Structure and Luminescence Properties of Eu3+-Doped Cubic Mesoporous Silica Thin Films

Eu3+ ions-doped cubic mesoporous silica thin films with a thickness of about 205 nm were prepared on silicon and glass substrates using triblock copolymer as a structure-directing agent using sol–gel spin-coating and calcination processes. X-ray diffraction and transmission electron microscopy analysis show that the mesoporous silica thin films have a highly ordered body-centered cubic mesoporous structure. High Eu3+ ion loading and high temperature calcination do not destroy the ordered cubic mesoporous structure of the mesoporous silica thin films. Photoluminescence spectra show two characteristic emission peaks corresponding to the transitions of5D0-7F1 and 5D0-7F2 of Eu3+ ions located in low symmetry sites in mesoporous silica thin films. With the Eu/Si molar ratio increasing to 3.41%, the luminescence intensity of the Eu3+ ions-doped mesoporous silica thin films increases linearly with increasing Eu3+ concentration

Computer modeling and description of nonstoichiometric apatites Cd5-η/2(VO4)3I1-η and Cd5-η/2(PO4)3Br1-η as modified chimney-ladder structures with ladder-ladder and chimney-ladder coupling

Diffraction patterns from apatite-structure compounds Cd5-η/2(TO4)3X1-η with T=P, V and X=Br, I show sheets of diffuse scattering normal to c* at incommensurate l=q (q=1.63 for Cd-V-I apatite and q=1.78 for Cd-P-Br apatite), because the c repeat of the average unit cell is shorter than two X diameters. The equilibrium X..X spacing along c defines the incommensurate periodicity c/q and stoichiometry (1-η)=q/2. The layers show a honeycomb texture for the Cd-V-I apatite, which is condensed into discrete spots for the Cd-P-Br compound. In both phases, X..X repulsions along 〈100〉 force neighboring rods of X atoms out of phase. In the Cd-P-Br phase, additional 〈210〉 attractions drive incipient formation of a rhombohedral superstructure. Average structure site occupancies and the observation of second-order diffuse layers at both l=2q and l=q+2 imply the existence of strong Cd..X in addition to X..X interactions. A three-dimensional computer model was used to produce finite-temperature structure simulations as a function of X..X interactions along 〈001〉, 〈100〉, and 〈210〉, and X..Cd interactions, from which diffraction patterns were calculated. The experimental patterns were fit and approximate values for the interaction energies obtained (hundreds to thousands of joules per mole). It was apparent that lock-in to commensurability caused by the X..Cd term and the formation of nonprimitive incommensurate modulated structures driven by X..X interactions were mutually antagonistic, and the actual structures are compromises between the two

Experience with e-PTFE membrane application to bone grafting of cleft maxilla

Previous clinical studies and animal experiments have demonstrated that the placement of expanded polytetrafluoroethylene (e-PTFE) membranes (GORE-TEX®) may be valuable for bone regeneration in nonosteogenic areas. This study aimed to explore the application of this technique to bone grafting of wide alveolopalatal clefts. Ten patients with bilateral clefts were selected and during a 2-week period, all received autogeneic cancellous iliac bone bilaterally. The membrane was placed nasally and orally on the larger cleft side and removed after 3-6 months. All patients have been followed for 14 months. Bone graft incorporation was successful except for one patient (membrane side), who was regrafted 1 year later. However, soft-tissue problems with membrane exposure occurred in the majority of patients, while on the nonmembrane side, healing was uneventful in all cases. Further research in membrane technology is necessary before this method can be accepted for cleft grafting. © 1995 Munksgaard International Publishers Ltd.link_to_subscribed_fulltex

Surfactant-templated mesoporous silica as a pigment in inkjet paper coatings

The feasibility of a novel type of surfactant-templated mesoporous silica particles as pigments in Inkjet paper has been evaluated. The surfactant-templated mesoporous silica pigments with small pores and narrow pore-size distribution were investigated, and compared to a typical silica gel with larger pores and broader pore-size distribution. The surfactant-templated pigments required significantly lower amounts of binder and gave improvements in colour richness and sharpness relative to the silica gel pigment

Saliva induces expression of antimicrobial peptides and promotes intracellular killing of bacteria in keratinocytes by epidermal growth factor receptor transactivation

Background: Wounds in the oral cavity, constantly exposed to both saliva and bacteria, heal quickly without infection. Furthermore, during licking of skin wounds, saliva promotes wound healing and plays a role in keeping the wound free of infection. Objectives: To investigate whether saliva induces expression of antimicrobial peptides (AMPs) in human epidermal keratinocytes and whether saliva promotes clearance of intracellular bacteria in these cells. Methods: Expression of AMPs was investigated in the oral mucosa and ex vivo injured skin by immunohistochemistry. Human beta-defensin-3 expression was investigated in epidermal keratinocytes after saliva stimulation, using real-time polymerase chain reaction and immunofluorescence. Results: We found higher expression of AMPs in the oral mucosa than in the epidermis. Saliva accelerated the injury-induced expression of AMPs in human skin ex vivo and was a potent inducer of the expression of AMPs in epidermal keratinocytes. The expression of AMPs was induced by metalloproteinase-dependent epidermal growth factor receptor (EGFR) transactivation mediated by a salivary lipid. Saliva increased the intracellular clearance of Staphylococcus aureus in keratinocytes through EGFR activation. Conclusions: These findings suggest a previously unreported role of saliva in innate immunity and demonstrate for the first time that saliva induces gene expression in epidermal keratinocytes