Ophthalmic Plast Reconstr Surg
November 2024
We report the measurement of the helicity asymmetry E for the pπ^{0} and nπ^{+} final states using, for the first time, an elliptically polarized photon beam in combination with a longitudinally polarized target at the Crystal Ball experiment at MAMI. The results agree very well with data that were taken with a circularly polarized photon beam, showing that it is possible to simultaneously measure polarization observables that require linearly (e.g.
View Article and Find Full Text PDFContext: Primary aldosteronism (PA) is a common secondary cause of hypertension. Literature regarding PA in pregnancy has demonstrated poor outcomes.
Objective: Compare the management and outcomes of PA in pregnancy to both high and low-risk matched controls.
Ophthalmic Plast Reconstr Surg
September 2022
Desmoid-type fibromatosis is a rare tumor, particularly in the orbit, with fewer than 10 cases of primary orbital desmoid-type fibromatosis reported in the literature. The authors present a case of an infant who presented with rapid onset of OD proptosis, disc edema, and hyperopic shift who was found to have a retrobulbar desmoid-type fibromatosis. After initial biopsy, due to risk of vision loss with complete excision, the tumor was treated with sorafenib, a tyrosine kinase inhibitor.
View Article and Find Full Text PDFDifferential cross sections for Compton scattering from the proton have been measured at scattering angles of 55°, 90°, and 125° in the laboratory frame using quasimonoenergetic linearly (circularly) polarized photon beams with a weighted mean energy value of 83.4 MeV (81.3 MeV).
View Article and Find Full Text PDFA precise measurement of the differential cross sections dσ/dΩ and the linearly polarized photon beam asymmetry Σ_{3} for Compton scattering on the proton below pion threshold has been performed with a tagged photon beam and almost 4π detector at the Mainz Microtron. The incident photons were produced by the recently upgraded Glasgow-Mainz photon tagging facility and impinged on a cryogenic liquid hydrogen target, with the scattered photons detected in the Crystal Ball/TAPS setup. Using the highest statistics Compton scattering data ever measured on the proton along with two effective field theories (both covariant baryon and heavy-baryon) and one fixed-t dispersion relation model, constraining the fits with the Baldin sum rule, we have obtained the proton electric and magnetic polarizabilities with unprecedented precision: α_{E1}=10.
View Article and Find Full Text PDFEur Phys J A Hadron Nucl
June 2021
The quasifree photon beam asymmetry, , has been measured at photon energies, , from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time.
View Article and Find Full Text PDFOphthalmic Surg Lasers Imaging Retina
October 2021
Background And Objective: To facilitate timely surgery and efficient use of operating room time, our practice uses a team-based approach so patients may undergo primary rhegmatogenous retinal detachment (RRD) surgery with a different surgeon instead of the diagnosing surgeon.
Patients And Methods: This was a retrospective cohort study of 331 eyes that underwent RRD surgery. Patients were divided into two groups: RRD surgery performed by the diagnosing surgon, and RRD surgery performed by a different surgeon.
Background: IgM nephropathy is a rare disease with variable clinical presentations and is an unusual cause of nephrotic syndrome. Histopathological findings typically include mesangial hypercellularity with IgM and complement deposition, though the spectrum may range from normal glomeruli through to focal and segmental glomerulosclerosis. Thromboembolism is a well recognised complication of nephrotic syndrome, but cerebral venous sinus thrombosis is rarely described.
View Article and Find Full Text PDFThe double-polarization observable E and helicity-dependent cross sections σ_{1/2}, σ_{3/2} have been measured for the photoproduction of π^{0} pairs off quasifree protons and neutrons at the Mainz MAMI accelerator with the Crystal Ball/TAPS setup. A circularly polarized photon beam was produced by bremsstrahlung from longitudinally polarized electrons and impinged on a longitudinally polarized deuterated butanol target. The reaction products were detected with an almost 4π covering calorimeter.
View Article and Find Full Text PDFPurpose: To evaluate the efficacy and safety of a bilayer dermal regenerative matrix for primary or complex/recurrent eyelid retraction.
Methods: Retrospective review of patients undergoing eyelid retraction repair using the bilayer dermal regenerative matrix from 2005 to 2019. Nineteen eyelid surgeries from 15 patients were identified.
We report a measurement of the spin polarization of the recoiling neutron in deuterium photodisintegration, utilizing a new large acceptance polarimeter within the Crystal Ball at MAMI. The measured photon energy range of 300-700 MeV provides the first measurement of recoil neutron polarization at photon energies where the quark substructure of the deuteron plays a role, thereby providing important new constraints on photodisintegration mechanisms. A very high neutron polarization in a narrow structure centered around E_{γ}∼570 MeV is observed, which is inconsistent with current theoretical predictions employing nucleon resonance degrees of freedom.
View Article and Find Full Text PDFOphthalmic Plast Reconstr Surg
March 2021
Ophthalmoplegia following cosmetic facial filler injections is a rare but serious complication. The authors report 2 cases of ophthalmoplegia following filler injection. In the first case, a 54-year-old female presented with acute onset headache, vomiting, and diplopia during malar and temporal injection of hyaluronic acid.
View Article and Find Full Text PDFPhys Rev Lett
November 2019
Virtual Compton scattering on the proton has been investigated at three yet unexplored values of the four-momentum transfer Q^{2}: 0.10, 0.20, and 0.
View Article and Find Full Text PDFIntroduction: The trauma population is aging and better prognostic measures for geriatric trauma patients are required. Frailty rather than age appears to be associated with poor outcomes. This systematic review aimed to identify the optimum frailty assessment instrument and timing of assessment in patients aged over 65 years admitted to hospital after traumatic injury.
View Article and Find Full Text PDFThe reactions γp→ηp and γp→η^{'}p are measured from their thresholds up to the center-of-mass energy W=1.96 GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections are obtained with unprecedented statistical accuracy, providing fine energy binning and full production-angle coverage.
View Article and Find Full Text PDFThe spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to extract the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the Δ(1232) region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron.
View Article and Find Full Text PDFWe present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the γ[over →]p[over →]→ηp reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI.
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