Caracterização parcial de um fragmento e detecção por RT-PCR de Rice Stripe Necrosis Virus

O enrolamento do arroz é uma doença viral emergente no Brasil causada pelo Rice stripe necrosis virus (RSNV) que é transmitido pelo protozoário Polymyxa graminis. RSNV é um membro do gênero Benyvirus com genoma dividido em 4 RNAs de fita simples no sentido positivo (ssRNA +). Em função da falta de conhecimento sobre a seqüência de nucleotídeos do seu genoma, a detecção de RSNV através de métodos moleculares não é utilizada. O objetivo deste trabalho foi identificar seqüências do genoma de RSNV que possibilitassem sua detecção em plantas de arroz através da técnica de transcrição reversa seguida da reação em cadeia da polimerase (RT-PCR). As seqüências do genoma foram identificadas a partir de clones de uma biblioteca de cDNAs obtidos de uma amostra do vírus parcialmente purificado. Os clones que hibridizaram com sondas sintetizadas a partir de RNA de plantas infectadas com RSNV foram seqüenciados e comparados às seqüências do GenBank. Um fragmento de 957 nt da extremidade 3’ da fita de um dos 4 RNAs genômicos de RSNV foi obtido. A análise da seqüência nucleotídeos desse fragmento não revelou qualquer similaridade com seqüências conhecidas, tampouco indicou uma possível função. Um par de oligonucleotídeos iniciadores foi desenhado a partir de um clone que potencialmente contém uma seqüência de RSNV. A especificidade e a sensibilidade da RT-PCR utilizando esse par de oligonucleotídeos iniciadores, bem como sua eficiência na detecção do vírus em diferentes partes da planta de arroz, foram avaliadas. Os resultados indicam que a RT-PCR é específica para RSNV e pode detectar o vírus em tecido oriundo das raízes, do colo e de folhas com distorção. Comparada ao diagnóstico da doença através da observação de sintomas e de estruturas do vetor, a RT-PCR é uma ferramenta confiável para a diagnose do enrolamento do arroz.

Global gene expression of the inner cell mass and trophectoderm of the bovine blastocyst

Background: The first distinct differentiation event in mammals occurs at the blastocyst stage when totipotent blastomeres differentiate into either pluripotent inner cell mass (ICM) or multipotent trophectoderm (TE). Here we determined, for the first time, global gene expression patterns in the ICM and TE isolated from bovine blastocysts. The ICM and TE were isolated from blastocysts harvested at day 8 after insemination by magnetic activated cell sorting, and cDNA sequenced using the SOLiD 4.0 system.Results: A total of 870 genes were differentially expressed between ICM and TE. Several genes characteristic of ICM (for example, NANOG, SOX2, and STAT3) and TE (ELF5, GATA3, and KRT18) in mouse and human showed similar patterns in bovine. Other genes, however, showed differences in expression between ICM and TE that deviates from the expected based on mouse and human.Conclusion: Analysis of gene expression indicated that differentiation of blastomeres of the morula-stage embryo into the ICM and TE of the blastocyst is accompanied by differences between the two cell lineages in expression of genes controlling metabolic processes, endocytosis, hatching from the zona pellucida, paracrine and endocrine signaling with the mother, and genes supporting the changes in cellular architecture, stemness, and hematopoiesis necessary for development of the trophoblast.

Effect of Er : YAG and diode lasers on the adhesion of blood components and on the morphology of irradiated root surfaces

Objectives: the aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM), the adhesion of blood components on root surfaces irradiated with Er:YAG (2.94 mu m) and GaAlAs Diode (808 nm) lasers and the effects on the morphology of irradiated root surfaces.Methods: One hundred samples of human teeth were obtained. They were previously planed and scaled with manual instruments and divided into five groups of 20 samples each: G1 (control group) - absence of treatment; G2 - Er:YAG laser (7.6 J/cm(2)); G3 - Er:YAG laser (12.9 J/cm(2)); G4 - Diode laser (90 J/cm(2)) and G5 - Diode laser (108 J/cm(2)). After these treatments, 10 samples of each group received a blood tissue but the remaining 10 did not. After laboratory treatments, the samples were obtained by SEM, the photomicrographs were analysed by the score of adhesion of blood components and the results were statistically analysed (Kruskall-Wallis and Mann-Whitney test).Results: In relation to the adhesion of blood components, the study showed no significant differences between the control group and the groups treated with Er:YAG laser (p = 0.9633 and 0.6229). Diode laser radiation was less effective than control group and Er:YAG laser radiation (p < 0.01).Conclusion: None of the proposed treatments increased the adhesion of blood components in a significant way when compared to the control group. Although the Er:YAG laser did not interfere in the adhesion of blood components, it caused more changes on the root surface, whereas the Diode laser inhibited the adhesion.

Spatial-temporal variation of Paralonchurus brasiliensis (Actinopterygii: Sciaenidae) density in relation to some environmental factors on the inner shelf of south-eastern Brazilian coast

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

Population structure, distribution and abundance patterns of the patagonian smoothhound Musmlus schmitti springer, 1939 (Chondrichthyes,Elasmobranchii, Triakidae) in the rio de la plata and inner continental shelf, SW Atlantic ocean (34 degrees-30'-39 degrees-30's)

A total number of 4824 Mustelus schmitti was sampled. Females ranged from 25 to 93 em in spring and from 28 to 90 cm in summer. Males ranged from 34 to 82 and from 28 to 77 cm, respectively. Length composition of the population showed significant differences between spring and summer being females larger than males. Total length distribution did not show significant differences between cruises. Males density varied significantly between cruises while for the females no significant variation was observed. In the spring cruise, both sexes occurred at depths lower than 50 in. Females occurred in the whole area with adult occurrence only above 35 degrees 30'S. Mature males occurred throughout the area, immature males occurring in two trawls in Samborombon Bay. The summer cruise showed a discontinuous distribution of the species along the study area resulting in spatial segregation in two groups with immature females predominating in both of them.

Descrição de Astyanax argyrimarginatus sp. n. (Characiformes, Characidae) procedente da bacia do Rio Araguaia, Brasil

Descreve-se uma espécie nova para o gênero Astyanax Baird & Girard. A. argyrimarginatus procede da bacia do Rio Araguaia, Brasil. Esta espécie pode ser identificada por possuir uma mancha umeral negra horizontalmente ovalada, uma mancha negra no pedúnculo caudal, que se estende à extremidade dos raios caudais medianos, duas barras verticais castanho-escuras na região umeral e uma faixa lateral negra conspícua, bordeada por uma estreita faixa prateada. São discutidos outros caracteres que distinguem a espécie nova das demais espécies do gênero Astyanax portadoras de uma mancha umeral horizontalmente ovalada.

Effects of Nd : YAG and Er : YAG lasers on the sealing of root canal fillings

Objective: the ability of the laser irradiation to promote the cleaning and disinfection of the radicular canal system has become this type of treatment in a viable and real alternative in endodontics. The purpose of this study was to evaluate the apical marginal sealing of root canal fillings after the irradiation with the laser of Nd:YAG or of Er:YAG. Materials and Methods: Forty-two human, extracted single-rooted teeth had their crowns sectioned and the root canals prepared with a no. 70 K-file. Then, they were dried and divided into three groups according to canal wall treatment: group 1: the canals were filled with EDTA for 3 min, followed by irrigation with 1% sodium hypochlorite solution; group 2: the canal walls were irradiated with Nd:YAG laser; and group 3: the canal walls were irradiated with Er:YAG laser. Afterwards, the root canals were obturated by the lateral condensation technique. The roots were externally waterproof, except in the apical foramen and immerged in 2% methylene blue aqueous solution during 48 hours. Results: the results showed that the largest infiltrations happened in the group 3-Er:YAG (7.3 mm), proceeded by the group 1-EDTA (1.6 mm) and by the group 2-Nd:YAG (0.6 mm). The group Er:YAG differed statistically of the others (p < 0.05). Conclusion: It was concluded that the Er:YAG laser intracanal irradiation previously to the root canal filling must be used with caution until future research is define the best parameters for it's use.

Effect of dental surface treatment with Nd:YAG and Er:YAG lasers on bond strength of resin composite to recently bleached enamel

The aim of this work is to evaluate the effect of surface treatment with Er:YAG and Nd:YAG lasers on resin composite bond strength to recently bleached enamel. In this study, 120 bovine incisors were distributed into two groups: group C: without bleaching treatment; group B: bleached with 35% hydrogen peroxide. Each group was divided into three subgroups: subgroup N: without laser treatment; subgroup Nd: irradiation with Nd:YAG laser; subgroup Er: irradiation with Er:YAG laser. The adhesive system (Adper Single Bond 2) was then applied and composite buildups were constructed with Filtek Supreme composite. The teeth were sectioned to obtain enamel-resin sticks (1 x 1 mm) and submitted to microtensile bond testing. The data were statistically analyzed by the ANOVA and Tukey tests. The bond strength values in the bleached control group (5.57 MPa) presented a significant difference in comparison to the group bleached and irradiated with Er:YAG laser (13.18 MPa) or Nd:YAG (25.67 MPa). The non-bleached control group presented mean values of 30.92 MPa, with statistical difference of all the others groups. The use of Nd:YAG and Er:YAG lasers on bleached specimens was able to improve the bond strengths of them.

Evaluation of the shear bond strength of a composite resin in sound, demineralized and hypermineralized bovine dentin after irradiation with Er:YAG and Nd:YAG lasers, employing a self-etching adhesive system

Background and Objectives. The adhesion of dental materials is important for the success of treatment. The aim of this study is to evaluate the bond strength of a composite resin applied with a self-etching adhesive system in different dentins after irradiation with Er:YAG and Nd:YAG lasers, observing their morphologic pattern using Scanning Electronic Microscopy (SEM). Materials and Methods. The buccal surface of 72 bovine incisors was worn until exposure of medium depth dentin. The specimens were divided into three groups; GI: normal, GII: demineralized and GIII: hypermineralized dentin. These were also divided into two subgroups; A-irradiated for 30 s with Er:YAG laser in noncontact mode at 40 mJ and 6 Hz and B- irradiated for 30 s with Nd:YAG laser in contact mode at 60 mJ and 10 Hz. The adhesive system Clearfil SE. Bond (Kuraray) and composite resin Tetric Ceram (Vivadent) were applied on the irradiated area by the incremental technique. After storage for 24 h in distilled water at 37 degrees C, the specimens were submitted to the shear strength test in a universal testing machine (EMIC) at a crosshead speed of 1.0 mm/min. Other specimens were made to be analyzed by SEM. Results. The results were statistically analyzed by Analysis of Variance and the Tukey test. Regardless of the type of dentin, the bond strength of specimens irradiated with the Nd:YAG laser (8,94 +/- 2,07) was higher compared to specimens irradiated with the Er:YAG laser (7,03 +/- 2,47); the highest bond strength was obtained for the group of hypermineralized dentin irradiated with the Nd:YAG laser. The SEM analysis showed that the Er:YAG laser caused opening of tubules and the Nd:YAG laser produced areas of fusion as well as regions of opening of dentinal tubules. Conclusions. The dentin showed different morphological patterns and the laser promote alterations on their surfaces, influencing the bond strength of the composite resin. (C) 2010 Laser Institute of America.

Assessment of external root temperature during root canal irradiation by Nd:YAG and Er:YAG lasers

Different types of laser have been widely studied for applicability in the oral health area. In the endodontic area, investigations with some types of laser have been conducted to establish safe parameters for clinical application in root canals. However, it has not been duly explained whether the temperature increase caused by laser irradiation could cause alteration in the temperature on the external surface of the root and, consequently, alterations in the cells of the periodontal ligament, causing resorption and even loss of the dental element. The proposal in this paper was to gauge the external root temperature in the apical and cervical regions of the roots of human teeth during root canal irradiation with Nd:yttrium aluminum garnet (YAG) and Er:YAG lasers using different parameters. The novel approach of this paper is the use of the technique of laser applications along the total length of the root canal with series of repetitive irradiation, however, using time of 1 s of irradiation associated with 1 s off to avoid cumulative thermal effects. Experimental results confirm the accuracy of the parameters and exposure regimen obtained. All the parameters used in this paper are acceptable from a clinical as well as a biological point of view. (C) 2009 Laser Institute of America.

On the calculation of inner products of Schur functions

Two methods for calculating inner products of Schur functions in terms of outer products and plethysms are given and they are easy to implement on a machine. One of these is derived from a recent analysis of the SO(8) proton-neutron pairing model of atomic nuclei. The two methods allow for generation of inner products for the Schur functions of degree up to 20 and even beyond.

Inner satellites of Neptune: I the disturbing function

In this work, we focus our attention to the expansion of the disturbing function (R) which governs the dynamics of a satellite (natural or artificial) in the Neptune-Triton system. What makes this problem quite unusual, is the fact that a small inner satellite can be strongly disturbed by Triton which is moving in a highly inclined and retrograde orbit. These features are unique in our solar system. Although a lot of retrograde satellites are currently known, all of them have negligible mass and the), do not offer almost any perturbation on the others satellites. However, in the case of the inner satellites of Neptune, Triton is an interesting exception. In a highly inclined orbit, the perturbation it exerts on the neighbouring satellites of Neptune cannot be ignored even for the present scenario. However, in the future, this perturbation will be much more important because due to the tides, the orbit of Triton is contracting, whereas the semi major axes of the remaining inner satellites of Neptune will remain almost unaffected by the tides. In this work we first obtain the disturbing function in the retrograde case. After that, we generalize R for arbitrary inclination. Several numerical tests are presented and a possible future case of resonant configuration is briefly discussed as well. (c) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

Population structure, distribution and abundance patterns of the patagonian smoothhound Mustelus schmitti Springer, 1939 (Chondrichthyes, Elasmobranchii, Triakidae) in the rio de La Plata and inner continental shelf , sw Atlantic ocean (34º30'-39º30'S)

Um total de 4824 Mustelus schmitti foi amostrado. As fêmeas apresentaram comprimento total de 25-93 cm na primavera e 28-90 cm no verão enquanto os machos apresentaram 34-82 e de 28-77 cm, respectivamente. A composição de comprimentos da população mostrou diferenças significativas entre primavera e verão sendo as fêmeas maiores do que os machos. A distribuição de comprimento total não variou significativamente entre cruzeiros. A densidade variou significativamente entre cruzeiros nos machos sendo que a variação não foi expressiva nas fêmeas. No cruzeiro da primavera, ambos os sexos ocorreram em profundidades menores do que 50 m, as fêmeas ocorrendo em toda a área de estudo, as adultas somente acima da latitude 35°30'S. Os machos adultos foram observados em toda a área sendo que os imaturos somente em dois arrastos na Bahia de Samborombón. O cruzeiro de verão mostrou uma distribuição descontínua da espécie ao longo da área de estudo, resultando na segregação espacial em dois grupos, com predominância de fêmeas imaturas em ambos.

Reversible holographic glasses using visible lasers

Antimony based glasses have been investigated for the first time regarding the possibility of holographic data storage using visible lasers sources. Changes in both refractive index and the absorption coefficient were measured using a holographic setup. The modulation of the optical constants is reversible by heat treatment. Bragg gratings were written under visible light of an Ar laser and erased thermally.