197,491 research outputs found
The proteomic investigation of chromatin functional domains reveals novel synergisms among distinct heterochromatin components
No full textChromatin is a highly dynamic, well-structured nucleoprotein complex of DNA and proteins that controls virtually all DNA transactions. Chromatin dynamicity is regulated at specific loci by the presence of various associated proteins, histones, post-translational modifications, histone variants, and DNA methylation. Until now the characterization of the proteomic component of chromatin domains has been held back by the challenge of enriching distinguishable, homogeneous regions for subsequent mass spectrometry analysis. Here we describe a modified protocol for chromatin immunoprecipitation combined with quantitative proteomics based on stable isotope labeling by amino acids in cell culture to identify known and novel histone modifications, variants, and complexes that specifically associate with silent and active chromatin domains. Our chromatin proteomics strategy revealed unique functional interactions among various chromatin modifiers, suggesting new regulatory pathways, such as a heterochromatin-specific modulation of DNA damage response involving H2A.X and WICH, both enriched in silent domains. Chromatin proteomics expands the arsenal of tools for deciphering how all the distinct protein components act together to enforce a given region-specific chromatin status
ESTABLISHMENT AND OPTIMIZATION OF THE CHROP APPROACH, COMBINING CHIP AND MS-BASED PROTEOMICS, FOR THE CHARACTERIZATION OF THE CHROMATOME AT DISTINCT FUNCTIONAL DOMAINS
No full textChromatin is a highly dynamic, well-structured nucleoprotein complex of DNA and proteins that controls virtually all DNA-transactions. Chromatin dynamicity is regulated at specific loci by the presence of various associated proteins, histones post-translational modifications, histone variants and DNA methylation. Until now the characterization of the proteomic component of chromatin domains has been held back by the challenge of enriching distinguishable, homogeneous regions for the subsequent mass spectrometry analysis and thus remains a very attractive unachieved goal. I contributed in this direction developing and optimizing a proteomic strategy that combines chromatin immunoprecipitation with quantitative proteomics based on stable isotope labeling by amino acids in cell culture to identify known and novel histone modifications, variants and complexes that specifically associate with silent and active chromatin domains. This chromatin proteomics strategy revealed unique functional interactions among various chromatin modifiers, thus suggesting new regulatory pathways, such as an heterochromatin-specific modulation of DNA damage response involving H2A.X and WICH, both enriched in silent domains. Chromatin proteomics expands the arsenal of tools for deciphering how all the distinct protein components act together to enforce a given region-specific chromatin status
Resine poli(ammido-amminiche): sintesi e studio degli equilibri di protonazione e complesso-formazione verso il Cu(II)
No full textImproved bottom-up strategy to efficiently separate hypermodified histone eptides through ultra-HPLC separation on a bench top Orbitrap instrument
No full textHistone post-translational modifications (hPTMs) play a crucial role in modulating chromatin structure and enforcing specific functional states on the underlying genome. Through the design of ad hoc analytical methods, MS has contributed significantly in the dissection of hPTMs, exhibiting specific strengths in identifying novel marks and assessing their combinatorial interplay. However, the comprehensive analysis of all individual isoforms of some hypermodified histone regions remains highly challenging with conventional proteomics platforms. Since complex hPTM patterns have unique functional outcomes on the genes, the implementation of new MS-proteomics solutions can boost epigenetic research. Here, we assessed the effectiveness of a new analytical platform-which combines ultra high-performance LC (UHPLC) with high-resolutionMS/MS analysis-in dissecting hypermodified regions from macrophage core histones. We compared the resolving power of this configuration with a standard setup based on HPLC-MS/MS and focused on two case-study peptides, H3 (27-40) and H4 (4-17). We observed that the novel platform resolves a much larger set of distinct peptide isoforms; among them some were resolved for the first time. A comprehensive analysis of hPTMs from macrophages was then carried out at basal state and upon lipopolysaccharide induction, to profile their temporal change in bulk chromatin during the inflammatory response
Analisi di contesto per la gestione di gravidanza, parto e puerperio, in un ospedale del Nord Uganda
No full textINTRODUZIONE: Ogni giorno, nel mondo, 800 donne perdono la vita per complicanze dovute a gravidanza e parto. Quasi la totalità di queste vivono in paesi del sud del pianeta. Uno dei fattori legati alla mortalità materna al parto è la mancata assistenza da parte dei professionisti sanitari. L’Uganda fa parte di questi paesi.
OBBIETTIVO: Osservare l’assistenza ostetrica presso l’ospedale St. Mary Lacor del Nord Uganda
MATERIALE E METODI: attraverso una permanenza partecipante nel mese di luglio 2015, è stato possibile raccogliere dati in merito alla gestione di gravidanza, parto e puerperio da parte delle ostetriche. Inoltre è stata raccolta un’intervista a un medico responsabile per comprendere l’accompagnamento ambulatoriale alla gravidanza.
RISULTATI: Le attività osservate e il materiale raccolto è stato organizzato secondo: le aree operative, l’utenza, i professionisti all’opera e il materiale cartaceo.
DISCUSSIONE E CONCLUSIONI: per quanto possibile, la realtà ugandese è stata confrontata con la realtà italiana della Clinica Mangiagalli, avente un bacino d’utenza simile. Ciò ha permesso di identificare comunanze e differenze e di analizzare criticamente gli elementi dell’assistenza ostetrica, nei rispettivi contesti.
PROPOSTE OPERATIVE: dal lavoro svolto è emerso che il St. Mary’s Lacor hospital rappresenta una struttura d’avanguardia nel contesto ugandese, questa realtà può essere sostenuta da collaborazione reciproca, che sviluppi “best practice”, apprendimento e formazione continua
Preparação e caracterização de filmes de poliuretano com potencial aplicação na liberação controlada de fármacos
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química.Filmes formados pela mistura de poliuretano (PU) e dibutil ftalato (DBF) como plastificante, foram estudados quanto às propriedades térmicas, mecânicas, morfológicas e avaliados quanto à potencial aplicação na permeação de paracetamol e cloridrato de diltiazem. Os deslocamentos nas bandas de infravermelho correspondentes a carbonila (região de 1730-1700 cm-1) e C-O (região de 1300-1000 cm-1) observadas com o aumento de DBF nos filmes PU/DBF sugerem a formação de ligações de hidrogênio entre os componentes. A característica amorfa dos filmes de PU/DBF foi confirmada pelas temperaturas de transição vítrea na faixa de 25-40 oC e os baixos valores de entalpia dos picos endotérmicos. As propriedades mecânicas dos filmes foram influenciadas pela quantidade de plastificante presente. Em relação ao PU puro, o módulo de elasticidade do sistema com 40% DBF foi aproximadamente três vezes menor, enquanto que a deformação do filme aumentou de 130% para 192%. A superfície dos filmes de PU puro ou com 10% DBF mostrou uma característica densa e sem poros. No sistema com 40% DBF forma observadas regiões com relevo aparente e com pouca porosidade, consistente com o baixo intumescimento (< 1%) em água e etanol. O coeficiente de permeabilidade do paracetamol aumentou de 0,7 x 10-6 cm s-1 (PU puro) para 9,5 x 10-4 cm s-1 (filme com 40% DBF) e o mecanismo dominante na permeação foi a difusão do fármaco através das cadeias poliméricas. Para os mesmos sistemas, os coeficientes de permeabilidade do diltiazem foram 8,4 x 10-6 cm s-1 e 28,4 x 10-6 cm s-1, respectivamente. Por outro lado, o mecanismo foi complexo, e dependendo da fração de DBF no filme, os modelos matemáticos de Higuchi e da lei de potências foram compatíveis com um mecanismo de liberação por difusão Fickiana (difusão) para PU puro e anômalo (sobreposição dos processos de difusão e erosão) para os filmes PU/DBF 80/20 e 60/40. As características mecânicas e os resultados de permeação obtidos no presente trabalho sugerem que os filmes PU/DBF apresentam viabilidade para utilização como sistemas de liberação controlada de fármacos, por exemplo, sistemas transdérmicos. Films formed by the mixture of polyurethane (PU) and dibutyl phthalalate (DBP) as plasticizer, were studied considering the thermal, mechanical and morphologic properties, and evaluated in terms of the potential application in the permeation of paracetamol and diltiazem chloridrate. The shifting of the infrared bands associated with the carbonyl group (region 1730-1700 cm-1) and C-O (region1300-1000 cm-1) observed with the increase of DBP in the PU/DBP films, suggested the formation of hydrogen bonds between the components. The amorphous characteristic of the PU/DBP films was confirmed by the glass transition temperatures in the range 25-40 oC and the low values of enthalpy of the endothermic peaks. The mechanical properties of the films were influenced by the amount of plasticizer. In comparison to pure PU, the modulus of elasticity for the system with 40% DBP was c.a. three times lower, and the elongation increased from 130% to 192%. The surface of the films of pure PU or with 10% DBP was dense and without porous. In the system with 40% DBP, regions with apparent relief and absence of porosity, consistent with the low swelling (< 1%) in water and ethanol, were observed. The coefficient of permeability of paracetamol increased from 0.7 x 10-6 cm s-1 (pure PU) to 9.5 x 10-4 cm s-1 (film with 40% DBP) and the main mechanism of permeation was a diffusion through the polymeric chains. For the same systems, the permeability coefficient of diltiazem were 8.4 x 10-6 cm s-1 and 28.4 x 10-6 cm s-1, respectively. On the other hand, the permeation mechanism was complex, and depending of the fraction of DBP in the film, the Higuchi and power law models were compatible with a mechanism by Fickian diffusion for pure PU and anomalous (diffusion and erosion) for PU/DBF films with 20% and 40% DBP. The mechanical properties and the permeation results obtained in this study suggest a viability to use PU/DBP films as systems for drug control release, such as, transdermal systems
Accurate Extrinsic Calibration of multiple Azure Kinect using a planar checkerboard
No full textInitially developed for entertainment, the Kinect, has become widely used in robotics, rehabilitation, and human-computer interaction thanks to its RGB-D image capture and body tracking capabilities. However, professional applications reveal limitations such as quantization noise, low resolution, and occlusion, which can compromise accuracy. A potential solution is the use of a properly calibrated Kinect network to ensure consistent output across cameras. This study proposes a flexible extrinsic calibration procedure for Kinect Azure cameras, based on 2D checkerboard corner detection. This method allows independent calibration of each camera without requiring a master-slave configuration. Calibration was tested with two- and four-camera setups, positioned at heights of 1.2 m and 2 m, with varying distances (1–2.29 m) and orientations relative to the checkerboard. Results showed high accuracy, with mean calibration errors (CE) below 1 cm under optimal conditions, reaching a minimum of 3.3 mm when the checkerboard was placed 1.75 m from the cameras. The proposed method proved effective in multi-camera setups, providing large calibration volumes. This study highlights the feasibility and flexibility of the proposed approach, with potential for future research with different sensors and varying conditions
«Egemonia con pochi soldi»: risorse, tradizione, etnicità. Caratteristiche e contraddizioni del colonialismo in Africa
No full textL’articolo esplora le origini e i tratti distintivi dei modelli coloniali in Africa, evidenziando i loro elementi coercitivi e violenti. Approfondisce il modo in cui il colonialismo ha influenzato le tradizioni, schiacciando le identità etniche e sfruttandone le risorse, specialmente agricole, al fine di mantenere l'ordine e il controllo sulle popolazioni autoctone. Sottolinea le sfide derivanti dalla limitatezza delle risorse disponibili per le amministrazioni coloniali, evidenziando il concetto di «egemonia con pochi soldi». Inoltre, analizza le dinamiche delle colonie in Africa meridionale e orientale, dove la presenza di coloni bianchi ha plasmato in modo unico lo sfruttamento coloniale. Esamina anche l'impatto a lungo termine di queste dinamiche sulla struttura socio-economica delle regioni
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