Viability and Infectivity of Plasmodium vivax Gametocytes in Short-Term Culture.

The control and elimination of malaria caused by Plasmodium vivax both represent a great challenge due to the biological aspects of the species. Gametocytes are the forms responsible for the transmission of the parasite to the vector and the search for new strategies for blocking transmission are essential in a scenario of control and elimination The challenges in this search in regard to P. vivax mainly stem from the lack of a long-term culture and the limitation of studies of gametocytes. This study evaluated the viability and infectivity of P. vivax gametocytes in short-term culture. The samples enriched in gametocytes using Percoll (i), using magnetic-activated cell sorting (MACS®) (ii), and using non-enriched samples (iii) were evaluated. After the procedures, gametocytes were cultured in IMDM medium for up to 48 h. Cultured P. vivax gametocytes were viable and infectious for up to 48 h, however differences in viability and infectivity were observed in the samples after 12 h of culture in relation to 0 h. Percoll-enriched samples were shown to be viable in culture for longer intervals than those purified using MACS®. Gametocyte viability after enrichment procedures and short-term culture may provide new avenues in the development of methods for evaluating P. vivax TB.

Stereometric characterization of Dinizia excelsa Ducke wood from Amazon rainforest using atomic force microscopy.

Dinizia excelsa Ducke under three different cut conditions were carefully analyzed. The morphology and stereometry of different wood cutting surfaces (longitudinal radial, longitudinal tangential, and transversal) were studied by SEM and AFM. The results obtained in this study suggest that both the height parameters and the advanced stereometric parameters of the surfaces did not reveal a significant difference, indicating that the spatial patterns do not change according to the type of cut. In this way, the surface microtexture does not vary depending on the cut type. Similarly, the Hurst's coefficients did not show any significant difference in the spectrum of the PSD fractal region. On the other hand, Minkowski functionals presented a morphological difference between the samples. These results showed that the microtexture of the wood surface does not change as a function of the type of cut submitted to the same polishing process.

Advanced Microtexture Study of Anacardium occidentale L. Leaf Surface From the Amazon by Fractal Theory.

This work applies stereometric parameters and fractal theory to characterize the structural complexity of the 3D surface roughness of Anacardium occidentale L. leaf using atomic force microscopy (AFM) measurements. Surface roughness was studied by AFM in tapping mode, in air, on square areas of 6,400 and 10,000 µm2. The stereometric analyses using MountainsMap Premium and WSXM software provided detailed information on the 3D surface topography of the samples. These data showed that the morphology of the abaxial and adaxial side of the cashew leaf is different, which was also observed in relation to their microtextures. Fractal analysis showed that the adaxial and abaxial sides have strong microtexture homogeneity, but the adaxial side presented higher surface entropy. These results show that image processing associated with fractal theory can be an indispensable tool for identifying plant species by their leaves because this species has singularities on each side of the leaf.

Stereometric characterization of kefir microbial films associated with Maytenus rigida extract.

The aim of this study was to report the first discussion of statistical parameters and possible applications related to the surface of kefir biofilms prepared with Maytenus rigida Mart. extract through micromorphology, using atomic force microscopy (AFM). Four different samples were produced. The reference contained demerara sugar with a concentration of 40 g/L and the others had added extract whose concentrations were 0.25, 0.50, and 0.75 g/L, respectively. AFM was used to image the surface in tapping mode, on square areas of 30 µm × 30 µm. Images were studied by the MountainsMap premium commercial software. The main parameter of the surface, roughness, grew with the increase of the extract concentration up to 0.50 g/L. In addition, asymmetry and kurtosis showed that the biofilm with the best peak distribution was the one with 0.25 g/L of plant extract. The other parameters followed the main results for the surface and were observed for the depth and volume parameters. The power spectrum density spectrum confirmed the reliability of the results for the sample with 0.25 g/L. Therefore, the sample with 0.25 g/L of plant extract produced the best balance in relation to the surface properties. These results showed that the biofilm morphology and microtexture were affected by the incorporation of the plant extract and can be useful to define possible applications.

Wettability and morphology of the leaf surface in cashew tree from the Amazon, Northern Brazil / Molhabilidade e morfologia da superfície da folha em cajueiro da Amazônia na Região Norte do Brasil

Leaves surfaces, which represent an interface with plants and the environment, have several structures with specific functions. Some foliar properties, including wettability and mechanical containment, are inferred in terms of cellular adaptation and the presence or absence of cuticular wax. Various morphological parameters, ranging from macro- to nano scales, are analyzed and contribute to the study of taxonomy, pharmacognosy, and ecology of plants. The aim of this paper was to analyze the effect and influence of epicuticular wax granules on the hydrophobicity of Anacardium occidentale L. leaf surfaces. Leaf specimens were directly examined with an environmental scanning electron microscope without metal coating. Images revealed epidermis ornament, stomata type, was, and trichomes. Static contact angle between water and the surface was also measured on both sides. On the adaxial side, an angle of 104.09° ± 0.95° was found, suggesting that adaxial surface is hydrophobic. On the abaxial side, the angle was 62.20° ± 1.60°, which indicates a hydrophilic nature, probably because of the greater amount of epicuticular wax on the adaxial leaf surface. The present investigation provided an important contribution to morphological and ultrastructural characterization of leaves of cashew tree, which is a plant of great medicinal and economic importance.

Superfícies de folhas têm diversas estruturas com funções específicas e contribuem para a relação delas com o meio ambiente. Algumas propriedades foliares, incluindo molhabilidade e contenção mecânica, são inferidas em termos de adaptação celular e da presença ou ausência de cera cuticular. Diversos parâmetros morfológicos, variando da macroescala até a nanoescala, são analisados e contribuem para o estudo de taxonomia, farmacognosia e ecologia de plantas. O objetivo deste trabalho foi analisar o efeito e a influência de grãos de cera epicuticular na hidrofobicidade da superfície de folhas de Anacardium occidentale L. Amostras de folha foram examinadas com um microscópio eletrônico de varredura ambiental sem recobrimento metálico. As imagens evidenciaram algumas características (epiderme, tipo de estômato, cera e tricomas). O ângulo de contato estático entre a água e a superfície também foi medido em ambos os lados. No lado adaxial, foi encontrado um ângulo de 104,09° ± 0,95°, sugerindo que esta é hidrofóbica. No lado abaxial, o ângulo foi de 62,20° ± 1,60°, que indica uma natureza hidrofílica, provavelmente devido à grande quantidade de cera epicuticular na superfície abaxial da folha. A presente investigação forneceu uma contribuição importante para a caracterização morfológica e ultra-estrutural de folhas de cajueiro, que é uma planta de grande importância econômica.

Studies on the ultrastructure in Anacardium occidentale L. leaves from Amazon in northern Brazil by scanning microscopy.

Leaves surfaces have various structures with specific functions and contribute to the relationship with the environment. On morphological studies are analyzed various parameters, ranging from macro scale through the micro scale to the nanometer scale, which contribute to the study of taxonomy, pharmacognosy, and ecology, among others. Functional structures found in leaves are responsible for the wide variety of surfaces and some behaviors are given in terms of cellular adaptation and the presence or absence of wax. This study reports the characterization of Anacardium occidentale L. leaf surface and the techniques used therein. A set of scanning electron microscope (SEM) and atomic force microscope (AFM) images performed on fresh leaf allowed observation of textured and heterogeneous profiles on both sides. SCANNING 38:329-335, 2016. © 2015 Wiley Periodicals, Inc.