1,538 research outputs found

    Apparent stiffness of vimentin intermediate filaments in living cells and its relation with other cytoskeletal polymers

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    The cytoskeleton is a complex network of interconnected biopolymers intimately involved in the generation and transmission of forces. Several mechanical properties of microtubules and actin filaments have been extensively explored in cells. In contrast, intermediate filaments (IFs) received comparatively less attention despite their central role in defining cell shape, motility and adhesion during physiological processes as well as in tumor progression. Here, we explored relevant biophysical properties of vimentin IFs in living cells combining confocal microscopy and a filament tracking routine that allows localizing filaments with ~20 nm precision. A Fourier-based analysis showed that IFs curvatures followed a thermal-like behavior characterized by an apparent persistence length (lp*) similar to that measured in aqueous solution. Additionally, we determined that certain perturbations of the cytoskeleton affect lp* and the lateral mobility of IFs as assessed in cells in which either the microtubule dynamic instability was reduced or actin filaments were partially depolymerized. Our results provide relevant clues on how vimentin IFs mechanically couple with microtubules and actin filaments in cells and support a role of this network in the response to mechanical stress.Fil: Smoler, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Coceano, Giovanna. Royal Institute of Technology; SueciaFil: Testa, Ilaria. Royal Institute of Technology; SueciaFil: Bruno, Luciana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Calculo. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Calculo; ArgentinaFil: Levi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentin

    Fasceite necrotizante cervical secundária a amigdalite bacteriana

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    A fasceite necrotizante cervical é uma infecção grave de partes moles do pescoço. Trata-se de entidade rara, porém quando presente tem como principal origem um foco infeccioso odontogênico. São descritos 4 casos de fasceite necrotizante cervical a partir de tonsilites e abscesso peritonsilar, os quais, foram admitidos e tratados na unidade de terapia intensiva. Um dos pacientes era portador de Diabetes Melittus não insulino- dependente e outro paciente havia recebido corticoterapia antes do desenvolvimento da infecção. Em um dos casos ocorreu mediastinite, insuficiência respiratória e o paciente evolui para o óbito em decorrência de choque séptico. Durante o tratamento, 3 pacientes evoluíram satisfatoriamente devido ao diagnostico precoce, tratamento cirúrgico agressivo e utilização de antibiótico terapia de largo espectro. A bactéria mais comumente encontrada foi o Streptococcus sp, mas flora mista com germes anaeróbios foi encontrada em 3 dos casos descritos. CONCLUSÕES: Deve-se suspeitar de tonsilite e abscesso peritonsilar como causa de fasceite necrotizante cervical para que tratamento agressivo e precoce seja realizado.Necrotizing fasciitis is a severe and potentially fatal soft tissue infection, but involvement of the head and neck is rare. We report on 4 cases of cervical necrotizing fasciitis arising from tonsillitis. One patient was diabetic and one had received steroids before disease development. One patient developed acute respiratory failure and died of septic shock. Three patients recovered, helped by early recognition, aggressive surgical intervention, appropriate broad-spectrum antibiotics, and supportive therapy. The common bacteria found in all abscess samples were Streptococcus sp., but mixed flora with anaerobic organisms was seen in all but 1 case. Tonsillitis and peritonsillar abscess must be suspected as a cause of cervical necrotizing fasciitis and a successful result can be achieved with immediate aggressive treatment

    The EPFL Logic Synthesis Libraries

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    We present a collection of modular open source C++ libraries for the development of logic synthesis applications. These libraries can be used to develop applications for the design of classical and emerging technologies, as well as for the implementation of quantum compilers. All libraries are well documented and well tested. Furthermore, being header-only, the libraries can be readily used as core components in complex logic synthesis systems.Comment: 11 pages, originally accepted at Int'l Workshop on Logic & Synthesis 2018, extended for Workshop on Open-Source EDA Technology 201

    Potential for lager beer production from saccharomyces cerevisiae strains isolated from the vineyard environment

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    Saccharomyces pastorianus, genetic hybrids of Saccharomyces cerevisiae and the Saccharomyces eubayanus, is one of the most widely used lager yeasts in the brewing industry. In recent years, new strategies have been adopted and new lines of research have been outlined to create and expand the pool of lager brewing starters. The vineyard microbiome has received significant attention in the past few years due to many opportunities in terms of biotechnological applications in the winemaking processes. However, the characterization of S. cerevisiae strains isolated from winery environments as an approach to selecting starters for beer production has not been fully investigated, and little is currently available. Four wild cryotolerant S. cerevisiae strains isolated from vineyard environments were evaluated as potential starters for lager beer production at laboratory scale using a model beer wort (MBW). In all tests, the industrial lager brewing S. pastorianus Weihenstephan 34/70 was used as a reference strain. The results obtained, although preliminary, showed some good properties of these strains, such as antioxidant activity, flocculation capacity, efficient fermentation at 15◦C and low diacetyl production. Further studies will be carried out using these S. cerevisiae strains as starters for lager beer production on a pilot scale in order to verify the chemical and sensory characteristics of the beers produced

    Biodiversity of Lactobacillus plantarum from traditional Italian wines

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    In this study, 23 samples of traditional wines produced in Southern Italy were subjected to microbiological analyses with the aim to identify and biotype the predominant species of lactic acid bacilli. For this purpose, a multiple approach, consisting in the application of both phenotypic (API 50CHL test) and biomolecular methods (polymerase chain reaction-denaturing gradient gel electrophoresis and 16S rRNA gene sequencing) was used. The results showed that Lactobacillus plantarum was the predominant species, whereas Lb. brevis was detected in lower amount. In detail, out of 80 isolates 58 were ascribable to Lb. plantarum and 22 to Lb. brevis. Randomly amplified polymorphic DNA-polymerase chain reaction was used to highlight intraspecific variability among Lb. plantarum strains. Interestingly, the cluster analysis evidenced a relationship between different biotypes of Lb. plantarum and their origin, in terms of wine variety. Data acquired in this work show the possibility to obtain several malolactic fermentation starter cultures, composed by different Lb. plantarum biotypes, for their proper use in winemaking processes which are distinctive for each wine

    Mastoiditis and facial paralysis as initial manifestations of Wegener's Granulomatosis

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    Wegener's Granulomatosis (WG) is characterized by necrotizing granulomas and vasculitis. If left untreated, the prognosis is poor - a 90% mortality rate within 2 years. Several authors have described the otologic manifestations of WG; these authors, however, have not mentioned the stage of the disease in which these findings present - whether as initial manifestations or subsequent to other findings. Aim: To describe three confirmed cases of WG with mastoiditis as the first manifestation, progressing to peripheral facial paralysis (PFP). Material and Method: A clinical series study. Patients diagnosed with WG that initially presented with otologic findings are described. Results: The three cases presented with unilateral otalgia, otorrhea, and hearing loss associated with ipsilateral PFP. None recovered in spite of the treatment; an investigation of associated diseases was therefore undertaken. Positive ANCA-C titers where detected in all patients, confirming the diagnosis of WG. Clinical improvement was seen after treatment of WG; the PFP regressed and hearing thresholds improved partially. Conclusion: Complications of otitis media (mastoiditis and PFP) that do not respond to the usual treatment require an investigation of associated diseases; WG should be included for an early diagnosis to change the prognosis in these patients.A Granulomatose de Wegener (GW) é caracterizada por granulomas necrotizantes e vasculite. Sem tratamento a doença tem prognóstico pobre com índice de mortalidade de 90% em 2 anos. Diversos autores citam as manifestações otológicas no curso da GW, entretanto não é especificado em que momento da doença elas apareceram, isto é, se como manifestação inicial ou subsequente a outros achados. Objetivo: Descrever três casos confirmados de GW que apresentaram inicialmente mastoidite e evoluíram com paralisia facial periférica (PFP). Material e Método: Estudo de série de casos. Pacientes diagnosticados com GW que apresentaram inicialmente manifestações otológicas são descritos. Resultados: Os três casos descritos abriram o quadro com otalgia, otorreia e hipoacusia unilateral, associada a paralisia facial periférica ipsilateral. Tiveram resposta inadequada aos tratamentos instituídos o que motivou uma investigação de outras doenças associadas. Nessas circunstâncias, detectaram-se títulos positivos de ANCA-C em todos pacientes, confirmando-se o diagnóstico de GW, após período variável de investigação. Institui-se o tratamento para GW observando-se melhora do quadro clínico, regressão da PFP e melhora parcial dos limiares auditivos. Conclusão: Complicações de otites médias agudas (mastoidite e PFP) refratárias as terapêuticas habituais impõem a investigação de doenças associadas e a GW deverá ser pesquisada para que se possa fazer o diagnóstico o mais precocemente possível, alterando desta forma o prognóstico destes pacientes.UNIFESP-EPM Departamento de Otorrinolaringologia e Cirurgia de Cabeça e PescoçoUNIFESP, EPM, Depto. de Otorrinolaringologia e Cirurgia de Cabeça e PescoçoSciEL

    Polypeptides from Hermetia illucens: a bio source for innovative materials in the framework of a circular economy model

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    Plastic waste reduction is one of the main challenges of the 21st century from an environmental and sustainability perspective. Still nowadays, relatively little plastic waste is collected for recycling (less than 10%) and a large fraction (approximately 20%) of Municipal Solid Waste (MSW) goes to landfill. At the global level, the generation of municipal solid waste (MSW) is estimated to be 2.5 billion tonnes per year, of which 30-55% is represented by the so-called organic fraction of municipal solid waste (OFMSW). While the use of alternative, plastic-like materials from natural sources could be one of the most appealing solutions, the massive occupation of agricultural soils for their supply is a big concern. In this scenario, waste valorization is gaining major relevance within the framework of circular economy models, with bio-conversion mediated from insects being one possible and effective answer. The project RICH (Turning Rubbish Into biobased materials: a sustainable CHain for the full valorization of organic waste) aims to develop an innovative and integrated circular economy chain, which, starting from the biotransformation of the organic fraction of municipal solid waste (OFMSW), allows the targeted production of biobased materials with high technological value, such as bioplastics and other advanced protein-based materials. In the present study, proteins and polypeptides were extracted from larvae of Hermetia illucens, also known as black soldier fly. Extracts were characterized by means of proteomics techniques such as BCA, SDSPAGE, and LC-MS analyses. Procedures were next defined to prepare materials such as films, tuning the mechanical properties, and investigating the correlation with the molecular structure. Elastic films were obtained and the elasticity was correlated with the chemical composition and the protocol for film preparation. The results so far obtained pave the way for the application of these materials in the biomedical and packaging fields, bringing us closer to the completion of a new circular economy model

    Innovative bioplastics from polypeptides of Hermetia illucens

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    The environmentally sustainable waste management, together with waste valorization, is one of the actual challenges pursued by the European Commission. UE policies are thus contributing in the frameworks of circular economy by promoting the extraction of high quality materials from wastes. At the European level, the generation of municipal solid waste (MSW) is estimated to be 500 kg per capita, of which 70% (discarded food, yard trimmings, paper and wood) is represented by the so-called organic fraction of municipal solid waste (OFMSW). In this scenario, organic waste valorization is gaining major relevance within circular economy models, with bioconversion mediated from insects being one possible and effective answer to the problem. The project RICH (Turning Rubbish Into biobased materials: a sustainable CHain for the full valorization of organic waste) aims to develop an innovative and integrated circular economy chain, which, starting from the biotransformation of the organic fraction of municipal solid waste (OFMSW), allows the targeted production of biobased materials with high technological value, such as bioplastics and other advanced protein-based materials. In the present study, proteins and polypeptides were extracted from larvae and pupae of Hermetia illucens, also known as Black Soldier Fly. The extraction efficiency from both stages was assessed. Crude extracts were characterized by means of proteomics techniques such as BCA, SDS-PAGE, and LC-MS analyses. State of art materials were prepared, investigating the correlation with the molecular structure through physical techniques (FTIR, Contact Angle, TGA). Results clearly points out a correlation between film-forming ability and the chosen larval stage, with extracts from Larvae at the 6th instar leading to the best results. A correlation with polypeptide chain length is proposed
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