Structural and electrical properties of Fe-doped TiO2 thin films

The present study discusses the effect of iron doping in TiO2 thin films deposited by rf sputtering. Iron doping induces a structural transformation from anatase to rutile and electrical measurements indicate that iron acts as an acceptor impurity. Thermoelectric power measurement shows a transition between n-type and p-type electrical conduction for an iron concentration around 0.13 at.%. The highest p-type conductivity at room temperature achieved by iron doping was 10(-6) S m(-1).

Audit report on the American Recovery and Reinvestment Act (ARRA) - Program of Competitive Grants for Worker Training and Placement in High Growth and Emerging Industry Sectors program for the Iowa Green Renewable Electrical Energy Network Inc. (IGREEN) for the year ended June 30, 2012

Audit report on the American Recovery and Reinvestment Act (ARRA) - Program of Competitive Grants for Worker Training and Placement in High Growth and Emerging Industry Sectors program for the Iowa Green Renewable Electrical Energy Network Inc. (IGREEN) for the year ended June 30, 2012

How single-trial electrical neuroimaging contributes to multisensory research.

This study details a method to statistically determine, on a millisecond scale and for individual subjects, those brain areas whose activity differs between experimental conditions, using single-trial scalp-recorded EEG data. To do this, we non-invasively estimated local field potentials (LFPs) using the ELECTRA distributed inverse solution and applied non-parametric statistical tests at each brain voxel and for each time point. This yields a spatio-temporal activation pattern of differential brain responses. The method is illustrated here in the analysis of auditory-somatosensory (AS) multisensory interactions in four subjects. Differential multisensory responses were temporally and spatially consistent across individuals, with onset at approximately 50 ms and superposition within areas of the posterior superior temporal cortex that have traditionally been considered auditory in their function. The close agreement of these results with previous investigations of AS multisensory interactions suggests that the present approach constitutes a reliable method for studying multisensory processing with the temporal and spatial resolution required to elucidate several existing questions in this field. In particular, the present analyses permit a more direct comparison between human and animal studies of multisensory interactions and can be extended to examine correlation between electrophysiological phenomena and behavior.

Atomic Force Microscopy Stiffness Tomography on Living Arabidopsis thaliana Cells Reveals the Mechanical Properties of Surface and Deep Cell-Wall Layers during Growth.

Cell-wall mechanical properties play a key role in the growth and the protection of plants. However, little is known about genuine wall mechanical properties and their growth-related dynamics at subcellular resolution and in living cells. Here, we used atomic force microscopy (AFM) stiffness tomography to explore stiffness distribution in the cell wall of suspension-cultured Arabidopsis thaliana as a model of primary, growing cell wall. For the first time that we know of, this new imaging technique was performed on living single cells of a higher plant, permitting monitoring of the stiffness distribution in cell-wall layers as a function of the depth and its evolution during the different growth phases. The mechanical measurements were correlated with changes in the composition of the cell wall, which were revealed by Fourier-transform infrared (FTIR) spectroscopy. In the beginning and end of cell growth, the average stiffness of the cell wall was low and the wall was mechanically homogenous, whereas in the exponential growth phase, the average wall stiffness increased, with increasing heterogeneity. In this phase, the difference between the superficial and deep wall stiffness was highest. FTIR spectra revealed a relative increase in the polysaccharide/lignin content.

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies

The aim of this study was to provide an insight into normative values of the ascending aorta in regards to novel endovascular procedures using ECG-gated multi-detector CT angiography. Seventy-seven adult patients without ascending aortic abnormalities were evaluated. Measurements at relevant levels of the aortic root and ascending aorta were obtained. Diameter variations of the ascending aorta during cardiac cycle were also considered. Mean diameters (mm) were as follows: LV outflow tract 20.3 +/- 3.4, coronary sinus 34.2 +/- 4.1, sino-tubular junction 29.7 +/- 3.4 and mid ascending aorta 32.7 +/- 3.8 with coefficients of variation (CV) ranging from 12 to 17%. Mean distances (mm) were: from the plane passing through the proximal insertions of the aortic valve cusps to the right brachio-cephalic artery (BCA) 92.6 +/- 11.8, from the plane passing through the proximal insertions of the aortic valve cusps to the proximal coronary ostium 12.1 +/- 3.7, and between both coronary ostia 7.2 +/- 3.1, minimal arc of the ascending aorta from left coronary ostium to right BCA 52.9 +/- 9.5, and the fibrous continuity between the aortic valve and the anterior leaflet of the mitral valve 14.6 +/- 3.3, CV 13-43%. Mean aortic valve area was 582.0 +/- 131.9 mm(2). The variation of the antero-posterior and transverse diameters of the ascending aorta during the cardiac cycle were 8.4% and 7.3%, respectively. Results showed large inter-individual variations in diameters and distances but with limited intra-individual variations during the cardiac cycle. A personalized approach for planning endovascular devices must be considered.

Distribution of artifactual gas on post-mortem multidetector computed tomography (MDCT)

L'imagerie est de plus en plus utilisée en médecine forensique. Actuellement, les connaissances nécessaires pour interpréter les images post mortem sont faibles et surtout celles concernant les artéfacts post mortem. Le moyen radiologique le plus utilisé en médecine légale est la tomodensitométrie multi-coupes (TDMC). Un de ses avantages est la détection de gaz dans le corps. Cette technique est utile au diagnostic d'embolie gazeuse mais sa très grande sensibilité rend visible du gaz présent même en petite quantité. Les premières expériences montrent que presque tous les corps scannés présentent du gaz surtout dans le système vasculaire. Pour cette raison, le médecin légiste est confronté à un nouveau problème : la distinction entre du gaz d'origine post-mortem et une embolie gazeuse vraie. Pour parvenir à cette distinction, il est essentiel d'étudier la distribution de ces gaz en post mortem. Aucune étude systématique n'a encore été réalisée à ce jour sur ce sujet.¦Nous avons étudié l'incidence et la distribution des gaz présents en post mortem dans les vaisseaux, dans les os, dans les tissus sous-cutanés, dans l'espace sous-dural ainsi que dans les cavités crânienne, thoracique et abdominale (82 sites au total) de manière à identifier les facteurs qui pourraient distinguer le gaz post-mortem artéfactuel d'une embolie gazeuse¦Les données TDMC de 119 cadavres ont été étudiées rétrospectivement. Les critères d'inclusion des sujets sont l'absence de lésion corporelle permettant la contamination avec l'air extérieur, et, la documentation du délai entre le moment du décès et celui du CT-scan (p.ex. rapport de police, protocole de réanimation ou témoin). La présence de gaz a été évaluée semi-quantitativement par deux radiologues et codifiée. La codification est la suivante : grade 0 = pas de gaz, grade 1 = une à quelques bulles d'air, grade 2 = structure partiellement remplie d'air, grade 3 = structure complètement remplie d'air.¦Soixante-quatre des 119 cadavres présentent du gaz (62,2%), et 56 (75,7%) ont montré du gaz dans le coeur. Du gaz a été détecté le plus fréquemment dans le parenchyme hépatique (40%); le coeur droit (ventricule 38%, atrium 35%), la veine cave inférieure (infra-rénale 30%, supra-rénale 26%), les veines sus-hépatiques (gauche 26%, moyenne 29%, droite 22 %), et les espaces du porte (29%). Nous avons constaté qu'une grande quantité de gaz liée à la putréfaction présente dans le coeur droit (grade 3) est associée à des collections de gaz dans le parenchyme hépatique (sensibilité = 100%, spécificité = 89,7%). Pour décrire nos résultats, nous avons construit une séquence d'animation qui illustre le processus de putréfaction et l'apparition des gaz à la TDMC post-mortem.¦Cette étude est la première à montrer que l'apparition post-mortem des gaz suit un modèle de distribution spécifique. L'association entre la présence de gaz intracardiaque et dans le parenchyme hépatique pourrait permettre de distinguer du gaz artéfactuel d'origine post-mortem d'une embolie gazeuse vraie. Cette étude fournit une clé pour le diagnostic de la mort due à une embolie gazeuse cardiaque sur la base d'une TDMC post-mortem.¦Abstract¦Purpose: We investigated the incidence and distribution of post-mortem gas detected with multidetector computed tomography (MDCT) to identify factors that could distinguish artifactual gas from cardiac air embolism.¦Material and Methods: MDCT data of 119 cadavers were retrospectively examined. Gas was semiquantitatively assessed in selected blood vessels, organs and body spaces (82 total sites).¦Results: Seventy-four of the 119 cadavers displayed gas (62.2%; CI 95% 52.8 to 70.9), and 56 (75.7%) displayed gas in the heart. Most gas was detected in the hepatic parenchyma (40%); right heart (38% ventricle, 35% atrium), inferior vena cava (30% infrarenally, 26% suprarenally), hepatic veins (26% left, 29% middle, 22% right), and portal spaces (29%). Male cadavers displayed gas more frequently than female cadavers. Gas was detected 5-84 h after death; therefore, the post-mortem interval could not reliably predict gas distribution (rho=0.719, p<0.0001). We found that a large amount of putrefaction-generated gas in the right heart was associated with aggregated gas bubbles in the hepatic parenchyma (sensitivity = 100%, specificity = 89.7%). In contrast, gas in the left heart (sensitivity = 41.7%, specificity = 100%) or in peri-umbilical subcutaneous tissues (sensitivity = 50%, specificity = 96.3%) could not predict gas due to putrefaction.¦Conclusion: This study is the first to show that the appearance of post-mortem gas follows a specific distribution pattern. An association between intracardiac gas and hepatic parenchymal gas could distinguish between post- mortem-generated gas and vital air embolism. We propose that this finding provides a key for diagnosing death due to cardiac air embolism.

Full-waveform inversion of cross-hole ground-penetrating radar data to characterize a gravel aquifer close to the Thur River, Switzerland

Cross-hole radar tomography is a useful tool for mapping shallow subsurface electrical properties viz. dielectric permittivity and electrical conductivity. Common practice is to invert cross-hole radar data with ray-based tomographic algorithms using first arrival traveltimes and first cycle amplitudes. However, the resolution of conventional standard ray-based inversion schemes for cross-hole ground-penetrating radar (GPR) is limited because only a fraction of the information contained in the radar data is used. The resolution can be improved significantly by using a full-waveform inversion that considers the entire waveform, or significant parts thereof. A recently developed 2D time-domain vectorial full-waveform crosshole radar inversion code has been modified in the present study by allowing optimized acquisition setups that reduce the acquisition time and computational costs significantly. This is achieved by minimizing the number of transmitter points and maximizing the number of receiver positions. The improved algorithm was employed to invert cross-hole GPR data acquired within a gravel aquifer (4-10 m depth) in the Thur valley, Switzerland. The simulated traces of the final model obtained by the full-waveform inversion fit the observed traces very well in the lower part of the section and reasonably well in the upper part of the section. Compared to the ray-based inversion, the results from the full-waveform inversion show significantly higher resolution images. At either side, 2.5 m distance away from the cross-hole plane, borehole logs were acquired. There is a good correspondence between the conductivity tomograms and the natural gamma logs at the boundary of the gravel layer and the underlying lacustrine clay deposits. Using existing petrophysical models, the inversion results and neutron-neutron logs are converted to porosity. Without any additional calibration, the values obtained for the converted neutron-neutron logs and permittivity results are very close and similar vertical variations can be observed. The full-waveform inversion provides in both cases additional information about the subsurface. Due to the presence of the water table and associated refracted/reflected waves, the upper traces are not well fitted and the upper 2 m in the permittivity and conductivity tomograms are not reliably reconstructed because the unsaturated zone is not incorporated into the inversion domain.

Model-based Segmentation and Image Fusion of 3D Computed Tomography and 3D Ultrasound of the Eye for Radiotherapy Planning

For radiotherapy treatment planning of retinoblastoma inchildhood, Computed Tomography (CT) represents thestandard method for tumor volume delineation, despitesome inherent limitations. CT scan is very useful inproviding information on physical density for dosecalculation and morphological volumetric information butpresents a low sensitivity in assessing the tumorviability. On the other hand, 3D ultrasound (US) allows ahigh accurate definition of the tumor volume thanks toits high spatial resolution but it is not currentlyintegrated in the treatment planning but used only fordiagnosis and follow-up. Our ultimate goal is anautomatic segmentation of gross tumor volume (GTV) in the3D US, the segmentation of the organs at risk (OAR) inthe CT and the registration of both. In this paper, wepresent some preliminary results in this direction. Wepresent 3D active contour-based segmentation of the eyeball and the lens in CT images; the presented approachincorporates the prior knowledge of the anatomy by usinga 3D geometrical eye model. The automated segmentationresults are validated by comparing with manualsegmentations. Then, for the fusion of 3D CT and USimages, we present two approaches: (i) landmark-basedtransformation, and (ii) object-based transformation thatmakes use of eye ball contour information on CT and USimages.

Visualization of aqueous shunt position and patency using anterior segment optical coherence tomography.

PURPOSE: To describe the use of anterior segment optical coherence tomography (AS-OCT) to clarify the position and patency of aqueous shunt devices in the anterior chamber of eyes where corneal edema or tube position does not permit a satisfactory view. DESIGN: Noncomparative observational case series. METHODS: Four cases are reported in which aqueous shunt malposition or obstruction was suspected but the shunt could not be seen on clinical examination. The patients underwent AS-OCT to identify the position and patency of the shunt tip. RESULTS: In each case, AS-OCT provided data regarding tube position and/or patency that could not be obtained by slit-lamp examination or by gonioscopy that influenced management. CONCLUSIONS: AS-OCT can be used to visualize anterior chamber tubes in the presence of corneal edema that precludes an adequate view or in cases where the tube is retracted into the cornea. In such cases, AS-OCT is useful in identifying shunt patency and position, which helps guide clinical decision making.

Value of positron emission tomography in full-thickness chest wall resections for malignancies.

Preoperative imaging for resection of chest wall malignancies is generally performed by computed tomography (CT). We evaluated the role of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in planning full-thickness chest wall resections for malignancies. We retrospectively included 18 consecutive patients operated from 2004 to 2006 at our institution. Tumor extent was measured by CT and PET, using the two largest perpendicular tumor extensions in the chest wall plane to compute the tumor surface assuming an elliptical shape. Imaging measurements were compared to histopathology assessment of tumor borders. CT assessment consistently overestimated the tumor size as compared to PET (+64% vs. +1%, P<0.001). Moreover, PET was significantly better than CT at defining the size of lesions >24 cm(2) corresponding to a mean diameter >5.5 cm or an ellipse of >4 cm x 7.6 cm (positive predictive value 80% vs. 44% and specificity 93% vs. 64%, respectively). Metabolic PET imaging was superior to CT for defining the extent of chest wall tumors, particularly for tumors with a diameter >5.5 cm. PET can complement CT in planning full-thickness chest wall resection for malignancies, but its true value remains to be determined in larger, prospective studies.