El confinamiento como una de las medidas decretadas en la emergencia sanitaria por el gobierno ecuatoriano para contrarrestar el impacto del virus SARS-CoV-2 o Covid-19, se ha visto reflejado en el ...comportamiento del consumidor. El propósito de este estudio es conocer los efectos que esta medida emergente ocasiona en el consumo de las personas, utilizando la medición de variables relacionadas con los factores personales, sociales, psicológicos y culturales. Se encuestó una muestra de 658 consumidores en cinco ciudades del Ecuador: Cuenca, Guayaquil, Loja, Machala y Quito. Se utilizó el Modelo de Ecuaciones Estructurales (SEM) para comprobar las hipótesis teóricas. Estas teorías fueron aceptadas considerando tres dimensiones: las cargas de los indicadores analizadas a través del test Loadings >0.7; la confiabilidad de consistencia interna medida a través del test de confiabilidad compuesta (CR) y Cronbach Alpha >0.7, para los constructos de comportamiento de compra, factores sociales, personales, psicológicos y culturales; y la validez convergente observadas a través del test Average Variance Extracted (AVE) > 0.5 para los cinco constructos. Los resultados muestran que las relaciones entre el comportamiento del consumidor y los factores personales, sociales, psicológicos y culturales se encuentran asociadas significativamente, lo cual proporciona algunas pautas para entender el comportamiento del consumidor y satisfacer mejor las necesidades en tiempo de crisis.
Every year, new organisms that survive and colonize adverse environments are discovered and isolated. Those organisms, called extremophiles, are distributed throughout the world, both in aquatic and ...terrestrial environments, such as sulfurous marsh waters, hydrothermal springs, deep waters, volcanos, terrestrial hot springs, marine saltern, salt lakes, among others. According to the ecosystem inhabiting, extremophiles are categorized as thermophiles, psychrophiles, halophiles, acidophiles, alkalophilic, piezophiles, saccharophiles, metallophiles and polyextremophiles. They have developed chemical adaptation strategies that allow them to maintain their cellular integrity, altering physiology or improving repair capabilities; one of them is the biosynthesis of extracellular polysaccharides (EPS), which constitute a slime and hydrated matrix that keep the cells embedded, protecting from environmental stress (desiccation, salinity, temperature, radiation). EPS have gained interest; they are explored by their unique properties such as structural complexity, biodegradability, biological activities, and biocompatibility. Here, we present a review concerning the biosynthesis, characterization, and potential EPS applications produced by extremophile microorganisms, namely, thermophiles, halophiles, and psychrophiles. A bibliometric analysis was conducted, considering research articles published within the last two decades. Besides, an overview of the culture conditions used for extremophiles, the main properties and multiple potential applications of their EPS is also presented.
•Extremophiles have developed adaptation strategies to maintain their cellular integrity.•Biosynthesis of extracellular polysaccharides (EPS) is one of their strategies.•EPS' structural diversity makes them competitive with current commercial polysaccharides.•EPS from extremophiles can be considered as new promising “green gold” in biotechnology.
Interest is growing in entrapping natural antimicrobial compounds (NACs) within polyhydroxyalkanoates (PHAs) to produce active food-biopackaging systems. PHAs are versatile polymeric macromolecules ...that can protect NAC activity by entrapment. This work reviews 75 original papers and 18 patents published in the last 11 years concerning PHAs as matrices for NACs to summarize the physicochemical properties, release, and antimicrobial activities of systems fabricated from PHAs and NACs (PHA/NAC systems). PHA/NAC systems have recently been used as active food biopackaging systems to inactivate foodborne pathogens and prolong food shelf life. PHAs protect NACs by increasing the degradation temperature of some NACs and decreasing their loss of mass when heated. Some NACs also transform the PHA/NAC systems into more thermostable, flexible, and resistant when interacting with PHAs while also improving the barrier properties of the systems. NAC release and activity are also prolonged when NACs are trapped within PHAs. PHA/NAC systems, therefore, represent ecologically friendly materials with promising applications.
•PHAs are suitable vehicles to protect natural antimicrobial compounds.•PHA/NAC systems are thermostable, flexible, and resistant to food biopackaging.•When NACs are entrapped in PHA matrices, their release is prolonged.•PHA/NAC systems should be tested on more food products to determine their efficacy.
Abstract
Background
Acute kidney injury (AKI) may develop in coronavirus disease 2019 (COVID-19) patients and may be associated with a worse outcome. The aim of this study is to describe AKI ...incidence during the first 45 days of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Spain, its reversibility and the association with mortality.
Methods
This was an observational retrospective case–control study based on patients hospitalized between 1 March and 15 April 2020 with SARS-CoV-2 infection and AKI. Confirmed AKI cases were compared with stable kidney function patients for baseline characteristics, analytical data, treatment and renal outcome. Patients with end-stage kidney disease were excluded.
Results
AKI incidence was 17.22% among 3182 admitted COVID-19 patients and acute kidney disease (AKD) incidence was 6.82%. The most frequent causes of AKI were prerenal (68.8%) and sepsis (21.9%). Odds ratio (OR) for AKI was increased in patients with pre-existent hypertension OR 2.58, 95% confidence interval (CI) 1.71–3.89 and chronic kidney disease (CKD) (OR 2.14, 95% CI 1.33–3.42) and in those with respiratory distress (OR 2.37, 95% CI 1.52–3.70). Low arterial pressure at admission increased the risk for Stage 3 AKI (OR 1.65, 95% CI 1.09–2.50). Baseline kidney function was not recovered in 45.73% of overall AKI cases and in 52.75% of AKI patients with prior CKD. Mortality was 38.5% compared with 13.4% of the overall sample population. AKI increased mortality risk at any time of hospitalization (hazard ratio 1.45, 95% CI 1.09–1.93).
Conclusions
AKI is frequent in COVID-19 patients and is associated with mortality, independently of acute respiratory distress syndrome. AKD was also frequent and merits adequate follow-up.
Graphical Abstract
This research aimed to analyze the viscoelastic behavior of mixed hydrogels based on low methoxyl citrus pectin (DE = 30.4%) and low acyl gellan, in the presence of calcium ions to assess the effect ...of each polysaccharide on the gelation and relaxation processes of the mixed systems. Linear viscoelastic properties were determined, and the experimental data were used to fit the generalized Maxwell model to obtain the hydrogels' relaxation times and average network mesh size. In most mixed gels, the co-gelification of gellan and pectin provided more rigid hydrogels characterized by narrow meshes (6.1–11.7 nm) and slower rearrangements of polymer chains (relaxation times (λ) between 16.7 and 55.2 s) compared to gellan gels (λ = 18.4–29.3 s). The viscoelastic behavior of the pectin-gellan gels suggests a macromolecular network organization where gellan junction zones predominate, and pectin contributes to reinforcing the mixed network. That organization generates more macromolecular interactions via calcium bridges and hydrogen bonds, promoted by the accessibility of anionic sites in both biopolymers and the low extent of branching (7 mol%) of pectin. The rheological analysis provides a new understanding concerning the hybrid pectin-gellan networks, which can be used to design new natural hydrogels for diverse applications such as biocompatible biomaterials and delivery vehicles.
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•Co-gelification of gellan and pectin provided more rigid gels than the single ones.•The viscoelastic properties of the mixed gels are governed by gellan.•Pectin-gellan gels showed higher relaxation times than gellan due to pectin's complex structure.
•First report on the production and characterization of exopolysaccharide produced by Haloferax mucosum.•Haloferax mucosum showed high exopolysaccharide (EPS) production of 7.15 g/L.•EPS had a high ...molecular mass of 152.•EPS exhibited high emulsion stability to extreme conditions and with different nonpolar solvents.
The physicochemical characterization and emulsifying functional properties of a novel exopolysaccharide (EPS) produced by haloarchaea Haloferax mucosum (DSM 27191) were investigated. This biopolymer has a high molecular weight of 152 kDa and important protein content of 10%. Different culture media compositions were investigated taking the ATCC 2185 medium as a base and supplementing with varying concentrations of yeast extract and glucose or sucrose as carbon sources to produce the EPS in a liquid medium. The highest EPS production (7.15 ± 0.44 g/L) was obtained at 96 h. EPS aqueous dispersions showed a non-Newtonian rheological behavior which was well fitted to the Cross equation. The EPS (at 0.32% w/w) was capable of stabilizing water-in-oil emulsions with different nonpolar solvents, including n-hexane, kerosene, chloroform, castor oil and mineral oil. EPS retained its emulsifying activity after to be incubated for one hour in a wide range of temperatures (25, 40, 70 and 100 °C), pH (4, 6.5, 7 and 12) and NaCl concentrations (0, 2.0 and 4.0 M). The viscoelastic behavior and stability of hexane-in-water emulsion were examined through oscillatory shear measurements.
Artificial Mitochondrial Transfer or Transplant (AMT/T) can be used to reduce the stress and loss of viability of damaged cells. In MitoCeption, a type of AMT/T, the isolated mitochondria and ...recipient cells are centrifuged together at 4 °C and then co-incubated at 37 °C in normal culture conditions, inducing the transfer. Ultraviolet radiation (UVR) can affect mitochondria and other cell structures, resulting in tissue stress, aging, and immunosuppression. AMT/T could be used to repair UVR cellular and mitochondrial damage. We studied if a mitochondrial mix from different donors (Primary Allogeneic Mitochondrial Mix, PAMM) can repair UVR damage and promote cell survival.
Using a simplified adaption of the MitoCeption protocol, we used peripheral blood mononuclear cells (PBMCs) as the recipient cell model of the PAMM in order to determine if this protocol could repair UVR damage. Our results showed that when PBMCs are exposed to UVR, there is a decrease in metabolic activity, mitochondrial mass, and mtDNA sequence stability as well as an increase in p53 expression and the percentage of dead cells. When PAMM MitoCeption was used on UVR-damaged cells, it successfully transferred mitochondria from different donors to distinct PBMCs populations and repaired the observed UVR damage.
Our results represent an advancement in the applications of MitoCeption and other AMT/T. We showed that PBMCs could be used as a PAMM source of mitochondria. We also showed that these mitochondria can be transferred in a mix from different donors (PAMM) to UVR-damaged, non-adherent primary cells. Additionally, we decreased the duration of the MitoCeption protocol.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Mining is known as one of the primary economic activities where exploitation of minerals and other materials have become essential for human development. However, this activity may represent a risk ...to the environment, starting from deforestation and ending with production of residues that might contain potentially toxic elements. Tailing deposits from historical mining are an example of waste that may represent an environmental concern when abandoned and exposed to environmental conditions. The town of Nacozari de Garcia, in northwestern Mexico, has three abandoned mine tailings (locally known as tailings I, II, and III) located around the urban area that represent important sources of dust and pollution. Images obtained using unmanned aerial vehicles (UAV) in conjunction with geochemical data are used to assess historic erosion calculation and pollution considering contamination and hazard indexes in tailings II and III. Digital elevation models of abandoned tailings were obtained using photogrammetry with UAV. A total of 37 surficial samples were collected from mine tailings to determine elemental concentrations (As, Cu, Pb, W, Zn) using portable X-ray fluorescence. Higher concentrations were found on samples from mine tailing II. Average concentrations followed the decreasing order of Cu > Zn > W > Pb > As for tailing II, whereas decreasing order of Cu > Zn > W > As > Pb was found for tailing III. Contamination Index (CI) values obtained from tailings II and III represent a low potential of pollution, whereas efflorescent crusts from these tailings represent a high potential of polluting soils and sediments by dust generation. Hazard Average Quotient (HAQ) values on both tailings suggest a very high potential of contamination if fluids infiltrate tailings and interact with surficial water and/or groundwater. Obtained surfaces of mine tailings II and III are 146,216 and 216,689 m
2
, respectively, which represent around 11% of the urbanized area. A loss mass of 321,675 tons was determined for mine tailing II, whereas 634,062 tons for tailing III, accounting for 0.96 million tons of total eroded mass. Since abandonment, calculated erosion rates of 493 t ha
−1
year
−1
(tailing II) and 232 t ha
−1
year
−1
(tailing III) are in agreement with those determined in other mining areas. CI and HAQ indexes provide good estimates of pollution associated with abandoned mine tailings from Nacozari de García. Historic erosion determined in these tailings is an environmental concern since eroded material and polluted water have been incorporated into the Moctezuma River, which feeds several villages, whose major activities include agriculture and livestock raising.
ABSTRACT
Background
Current guidelines establish the same hemoglobin (Hb) and iron biomarkers targets for hemodialysis (HD) and peritoneal dialysis (PD) in patients receiving ...erythropoiesis-stimulating agents (ESAs) even though patients having PD are usually younger, more active and less comorbid. Unfortunately, specific renal anemia anemia in chronic kidney disease (aCKD) trials or observational studies on PD are scanty. The aims of this study were to describe current aCKD management, goals and adherence to clinical guidelines, identifying opportunities for healthcare improvement in PD patients.
Methods
This was a retrospective, nationwide, multicentre study including patients from 19 PD units. The nephrologists collected baseline data, demographics, comorbidities and data related to anemia management (laboratory values, previously prescribed treatments and subsequent adjustments) from electronic medical records. The European adaptation of KDIGO guidelines was the reference for definitions, drug prescriptions and targets.
Results
A total of 343 patients (mean age 62.9 years, 61.2% male) were included; 72.9% were receiving ESAs and 33.2% iron therapy 20.7% intravenously (IV). Eighty-two patients were receiving ESA without iron therapy, despite 53 of them having an indication according to the European Renal Best Practice guidelines. After laboratory results, iron therapy was only started in 15% of patients. Among ESA-treated patients, 51.9% had an optimal control hemoglobin (Hb) 10–12 g/dL and 28.3% between 12–12.9 g/dL. Seventeen patients achieved Hb >13 g/dL, and 12 of them remained on ESA after overshooting. Only three patients had Hb <10 g/dL without ESAs. Seven patients (2%) met criteria for ESA resistance (epoetin dose >300 IU/kg/week). The highest tertile of erythropoietin resistance index (>6.3 UI/kg/week/g/dL) was associated with iron deficiency and low albumin corrected by renal replacement therapy vintage and hospital admissions in the previous 3 months.
Conclusion
Iron therapy continues to be underused (especially IV). Low albumin, iron deficiency and prior events explain most of the ESA hyporesponsiveness. Hb targets are titrated to/above the upper limits. Thus, several missed opportunities for adequate prescriptions and adherence to guidelines were identified.
Lay Summary
Renal anemia is common in peritoneal dialysis (PD) patients. Current guidelines recommend how to diagnose and treat it with iron and erythropoiesis-stimulating agents (ESAs). Unfortunately, evidence in PD is weaker and most recommendations have been adapted from hemodialysis patients. Our retrospective study describes current anemia practices and the degree of adherence to clinical guidelines in a sample representing 12% of PD patients in our country. The key findings are: a relevant percentage of prescriptions do not conform to guidelines; and hemoglobin targets are titrated upwards, even above 12 g/dL in PD. Iron deficiency, malnutrition and previous events accounted for most of the ESA hyporesponse, and iron therapy (especially intravenous) continues to be underused. This should promote improvement strategies such as: structured dissemination of guidelines; clinical routes for in-hospital intravenous iron administration to PD patients; and computer-assisted prescription tools and early identification of ESA resistance or inflammation. Lastly, specific studies on anemia in PD patients are needed to generate reliable evidence to individualize prescriptions and targets in this population.
Graphical Abstract
Graphical Abstract
Surface‐Active Biomolecules (SAB) obtained from microbial sources are safe alternatives to chemically synthesized counterparts for many environmental and industrial applications. These applications ...frequently involve the exposure of the SAB to extreme factors making necessary to seek for molecules that are able to function under such conditions. In this work, the polyextremophilic bacterium Salibacterium sp. 4CTb is reported as a SAB producer. Its emulsifier activity increased almost twofold when the C/N ratio and culture conditions were modified. The partially purified molecule was able to form stable emulsions under extreme conditions (70 °C, pH 12, and 4 M NaCl) better than other commercial molecules, and reduced the surface tension of the water to 49.78 mN m−1 with critical micelle concentration (CMC) of 15.1 mg L−1. Carbohydrate, lipid, and protein assays, accompanied by the Fourier Transform Infra‐Red (FTIR) and electrospray ionization mass spectroscopy (ESI‐MS) results, indicate the lipopeptide nature of the compound with masses around 645 and 746 Da. The SAB obtained from Salibacterium sp. 4CTb may be suitable for electrical, food, pharmaceutical and cosmetic industries, agriculture, and environmental applications, among others.
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