35 research outputs found
OsteoBLAST: Computational Routine of Global Molecular Analysis Applied to Biomaterials Development
For bone purposes, surface modifications are a common trend in biomaterials research
aiming to reduce the time necessary for osteointegration, culminating in faster recovery
of patients. In this scenario, analysis of intracellular signaling pathways have emerged
as an important and reliable strategy to predict biological responses from in vitro
approaches. We have combined global analysis of intracellular protein phosphorylation,
systems biology and bioinformatics into an early biomaterial analysis routine called
OsteoBLAST. We employed the routine as follows: the PamChip tyrosine kinase assay
was applied to mesenchymal stem cells grown on three distinct titanium surfaces:
machined, dual acid-etched and nanoHA. Then, OsteoBLAST was able to identify
the most reliable spots to further obtain the differential kinome profile and finally to
allow a comparison among the different surfaces. Thereafter, NetworKIN, STRING, and
Cytoscape were used to build and analyze a supramolecular protein-protein interaction
network, and DAVID tools identified biological signatures in the differential kinome for
each surface
Preparation and characterization of nanocrystalline h-BN films prepared by PECVD method
Deciphering The Preservation Of Fossil Insects: A Case Study From The Crato Member, Early Cretaceous Of Brazil
Exceptionally well-preserved three-dimensional insects with fine details and even labile tissues are ubiquitous in the Crato Member Konservat LagerstÀtte (northeastern Brazil). Here we investigate the preservational pathways which yielded such specimens. We employed high resolution techniques (EDXRF, SR-SXS, SEM, EDS, micro Raman, and PIXE) to understand their fossilisation on mineralogical and geochemical grounds. Pseudomorphs of framboidal pyrite, the dominant fossil microfabric, display size variation when comparing cuticle with inner areas or soft tissues, which we interpret as the result of the balance between ion diffusion rates and nucleation rates of pyrite through the originally decaying carcasses. Furthermore, the mineral fabrics are associated with structures that can be the remains of extracellular polymeric substances (EPS). Geochemical data also point to a concentration of Fe, Zn, and Cu in the fossils in comparison to the embedding rock. Therefore, we consider that biofilms of sulphate reducing bacteria (SRB) had a central role in insect decay and mineralisation. Therefore, we shed light on exceptional preservation of fossils by pyritisation in a Cretaceous limestone lacustrine palaeoenvironment. © 2016 Osés et al.20161
A search for resonances decaying into a Higgs boson and a new particle X in the XH â qqbb final state with the ATLAS detector
A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fbâ1 of protonâproton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance
Broad-scale patterns of body size in squamate reptiles of Europe and North America
Aim To document geographical interspecific patterns of body size of European and North American squamate reptile assemblages and explore the relationship between body size patterns and environmental gradients. Location North America and western Europe. Methods We processed distribution maps for native species of squamate reptiles to document interspecific spatial variation of body size at a grain size of 110 x 110 km. We also examined seven environmental variables linked to four hypotheses possibly influencing body size gradients. We used simple and multiple regression, evaluated using information theory, to identify the set of models best supported by the data. Results Europe is characterized by clear latitudinal trends in body size, whereas geographical variation in body size in North America is complex. There is a consistent association of mean body size with measures of ambient energy in both regions, although lizards increase in size northwards whereas snakes show the opposite pattern. Our best models accounted for almost 60% of the variation in body size of lizards and snakes within Europe, but the proportions of variance explained in North America were less than 20%. Main conclusions Although body size influences the energy balance of thermoregulating ectotherms, inconsistent biogeographical patterns and contrasting associations with energy in lizards and snakes suggest that no single mechanism can explain variation of reptile body size in the northern temperate zone
Estudo do componente arbĂłreo de dois trechos da Floresta OmbrĂłfila Densa Submontana em Ubatuba (SP)
Effects of cold SF6 plasma treatment on a-C:H, polypropylene and polystyrene
The effects of cold SF6 plasma treatment on amorphous hydrogenated carbon (FA), polypropylene (PP) and polystyrene (PS) were investigated as functions of gas pressure and applied power. An anticipated increase in hydrophobicity was confirmed by the greater water contact angles, Ξ, observed after all the treatments. Under the best conditions Ξ was increased by 50.8°, 57.2° and 21°, respectively. A rise and fall in Ξ was observed as the pressure of SF6 was increased, this trend being most consistent for FA. Although the plasma treatments caused some changes in surface roughness, measured using profilometry, there were no clear correlations between this parameter and Ξ. As revealed by Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS), the treated surfaces were fluorinated. As the degree of fluorination under optimal conditions was 2.2 at.%, 10.4 at.% and 36.3 at.% for the FA, PP and PS, respectively, this factor was not alone responsible for the observed increases in Ξ. Sulfur was attached to the surface of all the treated samples. The relative surface carbon content was reduced by the treatments. The main causes of the changes in Ξ upon treatment were the induced compositional and structural changes. Ageing for ten days caused a typical decrease in Ξ of ~10°, probably caused by rotation of hydrophobic surface groups into the surface385CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQCOORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESPsem informaçãosem informação2017/15853-
Hydrogenated amorphous carbon as protective coating for a forming tool
This paper investigates the performance of hydrogenated amorphous carbon (a-C:H) films as protective coatings for a forming tool made from AISI M2 steel coated with a titanium nitride (TiN) PVD commercial layer. The samples were initially cleaned in ultrasonic baths and subsequently in a plasma ablation procedure. Films were then deposited by plasma immersion ion implantation using 91% of acetylene and 9% of argon at a total pressure of 5.5Â Pa. Samples were biased with high voltage negative pulses, P (TÂ =Â 3.33Â ms, pulse on-time: 0.03Â ms, pulse off-time: 3.30Â ms and application rate: 299Â Hz) with amplitudes varying from 1.000 to 4.000Â V. The chemical structure and composition of the films were evaluated by infrared spectroscopy. The roughness was determined by profilometry while the surface topography and morphology were investigated by atomic force microscopy and scanning electron microscopy, respectively. The friction coefficient was determined by the ball on disk technique. A decrease in the proportion of C-H and O-H groups was observed while the concentration of dangling bonds enhanced with increasing P. Sharp structures were detected on the film surface affecting roughness in two different ways: it increased with enhancing pulse magnitude in the smoothest substrate (AISI M2) and decreased in the roughest one (AISI M2-TiN). The best tribological result was found for the sample deposited with 3.600Â V of bias onto TiN-AISI M2 steel
Influence Of Nitrogen Implantation On The Properties Of Polymer Films Deposited In Benzene Glow Discharges
Investigations of the structural, optical and electrical properties of plasma-polymerized benzene films were carried out as a function of the ion fluence. The films were obtained from rf (40 MHz, 70 W) plasmas of benzene and afterwards implanted with 170 keV molecular nitrogen ions (N+ 2) with fluences Ί ranging from 1017 to 1021 m-2. Infrared (IR) and ultraviolet-visible (UV-VIS) spectroscopy were used to analyze the chemical and the electronic structure of the films, respectively. Further structural informations were obtained from etching experiments using an oxygen plasma. Electrical resistivity measurements were performed by the two-point probe technique. With rising ion fluence, the IR spectra of the implanted films reveal an increasing loss of hydrogen, the formation of new single and condensed aromatic structures and oxygen-containing functional groups. The latter are formed from reactions between the free radicals created upon ion implantation and oxygen from ambient air. The optical gap EG, calculated from the UV-VIS spectra of the films, showed a decrease from 1.6 to 0.9 eV as Ί increased from 0 to 1019 m-2. The electrical resistivity p of the films decreases significantly with the fluence. The decreases in EG and Ï are attributed to an increase in the overlap of the Ï-orbitals. The plasma etching experiments show that at low ion fluences, polymer chain degradation prevails. The highly chemically resistant polymer surface developed under high fluences suggests a strongly cross-linked structure. © 1998 Elsevier Science B.V. All rights reserved.1411-4211215Lee, E.H., (1996) Polyimides: Fundamental Aspects and Technological Applications, , K. Mittal, M. Ghosh (Eds.), ch. 17, Marcel Dekker, New YorkSvorcik, V., Rybka, V., Endrst, R., Hnatowicz, V., Kvitek, J., (1993) J. Electrochem. Soc., 140, p. 542Lee, E.H., Lewis, M.B., Blau, P.J., Mansur, L.K., (1991) J. Mater. Res., 6, p. 610Kaplan, M.L., Forrest, S.R., Schmidt, P.H., Venkatesan, T., (1984) J. Appl. Phys., 55, p. 732Svorcik, V., Endrst, R., Rybka, V., Hnatowicz, V., Cerny, F., (1994) J. Electrochem. Soc., 141, p. 582Lee, E.H., Rao, G.R., Mansur, L.K., (1996) TRIP, 4, p. 229Yasuda, H., (1985) Plasma Polymerization, , Academic Press, New YorkDurrant, S.F., Marçal, N., Castro, S.G., Vinhas, R.C., Bica De Moraes, M.A., Nicola, J.H., (1995) Thin Solid Films, 259, p. 139Lewis, M.B., Lee, E.H., (1991) Nucl. Instr. and Meth. B, 61, p. 457Loh, I.H., Oliver, R.W., Sioshansi, P., (1988) Nucl. Instr. and Meth. B, 34, p. 337Smalley, R.K., Wakefield, B.J., (1975) An Introduction to Spectroscopic Methods for the Identification of Organic Compounds, 1, p. 184. , F. Scheinmann (Ed.), Pergamon Press, New YorkDurrant, S.F., Mota, R.P., Bica De Moraes, M.A., (1992) J. Appl. Phys., 71, p. 448Dearnaley, G., (1973) Ion Implantation, , G. Dearnaley, J.H. Freeman, R.S. Nelson, J. Stephen (Eds.), ch. 1., North-Holland, Amsterda