High-energy photoemission final states beyond the free-electron approximation.

Three-dimensional (3D) electronic band structure is fundamental for understanding a vast diversity of physical phenomena in solid-state systems, including topological phases, interlayer interactions in van der Waals materials, dimensionality-driven phase transitions, etc. Interpretation of ARPES data in terms of 3D electron dispersions is commonly based on the free-electron approximation for the photoemission final states. Our soft-X-ray ARPES data on Ag metal reveals, however, that even at high excitation energies the final states can be a way more complex, incorporating several Bloch waves with different out-of-plane momenta. Such multiband final states manifest themselves as a complex structure and added broadening of the spectral peaks from 3D electron states. We analyse the origins of this phenomenon, and trace it to other materials such as Si and GaN. Our findings are essential for accurate determination of the 3D band structure over a wide range of materials and excitation energies in the ARPES experiment.

Investigation of Aggregation and Disaggregation of Self-Assembling Nano-Sized Clusters Consisting of Individual Iron Oxide Nanoparticles upon Interaction with HEWL Protein Molecules.

In this paper, iron oxide nanoparticles coated with trisodium citrate were obtained. Nanoparticles self-assembling stable clusters were ~10 and 50-80 nm in size, consisting of NPs 3 nm in size. The stability was controlled by using multi-angle dynamic light scattering and the zeta potential, which was -32 ± 2 mV. Clusters from TSC-IONPs can be destroyed when interacting with a hen egg-white lysozyme. After the destruction of the nanoparticles and proteins, aggregates are formed quickly, within 5-10 min. Their sizes depend on the concentration of the lysozyme and nanoparticles and can reach micron sizes. It is shown that individual protein molecules can be isolated from the formed aggregates under shaking. Such aggregation was observed by several methods: multi-angle dynamic light scattering, optical absorption, fluorescence spectroscopy, TEM, and optical microscopy. It is important to note that the concentrations of NPs at which the protein aggregation took place were also toxic to cells. There was a sharp decrease in the survival of mouse fibroblasts (Fe concentration ~75-100 µM), while the ratio of apoptotic to all dead cells increased. Additionally, at low concentrations of NPs, an increase in cell size was observed.

Fraction of Exhaled Nitric Oxide Levels Are Elevated in People Living With Human Immunodeficiency Virus Compared to Uninfected Controls, Suggesting Increased Eosinophilic Airway Inflammation.

BACKGROUND: Increased risk of asthma and chronic obstructive pulmonary disease has been reported in people living with human immunodeficiency virus (PLWH). Fraction of exhaled nitric oxide (FeNO) is a marker of eosinophilic airway inflammation. We assessed FeNO levels in PLWH and matched uninfected controls and investigated whether human immunodeficiency virus (HIV) status is independently associated with elevated FeNO. METHODS: FeNO was quantified by NIOX Vero and pulmonary function was assessed by spirometry in 432 PLWH from the Copenhagen Comorbidity in HIV Infection Study and in 1618 age- and sex-matched uninfected controls from the Copenhagen General Population Study. Elevated FeNO was defined as ≥25 parts per billion. Associations between FeNO and HIV status were adjusted for known potential confounders. RESULTS: Mean age of PLWH was 50.7 (standard deviation [SD], 11.1) years and 97.4% received combination antiretroviral therapy. PLWH had higher FeNO than uninfected controls (median, 17.0 [interquartile range {IQR}, 11.0-26.0] vs 13.0 [IQR, 9.0-19.0]; P < .001). Also, PLWH had a higher prevalence of elevated FeNO than uninfected controls (27.5% vs 12.3%; P < .001). This association remained after adjusting for age, sex, height, smoking status, use of airway medication, blood eosinophils, and immunoglobulin E (adjusted OR [aOR], 3.56 [95% CI, 2.51-5.04]; P < .001). Elevated FeNO was associated with self-reported asthma (aOR, 2.65 [95% CI, 1.66-4.24]; P < .001) but not with airflow limitation (aOR, 1.07 [95% CI, .71-1.62]; P = .745). CONCLUSIONS: HIV status was independently associated with elevated FeNO, suggesting increased eosinophilic airway inflammation. The potential impact on chronic lung disease pathogenesis needs further investigation.

Topological electronic structure and Rashba effect in Bi thin layers: theoretical predictions and experiments.

The goal of the present review is to cross-compare theoretical predictions with selected experimental results on bismuth thin films exhibiting topological properties and a strong Rashba effect. The theoretical prediction that a single free-standing Bi(1 1 1) bilayer is a topological insulator has triggered a large series of studies of ultrathin Bi(1 1 1) films grown on various substrates. Using selected examples we review theoretical predictions of atomic and electronic structure of Bi thin films exhibiting topological properties due to interaction with a substrate. We also survey experimental signatures of topological surface states and Rashba effect, as obtained mostly by angle- and spin-resolved photoelectron spectroscopy.

A model for quantitative correction of coronary calcium scores on multidetector, dual source, and electron beam computed tomography for influences of linear motion, calcification density, and temporal resolution: a cardiac phantom study.

PURPOSE: The objective of this study is to quantify the influence of linear motion, calcification density, and temporal resolution on coronary calcium determination using multidetector computed tomography (MDCT), dual source CT (DSCT), and electron beam tomography (EBT) and to find a quantitative method which corrects for the influences of these parameters using a linear moving cardiac phantom. METHODS: On a robotic arm with artificial arteries with four calcifications of increasing density, a linear movement was applied between 0 and 120 mm/s (step of 10 mm/s). The phantom was scanned five times on 64-slice MDCT, DSCT, and EBT using a standard acquisition protocol. The average Agatston, volume, and mass scores were determined for each velocity, calcification, and scanner. Susceptibility to motion was quantified using a cardiac motion susceptibility (CMS) index. Resemblance to EBT and physical volume and mass was quantified using a Delta index. RESULTS: Increasing motion artifacts were observed at increasing velocities on all scanners, with increasing severity from EBT to DSCT to 64-slice MDCT. The calcium score showed a linear dependency on motion from which a correction factor could be derived. This correction factor showed a linear dependency on the mean calcification density with a good fit for all three scoring methods and all three scanners (0.73 < or = R2 < or = 0.95). The slope and offset of this correction factor showed a linear dependency on temporal resolution with a good fit for all three scoring methods and all three scanners (0.83 < or = R2 < or = 0.98). CMS was minimal for EBT and increasing values were observed for DSCT and highest values for 64-slice MDCT. CMS was minimal for mass score and increasing values were observed for volume score and highest values for Agatston score. For all densities and scoring methods DSCT showed on average the closest resemblance to EBT calcium scores. When using the correction factor, CMS index decreased on average by 15% and Delta index decreased by 35%. CONCLUSIONS: Calcium scores determined on DSCT and 64-slice MDCT are highly susceptible to motion as compared to EBT. The mass score is less susceptible to motion compared to volume and Agatston score. Calcium scores determined on DSCT bear a closer resemblance to EBT obtained calcium scores than 64-slice MDCT. In addition, the calcium score is highly dependent on the average density of individual calcifications and the dependency of the calcium score on motion showed a linear behavior on calcification density. From these relations, a quantitative method could be derived which corrects the measured calcium score for the influence of linear motion, mean calcification density, and temporal resolution.

Investigation of a mumps outbreak among university students with two measles-mumps-rubella (MMR) vaccinations, Virginia, September-December 2006.

Following the clinical diagnosis of the first case of mumps on September 22, 2006 at the University of Virginia (UVA), 52 suspected cases were identified through active surveillance for mumps by the end of December 2006. Samples were collected from 47 students who presented with parotitis despite a documented history of two doses of measles, mumps, and rubella (MMR) vaccine. Six of 47 serum samples (13%) were positive for mumps IgM, and 46/47 specimens were positive for mumps IgG. Endpoint titration of acute phase serum samples from laboratory-confirmed cases did not provide evidence that elevated serum IgG is a consistent marker for infection among cases due to secondary vaccine failure. Buccal swab samples from 39 of the 47 students were tested by real-time reverse transcription-polymerase chain reaction (RT-PCR) and/or viral culture. Mumps virus or mumps RNA was detected in 12 of 39 buccal samples (31%). Genetic analysis of the virus from the outbreak at UVA indicated that the outbreak was not linked to the large mumps outbreak in the Midwestern US that occurred earlier in 2006. Our findings support the use of viral detection to improve laboratory diagnosis of mumps among persons who have received two doses of MMR.