895 research outputs found

    Surfaces mimicking glycosaminoglycans trigger different response of stem cells via distinct fibronectin adsorption and reorganization

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    We report on the utility of a platform created by self-assembled monolayers to investigate the influence of the degree of sulfation of glycosaminoglycans (GAGs) on their interactions with fibronectin (Fn) and the impact of these interactions on the adhesion and morphology of human adipose derived stem cells (ASCs). We used the label-free QCM-D, AFM and SPR to follow the changes in the protein adlayer in close proximity to the substrates surface and QCM-D in combination with live imaging to characterize the adherent cells. Our results suggest that Fn interactions with GAGs are governed by both H-bonding and electrostatic forces. Strong electrostatic interactions cause irreversible change in the protein conformation, while the weaker H-bonding only partially restricts the protein flexibility, allowing Fn reorganization and exposure of its binding sites for ASC adhesion. These findings imply that a delicate balance between these two types of forces must be considered in the design of biomaterials that mimic GAGs.We acknowledge EU for financial support (FP7/2007-2013, under Grants REGPOT-CT2012-316331-POLARIS and ERC- 2012-ADG-20120216-321266 for the project ComplexiTE). I.P. is thankful to the Portuguese Foundation for Science and Technology (IF/00032/2013). The authors are very grateful to Dr. Raquel Teixeira for her help with the treatment and discussion of the MP-SPR data

    3D hydrogel mimics of the tumor microenvironment: the interplay among hyaluronic acid, stem cells and cancer cells

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    The present work reports on a 3D model of the tumor microenvironment that contains hyaluronic acid (HA) and alginate, and demonstrates the utility of this model to study the effect of HA size on the crosstalk between cancer cells and mesenchymal stem cells (MSCs). The system incorporates a core that contains HA of specific size (i.e. 6.4, 741 or 1500 kDa) with encapsulated epithelial MKN45 cancer cells and a shell with MSCs that mimic the presence of stem cells next to the tumor site. It was found that short HA (i.e. 6.4 kDa) promotes the invasion of cancer cells from the core to the shell, whereas longer HA (i.e. 741 and 1500 kDa) recruits the MSCs into the core, i.e. the tumor site, where a reduction of the formation of cancer cell aggregates was observed. In summary, the developed 3D model recapitulates some key tumor features related to the effect of HA size on both cancer cell invasiveness and MSC behavior at the tumor site.We acknowledge the financial support from the European Commission and the Horizon 2020 - WIDESPREAD programme, under the grant agreement number #668983-FORECAST. SA acknowledges the Portuguese Foundation for Science and Technology for her PhD grant (SFRH/BD/112075/2015)

    Self-perceived normality in defecation habits

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    Background: Available information on normal bowel habits was mainly gathered by means of telephone interviews or mailed questionnaires. Aims: We undertook a prospective study to evaluate the defecatory habits in subjects perceiving themselves as normal concerning this function. Subjects and Methods: A questionnaire (4-week diary with "yes-no" daily answers to six questions concerning bowel habits) was distributed to 204 subjects perceiving their defecation behaviour as normal. Results: The completed questionnaire was returned by 140 subjects. No significant differences were found between sexes or age groups for any variable, even though straining at stool and feeling of incomplete and/or difficult evacuation showed a trend to increase with age. No subject had less than three bowel movements per week or more than three per day. The percentage of symptoms linked to an abnormal defecatory behaviour was well below 10%. Fifty-five percent of subjects reported at least one parameter of abnormal functioning; the most frequent was straining at stool and the rarer was the manual manoeuvres to help defecation. Conclusions: In normal subjects the prevalence of symptoms considered in Rome II criteria as part of an abnormal defecatory behaviour (in more than 25% of defecations) is well below 10%, manual manoeuvres are almost never used to help defecation, and the frequency of defecations is at least three per week. © 2005 Editrice Gastroenterologica Italiana S.r.l

    Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

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    We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom

    Tiges prestades: PoĂštiques de resistĂšncia en temps de pandĂšmia

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    [cat] La mostra, combinatĂČria de formats, tĂšcniques i processos, tĂ© un nexe comĂș: l’exploraciĂł –conceptual i formal– que han fet artistes-docents –sols o en companyia– en perĂ­odes de confinament –obligat o voluntari– i en els seus espais de treball personal. Compta amb la participaciĂł de: AnaĂŻs Civit LĂłpez, Andrea MartĂ­nez Arroyo, EulĂ lia Grau i Costa, Jaume R. VallverdĂș, Joan Miquel Porquer Rigo, Juancho Pacheco Puig, Julio CĂ©sar Ortega, Laia Moreto i Sara SĂĄnchez, Lucido Petrillo, Pablo Romero i Rafael Romero. Amb la col·laboraciĂł de: Grup d’InnovaciĂł Docent Consolidat ATESI (Art, Territori, EstratĂšgia docent, Sostenibilitat i IntervenciĂł social, GINDOC-UB/162)

    Standalone vertex ïŹnding in the ATLAS muon spectrometer

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    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

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    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ Îł, H → Z Z∗ →4l and H →W W∗ →lÎœlÎœ. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined ïŹts probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

    Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

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    A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction
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