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Growth and Characterization of AgGa$Se_2$ Single Crystal Thin Films by Hot Wall Epitaxy (Hot Wall Epitaxy (HWE)법에 의한 AgGa$Se_2$ 단결정 박막 성장과 특성)

  • Hong, Gwang-Jun;Lee, Gwan-Gyo;Park, Jin-Seong
    • Korean Journal of Materials Research
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    • v.11 no.5
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    • pp.419-426
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    • 2001
  • The stochiometric $AgGaSe_2$ polycrystalline mixture of evaporating materials for the $AgGaSe_2$ single crystal thin film was prepared from horizontal furnace. To obtain the single crystal thin films, $AgGaSe_2$ mixed crystal and semi-insulating GaAs(100) wafer were used as source material and substrate for the Hot Wall Epitaxy (HWE) system, respectively. The source and substrate temperature were fixed at$ 630^{\circ}C$ and $420^{\circ}C$, respectively. The thickness of grown single crystal thin films is 2.1$\mu\textrm{m}$. The single crystal thin films were investigated by photoluminescence and double crystal X-ray diffraction(DCXD) measurement. The carrier density and mobility of AgGaSe$_2$ single crystal thin films measured from Hall effect by van der Pauw method are $4.89\Times10^{17}$ cm$^{-3}$ , 129cm2/V.s at 293K, respectively. From the Photocurrent spectrum by illumination of perpendicular light on the c-axis of the AgGaSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting $$\Delta$S_{o}$ and the crystal field splitting $\Delta$C$_{r}$, were 0.1762eV and 0.2474eV at 10K, respectively. From the photoluminescence measurement of AgGaSe$_2$ single crystal thin film, we observed free excision (EX) observable only in high quality crystal and neutral bound exciton ($D^{o}$ , X) having very strong peak intensity. And, the full width at half maximum and binding energy of neutral donor bound excition were 8mev and 14.1meV, respectively. By Haynes rule, an activation energy of impurity was 141 meV.ion energy of impurity was 141 meV.

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Analysis Corrosion Products Formed on the Great Buddha Image of Kotokuin Temple in Kamakura (고덕원 국보 동조아미타여래좌상의 표면에 생성한 부식생성물의 해석)

  • Matsuda Shiro;Aoki Shigeo;Kang, Dai-il
    • 보존과학연구
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    • s.17
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    • pp.161-182
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    • 1996
  • In natural atmosphere, copper and copper alloy have been used to make buddha statues and ornaments of historic buildings since the abovementioned metals have corrosion resistance in some extent, and the patinaformed on the surface of the metals has provided the people aesthetic satisfaction with its beauty. But in atmosphere polluted by $SO_x$and $NO_x$, the patina layer does not work as a protective film, and it allows damages of the metal. Since 1992, Tokyo National Research Institute of Cultural Properties(TNRICP)has conducted studies on the influence of atmospheric pollution on metal cultural property held under open air. The Great Buddha Image which is located in Kamakura about 50km west from Tokyo, has been selected as one of the objects to study because it is made by copper alloy and it has stood exposed in the air for about a few hundreds years. Furthermore it is also the reason to study on it that there are many cultural properties in the surroundings of it. We have analysed the components and the structure of the corrosion products formed on the surface of the Buddha, have carried out exposure tests using the alloy samples which have simulated the components of the Great Image, and have observed climated and polluted air in order to discuss the relation between corrosion of metals in open air and conditions of the atmosphere. In this paper, the authors have described the components and the structure of the corrosion product formed on the surface of the Great Image by means of X-ray fluorescence spectroscopy and X-ray diffraction. The conclusions are as follows. (1) Sulfate patina composed mainly with brochantite were detected on the all sides of the Image and the amount of the patina is found more on the back of the Image facing to north. (2) Antlerite were detected on the back and a park of the left side facing to west, and formation of it was considered to have close relation with malignant atmosphere. (3) A big amount of chloride patina which mainly composed of atacamite were observed on the front facing to south. (4) Carbonate patina mainly composed of malachite were detected on the area where brochantite was often detected as well. It suggested that malachite had been transformed into brochantite by deteriorated atmosphere. (5) On the all sides of the Image, patina were observed together with copper oxides mainly composed of cuprous oxide. It showed that the surface layer of the Image consists of two layers : inner layer of oxide and outer layer of patina. (6) Corrosion products of lead which was a component of copperalloy were detected on the all sides : the main lead product found on the front was chlorophosphate whereas the one on the back was sulfate.

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Relationship between iron deficiency anemia and febrile convulsion in infants (영아에서 철결핍 빈혈과 열성경련과의 상관관계)

  • Jun, Youn Soo;Bang, Ho Il;Yu, Seung Taek;Shin, Sae Ron;Choi, Du Young
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.392-396
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    • 2010
  • Purpose : The association between iron deficiency anemia and febrile convulsion in infants has been examined in several studies with conflicting results. Therefore, the authors aimed to evaluate the precise relationship involved. Methods : In this case-control study, the authors assessed 100 children with a diagnosis of febrile convulsion, aged between 9 months and 2 years, during January 2007 to July 2009. The control group consisted of 100 febrile children without convulsion; controls were closely matched to the cases by age, gender, and underlying disease. Results : The mean ages of the febrile convulsion and control group were $16.3{\pm}7.4$ and $15.8{\pm}6.1$ months, respectively, and the two groups had no differences in clinical features. Iron deficiency anemia (Hb <10.5 gm/dL) was more frequent in the febrile convulsion group than in the control group, although there was no statistical significance. Unexpectably, the RDW (red blood cell distribution width) was significantly lower and the MCNC (mean corpuscular hemoglobin concentration) was significantly higher among seizure cases than among the controls (P <0.05). There is no statistical difference between simple and complex febrile groups in the clinical and laboratory profiles. On multiple logistic regression analysis, iron deficiency anemia was more frequent, but the RDW was lower, among the cases with febrile convulsion, compared with the controls. Conclusions : Our study suggests that the iron deficiency anemia is associated with febrile convulsion, and screening for iron deficiency anemia should be considered in children with febrile convulsions.

Effect of Temperature on Hatchability of Overwintering Eggs and Nymphal Development of Pochazia shantungensis (Hemiptera: Ricaniidae) (갈색날개매미충(Pochazia shantungensis) 월동알 부화와 약충 발육에 미치는 온도의 영향)

  • Choi, Duck-Soo;Ko, Sug-Ju;Ma, Kyeong-Cheul;Kim, Hyo-Jeong;Lee, Jin-Hee;Kim, Do-Ik
    • Korean journal of applied entomology
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    • v.55 no.4
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    • pp.453-457
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    • 2016
  • This study investigates the hatching periods and hatchability of the eggs of Pochazia shantungensis at different collection times from 2011 to 2014, and the effect of temperature on the growth of P. shantungensis nymphs in an area of its outbreak. The hatchability of P. shantungensis eggs varies with their collection time; their hatchability in late November was higher than that in March of the next year, but no difference was observed in their hatching periods. The hatching periods of the eggs were 51.2, 31.3, 24.8, 19.4, 17.1, and 19.4 days at 15, 18, 21, 24, 27, and $30^{\circ}C$, respectively. The hatchability was above 70% at temperatures ranging from 18 to $27^{\circ}C$. The hatching time of the overwintered eggs in the Gurye region in Korea was reduced by 9 days from 2011 to 2014. The hatching rate was relatively higher when the average temperature in the winter season was relatively warmer. The dvelopmental periods of the first to fifth nymphs were 82.8, 58.0, 45.8, and 39.6 days at 18, 21, 24, and $27^{\circ}C$, respectively, at the relative humidity of 40~70%, and a photoperiod off 14 h light:10 h dark. The higher the temperature, the shorter the developmental period. At $30^{\circ}C$, all life stages after the fourth nymph died. Thus, the optimum growth temperature was estimated to be $27^{\circ}C$. For all life stages from the egg to the fourth nymph, the relationship between the temperature and developmental rate was expressed by the linear equation Y = 0.0015 X - 0.014. The lower developmental threshold was $9.3^{\circ}C$ and the effective cumulative temperature was 693.3 degree-days. The lower developmental threshold of approximately $3.8^{\circ}C$ was the lowest at the fourth nymph stage.

의료인의 호스피스가정간호에 대한 지식과 태도 조사연구

  • Kim, Ok-Gyeom
    • Korean Journal of Hospice Care
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    • v.2 no.2
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    • pp.28-48
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    • 2002
  • The advances of medical technologies have not only prolonged human life span, but also extended suffering period for the patients with incurable medical diseases. Hospice movement was developed to help these patients keep dignity and lives peaceful at the end of their life. Since many patients prefer to spend the last moment of life at home with their family, hospice home care has become very popular worldwide. The purpose of this study for a promotion and development of hospice home care in Korea, and features basic research on medical profession's knowledge and attitudes to hospice home care. This study which was used for the research questionnaires developed by the researcher that were answered by 100 physicians and 127 nurses in a general hospital. Data were collected from April 22, 2002 to May 10, 2002. The SPSS was used to make a comparative analysis of the frequency, percentile, ANOVA, and x2-test. The results of the study were as follows; 1.The medical profession showed high level of knowledge of the definition and philosophy of hospice. However, the physician group of the examinees showed insufficient knowledge of the fact that hospice care includes bereavement care, while the nurse group's response to the same question showed a significant difference(x2=10.752, p=.001). 2.For whom the hospice home care is provided, 95.6% of the respondents showed very high level of knowledge as answering that the incurable terminal illness patients and their families are the beneficiaries of hospice care. The respondents counted nurses, volunteers, pastors, physicians and social workers, consecutively, as hospice care providers. More nurse were positive toward pastors than physicians in regarding as a hospice care provider by a significant difference(x2=11.634, p=.001). 3.For when to referral hospice home care to the patients, only 34.2% answered that patients with less than 6 months of survival time are advised to receive hospice care, reflecting very low level of knowledge. 23.0% of the physicians and 48.0% of the nurses answered that hospice care should be provided when death is imminent, making a significant difference between the two groups(x2=6.413, p=.000). 4.To promote hospice activities, 87.2% pointed out that it is crucial to make general people, including those engaging in the medical field, more aware of hospice. 79.7% answered that a national hospice management should be developed, marking a significant difference between the physician group and nurse group(x2=10.485, p=.001). 5.Advantages of hospice home care are 87.2% responded that patients can have better rest at home receiving hospice home care. Economical merit was brought forward as one of the advantages also, where there was a significant difference between the physicians group and nurse group(x2=7.009, p=.008). 6.The medical professions' attitude to hospice home care are 92.8% of the physicians answered that they would advise incurable terminally ill patients to be discharged from hospital, with 44.3% of them advising the patients to receive hospice home care after leaving the hospital. From the nurses' point of view, 20.9% of the terminally ill patients are being referred to hospice home care after discharge, which makes a significant difference from the physicians' response(x2=19.121, p=.001). 7. 30.6% of physicians have referred terminally ill patients to hospice home care, 75.9% of whom were satisfied with their decision. Those physicians who have never referred their patients to hospice home care either did not know how to do it(66.7%) or were afraid of losing trust by giving the patients an impression of giving up(27.3%). 94.9% of the physicians responded that they would refer their last stage patients to a doctor who is involving palliative care. 8.Only 36.2% of nurses have suggested to physicians that refer the terminally ill patients discharged from the hospital to hospice home care. Once suggested, 95.8% of the physicians have accepted the suggestion. Nurses were reluctant to suggest hospice home care to the physicians, as 48.8% of the nurses said they did not want to. From the result of this study the following conclusion can be drawn, the medical profession's awareness of general hospice care has been increased greatly compared to the results of the previously performed studies. However, this study result also shows that their knowledge of hospice home care is not good enough yet. There is a need for high recommended that medical education institute and develop regular courses on various types of hospice care. Medical field training courses for physicians and nurses will be very helpful as well. It is also important to train hospice experts such as palliative physicians and develop a national hospice management urgently in order to improve the hospice care in Korea.

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Die Organisation von Mikrostrukturen der zweisprachigen $W\"{o}rterb\"{u}cher$ Deutsch/Koreanisch (독-한 두말사전의 미시구조 조직)

  • Kim Kyong
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.5
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    • pp.183-202
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    • 2002
  • Die vorliegende Arbeit verfolgt zwei Ziele: zum einen sollen die Entwicklungen in der modernen zweisprachigen Lexikographie mit Ausgangssprache Deutsch skizzenhaft vorgestellt und einige Forschungsdefizite benannt werden, zum anderen sollen die Ergebnisse und Methoden der neueren Lexikographie anhand von Beispielartikeln der drei $einschl\"{a}gigen$ deutsch-koreanischen $Gro{\ss}w\"{o}rterblicher$ kontrastiert und diskutiert werden. Zuerst wird eine Typologie der zweisprachigen $W\"{o}rterb\"{u}cher$ erstellt, derzufolge es jeweils 2 aktive und 2 passive Worterblicher pro Sprachenpaar gibt. Das Aktiv-Passiv­Prinzip gilt als ein grundlegender Ausgangspunkt $f\"{u}r$ die zweisprachige Lexikographie. Eine Erweiterung der Unterscheidungskriterien scheint nicht $zweckm\"{a}{\ss}ig$ und angesichts praktischer Schwierigkeiten auch kaum realisierbar. $Pl\"{a}diert\;wird\;f\"{u}r\;eine\;st\"{a}rkere\;Ber\"{u}cksichtigung$ der Benutzungssituationen, zu denen z.B. der Grad der Sprachbeherr­schung der jeweiligen Benutzergruppe, die $m\"{o}glichen\;Benutzungsanl\"{a}sse$, der Kenntnisstand $bez\"{u}glich$ der Benutzerhinweise sowie die technische Geschicklichkeit bei der $W\"{o}rterbuch-benutzung\;etc.\;zu\;z\"{a}hlen$ sind. In makrostruktueller Hinsicht werden die Selektion und die Anordnung der Lemmata diskutiert. Bei der Lemmaauswahl $w\"{a}re\;es\;w\"{u}nschenswert$, auf der Grundlage eines Lemmavergleiches der verschiedensten Quellenworterbucher ein datenbasiertes Korpus zu erstellen. Dazu $k\"{o}nnten$ folgende Materialien ausgewertet werden: (1) einsprachige allgemeine (ad spezielle) $W\"{o}rterb\"{u}cher$ (z.B. Deutsch/Koreanisch), (2) zweisprachige allgemeine (od spezielle) Worterblicher (z.B. Deutsch-Koreanisch, Deutsch-Englisch) etc. Die $blo{\ss}e\;\"{U}bersetzung$ lediglich eines einzigen $Quellenw\"{o}rterbuches\;k\"{o}nnte$ dagegen zu $unerw\"{u}nschten\;Einseitigkeiten\;f\"{u}hren$. Was die Anordnung der Lemmata in zweisprachigen $W\"{o}rterb\"{u}chern$ betrifft, $k\"{o}nnen$ dieselben drei makrostrukturellen Typen unterschieden werden, wie in einsprachigen $W\"{o}rterb\"{u}chern$: (1) glattalphabetisch, (2) nischenalphabetisch, (3) nestalphabetisch. Unter den zu untersuchenden $W\"{o}rterb\"{u}chern$ weisen das EDK und das HDK die nischenalpha­betische Makrostruktur auf, das MDK ist dagegen nestalphabetisch angeordnet. Je nachdem, wie die Polysemiestruktur und die Mehr-Wort-Einheit kombinieren, werden die drei Arten der Mikrostruktur unterschieden: (1) die integrierte Mikrostruktur, (2) die nichtintegrierte Mikrostruktur, (3) die partiell integrierte Mikrostruktur. $W\"{a}hrend$ das EDK und das HDKeine integrierte Mikrostruktur besitzen, weist das HDK eine partiell integrierte Mikrostruktur auf. Die Artikelgestaltung durch die nichtintegrierte Mikrostruktur, die $h\"{a}ufig$ in der zweisprachigen Lexikographie angewandt wird und entsprechende Vorteile besitzt, sallte $k\"{u}nftig\;als\;Gestaltungsm\"{o}glichkeit\;st\"{a}rker$in Betracht gezogen werden. In Bezug auf die Organisation der Mikrostruktur werden vier Bauteile, das sind Lemma-, $\"{A}quivalent-$, Diskriminator- und Beispielangaben untersucht. Die $\"{U}bersetzungs\"{a}quivalente$ werden je nach dem lexikalisch-semantischen Abdeckungsgrad mit dem Lemma in drei Typen eingeteilt: (1) $Voll\"{a}quivalent,\;(2)\;Teil\"{a}quivalent,\;(3)\;Null\"{a}quivalent$. In der Mehrheit kommen die Teil- oder $Null\"{a}quivalente$ vor, weil die ausgangssprachlichen Lemmata und die zielsprachlichen $\"{A}quivalente$ in sich Polysemiestruktur aufweisen. $Informationsm\"{a}ngel$ auszugleichen ist die Funktion des Diskriminators, in dem Glosse, Markierungen und metasprachliche $Erl\"{a}uterungen$ zusammenwirken. $Verbesserungsw\"{u}rdig\;sind\;die\;g\"{a}ngigen$ deutsch-koreanischen $W\"{o}rterb\"{u}cher$ var allem im Hinblick auf die stilistischen Markierungen; die Inkongruenz des Stils zwischen den beiden verschiedenen Sprachen wird bislang zu wenig $ber\"{u}cksichtigt$ und sagar in ein und demselben $W\"{o}rterbuch$ nicht konsequent dargestellt. Trotz der relativen $Geringsch\"{a}tzung$ von Beispielangaben in der $europ\"{a}ischen$ zweisprachigen passiven Lexikographie sallte diesen in deutsch-koreanischen $W\"{o}rterb\"{u}chern$ mehr Aufmerksamkeit gewidrnet werden. Sie sind dem koreanischen Benutzer eine wichtige Hilfe, indem sie die $\"{A}quivalentenangaben\;implizite\;erg\"{a}nzen$ und Informationen $\"{u}ber$ die syntaktisch-semantische und pragmatische Kontextrestriktion bieten. $Dar\"{u}berhinaus$ stellen sie selbst interessante kulturelle, geistige und landeskundliche etc. Informationen dar. Was den Artikelaufbau betrifft, wird das Van Dale-Modell diskutiert, d.h. das kategoriell-semantisch-alphabetische Prinzip, das trotz mancher Kritikpunkte viele interessante Anregungen $f\"{u}r$ die zweisprachige Lexikographie Deutsch-Koreanisch bietet, wo z.B. noch nicht die $Pr\"{a}positionen$ in der Beispielangabe durch typographische Hervorhebung $pr\"{a}sentiert$ worden sind. Aus $Platzgr\"{u}nden$ sind hier nur wenige Beispielartikel mit substantivischen Lemmata $angef\"{u}hrt$ und analysiert worden. Um die $h\"{o}here$ Generalisierbarkeit zu erreichen, brauchen die Untersuchungs- materialien mindestens einen bestimmten Umfang. Derartige empirische Forschungen $k\"{o}nnen$ als Impulse dazu beitragen, $k\"{u}nftige\;W\"{o}rterb\"{u}cher$ im Sinne einer $Ber\"{u}cksichtigung$ neuerer lexikographischer Erkenntnisse verbessern zu helfen.

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Eotaxin mRNA Expression in Bronchial Mucosa of Patients with Asthma (천식 환자의 기관지 조직에서 Eotaxin mRNA 발현에 관한 연구)

  • In, Kwang-Ho;Cho, Jae-Yun;Kang, Sae-Yong;Lee, Sang-Youb;Shim, Jae-Jeong;Kang, Kyung-Ho;Yoo, Se-Hwa;Na, Young-Soon;Kim, Han-Gyum
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.4
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    • pp.697-704
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    • 1998
  • Background: Asthma is a chronic inflammatory disease of the airways characterized by a marked infiltration of eosinophils in the bronchial mucosa. Asthmatic bronchial mucosa produces many factors described as being chemotactic for inflammatory cells. IL-5, RANTES, and MCP-1 alpha are the chemotactic factors for eosinophils, but their roles are controversial. Recently eotaxin that is a potent eosinophil chemoattractant cytokine was detected in a guinea-pig model of allergic airway inflammation, and human eotaxin was cloned. Eotaxin is a specific chemoattractant for eosinophils, but its role in asthma is not confirmed. We examined the in vivo expression of eotaxin in bronchi of asthmatic patients. Methods : 11 asthmatics and 2 normal controls were enrolled. All subjects were underwent bronchoscopy with bronchial biopsies in 2nd or 3rd carina. RNA extraction from biopsy samples was done by acid-guanidium method. Semi-quantitaive RT-PCR was done for evaluation of eotaxin mRNA expression The extent of eosinophil infiltration was evaluated by counting the eosinophils in submucosa in HPF of microscope. Results : Eotaxin mRNA expressed in symptomatic, uncontrolled asthma. Steroid inhibited expression of eotaxin mRNA in asthma. Expression of eotaxin mRNA correlated with eosinophil infiltration in bronchial tissues. Conclusion: Expression of eotaxin mRNA increases in uncontrolled asthma and eotaxin is involved in the recruitment of eosinophils.

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The Expression of IL-8 and GRO$\alpha$/MGSA in HUVEC Stimulated by the TNF-$\alpha$ and IL-1 (TNF-$\alpha$와 IL-1 자극에 의한 제대정맥내피세포에서의 IL-8 및 GRO/MGSA의 발현)

  • Song, Jeong-Sup;Shin, Moon-Sun;Ahn, Joong-Hyun;Moon, Hwa-Sik;Park, Sung-Hak
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.3
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    • pp.338-349
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    • 1999
  • Polymorphonuclear leukocytes(PMN) are the predominant inflammatory cells recruited in acute lung injury such as adult respiratory distress syndrome, pneumonia and also chronic lung disease such as idiopathic pulmonary fibrosis and pulmonary emphysema. Interleukin-8(IL-8) is an 8,000 D protein produced by many cells and has potent neutrophil chemoattractant and activating properties. The GRO, also called melanoma growth-stimulatory activity(MGSA), referring to a peptide of 73 amino acids, was reported to be mitogenic for cultured human melanoma cells. Mature GRO/MGSA has marked sequence similarity to IL-8. In view of the structural similarities to IL-8, it was of particular interest to test GRO for neutrophil activating and chemotactic properties. We found a significant release of IL-8 and GRO/MGSA from the cultured human umbilical vein endothelial cell(HUVEC) which was stimulated either with TNF$\alpha$ or IL-1$\beta$ and also found the expression of IL-8 and GRO/MGSA mRNA. Neutrophil chemotactic activity was enhanced in accordance with the increased IL-8 and GRO/MGSA. Our study also suggest that the IL-8 is more important in the increased neutrophil chemotactic activity than GRO/MGSA when endothelial cell is stimulated with TNF$\alpha$ or IL-1$\beta$ in vitro.

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Study of Rat Mammary Epithelial Stem Cells In Vivo and In Vitro (생체 및 시험관에서 유선 상피 모세포의 분리와 동정)

  • Nam Deuk Kim;Kee-Joo Paik
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.3
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    • pp.470-486
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    • 1995
  • Mammary epithelial cells contain a subpopulation of cells with a large proliferativ potential which are responsible for the maintenance of glandular cellularity and are the progenitor cells of mammary cancer. These clonogens give rise to multicellular clonal alveolar or ductal units(AU or DU) on transplantation and hormonal stimulation. To isolate putative mammary clonogens, enzymatically monodispersed rat mammary epithelial cells from organoid cultures and from intact glands are sorted by flow cytometry according to their affinity for FITC labeled peanut lectin(PNA) and PE labeled anti-Thy-1.1 antibody(Thy-1.1) into four subpopulations : cells negative to both PNA and Thy-1.1(B-), PNA+cells, Thy-1.1+cells, and cells positive to both reagents(B+). The in vivo transplantation assays indicate that the clonogenic fractions of PNA+cells from out-growths of organoids in primary cultures for three days in complete hormone medium(CHM) are significantly higher than those of cells from other subpopulations derived from cultrues or from intact glands. Extracellular matrix(ECM) is a complex of several proteins that regulated cell function ; its role in cell growth and differentiation and tissue-specific gene expression. It can act as a positive as well as a negative regulator of cellular differentiation depending on the cell type and the genes studied. Regulation by ECM is closely interrelated with the action of other regulators of cellular function, such as growth factors and hormones. Matrigel supports the growth and development of several different multicellular colonies from mammary organoids and from monodispersed epithelial cells in culture. Several types of colonies are observed including stellate colonies, duct-like structures, two- and three-dimensional web structures, squamous organoids, and lobulo-duct colonies. Organoids have the greatest proliferative potential and formation of multi-cellular structures. Phase contrast micrographs demonstrate extensive intracellular lipid accumulation within the web structures and some of duct-like colonies. At the immunocytochemical and electron micrograph level, casein proteins are predominantly localized near the apical surface of the cells or in the lumen of duct-like or lobulo-duct colonies. Squamous colonies are comprised of several layers of squamous epithelium surrounding keratin pearls as is typical fo squamous metaplasia(SM). All-trans retinoic acid(RA) inhibits the growth of SM. The frequency of lobulo-ductal colony formation increased with the augmentation of RA concentration in these culture conditions. The current study models could provide powerful tools not only for understanding cell growth and differentiation of epithelial cells, but also for the isolation and characterization of mammary clonogenic stem cells.

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Synthesis of Fully Dehydrated Partially Cs+-exchanged Zeolite Y (FAU, Si/Al = 1.56), |Cs45Na30|[Si117Al75O384]-FAU and Its Single-crystal Structure

  • Seo, Sung-Man;Kim, Ghyung-Hwa;Lee, Seok-Hee;Bae, Jun-Seok;Lim, Woo-Taik
    • Bulletin of the Korean Chemical Society
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    • v.30 no.6
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    • pp.1285-1292
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    • 2009
  • Large single crystals of zeolite, |$Na_{75}$|[$Si_{117}Al_{75}O_{384}$]-FAU (Na-Y, Si/Al = 1.56), were synthesized from gels with composition of 3.58Si$O_2$ : 2.08NaAl$O_2$ : 7.59NaOH : 455$H_2$O : 5.06TEA : 2.23TCl. One of these, a colorless single-crystal was ion exchanged by allowing aqueous 0.02 M CsOH to flow past the crystal at 293 K for 3 days, followed by dehydration at 673 K and 1 ${\times}\;10^{-6}$ Torr for 2 days. The crystal structure of fully dehydrated partially $Cs^+$-exchanged zeolite Y, |$Cs_{45}Na_{30}$|[$Si_{117}Al_{75}O_{384}$]-FAU per unit cell (a = 24.9080(10) $\AA$) was determined by single-crystal X-ray diffraction technique in the cubic space group Fd $\overline{3}$ m at 294(1) K. The structure was refined using all intensities to the final error indices (using only the 877 reflections with $F_o\;>\;4{\sigma}(F_o))\;R_1$ = 0.0966 (Based on F) and $R_2\;=\;0.2641\;(Based\;on\;F^2$). About forty-five $Cs^+$ ions per unit cell are found at six different crystallographic sites. The 2 $Cs^+$ ions occupied at site I, at the centers of double 6-ring (D6Rs, Cs-O = 2.774(10) $\AA$ and O-Cs-O = 88.9(3) and 91.1(3)$^o$). Two $Cs^+$ ions are found at site I’ in the sodalite cavity; the $Cs^+$ ions were recessed 2.05 $\AA$ into the sodalite cavity from their 3-oxygen plane (Cs-O = 3.05(3) $\AA$ and O-Cs-O = 77.4(13)$^o$). Site-II’ positions (opposite single 6-rings in the sodalite cage) are occupied by 7 $Cs^+$ ions, each of which extends 2.04 $\AA$ into the sodalite cage from its 3-oxygen plane (Cs-O = 3.067(11) $\AA$ and O-Cs-O = 80.1(3)$^o$). The 26 $Cs^+$ ions are nearly three-quarters filled at site II in the supercage, being recessed 2.34 $\AA$ into the supercage (Cs-O = 3.273(8) $\AA$ and O-Cs-O = 74.3(3)$^o$). The 4 $Cs^+$ ions are found at site III deep in the supercage (Cs-O = 3.321(19) and 3.08(3) $\AA$), and 4 $Cs^+$ ions at another site III’ (Cs-O = 2.87(4) and 3.38(4) $\AA$). About 30 $Na^+$ ions per unit cell are found at one crystallographic site; The $Na^+$ ions are located at site I’ in the sodalite cavity opposite double 6-rings (Na-O = 2.578(11) $\AA$ and O-Na-O = 97.8(4)$^o$).