Optical Magnetometer Array for Fetal Magnetocardiography

We describe an array of spin-exchange relaxation free optical magnetometers designed for detection of fetal magnetocardiography (fMCG) signals. The individual magnetometers are configured with a small volume with intense optical pumping, surrounded by a large pump-free region. Spin-polarized atoms that diffuse out of the optical pumping region precess in the ambient magnetic field and are detected by a probe laser. Four such magnetometers, at the corners of a 7 cm square, are configured for gradiometry by feeding back the output of one magnetometer to a field coil to null uniform magnetic field noise at frequencies up to 200 Hz. Using this array, we present the first measurements of fMCG signals using an atomic magnetometer

Dijet Cross Section and Longitudinal Double Spin Asymmetry Measurements in Polarized Proton-proton Collisions at \sqrt{s}=200 GeV at STAR

These proceedings show the preliminary results of the dijet cross sections and the dijet longitudinal double spin asymmetries A_LL in polarized proton-proton collisions at \sqrt{s} = 200 GeV at the mid-rapidity |eta| < 0.8. The integrated luminosity of 5.39 pb^{-1} collected during RHIC Run-6 was used in the measurements. The preliminary results are presented as functions of the dijet invariant mass M_jj. The dijet cross sections are in agreement with next-to-leading-order pQCD predictions. The A_LL is compared with theoretical predictions based on various parameterizations of polarized parton distributions of the proton. Projected precision of data analyzed to date from Run-9 are shown.Comment: 8 pages, 5 figures, Proceedings of the SPIN2010 conference (Juelich, Germany, 2010

Phantom and clinical evaluation of the effect of full Monte Carlo collimator modelling in post-SIRT yttrium-90 Bremsstrahlung SPECT imaging

Background: Post-therapy SPECT/CT imaging of Y-90 microspheres delivered to hepatic malignancies is difficult, owing to the continuous, high-energy Bremsstrahlung spectrum emitted by Y-90. This study aimed to evaluate the utility of a commercially available software package (HybridRecon, Hermes Medical Solutions AB) which incorporates full Monte Carlo collimator modelling. Analysis of image quality was performed on both phantom and clinical images in order to ultimately provide a recommendation of an optimum reconstruction for post-therapy Y-90 microsphere SPECT/CT imaging. A 3D-printed anthropomorphic liver phantom was filled with Y-90 with a sphere-to-background ratio of 4:1 and imaged on a GE Discovery 670 SPECT/CT camera. Datasets were reconstructed using ordered-subsets expectation maximization (OSEM) 1-7 iterations in order to identify the optimal OSEM reconstruction (5 iterations, 15 subsets). Quantitative analysis was subsequently carried out on phantom datasets obtained using four reconstruction algorithms: the default OSEM protocol (2 iterations, 10 subsets) and the optimised OSEM protocol, both with and without full Monte Carlo collimator modelling. The quantitative metrics contrast recovery (CR) and background variability (BV) were calculated. The four algorithms were then used to retrospectively reconstruct 10 selective internal radiation therapy (SIRT) patient datasets which were subsequently blind scored for image quality by a consultant radiologist. Results: The optimised OSEM reconstruction (5 iterations, 15 subsets with full MC collimator modelling) increased the CR by 42% (p <0.001) compared to the default OSEM protocol (2 iterations, 10 subsets). The use of full Monte Carlo collimator modelling was shown to further improve CR by 14% (30 mm sphere, CR = 90%, p <0.05). The consultant radiologist had a significant preference for the optimised OSEM over the default OSEM protocol (p <0. 001), with the optimised OSEM being the favoured reconstruction in every one of the 10 clinical cases presented. Conclusions: OSEM (5 iterations, 15 subsets) with full Monte Carlo collimator modelling is quantitatively the optimal image reconstruction for post-SIRT 90Y Bremsstrahlung SPECT/CT imaging. The use of full Monte Carlo collimator modelling for correction of image-degrading effects significantly increases contrast recovery without degrading clinical image quality.Peer reviewe

Modern approaches to pediatric brain injury therapy.

Each year, pediatric traumatic brain injury (TBI) accounts for 435,000 emergency department visits, 37,000 hospital admissions, and approximately 2,500 deaths in the United States. TBI results in immediate injury from direct mechanical force and shear. Secondary injury results from the release of biochemical or inflammatory factors that alter the loco-regional milieu in the acute, subacute, and delayed intervals after a mechanical insult. Preliminary preclinical and clinical research is underway to evaluate the benefit from progenitor cell therapeutics, hypertonic saline infusion, and controlled hypothermia. However, all phase III clinical trials investigating pharmacologic monotherapy for TBI have shown no benefit. A recent National Institutes of Health consensus statement recommends research into multimodality treatments for TBI. This article will review the complex pathophysiology of TBI as well as the possible therapeutic mechanisms of progenitor cell transplantation, hypertonic saline infusion, and controlled hypothermia for possible utilization in multimodality clinical trials

Assessing the Relationship between Sources of Stress and Symptom Changes among Persons with IBD over Time: A Prospective Study

Objective. To describe the sources of stress for persons with IBD and changes with changes in symptoms. Methods. 487 participants were recruited from a population-based IBD registry. Stress was measured at study entry and three months later, using a general stress measure and the Sources of Stress Scale. Four symptom pattern groups were identified: persistently inactive, persistently active, inactive to active, and active to inactive. Results. General stress levels were stable within each symptom pattern group over the three-month period, even for those with changing symptom activity. The persistently active group had higher general stress at month 0 and month 3 than the persistently inactive group and higher mean ratings of most sources of stress. IBD was rated as a highly frequent source of stress by 20–30% of the persistently active group compared to 1-2% of the inactive group. Finances, work, and family were rated as high frequency stresses in the persistently active group at a similar level to IBD stress. In the groups with fluctuating symptoms, there was little change in stress ratings with changes in symptom activity. Conclusion. Stress was experienced across several domains in addition to stress related to IBD. Persons with active symptoms may benefit from targeted stress interventions

Structural development, thermal evolution, and tectonic significance of a Cordilleran basement thrust terrane, Maria fold and thrust belt, west-central Arizona

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1989.Lindgren second copy is bound in one vol.Chapter 3 co-authored by Matthew T. Heizler; chapter 4 co-authored by J. Douglas Walker. 4 folded leaves inserted in pocket of v. 1.Includes bibliographical references.by James Howard Knapp.Ph.D

Late night salivary cortisol and cortisone should be the initial screening test for Cushing’s syndrome

Endogenous Cushing’s syndrome (CS) poses considerable diagnostic challenges. Although late night salivary cortisol (LNSC) is recommended as a first line screening investigation, it remains the least widely used test in many countries. The combined measurement of LNSC and late-night salivary cortisone (LNS cortisone) has shown to further improve diagnostic accuracy1. We present a retrospective study in a tertiary referral centre comparing LNSC, LNS cortisone, overnight dexamethasone suppression test, low dose dexamethasone suppression test and 24-hour urinary free cortisol results of patients investigated for CS. Patients were categorised into those who had CS (21 patients) and those who did not (33 patients).LNSC had a sensitivity of 95% and a specificity of 91%. LNS cortisone had a specificity of 100% and a sensitivity of 86%. With an optimal cut-off for LNS cortisone of >14.5 nmol/l the sensitivity was 95.2%, and the specificity was 100% with an area under the curve of 0.997, for diagnosing CS. Saliva collection is non-invasive and can be carried out at home.We therefore advocate simultaneous measurement of LNSC and LNS cortisone as the first-line screening test to evaluate patients with suspected CS