• Title/Summary/Keyword: Characteristic Appearance

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Anatomical Study of Chordodes koreensis in the Parasitic Phase Using Electron Microscopy (개의 구토물에서 분리한 오디흑연가시(철선충)의 전자현미경을 이용한 해부학적 소견)

  • Son, Hwa-Young;Chae, Joon-Seok;Kim, Nam-Soo;Kim, Hyeon-Cheol;Cho, Jeong-Gon;Park, Bae-Keun
    • Journal of Veterinary Clinics
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    • v.26 no.6
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    • pp.586-590
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    • 2009
  • Horsehair worms (Chordodes koreensis) develop as parasites in the bodies of grasshoppers, crickets, cockroaches, and some beetles. Chordodes koreensis is an accidental parasite of humans, livestock, or pets and poses no public health threat. The male of Chordodes koreensis in the later larval stage from canine vomitus was investigated by the scanning and transmission electron microscopy. In cross sections, the body wall is composed of four components namely epicuticle, cuticle, epidermis, and muscle layers. The parenchymal tissue fills the rest of the body and surrounds the visceral organs such as intestine, and ventral nerve cord but testes were not found. The epicuticle is a thin superficial layer whose surface shows rows of polygonal elevations called areoles. The cuticle has 17 layers of collagenous fibers spirally wound about the long axis of the worm. The section through the cuticle reveals the layers of large fibers cut obliquely lengthwise, alternating with layers of fibers sectioned obliquely crosswise. The layers of large fiber formed a double helix about longitudinal axis of the worm. The epidermis is a single layer. The muscles were interrupted by the nervous lamella in the only midventral portion. The medulla of muscle plate is composed of lightly stained cytoplasm, mitochondria, weakly developed endoplasmic reticulum, and glycogen granules. Between the medulla of a cell and the plasmalemma lies a broad cortical zone of myofilaments. The circular muscles are absent. The characteristic feature of the cytoplasm is that there was no content in peripheral mesenchyme, but was an abundance of large clear vacuoles which give the cytosome a foamy appearance. The nucleus of mesenchyme is not easily identified in our specimens.

Hybrid MBE Growth of Crack-Free GaN Layers on Si (110) Substrates

  • Park, Cheol-Hyeon;O, Jae-Eung;No, Yeong-Gyun;Lee, Sang-Tae;Kim, Mun-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.183-184
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    • 2013
  • Two main MBE growth techniques have been used: plasma-assisted MBE (PA-MBE), which utilizes a rf plasma to supply active nitrogen, and ammonia MBE, in which nitrogen is supplied by pyrolysis of NH3 on the sample surface during growth. PA-MBE is typically performed under metal-rich growth conditions, which results in the formation of gallium droplets on the sample surface and a narrow range of conditions for optimal growth. In contrast, high-quality GaN films can be grown by ammonia MBE under an excess nitrogen flux, which in principle should result in improved device uniformity due to the elimination of droplets and wider range of stable growth conditions. A drawback of ammonia MBE, on the other hand, is a serious memory effect of NH3 condensed on the cryo-panels and the vicinity of heaters, which ruins the control of critical growth stages, i.e. the native oxide desorption and the surface reconstruction, and the accurate control of V/III ratio, especially in the initial stage of seed layer growth. In this paper, we demonstrate that the reliable and reproducible growth of GaN on Si (110) substrates is successfully achieved by combining two MBE growth technologies using rf plasma and ammonia and setting a proper growth protocol. Samples were grown in a MBE system equipped with both a nitrogen rf plasma source (SVT) and an ammonia source. The ammonia gas purity was >99.9999% and further purified by using a getter filter. The custom-made injector designed to focus the ammonia flux onto the substrate was used for the gas delivery, while aluminum and gallium were provided via conventional effusion cells. The growth sequence to minimize the residual ammonia and subsequent memory effects is the following: (1) Native oxides are desorbed at $750^{\circ}C$ (Fig. (a) for [$1^-10$] and [001] azimuth) (2) 40 nm thick AlN is first grown using nitrogen rf plasma source at $900^{\circ}C$ nder the optimized condition to maintain the layer by layer growth of AlN buffer layer and slightly Al-rich condition. (Fig. (b)) (3) After switching to ammonia source, GaN growth is initiated with different V/III ratio and temperature conditions. A streaky RHEED pattern with an appearance of a weak ($2{\times}2$) reconstruction characteristic of Ga-polarity is observed all along the growth of subsequent GaN layer under optimized conditions. (Fig. (c)) The structural properties as well as dislocation densities as a function of growth conditions have been investigated using symmetrical and asymmetrical x-ray rocking curves. The electrical characteristics as a function of buffer and GaN layer growth conditions as well as the growth sequence will be also discussed. Figure: (a) RHEED pattern after oxide desorption (b) after 40 nm thick AlN growth using nitrogen rf plasma source and (c) after 600 nm thick GaN growth using ammonia source for (upper) [110] and (lower) [001] azimuth.

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Molecular Aspects of Japanese Encephalitis Virus Persistent Infection in Mammalian Cells

  • Park Sun-Hee;Won Sung Yong;Park Soo-Young;Yoon Sung Wook;Han Jin Hyun;Jeong Yong Seok
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2000.05a
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    • pp.23-36
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    • 2000
  • Japanese encephalitis virus (JEV) is the causative agent of a mosquito-borne encephalitis and is transmitted to human via persistently infected mosquito vectors. Although the virus is known to cause only acute infection, there were reports that showed neurological sequelae, latent infection in peripheral mononuclear cells, and recurrence of the disease after acute encephalitis. Innate resistance of certain cell lines, abnormal SN1 expression of the virus, and anti-apoptotic effect of cullular bcl-2 have been suggested as probable causes of JEV persistence even in the absence of defective interfering (DI) particles. Although possible involvement of DI particles in JEV persistence was suggested, neither has a direct evidence for DI presence nor its molecular characterization been made. Two questions asked in this study are whether the DI virus plays any role in JEV persistent infection if it is associated with and what type of change(s) can be made in persistently infected cells to avoid apoptosis even with the continuous virus replication, DI-free standard stock of JEV was infected in BHK-21, Vero, and SW13 cells and serial high multiplicity passages were performed in order to generate DI particles. There different-sized DI RNA species which were defective in both structural and nonstructural protein coding genes. Rescued ORFs of the DI genome maintained in-frame and the presence of replicative intermediate or replicative form RNA of the DI particles confirmed their replication competence. On the other hand, several clones with JEV persistent infection were established from the cells survived acute infections during the passages. Timing of the DI virus generation during the passages seemed coincide to the appearance of persistently infected cells. The DI RNAs were identified in most of persistently infected cells and were observed throughout the cell maintenance. One of the cloned cell line maintained the viral persistence without DI RNA coreplication. The cells with viral persistence released the reduced but continuous infectious JEV particle for up to 9 months and were refractory to homologous virus superinfection but not to heterologous challenges. Unlike the cells with acute infection these cells were devoid of characteristic DNA fragmentation and JEV-induced apoptosis with or without homologous superinfection. Therefore, the DI RNA generated during JEV undiluted serial passage on mammalian cells was shown to be biologically active and it seemed to be responsible, at least in part, for the establishment and maintenance of the JEV persistence in mammalian cells. Viral persistence without DI RNA coreplication, as in one of the cell clones, supports that JEV persistent infection could be maintained with or without the presence of DI particles. In addition, the fact that the cells with JEV persistence were resistant against homologous virus superinfection, but not against heterologous one, suggests that different viruses have their own and independent pathway for cytopathogenesis even if viral cytopathic effect could be converged to an apoptosis after all.

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Antioxidant Activity and Quality Characteristics of Pork Patties Added with Saltwort (Salicornia herbacea L.) Powder (함초(Salicornia herbacea L.)분말을 첨가한 돈육패티의 항산화활성 및 품질특성)

  • Joo, Shin Youn;Choi, Hae Yeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.8
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    • pp.1189-1196
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    • 2014
  • This study investigated the effects of saltwort powder on the antioxidant activity and quality characteristics of patties added with saltwort powder. Patties were prepared with different amounts (0, 1, 2, and 3%) of saltwort powder. The total phenolic content, DPPH free radical scavenging activity, and pH of patties increased with increasing saltwort powder content (P<0.05). In particular, the moisture content and cooking loss of the group added with 2% saltwort powder were the highest and lowest, respectively (P<0.05). As the content of saltwort powder increased, $L^*$ and $a^*$ values decreased while $b^*$ value increased. Texture analysis showed that the hardness, chewiness, and gumminess of the control group were lower than those of the treated group (P<0.05). Consumer acceptability showed that 1% and 2% saltwort powder groups scored higher in terms of overall preference, appearance, color, taste, and texture compared to the other groups. Characteristic intensity rating of saltwort patties showed that as more saltwort powder was added, saltwort taste intensified; however, the increase did not affect juiciness, off flavor, or salty taste of the patties. Judging from the results, it was concluded that the addition of saltwort powder to patties in processing can enhance the preference, quality, and antioxidant activities of the patties, which elevates the value of patties.

The Likert Scale Attention Points Applied to Research on Attitude and Interests on Science Education (과학교육의 태도와 흥미 연구에서 리커트 척도 활용의 유의점)

  • Park, HyunAe;Bae, Sungwoo;Park, Jongseok
    • Journal of The Korean Association For Science Education
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    • v.34 no.4
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    • pp.385-391
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    • 2014
  • We use a scale mainly for quantification when we study the psychological characteristics that we cannot observe. The utilization of a scale is frequent in scientific educational studies. The convenience offered by Likert scale, which is among the most frequently used, enable us to grasp characteristic attitude or recognition in students, and evaluate them against an affective domain. But a lot of errors occur, and has been noted as well in the case of utilizing Likert scale in the process. A central tendency in the utilization of Likert scale appears in this study, and the trend analyzes according to study objects and study contents, but we intend to find a way to utilize Likert scale. The results of study made on our countryside students show that the answers tend to get concentrated and a central tendency appears. Our countryside students were aware of the eyes surroundings them, have respect for elders through social experiences, and have had troubles with differentiated expression or personality in the group and cultural environments. According to the object of study, the central tendency appears more among older students than younger students, more among general students than gifted students. In the contents of study, the central tendency has been given more appearance in scope and their exposure has relatively been in large domain. Therefore when utilizing Likert scale in scientific education study, an error of central tendency appears as if they are results of the study. So, when applying the Likert scale to scientific study, we need to consider sociocultural environment, characteristics of an object and contexts of study. This enables avoiding dependence on numerical value of the utilization results, and interpret them correctly.

Quality Characteristics of Pudding Using Tarak, Traditional Fermented Milk (전통발효유 타락을 이용한 푸딩의 품질 특성)

  • Ko, Seong-Hee;Lee, Kyung-Yeoun
    • Culinary science and hospitality research
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    • v.20 no.3
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    • pp.90-99
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    • 2014
  • Tarak is our own traditional fermented milk, which is made from lactic acid fermentation by using makgeolli as inoculum for milk or fermented by using Tarak that had already made. we made our own traditional fermented milk and Tarak Pudding by the traditional fermented milk, and then, we investigated the quality characteristics of Tarak Pudding on the addition rates of Tarak. As a result, the more the amount of Tarak, the more the contents of crude protein, crude fat and crude ash of Tarak Pudding according to the percentage of addition of Tarak meaningfully, except for its moisture content (p<0.05). While the pH decreased with more Tarak, the acidity significantly increased. In the case of sugar content, TP 1, 2, and 3 were higher than the control group, and TP 4 showed the higher sugar content(p<0.05). As the result of measurement of chromaticity of Tarak Pudding, the L value of the control group was 38.80. However, it increased with more addition of Tarak, while a value decreased. For the b value, it significantly increased with more Tarak. In the measure of texture, there were significant differences between the control group and the samples in hardness, springiness, cohesiveness, chewiness, and adhesiveness (p<0.05). The sensory evaluation result showed that there were meaningful differences among the samples in their appearance, taste, flavor, texture and overall acceptance. However, due to distinctive sour and odor of Tarak, TP 3 (75% addition) than TP 4 (100% addition) was considered to be desirable.

A study on the Characteristics of the Adult Men Sound as by Sasang Constitution Analysed with PSSC-2004 (사상체질음성분석기(四象體質音聲分析機)(PSSC-2004)를 통한 성인남성(成人男性)의 체질별(體質別) 음향특성(音響特性))

  • Kim, Dong-Jun;Jung, Woon-Ki;Choi, Jae-Wan;Kim, Dal-Rae;Jeon, Jong-Weon
    • Journal of Sasang Constitutional Medicine
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    • v.17 no.1
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    • pp.67-83
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    • 2005
  • 1. Objectives The purpose of this study lies on the objectification of the Sasang Constitutional diagnosis. This study was analyzing the constitutional characteristic of adult men voices by PSSC-2004. 2. Methods The study was conducted on the subjects inputted /a/ 2.5-3 sec of 231 adult men voices to PSSC-2004. The statistical analyses are applied to three groups: total group, under 55 year-old group, over 55 year-old group. The group of total 231 was composed with 5 Taeyangins, 32 Soyangins, 102 Taeumins and 92 Soeumins. The under 55 years old group was composed with 4 Taeyangins, 23 Soyangins, 83 Taeumins and 77 Soeumins. The over 55 year-old group was composed with 1 Taeyangin, 9 Soyangins, 19 Taeumins and 15 Soeumins. 3. Results 1) In total group, the Soeumin's mean value of center pitch(4)$(1,000{\sim}2,000Hz)$ was significantly high compared with the others (P=0.034). 2) In total group, the Soeumin's group 3 APQ was significantly low compared with the others (P=0.042). 3) In under 55 year-old group, the Soeumin's center value of center pitch 4$(1,000{\sim}2,000Hz)$ was significantly high compared with the others (P=0.025) 4) In over 55 year-old group, no statistical significance was found between the Taeyangin, Soyangin, Taeumin and Soeumin. 4. Conclusions In under 55 year-old group, Soeumin's voice showed high pitched sound (clearness) at the low frequency (1000-2000Hz). In over 55 year-old group, there is no significant differences. This fits in with that 'Soeumin's voice is 'Yu-tone' born by 'Shang-tone', very short and high.' 'Yu-tone' corresponds to 'Ra' and witch is highest among Gong, Shang, Gao, Chi and Yu. This is related with the appearance that the Soeumin's voice is weak, thin and high tone. Therefore it is supposed that Soeumin adult men's voices are thick, and there are vibrations of the ending. It is accepted one of the Soeumin's characters like as a mild tremor of limbs and deep breath caused by Soeumin's Qi-deficiency. This outcome accords with the theory that Soeumin's Qi is less than the Other constitutions.

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Antibacterial activity and sensory characteristic of sauce for raw fish with tea extract and garlic vinegar (차추출물과 마늘식초를 이용한 생선회용 소스의 항균활성 및 관능특성)

  • Han, Young Sun;Choi, Hye Jin;Lee, Seung Ri;Kwon, Mun-Ju;Heo, Myung Je;Jo, Nam-Gyu;Kim, Hye Young
    • Food Science and Preservation
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    • v.23 no.5
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    • pp.704-710
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    • 2016
  • This study was conducted to investigate the antibacterial activities and sensory properties of a sauce containing tea extract and garlic vineger against raw fish. The sauce was evaluated antibacterial activity against Vibrio parahaemolyticus and Vibrio vulnificus which is considered as one of the major food borne pathogens. As a result, the sauce inhibited the growth of V. parahaemolyticus and V. vulnificus distinctly. In addition, the sauce with soy sauce and Kochujang showed the restricted growth of Vibrio parahaemolyticus and Vibrio vulnificus in sliced raw flatfish. Sensory evaluations were measured by 7-point hedonic scale using sliced raw flatfish with the sauce mixed with Kochujang and soy sauce. The score of texture in the sauce with Kochujang was significantly higher than that of regular Chokochujang (p<0.05). Moreover, total preference including appearance, texture, aroma and taste were significantly higher in the sauce with soy sauce than those of regular soy sauce (p<0.05). Consequently, the soy sauce with tea extract and garlic vinegar may enhance the satisfaction of consumer and antimicrobial activity that against V. parahaemolyticus and V. vulnificus, resulting in potential reduction the outbreaks of food borne pathogens.

Transmission of Paulownia witches'-broom virus by tobacco leaf bug, Cyrtopeltis tenuis REUTER (담배장님노린재 (Cyrtopeltis tenuis REUTER)에 의한 오동나무천구 소병(도깨비집병) 바이러스의 매개전염)

  • La Y. J.;Pyun B. H.;Shim K. J.
    • Korean journal of applied entomology
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    • v.5_6
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    • pp.1-7
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    • 1968
  • The present investigation was initiated to find out the possible insect vector of the paulownia witches'-broom virus disease. 1. Among a number of piercing-sucking mouth type insects that were feeding on the witches'-broom infected Paulownia leaves, the tobacco leaf bug, Cyrtopeltis tenuis REUTER, was most abundant. Eggs, nymphs and adults of Cyrtopeltis tenuis were observed from the mid-August through the end of October. 2. It was found that Paulownia witches'-broom virus is transmitted by Cyrotopeltis tenuis. 3. On young Pnulownia plants, first symptom appeared twenty days after exposure to virus-bearing colonies of Cyrtopeltis tenuis. Forty days after exposure to these viruliferous insects, the characteristic symptom of Paulownia witches'-broom was apparent. 4. Paulownia witches' -broom virus was also transmitted by Cyrtopeltis tenuis to calendula and morning glory. No app"rent symptom was observed from tomato, carrot. aster, zinnia, cosmos, soybean and plantago at least until sixty days after exposure to the viruliferous colonies of Cyrtopeltis tenuis. 5. Calendula and morning glory appear to be highly suitable test plants for Paulownia witches'-broom vims because of their relatively short incubation period and distinct symptom appearance.

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Effect of Cation Substitution on the Lattice Vibration and Crystal Structure of Magnetic RuSr1.9A0.1GdCu2O8 (A = Ca, Sr, and Ba) Superconductors

  • Kim, Tae-Woo;Yang, In-Sang;Hwang, Seong-Ju
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2559-2562
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    • 2009
  • The lattice vibration and crystal structure of alkaline earth metal-substituted $RuSr_{1.9}A_{0.1}GdCu_{2}O_{8}$ (A = Ca, Sr, and Ba) have been investigated with micro-Raman spectroscopy. The present $RuSr_{1.9}A_{0.1}GdCu_{2}O_{8}$ materials show not only several weak Raman peaks corresponding to the vibrations of $O_{Cu}$ and $O_{Ru}$ but also strong characteristic phonon lines related to $O_{Sr}$ vibration mode. A comparison between the frequency of $O_{Sr}$ vibration and the bond distances of (Ru$O_{Sr}$) and (Cu‒$O_{Sr}$) in the present ruthenocuprates reveals that the vibration energy of $O_{Sr}$ is mainly dependent on the bond distance of (Ru‒$O_{Sr}$). The peak splitting of the $O_{Sr}$ phonon lines was observed for the unsubstituted $RuSr_{1.9}A_{0.1}GdCu_{2}O_{8}$, suggesting the existence of two different (Ru‒$O_{Sr}$) bond distances. Such a peak splitting caused by the appearance of low-energy shoulder reflects the presence of internal charge transfer pathway from the $RuO_2$ plane to the superconductive $CuO_2$ one. After the substitution of Sr with Ca or Ba, the low-energy shoulder peak of $O_{Sr}$ vibration becomes suppressed, underscoring the depression of internal charge transfer between the $RuO_2$ and $CuO_2$ planes. The weakened role of $RuO_2$ layer as charge reservoir in the $RuSr_{1.9}A_{0.1}GdCu_{2}O_{8}$8 (A = Ca, Ba) would be responsible for the depression of $T_c$ upon the Ca/Ba substitution.