Immobilization and Characterization of <Emphasis Type="Italic">E. gracilis</Emphasis> Extract with Enriched Laminaribiose Phosphorylase Activity for Bienzymatic Production of Laminaribiose

Immobilization methods and carriers were screened for immobilization of Euglena gracilis extract with laminaribiose phosphorylase activity. The extract was successfully immobilized on three different carriers via covalent linkage. Suitable immobilization carriers were Sepabeads EC-EP/S and ECR 8209M with epoxy groups and ECR 8309M with amino groups as functional units. Immobilization on Sepabeads EC-EP/S resulted in highest retained activity (65%). The immobilizates were characterized for pH, temperature, and buffer molarity preferences. The immobilized enzyme lost 48% of its activity when used seven times. Together with sucrose phosphorylase, laminaribiose phosphorylase was successfully applied for bienzymatic production of laminaribiose from sucrose and glucose with a final laminaribiose concentration of 14.3 ± 2.1 g/L (20% yield).     

ChemInform Abstract: Evaluation of Tavorite‐Structured Cathode Materials for Lithium‐Ion Batteries Using High‐Throughput Computing.

Tavorite‐structured oxyphosphates, fluorophosphates, oxysulfates, and fluorosulfates are evaluated for use as cathode materials in lithium ion batteries and activation energies for lithium diffusion through LiVO(PO₄), LiV(PO₄)F, and LiFe(SO₄)F are calculated.     

Post‐Plasma Grafting of AEMA as a Versatile Tool to Biofunctionalise Polyesters for Tissue Engineering

In the last decade, substantial research in the field of post‐plasma grafting surface modification has focussed on the introduction of carboxylic acids on surfaces by grafting acrylic acid (AAc). In the present work, we report on an alternative approach for biomaterial surface functionalisation. Thin poly‐ε‐caprolactone (PCL) films were subjected to a dielectric barrier discharge Ar‐plasma followed by the grafting of 2‐aminoethyl methacrylate (AEMA) under UV‐irradiation. X‐ray photoelectron spectroscopy (XPS) confirmed the presence of nitrogen. The ninhydrin assay demonstrated, both quantitatively and qualitatively, the presence of free amines on the surface. Confocal fluorescence microscopy (CFM), atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to visualise the grafted surfaces, indicating the presence of pAEMA. Static contact angle (SCA) measurements indicated a permanent increase in hydrophilicity. Furthermore, the AEMA grafted surfaces were applied for comparing the physisorption and covalent immobilisation of gelatin. CFM demonstrated that only the covalent immobilisation lead to a complete coverage of the surface. Those gelatin‐coated surfaces obtained were further coated using fibronectin. Osteosarcoma cells demonstrated better cell‐adhesion and cell‐viability on the modified surfaces, compared to the pure PCL films.

     

Evaluation of standard and advanced preprocessing methods for the univariate analysis of blood serum 1H-NMR spectra

Proton nuclear magnetic resonance (¹H-NMR)-based metabolomics enables the high-resolution and high-throughput assessment of a broad spectrum of metabolites in biofluids. Despite the straightforward character of the experimental methodology, the analysis of spectral profiles is rather complex, particularly due to the requirement of numerous data preprocessing steps. Here, we evaluate how several of the most common preprocessing procedures affect the subsequent univariate analyses of blood serum spectra, with a particular focus on how the standard methods perform compared to more advanced examples. Carr–Purcell–Meiboom–Gill 1D ¹H spectra were obtained for 240 serum samples from healthy subjects of the Asklepios study. We studied the impact of different preprocessing steps—integral (standard method) and probabilistic quotient normalization; no, equidistant (standard), and adaptive-intelligent binning; mean (standard) and maximum bin intensity data summation—on the resonance intensities of three different types of metabolites: triglycerides, glucose, and creatinine. The effects were evaluated by correlating the differently preprocessed NMR data with the independently measured metabolite concentrations. The analyses revealed that the standard methods performed inferiorly and that a combination of probabilistic quotient normalization after adaptive-intelligent binning and maximum intensity variable definition yielded the best overall results (triglycerides, R = 0.98; glucose, R = 0.76; creatinine, R = 0.70). Therefore, at least in the case of serum metabolomics, these or equivalent methods should be preferred above the standard preprocessing methods, particularly for univariate analyses. Additional optimization of the normalization procedure might further improve the analyses.     

A Deployable In Vivo EPR Tooth Dosimeter for Triage After a Radiation Event Involving Large Populations

In order to meet the potential need for emergency large-scale retrospective radiation biodosimetry following an accident or attack, we have developed instrumentation and methodology for in vivo electron paramagnetic resonance spectroscopy to quantify concentrations of radiation-induced radicals within intact teeth. This technique has several very desirable characteristics for triage, including independence from confounding biologic factors, a non-invasive measurement procedure, the capability to make measurements at any time after the event, suitability for use by non-expert operators at the site of an event, and the ability to provide immediate estimates of individual doses. Throughout development there has been a particular focus on the need for a deployable system, including instrumental requirements for transport and field use, the need for high throughput, and use by minimally trained operators.Numerous measurements have been performed using this system in clinical and other non-laboratory settings, including in vivo measurements with unexposed populations as well as patients undergoing radiation therapies. The collection and analyses of sets of three serially-acquired spectra with independent placements of the resonator, in a data collection process lasting approximately five minutes, provides dose estimates with standard errors of prediction of approximately 1 Gy. As an example, measurements were performed on incisor teeth of subjects who had either received no irradiation or 2 Gy total body irradiation for prior bone marrow transplantation; this exercise provided a direct and challenging test of our capability to identify subjects who would be in need of acute medical care.     

Polysulfobetaine films prepared by electrografting technique for reduction of biofouling on electroconductive surfaces

The sulfobetaine films were prepared on stainless steel and golden surfaces. In the first step, the poly(2-(dimethylamino)ethyl methacrylate) film was created by employing the electrografting polymerization technique. In the second step, this film was modified to polysulfobetaine, i.e. the polymer film bearing the zwitterionic groups. The presence of the electrografted film and its modification were determined by contact angle measurements, infrared spectroscopy in reflectance mode and X-ray photoelectron spectroscopy. The prepared films were homogeneous with the thickness from about 5 to 26 nm as determined by X-ray photoelectron spectroscopy. The atomic force microscopy measurements showed the increase of surface roughness upon the surface coating. In vitro tests using adherent RAT-2 fibroblast cells and fluorescently labelled bovine serum albumin proteins showed that prepared polysulfobetaine films can be used in applications requiring the resistance against cell attachment and biofouling.     

Relative symplectic subquadrangle hemisystems of the Hermitian surface

We introduce the notion of relative subquadrangle regular system of a generalized quadrangle. A relative subquadrangle regular system of order m on a generalized quadrangle S of order (s, t) is a set \({\mathcal R}\) of embedded subquadrangles with a prescribed intersection property with respect to a given subquadrangle T such that every point of S T lies on exactly m subquadrangles of \({\mathcal R}\) . If m is one half of the total number of such subquadrangles on a point we call \({\mathcal R}\) a relative subquadrangle hemisystem with respect to T. We construct two infinite families of symplectic relative subquadrangle hemisystems of the Hermitian surface \({{\mathcal H}(3,q^2)}\) , q even.     

Modelling the future of the Canadian cardiac surgery workforce using system dynamics

Due to the high costs and lengthy lead times involved with training health human resources such as physicians and surgeons, combined with the serious burden borne by the general population when health care provider shortages occur, advance planning of resource requirements is critical. This is particularly true in light of current demographic trends and Canada’s ageing population, which will potentially increase demand for health care providers in the future while also leading to the retirement of many of the providers currently practicing. The purpose of this research was to develop a model simulating the workforce within a single specialty at a national level, which includes students training to enter the profession, providing a tool that would help to inform future resource planning. We present the details of this model, developed using system dynamics modelling, and demonstrate it using the example of cardiac surgeons in Canada.