Learning cardiopulmonary resuscitation theory with face-to-face versus audiovisual instruction for secondary school students: a randomized controlled trial.

Objectives: To compare secondary students' learning of basic life support (BLS) theory and the use of an automatic external defibrillator (AED) through face-to-face classroom instruction versus educational video instruction.

Material And Methods: A total of 2225 secondary students from 15 schools were randomly assigned to one of the following 5 instructional groups: 1) face-to-face instruction with no audiovisual support, 2) face-to-face instruction with audiovisual support, 3) audiovisual instruction without face-to-face instruction, 4) audiovisual instruction with face-to-face instruction, and 5) a control group that received no instruction. The students took a test of BLS and AED theory before instruction, immediately after instruction, and 2 months later.

Panchromatic porous specular back reflectors for efficient transparent dye solar cells.

A panchromatic specular reflector based dye solar cell is presented herein. Photovoltaic performance of this novel design is compared to that of cells in which standard diffuse scattering layers are integrated. The capability of the proposed multilayer structures to both emulate the broad band reflection of diffuse scattering layers of standard thickness (around 5 microns) and give rise to similarly high light harvesting and power conversion efficiencies, yet preserving the transparency of the device, is demonstrated.

Angular response of photonic crystal based dye sensitized solar cells.

Herein we report an experimental analysis of the performance of photonic crystal based dye solar cells (PC-DSCs) as the incident light angle moves away from the normal with respect to the cell surface. Nanoparticle multilayers operating at different wavelength ranges were coupled to the working electrode of a dye solar cell for this study. The interplay between optical and photovoltaic properties with the incident light angle is discussed.

Characterization of mesoporous thin films by specular reflectance porosimetry.

The pore size distribution of mesoporous thin films is herein investigated through a reliable and versatile technique coined specular reflectance porosimetry. This method is based on the analysis of the gradual shift of the optical response of a porous slab measured in quasi-normal reflection mode that occurs as the vapor pressure of a volatile liquid varies in a closed chamber. The fitting of the spectra collected at each vapor pressure is employed to calculate the volume of solvent contained in the interstitial sites and thus to obtain adsorption-desorption isotherms from which the pore size distribution and internal and external specific surface areas are extracted.

Integration of gold nanoparticles in optical resonators.

The optical absorption of one-dimensional photonic crystal based resonators containing different types of gold nanoparticles is controllably modified by means of the interplay between planar optical cavity modes and localized surface plasmons. Spin-casting of metal oxide nanoparticle suspensions was used to build multilayered photonic structures that host (silica-coated) gold nanorods and spheres. Strong reinforcement and depletion of the absorptance was observed at designed wavelength ranges, thus proving that our method provides a reliable means to modify the optical absorption originated at plasmonic resonances of particles of arbitrary shape and within a wide range of sizes.

On the organization of the nucleosomes associated with telomeric sequences.

The functions of telomeres and, probably, of interstitial telomeric sequences (ITSs) are influenced by their chromatin structure and organization. Telomeres in higher eukaryotes fold into nucleosomes that are about 20-40 bp shorter than the nucleosomes associated with bulk chromatin. Although the functional relevance of this short nucleosomal organization remains unknown, it is believed that short nucleosomes should contribute to telomere function.