New self-assembled supramolecular hydrogels based on dehydropeptides

Supramolecular hydrogels rely on small molecules that self-assemble in water as a result of the cooperative effect of several relatively weak intermolecular interactions. Peptide-based low molecular weight hydrogelators have attracted enormous interest owing to the simplicity of small molecules combined with the versatility and biocompatibility of peptides. In this work, naproxen, a well known non-steroidal anti-inflammatory drug, was N-conjugated with various dehydrodipeptides to give aromatic peptide amphiphiles that resist proteolysis. Molecular dynamics simulations were used to obtain insight into the underlying molecular mechanism of self-assembly and to rationalize the design of this type of hydrogelators. The results obtained were in excellent agreement with the experimental observations. Only dehydrodipeptides having at least one aromatic amino acid gave hydrogels. The characterization of the hydrogels was carried out using transmission electron microscopy (TEM), circular dichroism (CD), fluorescence spectroscopy and also rheological assays.

Critical analyses of the introduction of liquid-based cytology in a public health service of the state of São Paulo, Brazil

OBJECTIVE The aim of this study was to compare the performance of the current conventional Pap smear with liquid-based cytology (LBC) preparations. STUDY DESIGN Women routinely undergoing their cytopathological and histopathological examinations at Fundação Oncocentro de São Paulo (FOSP) were recruited for LBC. Conventional smears were analyzed from women from other areas of the State of São Paulo with similar sociodemographic characteristics. RESULTS A total of 218,594 cases were analyzed, consisting of 206,999 conventional smears and 11,595 LBC. Among the conventional smears, 3.0% were of unsatisfactory preparation; conversely, unsatisfactory LBC preparations accounted for 0.3%. The ASC-H (atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion) frequency did not demonstrate any differences between the two methods. In contrast, the incidence of ASC-US (atypical squamous cells of undetermined significance) was almost twice as frequent between LBC and conventional smears, at 2.9 versus 1.6%, respectively. An equal percentage of high-grade squamous intraepithelial lesions were observed for the two methods, but not for low-grade squamous intraepithelial lesions, which were more significantly observed in LBC preparations than in conventional smears (2.2 vs. 0.7%). The index of positivity was importantly enhanced from 3.0% (conventional smears) to 5.7% (LBC). CONCLUSIONS LBC performed better than conventional smears, and we are truly confident that LBC can improve public health strategies aimed at reducing cervical lesions through prevention programs.

A supervisão pedagógica como prática de transformação: o lugar das narrativas profissionais

Este texto tem como objetivo discutir o lugar das narrativas profissionais, de natureza autobiográfica, produzidas por professores em contexto de formação pós-graduada em supervisão pedagógica. Começando pela discussão do conceito de qualidade em educação, e que radica numa concepção de educação para o desenvolvimento sustentável e para a transformação de pessoas e de contextos, a autora passa para uma análise do papel dos professores no desenvolvimento de práticas pedagógicas de qualidade. Embora os contextos de educação e de formação tenham um papel determinante, os professores, principalmente através das expectativas que detêm face aos seus alunos, têm um papel crucial no combate a formas de discriminação e de exclusão nas escolas. O conceito de supervisão que informa este texto também se coloca ao serviço da qualidade em educação enunciada, ao ser tomado enquanto teoria e prática de regulação crítica e colaborativa da pedagogia e do desenvolvimento profissional, numa visão da educação para a transformação e para a sustentabilidade. O texto finaliza com a ilustração do modo como as narrativas profissionais se constituem enquanto estratégias de autossupervisão do trabalho docente num contexto de formação pós-graduada. Desenvolvidas em contextos profissionais, e estabelecendo pontes entre o conhecimento acadêmico e experiencial, elas incidem na análise dos modos como o trabalho docente se coloca (ou não) ao serviço de uma pedagogia e de um desenvolvimento profissional docente assente em valores de sustentabilidade e de transformação, identificando os constrangimentos estruturais e apontando rumos de ação.

Self-evaluated burden in adults with attention-deficit hyperactivity disorder (ADHD): a pilot study

OBJECTIVES: To investigate feasibility and easiness of administration of a brief and simple instrument addressing impairment associated with adult attention deficit hyperactivity disorder (ADHD) and if ADHD subtypes were correlated to specific profiles of self-reported impairment. METHODS: Thirty-five adults (19 men and 16 women; mean age of 31.74 years) diagnosed with ADHD according to DSM-IV with a semi-structured interview (K-SADS PL) were asked to fill out a Likert scale covering six different functional areas (academic, professional, marital, familiar, social and daily activities). Clinicians questioned patients about their understanding of the questionnaire and investigated their answers in more details to check consistency of their answers. RESULTS: No patient reported difficulties in understanding the questionnaire. Further questioning of patients' answers confirmed their choices in the six areas. Academic burden had the highest average score in the whole sample, followed by professional burden. Social area had the lowest average score in this sample.

Self-compacting concrete and conventional concrete in the arena Pernambuco: comparative study of durability indicators and economic feasibility

This study addressed the application, strength and durability of self-compacting concrete (SCC) in a large-scale construction site, comparing its performance with vibrated conventional concrete (CC) with similar characteristics, assessing its economic feasibility. The studies were undertaken in the Arena Pernambuco project and involved the concreting during May, June and July 2012, for data collection, accompanying the routine concrete control tests and performing specific strength and durability tests. The SCC compressive strength was on average 4.5% higher than the CC one, and its formwork reinforced to withstand greater lateral pressure of the fresh concrete. The durability indicators results were in favour of SCC, which cost was 13.5% higher than CC.

Abordagem histórica e institucional da mudança em contabilidade de gestão: o caso da normalização nos hospitais públicos portugueses

A teoria institucional constituiu o enquadramento no qual foi suportada a pergunta geral desta investigação: como e porquê a Normalização da Contabilidade de Gestão (NCG) nos hospitais públicos portugueses surgiu e evoluiu? O objetivo geral foi compreender de forma profunda o surgimento e a mudança nas regras de NCG dos hospitais públicos portugueses no período histórico 1954-2011. Face ao enquadramento institucional que justificou uma investigação interpretativa, foi usado como método de investigação um estudo de caso explanatório. A evidência sobre o caso da NCG nos hospitais públicos portugueses foi recolhida em documentos e através de 58 entrevistas realizadas em 47 unidades de análise (nos serviços centrais de contabilidade do Ministério da Saúde e em 46 hospitais públicos, num total de 53 existentes). Quanto aos principais resultados obtidos, no período 1954-1974, as regras criadas pelo poder político para controlo dos gastos públicos e a contabilidade orçamental de base de caixa estiveram na génese dos primeiros conceitos de Contabilidade de Gestão (CG) para os serviços públicos de saúde portugueses. A transição de um regime ditatorial para um regime democrático (25 de Abril de 1974), a criação do Plano Oficial de Contabilidade (POC/77) e a implementação de um estado social com Serviço Nacional de Saúde (SNS) criaram a conjuntura crítica necessária para o surgimento de um Plano Oficial de Contabilidade para os Serviços de Saúde (POCSS/80) que incluiu regras de CG. A primeira edição do Plano de Contabilidade Analítica dos Hospitais (PCAH), aprovada em 1996, não foi uma construção de raiz, mas antes uma adaptação para os hospitais das regras de CG incluídas no POCSS/91 que havia revisto o POCSS/80. Após o início da implementação do PCAH, em 1998, ocorreram sequências de autorreforço institucionalizadoras destas normas, no período 1998-2011, por influência de pressões isomórficas coercivas que delinearam um processo de evolução incremental cujo resultado foi uma reprodução por adaptação, num contexto de dependência de recursos. Vários agentes internos e externos pressionaram, no período 2003-2011, através de sequências reativas para a desinstitucionalização do PCAH em resposta ao persistente fenómeno de loose coupling. Mas o PCAH só foi descontinuado nos hospitais com privatização da governação e rejeição dos anteriores sistemas de informação. Ao nível da extensão da teoria, este estudo de caso adotou o institucionalismo histórico na investigação em CG, quanto se sabe pela primeira vez, que se mostra útil na interpretação dos processos e dos resultados da criação e evolução de instituições de CG num determinado contexto histórico. Na condição de dependência de recursos, as sequências de autorreforço, via isomorfismo coercivo, tendem para uma institucionalização com fenómeno de loose coupling. Como resposta a este fenómeno, ocorrem sequências reativas no sentido da desinstitucionalização. Perante as pressões (políticas, funcionais, sociais e tecnológicas) desinstitucionalizadoras, o fator governação privada acelera o processo de desinstitucionalização, enquanto o fator governação pública impede ou abranda esse processo.

Evaluation of the performance of steel fibre reinforced self-compacting concrete in elevated slab systems; from the material to the structure

Degree of Doctor of Philosophy of Structural/Civil Engineering

Concise server-wide causality management for eventually consistent data stores

Large scale distributed data stores rely on optimistic replication to scale and remain highly available in the face of net work partitions. Managing data without coordination results in eventually consistent data stores that allow for concurrent data updates. These systems often use anti-entropy mechanisms (like Merkle Trees) to detect and repair divergent data versions across nodes. However, in practice hash-based data structures are too expensive for large amounts of data and create too many false conflicts. Another aspect of eventual consistency is detecting write conflicts. Logical clocks are often used to track data causality, necessary to detect causally concurrent writes on the same key. However, there is a nonnegligible metadata overhead per key, which also keeps growing with time, proportional with the node churn rate. Another challenge is deleting keys while respecting causality: while the values can be deleted, perkey metadata cannot be permanently removed without coordination. Weintroduceanewcausalitymanagementframeworkforeventuallyconsistentdatastores,thatleveragesnodelogicalclocks(BitmappedVersion Vectors) and a new key logical clock (Dotted Causal Container) to provides advantages on multiple fronts: 1) a new efficient and lightweight anti-entropy mechanism; 2) greatly reduced per-key causality metadata size; 3) accurate key deletes without permanent metadata.

Design of bio-based supramolecular structures through self-assembly of α-lactalbumin and lysozyme

Bovine α-lactalbumin (α-La) and lysozyme (Lys), two globular proteins with highly homologous tertiary structures and opposite isoelectric points, were used to produce bio-based supramolecular structures under various pH values (3, 7 and 11), temperatures (25, 50 and 75 °C) and times (15, 25 and 35 min) of heating. Isothermal titration calorimetry experiments showed protein interactions and demonstrated that structures were obtained from the mixture of α-La/Lys in molar ratio of 0.546. Structures were characterized in terms of morphology by transmission electron microscopy (TEM) and dynamic light scattering (DLS), conformational structure by circular dichroism and intrinsic fluorescence spectroscopy and stability by DLS. Results have shown that protein conformational structure and intermolecular interactions are controlled by the physicochemical conditions applied. The increase of heating temperature led to a significant decrease in size and polydispersity (PDI) of α-La–Lys supramolecular structures, while the increase of heating time, particularly at temperatures above 50 °C, promoted a significant increase in size and PDI. At pH 7 supramolecular structures were obtained at microscale – confirmed by optical microscopy – displaying also a high PDI (i.e. > 0.4). The minimum size and PDI (61 ± 2.3 nm and 0.14 ± 0.03, respectively) were produced at pH 11 for a heating treatment of 75 °C for 15 min, thus suggesting that these conditions could be considered as critical for supramolecular structure formation. Its size and morphology were confirmed by TEM showing a well-defined spherical form. Structures at these conditions showed to be stable at least for 30 or 90 days, when stored at 25 or 4 °C, respectively. Hence, α-La–Lys supramolecular structures showed properties that indicate that they are a promising delivery system for food and pharmaceutical applications.

Synthesis of new peptide derivatives that self-assemble into nanostructured hydrogels for biomedical applications

Tese de Doutoramento em Ciências (área de especialização em Química)

Preditores de prováveis transtornos mentais comuns (TMC) em prostitutas utilizando o Self-Reporting Questionnaire

Objetivo Avaliar a prevalência de prováveis transtornos mentais comuns (TMC) e os fatores associados em um grupo de prostitutas de Minas Gerais. Métodos Estudo transversal utilizando o Self-Reporting Questionnaire (SRQ-20) em mulheres cadastradas na Associação de Prostitutas de Minas Gerais (Aprosmig). Avaliaram-se características sociodemográficas e aspectos do trabalho na prostituição. Teste do qui-quadrado foi empregado na análise de associação entre variáveis categóricas sociodemográficas e a presença de prováveis TMC. A análise dos fatores associados à presença de prováveis TMC foi realizada por meio de modelo de regressão logística. Resultados Foram entrevistadas 216 prostitutas. A prevalência global de prováveis TMC foi de 57,9%, mais observada em mulheres com baixa escolaridade, história de violência física e ingresso precoce na prostituição. Conclusão Os resultados deste estudo mostraram que a prevalência de prováveis TMC entre prostitutas foi superior à observada na população geral, indicando a necessidade de melhorar os cuidados com a saúde dessas mulheres.

Semipermeable capsules wrapping a multifunctional and self-regulated co-culture microenvironment for osteogenic differentiation

A new concept of semipermeable reservoirs containing co-cultures of cells and supporting microparticles is presented, inspired by the multi-phenotypic cellular environment of bone. Based on the deconstruction of the â stem cell nicheâ , the developed capsules are designed to drive a self-regulated osteogenesis. PLLA microparticles functionalized with collagen I, and a co-culture of adipose stem (ASCs) and endothelial (ECs) cells are immobilized in spherical liquified capsules. The capsules are coated with multilayers of poly(L-lysine), alginate, and chitosan nano-assembled through layer-by-layer. Capsules encapsulating ASCs alone or in a co-culture with ECs are cultured in endothelial medium with or without osteogenic differentiation factors. Results show that osteogenesis is enhanced by the co-encapsulation, which occurs even in the absence of differentiation factors. These findings are supported by an increased ALP activity and matrix mineralization, osteopontin detection, and the up regulation of BMP-2, RUNX2 and BSP. The liquified co-capsules also act as a VEGF and BMP-2 cytokines release system. The proposed liquified capsules might be a valuable injectable self-regulated system for bone regeneration employing highly translational cell sources.

Influence of different fibers on the change of pore pressure of self-consolidating concrete exposed to fire

The focus of this paper is given to investigate the effect of different fibers on the pore pressure of fiber reinforced self-consolidating concrete under fire. The investigation on the pore pressure-time and temperature relationships at different depths of fiber reinforced self-consolidating concrete beams was carried out. The results indicated that micro PP fiber is more effective in mitigating the pore pressure than macro PP fiber and steel fiber. The composed use of steel fiber, micro PP fiber and macro PP fiber showed clear positive hybrid effect on the pore pressure reduction near the beam bottom subjected to fire. Compared to the effect of macro PP fiber with high dosages, the effect of micro PP fiber with low fiber contents on the pore pressure reduction is much stronger. The significant factor for reduction of pore pressure depends mainly on the number of PP fibers and not only on the fiber content. An empirical formula was proposed to predict the relative maximum pore pressure of fiber reinforced self-consolidating concrete exposed to fire by considering the moisture content, compressive strength and various fibers. The suggested model corresponds well with the experimental results of other research and tends to prove that the micro PP fiber can be the vital component for reduction in pore pressure, temperature as well spalling of concrete.

Contributos dos ambientes digitais online para a aprendizagem em contexto de atividades de apoio extraescolar

Dissertação de mestrado em Ciências da Educação (área de especialização em Tecnologia Educativa)