110 research outputs found
Comparison of Enzymatic and Acidic Fractionation of Corn Fiber for Glucose-rich Hydrolysate and Bioethanol Production by Candida boidinii
Corn fiber is a by-product of the corn wet milling process and a promising raw material to produce bioethanol in a bio-refinery process. In this study, enzymatic and acidic fractionations of corn fiber were compared with particular attention to produce glucose-rich hydrolyzates. The acidic fractionation contained two, sequential, sulphuric acid-catalyzed, hydrolysis steps based on our previous study. In the enzymatic fractionation process, corn fiber was pre-treated by soaking in aqueous ammonia (18.5 % (w/w) dry matter, 15 % (w/w) ammonia solution, 24 hours) and then hydrolyzed by using Hemicellulase (NS 22002) enzyme cocktail. The cellulose part of the solid residues obtained after the acidic and enzymatic fractionation processes was enzymatically hydrolyzed by using Cellic Ctec2 and Novozymes 188 (12.5 % (w/w) dry matter, 50 °C, 72 hours). Cellulose hydrolysis after the acidic and enzymatic fractionation resulted in a supernatant containing 64 g/L and 25 g/L glucose, respectively. Therefore, ethanol fermentation experiments were performed in Separated Hydrolysis and Fermentation (SHF) and Simultaneous Saccharification and Fermentation (SSF) configurations after the acidic fractionation of corn fiber. SHF configuration was found to be more advantageous regarding the achievable ethanol yield. Although the fermentation with Candida boidinii NCAIM Y.01308 was accomplished within longer time (43 hours) compared to Saccharomyces cerevisiae (5 hours), the achieved ethanol yields were similar (79%) during the SHF process. It was concluded that acidic fractionation is more efficient to produce glucose-rich hydrolyzate from corn fiber compared to enzymatic fractionation, and Candida boidinii is suitable for ethanol fermentation on the glucose-rich hydrolyzate
Herramientas para la evaluación de la eficacia de vacunas terapéuticas frente al VIH
[spa] Aunque el nĂşmero de nuevos casos lleva descendiendo desde 1996, la poblaciĂłn de personas que viven con el VIH sigue creciendo año tras año, ya que su esperanza de vida se acerca cada vez más a la poblaciĂłn general. Esto se debe principalmente a la disminuciĂłn de casos que progresan a SIDA debido a una oferta cada vez más amplia de TARVc, pero tambiĂ©n a un mayor entendimiento de los fenĂłmenos “no SIDA” relacionados con la infecciĂłn, lo que facilita una atenciĂłn integral mejorada de los pacientes. AĂşn asĂ, existe amplio consenso de que la estrategia Ăłptima para acabar con la pandemia serĂa un tratamiento curativo eficaz y seguro, pero la inmensa mayorĂa de los innumerables intentos de alcanzar este objetivo han fracasado. No obstante, existen algunos mĂ©todos que – en base de la evidencia disponible – parecen prometedores, de los cuales destacan las vacunas terapĂ©uticas. Por otro lado, el estudio de las vacunas terapĂ©uticas, siendo este un campo relativamente joven, todavĂa no ha acabado de resolver algunos retos teĂłricos y metodolĂłgicos básicos importantes. Primero, en ausencia de un mĂ©todo curativo de comparaciĂłn, no existe un consenso amplio sobre quĂ© correlatos de eficacia son los más Ăştiles a la hora de evaluar nuevos tratamientos. Esta situaciĂłn genera dificultades significativas a la hora de interpretar y comparar estudios con diseños muy dispares. Además, para medir la mayorĂa de los end-points habituales es preciso retirar el tratamiento antirretroviral durante varios meses, lo que levanta cuestiones Ă©ticas relacionadas con la seguridad del paciente. Por tanto, definir marcadores subrogados tempranos de eficacia – que podrĂan permitir prescindir de ATIs prolongadas – debe ser un objetivo de máxima prioridad. Una de las causas más relevantes que dificultan el logro de este objetivo es el entendimiento incompleto de la patogenia del VIH y de la naturaleza de una respuesta inmunolĂłgica eficaz. Es evidente que será necesario ampliar el abanico de la metodologĂa de investigaciĂłn cientĂfica para acercarnos a este fin, y es esperable que datos obtenidos con los mĂ©todos novedosos de biologĂa de sistemas puedan ser de gran utilidad. Los tres trabajos incluidos en esta tesis doctoral tratan de abordar algunos de los aspectos más importantes de esta problemática, y proponen ofrecer nuevas herramientas para la evaluaciĂłn de la eficacia de vacunas terapĂ©uticas frente al VIH. En el primero se lleva a cabo un análisis exhaustivo de diferentes medidas de eficacia virolĂłgicas en estudios con ATI, con la intenciĂłn de establecer correlaciones entre ellos y comprobar si existe algĂşn parámetro que pueda “resumir” los demás parámetros de forma fiable, y por tanto pueda ser recomendada como end-point primario en futuros estudios sobre vacunas terapĂ©uticas. En el segundo trabajo se intenta construir un modelo predictivo de control virolĂłgico durante ATI mediante un mĂ©todo sencillo de aprendizaje automático. En el Ăşltimo trabajo se explora la utilidad del análisis transcriptĂłmico en predecir la respuesta virolĂłgica en un ensayo clĂnico parcialmente exitoso con una vacuna terapĂ©utica basada en cĂ©lulas dendrĂticas
Effects of pH and Aeration Conditions on Xylitol Production by Candida and Hansenula Yeasts
During the fermentative production of xylitol the following environmental parameters have a controlling effect on the xylitol yield: concentration of monosaccharides, temperature, aeration and pH. The purpose of the present work was to evaluate xylitol production by four yeast strains at different pH values and oxygen transfer rates (OTRs). The highest xylitol yields were obtained under the following conditions: Candida parapsilosis: pH 5.0, OTR 6.1 mmol L-1 h-1;Candida guilliermondii: pH 4.5, OTR 5.7 mmol L-1 h-1; Candida boidinii: pH 6.0, OTR 5.7 mmol L-1 h-1; Hansenula anomala: pH 4.5, OTR 2.8 mmol L-1 h-1 using 50 g L-1 initial xylose concentration
Process considerations of a biorefinery producing value-added products from corn fibre
Corn fibre, a co-product of corn wet milling, can be a suitable raw material of a biorefinery producing biofuels and value-added chemicals. The simulated process is able to produce bioethanol, biomethane and xylitol synergistically, while it also covers its own heat demand. The proposed plant consists of the following process steps: fractionation, enzymatic hydrolysis and ethanol fermentation, distillation and dehydration, anaerobic digestion, biogas upgrading, aerobic waste water treatment, combined heat and power production, xylitol fermentation and recovery. Various scenarios of the biorefinery were investigated and the process configurations were compared in terms of energy efficiency, or mass flows of the products. Incineration of the sludge and production of district heat are found to be effective methods to increase the energy efficiency, on which aerobic sludge yield has a great effect. The solid-liquid separations, which are carried out in filterpress, have a curial role in terms of energy efficiency
. Combustion of the solid part of cellulose hydrolysis residue is favourable compared with the anaerobic digestion, except if the dry matter content of the filterpressed solid was set to 30% instead of 40%. The amounts of the produced xylitol and biomethane are variable, which ensures the ability of market adaptation for the biorefinery
Autoimmun endokrin kórképek társulásai = Associations of autoimmune disorders in endocrine diseases
Napjainkban egyre több adat van a neuroendokrin Ă©s az immunrendszer közötti kapcsolatra. A molekuláris genetikai kutatások eredmĂ©nyei bizonyĂtották, hogy a neurotranszmitterek, a hormonok Ă©s a citokinek az alapjai ennek a közös nyelvnek. Bebizonyosodott, hogy az immunrendszer kĂ©pes neurotranszmitterek, hormonok, az endokrin rendszer pedig citokinek termelĂ©sĂ©re. Ez az integratĂv (holisztikus) szemlĂ©let teszi lehetĹ‘vĂ© a pszicho-neuro-endokrin-immun rendszer Ă©lettani Ă©s kĂłros működĂ©sĂ©nek megismerĂ©sĂ©t. Az autoimmun kĂłrkĂ©pek társulásai Ă©s az autoimmun poliendokrin szindrĂłmák heterogĂ©n betegsĂ©gcsoportot kĂ©peznek, amelyeknek lĂ©nyege a saját antigĂ©nnel szemben csökkent vagy megszűnt tolerancia. A molekuláris genetikai kutatások a szervspecifikusnak nevezett kĂłrkĂ©pek társulásainak mechanizmusát tárták fel. Az 1-es tĂpusĂş autoimmun poliendokrin szindrĂłma jellemzĹ‘je, hogy legalább kettĹ‘ jelen van a három kardinális betegsĂ©gbĹ‘l: Addison-kĂłr, autoimmun hypoparathyreosis Ă©s mucocutan candidiasis. Ennek a ritka, autoszomális szindrĂłmának az oka az autoimmun regulátor gĂ©n (AIRE) mutáciĂłja. A 2-es tĂpusĂş autoimmun poliendokrin szindrĂłmában az Addison-kĂłr, az autoimmun pajzsmirigybetegsĂ©gek egyike Ă©s/vagy 1-es tĂpusĂş diabetes mellitus társul egymással. A 3-as tĂpusĂş poliendokrin szindrĂłmát az autoimmun pajzsmirigybetegsĂ©g, az 1-es tĂpusĂş diabetes mellitus jellemzi. Az 1-es tĂpusĂş poliendokrin szindrĂłmátĂłl eltĂ©rĹ‘en a 2-es Ă©s a 3-as tĂpusĂşakat egyes HLA-antigĂ©nek társulásai jellemzik. Az egyes betegsĂ©gekre hajlamosĂtĂł genetikai faktorok megismerĂ©se lehetĹ‘vĂ© teszi, hogy jobban megĂ©rtsĂĽk a közös autoimmun mechanizmust, Ă©s lehetĹ‘sĂ©get nyĂşjt a korai kezelĂ©shez Ă©s megelĹ‘zĂ©shez egyaránt.
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Increasing data are known for dialogue between neuroendocrine and immune systems recently. Results of molecular genetic studies provided evidences for common languages of these systems by various signals including neurotransmitters, hormones, cytokines. It is proved the immune system is able to produce neurotransmitters and hormones and endocrine organs can even result in cytokines. This new integrative approach allows to investigate the physiologic events and diseases as interactions between the psycho-neuro-endocrine-immune systems. The autoimmune polyendocrine syndromes constitute a heterogeneous group of disorders characterized by loss of immune tolerance to self-antigens. In spite of distinct clinical pictures, molecular genetic studies revealed a common molecular mechanism in the associations of organ-specific diseases. Autoimmune polyendocrine syndrome-1 is characterized by associations at least two out of three cardinal signs: Addison’s disease, autoimmune hypoparathyroidism and mucocutaneous candidiasis. This is a rare autosomal recessive syndrome induced by mutations in autoimmune regulator gene. Autoimmune polyendocrine syndrome-2 occurs more frequently and defined as the coexistence of Addison’s disease, autoimmune thyroid disease and/or type-1 diabetes mellitus. Autoimmune polyendocrine syndrome-3 is characterized by association of autoimmune thyroid disease and type-1 diabetes mellitus. The HLA and other genes proved to be important in associations of the syndrome-2 and 3 in contrast to autoimmune polyendocrine syndrome–1. Identification of predisposing genetic helps to understand the common mechanisms and provide possibility for early therapy and prevention as well
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