Purpose: To evaluate outcomes of ultracomplex retinal detachment (UCRD) repairs performed at a large county hospital.
Materials And Methods: Retrospective chart review of patients who underwent a UCRD repair, defined as a funnel retinal detachment (RD), RD associated with ocular trauma, or RD requiring retinectomy, 5000 centistoke silicone oil or perfluorocarbon heavy liquid (PFO). The outcomes examined were visual acuity (VA), anatomic success, and phthisis development.
We report the measurement of impulsive stimulated x-ray Raman scattering in neutral liquid water. An attosecond pulse drives the excitations of an electronic wavepacket in water molecules. The process comprises two steps: a transition to core-excited states near the oxygen atoms accompanied by transition to valence-excited states.
View Article and Find Full Text PDFNew, hard x-ray free electron lasers (FEL) produce intense femtosecond-to-attosecond pulses at angstrom wavelengths, giving access to the fundamental spatial and temporal scales of matter. These revolutionary light sources open the door to applying the suite of nonlinear, optical spectroscopy methods at hard x-ray photon energies. Nonlinear spectroscopy with hard x-rays can allow for measuring the coherence properties of short wavelength excitations with atomic specificity and for understanding how high energy excitations couple to other degrees of freedom in atomic, molecular or condensed-phase systems.
View Article and Find Full Text PDFWe demonstrate the generation of extreme-ultraviolet (XUV) free-electron laser (FEL) pulses with time-dependent polarization. To achieve polarization modulation on a femtosecond timescale, we combine two mutually delayed counterrotating circularly polarized subpulses from two cross-polarized undulators. The polarization profile of the pulses is probed by angle-resolved photoemission and above-threshold ionization of helium; the results agree with solutions of the time-dependent Schrödinger equation.
View Article and Find Full Text PDFX-ray free-electron laser sources enable time-resolved X-ray studies with unmatched temporal resolution. To fully exploit ultrashort X-ray pulses, timing tools are essential. However, new high repetition rate X-ray facilities present challenges for currently used timing tool schemes.
View Article and Find Full Text PDFBackground: Debriefing in the pediatric emergency department (PED) is an invaluable tool to improve team well-being, communication, and performance. Despite evidence, surveys have reported heavy workload as a barrier to debriefing leading to missed opportunities for improvement in an already busy ED. The study aims to determine the association between the incidence of debriefing after pediatric trauma resuscitations and PED crowding.
View Article and Find Full Text PDFAn open-loop control scheme of molecular fragmentation based on transient molecular alignment combined with single-photon ionization induced by a short-wavelength free electron laser (FEL) is demonstrated for the acetylene cation. Photoelectron spectra are recorded, complementing the ion yield measurements, to demonstrate that such control is the consequence of changes in the electronic response with molecular orientation relative to the ionizing field. We show that stable CH cations are mainly produced when the molecules are parallel or nearly parallel to the FEL polarization, while the hydrogen fragmentation channel (CH → CH + H) predominates when the molecule is perpendicular to that direction, thus allowing one to distinguish between the two photochemical processes.
View Article and Find Full Text PDFIntroduction: Vaso-occlusive crises (VOCs) are the leading cause of emergency department (ED) visits and hospitalizations in patients with sickle cell disease (SCD). Timely administration of analgesia, within 60 minutes of patient registration, is the standard of care for SCD patients with VOCs. Patients with VOCs have longer times to initial analgesia compared to similar painful conditions.
View Article and Find Full Text PDFObjectives: Widespread Haemophilus influenzae and Streptococcus pneumoniae immunization has decreased occult bacteremia and bacterial meningitis rates. Practice has evolved in pediatric emergency departments (PEDs) to favor fewer diagnostic tests for and empiric treatment of invasive bacterial infection. We lack evidence-based guidance on evaluation and treatment of unimmunized (UnI) or underimmunized (UnderI) febrile children.
View Article and Find Full Text PDFBackground Recent studies have shown a higher incidence of complications from acute appendicitis in Hispanic populations. Hispanic ethnicity alone has been shown to be a risk factor. In contrast, one study found little evidence of racial disparities in complication rates.
View Article and Find Full Text PDFBackground: The objectives of this study were: 1) estimate the impact and severity of both diagnosed and undiagnosed depression in the general US population 2) explore the demographics of depression based on its common symptoms 3) interpret Patient Health Questionnaire-9 (PHQ-9) scores to improve accuracy in identifying individuals with depression.
Methods: A random sample of 200 individuals was selected from a general US adult population to complete the Patient Health Questionnaire-9 (PHQ-9).
Results: Only 39.
Strong-field ionization of nanoscale clusters provides excellent opportunities to study the complex correlated electronic and nuclear dynamics of near-solid density plasmas. Yet, monitoring ultrafast, nanoscopic dynamics in real-time is challenging, which often complicates a direct comparison between theory and experiment. Here, near-infrared laser-induced plasma dynamics in ∼600 nm diameter helium droplets are studied by femtosecond time-resolved x-ray coherent diffractive imaging.
View Article and Find Full Text PDFThe COVID-19 pandemic introduced lockdown and social distancing measures that made new methods of healthcare essential. Telehealth was introduced as a temporary measure but is being considered as a more permanent form of healthcare, particularly in rural areas, to provide more equitable healthcare. A survey was conducted on 200 rural dwellers (residents) regarding their experience with rural healthcare, any barriers to adequate healthcare, and openness to telehealth.
View Article and Find Full Text PDFIn quantum systems, coherent superpositions of electronic states evolve on ultrafast time scales (few femtoseconds to attoseconds; 1 attosecond = 0.001 femtoseconds = 10 seconds), leading to a time-dependent charge density. Here we performed time-resolved measurements using attosecond soft x-ray pulses produced by a free-electron laser, to track the evolution of a coherent core-hole excitation in nitric oxide.
View Article and Find Full Text PDFJ Cataract Refract Surg
February 2022
In-the-bag intraocular lens (IOL) dislocation is a well-known complication after cataract surgery. As the number of cataract surgeries performed annually continues to increase, so will the incidence of IOL dislocations requiring surgical correction. Described is a new technique for rescue and refixation of a single-piece acrylic IOL.
View Article and Find Full Text PDFJ Synchrotron Radiat
September 2021
The design of an angular array of electron time-of-flight (eToF) spectrometers is reported, intended for non-invasive spectral, temporal, and polarization characterization of single shots of high-repetition rate, quasi-continuous, short-wavelength free-electron lasers (FELs) such as the LCLS II at SLAC. This array also enables angle-resolved, high-resolution eToF spectroscopy to address a variety of scientific questions on ultrafast and nonlinear light-matter interactions at FELs. The presented device is specifically designed for the time-resolved atomic, molecular and optical science endstation (TMO) at LCLS II.
View Article and Find Full Text PDFShort-wavelength free-electron lasers with their ultrashort pulses at high intensities have originated new approaches for tracking molecular dynamics from the vista of specific sites. X-ray pump X-ray probe schemes even allow to address individual atomic constituents with a 'trigger'-event that preludes the subsequent molecular dynamics while being able to selectively probe the evolving structure with a time-delayed second X-ray pulse. Here, we use a linearly polarized X-ray photon to trigger the photolysis of a prototypical chiral molecule, namely trifluoromethyloxirane (CHFO), at the fluorine K-edge at around 700 eV.
View Article and Find Full Text PDF[This corrects the article DOI: 10.1017/cts.2021.
View Article and Find Full Text PDFThe success rate for translation of newly engineered medical technologies into clinical practice is low. Traversing the "translational valleys of death" requires a high level of knowledge of the complex landscape of technical, ethical, regulatory, and commercialization challenges along a multi-agency path of approvals. The Indiana Clinical and Translational Sciences Institute developed a program targeted at increasing that success rate through comprehensive training, education, and resourcing.
View Article and Find Full Text PDFWe report the demonstration of optical compression of an electron beam and the production of controllable trains of femtosecond, soft x-ray pulses with the Linac Coherent Light Source (LCLS) free-electron laser (FEL). This is achieved by enhanced self-amplified spontaneous emission with a 2 μm laser and a dechirper device. Optical compression was achieved by modulating the energy of an electron beam with the laser and then compressing with a chicane, resulting in high current spikes on the beam which we observe to lase.
View Article and Find Full Text PDFWe present a novel, highly versatile, and self-referenced arrival time monitor for measuring the femtosecond time delay between a hard X-ray pulse from a free-electron laser and an optical laser pulse, measured directly on the same sample used for pump-probe experiments. Two chirped and picosecond long optical supercontinuum pulses traverse the sample with a mutually fixed time delay of 970 fs, while a femtosecond X-ray pulse arrives at an instant in between both pulses. Behind the sample the supercontinuum pulses are temporally overlapped to yield near-perfect destructive interference in the absence of the X-ray pulse.
View Article and Find Full Text PDFMolecules can sequentially absorb multiple photons when irradiated by an intense X-ray pulse from a free-electron laser. If the time delay between two photoabsorption events can be determined, this enables pump-probe experiments with a single X-ray pulse, where the absorption of the first photon induces electronic and nuclear dynamics that are probed by the absorption of the second photon. Here we show a realization of such a single-pulse X-ray pump-probe scheme on N[Formula: see text] molecules, using the X-ray induced dissociation process as an internal clock that is read out via coincident detection of photoelectrons and fragment ions.
View Article and Find Full Text PDFIn this work, we continue our study of a new method for the detection of ionizing radiation with the potential for a dramatic improvement in coincidence time resolution (CTR) for time-of-flight positron emission tomography (ToF-PET) using the modulation of a material's optical properties instead of the scintillation mechanism. Our previous work has shown that for non-scintillation materials such as bismuth silicon oxide (BSO) and cadmium telluride (CdTe), their refractive index can be modulated by annihilation photon interactions. The ultrafast nature of this process however remains unexplored.
View Article and Find Full Text PDFFree-electron lasers provide a source of x-ray pulses short enough and intense enough to drive nonlinearities in molecular systems. Impulsive interactions driven by these x-ray pulses provide a way to create and probe valence electron motions with high temporal and spatial resolution. Observing these electronic motions is crucial to understand the role of electronic coherence in chemical processes.
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