Cell response to plasma electrolytic oxidation surface-modified low-modulus β-type titanium alloys.

Plasma electrolytic oxidation (PEO) has been demonstrated to be an effective surface treatment for enhancing the osteoconduction and osseointegration of commercially pure α-Ti (CP α-Ti) dental implant materials for clinical application. To explore the feasibility of extending the application of PEO to low-modulus β-type titanium alloys for load-bearing orthopaedic implants, a thorough understanding of the effect of substrate material on the biological performance of the PEO-treated surface is required. A 10 kW 50 Hz KeroniteTM processing unit was used to modify the surface of low-modulus near β-Ti13Nb13Zr and β-Ti45Nb substrates. CP α-Ti and (α + β)-Ti6Al4V were also used in parallel as reference materials. In vitro culture of foetal human osteoblast (fHOb) cells on PEO-treated low-modulus near β-Ti13Nb13Zr and β-Ti45Nb alloys revealed comparable behaviour to that seen with CP α-Ti and (α + β)-Ti6Al4V with respect to metabolic activity, collagen production, matrix formation and matrix mineralisation. No difference was observed in TNF-α and IL-10 cytokine release from CD14+ monocytes as markers of inflammatory response across samples. Cell interdigitation into the porous structure of the PEO coatings was demonstrated and cell processes remained adherent to the porous structure despite rigorous sonication. This study shows that PEO technology can be used to modify the surface of low-modulus β-type titanium alloys with porous structure facilitating osseointegration, without impeding osteoblast activity or introducing an untoward inflammatory response.European Commission FP7 International training Network National Institute for Health Research Cambridge Biomedical Research Centr

The isotropic-nematic interface in suspensions of hard rods: Mean-field properties and capillary waves

We present a study of the isotropic-nematic interface in a system of hard spherocylinders. First we compare results from Monte Carlo simulations and Onsager density functional theory for the interfacial profiles of the orientational order parameter and the density. Those interfacial properties that are not affected by capillary waves are in good agreement, despite the fact that Onsager theory overestimates the coexistence densities. Then we show results of a Monte Carlo study of the capillary waves of the interface. In agreement with recent theoretical investigations (Eur.Phys.J. E {\bf 18} 407 (2005)) we find a strongly anistropic capillary wave spectrum. For the wave-numbers accessed in our simulations, the spectrum is quadratic, i.e.elasticity does not play a role. We conjecture that this effect is due to the strong bending rigidity of the director field in suspensions of spherocylinders.Comment: 8 pages, 10 figure

Sustainable metal-free carbogels as oxygen reduction electrocatalysts

crosscheck: This document is CrossCheck deposited related_data: Supplementary Information copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal history: Received 5 March 2017; Accepted 2 May 2017; Accepted Manuscript published 2 May 2017Kathrin Preuss would like to thank the Materials Research Institute of Queen Mary, University of London for a PhD studentship. Liviu C. Tănase and Cristian M. Teodorescu acknowledge funding from the UEFISCDI Agency through the Project PN-II-RU-TE-2014-4-0456 and by the NIMP Core Project PN16-48012, both projects being granted by the Romanian Ministry of Research and Innovation

Survival trends and complications in surgical interventions for colorectal cancer: an overview of patients hospitalized in Clinical Emergency Hospital Bucharect

The preoperative imaging diagnosis of rectal cancer lies at the heart of oncological staging and has a crucial influence on patient management and therapy planning. Rectal cancer is common, and accurate preoperative staging of tumors using high-resolution magnetic resonance imaging (MRI) is a crucial part of modern multidisciplinary team management (MDT). Indeed, rectal MRI has the ability to accurately evaluate a number of important findings that maBay impact patient management, including distance of the tumor to the mesorectal fascia, presence of lymph nodes, presence of extramural vascular invasion (EMVI), and involvement of the anterior peritoneal reflection/peritoneum and the sphincter complex. Many of these findings are difficult to assess in nonexpert hands. In this lecture, we present currently used staging modalities with focus on MRI, including optimization of imaging techniques, tumor staging, interpretation help as well as essentials for reporting

Reaction coordinates for the flipping of genetic switches

We present a detailed analysis, based on the Forward Flux Sampling (FFS) simulation method, of the switching dynamics and stability of two models of genetic toggle switches, consisting of two mutually-repressing genes encoding transcription factors (TFs); in one model (the exclusive switch), they mutually exclude each other's binding, while in the other model (general switch) the two transcription factors can bind simultaneously to the shared operator region. We assess the role of two pairs of reactions that influence the stability of these switches: TF-TF homodimerisation and TF-DNA association/dissociation. We factorise the flipping rate k into the product of the probability rho(q*) of finding the system at the dividing surface (separatrix) between the two stable states, and a kinetic prefactor R. In the case of the exclusive switch, the rate of TF-operator binding affects both rho(q*) and R, while the rate of TF dimerisation affects only R. In the case of the general switch both TF-operator binding and TF dimerisation affect k, R and rho(q*). To elucidate this, we analyse the transition state ensemble (TSE). For the exclusive switch, varying the rate of TF-operator binding can drastically change the pathway of switching, while changing the rate of dimerisation changes the switching rate without altering the mechanism. The switching pathways of the general switch are highly robust to changes in the rate constants of both TF-operator and TF-TF binding, even though these rate constants do affect the flipping rate; this feature is unique for non-equilibrium systems.Comment: 24 pages, 7 figure