133 research outputs found
Development of Antibacterial Steel Surfaces Through Laser Texturing
[Abstract] The aim of the present study was to develop novel antibacterial touch surfaces through the laser texturing optimization of stainless steel. A wide range of laser fluence (2.11 J/cm2–5.64 J/cm2) and scanning interval (10 µm–30 ÎĽm) parameters were explored. The impact of surfaces with different patterns, wettability, and oxidation states on the antimicrobial behavior of Escherichia coli K-12 and biofilm hyper-producing Acinetobacter baumannii MAR002 was assessed. Modification of laser input enacted topographical changes with high scanning intervals leading to ordered surface patterns, while increasing the laser fluence to 5.64 J/cm2 created larger and less ordered plateaus and valleys. Texturing also drove a transition from a hydrophilic starting surface with a contact angle of 80.67° ± 3.35° to hydrophobic (138°–148°). Antimicrobial analysis and bioluminescence assays of E. coli, alongside biofilm forming test through A. baumannii MAR002 indicated the ability of laser texturing to produce effective bactericidal touch surfaces. No simple correlation was found between wettability and bacterial behavior, revealing that proliferation is dependent on roughness, oxidation, and wettability. For the conditions selected in this study, a laser fluence of 5.64 J/cm2 and a scanning interval of 10 µm showcased the lowest amount of recovered bacteria after 30 min.This research was supported by Project Nos. 592 p-01216A and IJCI-2016-29524 (awarded to A.P.G.), funded by the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and MINECO, respectively. This manuscript is part of Process Design to Prevent Prosthetic Infections (Grant No. EP/P02341X/1)Sociedad Española de Enfermedades Infecciosas y MicrobiologĂa ClĂnica; 592 p-01216AReino Unido. Engineering and Physical Sciences Research Council; EP/P02341X/
Parasitic Nematodes Modulate PIN-Mediated Auxin Transport to Facilitate Infection
Plant-parasitic nematodes are destructive plant pathogens that cause significant yield losses. They induce highly specialized feeding sites (NFS) in infected plant roots from which they withdraw nutrients. In order to establish these NFS, it is thought that the nematodes manipulate the molecular and physiological pathways of their hosts. Evidence is accumulating that the plant signalling molecule auxin is involved in the initiation and development of the feeding sites of sedentary plant-parasitic nematodes. Intercellular transport of auxin is essential for various aspects of plant growth and development. Here, we analysed the spatial and temporal expression of PIN auxin transporters during the early events of NFS establishment using promoter-GUS/GFP fusion lines. Additionally, single and double pin mutants were used in infection studies to analyse the role of the different PIN proteins during cyst nematode infection. Based on our results, we postulate a model in which PIN1-mediated auxin transport is needed to deliver auxin to the initial syncytial cell, whereas PIN3 and PIN4 distribute the accumulated auxin laterally and are involved in the radial expansion of the NFS. Our data demonstrate that cyst nematodes are able to hijack the auxin distribution network in order to facilitate the infection process
A comprehensive survey of the analytical, numerical and experimental methodologies for dynamics of multibody mechanical systems with clearance or imperfect joints
"Available online 19 December 2017"A comprehensive survey of the literature of the most relevant analytical, numerical, and experimental approaches for the kinematic and dynamic analyses of multibody mechanical systems with clearance joints is presented in this review. Both dry and lubricated clearance joints are addressed here, and an effort is made to include a large number of research works in this particular field, which have been published since the 1960′s. First, the most frequently utilized methods for modeling planar and spatial multibody mechanical systems with clearance joints are analyzed, and compared. Other important phenomena commonly associated with clearance joint models, such as wear, non-smooth behavior, optimization and control, chaos, and uncertainty and links’ flexibility, are then discussed. The main assumptions procedures and conclusions for the different methodologies are also examined and compared. Finally, future developments and new applications of clearance joint modeling and analysis are highlighted.This research was supported in part by the China 111 Project (B16003) and the National Natural Science
Foundation of China under Grants 11290151, 11472042 and 11221202. The work was also supported by the
Portuguese Foundation for Science and Technology with the reference project UID/EEA/04436/2013, by
FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização
(POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio
Die effektive Wärmeleitfähigkeit in Kugelschüttungen unter besondererBerücksichtigung des Hochtemperatur-Reaktors
Cell and quasihomogeneous models for determining of the effective thermal conductivity in packed beds are compared and their evidence is investigated by own experimental data both in the high and low temperature range under consideration of the stationary fluid. The quasihomogeneous model is extended to packed beds with spheres of relatively low thermal conductivity. The void radiation heat transfer is considered theoretically and is determined experimentally. Simplified formulas are presented for the computation of the effective thermal conductivity on the core of a high temperature reactor within a temperature range of 2500 °C
Experimentelle Untersuchungen zur Thermohydraulik in Kugelschüttungen im Vergleich mit dem Rechenprogramm Thermix-2D : die Untersuchung des dispersiven Wärmetransportes am Beispiel einer Kaltgassträhne
The computer code THERMIX-2D is tested with regard to the formalism for the effektive heat conductivity by experimental data. Exspecially the part of dispersion is investigated. In addition to the heated main stream a cooler gasstream is injected into the center of the packed bed. The thermal compensation is measured and calculated
Noise characteristics of asymmetric multi-junction HTS rf-SQUID magnetometer and gradiometer on bicrystal substrates
Vegan diet and orthorexia
it may be true that vegans do have higher scores on the DOS, but they are far from exceeding the cut-off point for orthorexic eating behavior; even the cut-off-point indicative of a risk for orthorexic eating behavior is not exceede
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