Synergistic Effect of PVDF-Coated PCL-TCP Scaffolds and Pulsed Electromagnetic Field on Osteogenesis

Bone exhibits piezoelectric properties. Thus, electrical stimulations such as pulsed electromagnetic fields (PEMFs) and stimuli-responsive piezoelectric properties of scaffolds have been investigated separately to evaluate their efficacy in supporting osteogenesis. However, current understanding of cells responding under the combined influence of PEMF and piezoelectric properties in scaffolds is still lacking. Therefore, in this study, we fabricated piezoelectric scaffolds by functionalization of polycaprolactone-tricalcium phosphate (PCL-TCP) films with a polyvinylidene fluoride (PVDF) coating that is self-polarized by a modified breath-figure technique. The osteoinductive properties of these PVDF-coated PCL-TCP films on MC3T3-E1 cells were studied under the stimulation of PEMF. Piezoelectric and ferroelectric characterization demonstrated that scaffolds with piezoelectric coefficient d₃₃ = −1.2 pC/N were obtained at a powder dissolution temperature of 100 °C and coating relative humidity (RH) of 56%. DNA quantification showed that cell proliferation was significantly enhanced by PEMF as low as 0.6 mT and 50 Hz. Hydroxyapatite staining showed that cell mineralization was significantly enhanced by incorporation of PVDF coating. Gene expression study showed that the combination of PEMF and PVDF coating promoted late osteogenic gene expression marker most significantly. Collectively, our results suggest that the synergistic effects of PEMF and piezoelectric scaffolds on osteogenesis provide a promising alternative strategy for electrically augmented osteoinduction. The piezoelectric response of PVDF by PEMF, which could provide mechanical strain, is particularly interesting as it could deliver local mechanical stimulation to osteogenic cells using PEMF.     

Discriminating constant from variable angular velocities in structure from motion

We investigated accuracy in discriminating between constant and variable angular velocities for orthographic projections of three-dimensional rotating objects. The reported judgments of "constant" or "variable" angular velocity were only slightly influenced by the projected angular velocities, but they were greatly affected by the variations of the deformation, a first-order component of the optic flow. When viewing either a rotating ellipsoidal volume or a planar surface that accelerated and decelerated over the course of rotation, observers' tendencies to report a variable angular velocity were increased when the temporal phase of the acceleration pattern increased the range of variation of the median deformation; the tendencies were decreased when the same acceleration pattern was used to decrease the range of variation of the median deformation. These results provide evidence contrary to the hypothesis that the visual system performs a mathematically correct analysis of the optic flow.     

Principal component analysis as a tool for studying interdependences among trace metals in edible mussels from the gulf of Trieste

Summary Principal component analysis has been applied to analyze the correlation matrix obtained from a (6 × 44) data matrix. The 6 trace metals are Co, Ni, Cu, Cd, Hg, and Pb, which are contained in the soft part of edible mussels (Mytilus galloprovincialis Lamarck) from a hatchery on the gulf of Trieste. In the space of eigenvectors, the dimensions are reduced to 3 principal axes, which account for about 77% of the total variance.The unrotated factor matrix obtained by the principal components shows that Co, Ni and Cu are bonded to the first principal component, Cd and Pb to the second, Hg to the third. This picture is also assessed by the Varimax-rotated matrix and it is tentatively explained, at least in part, by considering the associations of the trace metals from various geographical sources.

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Hauptkomponentenanalyse für das Studium der Assoziationen unter Spurenmetallen in Miesmuscheln im Golf von Triest

Zusammenfassung Die Hauptkomponentenanalyse wurde auf die Korrelationsmatrix, die aus der (6 × 44) Datenmatrix hervorgeht, angewandt. Die 6 Spurenmetalle sind Co, Ni, Cu, Cd, Hg, Pb, die im Miesmuschelnfleisch (Mytilus galloprovineialis Lamarck) gefunden werden. Die Miesmuschelnproben stammen aus der Zucht des Golfes von Triest. In dem Eigenvektorraum werden die Dimensionen auf drei Hauptachsen reduziert, die ungefähr 77% der totalen Varianz erklären.Die unrotierte Faktorenmatrix, die aus den Hauptkomponenten hervorgeht, zeigt, daß Co, Ni, Cu an die erste Hauptkomponente, Cd und Pb an die zweite, Hg an die dritte gebunden sind. Dieses Bild wird von der Varimax-rotierten Matrix bestätigt und es findet eine Erklärung in der Herkunft der Spurenmetalle.

     

The Periplasmic Oxidoreductase DsbA Is Required for Virulence of the Phytopathogen Dickeya solani

In bacteria, the DsbA oxidoreductase is a crucial factor responsible for the introduction of disulfide bonds to extracytoplasmic proteins, which include important virulence factors. A lack of proper disulfide bonds frequently leads to instability and/or loss of protein function; therefore, improper disulfide bonding may lead to avirulent phenotypes. The importance of the DsbA function in phytopathogens has not been extensively studied yet. Dickeya solani is a bacterium from the Soft Rot Pectobacteriaceae family which is responsible for very high economic losses mainly in potato. In this work, we constructed a D. solani dsbA mutant and demonstrated that a lack of DsbA caused a loss of virulence. The mutant bacteria showed lower activities of secreted virulence determinants and were unable to develop disease symptoms in a potato plant. The SWATH-MS-based proteomic analysis revealed that the dsbA mutation led to multifaceted effects in the D. solani cells, including not only lower levels of secreted virulence factors, but also the induction of stress responses. Finally, the outer membrane barrier seemed to be disturbed by the mutation. Our results clearly demonstrate that the function played by the DsbA oxidoreductase is crucial for D. solani virulence, and a lack of DsbA significantly disturbs cellular physiology.     

Antiviral activity of donkey milk protein fractions on echovirus type 5

Antiviral activity of Ragusano donkeys' milk proteins was investigated for the effect on echovirus type 5, known to infect the gastrointestinal tract of humans. Three protein fractions were tested; casein (CN), whey protein (WP) and a low molecular whey protein fraction (LWP; <30,000 Da). The antiviral activity of WP and LWP was tested on echovirus type 5 at three concentrations (1, 5 and 10 mg mL^?1); CN was assessed only at the lower concentration. All donkey milk protein fractions showed significant inhibition on virus replication at the concentration of 1 mg mL^?1, and both WP and LWP fractions showed significant inhibition on the virus replication at all concentrations tested. The strongest antiviral effect was observed for the WP fraction. These findings show that the different whey proteins in donkey milk, probably acting in synergy, exert antiviral activity on echovirus 5 and might contribute to prevent gastrointestinal virus infections in humans.     

Ligand Binding Promiscuity of Human Liver Fatty Acid Binding Protein: Structural and Dynamic Insights from an Interaction Study with Glycocholate and Oleate

Human liver fatty acid binding protein (hL‐FABP) has been reported to act as an intracellular shuttle of lipid molecules, thus playing a central role in systemic metabolic homeostasis. The involvement of hL‐FABP in the transport of bile salts has been postulated but scarcely investigated. Here we describe a thorough NMR investigation of glycocholate (GCA) binding to hL‐FABP. The protein molecule bound a single molecule of GCA, in contrast to the 1:2 stoichiometry observed with fatty acids. GCA was found to occupy the large internal cavity of hL‐FABP, without requiring major conformational rearrangement of the protein backbone; rather, this led to increased stability, similar to that estimated for the hL‐FABP:oleate complex. Fast‐timescale dynamics appeared not to be significantly perturbed in the presence of ligands. Slow motions (unlike for other proteins of the family) were retained or enhanced upon binding, consistent with a requirement for structural plasticity for promiscuous recognition.     

Principal component analysis for the identification of pollution sources in mussel survey by trace metals

Summary Principal component analysis has been applied to analyze the correlation matrix obtained from a 8 × 43 data matrix. The 8 trace metals are Mn, Co, Ni, Cu, Zn, Cd, Hg, Ph, which are contained in the soft part of mussels (Mytilus galloprovincialis Lamarck). Mussels were sampled from two sites in the Gulf of Trieste. In both samples, 76–78% of the total variance is explained by the four principal components. The orthogonally rotated factor matrix indicates that Co and Ni are bonded to the first principal component and Cd and Pb to the first (site 2) or second principal component (site 1). The origin of trace metals in the soft part of mussels from the Gulf of Trieste is discussed.

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Analyse der Hauptkomponenten zur Identifizierung der Verunreinigungsursachen von Muscheln über die Spurenmetalle

Zusammenfassung Die Analyse der Hauptkomponenten wurde auf die Korrelationsmatrix, die aus der 8 × 43-Datenmatrix hervorgeht, angewandt. Diese 8 Spurenmetalle sind Mn, Co, Ni, Cu, Zn, Cd, Hg, Pb, die im Fleisch der Miesmuscheln (Mytilus galloprovincialis Lamarck) gefunden worden sind. Die Miesmuscheln stammen aus zwei Gegenden des Golfes von Triest. Vier Hauptkomponenten erklären 76–78 % der totalen Varianz der beiden Stichproben. Die orthogonale-rotierte Faktorenmatrix zeigt, daß Co und Ni an die erste Hauptkomponente und Cd und Pb an die erste (Lage 2) oder an die zweite Hauptkomponente (Lage 1) gebunden sind. Die Herkunft der Spurenmetalle im Muschelfleisch aus dem Golf von Triest wird diskutiert.

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L. Felician is the author of the statistical analysis for site 1 as a part of his thesis in Commodity Science, Faculty of Economics, University of Trieste- L. Gabrielli Favretto is the author of the statistical analysis of the data for site 2. All authors contributed to the rest of the paper     

Investigation of trace element content of cheese

Nine trace elements (Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd, Pb) were determined in cheese by atomic absorption spectrophotometry with electrothermal atomization in a graphite tube, using the ashing procedure. Associations among mineral constituents were studied by means of principal component analysis, which allows determination of interdependences among trace elements in foods. A test for normality was used to investigate monovariate distributions, in order to estimate the symmetry of data vector. The correlation matrix was used as a starting matrix for principal component analysis; nine variables were reduced to four principal components. The clusters of elements appear to be determined by their origin.     

Multivariate data analysis of some xenobiotic trace metals in mussels from the Gulf of Trieste

Summary The concentration of Cd, Hg and Pb in the soft part of mussels has been studied by means of bi-and multi-variate statistical approaches. In particular, the principal component analysis has been applied to study the association among these toxic metals in mussels sampled from the gulf of Trieste, which is a critical area as far as mercury pollution is concerned.

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Mehrdimensionale Analyse der Daten einiger xenobiotischer Spurenmetalle in Miesmuscheln aus dem Golf von Triest

Zusammenfassung Der Gehalt von Cd, Hg und Pb in Miesmuschelfleisch wurde nach einer statistischen mehrdimensionalen Analyse untersucht. Besonders wurde die Hauptkomponentenanalyse zum Studium der Assoziationen dieser toxischen Metalle in Miesmuscheln angewandt. Die Miesmuschelproben stammten aus dem Golf von Triest, ein kritisches Gebiet für Quecksilberverunreinigungen.

     

A tool to assure the geographical origin of local food products (glasshouse tomatoes) using labeling with rare earth elements

BACKGROUND

Trace element fingerprinting has been widely used for identification of provenance of regional food. In the case of products from conventional agriculture, it is expected that the elemental composition will comply with that of the commercially available substrate of the plants. Therefore, for products without a direct relationship with the regional soil the region‐specific differences in elemental composition are no longer recognizable. The idea of this work is the labeling of tomatoes with rare earth elements (REE) in the ultra‐trace range for food authentication.

RESULTS

Labeling of tomatoes was carried out either by watering the soil with Nd‐ and Er‐spiked water or by adding these elements as solid oxides to the soil. In both cases enrichment of Nd and Er relative to the control group was detected in tomato fruits and leaves using inductively coupled plasma–mass spectrometry. Tomato plants rapidly absorb the dissolved REE from the irrigation water, and watering for a short period just before ripeness is sufficient to induce REE labels.

CONCLUSION

Labeling with trace amounts of REE could potentially be used to assure the provenance of tomatoes of local origin and separate these from products of foreign origin. © 2018 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.