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1.
Pharmacol Res ; 202: 107130, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38447748

RESUMEN

Pharmacology has broadened its scope considerably in recent decades. Initially, it was of interest to chemists, doctors and pharmacists. In recent years, however, it has been incorporated into the teaching of biologists, molecular biologists, biotechnologists, chemical engineers and many health professionals, among others. Traditional teaching methods, such as lectures or laboratory work, have been superseded by the use of new pedagogical approaches to enable a better conceptualization and understanding of the discipline. In this article, we present several new methods that have been used in Spanish universities. Firstly, we describe a teaching network that has allowed the sharing of pedagogical innovations in Spanish universities. A European experience to improve prescribing safety is described in detail. The use of popular films and medical TV series in biomedical students shows how these audiovisual resources can be helpful in teaching pharmacology. The use of virtual worlds is detailed to introduce this new approach to teaching. The increasingly important area of the social aspects of pharmacology is also considered in two sections, one devoted to social pharmacology and the other to the use of learning based on social services to improve understanding of this important area. Finally, the use of Objective Structured Clinical Evaluation in pharmacology allows to know how this approach can help to better evaluate clinical pharmacology students. In conclusion, this article allows to know new pedagogical methods resources used in some Spanish universities that may help to improve the teaching of pharmacology.


Asunto(s)
Farmacología Clínica , Farmacología , Humanos , Aprendizaje , Farmacología Clínica/educación , Personal de Salud , Farmacología/educación
2.
Astrobiology ; 22(7): 800-811, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35639110

RESUMEN

Samples of α-glycine (α-GLY; 230-350 nm) were irradiated in laboratory as a function of electron beam energies (0.25, 0.50, and 1.00 keV) at room temperature (293-295 K). The evolution of α-glycine irradiation process was monitored in real time by infrared spectroscopy (Fourier transform infrared - FTIR), through specific spectral bands: 2610, 2124, 1410, and 1333 cm-1. A phenomenological model is proposed to describe the column density decay when thick organic samples are processed by ionizing beams. The α-glycine radiolysis has exhibited transient and stationary modes in such thickness films. The first stage is mainly described by one exponential decay, whereas the latter foremost decays linearly; compaction processes have been neglected; glycine dissociation and sputtering processes are assumed to be responsible for the damage caused by the electron beam impact through the solid film. The second (stationary) stage is due to equilibrium between a partially shielded bulk radiolysis and sputtering of protective layers. The decay rates are measured for the transient and stationary modes and allow determining the processing velocity of the samples as a function of the electron beam energy. Finally, the model is applied to space weathering to find out the typical sputtering rate of organic compounds on the surface of astrophysical analogs with no protection layers attacked by solar wind (SW) electrons at ≈1 AU. Although the velocity of processing materials in SW has natural competing effects, such as regolith overturn by impacts of micro- and macrometeorites and downslope motion of material that is unstable due to changes in the geopotential of the airless bodies (e.g., asteroid 101955 Bennu), these competing processes are not included in the simulations presented here.


Asunto(s)
Electrones , Tiempo (Meteorología) , Glicina , Espectrofotometría Infrarroja
4.
J Acoust Soc Am ; 150(5): 3914, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34852606

RESUMEN

Two residual networks are implemented to perform regression for the source localization and environment classification using a moving mid-frequency source, recorded during the Seabed Characterization Experiment in 2017. The first model implements only the classification for inferring the seabed type, and the second model uses regression to estimate the source localization parameters. The training is performed using synthetic data generated by the ORCA normal mode model. The architectures are tested on both the measured field and simulated data with variations in the sound speed profile and seabed mismatch. Additionally, nine data augmentation techniques are implemented to study their effect on the network predictions. The metrics used to quantify the network performance are the root mean square error for regression and accuracy for seabed classification. The models report consistent results for the source localization estimation and accuracy above 65% in the worst-case scenario for the seabed classification. From the data augmentation study, the results show that the more complex transformations, such as time warping, time masking, frequency masking, and a combination of these techniques, yield significant improvement of the results using both the simulated and measured data.

5.
Bull Environ Contam Toxicol ; 105(1): 86-94, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32577782

RESUMEN

The distribution, seasonal variation and sources of 16 polycyclic aromatic hydrocarbons (PAH) from suspended particulate matter (SPM) of the Aurá River, a small amazon typical river located in Northern Brazil, were determined. Gas chromatography-mass spectrometry analysis of SPM revealed a mixture of PAH from different origins and a seasonal variation of PAH primary source for the studied area. Pyrene was the dominant PAH in both studied periods. Total PAH content (ΣPAH) ranged from lower than quantification limit (< LOQ) to 2498.2 ng g-1 dw during the dry season and < LOQ to 2865.8 ng g-1 dw during the wet season. Low molecular weight PAH (LMW) represented 51% of ΣPAH during the dry season and 29% during the wet season. It was noted, by comparing previous data, that the main source of these compounds was altered after the deactivation of an irregular landfill next to the river.


Asunto(s)
Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Brasil , China , Cromatografía de Gases y Espectrometría de Masas , Sedimentos Geológicos/química , Material Particulado/análisis , Pirenos , Ríos/química , Estaciones del Año , Urbanización
6.
Data Brief ; 30: 105597, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32382609

RESUMEN

The data shown in this document provides all the experimental data that complement the article published in Carbohydrate Polymers entitled "Influence of operating conditions on Proton Conductivity of Nanocellulose films using two Agroindustrial Wastes: Sugarcane Bagasse and Pinewood Sawdust" [1]. The data of this paper are the result of a large series of experiments to optimize the extraction of cellulose nanocrystalline (CNC) from these two agro-industrial wastes: sugarcane Bagasse (SCB) and pinewood sawdust (PSW). The conditions of pretreatment (5 wt.% or 10 wt.% of NaOH) and hydrolysis temperature (60, 75 and 90°C) in an aqueous solution of 45 wt.% of H2SO4 were analyzed exhaustively. The data includes the characterization by Fourier transform infrared (FT-IR), Differential Scanning Calorimetry/Thermogravimetric Analysis (DSC/TGA), Dynamic Light Scattering (DLS), X-ray diffraction (XRD) patterns, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) micrographs with their corresponding SAED patterns and nanoindentation tests. Additionally, photographs during the isolation of cellulose nanocrystalline in dependence of the syntheses parameters. It is also included the data that complement the molecular dynamic simulation generated by GLYCAM carbohydrate builder based on the coordinates for alpha and beta cellulose considering a microfibril of 5, 10 and 20 glucosyl residues (degree of polymerization, DP). Overall data have not been previously published and are available contributing to a better understanding of the CNCs isolation through different pretreatment concentrations and temperatures of processing.

7.
Carbohydr Polym ; 238: 116171, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32299564

RESUMEN

Cellulose nanocrystals (CNCs) were isolated from two-agroindustrial wastes: sugarcane bagasse (SCB) and pinewood sawdust (PWS), to analyze their chemical, structural, morphological, and proton conduction properties in dependence of the synthesis parameters. In both sources, the isolated CNCs correspond to the monoclinic phase of cellulose type I and II. For SCB, the smallest CNCs were isolated, in a range of 3-10 nm, with 5 wt.% of NaOH and 60 °C of acid hydrolysis. PWS displayed the smallest sizes at 75 °C and 10 wt.% NaOH (40-110 nm). Membrane characterization suggests that isolated CNCs, between 75 and 90 °C of acid hydrolysis and 10 wt.% NaOH from both SCB and PWS sources, displayed an important increase in the proton conductivity, 1.23(±0.61)×10-5 and 9.26 (±0.24)×10-5 S-m-1, respectively. Thus, with proper synthesis conditions, CNCs can be potentially used as based element to obtain other proton conductor materials to fabricate PEMs.

8.
Data Brief ; 24: 104026, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31193984

RESUMEN

The treatment of agroindustrial residues is an alternative to waste management and obtain products with added value. In this article, we describe the confocal microscopy images, the microbiological data, policosanol content and color measurement linked to the paper "production of dietary fibers from sugarcane bagasse and sugarcane tops using microwave - assisted alkaline treatments". The data contain photographs after elaboration of noodles-type pasta and chapatti-type fermented bread; the confocal laser scanning micrographs, before and after including sugarcane bagasse and sugarcane tops fibers in foods. Microbiological analyses of total coliforms, molds and yeasts, and aerobic mesophiles were also presented according to Mexican Standard NOM- 247-SSA1-2008 which confirmed that the food is safe for human consumption. The data provided in this article have not been previously published and are available to enable critical or extended analyses.

9.
Astrobiology ; 19(9): 1123-1138, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31084501

RESUMEN

Glycine is an amino acid that has already been detected in space. It is relevant to estimate its resistance under cosmic radiation. In this way, a sublimate of glycine in α-form on KBr substrate was exposed in the laboratory to a 1.0 keV electron beam. The radiolysis study was performed at 40 K, 80 K, and 300 K sample temperatures. These temperatures were chosen to cover characteristics of the outer space environment. The evolution of glycine compaction and degradation was monitored in real time by infrared spectroscopy (Fourier-transform infrared) by investigation in the spectral ranges of 3500-2100, 1650-1200, and 950-750 cm-1. The compaction cross-section increases as the glycine temperature decreases. The glycine film thickness layer of ∼160 nm was depleted completely after ∼15 min at 300 K under irradiation with ∼1.4 µA beam current on the target, whereas the glycine depletion at 40 K and 80 K occurred after about 4 h under similar conditions. The destruction cross-section at room temperature is found to be (13.8 ± 0.2) × 10-17 cm2, that is, about 20 times higher than the values for glycine depletion at lower temperatures (<80 K). Emerging and vanishing peak absorbance related to OCN- and CO bands was observed in 2230-2100 cm-1 during the radiolysis at 40 K and 80 K. The same new IR bands appear in the range of 1600-1500, 1480-1370, and 1350-1200 cm-1 after total glycine depletion for all temperature configurations. A strong N-H deformation band growing at 1510 cm-1 was observed only at 300 K. Finally, the destruction cross-section associated to tholin decay at room temperature is estimated to be (1.30 ± 0.05) × 10-17 cm2. In addition, a correlation between the formation cross-sections for daughter and granddaughter molecules at 300 K is also obtained from the experimental data.


Asunto(s)
Electrones , Glicina/efectos de la radiación , Temperatura , Cristalografía por Rayos X , Glicina/química , Espectroscopía Infrarroja por Transformada de Fourier , Factores de Tiempo
11.
Brain Inj ; : 1-9, 2018 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-30388898

RESUMEN

OBJECTIVES: The Montreal Cognitive Assessement (MoCA) is a brief and standardized cognitive screening tool that has been used with several clinical populations. The aim of this study was to screen the early cognitive status of patients following mild traumatic brain injury (mTBI) with the MoCA. METHODS: The MoCA was administered within the first 2 weeks post-injury to 42 patients with uncomplicated mTBI, 92 patients with complicated mTBI and 50 healthy controls. RESULTS: Patients with complicated mTBI had a significantly lower performance (more impairments) on the total score of the MoCA than both the group with uncomplicated mTBI and the control group. Also, the group with uncomplicated mTBI had a significantly lower performance than controls. Moreover, age, education and TBI severity had a significant effect on the MoCA total score where younger, more educated and patients with less severe (higher GCS score) mTBI performed significantly better. CONCLUSIONS: The MoCA may be clinically useful to acutely screen cognition following mTBI.

12.
Anaesthesia ; 73(11): 1368-1371, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30151989

RESUMEN

It is unclear whether the time of day for emergency surgery is associated with postoperative mortality. We assessed this association in 9319 patients who had emergency surgery as their first surgery at the Jewish General Hospital, Montreal, QC, Canada from April 2010 to March 2015. Of the 7362 (80%) patients with complete data, 168 (2.3%) died within 30 postoperative days. There was no significant association of time of day with postoperative mortality, with adjusted OR (95%CI) of 1.61 (0.96-2.72) for night vs. day, p = 0.07; 1.29 (0.78-2.13) for night vs. evening, p = 0.33; and 1.26 (0.89-1.78) for evening vs. day, p = 0.20. Studies of more patients and more factors, with longer follow-up, should be carried out to exclude important associations of time of emergency surgery with postoperative mortality and morbidity.


Asunto(s)
Mortalidad Hospitalaria , Complicaciones Posoperatorias/mortalidad , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Quebec/epidemiología , Factores de Riesgo , Factores de Tiempo
13.
EJVES Short Rep ; 36: 5-8, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29296682

RESUMEN

OBJECTIVE/BACKGROUND: This study is a case report that addresses the key aspects of vascular reconstruction, as well as the intraoperative complications, postoperative morbidity, and possibility of adjunctive therapy. METHODS: This article reports the case of a 46 year old female patient with a leiomyosarcoma located in the middle segment of the inferior vena cava (between the renal and hepatic veins) who underwent surgical resection with vena cava reconstruction and insertion of a tubular graft made of a synthetic material. RESULTS: This case report reveals that surgical resection of the tumor with the insertion of a smaller-caliber tubular graft provide better patency of the vena cava reconstruction, which was maintained for a year after surgery. In addition, the patient was asymptomatic for lower limb edema, despite having a local recurrence after one year. Surgical resection is the treatment of choice for leiomyosarcoma of the inferior vena cava (LIVC) and is the only therapy that offers a chance of cure. Several surgical techniques are used for this condition, especially, reconstruction with a vascular graft using natural or synthetic materials. CONCLUSION: Due to the aggressiveness of the disease, this study suggests that surgical intervention used may have no influence on a patient's survival outcome. However, vascular reconstruction with a smaller-caliber tubular graft may yield a better prognosis for patients in terms of postoperative symptoms, such as edema and thrombosis.

14.
Rev Calid Asist ; 31(2): 84-98, 2016.
Artículo en Español | MEDLINE | ID: mdl-26597029

RESUMEN

OBJECTIVE: Describe the inappropriate prescription to polymedicated patients over 65 years old in rural areas. MATERIAL AND METHOD: An observational, descriptive, cross-sectional study conducted in health care units in the Guadalhorce Valley, a rural area of Malaga, Spain. The district has a catchment population of about 144,993 inhabitants. This study is focused on the population that is older than 65 years, and who use 10 or more medications (4.344 patients). The study has as a primary variable: the rates of inappropriate prescription. These are classified using the Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) criteria, as well as the criteria of the strategy of the approach to polymedicated of the Andalusian Health System. An application was used to create individualised forms that identified inappropriate prescribing criteria. For each patient, we used variables, such as the unit, drug group, medications, dose, and use of the STOPP and Andalusian Health System criteria were recorded for each patient. RESULTS: More than one-third (35.5%) of all patients have inappropriate prescription, according to STOPP criteria, related to some health problem (direct problems). The large majority (94%) have potentially inappropriate prescription according to the criteria of the Andalusian Health System. If the criteria directly related to prescribing medication for people over 65 (general) is taken into account, 100% of patients have some form of inappropriate or potentially inappropriate prescribing. CONCLUSIONS: The prevalence of polypharmacy and inappropriate prescription is a real problem in the population over 65 years old. An informatics tool provides us with the facilities to identify and approach inappropriate prescribing.


Asunto(s)
Prescripción Inadecuada , Polifarmacia , Salud Rural , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Prescripción Inadecuada/prevención & control , Masculino , Prevalencia , España
15.
Skin Res Technol ; 22(3): 263-75, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26333046

RESUMEN

BACKGROUND: The clinical use of non-invasive instrumentation to evaluate skin characteristics for diagnostic purposes and to evaluate treatment outcomes has become more prevalent. The purpose of this study was to generate normative data for skin elasticity, erythema (vascularity), melanin (pigmentation), and thickness across a broad age range at a wide variety of anatomical locations using the Cutometer(®) (6 mm probe), Mexameter(®) , and high-frequency ultrasound in a healthy adult sample. METHODS: We measured skin characteristics of 241 healthy participants who were stratified according to age and gender. Sixteen different anatomical locations were measured using the Cutometer(®) for maximum skin deformation, gross elasticity, and biological elasticity, the Mexameter(®) for erythema and melanin, and high-frequency ultrasound for skin thickness. Standardized measurement procedures were applied for all participants. RESULTS: The means and standard deviations for each measured skin characteristic for females and males across five different age groups (20-29, 30-39, 40-49, 50-59, 60-69, and 70-85 years old) are presented. As previously described, there were variations in skin characteristics across age groups, anatomical locations, and between females and males highlighting the need to use site specific, age and gender matched data when comparing skin characteristics. CONCLUSION: The reported data provides normative data stratified by anatomical location, age, and gender that can be used by clinicians and researchers to objectively determine whether patients' skin characteristics vary significantly from healthy subjects.


Asunto(s)
Envejecimiento/fisiología , Módulo de Elasticidad/fisiología , Eritema/fisiopatología , Melaninas/metabolismo , Fenómenos Fisiológicos de la Piel , Piel/anatomía & histología , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/patología , Simulación por Computador , Eritema/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Caracteres Sexuales
16.
Pituitary ; 19(2): 202-9, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26700946

RESUMEN

PURPOSE: Prolactin can affect autoimmune response and evidence suggests that hyperprolactinemia can primarily precipitate autoimmunity. We postulate that patients with prolactinomas are more prone to autoimmune disease (AID). METHODS: We conducted a retrospective case-control study comparing prevalence of AID in 100 prolactinoma patients (PRL-P, cases) and 100 age- and gender-matched non-functioning pituitary adenoma patients (NFPA-P, controls) assessed at the Neuroendocrine Clinics of the McGill University Health Centre between January 2005 and December 2014. Comparisons were done using a conditional logistic regression (CLR) analysis. Multiple imputation was used to account for missing data values. RESULTS: Sixty-eight women and 32 men were in each group. Median age was 37 years for PRL-P and 46 years for NFPA-P. AID was diagnosed in 28/100 cases and 16/100 controls. Autoimmune thyroid disease was the most common AID reported in both groups, representing 70 and 61% of the AID diagnoses respectively. CLR analysis revealed a multiplicative interaction effect between AID prevalence and age (p 0.004). Odds ratios for AID in PRL-P compared to NFPA-P increase with age and become significant at age 43, reaching 4.17 (95% CI 1.26, 13.82) at age 45 and 8.09 (95% CI 1.96, 33.43) at age 50 (p 0.05). CONCLUSION: Our data showed a higher prevalence of AID in both PRL-P and NFPA-P than in a reference population. In both groups, prevalence of AID increased with age, given a multiplicative interaction effect. A significant higher prevalence of autoimmunity in PRL-P compared with NFPA-P occurs after age 43. These associations may have significant implications for the management of prolactinoma patients.


Asunto(s)
Adenoma/epidemiología , Enfermedades Autoinmunes/epidemiología , Neoplasias Hipofisarias/epidemiología , Prolactinoma/epidemiología , Adenoma/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades Autoinmunes/complicaciones , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Hipofisarias/complicaciones , Prevalencia , Prolactinoma/complicaciones , Estudios Retrospectivos , Adulto Joven
17.
J Nutr Biochem ; 26(5): 549-55, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25725506

RESUMEN

The aim of the present study was to determine the role of the catechol group in the antioxidant and neuroprotective effects of minor components of virgin olive oil in rat brain tissue. Hydroxytyrosol ethyl ether (HT, 2 OH), tyrosol ethyl ether (Ty, 1 OH) and 3,4-di-ortho-methylidene-hydroxytyrosol ethyl ether (MET, no OH) were compared. Oxidative stress was induced with ferrous salts (lipid peroxidation induction), diethylmaleate (depletion of glutathione) and hypoxia-reoxygenation in brain slices. Lipid peroxidation was inhibited in direct proportion to the number of OH groups: HT>Ty>MET. Exposure to HT led to partial recovery of the glutathione system after chemical inhibition or hypoxia-reoxygenation. All three compounds inhibited cell death in hypoxia-reoxygenation experiments (HT≥Ty>MET). Peroxynitrite formation (3-nitrotyrosine) and inflammatory mediators (prostaglandin E2 and interleukin 1ß) were inhibited by all three compounds. In conclusion, the presence of OH groups in the molecule of these phenolic compounds from virgin olive oil is a determinant factor in their antioxidant effect in brain tissue, but this antioxidant effect is not the only explanation for their neuroprotective effect.


Asunto(s)
Encéfalo/efectos de los fármacos , Catecoles/farmacología , Fármacos Neuroprotectores/farmacología , Aceite de Oliva/química , Animales , Encéfalo/metabolismo , Muerte Celular/efectos de los fármacos , Masculino , Nitrosación , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Wistar
18.
Heredity (Edinb) ; 114(2): 185-94, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25227258

RESUMEN

The link between life history traits and mating systems in diploid organisms has been extensively addressed in the literature, whereas the degree of selfing and/or inbreeding in natural populations of haploid-diploid organisms, in which haploid gametophytes alternate with diploid sporophytes, has been rarely measured. Dioecy has often been used as a proxy for the mating system in these organisms. Yet, dioecy does not prevent the fusion of gametes from male and female gametophytes originating from the same sporophyte. This is likely a common occurrence when spores from the same parent are dispersed in clumps and recruit together. This pattern of clumped spore dispersal has been hypothesized to explain significant heterozygote deficiency in the dioecious haploid-diploid seaweed Chondrus crispus. Fronds and cystocarps (structures in which zygotes are mitotically amplified) were sampled in two 25 m(2) plots located within a high and a low intertidal zone and genotyped at 5 polymorphic microsatellite loci in order to explore the mating system directly using paternity analyses. Multiple males sired cystocarps on each female, but only one of the 423 paternal genotypes corresponded to a field-sampled gametophyte. Nevertheless, larger kinship coefficients were detected between males siring cystocarps on the same female in comparison with males in the entire population, confirming restricted spermatial and clumped spore dispersal. Such dispersal mechanisms may be a mode of reproductive assurance due to nonmotile gametes associated with putatively reduced effects of inbreeding depression because of the free-living haploid stage in C. crispus.


Asunto(s)
Chondrus/genética , Células Germinativas de las Plantas/crecimiento & desarrollo , Chondrus/fisiología , Diploidia , Genética de Población , Genotipo , Haploidia , Homocigoto , Endogamia , Datos de Secuencia Molecular , Reproducción/genética
19.
Aquat Toxicol ; 150: 220-8, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24704518

RESUMEN

The brown alga Dictyota kunthii is one of the dominant species in the coastal areas of northern Chile affected by copper enrichment due to accumulated mining wastes. To assess its physiological plasticity in handling copper-mediated oxidative stress, 4-days copper exposure (ca. 100 µg/L) experiments were conducted with individuals from a copper impacted area and compared with the responses of plants from a non-impacted site. Several biochemical parameters were then evaluated and compared between populations. Results showed that individuals from the copper-impacted population normally displayed higher levels of copper content and antioxidant enzymes activity (catalase (CAT), ascorbate peroxidase (AP), dehydroascorbate reductase (DHAR), glutathione peroxidase (GP) and peroxiredoxins (PRX)). After copper exposure, antioxidant enzyme activity increased significantly in plants from the two selected sites. In addition, we found that copper-mediated oxidative stress was associated with a reduction of glutathione reductase (GR) activity. Moreover, metabolic profiling of extracellular metabolites from both populations showed a significant change after plants were exposed to copper excess in comparison with controls, strongly suggesting a copper-induced release of metabolites. The copper-binding capacity of those exudates was determined by anodic stripping voltammetry (ASV) and revealed an increased ligand capacity of the medium with plants exposed to copper excess. Results indicated that D. kunthii, regardless their origin, counteracts copper excess by various mechanisms, including metal accumulation, activation of CAT, AP, DHAR, GP and PRX, and an induced release of Cu binding compounds. Thus, plasticity in copper tolerance in D. kunthii seems constitutive, and the occurrence of a copper-tolerant ecotype seems unlikely.


Asunto(s)
Cobre/toxicidad , Phaeophyceae/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Activación Enzimática/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Oxidorreductasas/metabolismo , Phaeophyceae/fisiología
20.
Appl Biochem Biotechnol ; 172(3): 1663-72, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24242163

RESUMEN

Atmospheric pressure O2 plasma was used to produce ozone in order to treat sugarcane bagasse as a function of particle sizes. The fixed bagasse moisture content was 50%. The delignification efficiency had small improvement due to ozonation process as a function of particle size, varying from 75 up to 80%. Few amounts of hemicellulose were removed, but the ozonation has not been affected significantly with particle size variance as well (from 30 up to 35%). The cellulose presented some losses below 1.0 mm size (8-15%) which was an unexpected result. The conversion of cellulose content into free sugar has shown a significant increase as the particle size has diminished as well. The best condition of the bagasse particle size was for 0.08 mm. For this case, a great quantity of cellulose (78.8%) was converted into glucose. Optical absorption spectroscopy was applied to determine ozone concentrations in real time where the samples with typical bagasse particle sizes equal or below to 0.5 mm had shown a better absorption of ozone in comparison with greater particle size samples.


Asunto(s)
Celulosa/química , Ozono/química , Saccharum/enzimología , Presión Atmosférica , Biomasa , Tamaño de la Partícula , Plasma/química
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