174,129 research outputs found

    Desarrollo de papeles biocativos por injerto de moléculas específicas en celulosa

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    Tesis (DCI)--FCEFN-UNC, 2019En la presente tesis se presenta el desarrollo de papeles bioactivos con potencial aplicaci√≥n en el envasado activo de alimentos. Para tal fin, se propuso el injerto de eugenol, un compuesto de origen natural con propiedades antimicrobiana, antioxidante y repelente de insectos, en celulosa, utilizando √°cido policarbox√≠lico como agente ligante. Con el objetivo de evaluar la escalabilidad del proceso propuesto, se estudiaron distintas tecnolog√≠as de curado, tales como calentamiento por convecci√≥n, infrarrojo, microondas y conducci√≥n. En todos los casos, se analizaron la influencia de las variables operativas sobre el avance de la reacci√≥n y propiedades finales del papel preparado, utilizando un dise√Īo de experimentos Doehlert para elegir las experiencias a realizar, y analizando los resultados mediante metodolog√≠a de superficie de respuesta y an√°lisis estad√≠stico ANOVA. Se pudo comprobar que la reacci√≥n de injerto de eugenol en papel comercial se produjo con √©xito en todas las tecnolog√≠as estudiadas. Asimismo, se encontraron las condiciones √≥ptimas de reacci√≥n para cada una de las tecnolog√≠as, para lo cual se busc√≥ un compromiso entre el avance de la reacci√≥n y las propiedades finales del material (mec√°nicas y color). A partir de estas condiciones, se prepararon papeles y se realiz√≥ una caracterizaci√≥n m√°s espec√≠fica para su aplicaci√≥n como envase de alimentos comparando los papeles modificados con el papel virgen. Se analizaron las propiedades mec√°nicas por ensayo de tracci√≥n, rasgado y punzonado y se midi√≥ la absorci√≥n de agua y la capacidad de degradaci√≥n. Por otro lado, las propiedades bioactivas analizadas fueron la actividad antioxidante, antimicrobiana, repelente e insecticida de gorgojos (T. castaneum y R. dominica). Una vez probado que el papel modificado presenta buenas caracter√≠sticas f√≠sicas y bioactivas para su posible aplicaci√≥n en el envasado de alimentos, se realizaron prototipos de envasado para harina, como alimento representativo de alimentos derivados de cereales, susceptibles al ataque de plagas. En este estudio se analiz√≥ la migraci√≥n de reactivos, propiedades organol√©pticas y conservaci√≥n del alimento, arrojando resultados promisorios para la industria de envases de alimentos. Finalmente, se realiz√≥ una comparaci√≥n de las tecnolog√≠as de curado ensayadas, analizando diferentes aspectos como avance de reacci√≥n, propiedades finales, apariencia, tiempo de reacci√≥n, consumo de energ√≠a, entre otros, como as√≠ tambi√©n disponibilidad y uso de estas tecnolog√≠as a escala industrial, seleccionando la tecnolog√≠a de conducci√≥n como la m√°s adecuada para una propuesta de escalado industrial.Fil: Muratore, Florencia. Universidad Nacional de C√≥rdoba. Facultad de Ciencias Exactas, F√≠sicas y Naturales; Argentina.Fil: Muratore, Florencia. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Instituto de Investigaci√≥n y Desarrollo en Ingenier√≠a de Procesos y Qu√≠mica Aplicada; Argentina

    Paleocirculation and paleoclimate conditions in the western Mediterranean basins over the last deglaciation: New insights from sediment composition variations

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    We present a high-resolution analysis of seven marine sediment records from the western Mediterranean in a transect from the Algero-Balearic basin to the Alboran Sea, spanning the last 20 ka, to decipher the paleoenvironmental and paleoceanographic evolution of the western Mediterranean Sea. To do so, diverse elemental ratios have been used for reconstructing sediment input variations and paleo-oxygen conditions. In particular, the Ti/Ca ratio has been used to reconstruct variations in the terrigenous and carbonate fractions. However, the specific sedimentary processes controlling this ratio are still poorly understood thus, we also provide new insights for appropriate interpretations in the studied zone. Our results suggest that the Ti/Ca ratio at the suborbital scale is mostly controlled by bottom current intensity, and less influenced by marine productivity, sea level variations and fluvial and eolian inputs. Comparison of diverse records within the western Mediterranean reveals that the Ti/Ca ratio depicted a similar trend in both regions, except during the Heinrich Stadial 1 (HS1) and the Middle Holocene. The HS1 is recorded as a single-phase event in the Algero-Balearic basin, whereas three phases are recognized in the Alboran Sea basin, with a relative minimum in the Ti/Ca ratio. Conversely, during the Middle Holocene, an increase in the Ti/Ca ratio is recorded in the Alboran Sea but not in the Algero-Balearic basin, which could be related to the establishment of the Alboran gyres. Redox sensitive proxies, in particular the Mo/Al, U/Al and Mn/Al ratios, point to different phases within the Organic Rich Layer 1 (ORL1): the ORL1a (15- 11.7 ka cal BP), characterized by more reducing conditions in the Alboran Sea sediments, and the ORL1b 11.7- ~9 ka cal BP) characterized by suboxic-ferruginous conditions. The sea level transgression, the enhanced fluvial input and the shelf flooding played a key role during the ORL1 onset and demise, ncreasing the sedimentation rate in the basin and preventing the organic matter oxidation. During the last 2 ka cal BP, an unprecedented common response is recognized in all the studied regions, showing an overall increase in the Ti/Ca ratio, which may be related to intensified human activity in the Mediterranean area, promoting a greater terrigenous input.Postprin

    Analysis of reliable deployment of TDOA local positioning architectures

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    .Local Positioning Systems (LPS) are supposing an attractive research topic over the last few years. LPS are ad-hoc deployments of wireless sensor networks for particularly adapt to the environment characteristics in harsh environments. Among LPS, those based on temporal measurements stand out for their trade-off among accuracy, robustness and costs. But, regardless the LPS architecture considered, an optimization of the sensor distribution is required for achieving competitive results. Recent studies have shown that under optimized node distributions, time-based LPS cumulate the bigger error bounds due to synchronization errors. Consequently, asynchronous architectures such as Asynchronous Time Difference of Arrival (A-TDOA) have been recently proposed. However, the A-TDOA architecture supposes the concentration of the time measurement in a single clock of a coordinator sensor making this architecture less versatile. In this paper, we present an optimization methodology for overcoming the drawbacks of the A-TDOA architecture in nominal and failure conditions with regards to the synchronous TDOA. Results show that this optimization strategy allows the reduction of the uncertainties in the target location by 79% and 89.5% and the enhancement of the convergence properties by 86% and 33% of the A-TDOA architecture with regards to the TDOA synchronous architecture in two different application scenarios. In addition, maximum convergence points are more easily found in the A-TDOA in both configurations concluding the benefits of this architecture in LPS high-demanded applicationS

    What is the importance of sperm subpopulations?

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    .The study of sperm subpopulations spans three decades. The origin, meaning, and practical significance, however, are less clear. Current technology for assessing sperm morphology (CASA-Morph) and motility (CASA-Mot) has enabled the accurate evaluation of these features, and there are many options for data classification. Subpopulations could occur as a result of the stage of development of each spermatozoon in the subpopulation. Spermatogenesis might contribute to the production of these subpopulations. Insights from evolutionary biology and recent molecular research are indicative of the diversity among male gametes that could occur from unequal sharing of transcripts and other elements through cytoplasmic bridges between spermatids. Sperm cohorts exiting the gonads would contain different RNA and protein contents, affecting the spermatozoon physiology and associations with the surrounding environmental milieu. Subsequently, these differences could affect how spermatozoa interact with the environmental milieu (maturation, mixing with seminal plasma, and interacting with the environmental milieu, or female genital tract and female gamete). The emergence of sperm subpopulations as an outcome of evolution, related to the reproductive strategies of the species, genital tract structures, and copulatory and fertilization processes. This kind of approach in determining the importance of sperm subpopulations in fertilization capacity should have a practical impact for conducting reproductive technologies, inspiring and enabling new ways for the more efficient use of spermatozoa in the medical, animal breeding, and conservation fields. This manuscript is a contribution to the Special Issue in memory of Dr. Duane GarnerS

    Identification of Hindbrain Neural Substrates for Motor Initiation in the hatchling Xenopus laevis Tadpole

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    Animal survival profoundly depends on the ability to detect stimuli in the environment, process them and respond accordingly. In this respect, motor responses to a sensory stimulation evolved into a variety of coordinated movements, which involve the control of brain centres over spinal locomotor circuits. The hatchling Xenopus tadpole, even in its embryonic stage, is able to detect external sensory information and to swim away if the stimulus is considered noxious. To do so, the tadpole relies on well-known ascending sensory pathway, which carries the sensory information to the brain. When the stimulus is strong enough, descending interneurons are activated, leading to the excitation of spinal CPG neurons, which causes the undulatory movement of swimming. However, the activation of descending interneurons that marks the initiation of motor response appears after a long delay from the sensory stimulation. Furthermore, the long-latency response is variable in time, as observed in the slow-summating excitation measured in descending interneurons. These two features, i.e. long-latency and variability, cannot be explained by the firing time and pattern of the ascending sensory pathway of the Xenopus tadpole. Therefore, a novel neuronal population has been proposed to lie in the hindbrain of the tadpole, and being able to 'hold' the sensory information, thus accounting for the long and variable delay of swim initiation. In this work, the role of the hindbrain in the maintenance of the long and variable response to trunk skin stimulation is investigated in the Xenopustadpole at developmental stage 37/38. A multifaceted approach has been used to unravel the neuronal mechanisms underlying the delayed motor response, including behavioural experiments, electrophysiology analysis of fictive swimming, hindbrain extracellular recordings and imaging experiments. Two novel neuronal populations have been identified in the tadpole's hindbrain, which exhibit activation patterns compatible with the role of delaying the excitation of the spinal locomotor circuit. Future work on cellular properties and synaptic connections of these newly discovered populations might shed light on the mechanism of descending control active at embryonic stage. Identifying supraspinal neuronal populations in an embryonic organism could aid in understanding mechanisms of descending motor control in more complex vertebrates

    Interactive Sonic Environments: Sonic artwork via gameplay experience

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    The purpose of this study is to investigate the use of video-game technology in the design and implementation of interactive sonic centric artworks, the purpose of which is to create and contribute to the discourse and understanding of its effectiveness in electro-acoustic composition highlighting the creative process. Key research questions include: How can the language of electro-acoustic music be placed in a new framework derived from videogame aesthetics and technology? What new creative processes need to be considered when using this medium? Moreover, what aspects of 'play' should be considered when designing the systems? The findings of this study assert that composers and sonic art practitioners need little or no coding knowledge to create exciting applications and the myriad of options available to the composer when using video-game technology is limited only by imagination. Through a cyclic process of planning, building, testing and playing these applications the project revealed advantages and unique sonic opportunities in comparison to other sonic art installations. A portfolio of selected original compositions, both fixed and open are presented by the author to complement this study. The commentary serves to place the work in context with other practitioners in the field and to provide compositional approaches that have been taken

    Interpersonal dynamics of women in midlife living with involuntary childlessness

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    Becoming a parent creates a new phase in adult development where the creation of a family brings new meanings and relational dimensions to one’s life. For people who are involuntarily childless, however, the absence of children can have a multifaceted impact on their everyday lives. Although extensive studies concerning childlessness have been conducted, past work has tended to have a clinical focus on women's infertility and fertility treatments and much less attention has been paid to how involuntarily childless people live beyond the phase of trying for a child while contemporaries pursue their lives with children. This study explores the experience of 11 White, heterosexual British women in midlife living with involuntary childlessness. To gain experiential insights, semi-structured interviews were conducted and transcripts analyzed using interpretive phenomenological analysis. Analysis reveals two interrelated key patterns exemplifying intrapersonal and interpersonal features. This paper focuses on the latter. The findings bring to light not only layers of complex relational issues caused by being involuntarily childless, but also different ways of reconstructing meaning in relational reconnections that impacted positively on developing generativity. The paper presents the dynamics unique to each woman and offers micro-level understandings helpful for health professionals, family therapists, life coaches, and researchers looking into childlessness and midlife/adult development

    The Idiosyncrasy of Involuntary Musical Imagery Repetition (IMIR) Experiences: The Role of Tempo and Lyrics

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    Involuntary musical imagery repetition (IMIR), colloquially known as ‚Äúearworms,‚ÄĚ is a form of musical imagery that arises involuntarily and repeatedly in the mind. A growing number of studies, based on retrospective reports, suggest that IMIR experiences are associated with certain musical features, such as fast tempo and the presence of lyrics, and with individual differences in music training and engagement. However, research to date has not directly assessed the effect of such musical features on IMIR and findings about individual differences in music training and engagement are mixed. Using a cross-sectional design (Study 1, n = 263), we examined IMIR content in terms of tempo (fast, slow) and presence of lyrics (instrumental, vocal), and IMIR characteristics (frequency, duration of episode and section) in relation to 1) the musical content (tempo and lyrics) individuals most commonly expose themselves to (music-listening habits), and 2) music training and engagement. We also used an experimental design (Study 2, n = 80) to test the effects of tempo (fast or slow) and the presence of lyrics (instrumental or vocal) on IMIR retrieval and duration. Results from Study 1 showed that the content of music that individuals are typically exposed to with regard to tempo and lyrics predicted and resembled their IMIR content, and that music engagement, but not music training, predicted IMIR frequency. Music training was, however, shown to predict the duration of IMIR episodes. In the experiment (Study 2), tempo did not predict IMIR retrieval, but the presence of lyrics influenced IMIR duration. Taken together, our findings suggest that IMIR is an idiosyncratic experience primed by the music-listening habits and music engagement of the individual

    Medicina personalizada en lactantes con cáncer: Estudio farmacogenético de polimorfismos relacionados con toxicidad y respuesta a la quimioterapia

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    Introducci√≥n La farmacogen√©tica es una herramienta de la ‚ÄúMedicina personalizada‚ÄĚ que contribuye a optimizar los tratamientos antineopl√°sicos, adapt√°ndolos a las caracter√≠sticas gen√©ticas particulares de cada individuo, maximizando su eficacia y minimizando su toxicidad. El lactante con c√°ncer es un paciente de particular vulnerabilidad y sus comorbilidades tiene una especial repercusi√≥n vital. El estudio farmacogen√©tico en esta poblaci√≥n resulta pionero y novedoso en nuestro medio. La identificaci√≥n de marcadores predictivos espec√≠ficos permitir√° individualizar m√°s la terap√©utica en esta poblaci√≥n tan fr√°gil y mejorar en consecuencia su calidad de vida y su pron√≥stico vital. Material y m√©todos Estudio de cohortes ambispectivo de pacientes oncol√≥gicos entre 1 y 18 meses de edad, receptores de quimioterapia en el Hospital La Fe de Valencia, en el periodo comprendido entre enero 2007 y agosto 2019. La parte retrospectiva comprende hasta diciembre 2015, el estudio prospectivo desde enero 2016 hasta agosto 2019. En primer lugar, se realiza un an√°lisis descriptivo de variables epidemiol√≥gicas, cl√≠nico/biol√≥gicas, terap√©uticas y pron√≥sticas de 72 pacientes con dichas caracter√≠sticas. Se describe la toxicidad derivada de sus 578 ciclos de quimioterapia (37 variables cl√≠nicas), el tiempo de seguimiento y su supervivencia (meses). En segundo lugar, se realiza un estudio anal√≠tico cuyo objetivo es correlacionar los polimorfismos gen√©ticos relacionados con la quimioterapia de 64 de los pacientes, la toxicidad grave secundaria al tratamiento (‚Č• grado 3 seg√ļn CTAE 4.0) y su supervivencia. El genotipado se realiza en el Centro Nacional de Genotipado (CEGEN) mediante la tecnolog√≠a MassArray (AgenaBioscience), previa configuraci√≥n de un panel farmacogen√©tico pedi√°trico en base a las evidencias recogidas en la base de datos PharmGKB, fichas t√©cnicas de los medicamentos y consorcios internacionales expertos. El an√°lisis estad√≠stico descriptivo se realiza con los programas Excel 2016 y R: las variables cualitativas con el recuento num√©rico (porcentaje) y las variables cuantitativas como mediana +/- rango intercuart√≠lico ante ausencia de normalidad en la distribuci√≥n de los datos (p <0,05, prueba de Kolmogorov-Smirnov). En el an√°lisis de supervivencia se utiliza el estimador Kaplan-Meier. El an√°lisis estad√≠stico anal√≠tico de correlaci√≥n entre polimorfismos y toxicidad se realiza mediante regresi√≥n log√≠stica penalizada por Elastic Net empleando R. El an√°lisis estad√≠stico anal√≠tico de correlaci√≥n entre polimorfismos y reca√≠da/muerte se realiza mediante regresi√≥n de Cox penalizada por Elastic Net. Resultados Las variables epidemiol√≥gicas, cl√≠nico/biol√≥gicas y terap√©uticas de los pacientes de la muestra son consecuentes con las descritas en la literatura del lactante con c√°ncer. Las neoplasias con mayor impacto negativo en la supervivencia son la leucemia mielobl√°stica aguda y los tumores del sistema nervioso central. La toxicidad m√°s prevalente es hematol√≥gica, digestiva e infecciosa. Existe correlaci√≥n entre la toxicidad grave secundaria a los quimioter√°picos en forma de anemia, neutropenia y/o trombopenia y 46 polimorfismos gen√©ticos diferentes. As√≠ mismo se encuentra asociaci√≥n estad√≠sticamente significativa entre la supervivencia global y la supervivencia libre de enfermedad y ciertos polimorfismos gen√©ticos (26 y 13 respectivamente). Los polimorfismos obtenidos pertenecen a genes encargados del transporte (6 genes) y metabolismo (17 genes) de los f√°rmacos, de la reparaci√≥n del material gen√©tico y la supresi√≥n tumoral (5 genes) y de otras funciones biol√≥gicas (4 genes). Conclusi√≥n Los resultados del presente estudio muestran correlaci√≥n estad√≠stica entre 46 polimorfismos de genes implicados en la cin√©tica farmacol√≥gica y la reparaci√≥n del material gen√©tico y la variabilidad en la toxicidad quimioter√°pica y supervivencia de pacientes lactantes con c√°ncer. En definitiva, aportaciones de la farmacogen√©tica que pueden contribuir a la optimizaci√≥n del tratamiento antineopl√°sico en esta poblaci√≥n particular y a la predicci√≥n de sus riesgos, de especial impacto en los supervivientes del c√°ncer infantil

    Uso de las histonas circulantes y sus modificaciones post-traduccionales como biomarcadores en sepsis y shock séptico

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    La sepsis es una afecci√≥n potencialmente mortal causada por una respuesta anormal del hu√©sped a una infecci√≥n, produciendo respuestas fisiol√≥gicas alteradas que da√Īan los propios tejidos del paciente y pueden provocar disfunci√≥n org√°nica e incluso la muerte. Asimismo, algunos pacientes s√©pticos progresan a shock s√©ptico, caracterizado por alteraciones circulatorias, celulares y metab√≥licas sustanciales que aumentan el riesgo de mortalidad. A pesar de que la sepsis se caracteriza por un mal funcionamiento del sistema inmunol√≥gico, lo que a su vez conduce a una respuesta inmune alterada e inmunosupresi√≥n, la alta complejidad de la fisiopatolog√≠a de la sepsis requiere una mayor investigaci√≥n para comprender las respuestas inmunes que ocurren durante la sepsis. Asimismo, las histonas extracelulares circulantes han ganado relevancia como mediadores citot√≥xicos en la sepsis, ya que act√ļan como patrones moleculares asociados a da√Īo, que inducen estr√©s oxidativo y activan el inflamasoma NLRP3. Estos mecanismos median la activaci√≥n de la piroptosis, un mecanismo de muerte celular programada que produce inflamaci√≥n mediante la expresi√≥n de IL-18, IL-1ő≤ and IL-1őĪ. Sin embargo, a pesar de la evidencia de activaci√≥n del inflamasoma en las c√©lulas inmunes durante la sepsis, se desconoce si las histonas extracelulares son capaces de activar los inflamasomas endoteliales y sus consecuencias. En este trabajo destacamos el papel previamente desconocido de las histonas extracelulares, mediando la activaci√≥n del inflamasoma NLRP3 y la piroptosis en las c√©lulas endoteliales, contribuyendo a la disfunci√≥n endotelial y la desregulaci√≥n de la respuesta inmune mediada por el endotelio. Asimismo, tambi√©n demostramos c√≥mo la acetilaci√≥n de histonas disminuye la activaci√≥n de la piroptosis. Adem√°s, demostramos que la piroptosis se produce en pacientes con shock s√©ptico y los niveles de histonas circulantes se correlacionan con la expresi√≥n de citoquinas proinflamatorias y citoquinas piropt√≥ticas, la liberaci√≥n de factores de adhesi√≥n endotelial y la gravedad de la enfermedad. Proponemos la piroptosis mediada por histonas como un nuevo objetivo para desarrollar intervenciones cl√≠nicas. De manera similar, hemos analizado las respuestas inmunorelacionadas que ocurren durante las primeras etapas de la sepsis con el objetivo de proporcionar nuevos datos comparando las cantidades de citoquinas, inmunomoduladores y otros mediadores endoteliales en pacientes cr√≠ticamente enfermos no s√©pticos, s√©pticos y de shock s√©ptico. Nuestro enfoque ayudar√° a caracterizar r√°pidamente las respuestas inmunes alteradas en pacientes s√©pticos y de shock s√©ptico ingresados en la Unidad de Cuidados Intensivos. Finalmente analizamos el papel de la metilaci√≥n del ADN en el control del sistema inmune s√©ptico. Nuestros resultados demostraron el papel central de la metilaci√≥n del ADN modulando la respuesta molecular en los pacientes de shock s√©ptico y contribuyendo a la inmunosupresi√≥n, a trav√©s de la alteraci√≥n de los patrones de metilaci√≥n de los promotores de IL-10 y TREM-2.Sepsis is a life-threatening condition caused by an abnormal host response to an infection that produce altered physiological responses which damages own tissues of the patient and can result in organ dysfunction and in some cases death. Likewise, a subset of septic patients progresses to septic shock, characterized by substantial circulatory, cellular and metabolic abnormalities, which substantially increase the risk of mortality. Sepsis is characterized by a malfunction of the immune system and it can lead to an altered immune response and immunosuppression. Moreover, the high complexity of the pathophysiology of sepsis requires of further investigation to characterize the immune responses in sepsis and septic shock. Likewise, circulating extracellular histones have gained relevance as cytotoxic mediators in sepsis pathophysiology, since they act as damage-associated molecular patterns, which induce oxidative stress and activate NLRP3 inflammasome. Subsequently, inflammasome mediates pyroptosis activation, a programmed cell death mechanism that produces inflammation through the release of IL-18, IL-1ő≤ and IL-1őĪ. However, despite inflammasome activation may occur in immune cells during sepsis, it is unknown if this process also takes place in endothelial cells and particularly whether extracellular histones are capable of activating endothelial inflammasomes and their consequences. In this work we highlight a previously unknown role for extracellular histones, that mediates the activation of NLRP3 inflammasome and pyroptosis in endothelial cells by contributing to endothelial dysfunction and the dysregulation of the immune response mediated by endothelium. Likewise, we demonstrated how histone acetylation decreases pyroptosis activation. Furthermore, we show how pyroptosis occurs in septic shock patients and how circulating histone levels correlate with the expression of pro-inflammatory and pyroptotic cytokines, the release of endothelial adhesion factors and septic shock severity. We propose histone-mediated pyroptosis as a new target to develop clinical interventions. Similarly, we have analyzed the immune-related responses occurring during the early stages of sepsis with the aim of providing new data by comparing the amounts of cytokines, immune modulators and other endothelial mediators in critically-ill non-septic patients, septic and septic shock patients. Our approach will help to rapidly characterize the altered immune responses in septic and septic shock patients admitted in the Intensive Care Unit. Finally, we also analyzed the role of DNA methylation in the control of septic immune system. Our results demonstrated the central role of DNA methylation modulating the molecular response in septic shock patients and contributing to immunosuppression, through the alteration of DNA methylation patterns of IL-10 and TREM2 promoters
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