Fluidodinâmica de sementes de brócolos em leito fluizado e leito de jorro

The spouted and fluidized bed technologies are usually employed in operations of drying, coating and granulation of particles by the chemical and pharmaceutical industries. The use of these techniques in agronomy is limited to the treatment of some species of seeds. In this work, the objective was to analyse the fluid-dynamics of fluidized and spouted beds when broccoli (Brassica oleracea L. var. Italica) seeds are used and also to verify the influence on seed germination after 60 min of seed exposition to spouting or fluidization, at room temperature. The fluid-dynamics was defined by the measurements of the bed pressure drop as a function of the air flow rate for different seeds loads. The experimental conditions were based on the physical properties of the seeds and were limited by the apparatus dimensions. The cone-cylindrical bed was constructed in plexyglass to permit flow visualization. The values of the parameters: maximum pressure drop, minimum spouting flow rate and pressure drop, and stable spout pressure drop were experimentally obtained from the fluid-dynamic analysis and were compared with the values calculated by empirical equations found in the literature. The same procedure was carried out with the fluidized bed and the important parameters for this regime were the air velocity and the bed pressure drop at minimum fluidization. The analysis of seed germination indicated that no damage was caused to the seeds by the spout or fluidization processes.

Qualidade pós-colheita de caqui 'fuyu' com utilização de diferentes concentrações de cobertura comestível

One of the main objectives of applying edible coatings on fruits surface is to create a protective film to reduce weight loss due to evaporation and transpiration and also to decrease the risk of fruit rot caused by environmental contamination, in order to improve the visual aspect. Therefore, it is possible to increase shelf life, and decrease post harvest losses. Persimmon is a much appreciated fruit, with high potential for export, but sensitive to handling and storage. This study aimed to evaluate the effect of applying the edible coating Megh Wax ECF-124 (18% of active composts, consisting of emulsion of carnauba wax, anionic surfactant, preservative and water) produced by Megh Industry and Commerce Ltda in three different concentrations (25, 50 and 100%) on post harvest quality of 'Fuyu' persimmon stored for 14 days. The attributes evaluated for quality were: firmness, pH, acidity, soluble solids, weight loss and color. The results showed that application of carnauba wax in different concentrations was effective on decreasing weight loss of persimmon cv. Fuyu and maintenance of color aspects. Treatment at lower concentration, 25%, showed lower rate of discharge, but high concentrations showed lower values of mass loss. Carnauba wax application showed a high potential for use on postharvest conservation, and can be applied together with other technologies, helping to maintain quality for export.

Determinação de substitutos da manteiga de cacau em coberturas de chocolate através da análise de triacilgliceróis

Brazilian regulations prohibit the addition of cocoa butter replacements to chocolate, in total or partial substitution. The objective of the present work was to check the quality standards of four of coating bitter Brasilian chocolate bars and five of coating milk chocolate bars, commercialized in Campinas. In order to check the possible addition of substitutes, the triacylglycerol composition was determined, and the results were analysed by Padley & Timms mathematical method. The triacylglycerol composition of each sample was determined by high temperature gas chromatography (HTGC). The presence of cocoa butter replacements was not detected in the brands of coating chocolate.

Influence of implant surfaces on osseointegration

The biological fixation between the dental implant surfaces and jaw bones should be considered a prerequisite for the long-term success of implant-supported prostheses. In this context, the implant surface modifications gained an important and decisive place in implant research over the last years. As the most investigated topic in, it aided the development of enhanced dental treatment modalities and the expansion of dental implant use. Nowadays, a large number of implant types with a great variety of surface properties and other features are commercially available and have to be treated with caution. Although surface modifications have been shown to enhance osseointegration at early implantation times, for example, the clinician should look for research evidence before selecting a dental implant for a specific use. This paper reviews the literature on dental implant surfaces by assessing in vitro and in vivo studies to show the current perspective of implant development. The review comprises quantitative and qualitative results on the analysis of bone-implant interface using micro and nano implant surface topographies. Furthermore, the perspective of incorporating biomimetic molecules (e.g.: peptides and bone morphogenetic proteins) to the implant surface and their effects on bone formation and remodeling around implants are discussed.

Flavoring agents present in a dentifrice can modify volatile sulphur compounds (VSCs) formation in morning bad breath

This study aimed to evaluate the effects of a flavor-containing dentifrice on the formation of volatile sulphur compounds (VSCs) in morning bad breath. A two-step, blinded, crossover, randomized study was carried out in 50 dental students with a healthy periodontium divided into two experimental groups: flavor-containing dentifrice (test) and non-flavor-containing dentifrice (control). The volunteers received the designated dentifrice and a new toothbrush for a 3 X/day brushing regimen for 2 periods of 30 days. A seven-day washout interval was used between the periods. The assessed parameters were: plaque index (PI), gingival index (GI), organoleptic breath scores (ORG), VSC levels (as measured by a portable sulphide monitor) before (H1) and after (H2) cleaning of the tongue, tongue coating (TC) wet weight and BANA test from TC samples. The intra-group analysis showed a decrease in ORG, from 3 to 2, after 30 days for the test group (p < 0.05). The inter-group analysis showed lower values in ORG, H1 and H2 for the test group (p < 0.05). There was no difference between the amount of TC between groups and the presence of flavor also did not interfere in the BANA results between groups (p > 0.05). These findings suggest that a flavor-containing dentifrice seems to prevent VSCs formation in morning bad breath regardless of the amount of TC in periodontally healthy subjects.

Bone response to a Ca- and P-enriched titanium surface obtained by anodization

This study evaluated bone response to a Ca- and P- enriched titanium (Ti) surface treated by a multiphase anodic spark deposition coating (BSP-AK). Two mongrel dogs received bilateral implantation of 3 Ti cylinders (4.1 x 12 mm) in the humerus, being either BSP-AK treated or untreated (machined - control). At 8 weeks postimplantation, bone fragments containing the implants were harvested and processed for histologic and histomorphometric analyses. Bone formation was observed in cortical area and towards the medullary canal associated to approximately 1/3 of implant extension. In most cases, in the medullary area, collagen fiber bundles were detected adjacent and oriented parallel to Ti surfaces. Such connective tissue formation exhibited focal areas of mineralized matrix lined by active osteoblasts. The mean percentages of bone-to-implant contact were 2.3 (0.0-7.2 range) for BSP-AK and 0.4 (0.0-1.3 range) for control. Although the Mann-Whitney test did not detect statistically significant differences between groups, these results indicate a trend of BSP-AK treated surfaces to support contact osteogenesis in an experimental model that produces low bone-to-implant contact values.

Influência de diferentes materiais de cobertura no conforto térmico de instalações para frangos de corte no oeste paulista

Este trabalho apresenta um estudo da influência de diferentes materiais de cobertura no conforto térmico de instalações destinadas à criação de frangos de corte. A pesquisa foi desenvolvida no Câmpus Experimental da UNESP de Dracena - SP. Quatro protótipos em escala real foram construídos, com área de 28 m² cada, cobertos com telha reciclada à base de embalagens longa vida, telha cerâmica, telha cerâmica pintada de branco e telha de fibrocimento. Os dados foram coletados durante o período de inverno de 2007, totalizando 90 dias. Com esses dados, foram calculados os índices de conforto térmico Carga Térmica Radiante (CTR) e a variável ambiental (Ta). Uma análise estatística por inferência e descritiva foi realizada com os valores do índice de conforto térmico e da variável ambiental. Com os resultados obtidos, é possível afirmar que a telha reciclada apresentou índices de conforto térmico semelhantes àqueles encontrados para as telhas cerâmicas. O protótipo coberto com telha de fibrocimento apresentou os maiores índices, e o coberto com telha cerâmica branca, os menores índices de conforto térmico. No entanto para o período de inverno e para os horários avaliados, todas as instalações apresentaram índices de conforto térmico fora da zona de termoneutralidade do frango de corte.

Absorption of metals and characterization of chemical elements present in three species of Gracilaria (Gracilariaceae) Greville: a genus of economical importance

Gracilaria Greville is a genus of seaweed that is economically explored by the cosmetic, pharmaceutical and food industries. One of the biggest problems associated with growing Gracilaria is the discharge of heavy metals into the marine environment. The absorption of heavy metals was investigated with the macroalga Gracilaria tenuistipitata Zhang et Xia, cultivated in a medium containing copper (Cu) and cadmium (Cd). In biological samples, EC50 concentrations of 1 ppm for cadmium and 0.95 ppm for copper were used. These concentrations were based on seaweed growth curves obtained over a period of six days in previous studies. ICP-AES was used to determine the amount of metal that seaweeds absorbed during this period. G. tenuistipitata was able to bioaccumulate both metals, about 17% of copper and 9% of cadmium. Basal natural levels of Cu were found in control seaweeds and in G. tenuistipitata exposed to Cd. In addition, the repertoire of other important chemical elements, as well as their concentrations, was determined for G. tenuistipitata and two other important seaweeds, G. birdiae Plastino & Oliveira and G. domingensis (Kützing) Sonder ex Dickie, collected in natural environments on the Brazilian shore.

A multi-screening approach for marine-derived fungal metabolites and the isolation of cyclodepsipeptides from Beauveria felina

Extracts obtained from 57 marine-derived fungal strains were analyzed by HPLC-PDA, TLC and ¹H NMR. The analyses showed that the growth conditions affected the chemical profile of crude extracts. Furthermore, the majority of fungal strains which produced either bioactive of chemically distinctive crude extracts have been isolated from sediments or marine algae. The chemical investigation of the antimycobacterial and cytotoxic crude extract obtained from two strains of the fungus Beauveria felina have yielded cyclodepsipeptides related to destruxins. The present approach constitutes a valuable tool for the selection of fungal strains that produce chemically interesting or biologically active secondary metabolites.

Characterization of thiol-functionalised silica films deposited on electrode surfaces

Thiol-functionalised silica films were deposited on various electrode surfaces (gold, platinum, glassy carbon) by spin-coating sol-gel mixtures in the presence of a surfactant template. Film formation occurred by evaporation induced self-assembly (EISA) involving the hydrolysis and (co)condensation of silane and organosilane precursors on the electrode surface. The characterization of such material was performed by IR spectroscopy, thermogravimetry (TG), elemental analysis (EA), atomic force microscopy (AFM), scanning electron microscopy (SEM) and cyclic voltammetry (CV).

Evaluation of capillaries with different inner coatings for DNA analysis using dilute polymer solutions by capillary electrophoresis

In this work three capillary columns, one with uncoated inner wall and two with covalently-bound internal coatings - poly(vinyl alcohol) (PVA) and poly(dimethylacrylamide) (PDMA) - both covalently covered - were used to separate DNA fragments and compared to DNA separation using replaceable polymer solutions. The separations were performed using hydroxyethylcellulose (HEC) (90-105 kDa) in concentrations ranging from 0.00 to 2.00% m/v. The results indicated that the separation efficiency was higher in the PVA capillary than in the PDMA in all evaluated concentrations of HEC. In addition, higher resolution was also observed in PVA-coated capillary since in PDMA the shape of the peaks was not reproducible when subsequent runs were performed. Contrary to what has previously been reported in the literature, no reasonable separation was possible in bare fused silica.

Catalytic enantioselective arylations: boron to zinc exchange as a powerful tool for the generation of transferable aryl groups

The transmetalation between boron and zinc is of great importance for application in organic synthesis, since it allows the formation of new carbon-carbon bonds between organometallic units and electrophiles. The direct arylation of aldehydes or more scarcely ketones, in a catalytic, enantioselective manner using chiral catalysts has been described recently. The enantiomerically enriched diarylmethanols obtained in these reactions are valuable precursors for important bioactive molecules. This review provides a synopsis of this ever-growing field and highlights some of the challenges that still remain.

Trypanocidal activity of Piper arboreum and Piper tuberculatum (Piperaceae)

In the scope of our ongoing research on bioactive agents from Brazilian flora, twenty-four extracts and fractions obtained from Piper arboreum Aub. and Piper tuberculatum Jacq. (Piperaceae) were screened for trypanocidal activity by using MTT colorimetric assay. The strongest activity was found in hexane fractions from the leaves of P. arboreum (IC50= 13.3 µg/ mL) and P. tuberculatum (IC50 = 17.2 µg/mL). Hexane fractions of the fruits of P. tuberculatum and P. arboreum showed potent toxic effects on epimastigote forms of Trypanosoma cruzi, with values of IC50 (µg/mL) of 32.2 and 31.3, respectively. Additionally, the phytochemical study of the hexane fraction of P. arboreum leaves furnished two pyrrolidine amides, piperyline (1) and 4,5-dihydropiperyline (2), which could be responsible, at least in part for the observed antiprotozoal activity.

Aspectos mecanísticos da bioatividade e toxicidade de nitrocompostos

Nitrocompounds are bioactive molecules used as antibacterial, antiparasitic and antitumoral agents. In the past of years, these molecules have been broadly studied in several fields, such as medicinal chemistry, organic chemistry, biochemical, toxicology and electrochemistry. The nitrocompounds mode of action involves the biotransformation of the nitro group, releasing intermediates in the redox process. Some of those intermediates attack enzymes, membranes and DNA, providing the basis for their biological activity and adverse effects. In this report, some aspects regarding the biological activity, mechanism of action and toxicity of nitrocompounds are explored, purposing the research of new bioactive derivatives having low toxicity.