34 resultados para Decamer
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Des de l'origen de les llengües, els pobles han tingut la necessitat de fer-se entendre. La traducció és una eina fonamental en la difusió i el coneixement de la diversitat, i el traductor, la peça que facilita l'apropament de les cultures. Però a l'hora de portar a terme el seu objectiu, no tots els traductors ho fan de la mateixa manera. Cal tenir en compte factors temporals, culturals, històrics, referencials, lingüístics, socials... elements que determinen el resultat final d'una traducció i les diferències entre les traduccions d'un mateix text. En aquest treball em proposo determinar les diferents estratègies que els traductors han seguit a l'hora de traduir al català el conte novè de la quarta jornada del Decameró de Giovanni Boccaccio.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The reactivity of three hexacationic arene ruthenium metallaprisms towards isolated nucleotides and a short DNA strand was investigated using NMR spectroscopy, ESI mass spectrometry, UV/Vis and circular dichroism spectroscopy. The metallaprism built from oxalato-bridging ligands reacts rapidly in the presence of deoxyguanosine monophosphate (dGMP) and deoxyadenosine monophosphate, while the benzoquinonato derivative only reacts with dGMP. On the other hand, the larger metallaprism incorporating naphtoquinonato bridges remains stable in the presence of nucleotides. The reactivity of the three hexacationic metallaprisms with the decameric oligonucleotide d(CGCGATCGCG)2 was also investigated. Analysis of the NMR, MS, UV/Vis and CD data suggests that no adducts are formed between the oligonucleotide and the metallaprisms, but electrostatic interactions, leading to partial unwinding of the double-stranded oligonucleotide, were evidenced
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A dumbbell double-stranded DNA decamer tethered with a hexaethylene glycol linker moiety (DDSDPEG), with a nick in the centre of one strand, has been synthesised. The standard NMR methods, E.COSY, TOCSY, NOESY and HMQC, were used to measure 1H, 31P and T1 spectral parameters. Molecular modelling using rMD-simulated annealing was used to compute the structure. Scalar couplings and dipolar contacts show that the molecule adopts a right-handed B-DNA helix in 38 mM phosphate buffer at pH 7. Its high melting temperature confirms the good base stacking and stability of the duplex. This is partly attributed to the presence of the PEG6 linker at both ends of the duplex that restricts the dynamics of the stem pentamers and thus stabilises the oligonucleotide. The inspection of the global parameters shows that the linker does not distort the B-DNA geometry. The computed structure suggests that the presence of the nick is not disturbing the overall tertiary structure, base pair geometry or duplex base pairing to a substantial extent. The nick has, however, a noticeable impact on the local geometry at the nick site, indicated clearly by NMR analysis and reflected in the conformational parameters of the computed structure. The 1H spectra also show much sharper resonances in the presence of K+ indicating that conformational heterogeneity of DDSDPEG is reduced in the presence of potassium as compared to sodium or caesium ions. At the same time the 1H resonances have longer T1 times. This parameter is suggested as a sensitive gauge of stabilisation.
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The crystal structure of the decanucleotide d(CGCAATTGCG)2 has been solved by a combination of molecular replacement and heavy-atom procedures and has been refined to an R factor of 20.2% at 2.7 A. It is not a fully base-paired duplex but has a central core of eight Watson-Crick base pairs flanked by unpaired terminal guanosines and cytosines. These participate in hydrogen-bonding arrangements with adjacent decamer duplexes in the crystal lattice. The unpaired guanosines are bound in the G+C regions of duplex minor grooves. The cytosines have relatively high mobility, even though they are constrained to be in one region where they are involved in base-paired triplets with G.C base pairs. The 5'-AATT sequence in the duplex region has a narrow minor groove, providing further confirmation of the sequence-dependent nature of groove width.
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Genetic diversity in Cassia brewsteri (F. Muell.) F. Muell. ex Benth. was assessed with Randomly Amplified DNA Fingerprints (RAFs). Thirty accessions of C. brewsteri collected from throughout its natural distribution were analysed with three random decamer primers, along with three accessions of C. tomentella (Benth.) Domin and a single accession of each of C. queenslandica C. T. White and C. marksiana (F. M. Bailey) Domin. The three primers yielded a reproducible amplification profile of 265 scorable polymorphic fragments for the 35 accessions. These molecular markers were used to calculate Nei and Li similarity coefficients between each pair of individuals. A matrix of dissimilarity of each pair of individuals was examined by multidimensional scaling (MDS). The analysis supports the division of C. brewsteri into two subspecies and the suggestion that intergradation of C. brewsteri and C. tomentella can occur where the distributions of these species meet.
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The phlebotomine sand fly Lutzomyia longipalpis has been incriminated as a vector of American visceral leishmaniasis, caused by Leishmania chagasi. However, some evidence has been accumulated suggesting that it may exist in nature not as a single but as a species complex. Our goal was to compare four laboratory reference populations of L. longipalpis from distinct geographic regions at the molecular level by RAPD-PCR. We screened genomic DNA for polymorphic sites by PCR amplification with decamer single primers of arbitrary nucleotide sequences. One primer distinguished one population (Marajó Island, Pará State, Brazil) from the other three (Lapinha Cave, Minas Gerais State, Brazil; Melgar, Tolima Department, Colombia and Liberia, Guanacaste Province, Costa Rica). The population-specific and the conserved RAPD-PCR amplified fragments were cloned and shown to differ only in number of internal repeats.
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PLOS ONE, 4(8):ARTe6820
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P-selectin glycoprotein ligand-1 (PSGL-1) interacts with selectins to support leukocyte rolling along vascular wall. L- and P-selectin bind to N-terminal tyrosine sulfate residues and to core-2 O-glycans attached to Thr-57, whereas tyrosine sulfation is not required for E-selectin binding. PSGL-1 extracellular domain contains decameric repeats, which extend L- and P-selectin binding sites far above the plasma membrane. We hypothesized that decamers may play a role in regulating PSGL-1 interactions with selectins. Chinese hamster ovary cells expressing wild-type PSGL-1 or PSGL-1 molecules exhibiting deletion or substitution of decamers with the tandem repeats of platelet glycoprotein Ibalpha were compared in their ability to roll on selectins and to bind soluble L- or P-selectin. Deletion of decamers abrogated soluble L-selectin binding and cell rolling on L-selectin, whereas their substitution partially reversed these diminutions. P-selectin-dependent interactions with PSGL-1 were less affected by decamer deletion. Videomicroscopy analysis showed that decamers are required to stabilize L-selectin-dependent rolling. Importantly, adhesion assays performed on recombinant decamers demonstrated that they directly bind to E-selectin and promote slow rolling. Our results indicate that the role of decamers is to extend PSGL-1 N terminus far above the cell surface to support and stabilize leukocyte rolling on L- or P-selectin. In addition, they function as a cell adhesion receptor, which supports approximately 80% of E-selectin-dependent rolling.
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HLA-A2-restricted cytolytic T cells specific for the immunodominant human tumor Ag Melan-A(MART-1) can kill most HLA-matched melanoma cells, through recognition of two naturally occurring antigenic variants, i.e., Melan-A nonamer AAGIGILTV and decamer EAAGIGILTV peptides. Several previous studies have suggested a high degree of TCR cross-reactivity to the two peptides. In this study, we describe for the first time that some T cell clones are exclusively nonamer specific, because they are not labeled by A2/decamer-tetramers and do not recognize the decamer when presented endogenously. Functional assays with peptides gave misleading results, possibly because decamers were cleaved by exopeptidases. Interestingly, nonapeptide-specific T cell clones were rarely Valpha2.1 positive (only 1 of 19 clones), in contrast to the known strong bias for Valpha2.1-positive TCRs found in decamer-specific clones (59 of 69 clones). Molecular modeling revealed that nonapeptide-specific TCRs formed unfavorable interactions with the decapeptide, whereas decapeptide-specific TCRs productively created a hydrogen bond between CDR1alpha and glutamic acid (E) of the decapeptide. Ex vivo analysis of T cells from melanoma metastases demonstrated that both nonamer and decamer-specific T cells were enriched to substantial frequencies in vivo, and representative clones showed efficient tumor cell recognition and killing. We conclude that the two peptides should be regarded as distinct epitopes when analyzing tumor immunity and developing immunotherapy against melanoma.
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In vitro regeneration of Arachis retusa was examined for the purpose of germplasm renewal and conservation. Random amplified polymorphic DNA (RAPD) fingerprinting was used to evaluate the genetic stability of plants derived from embryo axes and apical segments. Ten arbitrary decamer primers were screened and five of them were selected. Ninety genomic regions were evaluated, with an average of 18 loci per clone. All amplified segments were monomorphic. The results indicate that recovered plants are genetically stable at the assessed genomic regions and that both regeneration processes are suitable for in vitro germplasm preservation of Arachis species.
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The objective of this study was to verify the genetic diversity between and within seven populations of Moxotó goat (n = 264) from the States of Pernambuco, Paraíba and Rio Grande do Norte, using RAPD (Random Amplified Polymorphic DNA). Moxotó, as well as other naturalized breeds, suffers genetic losses due to the indiscriminate miscegenation with breeds raised in the Northeast Region of Brazil. The genetic characterization of these genetic resources is essential to conservation and breeding programs. DNA was extracted from lymphocytes using a non-organic protocol. The 16 primers used were selected from 120 decamer oligonucleotide primers and generated 56 polymorphic bands. The analysis of molecular variance (AMOVA) showed that the greater part of total genetic variability (71.55%) was due to differences between individuals within populations, while 21.21% was among populations. The analysis of variance among the pairs of populations demonstrated that the populations located in Floresta, PE x Angicos, RN presented a smaller value of intrapopulational differentiation (8.9%), indicating low genetic variability among them. Nei's genetic distances varied between 0.0546 and 0.1868 in the populations. The dendrogram generated showed that the Canindé breed, used as outgroup, clustered with the populations of Moxotó, indicating a possible common origin of the naturalized goat breeds.
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We have determined high-resolution crystal structures of the complexes of HLA-A2 molecules with two modified immunodominant peptides from the melanoma tumor-associated protein Melan-A/Melanoma Ag recognized by T cells-1. The two peptides, a decamer and nonamer with overlapping sequences (ELAGIGILTV and ALGIGILTV), are modified in the second residue to increase their affinity for HLA-A2. The modified decamer is more immunogenic than the natural peptide and a candidate for peptide-based melanoma immunotherapy. The crystal structures at 1.8 and 2.15 A resolution define the differences in binding modes of the modified peptides, including different clusters of water molecules that appear to stabilize the peptide-HLA interaction. The structures suggest both how the wild-type peptides would bind and how three categories of cytotoxic T lymphocytes with differing fine specificity might recognize the two peptides.
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Es proposa fer un estudi d'un col·loqui valencià de l'època baix medieval, molt poc conegut i emmarcat en la literatura satírica valenciana. Es contextualitza l'obra en el corrent satíric valencià de l'època i s'analitza el text i els personatges en relació als tòpics del gènere (anticlericalisme, misogínia, erotisme i incapacitat sexual). L'anàlisi dels personatges descriu tots els tipus establerts (la vídua, el vell, l'alcavota, el clergue, el burgès, etc.). L'estudi fa també un acostament comparatiu a d'altres obres satíriques de l'època en d'altres literatures, com el Decameró i Els contes de Canterbury.
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In HLA-A2 individuals, the CD8 T cell response against the differentiation Ag Melan-A is mainly directed toward the peptide Melan-A26-35. The murine Melan-A24-33 sequence encodes a peptide that is identical with the human Melan-A26-35 decamer, except for a Thr-to-Ile substitution at the penultimate position. Here, we show that the murine Melan-A24-33 is naturally processed and presented by HLA-A2 molecules. Based on these findings, we compared the CD8 T cell response to human and murine Melan-A peptide by immunizing HLA-A2 transgenic mice. Even though the magnitude of the CTL response elicited by the murine Melan-A peptide was lower than the one elicited by the human Melan-A peptide, both populations of CTL recognized the corresponding immunizing peptide with the same functional avidity. Interestingly, CTL specific for the murine Melan-A peptide were completely cross-reactive against the orthologous human peptide, whereas anti-human Melan-A CTL recognized the murine Melan-A peptide with lower avidity. Structurally, this discrepancy could be explained by the fact that Ile32 of murine Melan-A24-33 created a larger TCR contact area than Thr34 of human Melan-A26-35. These data indicate that, even if immunizations with orthologous peptides can induce strong specific T cell responses, the quality of this response against syngeneic targets might be suboptimal due to the structure of the peptide-TCR contact surface.