Versatile biomimetic conductive polypyrrole films doped with hyaluronic acid of different molecular weights

Electrically conductive polypyrrole (PPy) is an intriguing biomaterial capable of efficient electrical interactions with biological systems. Especially, biomimetic PPy-based biomaterials incorporating biomolecules, such as hyaluronic acid (HA), can impart the characteristic biological interactions with living cells/tissues to the conductive biomaterials. Here we report the effects of the molecular weight (MW) of HA on PPy-based biomaterials. We utilized HA of a wide range of MW (35 × 103 Da–3 × 106 Da) as dopants during the electrochemical production of PPy/HA films and their characterization of materials and cellular interactions. With increases in the MWs of HA dopants, PPy/HA exhibited more hydrophilic, higher electrochemical activity and lower impedance. In vitro studies revealed that PPy films doped with low MW HA were supportive to cell adhesion and growth, while PPy films doped with high MW HA were resistant to cell attachment. Subcutaneous implantation of the PPy/HA films for 4 weeks revealed that all the PPy/HA films were tissue compatible. We successfully demonstrate the importance of HA dopant MWs in modulating the chemical and electrical properties of the materials and cellular responses to the materials. Such materials have potential for various biomedical applications, including as tissue engineering scaffolds and as electrodes for neural recording and neuromodulation. Statement of Significance: Hyaluronic acid (HA)-doped polypyrrole (PPy) films were electrochemically synthesized as novel biomimetic conductive materials capable of efficient electrical signaling and preferential biological interactions. Molecular weights (MWs) of HA varied in a wide range (35 × 103–2 × 106 Da) and critically determine chemical, electrochemical, and biological properties of PPy/HA. Especially, PPy films with low MW HA markedly support cell adhesion and growth, while PPy films with high MW HA are resistant to cell attachment. Furthermore, PPy/HA exhibits greatly improved tissue compatibility and in vivo EMG signal recording ability. We for the first time demonstrate that biomimetic PPy/HA-based biomaterials can serve as versatile and effective platforms for various biomedical applications, such as tissue engineering scaffolds and bioelectrodes. © 2018 Acta Materialia Inc

Oxygen radical-mediated oxidation reactions of an alanine peptide motif - density functional theory and transition state theory study

Background: Oxygen-base (O-base) oxidation in protein backbone is important in the protein backbone fragmentation due to the attack from reactive oxygen species (ROS). In this study, an alanine peptide was used model system to investigate this O-base oxidation by employing density functional theory (DFT) calculations combining with continuum solvent model. Detailed reaction steps were analyzed along with their reaction rate constants. Results: Most of the O-base oxidation reactions for this alanine peptide are exothermic except for the bond-breakage of the C-alpha-N bond to form hydroperoxy alanine radical. Among the reactions investigated in this study, the activated energy of OH alpha-H abstraction is the lowest one, while the generation of alkylperoxy peptide radical must overcome the highest energy barrier. The aqueous situation facilitates the oxidation reactions to generate hydroxyl alanine peptide derivatives except for the fragmentations of alkoxyl alanine peptide radical. The C-alpha-C-beta bond of the alkoxyl alanine peptide radical is more labile than the peptide bond. Conclusion: the rate-determining step of oxidation in protein backbone is the generation of hydroperoxy peptide radical via the reaction of alkylperoxy peptide radical with HO2. The stabilities of alkylperoxy peptide radical and complex of alkylperoxy peptide radical with HO2 are crucial in this O-base oxidation reaction

Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube

We have studied the afterpulse of a hemispherical photomultiplier tube for an upcoming reactor neutrino experiment. The timing, the amplitude, and the rate of the afterpulse for a 10 inch photomultiplier tube were measured with a 400 MHz FADC up to 16 \ms time window after the initial signal generated by an LED light pulse. The time and amplitude correlation of the afterpulse shows several distinctive groups. We describe the dependencies of the afterpulse on the applied high voltage and the amplitude of the main light pulse. The present data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure

Search for sterile neutrino oscillation using RENO and NEOS data

We present a reactor model independent search for sterile neutrino oscillation using 2\,509\,days of RENO near detector data and 180 days of NEOS data. The reactor related systematic uncertainties are significantly suppressed as both detectors are located at the same reactor complex of Hanbit Nuclear Power Plant. The search is performed by electron antineutrino\,($\overline{\nu}_e$) disappearance between six reactors and two detectors with baselines of 294\,m\,(RENO) and 24\,m\,(NEOS). A spectral comparison of the NEOS prompt-energy spectrum with a no-oscillation prediction from the RENO measurement can explore reactor $\overline{\nu}_e$ oscillations to sterile neutrino. Based on the comparison, we obtain a 95\% C.L. excluded region of $0.1<|\Delta m_{41}^2|<7$\,eV$^2$. We also obtain a 68\% C.L. allowed region with the best fit of $|\Delta m_{41}^2|=2.41\,\pm\,0.03\,$\,eV$^2$ and $\sin^2 2\theta_{14}$=0.08$\,\pm\,$0.03 with a p-value of 8.2\%. Comparisons of obtained reactor antineutrino spectra at reactor sources are made among RENO, NEOS, and Daya Bay to find a possible spectral variation.Comment: 6 pages, 5 figures: This manuscript has been significantly revised by the joint reanalysis by RENO and NEOS Collaborations. (In the previous edition, the RENO collaboration used publicly available NEOS data to evaluate the expected neutrino spectrum at NEOS.

Vegetation in urban streets, squares, and courtyards

One of various ways in which vegetation cover used in the greening of urban areas can help improve the health and well-being of people is in how it changes the acoustic environment. This chapter presents findings of computer simulations and scale modelling to examine and quantify the effectiveness of green roof and green wall (vertical garden) systems in reducing road traffic noise for streets, squares, and roadside courtyards. Noise reduction by sound absorption in reflected and diffracted (over roofs) sound paths is investigated. Particular attention is paid to the importance of vegetation placement relative to the receiver/listening positions. Because the soil substrate used for the vertical walls has good sound absorption properties, it also can be used for green barriers. In this chapter, the effects of a low barrier made of green wall substrate are studied for an installation on the ground and on the top of buildings surrounding a courtyard

Toolbox from the EC FP7 HOSANNA project for the reduction of road and rail traffic noise in the outdoor environment

yesThis paper offers a brief overview of innovative methods for road and rail traffic noise reduction between source and receiver. These include using new barrier designs, planting of trees, treatments of ground and road surfaces and greening of building façades and roofs using natural materials, like vegetation, soil and other substrates in combination with recycled materials and artificial elements. The abatements are assessed in terms of numerically predicted sound level reductions, perceptual effects and cost–benefit analysis. Useful reductions of noise from urban roads and tramways are predicted for 1-m-high urban noise barriers and these are increased by adding inter-lane barriers. A 3 m wide 0.3 m high lattice ground treatment, a carefully planted 15-m-wide tree belt and replacing 50 m of paved areas by grassland are predicted to give similar reductions. Tree belts are shown to be very cost-effective and combining tall barriers with a row of trees reduces the negative impact of wind. Green roofs may significantly reduce the noise at the quiet side of buildings

The fungal metabolite eurochevalierine, a sequiterpene alkaloid, displays anti-cancer properties through selective sirtuin 1/2 inhibition

NAD+-dependent histone deacetylases (sirtuins) are implicated in cellular processes such as proliferation, DNA repair, and apoptosis by regulating gene expression and the functions of numerous proteins. Due to their key role in cells, the discovery of small molecule sirtuin modulators has been of significant interest for diverse therapeutic applications. In particular, it has been shown that inhibition of sirtuin 1 and 2 activities is beneficial for cancer treatment. Here, we demonstrate that the fungal metabolite eurochevalierine from the fungus Neosartorya pseudofischeri inhibits sirtuin 1 and 2 activities (IC50 about 10 µM) without affecting sirtuin 3 activity. The binding modes of the eurochevalierine for sirtuin 1 and 2 have been identified through computational docking analyses. Accordingly, this sequiterpene alkaloid induces histone H4 and α-tubulin acetylation in various cancer cell models in which it induces strong cytostatic effects without affecting significantly the viability of healthy PBMCs. Importantly, eurochevalierine targets preferentially cancer cell proliferation (selectivity factor 7), as normal human primary CD34+ stem/progenitor cells were less affected by the treatment. Finally, eurochevalierine displays suitable drug-likeness parameters and therefore represent a promising scaffold for lead molecule optimization to study the mechanism and biological roles of sirtuins and potentially a basis for development into therapeutics. © 2018 by the authors.Acknowledgments: M.S. was supported by a “Waxweiler grant for cancer prevention research” from the Action Lions “Vaincre le Cancer.” This work was supported by Télévie Luxembourg, the «Recherche Cancer et Sang» foundation and the «Recherches Scientifiques Luxembourg» association. The authors thank the «Een Häerz fir Kriibskrank Kanner» association and the Action Lions “Vaincre le Cancer” for generous support. M.Die. and B.W.H. are supported by the Tumor Microenvironment GCRC (2011-0030001) from the National Research Foundation funded by the Ministry of Science and ICT of Korea. R.K. is a director of research with the Fonds National de la Recherche Scientifique (FNRS; Belgium)

Measurement of single pi0 production in neutral current neutrino interactions with water by a 1.3 GeV wide band muon neutrino beam

Neutral current single pi0 production induced by neutrinos with a mean energy of 1.3 GeV is measured at a 1000 ton water Cherenkov detector as a near detector of the K2K long baseline neutrino experiment. The cross section for this process relative to the total charged current cross section is measured to be 0.064 +- 0.001 (stat.) +- 0.007 (sys.). The momentum distribution of produced pi0s is measured and is found to be in good agreement with an expectation from the present knowledge of the neutrino cross sections.Comment: 6 pages, 4 figures, Submitted to Phys. Lett.

Immune-Related Gene Expression in Two B-Complex Disparate Genetically Inbred Fayoumi Chicken Lines Following Eimeria maxima Infection

To investigate the influence of genetic differences in the MHC on susceptibility to avian coccidiosis, M5.1 and M15.2 B-haplotype-disparate Fayoumi chickens were orally infected with live Eimeria maxima oocysts, and BW gain, fecal oocyst production, and expression of 14 immune-related genes were determined as parameters of protective immunity. Weight loss was reduced and fecal parasite numbers were lower in birds of the M5.1 line compared with M15.2 line birds. Intestinal intraepithelial lymphocytes from M5.1 chickens expressed greater levels of transcripts encoding interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, IL-8, IL-12, IL-15, IL-17A, inducible nitric oxide synthase, and lipopolysaccharide-induced tumor necrosis factor-α factor and lower levels of mRNA for IFN-α, IL-10, IL-17D, NK-lysin, and tumor necrosis factor superfamily 15 compared with the M15.2 line. In the spleen, E. maxima infection was associated with greater expression levels of IFN-γ, IL-15, and IL-8 and lower levels of IL-6, IL-17D, and IL-12 in M5.1 vs. M15.2 birds. These results suggest that genetic determinants within the chicken MHC influence resistance to E. maxima infection by controlling the local and systemic expression of immune-related cytokine and chemokine genes