Search results

Filter

Filetype

Your search for "*" yielded 528225 hits

Assessment of Free Gas in the Tibial Condyle Bone of the Human Knee by Diode Laser Spectroscopy with Possible Application to Arthrosis Diagnostics

The gas in scattering media absorption spectroscopy (GASMAS) technique was used to investigate the possible presence of free gas pores in human condyle bones, extracted from the tibia in knee revision surgical procedures in response to arthrosis development. Following earlier studies showing free gas presence in femoral head bones, decaying because of inadequate blood flow, we investigated condyle

Modeling the morphology of self-assisted GaP nanowires grown by molecular beam epitaxy

The morphologies of self-assisted GaP nanowires grown by gas source MBE in regular arrays on silicon substrates are modeled by a kinetic equation for the nanowire radius versus the position along the nanowire axis. The most important growth parameter that governs the nanowire morphology is the V/III flux ratio. Sharpened nanowires with a stable radius equal to only 12 nm at a V/III flux ratio of 6

Impact of DOI in a Clinical SPECT/MRI System : A Simulation Study

A novel SPECT/MRI scanner has been modelled and tested here using Monte Carlo simulation software, SIMIND. The INSERT SPECT/MRI system faces challenges with event reconstruction due to photon depth of interaction. The novel SPECT system is subject to parallax errors due to its crystal size and slit aperture collimator. We present a simple measure of the DOI errors through SIMIND experiments; by mo

Executive functions in birds

Executive functions comprise of top-down cognitive processes that exert control over information processing, from acquiring information to issuing a behavioral response. These cogni- tive processes of inhibition, working memory, and cognitive flexibility underpin complex cognitive skills, such as episodic memory and planning, which have been repeatedly investigated in several bird species in recen

Monte Carlo simulations of the GE discovery alcyone CZT SPECT system

Compact SPECT systems with cadmium zinc telluride (CZT) solid-state detectors with improved energy resolution and shorter acquisition times have recently been introduced. These systems have, however, different energy characteristics compared to NaI(Tl) crystal-based cameras. There is therefore a need to develop new simulation models for these cameras. We modeled the charge transport within the CZT

Hematological Toxicity in Mice after High Activity Injections of 177Lu-PSMA-617

Prostate cancer (PC) is one of the most common malignancies affecting men, with poor prognosis after progression to metastatic castration-resistant prostate cancer (mCRPC). Radioligand therapy (RLT) targeting the overexpressed PSMA on PC cells, with, e.g., 177Lu-PSMA-617, has been effective in reducing tumor burden and prolonging survival in mCRPC. However, it is not a curative method with kidney

Hormone-sensitive lipase is localized at synapses and is necessary for normal memory functioning in mice

Hormone-sensitive lipase (HSL) is mainly present in adipose tissue where it hydrolyses diacylglycerol. Although expression of HSL has also been reported in the brain, its presence in different cellular compartments is uncertain, and its role in regulating brain lipid metabolism remains hitherto unexplored. We hypothesized HSL might play a role in regulating the availability of bioactive lipids nec

Normal State of Nd1-xSrxNiO2 from Self-Consistent GW+EDMFT

Superconductivity with a remarkably high Tc has recently been observed in hole-doped NdNiO2, a material that shares similarities with the high-Tc cuprates. This discovery promises new insights into the mechanism of unconventional superconductivity, but at the modeling level, there are fundamental issues that need to be resolved. While it is generally agreed that the low-energy properties of cuprat

Evidence of half-integer Shapiro steps originated from nonsinusoidal current phase relation in a short ballistic InAs nanowire Josephson junction

We report on half-integer Shapiro steps observed in a gate-tunable short ballistic InAs nanowire Josephson junction. We observed the Shapiro steps of the short ballistic InAs nanowire Josephson junction and found the half-integer steps in addition to the conventional integer steps. In this Josephson junction device the junction transmission can be varied with gate voltage. From measurements of the

Orbital dynamics during an ultrafast insulator to metal transition

We present ultrafast resonant inelastic X-ray scattering (RIXS) experiments performed at the vanadium L edge to track changes in the electronic structure of V2O3, a classical Mott-Hubbard material. The probed orbital excitations within the d shell of the V ion show a sub-ps time response, which evolves at later times to a state that appears electronically indistinguishable from the high-temperatur

Screening from eg states and antiferromagnetic correlations in d(1,2,3) perovskites : A GW+EDMFT investigation

We perform a systematic ab initio study of the electronic structure of Sr(V,Mo,Mn)O3 perovskites, using the parameter-free GW+EDMFT method. This approach self-consistently calculates effective interaction parameters, taking into account screening effects due to nonlocal charge fluctuations. Comparing the results of a three-band (t2g) description to those of a five-band (t2g+eg) model, it is shown

Cardiovagal Function Measured by the Deep Breathing Test : Relationships With Coronary Atherosclerosis

Background The cardiovagal function can be assessed by quantification of respiratory sinus arrhythmia (RSA) during a deep breathing test. However, population studies of RSA and coronary atherosclerosis are lacking. This population-based study examined the relationship between RSA during deep breathing and coronary atherosclerosis, assessed by coronary artery calcium score (CACS). Methods and Resul

Geometrical Confinement Modulates the Thermoresponse of a Poly (N-isopropylacrylamide) Brush

The structure of grafted-from poly(N-isopropylacrylamide) (PNIPAM) brushes is investigated as a function of confining stress and system temperature using neutron reflectometry (NR), numerical self-consistent field theory, and the reanalysis of colloid probe atomic force microscopy (AFM) data from the literature. For NR experiments, confinement is achieved using a custom-made sample environment, an

Enrichment of charged monomers explains non-monotonic polymer volume fraction profiles of multi-stimulus responsive copolymer brushes

Multi-stimulus responsive poly(2-(2-methoxyethoxy)ethyl methacrylate-co-2-(diethylamino)ethyl methacrylate) [P(MEO2MA-co-DEA)] 80:20 mol % copolymer brushes were synthesized on planar silica substrates via surface-initiated activators continuously regenerated via electron transfer atom transfer radical polymerization. Brush thickness was sensitive to changes in pH and temperature as monitored with

Poly (N-isopropylacrylamide) response to salt concentration and anion identity: a brush-on-brush study

The stability of poly(N-isopropylacrylamide) (PNIPAM) brush-modified colloidal silica particles was compared to asymmetric and symmetric PNIPAM brush direct force measurements in the presence of 1, 10, and 500 mM aqueous salt solution of KCl, KNO3, and KSCN between 10 and 45 °C. Dynamic light scattering measurements highlighted subtle variations in the salt-mediated thermoresponse, while atomic fo

Temperature dependent specific ion effects in mixed salt environments on a thermoresponsive poly(oligoethylene glycol methacrylate) brush

The temperature induced swelling/collapse transition of poly(oligoethylene glycol methacrylate) (POEGMA) brushes has been investigated in electrolyte solutions comprised of multiple anions. The behaviour of a POEGMA brush in mixed salt environments of potassium acetate (KCH3COO, causes collapse) and thiocyanate (KSCN, causes swelling), two ions at opposite ends of the Hofmeister series, has been m

Combined experimental and theoretical study of weak polyelectrolyte brushes in salt mixtures

The swelling behavior of a hydrophobic poly(2diisopropylamino)ethyl methacrylate (PDPA) brush immersed in aqueous solutions of single and mixed salts has been investigated using ellipsometry and numerical self-consistent field (nSCF) theory. As a function of solution ionic strength, the osmotic and salted brush regimes of weak polyelectrolyte brushes as well as substantial specific anion effects i

Influence of molecular weight on PNIPAM brush modified colloidal silica particles

The effect of molecular weight and temperature on the phase transition and internal structure of poly(N-isopropylacrylamide) brush modified colloidal silica particles was investigated using dynamic light scattering (DLS) and small angle neutron scattering (SANS) between 15 and 45 °C. Dry particle analysis utilising transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT

Specific ion effects on thermoresponsive polymer brushes: Comparison to other architectures

Thermoresponsive polymers have received significant research attention as smart materials with particular interest in biomedical applications. The composition and architecture are known to strongly influence the thermoresponsive properties of the materials. For example, the strong overlap of end-grafted polymer chains in polymer brushes leads to a broader collapse transition relative to linear ung