• Title/Summary/Keyword: Characterisation

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Characterisation and Clinical Significance of FLT3-ITD and non-ITD in Acute Myeloid Leukaemia Patients in Kelantan, Northeast Peninsular Malaysia

  • Yunus, Noraini Mat;Johan, Muhammad Farid;Al-Jamal, Hamid Ali Nagi;Husin, Azlan;Hussein, Abdul Rahim;Hassan, Rosline
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.12
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    • pp.4869-4872
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    • 2015
  • Background: Mutations of the FMS-like tyrosine kinase-3 (FLT3) receptor gene may promote proliferation via activation of multiple signaling pathways. FLT3-internal tandem duplication (FLT3-ITD) is the most common gene alteration found in patients diagnosed with acute myeloid leukaemia (AML) and has been associated with poor prognosis. Materials and Methods: We performed mutational analysis of exons 14-15 and 20 of the FLT3 gene in 54 AML patients using PCR-CSGE (conformational sensitive gel electrophoresis) followed by sequencing analysis to characterise FLT3 mutations in adult patients diagnosed with AML at Hospital USM, Kelantan, Northeast Peninsular Malaysia. Results: FLT3 exon 14-15 mutations were identified in 7 of 54 patients (13%) whereas no mutation was found in FLT3 exon 20. Six ITDs and one non-ITD mutation were found in exon 14 of the juxtamembrane (JM) domain of FLT3. FLT3-ITD mutations were associated with a significantly higher blast percentage (p-value = 0.008) and white blood cell count (p-value = 0.023) but there was no significant difference in median overall survival time for FLT3-ITD+/FLT3-ITD- within 2 years (p-value = 0.374). Conclusions: The incidence of FLT3-ITD in AML patients in this particular region of Malaysia is low compared to the Western world and has a significant association with WBC and blast percentage.

Purification and Characterisation of a Burkholderia pseudomallei Protease Expressed in Recombinant E. coli

  • Ling, Jessmi M.L.;Nathan, Sheila;Hin, Lee Kok;Mohamed, Rahmah
    • BMB Reports
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    • v.34 no.6
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    • pp.509-516
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    • 2001
  • A genomic DNA fragment that contains the gene, which codes for a novel extracellular serine protease in Burkholderia pseudomallei, was cloned by using pQE40 as a vector. It was maintained in Escherichia coli JM109. The expression of the gene(s) resulted in the production of a 52 kDa protease. The recombinant protease was purified from the culture filtrate via ammonium sulfate fractionation, gel filtration, and anion-exchange chromatography. The purified protease had an optimum pH and temperature of pH 8.9 and $38^{\circ}C$, respectively. The protease activity was inhibited by EGTA, EDTA, and PMSF, but not 1,10-phenanthroline. The first 11 amino acid residues from the N-terminus of the purified protease were identified as LAPNDPYYYGY. PNDPYY was found to show homology to the Bacillus cereus microbial serine protease and B. subtilis PD498 serine protease. These results indicate that the protease that was purified in this study is an extracellular calcium-dependent serine protease. The purified protease was able to digest the human serum 19A, IgG, albumin, and transferrin, as well as bovine muscle actin and myosin. Furthermore, it was able to promote or cause dermonecrosis in experimental rabbits. These results propose the possible role of a novel B. pseudomallei extracellular calcium-dependent serine protease in the virulence of the pathogen.

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Influence of Bath Temperature on Electroless Ni-B Film Deposition on PCB for High Power LED Packaging

  • Samuel, Tweneboah-Koduah;Jo, Yang-Rae;Yoon, Jae-Sik;Lee, Youn-Seoung;Kim, Hyung-Chul;Rha, Sa-Kyun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.323-323
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    • 2013
  • High power light-emitting diodes (LEDs) are widely used in many device applications due to its ability to operate at high power and produce high luminance. However, releasing the heat accumulated in the device during operating time is a serious problem that needs to be resolved to ensure high optical efficiency. Ceramic or Aluminium base metal printed circuit boards are generally used as integral parts of communication and power devices due to its outstanding thermal dissipation capabilities as heat sink or heat spreader. We investigated the characterisation of electroless plating of Ni-B film according to plating bath temperature, ranging from $50^{\circ}C$ to $75^{\circ}C$ on Ag paste/anodised Al ($Al_2O_3$)/Al substrate to be used in metal PCB for high power LED packing systems. X-ray diffraction (XRD), Field-Emission Scanning Electron Microscopy (FE-SEM) and X-ray Photoelectron Spectroscopy (XPS) were used in the film analysis. By XRD result, the structure of the as deposited Ni-B film was amorphous irrespective of bath temperature. The activation energy of electroless Ni-B plating was 59.78 kJ/mol at the temperature region of $50{\sim}75^{\circ}C$. In addition, the Ni-B film grew selectively on the patterned Ag paste surface.

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PROTO-TYPE INSTALLATION OF A DOUBLE-STATION SYSTEM FOR THE OPTICAL-VIDEO-DETECTION AND ORBITAL CHARACTERISATION OF A METEOR/FIREBALL IN SOUTH KOREA

  • Hinse, Tobias C.;Kim, Woo-Kyum;Ahn, Sang-Hyeon;Lee, Jae-Keun;Park, Jun-Hyeong;Lee, Young-Woo;Jeong, Woo-Jung;Woo, Sang-Min
    • Publications of The Korean Astronomical Society
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    • v.32 no.3
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    • pp.381-405
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    • 2017
  • We give a detailed description of the installation and operation of a double-station meteor detection system which formed part of a research & education project between Korea Astronomy Space Science Institute (KASI) and Daejeon Science Highschool. A similar system is currently not existing in South Korea. A total of six light-sensitive CCD cameras were installed with three cameras at SOAO and three cameras at BOAO observatory. A double-station observation of a meteor event enables the determination of the three-dimensional heliocentric orbit in space. This project was initiated in response to the Jinju fireball event in March 2014. The cameras were installed in October/November 2014. The two stations are identical in hardware as well as software. Each station employes sensitive "Watec-902H2" cameras in combination with relatively fast f/1.2 lenses. Various fields of views were used for measuring differences in detection rates of meteor events. We employed the SonotaCo UFO software suite for meteor detection and their subsequent analysis. The system setup as well as installation/operation experience is described and first results are presented. We also give a brief overview of historic as well as recent meteor (fall) detections in South Korea. For more information please consult http://meteor.kasi.re.kr.

High Level of Soluble Expression in Escherichia coli and Characterisation of the Cloned Bacillus thuringiensis Cry4Ba Domain III Fragment

  • Chayaratanasin, Poramed;Moonsom, Seangdeun;Sakdee, Somsri;Chaisri, Urai;Katzenmeier, Gerd;Angsuthanasombat, Chanan
    • BMB Reports
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    • v.40 no.1
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    • pp.58-64
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    • 2007
  • Similar to the other known structures of Bacillus thuringiensis Cry $\delta$-endotoxins, the crystal structure of the 65-kDa activated Cry4Ba toxin comprises three domains which are, from the N- to C-terminus, a bundle of $\alpha$-helices, a three-$\beta$-sheet domain, and a $\beta$-sandwich. To investigate the properties of the C-terminal domain III in isolation from the rest of the toxin, the cloned Cry4Ba-domain III was over-expressed as a 21-kDa soluble protein in Escherichia coli, which cross-reacted with anti-Cry4Ba domain III monoclonal antibody. A highly-purified domain III was obtained in a monomeric form by ion-exchange and size-exclusion FPLC. Circular dichroism spectroscopy indicated that the isolated domain III fragment distinctly exists as a $\beta$-sheet structure, corresponding to the domain III structure embodied in the Cry4Ba crystal structure. In vitro binding analysis via immuno-histochemical assay revealed that the Cry4Ba-domain III protein was able to bind to the apical microvilli of the susceptible Stegomyia aegypti larval midguts, albeit at lower-binding activity when compared with the full-length active toxin. These results demonstrate for the first time that the C-terminal domain III of the Cry4Ba mosquito-larvicidal protein, which can be isolated as a native folded monomer, conceivably participates in toxin-receptor recognition.

A rock mass assessment procedure based on quantitative geophysical log analysis of coal measure sequences (탄층에 대한 정량적 물리검층에 기초한 암반 평가 과정)

  • Hatherly Peter;Medhurst Terry;Sliwa Renate;Turner Roland
    • Geophysics and Geophysical Exploration
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    • v.8 no.1
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    • pp.112-117
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    • 2005
  • Geophysical logging is routinely undertaken as part of most coal mine exploration programs. Currently, the main application for the logs is to determine coal seam depth and to qualitatively estimate coal quality, lithology, and rock strength. However, further information can be obtained, if quantitative log interpretation is made. To assist in the uptake of quantitative interpretation, we discuss log responses in terms of the mineralogy of the clastic sedimentary rocks frequently found in the Australian black coal mining areas of the Sydney and Bowen Basins. We find that the log responses can be tied to the mineralogy with reasonable confidence. Ambiguities in the interpretation will be better resolved if a full suite of logs is run. A method for checking for internal consistency, by comparing calculated and observed velocities, is also described. A key driver for quantitative interpretation is geotechnical characterisation. We propose a classification system for clastic rocks that takes into consideration physical rock properties that can be inferred from geophysical logs.

Strength Characterisation of Composite Securement Device in the Vehicle by FE Analysis (유한요소해석을 통한 차량내 복합재 휠체어 고정구의 구조 강도 특성 평가)

  • Ham, Seok-Woo;Yang, Dong-Gyu;Son, Seung-Neo;Eo, Hyo-Kyoung;Kim, Gyeong-Seok;Cheon, Seong S.
    • Composites Research
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    • v.32 no.4
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    • pp.171-176
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    • 2019
  • In this paper, the strength of the composite securement device was characterised by FE analysis. Preliminary frontal crash analysis for the vehicle, equipped with the conventional steel securement device, was carried out according to the ISO 10542 for special transportation to obtain loading data, which were applied to securement device during crash. The securement device consists of block, guide and rail and the weight fraction of rail was the highest among them, therefore, it is desirable to reduce weight of rail by applying carbon/epoxy composite. Also, it was found that 27% of lightweight effect was obtained by hybrid rail that bottom part was replaced by a composite compared to the conventional rail, i.e., made of SAPH 440, without sacrificing the structural strength.

CATHARE simulation results of the natural circulation characterisation test of the PKL test facility

  • Salah, Anis Bousbia
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1446-1453
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    • 2021
  • In the past, several experimental investigations aiming at characterizing the natural circulation (NC) behavior in test facilities were carried out. They showed a variety of flow patterns characterized by an inverted U-shape of the NC flow curve versus primary mass inventory. On the other hand, attempts to reproduce such curves using thermal-hydraulic system codes, showed 10-30% differences between the measured and calculated NC mass flow rate. Actually, the used computer codes are generally based upon nodalization using single U-tube representation. Such model may not allow getting accurate simulation of most of the NC phenomena occurring during such tests (like flow redistribution and flow reversal in some SG U-tubes). Simulations based on multi-U-tubes model, showed better agreement with the overall behavior, but remain unable to predict NC phenomena taking place in the steam generator (SG) during the experiment. In the current study, the CATHARE code is considered in order to assess a NC characterization test performed in the four loops PKL facility. For this purpose, four different SG nodalizations including, single and multi-U-tubes, 1D and 3D SG inlet/outlet zones are considered. In general, it is shown that the 1D and 3D models exhibit similar prediction results up to a certain point of the rising part of the inverted U-shape of the NC flow curve. After that, the results bifurcate with, on the one hand, a tendency of the 1D models to over-predict the measured NC mass flow rate and on the other hand, a tendency of the 3D models to under-predict the NC flow rate.

Modelling the critical state behaviour of granular soils: Application of NorSand constitutive law to TP-Lisbon sand

  • Antonio Viana da Fonseca;Fausto Molina-Gomez;Cristiana Ferreira;Julieth Quintero
    • Geomechanics and Engineering
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    • v.34 no.3
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    • pp.317-328
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    • 2023
  • The soil behaviour can be represented by numerical modelling of element testing using diverse constitutive models. However, not all constitutive models allow the simulation of the stress-strain response at the critical state in granular soils with both contractive and dilative behaviour. Moreover, the accuracy of these models depends highly on the quality of the experimental data used for their calibration. This study addresses the modelling of the critical state behaviour of an alluvial natural soil from the Lower Tagus Valley (south of Portugal), known as TP-Lisbon sand, using the NorSand constitutive law. For this purpose, a series of numerical simulations of element testing was carried out using two algorithms performed in Visual Basic (VB) and Fast Lagrangian Analysis of Continua (FLAC). Moreover, this study presents the characterisation of of NorSand parameters from an accurate experimental programme based on triaxial and bender element testing. This experimental program allowed defining: (i) the critical state locus, (ii) the stress-dilatancy, and (iii) the soil elasticity of TP-Lisbon sand -all fundamental to calibrate the contractive and dilative behaviour of such alluvial soil. The results revealed a good agreement between experimental data and NorSand simulations using VB and FLAC. Therefore, this study showed that the quality of laboratory testing procedures and its good interpretation enables NorSand constitutive law to capture representatively the non-associated plastic strains, often expressed by the state parameter, allowing a representation of soil behaviour of alluvial soils within the critical state soil mechanics framework for different state parameters.

Determining Potential Link between Environmental and Clinical Isolates of Cryptococcus neoformans/Cryptococcus gattii Species Complexes Using Phenotypic and Genotypic Characterisation

  • Kenosi Kebabonye;Mosimanegape Jongman;Daniel Loeto;Sikhulile Moyo;Wonderful Choga;Ishmael Kasvosve
    • Mycobiology
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    • v.51 no.6
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    • pp.452-462
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    • 2023
  • Opportunistic infections due to Cryptococcus neoformans and C. gattii species complexes continue to rise unabated among HIV/AIDS patients, despite improved antifungal therapies. Here, we collected a total of 20 environmental and 25 presumptive clinical cryptococcal isolates from cerebrospinal fluid (CSF) samples of 175 patients enrolled in an ongoing clinical trial Ambition 1 Project (Botswana-Harvard Partnership). Identity confirmation of the isolates was done using MALDI-TOF MS and PCR. We describe the diversity of the isolates by PCR fingerprinting and sequencing (Oxford Nanopore Technology) of the intergenic spacer region. Mating types of the isolates were determined by amplification of the MAT locus. We report an unusual prevalence of 42.1% of C. neoformans × C. deneoformans hybrids Serotype AD (n = 16), followed by 39.5% of C. neoformans Serotype A (n = 15), 5.3% of C. deneoformans, Serotype D (n = 2), 7.9% of C. gattii (n = 3), and 5.3% of C. tetragattii (n = 2) in 38 representative isolates that have been characterized. Mating type-specific PCR performed on 38 representative environmental and clinical isolates revealed that 16 (42.1%) were MATa/MAT𝛼 hybrids, 17 (44.7%) were MAT𝛼, and five (13.2%) possessed MATa mating type. We used conventional and NGS platforms to demonstrate a potential link between environmental and clinical isolates and lay a foundation to further describe mating patterns/history in Botswana.