Search results for "tracer"

Bimodal tracers synthesis for medical imaging PET/MRI

2015

Today physicians can use a wide variety of medical imaging techniques to establish early and accurate diagnosis. Nevertheless, each modality has its own advantages and drawbacks. This is why bi- or multimodality approach seems interesting. Among them, PET/MRI combination seems very promising because it can bring complementary informations. It is therefore necessary to inject to patients tracers specific to each imaging modality. This work described the synthesis of molecular platforms for MRI and PET imaging, according to 2 different strategies. The first one consisted in the synthesis of a DO3A macrocycle allowing the chelation of both gadolinium for MRI and gallium 68 for PET. The aim her…

1987

[68Ga]Ga-DATA5m.SA.FAPi PET/CT: Specific Tracer-uptake in Focal Nodular Hyperplasia and potential Role in Liver Tumor Imaging.

2020

Mobility, interdiffusion, and tracer diffusion in lattice-gas models of two-component alloys

1989

The transport properties of lattice-gas models of alloys with two particle species are studied. The numbers of the particles and vacancies are conserved, and the two particle species have different exchange rates with the vacancies. The mobility and interdiffusion is described by the linear Onsager theory of transport. The Onsager coefficients are estimated from numerical simulations of the mobilities. A recently proposed relation between the Onsager coefficients of the random-alloy model is verified. The interdiffusion of the two species is directly monitored in the simulations; it is well described by the estimated Onsager coefficients. The results on interdiffusion are compared with simu…

Immunohistochemical Investigation in Experimental Intracerebral Hemorrhage (ICH) and Its Correlation with Findings in Clinical Studies

1986

Since McKissock et al. 1961 investigated the effects of surgical and conservative treatment of ICH on final outcome it is well known that systemic hypertension worsens the prognosis of this serious cerebrovascular disease. Our own studies on this problem have revealed differences in final outcome, as well as in level of consciousness after ICH, between normotensive and hypertensive patients. Whilst 30.6% of the normotensive patients died, 48.1% of the hypertensive patients had a lethal outcome.

Tropical troposphere to stratosphere transport of carbon monoxide and long-lived trace species in the Chemical Lagrangian Model of the Stratosphere (…

2014

Variations in the mixing ratio of trace gases of tropospheric origin entering the stratosphere in the tropics are of interest for assessing both troposphere to stratosphere transport fluxes in the tropics and the impact of these transport fluxes on the composition of the tropical lower stratosphere. Anomaly patterns of carbon monoxide (CO) and long-lived tracers in the lower tropical stratosphere allow conclusions about the rate and the variability of tropical upwelling to be drawn. Here, we present a simplified chemistry scheme for the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the simulation, at comparatively low numerical cost, of CO, ozone, and long-lived trace substances…

The impact of overshooting deep convection on local transport and mixing in the tropical upper troposphere/lower stratosphere (UTLS)

2015

Abstract. In this study we examine the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection to a deep convective system. We use the Advanced Research Weather and Research Forecasting (WRF-ARW) model with a horizontal resolution of 333 m to examine this downward transport. The simulation reproduces the deep convective system, its timing and overshooting altitudes reasonably well compared to radar and aircraft observations. Passive tracers initialised at pre-storm times indicate the downward transport of air from the stratosphere to the upper troposphere as well as upward tr…

2015

Abstract. A recent parcel model study (Reutter et al., 2009) showed three deterministic regimes of initial cloud droplet formation, characterized by different ratios of aerosol concentrations (NCN) to updraft velocities. This analysis, however, did not reveal how these regimes evolve during the subsequent cloud development. To address this issue, we employed the Active Tracer High Resolution Atmospheric Model (ATHAM) with full microphysics and extended the model simulation from the cloud base to the entire column of a single pyro-convective mixed-phase cloud. A series of 2-D simulations (over 1000) were performed over a wide range of NCN and dynamic conditions. The integrated concentration …

Frequency-dependent response and dynamic disorder

1991

Abstract This paper discusses selected aspects of the application of dynamic percolation models to ionic transport in mixed-ion superionic conductors. The discussion is based on an AB lattice gas model with hard-core repulsions and a ratio of τ, 0 ⩽ τ ⩽ ∞, between the transition rates of particles A and B. The frequency-dependent conductivity for a tracer particle is calculated within an effective-medium theory. The motion of the background B-particles is regarded as providing a fluctuating disordered environment for the tracer particles A. A crossover frequency separating high-frequency and low-frequency response is found which scales with τ as ω c ∼ τ 1 2 . The results for the dc limit ar…

Gallium-68 and scandium-44 labelled radiotracers based on curcumin structure linked to bifunctional chelators: Synthesis and characterization of pote…

2019

Abstract Curcumin metal complexes showed widespread applications in medicine and can be exploited as a lead structure for developing new tracers for nuclear medicine application. Herein, the synthesis, chemical characterization and radiolabelling with gallium-68 and scandium-44 of two new targeting vectors based on curcumin scaffolds and linked to the chelators 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid (NODAGA) and 1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)]amino-6-methylperhydro-1,4-diazepine (AAZTA) are reported. Synthesis of the precursors could be achieved with a 13% and 11% yield and radiolabelling generally afforded rapid incorporation under mild conditions (>95%). Sta…