Clinicians may want to consider use of the supine method given the higher reliability, validity, and similar precision and clinical accuracy.

Objective: To present athletic trainers with recommendations for the content and administration of the preparticipation physical examination (PPE) as well as considerations for determining safe participation in sports and identifying disqualifying conditions.Background: Preparticipation physical examinations have been used routinely for nearly 40 years. However, considerable debate exists as to their efficacy due to the lack of standardization in the process and the lack of conformity in the information that is gathered. With the continuing rise in sports participation at all levels and the growing number of reported cases of sudden death in organized athletics, the sports medicine community should consider adopting a standardized process for conducting the PPE to protect all parties.Recommendations: Recommendations are provided to equip the sports medicine community with the tools necessary to conduct the PPE as effectively and efficiently as possible using available scientific evidence and best practices. In addition, the recommendations will help clinicians identify those conditions that may threaten the health and safety of participants in organized sports, may require further evaluation and intervention, or may result in potential disqualification.

No abstract

Highly efficient chalcopyrite photovoltaic cells display complex distributions of sodium dopant and gallium: how are these distributions related to each other?

This study examines zinc(II)–chitosan complexes as a bio-sorbent for phosphate removal from aqueous solutions. The bio-sorbent is prepared and is characterized via Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Point of Zero Charge (pHPZC)–drift method. The adsorption capacity of zinc(II)–chitosan bio-sorbent is compared with those of chitosan and ZnO–chitosan and nano-ZnO–chitosan composites. The effect of operational parameters including pH, temperature, and competing ions are explored via adsorption batch mode. A rapid phosphate uptake is observed within the first three hours of contact time. Phosphate removal by zinc(II)–chitosan is favored when the surface charge of bio-sorbent is positive/or neutral e.g., within the pH range inferior or around its pHPZC, 7. Phosphate abatement is enhanced with decreasing temperature. The study of background ions indicates a minor effect of chloride, whereas nitrate and sulfate show competing effect with phosphate for the adsorptive sites. The adsorption kinetics is best described with the pseudo-second-order model. Sips (R2 > 0.96) and Freundlich (R2 ≥ 0.95) models suit the adsorption isotherm. The phosphate reaction with zinc(II)–chitosan is exothermic, favorable and spontaneous. The complexation of zinc(II) and chitosan along with the corresponding mechanisms of phosphate removal are presented. This study indicates the introduction of zinc(II) ions into chitosan improves its performance towards phosphate uptake from 1.45 to 6.55 mg/g and provides fundamental information for developing bio-based materials for water remediation.

No abstract

A number of applications in nanoplasmonics utilize noble metals, gold (Au) and silver (Ag), as the materials of choice. However, these materials suffer from problems of poor thermal and chemical stability with significant dissipative losses under high-temperature conditions. In this regard, semiconductor nanoparticles have attracted attention with their promising characteristics of highly tunable plasmonic resonances, low ohmic losses, and greater thermochemical stability. Here, the size-dependent thermoplasmonic properties of semiconducting silicon and gallium arsenide nanoparticles are investigated to compare them with Au nanoparticles using Mie theory. To this end, experimentally estimated models of dielectric permittivity are employed. Among the various permittivity models for Au, the Drude-Lorentz (DL) and the Drude and critical points (DCP) models are further compared. Results show a redshift in the scattering and absorption resonances for the DL model while the DCP model presents a blueshift. A massive Drude broadening contributes strongly to the damping of resonances in Au nanoparticles at elevated temperatures.In contrast, the semiconductor nanoparticles do not exhibit significant deterioration in their scattering and absorption resonances at high temperatures. In combination with low dissipative damping, this makes the semiconductor nanoparticles better suited for high-temperature applications in nanoplasmonics wherein the noble metals suffer from excessive heating.

We study the plasmonic properties of arrays of atomic chains which comprise noble (Cu, Ag, and Au) and transition (Pd, Pt) metal atoms using time-dependent density-functional theory. We show that the response to the electromagnetic radiation is related to both physics, the geometry-dependent confinement of sp-valence electrons, and chemistry, the energy position of d-electrons in the different atomic species and the hybridization between d and sp electrons. As a result it is possible to tune the position of the surface plasmon resonance, split it to several peaks, and eventually achieve broadband absorption of radiation. Mixing the arrays with transition metals can strongly attenuate the plasmonic behaviour. We analyze the origin of these phenomena and show that they arise from rich interactions between single-particle electron-hole and collective electron excitations. The tunability of the plasmonic response of 1 arXiv:1810.00404v1 [cond-mat.mes-hall] 30 Sep 2018 arrays of atomic chains, which can be realized on solid surfaces, opens wide possibilities for their applications. In the present study we obtain guidelines how the desired properties can be achieved.