Long-Term Bonding Efficacy of CAD/CAM Hybrid Restorative Materials and Universal Adhesives.

OBJECTIVES: In-office and lab milled prostheses are the staple for indirect restorations. It is therefore critical to determine their long-term bonding durability. METHODS: CAD/ CAM blocks of two classes of restorative materials: 1) a nano-ceramic reinforced polymer matrix (NCPM) and, 2) a polymer-infiltrated ceramic network (PICN) were bonded using four different universal adhesives (UA) and silane systems. A lithium disilicate glassceramic (LDS) was used as a reference. The blocks were bisected and bonded with different UA/resin-cement pairs. Bonded blocks were then cut into 1.0x1.0x12.0 mm bar specimens for microtensile bond testing. Half the bars were subjected to bond strength testing immediately and the other half after aging by 50,000 thermal cycles between 5°C and 55°C. ANOVA and post-hoc tests were used to compare mean bond strength among groups. RESULTS: NCPM presented consistently high bond strength regardless of bonding techniques, while the bond strength of PICN and LDS were lower when bonded with UA relative to traditional silanes. The more hydrophilic UA produced higher bond strengths. DISCUSSION: Glass-ceramics exhibited lower bond strength with UA than the conventional etch-rinse-silane techniques. However, UAs preserved bonding interface in the long-term. SIGNIFICANCE: NCPM displayed superior bond strength relative to PICN and LDS regardless of the type of adhesives and bonding techniques.

Endodontic Access Effect on Full Contour Zirconia and Lithium Disilicate Failure Resistance.

OBJECTIVES: To evaluate the effect of endodontic access on the failure load resistance of both adhesively and conventionally luted, full-contour monolithic yttria-stabilized zirconium dioxide (Y-TZP) and adhesively luted lithium disilicate (LD) crowns cemented on prepared teeth. METHODS AND MATERIALS: Seventy-two human maxillary molars were prepared per respective guidelines for all-ceramic crowns with one group (n=24) restored with LD and the other (n=48) receiving Y-TZP crowns. Preparations were scanned using computer-aided design/computer-aided milling (CAD/CAM) technology, and milled crowns were sintered following manufacturer recommendations. All LD crowns and half (n=24) of the Y-TZP crowns were adhesively cemented, while the remaining Y-TZP specimens were luted using a conventional glass ionomer cement (GIC). One LD group, one Y-TZP adhesive group, and one GIC-luted group (all n=12) then received endodontic access preparations by a board-certified endodontist: the pulp chambers were restored with a dual-cure, two-step, self-etch adhesive and a dual-cure resin composite core material. The access preparations were restored using a nano-hybrid resin composite after appropriate ceramic margin surface preparation. After 24 hours, all specimens were loaded axially until failure; mean failure loads were analyzed using Mann-Whitney U test (α=0.05). RESULTS: Endodontic access did not significantly reduce the failure load of adhesively luted LD or Y-TZP crowns, but Y-TZP crowns with GIC cementation demonstrated significantly less failure load. CONCLUSIONS: These initial findings suggest that endodontic access preparation may not significantly affect failure load resistance of adhesively luted Y-TZP and LD crowns. Definitive recommendations cannot be proposed until fatigue testing and coronal seal evaluations have been accomplished.

Microplastics in beluga whales (Delphinapterus leucas) from the Eastern Beaufort Sea.

Microplastics (MPs, particles <5 mm) represent an emerging global environmental concern, having been detected in multiple aquatic species. However, very little is known about the presence of MPs in higher trophic level species, including cetaceans. We worked with community based monitors and Inuvialuit hunters from Tuktoyaktuk (Northwest Territories, Canada) to sample seven beluga whales (Delphinapterus leucas) in 2017 and 2018. Microplastics were detected in the gastrointestinal tracts in every whale. We estimate that each whale contained 18 to 147 MPs in their GI tract (average of 97 ±â€¯42 per individual). FTIR-spectroscopy revealed over eight plastic polymer types, with nearly half being polyester. Fibres made up 49% of MPs. The diversity of MP shapes and polymeric identities in beluga points to a complex source scenario, and ultimately raises questions regarding the significance and long-term exposure of this pollutant in this ecologically and culturally valuable species.

Properties of a New Nanofiber Restorative Composite.

A new nanofiber-reinforced hybrid composite (NovaPro Fill, Nanova) was recently introduced with reportedly improved mechanical properties. The purpose of this study was to compare the properties (flexural strength/modulus, degree of conversion [DC], depth of cure, and polymerization shrinkage) of the nanofiber composite to those of traditional hybrid composites (Filtek Z250, 3M ESPE; Esthet-X HD, Dentsply). To determine flexural strength and modulus, composite was placed in a rectangular mold, light-cured, stored for 24 hours, and then fractured in a universal testing machine. For degree of conversion, composite was placed in a cylindrical mold, light-cured, and stored for 24 hours. Measurements were made at the top and bottom surfaces using Fourier Transform Infrared Spectroscopy. To determine depth of cure, composite was placed in a cylindrical mold and light-cured. Uncured composite was scraped until polymerized resin was reached. Remaining composite was measured and divided by two. Polymerization shrinkage was determined by placing the composite material on a pedestal in a video-imaging device while light-curing. Shrinkage was determined after 10 minutes. Data were analyzed with one-way analysis of variance and Tukey post hoc test per property (α=0.05). Compared to Filtek Z250, NovaPro Fill had significantly lower flexural strength and modulus, greater volumetric shrinkage, and similar depth of cure, but greater top and bottom DC. Compared to Esthet-X HD, NovaPro Fill had similar flexural strength, shrinkage, and top and bottom DC, but significantly greater depth of cure and flexural modulus.

Linear Coefficient of Thermal Expansion Evaluation of Glass Ionomer and Resin-Modified Glass Ionomer Restorative Materials.

OBJECTIVE: The purpose of this evaluation was to evaluate the linear coefficient of thermal expansion (LCTE) of 12 conventional glass ionomer (GIC) and four resin-modified glass ionomer (RMGI) restorative materials. METHODS: GIC and RMGI specimens (2 mm × 5 mm × 5 mm) were fabricated (n=12) following manufacturer instructions and were placed in 0.2M phosphate-buffered saline and stored at 37°C and 98% humidity for one week. Specimens had LCTE determined with a thermomechanical analysis (TMA) unit using a 15°C-50°C heating cycle as well as a 50°C-15°C cooling cycle at a 5°C/min rate, using a 3-mm ball-point probe under 0.02 N probe pressure with all specimens kept saturated with PBS using a specially designed quartz container. Each specimen was tested three times, with the mean representing the specimen LCTE. Mean results between specimen heating and cooling were compared with paired Wilcoxon sign rank test, while results between materials were compared with Kruskal-Wallis/Dunn's ( α=0.05). RESULTS: GIC LCTE ranged from approximately 5°C to 20°C ppm °K-1, while the RMGI LCTE ranged from approximately 25°C to 47°C ppm °K-1. With some exception, the LCTE during cooling displayed a greater trend. SIGNIFICANCE: Under moisture conditions similar to the oral cavity, GIC materials overall had LCTE values closer to that reported for tooth structure. RMGI materials displayed higher values, which was thought to be related to the amount of resin in the matrix. A generally greater LCTE trend with cooling for all materials was noted, but the small magnitude of the difference is presently thought to be of minor clinical significance.

Discovery and spectroscopy of the young jovian planet 51 Eri b with the Gemini Planet Imager.

Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric compositions and luminosities, which are influenced by their formation mechanisms. Using the Gemini Planet Imager, we discovered a planet orbiting the ~20-million-year-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water-vapor absorption. Modeling of the spectra and photometry yields a luminosity (normalized by the luminosity of the Sun) of 1.6 to 4.0 × 10(-6) and an effective temperature of 600 to 750 kelvin. For this age and luminosity, "hot-start" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the "cold-start" core-accretion process that may have formed Jupiter.

Gender differences between predictors of HIV status among PWID in Ukraine.

BACKGROUND: The HIV epidemic in Ukraine is among the largest in Europe. While traditionally the epidemic has spread through injection risk behavior, sexual transmission is becoming more common. Previous research has found that women in Ukraine have higher rates of HIV and engage in more HIV risk behavior than men. This study extended that work by identifying risk factors that differentially predict men and women's HIV status among people who inject drugs (PWID) in Ukraine. METHODS: From July 2010 to July 2013, 2480 sexually active PWID with unknown HIV status were recruited from three cities in Ukraine through street outreach. The average age was 31 years old. RESULTS: Women, who made up twenty-eight percent of the sample, had higher safe sex self-efficacy (p<.01) and HIV knowledge (p<.001) than men, but scored higher on both the risky injection (p<.001) and risky sex (p<.001) composite scores than men. Risky sex behaviors were associated with women's HIV status more than men's. We also report results identifying predictors of risky injection and sex behaviors. CONCLUSIONS: Gender-specific interventions could address problem of HIV risk among women who inject drugs in a country with a growing HIV epidemic. Our findings suggest specific ways in which intervention efforts might focus on groups and individuals who are at the highest risk of contracting HIV (or who are already HIV positive) to halt the spread of HIV in Ukraine.

Factors associated with the adoption of a smoking ban in Quebec households.

The home represents an important source of exposure to environmental tobacco smoke for non-smokers, including children, who live with smokers. Our goal is to identify the sociodemographic factors associated with the adoption of smoking bans in "smoker households" in Quebec. Selected associations are compared with three other Canadian provinces (Ontario, British Columbia and Nova Scotia). This is a cross-sectional study involving 2648 respondents. Logistic regression analysis is employed. Few smoker households in Quebec (21%) have a ban on smoking; the presence of a non-smoker is strongly linked to the existence of such a ban; the presence of a child under the age of 6 is less strongly associated with the adoption of a ban in Quebec than in the other provinces, and the presence of an adolescent shows no association whatsoever. In addition to the child health benefits of household smoking bans, greater emphasis should be placed on the impact that such bans can have on children's future smoking behaviour. One option from a health promotion standpoint might be to organize a campaign aimed at non-smokers who live with smokers, in order to urge them to be less tolerant of environmental tobacco smoke.

Host inflammatory response profiling in preeclampsia using an in vitro whole blood stimulation model.

The pathophysiology of preeclampsia (PET) implicates an inflammatory dysfunction. This study profiled this host response by challenging whole blood with lipopolysaccharide. Multiplex immunoassays determined interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12(p70), IL-13, IL-17, granulocyte/granulocyte macrophage-colony stimulating factors (G-CSF/GM-SCF), interferon(IFN)-gamma, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein-1beta and tumor necrosis factor (TNF)-alpha levels. Secretory capacity was expressed in pg/million white cells or monocytes (+/-SEM). PET featured significantly higher IL-1beta, IL-2, IL-10, IL-13, G-CSF, IFN-gamma, MCP-1 and TNF-alpha monocyte secretory capacities (p < 0.05). The PET group exhibited an inflammatory hyper-responsiveness (p < 0.01) which was poorly described by the traditional Th1:Th2 dichotomy.

Magnetic resonance imaging in prostate cancer: the value of apparent diffusion coefficients for identifying malignant nodules.

The aim of this work was to determine the potential of diffusion weighted magnetic resonance imaging (DW-MRI) for identifying prostate cancer by comparing apparent diffusion coefficients (ADCs) from malignant peripheral zone (PZ) nodules with values from the non-malignant PZ and the predominantly benign central gland (CG). 33 patients with elevated prostate specific antigen (PSA) aged 52-78 years (30 patients with biopsy proven prostate cancer) underwent endorectal MRI with T2 weighted and echo planar diffusion weighting (b = 0 mm2 s(-1), 300 mm2 s(-1), 500 mm2 s(-1) and 800 mm2 s(-1)) sequences. ADCs were measured from 30 malignant PZ nodules (identified on T2 weigting and positive biopsy; median region of interest (ROI) size 41 mm2), 33 CG regions (predominantly benign nodules; median ROI size 218 mm2) and 18 non-malignant PZ regions (ipsilateral biopsies all benign; median ROI size 54.5 mm2). ADCs were (mean+/-standard deviation (SD); mm2 s(-1)): malignant PZ nodules 1.30+/-0.30x10(-3), CG 1.46+/-0.14x10(-3) and non-malignant PZ 1.71+/-0.16x10(-3). Differences between all three groups were statistically significant (p = 0.01 malignant PZ vs CG; p = 0.0001 malignant PZ vs non-malignant PZ and p = 0.0001 CG vs non-malignant PZ). Using receiver operating characteristic curves, cut-off values of 1.39x10(-3) mm2 s(-1) differentiated malignant PZ nodules from predominantly benign CG (sensitivity 60%, specificity 76%) and of 1.6x10(-3) mm2 s(-1) identified malignant from non-malignant PZ (sensitivity 86.7%, specificity 72.2%). These results suggest that DW-MRI has the potential to increase the specificity of prostate cancer detection because ADCs are significantly lower in malignant compared with non-malignant prostate tissue.

Endoplasmic reticulum stress and trophic factor withdrawal activate distinct signaling cascades that induce glycogen synthase kinase-3 beta and a caspase-9-dependent apoptosis in cerebellar granule neurons.

Loss of trophic or activity-dependent survival signals is commonly recognized as a stimulus for neuronal apoptosis and may play a significant role in neurodegeneration. Recent data have also implicated endoplasmic reticulum (ER) stress as an important factor in some neurodegenerative conditions. However, whether shared or unique apoptotic cascades are activated by trophic factor withdrawal (TFW) versus ER stress in primary neurons has not previously been investigated. In primary cultures of rat cerebellar granule neurons (CGNs), the ER stressor brefeldin A activated a discrete pathway involving the following: (1) stimulation of the ER resident kinase PERK, (2) enhanced phosphorylation of the translation initiation factor eIF2alpha, and (3) increased expression and nuclear localization of the transcription factor Gadd153/CHOP. ER stress-induced CGN apoptosis was blocked by an antagonist of IP3 receptor-mediated Ca2+ release, 2-aminoethoxydiphenyl borate (2-APB), and by expression of ER-targeted Bcl-2. In contrast, CGN apoptosis elicited by TFW (i.e., removal of serum and depolarizing extracellular potassium) did not display any ER stress component nor was it blocked by either 2-APB or ER-Bcl-2. Despite these apparent differences, both brefeldin A and TFW induced dephosphorylation (activation) of glycogen synthase kinase-3beta (GSK-3beta). Moreover, inhibitors of GSK-3beta (IGF-I, lithium) and caspase-9 (LEHD-fmk) significantly protected CGNs from apoptosis induced by either ER stress or TFW. These data indicate that ER stress and TFW elicit distinct signals that activate GSK-3beta and intrinsic apoptosis in neurons.

Production of class A biosolids with anoxic low dose alkaline treatment and odor management.

The feasibility of full-scale anoxic disinfection of dewatered and digested sludge from Winnipeg, Manitoba with low lime doses and lagoon fly ash was investigated to determine if a class A product could be produced. Lime doses of 50 g, 100 g, and 200 g per kg of biosolids (dry) were used along with fly ash doses of 500 g, 1,000 g, and 1,500 g per kg of biosolids (dry). The mixed product was buried in eight-10 cubic metre trenches at the West End Water Pollution Control Center in Winnipeg. The trenches were backfilled with dirt and trapped to simulate anoxic conditions. Sampling cages were packed with the mixed product and pathogens non-indigenous to Winnipeg's biosolids. The cages were buried amongst the mixed biosolids in the trench. The non-indigenous pathogens spiked in the laboratory were the helminth Ascaris suum and the enteric virus reovirus. Samples were removed at days 12, 40, 69, 291, and 356 and were tested for the presence of fecal Coliform, Clostridium perfringens spores, Ascaris suum eggs, and reovirus. The pH, total solids, and free ammonia content of the mixed product were also determined for each sample. Odor was quantified for samples at both 291 and 356 days. Fecal Coliform bacteria and reovirus were completely inactivated for doses as low as 100 g lime per kg biosolids (dry) and 50 g lime + 500 g fly ash per kg biosolids (dry). Spores of the bacteria C. perfringens experienced a 4-log reduction when treated with 100 g lime per kg biosolids and a 5-log reduction when treated with doses as low as 50 g lime + 500 g fly ash per kg biosolids (dry) after 69 days. Ascaris eggs were completely inactivated in 5 gram packets for all treatments involving 100 g lime per kg biosolids (dry) after 69 days. Class A pathogen requirements were met for all treatments involving a lime dose of at least 100 g per kg biosolids. The odor potential from the produced biosolids is also assessed.

Minimum detectable level of Salmonellae using a binomial-based bacterial ice nucleation detection assay (BIND).

A modified bacterial ice nucleation detection (BIND) assay was used for rapid and sensitive detection of several Salmonella species. For the BIND assay, Salmonella cells are infected with bacteriophage genetically modified to contain DNA encoding an ice nucleation protein (INP). After infection, de novo protein synthesis occurs and INPs are incorporated into the outer membrane of the organism. After supercooling (-9.3 degrees C), only buffer solutions containing transfected salmonellae freeze, causing a phase-sensitive dye to change color. This technique, and a probability-based protocol modification, provided quantitative detection with a minimum detectable level (MDL) of 2.0 +/- 0.3 S. enteritidis cells/mL in buffer (about 3 h). The MDLs for S. typhimurium DT104 and S. abaetetuba were 4.2 +/- 0.2 and 11.1 +/- 0.4 cells/mL, respectively. Using salmonellae-specific immunomagnetic bead separation technology in conjunction with the modified BIND protocol, we achieved an MDL of about 4.5 S. enteritidis cells/mL with an apparent capture efficiency of 56%.

Deletion of Dad1 in mice induces an apoptosis-associated embryonic death.

Dad1 is a putative anti-apoptosis gene identified in several distantly related organisms. Expression of Dad1 in transfected cells inhibits apoptosis in vitro. To determine whether Dad1 has a similar function in vivo, we used gene targeting to delete Dad1. Heterozygous adult mice (+/-) show no obvious phenotype or abnormalities, but genotype analysis of over 100 offspring from heterozygous matings detected no weanling, homozygous Dad1 null (-/-) mice. Subsequent analysis of embryos from heterozygous matings detected Dad1 null (-/-) embryos at E3.5 but no later, suggesting Dad1 is required for development beyond the late blastocyst stage. Increased levels of apoptosis were observed in cultured embryos lacking a functional copy of the gene, consistent with an anti-apoptotic role for Dad1.

Neonatal and pediatric outcome of infants born to mothers with antiphospholipid syndrome.

OBJECTIVE: To determine any adverse outcome to infants born to mothers with Antiphospholipid Syndrome (APS). DESIGN: Case control study with retrospective data collection and prospective pediatric review. SETTING: Regional Recurrent Miscarriage Clinic based at a University Teaching Hospital. PARTICIPANTS: Infants (n = 62) of mothers with APS, compared to 124 index cases randomly selected from the delivery register, matched for gestation and sex who delivered between 1992 and 1997. RESULTS: Sixty two infants born to 55 women with APS were reviewed to study the neonatal outcome. The prematurity rate for the group was 10%, compared to 8.5% for the total hospital population over the same period of time. Twenty-one percent (21%) had birth weights less than or equal to the 10th centile, which was not statistically significant compared to matched controls. The presence of dual parameter positivity (lupus anticoagulant and anticardiolipin antibody) for APS is clearly associated with a higher incidence of growth restriction. All children were normal on neurodevelopmental and physical examination at pediatric review. CONCLUSIONS: There was a low rate of preterm delivery. Although the incidence of growth restriction of 21% is higher than expected it was not statistically significant. There were no developmental abnormalities on follow-up of these children.

Intra-uterine death due to umbilical cord thrombosis secondary to antiphospholipid syndrome.

This is a case of intra-uterine death due to a thrombotic event on the fetal side of circulation in a woman who was subsequently diagnosed with Antiphospholipid Syndrome.