• Title/Summary/Keyword: Weak localization

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Ultrastructural Localization of ZnT3 and Zinc Ions in the Mouse Choroid Plexus (생쥐 맥락얼기에 분포하는 ZnT3 및 zinc 이온의 조직화학적 동정)

  • Kim, Sung-Joo;Kim, Yong-Kuk;Sun, Yuan-Jie;Kim, Soo-Jin;Jeong, Young-Gil;Yu, Yun-Cho;Jo, Seung-Mook
    • Applied Microscopy
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    • v.32 no.4
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    • pp.377-383
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    • 2002
  • We have detected the murine zinc transporter, ZnT3, and zinc ions in the mouse choroid plexus by immunocytochemistry (ICC) and zinc selenium autometallography ($ZnSe^{AMG}$), respectively. BALB/c mice served as experimental animals. Routine floating ABC immunocytochemical procedures were used for the ZnT3 immunocytochemistry, and the mice were injected intraperitoneally (i.p.) with sodium selenide (10 mg/kg) for the zinc selenium autometallography. The choroid plexus showed weak immunoreactivity (Ir) for ZnT3. At high magnification, ZnT3-Ir was seen to be located in the choroid epithelium and the connective tissue of the capillaries. At the EM level, a high electron density of ZnT3-immunoreactivity was restricted to vesicle membranes as well as microvilli in the apical membrane. In contrast, immunostaining of ZnT3 was completely absent in the basolateral plasma membrane and other cell organelles. After silver enhancement, fine $ZnSe^{AMG}$ grains were observed in both the epithelial and endothelial cells of the choroid plexus. Few $ZnSe^{AMG}$ grains present in the cell bodies of the choroid epithelial cells were located in multivesicular bodies. It is striking that very many $ZnSe^{AMG}$ grains were observed in the endothelial cells of the capillaries. These findings establish the choroid plexus as a non-neuronal pool of zinc ions in the brain, although the functional significance of this pool is not clear. The choroid epithelium, however, may play an important role in the transportation of zinc between the CSF and brain tissue.

Expression characterization and transcription regulation analysis of porcine Yip1 domain family member 3 gene

  • Ni, Dongjiao;Huang, Xiang;Wang, Zhibo;Deng, Lin;Zeng, Li;Zhang, Yiwei;Lu, Dongdong;Zou, Xinhua
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.3
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    • pp.398-407
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    • 2020
  • Objective: The Yip1 domain family (YIPF) proteins were proposed to function in endoplasmic reticulum (ER) to Golgi transport and maintenance of the morphology of the Golgi, which were homologues of yeast Yip1p and Yif1p. YIPF3, the member 3 of YIPF family was a homolog of Yif1p. The aim of present study was to investigate the expression and regulation mechanism of porcine YIPF3. Methods: Quantitative realtime polymerase chain reaction (qPCR) was used to analyze porcine YIPF3 mRNA expression pattern in different tissues and pig kidney epithelial (PK15) cells stimulated by polyinosine-polycytidylic acid (poly [I:C]). Site-directed mutations combined with dual luciferase reporter assays and electrophoretic mobility shift assay (EMSA) were employed to reveal transcription regulation mechanism of porcine YIPF3. Results: Results showed that the mRNA of porcine YIPF3 (pYIPF3) was widely expressed with the highest levels in lymph and lung followed by spleen and liver, while weak in heart and skeletal muscle. Subcellular localization results indicated that it expressed in Golgi apparatus and plasma membranes. Upon stimulation with poly (I:C), the level of this gene was dramatically up-regulated in a time- and concentration-dependent manner. pYIPF3 core promoter region harbored three cis-acting elements which were bound by ETS proto-oncogene 2 (ETS2), zinc finger and BTB domain containing 4 (ZBTB4), and zinc finger and BTB domain containing 14 (ZBTB14), respectively. In which, ETS2 and ZBTB4 both promoted pYIPF3 transcription activity while ZBTB14 inhibited it, and these three transcription factors all played important regulation roles in tumorigenesis and apoptosis. Conclusion: The pYIPF3 mRNA expression was regulated by ETS2, ZBTB4, and ZBTB14, and its higher expression in immune organs might contribute to enhancing ER to Golgi transport of proteins, thus adapting to the immune response.

Impact of National Culture on Service Quality Evaluations : Comparison of Korea and Anglo-Saxon Countries (국가문화가 서비스품질의 평가에 미치는 영향 : 한국과 영·미권 국가의 비교)

  • Nam, Sung-Jip
    • Journal of Distribution Science
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    • v.13 no.11
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    • pp.93-100
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    • 2015
  • Purpose - The objective of this research is to investigate whether national culture influences consumers' service evaluations. The services industry is receiving increasing attention from academia and practitioners as its position grows in global markets. Standardization or localization is a traditional managerial decision in global business. As the boundaries of services expand across national borders, firms are required to decide whether to standardize services or adjust to local needs. Though it is imperative to reflect global perspectives in marketing theories, these perspectives are mostly based on Western conceptualization of the world. Through a comparison of consumer groups from two culturally remote countries, service quality evaluation mechanisms are examined based on similar stimuli. The study tries to expand service marketing perspectives across national borders. Research design, data, and methodology - Eastern and Western countries are known to be culturally distinct. One Eastern and one Western country were chosen: an Anglo-Saxon country (the U.S., England, and Australia) and South Korea. In Hofstede's cultural dimensions, the differences between the two are pronounced. The Anglo-Saxon based countries share many similarities. Samples of the same sites are targeted. Questionnaires using a service quality scale (SERVQUAL) and a customer satisfaction scale were distributed. Utilizing Hofstede's typology of culture, the service evaluation mechanisms of the respondents from the two groups are evaluated. Three hypotheses are proposed from the review of the literature. These are service evaluation habits, importance of service quality dimensions for the individualistic/collectivistic countries, and strong/weak uncertainty avoidance cultures. Consumers from the individualistic countries are considered to care about themselves and demand a higher level of responsiveness and assurance. On the other hand, consumers from high uncertainty avoidance cultures are assumed to rely more on tangible questions of service quality, as these are the only predictable service quality indicators. A t-test and regression analysis are applied to validate the constructs. Results - The respondents from the Anglo-Saxon countries are more generous on service evaluations than Koreans. Researchers have indicated that Americans tend to give higher service evolution scores than European, Mexican, and Korean counterparts. The tendency is the same here. The sample from Anglo-Saxon countries demonstrated higher service evaluation scores on every dimension of SERVQUAL. For the second hypothesis, the respondents from the collectivistic culture rely less on core service dimensions (assurance and responsiveness) due to their tendency to place more value on group harmony than individual interest. However, the third hypothesis was not validated. Conclusions - The study attempted to expand the scope of service marketing to reflect cross-national perspectives. Service quality is known to have a strong influence on customer satisfaction and loyalty behavior. However, this research demonstrated that individuals from different cultural territories respond heterogeneously to the same stimuli. Scholars argue that national cultures are main factors in such deviated behavior. Scholars and global managers should be aware of differences in consumer value judgment mechanisms such as satisfaction, expectations, and perceptions.

Immuno-Electron Microscopic Studies on the Localization of Serotonin and Somatostatin in the Optic Lobes of Cephalopods (Todarodes pacificus and Octopus minor) Inhabiting the Korean Waters (한국 연근해산 두족류 (Todarodes pacificus and Octopus minor) 시엽 (Optic lobe)내 Serotonin 및 Somatostatin의 분포에 관한 면역전자현미경적 연구)

  • Chang, Nam-Sub;Han, Jong-Min;Kim, Sang-Won;Lee, Kwang-Ju;Hwang, Sun-Jong;Lee, Jung-Chan
    • Applied Microscopy
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    • v.32 no.3
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    • pp.247-255
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    • 2002
  • In this study, we carried out immunostaining and immunogold labeling with antibodies to serotonin and somatostatin to examine the characteristics and functions of the neurons that secrete neurotransmitters in optic lobes of Todarodes pacificus and Octopus minor. As a result of immunostaining with anti-somatostatin, the nerve cells of Todarodes pacificus reacted as similar to the anti-serotonin, but in Octopus minor, only large cells in the outer granule cell layer reacted positively. In the immunogold labeling with anti-serotonin, the nerve cells in the inner grande cell layer and medulla of Todarodes pacificus reacted strongly, 30 gold particles being labeled per $0.5{\mu}m^2$ of the cytoplasm. However, in Octopus minor, only 17 gold particles were labeled, which stated a weak reaction. On the other hand, in the anti-somatostatin case, the nerve cells in the outer and inner granule cell layers and medulla of Todarodes pacificus showed strong reaction, 30 gold particles being labeled per $0.5{\mu}m^2$ of the cytoplasm while the nerve cells in the outer granule cell layer of Octopus minor reacted weakly, about 3 gold particles being labeled per the equivalent area. As a result of immunostaining and immunogold labeling with two types of antibodies to each part of the optic lobes, we found that the reactive nerve cells were distributed differently in the two species. In particular, the degree of reactivity to the immunostaining and immunogold labeling appeared stronger in Todarodes pacificus than in Octopus minor.

Immunocytochemistry of Metallothionein Expression in Developing Rat Liver (발생중인 흰쥐 간에서의 Metallothionein 발현에 관한 면역세포화학적 연구)

  • Oh, Seung-Han;Ahn, Young-Mo;Shin, Kil-Sang;Kim, Wan-Jong
    • Applied Microscopy
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    • v.34 no.3
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    • pp.171-178
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    • 2004
  • Metallothionein (MT) is a family of ubiquitous, low molecular weight (6-7 kDa), cysteine-rich protein with a high affinity to metal ions and has no aromatic amino acids and histidine. Some of the known functions of MT include detoxification of heavy metals and alkylating agents and neutralization of free radicals. Also, this protein may affect a number of cellular processes including gene expression, apoptosis, proliferation and differentiation. But, its actual functions are still not clear. The present study was undertaken to examine immunocytochemically the localization of MT in developing rat liver. On the day 11 of gestation, the fetal rat liver has already been formed and contained numerous oval cells with high nuclear cytoplasmic ratio, which were the progenitors of hepatic parenchymal cells, but no reaction products of MT were detected at this time. And then, positive reactions against MT started to appear predominantly in the parenchymal cells of liver from the 13th day after gestation. Reaction products, immunogold particles or brown coloration, were localized at both the nucleus and the cytoplasm of the parenchymal cells, except mitochondria. The intensity of this reaction gradually increased, and exhibited the strongest at birth. The intensity of MT staining and immunogold labelling diminished with growth, and by the 15th day after birth weak positive reaction was observed in the cells. In brief, positive reactions for MT were observed in the oval cells and the parenchymal cells during fetal stage, meanwhile they were present only in the parenchymal cells after birth. The present results suggest that MT possibly involves parechymal cell proliferation and differentiation through the storage or the supply of various metal ions in the developing rat liver.

Localization and characteristics of lactate and palate dehydrogenase in the sparganum and adult worm of Spirometra erinacei (만손열두조충에서 젖산탈수소효소와 말산탈수소효소의 분포와 특징)

  • Gwak, Gi-Hun;Jeon, Eun-U;Kim, Chang-Hwan
    • Parasites, Hosts and Diseases
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    • v.34 no.1
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    • pp.59-68
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    • 1996
  • This study investigated the enzyme histochemical localization and characteristics of lactate (LDH) and malate dehydrogenase (MDH) related with the oxidation-reduction metabolism in the sparganum and adult of 5. erinacei. By enzyme histochemical assay, activity of LDH was strong in the tegument and subtegumental muscle layers of the adult and sparganum. Activity of MDH was strong in the tegument of the sparganum and subtegumental muscle layers of the adult. However it was weak in the tegument of the adult. By electrophoresis, 45 kDa band was major and common in LDH of adults and spargana. The 150 kDa molecule was the major and common band in MDH of adults and r -spargana (from experimentally infected rats) . By isoelectrofocusing, isoelectric points (Pl) or 4 MDH isogyme from adult worm were 6.0.6.5, 6.7 and 7.1, respectively. Pl 6.0 was the major band. The active range of pH for MDH was about pH 6-8 and the optimum pH was pH 7 The effective temperature on the MDH was about $30^{\circ}C$$50^{\circ}C$ and the optimum temperature was about 40℃ in spargana md adult worm. In the stability against heat, when MDH was heated at 85℃ for 10 seconds, the activity was denatured perfectly. Maximum activity or MDH was 19.4 unit in the s-sparganum (from snakes), 24.5 unit in the r-sparganum (from rats) and 108.0 unit in the adult worm. The maximum activity was higher in adults than in spargana. The present result showed us that the nutrients absorbed through the tegument were transferred into inner tissues and were utilized as the source of metabolism. According to the habitat of the parasite, the isozymes of LDH and MDH are activated differently, and by this different activation the sparganum and adult can adapt themselves to parasitic circumstances.

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The Changes of System Design Premises and the Structural Reforms of Korean Government S&T Development Management System (시스템 설계전제의 변화와 공공부문 과학기술발전관리시스템 구조의 개혁)

  • 노화준
    • Journal of Technology Innovation
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    • v.5 no.2
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    • pp.1-21
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    • 1997
  • The objective of this paper is to think about what structural reforms of the Korean government S&T development management system might be. Korean society is currently experiencing a drastic socio-economic transformation. The results of this transformation should be reflected on the determining process of the directions and breadths of structural reforms of government S&T development management system. Because the government system design will be based on the premises of socio-economic conditions under which administrative activities perform and also this socio-economic changes can influence on changes of the premises of government management system design. Moreover, S&T development management system is a subsystem of government system so that the directions of structural reform of those subsystems should be considered in the broad framework changes in the development management system of the government. For the last forty years, the Korean government S&T development management system has been based on the premises including transformation from an agrarian society to an industrial society, authoritarianism and centrally controlled institutions, and exteremely small portions of private investments for science and thechonology R & D of the total. Recently, however, the premises of Korean government S&T development management system have rapidly changed. the characteristics of these changes are including tranformation from an industrial society to a knowledge and information intensive society, globalization, localization, and relatively large portion of private investments for science and technology R & C of the total. The basis of government reforms in Korea was the realization of the performances and values through the enhancement of national competitive capacity, attainment of lean government, decentralization and autonomy. However, the Korean government has attached a symbolic value of strategic organizations representing strong policy intentions of government for the science and technology based development. Most problems associated with the Korean government S&T development management system have grown worse during 1990s. Many people perceive that considerable part of this problem was generated because the government could not properly adapt itself to new administrative environment and the paradigm shift in its role. First of all, the Korean government S&T development management system as a whole failed to develop an integrated vision under which processes in formulating science and thechology development goals and developing consistent government plans concerning science and technology development are guided. Second, most of the local governments have little organizational capacity and manpowers to handle localized activities to promote science and technology in their regions. Third, the measure to coordinate and set priorities to invest resources for the development of science and technology was not effective. Fourth, the Most has been losing its reputation as the symbol of ideological commitment of the top policy maker to promote science and technology. Various ideas to reform government S&T development management system have been suggested recently. Most frequently cited ideas are as follow : (ⅰ)strengthen the functions of MoST by supplementing the strong incentive and regulatory measures; (ⅱ)create a new Ministry of Education, Science & Technology and Research by merging the Ministry of Education and the MoST; (ⅲ)create a new Ministry of Science & Technology and Industry ; and(ⅳ)create a National Science and Technology Policy Council under the chairmanship of the President. Four alternatives suggested have been widely discussed among the interested parties and they each have merits as well as weaknesses. The first alternative could be seen as an alternative which cannot resolve current conflicts among various ministries concerning priority setting and resource allocation. However, this alternatives can be seen as a way of showing the top policymaker's strong intention to emphasize science and technology based development. Second alternative is giving a strategic to emphasize on the training and supplying qualified manpower to meet knowledge and information intensive future society. This alternative is considered to be consistent with the new administrative paradigm emphasizing lean government and decentralization. However, opponents are worrying about the linkages and cooperative research between university and industry could be weakening. The third alternative has been adopted mostly in nations which have strong basic science research but weak industrial innovation traditions. Main weakness of this alternative for Korea is that Korean science and technology development system has no strong basic science and technology research traditions. The fourth alternative is consistent with new administrative paradigms and government reform bases. However, opponents to this alternative are worried that the intensive development of science and technology because of Korea's low potential research capabilities in science and technology development. Considerning the present Korean socio-economic situation which demands highly qualified human resources and development strategies which emphasizes the accumulations of knowledge-based stocks, I would like to suggest the route of creating a new Ministry of Education, Science & Technology and Research by intergrating education administration functions and science & technology development function into one ministry.

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High quality topological insulator Bi2Se3 grown on h-BN using molecular beam epitaxy

  • Park, Joon Young;Lee, Gil-Ho;Jo, Janghyun;Cheng, Austin K.;Yoon, Hosang;Watanabe, Kenji;Taniguchi, Takashi;Kim, Miyoung;Kim, Philip;Yi, Gyu-Chul
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.284-284
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    • 2016
  • Topological insulator (TI) is a bulk-insulating material with topologically protected Dirac surface states in the band gap. In particular, $Bi_2Se_3$ attracted great attention as a model three-dimensional TI due to its simple electronic structure of the surface states in a relatively large band gap (~0.3 eV). However, experimental efforts using $Bi_2Se_3$ have been difficult due to the abundance of structural defects, which frequently results in the bulk conduction being dominant over the surface conduction in transport due to the bulk doping effects of the defect sites. One promising approach in avoiding this problem is to reduce the structural defects by heteroepitaxially grow $Bi_2Se_3$ on a substrate with a compatible lattice structure, while also preventing surface degradation by encapsulating the pristine interface between $Bi_2Se_3$ and the substrate in a clean growth environment. A particularly promising choice of substrate for the heteroepitaxial growth is hexagonal boron nitride (h-BN), which has the same two-dimensional (2D) van der Waals (vdW) layered structure and hexagonal lattice symmetry as $Bi_2Se_3$. Moreover, since h-BN is a dielectric insulator with a large bandgap energy of 5.97 eV and chemically inert surfaces, it is well suited as a substrate for high mobility electronic transport studies of vdW material systems. Here we report the heteroepitaxial growth and characterization of high quality topological insulator $Bi_2Se_3$ thin films prepared on h-BN layers. Especially, we used molecular beam epitaxy to achieve high quality TI thin films with extremely low defect concentrations and an ideal interface between the films and substrates. To optimize the morphology and microstructural quality of the films, a two-step growth was performed on h-BN layers transferred on transmission electron microscopy (TEM) compatible substrates. The resulting $Bi_2Se_3$ thin films were highly crystalline with atomically smooth terraces over a large area, and the $Bi_2Se_3$ and h-BN exhibited a clear heteroepitaxial relationship with an atomically abrupt and clean interface, as examined by high-resolution TEM. Magnetotransport characterizations revealed that this interface supports a high quality topological surface state devoid of bulk contribution, as evidenced by Hall, Shubnikov-de Haas, and weak anti-localization measurements. We believe that the experimental scheme demonstrated in this talk can serve as a promising method for the preparation of high quality TI thin films as well as many other heterostructures based on 2D vdW layered materials.

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