Purificació i anàlisi d’exosomes

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2020, Tutor: Fernando BenaventeExosomes are 30-150 nm extracellular nanovesicles that can be found in biological fluids such as blood, urine, sweat, tears, etc. They are secreted by all types of cells through exocytosis processes. Exosomes contain a wide variety of biological relevant molecules such as lipids, proteins, mRNAs, and microRNAs. They are thought to function as messengers between cells due to their ability to endocytosis and membrane fusion. Therefore, they are involved in many physiological and pathological processes, including tumor initiation and immune response. In this study, as an alternative to the techniques traditionally used to isolate exosomes, such as ultracentrifugation, it was explored polyethylene glycol (PEG) precipitation, which allows a facile, low-cost and effective isolation of exosomes from blood serum. Different variables of the method were studied, and the size of the isolated exosomes was measured by dynamic light scattering (DLS). In addition, a novel capillary electrophoresis (CE) with ultraviolet (UV) detection method was developed to complement these particle size measurements. Different concentrations of hydroxypropyl cellulose (HPC, 0.2, 0.5, 0.8% v/v) were added in the background electrolyte (BGE, 0.1 M tris + 0.25 M boric acid pH= 7.9) to reduce the adsorption of the exosomes to the inner wall of the separation capillary. The best results were obtained with a 0.5% v/v of HPC in the BGE. In order to homogenize the charge of the exosomes and make the separation only size dependent 0.1% v/v of sodium dodecyl sulfate (SDS) was also added to the BGE. Under these optimized conditions, a characteristic electrophoretic profile of the isolated exosomes was obtained, and separation showed the highest reproducibility and shortest analysis time

L’acromégalie du sujet âgé: quelles particularités?

Les adénomes somatotropes de la personne âgée sont rares, et caractérisés par un retard diagnostique, un tableau clinique peu bruyant. Leurs critères diagnostiques rejoignent ceux des patients plus jeunes. La chirurgie, si possible, reste le traitement de choix de l’acromégalie du sujet âgé. Les analogues de la somatostatine ont montré leur efficacité dans le traitement de ces patients. Le pronostic des patients acromégales est inversement corrélé à l’âge du patient, à la durée de la maladie, au dernier taux de GH sous traitement. L’âge est un déterminant majeur de la mortalité en dehors de l’évolutivité de l’acromégalie. Nous rapportons trois observations de patientes acromégales âgées respectivement de 75, 70 et 66 ans avec une revue de la littérature.Mots clés: Acromégalie, sujet âgé, chirurgie hypophysaire, pronosticEnglish Title: Acromegaly features in the aging populationEnglish AbstractSomatotroph adenomas are rare in the aging population. Diagnosis of somatotroph adenomas is often long delayed and they are characterized by atypical clinical picture. Their diagnostic criteria are similar to those used for younger patients. Surgery, if possible, is the treatment of choice for acromegaly in the elderly. Somatostatin analogues have shown to be effective in these patients. Prognosis is inversely correlated with patient’s age, duration of disease and last GH level under treatment. Beside evolution of disease, age is a major determinant of mortality. We report three cases of elderly patients with acromegaly aged 75, 70 and 66 years respectively with a literature review.Keywords: Acromegaly, aging population, pituitary surgery, prognosi

Comparative Study of Amazigh Speech Recognition Systems Based on Different Toolkits and Approaches

The objective of this study is to evaluate and contrast the performance of different ASR approaches applied to the Amazigh language. Markovian modelling techniques, including Hidden Markov Models with Gaussian mixture distribution, Convolutional Neural Network, size of vocabulary, and lastly, the choice of decoder, whether Sphinx or HTK, by conducting a comprehensive analysis and comparison of these factors, this paper aims to provide valuable insights into the development of effective ASR systems for the Amazigh language. The findings will contribute to advancing the field of Amazigh ASR and aid in the selection of appropriate techniques and tools for future research and development efforts

From side streams to building blocks: gas phase conversion of biomass-derived feedstocks to valuable monomers

This thesis describes the chemical conversion of methyl levulinate (ML), a biorefinery side stream, to the valuable monomers methyl vinyl ketone (MVK) and methyl acrylate (MA). In the first part of the project, platinum 5 wt% on sulfided carbon was found to afford up to 18% yield of MVK from ML at 300°C. In the second part of the project, conversion of ML to methyl-3-acetoxypropanoate (M3AP) through a Baeyer-Villiger (BV) oxidation was studied. The thus-formed M3AP could be successfully converted to methyl acrylate (MA) in 97% yield via elimination of acetic acid in the gas phase at 600 °C.Diese Dissertation beschreibt die chemische Umwandlung von Methyllevulinat (ML) in die wertvollen Monomere Methylvinylketon (MVK) und Methylacrylat (MA). In dem ersten Teil des Projekts wurde festgestellt, dass 5 Gew .-% Platin auf sulfidiertem Kohlenstoff bis zu 18% MVK-Ausbeute aus ML bei 300 ° C liefern. In dem zweiten Teil des Projekts wurde die Umwandlung von ML in Methyl-3-acetoxypropanoat (M3AP) durch eine Baeyer-Villiger Oxidation untersucht. Das so gebildete M3AP konnte erfolgreich in 97% Ausbeute durch Eliminierung von Essigsäure in der Gasphase bei 600 °C in MA umgewandelt werden

La plaie cranio-cérébrale chez l’oxycéphale: quelle précaution prendre pour le traiter?

L'oxycéphalie isolée est une forme non syndromique des craniosténoses d'apparition tardive, elle est  responsable d'hypertension intracrânienne insidieuse pouvant aboutir, sinon traitée précocement, à la cécité et à la débilité mentale. En général méconnue, elle peut être révélée par tout phénomène pouvant  décompenser l'hypertension intracrânienne latente. Nous présentons un cas rare d'oxycéphalie révélée par un traumatisme crânien. Un jeune garçon de cinq ans s'est présenté avec une tuméfaction pariétale droite non réductible suite à une plaie cranio-cérébrale opérée à deux reprises à l'âge de trois ans puis six mois plus tard. Le bilan neuroradiologique a objectivé une hernie cérébrale avec empreintes digitiformes diffuses et une fusion des sutures crâniennes. Un bilan ophtalmologique a montré un strabisme convergent droit et un fond d'oeil normal. Une chirurgie d'expansion crâniennea été réalisée. L'évolution post-opératoire était favorable.  L'oxycéphalie harmonieuse peut passer inaperçue et un traumatisme crânien même bénin peut la révéler.Key words: Mots clé: Oxycéphalie, plaie cranio-cérébrale, craniosténose

Flaws linked to lime in pottery of Marrakech (Morocco)

The studied clayey materials come from soil of Marrakech Haouz Plain. We discussed the influence of grain size, mineralogical and chemical composition of these raw materials on the lime behaviour in pottery shards. In this paper we propose some recommendations to inhibit lime blowing and the efflorescences responsible for flaws. The application of such recommendations will improve the quality of produced pottery and the income of potters in the region.Peer reviewe

Moroccan dialect NLP resources for Data Engineering and Intelligent Systems

Dialectal resources can provide valuable information for scientific research in many domains. They can play an important role in scientific research, especially in the fields of linguistics, sociology, anthropology, psychology, digital transformation, and artificial intelligence. NLP can also play an important role in decision-making by enabling the analysis of large volumes of textual data to extract relevant information. Data relevance is a key factor in decision-making, and companies wishing to join the trend must have all NLP resources at their disposal. In this paper, we will present the different resources and systems developed for Data Engineering and Intelligent Systems for Moroccan dialects

Estudi de molècules orgàniques fòssils per a la caracterització dels esdeveniments climàtics ocorreguts durant períodes glacials i interglacials

[cat] Arribar a comprendre les causes i efectes dels canvis globals i les interaccions sinèrgiques del sistema climàtic continua sent un repte científic complex. Els informes del Panell Intergovernamental sobre el Canvi Climàtic (IPCC) han proporcionat avenços substancials en la comprensió del canvi climàtic. No obstant, es basen en l'extrapolació de les condicions actuals i s'hauria de tenir en compte que en el passat l'evolució natural del clima ha manifestat reorganitzacions importants. La matèria orgànica (MO) sedimentària està formada per una gran varietat de components, de diferents estructures, característiques geoquímiques, fonts i estat de conservació. La matèria orgànica, tot i que originalment forma part de diferents organismes (Bacteria, Archaea o Eucarya), acaba acumulant-se en arxius sedimentaris de milers d’anys d’antiguitat, on es preserva, tot deixant registrades les condicions ambientals de l’hàbitat on vivien aquells organismes que les varen sintetitzar originalment. D’aquesta manera, les molècules orgàniques fòssils proporcionen una biblioteca molt valuosa d’esdeveniments climàtics, donat que, per exemple, proporcionen informació sobre temperatura, balanç hídric, productivitat primària fotosintètica, processos d’alteració diagenètica o l’activitat pre/post- deposicional (metanogènesi, oxidació aeròbica, etc.). En aquest context, la memòria de Tesi Doctoral que s’ha elaborat se centra en l’anàlisi de molècules orgàniques fòssils dipositades en sediments marins situats a la plataforma continental de la Península Ibèrica, amb l’objectiu de determinar l'origen, distribució, evolució i processos d'alteració de la matèria orgànica sedimentaria, i contribuir a la reconstrucció de les condicions ambientals que van tenir lloc en el passat. Amb aquesta finalitat, es van agafar sediments marins del testimoni IODP U1385 situats en la confluència de l'oceà Atlàntic i Mar Mediterrani. Aquesta àrea d'estudi té un gran interès perquè correspon a una regió sensible als canvis climàtics ràpids, sotmesa a la influència de l’entrada de compostos continentals i de processos d’aflorament d’aigua profunda, que juntament amb taxes elevades de sedimentació, afavoreix l’acumulació ràpida i la preservació de la matèria orgànica sedimentària. Paral·lelament, la recerca desenvolupada també va incloure la generació d'una base de dades de temperatura d'alta resolució temporal. L’element essencial d’aquesta base provenia dels arxius d’alquenones, juntament amb altres marcadors derivats de diferents registres ambientals, tals com els testimonis de gel i els espeleotemes. Aquesta base de dades nova té com a objectiu proporcionar informació sobre l'estructura espacial i temporal dels esdeveniments/transicions de la temperatura superficial del mar, les relacions de fase entre les variacions del clima regional, els canvis globals i el forçament extern del clima.[eng] To understand the causes and effects of global changes and synergistic interactions of the climate system still remains a complex scientific challenge. The reports of the Intergovernmental Panel on Climate Change (IPCC) have provided substantial advances in the understanding of climate change. However, it’s based on extrapolation of current conditions and should take into account that in the past the natural climate evolution has expressed major reorganizations. Sedimentary organic matter (OM) includes a variety of components, different structures, geochemical features, sources and conditions. Organic matter, although originally forming part of different organisms (Bacteria, Archaea or Eucarya), finally accumulates on sedimentary archives thousands of years old, where it remains perfectly preserved, while registering the environmental conditions from the habitat of its former synthesizers. Thus, fossil organic molecules represent an invaluable library of climatic events because they provide information, e.g. temperature, hydrological balance, primary photosynthetic production, diagenetic alteration processes or pre/post-depositional activity (methanogenesis, aerobic oxidation, etc). In this context, the thesis focuses on the analysis of fossil organic molecules deposited in marine sediments located on the continental shelf of the Iberian Peninsula. The aim of this research line focuses on determining the origin, distribution, evolution and alteration processes of sedimentary organic matter and contributes to the reconstruction of environmental conditions that occurred in the past. To this end, deep sea sediments samples were obtained from IODP U1385 located at the confluence of the Atlantic Ocean and the Mediterranean Sea. This study area is well known as a source of rapidly accumulating and preservation sedimentary OM and represents an important area for investigating past climate variability, subject to the influence of the entry of continental compounds by river discharge and upwelling phenomena. In parallel, the research line also included the creation of a high resolution database of alkenone-derived sea surface temperatures, together with other markers derived from different environmental records such as ice cores and speleothems. This new database aims to provide information about the spatial and temporal structure of sea surface temperature events/transitions, regional and global climate changes, and external forcings