[en] With the utilization of high energies in cancer treatment, the radiotherapeutic techniques have been improved and an optimal effectiveness has been obtained. The main aim of a therapeutic technique is to distribute most of the absorbed energy dose at the level of tumour-including target-volume correctly defined by sparing as far as possible the surrounding tissues. With regard to 200-250 Kv classical plants, a series of significant advantages has been shown for high-energy beams. (GC)

[en] Congenital abnormalities of the bronchi have been classically described with chest X-rays, conventional tomography, bronchography, CT and MR imaging. Recently, the capacity of spiral CT to explore a complete volume with no gap and excellent multiplanar reformations has been emphasized. The contribution of this technique to the analysis of congenital anomalies of tracheobronchial branching patterns encountered in adult patients is illustrated. Agenesis, aplasia, and hypoplasia are discussed, followed by bronchial atresia and abnormalities of bronchial divisions. In most cases spiral CT permits a full and correct evaluation of the malformation as well as its associated anomalies. It appears therefore to be the preferable technique for studying such anomalies of the tracheobronchial tree. Moreover, knowledge of CT aspects of the main congenital bronchial abnormalities along with complete visualization of the tracheobronchial tree will probably lead to detection of more incidental anomalies. (orig.)

[en] CT fluoroscopy facilitates CT-guided biopsy procedures by allowing visualization of the needle trajectory from skin entry to the target point, allowing procedures to be performed more rapidly and efficiently. (authors)

[en] High-resolution computed tomography (HRCT) provides precise imaging of lung parenchyma and is most useful in the investigation of diffuse interstitial lung disease (DILD). It involves thin collimation and high frequency reconstruction algorithm, and requires knowledge of the secondary pulmonary lobule anatomy. Its interpretation is facilitated by recognition of elementary signs (peri-broncho-vascular thickening, septal thickening, ground glass attenuation, etc.) which can be grouped in a HRCT pictorial glossary. In a quiz format, readers are asked to diagnose twelve cases of classical DILD with clinical correlation. (authors)

[en] A small number of cases of cigarette-smoking-associated respiratory bronchiolitis (RB) with positive findings on the chest radiograph have been reported in the literature. High-resolution computed tomography (HRCT) findings are available in even fewer cases. We describe the case of an asymptomatic female smoker presenting with a reticulomicronodular infiltrate on a routine chest radiograph. High-resolution CT was characterized by ground-glass opacities and centrilobular micronodules with an upper lobe predominance. Surgical biopsy revealed peribronchiolar lesions, with accumulation of brown pigmented macrophages in the lumen of alveolar and bronchiolar lumen, consistent with the pathologic diagnosis of RB. (orig.)

[en] Full text: Using a recent reformulation of Floquet theory, we discuss the dynamical role of the absolute phase in the photofragmentation of molecules subjected to laser pulses. We show how the dependance of Floquet states on an absolute phase is related to the complexity of the dressed molecular scheme and to the multiphoton character of the molecular dynamics. The general theory is applied to the study of the photodissociation of H₂⁺ in a 400 nm periodic laser pulse, repeated with a frequency lying in the IR. The dependence of the dynamics on the phase of the pulse envelope is highlighted through an effect previously called dynamical dissociation quenching (DDQ) and through photofragments kinetic energy spectra. These spectra allow us to map out the Floquet content of the dynamics, i.e. its multiphoton character both with respect to the carrier-wave frequency, which gives rise to the usual bond-softening (BS) mechanism, and with respect to the pulse modulation frequency in the IR. The synchronization of this pulse modulation with the wavepackets motion governs the DDQ effect in this UV-vis pulsed excitation case. Refs. 2 (author)

[en] The authors discuss how in order to define the functional domains of the human androgen receptor, complementary DNA (cDNA) clones encoding the human androgen receptor (hAR) have been isolated from a human testis λgtll cDNA library using synthetic oligonnucleotide probes, homologous to segments of the human glucocorticoid, estradiol and progesterone receptors. The cDNA clones corresponding to the human glucocorticoid, estradiol and progesterone receptors were eliminated after cross-hybridization with their respective cDNA probes and/or after restriction mapping of the cDNA clones. The remaining cDNA clones were classified into different groups after analysis by restriction digestion and cross-hybridization. Two of the largest cDNA clones from each group were inserted into an expression vector in both orientations. The linearized plasmids were used as templates in in vitro transcription with T7 RNA polymerase. Subsequent in vitro translation of the purified transcripts in rabbit reticulocyte lysate followed by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) permitted the characterization of the encoded polyeptides. The expressed proteins larger than 30,000 Da were analyzed for their ability to bind tritium-labelled dihydrotestosterone ([³H] DHT) with high affinity and specificity

[en] Using a recent reformulation of Floquet theory [S. Guerin and H. R. Jauslin, Adv. Chem. Phys. 125, 1 (2003)], we discuss the dynamical role of the absolute phase in the photofragmentation of molecules subjected to laser pulses. We show how the dependence of Floquet states on an absolute phase is related to the complexity of the dressed molecular scheme and to the multiphoton character of the molecular dynamics. The general theory is applied to the study of the photodissociation of H₂⁺ in a 400-nm periodic laser pulse, repeated with a frequency lying in the IR. The dependence of the dynamics on the phase of the pulse envelope is highlighted through an effect previously called dynamical dissociation quenching (DDQ) [F. Chateauneuf et al., J. Chem. Phys. 108, 3974 (1998)] and through photofragment kinetic energy spectra. These spectra allow us to map out the Floquet content of the dynamics - i.e., its multiphoton character both with respect to the carrier-wave frequency, which gives rise to the usual bond-softening mechanism, and with respect to the pulse modulation frequency in the IR. The synchronization of this pulse modulation with the wave packet motion governs the DDQ effect in this uv-visible pulsed excitation case

[en] The oxi-hydroxides, present at trace level in uranium mill tailings, are responsible of about 70% of the 226 radium sorption, half being fixed on crystallized forms. This radionuclide (half time=1622y), present at high level (50 to 100kBq.kg^-1), can be released in groundwater, involving a possible contamination of the food chain (actual concentration limit=0.37Bq.1^-1). So, it is very important to point out the mechanisms of the radium sorption/desorption on crystallized oxi-hydroxides as a function of chemical conditions of the system. The radium sorption on synthetic goethite α-FeOOH has been studied as a function of contact time, initial radium activity, pH, sodium and calcium concentrations. The results show that, after one hour of contact time (necessary to reach equilibrium), the radium sorption increases widely in a pH range 6-7. The increase of Na⁺ concentration is without influence on the radium sorption, indicating the low interactions between sodium and surface sites. At the opposite, the presence of calcium in solution decreases widely the radium sorption, that indicates a competition between calcium and radium for the same kind of sorption sites of the oxi-hydroxide surface. The percentage of radium desorbed increases widely with time, from 1 to 120h and becomes constant at a time higher than 120h. This long equilibrium time for desorption in comparison with sorption one can be explain by a local evolution of the sorption sites of the solid, which become less accessible for the solution in contact. (author)

[en] Ruthenium extraction with uranium and plutonium during the reprocessing of nuclear used fuel is an important element to follow because its presence leads to a decrease of the decontamination factors and causes enhanced radiolysis of the solvent. A study was carried out on the speciation of ruthenium in both aqueous and organic phases by complementary spectroscopic techniques such as Fourier Transform Infrared spectroscopy (FTIR) and X-ray absorption spectroscopy. The results show a different Ru extraction behavior depending on the initial HNO_3 conditions (1 M - 4 M). It also provides evidence of a second shell TBP-Ru complexation. By providing a better understanding of the ruthenium extraction mechanism, this study will help to support the modeling of related processes