Dental Health and Mortality in People With End-Stage Kidney Disease Treated With Hemodialysis: A Multinational Cohort Study

Background Dental disease is more extensive in adults with chronic kidney disease, but whether dental health and behaviors are associated with survival in the setting of hemodialysis is unknown. Study Design Prospective multinational cohort. Setting & Participants 4,205 adults treated with long-term hemodialysis, 2010 to 2012 (Oral Diseases in Hemodialysis [ORAL-D] Study). Predictors Dental health as assessed by a standardized dental examination using World Health Organization guidelines and personal oral care, including edentulousness; decayed, missing, and filled teeth index; teeth brushing and flossing; and dental health consultation. Outcomes All-cause and cardiovascular mortality at 12 months after dental assessment. Measurements Multivariable-adjusted Cox proportional hazards regression models fitted with shared frailty to account for clustering of mortality risk within countries. Results During a mean follow-up of 22.1 months, 942 deaths occurred, including 477 cardiovascular deaths. Edentulousness (adjusted HR, 1.29; 95% CI, 1.10-1.51) and decayed, missing, or filled teeth score ≥ 14 (adjusted HR, 1.70; 95% CI, 1.33-2.17) were associated with early all-cause mortality, while dental flossing, using mouthwash, brushing teeth daily, spending at least 2 minutes on oral hygiene daily, changing a toothbrush at least every 3 months, and visiting a dentist within the past 6 months (adjusted HRs of 0.52 [95% CI, 0.32-0.85], 0.79 [95% CI, 0.64-0.97], 0.76 [95% CI, 0.58-0.99], 0.84 [95% CI, 0.71-0.99], 0.79 [95% CI, 0.65-0.95], and 0.79 [95% CI, 0.65-0.96], respectively) were associated with better survival. Results for cardiovascular mortality were similar. Limitations Convenience sample of clinics. Conclusions In adults treated with hemodialysis, poorer dental health was associated with early death, whereas preventive dental health practices were associated with longer survival

Real-time studies of Ge growth on nanostructured Si substrates

Nanostructured substrates are an interesting path towards the production of quantum dots devoted to microelectronic applications. In this work we report results on the effects of different nanopatterning methods to obtain lateral ordering of Ge islands grown on Si. By using Scanning Tunneling Microscopy we have studied in real-time the wetting layer growth and islands formation on nanopatterned Si substrates at 500 °C. We compare results obtained on Si substrates nanopatterned by using two different techniques: STM lithography and natural patterning induced by surface instabilities such as step bunching. Different issues on both cases have been addressed: substrate preparation, Ge dots placement and growth mode. We have observed that, on Si(001), the Ge islands nucleate near the holes and on Si(111) step bunching can guide the growth of aligned rows of islands.</p

Qualification of a sublimation tool applied to the case of metalorganic chemical vapor deposition of In2O3 from In(tmhd)3 as a solid precursor

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Self-ordering of Ge islands on step-bunched Si(111) surfaces

The controlled positioning of germanium (Ge) islands on silicon(111) without lithographic patterning was studied. The step-bunched (SB) silicon(111) surfaces were used as templates. Scanning tunneling microscope images showed that the Ge islands were regularly spaced. The results show an ordered distribution of equally spaced rows of islands on the wide terraces of SB substrates

Photoluminescence efficiency of self-assembled Ge nanocrystals

For self-assembled Ge nanocrystals (NCs), the predicted nonlinear increase in the photoluminescence (PL) efficiency with decreasing NC diameter has been evaluated using the NC size distribution observed from transmission electron microscopy. The NCs were formed by thermal annealing of an amorphous Ge layer deposited by molecular beam epitaxy on a thin SiO2 layer on Si(001). For the present range of particle sizes (2.5\u201360 nm), the NC PL appeared primarily as a wide near-IR band near 800 meV. The peak energy of the PL band reflects the average NC size, and its shape depends on the NC size distribution. Using both the k \ub7 p and tight binding models, the PL energy spectrum was transformed into the PL variation with NC size. For smaller diameter NCs, the band shape contains significant bandgap enlargement due to quantum confinement. The present results show how NC size distributions can be obtained from the PL data.Peer reviewed: YesNRC publication: Ye

Control of carbon content in amorphous GeTe films deposited by Plasma Enhanced Chemical Vapor deposition (PE-MOCVD) for Phase-Change Random Access Memory applications

International audienceAmorphous and smooth GeTe thin films are deposited on 200 mm silicon substrates by plasma enhanced—metal organic chemical vapor deposition (PE–MOCVD) using the commercial organometallic precursors TDMAGe and DIPTe as Ge and Te precursors, respectively. X-ray photoelectron spectroscopy (XPS) measurements show a stoichiometric composition of the deposited GeTe films but with high carbon contamination. Using information collected by Optical Emission Spectroscopy (OES) and XPS, the origin of carbon contamination is determined and the dissociation mechanisms of Ge and Te precursors in H2 + Ar plasma are proposed. As a result, carbon level is properly controlled by varying operating parameters such as plasma radio frequency power, pressure and H2 rate. Finally, GeTe films with carbon level as low as 5 at. % are obtaine

Study of the Functional Properties of ITO grown by Metalorganic Chemical Vapor Deposition from different Indium and Tin Precursors

International audienceFunctional properties of tin doped indium oxide (ITO) layers grown by MOCVD from different indium and tin precursors are investigated. Selected indium precursors are In(acac)3, In(tmhd)3 and InMe2OtBu, and tin precursors are DBTDA and Sn(acac)2. ITO layers are optically and electrically characterized to determine the better doping conditions. Differences in electrical properties of ITO layers are found when using InMe2OtBu, as compared to In(acac)3 and to In(tmhd)3. The best films present a resistivity of 2.5 × 10−4 Ω cm and a transmittance higher than 84% for high deposition temperatures (T ⩾ 600 °C). The nature of tin precursors modifies the optimal doping at which these characteristics are achieved. When doped by DBTDA optimal doping is 8 at.%, therefore close to the solubility limit of tin in In2O3 matrix; but when using Sn(acac)2, or In(acac)3/DBTDA combination, best functional characteristics are obtained for the maximal doping content obtained, i.e. 2.5 at.%. For optimized conditions, the resistivity decreases when deposition temperature increases except when using the couple InMe2OtBu/DBTDA without oxygen addition during deposition. For this combination of precursors a resistivity of 1 × 10−3 Ω cm is obtained at a deposition temperature of 350 °C and remains constant up to 600 °C. Only the films obtained from InMe2OtBu/DBTDA are crystalline state at a deposition temperature of 350 °C

STM Studies : Spatial Resolution Limits to Fit Observations in Nanotechnology

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Growth of lanthanide-doped YF3 thin films by pulsed liquid injection MOCVD: Influence of deposition parameters on film microstructure

International audienceYttrium fluoride (YF3) is a potential candidate as an ideal host material for rare-earth (RE) ions that allow the up- and down-conversion of light. We describe the deposition of Er/Yb co-doped YF3 thin films on Si(111) wafers using low pressure pulsed liquid injection MOCVD. Films were grown through the thermal decomposition of Y/RE(hfac)(3) precursors dissolved in dimethoxyethane (0.05 M) under 5 torr of an O-2/Ar atmosphere at different substrate temperatures between 450 degrees C and 650 degrees C. The film microstructure strongly depends on the operational conditions of the deposition and an optimization of the gas flow, oxygen content, pulse duration and deposition temperature was achieved. Under optimized conditions, films deposited at 590 degrees C showed the best quality and no crack formation was observed on Si(111) for a film thickness <100 nm. These films have been characterized by SEM, AFM, XRD and Raman techniques. Optical measurements, including the dispersion of the refractive index and light transmission, were performed on the Er/Yb:YF3 films grown under optimized conditions. (C) 2013 Elsevier B.V. All rights reserved