Comportamento dos amebócitos circulantes de moluscos planorbídeos frente ao parasitismo por larvas de Schistosoma mansoni, inoculação de tinta nanquim e fratura da concha

Foi estudado o comportamento dos amebócitos circulantes de Biomphalaria glabrata e Biomphalaria tenagophila mediante à infecção pelo Schistosoma mansoni, à inoculação de tinta Nanquim e à fratura da concha. Foi realizada contagem diferencial de amebócitos na hemolinfa, dando-se ênfase aos tipos de células encontradas em cada amostra; avaliação histopatológica dos moluscos submetidos à exposição aos miracídios de S. mansoni; e análise da morfologia dos amebócitos através de microscopia de fase. Foi verificada correlação entre a variação do número de amebócitos circulantes e a reação tecidual. Em Biomphalaria tenagophila somente houve aumento do número de amebócitos estrelados quando os moluscos eram infectados por S. mansoni, o que sugere a especificidade da reação ao parasitismo. Comparando os resultados obtidos em B. glabrata e B. teganophila, concluiu-se que esses moluscos apresentam comportamentos amebocitários diferentes frente aos diversos estímulos utilizados.

Morfologia do Mycobacterium leprae hominis e do M. leprae muris: estudo baseado na microscopia electrônica e de contraste de fases

Hansen's Bacillus: By electron microscopy this bacillus shows membrane and halo, this being more visible when sorrounding the globi or bundles of bacilli; shows, also, free granules of various sizes which were before considered as dust of the dyes; shows external granules bound with the membrane and some times branching. By phases contrast microscopy examining leproma suspensions and subcataneous lymph at 400 x we saw many free granules with intense rotatory movement; granulated bacilli with screw, skip or stroke motion, producing slow progressive motion. All such elementes are surrounded by a halo, corresponding to the classical gloea. By a patient and delayed examination we were able to see that the internal granules are motile and help the progression of the bacilli, giving the impression that the cytoplasm is liquid. By a lasting observation we could see the larger granules form prolapse, like a pseudopode and abandon the bacilli and going in very rapid rotatory movement. There are branched bacilli; there are pedunculated fred granules like comets. The addition of a drop of formol at the preparation stops all movements. Stefansky's Bacillus: Repeated examination by RCA electron microscope, type EMU-25 of fresh suspensions of rat lepromas, led us to confirm the close relationship between human and murine leprosy agents. We examined also material from carabo (Lepra bubalorum) from Java, but due to fixation, the material was unsuitable for comparative studies. The Stefansky's bacilli showed also emmbranes and halos, internal or external granules (smaller than those of Hansen's bacillus). The bacilli shaded by chromium look thicker and shorter than those of Hansen. Due to electron bombardment both, Hansen's and Stefansky's baccilli suffer considerable alterations in their structure, showing black barrs of chromatin condensation at their extremities as also in their centers. By phase microscopy the Stefansky's bacilli showed elements with 1, 2 (bipolar), 3 or more internal small granules, developing identical movements as those of Hansen. The globi seem to be non-motile but the free bacilli appearing around the globi show intense movement. At 1000 x the examination is less satisfactory than at 400 x. The addition of formol solution in the preparation suppresses all movements, even the brownian, but the material becomes more suitable for the study of static morphology of the bacilli. CONCLUSION - The electron and phases contrast microscopy of leprous material from different types and phases of the disease may explain some of the unknown aspects of the biology and morphology of the bacilli.

Geração e controle das cores luz primárias em vidros para dispositivos "full color"

We are working in a new multi-doped glassy material to generate simultaneously the three primary light color (by addition) of the visible spectrum, with the control of the intensity of each one, allowing the simulation of any color: a full-color generator device. Tm+3, Tb+3 and Eu+3 ions were used (0.01 to 5,0 mol%) as blue, green and red narrow line emitters. A wide color gamut was obtained under ultraviolet excitation by varying the material composition. The chromaticity diagram is covered, including the white simulation.

Dispositivos poliméricos eletroluminescentes

Here we present an overview of electroluminescent devices that use conjugated polymers as the active media. The principal components of the devices are described and we show some examples of conjugated polymers and copolymers usually employed in polymeric light emitting devices (PLED). Some aspects of the photo and electroluminescence properties as well as of the energy transfer processes are discussed. As an example, we present some of the photophysical properties of poly(fluorene)s, a class of conjugated polymers with blue emission.

Estudo comparativo de métodos de preparo de amostras de tinta para a determinação de metais e metalóides por técnicas de espectrometria atômica

This work deals with paint decomposition methods for major, minor and trace elements determination. Three methods were investigated: (1) decomposition in closed quartz vessel and heating in microwave oven; (2) decomposition in open vessel using HNO3 and ashing, following the ASTM D 3335-85a method; and (3) decomposition in open vessel using HNO3 + HF and ashing. Paints of different types and colours were analyzed, in which several elements were determined using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP OES). It was observed that method (1) is appropriate for trace, minor and major elements determination, while method (3) is appropriate for Ti.

Aplicación de una lengua electrónica voltamétrica para la clasificación de vinos y estudio de correlación con la caracterización química y sensorial

This paper presents the analytical application of a novel electronic tongue based on voltammetric sensors array. This device was used in the classification of wines aged in barrels of different origins and toasting levels. Furthermore, a study of correlation between the response of the electronic tongue and the sensory and chemical characterization of samples was carried out. The results were evaluated by applying both principal component analysis and cluster analysis. The samples were clearly classified. Their distribution showed a high correspondence degree with the characteristics of the analyzed wines, it also showed similarity with the classification obtained from organoleptic analysis.

Reator de UV-Ozônio com lâmpada a vapor de mercúrio a alta pressão modificada para tratamento superficial de óxidos transparentes condutivos utilizados em dispositivos poliméricos eletroluminescentes

An UV-Ozone reactor was developed with an ignition tube extracted into HID mercury lamp used to irradiation on zinc oxide (ZnO) and fluorinated tin oxide (FTO) films for PLEDs devices. Different exposures times were used. In contact angle measurements revealed better results for ZnO and FTO by 15 and 5 min, respectively. In Diffuse Reflectance Infra-red Fourier Transformed (DRIFT) spectroscopy allowed the observation of water, hydrocarbon and carbon dioxide adsorbed on the untreated TCO surfaces. After the UV-Ozone treatment the contaminants were significantly reduced or eliminated and the PLEDs devices decreased threshold voltages in comparison with respectively untreated TCOs.

Processamento de cartuchos de impressoras de jato de tinta: um exemplo de gestão de produto pós-consumo

This work presents a route for processing spent ink-jet cartridges in an experimental course. The disassembly of the cartridges requires several steps and the recognition of their different components is essential to define the best final destination (recycling, co-processing). The plastic strips were chemically processed so as to recover gold and copper. The students recognized the difficulty of processing multicomponent wastes and the importance of the chemical work under the best safety conditions; they also experienced many laboratory techniques and recognized the value of the selective collection and the reverse logistics to reach a viable commercial scale recycling.

Influência de diferentes solventes utilizados na deposição de filme de poli(9-vinilcarbazol) em dispositivos OLEDs

This work studies the influence of the film deposition process on light emission performance and on threshold voltage of OLEDs, with architecture glass/ITO/PEDOT:PSS/PVK/Alq3/Al. The commercial PVK was dissolved in different solvents such as: chloroform, tetrahydrofuran, 1,2,4-trichlorobenzene and trimethylpentane. OLEDs were characterized by current-voltage and revealed a significant influence of the solvents, although all devices emitted green electroluminescence. A difference in threshold voltage up to 10 V was observed among OLEDs prepared from different solvents. The 1,2,4-trichlorobenzene showed best performance, presenting lowest treshold voltage (≈ 6 V), followed by tetrahydrofuran (≈ 8 V), trimethylpentane (≈ 14 V) and chloroform (≈ 16 V).

Máscaras mecânicas de sombra por eletrocorrosão para dispositivos eletro-ópticos

Shadow masks are used in manufacturing processes for electro-optic devices to transfer patterns with different shapes and dimensions. For fabrication of organic based devices, shadow masks should be made of materials stable against organic solvents, high temperature, and robust, remaining unchanged after multiple cycles of use and fixation. Thus, stainless steel is suitable for shadow masks. A simple, cheap and quick method of obtaining shadow masks by electrochemical corrosion of stainless steel is reported. The shadow mask was used to evaporate cathode material to obtain an organic light emitting diode with active area of 9 mm². This device exhibited a turn-on voltage of 5 V and luminance of 14 cd/m².

Avaliação de dispositivos de captura de imagens digitais para detecção colorimétrica em microzonas impressas

This report describes a study about the feasibility of using a conventional digital camera, a cell-phone camera, an optical microscope, and a scanner as digital image capture devices on printed microzones. An array containing nine circular zones was drawn using graphics software and printed onto transparency film by a laser printer. Due to its superior analytical performance, the scanner was chosen for the quantitative determination of Fe2+ in pharmaceutical samples. The data achieved using scanned images did not differ statistically from those attained by the reference spectrophotometric method at the confidence level of 0.05.

DISPOSITIVOS DGT MODIFICADOS COM MATERIAIS ALTERNATIVOS PARA USO NA ESPECIAÇÃO DE ELEMENTOS TRAÇO

The use of MT-K10 Montmorillonite immobilized onto agarose was investigated in this work as an alternative binding phase in Diffusive Gradient in Thin Film (DGT) devices for the determination of metallic labile species. In addition, agarose itself was also used as the diffusive phase. The percentage of sorption of Zn2+, Cu2+, Cr3+, Mn2+, Cd2+, Pb2+, and Ni2+ onto the binding phase was higher than 80% and the desorption process for all elements was also greater than 75%. Elution factors were determined experimentally, ranging from 0.74 for Zn2+ and 0.90 for Cr3+ and Pb2+. The accumulation of all species was linear with time, in agreement with the Fick's 1st law of diffusion. The deployment of the alternative devices in natural waters was compared to commercial devices. Labile concentrations determined by the alternative devices were slightly superior compared to results obtained with the deployment of original DGT devices due to the less restrictive pores of agarose.