Plant Polyphenols as Antioxidant and Antibacterial Agents for Shelf‐Life Extension of Meat and Meat Products: Classification,Structures, Sources,and Action Mechanisms

Oxidative processes and meat spoilage bacteria are major contributors to decreasing the shelf‐life of meat and meat products. Oxidative processes occur during processing, storage, and light exposure, lowering the nutritional and sensory value and acceptability of meat and generating toxic compounds for humans. Polyphenols inhibit oxidative processes in 3 ways: as reactive species scavengers, lipoxygenase inhibitors, and reducing agents for metmyoglobin. Thus, polyphenols are candidate antioxidants for meat and meat products. The cross‐contamination of meat with spoilage and pathogenic microorganisms can occur in production lines and result in economic losses. The ability of polyphenols to interact with bacterial cell wall components and the bacterial cell membrane can prevent and control biofilm formation, as well as inhibit microbial enzymes, interfere in protein regulation, and deprive bacterial cell enzymes of substrates and metal ions. Thus, polyphenols are candidate antimicrobial agents for use with meat and meat products. Commercially available polyphenols can decrease primary and secondary lipid peroxidation levels, inhibit lipoxygenase activity, improve meat color stability, minimize the degradation of salt‐soluble myofibrillar protein and sulfhydryl groups, and retard bacterial growth. Further studies are now needed to clarify the synergistic/antagonistic action of various polyphenols, and to identify the best polyphenol classes, concentrations, and conditions of use.     

Poly(dopamine) assisted deposition of adherent PPy film on Ti substrate

This study aims to address an issue to a subject that is still less present in literature: the adherence of polypyrrole (PPy) films on bioinert substrate. The poly(dopamine) (PDA) assisted deposition of PPy film on titanium substrate was performed in two steps. The chemical self-polymerization of dopamine was performed as a preliminary step from dopamine in Tris buffer solution on titanium substrate. Then, the resulted poly(dopamine) layer consisting of anchors with strong interactions with Ti surface was a new suitable substrate for polypyrrole film electrochemical deposition. The new PDA–PPy films were characterized in terms of interest properties for the desired biomedical applications: adherence, electrochemical stability of PDA–PPy film, wettability, topography, morphology and antibacterial effect. The poly(dopamine) assisted deposition of PPy film has been shown to be a facile and efficient route to improve the adhesion of PPy film on titanium maintaining or improving the properties of polymeric film.     

The Development of Honey Recognition Models Based on the Association between ATR-IR Spectroscopy and Advanced Statistical Tools

The newly developed prediction models, having the aim to classify Romanian honey samples by associating ATR-FTIR spectral data and the statistical method, PLS-DA, led to reliable differentiations among the samples, in terms of botanical and geographical origin and harvesting year. Based on this approach, 105 out of 109 honey samples were correctly attributed, leading to true positive rates of 95% and 97% accuracy for the harvesting differentiation model. For the botanical origin classification, 83% of the investigated samples were correctly predicted, when four honey varieties were simultaneously discriminated. The geographical assessment was achieved in a percentage of 91% for the Transylvanian samples and 85% of those produced in other regions, with overall accuracy of 88% in the cross-validation procedure. The signals, based on which the best classification models were achieved, allowed the identification of the most significant compounds for each performed discrimination.     

Antimicrobial activity of the surface coatings on TiAlZr implant biomaterial

This study is devoted to antimicrobial activity of new surface coatings on TiAlZr. Ti alloys such as TiAlZr are used as implant biomaterials, but, despite the good behavior of such alloys in simulated conditions, bacterial infections appear after the introduction of an implant into the body. The infections are typically caused by the adherence and colonization of bacteria on the surfaces of the implants. The study presents preparation and surface morphology characterization of coatings obtained via anodizing, as well as biomimetic coatings with hydroxyapatite and silver ions with and without antibiotic. The percentage inhibition of Escherichia coli bacteria growth was evaluated for each of the studied coating, and a Trojan-horse model of silver nanoparticles (nAg) antibacterial activity at interface was proposed. Such coatings could be more important taking into account that antibacterial treatments with antibiotics are becoming less effective due to their intensive use.     

Highly accurate photopyroelectric measurement of thermal diffusivity of vegetable oils

High‐accuracy photopyroelectric measurements, in the thermal‐wave‐resonator‐cavity configuration, were performed in order to measure the thermal diffusivity of some vegetable oils. The high resolution (relative error ±0.5%) of the above method allows for the detection of small changes in the values of this dynamic thermal parameter. The accuracy of the results is mainly due to the possibility to precisely control the variation (30‐nm step) of sample thickness, a proper selection of the range of the thickness scan (2 µ_m < L_m < 4 µ_m ? 5 µ_m), and an iterative procedure of data analysis. A correlation between thermal diffusivity and the fatty acid composition (obtained via gas chromatography) is suggested for some fresh (sunflower, hemp, flax, and soybean) oils and for hemp oil exposed to a microwave field: Thermal diffusivity appears to be determined by the overall content of polyunsaturated fatty acids.     

A new approach for patterning epiclon-based polyimide precursor films using a lyotropic liquid crystal template

Blends of hydroxypropyl cellulose (HPC) in lyotropic phase have been prepared with a new epiclon-based poly(amic acid) (PAA) in different ratios. The detailed surface morphology of the PAA/HPC films was examined by polarized light microscopy (PLM) and atomic force microscopy (AFM). Besides the specific interactions, such as the hydrogen bonds between PAA and the liquid crystalline component, a slight cross-linking produced in the PAA structure by UV irradiation stabilized the resulting morphology. The effect of UV exposure and the influence of the HPC component weight ratio on the morphology developed by the PAA/HPC blends were investigated. The band texture, typical for lyotropic HPC solutions, evidencing different intensities and dimensions, is observed from atomic force microscopy images in PAA/HPC, being distinguished even at high PAA content and is also maintained after HPC removal with a selective solvent, namely acetone. These results lie at the basis of future investigations concerning high performance mixed alignment layers used in display devices or cell culture substrates with tuned morphology.     

In vitro assessment of tooth color changes due to orthodontic treatment using knowledge discovery methods

Esthetic dentistry imposes several demands on the artistic abilities of the dentist, and knowledge of the underlying scientific principles of tooth color is considered to be essential by Sikri. The supervised classification methods, such as the artificial neural networks, the support vector machines, and also the Bayesian classifier, and the feature selection methods, such as decision trees, genetic algorithms and neural networks, as well as independent component analysis combined with least square support vector machines, were applied successfully in the medical field but were less implemented in the dental analysis domain. This study was conducted on extracted premolars from people who required orthodontic treatment. Data gathering was done using spectrophotometric recordings of tooth color parameters before and after accelerated bleaching, staining, and control procedures on extracted teeth on which was simulated orthodontic treatment. Comparison between data mining techniques and classical statistical interpretation of data was done. The results demonstrated the usefulness of these innovating data assessment techniques in the dental field.     

Expanding a multilingual media monitoring and information extraction tool to a new language: Swahili

The Europe Media Monitor (EMM) family of applications is a set of multilingual tools that gather, cluster and classify news in currently fifty languages and that extract named entities and quotations (reported speech) from twenty languages. In this paper, we describe the recent effort of adding the African Bantu language Swahili to EMM. EMM is designed in an entirely modular way, allowing plugging in a new language by providing the language-specific resources for that language. We thus describe the type of language-specific resources needed, the effort involved, and ways of boot-strapping the generation of these resources in order to keep the effort of adding a new language to a minimum. The text analysis applications pursued in our efforts include clustering, classification, recognition and disambiguation of named entities (persons, organisations and locations), recognition and normalisation of date expressions, as well as the identification of reported speech quotations by and about people.     

Diamagnetic levitation enhances growth of liquid bacterial cultures by increasing oxygen availability

Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to reproduce aspects of weightlessness, on the Earth. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 h, to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture and reduces the sedimentation rate of the cells. Further experiments and microarray gene analysis show that the increase in growth rate is owing to enhanced oxygen availability. We also demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause convection during the aerobic phases of bacterial growth. We propose that this convection enhances oxygen availability by transporting oxygen around the liquid culture. Since this process results from the strong magnetic field, it is not present in other weightless environments, e.g. in Earth orbit. Hence, these results are of significance and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.