Efeito de deltametrina na biologia de Oligonychus ilicis (McGregor) (Acari: Tetranychidae) em laboratório

Estudou-se a oviposição, desenvolvimento, fecundidade e sobrevivência de Oligonychus ilicis (McGregor) (Acari: Tetranychidae), sobre discos de folhas de cafeeiro (Coffea arabica L.) submetidos à aplicação do piretróide deltametrina. em laboratório, deltametrina não interferiu no número de ovos postos pelas fêmeas em discos tratados; no período de incubação; na viabilidade dos ovos; e na duração do ciclo biológico da fêmea. em contrapartida, o inseticida causou aumento na duração da fase pós-embrionária (larva-adulto) da fêmea em 17,4% e do macho em 17,2%, duração do ciclo biológico do macho em 0,7%, e afetou a sobrevivência de machos e fêmeas em até 63,9%. As fêmeas descendentes de progênies criadas sobre discos de folhas tratadas com deltametrina apresentaram um aumento de 31,9% na oviposição.

Tipos de resistência a Alabama argillacea (Huebner) (Lepidoptera: Noctuidae) envolvidos em genótipos de algodoeiro: I - não-preferência

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Arrays of gold microelectrodes made from split integrated circuit chips

A simple and inexpensive way to fabricate arrays of gold microelectrodes is proposed. Integrated circuit chips are sawed through their middle, normal to the longest axis, leading to destruction of the silicon circuit and rupture of the gold wires that interconnect it with the external terminals. Polishing the resulting rough surface converts the tips of the wires embedded in the chip halves into arrays of gold microdisks of about 25 mu m diameter. The number of active microelectrodes (MEs), of an array depends on the number of pins in the chip, n, being typically (n/2)-4. These MEs can be used individually or externally interconnected in any combination. X-ray images of the chips and micrographs of the resulting surface of the polished arrays have revealed variable distances between neighbor MEs, which are, however, larger than 10 times the radius of the disks. This feature of the MEs prevents diffusional cross-talk between electrodes. The use of these microdisk electrodes for analytical purposes exhibits sigmoidal voltammograms, and chronoamperometric experiments confirm the nonlinear i vs. t(1/2) plots, typical for processes where radial diffusion prevails. Satisfactory uniformity was observed for the response of each electrode of an array, indicating similarity of geometry and disk areas. The potentialities of these MEs were demonstrated by the determination of cadmium at ppb levels using square wave voltammetry with preconcentration. Due to the relative ease with which these MEs can be manufactured and their good performance in (chemical) analysis, wide applications in electrochemistry and electroanalysis is envisioned.

Effectiveness of surface protection for resin-modified glass-ionomer materials

Objective: the purpose of this study was to evaluate the effectiveness of various surface treatments for resin-modified glass-ionomer restorative materials by determining dye uptake spectrophotometrically. Method and materials: Two hundred twenty-four specimens, 4.1 mm in diameter and 2.0 mm thick, were made of 3 materials: Vitremer, Fuji II LC, and Photac-Fil Aplicap. Specimens were divided into 15 groups. The positive and negative control specimens remained unprotected, while the experimental specimens were protected with Heliobond light-activated bonding resin, Colorama nail varnish, or surface coatings indicated by the manufacturers of the glass-ionomer materials. Finishing Gloss for Vitremer, Fuji Varnish for Fuji II LC, and Ketac Glaze for Photac-Fil. The disks were immersed in 0.05% methylene blue for 24 hours except for the negative control group, which was immersed in deionized water. After 24 hours, the disks were removed, washed, and individually placed in 1 mL of 65% nitric acid for 24 hours. The solutions were centrifuged and the spectrophotometric absorbance was determined at 606 nm. The dye uptake was expressed in micrograms of dye per milliliter, and the results were analyzed with the Kruskal-Wallis test. Results: There were no differences in dye uptake among the 3 resin-modified glass-ionomer restorative materials, however, all of them required surface protection. Conclusion: the best surface protection for the 3 evaluated materials was obtained with Heliobond light-activated bonding resin.

Fractals de Rauzy

We study arithmetical and topological properties of a class of Rauzy Fractals. In particular, we give a parametrization of the boundaries of these sets and show that they are quasi-disks.

Gold electrodes from recordable CDs

Gold electrodes are widely used in electrochemistry and electroanalytical chemistry. The notable performance when used in stripping analysis of many ionic species and the extraordinary affinity of thio compounds for its surface make these electrodes very suitable for many applications. This paper reports a simple and novel way to construct gold electrodes (CDtrodes) using recordable CDs as the gold source. The nanometer thickness of the gold layer of recordable disks (50-100 mm) favors the construction of band nanoelectrodes with areas as small as 10(-6) cm(2). The plane surface can be easily used for the construction of conventional-sized gold electrodes for batch or now injection analysis or even to obtain electrodes as large as 100 cm(2). The low price of commercial recordable CDs allows a one way use. The evaluation and applicability of these electrodes in the form of nanoelectrodes, in batch and associated with flow cells, are illustrated in this paper.

Cryopreservation of Agaricus blazei in liquid nitrogen using dmso as cryoprotectant

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

Speciation of lead in seawater and river water by using Saccharomyces cerevisiae immobilized in agarose gel as a binding agent in the diffusive gradients in thin films technique

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

Use of Saccharomyces cerevisiae immobilized in agarose gel as a binding agent for diffusive gradients in thin films

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

Evaluation of the Effects of Endodontic Materials on Fibroblast Viability and Cytokine Production

Introduction: Recently, a new sealer composed of Portland cement named Endo-CPM-Sealer was developed. The aim of this study was to investigate the effects of Endo-CPM-Sealer (EGEO SRL, Buenos Aires, Argentina), Sealapex (Sybron Endo, Glendora, CA), and Angelus MTA (Angelus, Londrina, Brazil) on cell viability and cytokine (interleukin [IL]-1 beta and IL-6) production by mouse fibroblasts. Methods: Millipore culture plate inserts with polyethylene tubes filled with materials were placed into 24-well cell culture plates with mouse fibroblasts. Cells cultured with only empty polyethylene tubes were used as the control. After 24 hours, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to evaluate the cell viability. For cytokine assay, mouse fibroblasts were incubated in 24-well flat-bottom plates with set material disks at the bottom. Cells cultured without the material disks served as the negative control. After 24 hours of incubation, culture media were collected for cytokine evaluation by using an enzyme-linked immunosorbent assay. The data were statistically analyzed by analysis of variance and Bonferroni correction. Results: Endo-CPM-Sealer, Sealapex, and Angelus MTA did not inhibit the cell viability. All materials induced IL-6 releasing, but the amount was not statistically significant compared with the control group. Angelus MTA induced IL-1 beta releasing significantly more than the control. Conclusions: All materials were not considered cytotoxic in fibroblast culture. (J Endod 2009;35:1577-1579)

Atividade predatória de Euseius citrifolius Denmark & Muma (Acari: Phytoseiidae) sobre Tenuipalpus heveae (Acari: Tenuipalpidae)

The rubber tree red false spider mite, Tenuipalpus heveae Baker, is an important pest of Hevea brasiliensis (Willd. ex. Adr. de Juss.) Muell. Arg. The phytoseiid mite Euseius citrifolius Dennmark & Muma has frequently been recorded on rubber tree crops. The objective of this work was to determine the predatory activity of E. citrifolius on the different life stages (egg, larva, nymph and adult) of T. heveae. The experiments were carried out in Petri dishes (9-cm diameter) containing a layer of wet cotton inside, onto which a disk of rubber tree leaf (2.5-cm diameter) was laid. The disks were taken from naturally infested leaves. Twenty specimens in the life stage that was to be tested were left on the disk and the others were eliminated; a predator life stage (larva, nymph or female) was obtained from a laboratory stock colony and put into each dish. For each tested life stage of E. citrifolius, 4 treatments (T. heveae life stages) and 20 replications were considered in a randomized block design. The observations were made after 24 hours for larvae and nymphs of the predator, and after 24, 48 and 72 hours for the females. E. citrifolius larvae and nymphs had a higher preference for T. heveae larvae followed by nymphs, eggs and adults. Within 72 hours, each predator female consumed 15.0 larvae, 14.5 nymphs, 7.4 adults or 2.2 eggs of T. heveae. It is concluded that E. citrifolius can feed on red false spider mites, the larva and nymph being the preferred stages.

Preferência alimentar de adultos de Metriona elatior Klug (Coleoptera: Chrysomelidae, Cassidinae) por diferentes híbridos de Solanum melogena Linnaeus (Solanaceae)

Feeding preference of adults of Metriona elatior Klug (Coleoptera: Chrysomelidae, Cassidinae) for different hybrids of Solanum melogena Linnaeus (Solanaceae). Metriona elatior Klug is a potential biocontrol agent for Solanum viarum Dunal (tropical soda apple), because larvae and adults feed on its leaves and this species shows a low dispersion rate. Specificity plays a major role in the feasibility of an organism as a biological control agent, especially in the inundative strategy. The feeding preference of M. elatior adults was evaluated to 14 eggplant (Solanum melogena Linnaeus) hybrids. Mass rearing was carried out under lab conditions, with the insect feeding directly on S. viarum leaves. The study started with dual and multiple choice tests in 24 and 48 hour feeding times, by offering leaf disks in Petri dish conditions. Survival and leaf consumption analysis were performed in newly adults in tropical soda apple and eggplant leaves kept turgid by immersing the petioles in water. The leaf area was measured before and after four days of insect exposure. M. elatior showed higher feeding preference, survival and consumption of the weed species, especially in comparison with the hybrid Ryoma. The highest feeding preference among the eggplant hybrids was observed in 'Minikuro Kowishiki'.

O Tempo de Corte com Discos Abrasivos Pode Ser Reduzido pelo Controle da Velocidade de Corte

This work presents an experimental study on the life of abrasive discs in cut-off type operations with two conditions of cutting speed. The cutting time is shown with a comparative analysis of the cutting speed.

In vitro evaluation of the antimicrobial activity of a castor oil-based irrigant

The antimicrobial activity of irrigating solutions - Endoquil (castor oil detergent), 2% chlorhexidine gluconate solution, and 0.5% NaOCI solution - was evaluated against Gram-positive cocci (Micrococcus luteus, Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Streptococcus mutans, and Streptococcus sobrinus), Gramnegative rods (Escherichia coli and Pseudomonas aeruginosa), and the yeast Candida albicans. Activity was evaluated using the two-layer agar diffusion technique. The base layer was obtained by pouring 10.0 ml of Muller Hinton Medium or 10.0 ml of Brain Heart Infusion agar in a Petri dish. After solidification a 5.0 ml seed layer of Muller Hinton Medium or Brain Heart Infusion agar with inoculum (106/ml) was added. Absorbent paper disks (6.0 mm in diameter) immersed in the solutions were placed at equidistant points. Plates were maintained at room temperature for 2 h for prediffusion of the solutions and incubated at 37°C for 24 h. The candle jar system was used for the Brain Heart Infusion agar plates. All tests were performed in duplicate. After incubation the medium was optimized with 0.05 g% triphenyltetrazolium chlorate gel and inhibition halos were measured. All bacterial strains were inhibited by 2.0% chlorhexidine gluconate. Endoquil was effective against Grampositive microorganisms, and 0.5% NaOCI was effective only against S. aureus. Copyright © 2001 by The American Association of Endodontists.

Preferência alimentar de adultos de Diabrotica speciosa (Ger.) (Coleoptera: Chrysomelidae) por genótipos de feijoeiro

Tests were carried out to evaluate resistance of common bean (Phaseolus vulgaris L.) to Diabrotica speciosa (Ger.) with the genotypes Goiano Precoce, Jalo Precoce, PR 95105146, PR 95105142 (Andean domestication center, AN), Emgopa 201 Ouro and IAPAR 57 (Middle American domestication center, MA). The experiments were conducted in 1998 and 1999, at the farm of UNESP-FCAV, Jaboticabal, SP, Brazil. The genotypes were planted in pots and 20 day-old leaflets were collected and foliar disks were cut of for the test. Two trials, a no-choice test and a free-choice test, were set up in BOD. In free-choice test, two disks of each genotype were kept in a 140-mm-diameter petri dish (total of 12 disks), where 12 adults were confined. In no-choice test, two disks of one genotype and two insects were placed in a 60-mm-diameter petri dish. A field experiment was conducted when 400 adults of D. speciosa were released. Fifteen leaflets per plot were collected 30 days after planting and the leaf area consumption was evaluated. A no-choice experiment was carried out with 20 day-old genotypes protected in individual cages and infested by 10 adults, for 72h. The MA genotypes were the most preferred on feeding tests conducted at BOD, field and individual cages, while the AN genotypes were less eaten.