Effects of Different Amine Activators on the Monomer Conversion, Biaxial Flexural Strength, and Color Stability of Experimental Provisional Dental Restorations

Objective The aim was to assess the effect of different amine activators including N, N-dimethyl-p-toluidine (DMPT) or Na-N-tolyglycine glycidyl methacrylate (NTGGMA) on chemical-activated monomer conversion, biaxial flexural strength (BFS), and color stability of composites for provisional dental restorations. Materials and Methods Two formulations of composites containing either DMPT (D-temp) or NTGGMA (N-temp) were prepared. The degree of monomer conversion was assessed. The BFS of the materials was tested using the ball-on-ring testing jig. The color difference (∆E00) of the materials after immersion in water was also determined. The commercial comparisons were Unifast (UF), Protemp (PT), Luxacrown, and Luxatemp (LT). Results The monomer conversion of D-temp (57.4 ± 1.3%) was comparable to that of N-temp (59.0 ± 1.3%). The conversion of both D-temp and N-temp were higher than that of PT (48.1 ± 3.4%) and LT (48.0 ± 1.6%). BFS of both D-temp (164.2 ± 18.1 MPa) and N-temp (168.6 ± 8.9 MPa) were comparable but higher than that of UF (119.8 ± 13.6 MPa). ∆E00 of D-temp (2.7 ± 0.7) and N-temp (2.5 ± 0.8) were comparable but higher than that of other commercial materials (0.6–1.2). Conclusion The use of DMPT or NTGGMA showed negligible effect on monomer conversion, BFS, and color stability of the experimental provisional restorations. The conversion and BFS of the experimental materials were in the range of that obtained from commercial bis-acryl-based materials. However, the color stability of the experimental materials was lower than that of commercial materials.

845. Children with Clinical Plasmodium falciparum Infection Have Increased Sharing of Haplotypes with Household Members as well as Temporally Proximal, Symptomatic Peers

Background Falciparum malaria transmission has failed to decline in proportion to control efforts in certain regions such as Bungoma county, western Kenya. One proposed strategy to eradicate malaria is ring testing and treatment; however, it remains unknown whether infections spread locally or if asymptomatically infected household members are a risk factor for clinical disease. Methods From April 2013 to June 2014, we enrolled 442 cases (RDT+ children hospitalized with malaria) and 442 matched controls; all household members of cases and controls were also enrolled and tested, of which 13.6% (n = 608/4449) were RDT+. From each RDT+ participant, parasite gDNA was PCR-amplified at both Pf circumsporozoite protein (csp) and apical membrane antigen 1 (ama1) loci, amplicons sequenced on an Illumina Miseq, and haplotypes inferred using dada2. Results We identified 120 csp and 180 ama1 unique haplotypes (Figure 1). We evaluated the genetic distance between infected individuals using three novel indices: sharing of parasite haplotypes on binary and proportional scales and the L1 norm. Case children median [IQR] binary/proportional sharing of both csp and ama1 haplotypes was significantly increased with members of their origin household (e.g., csp binary sharing: origin = 50.3 [0–87.5] vs. similar household = 0 [0–50.3]; P = 0.01; Wilcoxon sign-rank test), indicating that cases are more likely to share haplotype-identical parasites with members of their own household (Figure 2). We also computed population-level haplotype sharing indices for all pairs of case children and observed no association between genetic relatedness and geographic distance. In contrast, we identified a strong inverse relationship between haplotype sharing and temporal distance, which we exploited to identify the molecular signature of an outbreak (Figure 3). Conclusion Overall, these findings suggest that, although haplotype sharing is more common within households, temporal rather than geographic proximity predicts parasite genetic similarity. The observation that identical haplotype combinations are found nearly simultaneously across the study area implies that ring testing approaches may not effectively reduce transmission. Disclosures All Authors: No reported Disclosures.

Pseudo-ring tests resolution for dynamic single faults in word-oriented memory

This paper presents single dynamic faults and methods for their detection. Such dynamic faults as dRDF, dDRDF and dIRF are considered in detail. Also, pseudo-ring testing and the principles of single dynamic faults detecting by pseudo-ring tests are considered. The paper presents the resolution determination results for pseudo-ring tests in relation to these faults in the word-oriented memory. Also, a comparative analysis of the pseudo-ring tests with known March tests is done. The results show that pseudo-ring tests with an algorithmic complexity of (30-60)N, where N is the number of all memory cells, can cover from 75 to 100% of all single dynamic faults. This advantage allows using pseudo-ring tests as an alternative to existing classical and March tests.