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Basseterre, Saint Kitts and Nevis

Crawled News Article
Site: http://phys.org/nanotech-news/

Research suggests we chew around 800 times in an average meal; that's almost a million times a year. We put our teeth under huge strain, and often require fillings to repair them. Fillings are typically made of a mixture of metals, such as copper, mercury, silver and tin, or composites of powdered glass and ceramic. Typical metal fillings can corrode and composite fillings are not very strong; Graphene on the other hand is 200 times stronger than steel and doesn't corrode, making it a prime new candidate for dental fillings. In the study, researchers from Iuliu Hatieganu University of Medicine and Pharmacy, the National Institute for Research and Development of Isotopic and Molecular Technologies, and the University of Agricultural Sciences and Veterinary Medicine in Romania, and Ross University School of Veterinary Medicine Basseterre in the West Indies investigated whether different forms of graphene are toxic to teeth. "The idea of the project was to add graphene into dental materials, in order to increase their resistance to corrosion as well as to improve their mechanical properties," explained Dr. Stela Pruneanu, one of the authors of the study from the National Institute for Research and Development of Isotopic and Molecular Technologies in Romania. "There is contradictory information regarding the cytotoxicity of graphene, so we first wanted to determine how toxic it is for teeth." Graphene comes in different forms, including graphene oxide, nitrogen-doped graphene and thermally reduced graphene oxide. The researchers tested how toxic these different types of graphene are in vitro for stem cells found in teeth. Thermally reduced graphene oxide was highly toxic, making it inappropriate as a dental filling material. Nitrogen-doped graphene caused membrane damage at high doses (20 and 40 micrograms per milliliter). However, it was shown to have antioxidant properties, so it could be useful if covered in a protective layer. Graphene oxide was least toxic to cells, making it an ideal candidate. "The results were very interesting and proved that graphene is appropriate for use in dental materials," said Dr. Gabriela Adriana Filip, one of the authors of the study and Associate Professor at Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca in Romania. "We believe that this research will bring new knowledge about the cytotoxic properties of graphene-based materials and their potential applications in dental materials." The next step for this research is for the team to make dental materials with graphene oxide and test how compatible they are with teeth, and how toxic they are to cells. The results are due to be published soon. Explore further: Graphene: A new tool for fighting cavities and gum disease? More information: Diana Olteanu et al. Cytotoxicity assessment of graphene-based nanomaterials on human dental follicle stem cells, Colloids and Surfaces B: Biointerfaces (2015). DOI: 10.1016/j.colsurfb.2015.10.023

Catalano S.,University of Calgary | Lejeune M.,University of Calgary | Liccioli S.,University of Calgary | Verocai G.G.,University of Calgary | And 6 more authors.
Emerging Infectious Diseases

Echinococcus multilocularis is a zoonotic parasite in wild canids. We determined its frequency in urban coyotes (Canis latrans) in Alberta, Canada. We detected E. multilocularis in 23 of 91 coyotes in this region. This parasite is a public health concern throughout the Northern Hemisphere, partly because of increased urbanization of wild canids. Source

Wilga C.A.D.,University of Rhode Island | Stoehr A.A.,University of Rhode Island | Stoehr A.A.,University of Massachusetts Dartmouth | Duquette D.C.,University of Rhode Island | And 3 more authors.
Environmental Biology of Fishes

Feeding behavior in the species of captive chondrichthyans is studied to clarify the functional mechanisms responsible for feeding ecology. Kinematics and pressure in the buccal, hyoid and pharyngeal regions were quantified in Squalus acanthias, Chiloscyllium plagiosum and Leucoraja erinacea using sonomicrometry and pressure transducers. Means and coefficients of variation were analyzed by species and by behavior to test for stereotypy and flexibility in the feeding mechanism. Several instances of mechanical stereotypy as well as flexibility were found in the feeding kinematics and pressure of the three chondrichthyan species. In general, Squalus acanthias shows more stereotyped feeding behavior than C. plagiosum and L. erinacea. Different aspects of feeding behavior stand out among the three species. Chiloscyllium plagiosum generates lowest pressures, S. acanthias achieves the greatest area changes, and L. erinacea has longer durations for manipulating prey. Capture events are functionally and behaviorally stereotyped while processing events are functionally and behaviorally flexible with the ability to use suction or compression to process the same food item. Squalus acanthias is a functional specialist and C. plagiosum is functionally a generalist, with both species exhibiting behavioral flexibility. Leucoraja erinacea is a functional and behavioral generalist. Using functional morphology to explain mechanical stereotypy and flexibility in the feeding behavior of three suction feeding chondrichthyan species has allowed a better understanding of specialist and generalist trophic behaviors. © 2011 Springer Science+Business Media B.V. Source

Herin D.V.,University of Texas Medical Branch | Bubar M.J.,University of Texas Medical Branch | Seitz P.K.,University of Texas Medical Branch | Thomas M.L.,University of Texas Medical Branch | And 5 more authors.
Frontiers in Psychiatry

The dopamine mesocorticoaccumbens pathway which originates in the ventral tegmental area (VTA) and projects to the nucleus accumbens and prefrontal cortex is a circuit important in mediating the actions of psychostimulants.The function of this circuit is modulated by the actions of serotonin (5-HT) at 5-HT2A receptors (5-HT2AR) localized to the VTA. In the present study, we tested the hypothesis that virally mediated overexpression of 5-HT2AR in the VTA would increase cocaine-evoked locomotor activity in the absence of alterations in basal locomotor activity. A plasmid containing the gene for the 5-HT2AR linked to a synthetic marker peptide (Flag) was created and the construct was packaged in an adeno-associated virus vector (rAAV-5-HT2AR-Flag). This viral vector (2 μl; 109-10 transducing units/ml) was unilaterally infused into the VTA of male rats, while control animals received an intra-VTA infusion of Ringer's solution.Virus-pretreated rats exhibited normal spontaneous locomotor activity measured in a modified open-field apparatus at 7, 14, and 21 days following infusion. After an injection of cocaine (15 mg/kg, ip), both horizontal hyperactivity and rearing were significantly enhanced in virus-treated rats (p < 0.05). Immunohistochemical analysis confirmed expression of Flag and overexpression of the 5-HT2AR protein. These data indicate that the vulnerability of adult male rats to hyperactivity induced by cocaine is enhanced following increased levels of expression of the 5-HT2AR in the VTA and suggest that the 5-HT2AR receptor in the VTA plays a role in regulation of responsiveness to cocaine. © 2013 Herin, Bubar, Seitz, Thomas, Hillman, Tarasenko, Wu and Cunningham. Source

Oosterik L.H.,Catholic University of Leuven | Tuntufye H.N.,Catholic University of Leuven | Tuntufye H.N.,Sokoine University of Agriculture | Janssens S.,Catholic University of Leuven | And 4 more authors.
BMC Research Notes

Background: Avian pathogenic Escherichia coli (APEC) are the major cause of economic losses in the poultry industry worldwide. Traditionally, antibiotics are used to treat and prevent colibacillosis in broilers. Due to resistance development other ways of preventing/treating the disease have to be found. Therefore during this study the nebulization of low concentrations of hydrogen peroxide (H2O2) was tested in the presence of chickens to lower pathogenicity of APEC. Results: Significantly higher total lesion scores and higher E. coli concentrations were found in the spleen of chickens exposed to 2 % H2O2 compared to those exposed to 1 % H2O2 and control chickens which had been exposed to nebulization with distilled water. Higher total lesions scores and E. coli concentrations in the spleen were found in chickens exposed to 1 % H2O2 in comparison to control chickens (not significant). Conclusion: H2O2 is rendering animals more prone to APEC infection contraindicating H2O2 nebulization in the presence of chickens. © 2015 Oosterik et al. Source

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