TitGer: uma planilha eletrônica para simulação de titulação de mistura de compostos polipróticos

The aim of this paper is to present a simple way of treating the general equation for acid-base titrations based on the concept of degree of dissociation, and to propose a new spreadsheet approach for simulating the titration of mixtures of polyprotic compounds. The general expression, without any approximation, is calculated a simple iteration method, making number manipulation easy and painless. The user-friendly spreadsheet was developed by using MS-Excel and Visual-Basic-for-Excel. Several graphs are drawn for helping visualizing the titration behavior. A Monte Carlo function for error simulation was also implemented. Two examples for titration of alkalinity and McIlvaine buffer are presented.

Sensor Fusion of Proprioception, Force and Vision in Estimation and Robot

Sensor-based robot control allows manipulation in dynamic environments with uncertainties. Vision is a versatile low-cost sensory modality, but low sample rate, high sensor delay and uncertain measurements limit its usability, especially in strongly dynamic environments. Force is a complementary sensory modality allowing accurate measurements of local object shape when a tooltip is in contact with the object. In multimodal sensor fusion, several sensors measuring different modalities are combined to give a more accurate estimate of the environment. As force and vision are fundamentally different sensory modalities not sharing a common representation, combining the information from these sensors is not straightforward. In this thesis, methods for fusing proprioception, force and vision together are proposed. Making assumptions of object shape and modeling the uncertainties of the sensors, the measurements can be fused together in an extended Kalman filter. The fusion of force and visual measurements makes it possible to estimate the pose of a moving target with an end-effector mounted moving camera at high rate and accuracy. The proposed approach takes the latency of the vision system into account explicitly, to provide high sample rate estimates. The estimates also allow a smooth transition from vision-based motion control to force control. The velocity of the end-effector can be controlled by estimating the distance to the target by vision and determining the velocity profile giving rapid approach and minimal force overshoot. Experiments with a 5-degree-of-freedom parallel hydraulic manipulator and a 6-degree-of-freedom serial manipulator show that integration of several sensor modalities can increase the accuracy of the measurements significantly.

Targeting striatal metabotropic glutamate receptor type 5 in Parkinson's disease: bridging molecular studies and clinical trials

Metabotropic glutamate (mGlu) receptors are G protein-coupled receptors expressed primarily on neurons and glial cells modulating the effects of glutamatergic neurotransmission. The pharmacological manipulation of these receptors has been postulated to be valuable in the management of some neurological disorders. Accordingly, the targeting of mGlu5 receptors as a therapeutic approach for Parkinson's disease (PD) has been proposed, especially to manage the adverse symptoms associated to chronic treatment with classical PD drugs. Thus, the specific pharmacological blocking of mGlu5 receptors constitutes one of the most attractive non-dopaminergic-based strategies for PD management in general and for the L-DOPA-induced diskynesia (LID) in particular. Overall, we provide here an update of the current state of the art of these mGlu5 receptor-based approaches that are under clinical study as agents devoted to alleviate PD symptoms.

Estudo cinético da decomposição térmica do pentaeretritol-tetranitrado (PETN)

The pentaerythritol-tetranitrate (PETN) is a nitroether used in explosives and propellant formulations. Due to its suitable properties, PETN is used in booster manufacture. Knowing the thermal decomposition behavior of an energetic material is very important for storage and manipulation, and the purpose of this work is to study the kinetic parameters of the decomposition of PETN, compare the results with literature data and to study the decomposition activation energy differences between two crystalline forms of PETN (tetragonal and needle) by means of differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FT-IR) is used to study the two crystalline forms.

Como si fuera posible recoger sentimientos = As if it were possible to collect suffering

Se trata de una propuesta como resultado del trabajo conjunto entre la escuela de Arte Pigment y el ESPAI ZERO1 del Museu Comarcal de la Garrotxa, destinado exclusivamente a exposiciones temporales de creación contemporánea y como continuidad de propuestas anteriores de colaboración: REPLICA23 y SONESNAT JUNIOR. Com si fos possible recollir el sofriment es un proyecto de la artista Anna Manel.la, y se consideró una propuesta interesante y un reto para conversar, intercambiar y crear con los alumnos sobre el tema de la exposición: la muerte y el sufrimiento. Asimismo porque es una artista conocida por los alumnos de la escuela Pigment, ya que anteriormente habían realizado un proyecto de apadrinamiento de esculturas y habitualmente ella participa en programas divulgativos en la escuela. El trabajo desarrollado centra el aprendizaje en la creación y en la investigación artística como ejes de los procesos de conceptualización con el objetivo de atender las dinámicas y los estímulos característicos de los niños. Facilitando procesos de búsqueda, exploración y manipulación sin condicionantes y promoviendo procesos autónomos en los que los mismos niños se planteen dudas e interrogantes y se enfrenten a situaciones cada vez mas complejas

Construccion y utilizacion de un electrodializador en serie para laboratorio

There are different concepts in electrochemistry that must be supported by a laboratory practice to better understand their importance in industrial applications. This work reports the procedure for manufacturing an electrodialyzer in series of two or more compartments with easy manipulation. Likewise, it reports the results obtained by using this system in the nitrate elimination from synthetic NaNO3 solutions at different concentrations. Among other results obtained in the electrodialysis of these solutions, the one that stands out is the demonstration of the linear relationship between the limiting current, obtained from the polarization curves, and nitrate concentration. Additionally, implementation of the separation treatment shows that the time of elimination of practically all ionic species depends on their concentration in solution and ranges between 50 and 80 min.

Estratégias de pré-concentração em eletroforese capilar (CE): parte 1. Manipulação da velocidade eletroforética do analito

Capillary electrophoresis has become a well-established and routine-based separation technique. It is based on the differences between charged analyte mobility in aqueous or organic electrolytes. Its major limitation is the sensitivity due to small sample injection volumes and the narrow diameter of the capillaries, especially when UV detection is used. There are a number of ways to increase the concentration sensitivity. This report shows some on-line preconcentration strategies to perform it in free solution capillary electrophoresis that are based on manipulation of the analyte electrophoretic velocity during the sample introduction (stacking, field amplification and transient isotachophoresis).

Estratégias de pré-concentração em eletroforese capilar: parte 2. Manipulação da velocidade da fase dispersa/secundária

This work describes CE preconcentration strategies based on the effect of manipulation of the disperse/secondary velocity. Introduced by Terabe et al. in 1984, micellar electrokinetic chromatography is a powerful separation approach that increases the usage of electrokinetic phenomena for the separation of nonionic compounds. The main disadvantage of MEKC is the low concentration sensitivity associated with the limited optical path length for on-capillary photometric detection and the limited volume of sample solution that can be injected. This paper compiles on-line concentration strategies for neutral analytes by sample stacking and sweeping in micellar electrokinetic chromatography.

Perfil químico de cultivares de feijão (phaseolus vulgaris) pela técnica de high resolution magic angle spinning (HR-MAS)

The application of one-dimensional proton high-resolution magic angle spinning (¹H HR-MAS) NMR combined with a typical advantages of solid and liquid-state NMR techniques was used as input variables for the multivariate statistical analysis. In this paper, different cultivars of beans (Phaseolus vulgaris) developed and in development by Embrapa - Arroz e Feijão were analyzed by ¹H HR-MAS, which have been demonstrated to be a valuable tool in its differentiation according chemical composition and avoid the manipulation of the samples as used in other techniques.

Determinação de parâmetros cinéticos em fluxo com câmara de gradiente e deteção espectrofotométrica: aplicação à reação entre o violeta de cristal e o ião hidróxido

A didactic experiment is proposed aimed to extend the Flow Injection Analysis (FIA) based methodology to the area of physical chemistry/chemical reactors for undergraduate labs. Our prime objective was to describe the use of a gradient chamber for determination of the rate constant for the reaction between crystal violet and the hydroxide ion. The study was complemented by determining the effect of temperature on the rate constant. The kinetic parameters, activation energy and reaction rate constant are determined based on an assumption of rate orders. The main didactic advantages of the proposed experimental set-up are the use of less reagents, contributing to a more environmental friendly experiment. The experiment illustrates also the reduction of associated errors and time by using automated analysis owing to decreased operator manipulation.

Compostos orgânicos voláteis na defesa induzida das plantas contra insetos herbívoros

The identification and manipulation of chemical compounds involved in vital activities of arthropods have the potential for developing less aggressive pest control strategies. Herbivory induces the emission of volatile organic compounds involved in the recruitment of natural enemies, plant-plant interactions and repellency of other herbivores. In this report, we review the main chemical groups of volatile organic compounds and their ecological functions, provide an overview of the signal transduction pathways activated upon herbivory, and review the current state of knowledge for practical applications in pest management. We conclude by proposing perspectives for future research.

APARATO ELETROQUÍMICO PARA SISTEMA DE AQUISIÇÃO DE DADOS MULTICANAL COM RESOLUÇÃO ESPAÇO-TEMPORAL

Spatiotemporal pattern formation in reaction-transport systems takes place spontaneously when the system is kept far from thermodynamic equilibrium. Targets, reaction fronts, waves, spirals, spots and stripes are some typical examples of selforganized structuring. In electrochemical systems, monitoring spatiotemporal patterns of potential in the solid/liquid interface can be done by the use of equally distributed microprobes located close to the working electrode. However, the physical size of each probe can limit the spatial resolution and alter mass transport properties. In contrast, the direct measurement of discrete electrodes does not suffer from this limitation and allows the accurate manipulation of the spatial coupling through changes in resistors connected to the electric circuit. In this paper, the development of an electrochemical setup for multichannel data acquisition with spatiotemporal resolution is described, especially to monitor low levels of currents usually observed in the electro-oxidation of small organic molecules.

Print-capture PCR for detection of tomato begomoviruses from plants and whiteflies

Print-capture (PC) Polymerase chain reaction (PCR) was evaluated as a novel detection method of plant viruses. Tomato (Lycopersicon esculentum) plants infected with begomovirus (fam. Geminiviridae, gen. Begomovirus) and viruliferous whiteflies were used to study the efficiency of the method. Print-capturing steps were carried out using non-charged nylon membrane or filter paper as the solid support for DNA printings. Amplified DNA fragments of expected size were consistently obtained by PCR from infected plants grown in a greenhouse, after direct application of printed materials to the PCR mix. However, virus detection from a single whitefly and from field-grown tomato samples required a high temperature treatment of printed material prior to PCR amplification. Comparison of nylon membrane and filter paper as the solid support revealed the higher efficiency of the nylon membrane. The application of print-capture PCR reduces the chances of false-positive amplification by reducing manipulation steps during preparation of the target DNA. This method maintains all the advantages of PCR diagnosis, such as the high sensitivity and no requirement of radioactive reagents.

Probiotic interventions in infancy: Benefit and Safety Assessment of Extended Applications

Immaturity of the gut barrier system in the newborn has been seen to underlie a number of chronic diseases originating in infancy and manifesting later in life. The gut microbiota and breast milk provide the most important maturing signals for the gut-related immune system and reinforcement of the gut mucosal barrier function. Recently, the composition of the gut microbiota has been proposed to be instrumental in control of host body weight and metabolism as well as the inflammatory state characterizing overweight and obesity. On this basis, inflammatory Western lifestyle diseases, including overweight development, may represent a potential target for probiotic interventions beyond the well documented clinical applications. The purpose of the present undertaking was to study the efficacy and safety of perinatal probiotic intervention. The material comprised two ongoing, prospective, double-blind NAMI (Nutrition, Allergy, Mucosal immunology and Intestinal microbiota) probiotic interventions. In the mother-infant nutrition and probiotic study altogether 256 women were randomized at their first trimester of pregnancy into a dietary intervention and a control group. The intervention group received intensive dietary counselling provided by a nutritionist, and were further randomized at baseline, double-blind, to receive probiotics (Lactobacillus rhamnosus GG and Bifidobacterium lactis) or placebo. The intervention period extended from the first trimester of pregnancy to the end of exclusive breastfeeding. In the allergy prevention study altogether 159 women were randomized, double-blind, to receive probiotics (Lactobacillus rhamnosus GG) or placebo 4 weeks before expected delivery, the intervention extending for 6 months postnatally. Additionally, patient data on all premature infants with very low birth weight (VLBW) treated in the Department of Paediatrics, Turku University Hospital, during the years 1997 - 2008 were utilized. The perinatal probiotic intervention reduced the risk of gestational diabetes mellitus (GDM) in the mothers and perinatal dietary counselling reduced that of fetal overgrowth in GDM-affected pregnancies. Early gut microbiota modulation with probiotics modified the growth pattern of the child by restraining excessive weight gain during the first years of life. The colostrum adiponectin concentration was demonstrated to be dependent on maternal diet and nutritional status during pregnancy. It was also higher in the colostrum received by normal-weight compared to overweight children at the age of 10 years. The early perinatal probiotic intervention and the postnatal probiotic intervention in VLBW infants were shown to be safe. To conclude, the findings in this study provided clinical evidence supporting the involvement of the initial microbial and nutritional environment in metabolic programming of the child. The manipulation of early gut microbial communities with probiotics might offer an applicable strategy to impact individual energy homeostasis and thus to prevent excessive body-weight gain. The results add weight to the hypothesis that interventions aiming to prevent obesity and its metabolic consequences later in life should be initiated as early as during the perinatal period.

Montaigne, philosophe au quotidien: vie privée et vie publique dans les essais

De concert avec ses fonctions politiques - et cela sur vingt ans -, Montaigne rédigea ses Essais que l'on considère trop souvent comme séparés de ses responsabilités publiques aujourd'hui reléguées à l'arrière plan de sa carrière d'écrivain. Nous voudrions arguer que ses Essais sont indissociables de sa vie publique. Certes, les préoccupations littéraires et politiques de Montaigne changent avec son temps, mais ce qui fonde la forme de l'essai - à savoir un discours profondément inscrit dans le présent - ne permet pas d'établir une différence théorique entre le privé et le public puisque les deux sont pratiquement inséparables quand ils sont réduits à leur unité la plus stricte qui se rapporte essentiellement au quotidien, car dans l'immédiat du vécu, le privé et le public sont pratiquement indissociables. Si une philosophie se dégage indubitablement des Essais, elle a peut-être plus à voir avec la manipulation constante effectuée par Montaigne entre le particulier (vie privée) et l'universel (vie publique) que sur le contenu de tel précepte moral ou dogme des écoles antiques. La temporalité de l'écriture et celle des événements ne sont pas en synchronie dans les Essais et Montaigne joue constamment sur cette image d'un livre privé (hors de toute temporalité historique) alors que les Essais sont conçus comme un objet lui permettant précisément l'accès à la vie publique. Cette philosophie du quotidien et du temps présent qui ressort des Essais ne saurait mettre à l'écart les considérations publiques et historiques qui rythment toujours l'écriture d'une vie bien particulière.