669 research outputs found

    Two mini-preparation protocols to DNA extraction from plants with high polysaccharide and secondary metabolites

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    Were standardized two previously reported standard plant DNA extraction methods, but improved them on mini preparations to use the samples for population genetic analysis. The combination of CTAB lysis procedure-solvent extraction and DNA column purification (DNeasy plant mini kit modification) enables a faster and reliable DNA extraction from all samples tested: Piper, Quercus, Zea and cacti species (considered “hard” extraction species), and this protocol uses smaller tissue samples than other mini or midi-prep protocols. We obtained high quality and DNA yields in all samples tested. This alternative protocol (CTAB lysis-solvent extraction based) is an excellent option if there are many samples to process and it is also a non expensive protocol. This method also produces good DNA quality but fewer yields. Both two protocols produce reproducible PCR pattern-bands amplification with all the genetic markers tested (RAPD’s and microsatellites). The DNA obtained was used in other molecular biology standard analysis methods, like enzymptic restriction patterns, ligation, sequencing and cloning with good results too

    The porin and the permeating antibiotic: A selective diffusion barrier in gram-negative bacteria

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    Gram-negative bacteria are responsible for a large proportion of antibiotic resistant bacterial diseases. These bacteria have a complex cell envelope that comprises an outer membrane and an inner membrane that delimit the periplasm. The outer membrane contains various protein channels, called porins, which are involved in the influx of various compounds, including several classes of antibiotics. Bacterial adaptation to reduce influx through porins is an increasing problem worldwide that contributes, together with efflux systems, to the emergence and dissemination of antibiotic resistance. An exciting challenge is to decipher the genetic and molecular basis of membrane impermeability as a bacterial resistance mechanism. This Review outlines the bacterial response towards antibiotic stress on altered membrane permeability and discusses recent advances in molecular approaches that are improving our knowledge of the physico-chemical parameters that govern the translocation of antibiotics through porin channel

    Effects of web-based electrocardiography simulation on strategies and learning styles

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    Objective: To identify the association between the use of web simulation electrocardiography and the learning approaches, strategies and styles of nursing degree students. Method: A descriptive and correlational design with a one-group pretest– posttest measurement was used. The study sample included 246 students in a Basic and Advanced Cardiac Life Support nursing class of nursing degree. Results: No significant differences between genders were found in any dimension of learning styles and approaches to learning. After the introduction of web simulation electrocardiography, significant differences were found in some item scores of learning styles: theorist (p < 0.040), pragmatic (p < 0.010) and approaches to learning. Conclusion: The use of a web electrocardiogram (ECG) simulation is associated with the development of active and reflexive learning styles, improving motivation and a deep approach in nursing students

    Interaction between acrylic substrates and RAD16-I peptide in its self-assembling

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    [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. 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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. 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    Social network types and functional dependency in older adults in Mexico

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    <p>Abstract</p> <p>Background</p> <p>Social networks play a key role in caring for older adults. A better understanding of the characteristics of different social networks types (TSNs) in a given community provides useful information for designing policies to care for this age group. Therefore this study has three objectives: 1) To derive the TSNs among older adults affiliated with the Mexican Institute of Social Security; 2) To describe the main characteristics of the older adults in each TSN, including the instrumental and economic support they receive and their satisfaction with the network; 3) To determine the association between functional dependency and the type of social network.</p> <p>Methods</p> <p>Secondary data analysis of the 2006 Survey of Autonomy and Dependency (N = 3,348). The TSNs were identified using the structural approach and cluster analysis. The association between functional dependency and the TSNs was evaluated with Poisson regression with robust variance analysis in which socio-demographic characteristics, lifestyle and medical history covariates were included.</p> <p>Results</p> <p>We identified five TSNs: diverse with community participation (12.1%), diverse without community participation (44.3%); widowed (32.0%); nonfriends-restricted (7.6%); nonfamily-restricted (4.0%). Older adults belonging to widowed and restricted networks showed a higher proportion of dependency, negative self-rated health and depression. Older adults with functional dependency more likely belonged to a widowed network (adjusted prevalence ratio 1.5; 95%CI: 1.1-2.1).</p> <p>Conclusion</p> <p>The derived TSNs were similar to those described in developed countries. However, we identified the existence of a diverse network without community participation and a widowed network that have not been previously described. These TSNs and restricted networks represent a potential unmet need of social security affiliates.</p

    Diversity, structure and sources of bacterial communities in earthworm cocoons.

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    Animals start interactions with the bacteria that will constitute their microbiomes at embryonic stage. After mating, earthworms produce cocoons externally which will be colonized with bacteria from their parents and the environment. Due to the key role bacterial symbionts play on earthworm fitness, it is important to study bacterial colonization during cocoon formation. Here we describe the cocoon microbiome of the earthworms Eisenia andrei and E. fetida, which included 275 and 176 bacterial species, respectively. They were dominated by three vertically-transmitted symbionts, Microbacteriaceae, Verminephrobacter and Ca. Nephrothrix, which accounted for 88% and 66% of the sequences respectively. Verminephrobacter and Ca. Nephrothrix showed a high rate of sequence variation, suggesting that they could be biparentally acquired during mating. The other bacterial species inhabiting the cocoons came from the bedding, where they accounted for a small fraction of the diversity (27% and 7% of bacterial species for E. andrei and E. fetida bedding). Hence, earthworm cocoon microbiome includes a large fraction of the vertically-transmitted symbionts and a minor fraction, but more diverse, horizontally and non-randomly acquired from the environment. These data suggest that horizontally-transmitted bacteria to cocoons may play an important role in the adaptation of earthworms to new environments or diets

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    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 cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Sexual Relationships in Hispanic Countries: a Literature Review

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    This is a pre-print of an article published in Current Sexual Health Reports. The final authenticated version is available online at: https://doi.org/10.1007/s11930-020-00272-6Purpose of Review: Sexuality is a complex dimension for which culture seems to play an important role, particularly in countries that are more traditional. This review summarizes the knowledge about sexual relationships in Hispanic countries, considering sexual debut, attitudes, behaviors, and satisfaction. Recent Findings: In line with the literature reviewed, the sexual double standard seems to be continuing to influence sexual relationships. Some countries show more open expressions of sexuality based on the level of gender inequality or sexualized context, and within countries, variables such as religious commitment, family characteristics, and access to resources may play important roles in sexuality. Summary: Future research, policies, and interventions should consider these specific characteristics, including these forms of expression of sexuality, in the adjustment of cross-cultural and cross-national strategies
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