1,856 research outputs found
Interaction between acrylic substrates and RAD16-I peptide in its self-assembling
[EN] Self-assembling peptides (SAP) are widely used as scaffolds themselves, and recently as fillers of microporous scaffolds, where the former provides a cell-friendly nanoenvironment and the latter improves its mechanical properties. The characterization of the interaction between these short peptides and the scaffold material is crucial to assess the potential of such a combined system. In this work, the interaction between poly(ethyl acrylate) (PEA) and 90/10 ethyl acrylate-acrylic acid copolymer P(EAcoAAc) with the SAP RAD16-I has been followed using a bidimensional simplified model. By means of the techniques of choice (congo red staining, atomic force microscopy (AFM), and contact angle measurements) the interaction and self-assembly of the peptide has proven to be very sensitive to the wettability and electro-negativity of the polymeric substrate.The authors acknowledge funding through the European Commission FP7 project RECATABI (NMP3-SL-2009-229239), and from the Spanish Ministerio de Ciencia e Innovacion through projects MAT2011-28791-C03-02 and -03. This work was also supported by the Spanish Ministerio de Educacion through M. Arnal-Pastor FPU 2009-1870 grant. The authors acknowledge the assistance and advice of Electron Microscopy Service of the UPV.Arnal Pastor, MP.; González-Mora, D.; García-Torres, F.; Monleón Pradas, M.; Vallés Lluch, A. (2016). Interaction between acrylic substrates and RAD16-I peptide in its self-assembling. Journal of Polymer Research. 23(9):173-184. https://doi.org/10.1007/s10965-016-1069-3S173184239Davis ME, Motion JP, Narmoneva DA, Takahashi T, Hakuno D, Kamm RD, Zhang S, Lee RT (2005) Injectable self-assembling peptide nanofibers create intramyocardial microenvironments for endothelial cells. Circulation 111(4):442–450Zhang S, Lockshin C, Cook R, Rich A (1994) Unusually stable beta-sheet formation in an ionic self-complementary oligopeptide. Biopolymers 34:663–672Zhang S, Altman M (1999) Peptide self-assembly in functional polymer science and engineering. Reac Func Polym 41:91–102Zhang S, Gelain F, Zhao X (2005) Designer self-assembling peptide nanofiber scaffolds for 3D tissue cell cultures. Semin Cancer Biol 15(5):413–420Zhang S, Zhao X, Spirio L, PuraMatrix (2005) Self-assembling peptide nanofiber scaffolds. In: Ma PX, Elisseeff J (eds) Scaffolding in tissue Engineering. CRC Press, Boca Raton, FL, pp. 217–238Sieminski AL, Semino CE, Gong H, Kamm RD (2008) Primary sequence of ionic self-assembling peptide gels affects endothelial cell adhesion and capillary morphogenesis. J Biomed Mater Res A 87(2):494–504Quintana L, Fernández Muiños T, Genove E, Del Mar Olmos M, Borrós S, Semino CE (2009) Early tissue patterning recreated by mouse embryonic fibroblasts in a three-dimensional environment. Tissue Eng Part A 15(1):45–54Garreta E, Genové E, Borrós S, Semino CE (2006) Osteogenic differentiation of mouse embryonic stem cells and mouse embryonic fibroblasts in a three-dimensional self-assembling peptide scaffold. Tissue Eng 12(8):2215–2227Semino CE, Merok JR, Crane GG, Panagiotakos G, Zhang S (2003) Functional differentiation of hepatocyte-like spheroid structures from putative liver progenitor cells in three-dimensional peptide scaffolds. Differentiation 71:262–270Thonhoff JR, Lou DI, Jordan PM, Zhao X, Compatibility WP (2008) Of human fetal neural stem cells with hydrogel biomaterials in vitro. Brain Res 1187:42–51Tokunaga M, Liu ML, Nagai T, Iwanaga K, Matsuura K, Takahashi T, Kanda M, Kondo N, Wang P, Naito AT, Komuro I (2010) Implantation of cardiac progenitor cells using self-assembling peptide improves cardiac function after myocardial infarction. J Mol Cell Cardiol 49(6):972–983Takei J (2006) 3-Dimensional cell culture scaffold for everyone: drug screening. Tissue engineering and cancer biology. AATEX 11(3):170–176McGrath AM, Novikova LN, Novikov LN, Wiberg MBD (2010) ™ PuraMatrix™ peptide hydrogel seeded with Schwann cells for peripheral nerve regeneration. Brain Res Bull 83(5):207–213Wang W, Itoh S, Matsuda A, Aizawa T, Demura M, Ichinose S, Shinomiya K, Tanaka J (2008) Enhanced nerve regeneration through a bilayered chitosan tube: The effect ofintroduction of glycine spacer into the CYIGSR sequence. J Biomed Mater Res Part A 85:919–928Sargeant TD, Guler MO, Oppenheimer SM, Mata A, Satcher RL, Dunand DC, Stupp SI (2008) Hybrid bone implants: self-assembly of peptide amphiphile nanofibers within porous titanium. Biomaterials 29(2):161–171Vallés-Lluch A, Arnal-Pastor M, Martínez-Ramos C, Vilariño-Feltrer G, Vikingsson L, Castells-Sala C, Semino CE, Monleón Pradas M (2013) Combining self-assembling peptide gels with three-dimensional elastomer scaffolds. Acta Biomater 9(12):9451–9460Valles-Lluch A, Arnal-Pastor M, Martinez-Ramos C, Vilarino-Feltrer G, Vikingsson L, Monleon Pradas M (2013) Grid polymeric scaffolds with polypeptide gel filling as patches for infarcted tissue regeneration. Conf Proc IEEE Eng Med Biol Soc 2013:6961–6964Soler-Botija C, Bagó JR, Llucià-Valldeperas A, Vallés-Lluch A, Castells-Sala C, Martínez-Ramos C, Fernández-Muiños T, Chachques JC, Monleón Pradas M, Semino CE, Bayes-Genis A (2014) Engineered 3D bioimplants using elastomeric scaffold, self-assembling peptide hydrogel, and adipose tissue-derived progenitor cells for cardiac regeneration. Am J Transl Res 6(3):291–301Martínez-Ramos M, Arnal-Pastor M, Vallés-Lluch A, Monleón Pradas M (2015) Peptide gel in a scaffold as a composite matrix for endothelial cells. J Biomed Mater Res Part A 103 A:3293–3302Rico P, Rodríguez Hernández JC, Moratal D, Altankov G, Monleón Pradas M, Salmerón-Sánchez M (2009) Substrate-induced assembly of fibronectin into networks: influence of surface chemistry and effect on osteoblast adhesion. Tissue Eng Part A 15(11):3271–3281Gugutkov D, Altankov G, Rodríguez Hernández JC, Monleón Pradas M, Salmerón Sánchez M (2010) Fibronectin activity on substrates with controlled -OH density. J Biomed Mater Res A 92(1):322–331Rodríguez Hernández JC, Salmerón Sánchez M, Soria JM, Gómez Ribelles JL, Monleón Pradas M (2007) Substrate chemistry-dependent conformations of single laminin molecules on polymer surfaces are revealed by the phase signal of atomic force microscopy. Biophys J 93(1):202–207Cantini M, Rico P, Moratal D, Salmerón-Sánchez M (2012) Controlled wettability, same chemistry: biological activity of plasma-polymerized coatings. Soft Matter 8:5575–5584Anselme K, Ponche A, Bigerelle M (2010) Relative influence of surface topography and surface chemistry on cell response to bone implant materials. Part 2: biological aspects. Proc Inst Mech Eng H J Eng Med 224:1487–1507Hartgerink JD, Beniash E, Stupp SI (2002) Peptide-amphiphile nanofibers: a versatile scaffold for the preparation of self-assembling materials. Proc Natl Acad Sci U S A 99(8):5133–5138Busscher HJ, Vanpelt AWJ, Deboer P, Dejong HP, Arends J (1984) The effect of surface roughening of polymers on measured contact angles of liquids. Colloids Surf 9:319–331Birdi, KS. (1997) Surface tension of polymers. In: Yildrim Erbil H, ed. Handbook of surface and colloid chemistry CRC Press, Boca Raton, p. 292.Collier JH (2003) MessersmithPB.Enzymatic modification of self-assembled peptide structures with tissue transglutaminase. Bioconjug Chem 14(4):748–755Kakiuchi Y, Hirohashi N, Murakami-Murofushi K (2013) The macroscopic structure of RADA16 peptide hydrogel stimulates monocyte/macrophage differentiation in HL60 cells via cholesterol synthesis. BiochemBiophys Res Commun 433(3):298–304Pérez-Garnes M, González-García C, Moratal D, Rico P, Salmerón-Sánchez M (2011) Fibronectin distribution on demixednanoscale topographies. Int J Artif Organs 34(1):54–63Salmerón-Sánchez M, Rico P, Moratal D, Lee TT, Schwarzbauer JE, García AJ (2011) Role of material-driven fibronectin fibrillogenesis in cell differentiation. Biomaterials 32(8):2099–2105Ye Z, Zhang H, Luo H, Wang S, Zhou Q, DU X, et al. (2008) Temperature and pH effects on biophysical and morphological properties of self-assembling peptide RADA16-I. J Pept Sci 14:152–162Keselowsky BG, Collard DM, García AJ (2004) Surface chemistry modulates focal adhesion composition and signaling through changes in integrin binding. Biomaterials 25:5947–5954Scotchford CA, Gilmore CP, Cooper E, Leggett GJ, Downes S (2002) Protein adsorption and human osteoblast-like cell attachment and growth on alkylthiol on gold self-assembled monolayers. J Biomed Mater Res 59:84–99Coelho NM, González-García C, Planell JA, Salmerón-Sánchez M, Altankov G (2010) Different assembly of type IV collagen on hydrophilic and hydrophobic substrata alters endothelial cells interaction. Eur Cell Mater 19:262–272Briz N, Antolinos-Turpin CM, Alió J, Garagorri N, Gómez Ribelles JL, Gómez-Tejedor JA (2013) Fibronectin fixation on poly(ethyl acrylate)-based copolymers. J Biomed Mater Res B Appl Biomater 101(6):991–997Owens DK, Wendt RC (1969) Estimation of the surface free energy of polymers. J Appl Polym Sci 13(8):1741–1747Soria JM, Martínez Ramos C, Bahamonde O, García Cruz DM, Salmerón Sánchez M, García Esparza MA, Casas C, Guzmán M, Navarro X, Gómez Ribelles JL, García Verdugo JM, Monleón Pradas M, Barcia JA (2007) Influence of the substrate's hydrophilicity on the in vitro Schwann cells viability. J Biomed Mater Res A 83(2):463–470Van Krevelen, DW. (1997) Properties of polymers. Chapter 13 mechanical properties of solid polymers. Elsevier, pp. 367–43
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
Global urban environmental change drives adaptation in white clover.
Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale
Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns
This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela – Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of different taxa
Pathogenic Huntingtin Repeat Expansions in Patients with Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.
We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington's disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry
Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes
Multimessenger NuEM Alerts with AMON
The Astrophysical Multimessenger Observatory Network (AMON), has developed a real-time multi-messenger alert system. The system performs coincidence analyses of datasets from gamma-ray and neutrino detectors, making the Neutrino-Electromagnetic (NuEM) alert channel. For these analyses, AMON takes advantage of sub-threshold events, i.e., events that by themselves are not significant in the individual detectors. The main purpose of this channel is to search for gamma-ray counterparts of neutrino events. We will describe the different analyses that make-up this channel and present a selection of recent results
Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an
Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
- …