Displaying publications 1 - 20 of 56 in total

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  1. Osahor AN, Tan CY, Sim EU, Lee CW, Narayanan K
    Anal Biochem, 2014 Oct 1;462:26-8.
    PMID: 24929088 DOI: 10.1016/j.ab.2014.05.030
    When recombineering bacterial artificial chromosomes (BACs), it is common practice to design the ends of the donor molecule with 50 bp of homology specifying its insertion site. We demonstrate that desired recombinants can be produced using intermolecular homologies as short as 15 bp. Although the use of shorter donor end regions decreases total recombinants by several fold, the frequency of recombinants with correctly inserted donor molecules was high enough for easy detection by simple polymerase chain reaction (PCR) screening. This observation may have important implications for the design of oligonucleotides for recombineering, including significant cost savings, especially for high-throughput projects that use large quantities of primers.
    Matched MeSH terms: Sequence Homology, Nucleic Acid*
  2. Basu K, Sriraam N, Richard RJ
    J Med Syst, 2007 Aug;31(4):247-53.
    PMID: 17685148
    For a given DNA sequence, it is well known that pair wise alignment schemes are used to determine the similarity with the DNA sequences available in the databanks. The efficiency of the alignment decides the type of amino acids and its corresponding proteins. In order to evaluate the given DNA sequence for its proteomic identity, a pattern matching approach is proposed in this paper. A block based semi-global alignment scheme is introduced to determine the similarity between the DNA sequences (known and given). The two DNA sequences are divided into blocks of equal length and alignment is performed which minimizes the computational complexity. The efficiency of the alignment scheme is evaluated using the parameter, percentage of similarity (POS). Four essential DNA version of the amino acids that emphasize the importance of proteomic functionalities are chosen as patterns and matching is performed with the known and given DNA sequences to determine the similarity between them. The ratio of amino acid counts between the two sequences is estimated and the results are compared with that of the POS value. It is found from the experimental results that higher the POS value and the pattern matching higher are the similarity between the two DNA sequences. The optimal block is also identified based on the POS value and amino acids count.
    Matched MeSH terms: Sequence Homology, Nucleic Acid*
  3. Heydari H, Mutha NV, Mahmud MI, Siow CC, Wee WY, Wong GJ, et al.
    Database (Oxford), 2014;2014:bau010.
    PMID: 24578355 DOI: 10.1093/database/bau010
    With the advent of high-throughput sequencing technologies, many staphylococcal genomes have been sequenced. Comparative analysis of these strains will provide better understanding of their biology, phylogeny, virulence and taxonomy, which may contribute to better management of diseases caused by staphylococcal pathogens. We developed StaphyloBase with the goal of having a one-stop genomic resource platform for the scientific community to access, retrieve, download, browse, search, visualize and analyse the staphylococcal genomic data and annotations. We anticipate this resource platform will facilitate the analysis of staphylococcal genomic data, particularly in comparative analyses. StaphyloBase currently has a collection of 754 032 protein-coding sequences (CDSs), 19 258 rRNAs and 15 965 tRNAs from 292 genomes of different staphylococcal species. Information about these features is also included, such as putative functions, subcellular localizations and gene/protein sequences. Our web implementation supports diverse query types and the exploration of CDS- and RNA-type information in detail using an AJAX-based real-time search system. JBrowse has also been incorporated to allow rapid and seamless browsing of staphylococcal genomes. The Pairwise Genome Comparison tool is designed for comparative genomic analysis, for example, to reveal the relationships between two user-defined staphylococcal genomes. A newly designed Pathogenomics Profiling Tool (PathoProT) is also included in this platform to facilitate comparative pathogenomics analysis of staphylococcal strains. In conclusion, StaphyloBase offers access to a range of staphylococcal genomic resources as well as analysis tools for comparative analyses. Database URL: http://staphylococcus.um.edu.my/.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  4. Ithoi I, Ahmad AF, Nissapatorn V, Lau YL, Mahmud R, Mak JW
    PLoS One, 2011;6(9):e24327.
    PMID: 21915311 DOI: 10.1371/journal.pone.0024327
    BACKGROUND: In Malaysia, researchers and medical practitioners are unfamiliar with Naegleria infections. Thus little is known about the existence of pathogenic Naegleria fowleri, and the resultant primary amoebic meningoencephalitis (PAM) is seldom included in the differential diagnosis of central nervous system infections. This study was conducted to detect the presence of Naegleria species in various environmental samples.

    METHODS/FINDINGS: A total of 41 Naegleria-like isolates were isolated from water and dust samples. All these isolates were subjected to PCR using two primer sets designed from the ITS1-ITS2 regions. The N. fowleri species-specific primer set failed to produce the expected amplicon. The Naegleria genus-specific primers produced amplicons of 408 bp (35), 450 bp (2), 457 bp (2) or 381 bp (2) from all 41 isolates isolated from aquatic (33) and dust (8) samples. Analysis of the sequences from 10 representative isolates revealed that amplicons with fragments 408, 450 and 457 bp showed homology with non-pathogenic Naegleria species, and 381 bp showed homology with Vahlkampfia species. These results concurred with the morphological observation that all 39 isolates which exhibited flagella were Naegleria, while 2 isolates (AC7, JN034055 and AC8, JN034056) that did not exhibit flagella were Vahlkampfia species.

    CONCLUSION: To date, pathogenic species of N. fowleri have not been isolated from Malaysia. All 39 isolates that produced amplicons (408, 450 and 457 bp) from the genus-specific primers were identified as being similar to nonpathogenic Naegleria. Amplicon 408 bp from 5 representative isolates showed 100% and 99.7% identity to Naegleria philippinensis isolate RJTM (AM167890) and is thus believed to be the most common species in our environment. Amplicons 450 bp and 457 bp were respectively believed to be from 2 new species of Naegleria, since representative isolates showed lower homology and had a longer base pair length when compared to the reference species in the Genbank, Naegleria schusteri (AJ566626) and Naegleria laresi (AJ566630), respectively.

    Matched MeSH terms: Sequence Homology, Nucleic Acid
  5. Lam TT, Jia N, Zhang YW, Shum MH, Jiang JF, Zhu HC, et al.
    Nature, 2020 07;583(7815):282-285.
    PMID: 32218527 DOI: 10.1038/s41586-020-2169-0
    The ongoing outbreak of viral pneumonia in China and across the world is associated with a new coronavirus, SARS-CoV-21. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection2. Although bats are probable reservoir hosts for SARS-CoV-2, the identity of any intermediate host that may have facilitated transfer to humans is unknown. Here we report the identification of SARS-CoV-2-related coronaviruses in Malayan pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin-associated coronaviruses that belong to two sub-lineages of SARS-CoV-2-related coronaviruses, including one that exhibits strong similarity in the receptor-binding domain to SARS-CoV-2. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 suggests that pangolins should be considered as possible hosts in the emergence of new coronaviruses and should be removed from wet markets to prevent zoonotic transmission.
    Matched MeSH terms: Sequence Homology, Nucleic Acid*
  6. Mohseni J, Boon Hock C, Abdul Razak C, Othman SN, Hayati F, Peitee WO, et al.
    Gene, 2014 Jan 1;533(1):240-5.
    PMID: 24103480 DOI: 10.1016/j.gene.2013.09.081
    Hyperargininemia is a very rare progressive neurometabolic disorder caused by deficiency of hepatic cytosolic arginase I, resulting from mutations in the ARG1 gene. Until now, some mutations were reported worldwide and none of them were of Southeast Asian origins. Furthermore, most reported mutations were point mutations and a few others deletions or insertions.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  7. Nomikou K, Dovas CI, Maan S, Anthony SJ, Samuel AR, Papanastassopoulou M, et al.
    PLoS One, 2009;4(7):e6437.
    PMID: 19649272 DOI: 10.1371/journal.pone.0006437
    Bluetongue virus (BTV) is the 'type' species of the genus Orbivirus within the family Reoviridae. The BTV genome is composed of ten linear segments of double-stranded RNA (dsRNA), each of which codes for one of ten distinct viral proteins. Previous phylogenetic comparisons have evaluated variations in genome segment 3 (Seg-3) nucleotide sequence as way to identify the geographical origin (different topotypes) of BTV isolates. The full-length nucleotide sequence of genome Seg-3 was determined for thirty BTV isolates recovered in the eastern Mediterranean region, the Balkans and other geographic areas (Spain, India, Malaysia and Africa). These data were compared, based on molecular variability, positive-selection-analysis and maximum-likelihood phylogenetic reconstructions (using appropriate substitution models) to 24 previously published sequences, revealing their evolutionary relationships. These analyses indicate that negative selection is a major force in the evolution of BTV, restricting nucleotide variability, reducing the evolutionary rate of Seg-3 and potentially of other regions of the BTV genome. Phylogenetic analysis of the BTV-4 strains isolated over a relatively long time interval (1979-2000), in a single geographic area (Greece), showed a low level of nucleotide diversity, indicating that the virus can circulate almost unchanged for many years. These analyses also show that the recent incursions into south-eastern Europe were caused by BTV strains belonging to two different major-lineages: representing an 'eastern' (BTV-9, -16 and -1) and a 'western' (BTV-4) group/topotype. Epidemiological and phylogenetic analyses indicate that these viruses originated from a geographic area to the east and southeast of Greece (including Cyprus and the Middle East), which appears to represent an important ecological niche for the virus that is likely to represent a continuing source of future BTV incursions into Europe.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  8. Tay ST, Rohani YM, Ho TM, Shamala D
    Microbiol. Immunol., 2005;49(1):67-71.
    PMID: 15665455
    The DNA sequences encompassing two hypervariable regions, VD II and III of the 56 kDa immunodominant protein gene of 21 Malaysian strains of Orientia tsutsugamushi were determined. Two strains demonstrated a 100% DNA homology with the Gilliam prototype strain, and one with TH1817 strain and TA678 strain respectively. High percentages of DNA similarity (95-99%) were observed with Karp (4 strains), Gilliam (2 strains), TH1817 (4 strains), TC586 (3 strains) and TA763 (1 strain). The remaining strains demonstrated the highest DNA similarity with TA763 (1 strain, 89%), TA678 (1 strain, 86%) and TA686 (1 strain, 87%). Our study provides additional evidence on the existence and the genetic heterogeneity of TA strains of the Southeast Asia and their closely related strains in Malaysia.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  9. Tsukaya H
    J Plant Res, 2005 Feb;118(1):13-8.
    PMID: 15654504
    Molecular variations of Spiranthes sinensis Ames var. australis (R.Br.) H. Hara et Kitam. ex Kitam. in Japan were examined to evaluate the validity of the seasonally differentiated groups and a dwarf form of the species, which is endemic to Yakushima Island, Japan. Sequence differences in the plastid trnL-F locus clearly distinguished Japanese S. sinensis var. australis from S. sinensis var. sinensis collected from Ryukyu. In contrast, the trnL-F sequence of S. sinensis var. australis from Sabah, Malaysia, clearly differed from that of Japanese S. sinensis var. australis, suggesting genetic heterogeneity of Spiranthes sinensis var. australis in Asia. Moreover, a molecular analysis based on the sequences of nuclear ITS1 regions indicated that there are two major groups of S. sinensis var. australis in Japan, with a geographic distribution boundary on Kyushu Island. However, the trnL-F and ITS1 sequences did not support the genetic differentiation of the seasonally differentiated groups or the dwarf form from the other Japanese individuals. Based on these molecular data, the systematic treatment of physiological and morphological variations in the Japanese population of S. sinensis. var. australis is discussed.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  10. Raja N, Shamsudin MN, Somarny W, Rosli R, Rahim RA, Radu S
    PMID: 11485069
    A total of 11 Vibrio cholerae isolates from 1996-1998 outbreaks in Malaysia and 4 V. alginolyticus were analyzed. Isolates were characterized by polymerase chain reaction (PCR) and Southern hybridization for the presence of the gene encoding zonula occludens toxin (zot). Screening of zot gene by PCR revealed the presence of this gene in V. cholerae and V. alginolyticus. The zot gene from one V. cholerae Ogawa isolate that was cloned in a pCR 2.1 TOPO vector was sequenced. The sequences obtained were 99% homologous to the zot gene sequence from the Gene Bank.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  11. Chansiri K, Kawazu S, Kamio T, Terada Y, Fujisaki K, Philippe H, et al.
    Vet Parasitol, 1999 Jun 15;83(2):99-105.
    PMID: 10392966
    Classification of Theileria parasites of south-east Asian countries is still ambiguous due to the lack of basic studies, especially their molecular genetic information. In this study, we included 6 known species and 14 unclassified Theileria parasite isolates: Theileria annulata, Theileria parva, Theileria taurotragi, Theileria sergenti, Theileria buffeli, Theileria types Sable, Theileria types A, B, B1, B2, C, D, E, F, G, G1, Theileria type Medan (Indonesia), Theileria type Ipoh (Malaysia) and Theileria type Thong Song (Thailand). Small subunit ribosomal RNA (srRNA) nucleotide sequence data were collected by PCR, cloning and dideoxy sequencing. The srRNA nucleotide sequences were aligned and analyzed by distance methods, maximum parsimony algorithms and maximum likelihood methods to construct phylogenetic trees. Bootstrap analysis was used to test the strength of the different phylogenetic reconstructions. The data indicated that all of the tree-building methods gave very similar results. This study identified two groups of Theileria, the pathogenic and benign groups, which are strongly supported by bootstrap analysis. The analysis also indicated that three subgroups (A, B and C) were generated within the benign Theileria group whereas the classification of Theileria type D and Thong Song is questionable. However, more basic information such as life cycle differences, vectors, modes of transmission, virulent and genetic/sexual compatability is essential for clearer taxonomic definition of the benign Theileria parasites.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  12. Teo CH, Tan SH, Othman YR, Schwarzacher T
    J. Biochem. Mol. Biol. Biophys., 2002 Jun;6(3):193-201.
    PMID: 12186754
    Ty1-copia-like retrotransposons have been identified and investigated in several plant species. Here, the internal region of the reverse transcriptase (RT) gene of Ty1-copia-like retrotransposons was amplified by PCR from total genomic DNA of 10 varieties of banana. Two to four clones from each variety were sequenced. Extreme heterogeneity in the sequences of Ty1-copia-like retrotransposons from all the varieties was revealed following sequence analysis of the reverse transcriptase (RT) fragments. The size of the individual RT gene fragments varied between 213 and 309 bp. Southern blots of genomic DNA digested from Musa acuminata and other banana varieties probed with W8 clone from M. acuminata and A4 clone from Pisang Abu Nipah showed similar strong, multiple restriction fragments together with other faint hybridization band patterns with variable intensities indicating the presence of many copies of the Ty1-copia-like retrotransposons in the genomes. There was no correlation between retroelement sequence and the banana species (with A or B genomes) from which it arose, suggesting that the probes are not useful for tracking genomes through breeding populations.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  13. Hashimoto K, Watanobe T, Liu CX, Init I, Blair D, Ohnishi S, et al.
    Parasitol Res, 1997;83(3):220-5.
    PMID: 9089716
    For elucidation of the taxonomic status of the Japanese Fasciola species, whole mitochondrial DNA of Fasciola hepatica from Australia, F. gigantica from Malaysia, and Fasciola sp. from Japan was digested with three four-base-cutting endonucleases: HinfI, MspI, and RsaI. The resulting digestion patterns showed that for each enzyme there were some bands specific for each geographical isolate and that the Japanese Fasciola sp. shared more bands with F. gigantica than with F. hepatica. Nucleotide sequences of two regions, the second internal transcribed spacer (ITS2) of the nuclear ribosomal RNA cluster and mitochondrial cytochrome c oxidase subunit I (COI), were also compared among them. The ITS2 sequence was highly conserved among the three isolates. F. gigantica and the Japanese Fasciola sp. were identical, but they differed from the Australian F. hepatica at six sites, one of which was a deletion. The COI sequence was less conserved but implied a similar relationship between the isolates. There seems no reason to regard the Japanese Fasciola sp. as anything other than a strain of F. gigantica.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  14. Poidinger M, Hall RA, Mackenzie JS
    Virology, 1996 Apr 15;218(2):417-21.
    PMID: 8610471
    The Japanese encephalitis (JE) serocomplex of flaviviruses comprises 10 members, 9 of which: Alfuy (ALF); Koutango (KOU); Kokobera (KOK); Kunjin (KUN); Murray Valley encephalitis (MVE); JE; Stratford (STR); Usutu (USU); and West Nile (WN) have been isolated from Africa, southern Europe, Middle East, Asia, and Australia. The tenth member, St. Louis encephalitis (SLE) virus, is confined to North, Central, and South America. For ALF, KOK, KOU, STR, and USU, no sequence data have as yet been reported, and little molecular phylogeny has been determined for this complex as a whole. Using a rapid, one-step RT-PCR and universal primers, we have amplified and sequenced a 450-600 base pair region of the virus genome encompassing the N terminus of the nonstructural protein NS5 and the 5' end of the 3' noncoding region, for several strains of all of these viruses, except USU and SLE viruses. These data, as well as published sequence data for other flaviviruses, were analyzed with the ClustalW and Phylip computer packages. The resultant phylogenetic data were consistent with some of the current flavivirus serological classification, showing a close relationship between ALF and MVE viruses and between KOK and STR viruses, but suggested that KOK and STR are distantly related to the other viruses and should perhaps be reclassified in their own serocomplex. The data also confirmed the close relationship between KUN and WN viruses and showed that an isolate of KUN virus from Sarawak may represent a "link" between these two virus species. In addition, the primary sequence data revealed a polymorphic region just downstream of the stop codon in the 3' end of the viral genomes.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  15. Lithanatudom SK, Chaowasku T, Nantarat N, Jaroenkit T, Smith DR, Lithanatudom P
    Sci Rep, 2017 07 27;7(1):6716.
    PMID: 28751754 DOI: 10.1038/s41598-017-07045-7
    Dimocarpus longan, commonly known as the longan, belongs to the family Sapindaceae, and is one of the most economically important fruits commonly cultivated in several regions in Asia. There are various cultivars of longan throughout the Thai-Malay peninsula region, but until now no phylogenetic analysis has been undertaken to determine the genetic relatedness of these cultivars. To address this issue, 6 loci, namely ITS2, matK, rbcL, trnH-psbA, trnL-I and trnL-trnF were amplified and sequenced from 40 individuals consisting of 26 longan cultivars 2 types of lychee and 8 herbarium samples. The sequencing results were used to construct a phylogenetic tree using the neighbor-joining (NJ), maximum likelihood (ML) and Bayesian inference (BI) criteria. The tree showed cryptic groups of D. longan from the Thailand-Malaysia region (Dimocarpus longan spp.). This is the first report of the genetic relationship of Dimocarpus based on multi-locus molecular markers and morphological characteristics. Multiple sequence alignments, phylogenetic trees and species delimitation support that Dimocarpus longan spp. longan var. obtusus and Dimocarpus longan spp. malesianus var. malesianus should be placed into a higher order and are two additional species in the genus Dimocarpus. Therefore these two species require nomenclatural changes as Dimocarpus malesianus and Dimocarpus obtusus, respectively.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  16. Mulders MN, Lipskaya GY, van der Avoort HG, Koopmans MP, Kew OM, van Loon AM
    J Infect Dis, 1995 Jun;171(6):1399-405.
    PMID: 7769273
    The genomic relationships of wild poliovirus type 1 strains recently isolated in Europe, the Middle East, and the Indian subcontinent was analyzed by automated amplicon sequencing of the VP1/2A junction region of the genome. Four major genotypes of poliovirus type 1 were found to circulate. Two genotypes were found predominantly in Eastern Europe, one of these in the Caucasian Region and the other in countries bordering the Black Sea. A third genotype circulated mainly in Egypt. The fourth and largest genotype circulated in the largest geographic area. Strains belonging to this genotype could be found in countries as far apart as Malaysia and Ukraine. Considerable genetic variation was observed among strains isolated in Egypt, Pakistan, and India, where poliovirus is endemic. Strains belonging to all four genotypes circulated in Pakistan. Data confirm the extent of poliovirus circulation in certain regions, stressing the need for intensification of vaccination in these regions.
    Matched MeSH terms: Sequence Homology, Nucleic Acid
  17. Xiao K, Zhai J, Feng Y, Zhou N, Zhang X, Zou JJ, et al.
    Nature, 2020 07;583(7815):286-289.
    PMID: 32380510 DOI: 10.1038/s41586-020-2313-x
    The current outbreak of coronavirus disease-2019 (COVID-19) poses unprecedented challenges to global health1. The new coronavirus responsible for this outbreak-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-shares high sequence identity to SARS-CoV and a bat coronavirus, RaTG132. Although bats may be the reservoir host for a variety of coronaviruses3,4, it remains unknown whether SARS-CoV-2 has additional host species. Here we show that a coronavirus, which we name pangolin-CoV, isolated from a Malayan pangolin has 100%, 98.6%, 97.8% and 90.7% amino acid identity with SARS-CoV-2 in the E, M, N and S proteins, respectively. In particular, the receptor-binding domain of the S protein of pangolin-CoV is almost identical to that of SARS-CoV-2, with one difference in a noncritical amino acid. Our comparative genomic analysis suggests that SARS-CoV-2 may have originated in the recombination of a virus similar to pangolin-CoV with one similar to RaTG13. Pangolin-CoV was detected in 17 out of the 25 Malayan pangolins that we analysed. Infected pangolins showed clinical signs and histological changes, and circulating antibodies against pangolin-CoV reacted with the S protein of SARS-CoV-2. The isolation of a coronavirus from pangolins that is closely related to SARS-CoV-2 suggests that these animals have the potential to act as an intermediate host of SARS-CoV-2. This newly identified coronavirus from pangolins-the most-trafficked mammal in the illegal wildlife trade-could represent a future threat to public health if wildlife trade is not effectively controlled.
    Matched MeSH terms: Sequence Homology, Nucleic Acid*
  18. Slack AT, Khairani-Bejo S, Symonds ML, Dohnt MF, Galloway RL, Steigerwalt AG, et al.
    Int J Syst Evol Microbiol, 2009 Apr;59(Pt 4):705-8.
    PMID: 19329592 DOI: 10.1099/ijs.0.002766-0
    A single Leptospira strain (designated Bejo-Iso9(T)) was isolated from a soil sample taken in Johor, Malaysia. The isolate showed motility and morphology typical of the genus Leptospira under dark-field microscopy. Cells were found to be 10-13 microm in length and 0.2 microm in diameter, with a wavelength of 0.5 microm and an amplitude of approximately 0.2 microm. Phenotypically, strain Bejo-Iso9(T) grew in Ellinghausen-McCullough-Johnson-Harris medium at 13, 30 and 37 degrees C, and also in the presence of 8-azaguanine. Serologically, strain Bejo-Iso9(T) produced titres towards several members of the Tarassovi serogroup, but was found to be serologically unique by cross-agglutinin absorption test and thus represented a novel serovar. The proposed name for this serovar is Malaysia. Phylogenetic analysis of 16S rRNA gene sequences placed this novel strain within the radiation of the genus Leptospira, with sequence similarities within the range 90.4-99.5% with respect to recognized Leptospira species. DNA-DNA hybridization against the three most closely related Leptospira species was used to confirm the results of the 16S rRNA gene sequence analysis. The G+C content of the genome of strain Bejo-Iso9(T) was 36.2 mol%. On the basis of phenotypic, serological and phylogenetic data, strain Bejo-Iso9(T) represents a novel species of the genus Leptospira, for which the name Leptospira kmetyi sp. nov. is proposed. The type strain is Bejo-Iso9(T) (=WHO LT1101(T)=KIT Bejo-Iso9(T)).
    Matched MeSH terms: Sequence Homology, Nucleic Acid
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