Search

In the event of a radiological accident involving external exposure of one or more victims and potential high doses, it is essential to know the dose distribution within the body in order to sort the victims according to the severity of the irradiation and then to take them to the most suitable medical facilities. However, there are currently few techniques that can be rapidly deployed on field and capable of characterizing an irradiation. Therefore, a numerical simulation tool has been designed. It can be implemented by a doctor/physicist pairing, projected within a limited time as close as possible to the irradiation accident and emergency response teams. Called SEED (Simulation of External ExposuresDosimetry), this tool (dedicated to dose reconstruction in case of external exposure) allows a rapid modeling of the irradiation scene and a visual exchange with the victims and witnesses of the event. The user can navigate in three dimensions in the accident scene thanks to a graphical user interface including a "first person" camera. To validate the performance of the SEED tool, two dosimetric benchmarking exercises were performed. The first consisted in comparing the dose value provided by SEED to that given by a reference calculation code: MCNPX. The purpose of the second validation was to perform an experiment irradiating a physical dummy equipped with dosimeters and to reconstruct this irradiation using SEED. These two validation protocols have shown satisfactory results with mean difference less than 2% and 12% for the first and second exercises, respectively. They confirm that this new tool is able to provide useful information to medical teams in charge of dosimetric triage in case of a major external exposure event.

In this Letter, we demonstrate that it is possible to form a two-dimensional (2D) silicenelike ${\mathrm{Si}}_{5}\mathrm{Ge}$ compound by replacing the Si atoms occupying on-top sites in the planarlike structure of epitaxial silicene on ${\mathrm{ZrB}}_{2}$(0001) by deposited Ge atoms. For coverages below 1/6 monolayer, the Ge deposition gives rise to a ${\mathrm{Si}}_{6\ensuremath{-}x}{\mathrm{Ge}}_{x}$ alloy (with $x$ between 0 and 1) in which the on-top sites are randomly occupied by Si or Ge atoms. The progressive increase of the valence band maximum with $x$ observed experimentally originates from a selective charge transfer from Ge atoms to Si atoms. These achievements provide evidence for the possibility of engineering the band structure in 2D SiGe alloys in a way that is similar for their bulk counterpart.

In modern radiotherapy, pretreatment patient-specific quality assurance (PSQA) generally consists in delivering the treatment plan to a phantom equipped with a detector and in comparing the measured dose and the dose calculated by the treatment planning system (TPS) in order to detect any gap between both dose distributions. Dosimetric gels have interesting properties for QA. In this work, the use of gel dosimetry together with a patient-based 3D printed phantom for personalized PSQA is investigated. CT images of a patient with a right mesencephalic brain tumor were used to generate a 3D printed phantom. Then it was filled with water and a radiochromic gel jar and irradiated according to the patient intracranial stereotactic plan using a Novalis TrueBeam STX accelerator. Measured dose distributions agree well with the calculated ones. Regarding 3D gamma-index (1 mm – 2%) estimated within the central 85% of the jar volume, 96.3% of points pass the test. In addition, 86.5% of the points pass the local 2D 3 mm-3% gamma-index. Results are promising but further work is needed to improve the protocol and investigate the possibility to extend it to end-to-end tests.

Contexte Suite au traitement par radioiode (I131) du cancer differencie de la thyroide, les glandes salivaires peuvent etre le siege d’inflammations, provoquant des troubles salivaires (TbS). L’incidence des TbS est mal connue ainsi que les facteurs de risque cliniques et genetiques. L’etude START vise a estimer l’incidence des TbS apres traitement par radioiode, individualiser les facteurs de risque cliniques, biomoleculaires et biochimiques, et valider une methode d’estimation dosimetrique pour calculer la dose recue au niveau des glandes salivaires et analyser les relations dose-reponse. Materiel/patients et methodes Cette cohorte inclut des patients atteints d’un cancer differencie de la thyroide et candidats a un traitement par I131 a l’hopital Pitie-Salpetriere. Trois visites sont organisees – avant traitement (T0), 6 mois (T6) et 18 mois post-traitement – et incluent des questionnaires valides. A T0 et T6, des prelevements et des mesures dynamiques du flux salivaires sont realises. Des dosimetres sont places le jour du traitement durant 5 jours au niveau des glandes salivaires et a la fourchette sternale. Des analyses genetiques et epigenetiques seront effectuees pour rechercher des biomarqueurs de predisposition aux TbS. Le protocole a ete enregistre sur clinicaltrials.gov ( NCT04876287 ). Resultats attendus A la fin des inclusions (04/2021), 139 patients ont ete inclus (45 et 94 patients traites par 1,1 et 3,7GBq respectivement). Le suivi a T6 est en cours. Les analyses statistiques permettront d’etudier les liens entre TbS et dose recue par les glandes salivaires, en tenant compte des facteurs cliniques associes. L’impact sur la qualite de vie des patients sera analyse.

In a previous work, a PENELOPE Monte Carlo model of a Cyberknife system equipped with fixed collimator was developed and validated for in-field dose evaluation. The aim of this work is to extend it to evaluate peripheral doses and to determine the precision of the treatment planning system (TPS) Multiplan in evaluating the off-axis doses. The Cyberknife

The structural transformations induced in Gd2O3 and Eu2O3 irradiated with high-energy ions (94-MeV Pb and 1042-MeV Xe), where ionization processes (electronic stopping) dominate the ion slowing-down, have been studied via the combination of XRD and Raman experiments. Irradiation induces a cubic-to-monoclinic phase transformation; the radiation-induced monoclinic phase shows strong preferential orientation. This structural modification is accompanied by changes in the photoluminescence properties of sesquioxides. The results show that swift heavy ion irradiation is a powerful tool to control the properties of oxides at the nanoscale.

Purpose: To investigate the optimal use of XR-RV3 GafChromic® films to assess patient skin dose in interventional radiology while addressing the means to reduce uncertainties in dose assessment. Methods: XR-Type R GafChromic films have been shown to represent the most efficient and suitable solution to determine patient skin dose in interventional procedures. As film dosimetry can be associated with high uncertainty, this paper presents the EURADOS WG 12 initiative to carry out a comprehensive study of film characteristics with a multisite approach. The considered sources of uncertainties include scanner, film, and fitting-related errors. The work focused on studying film behavior with clinical high-dose-rate pulsed beams (previously unavailable in the literature) together with reference standard laboratory beams. Results: First, the performance analysis of six different scanner models has shown that scan uniformity perpendicular to the lamp motion axis and that long term stability are the main sources of scanner-related uncertainties. These could induce errors of up to 7% on the film readings unless regularly checked and corrected. Typically, scan uniformity correction matrices and reading normalization to the scanner-specific and daily background reading should be done. In addition, the analysis on multiple film batches has shown that XR-RV3 films have generally good uniformity within one batch (

Il existe peu de donnees relatives aux difficultes d’observance d’un traitement chez les femmes impliquees dans le commerce du sexe (FISC). Nous avons etudie la capacite de ces femmes a prendre un traitement prolonge, en evaluant l’impact de la communication avec l’entourage sur l’observance d’un tel traitement. Les donnees ont ete collectees a partir des entretiens d’observance realises dans le cadre de la phase pilote d’un essai therapeutique qui necessitait la prise d’un traitement prolonge de trois mois. Nous avons compare l’observance du traitement chez les femmes qui ont informe leur entourage sur la prise de traitement a celle des femmes qui dissimulaient la prise du traitement. Nous avons prete une attention particuliere aux difficultes d’integration du medicament dans l’espace social. L’observance chez les femmes qui ont dissimule leur traitement etait comparable a celle des femmes qui avaient communique avec l’entourage. Le manque d’attente sociale, la peur des supputations de l’entourage sur la serologie VIH etaient les obstacles principaux a la communication sur le traitement. Plus que la communication sur le traitement, c’est la perception du traitement qui a joue un grand role dans les difficultes d’observance. Cette phase pilote montre que les FICS ne parviennent pas a associer l’entourage a la prise du traitement meme s’il est informe ; cependant, meme sans soutien social, cette population peut suivre un traitement prolonge avec une bonne observance, a condition qu’un soutien psychologique specifique soit mis en place a l’initiation et pendant le suivi du traitement.

Since 2001, the SPIRAL I Facility (Systeme de Production d’Ions Radioactifs en Ligne, version I) located at GANIL in Caen (France) has delivered radioactive ion beams mainly of “light” gaseous elements, from He to Kr. In March 2004, a beam of some pps of 31Ar (15 ms) was produced. Very soon, a new target-and-ion-source system (TISS) will be tested for the production of radioactive multi-charged ions of alkaline elements. For making radioactive ion beams of heavier elements, the SPIRAL II project is under study. The proposed technique is to produce heavy fragments by fission of uranium induced by neutrons, themselves produced by a 200 kW deuteron beam hitting a carbon converter. The technical studies should be completed by the end of 2004. After a short presentation of results from the operation of SPIRAL I, the design of the SPIRAL II target and ion-source system is presented.

We report a series of measurements performed to characterize the atom-to-ion transformation time in singly charged electron cyclotron resonance ion sources (ECRISs). Three ECRISs were used with He, Ne, Ar and Kr noble gases. The transformation time as a function of the support gas flow, the ionization efficiency, and source volume is presented and compared to a calculation made with a simple dynamic model.

TruView™ is a new water-equivalent reusable Fricke gel dosimeter based on MethylThymolBlue reactive dye. Details of the characterisation of the TruView™ MTB gel dosimeter by spectrophotometric measurements and of its reading with the Optical-CT Scanner Vista™ are described. In this study, the different parameters influencing TruView™ dose response have been studied and its performances have been compared to chamber and diodes measurements. This gel presents a linear response with dose up to 20 Gy, independent in the investigated range of photon beam energy and dose rate and also a good intra-batch uniformity. Ions diffusion into the matrix homogenizes the gel after a week, losing dosimetric information but allowing a new irradiation to be performed. However, auto-oxidation happens before and after irradiation, degrading the dosimeter response and stability. Storage and reading conditions affect the response as well.

Hospitals have to deal strong with economic constraints and increasing requirements in terms of quality and safety of care. To address these constraints, one solution could be the adoption of approaches from the industry sector. Following the decree of April 6, 2011 on the quality management of the medication use process, some of these approaches, such as risk management, are now part of the everyday work of healthcare professionals. However, other approaches, such as business process improvement, are still poorly developed in the hospital setting. In this general review, we discuss the main approaches of business process improvements that have been used in hospitals by focusing specifically on one of the newest and most currently used: Lean.

In this work, a method is developed to decompose or substructure large-scale micromechanical simulations into a set of computationally smaller problems. In the approach the global domain is partitioned into nonoverlapping subdomains. On the interior subdomain partitions an approximate globally kinematically admissible solution is projected. This allows the subdomains to be mutually decoupled, and therefore separately solvable. The subdomain boundary value problems are solved with the exact microstructural representation contained within their respective boundaries, but with approximate displacement boundary data. The resulting microstructural solution is the assembly of the subdomain solutions, each restricted to its corresponding subdomain. The approximate solution is far more inexpensive to compute than the direct problem. A posteriori error bounds are developed to quantify the quality of the approximate solution. Numerical simulations are presented to illustrate the essential concepts.

The extracellular matrix (ECM), constituting the follicular basal lamina and present also between follicular cells and in the follicular fluid, is believed to regulate granulosa cell (GC) function during follicular development. Ovine GCs isolated from small (1-3 mm in diameter) or large (4-7 mm in diameter) antral follicles were cultured on various pure ECM components (type I collagen, fibronectin, laminin), synthetic substrata enhancing (RGD peptides) or impairing (poly 2-hydroxyethylmethacrylate (poly-hema)) cell adhesion, or in the presence of heparin. The effects of these factors, used alone or in combination with IGF-I and/or FSH, were evaluated in terms of GC spread, survival, proliferation and steroidogenesis. When grown on type I collagen (CI) gel, poly-hema or heparin, GCs from both large and small follicles exhibited a round shape and a low proliferation rate. Compared with non-coated plastic substratum as a control, these ECM or synthetic compounds enhanced estradiol secretion and reduced progesterone secretion by large-follicle GCs. In contrast, GCs from both large and small follicles spread extensively on CI coating, fibronectin, laminin and RGD peptides. Fibronectin and laminin dramatically increased the proliferation rate and enhanced survival of GCs from both origins. Moreover, fibronectin, laminin and RGD peptides reduced estradiol secretion by large-follicle GCs. Unexpectedly, CI coating increased estradiol secretion and reduced progesterone secretion by large-follicle GCs, suggesting that type I collagen was able to maintain estradiol secretion independently of GC shape. Finally, GC responsiveness to IGF-I and FSH, in terms of proliferation and steroidogenesis, was generally maintained when cells were grown on ECM components, RGD peptides and in the presence of heparin. However, when large-follicle GCs were grown as non-adherent clusters (as observed on poly-hema) basal and IGF-I- and/or FSH-stimulated progesterone secretions were totally abolished. Overall, this study shows that GC shape, survival, proliferation and steroidogenesis can be modulated in vitro by pure ECM components in a specific and coordinated manner. It is suggested that, in vivo, fibronectin and laminin would sustain follicular development by enhancing the survival and proliferation of GCs, whereas type I collagen might participate in the maintenance of estradiol secretion in large antral follicles.

Radon is ubiquitous in the biosphere and present in soils and building materials. It accounts for about half of our total irradiation dose from natural sources. An association has been demonstrated in uranium miners between their exposure to radon and its decay products and an excess risk of lung cancer, however, any effect of domestic radon exposure in the production of lung cancer remains unclear. Epidemiologic and dosimetric approaches have been used to study the problem, but there is considerable variation between the results from each method. To better estimate the risk a European large-scale research programme has been conducted. One aim of the study was to better characterise the size distribution of particulates carrying radon progeny including their variation with time and ambient conditions. A methodology was developed to measure the particulate size distribution, unattached fraction and the equilibrium factor of 222Rn short-lived daughters. Measurements were made in a traditional dwelling built on a granitic soil in Brittany. Over 11 months, radon activity concentration was on average 1,420 Bq·m–3 (240–2,800 Bq·m–3), but it was concluded that such an approach only allows assessment of the dose as the sum of the unattached and attached forms.

Starting in 1996, nonlinear approximation algorithms used for the determination of size distributions of ''unattached'' radon progeny from measurements made with diffusional size classification instruments were compared. Seven participants (one American and six European) took part using various techniques (Simplex, Expectation Maximization, Extreme Value Estimation, Twomey, and Random Walk) which are widely used for this type of work. Simulated input data was supplied to the participants. Their output data indicated that the quality of the results varied according to the algorithm used. This was particularly the case when retrieving parameters from bimodal distributions where large inaccuracies were shown. Variations were found between participants using basically identical algorithms. The influence of measurement uncertainties was investigated and indicated a serious reduction of retrieval accuracy, especially for algorithms with better than average performance for precise data. This work suggests that w...

A new method is presented to estimate mean activity concentration and mean size distribution of nanometer 218Po over long time, i.e. several weeks in indoor atmospheres. It uses an annular channel, equipped with an LR 115 solid-state alpha-track detector, as diffusion sampler. Design, experimental characterisation and analytical methods are described. The calibration was carried out in a 0.35 m3 test radon chamber without aerosol particles by comparing the number of tracks registered on the film detector with the nanometer 218Po particle concentrations measured in parallel with a classical single screen-filter method. A calibration factor of 0.107 tracks cm-2 h-1 was established. The size distribution of these nanometer radioactive particles in the range of 0.5–5 nm was reconstructed from the track density recorded on the detector film with non-linear inversion techniques.

NESTER; International audience; ISOL beams of $^{19-22}$O were produced at ISOLDE and GANIL. At ISOLDE the neutron-rich oxygen isotopes are produced by 1.4 GeV proton-induced reactions in a UCx/graphite target. The target is connected via a water-cooled transfer line (to retain all non-volatile isobars) to an ISOLDE type FEBIAD ion source where the released CO is dominantly ionized as CO+. $^{19-22}$O beams were also produced at SPIRAL (GANIL). A 77.5 MeV/nucleon 36S beam was fragmented in a thick graphite target, coupled by a cold transfer tube to an ECR ion source which ionizes the released CO dominantly as O$^+$ and CO$^+$.

The use of small photon fields is now an established practice in stereotactic radiosurgery and radiotherapy. However, due to a lack of lateral electron equilibrium and high dose gradients, it is difficult to accurately measure the dosimetric quantities required for the commissioning of such systems. Moreover, there is still no metrological dosimetric reference for this kind of beam today. In this context, the first objective of this work was to determine and to compare small fields output factors (OF) measured with different types of active detectors and passive dosimeters for three types of facilities: a CyberKnife(®) system, a dedicated medical linear accelerator (Novalis) equipped with m3 microMLC and circular cones, and an adaptive medical linear accelerator (Clinac 2100) equipped with an additional m3 microMLC. The second one was to determine the kQclin,Qmsr (fclin,fmsr) correction factors introduced in a recently proposed small field dosimetry formalism for different active detectors.Small field sizes were defined either by microMLC down to 6 × 6 mm(2) or by circular cones down to 4 mm in diameter. OF measurements were performed with several commercially available active detectors dedicated to measurements in small fields (high resolution diodes: IBA SFD, Sun Nuclear EDGE, PTW 60016, PTW 60017; ionizing chambers: PTW 31014 PinPoint chamber, PTW 31018 microLion liquid chamber, and PTW 60003 natural diamond). Two types of passive dosimeters were used: LiF microcubes and EBT2 radiochromic films.Significant differences between the results obtained by several dosimetric systems were observed, particularly for the smallest field size for which the difference in the measured OF reaches more than 20%. For passive dosimeters, an excellent agreement was observed (better than 2%) between EBT2 and LiF microcubes for all OF measurements. Moreover, it has been shown that these passive dosimeters do not require correction factors and can then be used as reference dosimeters. Correction factors for the active detectors have then been determined from the mean experimental OF measured by the passive dosimeters.Four sets of correction factors needed to apply the new small field dosimetry formalism are provided for several active detectors. A protocol for small photon beams OF determination based on passive dosimeters measurements has been recently proposed to French radiotherapy treatment centers.

International audience; The emergence of very large hierarchies that result from the increase in available data raises many problems of visualization and navigation. On datasets of such scale, classical graph drawing methods do not take advantage of certain human cognitive skills such as shape recognition. These cognitive skills could make it easier to remember the global structure of the data. In this paper, we propose a method that is based on the use of nested irregular shapes. We name it GosperMap as we rely on the use of a Gosper Curve to generate these shapes. By employing human perception mechanisms that were developed by handling, for example, cartographic maps, this technique facilitates the visualization and navigation of a hierarchy. An algorithm has been designed to preserve region containment according to the hierarchy and to set the leaves' sizes proportionally to a property, in such a way that the size of non-leaf regions corresponds to the sum of their children's sizes. Moreover, the input ordering of the hierarchy's nodes is preserved, i.e., the areas that represent two consecutive children of a node in the hierarchy are adjacent to one another. This property is especially useful because it guarantees some stability in our algorithm. We illustrate our technique by providing visualization examples of the repartition of tax money in the U.S. over time. Furthermore, we validated the use of the GosperMap in a professional documentation context. and show the stability and ease of memorization for this type of map.

Background: Interventions targeting core groups such as high-risk women in Africa have focused mostly on HIV prevention. In this marginalized group, the delegation of HIV care to public services may jeopardize the effectiveness of prevention activities. We assessed the effect of an intervention combining prevention and care among high-risk women on HIV exposure and treatment outcomes. Methods: In Burkina Faso, high-risk women were recruited by peer educators in an open-cohort study with 4-monthly follow-up visits. Primary prevention included peer-led information, education and communication sessions, condom distribution, regular HIV counselling and testing, and sexually transmitted infections management. Participants were offered free medical care including antiretroviral therapy (ART) and treatment adherence support by psychologists. Results: From December 2003, 658 high-risk women were enrolled and followed up for a median 20.8 months. Seven of the 489 HIV-uninfected women seroconverted (HIV incidence 0.9 of 100 person-years, 95% confidence interval: 0.24 to 1.58). HIV incidence tended to be higher during the first 8 months of follow-up than thereafter (1.43 vs. 0.39 per 100 person-years). Among 47 of 169 HIV-seropositive women who started ART, 79.4% achieved undetectable plasma viral load 6 months after initiation and 81.8% at 36 months. Condom use at last sexual intercourse with clients increased from 81.7% at enrollment to 98.2% at 12 months (P < 0.001) and from 67.2% to 95.9% (P < 0.001) with regular clients. Conclusions: The integration of HIV care services, including the provision and support of ART, with a peer-led primary prevention package is pivotal to reduce HIV incidence and is likely to modify the local HIV dynamics.

A study of inclusive production of the meson resonances ρ0, K*0 (892), f{hook}0 (975) and f{hook}2 (1270) in hadronic decays of the Z0 is presented. The measured mean meson multiplicity per hadronic event is 0.83 ± 0.14 for the ρ0 0.64 ± 0.24 for the K*0 (892), 0.10 ± 0.04 for the f{hook}0 (975) in the momentum range p > 0.05pbeam (xp > 0.05) and 0.11 ± 0.05 for the f{hook}2 (1270) for xp > 0.1. These values and the corresponding differential cross sections ( 1 σhadr) dσ dxp for the vector mesons are in good agreement with the predictions of the JETSET 7.3 PS and HERWIG 5.4 models. The f{hook}2 (1270) production is overestimated by HERWIG but its xp-shape is correctly reproduced. The measured ratios of the production cross sections σ(f{hook}2(1270)) σ(ρ0) = 0.22 ± 0.08 and σ(f{hook}2(1270)) σ(f{hook}0(975)) = 3-1 +7 for xp > 0.1 are consistent with the results obtained in hadronic reactions. © 1993.

A specific 135-kDa protein was purified from porcine cauda epididymal fluid. Analysis of its N-terminal amino acid sequence revealed it to be a new protein. Stable clones of hybridomas that produced monoclonal antibodies against the purified 135-kDa protein were established. A clone, B-11, reacting both with epididymal fluid and with sperm plasma membranes was selected and used in this study. Immunoblotting analysis showed that B-11 reacted only with a 135-kDa protein among epididymal fluid proteins. In contrast, B-11 did not recognize a similar 135-kDa sperm protein but did strongly react with a 27-kDa protein among sperm membrane proteins, extracted by NP-40 in the presence of protease inhibitors. B-11 also reacted only with a 27-kDa protein fragment among trypsin digests of the 135-kDa epididymal protein. The 135-kDa protein was first detected, by ELISA or immunoblotting analysis, at the beginning of the corpus epididymis. Maximal levels were reached in the distal corpus and levels were slightly decreased in the cauda epididymis. On the other hand, the surface of caput sperm were found to contain small amounts of antigen(s), the concentration of which gradually increased during epididymal transit. In immunocytochemical studies, the antigen was detectable in the epithelial cells from the initial segment to the corpus of the epididymis but not in the caudal cells. In the lumen, the presence of the 135 kDa protein was apparent in the corpus (at a maximum in the middle and distal corpus) and to a lesser degree in the caudal lumen. The 27-kDa protein was distributed all over the equatorial region of the acrosome of less than 10% of caput epididymal sperm. As sperm passed through the corpus epididymis, the percentage of immunoreactive cells increased and the protein was restricted to specific domains of the sperm head. Thus, on the mature sperm, antigen was localized in a crescent-shaped area of the equatorial segment just behind the anterior part of the acrosome and on the apical rim of the sperm head. This is the first observation of a sperm surface antigen derived from an epididymal protein as a proteolytic fragment that interacts with specific regions of the sperm membrane during the process of spermatozoa maturation.

The number of HIV trials in Africa is increasing, and they target population groups with high HIV incidence, such as sex workers. Little information, however, is available about the adherence to long-term therapy among such marginalized groups with few economic resources and poor social and family support. A project called "Yerelon" ("know herself" in the Dioula language) began in 1998 in Bobo-Dioulasso to improve the health of women involved in commercial sex through STI/HIV prevention and care adapted to them. This study was conducted before introducing long-term treatment to the population, to assess the effect of communication with those around them on the capacity of these vulnerable women to adhere to drug prescriptions.The study was based on interviews conducted during the pilot phase of a 3-month trial of vitamins with potential participants. It concerned two groups of women: one group was infected with HIV (N = 22), the other was not (N = 20); all women in both groups were infected by HSV-2, however. For 5 weeks, the two psychologists of the study team in charge of adherence assessment carried out weekly in-depth interviews with the participants. The qualitative data analysis was organised around several themes. The data were related to aspects of communication with family and friends, serologic results, and adherence.According to our definition of communication about treatment, 20 participants communicated with their family and friends; adherence was good for all but three of them. Women who reported that they were married or living with someone (7/42) nearly all spoke about the study treatment (06/07) with him. Of 16 participants living in a family, 10 communicated with them about the treatment. On the other hand, as seems logical, single women who lived alone spoke less often about the treatment with family and friends (04/19). Talking about the treatment did not appear to involve the family or friends in the treatment; no one reminded any participant, whether she lived alone or in a family, to take her medicine. Nor did this discussion seem "helpful" to any of the women. Twenty-two participants hid the study treatment from family and friends; adherence was good for all but two of these. Social management of the treatment was related to HIV serologic status and relationships with family and friends. Concern about gossip about HIV status made it difficult to integrate the treatment into conversation. Those who did not agree to communicate with their family about the treatment did not even take the drug in the sight of the others. Sometimes, refusal to communicate was aimed at avoiding disapproval when the family did not have a favorable perception of prolonged treatment. Hiding the treatment was not an obstacle to good adherence. Adherence was related to perception of the treatment more than to communication about it.Adherence was similar in cases with and without communication. It appeared that these marginalized women, without social networks, were able to adhere correctly to a long-term treatment. To minimize the risks of non-adherence, the support system planned must take into account the factors influencing perceptions of the drug. Specific psychological support centered on the relation with the drug appears necessary during treatment initiation and follow up.

International audience; The design of radioactive ion production systems by Isotope Separator On Line method requires knowledge of diffusion features of atoms out of solids. With respect to the large number of possible diffusing atoms in target material, it is often difficult to find the right information in the literature, and inter-comparisons are often difficult due to differences in the experimental techniques and conditions. The TARGISOL European collaboration has the aim to study the relevant variables governing the release of radioactive elements from targets, to produce new radioactive ion beams and to build a data base which can facilitate the design of radioactive ion beam setups. The role of GANIL in this collaboration is to develop and produce new radioactive beams and provide new diffusion coefficient data. For this purpose, GANIL has designed a new system which removes part of the problems of comparing data. The approach is systematic measurements of release properties from several targets using the same process, the same apparatus and during the same experiment. This new approach will be presented with the set-up and the characterizing tests of the apparatus. Results of two experimental periods will be presented at this conference

International audience; This work has been carried out at GANIL within the ambit of the TARGISOL European collaboration which aims to study the relevant variables governing the release of radioactive elements from targets in an ISOL system. This work shows how it has been possible to extract diffusion coefficients for 35Ar atoms diffusing out of graphite targets from release time measurements by using an analytic description of the release times. The diffusion coefficients and efficiencies are presented and compared with results obtained using a “continuous” method.

International audience; An original approach to the time behavior of an isotope-separator-on-line production system is proposed in the case of a production system where the target and the ion source are connected through a conductance much larger than that of the exit hole of the source. One major goal of this article is to derive the analytical expression of the response time of the system for noble gases from statistical parameters only, which can be deduced from a few simple measurements. The validity limits of the expression of the total efficiency are given, and the calculations are compared to the results obtained at GANIL during operation of SPIRAL 1, using a carbon target close coupled to a multicharged electron cyclotron resonance ion source. The final analytical expression for the total efficiency shows that the usual product of diffusion efficiency, effusion efficiency, and ionization efficiency cannot be applied in our case. We show how it is possible to predict the atom-to-ion transformation efficiency for radioactive isotopes of noble gas using response times measured for stable isotopes.

International audience; The 100 kV platform used for the production of primary beams has been modified in order to increase the beam intensity. The configuration of the new platform is described and preliminary results are reported. A gain intensity of a factor of 2 has already been obtained for sulfur: $^{36}$S (65% enriched) 3.2 kW at 77.5 MeV/u, i.e., 1.14 p$\mu$A, as well as for nickel: $^{58}$Ni (68%) 1.5 kW at 74.5 MeV/uA, i.e., 0.35 p$\mu$A.

International audience; A new system has been designed to inject the 10 GHz rf power in the NANOGAN III ion source dedicated to the ionization of exotic atoms from the production target of the SPIRAL system at GANIL. The present system, based on a rectangular-to-coaxial transition equipped with a tuning piston, has been replaced by a direct rectangular-to-circular wave guide to feed the plasma of the source. We present the constraints related to the rf injection and a comparison is given of the present and new injection systems.

Production of radioactive ions has started at GANIL on the SPIRAL facility since 2001 and numerous multicharged radioactive ion beams have been delivered for high energy nuclear experiments. This article makes an overview of the different beams that have been produced. In the mean time, an important R and D research program is continued in oder to produce new species of radioactive elements. A new concept of multicharged radioactive production that couples a monocharged ion source, based on the monolithe concept, to an ecr ion source like nanogan3 is under developments and is described The development of monocharged ion sources with high efficiencies is also motivated by a new big project that is under studies at GANIL : the SPIRAL 2 Project. The goal of this project consists in extending the disponible radioactive ion beams to very heavy elements created with a new method of production : while the spiral 1 facility uses the projectile fragmentation for radioactive nuclei production, the spiral 2 project is based on the fission of a Uranium carbide target induced by a neutron flow created by a high intensity deuton beam. The principle and an overview of the project is presented.Production of radioactive ions has started at GANIL on the SPIRAL facility since 2001 and numerous multicharged radioactive ion beams have been delivered for high energy nuclear experiments. This article makes an overview of the different beams that have been produced. In the mean time, an important R and D research program is continued in oder to produce new species of radioactive elements. A new concept of multicharged radioactive production that couples a monocharged ion source, based on the monolithe concept, to an ecr ion source like nanogan3 is under developments and is described The development of monocharged ion sources with high efficiencies is also motivated by a new big project that is under studies at GANIL : the SPIRAL 2 Project. The goal of this project consists in extending the disponible radioactive ion beams to very heavy elements created with a new method of production : while the spiral 1 facility uses the projectile fragmentation for radioactive nuclei production, the spiral 2 project ...

International audience; MONOBOB, a new electron cyclotron resonance ion source (ECRIS) has been designed to ionise the radioactive elements coming from the production target of the SPIRAL II project. The goal was to build a long-lived ECRIS to work in the hostile environment of the target while presenting good ionisation efficiencies for gases. The numerous constraints related to the operation in a facility classed as ‘nuclear' have been taken into account during the design of the source. In this paper, however, we have concentrated in particular on (i) the radiation hardness of the magnetic structure, (ii) the injection of the RF power, (iii) the ionisation efficiency for noble gases, (iv) the ability of the source to work despite major outgassing and (v) the beam emittance. The first version of this source was tested to validate its principle by measurements of its performance. The results obtained with He, Ne and Ar permit us to predict ionisation efficiencies for Kr and Xe of the order of 80%, even with outgassing flows of the order of 1.2 × $10^16$ particle $s_1$. Under the same working conditions, between 60% and 80% of the beam current is included within an emittance of 30$\pi$ mm mrad at 20 kV, which could still be improved. Using the results obtained with the first version of the source, a second version respecting all the SPIRAL II constraints has now been designed and is under construction.

International audience; Two new target-source systems have been realized and used to produce radioactive elements with primary beams of 78Kr (68.5 A MeV) and 36Ar (95 A MeV). The production yields of 73,72Kr, 35,33,32Ar, 30,29P, 31,30S, 34,33,32Cl and of some other condensable elements such as 73,72Br and 73,71Se are presented. The results of the improvements between the two versions of the production system are discussed.

Homocysteine, derived from the metabolism of methionine, is claimed as a proatherogenic factor that leads to vascular dysfunction. To gain better insight into the molecular mechanisms involved, homocysteine was tested on a model of murine endothelial cells cultured in vitro, using a prototype DNA chip. The DNA chip was designed to follow the expression at the mRNA level of some major proinflammatory genes; TNF-alpha was used as a positive control.

This paper presents a necessary and sufficient condition for the factorizability of higher order spectra of complex signals. Such a factorizability condition can be used to test if a complex signal can model the output of a linear and time invariant system driven by a stationary non-Gaussian white input. The condition developed here is based on the symmetries of higher order spectra and on an extension of a formula proposed by Marron et al. (1990) to unwrap third order spectrum phases. It is an identity between the products of six higher order spectra values (which reduces to four values if only phases are considered). Our factorizability test requires no phase unwrapping, unlike existing methods developed in the cepstral domain. Moreover its extension to the N-th order case is direct. Simulations illustrate the deviation to this factorizability condition in a factorizable case (linear system) and a non-factorizable case (non-linear system).

In this paper we give an analytic optimal solution to the identification problem of non minimum phase systems using the fourth order spectra. We show that this solution is in first approximation equivalent to the solution given by the well-known kurtosis maximization method. The proposed solution gives the phase of the system transfer function, the modulus can be obtained from the second order statistics. However this solution requires trispectrum phase unwrapping as the trispectrum phase is known in the interval [-/spl pi/,/spl pi/] but needs to be unwrapped in the interval [-4/spl pi/,4/spl pi/] in order to obtain the optimal solution. Therefore, we present different phase unwrapping solutions. Next, we propose a method to improve the trispectrum phase estimation using a factorizability condition. Simulation results are given and the algorithm shows good behavior even with few data.

Human immunodeficiency virus (HIV)-associated bacillary angiomatosis has rarely been described in Africa. We report here the first case in Côte d'Ivoire. Although in industrialised countries bacillary angiomatosis has been described in patients with low CD4 count, this episode occurred in the first year following HIV-seroconversion in an adult patient with more than 500 CD4 cells per cubic millimetre. Symptoms rapidly and totally disappeared under erythromycin treatment, although with a relapse two years after the end of the first episode. In Africa where people living with HIV often present chronic cutaneous lesions, bacillary angiomatosis may be under-diagnosed. Bacillary angiomatosis must be systematically considered in face of lesions similar to Kaposi's sarcoma. Improving knowledge on symptoms of bacillary angiomatosis in Africa should lead to better treatment and a better estimation of its true frequency which may be underestimated.

In insects, the transport of airborne, hydrophobic odorants and pheromones through the sensillum lymph is accomplished by olfactory-binding proteins (CBPs). We report the structural characterization of a honeybee OBP called ASP1 found in workers and drones, previously observed to bind queen pheromone components. A novel method based on ion-spray mass spectrometry analysis of cyanylation-induced cleavage products of partially reduced protein with Tris(2-carboxyethyl)phosphine was needed to determine the recombinant ASP1 disulfide bond pairing. It was observed to be Cys(I)-Cys(III), Cys(II)-Cys(V), Cys(IV)-Cys(VI), similar to those already described for other OBPs from honeybee and Bombyx mori suggesting that this pattern occurs commonly throughout the diverse family of insect OBPs. Circular dichroism revealed that ASP1 is an all-alpha protein in accordance with NMR preliminary data, but unlike lipocalin-like vertebrate OBPs.

This study aimed to determine the physiological role of laminin (LN) and its receptor, alpha(6)beta(1) integrin, in controlling the functions of granulosa cells (GC) during follicular development in sheep ovary. Immunohistochemistry experiments showed the presence of increasing levels of LN (P

In order to characterise the behaviour of radon decay products under domestic conditions, long-term measurements were carried out from May 1997 to April 1998 in a typical dwelling located in Brittany (France). In particular, the unattached fraction and equilibrium factor were continuously measured. Moreover, the size distributions of unattached and attached radon daughters were investigated by using specific instruments implemented in the laboratory. All these experiments were carried out under different typical aerosol conditions. The results evidenced the strong influence exerted by the characteristics (concentration, size) of ambient aerosol on these different parameters.

In insects, the transport of airborne, hydrophobic odorants and pheromones through the sensillum lymph is generally thought to be accomplished by odorant-binding proteins (OBPs). We report the structural and functional properties of a honeybee OBP called ASP2, heterologously expressed by the yeast Pichia pastoris. ASP2 disulfide bonds were assigned after classic trypsinolysis followed by ion-spray mass spectrometry combined with microsequencing. The pairing [Cys(I)-Cys(III), Cys(II)-Cys(V), Cys(IV)-Cys(VI)] was found to be identical to that of Bombyx mori OBP, suggesting that this pattern occurs commonly throughout the highly divergent insect OBPs. CD measurements revealed that ASP2 is mainly constituted of alpha helices, like other insect OBPs, but different from lipocalin-like vertebrate OBPs. Gel filtration analysis showed that ASP2 is homodimeric at neutral pH, but monomerizes upon acidification or addition of a chaotropic agent. A general volatile-odorant binding assay allowed us to examine the uptake of some odorants and pheromones by ASP2. Recombinant ASP2 bound all tested molecules, except beta-ionone, which could not interact with it at all. The affinity constants of ASP2 for these ligands, determined at neutral pH by isothermal titration calorimetry, are in the micromolar range, as observed for vertebrate OBP. These results suggest that odorants occupy three binding sites per dimer, probably one in the core of each monomer and another whose location and biological role are questionable. At acidic pH, no binding was observed, in correlation with monomerization and a local conformational change supported by CD experiments.

In Saccharomyces cerevisiae, the existence of PYC1 and PYC2 encoding cytosolic pyruvate carboxylase isoform I and II is rather puzzling, owing to the lack of potent differential gene regulation by the carbon sources. We report several findings indicating that these two genes are differentially regulated by the nature of the nitrogen source. In wild-type cells, the activity of pyruvate carboxylase, which is the sum of pyruvate carboxylase isoform I and II, was two- to fivefold lower in carbon medium containing aspartate, asparagine, glutamate or glutamine instead of ammonium as the nitrogen source, whereas it was 1.5- to threefold higher when the ammonium source was substituted by arginine, methionine, threonine or leucine. These enzymatic changes were independent of the nature of the carbon source and closely correlated to the changes in beta-galactosidase from PYC1-lacZ gene fusion and in PYC1 transcripts. Transfer of exponentially growing cells of the pyc2 mutant from an aspartate or a glutamate medium to an ammonium medium caused a fivefold increase in PYC1 mRNA in less than 30 min, whereas in the inverse experiment, PYC1 transcripts returned within 30 min to the low levels found in aspartate/glutamate medium. By contrast, these conditions affected neither the pyruvate carboxylase activity encoded by PYC2 nor PYC2 mRNA. Considering that changes in PYC1 expression inversely correlated with changes in alpha-ketoglutarate concentration or in alpha-ketoglutarate/glutamate ratio following the nitrogen shift experiments, and taking into account the pivotal role of this metabolite in ammonium assimilation, it is suggested that changes in alpha-ketoglutarate or in the alpha-ketoglutarate/glutamate ratio might be implicated in triggering the nitrogen effects on PYC1 expression. The physiological significance of the differential sensitivity of PYC1 and PYC2 genes with respect to the nitrogen source in the growth medium is also discussed.

After characterization of a novel odorant-binding protein (OBP) variant isolated from the rat nasal mucus, the corresponding cDNA was cloned by RT-PCR. Recombinant OBP-1F, the sequence of which is close to that of previously reported rat OBP-1, has been secreted by the yeast Pichia pastoris at a concentration of 80 mg.L-1 in a form identical to the natural protein as shown by MS, N-terminal sequencing and CD. We observed that, in contrast with porcine OBP-1, purified recombinant OBP-1F is a homodimer exhibiting two disulfide bonds (C44-C48 and C63-C155), a pairing close to that of hamster aphrodisin. OBP-1F interacts with fluorescent probe 1-aminoanthracene (1-AMA) with a dissociation constant of 0.6 +/- 0. 3 microM. Fluorescence experiments revealed that 1-AMA was displaced efficiently by molecules including usual solvents such as EtOH and dimethylsulfoxide. Owing to the large OBP-1F amounts expressed, we set up a novel biomimetic assay (volatile-odorant binding assay) to study the uptake of airborne odorants without radiolabelling and attempted to understand the odorant capture by OBP in the nasal mucus under natural conditions. The assay permitted observations on the binding of airborne odorants of different chemical structures and odors (2-isobutyl-3-methoxypyrazine, linalool, isoamyl acetate, 1-octanal, 1-octanol, dimethyl disulfide and methyl thiobutyrate). Uptake of airborne odorants in nearly physiological conditions strengthens the role of OBP as volatile hydrophobic odorant carriers in the mucus of the olfactory epithelium through the aqueous barrier towards the chemo-sensory cells.