Determination of surface properties of various substrates using TiO<Subscript>2</Subscript> nanorod coatings with tunable characteristics

We present a novel approach to cover different substrates with thin light-sensitive layers that consist of organic-capped TiO₂ nanorods (NRs). Such NR-based coatings exhibit an increasing initial hydrophobicity with increasing NR length, and they demonstrate a surface transition from this highly hydrophobic state to a highly hydrophilic one under selective UV–laser irradiation. This behaviour is reversed under long dark storage. Infrared spectroscopy measurements reveal that light-driven wettability changes are accompanied by a progressive hydroxylation of the TiO₂ surface. The surfactant molecules that cover the NRs do not appear to suffer for any significant photocatalytic degradation.     

Chitosan/whey protein film as active coating to extend Ricotta cheese shelf-life

Shelf-life extension of Ricotta cheese coated with a chitosan/whey protein edible film and stored under modified atmosphere at 4 °C was evaluated. The chitosan/whey protein film had 35% and 21% lower oxygen and carbon dioxide permeability, respectively, and about three times higher water vapor permeability than film prepared with chitosan alone. Over a 30-day storage period, no differences in the pH of control and coated Ricotta cheeses were observed. While the titratable acidity of the control increased linearly during the first two weeks and remained constant for the rest of the storage period, the corresponding values for coated Ricotta cheese did not change significantly during the first 21 days and reached the acidity level (0.34 ± 0.02 milliequivalent/100 g of analyzed sample) of the control only on day 30. The viable numbers of lactic acid bacteria and mesophilic and psychrotrophic microorganisms were significantly lower (p < 0.05) in the chitosan/whey protein coated cheese, compared to the control, at each storage time. Our findings suggest a potential utility of chitosan/whey protein coatings to extend fresh dairy product shelf-life.     

Solid-Phase Microextraction Coupled to Fast Gas Chromatography for the Determination of Migrants from Polystyrene-Packaging Materials into Yoghurt

In view of the importance of a rapid determination of migrants in food, a headspace solid-phase microextraction coupled with fast high-resolution capillary gas chromatography (HS-SPME/fast GC) method has been developed for the rapid determination of styrene and ethylbenzene in polystyrene-packaged yoghurt. The method accuracy is satisfactory with recoveries ranging from 97% to 105%. The developed method was applied to the study of the variation in migrant content during the shelf-life of commercial-packaged yoghurts. Compared with conventional SPME/GC, the employment of a SPME/fast GC method led to reduction of both the SPME equilibration and analyte separation time; the method allowed the determination of styrene and ethylbenzene in about 15 min (including sampling, extraction and analysis). At the same time, several volatile organic compounds belonging to the key aroma compounds of the fermented milks were identified. The coefficient of variation in terms of peak area and retention time was included between 3% and 4% for all the components identified. Styrene and ethylbenzene have been quantified using the standard addition method. Calibration curves were linear for both the compounds in the range from 1 to 10 ng g⁻¹ for ethybenzene and from 2 to 25 ng g⁻¹ for styrene. Detection limits ranged from 0.5 to 0.6 ng g⁻¹ and quantification limits from 1.0 to 2.2 ng g⁻¹.     

Distribution of epidemic clonal genetic markers among Listeria monocytogenes 4b isolates

Recent genome sequencing of isolates of Listeria monocytogenes serotype 4b implicated in some major outbreaks of foodborne listeriosis has revealed unique genetic markers in these isolates. The isolates were grouped into two distinct epidemic clones, ECI and ECII. In the present study, selected ECI- and ECII-specific genetic markers were detected in 16 and 15 of 89 L. monocytogenes 4b isolates, respectively. The ECI markers were found in 6 of 34 clinical isolates, 9 of 50 food isolates, and 1 of 5 environmental isolates, and the ECII markers were detected in 7 of 34 clinical isolates, 7 of 50 food isolates, and 1 of 5 environmental isolates. Hence, of the isolates with the epidemic clonal genetic markers, 38% (13 of 34) were of clinical origin, 32% (16 of 50) were of food origin, and 40% (2 of 5) were of environmental origin. The predominance of the epidemic clonal markers among the clinical and environmental isolates supports the hypothesis that these markers are correlated with the pathogenic potential of strains and with their environmental persistence. Several isolates had only one epidemic clonal marker, either the ECI-specific marker 133 or the ECII-specific marker 4bSF18. Pulsed-field gel electrophoresis analysis revealed higher genomic diversity among the strains with ECII-like characteristics than among those strains carrying the ECI-specific genetic markers.     

Osmotic stress response in the wine yeast Dekkera bruxellensis

Dekkera bruxellensis is mainly associated with lambic beer fermentation and wine production and may contribute in a positive or negative manner to the flavor development. This yeast is able to produce phenolic compounds, such as 4-ethylguaiacol and 4-ethylphenol which could spoil the wine, depending on their concentration. In this work we have investigated how this yeast responds when exposed to conditions causing osmotic stress, as high sorbitol or salt concentrations. We observed that osmotic stress determined the production and accumulation of intracellular glycerol, and the expression of NADH-dependent glycerol-3-phosphate dehydrogenase (GPD) activity was elevated. The involvement of the HOG MAPK pathway in response to this stress condition was also investigated. We show that in D. bruxellensis Hog1 protein is activated by phosphorylation under hyperosmotic conditions, highlighting the conserved role of HOG MAP kinase signaling pathway in the osmotic stress response.     

B7-H3/CD276 Inhibitors: Is There Room for the Treatment of Metastatic Non-Small Cell Lung Cancer?

The striking clinical outcomes of antibody-based immunotherapy, through the inhibitors of cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and the programmed cell death protein-1 (PD-1) and its ligand (PD-L1) axis, have driven research aimed at identifying further clinically relevant tumor antigens that can serve as targets in solid tumors. B7 homolog 3 protein (B7-H3, also known as CD276) is a member of the B7 family overexpressed in tumor tissues, including non-small cell lung cancer (NSCLC), while showing limited expression in normal tissues, becoming an attractive and promising target for cancer immunotherapy. B7-H3 expression in tumors has been demonstrated to be associated with poor prognosis. In addition to its role in immune modulation, B7-H3 also promotes pro-tumorigenic functions such as tumor migration, invasion, metastases, resistance, and metabolism. In this review, we will provide an overview of this newly characterized immune checkpoint molecule and its development in the management of metastatic NSCLC.     

Titanium-based solid catalysts for transesterification of methyl-methacrylate by 1-butanol: the homogeneous catalysis contribution

Titanium-based solid catalysts were prepared according to two different procedures. In order to improve the stability of the SiOTi bond in the titanium grafted silica catalysts, the surface remaining hydroxyl groups were passivated to prevent the titanium leaching by SiOTi bond solvolysis. This was performed by grafting trimethoxy-silane groups on isolated silanols of silica, after or before metal grafting. The synthesised materials were characterised by FT-IR spectroscopy, and their catalytic properties evaluated in the reaction of transesterification of methyl-methacrylate (MMA) with 1-butanol (BuOH) in liquid phase to produce butyl-methacrylate (BuMA). An important titanium leaching (18–35%) was always detected with all the solid catalysts.

Investigation of the behaviour of Ti(OBu)₄ as homogeneous catalyst for very small concentrations of titanium was carried out in order to evaluate the catalytic contribution of the active dissolved species. We demonstrate here that the catalytic activity is mainly due to the homogeneous catalysis.     

Normal Retinotopy in Primary Visual Cortex in a Congenital Complete Unilateral Lesion of Lateral Geniculate Nucleus in Human: A Case Study

Impairment of the geniculostriate pathway results in scotomas in the corresponding part of the visual field. Here, we present a case of patient IB with left eye microphthalmia and with lesions in most of the left geniculostriate pathway, including the Lateral Geniculate Nucleus (LGN). Despite the severe lesions, the patient has a very narrow scotoma in the peripheral part of the lower-right-hemifield only (beyond 15° of eccentricity) and complete visual field representation in the primary visual cortex. Population receptive field mapping (pRF) of the patient’s visual field reveals orderly eccentricity maps together with contralateral activation in both hemispheres. With diffusion tractography, we revealed connections between superior colliculus (SC) and cortical structures in the hemisphere affected by the lesions, which could mediate the retinotopic reorganization at the cortical level. Our results indicate an astonishing case for the flexibility of the developing retinotopic maps where the contralateral thalamus receives fibers from both the nasal and temporal retinae.