ABSTRACT
Background: Weight in individuals can affect the saliva structure, which has an essential role in caries prevention. Aim: This meta-analysis aimed to compare individuals with obesity (OB)/overweight (OW) and normal weight (NW) in terms of salivary flow rate (SFR), salivary pH (SpH), salivary buffer capacity (SBC). Materials and Methods: After electronic databases (Web of Science, PubMed, Scopus, Cochrane Library, and Open Grey databases) were screened, studies were selected depending on inclusion criteria. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias in individual studies. Mean differences (MD) were used to measure the effect estimates in the comparisons of OB vs NW, OW vs NW, and OB+OW vs NW. Additional analyzes such as subgroup, moderator, sensitivity, and grade were also performed. Results: 24 studies and 2072 participants (SFR: 748 OB, 896 NW, SpH: 137 OB, 166 NW, SBC: 62 OB, 63 NW) were included in the quantitative synthesis. Significantly lower SFR was found in the group with OB compared to NW when saliva was stimulated (MD = -0.21, 95% CI [-0.30, -0.12], P < 0.001), but no significance was obtained when saliva was unstimulated (MD = -0.02, 95% CI [-0.11, 0.06], P = 0.55). No significant difference was found in the group with OB compared to NW in SpH (MD = -0.07, 95% CI [-0.26,0.12], P = 0.48) and SBC (MD = -1.10, 95% CI [-2.29,0.09], P = 0.07). Conclusions: SFR significantly decreases in individuals with OB, notably when saliva is stimulated. Besides, the decrease in SFR is much more prominent in adolescence and adulthood than in childhood. Furthermore, the increase in the severity of OB causes a much greater decrease in SFR. However, regarding SpH and SBC, no significant association exists.
Subject(s)
Obesity , Overweight , Adolescent , Adult , Body Mass Index , Humans , Hydrogen-Ion Concentration , SalivaABSTRACT
Understanding how edge misfit dislocations (MDs) form in a GeSi/Si(001) film has been a long standing issue. The challenge is to find a mechanism accounting for the presence of these dislocations at the interface since they are not mobile and cannot nucleate at the surface and glide towards the interface. Furthermore, experiments can hardly detect the nucleation and early stages of growth because of the short time scale involved. Here we present the first semi-quantitative atomistic calculation of the formation of edge dislocations in such films. We use a global optimization method and density functional theory calculations, combined with computations using potential energy functions to identify the best mechanisms. We show that those previously suggested are relevant only for a low film strain and we propose a new mechanism which accounts for the formation of edge dislocations at high film strain. In this one, a 60° MD nucleates as a "split" half-loop with two branches gliding on different planes. One branch belongs to the glide plane of a complementary 60° MD and therefore strongly favors the formation of the complementary MD which is immediately combined with the first MD to form an edge MD.
ABSTRACT
The size dependence of the phase diagram of nanoalloys with a tendency to phase separate is investigated. As the critical temperature may depend on both the size and the morphology of the nanoparticles, we consider nanowires with different cross-sections and also nanotubes with different circumferences. The variation of the critical temperature with the length of all these nanoparticles is systematically studied using Monte Carlo simulations based on an Ising model. A non-monotonic variation of the critical temperature is observed as a function of the length. The maximal value of the critical temperature is reached when the length and the circumference of the nanoparticles are similar. The phase diagrams obtained within two thermodynamic ensembles (the canonical ensemble and the pseudo grand canonical ensemble) are compared and discussed in terms of the behaviour of a single particle or an assembly of nanoparticles in mutual equilibrium with each other.
ABSTRACT
We present a comprehensive study of the equilibrium properties of two codeposited species for an alloy that forms an ideal solution, on a one-dimensional chain. By use of a cluster description we provide exact formulae of the coverages, the total density of clusters, the cluster size distribution, and the chemical composition of each cluster. These analytical results, that are proved to be in agreement with Monte Carlo simulations, strongly differ from the ones derived in the mean-field framework. Indeed, we show by depicting the codeposit at the macroscopic, mesoscopic, and atomic scales, that its features are to be related to the chemical heterogeneities at the edges of the clusters.
