Common acoustic phonon lifetimes in inorganic and hybrid lead halide perovskites.

The acoustic phonons in the organic-inorganic lead halide perovskites have been reported to have anomalously short lifetimes over a large part of the Brillouin zone. The resulting shortened mean free paths of the phonons have been implicated as the origin of the low thermal conductivity. We apply neutron spectroscopy to show that the same acoustic phonon energy linewidth broadening (corresponding to shortened lifetimes) occurs in the fully inorganic CsPbBr by comparing the results on the organic-inorganic CHNHPbCl.

Structure and interstitial iodide migration in hybrid perovskite methylammonium lead iodide.

Hybrid perovskites form an emerging family of exceptional light harvesting compounds. However, the mechanism underpinning their photovoltaic effect is still far from understood, which is impeded by a lack of clarity on their structures. Here we show that iodide ions in the methylammonium lead iodide migrate via interstitial sites at temperatures above 280 K.

Suppression of α-Amylase inactivation in the presence of ethanol: Application of a two-step model.

A number of years ago we reported a two-step inactivation mechanism for α-amylase (enzyme) on the basis of theoretical and experimental studies in aqueous solutions. In the first step the metal (Ca ) ion dissociates reversibly from the enzyme followed by an irreversible thermal inactivation of the apoenzyme. In this study we report inactivation of the enzyme in the presence of ethanol-water solutions.

The diagnostic accuracy of magnetic resonance imaging and ultrasonography in gluteal tendon tears--a systematic review.

Gluteal tendon tears are one of the many pathologies causing pain around the greater trochanter that are often labelled as trochanteric bursitis. We systematically reviewed the peer-reviewed literature to establish the accuracy of magnetic resonance imaging and ultrasonography in the diagnosis of gluteal tendon tears in patients with persistent lateral hip pain or Greater Trochanteric Pain Syndrome (GTPS). 7 studies met the inclusion criteria, comparing either imaging modality with a reference standard of surgical findings.

Hip protectors: recommendations for biomechanical testing--an international consensus statement (part I).

Introduction: Hip protectors represent a promising strategy for preventing fall-related hip fractures. However, clinical trials have yielded conflicting results due, in part, to lack of agreement on techniques for measuring and optimizing the biomechanical performance of hip protectors as a prerequisite to clinical trials.

Methods: In November 2007, the International Hip Protector Research Group met in Copenhagen to address barriers to the clinical effectiveness of hip protectors.