[The first steps towards advanced practice for radiation therapists]. / Les prémices de la pratique avancée pour le manipulateur en radiothérapie.

The implementation of advanced practice in RT requires evidence regarding the clinical practices of radiation therapists (RTT) in the field. In this context, the goal of this article is to report the roles assigned to RTT in order to meet the demands of patients, RT services, and/or healthcare professionals. As part of the French Society of Oncologic Radiotherapy's congress, the Radiotherapy Committee of the French Association of radiographers presented a scientific program encompassing three main themes: patient follow-up by a RTT, the expertise of an RTT in Image Guided Radiation Therapy (IGRT), Adaptive Radiotherapy (ART), and the involvement of a RTT in research. This article presents an overview of five oral presentations that highlight concrete examples of roles assigned to RTTs in these specific domains. The follow-up of patients has been assigned to RTT. Research and development have been recognized as activities in which RTT play a significant role. The establishment of RTT specializing in IGRT has been reported to facilitate decision-making and is essential in ensuring professional expertise. Lastly, there is a need to enhance RTT skills in adaptive RT to support the implementation of this technique. These roles described as advanced practice meet needs and require a specific organisational framework and appropriate education and training (master type). Activities such as post-RT follow-up, validation of positioning imaging, delineation, writing research protocols, and involvement in the development of technological innovations were identified as essential tasks that can be assigned to RTT.

Diagnostic Pitfall of Platypnea-Orthodeoxia Syndrome Caused by Atrial Septal Defect after Right Pneumonectomy.

We describe a case of platypnea-orthodeoxia syndrome (POS) due to atrial septal defect (ASD) occurring in the early postoperative course of a right pneumonectomy. Deformation of the atrial septum after right pneumonectomy deviates the blood from the inferior vena cava to ASD during the sitting position creating, a massive right-to-left shunt. Diagnosis can initially be missed by making contrast bubble test through the superior vena cava. The atrial septal defect was then closed using the surgical technique, allowing an instantaneous improvement of hematosis.

The role of Rydberg states in photoionization of NO2 and (NO+, O-) ion pair formation induced by one VUV photon.

We report a combined experimental and theoretical study of photoionization (PI) of the NO2 molecule into the NO2(+) (X (1)Σg(+)) ground state and the photodissociation of NO2 into the NO(+)((1)Σ(+)) + O(-)((2)P) ion pair. These processes were induced by 10.9 eV-13 eV synchrotron radiation and the products were detected using electron-ion or O(-)-NO(+) coincident momentum spectroscopy. The results demonstrate the strong influence of [R(∗)(4b2)(-1), nlα(i), v2(')] Rydberg states vibrationally resolved in the v2(') bending modes for both processes. In particular, we emphasize two regions around 11.5 eV and 12.5 eV that were studied in more detail for their relevance to 400 nm multiphoton ionization induced by femtosecond pulses. The photoelectron energy spectra and asymmetry parameters support the existence of two PI mechanisms, as probed with the help of fixed-nuclei frozen-core Hartree-Fock calculations. We found significant deviations from Franck-Condon ionization predictions which may be assigned to vibronic coupling of NO2(∗) states such as that induced by a conical intersection. The limited agreement between theory and experiment, even for the non-resonant processes, indicates the need for calculations that go beyond the approximations used in the current study. Ion pair formation leads to strong vibrational and rotational excitation of the NO(+)((1)Σ(+),v) product, with an ion fragment angular anisotropy depending on both the v2(') bending quantum number of the excited parent molecule and the v vibrational level of the fragment.

Circular dichroism in photoionization of H2.

Circular dichroism is a consequence of chirality. However, nonchiral molecules can also exhibit it when the measurement itself introduces chirality, e.g., when measuring molecular-frame photoelectron angular distributions. The few such experiments performed on homonuclear diatomic molecules show that, as expected, circular dichroism vanishes when the molecular-frame photoelectron angular distributions are integrated over the polar electron emission angle. Here we show that this is not the case in resonant dissociative ionization of H2 for photons of 30-35 eV, which is the consequence of the delayed ionization from molecular doubly excited states into ionic states of different inversion symmetry.

Ion pair formation in multiphoton excitation of NO(2) using linearly and circularly polarized femtosecond light pulses: kinetic energy distribution and fragment recoil anisotropy.

The NO(2) ion pair photodissociation dynamics leading to NO(+)(X(1)Sigma(+),v) + O(-)((2)P(3/2) or (2)P(1/2)), induced by a 1 kHz femtosecond laser with wavelengths near 400 nm, has been characterized using the coincidence vector correlation method. The ion pair production after four-photon absorption reaches more than 15% of the primary ionization. The kinetic energy release of the fragments demonstrates a significant vibrational excitation of the NO(+)(X(1)Sigma(+),v) molecular fragment. Recoil ion fragment emission is strongly aligned along the polarization axis of linearly polarized light or preferentially emitted in the plane perpendicular to the propagation axis of circularly polarized light. The formalism describing the recoil anisotropy for bound-to-bound n-photon transition inducing prompt axial recoil dissociation of a nonlinear molecule has been developed to interpret the measured anisotropies in terms of excitation pathways via near-resonant intermediate states of specific symmetries. Possible reaction pathways are discussed that are consistent with the data and supported by calculations of potential energy surfaces and transition moments.

Quantitative determination of the size dependence of surface plasmon resonance damping in single Ag@SiO(2) nanoparticles.

The optical extinction spectra of single silver nanoparticles coated with a silica shell were investigated in the size range 10-50 nm. Measurements were performed using the spatial modulation spectroscopy technique which permits independent determination of both the size of the metal nanoparticle under study and the width of its localized surface plasmon resonance (LSPR). These parameters can thus be directly correlated at a single particle level for the first time. The results show a linear increase of the width of the LSPR with the inverse diameter in the small size regime (less than 25 nm). For these nanoparticles of well-controlled environment, this can be ascribed to quantum confinement of electrons or, classically, to increase of the electron surface scattering processes. The impact of this effect was measured quantitatively and compared to the predictions by theoretical models.

Influence of structure on the optical limiting properties of nanotubes.

We investigate the role of carbon nanotubes structure on their optical limiting properties. Samples of different and well-characterized structural features are studied by optical limiting and pump-probe experiments. The influence of the diameter's size on the nano-object is demonstrated. Indeed, both nucleation and growth of gas bubbles are expected to be sensitive to diameter.

Direct measurement of the single-metal-cluster optical absorption.

The absorption of a single isolated metal cluster is directly measured using a novel far-field optical technique based on modulation of its position. Single gold nanoparticles with average diameters down to 5 nm, dispersed on a transparent substrate, are optically detected and their absolute absorption cross section determined.

[Off-pump beating heart coronary artery bypass. Technical points of view and surgical results]. / Pontage coronaire à coeur battant. Aspects techniques et résultats hospitaliers.

A consecutive series of 746 patients undergoing heart beating myocardial revascularization was reviewed. An average of 2.30 grafts/patients was performed. The rate of mortality in the first 30 postoperative days was 0.28%. Two cases had to be terminated on-pump. We used the inotropic drugs in 0.6% of cases. The postoperative events were: atrial fibrillation (12.6%), myocardial infarction (0.3%). The rate of transfusion was 7.4%. The extubation was performed in the first 24 h postoperatively in 94.7% of cases. The majority of patients (91.3%) left the hospital in the first 8 d postoperatively. Off pump coronary artery bypass grafting gives good result for the most of the patients even for those with multiple vessel disease and high operating risk.

Evaluation of pharmacological aids on physical performance after a transmeridian flight.

PURPOSE: The purpose of this study was to evaluate physical performance (static and dynamic) of U.S. Air Force reservists after an eastbound air travel across seven time zones and to estimate the pharmacological aids slow-release caffeine and melatonin versus placebo in attempt to overcome the decline in performance. METHODS: 27 American volunteers were randomly divided into three groups: caffeine 300 mg, melatonin 5 mg, and placebo (lactose capsules). Two days before the flight and 10 d after, three tests were performed: hand grip strength test (static performance), squat jump test (maximal height), and multiple jump test (power and endurance). All measures were repeated twice a day: morning and afternoon. RESULTS: In placebo conditions, the static performance of the dominant hand decreased significantly during the first three mornings and tended to decrease the fourth morning. Simultaneously, the caffeine group's static performance increased significantly, whereas the melatonin group maintained its levels. No significant differences were observed the afternoons. No statistical differences appeared for the nondominant hand in the mornings or afternoons. Dynamic capacities presented no significant degradation after the travel. In the placebo group, for the squat jump test, performance increased from the fourth day. No real explanation can be given about this result. CONCLUSIONS: We demonstrated that slow-release caffeine and melatonin might be used to compensate for jet-lag troubles and particularly for the static physical performance decrease. The slow-release caffeine seems to be the best treatment, but its effects are only demonstrated on previously damaged performance. These preliminary results need further investigation, but we are the first to report a beneficial effect of slow-release caffeine and melatonin on physical performances after jet-lag.

Is a prosthetic ring required for mitral repair of mitral insufficiency due to posterior leaflet prolapse? Long-term results in 96 patients submitted to repair with no ring.

OBJECTIVE: It is a common statement that every mitral repair should be stabilized by some type of prosthetic mitral ring. In the very specific situation of isolated prolapse of the posterior leaflet (PPL), this statement may be enhanced by the possible anatomically discontinuity of the mitral annulus. This article concerns 96 patients with 'isolated' PPL (IPPL) who were operated upon without ring insertion. Long-term follow-up was obtained in order to ascertain the survival, stability of the repair and the need for reoperation, thus justifying or not the lack of use of a ring. METHODS: A total of 96 patients, 70 male and 26 female, underwent mitral repair for mitral insufficiency (MI) almost exclusively caused by PPL. Age ranged from 33 to 81 years (mean 60.7+/-11.3). All underwent quadrangular resection of the prolapsed portion and plication of the annulus. In 69 cases local stabilization was achieved by four U stitches, two on each side of the plication, passed through and sutured on some flexible material, 2-3 cm in length. Twenty seven patients had no such local reinforcement. RESULTS: There was one case of early death (1%) caused by refractory hypoxemia in a patient with long lasting pre-operative pulmonary edema. Two patients were lost for follow-up after 2 months. Follow-up was from 0.2 to 14.7 years (mean 4.5), for a total of 422.7 patient-years. There were four late deaths at a mean of 6-year follow-up (0.9-10 years). Actuarial survival was 95.5 and 90.5% at 5 and 8 years, respectively. Event-free for recurrence of significant mitral insufficiency (MI) was 96 and 92% at 5 and 8 years. Event-free of thromboembolic or hemorrhagic events was 84.3 and 72.3% at 5 and 8 years. Event-free from reoperation was 97.8 and 94% at 5 and 8 years. CONCLUSION: One can conclude that (a) IPPL repair without insertion of a ring is safe and long-lasting (b) the incidence of late death, recurrence of MI, thromboembolic/hemorrhagic events, need for reoperation, is not higher in this subset of patients than in conventional repair (c) such repair might work better and for a longer time, as reaction and sclerosis resulting from ring insertion are avoided (d) minor advantages could be due to an easier surgical procedure, especially through a minimally invasive approach.

[Surgery for aneurysms of the subrenal abdominal aorta after the age of 70 years: survival and quality of life]. / La chirurgie des anévrismes de l'aorte abdominale sous-rénale après 70 ans: survie et qualité de vie.

The aim of this study was to assess results of surgery for aneurysms of the abdominal aorta in patients over 70 years of age. Survival and quality of life were used as assessment criteria. Files of 277 patients over 70 years of age who had undergone surgery for an aneurysm of the subrenal abdominal aorta between 1974 and 1992 were examined retrospectively. There were 246 men and 31 women of whom 230 were under 80 and 47 over 80 years of age. The operation was programmed in 145 cases and was an emergency procedure in 132 (45 ruptures and 87 painful fissurations). Perioperative mortality was 1.4% in programmed surgery and 19.7% in emergency surgery. Overall actuarial survival was 60.07% at 5 years and 26.04% at 10 years. Quality of life after the operation was unchanged in 56.1%, improved in 19.3% and worse in 24.6%. Surgery for aneurysm of the subrenal abdominal aorta is justified in patients over 70 years of age. It can provide satisfactory survival in good quality of life conditions.