensis, namely ferredoxin-$NADP^+$ reductase and ATP binding cassette (ABC) transport system protein. These proteins were only expressed in the control sample and were downregulated or not expressed at all in the exposed sample. Consequently, this study conclusively proves that CCMs are only inducted at low $CO_2$ concentrations and are not functional at high $CO_2$ concentration.

• 정보처리학회논문지D
• /
• 제13D권4호
• /
• pp.583-592
• /
• 2006

제품 계열 기반 소프트웨어 개발 방법은 개발 조직이 보유하고 있는 품질이 보장된 핵심 자산의 재사용을 통해 제품의 개발 생산성을 획기적으로 향상시켜 시장 적시성을 맞출 수 있는 실용적이고 중요한 소프트웨어 개발 방법으로 빠르게 자리를 잡아가고 있다. 하지만 제품 계열의 특성 정의, 평가, 예측 및 개선을 위한 측정은 단일 프로젝트에서의 측정과는 달리, 개별 제품의 개발 및 유지를 위한 제품 개발 프로젝트의 수행도 특성뿐만 아니라 제품을 생산하기 위한 핵심 자산의 사용 및 핵심 자산의 개발과 전체적인 제품 계열의 수행도 까지도 고려해야 하기 때문에 무척 힘든 일이다. 따라서 제품 계열의 수행도를 측정하기 위해서는 일관성 있고 반복적이며, 효과적인 접근 방법이 제시될 필요가 있다. 본 논문은 제품 계열의 수행도 특성과 적용 방법의 다양성을 고려한 제품 계열을 위한 컨텍스트 기반 측정 지표의 도출방법을 제시하고 있다. 이 방법은 제품 계열의 측정 지표를 도출하기 위한 세부적인 절차와 작업의 결과로 생성되는 산출물의 양식을 제시하고 있다. 또한 연구 결과의 효과를 제시하기 위하여, 제품 계열의 기술적 관리 영역에 대한 주요 활동을 측정하기 위한 지표와 적용 사례를 함께 제시한다. 다양한 제품 계열 기반의 특성을 충분히 고려하여 제품 계열을 구축하거나 소프트웨어 제품을 생산할 때, 관리하고자 하는 속성을 파악할 수 있는 체계적인 접근 방법은 적용 상황 및 이해관계자의 관점에 따라 원하는 측정 지표를 효과적으로 도출할 수 있도록 한다.

• 한국수정란이식학회지
• /
• 제21권3호
• /
• pp.191-198
• /
• 2006

본 연구는 $2001{\sim}2005$년(5년간) 제주도에서 사육중인 제주 한우와 흑우를 체내 수정란의 생산과 수정란 이식 기술을 통하여 조기 증식하고자 실시하였다. 한우 고등 등록우 286두와 흑우 경산우 69두(총 355두)에 대하여 발정 주기에 관계없이 CIDR를 질내에 삽입 후 7일째부터 성선 자극 호르몬($Folltropin^{(R)}-V$) 400 mg을 50 mg씩 균등하게 나누어 4일간 12시간 간격으로 근육주사하였다. 투여 6회째에 CIDR를 제거하였으며, 동시에 $PGF_{2{\alpha}}$ 25mg을 근육 주사하여 과배란을 유기하였다. 공란우의 인공수정은 $PGF_{2{\alpha}}$투여 후 발정을 확인하고 12 시간 간격으로 3회 인공 수정하였으며, 2회 인공 수정시 GnRH $250{\mu}g$을 근육 주사하였다. 수정란 회수는 1차 인공 수정 후 $7{\sim}8$일째에 비외과적 방법으로 채란하였다. 수란우는 CIDR를 7일간 삽입하였다가 제거하는 동시에 $PGF_{2{\alpha}}$ 25 mg을 근육 주사하여 공란우와 발정을 동기화 시켰다. 수정란 이식은 발정이 동기화된 수란우 1,219두에 대하여 6명의 수정란 이식 시술자가 비외과적 방법으로 황체가 존재하는 자궁각에 이식하였다. 한우 및 흑우 공란우의 평균 회수 총 난자수 및 이식 가능 수정란 수는 각각 7.4개 및 4.7개 였으며, 회수 총 난자수는 2 품종간에 차이가 없었으나, 이식 가능 수정란 수는 한우(5.0개)가 흑우(3.5개)에 비해 많았다(p<0.05). 공란우의 반복 과배란 처리에 따라 흑우에서는 과배란처리 두수 대비 수정란 채란우 비율이 감소되었으며(p<0.05), 한우에서는 회수 총 난자수 및 이식 가능 수정란 수의 감소가 나타났다(p<0.05). 과배란 처리 계절에 따른 수정란 회수 성적은 여름(5.6개)이 겨울(2.9개)에 비해 이식 가능 수정란의 수가 많았다(p<0.01). 수정란 이식 후 수태율은 평균 40%를 나타내었으며, 공란우의 품종간 차이가 없었으며, 이식년도가 2001년에서 2004년으로 경과될 때 수태율이 증가하였으며(p<0.05), 수정란 이식 시술자에 따른 수태율의 차이가($33.0{\sim}45.9%$) 인정되었다(p<0.01). 본 연구의 결과는 제주 한우 및 흑우에서 CIDR를 이용한 과배란 처리 및 수란우의 발정동기화 처리는 한우 체내 수정란의 안정적인 생산과 수란우의 준비가 가능함을 보여 주었다.

• 한국가축번식학회지
• /
• 제26권4호
• /
• pp.361-368
• /
• 2002

The onset of pronucleus formation and DNA synthesis in porcine oocytes following the injection of porcine or murine sperm was determined in order to obtain insights into species-specific paternal factors that contribute to fertilization. After 44h in vitro maturation, spermatozoa was injected into the cytoplasm of oocytes. After injection, all oocytes were transferred to NCSU23 medium and cultured at 39'E under 5% CO2 in air. Similar frequencies of oocytes with female pronuclei were observed after injection with porcine sperm or with murine sperm. In contrast, male pronuclei formed 8 to 9 h following the injection of porcine sperm, and 6 to 8 h following the injection of murine sperm. After pronucleus formation maternally derived microtubules were assembled and appeared to move both male and female pronuclei to the oocyte center. A few porcine oocytes entered metaphase 22 h after the injection of murine sperm, but normal cell division was not observed. The mean time of onset of S-phase in male pronuclei was 9.7 h following porcine sperm injection and 7.4 h following mouse sperm injection. These results suggested that DNA synthesis was delayed in both pronuclei until the sperm chromatin fully decondensed, and the sperm nuclear decondensing activity and microtubule nucleation abilities of the male centrosome are cell cycle dependent.