Review of nanomaterials in dentistry: interactions with the oral microenvironment, clinical applications, hazards, and benefits.

Interest in the use of engineered nanomaterials (ENMs) as either nanomedicines or dental materials/devices in clinical dentistry is growing. This review aims to detail the ultrafine structure, chemical composition, and reactivity of dental tissues in the context of interactions with ENMs, including the saliva, pellicle layer, and oral biofilm; then describes the applications of ENMs in dentistry in context with beneficial clinical outcomes versus potential risks. The flow rate and quality of saliva are likely to influence the behavior of ENMs in the oral cavity, but how the protein corona formed on the ENMs will alter bioavailability, or interact with the structure and proteins of the pellicle layer, as well as microbes in the biofilm, remains unclear. The tooth enamel is a dense crystalline structure that is likely to act as a barrier to ENM penetration, but underlying dentinal tubules are not. Consequently, ENMs may be used to strengthen dentine or regenerate pulp tissue. ENMs have dental applications as antibacterials for infection control, as nanofillers to improve the mechanical and bioactive properties of restoration materials, and as novel coatings on dental implants. Dentifrices and some related personal care products are already available for oral health applications. Overall, the clinical benefits generally outweigh the hazards of using ENMs in the oral cavity, and the latter should not prevent the responsible innovation of nanotechnology in dentistry. However, the clinical safety regulations for dental materials have not been specifically updated for ENMs, and some guidance on occupational health for practitioners is also needed. Knowledge gaps for future research include the formation of protein corona in the oral cavity, ENM diffusion through clinically relevant biofilms, and mechanistic investigations on how ENMs strengthen the tooth structure

La Station de séries Temporelles (SPOT) de l'Océan Pacifique Sud : un premier aperçu sur la communauté des diazotrophes

International audienceThe SPOT station (168°E-20°S,-4500 m) is a recent deep-sea and multidisciplinary marine research observation station whose objective is to establish the first long-time series of basic parameters in the South West Pacific. The primary studies concern the biodiversity, the productivity of key Plankton Functional Types, the biogeochemistry of carbon and nitrogen cycles, and their impact on the reef and coastal ecosystems' productivity. SPOT station is based on the same philosophy of long-lasting observation as HOT (Hawaii Ocean Time-series). The data will be used to describe and understand the seasonal and long-term variations of the SouthWest Pacific ecosystem related to ENSO (El Niño Southern Oscillation)

La Station de séries Temporelles (SPOT) de l'Océan Pacifique Sud : un premier aperçu sur la communauté des diazotrophes

International audienceThe SPOT station (168°E-20°S,-4500 m) is a recent deep-sea and multidisciplinary marine research observation station whose objective is to establish the first long-time series of basic parameters in the South West Pacific. The primary studies concern the biodiversity, the productivity of key Plankton Functional Types, the biogeochemistry of carbon and nitrogen cycles, and their impact on the reef and coastal ecosystems' productivity. SPOT station is based on the same philosophy of long-lasting observation as HOT (Hawaii Ocean Time-series). The data will be used to describe and understand the seasonal and long-term variations of the SouthWest Pacific ecosystem related to ENSO (El Niño Southern Oscillation)

La Station de séries Temporelles (SPOT) de l'Océan Pacifique Sud : un premier aperçu sur la communauté des diazotrophes

International audienceThe SPOT station (168°E-20°S,-4500 m) is a recent deep-sea and multidisciplinary marine research observation station whose objective is to establish the first long-time series of basic parameters in the South West Pacific. The primary studies concern the biodiversity, the productivity of key Plankton Functional Types, the biogeochemistry of carbon and nitrogen cycles, and their impact on the reef and coastal ecosystems' productivity. SPOT station is based on the same philosophy of long-lasting observation as HOT (Hawaii Ocean Time-series). The data will be used to describe and understand the seasonal and long-term variations of the SouthWest Pacific ecosystem related to ENSO (El Niño Southern Oscillation)

Chasing Phosphohistidine, an Elusive Sibling in the Phosphoamino Acid Fa mily

This year (2012) marks the 50th anniversary of the discovery of protein histidine phosphorylation. Phosphorylation of histidine (pHis) is now widely recognized as being critical to signaling processes in prokaryotes and lower eukaryotes. However, the modification is also becoming more widely reported in mammalian cellular processes and implicated in certain human disease states such as cancer and inflammation. Nonetheless, much remains to be understood about the role and extent of the modification in mammalian cell biology. Studying the functional role of pHis in signaling, either in vitro or in vivo, has proven devilishly hard, largely due to the chemical instability of the modification. As a consequence, we are currently handicapped by a chronic lack of chemical and biochemical tools with which to study histidine phosphorylation. Here, we discuss the challenges associated with studying the chemical biology of pHis and review recent., progress that offers some hope that long-awaited biochemical reagents for studying this elusive posttranslational modification (PTM) might soon be availableclose353