A Nonstaining and Tasteless Hydrophobic Salt of Chlorhexidine

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Memórias midiatizadas: percepções sobre ciência reconfiguradas a partir do consumo midiático

This piece focuses on the issue of media in the contemporary context, taking for its object the sociocultural phenomenon of mediatization‟, understood as the dilution of media culture in the everyday life, according to the perspective from Fausto Neto (2008) e Sodré (2002). This phenomenon is viewed from the angle of reception, that is, one that considers the individuals as pro-actives in this dynamic. The media culture is perceived as a fundamental element in the process of social structuring, and also is taken as a symbolic arm of great importance for the elaboration of the notion of reality as it interferes with the flow of information. Thus, we emphasize the process of symbolic consumption that we do with media content (Canclini, 1999), through a dynamic of appropriation and reframing, given from the interweaving of the meanings proposed with extra-media elements, recaptured from the perspective of mediations, by Barbero (2006), which concerns the articulation of the contents we appropriate from media with interactions from other social practices. We also consider the dimension of memory according to Sarlo (2007) and Halbwachs (2004) in order to, through speeches made in its scope, reach empirically the phenomenon of mediatization‟, and overlapping it, the media consumption on a specific theme, "science". Nevertheless, in terms of field work, we use the technique of in-depth interviews, so that the speech of our interviewers was our corpus. Through their narratives, speeches considered by us as memory-related, we visualize the dynamics of media consumption on given topic. At the level of conclusions, we realize that mediatization‟ as a phenomenon occurred, but its flows and orders showed discontinuities and pluralities not initially conceived; regarding the consumption of science through media, we see hybrid perceptions by our respondents, that is, one that include both elements aligned with the positivist conception of science - which we consider to be the view of science proposed by the media and elements that would contradict this view

Os argumentos transcendentais: kant e o problema de hume

This work whose title is "The transcendental arguments: Kant Andy Hume's problem" has as its main objective to interpret Kant's answer to Hume's problem in the light of the conjunction of the causality and induction themes which is equivalent to skeptical- naturalist reading of the latter. In this sense, this initiative complements the previous treatment seen in our dissertation, where the same issue had been discussed from a merely skeptical reading that Kant got from Hume thought and was only examined causality. Among the specific objectives, we list the following: a) critical philosophy fulfills three basic functions, a founding, one negative and one would argue that the practical use of reason, here named as defensive b) the Kantian solution of Hume's problem in the first critisism would fulfill its founding and negative functions of critique of reason; c) the Kantian treatment of the theme of induction in other criticisms would will fulfill the defense function of critique of reason; d) that the evidence of Kant's answer to Hume's problem are more consistent when will be satisfied these three functions or moments of criticism. The basic structure of the work consists of three parts: the first the genesis of Hume's problem - our intention is to reconstruct Hume's problem, analyzing it from the perspective of two definitions of cause, where the dilution of the first definition in the second match the reduction of psychological knowledge to the probability of following the called naturalization of causal relations; whereas in the second - Legality and Causality - it is stated that when considering Hume in the skeptic-naturalist option, Kant is not entitled to respond by transcendental argument A􀁴B; A⊢B from the second Analogy, evidence that is rooted in the position of contemporary thinkers, such as Strawson and Allison; in third part - Purpose and Induction - admits that Kant responds to Hume on the level of regulative reason use, although the development of this test exceeds the limits of the founding function of criticism. And this is articulated in both the Introduction and Concluding Remarks by meeting the defensive [and negative] function of criticism. In this context, based on the use of so-called transcendental arguments that project throughout the critical trilogy, we provide solution to a recurring issue that recurs at several points in our submission and concerning to the "existence and / or the necessity of empirical causal laws. In this light, our thesis is that transcendental arguments are only an apodictic solution to the Hume s skeptical-naturalist problem when is at stake a practical project in which the interest of reason is ensured, as will, in short, proved in our final considerations

High-performance liquid chromatographic determination of amfepramone hydrochloride, mazindol, and diazepam in tablets

Simple and rapid procedures were developed for the quantification of amfepramone hydrochloride and diazepam and mazindol and diazepam in tablets using high performance liquid chromatography (HPLC) with UV detection. These techniques provided conditions for the separation of each active ingredient from the complex matrices of the dosage forms by dilution or extraction in methanol. Isocratic reversed phase chromatography was performed using acetonitrile, methanol, and aqueous 0,1% ammonium carbonate (70:10:20, v/v/v) as a mobile phase, Radial-Pak C-18 column (100 x 8 mm id, 4 mu m), a column temperature of 25+/-1 degrees C and detection at 255 nm. The calibration curves were linear over a wide concentration range (100-1000 mu g.mL(-1) to amfepramone hydrochloride and mazindol and 10-100 mu g.mL(-1) to diazepam) with good correlation factors of 0.9978, 0.9956 and 0.9997 for amfepramone hydrochloride, mazindol, and diazepam, respectively.Mean recoveries obtained from the two kinds of samples ranged from 83.2 to 102.5%, with coefficients of variation ranging from 1.0 to 6.1.These results demonstrated the efficiency of the proposed methods, as well as advantages such as simplicity and short duration of analysis.

Amphotericin B Microemulsion Reduces Toxicity and Maintains the Efficacy as an Antifungal Product

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise farmacognóstica e atividade antibacteriana de extratos vegetais empregados em formulação para a higiene bucal

A utilização de extratos vegetais vem se tornando uma alternativa importante para a prevenção de doenças periodontais. Este trabalho objetivou desenvolver uma formulação de enxagüatório bucal, contendo, em associação, extratos hidroalcoólicos de Rosmarinus officinalis, Plantago major, Tabebuia impetiginosa, Achillea millefollium e Nasturtium officinale; avaliar sua composição farmacognóstica e sua atividade antibacteriana, como também da fórmula proposta. Foram realizados estudos de pré-formulação e análises farmacognósticas para as espécies vegetais. A atividade antibacteriana in vitro foi observada por meio dos métodos de difusão em disco de papel, por hole- plate e por template, frente a Staphylococcus aureus, Bacillus subtilis, Escherichia colik, Enterococcus faecalis e Pseudomonas aeruginosa. A concentração inibitória mínima (CIM) foi determinada por meio do método de macrodiluições sucessivas em caldo. Os resultados obtidos apresentaram-se de acordo com o histórico farmacognóstico das drogas estudadas. Todas as bactérias foram inibidas pelos extratos, observando-se que as espécies S. aureus e B. subtilis mostraram, aparentemente, maior sensibilidade. A CIM variou, em relação a sensibilidade de cada espécie bacteriana estudada, de 312,5 µL/mL a 1250 µL/mL para os extratos vegetais e de 625 µL/mL a 2500 µL/mL para o enxaguatório bucal. São necessários estudos complementares para a confirmação da eficácia deste produto e sua utilização na prevenção de doenças periodontais.

Screening for antimicrobial activity of natural products using a microplate photometer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A evolução do lítio em estrelas do tipo-solar através do diagrama HR

Important advances have been made along the last decade in the study of the lithium behavior in solar-type stars. Among the most important discoveries what attracts attention is that the distribution of lithium abundance in the late F-type giant stars tends to be discontinuous, at the same time of a sudden decline in rotation and a gradual decline according to the temperature for giant red stars of such spectral type. Other studies have also shown that synchronized binary systems with evolved components seem to keep more of their original lithium than the unsynchronized systems. evertheless, the connection between rotation and lithium abundance as well as the role of tidal effects on lithium dilution seem to be more complicated matters, depending on mass, metallicity and age. This work brings an unprecedented study about the behavior of lithium abundance in solartype evolved stars based on an unique sample of 1067 subgiant, giant and supergiant stars, 236 of them presenting spectroscopic binary characteristics, with precise lithium abundance and projected rotational speed. Now the lithium-rotation connection for single and binary evolved stars is analyzed taking into account the role of mass and stellar age

Antimicrobial, Cytotoxic and Antioxidant Activities and Determination of the Total Tannin Content of Bark Extracts Endopleura uchi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo de sistemas complexos com interações de longo alcance : percolação, redes e tráfego

In this thesis we investigate physical problems which present a high degree of complexity using tools and models of Statistical Mechanics. We give a special attention to systems with long-range interactions, such as one-dimensional long-range bondpercolation, complex networks without metric and vehicular traffic. The flux in linear chain (percolation) with bond between first neighbor only happens if pc = 1, but when we consider long-range interactions , the situation is completely different, i.e., the transitions between the percolating phase and non-percolating phase happens for pc < 1. This kind of transition happens even when the system is diluted ( dilution of sites ). Some of these effects are investigated in this work, for example, the extensivity of the system, the relation between critical properties and the dilution, etc. In particular we show that the dilution does not change the universality of the system. In another work, we analyze the implications of using a power law quality distribution for vertices in the growth dynamics of a network studied by Bianconi and Barabási. It incorporates in the preferential attachment the different ability (fitness) of the nodes to compete for links. Finally, we study the vehicular traffic on road networks when it is submitted to an increasing flux of cars. In this way, we develop two models which enable the analysis of the total flux on each road as well as the flux leaving the system and the behavior of the total number of congested roads

Estudo de propriedades críticas em sistemas complexos: método de procura automática em sistemas tipo Ising e percolação de longo alcance

The new technique for automatic search of the order parameters and critical properties is applied to several well-know physical systems, testing the efficiency of such a procedure, in order to apply it for complex systems in general. The automatic-search method is combined with Monte Carlo simulations, which makes use of a given dynamical rule for the time evolution of the system. In the problems inves¬tigated, the Metropolis and Glauber dynamics produced essentially equivalent results. We present a brief introduction to critical phenomena and phase transitions. We describe the automatic-search method and discuss some previous works, where the method has been applied successfully. We apply the method for the ferromagnetic fsing model, computing the critical fron¬tiers and the magnetization exponent (3 for several geometric lattices. We also apply the method for the site-diluted ferromagnetic Ising model on a square lattice, computing its critical frontier, as well as the magnetization exponent f3 and the susceptibility exponent 7. We verify that the universality class of the system remains unchanged when the site dilution is introduced. We study the problem of long-range bond percolation in a diluted linear chain and discuss the non-extensivity questions inherent to long-range-interaction systems. Finally we present our conclusions and possible extensions of this work

Efeitos de acoplamentos biquadráticos e campos aleatórios em vidros de spins

In this work we have studied the effects of random biquadratic and random fields in spin-glass models using the replica method. The effect of a random biquadratic coupling was studied in two spin-1 spin-glass models: in one case the interactions occur between pairs of spins, whereas in the second one the interactions occur between p spins and the limit p > oo is considered. Both couplings (spin glass and biquadratic) have zero-mean Gaussian probability distributions. In the first model, the replica-symmetric assumption reveals that the system presents two pha¬ses, namely, paramagnetic and spin-glass, separated by a continuous transition line. The stability analysis of the replica-symmetric solution yields, besides the usual instability associated with the spin-glass ordering, a new phase due to the random biquadratic cou¬plings between the spins. For the case p oo, the replica-symmetric assumption yields again only two phases, namely, paramagnetic and quadrupolar. In both these phases the spin-glass parameter is zero. Besides, it is shown that they are stable under the Almeida-Thouless stability analysis. One of them presents negative entropy at low temperatures. We developed one step of replica simmetry breaking and noticed that a new phase, the biquadratic glass phase, emerge. In this way we have obtained the correct phase diagram, with.three first-order transition lines. These lines merges in a common triple point. The effects of random fields were studied in the Sherrington-Kirkpatrick model consi¬dered in the presence of an external random magnetic field following a trimodal distribu¬tion {P{hi) = p+S(hi - h0) +Po${hi) +pS(hi + h0))- It is shown that the border of the ferromagnetic phase may present, for conveniently chosen values of p0 and hQ, first-order phase transitions, as well as tricritical points at finite temperatures. It is verified that the first-order phase transitions are directly related to the dilution in the fields: the extensions of these transitions are reduced for increasing values of po- In fact, the threshold value pg, above which all phase transitions are continuous, is calculated analytically. The stability analysis of the replica-symmetric solution is performed and the regions of validity of such a solution are identified

Lítio e parâmetros orbitais em sistemas binários com componentes evoluídas

One of the best established properties of the single late type evolved stars is that their rotational velocity and lithium content decrease with effective temperature and age. Nevertheless, the root cause of this property, as well as the link between rotation and lithium abundance and, in particular, the effects of binarity on rotation and lithium content in binary systems with evolved component, are not yet completely established. How does the gravitational tides, in binary systems, affects rotational evolution and lithium dilution? Trying to answer these questions, we have carried out an observational survey, in the lithium region centered at the lithium I line A6707.81A, for a large sample of about 100 binary systems with evolved component along the spectral range F, G and K, with the CES spectrometer mounted at the CAT 1.44 m Telescope of the ESO, La Silla, Chile. By combining the abundances of lithium issued from these observations with rotational velocity and orbital parameters, we have found a number of important results. First of all, we confirm that in this class of binary systems rotation is effectively affected by tidal effects. Binary systems with orbital period lower than about 100 days and circular or nearly circular orbits, present rotational velocity enhanced in relation to the single giant stars and to the binary systems with an orbital period larger than 100 days. This is clearly the result of the synchonization between the rotational and orbital motions due to tidal effects. In addition, we have found that lithium abundances in binary systems with giant components present the same gradual decreasing with effective temperature, observed in the single giants of same luminosity class and spectral types. We have found no lithium-rich binary systems, in contrast with single giants. A remarkable result from the present study is the one showing that synchronized binary systems with giant component retains more of their original lithium than the unsynchronized systems. In fact, we have found a possible "inhibited zone", in which synchronized binary systems with giant component having lithium abundance lower than a threshold level should be unusual. Finally, the present study also shows that the binary systems with giant component presenting the highest lithium contents are those with the highest rotation rates

Aglomerado estelar M67: processos de diluição e a evolução do Momentum Angular

Galactic stellar clusters have a great variety of physical properties that make valuable probes of stellar and galactic chemical evolution. Current studies show a discrepancy between the standard evolutionary models and observations, mainly considering the level of mixing and convective dilution of light elements, as well as to the evolution of the angular momentum. In order to better settle some of these properties, we present a detailed spectroscopic analysis of 28 evolved stars, from the turn-off to the RGB, belonging to the stellar open cluster M67. The observations were performed using UVES+FLAMES at VLT/UT2. We determined stellar parameters and metallicity from LTE analysis of Fe I and Fe II lines between 420 1100 nm. The Li abundance was obtained using the line at 6707.78 ˚A, for the whole sample of stars. The Li abundances of evolved stars of M67 present a gradual decreasing when decreasing the effective temperature. The Li dilution factor for giant stars of M67 with Teff ∼ 4350K is at least 2300 times greater than that predicted by standard theory for single field giant stars. The Li abundance as a function of rotation exhibits a good correlation for evolved stars of M67, with a much smaller dispersion than the field evolved stars. The mass and the age seem to be some of the parameters that influence this connection. We discovered a Li-rich subgiant star in M67 (S1242). It is member of a spectroscopic binary system with a high eccentricity. Its Li abundance is 2.7, the highest Li content ever measured for an evolved star in M67. Two possibilities could explain this anomalous Li content: (i) preservation of the Li at the post turn off stage due to tidal effects, or (ii) an efficient dredge-up of Li, hidden below the convective zone by atomic diffusion occurring in the post turn off stage. We also study the evolution of the angular momentum for the evolved stars in M67. The results are in agreement with previous studies dedicated to evolved stars of this cluster, where stars in the same region of the CM-diagram have quite similar rotations, but with values that indicate an extra breaking along the main sequence. Finally, we analize the distributions of the average rotational velocity and of the average Li abundance as a function of age. With relation to the average Li abundances, stars in clusters and field stars present the same type of exponencial decay law t−β. Such decay is observed for ages lesser than 2 Gyr. From this age, is observed that the average Li abundance remain constant, differently of the one observed in the rotation age connection, where the average rotational velocity decreases slowly with age

Eficácia do bochecho de quitosana a 0,4% sobre o biofilme e bactérias orais

The purpose of this study was evaluate the effectiveness of the chitosan at 0.4 with high molecular weight and high deacetylation degree mouthrinse over the total decrease of the streptococci, Streptococcus mutans, lactobaci/li and over the perceptible bacterial film and gingival bleeding indices. For that, a total of 68 healthy students between 11 and 13 years old, not allergic to crustacean and not users of antibiotics or antimicrobial agent for the last three months or during the treatment, was selected. From those, thirty two individuaIs used the mouthrinse test, and thirty six, the control one. The participants rinsed 10 mL of the solutions twice a day, one during the moming (which was supervised), and another one during the aftemoon (which was not supervised), for fifteen days. The saliva collect for the microbiological analysis, as well as the perceptible bacterial film and gingival bleeding indices check, were made before the use ofthe mouthrinses (base line), immediately after the last mouthrinse on the day (zero time) and fifteen days after (fifteen time). These data were collected at school and the saliva was carried inside the ice to the laboratory. The samples were diluted, and 0.1 mL ofthe 10 -1 dilution was seeded in Rogosa SL agar, for further analysis of the total of lactobaci/lus~ 0.1 mL of the 10-4 dilution in Mitis Salivarius with bacitracin, for S. mutans analysis; and 0.1 mL of the 10-6 dilution in Mitis Salivarius for the analysis ofthe total of streptococcus. The Rogosa SL agar plates were incubated in aerobic at 37°C for 72 hours and the MSB and the MS were incubated in anaerobic in Gaspak@ jars at 37°C for 48 hours for further count ofColonies Former Units (CFUs). The assay was made in duplicate for each bacterial group analyzed. The number of CFUs transformed in LOGlO was analyzed according to the following tests: ANOV A, t of Paired and Not Paired Student, Friedman, Man-Whitney and square-qui test. On the base line, alI the variables analyzed were similar on both tested groups. On both groups, for the total of streptococcus there was no significant difference along the time and for S. mutans there was a statistic significant increase of the CFUs from the base line to the zero time. For the total of lactobaccilus there was no significant difference on the test group along the time, and on the control there was a significant increase ofthe CFUs ITom the base line to the zero time. For both groups, there was significant decrease ofthe perceptible bacterial film index along the time, and that can be explained by the mechanic effect of the mouthrinse over the bacterial film and by the participation of the students on the research which could have motivated him to a better toothbrushing (Hawthome effect). The gingival bleeding index also showed a decrease along the time, even though it was not significant. Therefore, the conclusion of this study was that the chitosan at 0.4 % mouthrinse was not effective on the CFUs reduction of the three bacterial groups analyzed, as well as on the reduction of the perceptible bacterial film and gingival bleeding indices