Optical and Thermal Design and Analysis of Phase-Change Metalenses for Active Numerical Aperture Control.

The control of a lens's numerical aperture has potential applications in areas such as photography and imaging, displays, sensing, laser processing and even laser-implosion fusion. In such fields, the ability to control lens properties dynamically is of much interest, and active meta-lenses of various kinds are under investigation due to their modulation speed and compactness. However, as of yet, meta-lenses that explicitly offer dynamic control of a lens's numerical aperture have received little attention.

Outcomes analysis of anterior and lateral approach for open repair of hip abductor tendons.

Background: Gluteal tendons tears are increasingly being recognised as a cause of recalcitrant trochanteric pain, but there is a paucity of robust studies analysing the type of tears, results and predictors of outcome.

Methods: Patients with gluteal tendon tears resistant to conservative treatment who underwent isolated open repair (IR) or total hip arthroplasty and concomitant repair (THA+repair) with a minimum 1-year follow-up were retrospectively assessed separately. Type of tear, surgical approach, and fixation methods were registered.

Medial soft-tissue complex of the knee: Current concepts, controversies, and future directions of the forgotten unit.

The medial side of the knee is comprised of ligaments, myotendinous and meniscal structures that work as a unit to stabilize the joint. The superficial medial collateral ligament is its core structure. Still, all elements of the medial side have load-sharing relationships, leading to a cascade of events in the scenario of insufficiency of any of them.

High-resolution inelastic x-ray scattering at the high energy density scientific instrument at the European X-Ray Free-Electron Laser.

We introduce a setup to measure high-resolution inelastic x-ray scattering at the High Energy Density scientific instrument at the European X-Ray Free-Electron Laser (XFEL). The setup uses the Si (533) reflection in a channel-cut monochromator and three spherical diced analyzer crystals in near-backscattering geometry to reach a high spectral resolution. An energy resolution of 44 meV is demonstrated for the experimental setup, close to the theoretically achievable minimum resolution.

An approach for the measurement of the bulk temperature of single crystal diamond using an X-ray free electron laser.

We present a method to determine the bulk temperature of a single crystal diamond sample at an X-Ray free electron laser using inelastic X-ray scattering. The experiment was performed at the high energy density instrument at the European XFEL GmbH, Germany. The technique, based on inelastic X-ray scattering and the principle of detailed balance, was demonstrated to give accurate temperature measurements, within [Formula: see text] for both room temperature diamond and heated diamond to 500 K.

Investigating off-Hugoniot states using multi-layer ring-up targets.

Laser compression has long been used as a method to study solids at high pressure. This is commonly achieved by sandwiching a sample between two diamond anvils and using a ramped laser pulse to slowly compress the sample, while keeping it cool enough to stay below the melt curve. We demonstrate a different approach, using a multilayer 'ring-up' target whereby laser-ablation pressure compresses Pb up to 150 GPa while keeping it solid, over two times as high in pressure than where it would shock melt on the Hugoniot.

Extreme Hardening of Pb at High Pressure and Strain Rate.

We study the high-pressure strength of Pb and Pb-4wt%Sb at the National Ignition Facility. We measure Rayleigh-Taylor growth of preformed ripples ramp compressed to ∼400  GPa peak pressure, among the highest-pressure strength measurements ever reported on any platform. We find agreement with 2D simulations using the Improved Steinberg-Guinan strength model for body-centered-cubic Pb; the Pb-4wt%Sb alloy behaves similarly within the error bars.

Inelastic response of silicon to shock compression.

The elastic and inelastic response of [001] oriented silicon to laser compression has been a topic of considerable discussion for well over a decade, yet there has been little progress in understanding the basic behaviour of this apparently simple material. We present experimental x-ray diffraction data showing complex elastic strain profiles in laser compressed samples on nanosecond timescales. We also present molecular dynamics and elasticity code modelling which suggests that a pressure induced phase transition is the cause of the previously reported 'anomalous' elastic waves.

Single Hit Energy-resolved Laue Diffraction.

In situ white light Laue diffraction has been successfully used to interrogate the structure of single crystal materials undergoing rapid (nanosecond) dynamic compression up to megabar pressures. However, information on strain state accessible via this technique is limited, reducing its applicability for a range of applications. We present an extension to the existing Laue diffraction platform in which we record the photon energy of a subset of diffraction peaks.

Grain-size-independent plastic flow at ultrahigh pressures and strain rates.

A basic tenet of material science is that the flow stress of a metal increases as its grain size decreases, an effect described by the Hall-Petch relation. This relation is used extensively in material design to optimize the hardness, durability, survivability, and ductility of structural metals. This Letter reports experimental results in a new regime of high pressures and strain rates that challenge this basic tenet of mechanical metallurgy.

Strength of shock-loaded single-crystal tantalum [100] determined using in situ broadband x-ray Laue diffraction.

The strength of shock-loaded single crystal tantalum [100] has been experimentally determined using in situ broadband x-ray Laue diffraction to measure the strain state of the compressed crystal, and elastic constants calculated from first principles. The inferred strength reaches 35 GPa at a shock pressure of 181 GPa and is in excellent agreement with a multiscale strength model [N. R.

Nanosecond white-light Laue diffraction measurements of dislocation microstructure in shock-compressed single-crystal copper.

Under uniaxial high-stress shock compression it is believed that crystalline materials undergo complex, rapid, micro-structural changes to relieve the large applied shear stresses. Diagnosing the underlying mechanisms involved remains a significant challenge in the field of shock physics, and is critical for furthering our understanding of the fundamental lattice-level physics, and for the validation of multi-scale models of shock compression. Here we employ white-light X-ray Laue diffraction on a nanosecond timescale to make the first in situ observations of the stress relaxation mechanism in a laser-shocked crystal.

ORION laser target diagnostics.

The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams.

Measurements of electron transport in foils irradiated with a picosecond time scale laser pulse.

The heating of solid foils by a picosecond time scale laser pulse has been studied by using x-ray emission spectroscopy. The target material was plastic foil with a buried layer of a spectroscopic tracer material. The laser pulse length was either 0.

Bragg diffraction using a 100 ps 17.5 keV x-ray backlighter and the Bragg diffraction imager.

A new diagnostic for measuring Bragg diffraction of petawatt-generated high-energy x rays off a laser-compressed crystal was designed and tested successfully at the Omega EP laser facility on static Mo and Ta (111) oriented single crystal samples using a 17.5 keV Mo Kα backlighter. The Bragg diffraction imager consists of a heavily shielded enclosure and a precisely positioned beam block attached to the enclosure by an aluminum arm.

Successful early mobilization of major cuff repair using a suture post.

Repair of massive rotator cuff tears in the elderly can be challenging because of degenerative, retracted, and contracted tendons producing an extensive defect. The quality of the tendon and particularly the bone of the proximal humerus is an inherent weakness in the repaired construct. We report a method that secures the rotator cuff to a fixation post placed in cortical bone at the surgical neck of the humerus, bypassing the weakest point.

Consequences of diagnostic delays in slipped capital femoral epiphysis.

Delay in diagnosis of slipped capital femoral epiphysis has important implications with regard to slip severity and long-term hip outcomes. The aims of this review were to identify the incidence of delayed diagnosis of slipped capital femoral epiphysis in the hospital to which the authors are affiliated, and the causes for such delays. A retrospective review was conducted of all patients admitted to the Women's and Children's Hospital in Adelaide between January 1997 and October 2004 with a diagnosis of slipped capital femoral epiphysis.

Pain management: clinician survey and institutional needs assessment.

In 1996, 738 BUMC clinicians, representing 8 disciplines and >24 specialties, were surveyed using the Clinician Survey and Institutional Needs Assessment. This survey was developed by the Education Development Center, Inc., and distributed to 50 participating health care institutions in 21 states as part of the Mayday Pain Management Project.

Fast-ion production from short-pulse irradiation of ethanol microdroplets.

We report on the first detailed measurements of ion energy distributions from microdroplet targets under ultrashort (100 fs), intense (10(16) Wcm(-2)) laser irradiation. Protons with kinetic energies of up to 20 keV are produced in a strongly anisotropic microexplosion. Modeling of the incident electromagnetic field indicates strong spatial variations over the surface of the microdroplet.

Assessing patient satisfaction with pain management through a continuous quality improvement effort.

A quasi-experimental study was conducted to evaluate patient satisfaction with pain management before and after a continuous quality improvement (CQI) project in a large, university medical center. The CQI project aim was to implement American Pain Society (APS) quality improvement guidelines regarding the recognition and prompt treatment of pain. A modified version of the questionnaire recommended by the APS Subcommittee on Quality Assurance Standards was used to survey 83 patients prior to implementation of the CQI effort and 89 patients one year later.

Digitally assisted acromioplasty: the effect of interscalene block on this new surgical technique.

Purpose: Interscalene brachial plexus (ISBP) block has been shown to be safe and effective for shoulder surgery with significant benefits. The purpose of this study was to introduce the technique of digitally assisted acromioplasty and assess the effect of ISBP on rehabilitation.

Type Of Study: Randomized controlled prospective trial.

Donor site morbidity after quadriceps tendon harvest for rotator cuff repair.

Background: The central quadriceps tendon provides a useful free tendon graft, although the morbidity of harvesting it is unknown in elderly patients.

Methods: The donor site morbidities of 10 patients after central quadriceps tendon (CQT) graft harvest were reviewed for rotator cuff repair. Patients were reviewed by questionnaire and clinical examination at a minimum of 5 months after surgery.

Effect of subcutaneous granulocyte colony-stimulating factor injectate volume on drug efficacy, site complications, and client comfort.

Purpose/objectives: To determine the effect of administering 1.6 ml (480 mcg) of granulocyte colony-stimulating factor (G-CSF) in one subcutaneous injection or two injections of 0.8 ml each.