An electrochemical study of acrylate bone adhesive permeability and selectivity change during in vitro ageing: a model approach to the study of biomaterials and membrane barriers

This study assessed the solute permeability of a family of UV and moisture cured acrylates-based adhesives during in vitro ageing in pH 7.4 buffer. Acrylates have a potential role in bone fracture fixation, but their inability to allow microsolute exchange between the fractured bone surfaces may contribute to ineffective healing. Cyclic voltammetry and chronoamperometry were used to determine the diffusion coefficients for various electrochemically active probe molecules (O2, H2O2, acetaminophen, catechol, uric acid and ascorbic acid) at proprietary acrylic, urethane – acrylate and cyanoacrylate adhesives. All adhesives proved to be impermeable for up to 9 days ageing, following which a near-exponential increase in permeability resulted for all solutes. At 18 days, the diffusion coefficients were in the range of 10-5 cm2s-1 for O2 and H2O2 and 10-6 cm2s-1 for the organic solutes; no transport selectivity was seen between the latter. Adhesive joint strength showed a direct, inverse, correlation with permeability, with the more hydrophilic cyanoacrylates showing the greatest loss of strength. Adhesive permeabilisation does not appear to be compatible with the retention of bonding strength, but it serves as a new non-destructive predictor of adhesion strength change during ageing and practical use

Forequarter amputations at the Moi teaching and referral hospital

Background: Forequarter amputation is an uncommon procedure. It is performed for high grade sarcomas of the proximal humerus, scapula and axillary region; that are not responding to induction chemotherapy or tumour progression with vascular invasion.Objective: To document the indications and results of forequarter amputations done at the Moi Teaching and Referral Hospital.Methods: Records of patients that had received a forequarter amputation in Moi Teaching and Referral Hospital between February 2012 and February 2017 were retrieved. The patient’s demographics, indication for surgery, complications and duration of survival post-operatively were noted and further analyzed.Results: A total of twelve patients were found that had a forequarter amputation done on their upper extremity. Eight were male while four were female. Ten patients (83.3%) were operated on for sarcomas including: synovial sarcoma, neurofibrosarcoma, Ewing’s sarcoma, Kaposi’s sarcoma, rhabdomyosarcoma, enchondroma, osteosarcoma and poorly differentiated sarcoma. Two patients (15.4%) were operated for squamous cell carcinoma. All the amputations were primary surgeries. Survival was 77.7% at six months and 44.4% after one year.Conclusion: The most common indication for forequarter amputation was a limb sarcoma. A one-year survival rate of 44.4% was found following forequarter amputation of a limb

Enhanced hydration stability of Bombyx mori silk fibroin/PEG 600 composite scaffolds for tissue engineering

Silk fibroin scaffolds obtained via regeneration by Ajisawa's reagent (CaCl2/H2O/EtOH, mole ratio 1:8:2) and freeze-drying followed by steam sterilization resulted unstable when incubated in physiological medium over 1-month period since the oxygen diffusivity and mechanical resistance to compression significantly decreased. Blending of regenerated silk fibroin with PEG 600 lead to a novel scaffold with an improved water stability. Multi-parameter characterization has revealed that scaffolds made by composite material were stable in physiological media over at least 1month of incubation. Interestingly, the presence of PEG has a notable impact on wettability and protein adsorption. This increase in hydrophilicity could be beneficial for initial cell adhesion and survival as well as for the adsorptive loading of growth factors

Dataset in support of the Southampton doctoral thesis 'Remote ischaemic conditioning as a novel therapy for necrotising enterocolitis'

Description of the data: There are essentially three datasets for this thesis. The first relates to a systematic review of NEC outcomes (Chapter 2) as consists of a single Microsoft Excel file with the details of the included papers and the data extracted from them. This systematic review is published as Jones, I H. and Hall, N.J. Contemporary Outcomes for Infants with Necrotizing Enterocolitis &ndash; A Systematic Review The Journal of Pediatrics 2020 220: 86-92.e3 The second relates to the primary research using an animal model of NEC. Each datafile is a Microsoft Excel file and contains multiple data points from each animal; including the macroscopic assessment of injury, microscopic assessment, using the Chiu-Park scoring system, serum cytokine analysis, and myeloperoxidase activity. In each case, the individual animal is identified by a unique, randomly generated 3-digit code. (Chapters 5-8 and 10). The Ethical approval for the animal work is included. Publication manuscripts in press / in production. The third set is the raw count from RNAseq transciptomics analysis of the intestine of animals in protocol 1a (plus controls). The datafile is a .csv file. Publication manuscript in production. </span

Anti-neutrophil cytoplasmic antibodies (ANCA) from patients with systemic vasculitis recognize restricted epitopes of proteinase 3 involving the catalytic site

ANCA with specificity for proteinase 3 (PR3), a neutrophil primary granule enzyme, are of diagnostic value in Wegener's granulomatosis (WG) and certain other forms of systemic vasculitis. There is evidence to suggest that they play a pathogenic role in disease, and that the interaction of ANCA with PR3 is likely to be important. We showed, using a resonant mirror biosensor, that C-ANCA from different patients recognized the same or closely related epitopes on PR3. Studies using linear peptides in the SPOT system confirmed the highly restricted nature of this interaction and identified five linear epitopes. Fluid-phase inhibition studies, using a different set of peptides, validated the sequences involved. Using a computer-generated model of the structure of PR3, four of five epitopes were shown to be intimately linked with the catalytic site. The restricted number of epitopes, and their location at the catalytic site, has important implications for the role of C-ANCA in the pathogenesis of vasculitis

Objectives, physics requirements and conceptual design of an ECRH system for JET

A study has been conducted to evaluate the feasibility of installing an electron cyclotron resonance heating (ECRH) and current drive system on the JET tokamak. The main functions of this system would be electron heating, sawtooth control, neoclassical tearing mode control to access high beta regimes and current profile control to access and maintain advanced plasma scenarios. This paper presents an overview of the studies performed in this framework by an EU-Russia project team. The motivations for this major upgrade of the JET heating systems and the required functions are discussed. The main results of the study are summarized. The usefulness of a 10 MW level EC system for JET is definitely confirmed by the physics studies. Neither feasibility issues nor strong limitations for any of the functions envisaged have been found. This has led to a preliminary conceptual design of the system.</p

Objectives, physics requirements and conceptual design of an ECRH system for JET

A study has been conducted to evaluate the feasibility of installing an electron cyclotron resonance heating (ECRH) and current drive system on the JET tokamak. The main functions of this system would be electron heating, sawtooth control, neoclassical tearing mode control to access high beta regimes and current profile control to access and maintain advanced plasma scenarios. This paper presents an overview of the studies performed in this framework by an EU-Russia project team. The motivations for this major upgrade of the JET heating systems and the required functions are discussed. The main results of the study are summarized. The usefulness of a 10 MW level EC system for JET is definitely confirmed by the physics studies. Neither feasibility issues nor strong limitations for any of the functions envisaged have been found. This has led to a preliminary conceptual design of the system