Ascorbic acid (AA) may contribute to restoring hemostatic balance after mental stress (MS) in overweight/obese adults. We aimed to determine the effects of AA administration on hemostatic responses ...to MS in overweight/obese men. Fourteen overweight/obesity men (27 ± 7 years; BMI: 29.7 ± 2.6 kg m
) performed the Stroop color-word stress task for 5 min after non-simultaneous infusion of placebo (PL, 0.9% NaCl) and AA (3 g). Blood was collected at baseline, during MS, and 60 min after MS to measure: activated partial thromboplastin time, prothrombin time, and fibrinogen concentration, by coagulometer; platelet-derived microvesicles (PMV, mv/μL), by flow cytometry; nitrite (μM), by chemiluminescence. In PL session, MS led to decreases in PTs (stress, p = 0.03; 60 min, p < 0.001), PT-INR (stress, p < 0.001; 60 min, p < 0.01), aPTTs (60 min, p = 0.03), aPTT ratio (60 min, p = 0.04) and fibrinogen (60 min, p = 0.04), while increased PT activity (60 min, p = 0.01) when compared to baseline. Furthermore, AA increased PTs (60 min, p < 0.001), PT-INR (60 min, p = 0.03) and decreased PT activity (60 min, p < 0.001) and fibrinogen (stress, p = 0.04) when compared to PL. Nitrite was increased in response to stress during AA session (p < 0.001 vs PL). There was no difference in PMV. Ascorbic acid prevented the impaired hemostatic profile and improved nitrite response to stress in the overweight and obese adults.
Based on colony spreading, chitosan from shrimp waste in agar media inhibited the growth of
Aspergillus niger by 47.26%; there were not differences (
P
>
0.05) with respect to commercial chitosan ...(Fluka, BioChemika) (56.16%). All chitosan films showed similar glass transition temperatures (
P
>
0.05) with respect to cellophane control; however, chemically, all chitosan films showed an increase in the
T
g values that could be related with the decrease (
P
≤
0.05) in elongation percentage with respect to the control film. According to FT-IR spectroscopic analysis of chitosan films, the fungistatic activity can be related to the hydrogen bonds’ formation between the amino groups of chitosan with the hydroxyl groups from polymer or sorbitol. The plasticizer addition increased (
P
≤
0.05) the elongation of chitosan films. The Young's module,
E, was lower (
P
≤
0.05) for all chitosan films comparing with cellophane. When incorporated into the composite films elaborated by casting, chitosan retained its fungistatic activity. Even though the activity against fungi growth was lower (15.66% for non-plasticized silage chitosan films, pC
S), a reduction (
P
≤
0.05) in the hyphae diameter of
A. niger was observed. Results suggest that it is feasible to elaborate antifungal chitosan films, with good thermal stability and acceptable mechanical properties for food packaging.
Aiming at evaluating the impact of the cation symmetry on the nanostructuration of ionic liquids (ILs), in this work, densities and viscosities as a function of temperature and small–wide angle X-ray ...scattering (SWAXS) patterns at ambient conditions were determined and analyzed for 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (asymmetric) and 1,3-dialkylimidazolium bis(trifluoromethylsulfonyl)imide (symmetric) series of ionic liquids. The symmetric IL series, C N/2C N/2imNTf2, presents lower viscosities than the asymmetric C N–1C1imNTf2 counterparts. For ionic liquids from C1C1imNTf2 to C6C6imNTf2, an odd–even effect in the viscosity along the cation alkyl side chain length was observed, in contrast with a linear increase found for the ones ranging between C6C6imNTf2 and C10C10imNTf2. The analysis of the viscosity data along the alkyl side chain length reveals a trend shift that occurs at C6C1imNTf2 for the asymmetric series and at C6C6imNTf2 for the symmetric series. These results are further supported by SWAXS measurements at ambient conditions. The gathered data indicate that both asymmetric and symmetric members are characterized by the occurrence of a distinct degree of mesoscopic structural organization above a given threshold in the side alkyl chain length, regardless the cation symmetry. The data also highlight a difference in the alkyl chain dependence of the mesoscopic cluster sizes for symmetric and asymmetric cations, reflecting a different degree of interdigitation of the aliphatic tails in the two families. The trend shift found in this work is related to the structural segregation in the liquid after a critical alkyl length size (CALS) is attained and has particular relevance in the cation structural isomerism with higher symmetry.
We combined year-round eddy covariance with biometry and biomass harvests along a chronosequence of boreal forest stands that were 1, 6, 15, 23, 40, ∼74, and ∼154 years old to understand how ...ecosystem production and carbon stocks change during recovery from stand-replacing crown fire. Live biomass (Clive) was low in the 1- and 6-year-old stands, and increased following a logistic pattern to high levels in the 74- and 154-year-old stands. Carbon stocks in the forest floor (Cforest floor) and coarse woody debris (CCWD) were comparatively high in the 1-year-old stand, reduced in the 6- through 40-year-old stands, and highest in the 74- and 154-year-old stands. Total net primary production (TNPP) was reduced in the 1- and 6-year-old stands, highest in the 23- through 74-year-old stands and somewhat reduced in the 154-year-old stand. The NPP decline at the 154-year-old stand was related to increased autotrophic respiration rather than decreased gross primary production (GPP). Net ecosystem production (NEP), calculated by integrated eddy covariance, indicated the 1- and 6-year-old stands were losing carbon, the 15-year-old stand was gaining a small amount of carbon, the 23- and 74-year-old stands were gaining considerable carbon, and the 40- and 154-year-old stands were gaining modest amounts of carbon. The recovery from fire was rapid; a linear fit through the NEP observations at the 6- and 15-year-old stands indicated the transition from carbon source to sink occurred within 11-12 years. The NEP decline at the 154-year-old stand appears related to increased losses from Clive by tree mortality and possibly from Cforest floor by decomposition. Our findings support the idea that NPP, carbon production efficiency (NPP/GPP), NEP, and carbon storage efficiency (NEP/TNPP) all decrease in old boreal stands.
Plastic yearly production has surpassed the 300milliontons mark and recycling has all but failed in constituting a viable solution for the disposal of plastic waste. As these materials continue to ...accumulate in the environment, namely, in rivers and oceans, in the form of macro-, meso-, micro- and nanoplastics, it becomes of the utmost urgency to find new ways to curtail this environmental threat. Multiple efforts have been made to identify and isolate microorganisms capable of utilizing synthetic polymers and recent results point towards the viability of a solution for this problem based on the biodegradation of plastics resorting to selected microbial strains.
Herein, the response of the fungus Zalerion maritimum to different times of exposition to polyethylene (PE) pellets, in a minimum growth medium, was evaluated, based on the quantified mass differences in both the fungus and the microplastic pellets used. Additionally, molecular changes were assessed through attenuated total reflectance Fourier transform Infrared Spectroscopy (FTIR-ATR) and Nuclear Magnetic Resonance (NMR).
Results showed that, under the tested conditions, Z. maritimum is capable of utilizing PE, resulting in the decrease, in both mass and size, of the pellets. These results indicate that this naturally occurring fungus may actively contribute to the biodegradation of microplastics, requiring minimum nutrients.
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•Plastic pollution is of growing concern as it accumulates in the environment.•Multiple microorganisms have been described as potential bioremediation solutions.•The potential of Zalerion maritimum in the biodegradation of polyethylene was tested.•Z. maritimum used polyethylene as evidenced by FTIR, NMR and SEM results.•The results highlight the prospective use of Z. maritimum as a bioremediation tool.
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•This is the first study on the purification of Cassia leiandra trypsin inhibitor (ClTI).•ClTI is a Kunitz-type inhibitor composed of a single 19,484Da polypeptide chain.•ClTI is an ...uncompetitive inhibitor with a Ki of 6.25×10−8M.•ClTI inhibits Aedes aegypti larval midgut proteases.•ClTI impairs the survival and larval cycle of Aedes aegypti (LC50 of 2.28×10−2M).
A trypsin inhibitor from Cassia leiandra seeds, named ClTI, was purified, characterized, and its insecticidal activity against Aedes aegypti evaluated. ClTI was purified by DEAE-Cellulose and trypsin-Sepharose 4B chromatography, with a 15.5-fold purification and 2.4% yield. ClTI is composed of a 19,484Da polypeptide chain as revealed by mass spectrometry, it is not a glycoprotein, its amino acid sequence is similar to other Kunitz-type inhibitors, and it comprises 35% β-sheets, 14% β-turns, and 50% disordered secondary structures. ClTI is an uncompetitive inhibitor of bovine trypsin (IC50 of 33.81×10−8M, Ki of 6.25×10−8M) stable over a broad range of pHs (2.2–10.0) and temperatures (30–70°C), but dithiothreitol led to a partial loss of the inhibitory activity. ClTI, at 4.65×10−6M, reduced in 50% the activity of the Ae. aegypti midgut proteases. ClTI also promoted acute toxicity on the 3rd instar larvae of Ae. aegypti, with an LC50 of 2.28×10−2M. Moreover, it caused a 24-h delay of the larvae development and 44% mortality after ten days of exposure. Altogether, these results suggest that ClTI has potential as a natural compound to control Ae. aegypti, a vector of several infection diseases.
There has been a considerable increase on research of the ecological consequences of microplastics released into the environment, but only a handful of works have focused on the nano-sized particles ...of polymer-based materials. Though their presence has been difficult to adequately ascertain, due to the inherent technical difficulties for isolating and quantifying them, there is an overall consensus that these are not only present in the environment – either directly released or as the result of weathering of larger fragments – but that they also pose a significant threat to the environment and human health, as well. The reduced size of these particulates (<1μm) makes them susceptible of ingestion by organisms that are at the base of the food-chain. Moreover, the characteristic high surface area-to-volume ratio of nanoparticles may add to their potential hazardous effects, as other contaminants, such as persistent organic pollutants, could be adsorbed and undergo bioaccumulation and bioamplification phenomena.
In this review, we describe the most relevant sources of nanoplastics and offer some insights into their fate once released into the environment. Furthermore, we overview the most prominent effects of these small particulates, while identifying the key challenges scientists currently face in the research of nanoplastics in the environment. Lastly, we give a brief summary of the economic impacts of the pollution caused by plastic litter – a potential key source of nanoplastics – in the oceans, the most common destination of these contaminants.
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•There has been a considerable increase of research on the fate o nanosized plastics.•These can pose a significant threat to both the environment and human health.•We reviewed their sources, fates and effects.•We identified the key challenges researchers face in this field.•Insights into the future of nanoplastics-related research are presented.
Abstract Sulfated polysaccharides from 11 species of tropical marine algae (one edible specie of Rhodophyta, six species of Phaeophyta and four species of Chlorophyta) collected from Natal city coast ...(Northeast of Brazil) were evaluated for their anticoagulant, antioxidant and antiproliverative in vitro activities. In the activated partial thromboplastin time (APTT) test, which evaluates the intrinsic coagulation pathway, seven seaweeds presented anticoagulant activity. Dictyota cervicornis showed the highest activity, prolonging the coagulation time to double the baseline value in the APTT with only 0.01 mg/100 μl of plasma, 1.4-fold lesser than Clexane® , a low molecular weight heparin. In the protrombin time (PT) test, which evaluates the extrinsic coagulation pathway, only Caulerpa cupresoides showed anticoagulant activity. All species collected showed antioxidant activities. This screening emphasized the great antioxidant potential (total capacity antioxidant, power reducing and ferrous chelating) of four species: C. sertularioide ; Dictyota cervicornis; Sargassum filipendula and Dictyopteris delicatula . After 72 h incubation, HeLa cell proliferation was inhibited ( p < 0.05) between 33.0 and 67.5% by S. filipendula ; 31.4 and 65.7% by D. delicatula ; 36.3 and 58.4% by Caulerpa prolifera and 40.2 and 61.0% by Dictyota menstrualis at 0.01–2 mg/mL algal polysaccharides. The antiproliferative efficacy of these algal polysaccharides were positively correlated with the sulfate content ( r = 0.934). Several polysaccharides demonstrated promising antioxidant, antiproliferative an/or anticoagulant potential and have been selected for further studies on bioguided fractionation, isolation and characterization of pure polysaccharides from these species as well as in vivo experiments are needed and are already in progress.
Inflammation is an organism's response to chemical or physical injury. It is split into acute and chronic inflammation and is the last, most significant cause of death worldwide. Nowadays, according ...to the World Health Organization (WHO), the greatest threat to human health is chronic disease. Worldwide, three out of five people die from chronic inflammatory diseases such as stroke, chronic respiratory diseases, heart disorders, and cancer. Nowadays, anti-inflammatory drugs (steroidal and non-steroidal, enzyme inhibitors that are essential in the inflammatory process, and receptor antagonists, among others) have been considered as promising treatments to be explored. However, there remains a significant proportion of patients who show poor or incomplete responses to these treatments or experience associated severe side effects. Seaweeds represent a valuable resource of bioactive compounds associated with anti-inflammatory effects and offer great potential for the development of new anti-inflammatory drugs. This review presents an overview of specialized metabolites isolated from seaweeds with in situ and in vivo anti-inflammatory properties. Phlorotannins, carotenoids, sterols, alkaloids, and polyunsaturated fatty acids present significant anti-inflammatory effects given that some of them are involved directly or indirectly in several inflammatory pathways. The majority of the isolated compounds inhibit the pro-inflammatory mediators/cytokines. Studies have suggested an excellent selectivity of chromene nucleus towards inducible pro-inflammatory COX-2 than its constitutive isoform COX-1. Additional research is needed to understand the mechanisms of action of seaweed's compounds in inflammation, given the production of sustainable and healthier anti-inflammatory agents.
In this review we focus on the idea of establishing connections between the mechanical properties of DNA-ligand complexes and the physical chemistry of DNA-ligand interactions. This type of ...connection is interesting because it opens the possibility of performing a robust characterization of such interactions by using only one experimental technique: single molecule stretching. Furthermore, it also opens new possibilities in comparing results obtained by very different approaches, in particular when comparing single molecule techniques to ensemble-averaging techniques. We start the manuscript reviewing important concepts of DNA mechanics, from the basic mechanical properties to the Worm-Like Chain model. Next we review the basic concepts of the physical chemistry of DNA-ligand interactions, revisiting the most important models used to analyze the binding data and discussing their binding isotherms. Then, we discuss the basic features of the single molecule techniques most used to stretch DNA-ligand complexes and to obtain "force × extension" data, from which the mechanical properties of the complexes can be determined. We also discuss the characteristics of the main types of interactions that can occur between DNA and ligands, from covalent binding to simple electrostatic driven interactions. Finally, we present a historical survey of the attempts to connect mechanics to physical chemistry for DNA-ligand systems, emphasizing a recently developed fitting approach useful to connect the persistence length of DNA-ligand complexes to the physicochemical properties of the interaction. Such an approach in principle can be used for any type of ligand, from drugs to proteins, even if multiple binding modes are present.
In this review we focus on the idea of establishing connections between the mechanical properties of DNA-ligand complexes and the physical chemistry of DNA-ligand interactions.
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