6,322 research outputs found
Variations in Cost for Magnetic Resonance Imaging Scans Based on Certificate of Need Regulations
To help control rising healthcare costs, states implemented certificate of need (CON) programs to prevent unnecessary duplication of healthcare resources. Today, 37 states and the District of Colombia have some form of CON. The scope of CON oversight varies between states, but most states have some type of regulation for MRI scanners, whether it be a direct requirement applicable to all MRI scanner projects or an indirect requirement that may only impact some MRI scanner projects. The study analyzed retrospective commercial billing data for over 275,000 encounters to quantify differences in costs for MRI scans in each state according to the type of CON requirements for MRI scanners. When the data were aggregated only by type of CON requirement, directly regulated states had the lowest mean payment amounts (p-value \u3c0.0001) followed by indirectly regulated states (p-value \u3c 0.0001) with unregulated states having the highest mean payment amounts. When only state mean payment amounts were considered, the variance was not significant. Based on these results, CON programs may result in lower costs on a per-unit basis
Electronic Properties of Small Neutral and Charged Beryllium Clusters
We determine the atomic and electronic structures for neutral and singly positively chargedberyllium clusters containing from two to six atoms using density functional theory in the local spin density approximation. Ions are moved with a steepest descent method and the electronic wave functions optimized using a fictitious dynamics with simulated annealing, as conceived by Car and Parrinello [Phys. Rev. Lett. 55, 2471 (1985)]. Shell-like orbitals, filling angular momentum states in the order: 1s 1p 2s 1d are obtained. We employ a Mulliken population analysis using an atomic basis to examine how the shell orbitals arise from atomic orbitals. This analysis also allows us to associate the electron density distribution and, in the case of a charged cluster, the distribution of the hole with atomic sites and with regions of overlap between atom pairs. We show quantitatively that the contribution to the bonding density from delocalization of the 1s state is hampered by the appearance of the antibonding 2s state. In the case of charged clusters we observe the tendency of the hole to distribute itself near the most exterior atomic sites in geometries of high symmetry. Keyword
Targeting glycolysis in proliferative kidney diseases
Glycolytic activity is increased in proliferating cells, leading to the concept that glycolysis could be a therapeutic target in cystic diseases and kidney cancer. Preclinical studies using the glucose analog 2-deoxy-d-glucose have shown promise; however, inhibiting glycolysis in humans is unlikely to be without risks. While proximal tubules are predominantly aerobic, later segments are more glycolytic. Understanding exactly where and why glycolysis is important in the physiology of the distal nephron is thus crucial in predicting potential adverse effects of glycolysis inhibitors. Live imaging techniques could play an important role in the process of characterizing cellular metabolism in the functioning kidney. The goal of this review is to briefly summarize recent findings on targeting glycolysis in proliferative kidney diseases and to highlight the necessity for future research focusing on glycolysis in the healthy kidney
Hippocampal and amygdala volumes in borderline personality disorder: A meta-analysis of magnetic resonance imaging studies
Gemini-South + FLAMINGOS Demonstration Science: Near-Infrared Spectroscopy of the z=5.77 Quasar SDSS J083643.85+005453.3
We report an infrared 1-1.8 micron (J+H-bands), low-resolution (R=450)
spectrogram of the highest-redshift radio-loud quasar currently known, SDSS
J083643.85+005453.3, obtained during the spectroscopic commissioning run of the
FLAMINGOS multi-object, near-infrared spectrograph at the 8m Gemini-South
Observatory. These data show broad emission from both CIV 1549 and CIII] 1909,
with strengths comparable to lower-redshift quasar composite spectra. The
implication is that there is substantial enrichment of the quasar environment,
even at times less than a billion years after the Big Bang. The redshift
derived from these features is z = 5.774 +/- 0.003, more accurate and slightly
lower than the z = 5.82 reported in the discovery paper based on the
partially-absorbed Lyman-alpha emission line. The infrared continuum is
significantly redder than lower-redshift quasar composites. Fitting the
spectrum from 1.0 to 1.7 microns with a power law f(nu) ~ nu^(-alpha), the
derived power law index is alpha = 1.55 compared to the average continuum
spectral index = 0.44 derived from the first SDSS composite quasar.
Assuming an SMC-like extinction curve, we infer a color excess of E(B-V) = 0.09
+/- 0.01 at the quasar redshift. Only approximately 6% of quasars in the
optically-selected Sloan Digital Sky Survey show comparable levels of dust
reddening.Comment: 10 pages, 1 figure; to appear in the Astrophysical Journal Letter
Control of polymorphism in coronene by the application of magnetic fields
Coronene, a polyaromatic hydrocarbon, has been crystallized for the first
time in a different polymorph using a crystal growth method that utilizes
magnetic fields to access a unit cell configuration that was hitherto unknown.
Crystals grown in magnetic field of 1 T are larger, have a different appearance
to those grown in zero field and retain their structure in ambient conditions.
We identify the new form, beta-coronene, as the most stable at low
temperatures. As a result of the new supramolecular configuration we report
significantly altered electronic, optical and mechanical properties.Comment: 32 pages, 17 figure
Expansion of Foxp3+ T-cell populations by Candida albicans enhances both Th17-cell responses and fungal dissemination after intravenous challenge
Research Funding Wellcome Trust, UK. Grant Numbers: 086827, 080088 NIH. Grant Number: DE022550Peer reviewedPublisher PD
MitoNeoD:a mitochondria-targeted superoxide probe
Mitochondrial superoxide (O2⋅−) underlies much oxidative damage and redox signaling. Fluorescent probes can detect O2⋅−, but are of limited applicability in vivo, while in cells their usefulness is constrained by side reactions and DNA intercalation. To overcome these limitations, we developed a dual-purpose mitochondrial O2⋅− probe, MitoNeoD, which can assess O2⋅− changes in vivo by mass spectrometry and in vitro by fluorescence. MitoNeoD comprises a O2⋅−-sensitive reduced phenanthridinium moiety modified to prevent DNA intercalation, as well as a carbon-deuterium bond to enhance its selectivity for O2⋅− over non-specific oxidation, and a triphenylphosphonium lipophilic cation moiety leading to the rapid accumulation within mitochondria. We demonstrated that MitoNeoD was a versatile and robust probe to assess changes in mitochondrial O2⋅− from isolated mitochondria to animal models, thus offering a way to examine the many roles of mitochondrial O2⋅−production in health and disease
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