L-amino acid oxidases are enzymes found in several organisms, including venoms of snakes, where they contribute to the toxicity of ophidian envenomation. Their toxicity is primarily due to enzymatic ...activity, but other mechanisms have been proposed recently which require further investigation. L-amino acid oxidases exert biological and pharmacological effects, including actions on platelet aggregation and the induction of apoptosis, hemorrhage, and cytotoxicity. These proteins present a high biotechnological potential for the development of antimicrobial, antitumor, and antiprotozoan agents. This review provides an overview of the biochemical properties and pharmacological effects of snake venom L-amino acid oxidases, their structure/activity relationship, and supposed mechanisms of action described so far.
Jatropha elliptica (Pohl) Oken, popularly known as teiu potato, is widely used in folk medicine as a purgative and in the treatment of snake bites. There is no scientific data on the physicochemical ...characterization or anti-nutritional compounds, nor are there any reports on the application of this root in the production of flours for food purposes. Thus, the objective of this work was to contribute with new knowledge concerning the production yield of teiu potato root flour, characterize its physical, chemical and technological properties, and determine its anti-nutritional and toxicological factors. The flour was obtained on three repetitions (batches) and all analyses were carried out in triplicate for each repetition. The flour production yield was 34.29%, and the product obtained was an orange powder with a carbohydrate content of 77.55 g·100 g-1, high contents of total dietary fiber (22.8 g·100 g-1), protein (8.3 g·100 g-1) and ash (3.5 g·100 g-1), and a low lipid (0.8 g·100 g-1) content. The thermogram of the flour showed three endothermic peaks: temperature of gelatinization of the flour starch (77.42 °C); glass transition (106.55 °C) and protein and lipid-amylose complexes (131.77 °C). The flour presented antioxidant potential (89.59% of DPPH discoloration), a high concentration of phenolic compounds (12.67 mg eq gallic acid·100 g-1), nitrates (4.4 g·Kg-1), tannins (5.4 g tannic acid·100 g-1) and trypsin inhibitors (4.3 UTI·mg-1). The teiu potato flour requiring further, more profound studies before being indicated for human nutrition, due to the presence of anti-nutritional factors and the toxicity presented in the test with Artemia salina.
In this chapter, we compare the pattern of pulvinar immunohistochemical staining for the calcium-binding proteins calbindin and parvalbumin and for the neurofilament protein SMI-32 in macaque, ...capuchin, and squirrel monkeys. This group of New and Old World primates shares five similar pulvinar subdivisions: PI
, PI
, PI
, PI
, and PI
. In the Old World macaque monkey, the inferior-lateral pulvinar can be subdivided into the P1 and P2 fields based on its connectivity with visual area V1. On the other hand, only the P1 field and no P2 was found in the New World capuchin monkey. Notably, the similarities in chemoarchitecture contrast with the distinct connectivity patterns and the different visuotopic organizations found across the species.
The composition of intestinal microbiota is widely believed to not only affect gut health but also influence behaviour. This study aimed to evaluate the probiotic characteristics, antioxidant ...activity, and antidepressant- and anxiolytic-like activities of
subsp.
LL95. This strain showed probiotic properties such as resistance in a simulated gastric tract model and survival at different concentrations of NaCl and bile salts. Moreover, antioxidant activity of LL95 was demonstrated through DPPH radical scavenging activity, scavenging of ABTS
radical and ferric ion reducing antioxidant power (FRAP) assays. Female C57BL/6 mice received LL95 orally at a dose of 10
UFC/day for 28 days. LL95 improved depressive- and anxiety-like behaviour, demonstrated by decreased immobility time in the tail suspension test and forced swim test and increased per cent of time spent in the open arms on the elevated plus maze. These findings indicate the potential antioxidant activity of LL95 and its role in behaviour, suggesting that probiotic may have therapeutic applications.
The N−doping of carbon nanotubes (CNTs) is widely accepted as an effective way to enhance the catalytic performance of CNT-supported Ni catalysts for CO2 methanation. To demonstrate, in a direct ...systematic comparison, the importance of N−doping for producing high-performance CO2 methanation catalysts, we developed two catalysts composed of 15 wt% Ni on pristine (Ni/CNT) and N−doped CNT (Ni/CNT−N) and correlated their catalytic performance with their properties. Compared to Ni/CNT, Ni/CNT−N achieved a higher XCO2 of 81.2% with SCH4 = 99.2% at a lower temperature of 400 °C, exhibiting excellent stability over 48 h time-on-stream testing. Our comprehensive comparative study demonstrated that the N−doped CNT support featured a better distribution of the Ni sites that were strongly interacting with the support, even with atomically dispersed Ni being observed by HAADF-STEM. This higher dispersion, enabled by the anchoring sites provided by the N−doping, is one of the main reasons for the enhanced performance of Ni/CNT−N, because it increases the H2 uptake capacity.
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We studied the spatial organization of directionally selective neurons in the cortical middle temporal visual area (area MT) of the Cebus monkey. We recorded neuronal activity from multielectrode ...arrays as they were stepped through area MT. The set of recording sites in each array penetration described a plane parallel to the cortical layers. At each recording site, we determined the preferred direction of motion. Responses recorded at successive locations from the same electrode in the array revealed gradual changes in preferred direction, along with occasional directional reversals. Comparisons of responses from adjacent electrodes at successive locations enabled electrophysiological imaging of the two-dimensional pattern of preferred directions across the cortex. Our results demonstrate a systematic organization for directionality in area MT of the New World Cebus monkey, which is similar to that known to exist in the Old World macaque. In addition, our results provide electrophysiological confirmation of map features that have been documented in other cortical areas and primate species by optical imaging. Specifically, the tangential organization of directional selectivity is characterized by slow continuous changes in directional preference, as well as lines (fractures) and points (singularities) that fragment continuous regions into patches. These electrophysiological methods also allowed a direct investigation of neuronal selectivities that give rise to map features. In particular, our results suggest that inhibitory mechanisms may be involved in the generation of fractures and singularities.
Science has greatly contributed to the advancement of technology and to the innovation of production processes and their applications. Cleaning products have become indispensable in today’s world, as ...personal and environmental hygiene is important to all societies worldwide. Such products are used in the home, in most work environments and in the industrial sectors. Most of the detergents on the market are synthesised from petrochemical products. However, the interest in reducing the use of products harmful to human health and the environment has led to the search for detergents formulated with natural, biodegradable surfactant components of biological (plant or microbiological) origin or chemically synthesised from natural raw materials usually referred to as green surfactants. This review addresses the different types, properties, and uses of surfactants, with a focus on green surfactants, and describes the current scenario as well as the projections for the future market economy related to the production of the different types of green surfactants marketed in the world.
How to cite: Farias CBB, Almeida FCG, Silva IA, et al. Production of green surfactants: Market prospects. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.02.002
The cost‐effectiveness and excellent performance of conductive‐carbon‐supported Ni‐based electrocatalysts make them attractive materials for hydrogen oxidation and evolution reactions. However, they ...were previously unused in gas‐phase hydrogenation reactions. In this work, we have expanded the applicability of commercially available advanced Ni/C, NiMo/C and NiRe/C materials from electrocatalysis to heterogeneous catalysis of CO2 methanation. Our catalytic testing efforts indicate that the monometallic Ni/C material demonstrates the best CO2 methanation properties, achieving an excellent CO2 conversion of 83 % at 400 °C with nearly complete selectivity to CH4 of 99.7 %, plus exhibiting intact performance during 90 h of time‐on‐stream testing. Such catalytic properties are among the highest reported to date among carbon‐supported Ni‐based methanation catalysts. Excellent performance of Ni/C stems from the good dispersion of the Ni nanoparticles over N‐containing carbon support material.
Supported nanoparticles: A new application for commercially available electrocatalysts was found in the heterogeneous methanation of CO2. A Ni/C catalyst achieved excellent performance, maintaining its activity over 90 h under reaction conditions. The bimetallic counterparts, NiMo/C and NiRe/C also exhibited good performance, although with lower conversion and, in the case of NiMo/C, lower stability. The study presents a new opportunity for the use of these materials.
Proton Exchange Membrane (PEM) water electrolysis (WE) produces H2 with a high degree of purity, requiring only water and energy. If the energy is provided from renewable energy sources, it releases ...“Green H2”, a CO2-free H2. PEMWE uses expensive and rare noble metal catalysts, which hinder their use at a large industrial scale. In this work, the electrocatalytic properties of Transition Metal Phosphides (TMP) catalysts supported on Carbon Black (CB) for Hydrogen Evolution Reaction (HER) were investigated as an alternative to Platinum Group Metals. The physico-chemical properties and catalytic performance of the synthesized catalysts were characterized. In the ex situ experiments, the 25% FeP/CB, 50% FeP/CB and 50% CoP/CB with overpotentials of −156.0, −165.9 and −158.5 mV for a current density of 100 mA cm−2 showed the best catalytic properties, thereby progressing to the PEMWE tests. In those tests, the 50% FeP/CB required an overpotential of 252 mV for a current density of 10 mA cm−2, quite close to the 220 mV of the Pt catalyst. This work provides a proper approach to the synthesis and characterization of TMP supported on carbon materials for the HER, paving the way for further research in order to replace the currently used PGM in PEMWE.
The physicochemical characteristics of nanostructured suspensions are important prerequisites for the success of new drug development. This work aimed to develop nanometric systems containing ...Cymbopogon densiflorus leaf essential oil and to evaluate their antimicrobial activity. The essential oil was isolated by hydrodistillation from leaves and analyzed by GC-MS. The main constituents were found to be trans-p-mentha-2,8-dien-1-ol, cis-p-mentha-2,8-dien-1-ol, trans-p-mentha-1(7),8-dien-2-ol, cis-piperitol, and cis-p-mentha-1(7),8-dien-2-ol. In silico prediction analysis suggested that this oil possesses antimicrobial potential and the main mechanism of action might be the peptidoglycan glycosyltransferase inhibition. Nanoemulsions were prepared by the phase inversion method, and liposomes were made by the film hydration method. Qualitative evaluation of the antimicrobial activity was performed by the diffusion disk assay with 24 microorganisms; all of them were found to be sensitive to the essential oil. Subsequently, this property was quantified by the serial microdilution technique, where the nanoformulations demonstrated improved activity in comparison with the free oil. Bactericidal action was tested by the propidium iodide method, which revealed that free essential oil and nanoemulsion increased cytoplasmic membrane permeability, while no difference was observed between negative control and liposome. These results were confirmed by images obtained using transmission electron microscopy. This study has shown an optimization in the antimicrobial activity of C. densiflorus essential oil by a nanoemulsion and a liposomal formulation of the active substances.
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