In search of the ideal periosteal flap for bone non-union: the chimeric fibula-periosteal flap

Vascularized periosteal flaps may increase union rates in recalcitrant long bone non-union. The fibula-periosteal chimeric flap utilizes periosteum raised on an independent periosteal vessel. This allows the periosteum to be inset freely around the osteotomy site, thereby facilitating bone consolidation. Patients and Methods: 10 patients underwent fibula-periosteal chimeric flaps (2016 – 2022) at Canniesburn Plastic Surgery Unit, UK. Preceding non-union 18.6 months, with bone gap 7.5 cm. Patients underwent pre-operative CT angiography to identify periosteal branches. A case-control approach was used. Patients acted as their own controls with one osteotomy covered by the chimeric periosteal flap and one without, although in two patients both osteotomies were covered by a long periosteal flap. Results: A chimeric periosteal flap was used in 12 of 20 osteotomy sites. Periosteal flap osteotomies had a primary union rate of 100% (11/11) versus those without 28.6% (2/7) (p=0.0025). Union occurred in the chimeric periosteal flaps at 8.5 months versus 16.75 in the control group (p=0.023). 1 case excluded from primary analysis due to recurrent mycetoma. Number needed to treat = 2, indicating that 2 patients would require a chimeric periosteal flap to avoid one non-union. Survival curves with hazards ratio 4.1, equating to 4 times higher chance of union with periosteal flaps (log rank p=0.0016). Conclusions: The chimeric fibula-periosteal flap may increase consolidation rates in difficult cases of recalcitrant non-union. This elegant modification of the fibula flap uses periosteum that is normally discarded, and adds to accumulating data supporting the use of vascularised periosteal flaps in non-union

VERITAS: the Very Energetic Radiation Imaging Telescope Array System

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) represents an important step forward in the study of extreme astrophysical processes in the universe. It combines the power of the atmospheric Cherenkov imaging technique using a large optical reflector with the power of stereoscopic observatories using arrays of separated telescopes looking at the same shower. The seven identical telescopes in VERITAS, each of aperture 10 m, will be deployed in a filled hexagonal pattern of side 80 m; each telescope will have a camera consisting of 499 pixels with a field of view of 3.5 deg VERITAS will substantially increase the catalog of very high energy (E > 100GeV) gamma-ray sources and greatly improve measurements of established sources.Comment: 44 pages, 16 figure

Organic electrode coatings for next-generation neural interfaces

Traditional neuronal interfaces utilize metallic electrodes which in recent years have reached a plateau in terms of the ability to provide safe stimulation at high resolution or rather with high densities of microelectrodes with improved spatial selectivity. To achieve higher resolution it has become clear that reducing the size of electrodes is required to enable higher electrode counts from the implant device. The limitations of interfacing electrodes including low charge injection limits, mechanical mismatch and foreign body response can be addressed through the use of organic electrode coatings which typically provide a softer, more roughened surface to enable both improved charge transfer and lower mechanical mismatch with neural tissue. Coating electrodes with conductive polymers or carbon nanotubes offers a substantial increase in charge transfer area compared to conventional platinum electrodes. These organic conductors provide safe electrical stimulation of tissue while avoiding undesirable chemical reactions and cell damage. However, the mechanical properties of conductive polymers are not ideal, as they are quite brittle. Hydrogel polymers present a versatile coating option for electrodes as they can be chemically modified to provide a soft and conductive scaffold. However, the in vivo chronic inflammatory response of these conductive hydrogels remains unknown. A more recent approach proposes tissue engineering the electrode interface through the use of encapsulated neurons within hydrogel coatings. This approach may provide a method for activating tissue at the cellular scale, however, several technological challenges must be addressed to demonstrate feasibility of this innovative idea. The review focuses on the various organic coatings which have been investigated to improve neural interface electrodes

Gelatin-Hyaluronic Acid Hydrogels with Tuned Stiffness to Counterbalance Cellular Forces and Promote Cell Differentiation

[EN] Cells interact mechanically with their environment, exerting mechanical forces that probe the extracellular matrix (ECM). The mechanical properties of the ECM determine cell behavior and control cell differentiation both in 2D and 3D environments. Gelatin (Gel) is a soft hydrogel into which cells can be embedded. This study shows significant 3D Gel shrinking due to the high traction cellular forces exerted by the cells on the matrix, which prevents cell differentiation. To modulate this process, Gel with hyaluronic acid (HA) has been combined in an injectable crosslinked hydrogel with controlled Gel-HA ratio. HA increases matrix stiffness. The addition of small amounts of HA leads to a significant reduction in hydrogel shrinking after cell encapsulation (C2C12 myoblasts). We show that hydrogel stiffness counterbalanced traction forces of cells and this was decisive in promoting cell differentiation and myotube formation of C2C12 encapsulated in the hybrid hydrogels.The authors are grateful for the financial support received from the Spanish Ministry through the MAT2013-46467-C4-1-R project (including the FEDER financial support), the BES-2011-046144, and the EEBB-I-14-08725 grants. CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. M.S.S. acknowledges ERC through HealInSynergy 306990.Poveda Reyes, S.; Moulisova, V.; Sanmartín Masiá, EDR.; Quintanilla-Sierra, L.; Salmerón Sánchez, M.; Gallego Ferrer, G. (2016). Gelatin-Hyaluronic Acid Hydrogels with Tuned Stiffness to Counterbalance Cellular Forces and Promote Cell Differentiation. Macromolecular Bioscience. 16(9):1311-1324. https://doi.org/10.1002/mabi.201500469S1311132416

Recent developments in genetics and medically assisted reproduction : from research to clinical applications

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.Peer reviewe

Detection potential of the KM3NeT detector for high-energy neutrinos from the Fermi bubbles

A recent analysis of the Fermi Large Area Telescope data provided evidence for a high-intensity emission of high-energy gamma rays with a E 2 spectrum from two large areas, spanning 50 above and below the Galactic centre (the ‘‘Fermi bubbles’’). A hadronic mechanism was proposed for this gamma-ray emission making the Fermi bubbles promising source candidates of high-energy neutrino emission. In this work Monte Carlo simulations regarding the detectability of high-energy neutrinos from the Fermi bubbles with the future multi-km3 neutrino telescope KM3NeT in the Mediterranean Sea are presented. Under the hypothesis that the gamma-ray emission is completely due to hadronic processes, the results indicate that neutrinos from the bubbles could be discovered in about one year of operation, for a neutrino spectrum with a cutoff at 100 TeV and a detector with about 6 km3 of instrumented volume. The effect of a possible lower cutoff is also considered.Published7–141.8. Osservazioni di geofisica ambientaleJCR Journalrestricte

Expansion cone for the 3-inch PMTs of the KM3NeT optical modules

[EN] Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average for angles up to 45 degrees with respect to the perpendicular. Ray-tracing calculations could reproduce the measurements, allowing to estimate an increase in the overall photocathode sensitivity, integrated over all angles of incidence, by 27% (for a single PMT). Prototype DOMs, being built by the KM3NeT consortium, will be equipped with these expansion cones.This work is supported through the EU, FP6 Contract no. 011937, FP7 grant agreement no. 212252, and the Dutch Ministry of Education, Culture and Science.Adrián Martínez, S.; Ageron, M.; Aguilar, JA.; Aharonian, F.; Aiello, S.; Albert, A.; Alexandri, M.... (2013). Expansion cone for the 3-inch PMTs of the KM3NeT optical modules. Journal of Instrumentation. 8(3):1-19. https://doi.org/10.1088/1748-0221/8/03/T03006S1198

How the "Northern Irish" national identity is understood and used by young people and politicians

The conventional understanding of the nation within social psychology is as a category of people or "imagined community." However, work within the discursive tradition shows that citizens tend to discuss nationhood in a variety of modes, including the use of nonhuman categories such as references to the physical landscape of the country. This article aims to give a more comprehensive overview of how young people understand the Northern Irish identity, a new and potentially inclusive national category in a divided society, and how politicians articulate it in rhetoric. In Study 1, students (N = 286) discussed this identity in 44 peer‐led focus groups. Thematic analysis of their discussions shows four distinct ways in which it is constructed: as a distinctive people, as an identity claim, as a "hot" political project, and as a "cold" or banal indicator of place. In Study 2, Members of the Legislative Assembly at Stormont (N = 49) responded to open‐ended questions about the Northern Irish identity. Each of the parties used different conceptualizations for rhetorical effect. These results give a deeper understanding of the multifaceted nature of national identity and its ability to promote political agendas

Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant