77 research outputs found

    Genome Sequence of Erythromelalgia-Related Poxvirus Identifies it as an Ectromelia Virus Strain

    Get PDF
    Erythromelagia is a condition characterized by attacks of burning pain and inflammation in the extremeties. An epidemic form of this syndrome occurs in secondary students in rural China and a virus referred to as erythromelalgia-associated poxvirus (ERPV) was reported to have been recovered from throat swabs in 1987. Studies performed at the time suggested that ERPV belongs to the orthopoxvirus genus and has similarities with ectromelia virus, the causative agent of mousepox. We have determined the complete genome sequence of ERPV and demonstrated that it has 99.8% identity to the Naval strain of ectromelia virus and a slighly lower identity to the Moscow strain. Small DNA deletions in the Naval genome that are absent from ERPV may suggest that the sequenced strain of Naval was not the immediate progenitor of ERPV

    Complete Chloroplast Genome Sequence of an Orchid Model Plant Candidate: Erycina pusilla Apply in Tropical Oncidium Breeding

    Get PDF
    Oncidium is an important ornamental plant but the study of its functional genomics is difficult. Erycina pusilla is a fast-growing Oncidiinae species. Several characteristics including low chromosome number, small genome size, short growth period, and its ability to complete its life cycle in vitro make E. pusilla a good model candidate and parent for hybridization for orchids. Although genetic information remains limited, systematic molecular analysis of its chloroplast genome might provide useful genetic information. By combining bacterial artificial chromosome (BAC) clones and next-generation sequencing (NGS), the chloroplast (cp) genome of E. pusilla was sequenced accurately, efficiently and economically. The cp genome of E. pusilla shares 89 and 84% similarity with Oncidium Gower Ramsey and Phalanopsis aphrodite, respectively. Comparing these 3 cp genomes, 5 regions have been identified as showing diversity. Using PCR analysis of 19 species belonging to the Epidendroideae subfamily, a conserved deletion was found in the rps15-trnN region of the Cymbidieae tribe. Because commercial Oncidium varieties in Taiwan are limited, identification of potential parents using molecular breeding method has become very important. To demonstrate the relationship between taxonomic position and hybrid compatibility of E. pusilla, 4 DNA regions of 36 tropically adapted Oncidiinae varieties have been analyzed. The results indicated that trnF-ndhJ and trnH-psbA were suitable for phylogenetic analysis. E. pusilla proved to be phylogenetically closer to Rodriguezia and Tolumnia than Oncidium, despite its similar floral appearance to Oncidium. These results indicate the hybrid compatibility of E. pusilla, its cp genome providing important information for Oncidium breeding

    Review of Matrix Metalloproteinases’ Effect on the Hybrid Dentin Bond Layer Stability and Chlorhexidine Clinical Use to Prevent Bond Failure

    Get PDF
    This review describes the relationship between dentin collagen hybrid bond layer degradation and the Matrix Metalloproteinases (MMPs) after their release by acid etch and rinse adhesives and self etching bonding adhesives that can reduce the bond stability over time. MMP-2, MMP-8 and MMP-9 are indicated as the active proteases that breakdown the collagen fibrils in the hybrid bond layer. Phosphoric acid in the acid etch and rinse bonding process and acid primers in the self etch process are implicated in the release of these proteases and their activation by several non-collagen proteins also released from dentin by the etching. MMPs are released in saliva by salivary glands, by cells in the gingival crevices to crevicular fluid and by pulpal odontoblasts cells to the dentinal fluids. These sources may affect the hybrid layer also. Evidence of the bond strength deterioration over time and the ability of Chlorhexidine to prevent bond deterioration by inhibiting MMP action are discussed. Dentin Bonding procedure utilizing Chlorhexidine for different application times and concentrations are being developed. The application of 2% Chlorhexidine to the phosphoric acid etch surface after rinsing off the acid is the only procedure that has been clinically tested for a longer period of time and shown to prevent bond strength degradation so far. The adoption of this procedure is recommended as means of improving bond stability at this time

    Youth–adult partnership: exploring contributions to empowerment, agency and community connections in Malaysian youth programs

    Get PDF
    Youth–adult partnership (Y–AP) has emerged as a key practice for enacting two features of effective developmental settings: supportive adult relationships and support for efficacy and mattering. Previous studies have shown that when youth, supported by adults, actively participate in organizational and community decision-making they are likely to show greater confidence and agency, empowerment and critical consciousness, and community connections. Most of the extant research on Y–AP is limited to qualitative studies and the identification of organizational best practices. Almost all research focuses on Western sociocultural settings. To address these gaps, 299 youth, age 15 to 24, were sampled from established afterschool and community programs in Malaysia to explore the contribution of Y–AP (operationalized as having two components: youth voice in decision-making and supportive adult relationships) to empowerment, agency and community connections. As hypothesized, hierarchical regressions indicated that program quality (Y–AP, safe environment and program engagement) contributed to agency, empowerment and community connections beyond the contribution of family, school and religion. Additionally, the Y–AP measures contributed substantially more variance than the other measures of program quality on each outcome. Interaction effects indicated differences by age for empowerment and agency but not for community connections. The primary findings in this inquiry replicate those found in previous interview and observational-oriented studies. The data suggests fertile ground for future research while demonstrating that Y–AP may be an effective practice for positive youth development outside of Western settings

    Effects of different chlorhexidine pretreatments on adhesion of metal brackets in vitro

    Get PDF
    OBJECTIVE: To investigate the effect of chlorhexidine applications in various forms and concentrations on adhesion and failure modes of metal brackets in vitro. MATERIAL AND METHODS: Ninety bovine enamel specimens were allocated to six groups (n=15). Metal brackets were bonded on all specimens after chlorhexidine pre-treatments forming the following groups: (1) untreated specimens (control); (2) 40% varnish (EC40, Biodent BV, Netherlands), remnants removed with brushing mimicking patient cleaning; (3) 40% varnish (EC40), remnants removed with brushing mimicking professional cleaning; (4) 1% varnish (Cervitec Plus, Ivoclar vivadent, Schaan, Liechtenstein), remnants not removed; (5) brushed with% 1 gel (Corsodyl, GlaxoSmithKline, Münchenbuchsee, Germany), remnants not removed; (6) immersed in 0.07% mouthrinse (Corsodyl, GlaxoSmithKline, Münchenbuchsee, Germany), remnant not rinsed. Debonding of brackets was performed using a universal testing machine. Data were analysed using one-way ANOVA and post-hoc Scheffé test. RESULTS: Group 4 performed significantly inferior than all the other groups and the control. Group 4 presented the highest number of adhesive failures at the enamel-resin interface whereas in other groups no failures at adhesive-resin interface was observed. CONCLUSION: Presence of chlorhexidine varnish prior to bracket bonding adversely affects adhesion. Concentration of chlorhexidine pre-treatment has no influence on shear bond strength
    corecore