Time Lens Photon Doppler Velocimetry (TL-PDV) for extreme measurements.

Capturing extreme surface velocities with  >50 km/s dynamic range, which arise in shock physics such as inertial confinement fusion (ICF), is beyond the reach of conventional photon Doppler velocimetry (PDV) systems due to the need for extremely large electrical bandwidth under such conditions. The recent ignition in ICF calls for new velocimetry that can measure velocities exceeding 100 km/s. Time lens PDV (TL-PDV) is a solution where the high frequency beat signal from a conventional PDV system is periodically temporally magnified in the optical domain using a time lens.

The ultra-acute steroid response to traumatic injury: a cohort study.

Objective: Trauma-induced steroid changes have been studied post-hospital admission, resulting in a lack of understanding of the speed and extent of the immediate endocrine response to injury. The Golden Hour study was designed to capture the ultra-acute response to traumatic injury.

Design: We conducted an observational cohort study including adult male trauma patients <60 years, with blood samples drawn ≤1 h of major trauma by pre-hospital emergency responders.

Investigating the potential of a prematurely aged immune phenotype in severely injured patients as predictor of risk of sepsis.

Background: Traumatic injury elicits a hyperinflammatory response and remodelling of the immune system leading to immuneparesis. This study aimed to evaluate whether traumatic injury results in a state of prematurely aged immune phenotype to relate this to clinical outcomes and a greater risk of developing additional morbidities post-injury.

Methods And Findings: Blood samples were collected from 57 critically injured patients with a mean Injury Severity Score (ISS) of 26 (range 15-75 years), mean age of 39.

Niobium-tantalum oxide as a material platform for linear and nonlinear integrated photonics.

Here we realize the first reported integrated photonic devices fabricated using sputtered niobium-tantalum oxide films. Sputtered niobium-tantalum oxide films are highly promising for integrated photonics as they are scalable to high volume manufacturing, possess high refractive index, and are transparent in the ultraviolet through near infrared wavelength range. At a wavelength near 1550 nm, we observe propagation losses as low as 0.

Relieving Pressure on the Emergency Department with a New Treatment Pathway for Hand Trauma Patients - A Three-Year Experience with 15,539 Patients.

Hand injuries are a significant and rising burden on the Emergency Department (ED), often leading to protracted waiting times for patients awaiting specialist input. To combat this, a new treatment pathway for hand trauma was introduced at our institution to reduce waiting times and pressure on the ED. The treatment pathway performance using waiting times, length of stay and cost metrics was measured prior to and following the introduction of a new treatment pathway.

Time-lens photon Doppler velocimetry (TL-PDV).

We describe a time lens (TL) to expand the dynamic range of photon Doppler velocimetry (PDV) systems. The principle and preliminary design of a TL-PDV system are explained and shown to be feasible through simulations. In a PDV system, an interferometer is used for measuring frequency shifts due to the Doppler effect from the target motion.

Kilohertz frame rate snapshot hyperspectral imaging of metal reactive materials.

We demonstrate a kilohertz frame rate snapshot hyperspectral imaging system suitable for high-speed imaging, which we name snapshot hyperspectral imager for emission and reactions (SHEAR). This system splits the sensor of a single high-speed camera to simultaneously capture a conventional image and a spectrally sheared response of the scene under study. Given the small, point-source-like nature of burning metal micro-particles, the spectral response of the species is captured without the need for a slit, as is needed in conventional imaging spectrometers.

Violence-related knife injuries in a UK city; epidemiology and impact on secondary care resources.

Background: The incidence of knife-related injuries is rising across the UK. This study aimed to determine the spectrum of knife-related injuries in a major UK city, with regards to patient and injury characteristics. A secondary aim was to quantify their impact on secondary care resources.

Prevention of Adrenal Crisis: Cortisol Responses to Major Stress Compared to Stress Dose Hydrocortisone Delivery.

Context: Patients with adrenal insufficiency require increased hydrocortisone cover during major stress to avoid a life-threatening adrenal crisis. However, current treatment recommendations are not evidence-based.

Objective: To identify the most appropriate mode of hydrocortisone delivery in patients with adrenal insufficiency who are exposed to major stress.

Mapping the Steroid Response to Major Trauma From Injury to Recovery: A Prospective Cohort Study.

Context: Survival rates after severe injury are improving, but complication rates and outcomes are variable.

Objective: This cohort study addressed the lack of longitudinal data on the steroid response to major trauma and during recovery.

Design: We undertook a prospective, observational cohort study from time of injury to 6 months postinjury at a major UK trauma centre and a military rehabilitation unit, studying patients within 24 hours of major trauma (estimated New Injury Severity Score (NISS) > 15).

Optical coherence tomography using physical domain data compression to achieve MHz A-scan rates.

The three-dimensional volumetric imaging capability of optical coherence tomography (OCT) leads to the generation of large amounts of data, which necessitates high speed acquisition followed by high dimensional image processing and visualization. This signal acquisition and processing pipeline demands high A-scan rates on the front end, which has driven researchers to push A-scan acquisition rates into the MHz regime. To this end, the optical time-stretch approach uses a mode locked laser (MLL) source, dispersion in optical fiber, and a single analog-to-digital converter (ADC) to achieve multi-MHz A-scan rates.

A minimally invasive lens-free computational microendoscope.

Ultra-miniaturized microendoscopes are vital for numerous biomedical applications. Such minimally invasive imagers allow for navigation into hard-to-reach regions and observation of deep brain activity in freely moving animals. Conventional solutions use distal microlenses.

The cortisol stress response induced by surgery: A systematic review and meta-analysis.

Objective: Surgery is a stressor that can be categorized by duration and severity and induces a systemic stress response that includes increased adrenal cortisol production. However, the precise impact of surgical stress on the cortisol response remains to be defined.

Design: We performed a systematic review and meta-analysis to assess the cortisol stress response induced by surgery and to stratify this response according to different parameters.

Widefield compressive multiphoton microscopy.

A single-pixel compressively sensed architecture is exploited to simultaneously achieve a 10× reduction in acquired data compared with the Nyquist rate, while alleviating limitations faced by conventional widefield temporal focusing microscopes due to scattering of the fluorescence signal. Additionally, we demonstrate an adaptive sampling scheme that further improves the compression and speed of our approach.

Secure communications using nonlinear silicon photonic keys.

We present a secure communication system constructed using pairs of nonlinear photonic physical unclonable functions (PUFs) that harness physical chaos in integrated silicon micro-cavities. Compared to a large, electronically stored one-time pad, our method provisions large amounts of information within the intrinsically complex nanostructure of the micro-cavities. By probing a micro-cavity with a rapid sequence of spectrally-encoded ultrafast optical pulses and measuring the lightwave responses, we experimentally demonstrate the ability to extract 2.

Silicon photonic physical unclonable function.

Physical unclonable functions (PUFs) serve as a hardware source of private information that cannot be duplicated and have applications in hardware integrity and information security. Here we demonstrate a photonic PUF based on ultrafast nonlinear optical interactions in a chaotic silicon micro-cavity. The device is probed with a spectrally-encoded ultrashort optical pulse, which nonlinearly interacts with the micro-cavity.

High-speed all-optical Haar wavelet transform for real-time image compression.

We present a high-speed single pixel flow imager based on an all-optical Haar wavelet transform of moving objects. Spectrally-encoded wavelet measurement patterns are produced by chirp processing of broad-bandwidth mode-locked laser pulses. A complete wavelet pattern set serially illuminates the object via a spectral disperser.

Wavelength multicasting through four-wave mixing with an optical comb source.

Based on four-wave mixing (FWM) with an optical comb source (OCS), we experimentally demonstrate 26-way or 15-way wavelength multicasting of 10-Gb/s differential phase-shift keying (DPSK) data in a highly-nonlinear fiber (HNLF) or a silicon waveguide, respectively. The OCS provides multiple spectrally equidistant pump waves leading to a multitude of FWM products after mixing with the signal. We achieve error-free operation with power penalties less than 5.

Compressive fluorescence imaging using a multi-core fiber and spatially dependent scattering.

We demonstrate imaging using a multi-core fiber with a scattering distal tip and compressed sensing signal acquisition. We illuminate objects with randomly structured speckle patterns generated by a coherent light source separately coupled through each fiber core to a ground glass diffuser at the distal end. Using the characterized speckle patterns and the total light collected from the object, we computationally recover pixelation-free object images with up to a seven times higher space-bandwidth product than the number of cores.

High-speed all-optical NAND/AND logic gates using four-wave mixing Bragg scattering.

A high-speed all-optical NAND logic gate is proposed and experimentally demonstrated using four-wave mixing Bragg scattering in highly nonlinear fiber. NAND/AND logic functions are implemented at two wavelengths by encoding logic inputs on two pumps via on-off keying. A 15.

Single-pixel imaging using compressed sensing and wavelength-dependent scattering.

We demonstrate two-dimensional imaging using illumination via a single-mode fiber with a multiply scattering tip and compressed sensing acquisition. We illuminate objects with randomly structured, but deterministic, speckle patterns produced by a coherent light source propagating through a TiO2-coated fiber tip. The coating thickness is optimized to produce speckle patterns that are highly sensitive to laser wavelength, yet repeatable.