1,721,340 research outputs found
Modeling Plasmonics and Molecular Plasmonics from an Atomistic Perspective
No full textThis study presents an atomistic yet classical approach coupled to a QM Hamiltonian, to predict plasmonic properties of nanostructured materials. The method enables large-scale simulations, also capturing quantum effects. Remarkably, it accurately reproduces computed reference data and experiments
Sunscreen and 25-Hydroxyvitamin D Levels: Friends or Foes? A Systematic Review and Meta-Analysis
No full textObjective: To evaluate the impact of sunscreen use on 25-hydroxyvitamin D (25(OH)D) levels, addressing conflicting findings from observational and interventional studies. Methods: Potentially eligible studies were identified from the PubMed/MEDLINE, Scopus, and Web of Science databases from inception to November 2024, utilizing a search strategy incorporating terms related to "sunscreen" and "vitamin D." The studies eligible addressed the questions define based on the Population, Intervention, Comparator, Outcome framework: What are 25(OH)D levels in patients exposing to sun applying or not sunscreen? This review followed Preferred Reported Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality assessment and the risk of bias were analyzed using Quality Assessment of Diagnostic Accuracy Studies version 2. Results: We included 22 studies in the qualitative synthesis, and 7 in the quantitative one, encompassing a total of 9470 participants. In vitro studies consistently showed that sunscreen blocks UV-B radiation, crucial for vitamin D3 production, while population-based studies reported mixed findings. Some studies linked sunscreen use to lower 25(OH)D levels, particularly in individuals with limited sun exposure, while others observed no significant impact. Meta-analysis showed that the adoption of sunscreen is associated to a reduction of 25(OH)D serum concentration (standardized mean difference = -2 ng/mL, 95% confidence interval -3, -1) with a not important heterogeneity across studies (I-square = 37%, P = .15). Conclusion: The existing evidence supports that sunscreen can impair vitamin D3 synthesis, and as a result decrease serum 25(OH)D levels, but further research is necessary to determine the broader health implications and guide public health recommendations
Behaviour of perennial ryegrass cultivars towards Puccinia coronata under field conditions in Central Italy
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Absorption spectra of xanthines in aqueous solution: A computational study
No full textWe present a detailed computational analysis of the UV/Vis spectra of caffeine, paraxanthine and theophylline in aqueous solution. A hierarchy of solvation approaches for modeling the aqueous environment have been tested, ranging from the continuum model to the non-polarizable and polarizable quantum mechanical (QM)/molecular mechanics (MM) models, with and without the explicit inclusion of water molecules in the QM portion. The computed results are directly compared with the experimental data, thus highlighting the role of electrostatic, polarization and hydrogen boding solute-solvent interactions
Theory and algorithms for chiroptical properties and spectroscopies of aqueous systems
Full text linkChiroptical properties and spectroscopies are valuable tools to study chiral molecules and assign absolute configurations. The spectra that result from chiroptical measurements may be very rich and complex, and hide much of their information content. For this reason, the interplay between experiments and calculations is especially useful, provided that all relevant physico-chemical interactions that are present in the experimental sample are accurately modelled. The inherent difficulty associated to the calculation of chiral signals of systems in aqueous solutions requires the development of specific tools, able to account for the peculiarities of water-solute interactions, and especially its ability to form hydrogen bonds. In this perspective we discuss a multiscale approach, which we have developed and challenged to model the most used chiroptical techniques. This journal i
Gravi attacchi di Septoria lavandulae su lavanda in Umbria
No full textDescrizione di una malattia grave della lavanda in Umbri
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