Complete nucleotide sequence, genomic organization and phylogenetic analysis of Citrus leprosis virus cytoplasmic type

The complete nucleotide sequence of the genomic RNA 1 (8745 nt) and RNA 2 (4986 nt) of Citrus leprosis virus cytoplasmic type (CiLV-C) was determined using cloned cDNA. RNA 1 contains two open reading frames (ORFs), which correspond to 286 and 29 kDa proteins. The 286 kDa protein is a polyprotein putatively involved in virus replication, which contains four conserved domains: methyltransferase, protease, helicase and polymerase. RNA 2 contains four ORFs corresponding to 15, 61, 32 and 24 kDa proteins, respectively. The 32 kDa protein is apparently involved in cell-to-cell movement of the virus, but none of the other putative proteins exhibit any conserved domain. The 5' regions of the two genomic RNAs contain a 'cap' structure and poly(A) tails were identified in the 3'-terminals. Sequence analyses and searches for structural and non-structural protein similarities revealed conserved domains with members of the genera Furovirus, Bromovirus, Tobravirus and Tobamovirus, although phylogenetic analyses strongly suggest that CiLV-C is a member of a distinct, novel virus genus and family, and definitely demonstrate that it does not belong to the family Rhabdoviridae, as previously proposed. Based on these results it was proposed that Citrus leprosis virus be considered as the type member of a new genus of viruses, Cilevirus.

Critical current degradation of Bi-2223 composite tapes induced by cyclic deformation and fatigue-related effects

Application of high temperature superconductor Bi2Sr2Ca2Cu3Ox. (Bi-2223) compound embedded in an Ag matrix requires the knowledge of critical current as a function of mechanical properties. Commercial tapes available in different types have been developed in industrial production scale in which a combination of small diameter filaments, long tape lengths and a ductile matrix results in a conductor with low crack formation and good tolerance against strain. The measurement of critical current and the evaluation of n-index from V-I characteristic curves of Bi-2223/Ag composite tapes subjected to an initial bending strain as a function of number of thermal cycles were done for two types of Bi-2223/Ag composite tapes: with and without steel tape reinforcement. The results showed that tapes with reinforcement presented small critical current degradation as a function of the number of thermal cycles whereas tapes without reinforcement exhibited steadily critical current degradation caused by the propagation of cracks. The n-index followed the same critical current behavior.

IFNG +874 T > A single nucleotide polymorphism is associated with leprosy among Brazilians

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, a low virulence mycobacterium, and the outcome of disease is dependent on the host genetics for either susceptibility per se or severity. The IFNG gene codes for interferon-gamma (IFN-gamma), a cytokine that plays a key role in host defense against intracellular pathogens. Indeed, single nucleotide polymorphisms (SNPs) in IFNG have been evaluated in several genetic epidemiological studies, and the SNP +874T > A, the +874T allele, more specifically, has been associated with protection against infectious diseases, especially tuberculosis. Here, we evaluated the association of the IFNG locus with leprosy enrolling 2,125 Brazilian subjects. First, we conducted a case-control study with subjects recruited from the state of So Paulo, using the +874 T > A (rs2430561), +2109 A > G (rs1861494) and rs2069727 SNPs. Then, a second study including 1,370 individuals from Rio de Janeiro was conducted. Results of the case-control studies have shown a protective effect for +874T carriers (OR(adjusted) = 0.75; p = 0.005 for both studies combined), which was corroborated when these studies were compared with literature data. No association was found between the SNP +874T > A and the quantitative Mitsuda response. Nevertheless, the spontaneous IFN-gamma release by peripheral blood mononuclear cells was higher among +874T carriers. The results shown here along with a previously reported meta-analysis of tuberculosis studies indicate that the SNP +874T > A plays a role in resistance to mycobacterial diseases.

Mechanical strength and subcritical crack growth under wet cyclic loading of glass-infiltrated dental ceramics

Objectives. Evaluate the flexural strength (sigma) and subcritical crack growth (SCG) under cyclic loading of glass-infiltrated alumina-based (IA, In-Ceram Alumina) and zirconia-reinforced (IZ, In-Ceram Zirconia) ceramics, testing the hypothesis that wet environment influences the SCG of both ceramics when submitted to cyclic loading.Methods. Bar-shaped specimens of IA (n = 45) and IZ ( n = 45) were fabricated and loaded in three-point bending (3P) in 37 degrees C artificial saliva (IA(3P) and IZ(3P)) and cyclic fatigued (F) in dry (D) and wet (W) conditions (IA(FD), IA(FW), IZ(FD), IZ(FW)). The initial sigma and the number of cycles to fracture were obtained from 3P and F tests, respectively. Data was examined using Weibull statistics. The SCG behavior was described in terms of crack velocity as a function of maximum stress intensity factor (K(Imax)).Results. The Weibull moduli (m = 8) were similar for both ceramics. The characteristic strength (sigma(0)) of IA and IZ was and 466 MPa 550 MPa, respectively. The wet environment significantly increased the SCG of IZ, whereas a less evident effect was observed for IA. In general, both ceramics were prone to SCG, with crack propagation occurring at K(I) as low as 43-48% of their critical K(I). The highest sigma of IZ should lead to longer lifetimes for similar loading conditions.Significance. Water combined with cyclic loading causes pronounced SCG in IZ and IA materials. The lifetime of dental restorations based on these ceramics is expected to increase by reducing their direct exposure to wet conditions and/or by using high content zirconia ceramics with higher strength. (C) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Cloning and expression of the cDNA encoding rat granulocyte colony-stimulating factor

Granulocyte colony-stimulating factor (G-CSF) acts on precursor hematopoietic cells to control the production and maintenance of neutrophils. Recombinant G-CSF (re-G-CSF)is used clinically to treat patients with neutropenia and has greatly reduced the infection risk associated with bone marrow transplantation. Cyclic hematopoiesis, a stem cell defect characterized by severe recurrent neutropenia, occurs in man and grey collie dogs, and can be treated by administration of re-G-CSF. Availability of the rat G-CSF cDNA would benefit the use of rats as models of gene therapy for the treatment of cyclic hematopoiesis. In preliminary rat experiments, retroviral-mediated expression of canine G-CSF caused neutralizing antibody formation which precluded long-term increases in neutrophil counts. To overcome this problem we cloned the rat G-CSF cDNA from RNA isolated from skin fibroblasts. The rat G-CSF sequence shared a high degree of identity in both the coding and non-coding regions with both the murine G-CSF (85%) and human G-CSF (74%). The signal peptides of murine and human G-CSF both contained 30 amino acids (aa), whereas the deduced signal sequence for rat G-CSF possessed 21 aa. A retrovirus encoding the rat G-CSF cDNA synthesized bioactive G-CSF from transduced vascular smooth muscle cells.

Nucleotide sequence of 5S rDNA and localization of the ribosomal RNA genes to metaphase chromosomes of the Tilapiine cichlid fish, Oreochromis niloticus

In this study, we report the cloning and nucleotide sequence of PCR-generated 5S rDNA from the Tilapiine cichlid fish, Oreochromis niloticus. Two types of 5S rDNA were detected that differed by insertions and/or deletions and base substitutions within the non-transcribed spacer (NTS). Two 5S rDNA loci were observed by fluorescent in situ hybridization (FISH) in metaphase spreads of tilapia chromosomes. FISH using an 18S rDNA probe and silver nitrate sequential staining of 5S-FISH slides showed three 18S rDNA loci that are not syntenic to the 5S rDNA loci.

Effect of cyclic compressive loading on the bond strength of an adhesive system to dentin after collagen removal

Purpose: The objective of this study was to verify the effect of cyclic compressive loading on the shear bond strength of an adhesive system following collagen removal. Materials and Methods: Sixty bovine teeth were divided into 4 groups based on the adhesive procedure used: groups 1 and 2 - etching with 35% phosphoric acid and application of the Single Bond adhesive system; groups 3 and 4 - after etching, a 10% sodium hypochlorite solution was applied for 1 min before the application of the adhesive. In all the specimens, a Z100 resin cylinder was built up over the bond area. Groups 2 and 4 were submitted to 500,000 cycles with a load of 100 N. Results: The mean values for the shear bond test (MPa) were: group 1: 7.37 ± 1.15; group 2: 5.72 ± 1.66; group 3: 5.95 ± 1.21; group 4: 3.66 ± 1.12. There was no difference between groups 1 and 2 (p > 0.01). Between groups 1 and 3, 2 and 4, and 3 and 4 there was a significant difference (p < 0.01). The majority of the specimens demonstrated an adhesive failure. Conclusion: The application of sodium hypochlorite on dentin decreased the values of shear bond strength, as did the load cycling in the group treated with sodium hypochlorite.

Effect of air-particle abrasion protocols on the biaxial flexural strength, surface characteristics and phase transformation of zirconia after cyclic loading

This study evaluated the effect of air-particle abrasion protocols on the biaxial flexural strength, surface characteristics and phase transformation of zirconia after cyclic loading. Disc-shaped zirconia specimens (Ø: 15mm, thickness: 1.2mm) (N=32) were submitted to one of the air-particle abrasion protocols (n=8 per group): (a) 50μm Al2O3 particles, (b) 110μm Al2O3 particles coated with silica (Rocatec Plus), (c) 30μm Al2O3 particles coated with silica (CoJet Sand) for 20s at 2.8bar pressure. Control group received no air-abrasion. All specimens were initially cyclic loaded (×20,000, 50N, 1Hz) in water at 37°C and then subjected to biaxial flexural strength testing where the conditioned surface was under tension. Zirconia surfaces were characterized and roughness was measured with 3D surface profilometer. Phase transformation from tetragonal to monoclinic was determined by Raman spectroscopy. The relative amount of transformed monoclinic zirconia (FM) and transformed zone depth (TZD) were measured using XRD. The data (MPa) were analyzed using ANOVA, Tukey's tests and Weibull modulus (m) were calculated for each group (95% CI). The biaxial flexural strength (MPa) of CoJet treated group (1266.3±158A) was not significantly different than that of Rocatec Plus group (1179±216.4A,B) but was significantly higher than the other groups (Control: 942.3±74.6C; 50μm Al2O3: 915.2±185.7B,C). Weibull modulus was higher for control (m=13.79) than those of other groups (m=4.95, m=5.64, m=9.13 for group a, b and c, respectively). Surface roughness (Ra) was the highest with 50μm Al2O3 (0.261μm) than those of other groups (0.15-0.195μm). After all air-abrasion protocols, FM increased (15.02%-19.25%) compared to control group (11.12%). TZD also showed increase after air-abrasion protocols (0.83-1.07μm) compared to control group (0.59μm). Air-abrasion protocols increased the roughness and monoclinic phase but in turn abrasion with 30μm Al2O3 particles coated with silica has increased the biaxial flexural strength of the tested zirconia. © 2013 Elsevier Ltd.

Nucleotide and phylogenetic analysis of human papillomavirus types 6 and 11 isolated from recurrent respiratory papillomatosis in Brazil

There are few studies about the distribution of natural molecular variants of low-risk HPVs. Our aim was to evaluate the E6 early gene variability among HPV-6 and HPV-11 isolates detected in recurrent respiratory papillomatosis (RRP) samples obtained in a cohort of Brazilian patients. We also performed a phylogenetic analysis in order to compare nucleotide sequences identified in our study with previously reported isolates from different anatomic sites (laryngeal papillomas, genital warts, cervical cancer and anal swabs) obtained from other parts of the world to determine the phylogenetic relationships of variants detected in Brazil. The complete coding region of the E6 gene of 25 samples was cloned and sequenced: 18 isolates of HPV-6 (72%) and 7 isolates of HPV-11 (28%). A total of four different HPV-6 genomic variants and two HPV-11 genomic variants was identified. It was not possible to correlate specific variants with disease severity. Phylogenetic trees for both HPV types were constructed enclosing both E6 sequences detected in our study and formerly published sequences. In both phylogenetic trees, the sequences from Brazil did not group together. We could not establish a geographical association between HPV-6 or HPV-11 variants, unlike HPV-16 and HPV-18. © 2013 Elsevier B.V.

Determination of Glycerol in Biodiesel Using a Nickel(II) Oxyhydroxide Chemically Modified Electrode by Cyclic Voltammetry

A glassy carbon electrode chemically modified with nickel oxyhydroxide from a nickel hexacyanoferrate (NiHCF) film was used to determine glycerol in biodiesel by cyclic voltammetry. The modified electrode exhibited a linear response to glycerol concentration in the range from 0.05 to 0.35mmol L-1, and a detection limit of 0.030mmol L-1. The glycerol concentration found in the biodiesel sample was 0.156mmol L-1. The method developed in this study showed a recovery of (100.3±5.0)%. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A method for improving the code rate and error correction capability of a cyclic code

Currently, there has been an increasing demand for operational and trustworthy digital data transmission and storage systems. This demand has been augmented by the appearance of large-scale, high-speed data networks for the exchange, processing and storage of digital information in the different spheres. In this paper, we explore a way to achieve this goal. For given positive integers n,r, we establish that corresponding to a binary cyclic code C0[n,n-r], there is a binary cyclic code C[(n+1)3k-1,(n+1)3k-1-3kr], where k is a nonnegative integer, which plays a role in enhancing code rate and error correction capability. In the given scheme, the new code C is in fact responsible to carry data transmitted by C0. Consequently, a codeword of the code C0 can be encoded by the generator matrix of C and therefore this arrangement for transferring data offers a safe and swift mode. © 2013 SBMAC - Sociedade Brasileira de Matemática Aplicada e Computacional.

Effects of a single nucleotide polymorphism in the leptin gene on the productive traits of dairy buffaloes (Bubalus bubalis)

The gene responsible for coding the leptin hormone has been associated with productive and reproductive traits in cattle. In dairy cattle, different polymorphisms found in the leptin gene have been associated with several traits of economic interest, such as energy balance, milk yield and composition, live weight, fertility and dry matter consumption. The aim of this study was to detect genetic variability in the leptin gene of buffaloes and to test possible associations with milk yield, fat and protein percentages, age at first calving and first calving interval. Three genotypes (AA, AG and GG) were identified by polymerase chain reaction-restriction fragment length polymorphism, which presented genotypic frequencies of 0.30, 0.54 and 0.16, respectively. The allele frequencies were 0.57 for the A allele and 0.43 for the G allele. No significant effects were found in the present study, but there is an indicative that leptin gene affects lipid metabolism. © 2013 Springer Science+Business Media Dordrecht.