The marine protected area (MPA) of the Espiritu Santo Archipelago (ESA; Gulf of California), is exposed to a high level of anthropogenic disturbances, consequently, the local authorities have ...deployed artificial reefs (shipwrecks) in the ESA area to increase fishing refuges, breeding sites, and tourist attractions. To explore the potential contribution of these artificial reefs as a conservation tool, we compared their benthic community structures (i.e. diversity and live cover categories) to those of the natural reefs. Our results indicate a higher abundance of mollusks on the artificial reefs compared to the natural reefs; a higher echinoderm abundance on the natural reefs; and a very similar species richness of hexacorals between the natural and artificial reefs, with 10 and 9 species recorded respectively. The natural reefs hosted a four-fold higher live cover of hexacorals than the artificial reefs, while the artificial reefs had a higher number of octocoral species, 8 versus 5 on the natural reefs. In addition, the artificial reefs had a 4.6 fold higher octocoral cover than the natural reefs. Overall findings indicate that the benthic community assemblages significantly differ between the natural and artificial reefs, which may be related to their location, structural composition, material, and morphology. These results suggest that shipwrecks have the potential to enhance local reef diversity by increasing the cover and abundance of certain benthic-associated species. Although the shipwrecks do not function as surrogate habitats for the adjacent natural rocky reefs, as no-take areas they provide suitable refuges for several target species (e.g. black coral and mollusks).
•The natural reefs hosted a four-fold higher live cover of hexacorals than the artificial reefs.•The artificial reefs had a higher number of octocoral species than the natural reefs.•The benthic community assemblages significantly differ between the natural and artificial reefs.•The studied shipwrecks provide refuge to commercially important species (e.g. black coral and mollusks).•The studied shipwrecks should not be considered as surrogate habitats for natural reefs.
In this study, acetone and methanol extracts of Hibiscus sabdariffa were obtained and used to supplement films made with potato starch and glycerol as plasticizers. Antimicrobial tests were carried ...out on the extracts and films, and the growth of Listeria monocytogenes was evaluated in film-coated sausage. The physicochemical properties of the processed films were evaluated. In in vitro tests, the acetonic extract produced greater inhibition halos than did the methanolic extract, with Escherichia coli being the most sensitive bacterial strain assayed. In the antimicrobial tests of the films, the most significant effect was observed for the films containing acetonic extract. When coated onto sausages, a more significant inhibitory effect against L. monocytogenes was observed when the sausage was vacuum-packed. The addition of extracts produced noticeable changes in the films, with those containing methanolic extracts exhibiting major changes. The glass transition temperature of the films was lower when methanolic extract was added than when acetonic extract Furthermore, the fracture tension was more greatly affected in the films containing methanolic extract. The permeability of the films containing methanolic extract was lower than that of the other films. These films also exhibited antimicrobial activity, and the addition of extracts modified their physicochemical properties.
•Acetone and methanol extracts of H. sabdariffa were obtained and used in the making of films.•The antimicrobial effect of the films obtained was evaluated in sausages.•Films with acetone extract presented greater inhibition halos.•Vacuum-packed H. sabdariffa film-coated sausages showed a higher inhibitory effect.
Heme, an iron-containing prosthetic group found in many proteins, carries out diverse biological functions such as electron transfer, oxygen storage and enzymatic reactions. Hemin, the oxidised form ...of heme, is used to treat porphyria and also to activate heme-oxygenase (HO) which catalyses the rate-limiting step in heme degradation. Our group has previously demonstrated that hemin displays antitumor activity in breast cancer (BC). The aim of this work has been to study the effect of hemin on protein expression modifications in a BC cell line to gain insight into the molecular mechanisms of hemin antitumor activity. For this purpose, we carried out proteome analysis by Mass Spectrometry (MS) which showed that 1309 proteins were significantly increased in hemin-treated cells, including HO-1 and the proteases that regulate HO-1 function, and 921 proteins were significantly decreased. Furthermore, the MS-data analysis showed that hemin regulates the expression of heme- and iron-related proteins, adhesion and cytoskeletal proteins, cancer signal transduction proteins and enzymes involved in lipid metabolism. By biochemical and cellular studies, we further corroborated the most relevant in-silico results. Altogether, these results show the multiple physiological effects that hemin treatment displays in BC and demonstrate its potential as anticancer agent.
In this article, the synthesis and characterization of NiPdPt (60:20:20 wt. %) nanoparticles supported on Vulcan carbon are analyzed towards the oxygen reduction reaction (ORR) in acid medium. We ...report a novel trimetallic nanocatalyst produced by a synthetic chemical route by reacting chemical reagents in oleylamine and oleic acid. The physical characterization of the synthesized nanoparticles was performed by X-ray diffraction (XRD), energy disperse X-ray spectroscopy (EDS) and scanning transmission electron microscopy (STEM). The presence of Ni, Pd, and Pt in the nanoparticles was confirmed by EDS and XRD. From STEM micrographs, a size distribution of nanoparticles in a range of 30–52 nm was obtained. In the electrocatalyst research, cyclic voltammetry (CV), CO-stripping, and rotating disk electrode (RDE) were employed for electrochemical evaluation of the synthesized nanoparticles in acid medium. The NiPdPt/C nanocatalyst showed superior mass and specific activity compared to the commercial Pt/C towards the ORR in acid medium.
•A novel NiPdPt/C trimetallic nanocatalyst was studied for the ORR.•The presence of Ni, Pd, and Pt in the nanoparticles was confirmed by EDS and XRD.•The mass activity of the NiPdPt/C nanocatalyst was superior compared to the Pt/C.
Scorpion venom causes renal injury and affects vascular ion-channels function. Centruroides margaritatus scorpion is found in Colombia and is frequently the cause of envenomation accidents; however, ...its renal impact has never been investigated.
To evaluate the effects of C. margaritatus venom (CmV) on renal parameters using isolated rat kidney and renal cell culture models.
Wistar rats (n = 5, weighing 240-300 g) were first perfused with Krebs-Henseleit solution containing 6 g 100 mL-1 bovine serum albumin. After 30 minutes, the kidneys were perfused with CmV to a final concentration of 10 μgmL-1; evaluation was performed by measuring Perfusion Pressure (PP), Renal Vascular Resistance (RVR), Urinary Flow (UF), Glomerular Filtration Rate (GFR), and percentage of electrolyte tubular transport. Moreover, kidney histological analyses and cell cytotoxicity in renal tubule epithelial cells (MDCK) and proximal tubular cells (LLC-MK2) were assessed.
CmV increased PP and RVR 60 min after perfusion. On the other hand, UF, GFR, and the percentages of sodium, potassium and chloride tubular transport decreased after experimental envenomation. UF dropped after 120 min, while GFR and percentage of electrolyte tubular transport diminished after 60, 90 and 120 min. CmV was not toxic to MDCK cell line but reduced the viability of LLC-MK2 cells at concentrations ranging from 6.25 to 200 μgmL-1. Histological analyses disclosed hydropic degeneration, edema, and protein deposits. Flow cytometry disclosed that cell death occurred predominantly by necrosis.
Our results suggest that C. margaritatus venom can trigger renal impairment, mainly in the proximal kidney tubule.
The weekly number of dengue cases in Peru, South America, stratified by province for the period 1994-2006 were analysed in conjunction with associated demographic, geographic and climatological data. ...Estimates of the reproduction number, moderately correlated with population size (Spearman ρ=0·28, P=0·03), had a median of 1·76 (IQR 0·83-4·46). The distributions of dengue attack rates and epidemic durations follow power-law (Pareto) distributions (coefficient of determination >85%, P<0·004). Spatial heterogeneity of attack rates was highest in coastal areas followed by mountain and jungle areas. Our findings suggest a hierarchy of transmission events during the large 2000-2001 epidemic from large to small population areas when serotypes DEN-3 and DEN-4 were first identified (Spearman ρ=-0·43, P=0·03). The need for spatial and temporal dengue epidemic data with a high degree of resolution not only increases our understanding of the dynamics of dengue but will also generate new hypotheses and provide a platform for testing innovative control policies.
•Molecularly imprinted polymer-Silicon (MIP-Si) nanocomposite was synthesized.•MIP-Si based all-solid-state (ASS) potentiometric sensor was developed.•The sensor showed high-selectivity for sarcosine ...in simulated body fluid.•It showed low detection limit (7.8 x 10−8 mol/L), thus is highly sensitive.•The sensor is stable for at least 150 days and shows highly reproducible results.
A novel nanocomposite based on molecularly imprinted polymer (MIP) polymerized over silica nanoparticles (Si) is used for the development of an all-solid-state (ASS) potentiometric sensor for determination of sarcosine, a biomarker for Prostate Cancer (PCa). This MIP-Si sensor has shown high selectivity in phosphate-buffered solution (PBS) and simulated body fluid (SBF). We have obtained a linear response (10−5–10−8 mol/L), with a low detection limit (7.8 × 10−8 mol/L) and a quick response time close to 30 s, being stable for at least 150 days. It is corroborated that the sensor is a stable, reproducible, and sensitive biosensing device for PCa detection.
The magnetoelectric properties of exchange-coupled Ni/CoFeB-based composite multiferroic microstructures are investigated. The strength and sign of the magnetoelastic effect are found to be strongly ...correlated with the ratio between the thicknesses of two magnetostrictive materials. In cases where the thickness ratio deviates significantly from one, the magnetoelastic behavior of the multiferroic microstructures is dominated by the thicker layer, which contributes more strongly to the observed magnetoelastic effect. More symmetric structures with a thickness ratio equal to one show an emergent interfacial behavior which cannot be accounted for simply by summing up the magnetoelastic effects occurring in the two constituent layers. This aspect is clearly visible in the case of ultrathin bilayers, where the exchange coupling drastically affects the magnetic behavior of the Ni layer, making the Ni/CoFeB bilayer a promising next-generation synthetic magnetic system entirely. This study demonstrates the richness and high tunability of composite multiferroic systems based on coupled magnetic bilayers compared to their single magnetic layer counterparts. Furthermore, because of the compatibility of CoFeB with present magnetic tunnel junction-based spintronic technologies, the reported findings are expected to be of great interest for the development of ultralow-power magnetoelectric memory devices.
► A Quasi-3D model of flow and solute transport in the vadose zone and phreatic aquifer. ► Model accounts for solute recycling of pumped water used for irrigation. ► Application for simulating ...salinity changes in the Alto Piura aquifer, Peru.
Studies of groundwater quality in arid and semi-arid lands show that irrigation return flow is one of major factors contributing to aquifer salinization. Existing mathematical models do not account explicitly for solute recycling during irrigation on a daily scale, which is considered as an important salinization input. The main objective of this research was to develop a mathematical numerical model that can simulate impact of irrigation return flow by coupling water and solute fluxes at the soil surface with quality of water pumped from the aquifer. This was obtained with a Quasi-3D model representing flow in the vadose zone – aquifer system by series of 1D Richards’ equations in a variably-saturated zone and by a 3D flow equation in groundwater. The 3D advection-dispersion equation is solved in the entire domain. Concentration of irrigation water is calculated at each time step as a function of concentration of both surface water and groundwater extracted at specific locations.
The model was applied to simulate the impact of irrigation on groundwater salinization of Alto Piura aquifer (Northern Peru) over thirty years. Three scenarios were considered: (i) use of flood irrigation and groundwater extraction (the present situation); (ii) increase of groundwater pumping by 50% compared to the first scenario; and (iii) transition from flood irrigation to drip irrigation, thus decreasing irrigation volume by around 60% compared to the first scenario. Results indicate that in different irrigation areas, the simulated increase rates of total dissolved solids in groundwater vary from 3–5 to 15–17mg/L/year, depending on hydrogeological and hydrochemical conditions, volumes of water extracted, and proportion between surface water and groundwater applied. The transition from flood irrigation to drip irrigation decreases the negative impact of return flow on groundwater quality; however drip irrigation causes faster soil salinization compared to flood irrigation. Irrigation return coefficients were calculated in the order of 21–23% and 22–24% for the first and second scenarios, respectively.
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