Líquido iônico [bmim.PF6] como solvente: um meio conveniente para estudos por fotólise por pulso de laser

The spectroscopic behavior of thioxanthone and benzil (diphenylethanedione or dibenzoyl) in the ionic liquid [bmim.PF6] has been investigated employing the laser flash photolysis technique. Triplet-triplet absorption spectra for these carbonyl compounds in [bmim.PF6] are similar to those observed in organic solvents. The triplet lifetime for thioxanthone in desogygenated samples is very long (71 μs), whereas in oxygen-saturated solution is 500 ns, which indicates the low oxygen solubility in this solvent. For benzil, lifetimes of 10 μs in [bmim.PF6] and 3.8 μs in acetonitrile were obtained. The decay for triplet thioxanthone and benzil follows a clear first order kinetics in [bmim.PF6], from which one can conclude that triplet-triplet annihilation is not an important decay process in this solvent.

Determinação da constante de velocidade absoluta para a reação de abstração de hidrogênio fenólico pelo estado excitado triplete de xantona em acetonitrila e no líquido iônico hexafluorfosfato de 1-butil-3-metil-imidazólio [bmim.PF6]

The triplet excited state of xanthone was generated and characterized by laser flash photolysis in acetonitrile (λmax=620 nm; t=1.8 ms) and in ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [bmim.PF6] (λmax=620 nm; t=3.0 ms). It reacts with phenols yielding the corresponding xanthone ketyl radical. Stern-Volmer plots for the reaction of triplet xanthone with phenols led to the determination of absolute rate constants for phenolic hydrogen abstraction in the order of ~10(9) Lmol-1s-1 in acetonitrile and ~10(8) Lmol-1s-1 in [bmim.PF6]. The lower diffusioncontrolled rate constant for [bmim.PF6] is responsible for the difference in the phenolic hydrogen abstraction rate constants in this solvent.

Determinação simultânea de topiramato, carbamazepina, fenitoína e fenobarbital em plasma empregando cromatografia a gás com detector de nitrogênio e fósforo

Topiramate and the other frequently co-administered antiepileptic drugs carbamazepine, phenytoin and phenobarbital were determined in 100 µL plasma samples by gas chromatography with nitrogen phosphorus detection (GC-NPD), after a one-step liquid-liquid extraction with ethyl acetate, followed by flash methylation with trimethylphenylammonium hydroxide. Total chromatographic run time was 12.5 min. Intra-assay and inter-assay precision was 2.5-7.3% and 1.6-5.2%, respectively. Accuracy was 100.1-104.2%. The limit of quantitation was 1 µg mL-1 for all analytes, proving suitable for routine application in therapeutic drug monitoring of antiepileptic drugs.

Ba-DOPED ZnO MATERIALS: A DFT SIMULATION TO INVESTIGATE THE DOPING EFFECT ON FERROELECTRICITY

ZnO is a semiconductor material largely employed in the development of several electronic and optical devices due to its unique electronic, optical, piezo-, ferroelectric and structural properties. This study evaluates the properties of Ba-doped wurtzite-ZnO using quantum mechanical simulations based on the Density Functional Theory (DFT) allied to hybrid functional B3LYP. The Ba-doping caused increase in lattice parameters and slight distortions at the unit cell angle in a wurtzite structure. In addition, the doping process presented decrease in the band-gap (Eg) at low percentages suggesting band-gap engineering. For low doping amounts, the wavelength characteristic was observed in the visible range; whereas, for middle and high doping amounts, the wavelength belongs to the Ultraviolet range. The Ba atoms also influence the ferroelectric property, which is improved linearly with the doping amount, except for doping at 100% or wurtzite-BaO. The ferroelectric results indicate the ZnO:Ba is an strong option to replace perovskite materials in ferroelectric and flash-type memory devices.

Hentriacontane: a leaf hydrocarbon from Syzygium jambos with stimulatory effects on the germination of urediniospores of Puccinia psidii

A crude Sohxlet extract from leaves of Syzygium jambos was sequentially fractionated using a silica gel flash column. A bioassay based on the numbers of urediniospores of Puccinia psidii that germinated in 2% water agar detected an active stimulant of germination when the fraction eluted with 100% n-hexane was used. The active fraction induced up to 88% increase in germination when added to a spore suspension in mineral oil. The active fraction was characterized as a hydrocarbon by ¹H nuclear magnetic resonance, 13C nuclear magnetic resonance, and infrared analysis. Gas chromatography-mass spectrometry analysis indicated that the fraction was a long-chain 436 MW hydrocarbon with corresponding to C31H64, namely hentriacontane. This is the first time such a compound proved to be involved with stimulation of fungal spore germination. These results may contribute to better understanding the infection process of rusts.

The destinal question of language

How can we think the destinal place of language in the essentially historical condition of our existence if such historicity cannot be understood on the basis of the labor of negativity alone? The attempt is made here to think language in a more originary manner, as non-negative finitude, that affirms what is outside dialectical-speculative closure, what is to come. The notion of 'destinal' itself is thus transformed. No longer being merely a categorical grasp of "entities presently given", language is an originary exposure to the event of arrival in its lightning flash. Destiny appears as that of the messianic arrival of the 'not yet' which is not a telos that the immanent movement of historical reason reaches by an irresistible force of the negative. This essay reads Schelling, Heidegger and Kierkegaard to think language as a "place" of exposure to the non-teleological destiny that may erupt even today, here and now, without any given conditionality.

Software interativo: ecocardiografia na avaliaçao da hipertensao arterial

A hipertensao arterial é uma doença muito prevalente, evoluindo com lesoes em órgaos-alvo, alta morbidade e mortalidade. A avaliaçao das repercussoes cardíacas pela ecocardiografia tem papel importante na conduçao clínica dos indivíduos hipertensos, e suas imagens podem ser utilizadas como ferramenta para o ensino. OBJETIVOS: Desenvolver e avaliar um software, construído com base em imagens ecocardiográficas, abordando de forma ilustrativa e interativa a estrutura e funçao cardíacas normais,bem como as alteraçoes induzidas pela hipertensao arterial. MÉTODOS: Foram selecionadas imagens ecocardiográficas de indivíduos normais e com comprometimento cardíaco determinado pela hipertensao (hipertrofia ventricular esquerda, miocardiopatia dilatada e infarto do miocárdio). Com estas imagens foi construído um software no programa multimídia Flash, que foi avaliado por estudantes de Medicina (n=38) e Enfermagem (n=18), também submetidos a pré- e pós-teste. RESULTADOS: Os alunos consideraram o software útil, atraente e adequado as atuais metodologias educacionais proativas,promovendo ganho de conhecimento na compreensao do comprometimento cardíaco na hipertensao arterial. Conclusao: O software foi bem avaliado e considerado útil na aquisiçao de conhecimento numa área específica mais prevalente do comprometimento da saúde do adulto.

Software Educacional: Nematelmintos de Aquisição Passiva

RESUMO Objetivo Desenvolver e avaliar um software educacional com base em imagens parasitológicas de helmintos, abordando de forma ilustrativa e interativa os nematelmintos de transmissão passiva, o que poderá ser útil a professores, profissionais e alunos de graduação das diferentes profissões da saúde na compreensão e identificação dessas verminoses, aproximando-os também da prática profissional. Metodologia O software foi construído com base em um banco de imagens do próprio autor, utilizando o multimídia Flashâ, que permite elaborar animações e simulações em linguagem vetorial, resultando em arquivos pequenos, que podem ser disponibilizados através da web ou em mídias ópticas e magnéticas. A avaliação do produto final foi feita por estudantes de Medicina. Resultados O software foi concluído e bem avaliado pelos estudantes do curso de Medicina (n=97) da Faculdade de Ciências Médicas e da Saúde (FCMS) da PUC/SP. Os pré e pós-testes do material mostraram consistente crescimento do conhecimento, seja por autoavaliação ou por questões objetivas fechadas. Conclusão Os resultados atuais permitem concluir que o software é de grande interesse educacional e poderá ser útil a estudantes, profissionais e docentes da área da saúde.

Determinação de fatores de empilhamento através do software Digitora

Este trabalho foi realizado com o objetivo de avaliar o uso do programa computacional Digitora na determinação de fatores de empilhamento. Para isto, foram utilizadas pilhas de madeira de eucalipto, empilhadas manualmente sobre o solo. Após as análises, verificou-se que: a) o software propiciou estimativas precisas dos fatores de empilhamento; b) houve uma leve tendência de superestimação dos fatores pelo Digitora; c) o treinamento do operador com relação à classificação dos pontos sobre as fotografias no Digitora é condição primordial para obtenção de estimativas precisas dos fatores de empilhamentos; e d) as fotografias deverão ser sempre tomadas com o flash e o ZOOM ativados.

Sistema automatizado para coleta de dados de umidade relativa e temperatura do ar

Algumas variáveis climáticas, tais como a temperatura do ar (T) e a umidade relativa do ar (UR) exercem grande influência sobre a produção agrícola. Uma vez combinadas adequadamente, podem resultar em incrementos quantitativos e qualitativos do produto final, o que as tornam indispensáveis no monitoramento e manejo dentro do ambiente de produção. A aquisição de dados é uma importante ferramenta que pode auxiliar nesse processo, resultando em maior eficiência e uso racional dos recursos. Desse modo, o presente trabalho teve por objetivo o desenvolvimento de um sistema de aquisição de dados (SAD) compacto, na forma de um datalogger (de construção simples), para monitorar T e UR. Os dados provenientes dos sensores utilizados são gravados numa memória do tipo flash drive (USB removível), que é posteriormente conectada a um computador para interpretação dos dados via software. A fim de avaliar o desempenho do SAD, os dados registrados foram comparados com os dados de uma estação meteorológica convencional e de uma automatizada, apresentando valores de UR próximos em ambos os casos. Para T, a substituição do amplificador operacional é necessária. Dessa forma, o SAD desenvolvido apresenta-se viável inclusive para aplicações em campo.

Comparison of full-field electroretinogram in diabetic and non diabetic dogs with cataracts

Being the commonest ocular disorder, dense cataracts disable fundoscopic examination and the diagnosis of retinal disorders, which dogs may be predisposed. The aim of this study was to compare the electroretinographic responses recorded according to the International Society for Clinical Electrophysiology of Vision human protocol to evaluate retinal function of diabetic and non diabetic dogs, both presenting mature or hypermature cataracts. Full-field electroretinogram was recorded from 66 dogs, with ages varying from 6 to 15 years old allocated into two groups: (1) CG, non diabetic cataractous dogs, and (2) DG, diabetic cataractous dogs. Mean peak-to-peak amplitude (microvolts) and b-wave implicit time (milliseconds) were determined for each of the five standard full-field ERG responses (rod response, maximal response, oscillatory potentials, single-flash cone response and 30 Hz flicker). Comparing CG to DG, ERGs recorded from diabetic dogs presented lower amplitude and prolonged b-wave implicit time in all ERG responses. Prolonged b-wave implicit time was statistically significant (p< 0.05) at 30 Hz flicker (24.0 ms versus 22.4 ms). These data suggests full-field ERG is capable to record sensible alterations, such as flicker's implicit time, being useful to investigate retinal dysfunction in diabetic dogs.

Electrophysiological measurements of spectral sensitivities: a review

Spectral sensitivities of visual systems are specified as the reciprocals of the intensities of light (quantum fluxes) needed at each wavelength to elicit the same criterion amplitude of responses. This review primarily considers the methods that have been developed for electrophysiological determinations of criterion amplitudes of slow-wave responses from single retinal cells. Traditional flash methods can require tedious dark adaptations and may yield erroneous spectral sensitivity curves which are not seen in such modifications as ramp methods. Linear response methods involve interferometry, while constant response methods involve manual or automatic adjustments of continuous illumination to keep response amplitudes constant during spectral scans. In DC or AC computerized constant response methods, feedback to determine intensities at each wavelength is derived from the response amplitudes themselves. Although all but traditional flash methods have greater or lesser abilities to provide on-line determinations of spectral sensitivities, computerized constant response methods are the most satisfactory due to flexibility, speed and maintenance of a constant adaptation level

Photophysical studies of zinc phthalocyanine and chloroaluminum phthalocyanine incorporated into liposomes in the presence of additives

The photophysical properties of zinc phthalocyanine (ZnPC) and chloroaluminum phthalocyanine (AlPHCl) incorporated into liposomes of dimyristoyl phosphatidylcholine in the presence and absence of additives such as cholesterol or cardiolipin were studied by time-resolved fluorescence, laser flash photolysis and steady-state techniques. The absorbance of the drugs changed linearly with drug concentration, at least up to 5.0 µM in homogeneous and heterogeneous media, indicating that aggregation did not occur in these media within this concentration range. The incorporation of the drugs into liposomes increases the dimerization constant by one order of magnitude (for ZnPC, 3.6 x 10(4) to 1.0 x 10(5) M-1 and for AlPHCl, 3.7 x 10(4) to 1.5 x 10(5) M-1), but this feature dose does not rule out the use of this carrier, since the incorporation of these hydrophobic drugs into liposomes permits their systemic administration. Probe location in biological membranes and predominant positions of the phthalocyanines in liposomes were inferred on the basis of their fluorescence and triplet state properties. Both phthalocyanines are preferentially distributed in the internal regions of the liposome bilayer. The additives affect the distribution of these drugs within the liposomes, a fact that controls their delivery when both are used in a biological medium, retarding their release. The addition of the additives to the liposomes increases the internalization of phthalocyanines. The interaction of the drugs with a plasma protein, bovine serum albumin, was examined quantitatively by the fluorescence technique. The results show that when the drugs were incorporated into small unilamellar liposomes, the association with albumin was enhanced when compared with organic media, a fact that should increase the selectivity of tumor targeting by these phthalocyanines (for ZnPC, 0.71 x 10(6) to 1.30 x 10(7) M-1 and for AlPHCl, 4.86 x 10(7) to 3.10 x 10(8) M-1).

Extracts of Azadirachta indica and Melia azedarach seeds inhibit folliculogenesis in albino rats

The seed oil of Azadirachta indica A. Juss (neem) is used in traditional medicine for its antidiabetic, spermicidal, antifertility, antibacterial, and wound healing properties. The present study was undertaken to investigate the quantitative aspects of follicular development in cyclic female albino rats (135 ± 10 g; 8 groups with 6 animals in each group) after oral administration of polar (PF) and non-polar (NPF) fractions of A. indica seed extract at 3 and 6 mg kg body weight-1 day-1 and Melia azedarach Linn. (dharek) seed extract at 24 mg kg body weight-1 day-1 for 18 days. The extracts were prepared using a flash evaporator at 35°C and then dissolved in olive oil to prepare doses on a per kg body weight basis. There was a significant reduction (P = 0.05) in the number of normal single layered follicles (A. indica: 0.67 ± 0.33 and 4.67 ± 2.03 after 3 and 6 mg/kg NPF, and 3.33 ± 1.67 and 1.00 ± 1.00 after 3 and 6 mg/kg PF vs control: 72.67 ± 9.14 and M. azedarach: 0.60 ± 0.40 and 1.80 ± 1.2 after 24 mg/kg PF and NPF, respectively, vs control: 73.40 ± 7.02) and follicles in various stages (I-VII) of follicular development in all treatment groups. These extracts also significantly reduced (P = 0.05) the total number of normal follicles in the neem (14.67 ± 5.93 and 1.00 ± 1.00 after 3 and 6 mg/kg PF and 3.67 ± 0.88 and 5.33 ± 2.03 after 3 and 6 mg/kg NPF) and dharek (13.00 ± 3.58 and 14.60 ± 2.25 after 24 mg/kg NPF and PF) treatments compared to control (216.00 ± 15.72 and 222.20 ± 19.52, respectively). Currently, indiscriminate use of persistent and toxic rodenticides to control rodent populations has created serious problems such as resistance and environmental contamination. Therefore, it becomes necessary to use ecologically safe and biologically active botanical substances that are metabolized and are not passed on to the next trophic level, and that interfere with the reproductive potential particularly growth and differentiation of follicles. This may help elevate the socio-economic status of the country. Thus, the present study is an attempt to investigate the effects of A. indica and M. azedarach seed extracts on reproduction of albino rats.