167 research outputs found

    Análisis corológico y novedades florísticas de la Sierra de los Filabres (Andalucía Oriental, España)

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    El conocimiento básico sobre la diversidad vegetal a escala local o regional es primordial para afrontar la conservación de la diversidad genética a mayor escala. En Andalucía oriental, la sierra de Los Filabres había quedado al margen de estudios intensivos sobre su flora. Abordamos la notificación de los taxones que resultan novedosos para la provincia de Almería y los que son interesantes ampliaciones de área de distribución. Analizamos la corología de los taxa que emanan del catálogo florístico, considerada una forma de medir la gamma diversidad del territorio. La flora de Los Filabres es primordialmente mediterránea, pero destaca un alto porcentaje de especies de área restringida, entre ellos los que también se presentan en el norte de África, y especialmente los endemismos. Por otro lado, en un área tan conspicua del sur ibérico que constituye una interesante encrucijada biogeográfica, resalta destacable el número de especies no citadas hasta el momento. En el caso de muchas especies que se encuentran en listados de protección, esta información corológica debe ser incorporada en los estudios de evaluación de su grado de amenaza. Muchos taxones son raros en esta sierra, por ser límite de área de distribución o por tener pocas poblaciones o por presentar pocos efectivos poblacionales. Por ello, la conservación a escala local resulta esencial para abordar la planificación y las estrategias de preservación de la biodiversidad global.Basic knowledge on plant diversity at local or regional scale is necessary to face the genetic diversity conservation at widest scale. In eastern Andalusia, Los Filabres Mountain had been to margin of intensive studies on its flora. We approached the notification of new taxa records in Almería province and those that are interesting enlargement of their distribution area. We analyzed the taxa chorology that emanates of the floristic catalogue, considered a gamma diversity measure of the territory. The flora from Los Filabres is fundamentally mediterranean, but restricted area distribution species emphasizes with high percentages, among them, those that also inhabit in North Africa, those that are endemics. On the other hand, in a so conspicuous area of the Iberian south that constitutes an interesting biogeography crossroads, the number of species no referenced until the moment stands out remarkable. In the case of many species that are in “red lists”, this chorological information should be incorporated in the studies of threat evaluation. Many taxa are rare in this mountain range, because of being limit of distribution area or because of have few populations or because of display few population individuals. For this reason, the local scale conservation is essential to approach the planning and the strategies of preservation of the global biodiversity

    Molecular Events behind the Selectivity and Inactivation Properties of Model NaK-Derived Ion Channels

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    Y55W mutants of non-selective NaK and partly K+-selective NaK2K channels have been used to explore the conformational dynamics at the pore region of these channels as they interact with either Na+ or K+. A major conclusion is that these channels exhibit a remarkable pore conformational flexibility. Homo-FRET measurements reveal a large change in W55–W55 intersubunit distances, enabling the selectivity filter (SF) to admit different species, thus, favoring poor or no selectivity. Depending on the cation, these channels exhibit wide-open conformations of the SF in Na+, or tight induced-fit conformations in K+, most favored in the four binding sites containing NaK2K channels. Such conformational flexibility seems to arise from an altered pattern of restricting interactions between the SF and the protein scaffold behind it. Additionally, binding experiments provide clues to explain such poor selectivity. Compared to the K+-selective KcsA channel, these channels lack a high affinity K+ binding component and do not collapse in Na+. Thus, they cannot properly select K+ over competing cations, nor reject Na+ by collapsing, as K+-selective channels do. Finally, these channels do not show C-type inactivation, likely because their submillimolar K+ binding affinities prevent an efficient K+ loss from their SF, thus favoring permanently open channel states.This work was partly supported by grants PGC2018-093505-B-I00 from the Spanish “Ministerio de Ciencia e Innovación”/FEDER, UE, and FCT-Fundação para a Ciência e a Tecnologia, I.P., under the scope of the project UIDB/04565/2020 and UIDP/04565/2020 of the Research Unit Institute for Bioengineering and Biosciences—iBB and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB

    Emerging treatment strategies in recurrent platinum-sensitive ovarian cancer: focus on trabectedin.

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    Ovarian cancer (OC) is the leading cause of death from gynecological malignancies. In spite of high response rates to the standard front-line treatment for advanced disease with cytoreductive surgical debulking, followed by platinum/taxane-based chemotherapy, most patients eventually relapse developing drug-resistant disease. Owing to the molecular heterogeneity, genetic instability and mutagenicity of OC, increases in survival might be achieved by translating recent insights at the morpho-molecular levels to individual therapeutic strategies. Several emerging treatments have been shown to be active in platinum-sensitive (PS) recurrent OC (ROC), but an optimal strategy still has not been established. Based on the recent results, it is likely that the introduction of novel non-platinum based chemotherapies and molecular targeted therapies will have a major impact on the management of ROC. Some current strategies are focused on the extension of platinum-free interval (PFI) in patients with PS, particularly in those with partially PS disease. Apparently, the PFI extension by an effective non-platinum intervention, such as trabectedin plus pegylated liposomal doxorubicin (PLD), may reduce cumulative platinum-induced toxicities leading to longer survival after the reintroduction of subsequent platinum. The introduction of novel therapies, such as the antiangiogenic monoclonal antibody bevacizumab, opens a new field of targeted therapies in this indication. In this review, we aim to outline the therapeutic potential of new emerging approaches, particularly the role of non-platinum therapy with trabectedin in combination with PLD in patients with PS ROC. © 2013 The Authors

    Study of the Functional Brain Connectivity and Lower-Limb Motor Imagery Performance After Transcranial Direct Current Stimulation

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    The use of transcranial direct current stimulation (tDCS) has been related to the improvement of motor and learning tasks. The current research studies the effects of an asymmetric tDCS setup over brain connectivity, when the subject is performing a motor imagery (MI) task during five consecutive days. A brain–computer interface (BCI) based on electroencephalography is simulated in offline analysis to study the effect that tDCS has over different electrode configurations for the BCI. This way, the BCI performance is used as a validation index of the effect of the tDCS setup by the analysis of the classifier accuracy of the experimental sessions. In addition, the relationship between the brain connectivity and the BCI accuracy performance is analyzed. Results indicate that tDCS group, in comparison to the placebo sham group, shows a higher significant number of connectivity interactions in the motor electrodes during MI tasks and an increasing BCI accuracy over the days. However, the asymmetric tDCS setup does not improve the BCI performance of the electrodes in the intended hemisphereThis research has been carried out in the framework of the project Walk — Controlling lower-limb exoskeletons by means of BMIs to assist people with walking disabilities (RTI2018-096677-B-I00Funded by the Spanish Ministry of Science and Innovation, the Spanish State Agency of Research and the European Union through the European Regional Development Fund;by the Consellería de Innovación, Universidades, Ciencia y Sociedad Digital (Generalitat Valenciana) and the European Social Fund in the framework of the project ‘Desarrollo de nuevas interfaces cerebro-m´aquina para la rehabilitaci`on de miembro inferior’ (GV/2019/009).Also, the Mexican Council of Science and Technology (CONACyT) provided J. A. Gaxiola-Tirado his scholarshi

    Isolation and characterization of an exopolymer produced by bacillus licheniformis: in vitro antiviral activity against enveloped viruses

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    The exopolymer (EPSp) produced by the strain B. licheniformis IDN-EC was isolated and characterized using different techniques (MALDI-TOF, NMR, ATR-FTIR, TGA, DSC, SEM). The results showed that the low molecular weight EPSp contained a long polyglutamic acid and an extracellular teichoic acid polysaccharide. The latter was composed of poly(glycerol phosphate) and was substituted at the 2-position of the glycerol residues with a αGal and αGlcNH2. The αGal O-6 position was also found to be substituted by a phosphate group. The antiviral capability of this EPSp was also tested on both enveloped (herpesviruses HSV, PRV and vesicular stomatitis VSV) and non-enveloped (MVM) viruses. The EPSp was efficient at inhibiting viral entry for the herpesviruses and VSV but was not effective against non-enveloped viruses. The in vivo assay of the EPSp in mice showed no signs of toxicity which could allow for its application in the healthcare sector.Peer reviewe

    Effect of a Virtual Reality Exercise on Patients Undergoing Haemodialysis: A Randomised Controlled Clinical Trial Research Protocol

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    High levels of inflammatory markers have been associated with a greater deterioration of renal function and cardiovascular morbidity and mortality. For its part, physical exercise has been shown to be beneficial in improving the functional, psychological, and inflammatory states of patients with chronic kidney failure (CKF) undergoing haemodialysis (HD) treatment, improving their health-related quality of life. In recent years, virtual reality (VR) has been studied and described as an effective and safe tool that improves patients’ adherence to exercise programs. For these reasons, we propose to analyse the effect of VR exercise on the functional, psychological, and inflammatory states of patients on HD, as well as their levels of adherence to exercise, and compare them with static pedalling exercises. We will randomise 80 patients with CKF into two blind groups: an experimental group, which will carry out an intradialytic exercise program with non-immersive VR (n = 40), and a control group, which will exercise with a static pedal (n = 40). Functional capacity, inflammatory and phycological status, and exercise adherence will be analysed. Higher levels of adherence to exercise are expected in the VR group, which will have greater effects on the patients’ functional capacity and psychological and inflammatory status. Keywords: end-stage kidney disease; renal dialysis; inflammation; physical fitness; psychological wellness; physical activity; virtual realitySección Deptal. de Radiología, Rehabilitación y Fisioterapia (Enfermería)Fac. de Enfermería, Fisioterapia y PodologíaTRUEpu

    Evaluating the impact of image preprocessing on iris segmentation

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    La segmentación del iris es una de las etapas más importantes en los sistemas de reconocimiento del iris. En este trabajo se aplican algoritmos de preprocesamiento de la imagen con el objetivo de evaluar su impacto en los porcentajes de segmentación exitosa del iris. Los algoritmos utilizados se basan en el ajuste del histograma, filtros Gaussianos y en la eliminación del reflejo especular en imágenes del ojo humano. Se aplica el método de segmentación introducido por Masek a 199 imágenes tomadas bajo condiciones no controladas, pertenecientes a la base de datos CASIA-irisV3, antes y después de aplicar los algoritmos de preprocesamiento. Posteriormente se evalúa el impacto de los algoritmos de preprocesamiento en el porcentaje de segmentación exitosa del iris por medio de una inspección visual de las imágenes, para determinar si las circunferencias detectadas del iris y de la pupila corresponden adecuadamente con el iris y la pupila de la imagen real. El algoritmo que generó uno de los mayores incrementos de los porcentajes de segmentación exitosa (pasa de 59% a 73%) es aquel que combina la eliminación de reflejos especulares, seguido por la aplicación de un filtro Gaussiano con máscara 5x5. Los resultados obtenidos señalan la importancia de una etapa previa de preprocesamiento de la imagen como paso previo para garantizar una mayor efectividad en el proceso de detección de bordes y segmentación del iris.Segmentation is one of the most important stages in iris recognition systems. In this paper, image preprocessing algorithms are applied in order to evaluate their impact on successful iris segmentation. The preprocessing algorithms are based on histogram adjustment, Gaussian filters and suppression of specular reflections in human eye images. The segmentation method introduced by Masek is applied on 199 images acquired under unconstrained conditions, belonging to the CASIA-irisV3 database, before and after applying the preprocessing algorithms. Then, the impact of image preprocessing algorithms on the percentage of successful iris segmentation is evaluated by means of a visual inspection of images in order to determine if circumferences of iris and pupil were detected correctly. An increase from 59% to 73% in percentage of successful iris segmentation is obtained with an algorithm that combine elimination of specular reflections, followed by the implementation of a Gaussian filter having a 5x5 kernel. The results highlight the importance of a preprocessing stage as a previous step in order to improve the performance during the edge detection and iris segmentation processes

    Accessibility of Cations to the Selectivity Filter of KcsA in the Inactivated State: An Equilibrium Binding Study

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    Cation binding under equilibrium conditions has been used as a tool to explore the accessibility of permeant and nonpermeant cations to the selectivity filter in three different inactivated models of the potassium channel KcsA. The results show that the stack of ion binding sites (S1 to S4) in the inactivated filter models remain accessible to cations as they are in the resting channel state. The inactivated state of the selectivity filter is therefore “resting-like” under such equilibrium conditions. Nonetheless, quantitative differences in the apparent KD’s of the binding processes reveal that the affinity for the binding of permeant cations to the inactivated channel models, mainly K+, decreases considerably with respect to the resting channel. This is likely to cause a loss of K+ from the inactivated filter and consequently, to promote nonconductive conformations. The most affected site by the affinity loss seems to be S4, which is interesting because S4 is the first site to accommodate K+ coming from the channel vestibule when K+ exits the cell. Moreover, binding of the nonpermeant species, Na+, is not substantially affected by inactivation, meaning that the inactivated channels are also less selective for permeant versus nonpermeant cations under equilibrium conditions.This work was partly supported by the grant BFU2015-66612-P from the Spanish MINECO/FEDER, UE. CD-G acknowledges support from Medical Biochemistry and Biophysics Doctoral Programme (M2B-PhD) and FCT Portugal (SFRH/PD/BD/135154/2017)

    Differential Effects of IGF-1R Small Molecule Tyrosine Kinase Inhibitors BMS-754807 and OSI-906 on Human Cancer Cell Lines

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    We have determined the effects of the IGF-1R tyrosine kinase inhibitors BMS-754807 (BMS) and OSI-906 (OSI) on cell proliferation and cell-cycle phase distribution in human colon, pancreatic carcinoma, and glioblastoma cell lines and primary cultures. IGF-1R signaling was blocked by BMS and OSI at equivalent doses, although both inhibitors exhibited differential antiproliferative effects. In all pancreatic carcinoma cell lines tested, BMS exerted a strong antiproliferative effect, whereas OSI had a minimal effect. Similar results were obtained on glioblastoma primary cultures, where HGUE-GB-15, -16 and -17 displayed resistance to OSI effects, whereas they were inhibited in their proliferation by BMS. Differential effects of BMS and OSI were also observed in colon carcinoma cell lines. Both inhibitors also showed different effects on cell cycle phase distribution, BMS induced G2/M arrest followed by cell death, while OSI induced G1 arrest with no cell death. Both inhibitors also showed different effects on other protein kinases activities. Taken together, our results are indicative that BMS mainly acts through off-target effects exerted on other protein kinases. Given that BMS exhibits a potent antiproliferative effect, we believe that this compound could be useful for the treatment of different types of tumors independently of their IGF-1R activation status.This research was funded by a Grant from Instituto de Salud Carlos III Grant PI012/02025 co-supported by FEDER funds and PRECIPITA crowdfunding platform from Fundación Española para la Ciencia y la Tecnología (Fecyt) to M. Saceda and AMACMED (Asociación de mujeres afectadas por cáncer de mama de Elche y Comarca) and Monica Moraleda donation to M. Saceda. The Spanish Ministry of Economy and Competitiveness (MINECO, Project RTI2018-096724-B-C21) and the Generalitat Valenciana (PROMETEO/2016/006) supported the work in the Encinar laboratory
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