183 research outputs found
DISSOLUTION OF CONCENTRATED SURFACTANT PASTE FROM MICRO TO PILOT PLANT SCALE
Complex fluids, widely used in many industrial applications, typically include amphiphilic molecules such as surfactants. Most of the surfactants used in products for fabric care, home care, and beauty care, such as detergents, or cosmetics have a complex microstructure and rheological behavior. At high concentrations, surfactant solutions self-assemble into lyotropic mesophases exhibiting complex rheology and viscoelasticity relevant for processing.1, 2 These molecules can rearrange themselves depending on both chemical structure and the process. Furthermore, the microstructure of the system strongly affects the properties of the finished product, which are the determining factors for the specific application. It is, therefore, necessary to identify and study the chemical-physical processes that involve such systems. Industrial processing of surfactant-based materials typically includes a water dissolution step. It is well established that both physicochemical and rheological parameters, such as raw material chemistry, type of solvent, temperature and flow conditions, play a key role in the dissolution process3. However, the mechanisms governing the dissolution process are not well understood. This explains the great interest in the dissolution of complex molecules in flow or in static conditions. As a matter of fact, understanding the dissolution of the concentrated surfactant solutions in different solvents is of fundamental importance for their effective industrial application.
In this work video microscopy will be used to investigate dissolution in well-controlled static conditions, and the sample microstructure changes will be observed; a microfluidic device will be rearranged to evaluate the effect of specific flow conditions with the aim to understand which is the controlling factor of the phenomenon and see differences from static results; in order to observe the process in a larger scale, a simple lab scale test will be set up and a Raman tool used to characterize the process in beaker with the aims to build a model to quantify the dissolution process and a correlation of this method with pilot plant scale test
Optimal sliding friction coefficient for isolated bridges in different soil conditions
The work evaluates the optimal properties of friction pendulum system (FPS) bearings for the seismic protection of bridge piers under earthquake excitations having different frequency characteristics representative of different soil conditions in order to reduce the seismic vulne-rability of infrastructures. A two-degree-of-freedom model is adopted to describe, respective-ly, the response of the infinitely rigid deck isolated by the FPS devices and the elastic behavior of the pier. By means of a non-dimensional formulation of the motion equations, a wide parametric analysis for several structural parameters is carried out. Seismic excitations, modelled as time-modulated filtered Gaussian white noise random processes having different intensities and frequency contents, are considered. Specifically, the filter parameters, which control the frequency contents, are properly calibrated to reproduce stiff, medium and soft soil conditions, respectively. Finally, the optimum values of the sliding friction coefficient able to minimize the pier displacements with respect to the ground are derived as a function of the structural properties, of the seismic input intensity and of the soil condition
"Electro-clinical Syndromes" with onset in Paediatric Age. the highlights of the clinical-EEG, genetic and therapeutic advances
The genetic causes underlying epilepsy remain largely unknown, and the impact of available genetic data on the nosology of epilepsy is still limited. Thus, at present, classification of epileptic disorders should be mainly based on electroclinical features. Electro-clinical syndrome is a term used to identify a group of clinical entities showing a cluster of electro-clinical characteristics, with signs and symptoms that together define a distinctive, recognizable, clinical disorder. These often become the focus of treatment trials as well as of genetic, neuropsychological, and neuroimaging investigations. They are distinctive disorders identifiable on the basis of a typical age onset, specific EEG characteristics, seizure types, and often other features which, when taken together, permit a specific diagnosis which, in turn, often has implications for treatment, management, and prognosis. Each electro-clinical syndrome can be classified according to age at onset, cognitive and developmental antecedents and consequences, motor and sensory examinations, EEG features, provoking or triggering factors, and patterns of seizure occurrence with respect to sleep. Therefore, according to the age at onset, here we review the more frequently observed paediatric electro-clinical syndrome from their clinical-EEG, genetic and therapeutic point of views
Congenital diarrhoeal disorders: advances in this evolving web of inherited enteropathies.
Congenital diarrhoeal disorders (CDDs) represent an evolving web of rare chronic enteropathies, with a typical onset early in life. In many of these conditions, severe chronic diarrhoea represents the primary clinical manifestation, whereas in others diarrhoea is only a component of a more complex multi-organ or systemic disorder. Typically, within the first days of life, diarrhoea leads to a life-threatening condition highlighted by severe dehydration and serum electrolyte abnormalities. Thus, in the vast majority of cases appropriate therapy must be started immediately to prevent dehydration and long-term, sometimes severe, complications. The number of well-characterized disorders attributed to CDDs has gradually increased over the past several years, and many new genes have been identified and functionally related to CDDs, opening new diagnostic and therapeutic perspectives. Molecular analysis has changed the diagnostic scenario in CDDs, and led to a reduction in invasive and expensive procedures. Major advances have been made in terms of pathogenesis, enabling a better understanding not only of these rare conditions but also of more common diseases mechanisms
Surface displaced alfa-enolase of Lactobacillus plantarum is a fibronectin binding protein
Background: Lactic acid bacteria of the genus Lactobacillus and Bifidobacterium are one of the most important health promoting groups of the human intestinal microbiota. Their protective role within the gut consists in out competing invading pathogens for ecological niches and metabolic substrates. Among the features necessary to provide health benefits, commensal microorganisms must have the ability to adhere to human intestinal cells and consequently to colonize the gut. Studies on mechanisms mediating adhesion of lactobacilli to human intestinal cells showed that factors involved in the interaction vary mostly among different species and strains, mainly regarding interaction between bacterial adhesins and extracellular matrix or mucus proteins. We have investigated the adhesive properties of Lactobacillus plantarum, a member of the human microbiota of healthy individuals. Results: We show the identification of a Lactobacillus plantarum LM3 cell surface protein (48 kDa), which specifically binds to human fibronectin (Fn), an extracellular matrix protein. By means of mass spectrometric analysis this protein was identified as the product of the L. plantarum enoA1 gene, coding the EnoA1 alfa-enolase. Surface localization of EnoA1 was proved by immune electron microscopy. In the mutant strain LM3-CC1, carrying the enoA1 null mutation, the 48 kDa adhesin was not anymore detectable neither by anti-enolase Western blot nor by Fn-overlay immunoblotting assay. Moreover, by an adhesion assay we show that LM3-CC1 cells bind to fibronectin-coated surfaces less efficiently than wild type cells, thus demonstrating the significance of the surface displaced EnoA1 protein for the L. plantarum LM3 adhesion to fibronectin. Conclusion: Adhesion to host tissues represents a crucial early step in the colonization process of either pathogens or commensal bacteria. We demonstrated the involvement of the L. plantarum Eno A1 alfa-enolase in Fn-binding, by studying LM3 and LM3-CC1 surface proteins. Isolation of LM3-CC1 strain was possible for the presence of expressed enoA2 gene in the L. plantarum genome, giving the possibility, for the first time to our knowledge, to quantitatively compare adhesion of wild type and mutant strain, and to assess doubtless the role of L. plantarum Eno A1 as a fibronectin binding protein. © 2009 Castaldo et al; licensee BioMed Central Ltd
Migraine treatment in developmental age: guidelines update
There is a serious lack of controlled studies on the pharmacological treatment of primary migraine in the developmental age; there is, consequently, an urgent need for new, evidence-based approaches to this long-neglected field of research. Moreover, previous studies have stated that the placebo response is greater in pediatric patients than in adults and that a reduction in the attack frequency in the absence of any pharmacological treatment is observed more frequently in pediatric migraine patients than in adults. Besides these preliminary considerations, the shorter duration of migraine attacks and other characteristic semeiological features of the clinical picture in children are such that the design of randomized controlled trial (RCT) is more problematic in the developmental age than in the adult. Bearing in mind all these weak points, the aim of this review was to summarize and update recent guidelines for the treatment of primary migraine in children and adolescents. The most recent guidelines are those published by the Italian Society for the study of Headache, the French Society for the study of Migraine and Headache, and the American Academy of Neurology. We have incorporated into these guidelines the results from the few, recent RCTs, clinical controlled trials, open-label studies, meta-analyses and reviews that have been published since 2004; owing to the lack of strong evidence in this field of research, we have sometimes even mentioned pilot noncontrolled studies, case series and expert opinions. Lastly, evidence was classified and the recommendations were categorized according to different levels
Sleep clinical record: an aid to rapid and accurate diagnosis of paediatric sleep disordered breathing
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Expectativas y preocupaciones de alumnos ingresantes a la Facultad de EducaciĂłn FĂsica de la UNT
Los objetivos que este proyecto se propone son (a) en los estudiantes ingresantes indagar sobre las dificultades de inserciĂłn y permanencia en el ámbito acadĂ©mico; (b) en los estudiantes que lograron superar el primer año , indagar sobre los mecanismos subjetivos de afrontamiento que operan como reforzadores y protectores, y les permiten continuar el recorrido acadĂ©mico; (c) informar los resultados a las autoridades universitaria y de las unidades acadĂ©micas, con el propĂłsito de producir conocimiento cientĂfico especĂfico y eventualmente usen el mismo como insumo; (d) segĂşn las respuestas que se obtengan de dichas esferas, el equipo tiene la disponibilidad de complementar la informaciĂłn y eventualmente colaborar con ellos para los pasos futuros.Eje: PsicologĂa educacional y orientaciĂłn vocacionalFacultad de PsicologĂ
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