967 resultados para Velasco, Lucio P.


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Detailed mechanisms for the formation of hydroxyl or alkoxyl radicals in the reactions between tetrachloro-p-benzoquinone (TCBQ) and organic hydroperoxides are crucial for better understanding the potential carcinogenicity of polyhalogenated quinones. Herein, the mechanism of the reaction between TCBQ and H2O2 has been systematically investigated at the B3LYP/6-311++G** level of theory in the presence of different numbers of water molecules. We report that the whole reaction can easily take place with the assistance of explicit water molecules. Namely, an initial intermediate is formed first. After that, a nucleophilic attack of H2O2 onto TCBQ occurs, which results in the formation of a second intermediate that contains an OOH group. Subsequently, this second intermediate decomposes homolytically through cleavage of the O-O bond to produce a hydroxyl radical. Energy analyses suggest that the nucleophilic attack is the rate-determining step in the whole reaction. The participation of explicit water molecules promotes the reaction significantly, which can be used to explain the experimental phenomena. In addition, the effects of F, Br, and CH3 substituents on this reaction have also been studied.

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Linkage disequilibrium (LD) mapping is commonly used as a fine mapping tool in human genome mapping and has been used with some success for initial disease gene isolation in certain isolated in-bred human populations. An understanding of the population history of domestic dog breeds suggests that LD mapping could be routinely utilized in this species for initial genome-wide scans. Such an approach offers significant advantages over traditional linkage analysis. Here, we demonstrate, using canine copper toxicosis in the Bedlington terrier as the model, that LD mapping could be reasonably expected to be a useful strategy in low-resolution, genome-wide scans in pure-bred dogs. Significant LD was demonstrated over distances up to 33.3 cM. It is very unlikely, for a number of reasons discussed, that this result could be extrapolated to the rest of the genome. It is, however, consistent with the expectation given the population structure of canine breeds and, in this breed at least, with the hypothesis that it may be possible to utilize LD in a genome-wide scan. In this study, LD mapping confirmed the location of the copper toxicosis in Bedlington terrier gene (CT-BT) and was able to do so in a population that was refractory to traditional linkage analysis.

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A high performance liquid chromatographic method for the simultaneous determination of five organochlorine pesticides (aldrin, p,€™-DDT, dieldrin, endrin, and heptachlor) was developed. The method was used to determine the levels of these pesticides in medicinal plant samples. Analysis was carried out using a Merck LiChrospher 100 RP C18 (5 μm) column with a gradient solvent system of acetonitrile-water and PDA UV detection (224 nm). Quantification was carried out by the external standard method. The limit of detection for the utilized method was below the local legal limits (ANZFA) for similar plant materials for all 5 pesticides excepting endrin. Medicinal plant extracts were further analyzed by conventional GC-ECD and GC-NPD means using SPE and GPC cleanup as required.

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Like most Australian states, the New South Wales Graduated Driver Licensing system requires all provisionally licensed drivers to display ‘P plates’ on their vehicle to indicate their licence status and facilitate enforcement. This paper examines whether the display of P plates increases compliance with driving laws in New South Wales. The driving behaviours of provisional drivers who reported always displaying their P plates were compared with those of drivers who sometimes drove without displaying their P plates. While no differences were found between the two groups on some behaviours, provisional drivers who did not always display their P plates indicated that they were less likely to obey the provisional speed limit and more likely to break the road rules if they knew they would not be caught. These results suggest that the requirement to display a P plate remains a priority to facilitate more general traffic law enforcement initiatives.

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Introduction: The delivery of health care in the 21st century will look like no other in the past. The fast paced technological advances that are being made will need to transition from the information age into clinical practice. The phenomenon of e-Health is the over-arching form of information technology and telehealth is one arm of that phenomenon. The uptake of telehealth both in Australia and overseas, has changed the face of health service delivery to many rural and remote communities for the better, removing what is known as the tyranny of distance. Many studies have evaluated the satisfaction and cost-benefit analysis of telehealth across the organisational aspects as well as the various adaptations of clinical pathways and this is the predominant focus of most studies published to date. However, whilst comments have been made by many researchers about the need to improve and attend to the communication and relationship building aspects of telehealth no studies have examined this further. The aim of this study was to identify the patient and clinician experiences, concerns, behaviours and perceptions of the telehealth interaction and develop a training tool to assist these clinicians to improve their interaction skills. Methods: A mixed methods design combining quantitative (survey analysis and data coding) and qualitative (interview analysis) approaches was adopted. This study utilised four phases to firstly qualitatively explore the needs of clients (patients) and clinicians within a telehealth consultation then designed, developed, piloted and quantitatively and qualitatively evaluated the telehealth communication training program. Qualitative data was collected and analysed during Phase 1 of this study to describe and define the missing 'communication and rapport building' aspects within telehealth. This data was then utilised to develop a self-paced communication training program that enhanced clinicians existing skills, which comprised of Phase 2 of this study to develop the interactive program. Phase 3 included evaluating the training program with 26 clinicians and results were recorded pre and post training, whilst phase 4 was the pilot for future recommendations of this training program using a patient group within a Queensland Health setting at two rural hospitals. Results: Comparisons of pre and post training data on 1) Effective communication styles, 2) Involvement in communication training package, 3) satisfaction pre and post training, and 4) health outcomes pre and post training indicated that there were differences between pre and post training in relation to effective communication style, increased satisfaction and no difference in health outcomes between pre and post training for this patient group. The post training results revealed over half of the participants (N= 17, 65%) were more responsive to non-verbal cues and were better able to reflect and respond to looks of anxiousness and confusion from a 'patient' within a telehealth consultation. It was also found that during post training evaluations, clinicians had enhanced their therapeutic communication with greater detail to their own body postures, eye contact and presentation. There was greater time spent looking at the 'patient' with an increase of 35 second intervals of direct eye contact and less time spent looking down at paperwork which decreased by 20 seconds. Overall 73% of the clinicians were satisfied with the training program and 61% strongly agreed that they recognised areas of their communication that needed improving during a telehealth consultation. For the patient group there was significant difference post training in rapport with a mean score from 42 (SD = 28, n = 27) to 48 (SD = 5.9, n = 24). For communication comfort of the patient group there was a significant difference between the pre and post training scores t(10) = 27.9, p = .002, which meant that overall the patients felt less inhibited whilst talking to the clinicians and more understood. Conclusion: The aim of this study was to explore the characteristics of good patient-clinician communication and unmet training needs for telehealth consultations. The study developed a training program that was specific for telehealth consultations and not dependent on a 'trainer' to deliver the content. In light of the existing literature this is a first of its kind and a valuable contribution to the research on this topic. It was found that the training program was effective in improving the clinician's communication style and increased the satisfaction of patient's within an e-health environment. This study has identified some historical myths that telehealth cannot be part of empathic patient centred care due to its technology tag.

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The nanostructured surface of biomaterials plays an important role in improving their in vitro cellular bioactivity as well as stimulating in vivo tissue regeneration. Inspired by the mussel’s adhesive versatility, which is thought to be due to the plaque–substrate interface being rich in 3,4-dihydroxy-L-phenylalamine (DOPA) and lysine amino acids, in this study we developed a self-assembly method to prepare a uniform calcium phosphate (Ca-P)/polydopamine composite nanolayer on the surface of b-tricalcium phosphate (b-TCP) bioceramics by soaking b-TCP bioceramics in Tris–dopamine solution. It was found that the addition of dopamine, reaction temperature and reaction time are three key factors inducing the formation of a uniform Ca-P/polydopamine composite nanolayer. The formation mechanism of a Ca-P/polydopamine composite nanolayer involved two important steps: (i) the addition of dopamine to Tris–HCl solution decreases the pH value and accelerates Ca and P ionic dissolution from the crystal boundaries of b-TCP ceramics; (ii) dopamine is polymerized to form self-assembled polydopamine film and, at the same time, nanosized Ca-P particles are mineralized with the assistance of polydopamine, in which the formation of polydopamine occurs simultaneously with Ca-P mineralization (formation of nanosized microparticles composed of calcium phosphate-based materials), and finally a self-assembled Ca-P/polydopamine composite nanolayer forms on the surface of the b-TCP ceramics. Furthermore, the formed self-assembled Ca-P/polydopamine composite nanolayer significantly enhances the surface roughness and hydrophilicity of b-TCP ceramics, and stimulates the attachment, proliferation, alkaline phosphate (ALP) activity and bone-related gene expression (ALP, OCN, COL1 and Runx2) of human bone marrow stromal cells. Our results suggest that the preparation of self-assembled Ca-P/polydopamine composite nanolayers is a viable method to modify the surface of biomaterials by significantly improving their surface physicochemical properties and cellular bioactivity for bone regeneration application.

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BACKGROUND: In single-group studies, chromosomal rearrangements of the anaplastic lymphoma kinase gene (ALK ) have been associated with marked clinical responses to crizotinib, an oral tyrosine kinase inhibitor targeting ALK. Whether crizotinib is superior to standard chemotherapy with respect to efficacy is unknown. METHODS: We conducted a phase 3, open-label trial comparing crizotinib with chemotherapy in 347 patients with locally advanced or metastatic ALK-positive lung cancer who had received one prior platinum-based regimen. Patients were randomly assigned to receive oral treatment with crizotinib (250 mg) twice daily or intravenous chemotherapy with either pemetrexed (500 mg per square meter of body-surface area) or docetaxel (75 mg per square meter) every 3 weeks. Patients in the chemotherapy group who had disease progression were permitted to cross over to crizotinib as part of a separate study. The primary end point was progression-free survival. RESULTS: The median progression-free survival was 7.7 months in the crizotinib group and 3.0 months in the chemotherapy group (hazard ratio for progression or death with crizotinib, 0.49; 95% confidence interval [CI], 0.37 to 0.64; P<0.001). The response rates were 65% (95% CI, 58 to 72) with crizotinib, as compared with 20% (95% CI, 14 to 26) with chemotherapy (P<0.001). An interim analysis of overall survival showed no significant improvement with crizotinib as compared with chemotherapy (hazard ratio for death in the crizotinib group, 1.02; 95% CI, 0.68 to 1.54; P=0.54). Common adverse events associated with crizotinib were visual disorder, gastrointestinal side effects, and elevated liver aminotransferase levels, whereas common adverse events with chemotherapy were fatigue, alopecia, and dyspnea. Patients reported greater reductions in symptoms of lung cancer and greater improvement in global quality of life with crizotinib than with chemotherapy. CONCLUSIONS: Crizotinib is superior to standard chemotherapy in patients with previously treated, advanced non-small-cell lung cancer with ALK rearrangement. (Funded by Pfizer; ClinicalTrials.gov number, NCT00932893.) Copyright © 2013 Massachusetts Medical Society.

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The E&P sector can learn much about asset maintenance from the space and satellite industry. Practitioners from both the upstream oil and gas industry and the space and satellite sector have repeatedly noted several striking similarities between the two industries over the years, which have in turn resulted in many direct comparisons in the media and industry press. The similarities between the two industries have even resulted in a modest amount of cross-pollinating between the respective supply chains. Because the operating conditions of both industries are so extreme, some oil and gas equipment vendors have occasionally sourced motors and other parts from aerospace contractors. Also, satellites are now being used to assess oil fires, detect subsidence in oil fields, measure oil spills, collect and transmit operational data from oil and gas fields, and monitor the movement of icebergs that might potentially collide with offshore oil and gas installations.

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A method is proposed to describe force or compound muscle action potential (CMAP) trace data collected in an electromyography study for motor unit number estimation (MUNE). Experimental data was collected using incre- mental stimulation at multiple durations. However, stimulus information, vital for alternate MUNE methods, is not comparable for multiple duration data and therefore previous methods of MUNE (Ridall et al., 2006, 2007) cannot be used with any reliability. Hypothesised ring combinations of motor units are mod- elled using a multiplicative factor and Bayesian P-spline formulation. The model describes the process for force and CMAP in a meaningful way.

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Anthocyanin accumulation is coordinated in plants by a number of conserved transcription factors. In apple (Malus × domestica), an R2R3 MYB transcription factor has been shown to control fruit flesh and foliage anthocyanin pigmentation (MYB10) and fruit skin color (MYB1). However, the pattern of expression and allelic variation at these loci does not explain all anthocyanin-related apple phenotypes. One such example is an open-pollinated seedling of cv Sangrado that has green foliage and develops red flesh in the fruit cortex late in maturity. We used methods that combine plant breeding, molecular biology, and genomics to identify duplicated MYB transcription factors that could control this phenotype. We then demonstrated that the red-flesh cortex phenotype is associated with enhanced expression of MYB110a, a paralog of MYB10. Functional characterization of MYB110a showed that it was able to up-regulate anthocyanin biosynthesis in tobacco (Nicotiana tabacum). The chromosomal location of MYB110a is consistent with a whole-genome duplication event that occurred during the evolution of apple within the Maloideae family. Both MYB10 and MYB110a have conserved function in some cultivars, but they differ in their expression pattern and response to fruit maturity.

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As high-throughput genetic marker screening systems are essential for a range of genetics studies and plant breeding applications, the International RosBREED SNP Consortium (IRSC) has utilized the Illumina Infinium® II system to develop a medium- to high-throughput SNP screening tool for genome-wide evaluation of allelic variation in apple (Malus×domestica) breeding germplasm. For genome-wide SNP discovery, 27 apple cultivars were chosen to represent worldwide breeding germplasm and re-sequenced at low coverage with the Illumina Genome Analyzer II. Following alignment of these sequences to the whole genome sequence of 'Golden Delicious', SNPs were identified using SoapSNP. A total of 2,113,120 SNPs were detected, corresponding to one SNP to every 288 bp of the genome. The Illumina GoldenGate® assay was then used to validate a subset of 144 SNPs with a range of characteristics, using a set of 160 apple accessions. This validation assay enabled fine-tuning of the final subset of SNPs for the Illumina Infinium® II system. The set of stringent filtering criteria developed allowed choice of a set of SNPs that not only exhibited an even distribution across the apple genome and a range of minor allele frequencies to ensure utility across germplasm, but also were located in putative exonic regions to maximize genotyping success rate. A total of 7867 apple SNPs was established for the IRSC apple 8K SNP array v1, of which 5554 were polymorphic after evaluation in segregating families and a germplasm collection. This publicly available genomics resource will provide an unprecedented resolution of SNP haplotypes, which will enable marker-locus-trait association discovery, description of the genetic architecture of quantitative traits, investigation of genetic variation (neutral and functional), and genomic selection in apple.

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We report a high-quality draft genome sequence of the domesticated apple (Malus × domestica). We show that a relatively recent (>50 million years ago) genome-wide duplication (GWD) has resulted in the transition from nine ancestral chromosomes to 17 chromosomes in the Pyreae. Traces of older GWDs partly support the monophyly of the ancestral paleohexaploidy of eudicots. Phylogenetic reconstruction of Pyreae and the genus Malus, relative to major Rosaceae taxa, identified the progenitor of the cultivated apple as M. sieversii. Expansion of gene families reported to be involved in fruit development may explain formation of the pome, a Pyreae-specific false fruit that develops by proliferation of the basal part of the sepals, the receptacle. In apple, a subclade of MADS-box genes, normally involved in flower and fruit development, is expanded to include 15 members, as are other gene families involved in Rosaceae-specific metabolism, such as transport and assimilation of sorbitol.

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The woodland strawberry, Fragaria vesca (2n = 2x = 14), is a versatile experimental plant system. This diminutive herbaceous perennial has a small genome (240 Mb), is amenable to genetic transformation and shares substantial sequence identity with the cultivated strawberry (Fragaria Ã- ananassa) and other economically important rosaceous plants. Here we report the draft F. vesca genome, which was sequenced to ×-39 coverage using second-generation technology, assembled de novo and then anchored to the genetic linkage map into seven pseudochromosomes. This diploid strawberry sequence lacks the large genome duplications seen in other rosids. Gene prediction modeling identified 34,809 genes, with most being supported by transcriptome mapping. Genes critical to valuable horticultural traits including flavor, nutritional value and flowering time were identified. Macrosyntenic relationships between Fragaria and Prunus predict a hypothetical ancestral Rosaceae genome that had nine chromosomes. New phylogenetic analysis of 154 protein-coding genes suggests that assignment of Populus to Malvidae, rather than Fabidae, is warranted.