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The role of EL2 in the infrared transmission images of defects in semi-insulating GaAs

  • Kang, Seong-Jun;Lee, Sung-Seok
    • Journal of information and communication convergence engineering
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    • v.9 no.6
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    • pp.725-728
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    • 2011
  • Infrared transmission images from GaAs semi insulating wafers were considered for years as directly related to the quantum absorption by electrons on fundamental states of deep centers, especially EL2. The satisfying correspondence of these images with the dislocations revealed by etching or X ray topography or infrared tomography led to the opinion that a strong concentration of EL2 centers was to be expected in the immediate vicinity of the dislocations. More recent work indicates that contrary to the expected behavior the photoqu$\acute{e}$nching of transmission images at T=80K does not appreciably change the image structure itself but more largely the uniform background level of absorption. Such investigations show that the transmission images of isolated dislocations (Indium doped materials) or cell structures of tangled dislocations (undoped materials) can be partly attributed to scattered light; similar operation at T=10K removes the dark features associated to EL2 but still preserves the skeleton of the pattern which is due to scattering. A result of the measurements is that dislocations must not be considered any longer as inexhaustive EL2 reservoirs. The lifetime of the photoqu$\acute{e}$nching mechanism is shown to vary differently for EL2 centers located close to the dislocations or in the matrix. In this paper we will develop the details of infrared image photoqu$\acute{e}$nching experiments in the vicinity of dislocations; undoped and In doped GaAs materials will be shown. These results will be discussed in the light of surface etching experiments.

Isolation of Human scFv Antibodies Specific for House Dust Mite Antigens from an Asthma Patient by Using a Phage Display Library

  • Jung, Wang-lim;Lee, Hee-kyung;Yong, Tae-soon;Cha, Sang-hoon
    • IMMUNE NETWORK
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    • v.2 no.2
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    • pp.91-95
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    • 2002
  • Background: In order to characterize human antibodies with specificity for mite allergens at the molecular level, a scFv phage display library was constructed using peripheral blood mononuclear lymphocytes from an asthma patient allergic to mite as Ig gene sources. Methods: Immunoglobulin $V_H$ and V gene fragments were obtained by polymerase chain reaction, and randomly combined in pCANTAB-5E vector. The resulting human scFv phage display library had $3{\times}10^4$ independent clones, and biopanning was performed with house dust mite extracts. Results: Four scFv clones specific for house dust mite extract were isolated. Immunoblot assay showed that our clones reacted to 25 kDa and 50~60 kDa proteins with unknown identity in mite extracts. Sequence analysis indicated that two clones (b7 and c15) are identical, and all clones belong to human $V_H3$ subgroup. On the other hand, light chain usage was different in that two clones (a2 and b7 / c15) belonging to V ${\kappa}4$ subgroup, but a4 used V ${\kappa}1$ light chain gene. Conclusion: Our approach should facilitate provision of useful information on the antibody responses against allergens at the molecular level in humans.

Assessment of Internal Fitness on Resin Crown Fabricated by Digital Light Processing 3D Printer

  • Kang, Wol;Kim, Min-Su;Kim, Won-Gi
    • Journal of dental hygiene science
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    • v.19 no.4
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    • pp.238-244
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    • 2019
  • Background: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method. Methods: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups. Results: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP. Conclusion: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

Flame Structure and Light Emission Characteristics in Coaxial Laminar Partially Premixed $CH_{4}/Air$ Flames;Effect of Central Fuel Injection (이중동축 메탄/공기 층류 부분 예혼합화염에서의 화염구조와 자발광 배출 특성;안쪽관 연료주입의 영향)

  • Oh, Jeong-Seog;Jeong, Yong-Ki;Jeon, Chung-Hwan;Chang, Young-June
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1116-1121
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    • 2004
  • In this study, the effect of central fuel injection on a coaxial laminar $CH_{4}/air$ flame was experimented at the defined premixing condition(${\Phi}=1.90$, ${\sigma}=50/75/100%$, x/D=10). The partial premixing parameter are the equivalence ratio that total fuel is fixed at 200cc/min, the fuel split degree which means the percentage of fuel entering the outer tube to the total amount, and the mixing distance indicating the nonreactant mixture's homogeneity between inner tube top and burner exit. The object is to investigate the flame structure and chemiluminescence characteristics of laminar partial premixed flame as changing mixing parameters. The radical signal was acquired from ICCD camera and PMT. Each intensity was compared with Abel inverted value for measuring the effect of background light on the peak signal location and the intensity at central preheat zone. The results show that the peak location of each radical was broaden as the fuel split degree increasing because the mixing quality was enhanced. and $OH^{\ast}$ is a good indicator for flame front between reaction and preheat zone. At last $CH_{2}^{\ast}$ has the same tendency with $CH^{\ast}$ but a thinner reaction zone than $CH^{\ast}$ due to a rapid decay on the burned gas side.

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A Study on the Posters of Swiss Graphic Style (스위스 그래픽 양식의 포스터에 관한 연구)

  • 홍성일;안창호
    • Archives of design research
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    • v.16 no.3
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    • pp.175-182
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    • 2003
  • The objective of this study is to systematically understand the swiss graphic style and examine the design ideology of designers and the visual features, with the focus on the posters that played the largest role in the formation and settlement of the swiss graphic style. Although through other visual designs such as editorial design, from the outside beyond posters, the swiss graphic style has evolved to exert a large influence around the world, based on the posters that served as the main medium for expression by designers and that were used the most in instigating the public, this study aims to cast light on the swiss graphic style, which has become recognized as the textbook of the graphic design around the world since the mid 20th century. First, the study casts light on the meaning of the creation of the graphic style through the background and the formation process, aiming to examine the visual features of the swiss graphic style and how they are integrated through the posters of Swiss designers. The personal activities and efforts of individual designers contributed significantly to the formation and development of a certain design style; however this study intends to identify the other equally important elements: the underlying social and cultural influence, the legacy of previous design styles and ideologies, the collective enthusiasm of designers, and the active progress of experimental research.

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Leukocyte Sequestration and Free Radical-Mediated Lung Injury in Ovine Cardiopulmonary bypass Using Membrane Oxygenator (양에서 막형 산화기를 사용하여 심폐바이패스할 경우 백혈구격리 및 자유라디칼로 중재되는 폐손상)

  • 김원곤;신윤철;서정욱
    • Journal of Chest Surgery
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    • v.32 no.11
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    • pp.978-983
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    • 1999
  • Background: Complement activation with transpulmonary leukocyte sequestration is considered a main mediator leading to ischemia-reperfusion lung(I-R) injury. We studied the role of leukocytes in the formation of I-R injury in ovine cardiopulmonary bypass(CPB) model with a membrane oxygenator. Material and Method: Five sheep were used. CPB circuitry consisted of a roller pump(American Optical Corp., Greenwich, CT, USA) and a membrane oxygenator(UNIVOX-IC, Bentley, Baxter Health Corp, Irvine, CA, USA). The CPB time was fixed at 120 min. Ten minutes after the start of CPB, total CPB was established. Thereafter a total CPB of 100 min was performed, followed by another 10 min of partial CPB. The CPB was discontinued and the animals were fully recovered. For measuring left and right atrial leukocyte counts, blood samples were taken before thoracotomy, 5 min and 109 in after the start of CPB, and 30 min and 120 min after weaning. C3a was measured before thoracotomy, 109 min after the start of CPB, and 30 min and 120 min after weaning. Plasma malondialdehyde(MDA) was checked before thoracotomy, 109 min after the start of CPB, and 30 min after weaning. One to two grams of lung tissue were taken for water content measurement before thoracotomy, 109 min after the start of CPB, and 30 min after weaning. Lung biopsy specimens were examined by light and electron microscopy. Result: Of 5 animals, 4 survived the experimental procedures. Of these, 3 animals survived on a long-term basis. No significant differences in transpulmonary gradients of leukocyte were found and no significant complement activation was expressed by C3a levels. MDA level did not show significant changes related to lung reperfusion despite an increase after the start of CPB. On both light and electron microscopic examinations, mild to moderate acute lung change was observed. Interstitial edema, leakage of erythrocytes into the alveolar space and endothelial cell swelling were the main findings. Water content of the lung showed a slight increase after the start of CPB, but there was no statistical significance. Conclusion: These findings indicate that ischemia-repersusion lung injury may not be from complement activation-leukocyte sequestration but from another source of oxygen free radicals related to CPB.

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A Study on the Meaning and interpretation of Urban Landscape in Architecture of Robert Venturi and Aldo Rossi (로버트 벤투리와 알도 로시 건축에서 도시 경관의 의미와 해석에 관한 연구)

  • Park, Hyung-Jin;Lee, Jong-Suk;Lee, Sang-Yeon
    • Korean Institute of Interior Design Journal
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    • v.21 no.2
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    • pp.23-34
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    • 2012
  • After the modern age, the rapid urbanizationhad a big impact on the then architecture. R. Venturi and A. Rossi are two of the leading architects, developing architecture in cities in the US and Europe respectively. This study shed light on a tangible and intangible meaning and interpretation of urban landscapes through their architectural thoughts and architectures. The followings are the physical and intangible meaning and interpretation in architectural thoughts and works of those two architects. Venturi understood that iconological landscapes at the roadside in large citiesare the nature of physical landscapes. To Venturi, the façades of buildings at the roadside are a part of signage such as traffic lights and road signs, and those façades have the meaning of symbolic systems beyond simple physical landscapes. To A. Rossi, types of buildings as physical townscapes are a key role supporting raw data of classification in architecture. And also, those types have significance of the basic data shedding light on the principles and history of cities. For intangible factors in R. Venturi's architecture, daily routine, function and use, time, a use for a building and others form complex architecture. And also, those factors describe shared values of the same period as the façades of buildings and complex symbols and formative lexicons in metaphorical terms. For A. Rossi's intangible factors, 'collective memory' is buried in inhabitants of the city, and with that, the city is a place for memory to its inhabitants. What is more, cities' monuments have intangible landscapes like 'sustainability', 'permanence' and so on. With lots of events happening throughoutcities, those monuments are the whole images of cities giving the value to the urban buildings that reside in cities. Finally, R. Venturi's all-encompassing complex architecture concept was extended on a tangible and intangible point of townscapes. It was found that A. Rossi's tangible thought was formed from the whole landscape of historic cities in then Italy as the background of time and place. Also, With types of urban buildings and 'collective memory', A. Rossi drew architectural norms and formats of unchangeable types.

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Validation of a simple binary scoring system for assessment of welfare measures of 10-day-old commercial broilers and their correlation with environmental parameters

  • Kumari, Priyanka;Choi, Hong-Lim;Metali, Shamira Hazi;Yussof, Siti Anisah Hazi;Han, Jiwoon
    • Journal of Animal Science and Technology
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    • v.57 no.3
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    • pp.9.1-9.5
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    • 2015
  • Background: A simple binary scoring system (SBSS) was developed and used to assess the welfare measures of commercial broiler chickens in South Korea. We also correlated welfare measures with environmental parameters of broiler house. Our measures of welfare included lameness, hock burn (HB) and foot pad dermatitis (FPD), whilst environmental parameters included air temperature, relative humidity, air speed, light intensity, air quality (in particular carbon dioxide ($CO_2$) and ammonia ($NH_3$) concentrations) and airborne microbes. Results: The effect of environmental parameters on welfare measures was apparent even on 10-day-old broilers. A non-parametric correlation analysis revealed significant correlations between environmental parameters and welfare measures. The key environmental parameters were relative humidity and light intensity. The results indicate that there is a need for proper control of environmental conditions on poultry farms, which could reduce health problems and subsequently reduce disease and mortality. Conclusions: In conclusion, the simplicity of SBSS makes it preferable over more complex scoring systems and allows a farmer to more easily assess the welfare measures on their own farm.

Decreased HDL-Dependent Paraoxonase and Arylesterase Enzyme Activity May Indicate a Worse Prognosis in Multiple Myeloma

  • Ellidag, Hamit Yasar;Aydin, Ozgur;Eren, Esin;Yilmaz, Necat;Ergin, Merve
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9847-9851
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    • 2014
  • Background: Multiple myeloma (MM) is a haematological cancer characterized by clonal proliferation of plasma cells.The aim of this study was to investigate the activity of serum paraoxonase-1 (PON1) and arylesterase (ARE) in multiple myeloma with and without free light chain excretion(FLCe-MM and NFLCe-MM); as well as to investigate possible alterations in oxidative stress parameters. Materials and Methods: Total thiol (T.thl), oxidative stress index (OSI), total oxidant status (TOS) and total antioxidant status (TAS) were examined in addition to the PON1 and ARE enzyme activities in twenty one FLCe-MM and nineteen NFLCe-MM subjects. Routine parameters like lipid panel, serum total protein, albumin, creatinine, blood urea nitrogen (BUN), uric acid and hemoglobin levels were compared with the oxidative stress markers. Results: Serum total protein, BUN, creatinin, and uric acid levels were significantly higher (p=0.04, p=0.001, p=0.001 and p=0.0022, respectively), while hemoglobin and albumin levels were significantly lower in FLCe-MM patients (p=0.009 and p=0.04,respectively). PON1 and ARE activities were significantly lower in patients with FLCe-MM compared to those with NFLCe-MM (p=0.001 and p=0.008, respectively). Conclusions: Depending on our results of prognostic markers of MM such as age, hemoglobin, albumin, and creatinine we feel confident to presume FLCe-MM as a subgroup with a worse prognosis. A decrease in PON1 and ARE activities may contribute to the prognosis and may be used as a prognostic tool in MM.

N-Region Addition in Immunoglobulin Kappa Light Chains in B Cell Subsets in Rheumatoid Arthritis: Evidence for Over-expression of TDT in B Lineage

  • Lee, Choong Won;Bridges, S. Louis Jr
    • IMMUNE NETWORK
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    • v.3 no.2
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    • pp.89-95
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    • 2003
  • Background: Unusually high amounts of N region addition and CDR3 length diversity were found in immunoglobulin (Ig) light chain Vk and Jk joins in patients with rheumatoid arthritis (RA). We sought to determine whether this finding is due to excessive activity of the enzyme responsible for N region addition (terminal deoxynucleotidyl transferase [TdT]) in B lineage cells in bone marrow or from positive antigenic selection of B cells with long CDR3 lengths. Methods: We used FACS to isolate $IgM^+/IgD^+$ B cells (predominantly naive) and $IgM^-/IgD^-$ B cells (predominantly class-switched) B cells from peripheral blood of a patient with RA known to have enrichment for long Vk CDR3s and from that of two normal controls. RT-PCR of VkIII transcripts was performed, followed by sequencing of individual cDNA clones. We analyzed the CDR3 lengths and N region additions in 97 clones. Results: There was enrichment for long CDR3 lengths (11 or 12 amino acids) in both $IgM^+/IgD^+$ and $IgM^-/IgD^-$ B cells in RA compared to B cell subsets in the normal controls. The $IgM^+/IgD^+$ B cell subset in RA was markedly enriched for N region addition and was similar to that seen in the $IgM^-/IgD^-$ subset. Conclusion: These data suggest that enrichment for N region addition and long CDR3 lengths in RA may result from unusually high or prolonged activity of TdT in bone marrow.