36 research outputs found

    Influencia de la velocidad de carga orgánica sobre el proceso de digestión anaerobia de aguas de lavado de aceitunas de almazara en reactores de lecho fluidizado

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    A study of the anaerobic digestion process of wastewaters from the washing of olives prior to the oil production process was carried out in a fluidized bed reactor with sepiolite immobilised biomass at 35°G. The bioreactor worked satisfactorily using Influent COD concentrations of 4.5,3.5,2.5 and 1.5 g COD/I for a hydraulic retention time (HRT) range of 4.5 to 1,25 days. COD removal efficiencies in the range 50-90% were achieved in the reactor, when evaluated at organic loading rates of between 0.46 and 2.25 g COD/I day using the highest influent substrate concentration (So = 4.5 g COD/I). COD and volatile fatty acid (VFA) concentration were Increased In parallel with the increase of organic loading rate in the reactor, VFA concentration showing a maximum value of 1.55 g acetic acid/I at the most unfavourable case studied (So = 4,5 g COD/I and HRT = 1.25 days). The increase in effluent VFA concentrations was always counteracted by the high alkalinity values (3440-4670 mg CaCO3/l) which brought about the high stability of the process and values of the alkalinity/VFA ratio lower than 0.3-0.5, except for the above-mentioned case, limit value over which the anaerobic process is destabilized. The yield coefficient of methane production was 0.281 methane STP/g COD removed.Se ha efectuado un estudio del proceso de digestión anaerobia en régimen continuo de aguas de lavado de aceitunas de almazara en un reactor de lecho fluidizado utilizando sepiolita como soporte de adhesión bacteriana a la temperatura de 35°C. El biorreactor operó de modo satisfactorio utilizando concentraciones de alimento de 4,5, 3,5, 2,5, y 1,5 g DQO/I en un rango de 4,5 a 1,25 días de tiempo de retención hidráulico (TRH). Se han obtenido porcentajes de eliminación de DQO entre el 50 y el 90% para velocidades de carga orgánica variables entre 0,46 y 2,25 g DQO/I día utilizando la concentración de alimento más elevada (So = 4,5 g DQO/I). La DQO y acidez volátil de los efluentes se incrementaron de forma paralela al aumentar la velocidad de carga orgánica en el reactor, presentando esta última un máximo valor de 1,55 g ácido acético/1 en el caso más desfavorable estudiado (So = 4,5 g DQO/I y TRH = 1,25 días). La subida de acidez volátil fue contrarrestada en todo momento por los elevados valores de alcalinidad (3440-4670 mg CaCO3/l) lo que determinó una alta estabilidad del proceso y que la relación acidez volátil/alcalinidad se mantuviera, salvo en el caso mencionado, por debajo del valor límite 0,3-0,4, por encima del cual el proceso anaerobio se desestabiliza. El coeficiente de rendimiento de producción en metano del proceso fue de 0,281 metano STP/g DQO eliminada

    Estudio cinético del proceso de digestión anaerobia de aguas de lavado de aceitunas de almazara en reactores de mezcla completa con microorganismos inmovilizados

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    A kinetic study of the continuous anaerobic digestion process of wastewaters from the washing of olives prior to the oil production process was carried out in a completely mixed reactor with sepiolite immobilised biomass at 35° C. Four influent COD concentrations, 4,5, 3,5, 2,5 y 1,5 g COD/I were used as substrate operating for a hydraulic retention time range of 4,5 to 1,25 days. The Michaelis-Menten model has been applied, obtaining the values of the maximum substrate utilization rate, k( (g COD/g VSS day), and the kinetic constant of the process, Ks (g COD/I), for each influent substrate concentration studied. The values of these parameters significantly decreased with decreasing concentration of influent wastewater, showing the highest values for the greatest influent substrate concentration used as feed. The microbial yield coefficient, Yx, and sludge decay rate coefficient, kd, were also determined to be 0,14 g VSS/g COD and 0,003 days-1 respectively.Se ha efectuado un estudio cinético del proceso de digestión anaerobia en régimen continuo de aguas de lavado de aceitunas de almazara en un reactor de mezcla completa utilizando sepiolita como soporte para la inmovilización de los microorganismos responsables del proceso, a la temperatura de 35° C. Se utilizan cuatro concentraciones de sustrato como alimento, 4,5, 3,5, 2,5 y 1,5g DQO/I, operando con cada una de ellas en un rango de tiempos de retención hidráulicos de 4,5 a 1,25 días. Para ello, se aplica el método cinético de Michaelis-Menten, obteniéndose los valores de la velocidad máxima de utilización de sustrato, k(g DQO/g SSV día), y de la constante cinética del proceso, Ks (g DQO/I), para cada concentración de sustrato objeto de estudio. Se observa que estas constantes cinéticas disminuyen de forma significativa al disminuir la concentración de sustrato en el alimento, presentando los valores más elevados para la mayor concentración utilizada. Los coeficientes de producción celular, Yx, y de muerte microbiana, kd, fueron 0,14 g SSV/g DQO y 0,003 días-1 respectivamente

    Detection of Changes on Parameters Related to Heart Rate Variability after Applying Current Interferential Therapy in Subjects with Non-Specific Low Back Pain

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    Interferential current therapy (ICT) is an electrotherapeutic intervention that combines the advantages of high permeability from middle frequency currents and efficient tissue stimulation from low frequency currents, delivering the maximum current with high tissue permeability. The aim was to evaluate the effects of ICT on heart rate variability (HRV) and on pain perception in patients with non-specific chronic low back pain (NSCLBP). In the study, 49 patients with NSCLBP were randomly divided into an experimental (EG) and a sham group (SG). All participants received a single intervention, ICT, or simulated intervention. Outcome measures including baseline (sit-down position) and postintervention (prone position) pain, heart rate (HR), time domain parameter (rMSSD), diameters of the Poincaré plot (SD1, SD2), stress score (SS), and sympathetic/parasympathetic (S/PS) ratio were investigated. In both groups, significant statistical differences were found in perceived pain and in all HRV parameters except in HRmax. Between-group comparisons showed statistically significant differences in all variables except for HRmin and HRmean in favor of the experimental group. These changes reported an increase in parasympathetic activity (rMSSD) (p < 0.05) and a decrease in sympathetic activity (increase in SD2 and decrease in SS) (p < 0.001) and perceived pain (p < 0.001), with a greater size effect (η2 = 0.44) in favor of the experimental group. In conclusion, a single session of ICT can shift the autonomic balance towards increase parasympathetic dominance and decrease the sympathetic dominance and intensity of pain perceived by patients with NSCLBP

    Molecular study of drought response in the Mediterranean conifer Pinus Pinaster Ait. : differential transcriptomic profiling reveals constitutive water deficit‐independent drought tolerance mechanisms

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    Adaptation of long‐living forest trees to respond to environmental changes is essential to secure their performance under adverse conditions. Water deficit is one of the most significant stress factors determining tree growth and survival. Maritime pine (Pinus pinaster Ait.), the main source of softwood in southwestern Europe, is subjected to recurrent drought periods which, according to climate change predictions for the years to come, will progressively increase in the Mediterranean region. The mechanisms regulating pine adaptive responses to environment are still largely unknown. The aim of this work was to go a step further in understanding the molecular mechanisms underlying maritime pine response to water stress and drought tolerance at the whole plant level. A global transcriptomic profiling of roots, stems, and needles was conducted to analyze the performance of siblings showing contrasted responses to water deficit from an ad hoc designed full‐sib family. Although P. pinaster is considered a recalcitrant species for vegetative propagation in adult phase, the analysis was conducted using vegetatively propagated trees exposed to two treatments: well‐watered and moderate water stress. The comparative analyses led us to identify organ‐specific genes, constitutively expressed as well as differentially expressed when comparing control versus water stress conditions, in drought‐sensitive and drought‐tolerant genotypes. Different response strategies can point out, with tolerant individuals being pre‐adapted for coping with drought by constitutively expressing stress‐related genes that are detected only in latter stages on sensitive individuals subjected to drought

    Clinical and ultrasound thyroid nodule characteristics and their association with cytological and histopathological outcomes: A retrospective multicenter study in high-resolution thyroid nodule clinics

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    Introduction: Thyroid nodules are a common finding. A high-resolution thyroid nodule clinic (HR-TNC) condenses all tests required for the evaluation of thyroid nodules into a single appointment. We aimed to evaluate the clinical outcomes at HR-TNCs. Design and Methods: A retrospective cross-sectional multicenter study including data from four HR-TNCs in Spain. We evaluated fine-needle aspiration (FNA) indications and the association between clinical and ultrasound characteristics with cytological and histopathological outcomes. Results: A total of 2809 thyroid nodules were included; FNA was performed in 82.1%. Thyroid nodules that underwent FNA were more likely larger, isoechoic, with microcalcifications, and in younger subjects. The rate of nondiagnostic FNA was 4.3%. A solid component, irregular margins or microcalcifications, significantly increased the odds of Bethesda IV-V-VI (vs. Bethesda II). Irregular margins and a solid component were independently associated with increased odds of malignancy. Thyroid nodules <20 mm and ≥20–<40 mm had a 6.5-fold and 3.3-fold increased risk for malignancy respectively in comparison with those ≥40 mm. Conclusion: In this large multicenter study, we found that the presence of a solid component and irregular margins are factors independently related to malignancy in thyroid nodules. Since nodule size ≥40 mm was associated with the lowest odds of malignancy, this cut-off should not be a factor leading to indicate thyroid surgery. HR-TNCs were associated with a low rate of nondiagnostic FNA

    Mediterranean Diet and its Effects on Silent Brain Infarcts in a Cohort of Patients With Atrial Fibrillation

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    [Background and Aims] The benefits of Mediterranean Diet (MeDiet) in prevention of cardiovascular diseases (CVD) in general and ischemic stroke (IS) have been extensively studied and reported. We hypothesize that the consumption of nutrients typical of MeDiet would also reduce the rate of silent brain infarcts (SBI) among AF patients.[Methods and Results] Patients with a history of AF who scored 0 to 1 in the CHADS2 score, ⩾50 years and with absence of neurological symptoms were selected from Seville urban area using the Andalusian electronic healthcare database. A 3T brain MRI was performed to all participants. Demographic and clinical data and food-frequency questionnaire (FFQ) were collected. Of the 443 scanned patients, 66 presented SBI. Of them 52 accepted to be scheduled for a clinical visit and were included in the diet sub study and 41 controls were matched per age and sex. There were no statistically significant differences in baseline characteristics. After logistic regression analysis, we found that a higher consumption of fiber from fruit was independently associated with a lower risk of SBI, while a higher consumption of high glycemic load (GL) foods was associated with a higher risk of SBI in a population with AF[Conclusion] Our findings support that MeDiet could be suggested as a prevention strategy for SBI in patients with AF.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The Spanish Ministry of Economy, Industry and Competitiveness (grant RTC-2016 5300-1), the Junta de Andalucía (grant PIN-0144-2016) and Neuroprotección Avanzada Reposicionando Drogas y Nutraceúticos para el Ictus en Andalucía: Proyecto NARDNIA (PE-0527-2019), the European Project ITRIBIS (registration number REGPOT-2013-1), and Cooperative Cerebrovascular Disease Research Network (INVICTUS+, RD16/0019/0015) supported the study. The Fundación Cajasol also contributed to the study.Peer reviewe

    Kinetic study of anaerobic digestion of wastewaters from the washing of olives prior to the oil production process in a completely mixed reactor with immobilised microorganisms

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    7 páginas, 3 figuras, 2 tablas.-- Articulo de investigación.[ES] Se ha efectuado un estudio cinético del proceso de digestión anaerobia en régimen continuo de aguas de lavado de aceitunas de almazara en un reactor de mezcla completa utilizando sepiolita como soporte para la inmovilización de los microorganismos responsables del proceso, a la temperatura de 35° C. Se utilizan cuatro concentraciones de sustrato como alimento, 4,5,3,5, 2,5 y 1,5g DQO/I, operando con cada una de ellas en un rango de tiempos de retención hidráulicos de 4,5 a 1,25 días. Para ello, se aplica el método cinético de Michaelis-Menten, obteniéndose los valores de la velocidad máxima de utilización de sustrato, /c(g DQO/g SSV día), y de la constante cinética del proceso, Ks (g DQO/I), para cada concentración de sustrato objeto de estudio. Se observa que estas constantes cinéticas disminuyen de forma significativa al disminuir la concentración de sustrato en el alimento, presentando los valores más elevados para la mayor concentración utilizada. Los coeficientes de producción celular, Yx, y de muerte microbiana, Ad, fueron 0,14 g SSV/g DQO y 0,003 días'\ respectivamente.[EN] A kinetic study of the continuous anaerobic digestion process of wastewaters from the washing of olives prior to the oil production process was carried out in a completely mixed reactor with sepiolite immobilised biomass at 35° C. Four influent COD concentrations, 4,5, 3,5, 2,5 y 1,5 g COD/I were used as substrate operating for a hydraulic retention time range of 4,5 to 1,25 days. The Michaelis-Menten model has been applied, obtaining the values of the maximum substrate utilization rate, k (g COD/g VSS day), and the kinetic constant of the process, Ks (g COD/I), for each influent substrate concentration studied. The values of these parameters significantly decreased with decreasing concentration of influent wastewater, showing the highest values for the greatest influent substrate concentration used as feed. The microbial yield coefficient, Yx, and sludge decay rate coefficient, Ad, were also determined to be 0,14 g VSS/g COD and 0,003 days"\ respectively.Queremos hacer constar nuestro agradecimiento a la Unión Europea (Proyecto AIR3-CT94-1355) y a la Junta de Andalucía por su ayuda para la realización de estos estudios.Peer reviewe

    Effect of organic loading rate on anaerobic digestion process of wastewaters from the washing of olives prior to the oil production process in a f luidized bed reactor

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    8 páginas, 7 figuras, 4 tablas.[ES] Se ha efectuado un estudio del proceso de digestión anaerobia en régimen continuo de aguas de lavado de aceitunas de almazara en un reactor de lecho fluidizado utilizando sepiolita como soporte de adhesión bacteriana a la temperatura de 35°C. El biorreactor operó de modo satisfactorio utilizando concentraciones de alimento de 4,5, 3,5, 2,5, y 1,5 g DQO/I en un rango de 4,5 a 1,25 días de tiempo de retención hidráulico (TRH). Se han obtenido porcentajes de eliminación de DQO entre el 50 y el 90% para velocidades de carga orgánica variables entre 0,46 y 2,25 g DQO/I día utilizando la concentración de alimento más elevada (So = 4,5 g DQO/I). La DQO y acidez volátil de los efluentes se incrementaron de forma paralela al aumentar la velocidad de carga orgánica en el reactor, presentando esta última un máximo valor de 1,55 g ácido acético/1 en el caso más desfavorable estudiado (So = 4,5 g DQO/I y TRH = 1,25 días). La subida de acidez volátil fue contrarrestada en todo momento por los elevados valores de alcalinidad (3440-4670 mg CaCOa/l) lo que determinó una alta estabilidad del proceso y que la relación acidez volátil/alcalinidad se mantuviera, salvo en el caso mencionado, por debajo del valor límite 0,3-0,4, por encima del cual el proceso anaerobio se desestabiliza. El coeficiente de rendimiento de producción en metano del proceso fue de 0,281 metano STP/g DQO eliminada.[EN] A study of the anaerobic digestion process of wastewaters from the washing of olives prior to the oil production process was carried out in a fluidized bed reactor with sepiolite immobilised biomass at 35°G. The bloreactor worked satisfactorily using Influent COD concentrations of 4.5,3.5,2.5 and 1.5 g COD/I for a hydraulic retention time (HRT) range of 4.5 to 1,25 days. COD removal efficiencies in the range 50-90% were achieved in tiie reactor, when evaluated at organic loading rates of between 0.46 and 2.25 g COD/I day using the highest influent substrate concentration (So = 4.5 g COD/I). COD and volatile fatty acid (VFA) concentration were Increased In parallel witii the increase of organic loading rate in the reactor, VFA concentration showing a maximum value of 1.55 g acetic acid/I at the most unfavourable case studied (So = 4,5 g COD/I and HRT = 1.25 days). The increase in effluent VFA concentrations was always counteracted by the high alkalinity values (3440-4670 mg CaCOa/l) which brought about the high stability of the process and values of the alkalinity/VFA ratio lower than 0.3-0.5, except for the above-mentioned case, limit value over which the anaerobic process is destabilized. The yield coefficient of metiiane production was 0.281 methane STP/g COD removed.Queremos hacer constar nuestro agradecimiento a la Unión Europea (Proyecto AIR3-CT94-1355) y a la Junta de Andalucía por su ayuda para la realización de estos estudios.Peer reviewe
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