37 research outputs found
Estrés oxidativo como diana de tratamiento experimental del Síndrome X Frágil
Introducción: El Síndrome X Frágil (SXF) se muestra como la causa más frecuente de DI hereditaria (Hagerman PJ, 2008), además de ser la principal enfermedad genética causante de autismo hereditario (Hagerman RJ y col, 2008). Los resultados reciente de un meta-análisis indicarían que la prevalencia del SXF es de: un varón de cada 7143 y en el caso de las mujeres sea de cada 11111 (Hunter J y col, 2014). La enfermedad se debe a la ausencia de la proteína Fragile Mental Retardation (FMRP) generada por el gen Fmr1.
El gen del discapacidad intelectual asociado al X frágil (Fragile Mental Retardation 1 gene) está localizado en la posición Xq27.3 del cromosoma sexual X. El silenciamiento génico del gen Fmr1 es consecuencia, generalmente, de unas series de modificaciones epigenéticas (Pietrobono R y col., 2005).
El ratón nulo para Fmr1, modelo animal del SXF, se generó por recombinación homologa provocando el silenciamiento génico por interrupción del exón 5 del gen Fmr1 (Bakker CE et al, 1994). Los ratones Fmr1-KO nos ayudan a la comprensión de la biología de la enfermedad para así generar tratamientos y métodos de diagnostico más eficaces para el SXF. Unas de las características fisiológicas del ratón Fmr1-KO es la presencia de estrés oxidativo (el Bekay et al., 2007), el estrés oxidativo es debido a un desequilibrio entre la producción de especies reactivas de oxigeno (ROS) y la defensa antioxidante endógena. El principal productor de ROS es la proteína NADPH oxidasa que, cuando está activa, produce al ion peróxido (utilizando a NADPH como cofactor) que por dismutación puede generar a peróxido de hidrogeno .
Objetivos: El objetivo de esta tesis doctoral es la aplicación de tratamientos en ratones Fmr1-KO procurándose ver mejorías comportamentales. Todos los tratamientos tienen actuación sobre la NADPH oxidasa (principal productor de ROS).
Resultados: Observamos que los ratones con SXF muestran variaciones en el metabolismo del oxido nítrico (NO), así como un aumento en el estrés nitroxidaivo y diferencias en la expresión de las distintas subunidades de la oxido nítrico sintasa en el cerebelo, hipocampo y corteza prefrontal de los ratones con SXF. Además podemos ver que la proteína Rac1 está sobreactivada en ratones carentes de la proteína FMRP, en las áreas cerebrales antes mencionadas.
Hay mejoría en el comportamiento de ratones nulos después de la aplicación de diversos tratamientos crónicos: inhibidor Rac1, apocinina y antioxidantes (vitamina C y vitamina E). Se observan mejorías significativas, según el tratamiento, en la hiperlocomoción, la cognición, el comportamiento relacionado con la ansiedad y el aprendizaje. Además de observarse mejorías en los parámetros de estrés oxidativo analizados: TBARs y oxidación de lípidos.
Mientras que con el tratamiento agudo con estatinas los ratones Fmr1-KO no muestran mejoría en ninguno de los paradigmas comportamentales y los parámetros de estrés oxidativo medidos.
Conclusiones: La aplicación de una combinación de moléculas reguladoras de la NADPH oxidasa y de sus productos, son un buen mecanismo para el tratamiento farmacológico del SXF
Effect of temperature and time on oxygen consumption by olive fruit: Empirical study and simulation in a non-ventilated container
Fermentation processes within olive fruit jeopardize the quality of the extracted oil. Aera-tion, temperature, and time play a crucial role in attaining the critical threshold at which an aerobic respiration shifts towards anaerobic. In this work, the O2 consumption and CO2 production of olive fruit kept in a closed container at different temperatures (5–45◦ C) were measured over 7 h. The data allowed us to describe the relationship between the temperature and the respiration rate as an Arrhenius function and simulate the oxygen consumption in the inner part of a container full of fruit with low aeration, considering the generated respiration heat over time. The simulation revealed that olives risk shifting to anaerobic respiration after 3 h at 25◦ C and less than 2 h at 35◦ C when kept in a non-ventilated environment. The results underline the irreversible damage that high day temperatures can produce during the time before fruit processing, especially during transport. Lowering, as soon as possible, the field temperature thus comes to the fore as a necessary strategy to guarantee the quality of the olives before their processing, like most of the fruit that is harvested at excessive temperatures
Olive Crown Porosity Measurement Based on Radiation Transmittance: An Assessment of Pruning Effect
Crown porosity influences radiation interception, air movement through the fruit orchard,
spray penetration, and harvesting operation in fruit crops. The aim of the present study was to develop
an accurate and reliable methodology based on transmitted radiation measurements to assess the
porosity of traditional olive trees under different pruning treatments. Transmitted radiation was
employed as an indirect method to measure crown porosity in two olive orchards of the Picual
and Hojiblanca cultivars. Additionally, three different pruning treatments were considered to
determine if the pruning system influences crown porosity. This study evaluated the accuracy
and repeatability of four algorithms in measuring crown porosity under different solar zenith angles.
From a 14 to 30 solar zenith angle, the selected algorithm produced an absolute error of less
than 5% and a repeatability higher than 0.9. The described method and selected algorithm proved
satisfactory in field results, making it possible to measure crown porosity at different solar zenith
angles. However, pruning fresh weight did not show any relationship with crown porosity due
to the great differences between removed branches. A robust and accurate algorithm was selected
for crown porosity measurements in traditional olive trees, making it possible to discern between
different pruning treatments
Mechanical canopy and trunk shaking for the harvesting mechanization of table olive orchards
Table olive harvesting is highly dependent on manual labour and may jeopardize the crop benefit. The introduction of a mechanical harvest system requires a global evaluation of the whole process. A trunk shaker along with shaker combs and a continuous canopy shaker harvester have been tested in two orchards with different tree training and layout to determine their feasibility to mechanical harvesting in table olives. For that purpose, several parameters have been evaluated. Canopy shaker required adapted orchard layout and hedge of canopies for reaching an acceptable harvesting efficiency about 80% and trunk shaker performed a higher efficiency of more than 95% but depended highly on labour. Both systems had a high field capacity about 0.15 ha h-1 but low for the trunk shaker considering the people (0.01 ha h-1 person-1). The vibration pattern that applied on branches was totally different although the quantitative tree damages were no significative different. There were no significant differences in fruit bruising between both systems, but there were between the different sampling points, mainly in the detachment. The fruit bruising index of the remaining fruit on canopy suggests that it is possible to perform a second harvest. Both mechanical systems are suitable for table olive harvesting whilst improving the efficiency of manual systems with bearable damages, but each one has pros and cons that must be considered bearing in mind that require an adaptation of the orchard where there are applied.
Highlights
Table olives mechanization is possible by integrating with the fruit liquid store.
Trunk shaker performed high efficiency in adapted orchards but depended on labour.
Canopy shakers require the adaption of orchard and machine for commercial purposes.
There were no differences in detached fruit bruising between both mechanical systems.
The bruising index of the remaining fruit on trees suggest second harvesting pass.Table olive harvesting is highly dependent on manual labour and may jeopardize the crop benefit. The introduction of a mechanical harvest system requires a global evaluation of the whole process. A trunk shaker along with shaker combs and a continuous canopy shaker harvester have been tested in two orchards with different tree training and layout to determine their feasibility to mechanical harvesting in table olives. For that purpose, several parameters have been evaluated. Canopy shaker required adapted orchard layout and hedge of canopies for reaching an acceptable harvesting efficiency about 80% and trunk shaker performed a higher efficiency of more than 95% but depended highly on labour. Both systems had a high field capacity about 0.15 ha h-1 but low for the trunk shaker considering the people (0.01 ha h-1 person-1). The vibration pattern that applied on branches was totally different although the quantitative tree damages were no significative different. There were no significant differences in fruit bruising between both systems, but there were between the different sampling points, mainly in the detachment. The fruit bruising index of the remaining fruit on canopy suggests that it is possible to perform a second harvest. Both mechanical systems are suitable for table olive harvesting whilst improving the efficiency of manual systems with bearable damages, but each one has pros and cons that must be considered bearing in mind that require an adaptation of the orchard where there are applied.
Highlights
Table olives mechanization is possible by integrating with the fruit liquid store.
Trunk shaker performed high efficiency in adapted orchards but depended on labour.
Canopy shakers require the adaption of orchard and machine for commercial purposes.
There were no differences in detached fruit bruising between both mechanical systems.
The bruising index of the remaining fruit on trees suggest second harvesting pass
The impact of donor age on the results of renal transplantation
Producción CientíficaBackground. The use of elderly donors is becoming more frequent. An increase in the donor’s age is
associated with a greater incidence of delayed graft function (DGF), chronic allograft nephropathy (CAN)
and worse graft survival. Poor renal graft function is a risk factor for cardiovascular (CV) complications
and, finally, for mortality of the patients. Methods. A total of 3365 adult patients transplanted in 1990 (n¼824), 1994 (n¼1075) and 1998 (n¼1466) with a functioning graft after the first year were included. The impact of donor age on renal function, DGF, acute rejection and other clinical factors was
evaluated according to two donor and recipient age categories: young (60
years old). Additionally, donor age was categorized by decades for the analysis of patient and graft survival, acute rejection and CV mortality. Results. Donor mean age significantly increased during the three transplantation periods. A total of 478 out of 3365 donors were older than 60 years. Elderly donors showed an increased risk of DGF (38.9 vs 28.8%) and CAN (56.8 vs 46.2%). Mean serum creatinine at 3 and 12 months and proteinuria were significantly higher in the old donor group. Incidence and severity of acute rejection were similar in both groups. Graft and patient survival were significantly lower in the old donor group. Also, risk of mortality due to CV events was also significantly higher. A linear increase in risk of graft loss, patient death or CV mortality was observed when donor age was divided into 10 year increase subsets. Conclusions. Donor age is a strong predictor of CAN and graft loss. Patient survival is also affected by donor age, particularly by a higher risk of CV mortality
Pozzolanic materials to reduce CO2 emissions: local solutions for a global issue.
Abstract de una keynote invitada.In recent decades, the cement sector has been looking for solutions to reduce the carbon footprint, being one of the most promising strategies, the replacement of clinker with supplementary cementitious materials, SCMs. However, the main limitation of this approach is the availability of suitable SCMs.
This work presents the study of three families of pozzolanic materials, Spanish calcined clays (CC), Natural Pozzolans (NP) and fly ashes (FA). The characterization of each family will be presented, with emphasis on the kaolinite content of the original clays and the amorphous contents of the natural pozzolans and fly ashes.
The results of the pozzolanic prediction tests will be compared: strength activity index, SAI, and R3 test according to ASTM C1897-20.
The SAI test has two important limitations: i) it gives false positives at 28 days, as does the addition of quartz (Qz) and ii) a minimum of 28 days is required to obtain the pozzolanic activity results.
In addition, the R3 test has proved to be useful in ruling out inert additions, such as quartz. Moreover, it presents a very good correlation between the heat emitted and the combined water at 7 days and the amount of kaolinite in clays or amorphous in ashes. However, the absolute values of heat and combined water cannot be compared between different families. That is, in the calcined clay family, it can be inferred that if the kaolinite content is higher than 50 wt%, the heat released should be between 500-700 J/g, whereas a fly ash with an amorphous content of around 70 wt% will release between 200-250 J/g.PID2020-114650RB-I00 grant from Spanish government, Master Builders Solutions Deutschland GmbH (Germany) and Buzzi Unicem SpA (Italy) are thanked for the funding.
Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
COVIDGR Dataset and COVID-SDNet Methodology for Predicting COVID-19 Based on Chest X-Ray Images
Currently, Coronavirus disease (COVID-19), one of the most infectious diseases in the 21st century, is diagnosed using RT-PCR testing, CT scans and/or Chest X-Ray (CXR) images. CT (Computed Tomography) scanners and RT-PCR testing are not available in most medical centers and hence in many cases CXR images become the most time/cost effective tool for assisting clinicians in making decisions. Deep learning neural networks have a great potential for building COVID-19 triage systems and detecting COVID-19 patients, especially patients with low severity. Unfortunately, current databases do not allow building such systems as they are highly heterogeneous and biased towards severe cases. This article is three-fold: (i) we demystify the high sensitivities achieved by most recent COVID-19 classification models, (ii) under a close collaboration with Hospital Universitario Clínico San Cecilio, Granada, Spain, we built COVIDGR-1.0, a homogeneous and balanced database that includes all levels of severity, from normal with Positive RT-PCR, Mild, Moderate to Severe. COVIDGR-1.0 contains 426 positive and 426 negative PA (PosteroAnterior) CXR views and (iii) we propose COVID Smart Data based Network (COVID-SDNet) methodology for improving the generalization capacity of COVID-classification models. Our approach reaches good and stable results with an accuracy of 97.72%±0.95% , 86.90%±3.20% , 61.80%±5.49% in severe, moderate and mild COVID-19 severity levels. Our approach could help in the early detection of COVID-19. COVIDGR-1.0 along with the severity level labels are available to the scientific community through this link https://dasci.es/es/transferencia/open-data/covidgr/This work was supported by the project DeepSCOP-Ayudas Fundación BBVA a Equipos de Investigación Científica en Big Data 2018, COVID19_RX-Ayudas Fundación BBVA a Equipos de Investigación Científica SARS-CoV-2 y COVID-19 2020, and the Spanish Ministry of Science and Technology under the project TIN2017-89517-P. S. Tabik was supported by the Ramon y Cajal Programme (RYC-2015-18136). A. Gómez-Ríos was supported by the FPU Programme FPU16/04765. D. Charte was supported by the FPU Programme FPU17/04069. J. Suárez was supported by the FPU Programme FPU18/05989. E.G was supported by the European Research Council (ERC Grant agreement 647038 [BIODESERT])
Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements
A comprehensive characterisation of atmospheric aerosols in the subtropical eastern North Atlantic
has been carried out using long-term ground-based Aerosol Robotic NETwork (AERONET) photometric observations over the period 2005–2020 from a unique network made up of four stations strategically located from
sea level to 3555 m on the island of Tenerife. This site can be considered a sentinel for the passage of airmasses
going to Europe from Africa, and therefore the aerosol characterisation performed here adds important information for analysing their evolution during their path toward Northern Europe. Two of these stations (Santa Cruz
de Tenerife – SCO – at sea level and La Laguna – LLO – at 580 m a.s.l.) are located within the marine atmospheric boundary layer (MABL), and the other two (Izaña – IZO – at 2373 m a.s.l. and Teide Peak – TPO – at
3555 m a.s.l.) are high mountain stations within the free troposphere (FT). Monthly climatology of the aerosol
optical depth (AOD), Ångström exponent (AE), aerosol concentration, size distribution and aerosol optical properties has been obtained for the MABL and FT. Measurements that are quite consistent across the four sites have
been used to categorise the main atmospheric scenarios, and these measurements confirm an alternation between
predominant background conditions and predominant dust-loaded Saharan air mass conditions caused by seasonal dust transport over the subtropical North Atlantic. Background conditions prevail in the MABL and FT for
most of the year, while dust-laden conditions dominate in July and August.The authors also acknowledge the support from ACTRIS, Ministerio
de Ciencia e Innovación, Spain, through the projects SYNERA
(PID2020-118793GA-I00) and ePOLAAR (RTI2018-097864-BI00) and from Junta de Castilla y León (grant no. VA227P20)
Micro-CT evaluation of bone grow concept of an implant with microstructured backtaper crestally and sub-crestally placed. Preliminary study in New Zealand rabbits tibia at one month
The primary purpose of this study was to determine the accuracy of micro-computed tomography (micro-CT) as a novel tool for the 3D analysis of bone density around dental implants in tibia rabbits. Six male New Zealand rabbits were used in our evaluation. One Copa SKY® (Bredent Medical GmbH & Co. K.G.) with a 3.5 mm diameter by 8.0 mm in length was placed within 12 tibia rabbits divided into two experimental groups: Group A (crestal placement) and Group B (sub-crestal placement). The animals were sacrificed at four weeks. Micro-CT evaluations showed a high amount of bone around all implants in the tibia rabbit bone. There was an increased formation of bone around the Copa SKY implants, mainly in the implants that were placed crestally. The most frequent density found in most implants was a medullary bone formation surrounding the implant; the density three (D3) was the most common type in all implants. The 3D model analysis revealed a mean bone volume (B.V.) of 31.24 ± 1.24% in crestal implants compared with the 43.12 ± 0.43% in sub-crestal implants. The mean actual contact implant to bone (B.I.C.) in the sub-crestal group was 51.76 ± 0.86%, compared to the 42.63 ± 0.75% in the crestal group. Compared to crestal implants, the Copa Sky implant placed sub-crestally allows for the formation of bone on top of the neck, thereby stimulating bone growth in tibia rabbits