982 resultados para Heterofunctional supports


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A series of 'pellicular' type supports were fabricated by direct gamma-radiation-mediated graft polymerisation of styrene onto polypropylene, followed by aminomethylation. Raman spectroscopy was used for measuring the level of penetration of polystyrene graft into polypropylene, and other structural features such as density of graft and depth of functionalisation. The kinetics of the coupling of fluorenylmethylcarbamate (Fmoc)-labelled amino acids, to the aminomethylated polystyrene grafts have been measured by UV absorption followed cleavage of the Fmoc chromophore. The Raman spectroscopy results showed that for this series of experiments the calculated rate coefficient for coupling of Fmoc-labelled amino acids was primarily dependent on graft thickness, but was also influenced by the proportion of polystyrene graft to polypropylene. In general, it was also shown that with increasing loading capacity of support the calculated rate coefficient for amino-acid coupling decreased correspondingly. In addition, a support that had both a high rate coefficient and a high loading capacity was prepared from polypropylene base material with a co-continuous porous structure (high surface area). (C) 2003 Society of Chemical Industry.

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Real structures can be thought as an assembly of components, as for instances plates, shells and beams. This later type of component is very commonly found in structures like frames which can involve a significant degree of complexity or as a reinforcement element of plates or shells. To obtain the desired mechanical behavior of these components or to improve their operating conditions when rehabilitating structures, one of the eventual parameters to consider for that purpose, when possible, is the location of the supports. In the present work, a beam-type structure is considered, and for a set of cases concerning different number and types of supports, as well as different load cases, the authors optimize the location of the supports in order to obtain minimum values of the maximum transverse deflection. The optimization processes are carried out using genetic algorithms. The results obtained, clearly show a good performance of the approach proposed. © 2014 IEEE.

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Selenium modified ruthenium electrocatalysts supported on carbon black were synthesized using NaBH4 reduction of the metal precursor. Prepared Ru/C electrocatalysts showed high dispersion and very small averaged particle size. These Ru/C electrocatalysts were subsequently modified with Se following two procedures: (a) preformed Ru/carbon catalyst was mixed with SeO2 in xylene and reduced in H2 and (b) Ru metal precursor was mixed with SeO2 followed by reduction with NaBH4. The XRD patterns indicate that a pyrite-type structure was obtained at higher annealing temperatures, regardless of the Ru:Se molar ratio used in the preparation step. A pyrite-type structure also emerged in samples that were not calcined; however, in this case, the pyrite-type structure was only prominent for samples with higher Ru:Se ratios. The characterization of the RuSe/C electrocatalysts suggested that the Se in noncalcined samples was present mainly as an amorphous skin. Preliminary study of activity toward oxygen reduction reaction (ORR) using electrocatalysts with a Ru:Se ratio of 1:0.7 indicated that annealing after modification with Se had a detrimental effect on their activity. This result could be related to the increased particle size of crystalline RuSe2 in heat-treated samples. Higher activity of not annealed RuSe/C catalysts could also be a result of the structure containing amorphous Se skin on the Ru crystal. The electrode obtained using not calcined RuSe showed a very promising performance with a slightly lower activity and higher overpotential in comparison with a commercial Pt/C electrode. Single wall carbon nanohorns (SWNH) were considered for application as ORR electrocatalysts' supports. The characterization of SWNH was carried out regarding their tolerance toward strong catalyzed corrosion conditions. Tests indicated that SWNH have a three times higher electrochemical surface area (ESA) loss than carbon black or Pt commercial electrodes.

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Bone tissue engineering requires a biocompatible scaffold that supports cell growth and enhances the native repair process. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV) is a biodegradable 3D scaffold with 88.1 â 0.3% porosity and pore size of 163.5 â 0.1 mm. Previous studies demonstrated the potential of PHB-HV as a scaffold in spinal cord repair. The aim of this study was to evaluate PHB-HV as a scaffold for bone regeneration by assessing the cytocompatability of this scaffold.

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Asthma is a chronic inflammatory disease of the airways that involves many cell types, amongst which mast cells are known to be important. Adenosine, a potent bronchoconstricting agent, exerts its ability to modulate adenosine receptors of mast cells thereby potentiating derived mediator release, histamine being one of the first mediators to be released. The heterogeneity of sources of mast cells and the lack of highly potent ligands selective for the different adenosine receptor subtypes have been important hurdles in this area of research. In the present study we describe compound C0036E08, a novel ligand that has high affinity (pK(i) 8.46) for adenosine A(2B) receptors, being 9 times, 1412 times and 3090 times more selective for A(2B) receptors than for A(1), A(2A) and A(3) receptors, respectively. Compound C0036E08 showed antagonist activity at recombinant and native adenosine receptors, and it was able to fully block NECA-induced histamine release in freshly isolated mast cells from human bronchoalveolar fluid. C0036E08 has been shown to be a valuable tool for the identification of adenosine A(2B) receptors as the adenosine receptors responsible for the NECA-induced response in human mast cells. Considering the increasing interest of A(2B) receptors as a therapeutic target in asthma, this chemical tool might provide a base for the development of new anti-asthmatic drugs.

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Increased male prevalence has been repeatedly reported in several neurodevelopmental disorders (NDs), leading to the concept of a "female protective model." We investigated the molecular basis of this sex-based difference in liability and demonstrated an excess of deleterious autosomal copy-number variants (CNVs) in females compared to males (odds ratio [OR] = 1.46, p = 8 × 10(-10)) in a cohort of 15,585 probands ascertained for NDs. In an independent autism spectrum disorder (ASD) cohort of 762 families, we found a 3-fold increase in deleterious autosomal CNVs (p = 7 × 10(-4)) and an excess of private deleterious single-nucleotide variants (SNVs) in female compared to male probands (OR = 1.34, p = 0.03). We also showed that the deleteriousness of autosomal SNVs was significantly higher in female probands (p = 0.0006). A similar bias was observed in parents of probands ascertained for NDs. Deleterious CNVs (>400 kb) were maternally inherited more often (up to 64%, p = 10(-15)) than small CNVs < 400 kb (OR = 1.45, p = 0.0003). In the ASD cohort, increased maternal transmission was also observed for deleterious CNVs and SNVs. Although ASD females showed higher mutational burden and lower cognition, the excess mutational burden remained, even after adjustment for those cognitive differences. These results strongly suggest that females have an increased etiological burden unlinked to rare deleterious variants on the X chromosome. Carefully phenotyped and genotyped cohorts will be required for identifying the symptoms, which show gender-specific liability to mutational burden.

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Dendritic cells (DCs) are professional APCs that have a role in the initiation of adaptive immune responses and tolerance. Among the tolerogenic mechanisms, the expression of the enzyme IDO1 represents an effective tool to generate T regulatory cells. In humans, different DC subsets express IDO1, but less is known about the IDO1-related enzyme IDO2. In this study, we found a different pattern of expression and regulation between IDO1 and IDO2 in human circulating DCs. At the protein level, IDO1 is expressed only in circulating myeloid DCs (mDCs) and is modulated by PGE2, whereas IDO2 is expressed in both mDCs and plasmacytoid DCs and is not modulated by PGE2. In healthy subjects, IDO1 expression requires the presence of PGE2 and needs continuous transcription and translation, whereas IDO2 expression is constitutive, independent from suppressor of cytokine signaling 3 activity. Conversely, in patients suffering from inflammatory arthritis, circulating DCs express both IDO1 and IDO2. At the functional level, both mDCs and plasmacytoid DCs generate T regulatory cells through an IDO1/IDO2-dependent mechanism. We conclude that, in humans, whereas IDO1 provides an additional mechanism of tolerance induced by proinflammatory mediators, IDO2 is stably expressed in steady-state conditions and may contribute to the homeostatic tolerogenic capacity of DCs.

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The population of industrialized societies has increased tremendously over the last century, raising the question on how an enhanced age affects cognition. The relevance of two models of healthy aging are contrasted in the present study that both target the functioning of the two cerebral hemispheres. The right hemi-aging model (RHAM) assumes that functions of the right hemisphere decline before those of the left hemisphere. The Hemispheric Asymmetry Reduction in Older Adults (HAROLD) Model suggests that the contralateral hemisphere supports the normally superior hemisphere in a given task resulting in a reduced hemispheric asymmetry overall. In a mixed design, 20 younger and 20 older adults performed both a task assessing a left (lateralized lexical decisions) and a right (sex decisions on chimeric faces) hemisphere advantage. Results indicated that lateralized performance in both tasks was attenuated in older as compared to younger adults, in particular in men. These observations support the HAROLD model. Future studies should investigate whether this reduced functional hemispheric asymmetry in older age results from compensatory processes or from a process of de-differentiation

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Brain invasion is a biological hallmark of glioma that contributes to its aggressiveness and limits the potential of surgery and irradiation. Deregulated expression of adhesion molecules on glioma cells is thought to contribute to this process. Junctional adhesion molecules (JAMs) include several IgSF members involved in leukocyte trafficking, angiogenesis, and cell polarity. They are expressed mainly by endothelial cells, white blood cells, and platelets. Here, we report JAM-C expression by human gliomas, but not by their normal cellular counterpart. This expression correlates with the expression of genes involved in cytoskeleton remodeling and cell migration. These genes, identified by a transcriptomic approach, include poliovirus receptor and cystein-rich 61, both known to promote glioma invasion, as well as actin filament associated protein, a c-Src binding partner. Gliomas also aberrantly express JAM-B, a high affinity JAM-C ligand. Their interaction activates the c-Src proto-oncogene, a central upstream molecule in the pathways regulating cell migration and invasion. In the tumor microenvironment, this co-expression may thus promote glioma invasion through paracrine stimuli from both tumor cells and endothelial cells. Accordingly, JAM-C/B blocking antibodies impair in vivo glioma growth and invasion, highlighting the potential of JAM-C and JAM-B as new targets for the treatment of human gliomas.

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The restriction fragment length polymorphism of the 195 bp repeated DNA sequence of Trypanosoma cruzi was analyzed among 23 T. cruzi stocks giving a reliable picture of the whole phylogenetic variability of the species. The profiles observed with the enzymes Hinf I and Hae III were linked together and supported the existence of two groups. Group 1 shows a 195 bp repeated unit (Hinf I) and high molecular weight DNA (Hae III), while group 2 presents a ladder profile for each enzyme, which is a characteristic of tandemly repeated DNA. The two groups, respectively, clustered stocks pertaining to the two principal lineages evidenced by isoenzyme and RAPD markers. The congruence among these three independent genomic markers corroborates the existence of two real phylogenetic lineages in T. cruzi. The specific monomorphic profiles for each major phylogenetic lineage suggest the existence of ancient sexuality and cryptic biological speciation.

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The genetic diversity of three temperate fruit tree phytoplasmas ‘Candidatus Phytoplasma prunorum’, ‘Ca. P. mali’ and ‘Ca. P. pyri’ has been established by multilocus sequence analysis. Among the four genetic loci used, the genes imp and aceF distinguished 30 and 24 genotypes, respectively, and showed the highest variability. Percentage of substitution for imp ranged from 50 to 68% according to species. Percentage of substitution varied between 9 and 12% for aceF, whereas it was between 5 and 6% for pnp and secY. In the case of ‘Ca P. prunorum’ the three most prevalent aceF genotypes were detected in both plants and insect vectors, confirming that the prevalent isolates are propagated by insects. The four isolates known to be hypo-virulent had the same aceF sequence, indicating a possible monophyletic origin. Haplotype network reconstructed by eBURST revealed that among the 34 haplotypes of ‘Ca. P. prunorum’, the four hypo-virulent isolates also grouped together in the same clade. Genotyping of some Spanish and Azerbaijanese ‘Ca. P. pyri’ isolates showed that they shared some alleles with ‘Ca. P. prunorum’, supporting for the first time to our knowledge, the existence of inter-species recombination between these two species.

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As Minister for Children, I am pleased to publish this paper which provides an overview of the income supports available for young parents. This paper has been commissioned as part of the evaluation of the Teenage Parents Support Initiative (TPSI) funded by the Department of Health and Children.The objective of this paper is to discuss the degree to which existing provision within the Irish welfare system meets the financial support needs of teenage parents, in particular, the level to which it meets the needs of different subgroups within the overall population of teenage parents. Download document here

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A sizable fraction of T cells expressing the NK cell marker NK1.1 (NKT cells) bear a very conserved TCR, characterized by homologous invariant (inv.) TCR V alpha 24-J alpha Q and V alpha 14-J alpha 18 rearrangements in humans and mice, respectively, and are thus defined as inv. NKT cells. Because human inv. NKT cells recognize mouse CD1d in vitro, we wondered whether a human inv. V alpha 24 TCR could be selected in vivo by mouse ligands presented by CD1d, thereby supporting the development of inv. NKT cells in mice. Therefore, we generated transgenic (Tg) mice expressing the human inv. V alpha 24-J alpha Q TCR chain in all T cells. The expression of the human inv. V alpha 24 TCR in TCR C alpha(-/-) mice indeed rescues the development of inv. NKT cells, which home preferentially to the liver and respond to the CD1d-restricted ligand alpha-galactosylceramide (alpha-GalCer). However, unlike inv. NKT cells from non-Tg mice, the majority of NKT cells in V alpha 24 Tg mice display a double-negative phenotype, as well as a significant increase in TCR V beta 7 and a corresponding decrease in TCR V beta 8.2 use. Despite the forced expression of the human CD1d-restricted TCR in C alpha(-/-) mice, staining with mCD1d-alpha-GalCer tetramers reveals that the absolute numbers of peripheral CD1d-dependent T lymphocytes increase at most by 2-fold. This increase is accounted for mainly by an increased fraction of NK1.1(-) T cells that bind CD1d-alpha-GalCer tetramers. These findings indicate that human inv. V alpha 24 TCR supports the development of CD1d-dependent lymphocytes in mice, and argue for a tight homeostatic control on the total number of inv. NKT cells. Thus, human inv. V alpha 24 TCR-expressing mice are a valuable model to study different aspects of the inv. NKT cell subset.

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The Public Health Agency is taking the opportunity to highlight this year's World No Tobacco Day which takes place on Tuesday 31 May.In Northern Ireland, around 340,000 people aged 16 and over smoke. Smoking contributes not only to many cancers, heart disease, bronchitis and asthma, but to other illnesses, including stroke. In fact, smoking causes around 2,700 deaths per year here, all of them avoidable.The PHA is committed to saving lives by reducing the percentage of people who smoke. The PHA:works with councils to ensure smoking-related laws are enforced; funds a range of support to smokers who want to quit; educates young people to not start smoking, through programmes like 'Teenage Kicks' and 'Smokebusters'. In January this year, the PHA also launched its smoking campaign 'Things to do before you die' to encourage smokers, particularly those aged 20-49, to stop smoking.Health Minister Edwin Poots said:"Smoking is the greatest cause of preventable illness and premature death in Northern Ireland. While good progress has been made in the last number of years to reduce the number of people who smoke, more needs to be done."I would appeal to all smokers to use the wide range of support services available to make every effort to stop smoking - it is the single best step you can take to improve your health and quality of life."Mark Mc Bride, Health Improvement Manager, PHA, said "Smoking is the single greatest preventable cause of death in the world today. Across Northern Ireland there are over 600 support services for people who wish to stop smoking. These are based in GP surgeries, community pharmacies, hospitals, community centres and workplaces."From April 2010 to end March 2011 more than 1 in 10 of all adult smokers sought help from the support services and approximately half had quit after four weeks. This is a substantial - roughly 50% increase - on previous years and shows the benefit of the PHA campaigns and the dedication of the many specialists who help smokers quit."I would encourage everyone who is either thinking about quitting or ready to log on to our Want 2 Stop website www.want2stop.info or to contacting the Smokers' Helpline on 0808 812 8008 a Quit Kit free of charge."

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Saturday 8 October 2011 marks World Hospice and Palliative Care Day. The Public Health Agency would like to celebrate and support hospice and palliative care around the world by raising awareness and understanding of the needs - medical, social, practical and spiritual - of people living with a life-limiting illness, and their families.This year's World Hospice and Palliative Care Day theme is 'Many diseases, manylives, many voices - palliative care fornon-communicableconditions'.The theme will focus on how people living with conditions thatare notinfectious can benefit from palliative care.Non-communicable diseases (NCDs), which include cardiovascular diseases, cancers, chronic respiratory conditions and diabetes, make up60% of deaths worldwide. The majority of thesedeaths occur in low and middle income countries, where palliative care is often not available. To get involved in World Hospice and Palliative Care Day, log on to www.worldday.org/get-involved/ which gives you ideas and suggestions on what you can do on the day to support people living with life-limiting illnesses, and their families.Mary Hinds, Director of Nursing and Allied Health Professions, PHA, and Chair of the Implementation Process for End of Life Care in Northern Ireland, said: "Good quality palliative and end of life care will be important for us all. 'Living Matters, Dying Matters' is a five year strategy for palliative and end of life care in Northern Ireland, established to ensure that any person living with a life-threatening illness lives well and dies well, irrespective of their condition or care setting. "It has been encouraging to see the plans being taken forward by the Health and Social Care Trusts in partnership with local hospices and other providers, and involving local people."We aim to ensure that people receiving palliative care, their families and carers, are provided with high quality care across all settings and conditions, and are supported to enjoy a good quality of life, maximising their potential through the course of their illness."There is still some progress to be made within the context of the review of health and social services. We are looking for statutory and voluntary services to work together to make a significant difference in improving access to high quality services for those with life-limiting conditions, and to develop innovative approaches to care."