148 research outputs found
Locally Destructive Skull Base Lesion: IgG4-related Sclerosing Disease
A unique case of IgG4 + sclerosing disease was diagnosed in the sphenoid sinus, a previously unreported location, and was treated in a novel manner. This study describes the clinical presentation and management of IgG4 sclerosing disease in the paranasal sinuses. A retrospective case review and review of the medical literature were performed. A 38-year-old woman with a 2-year history of constant frontal headaches presented to our clinic. Imaging showed bony destruction of the sphenoid sinus and sellar floor. The patient underwent a right-sided sphenoidotomy with debridement and biopsy. Pathological evaluation showed a dense plasmacytic infiltrate with >150 IgG4 + cells/high-power field. She was subsequently started on a nasal corticosteroid with improved patency of the sphenoid antrostomy. We report an unusual case of a middle-aged woman who presented with IgG4-sclerosing disease (IGSD) isolated to the sphenoid sinus. Although our knowledge concerning treatment in extrapancreatic organs is lacking, there is evidence that glucocorticoid treatment improves nasal sinus opacification on CT findings (Sato Y, Ohshima K, Ichimura K, et al., Ocular adnexal IgG4-related disease has uniform clinicopathology, Pathol Int 58:465–470, 2008). This case study and literature review adds to the growing literature describing IGSD in the head and neck and more specifically isolated to the sphenoid sinus with preliminary data concerning local control with topical steroids
Ticagrelor versus Clopidogrel in Patients with Acute Coronary Syndromes
Background
Ticagrelor is an oral, reversible, direct-acting inhibitor of the adenosine diphosphate
receptor P2Y12 that has a more rapid onset and more pronounced platelet
inhibition than clopidogrel.
Methods
In this multicenter, double-blind, randomized trial, we compared ticagrelor (180-mg
loading dose, 90 mg twice daily thereafter) and clopidogrel (300-to-600-mg loading
dose, 75 mg daily thereafter) for the prevention of cardiovascular events in 18,624
patients admitted to the hospital with an acute coronary syndrome, with or without
ST-segment elevation.
Results
At 12 months, the primary end point — a composite of death from vascular causes,
myocardial infarction, or stroke — had occurred in 9.8% of patients receiving ticagrelor
as compared with 11.7% of those receiving clopidogrel (hazard ratio, 0.84;
95% confidence interval [CI], 0.77 to 0.92; P<0.001). Predefined hierarchical testing
of secondary end points showed significant differences in the rates of other composite
end points, as well as myocardial infarction alone (5.8% in the ticagrelor
group vs. 6.9% in the clopidogrel group, P = 0.005) and death from vascular causes
(4.0% vs. 5.1%, P = 0.001) but not stroke alone (1.5% vs. 1.3%, P = 0.22). The rate of
death from any cause was also reduced with ticagrelor (4.5%, vs. 5.9% with clopidogrel;
P<0.001). No significant difference in the rates of major bleeding was found
between the ticagrelor and clopidogrel groups (11.6% and 11.2%, respectively;
P = 0.43), but ticagrelor was associated with a higher rate of major bleeding not related
to coronary-artery bypass grafting (4.5% vs. 3.8%, P = 0.03), including more
instances of fatal intracranial bleeding and fewer of fatal bleeding of other types.
Conclusions
In patients who have an acute coronary syndrome with or without ST-segment elevation,
treatment with ticagrelor as compared with clopidogrel significantly reduced
the rate of death from vascular causes, myocardial infarction, or stroke without an
increase in the rate of overall major bleeding but with an increase in the rate of non–
procedure-related bleeding. (ClinicalTrials.gov number, NCT00391872.
The T2K experiment
The T2K experiment is a long baseline neutrino oscillation experiment. Its main goal is to measure the last unknown lepton sector mixing angle θ13 by observing νe appearance in a νμ beam. It also aims to make a precision measurement of the known oscillation parameters, and sin22θ23, via νμ disappearance studies. Other goals of the experiment include various neutrino cross-section measurements and sterile neutrino searches. The experiment uses an intense proton beam generated by the J-PARC accelerator in Tokai, Japan, and is composed of a neutrino beamline, a near detector complex (ND280), and a far detector (Super-Kamiokande) located 295 km away from J-PARC. This paper provides a comprehensive review of the instrumentation aspect of the T2K experiment and a summary of the vital information for each subsystem
Measurement of charged-particle multiplicities in gluon and quark jets in p(p)over-bar collisions at root s=1.8 TeV
We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, N-q and N-g, produced at the Fermilab Tevatron in p (p) over bar collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of θ(c)=0.28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q=E-jetθ(c) varies in the range from 12 to 25 GeV. At Q=19.2 GeV, the ratio of multiplicities r=N-g/N-q is found to be 1.64&PLUSMN; 0.17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations
Spectral line-shapes investigation with Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectroscopy
A review of recent experiments involving a newly developed Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectroscopy (PDH-locked FS-CRDS) system is presented. By comparison to standard FS-CRDS, the PDH lock of the probe laser to the ring-down cavity optimized coupling into the cavity, thus increasing the ring-down signal acquisition rate nearly 300-fold to 14 kHz and reducing the noise-equivalent absorption coefficient by more than an order of magnitude to 7 × 10−11 cm−1. We discuss how averaging approximately 1000 spectra yielded a signal-to-noise ratio of 220000. We also discuss how the spectrum frequency axis was linked to an optical frequency comb, thus enabling absolute frequency measurements of molecular optical transitions at sub-MHz levels. Applications of the spectrometer to molecular line-shape studies are also presented. For these investigations, we use semi-classical line-shape models that consider the influence of Dicke narrowing as well as the speed dependence of the pressure broadening and shifting to fit spectra. We show that the improved precision and spectrum fidelity of the spectrometer enable precise determinations of line-shape parameters. We also discuss the importance of line-shape analysis with regard to the development of new spectroscopic databases as well as in the optical determination of the Boltzmann constant
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