Microbial and physicochemical modifications of hake (Merluccius merluccius) steaks stored under carbon dioxide enriched atmospheres

Microbial counts (total viable, Brochothrix thermosphacta, lactic acid bacteria and Enterobacteriaceae), biochemical parameters [pH, total volatile nitrogen, nucleotide breakdown products, non‐volatile amines, D (−) and L (+) lactic acid and short‐chain fatty acids] and sensory attributes (colour and odour) of refrigerated (2 °C) hake (Merluccius merluccius) steaks under carbon dioxide enriched air (CO₂ /air, 20/80 v/v and CO₂ /air, 40/60 v/v) and air atmospheres were determined. When compared with air, sensory results showed shelf‐life extension of 4 and 11 days for 20% and 40% CO₂‐enriched atmospheres, respectively. Microbial and biochemical results also revealed that the 40% CO₂‐enriched atmosphere was the most effective packaging type for refrigerated hake. © 2000 Society of Chemical Industry     

Comparative study of natural carob fibre and psyllium husk in rats. Influence on some aspects of nutritional utilisation and lipidaemia

The effects of the addition of 100 g kg⁻¹ of psyllium husk (PSY), cellulose (CEL) or natural carob fibre (NCF) to a semi‐synthetic diet on fat (FD) and nitrogen (NF) digestibility coefficients, metabolic nitrogen utilisation (MNU), net nitrogen utilisation (NNU) and total serum cholesterol and triglyceride levels, were studied in male ‘Wistar’ rats. No significant differences were observed between the three fibres with respect to the weight increase of the animals or MNU. Significant differences were recorded for the FD of the NCF group (0.91±0.01) compared to the CEL group (0.95±0.01), as well as on ND (0.88±0.00 NCF group, 0.88±0.00 PSY group and 0.95±0.00 CEL group) and NNU. None of these indexes showed differences between the groups PSY and NCF. For the serum cholesterol levels, there were no significant differences between the non‐hypercholesterolaemic groups fed PSY, CEL or NCF; in those in which hypercholesterolaemia was induced (cholesterol and bile bovine 8.3 g kg⁻¹), significantly lower values were found in the NCF group (166±17 mg dl⁻¹ ) than in the PSY group (343±61 mg dl ⁻¹) and in the CEL group (386±48 mg dl⁻¹). © 1999 Society of Chemical Industry     

Jahreszeitliche Schwankungen in der Zusammensetzung von Klärschlamm bei der Betrachtung eines Klärwerks

By evaluating sewage sludge analysis data from a large German sewage treatment plant (>1 million population equivalents), seasonal fluctuations in the composition of the sewage sludge could be identified. These fluctuations include a periodic decrease in carbon content and an increase in ash content in the middle of the year. Various wastewater and sludge treatment processes as well as climatic influences could be identified as causes for this trend. The investigation of the contents of various heavy metals and trace elements in the sewage sludge also showed partly strong fluctuations in the course of the year, which can have an influence on the utilization possibilities of the sewage sludge.     

Do cyprinid fish use lateral flow-refuges during hydropeaking?

Hydropeaking caused by small-scale hydropower plants creates rapid changes in the intensity, frequency, and persistence of river flows. These changes can induce stress in fish across all life-stages and, may negatively impact fish communities. Rapid increases in the flow velocity may cause fish to avoid unstable habitats, seeking out nearby refuges to reduce their energy expenditure. A lateral flow-refuge constructed from maritime plywood (0.4 m wide × 0.5 m long × 0.4 m high) was installed in the left river bank, 40 m downstream of the Bragado hydropower plant. A multispectral stereo underwater camera trap was installed inside the flow-refuge to monitor fish over one-month period. The camera recorded images continuously both during base and peak flow conditions. Two different peak-flow conditions were detected: peak and high peak-flow conditions. The peak flow conditions correspond to a turbine discharge of 0.67 m³/s (peak), and 2.1 m³/s (high peak) at full load. The base-flow condition corresponded to a discharge of 0.064 m³/s. The fish presence inside the refuge was observed to be significantly higher during the peak condition when compared with the base and high peak conditions. These findings strongly indicate that the flow during the high peak condition prevented fish from using the flow-refuge due to the increase in the current. We hypothesize that this may be due to the increase in the current velocity and increased levels of ambient turbulence near the refuge. An alternate hypothesis is that the spatial distribution of velocities and depths during the high peak condition induced fish to inhabit areas with poor access to the refuge. The results of this study indicate that fish refuges can be used to successfully mitigate hydropeaking, and that their use by fish can depend on the flow regime.     

Laser-Induced,Green and Biocompatible Paper-Based Devices for Circular Electronics

The growing usage and consumption of electronics-integrated items into the daily routine has raised concerns on the disposal and proper recycling of these components. Here, a fully sustainable and green technology for the fabrication of different electronics on fruit-waste derived paper substrate, is reported. The process relies on the carbonization of the topmost surface of different cellulose-based substrates, derived from apple-, kiwi-, and grape-based processes, by a CO₂ laser. By optimizing the lasing parameters, electronic devices, such as capacitors, biosensors, and electrodes for food monitoring as well as heart and respiration activity analysis, are realized. Biocompatibility tests on fruit-based cellulose reveal no shortcoming for on-skin applications. The employment of such natural and plastic-free substrate allows twofold strategies for electronics recycling. As a first approach, device dissolution is achieved at room temperature within 40 days, revealing transient behavior in natural solution and leaving no harmful residuals. Alternatively, the cellulose-based electronics is reintroduced in nature, as possible support for plant seeding and growth or even soil amendment. These results demonstrate the realization of green, low-cost and circular electronics, with possible applications in smart agriculture and the Internet-of-Thing, with no waste creation and zero or even positive impact on the ecosystem.     

Giant Polarization in Quasi-Adiabatic Ferroelectric Na+ Electrolyte for Solid-State Energy Harvesting and Storage

The advent of new solid-state energy storage devices to tackle the electrical revolution requires the usage of nonlinear behavior leading to emergent phenomena. The ferroelectric analyzed herein belongs to a family of electrolytes that allow energy harvesting and storage as part of its self-charging features when thermally activated. The Na_2.99Ba_0.005ClO electrolyte shows quasi-adiabatic behavior with a continuous increase in polarization upon cycling, displaying almost no hysteresis. The maximum polarization obtained at a weak electric field is giant and similar to the remanent polarization. It depends on the temperature with a pyroelectric coefficient of 5.37 C m⁻² °C⁻¹ from −5 to 46 °C. The emergence occurs via negative resistance and capacitance. The glass transition is found to have its origins in the sharp depolarization at 46 – 48 °C. Above –10 °C, at ≈ –5 °C, another thermal anomaly may rely on the topologic characteristics of the A_3–2xBa_xClO (A = Li, Na, K) glass electrolytes enabling positive feedback of the current of electrons throughout the surface of the inner cell. The phenomena may pave the way toward a better understanding of dipolar nanodomain fragile glasses with exceptional ferroelectric characteristics to architect energy harvesting and storage devices based on multivalent thermally activated Na⁺-ion-ion electrolytes.     

Insights into coconut oil's anti-obesity potential: In vitro modulation of lipidic accumulation,adipolysis, and immune response

The purpose of this work was to evaluate coconut oil's effect on lipid metabolism-related diseases and immune response using in vitro models. The coconut oil doses were selected according to the results of the safety evaluation performed through genotoxicity and cytotoxicity tests. Then its capacity to modulate obesity-related metabolism was evaluated by measuring adipolysis in 3T3-L1 differentiated adipocytes and hepatic lipid accumulation in hepatocytes (Hep G2). The immunomodulatory activity was evaluated using Caco-2 cells and quantifying pro-inflammatory cytokines’ production (IL-6, IL-8, and TNF-α). Coconut oil, mainly comprised of medium-chain fatty acids (>60% of total fatty acids), showed a high antioxidant capacity (125.76 ± 11.63 µM trolox equivalent/mL). The results showed that coconut oil was capable of reducing 68% of the lipid accumulation in hepatocytes and 42% in adipocytes. It was also capable of modulating the immune response in IL-1β Caco-2 stimulated cells, reducing IL-6 secretion (22% in the presence of 10 mg/mL of coconut oil and by 19% when 15 mg/mL) and TNF-α secretion (90% and 42% in the presence of 15 or 10 mg/mL of coconut oil, respectively). In short, coconut oil shows great potential for the development of functional foods and nutraceuticals targeting lipid metabolism-related diseases. Practical applications: This study describes the impact of organic virgin coconut oil on obesity-related metabolism and immune response. Despite the high content of saturated fatty acids, this vegetable oil has several beneficial effects in the obesity context by the reduction of lipid accumulation. Coconut oil can reduce lipid accumulation in hepatocytes and adipocytes. Coconut oil is capable of modulating the immune response in gut cells.     

Evaluating the Efficiency of Chitosan-Graphene Oxide Hybrid Hydrogels as Drug Delivery Systems

With the objective of creating an electro-responsive and antimicrobial device suitable as delivery system for Rose Bengal (RB) to the skin, a hybrid hydrogel combining Chitosan (CS) and Graphene Oxide (GO) are designed, serving as functional polymer support and active filling element, respectively. The hybrid system, synthesized using tripolyphosphate as a crosslinker via ionic gelation, shows a uniform and homogeneous surface, as verified by SEM investigations, high biocompatibility when tested on human fibroblast lung cells MRC-5 cells, and biodegradability in phosphate buffered medium at physiological pH. Drug loading and release experiments, extensively analyzed using suitable mathematical modeling, shows the enhancement of the binding efficiency conferred by GO (534 and 979 mg g⁻¹ for blank and hybrid hydrogels, respectively) and an electro-responsive behavior (maximum BR release of 36 and 23% at 0 and 12 V, respectively). Additionally, hybrid hydrogel is found to prevent the adhesion of methicillin-resistant Staphylococcus aureus and to kill the bacterial cells by taking advantage of the sustained release of the antimicrobial RB.