An overview of analytical methods for determining the geographical origin of food products

There is an increasing interest by consumers for high quality food products with a clear geographical origin. These products are encouraged and suitable analytical techniques are needed for the quality control. This overview concerns an investigation of the current analytical techniques that are being used for the determination of the geographical origin of food products. The analytical approaches have been subdivided into four groups; mass spectrometry techniques, spectroscopic techniques, separation techniques, and other techniques. The principles of the techniques together with their advantages and drawbacks, and reported applications concerning geographical authenticity are discussed. A combination of methods analysing different types of food compounds seems to be the most promising approach to establish the geographical origin. Chemometric analysis of the data provided by the analytical instruments is needed for such a multifactorial approach.     

Escherichia coli O157:H7 outbreak linked to raw milk cheese in Quebec, Canada: use of exact probability calculation and casecase study approaches to foodborne outbreak investigation

The analytical studies used to investigate foodborne outbreak are mostly case-control or retrospective cohort studies. However, these studies can be complex to perform and susceptible to biases. This article addresses basic principles of epidemiology, probability, and the use of case-case design to identify the source of an Escherichia coli O157:H7 outbreak linked to raw milk cheese consumption in Quebec, Canada; a small number of cases with the same pulsed-field gel electrophoresis (PFGE) profile were involved. Between 4 December 2008 and 15 January 2009, a cumulative total of 16 E. coli O157:H7 cases with the same PFGE profile were reported to Quebec public health authorities. Among the first six cases reported, three had consumed raw milk cheese from the same producer (cheese A). Raw milk cheese is consumed by about 2 % of the Quebec population. By using the exact probability calculation, it was found that a significantly higher proportion of E. coli O157:H7 cases (with the specific PFGE profile) than expected had consumed cheese A (P < 0.001). These computations were updated during the course of the investigation to include subsequent cases and gave the same results. A case-case study corroborated this result. This article considers alternative statistical and epidemiological approaches to investigate a foodborne outbreak-in particular with an exact probability calculation and case-case comparisons. This approach could offer a fast and inexpensive alternative to regular case-control studies to target public health actions, particularly during a foodborne outbreak.     

Kinetics study on cnt‐supported RuKCo FTS catalyst in a fixed bed reactor

The rate of syngas (H₂/CO) consumption over a RuKCo/CNT Fischer–Tropsch synthesis (FTS) catalyst was measured in a fixed bed microreactor at 210–225°C, 2–3.5 MPa, H₂/CO feed molar ratios of 1–2.5, and gas hourly space velocity (GHSV) range of 2700–3600 h^?1. The data have been used to model the kinetics of the FTS reactions within the range of the studied conditions. One empirical power law model and four semi‐empirical kinetic models based on Langmuir–Hinshelwood‐type equation have been evaluated. The best fitting was obtained with the equation: similar to that proposed by Brötz et al. The estimated activation energy (E = 80–85 kJ/mol) is lower than that is reported in the literature. The validity of these results are restricted to fixed beds with the given catalyst in the tested conversion regime.     

Epigenetic Regulation of the Hippocampus,with Special Reference to Radiation Exposure

The hippocampus is crucial in learning, memory and emotion processing, and is involved in the development of different neurological and neuropsychological disorders. Several epigenetic factors, including DNA methylation, histone modifications and non-coding RNAs, have been shown to regulate the development and function of the hippocampus, and the alteration of epigenetic regulation may play important roles in the development of neurocognitive and neurodegenerative diseases. This review summarizes the epigenetic modifications of various cell types and processes within the hippocampus and their resulting effects on cognition, memory and overall hippocampal function. In addition, the effects of exposure to radiation that may induce a myriad of epigenetic changes in the hippocampus are reviewed. By assessing and evaluating the current literature, we hope to prompt a more thorough understanding of the molecular mechanisms that underlie radiation-induced epigenetic changes, an area which can be further explored.     

The effect of chemical composition on the miscibility of styrene/acrylonitrile/fumaronitrile terpolymers with styrene/acrylonitrile copolymers

Blends were prepared of styrene–acrylonitrile–fumaronitrile (SANFN) terpolymers with styrene–acrylonitrile (SAN) copolymers and of SANFN terpolymers with SANFN terpolymers of different compositions. Miscibility was determined by differential scanning calorimetry. For three SANFN terpolymer compositions containing 11–17% fumaronitrile, a range of miscible SAN copolymers was defined. The miscibility can be predicted by using a Flory–Huggins-type mean-field approach.     

Multilevel surrogate modeling of an amine scrubbing process for CO2capture

Surrogate models provide a powerful method for simplifying calculations within complex simulations. While surrogate models are broadly applied within chemical engineering, little research exists investigating the level of surrogacy's impact on a simplified process model. In this work, artificial neural networks (ANN) and Kriging models are used as surrogate models at the process, process unit, and thermodynamic levels for a CO₂ amine scrubbing process. The surrogated models are evaluated against an Aspen Plus simulation for accuracy, convergence behavior, computational cost, and ability to extrapolate. The thermodynamic and process unit models can better handle discontinuous, non-smooth behavior, and convergence issues in the surrogated truth model, but poor conditioning in the final system of equations results in a lower accuracy and convergence rate than the process level surrogate. Beyond model accuracy, availability of diverse data, intended re-usability, and the desired outputs must be considered when selecting a level of abstraction.     

Digital screening methodology for the directed evolution of transglycosidases

Engineering of glycosidases with efficient transglycosidasesactivity is an alternative to glycosyltransferases or glycosynthasesfor the synthesis of oligosaccharides and glycoconjugates. However,the engineering of transglycosidases by directed evolution methodologiesis hampered by the lack of efficient screening systems for sugar-transferactivity. We report here the development of digital imaging-basedhigh-throughput screening methodology for the directed evolutionof glycosidases into transgalactosidases. Using this methodology,we detected transglycosidase mutants in intact Escherichia colicells by digital imaging monitoring of the activation of non-or low-hydrolytic mutants by an acceptor substrate. We screenedseveral libraries of mutants of β-glycosidase from Thermusthermophilus using this methodology and found variants withup to a 70-fold overall increase in the transglycosidase/hydrolysisactivity ratio. Using natural disaccharide acceptors, thesetransglycosidase mutants were able to synthesise trisaccharides,as a mixture of two regioisomers, with up to 76% yield.     

The Role of Innate and Adaptive Immune Cells in Skeletal Muscle Regeneration

Skeletal muscle regeneration is highly dependent on the inflammatory response. A wide variety of innate and adaptive immune cells orchestrate the complex process of muscle repair. This review provides information about the various types of immune cells and biomolecules that have been shown to mediate muscle regeneration following injury and degenerative diseases. Recently developed cell and drug-based immunomodulatory strategies are highlighted. An improved understanding of the immune response to injured and diseased skeletal muscle will be essential for the development of therapeutic strategies.     

Molecular Genetics of Conjunctival Melanoma and Prognostic Value of TERT Promoter Mutation Analysis

The aim of this study was exploration of the genetic background of conjunctival melanoma (CM) and correlation with recurrent and metastatic disease. Twenty-eight CM from the Rotterdam Ocular Melanoma Study group were collected and DNA was isolated from the formalin-fixed paraffin embedded tissue. Targeted next-generation sequencing was performed using a panel covering GNAQ, GNA11, EIF1AX, BAP1, BRAF, NRAS, c-KIT, PTEN, SF3B1, and TERT genes. Recurrences and metastasis were present in eight (29%) and nine (32%) CM cases, respectively. TERT promoter mutations were most common (54%), but BRAF (46%), NRAS (21%), BAP1 (18%), PTEN (14%), c-KIT (7%), and SF3B1 (4%) mutations were also observed. No mutations in GNAQ, GNA11, and EIF1AX were found. None of the mutations was significantly associated with recurrent disease. Presence of a TERT promoter mutation was associated with metastatic disease (p-value = 0.008). Based on our molecular findings, CM comprises a separate entity within melanoma, although there are overlapping molecular features with uveal melanoma, such as the presence of BAP1 and SF3B1 mutations. This warrants careful interpretation of molecular data, in the light of clinical findings. About three quarter of CM contain drug-targetable mutations, and TERT promoter mutations are correlated to metastatic disease in CM.