991 research outputs found
Nanostructured 3D Constructs Based on Chitosan and Chondroitin Sulphate Multilayers for Cartilage Tissue Engineering
Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL) and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT) and chondroitin sulphate (CS) on either bidimensional glass surfaces or 3D packet of paraffin spheres. 2D CHT/CS multi-layered constructs proved to support the attachment and proliferation of bovine chondrocytes (BCH). The technology was transposed to 3D level and CHT/CS multi-layered hierarchical scaffolds were retrieved after paraffin leaching. The obtained nanostructured 3D constructs had a high porosity and water uptake capacity of about 300%. Dynamical mechanical analysis (DMA) showed the viscoelastic nature of the scaffolds. Cellular tests were performed with the culture of BCH and multipotent bone marrow derived stromal cells (hMSCs) up to 21 days in chondrogenic differentiation media. Together with scanning electronic microscopy analysis, viability tests and DNA quantification, our results clearly showed that cells attached, proliferated and were metabolically active over the entire scaffold. Cartilaginous extracellular matrix (ECM) formation was further assessed and results showed that GAG secretion occurred indicating the maintenance of the chondrogenic phenotype and the chondrogenic differentiation of hMSCs
A luta internacional contra a Aids no campo dos direitos humanos: uma análise do encontro “Stop Aids” na ONU, ou como se constroem os discursos globais sobre os direitos
A partir de observações etnográficas realizadas em eventos organizados pela e na sede da ONU em Nova York, Estados Unidos, interessa-nos dar inteligibilidade às tensões de um cenário marcado por dissensos em níveis diversos. Não são os processos de construção de consensos ou os interesses hegemônicos o foco desta reflexão. Nosso objetivo, é mapear e analisar o peso de outros atores, que está longe de ser negligenciável, em algumas discussões específicas, sobretudo aquelas que dão lugar no formato de conferências e encontros. O “2016 High-Level Meeting on Ending Aids” foi, dentre vários meetings observados, o evento que escolhemos para analisar como os atores sociais interagem para ‘fazer’ a ONU.Based on ethnographic observations at events organized by and at the UN headquarters in New York, the United States, we are interested in giving intelligibility to the tensions of a scenario marked by dissent at different levels. It is not the processes of consensus building or hegemonic interests that are the focus of this analysis. Our objective is to map and analyze the weight of other actors that is far from negligible in some specific discussions, especially those that give way in the form of conferences and meetings. The "2016 High-Level Meeting on Ending Aids" was, among many meetings observed, the event we chose to analyze how social actors interact to 'make' the UN
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
Online dispute resolution: an artificial intelligence perspective
Litigation in court is still the main dispute resolution mode. However, given the amount
and characteristics of the new disputes, mostly arising out of electronic contracting, courts are
becoming slower and outdated. Online Dispute Resolution (ODR) recently emerged as a set of
tools and techniques, supported by technology, aimed at facilitating conflict resolution. In this
paper we present a critical evaluation on the use of Artificial Intelligence (AI) based techniques in
ODR. In order to fulfill this goal, we analyze a set of commercial providers (in this case twenty
four) and some research projects (in this circumstance six). Supported by the results so far
achieved, a new approach to deal with the problem of ODR is proposed, in which we take on some
of the problems identified in the current state of the art in linking ODR and AI.The work described in this paper is included in TIARAC - Telematics and
Artificial Intelligence in Alternative Conflict Resolution Project (PTDC/JUR/71354/2006), which
is a research project supported by FCT (Science & Technology Foundation), Portugal. The work
of Davide Carneiro is also supported by a doctoral grant by FCT (SFRH/BD/64890/2009).Acknowledgments. The work described in this paper is included in TIARAC - Telematics and Artificial Intelligence in Alternative Conflict Resolution Project (PTDC/JUR/71354/2006), which is a research project supported by FCT (Science & Technology Foundation), Portugal. The work of Davide Carneiro is also supported by a doctoral grant by FCT (SFRH/BD/64890/2009)
A New Heterobinuclear FeIIICuII Complex with a Single Terminal FeIII–O(phenolate) Bond. Relevance to Purple Acid Phosphatases and Nucleases
A novel heterobinuclear mixed valence complex [Fe^IIICu^II(BPBPMP)(OAc)_2]ClO_4, 1, with the unsymmetrical N_5O_2 donor ligand 2-bis[{(2-pyridylmethyl)aminomethyl}-6-{(2-hydroxybenzyl)(2-pyridylmethyl)} aminomethyl]-4-methylphenol (H_2BPBPMP) has been synthesized and characterized. A combination of data from mass spectrometry, potentiometric titrations, X-ray absorption and electron paramagnetic resonance spectroscopy, as well as kinetics measurements indicates that in ethanol/water solutions an [Fe^III-(nu)OH-Cu^IIOH_2]+ species is generated which is the likely catalyst for 2,4-bis(dinitrophenyl)phosphate and DNA hydrolysis. Insofar as the data are consistent with the presence of an Fe_III-bound hydroxide acting as a nucleophile during catalysis, 1 presents a suitable mimic for the hydrolytic enzyme purple acid phosphatase. Notably, 1 is significantly more reactive than its isostructural homologues with different metal composition (Fe^IIIM^II, where M^II is Zn^II, Mn^II, Ni^II,or Fe^II). Of particular interest is the observation that cleavage of double-stranded plasmid DNA occurs even at very low concentrations of 1 (2.5 nuM), under physiological conditions (optimum pH of 7.0), with a rate enhancement of 2.7 x 10^7 over the uncatalyzed reaction. Thus, 1 is one of the most effective model complexes to date, mimicking the function of nucleases
Human BRCA1-BARD1 ubiquitin ligase activity counters chromatin barriers to DNA resection
The opposing activities of 53BP1 and BRCA1 influence pathway choice of DNA double-strand break repair. How BRCA1 counters the inhibitory effect of 53BP1 on DNA resection and homologous recombination is unknown. Here we identify the site of BRCA1-BARD1 required for priming ubiquitin transfer from E2~ubiquitin. We demonstrate that BRCA1-BARD1’s ubiquitin ligase activity is required for repositioning 53BP1 on damaged chromatin. We confirm H2A ubiquitylation by BRCA1-BARD1 and show that an H2A-ubiquitin fusion protein promotes DNA resection and repair in BARD1 deficient cells. We show BRCA1-BARD1 function in homologous recombination requires the chromatin remodeler SMARCAD1. SMARCAD1 binding to H2A-ubiquitin, optimal localization to sites of damage and activity in DNA repair requires its ubiquitin-binding CUE domains. SMARCAD1 is required for 53BP1 repositioning and the need for SMARCAD1 in Olaparib or camptothecin resistance is alleviated by 53BP1 loss. Thus BRCA1- BARD1 ligase activity and subsequent SMARCAD1-dependent chromatin remodeling are critical regulators of DNA repair
Ectopic Cushing's Syndrome Unveiling a Metastatic Parotid Carcinoma
Introduction. Adrenocorticotropic hormone (ACTH) ectopic production is a rare cause of Cushing syndrome (CS). The most commonly associated tumours are small-cell lung carcinoma along with bronchial and thymic carcinoids. To date, only 5 cases have been published in the literature featuring ectopic ACTH secretion from metastatic acinic cell carcinoma (ACC) of the parotid gland. We hereby describe a very uncommon case of ectopic CS (ECS) unveiling a metastatic parotid ACC. Case Presentation. A 46-year-old man with hypertension and dyslipidemia diagnosed 4-months before, as well as new-onset diabetes mellitus unveiled 1-month earlier, was referred to emergency department for hypokalemia. Hormonal study and dynamic biochemical tests performed indicated ECS. Imaging and cytological findings pointed toward a likely primary right parotid malignancy with liver metastases. Somatostatin receptor scintigraphy has shown an increased uptake in the parotid gland and mild expression in liver metastasis. The patient underwent right parotidectomy, and histopathologic examination confirmed ACC. Meanwhile, hypercortisolism was managed with metyrapone, ketoconazole, and lanreotide. Despite chemotherapy onset, a rapid disease progression and clinical course deterioration was observed. Conclusion. The present report highlights a rare ECS, exposing a metastatic parotid ACC, with an aggressive and challenging clinical course, representing the first case whose diagnosis of ECS came prior to ACC
Search for R-parity-violating supersymmetry in events with four or more leptons in sqrt(s) =7 TeV pp collisions with the ATLAS detector
A search for new phenomena in final states with four or more leptons (electrons or muons) is presented. The analysis is based on 4.7 fb−1 of proton-proton collisions delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in two signal regions: one that requires moderate values of missing transverse momentum and another that requires large effective mass. The results are interpreted in a simplified model of R-parity-violating supersymmetry in which a 95% CL exclusion region is set for charged wino masses up to 540 GeV. In an R-parity-violating MSUGRA/CMSSM model, values of m 1/2 up to 820 GeV are excluded for 10 < tan β < 40
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