217 research outputs found
Impact of rGO-coated PEEK and lattice on bone implant
© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).The composite coating can effectively inhibit bacterial proliferation and promote the expression of bone-building genes in-vitro. Therefore, a novel production was used to produce poly-ether-ether-ketone, and reduced graphene oxide (PEEK-rGO) scaffolds with ratios of 1–3%, combining a different lattice for a bone implant. An inexpensive method was developed to prepare the new coatings on the PEEK scaffold with reduced graphene oxide (rGO). Mechanical testing, data analysis and cell culture tests for in-vitro biocompatibility scaffold characterisation for the PEEK composite were conducted. Novel computation microanalysis of four-dimensional (4D) printing of microstructure of PEEK-rGO concerning the grain size and three dimensional (3D) morphology was influenced by furrow segmentation of grains cell growth on the composite, which was reduced from an average of 216–155 grains and increased to 253 grains on the last day. The proposed spherical nanoparticles cell grew with time after dispersed PEEK nanoparticles in calcium hydroxyapatite (cHAp) grains. Also, the mechanical tests were carried out to validate the strength of the new composites and compare them to that of a natural bone. The established 3D-printed PEEK composite scaffolds significantly exhibited the potential of bone implants for biomimetic heterogeneous bone repair.Peer reviewedFinal Published versio
Mixed RF-VLC Relaying Systems for Interference-Sensitive Mobile Applications
Due to their Radio-Frequency (RF) immunity, Visible Light Communications
(VLC) pose as a promising technology for interference sensitive applications
such as medical data networks. In this paper, we investigate mixed RF-VLC
relaying systems especially suited for this type of applications that support
mobility. In this system setup, the end-user, who is assumed to be on a vehicle
that is in dynamic movement, is served by an indoor VLC system, while the
outdoor data traffic is conveyed through multiple backhaul RF links.
Furthermore, it is assumed that a single backhaul RF link is activated by the
mobile relay and due to feedback delay, the RF link activation is based on
outdated channel state information (CSI). The performance of this system is
analyzed in terms of outage probability and bit error rate (BER), and novel
closed form analytical expressions are provided. Furthermore, the analysis is
extended for the case where the average SNR over the RF links and/or LED
optical power is high, and approximate analytical expressions are derived which
determine performance floors. Numerical results are provided which demonstrate
that the utilization of multiple RF backhaul links can significantly improve
overall RF-VLC system performance when outage/BER floors are avoided. This
calls upon joint design of both subsystems. Additionally, the outdated CSI
exploited for active RF selection can significantly degrade the quality of
system performance.Comment: Published in IEEE Transactions on Vehicular Technolog
XR-RF Imaging Enabled by Software-Defined Metasurfaces and Machine Learning: Foundational Vision, Technologies and Challenges
We present a new approach to Extended Reality (XR), denoted as iCOPYWAVES,
which seeks to offer naturally low-latency operation and cost-effectiveness,
overcoming the critical scalability issues faced by existing solutions.
iCOPYWAVES is enabled by emerging PWEs, a recently proposed technology in
wireless communications. Empowered by intelligent (meta)surfaces, PWEs
transform the wave propagation phenomenon into a software-defined process. We
leverage PWEs to i) create, and then ii) selectively copy the scattered RF
wavefront of an object from one location in space to another, where a machine
learning module, accelerated by FPGAs, translates it to visual input for an XR
headset using PWEdriven, RF imaging principles (XR-RF). This makes for an XR
system whose operation is bounded in the physical layer and, hence, has the
prospects for minimal end-to-end latency. Over large distances,
RF-to-fiber/fiber-to-RF is employed to provide intermediate connectivity. The
paper provides a tutorial on the iCOPYWAVES system architecture and workflow. A
proof-of-concept implementation via simulations is provided, demonstrating the
reconstruction of challenging objects in iCOPYWAVES produced computer graphics
Hydrated Lanthanoid Complexes of 5-(2'-Pyridyl)tetrazole Formed in the Presence of Dimethyl Sulfoxide
Reaction of DMSO solvates of lanthanoid nitrates or perchlorates with 5-(2'-pyridyl)tetrazole (pytz) and triethylamine in organic solvents resulted in the unexpected crystallization of hydrates, rather than DMSO solvates. This was confirmed by the structural characterization of [Eu(pytz)3(H2O)3]. Decreasing the metal:ligand ratio in the reaction mixture resulted in the crystallization of a complex salt formulated as [Y(pytz)2(H2O)4](pytz).(Hpytz).4H2O; once again DMSO was absent from the product. Interestingly, the omission of base from one reaction resulted in the serendipitous crystallization of Hpytz in a zwitterionic form, unlike the neutral ligand structure reported previously
Microfluidization of Graphite and Formulation of Graphene-Based Conductive Inks
We report the exfoliation of graphite in aqueous solutions under high shear rate [∼ 10 s] turbulent flow conditions, with a 100% exfoliation yield. The material is stabilized without centrifugation at concentrations up to 100 g/L using carboxymethylcellulose sodium salt to formulate conductive printable inks. The sheet resistance of blade coated films is below ∼2Ω/□. This is a simple and scalable production route for conductive inks for large-area printing in flexible electronics.We acknowledge funding from EU Graphene Flagship, ERCs grants Hetero2D, HiGRAPHINK, 3DIMAGEEPSRC, ESTEEM2, BIHSNAM, KNOTOUGH, and SILKENE, EPSRC grants EP/K01711X/1, EP/K017144/1, and EP/N010345/1, a Vice Chancellor award from the University of Cambridge, a Junior Research Fellowship from Clare College and the Cambridge NanoCDT and Graphene Technology CDT. We thank Chris Jones for useful discussions, and Imerys Graphite and Carbon for graphite powders
Foxp3 expression in human cancer cells
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Relationship between the anti-inflammatory properties of salmeterol/fluticasone and the expression of CD4+CD25+Foxp3+ regulatory T cells in COPD
<p>Abstract</p> <p>Background</p> <p>Salmeterol and fluticasone combination (SFC) has anti-inflammatory effects and improves clinical symptoms in patients with chronic obstructive pulmonary disease (COPD). However, the anti-inflammatory mechanism of SFC remains unclear. In this study, we investigated the inflammatory responses of COPD, as well as the relationship of the inflammatory factors with the levels of CD4<sup>+</sup>CD25<sup>+</sup>Foxp3<sup>+ </sup>regulatory T cells (Foxp3<sup>+</sup>Tregs) after SFC therapy.</p> <p>Methods</p> <p>Twenty-one patients with moderate or severe COPD received treatment with 50/500 μg of SFC twice a day for 12 weeks. Before and after treatment, the patients were evaluated using the Modified Medical Research Council (MMRC) dyspnea scale and by conducting a 6-min walk test. The number of neutrophils, monocytes and lymphocytes in induced sputum were counted. Levels of cytokines, including pre-inflammatory IL-8, TNF-α, IL-17A and cytokine IL-10, in the sputum supernatant and peripheral blood were measured by ELISA. The proportion of Foxp3<sup>+</sup>Tregs in the total CD4<sup>+ </sup>T cell of the peripheral blood was determined by flow cytometry. The relationship between IL-17A levels and the percentage of Foxp3<sup>+</sup>Tregs was analyzed by statistical analysis.</p> <p>Results</p> <p>After treatment with SFC, the forced expiratory volume in 1 s as a percentage of predicted values (FEV1%) and the 6-min walk distance in the COPD patients significantly increased, while dyspnea scores decreased. The total number of cells, neutrophils, and the percentage of neutrophils in induced sputum reduced notably, while the proportion of monocytes was significantly increased. Levels of the inflammatory cytokines IL-8, TNF-α, and IL-17A in the sputum supernatant and in the blood were markedly lowered, while IL-10 levels were unchanged. The proportion of Foxp3<sup>+</sup>Tregs in the total CD4<sup>+</sup>T cell population in the peripheral blood was drastically higher than that before treatment. The level of IL-17A was negatively correlated with the proportion of Foxp3<sup>+</sup>Tregs in CD4<sup>+</sup>T cells.</p> <p>Conclusion</p> <p>SFC can reduce the levels of inflammatory factors and improve symptoms of COPD. The levels of inflammatory factors are associated with the variation of Foxp3<sup>+</sup>Tregs in COPD.</p> <p>Trial registration</p> <p>This study was registered with <url>http://www.chictr.org</url> (Chinese Clinical Trial Register) as follows: ChiCTR-TNC-10001270</p
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