Search results for " Emission"
showing 10 items of 1496 documents
Whole-body MRI radiomics model to predict relapsed/refractory Hodgkin Lymphoma: A preliminary study.
2022
Purpose A strong prognostic score that enables a stratification of newly diagnosed Hodgkin Lymphoma (HL) to identify patients at high risk of refractory/relapsed disease is still needed. Our aim was to investigate the potential value of a radiomics analysis pipeline from whole-body MRI (WB-MRI) exams for clinical outcome prediction in patients with Hodgkin Lymphoma (HL). Materials and methods Index lesions from baseline WB-MRIs of 40 patients (22 females; mean age 31.7 ± 11.4 years) with newly diagnosed HL treated by ABVD chemotherapy regimen were manually segmented on T1-weighted, STIR, and DWI images for texture analysis feature extraction. A machine learning approach based on the Extra T…
SPECT Bone scintigraphy of benign and malignant lesions of the spine
1989
70 patients were examined with planar and SPECT bone scintigraphy. SPECT proved to be superior over planar bone scanning for imaging of traumatic, inflammatory, and malignant bone lesions. SPECT provides three-dimensional information and, therefore, delineates the exact location and extension of lesions. It also has a higher sensitivity than planar bone scintigraphy. The three-dimensional bone scan generates complementary diagnostic information which often facilitates an adequate therapy protocol.
Revealing deterministic structures in click-evoked otoacoustic emissions.
2000
Click-evoked otoacoustic emissions (CEOAEs) were studied by means of recurrence quantification analysis (RQA) and were found to be endowed with a relevant amount of deterministic structuring. Such a structure showed highly significant correlation with the clinical evaluation of the signal over a data set including 56 signals. Moreover, 1) one of the RQA variables, Trend, was very sensitive to phase transitions in the dynamical regime of CEOAEs, and 2) appropriate use of principal component analysis proved able to isolate the individual character of the studied signals. These results are of general interest for the study of auditory signal transduction and generation mechanisms.
A Single-Channel Algorithm for Land-Surface Temperature Retrieval From ASTER Data
2010
This letter presents an adaptation to Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data of the generalized single-channel (SC) algorithm developed by JimE?nez-MuN?oz and Sobrino, also adapted to the Landsat thermal-infrared (TIR) channel (band 6) later by JimE?nez-MuN?oz The SC algorithm relies on the concept of atmospheric functions (AFs), which are dependent on atmospheric transmissivity, upwelling, and downwelling atmospheric radiances. These AFs are fitted versus the atmospheric water-vapor content for operational purposes, despite the fact that other computation options are also possible. The SC algorithm has been adapted to ASTER TIR bands 13 (10.659 ?m) and …
Multisensor comparison of NDVI for a semi‐arid environment in Spain
2009
The joint use of multiresolution sensors from different satellites offers many opportunities to describe vegetation and its dynamics. This paper introduces the concept of a virtual constellation (defined as an ensemble of all Earth Observation satellites in orbit that satisfy common requirements) for agricultural applications and contributes to providing the necessary inter-sensor calibration methodology for spectral reflectances and NDVI. For this purpose, we performed an observational study, comparing reflectances and the Normalized Difference Vegetation Index (NDVI), from near-synchronous image pairs of Landsat 7 Enhanced Thematic Mapper Plus (ETM+), as the reference sensor and Landsat 5…
Improved land surface emissivities over agricultural areas using ASTER NDVI
2006
Abstract Land surface emissivity retrieval over agricultural regions is important for energy balance estimations, land cover assessment and other related environmental studies. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) produces images of sufficient spatial resolution (from 15 m to 90 m) to be of use in agricultural studies, in which fields of crops are too small to be well-resolved by low resolution sensors. The ASTER project generates land surface emissivity images as a Standard Product (AST05) using the Temperature/Emissivity Separation (TES) algorithm. However, the TES algorithm is prone to scaling errors in estimating emissivities for surfaces with low s…
Accuracy of ASTER Level-2 thermal-infrared Standard Products of an agricultural area in Spain
2007
Abstract The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) collects five-channel thermal-infrared images that are calibrated, corrected for atmospheric effects, and then converted to land surface temperature and emissivity products by the ASTER Temperature/Emissivity Separation (TES) algorithm. TES scales low- and high-contrast surfaces differently, and has been validated over water (low contrast) and rock (high contrast). Performance of TES over agricultural areas, however, has not been evaluated specifically. To address this issue, field measurements of “ground truth” were made over bare soil in addition to green grass, alfalfa and corn, at an agricultural researc…
Die nächste Generation „atypischer” Antipsychotika: Der Beitrag der Positronenemissionstomographie
2003
Almost fifteen years of research with Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) have led to a profound understanding of the relationships between antipsychotic doses and plasma levels on the one hand and occupancy of (striatal) D 2 -like dopamine receptors on the other hand as well as with the associated clinical effects and side effects. Furthermore, with the development of clinically atypical" antipsychotics PET studies helped to generate hypotheses regarding the essential pharmacological properties of this heterogeneous class of drugs. Possible mechanisms of action include combined D 2 -/5-HT 2 antagonism, preferential mesolimbic binding, a…
Nucleation particles in diesel exhaust: composition inferred from in situ mass spectrometric analysis.
2005
Mass spectrometric measurements of size and composition of diesel exhaust particles have been performed under various conditions: chassis dynamometer tests, field measurements near a German motorway, and individual car chasing. Nucleation particles consisting of volatile sulfate and organic material could be detected both at the chassis dynamometer test facility and during individual car chasing. We found evidence that if nucleation occurs, sulfuric acid/water is the nucleating agent. Low-volatile organics species condense only on the preexisting sulfuric acid/water clusters. Nucleation was found to depend strongly on various parameters such as exhaust dilution conditions, fuel sulfur conte…
Possible markers of traffic-related emissions
2007
Looking for robust indicators of motor vehicle emissions it has been found that brake wear and linings are significant contributors of Cu, Mo and Sb to air particulate matter. These trace elements, whose mutual ratios in airborne particulate matter resulted quite different from those in crustal material, appear to be available fingerprinting tools to identify the contribution of on-road vehicles to traffic-derived particulate matter. In this study, the results of analytical determinations of Cu, Mo and Sb on PM(10), PM(2.5), vegetation and brake dust samples, together with gas (CO, NOx) concentrations, are discussed. Highly significant correlations among Cu, Sb and Mo were observed in parti…