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[en] Both SEEG and CAT can be used to assess tumor volumes, and this paper presents correlations between the two methods under stereotaxic conditions. Histologic confirmation is used in a few cases. In the majority of low density tumors it seems likely that SEEG allows precise limit determination. For tumors with enhancement after IV contrast it seems that CAT permits easy differentiation between tumor and edema. CAT and SEEG are in good agreement for metastases but not for glioblastomas. With the latter it seems probable that SEEG overestimates the tumor volume. (C.F.)
[en] Nickel diacetate tetrahydrate, [Ni(acetate)2·4H2O] and nickel diacetate dimethylaminoethanol, [Ni(acetate)2(dmaeH)2] were successfully used to deposit NiOx thin films on conductive glass substrates by sol-gel techniques for large area electrochromic applications. Homogeneous one layer films 100 nm thick were deposited by spin coating 0.5 M [Ni(acetate)2·4H2O] in dmaeH at 1000 rpm and by dip coating methods. The NiOx films were characterised by X-ray diffraction, transmission electron microscopy and atomic force microscopy. The thin film electrochromic performances were characterised by means of optical (transmittance) and electrochemical (cyclic voltammetry) methods. On early cycling NiOx thin films present an activation period, related to an increase in capacity. The electro-optical data show an increase in the electrochromic response (i.e. an increase in contrast and colouration efficiency) upon cycling. Following this initial activation period a steady state is reached in which the thin films reversibly switch from transparent to brown. The anodically coloured NiOx thin films are therefore suitable for use in a complete electrochromic cell with tungsten oxide as the cathodic colouring layer. However, the films are not fully stable with long cycling
[en] Stereotaxic interstitial radiotherapy of a cerebral tumor can be considered satisfactory when the correct isodose is administered to the totality of the tumor volume while sparing the neighboring healthy cerebral tissue. This objective implies to achieve, under stereotactic conditions, the most perfect spatial representation of tumor volume that can be attained. CT scan studies have already brought about great progress in this domain. Nevertheless, this progress will be possible and effective only if two conditions can be met. 1 - That we can add CT scan images to our stereotaxic arsenal with all the geometric rigour required by this context. 2 - That we can, for every case define without ambiguity, at the border of a lesion, the relationship existing between the limits of the density image and the limits of the actual tumor as they could be confirmed histologically. This paper examines the means whereby, and to what extent, these two conditions can be met. This work is based on a study of 166 patients, studied stereotaxically. All of them showed CT brain scan evidence of abnormal density patterns considered, a priori, to represent expansive supratentorial lesions. (Auth.)
[en] Three hundred and fifty two patients with brain metastases have been treated by radiation therapy at the Foundation Bergonie between 1971 and 1982. Among the many characteristics studied, only the increased intracranial pressure, the neurological status and the extraneurologic metastases are of prognostic value. Radiation therapy improves the duration and quality of survival. It appears that a semi-concentrated irradiation (20 grays in 5 fractions and 5 days repeated after one month rest) is a brief, well tolerated and effective treatment
[fr]Trois cent cinquante-deux malades porteurs de metastases cerebrales ont ete traites par radiotherapie a la Fondation Bergonie de 1971 a 1982. Parmi les nombreuses caracteristiques etudiees, seule l'importance du syndrome d'hypertension intracranienne, l'etat neurologique et l'evolution de l'etat neoplasique extra-neurologique ont une incidence pronostique. L'interet de la radiotherapie est retrouve: elle ameliore la duree et la qualite de la survie. Dans ses modalites d'application une irradiation semi-concentree de 20 grays en 5 fractions et 5 jours renouvelee apres 1 mois de repos therapeutique est apparue satisfaisante car breve, tolerable et efficace
[en] Highlights: • Eco-friendly gelatin based electrolyte containing Iodide/triiodide I−/I3− redox mediator. • Integration in Electrochromic Device based on anchored-nanostructured TiO2-viologen. • White to Blue Switch for ECDs stable for thousand cycles. - Abstract: In the present study, a novel gel electrolyte composition combining lithium iodide LiI in 1-butyl-3-methylimidazolium iodide (BMII) ionic liquid,triiodide I3-/I- redox mediator and biodegradable gelatin is proposed for electrochromic devices (ECDs). More precisely, ECDs are assembled using viologen anchored − nanostructured TiO2 (deposited on FTO glass substrate by doctor blading at low temperature) as electrochromic material, FTO as counter-electrode and the gel electrolyte as redox mediator in between. Fast switching times and high cycling stability, up to 20000 cycles, are recorded. The optical reflectance modulation at 550 nm between white and blue color reaches a contrast value ΔR of about 19% in less than 4 seconds after 100 cycles.
[en] External stereotactic radiotherapy allows to irradiate a small and carefully delimited intracranial volume according to the spatial definition of the target. To determine the distribution of the dose in the volume irradiated, a dosimetric programme adapted to particular treatment conditions (arc therapy in the frontal and oblique planes converging onto the centre of the target volume with circular beams 8 to 20 mm in diameter using 18 MV X photons) is developed. The principle of the programme is a 3D reconstruction based on ten transverse CT slices. This reconstruction, related to the stereotactic coordinates defined during stereotactic localization, visualises the outline of each oblique frontal treatment plane and the outline of the three perpendicular reference planes passing through the centre of the target volume (i.e. transverse, sagittal, coronal). The isodose distribution is then calculated in the planes defined by these reconstructions. Under treatment conditions, the parameters measured for each beam with their additional collimation are used. An evaluation of this software performed on a phantom consisting of a skull containing a defined target, is presented
[fr]La radiotherapie en condition stereotaxique permet de donner de fortes doses de radiations dans un petit volume intracranien, grace a la precision de la definition spatiale de la cible. Pour figurer la distribution de la dose dans le volume d'irradiation, on utilise un logiciel de dosimetrie adapte aux conditions particulieres de traitement (arctherapie dans des plans frontaux obliques, convergents au centre du volume cible, avec des faisceaux circulaires de 8 a 20 mm de diametre, par des photons X de 18 MV). Le principe de ce logiciel est une reconstruction 3-D a partir de dix coupes scanographiques transversales. Cette reconstruction, rapportee aux coordonnees definies lors du reperage stereotaxique, permet d'obtenir: le contour de chaque plan frontal oblique de traitement, le contour des trois plans orthogonaux de reference passant par le centre du volume cible (i.e. transversal, sagittal, coronal). La distribution isodose est ensuite calculee dans les plans definis par ces reconstructions. On utilise dans les conditions de traitement les caracteristiques mesurees pour chaque faisceau avec leur collimation additionnelle. On presente un controle de validation de ce logiciel realise sur un fantome constitue d'un crane dans lequel une cible a ete definie
[en] Enhanced sorption properties of ball-milled MgH2 are reported by adding NbF5. Among various catalyst amounts, 2 mol% of NbF5 reveals to be the optimum concentration leading to significant reduction of the desorption temperature as well as faster kinetics of ball-milled MgH2. At 200 deg. C, temperature at which MgH2 does not show any activity, MgH2NbF5/2mol% composite desorbs 3.2 wt.% of H2 in 50 mins. Interestingly, the addition of NbF5 is also associated with an increase in the desorption pressure. At 300 deg. C, MgH2NbF5/2mol% composite starts to desorb hydrogen at 600 mbar in comparison with 1 mbar for MgH2. Further improvements were successfully achieved by pre-grinding NbF5 prior to ball-milling the catalyst with MgH2. Such pre-ground NbF5 catalyzed MgH2 composite desorbs 3 wt.% of H2 at 150 deg. C. Improved properties are associated with smaller activation energies down to values close to the enthalpy of formation of MgH2. Finally, the mechanism at the origin of the enhancement is discussed in terms of catalyst stability, MgF2 formation and electronic density localization
[en] Si-doped Zinc Oxide (SxZO, x from 0 to 4.5 at.%) thin films are grown at room temperature under an oxygen pressure of 1.0 Pa, using Pulsed Laser Deposition. Hall effect measurements report a decrease in resistivity as Si concentration increases from x = 0 to x ∼ 1.5% (ρS1.5ZO = 9 × 10−4 Ω cm) followed by an increase in resistivity as the Si content further increases. The enhancement in resistivity as x increases above ∼ 1.5% is associated with a decrease in carrier mobility with no further increase in carrier concentration; it suggests that the additional Si atoms are not only electrically inactive but also act as electron trapping centers suggesting that they are not well incorporated in the ZnO structure. Such observation well agrees with the decrease in crystallinity observed with Si content leading to amorphous films for x as low as 1%, when deposited on glass substrate. Finally, a resistivity as low as 3.3 × 10−4 Ω cm is reported for S1.5ZO thin films deposited at 100 °C. - Highlights: ► Room temperature deposition of transparent and conductive ZnO:Si (SZO) thin films ► Low resistivity of 3.3 × 10−4 Ω cm for 1.5 at.% of Si in SZO thin films ► Comparable electrical performances as the state of the art In2O3:Sn
[en] Silicon doped Zinc Oxide thin films, so-called SZO, were deposited at room temperature on glass and plastic substrates by co-sputtering of ZnO and SiO2 targets. The influence of the SiO2 target power supply (from 30 to 75 W) on the SZO thin film composition and crystallinity is discussed. Si/Zn atomic ratio, determined by X-ray microprobe, increases from 1.2 to 8.2 at.%. For Si/Zn ratio equal and lower than 3.9%, SZO (S3.9ZO) thin films exhibit the Wurzite structure with the (0 0 2) preferred orientation. Larger Si content leads to a decrease in crystallinity. With Si addition, the resistivity decreases down to 3.5 × 10−3 Ω·cm for SZO thin film containing 3.9 at.% of Si prior to an increase. The mean transmittance of S3.9ZO thin film on glass substrate approaches 80% (it is about 90% for the film itself) in the visible range (from 400 to 750 nm). Co-sputtered SZO thin films are suitable candidates for large area transparent conductive oxides. - Highlights: ► Si doped ZnO thin films by co-sputtering of ZnO and SiO2 targets. ► Minimum of resistivity for Si doped ZnO thin films containing 3.9% of Si. ► Si and O environments by X-ray Photoelectron Spectroscopy.
[en] Highlights: • Room Temperature Deposition of WO3 thin films on paper substrate. • UV irradiation of WO3 nano particles. • Electrochromic Performances in ionic liquid electrolyte. - Abstract: Successful preparation of tungsten oxide thin films on paper substrate, using a novel room temperature deposition method involving the connection of tungsten oxide nanoparticles by UV-irradiation, is reported. WO3 thin films, prepared from synthesized monoclinic WO3 powder as compared to commercial ones, show higher electrochemical activity and good cycling stability in 0.3 M trifluoromethanesulfonimide (HTFSI) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI) ionic liquid electrolyte versus Pt as counter electrode. Electrochromic performances of complete devices using Prussian Blue (PB) as complementary counter electrode and 0.3 M Lithium Bis(Trifluoromethanesulfonyl)Imide LiTFSI in BMITFSI plastified with polymethylmetacrylate (PMMA) membrane electrolyte are associated with a contrast in reflectance of 13%, from a yellow to a blue color