4,082 research outputs found
Turning it inside out: The organization of human septin heterooligomers.
Septin family proteins are quite similar to each other both within and between eukaryotic species. Typically, multiple discrete septins co-assemble into linear heterooligomers (usually hexameric or octameric rods) with a variety of cellular functions. We know little about how incorporation of different septins confers different properties to such complexes. This issue is especially acute in human cells where 13 separate septin gene products (often produced in multiple forms arising from alternative start codons and differential splicing) are expressed in a tissue-specific manner. Based on sequence alignments and phylogenetic criteria, human septins fall into four distinct groups predictive of their interactions, that is, members of the same group appear to occupy the same position within oligomeric septin protomers, which are "palindromic" (have twofold rotational symmetry about a central homodimeric pair). Many such protomers are capable of end-to-end polymerization, generating filaments. Over a decade ago, a study using X-ray crystallography and single-particle electron microscopy deduced the arrangement within recombinant heterohexamers comprising representatives of three human septin groups-SEPT2, SEPT6, and SEPT7. This model greatly influenced subsequent studies of human and other septin complexes, including how incorporating a septin from a fourth group forms heterooctamers, as first observed in budding yeast. Two recent studies, including one in this issue of Cytoskeleton, provide clear evidence that, in fact, the organization of subunits within human septin heterohexamers and heterooctamers is inverted relative to the original model. These findings are discussed here in a broader context, including possible causes for the initial confusion
Eosinophilic fasciitis (Shulman's disease): review and comparative evaluation of seven patients.
OBJECTIVES:
Eosinophilic fasciitis (EF) was described in 1974 by Shulman as a rare fibrosing connective tissue disease of unknown etiology. An undetermined trigger is thought to lead to the degranulation of eosinophils that interact with fibroblasts and express fibrogenic cytokines including the transforming factor of tumor growth a and b and interleukins 1 and 6. The purpose of this study was to summarize seven cases of EF in a central hospital.
MATERIAL AND METHODS:
This was a retrospective and descriptive study of a population with EF of a central hospital. All patients diagnosed with EF in a hospital unit were admitted to the study between January 1, 2005, and April 30, 2018.
RESULTS:
A total of seven patients diagnosed with EF were analyzed. The median age of the population at the time of diagnosis was 56 years, and 57% of the patients were women. All patients had elevated peripheral eosinophilia and sedimentation rate, and only one patient had hypergammaglobulinemia. All patients had edema and cutaneous thickening of the limbs, 57% had constitutional symptoms, and 57% had inflammatory arthritis with joint contracture. Prednisolone (PDN) therapy was initiated in all patients, and only in two was the association of PDN with methotrexate (MTX) initially performed. In one patient triple therapy of PDN, MTX, and cyclosporine was required. At the time of this publication, only one patient maintains active disease, and tocilizumab has been initiated.
CONCLUSIONS:
Recent studies show a more favorable response from the combination of PDN and MTX than from PDN alone. Considering the rarity of the disease, more long-term studies are needed regarding the etiopathogenetics, progression, recurrence of EF, and new effective therapies.info:eu-repo/semantics/publishedVersio
Temperatura-base inferior e estacionalidade de produção de gramĂneas forrageiras tropicais.
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Towards a taxonomy of innovation systems
The concept of National Innovation System (NIS) has been recently applied in the context of developing nations even tough it was originally developed in relation to the more developed economies (Japan, Scandinavian countries, US etc.). This raises the methodological problem of knowing whether what was learnt in the study of more advanced NISs is relevant for all sorts of economies regardless the maturity of their actual innovation systems. With this question in mind an exploratory exercise is implemented. First a technique for mapping different NIS is put forward and next based on such mapping a taxonomy of NISs is proposed. The technique although simple in the steps it requires shows analytical potential. The cartography it generates allows one to compare directly different countries, by visualizing in bi-dimensional space the graphic pattern of the relevant dimensions of their respective NISs. This technique is applied to 69 countries (87.4% of the world population) and a set of 29 indicators is used to examine these NISs along eight major dimensions. With the resulting data, and with the help of cluster analysis, a taxonomy of innovation systems is proposed. That taxonomy which contains 6 major types of NISs indicates that what differentiates most the individual systems is their performance in three critical dimensions: innovation, diffusion and basic and applied knowledge. Country size and the natural resources endowment of the economies also emerge as important contingency factors underlying the overall dynamics of different NISs.innovation; national innovation systems; economic development.
O fado e “as regras da arte”: “autenticidade”, “pureza” e mercado
Fado is the most important genre of Portuguese popular music. It is part of hegemonic representations of nationality and an icon of Lisbon. Also, fado has an outstanding place in music market, nationally and abroad. By contrast, among the representations that legitimate the “authenticity” of fado, one can find a strong defense of amateur dispositions. Some fadistas (fado singers) say that “true” fado is never (and, ideally, could never be) a way to make a living; it should always be an expression of the soul. The obvious echoes of the “l’art pour l’art” discourse from the 19th century can be recognized here. This paper aims to question: how can this discourse be reproduced today? What are its meanings? Are there contradictions between the existence of this discourse and market projection of the genre
Estudo da solubilidade de diferentes corantes tĂŞxteis em diĂłxido de carbono supercrĂtico
Utilizando um mĂ©todo de medida dinâmico, determinou-se experimentalmente a solubilidade de corantes tĂŞxteis em CO2 supercrĂtico, para pressões entre 120 bar (12MPa) a 400 bar (40 MPa) e temperaturas de 60°C (333.2K) a 120°C (393.2K). O equipamento utilizado consiste em 3 secções distintas: zona de compressĂŁo, zona de equilĂbrio e zona de expansĂŁo.
Dos resultados obtidos para as isotĂ©rmicas, verificou-se que a solubilidade aumenta com o incremento da pressĂŁo. Em relação Ă influĂŞncia da temperatura, constatou-se que as pressões mais baixas os corantes apresentam uma diminuição na solubilidade em CO2 supercrĂtico com o incremento da temperatura, no entanto, a partir de uma determinada pressĂŁo (cerca de 225bar), quanto maior a temperatura de estudo, maior a solubilidade dos compostos.
Obtiveram-se valores de solubilidade na ordem dos 2,9x10-6 a 2,9x10-4 para o Quinizarina com uma reprodutibilidade média de ±3,3%, de 1,4x10-6 a 3,2x10-4 para o Red 9 com uma reprodutibilidade média de ±2,5% de 7,8x10-8 a 2,2x10-5 para o Blue 14 com uma reprodutibilidade média de ±3,0% e finalmente de 6,63x10-8 a 4,9x10-7 para o Blue 1, com uma reprodutibilidade média de ±4,5%.
A comparação com os resultados experimentais da bibliografia permitiu verificar a actual discrepância de valores existentes para estes corantes e a importância de novos resultados e mais rigorosos, com o objectivo de analisar os mĂ©todos de determinação de solubilidade em fluidos supercrĂticos.
ApĂłs a análise dos resultados obtidos, foi efectuada a modelação dos mesmos recorrendo a modelos semi-empĂricos, verificando-se que o modelo mais adequado ao corante Quinizarina Ă© o modelo de Bartle et al, para o qual se obteve um desvio relativo mĂ©dio percentual (AARD) de 2,94%. Relativamente ao corante Red 9 e Blue 14, o modelo que melhor define o comportamento de Chrastil, obtendo-se um AARD de 0,870% e o 1,47% respectivamente, enquanto que para o Blue 1 Ă© o modelo de Kummar e Jonhson, com um AARD de 0,218%.
Além da modelação efectuada, foram ainda determinados os valores de entalpias de vaporização e solvatação para os diferentes compostos
Disadvantaged youths’ subjective well-being: the role of gender, age, and multiple social support attunement
This paper explores the relationship between gender, age, Multiple Social Support Attunement (MSSA), and disadvantaged youths’ Subjective Well-Being (SWB). MSSA is defined as social support patterns regarding multiple sources. In this study, MSSA patterns included closest family member, mentor, and best friend support. SWB was measured in terms of quality-of-life, social anxiety, and depression. Two hundred and thirty-six adolescents aged between 12 and 18 years old (M = 14.10; SD = 1.78; 60.20% boys) participated in this study. A three-class solution was retained after Latent Class Analysis (LCA) was conducted, guaranteeing a more balanced participant distribution and a more feasible comparison between MSSA patterns. Further analyses showed that MSSA patterns were associated with disadvantaged youths’ quality-of-life, social anxiety and depression, regardless of age and gender effects. These associations were more generalized and systematic than those between gender or age and the selected well-being indicators. High MSSA also emerged as an optimal pattern to improve disadvantaged youths’ SWB, especially among early adolescents. Recommendations are made to improve MSSA assessment in social interventions, as well as to promote cross-generational activities that may help to activate high MSSA shared by peers and significant adults.info:eu-repo/semantics/acceptedVersio
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