Side-stream lignins: Potential antioxidant and antimicrobial agents in milk.

In recent years, lignin has drawn increasing attention due to its intrinsic antibacterial and antioxidant activities, biodegradability, and biocompatibility. Yet, like several other biogenic structures, its compositional heterogeneity represents a challenge to overcome. In addition, there are few studies regarding food applications of lignin. Herein, we evaluate the antimicrobial and antioxidant effects of lignin from two different sources. These lignins were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) and hydrogen nuclear magnetic resonance (1H NMR) spectroscopies. Their antibacterial and antioxidant capacities (DPPH and Folin-Ciocalteu methods) were also investigated. Susceptibility tests were performed with the minimal inhibitory (MIC) and bactericidal (MBC) concentrations using the micro-broth dilution technique. Kraft lignin presented higher radical-scavenging and antibacterial activities than alkali lignin, indicating the dependence of antioxidant and antibacterial activities on the precursor biomass. Scanning electron microscopy shows morphologic changes in the bacteria after exposure to lignin, while confocal microscopy suggests that kraft lignin has affinity towards bacterial surfaces and the ability to cause cell membrane destabilization. Lignin inhibited the growth of Staphylococcus aureus and Salmonella Enteritidis in skimmed milk, herein taken as food model. Our results suggest that lignins are promising candidates for green additives to improve quality and safety within the food chain.

Bartonella in Norway rats (Rattus norvegicus) from the urban slum environment in Brazil.

Bartonella are rodent-borne bacteria that cause varied human etiologies. Studies on synanthropic rodents are rare, causing gaps in epidemiological knowledge. We tested bloodclot samples from 79 rats from an urban slum in Salvador, Brazil through PCR targeting gltA gene. Nine samples (11.4%) were positive: six had 100% identity with Bartonella sp. isolate JF429580 and 99.5% with B. queenslandensis strain AUST/NH8; three were 100% identical to isolate JF429532 and 99.7% to B. tribocorum. This is the second report on urban rat Bartonella indicating bacterial circulation at detectable rates. Its presence in rats from vulnerable human settlements demands public health attention.

Exercise Reshapes the Brain: Molecular, Cellular, and Structural Changes Associated with Cognitive Improvements.

Physical exercise is well known as a non-pharmacological and holistic therapy believed to prevent and mitigate numerous neurological conditions and alleviate ageing-related cognitive decline. To do so, exercise affects the central nervous system (CNS) at different levels. It changes brain physiology and structure, promoting cognitive improvements, which ultimately improves quality of life. Most of these effects are mediated by neurotrophins release, enhanced adult hippocampal neurogenesis, attenuation of neuroinflammation, modulation of cerebral blood flow, and structural reorganisation, besides to promote social interaction with beneficial cognitive outcomes. In this review, we discuss, based on experimental and human research, how exercise impacts the brain structure and function and how these changes contribute to cognitive improvements. Understanding the mechanisms by which exercise affects the brain is essential to understand the brain plasticity following exercise, guiding therapeutic approaches to improve the quality of life, especially in obesity, ageing, neurodegenerative disorders, and following traumatic brain injury.

Versatile Assembly of Metal-Phenolic Network Foams Enabled by Tannin-Cellulose Nanofibers.

Metal-phenolic network (MPN) foams are prepared using colloidal suspensions of tannin-containing cellulose nanofibers (CNFs) that are ice-templated and thawed in ethanolic media in the presence of metal nitrates. The MPN facilitates the formation of solid foams by air drying, given the strength and self-supporting nature of the obtained tannin-cellulose nanohybrid structures. The porous characteristics and (dry and wet) compression strength of the foams are rationalized by the development of secondary, cohesive metal-phenolic layers combined with a hydrogen bonding network involving the CNF. The shrinkage of the MPN foams is as low as 6% for samples prepared with 2.5-10% tannic acid (or condensed tannin at 2.5%) with respect to CNF content. The strength of the MPN foams reaches a maximum at 10% tannic acid (using Fe(III) ions), equivalent to a compressive strength 70% higher than that produced with tannin-free CNF foams. Overall, a straightforward framework is introduced to synthesize MPN foams whose physical and mechanical properties are tailored by the presence of tannins as well as the metal ion species that enable the metal-phenolic networking. Depending on the metal ion, the foams are amenable to modification according to the desired application.

Edible films and coatings - Not just packaging materials.

Edible films and coatings (EFC) are macromolecular-based structures forming thin layers that are usually studied as tools to improve food stability, sometimes being considered as parts of both the packaging system and the food itself. However, EFC are not mere packaging materials, and sometimes they do not even play roles related to those of packaging. This graphical review summarizes possible roles of EFC, including primary packaging, keeping water activity gradients between food components, controlling mass transfer on food processing, carrying active components, or serving as sources of sensory appeal. EFC may even be designed in a way that two or more of those roles may be played simultaneously.

A Systematic Review of the geographic distribution of pathogenic Leptospira serovars in the Americas, 1930-2017.

Leptospirosis is an important public health problem caused by Leptospira. The objective is to characterize the geographic distribution of pathogenic leptospira serovars in the Americas through a systematic review of the literature between 1930-2017. Searches were conducted in six scientific databases (PubMed, Web of Science, Embase, Lilacs, Scopus and Cochrane). We included studies conducted unambiguously in the Americas, that investigated infection of Leptospira in humans and animals in their natural environments with serovar identification. 283 articles were included, of which 69 were studies in humans, 86 in wild animals, and 182 in domestic animals. Most of them conducted in Brazil (104, 36.7%) and in rural environments (158, 55.8%). Bovines, equines and dogs where the most frequently studied domestic species. However, a large diversity including 80 species of wild animals were studied. Icterohaemorrhgiae, Canicola, Pomona and Grippotyphosa were the most common serovars, described in 46 (16.2%), 38 (13.3%), 32 (11.3%) and 26 (9%) of the articles, respectively. The Results indicate a large concentration of studies in Latin America, with emphasis on Brazil, in wild mammals and three main domestic animal groups. Our results emphasize the need for studies that delve into the relationships of the epidemiological cycle, environment, and health.

Nanocellulose Removes the Need for Chemical Crosslinking in Tannin-Based Rigid Foams and Enhances Their Strength and Fire Retardancy.

Thermal insulation and fire protection are two of the most critical features affecting energy efficiency and safety in built environments. Together with the associated environmental footprint, there is a strong need to consider new insulation materials. Tannin rigid foams have been proposed as viable and sustainable alternatives to expanded polyurethanes, traditionally used in building enveloping. Tannin foams structure result from polymerization with furfuryl alcohol via self-expanding. We further introduce cellulose nanofibrils (CNFs) as a reinforcing agent that eliminates the need for chemical crosslinking during foam formation. CNF forms highly entangled and interconnected nanonetworks, at solid fractions as low as 0.1 wt %, enabling the formation of foams that are ca. 30% stronger and ca. 25% lighter compared to those produced with formaldehyde, currently known as one of the best performers in chemically coupling tannin and furfuryl alcohol. Compared to the those chemically crosslinked, our CNF-reinforced tannin foams display higher thermal degradation temperature (peak shifted upward, by 30-50 °C) and fire resistance (40% decrease in mass loss). Furthermore, we demonstrate partially hydrophobized CNF to tailor the foam microstructure and derived physical-mechanical properties. In sum, green and sustainable foams, stronger, lighter, and more resistant to fire are demonstrated compared to those produced by formaldehyde crosslinking.

Does early specialization provide an advantage in physical fitness development in youth basketball?

The present study examined the influence of the specialization onset on the magnitude and patterns of changes in basketball-specific physical fitness within a competitive season and developmental fitness trends between 11 and 17 years in young basketball players. Repeated measures of 181 young basketball players (female, n = 40; male, n = 141) were examined. Anthropometry, age, estimated maturity status, and basketball-specific physical fitness (assessed with the countermovement jump, line drill, and yo-yo intermittent recovery level-1 and fitness score) were considered. Players were grouped by the onset of specialization as related to biological maturation milestones (pre-puberty, mid-puberty, and late-puberty specialization). The within-season and developmental changes in physical fitness were fitted using multilevel modeling in a fully Bayesian framework. The fitness outcomes were similar between-player and within-player changes when grouped by specialization across a season. Fitness improvements across a season were apparent for female players, while male players maintained their performance levels. There was no variation in the patterns of physical fitness development between 11 and 17 years associated with the onset of specialization. Conditional on our data and models, the assumption that early sport specialization provides a physical fitness advantage for future athletic success does not hold.

Regioselective and water-assisted surface esterification of never-dried cellulose: nanofibers with adjustable surface energy.

A new regioselective route is introduced for surface modification of biological colloids in the presence of water. Taking the case of cellulose nanofibers (CNFs), we demonstrate a site-specific (93% selective) reaction between the primary surface hydroxyl groups (C6-OH) of cellulose and acyl imidazoles. CNFs bearing C6-acetyl and C6-isobutyryl groups, with a degree of substitution of up to 1 mmol g-1 are obtained upon surface esterification, affording CNFs of adjustable surface energy. The morphological and structural features of the nanofibers remain largely unaffected, but the regioselective surface reactions enable tailoring of their interfacial interactions, as demonstrated in oil/water Pickering emulsions. Our method precludes the need for drying or exchange with organic solvents for surface esterification, otherwise needed in the synthesis of esterified colloids and polysaccharides. Moreover, the method is well suited for application at high-solid content, opening the possibility for implementation in reactive extrusion and compounding. The proposed acylation is introduced as a sustainable approach that benefits from the presence of water and affords a high chemical substitution selectivity.

The Food-Materials Nexus: Next Generation Bioplastics and Advanced Materials from Agri-Food Residues.

The most recent strategies available for upcycling agri-food losses and waste (FLW) into functional bioplastics and advanced materials are reviewed and the valorization of food residuals are put in perspective, adding to the water-food-energy nexus. Low value or underutilized biomass, biocolloids, water-soluble biopolymers, polymerizable monomers, and nutrients are introduced as feasible building blocks for biotechnological conversion into bioplastics. The latter are demonstrated for their incorporation in multifunctional packaging, biomedical devices, sensors, actuators, and energy conversion and storage devices, contributing to the valorization efforts within the future circular bioeconomy. Strategies are introduced to effectively synthesize, deconstruct and reassemble or engineer FLW-derived monomeric, polymeric, and colloidal building blocks. Multifunctional bioplastics are introduced considering the structural, chemical, physical as well as the accessibility of FLW precursors. Processing techniques are analyzed within the fields of polymer chemistry and physics. The prospects of FLW streams and biomass surplus, considering their availability, interactions with water and thermal stability, are critically discussed in a near-future scenario that is expected to lead to next-generation bioplastics and advanced materials.

Deconstruction and Reassembly of Renewable Polymers and Biocolloids into Next Generation Structured Materials.

This review considers the most recent developments in supramolecular and supraparticle structures obtained from natural, renewable biopolymers as well as their disassembly and reassembly into engineered materials. We introduce the main interactions that control bottom-up synthesis and top-down design at different length scales, highlighting the promise of natural biopolymers and associated building blocks. The latter have become main actors in the recent surge of the scientific and patent literature related to the subject. Such developments make prominent use of multicomponent and hierarchical polymeric assemblies and structures that contain polysaccharides (cellulose, chitin, and others), polyphenols (lignins, tannins), and proteins (soy, whey, silk, and other proteins). We offer a comprehensive discussion about the interactions that exist in their native architectures (including multicomponent and composite forms), the chemical modification of polysaccharides and their deconstruction into high axial aspect nanofibers and nanorods. We reflect on the availability and suitability of the latter types of building blocks to enable superstructures and colloidal associations. As far as processing, we describe the most relevant transitions, from the solution to the gel state and the routes that can be used to arrive to consolidated materials with prescribed properties. We highlight the implementation of supramolecular and superstructures in different technological fields that exploit the synergies exhibited by renewable polymers and biocolloids integrated in structured materials.

A numerical investigation of the effect of external resistance and applied potential on the distribution of periodicity and chaos in the anodic dissolution of nickel.

The oscillatory electrodissolution of nickel is one among several reactions utilized as a model-system to study the emergence of oscillations and pattern formation in electrochemical interfaces, in addition to frequently providing experimental proofs for theoretical predictions in synchronization engineering. The reaction was modeled in 1992 by Haim and co-workers [J. Phys. Chem. 1992, 96, 2676] and since then the model has been used with great success. Although some numerical studies have been done in this regard, there is apparently no detailed investigation of the effect of control parameters on the complex dynamics of nickel dissolution. Here, we provide a well-detailed and rigorous analysis of the effect of the external resistance and applied potential by simulating high-resolution phase diagrams based on the calculation of Lyapunov exponents and isospike diagrams. Our findings clearly indicate a strong dependence of the self-similar periodic islands, the so-called shrimps (i.e., periodic islands within chaotic domains in the parameter space), with the control parameters. Overall, we have observed a low density of periodic structures in the phase diagrams, being completely suppressed for large values of resistance and potential. The shrimp-like structures become gradually elongated with an increase of the control parameters to the point where only diagonally aligned periodic bands intertwined with chaotic domains are present. Interestingly, period-doubling cascades were observed not only on the shrimps but also on the periodic bands. The detailed distribution of chaos and periodicity of oscillatory electrodissolution reactions in resistance-potential phase diagrams can bring, for instance, important information to experimentalists to set a desired dynamic behavior and, therefore, to create novel nanostructured self-organized materials.

Upcycling Microbial Cellulose Scraps into Nanowhiskers with Engineered Performance as Fillers in All-Cellulose Composites.

Cellulose is everywhere and renovates in nature continuously and rapidly, while petroleum does not. Unlike the latter, cellulose biodegrades and may represent a carbon sink. Inspired by the multiscale architecture of cellulose, we report on all-cellulose composites comprising cellulose ether as a matrix and highly pure bacterial cellulose nanocrystals (BCNCs) as fillers. Optimum performance as a packaging material was achieved by engineering BCNC surface chemistry as well as the filler-in-matrix dispersion, targeting the replacement of unsustainable, fossil-derived plastics intended for single-use applications. Cost could pose a hurdle, eliminated through the valorization of underutilized scraps from industrial operations, which is also in line with the circular bioeconomy in terms of the integral use of biomass. As far as performance, the optically transparent hydroxypropyl methylcellulose (HPMC) films presented improved tensile strength (from 61 ± 6 to 86 ± 9 MPa) and Young's modulus (from 1.5 ± 0.2 to 2.7 ± 0.4 GPa) while reduced elongation at break (from 15 ± 2 to 12 ± 2%) and water vapor permeability (from 0.40 ± 0.02 to 0.31 ± 0.01 g mm h-1 m-2 kPa-1) when filled with only 5 wt % of (120 ± 31) nm long, (13 ± 3) nm wide, 88% crystalline BCNC. This dual, win-win effect of BCNCs on the mechanical and barrier properties of HPMC films was enabled by a suitable dispersion state, achieved via high-energy mixing, and quenched by casting. This study adds to the current literature on all-cellulose composites and helps pave the route for the technical and economical feasibilities of replacing non-renewable, non-biodegradable plastics in short-term applications by materials that are both renewable and biodegradable, that are also produced through green protocols and isolated from surplus biomass, and that still perform similarly or even better.

Microbial nanocellulose adherent to human skin used in electrochemical sensors to detect metal ions and biomarkers in sweat.

The pursuit of biocompatible, breathable and skin-conformable wearable sensors has predominantly focused on synthetic stretchable hydrophobic polymers. Microbial nanocellulose (MNC) is an exceptional skin-substitute natural polymer routinely used for wound dressing and offers unprecedented potential as substrate for wearable sensors. A versatile strategy for engineering wearable sensing platforms is reported, with sensing units made of screen-printed carbon electrodes (SPCEs) on MNC. As-prepared SPCEs were used to detect the toxic metals cadmium (Cd2+) and lead (Pb2+) with limits of detection of 1.01 and 0.43 µM, respectively, which are sufficient to detect these metal ions in human sweat and urine. SPCEs functionalized through anodic pre-treatments were used for detecting uric acid and 17ß-estradiol in artificial sweat, with detection limits of 1.8 µM and 0.58 µM, respectively. The electrochemical treatment created oxygen groups on the carbon surfaces, thus improving wettability and hydrophilicity. MNC was herein exploited as an adhesive-free, yet highly skin-adherent platform for wearable sensing devices that also benefit from the semi-permeable, non-allergenic, and renewable features that make MNC unique within the pool of materials that have been used for such a purpose. Our findings have clear implications for the developments on greener and more biocompatible but still efficient substrates and may pave the route for combining immunosensing devices with drug delivery therapies.

DOES EVOLUTIONARY BIOLOGY HELP THE UNDERSTANDING OF METABOLIC SURGERY? A FOCUSED REVIEW.

INTRODUCTION: Vertical gastrectomy and different bowel functions. The wide net of physiological issues involved in metabolic surgery is extremely complex. Nonetheless, compared anatomy and phisiology can provide good clues of how digestive tracts are shaped for more or less caloric food, for more or less fiber, for abundance and for scarcity. OBJECTIVE: To review data from Compared Anatomy and Physiology, and in the Evolutionary Sciences that could help in the better comprehension of the metabolic surgery. METHOD: A focused review of the literature selecting information from these three fields of knowledge in databases: Cochrane Library, Medline and SciELO, articles and book chapters in English and Portuguese, between 1955 and 2019, using the headings "GIP, GLP-1, PYY, type 2 diabetes, vertebrates digestive system, hominid evolution, obesity, bariatric surgery ". RESULTS: The digestive tract of superior animals shows highly specialized organs to digest and absorb specific diets. In spite of the wide variations of digestive systems, some general rules are observed. The proximal part of the digestive tract, facing the scarcity of sugars, is basically dedicated to generate sugar from different substrates (gluconeogenesis). Basic proximal gut tasks are to proportionally input free sugars, insulin, other fuels and to generate anabolic elements to the blood, some of them obesogenic. To limit the ingestion by satiety, by gastric emptying diminution and to limit the excessive elevation of major fuels (sugar and fat) in the blood are mostly the metabolict asks of the distal gut. A rapid and profound change in human diet composition added large amounts of high glycemic index foods. They seem to have caused an enhancement in the endocrine and metabolic activities of the proximal gut and a reduction in these activities of the distal gut. The most efficient models of metabolic surgery indeed make adjustments in this proximal/distal balance in the gut metabolic activities. CONCLUSION: Metabolic surgery works basically by making adjustments to the proximal and distal gut metabolic activities that resemble the action of natural selection in the development the digestive systems of superior animals.

Escalating the technical bounds for the production of cellulose-aided peach leathers: From the benchtop to the pilot plant.

This contribution falls within the context of sustainable functional materials. We report on the production of fruit leathers based chiefly on peach pulp, but combined with hydroxypropyl methylcellulose (HPMC) as binding agent and cellulose micro/nanofibrils (CMNF) as fillers. Increased permeability to moisture (from 0.9 to 5.6 g mm kPa-1 h-1m-2) and extensibility (from 10 to 17%) but reduced mechanical resistance (67-2 MPa) and stiffness (1.8 GPa-18 MPa) evidenced the plasticizing effect of peach pulp in HPMC matrix, which was reinforced by CMNF. A ternary mixture design allowed building response surfaces and optimizing leather composition. The laboratory-scale leather production via bench casting was extended to a pilot-scale through continuous casting. The effect of scaling up on the nutritional and sensory features of the peach leather was also depicted. The herein established composition-processing-property correlations are useful to support the large-scale production of peach leather towards applications both as packaging materials and as nutritional leathers.

First record of mass wild waterfowl mortality due to Clostridium botulinum in Brazilian semiarid.

In 2008, 270 wild birds from aquatic environments were found dead or debilitated on the banks of smaller lakes that had been formed due to the decrease in the level of the holding lake of the Sobradinho Dam located on the São Francisco River in the Caatinga of Bahia, Brazil. The outbreak occurred months after the dam's partial drainage, with the formation of puddles that accumulated decomposing organic material. Amongst the 270 individuals examined and/or found dead, the majority (50%) of the birds found belonged to the Anatidae family. The debilitated birds presented neurological clinical signs including lack of motor coordination, weakness, grave flaccid paralysis in the legs, wings, neck and eyelids, diarrhea, and dyspnea. Tissue samples of the birds were collected, as were water samples and samples of the substrate of the lakes. Zoonotic arboviroses or heavy metals were not detected. Analyses of liver and digestive tract content samples through bioassay and serum neutralization in mice revealed the presence of type C botulinic toxin in the viscerae samples, and type D in sediment samples. According to our knowledge, this is the first record of an outbreak of botulism in wild birds in natural conditions in Brazil.

Ecological mechanisms explaining interactions within plant-hummingbird networks: morphological matching increases towards lower latitudes.

Interactions between species are influenced by different ecological mechanisms, such as morphological matching, phenological overlap and species abundances. How these mechanisms explain interaction frequencies across environmental gradients remains poorly understood. Consequently, we also know little about the mechanisms that drive the geographical patterns in network structure, such as complementary specialization and modularity. Here, we use data on morphologies, phenologies and abundances to explain interaction frequencies between hummingbirds and plants at a large geographical scale. For 24 quantitative networks sampled throughout the Americas, we found that the tendency of species to interact with morphologically matching partners contributed to specialized and modular network structures. Morphological matching best explained interaction frequencies in networks found closer to the equator and in areas with low-temperature seasonality. When comparing the three ecological mechanisms within networks, we found that both morphological matching and phenological overlap generally outperformed abundances in the explanation of interaction frequencies. Together, these findings provide insights into the ecological mechanisms that underlie geographical patterns in resource specialization. Notably, our results highlight morphological constraints on interactions as a potential explanation for increasing resource specialization towards lower latitudes.

Cogrinding Wood Fibers and Tannins: Surfactant Effects on the Interactions and Properties of Functional Films for Sustainable Packaging Materials.

We report on the combination of cellulose nanofibrils (CNFs) and condensed tannins from Acacia mearnsii for the development of hybrid, functional films. The tannins are fractionated and concentrated in polyphenolics that are used for functional components in the hybrid materials. Cogrinding of wood fibers with the tannins in aqueous media allows simultaneous fiber deconstruction and in situ binding of tannins on the freshly exposed cellulosic surfaces. Hence, a tightly bound bicomponent system is produced, which is otherwise not possible if typical adsorption protocols are followed, mainly due to the extensive hydration typical of CNFs. A nonionic surfactant is used to tailor the cellulose-tannin interactions. The proposed strategy not only enables the incorporation of tannins with CNFs but also endows a high and prolonged antioxidant effect of films formed by filtration. Compared to tannin-free films, those carrying tannins are considerably more hydrophobic. In addition, they show selective absorption of ultraviolet light while maintaining optical transparency in the visible range. The proposed simple protocol for incorporating tannins and surfactants with CNFs is suitable to produce functional materials. This is possible by understanding associated interfacial phenomena in the context of sustainable materials within the concept of the circular bioeconomy.