Isolation and evaluation of anti-listeria lactococcus lactis from vegetal sources

This chapter describes methods used to isolate, identify, and partially characterize lactic acid bacteria (LAB) which exhibit inhibitory activity against Listeria monocytogenes from foods. Vegetal (plant based) sources\ua0are rich in naturally occurring LAB and therefore provide an easily accessible source of strains with potential antimicrobial activity for use in food-processing applications. From our previous work, the majority of LAB with inhibitory activity against L. monocytogenes were identified as generally recognized as safe (GRAS) Lactococcus lactis. Although these bacteria are most commonly known for their role in industrial dairy fermentations, they are believed to have originally derived from natural plant-based habitats. These isolates with anti-Listeria activity were all found to carry the genes involved in the production of nisin, which is an approved food-grade preservative (E234). These isolates may find various applications for in situ production of nisin allowing control of L. monocytogenes in various fermented and non-fermented foods and other environments

Children overclaim more knowledge than adults do, but for different reasons

Overclaiming is the phenomenon whereby people claim more knowledge of a topic than they actually have. In adults, this behavior is related to the extent to which they consider themselves an expert on that topic and may be related to impression management. We investigated the emergence of this phenomenon by developing a child-friendly overclaiming questionnaire (OCQ)—the Child-OCQ. We measured the tendency of children (5–10\ua0years of age old;\ua0N\ua0=\ua094) to claim knowledge of items that did not exist for a variety of topics (places, characters, animals, food, and musical instruments). We also examined the relationship between children’s overclaiming of knowledge and their self-perceived liking of, and expertise in, the topics. To validate our scale, an adult sample (N\ua0=\ua051) completed both the Child-OCQ and a standardized adult OCQ, the OCQ-150, showing similar overclaiming patterns on both measures. Although overclaiming behaviors decreased throughout childhood, even children as old as 10\ua0years were not adult-like and were more likely to overclaim knowledge than adults. In addition, we did not find strong evidence that children’s perceived expertise on a topic influenced their tendency to overclaim knowledge, suggesting that the mechanisms behind the overclaiming phenomenon are different in children and do not reflect impression management until later during adolescence or adulthood

Extremely efficient flexible organic solar cells with a graphene transparent anode: Dependence on number of layers and doping of graphene

Graphene has shown tremendous potential as a transparent conductive electrode (TCE) for flexible organic solar cells (OSCs). However, the trade-off between electrical conductance and transparency as well as surface roughness of the graphene TCE with increasing layer number limits power conversion efficiency (PCE) enhancement and its use for large-area OSCs. Here, we use a 300 nm-thick poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c]-[1,2,5]thiadiazole)]:[6,6]-phenyl-C-butyric acid methyl ester blend as the photoactive layer and a benzimidazole (BI)-doped graphene as the transparent anode to demonstrate efficient OSCs with good flexibility. It is found that 3 layer (L) graphene had the best balance between sheet resistance, optical transmittance and surface roughness for optimized cell design. A 0.2 cm cell with a 3L BI-doped graphene anode had a PCE of 6.85%, which is one of the highest PCE values reported so far for flexible graphene anode-based OSCs. The flexible cells were mechanically robust, showing only a small performance degradation during up to 250 flexing cycles. Moreover, the combination of the thick photoactive layer with the optimized 3L BI-doped graphene TCE enabled production of 1.6 cm flexible OSCs with a PCE of 1.8%. Our work illustrates the importance of graphene TCE development for flexible OSCs as well as other wearable optoelectronic devices

Effect of long-term no-tillage and nitrogen fertilization on phosphorus distribution in bulk soil and aggregates of a Vertisol

Much remains unknown regarding the behaviour of P in cropping soils. We have examined a low-input long-tern cropping system not receiving P fertilizers in subtropical Queensland (Australia) in order to determine how, after 50 y, P concentration and distribution in bulk soils and in soil aggregates is affected by tillage practices (no tillage [NT] and conventional tillage [CT]) and by N fertilization. For the bulk soil, neither the tillage practice nor N fertilization altered concentrations of total P, inorganic P (P), or organic P (P) despite soil organic C concentrations differing significantly depending upon both tillage and N fertilization. Although bulk concentrations of P did not differ significantly, we observed significant changes in NaHCO-P, 1 M HCl-P, NaOH-P, NaOH-P determined using sequential extraction, seemingly due to changes in pH associated with N fertilization. We also used sequential fractionation to examine the forms of P in the various water-stable aggregate sizes, finding that the tillage practices and N fertilization did not cause significant changes in either the distribution of the various aggregate sizes nor did it cause marked changes in the forms of P in these various aggregates. Thus, our data illustrate that even though the long-term usage of NT in low-input soils may cause a comparative increase in TOC, there was not a concomitant increase in P, with this being important for soil fertility and functioning. This information assists in understanding how management practices alter P behaviour in long-term, low-input subtropical cropping soils, as is required to manage these soils more appropriately

In-situ surface self-reconstruction in ternary transition metal dichalcogenide nanorod arrays enables efficient electrocatalytic oxygen evolution

Water splitting has received more and more attention because of its huge potential to generate clean and renewable energy. The highly active and durable oxygen evolution reaction (OER) catalysts play a decisive factor in achieving efficient water splitting. The identification of authentic active origin under the service conditions can prompt a more reasonable design of catalysts together with well-confined micro-/nano-structures to boost the efficiency of water splitting. Herein, Fe, Co, and Ni ternary transition metal dichalcogenide (FCND) nanorod arrays on Ni foam are purposely designed as an active and stable low-cost OER pre-catalyst for the electrolysis of water in alkaline media. The optimized FCND catalyst demonstrated a lower overpotential than the binary and unary counterparts, and a 27-fold rise in kinetic current density at the overpotential of 300 mV compared to the nickel dichalcogenide counterpart. Raman spectra and other structural characterizations at different potentials reveal that the in-situ surface self-reconstruction from FCND to ternary transition metal oxyhydroxides (FCNOH) on catalyst surfaces initiated at about 1.5 V, which is identified as the origin of OER activity. The surface self-reconstruction towards FCNOH also enables excellent stability, without fading upon the test for 50 h

Amines modulation and passivation yields record perovskite optoelectronic devices

Primary amines function well in defect passivation, crystal modulation, and surface functionalization in perovskite solar cells and perovskite light-emitting diodes, yielding record performances

Utilising venom activity to infer dietary composition of the Kenyan horned viper (Bitis worthingtoni)

Bitis are well known for being some of the most commonly encountered and medically important snake species in all of Africa. While the majority of species possess potently anticoagulant venom, only B. worthingtoni is known to possess procoagulant venom. Although known to be the basal species within the genus, B. worthingtoni is an almost completely unstudied species with even basic dietary information lacking. This study investigated various aspects of the unique procoagulant effects of B. worthingtoni venom. Coagulation assays determined the primary procoagulant effect to be driven by Factor X activating snake venom metalloprotease toxins. In addition to acting upon the mammalian blood clotting cascade, B. worthingtoni venom was also shown to clot amphibian plasma. As previous studies have shown differences in clotting factors between amphibian and mammalian plasmas, individual enzymes in snake venoms acting on plasma clotting factors can be taxon-selective. As venoms evolve under purifying selection pressures, this suggests that the procoagulant snake venom metalloprotease toxins present in B. worthingtoni have likely been retained from a recent common ancestor shared with the related amphibian-feeding Proatheris superciliaris, and that both amphibians and mammals represent a substantial proportion of B. worthingtoni current diet. Thus, taxon-specific actions of venoms may have utility in inferring dietary composition for rare or difficult to study species. An important caveat is that to validate this hypothesis field studies investigating the dietary ecology of B. worthingtoni must be conducted, as well as further investigations of its venom composition to reconstruct the molecular evolutionary history of the toxins present

Toluene diisocyanate-induced inflammation and airway remodeling involves autophagy in human bronchial epithelial cells

Toluene-diisocyanate (TDI) is one of the main causes of occupational asthma. To study the role of autophagy in TDI-induced airway inflammation and airway remodeling in bronchial airway epithelial (16HBE) cells. We treated 16HBE cells with TDI-human serum albumin (TDI-HSA) conjugate to observe reactive oxygen species (ROS) release, autophagy activation, airway inflammation and airway remodeling. 3-Methyladenine (3-MA) and Rapamycin (Rapa) intervention were used to explore the effects of autophagy on inflammatory response and protein expression related to airway remodeling in 16HBE cells treated with TDI-HSA. Experimental results suggested that various concentrations of TDI-HSA (0, 40, 80 and 120 μg/mL) increased the release of ROS and the expression of Nrf2, activated autophagy and increased the expression of AMPK, Beclin-1, LC3 and decreased the expression of p62, promoted the levels of IL-5, IL-6 and IL-8 in 16HBE cells. Results also showed that E-cadherin expression decreased but an increase was observed in α-SMA and MMP-9 in the TDI-HSA group. The treatment of TDI-HSA combined with Rapa aggravated the above reaction whereas the inverse was true for TDI-HSA combined with 3-MA. These results indicated that autophagy is involved in TDI-induced airway inflammation and airway remodeling as a positive regulatory mechanism, inhibiting autophagy can significantly alleviate the TDI-induced inflammatory response and attenuate airway remodeling protein expression in 16HBE cells