Atividade antiangiogênica da forma recombinante da proteína 21 de Trypanosoma cruzi

Chagas disease, caused by the parasite Trypanosoma cruzi, is the cause of Chronic chagasic cardiomyopathy (CCC). The prospection of innovative therapeutic agents against CCC is a major task. The recombinant form of 21 (rP21), a secreted T. cruzi protein involved in host cell invasion and on progression of chronic inflammatory processes have been studied as a potential novel therapeutic target. Our present work aimed to verify and investigate the impact of rP21 in the formation of blood vessels in vitro and in vivo. First, tEnd cells were treated with different concentrations of rP21 or bacterial extract and viability and cellular adhesion were evaluated by MTT and angiogenesis inhibition by Matrigel tube formation assay and murine model. To verify the proteolytic activity of rP21 on extracellular matrix (ECM) components, fibrinogen, matrigel and fibronectin was incubated with rP21 or not. In addition, we performed proliferation assays and cell cycle analysis. Furthermore, the accumulation and distribution of F-actin was determined by Phalloidin staining using ImageJ software. Finally, tEnd cells were incubated with rP21 and the mRNA levels were analyzed by real-time PCR. Our results showed that rP21 did not alter cell viability and adhesion, but strongly inhibited vessel formation in vitro and in vivo. Tube formation assay showed that angiogenesis inhibition was dependent of the CXCR4-rP21 binding. In addition to these results, we observed that the rP21 was able to inhibit cell proliferation and promoted a significant reduction in the number of 4n cells (G2/M phase). Moreover, we found that rP21 significantly increased F-actin levels and this protein was able to modulate expression of genes related to angiogenesis and actin cytoskeleton. However, rP21 showed no significant activity on the matrix components. In this sense, we conclude that the rP21-endothelial cells (ECs) interaction via CXCR4 promotes inhibition of vessel formation through a cascade of intracellular events, such as inhibition of ECs proliferation and modulation of the expression of molecules associated with angiogenic processes and actin cytoskeleton.

Tomografia a coerenza ottica: principi ed applicazioni

La tomografia a coerenza ottica (Optical Coherence Tomography, OCT) rappresenta fondamentalmente una nuova modalità di diagnostica per immagini non invasiva e ad alta risoluzione. L’OCT fornisce immagini, sotto forma di sezioni trasversali o tomografiche, delle microstrutture dei tessuti biologici tramite la misura del ritardo dell’eco e dell’intensità della luce retrodiffusa o riflessa dal campione in analisi. L’OCT è una potente tecnica poiché fornisce in tempo reale immagini in situ delle strutture tissutali normali o patologiche, con una risoluzione da 1 a 15 micron, che è da uno a due ordini di grandezza maggiore rispetto alle tecniche per immagini convenzionali come ultrasuoni, risonanza magnetica o tomografia computerizzata. Tutto questo senza la necessità di ottenere e analizzare un campione tramite biopsia e studio istopatologico. Sin dall’inizio della sua utilizzazione nel 1991, l’OCT è stata impiegata in un vasto spettro di applicazioni cliniche, principalmente l'oftalmologia. In strutture non trasparenti, diverse da quelle oculari, la profondità massima esplorabile è limitata a 2-3 mm a causa dei fenomeni di attenuazione secondari e alla dispersione della luce. Inoltre, i numerosi sviluppi fatti dalla tecnologia OCT hanno portato ad alte velocità di acquisizione e, grazie all’utilizzo di sorgenti laser di ultima generazione, risoluzioni assiali dell’ordine di 1 micrometro. Dunque, la tomografia a coerenza ottica può essere sfruttata: - Quando la biopsia escissionale è pericolosa o impossibile. - Quando si rischiano errori di campionamento, come guida alla biopsia in modo da ridurre errori nel prelievo del campione. - Come guida alla procedura d’intervento, in associazione alle procedure di cateterismo, endoscopia e laparoscopia.

Recente evoluzione delle tecnologie PET-RMN

La PET/RMN è un ibrido delle tecnologie di imaging che incorpora la risonanza magnetica nucleare (RMN), che fornisce un'imaging di tipo morfologico, e la tomografia ad emissione di positroni (PET), che fornisce un'imaging di tipo funzionale. Questa nuova tecnologia trova applicazioni in campo oncologico, cardiovascolare e nello studio del sistema nervoso centrale (SNC). La realizzazione di questa nuova tecnologia ha comportato diverse sfide tecniche per la combinazione delle due apparecchiature, che sono state risolte con diversi approcci. Lo sviluppo futuro della PET/RMN sarà guidato da molteplici fattori tra i quali l'eliminazione degli eventuali disturbi e la necessità di accordi per i rimborsi dell'esame. Tutt'ora esistono tre diversi produttori al mondo : Simens, Philips e GE (General Electric), i quali hanno diverse tecnologie e diversi metodi di analisi. La prima apparecchiatura PET/RMN in Italia è stata acquistata dall'ospedale di Padova nel gennaio 2015, mentre negli altri paesi aveva già fatto la sua comparsa dal 2011.

Innovazione nella Diagnostica per Immagini: l’integrazione PET/RMN

Nell'ambito della Diagnostica per Immagini, l'imaging ibrido sta assumendo un ruolo fondamentale in molte applicazioni cliniche, tra cui oncologia, neurologia e cardiologia. La possibilità di integrare informazioni complementari, funzionali e morfologiche, in un'unica immagine, permette di valutare con estrema accuratezza varie tipologie di malattie, diminuendo i tempi di acquisizione e i disagi per i pazienti. La risonanza magnetica, in sostituzione alla TAC nel sistema integrato PET/TC, introduce notevoli vantaggi quali l'acquisizione simultanea dei dati, l'ottimo contrasto dei tessuti molli, l'assenza di radiazioni ionizzanti e la correzione degli artefatti da movimento; ciò migliora l'accuratezza delle immagini e, di conseguenza, il processo diagnostico. Nonostante sia un interessante strumento di diagnostica e l'apice dello sviluppo tecnologico in imaging nucleare, vi sono alcune problematiche che ne impediscono la diffusa adozione, tra cui le interferenze reciproche tra le due modalità, i costi elevati e ancora una ridotta pubblicazione di articoli al riguardo.

Studio ed Analisi di un refrigeratore magnetico

Nella tesi si affronta l'argomento della refrigerazione magnetica. La tematica è affrontata a partire dal principio fisico che c'è alla base fino ad arrivare ai prototipi relaizzati nel corso degli anni. Si conclude con lo stato attuale della refrigerazione magnetica, facendo un' ipotesi progettuale di un potenziale refrigeratore magnetico.

Avaliação do impacto das condições de operação na qualidade do sinal : processamento de dados de reflexão sísmica de multicanal

Através do processamento de dados sísmicos convertem-se registos de campo em secções sísmicas com significado geológico, que revelam informações e ajudam a delinear as camadas geológicas do subsolo e identificar estruturas soterradas. Portanto, a interpretação dos dados sísmicos só é boa se o processamento também o for. Este trabalho é resultado de um estágio curricular na empresa de prospecção geofísica GeoSurveys, que consistiu principalmente em processar 18 linhas de dados de sísmica de reflexão multicanal de alta resolução adquiridas na ilha de Pulau Tekong em Singapura, que têm como finalidade investigação do solo da baia desta mesma ilha. Estes dados foram cedidos à GeoSurveys para fins académicos, caso em que se inclui esta dissertação. Para atingir os objectivos propostos que consistiam em avaliar o impacto das condições de operação na qualidade do sinal sísmico e interpretação das linhas, fez-se o processamento das linhas utilizando um fluxo processamento padrão utilizado na empresa, com recurso ao software Radex Pro. Este fluxo de processamento tem como mais-valia o método de correcções estáticas, o UHRS trim statics, além das técnicas habituais utilizadas para melhorar a resolução das secções sísmicas como é o caso da desconvolução, a atenuação de ruído através do stacking, correcções de NMO, e migração, entre outras técnicas. A interpretação das linhas sísmicas processadas foi feita no software Kingdom Suite (IHS), através da distinção da configuração interna dos reflectores em cada secção sísmica, estabelecendo deste modo as principais unidades sismo-estratigráficas e identificando as zonas de interface que delimitam os horizontes principais. Foi feito ainda um estudo geológico sumário da área de pesquisa e da evolução geodinâmica da região.

Proposta per un maglev urbano. Lineamenti di un progetto di ricerca industriale per lo sviluppo di un sistema di trasporto innovativo

L'oggetto della proposta è un sistema di trasporto guidato di media potenzialità destinato alle aree metropolitane, basato sulla tecnologia della levitazione magnetica. Utilizza magneti permanenti ad alta energia per la sostentazione; un motore lineare sincrono per la propulsione; un dispositivo meccanico, o elettromagnetico, per stabilizzare la guida assicurata dagli stessi magneti della sostentazione. Il contenuto innovativo dell'oggetto non si limita alla parte non convenzionale (levitazione), ma investe tutto il sistema, poiché l'offerta industriale di un sistema destinato alle aree metropolitane è vincente solo se riferita ad un sistema completo (infrastruttura, veicoli, alimentazione, sistema di sicurezza, modello di esercizio, gestione, manutenzione, …). Si descrive inoltre la particolare soluzione inedita con abitacolo sospeso al di sotto dell'involucro tecnologico (comprendente magneti di sostentamento, motore lineare, sistema di guida, sospensione secondaria).

Desenvolvimento de um método para correção de curvas de desempenho em bombas centrífugas submersas operando com fluidos viscosos

Electrical Submersible Pump (ESP) is used as an artificial lift technique. However, pumping viscous oil is generally associated with low Reynolds number flows. This condition leads to a performance degradation respect to the performance expected from the regular operation with water that most of the centrifugal pumps are originally designed for. These issues are considered in this investigation through a numerical study of the flow in two different multistage, semi-axial type ESPs. This investigation is carried out numerically using a Computational Fluid Dynamics (CFD) package, where the transient RANS equations are solved numerically. The turbulence is modeled using the SST model. Head curves for several operating conditions are compared with manufacturer’s curves and experimental data for a three-stage ESP, showing good agreement for a wide range of fluid viscosities and rotational speeds. Dimensionless numbers (n, n, n e Re) are used to investigate performance degradation of the ESPs. In addition, flow phenomena through the impellers of the ESPs are investigated using flow field from numerical results. Results show that performance degradation is directly related to rotational Reynolds number, Re. In addition, it was verified that performance degradation occurs for constant normalized specific speedn, which shows that performance degradation occurs similarly for different centrifugal pumps. Moreover, experimental data and numerical results agreed with a correlation from literature between head and flow correction factors proposed by Stepanoff (1967). A definition of modified Reynolds number was proposed and relates the head correction factor to viscosity. A correlation between head correction factor and the modified Reynolds number was proposed, which agreed well with numerical and experimental data. Then, a method to predict performance degradation based on the previous correlations was proposed. This method was compared with others from literature. In general, results and conclusions from this work can also be useful to bring more information about the flow of highly viscous fluids in pumps, especially in semi-axial, multistage ESPs.

Atividade antioxidante e antiproliferativa de extratos de folhas de Plukenetia volubilis L. (EUPHORBIACEAE)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Parâmetros citogenéticos de espécies comerciais de carangidae (perciformes), com vistas a sua empregabilidade na conservação biológica e piscicultura marinha

Worldwide, families Carangidae and Rachycentridae represent one of the groups most important commercial fish, used for food, and great potential for marine aquaculture. However, the genetic bases that can underpin the future cultivation of these species, cytogenetic between these aspects are very weak. The chromosomal patterns have provided basic data for the exploration of biotechnological processes aimed at handling chromosomal genetic improvement, such as induction of polyploidy, androgenesis and ginogenesis, as well as obtaining monosex stocks and interspecific hybridizations. This paper presents a comprehensive cytogenetic survey in 10 species, seven of the family Carangidae and the monotypic family Rachycentridae. Classical cytogenetic analysis and in situ mapping of multigene sequences were employed, and additionally for the genus Selene and morphotypes of Caranx lugubris, comparisons were made using geometric morphometrics. In general, conservative species exhibit a marked chromosome number (2n=48). Although present in large part, different karyotypic form, retain many characteristics typical of chromosomal Order Perciformes, the high number of elements monobrachyal, Ag-NORs/18S rDNA sites and heterochromatin simply reduced, preferably centromeric. The main mechanisms involved in karyotypic diversification are the pericentric inversions, with secondary action of centric fusions. In addition to physical mapping and chromosome detail for the species are presented and discussed patterns of intra-and interspecific diversity, cytotaxonomic markers. This data set provides a better understanding of these patterns caryoevolutyonary groups and conditions for the development of protocols based on Biotechnology for chromosomal manipulation Atlantic these species

Mapeamento cromossômico de genes ribossomais em espécies estuarinas da família Gerreidae Identificação de uniformidade cariotípica e sua empregabilidade com fins biotecnológicos - REPROGEN

Perciformes are dominant in the marine environment, characterized as the largest and most diverse fish group. Some families, as Gerreidae, popularly known as silver jennies, carapebas, or mojarras have a high economic potential to marine fish farming, natural explotation and game fishing. Genetic information of these species are of fundamental importance for their management and production. Despite exist over 13,000 marine fish species described, only 2% were cytogenetically analyzed and less than 1% have some reproductive characteristics known. Induced breeding, cytogenetic characterization and cryopreservation of gametes, represent important areas in applied fish studies. In this project cytogenetic analyzes were performed to acess genetic aspects of Gerreidae species, distributed in coastal and estuarine regions of Northeast Brazil. Different methods for identifying chromosomal regions were employed using conventional techniques (Ag-NORs, C-banding), staining with base-specific fluorochromes (DAPI-CMA3), and physical mapping of ribosomal genes 18S and 5S rDNA, through hybridization in situ with fluorescent probes (FISH). The six species analyzed showed remarkable chromosome conservatism. The 18S and 5S ribosomal genes when analyzed in phylogenetic perspective demonstrate varied evolutionary dynamics, suggesting ocurrence of stasis process in some groups and greater dynamism in others. Double FISH with 18S and 5S probes showed both how efficient cytotaxonomic markers in the homogeneous karyotypes of this group of species. The karyotypic pattern identified in addition to the evolutionary aspects of karyotype, are suggestive of existence of low potential of post-zygotic barrier, prompting further research to prospect for artificial interspecific hybridization of these species of commercial importance

Avaliação da influência do nacl em pastas de cimento portland para cimentação de poços de petróleo em zonas evaporíticas

One of the major current challenges for oilwell companies is the extraction of oil from evaporitic zones, also known as pre-salt basins. Deep reservoirs are found under thick salt layers formed from the evaporation of sea water. Salt layers seal the flow of oil from underneath rock formations, which store hydrocarbons and increase the probability of success in oil and gas exploration. Oilwells are cemented using Portland-based slurries to promote mechanical stability and zonal isolation. For pre-salt oilwells, NaCl must be added to saturate the cement slurries, however, the presence of salt in the composition of slurries affects their overall behavior. Therefore, the objective of the present study was to evaluate the effect of the addition of 5 to 25% NaCl on selected properties of Portland-based slurries. A series of tests were carried out to assess the rheological behavior, thickening time, free water and ultrassonic compressive strength. In addition, the slurries were also characterized by thermal analysis, X ray diffraction and scanning electron microscopy. The results showed that the addition of NaCl affected the thickening time of the slurries. NaCl contents up to 10% shortened the thickening time of the slurries. On the other hand, concentrations in excess of 20% not only extended the thickening time, but also reduced the strength of hardened slurries. The addition of NaCl resulted in the formation of a different crystalline phase called Friedel´s salt, where free chlorine is bonded to tricalcium aluminate

Pseudomonas fluorescentes provenientes da rizosfera de solanáceas no controle de Ralstonia solanacearum em tomateiro

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Fitopatologia, Programa de Pós-Graduação em Fitopatologia, 2015.

Descrição do resistoma de solo de Cerrado stricto sensu e o potencial de dioxigenases metagenômicas na resistência antimicrobiana e em processos de biorremediação

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2016.

Influência da adição do NaCl e KCl em sistemas de pastas contendo sílica para poços de petróleo em zonas evaporíticas e carbonáticas

One of the major challenges faced nowadays by oil companies is the exploration of pre-salt basins. Thick salt layers were formed in remote ages as a consequence of the evaporation of sea water containing high concentrations of NaCl and KCl. Deep reservoirs can be found below salt formations that prevent the outflow of oil, thus improving the success in oil prospection. The slurries used in the cement operations of salt layers must be adequate to the properties of those specific formations. At the same time, their resulting properties are highly affected by the contamination of salt in the fresh state. It is t herefore important to address the effects of the presence of salt in the cement slurries in order to assure that the well sheath is able to fulfill its main role to provide zonal isolation and mechanical stability. In this scenario, the objective of the present thesis work was to evaluate the effect of the presence of NaCl and KCl premixed with cement and 40% silica flour on the behavior of cement slurries. Their effect in the presence of CO2 was also investigated. The rheological behavior of slurries containing NaCl and KCl was evaluated along with their mechanical strength. Thermal and microstructural tests were also carried out. The results revealed that the presence of NaCl and KCl affected the pozzolanic activity of silica flour, reducing the strength of the hardened slurries containing salt. Friedel´s salt was formed as a result of the bonding between free Cl- and tricalcium aluminate. The presence of CO2 also contributed to the degradation of the slurries as a result of a process of carbonation/bicarbonataion