Impact of COVID-19 on 2020 transplant activity and waiting lists in France✰,✰✰.

The COVID-19 pandemic strongly affected organ procurement and transplantation in France, despite the intense efforts of all participants in this domain. In 2020, the identification and procurement of deceased donors fell by 12% and 21% respectively, compared with the mean of the preceding 2 years. Similarly, the number of new registrations on the national waiting list declined by 12% and the number of transplants by 24%. The 3-month cumulative incidence of death or drop out for worsening condition of patients awaiting a liver transplant was significantly greater in 2020 compared to the previous 2 years. Continuous monitoring at the national level of early post-transplant outcomes showed no deterioration for any organ in 2020. At the end of 2020, less than 1% of transplant candidates and less than 1% of graft recipients - of any organ - had died of COVID-19.

Digital proximity tracing on empirical contact networks for pandemic control.

Digital contact tracing is a relevant tool to control infectious disease outbreaks, including the COVID-19 epidemic. Early work evaluating digital contact tracing omitted important features and heterogeneities of real-world contact patterns influencing contagion dynamics. We fill this gap with a modeling framework informed by empirical high-resolution contact data to analyze the impact of digital contact tracing in the COVID-19 pandemic. We investigate how well contact tracing apps, coupled with the quarantine of identified contacts, can mitigate the spread in real environments. We find that restrictive policies are more effective in containing the epidemic but come at the cost of unnecessary large-scale quarantines. Policy evaluation through their efficiency and cost results in optimized solutions which only consider contacts longer than 15-20 minutes and closer than 2-3 meters to be at risk. Our results show that isolation and tracing can help control re-emerging outbreaks when some conditions are met: (i) a reduction of the reproductive number through masks and physical distance; (ii) a low-delay isolation of infected individuals; (iii) a high compliance. Finally, we observe the inefficacy of a less privacy-preserving tracing involving second order contacts. Our results may inform digital contact tracing efforts currently being implemented across several countries worldwide.

Molar Incisor Hypomineralization: Etiology, Clinical Aspects, and a Restorative Treatment Case Report.

CLINICAL RELEVANCE: Total-etch adhesive systems and resin composite are clinically viable dental materials for esthetic restorations in teeth presenting white/yellow/brown hypomineralization stains. SUMMARY: Molar-incisor hypomineralization (MIH) is a condition that negatively affects enamel and dentin, especially the first molars and permanent incisors, causing esthetic and functional problems. The present clinical case report presents and discusses the etiology and clinical characteristics of MIH and describes a restorative protocol for MIH-affected teeth.

Research plans in Europe for radiation health hazard assessment in exploratory space missions.

The European Space Agency (ESA) is currently expanding its efforts in identifying requirements and promoting research towards optimizing radiation protection of astronauts. Space agencies use common limits for tissue (deterministic) effects on the International Space Station. However, the agencies have in place different career radiation exposure limits (for stochastic effects) for astronauts in low-Earth orbit missions. Moreover, no specific limits for interplanetary missions are issued. Harmonization of risk models and dose limits for exploratory-class missions are now operational priorities, in view of the short-term plans for international exploratory-class human missions. The purpose of this paper is to report on the activity of the ESA Topical Team on space radiation research, whose task was to identify the most pertinent research requirements for improved space radiation protection and to develop a European space radiation risk model, to contribute to the efforts to reach international consensus on dose limits for deep space. The Topical Team recommended ESA to promote the development of a space radiation risk model based on European-specific expertise in: transport codes, radiobiological modelling, risk assessment, and uncertainty analysis. The model should provide cancer and non-cancer radiation risks for crews implementing exploratory missions. ESA should then support the International Commission on Radiological Protection to harmonize international models and dose limits in deep space, and guarantee continuous support in Europe for accelerator-based research configured to improve the models and develop risk mitigation strategies.

Contaminants of emerging concern in freshwater fish from four Spanish Rivers.

This study investigated the occurrence of 135 contaminants of emerging concern (CECs) - pharmaceuticals, pesticides, a set of endocrine disrupting compounds (EDCs) (parabens, bisphenols, hormones, triazoles, organophosphorus flame retardants and triclosan), UV-filters, perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) - in 59 fish samples, collected in 2010 in 4 Spanish Rivers (Guadalquivir, Júcar, Ebro and Llobregat). Of the 135 CECs, 76 including 8 pharmaceuticals, 25 pesticides, 10 EDCs, 5 UV-filters, 15 PFASs and 13 HFRs were detected. Pharmaceuticals were the less frequently found and at lower concentrations. Pesticides, EDCs, UV-filters, PFASs and HFRs were detected more frequently (>50% of the samples). The maximum concentrations were 15 ng/g dry weight (dw) for pharmaceuticals (diclofenac), 840 ng/g dw for pesticides (chlorpyrifos), 224 ng/g dw for EDCs (bisphenol A), 242 ng/g dw for UV-filters (EHMC), 1738 ng/g dw for PFASs (PFHxA) and 64 ng/g dw for HFRs (Dec 602). The contaminants detected in fish are commonly detected also in sediments. In light of current knowledge, the risk assessment revealed that there was no risk for humans related to the exposure to CECs via freshwater fish consumption. However, results provide detailed information on the mixtures of CECs accumulated that would be very useful to identify their effects on aquatic biota.

A two-phase sampling survey for nonresponse and its paradata to correct nonresponse bias in a health surveillance survey.

BACKGROUND: The decline in participation rates in surveys, including epidemiological surveillance surveys, has become a real concern since it may increase nonresponse bias. The aim of this study is to estimate the contribution of a complementary survey among a subsample of nonrespondents, and the additional contribution of paradata in correcting for nonresponse bias in an occupational health surveillance survey. METHODS: In 2010, 10,000 workers were randomly selected and sent a postal questionnaire. Sociodemographic data were available for the whole sample. After data collection of the questionnaires, a complementary survey among a random subsample of 500 nonrespondents was performed using a questionnaire administered by an interviewer. Paradata were collected for the complete subsample of the complementary survey. Nonresponse bias in the initial sample and in the combined samples were assessed using variables from administrative databases available for the whole sample, not subject to differential measurement errors. Corrected prevalences by reweighting technique were estimated by first using the initial survey alone and then the initial and complementary surveys combined, under several assumptions regarding the missing data process. Results were compared by computing relative errors. RESULTS: The response rates of the initial and complementary surveys were 23.6% and 62.6%, respectively. For the initial and the combined surveys, the relative errors decreased after correction for nonresponse on sociodemographic variables. For the combined surveys without paradata, relative errors decreased compared with the initial survey. The contribution of the paradata was weak. CONCLUSION: When a complex descriptive survey has a low response rate, a short complementary survey among nonrespondents with a protocol which aims to maximize the response rates, is useful. The contribution of sociodemographic variables in correcting for nonresponse bias is important whereas the additional contribution of paradata in correcting for nonresponse bias is questionable.

[Surveillance of work-related suicide in France: An exploratory study]. / Surveillance des suicides liés au travail en France : une étude exploratoire.

BACKGROUND: Despite a large media coverage of the phenomenon, the number of work-related suicides is currently unknown in France. There are nevertheless some data available to document this important issue. The aim of this study was to explore the feasibility of an epidemiological surveillance system for work-related suicides designed to quantify and describe work-related suicides mainly according to economic sectors and occupational categories. METHODS: Existing data sources in France were identified and evaluated for their relevance and their potential use in a multi-sources surveillance system. A regional pilot study was performed using the main relevant sources identified to investigate different aspects of the system design. RESULTS: Four major data sources were identified to be used to describe work-related suicides: death certificates, social insurance funds, data collected by the officers of the labor inspectorate and data collected from autopsy reports in forensic departments. The regional pilot study gave an estimate of 28 cases of work-related suicide in two years. CONCLUSION: The findings point out the difficulties involved and the criteria for successful implement of such a system. The study provides some solutions for carrying out this system, the achievement of which will depend upon particular resources and partners' agreements. Recommendations for the next steps have been made based on this work, including possible collaboration with forensic departments, which collect essential data for surveillance.

Simultaneous determination of 16 organophosphorus flame retardants and plasticizers in fish by liquid chromatography-tandem mass spectrometry.

In this work a method to analyze simultaneously sixteen organophosphorus flame retardants (OPFRs) by liquid chromatography-quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS) in fish samples was successfully developed. Sample preparation strategies, including different extraction techniques and clean-ups were tested. The chosen methodology is based on the extraction of 0.25 g of dried fish by ultrasound and clean-up by solid phase extraction (SPE) with a tandem of C18 and basic alumina cartridges. Recoveries were between 45 to 115%, with RSDs lower than 25%. mLODs and mLOQs were between 0.34-11.6 ng/g lw and 1.12-38.8 ng/g lw, respectively, with the exception of Tris(tribromoneopentyl)phosphate (TBNPP) (37.4 and 125 ng/g lw, respectively) and Tris(isopropyl-phenyl)phosphate (IPPP) (51.6 and 172 ng/g lw, respectively) which had higher limits. The developed method was applied to twelve river fish samples. Thirteen out of sixteen analyzed compounds were detected. At least, one of the sixteen studied OPFRs was detected in all the analyzed samples, with ΣOPFR levels up to 2423 ng/g lw. This is the first study reporting IPPP and Isodecyldiphenyl phosphate (IDPP) levels in biota samples. Moreover, levels found for IPPP are quite high (up to 601 ng/g lw) and thus it is important to consider in the future development of analytical methodologies for OPFR analysis.

Antimicrobial photodynamic therapy and dental plaque: a systematic review of the literature.

BACKGROUND: The aim of this study was to perform a systematic review of the literature on the efficacy of antimicrobial photodynamic therapy (PDTa) on cariogenic dental biofilm. TYPES OF STUDIES REVIEWED: Studies in vivo, in vitro, and in situ were included. Articles that did not address PDTa, those that did not involve cariogenic biofilm, those that used microorganisms in the plankton phase, and reviews were excluded. Data extraction and quality assessments were performed independently by two raters using a scale. RESULTS: Two hundred forty articles were retrieved; only seventeen of them met the eligibility criteria and were analyzed in the present review. Considerable variability was found regarding the methodologies and application protocols for antimicrobial PDTa. Two articles reported unfavorable results. PRACTICAL IMPLICATIONS: The present systematic review does not allow drawing any concrete conclusions regarding the efficacy of antimicrobial PDTa, although this method seems to be a promising option.

Emerging and historical halogenated flame retardants in fish samples from Iberian rivers.

Forty-eight fish samples from the Llobregat, Ebro, Júcar and Guadalquivir river basins (Spain), were analyzed for polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB) and halogenated norbornenes (HNs). The most contaminated river basin was the Llobregat, followed by the Ebro, Júcar and Guadalquivir for almost every analyzed contaminant. Most abundant PBDE congener was BDE-47 (BDL-396 ng/g lw) and the most abundant halogenated norbornene was Dechlorane-602 (BQL-174 ng/g lw). Fanti was calculated to determine the different bioaccumulation/biodegradation of syn-DP and anti-DP. Biota to sediment accumulation factor was calculated in order to compare the bioaccumulation capacity of emerging flame retardants with that of "classical" PBDEs. It was found that bioaccumulation of halogenated norbornenes is lower than that of PBDEs. BDE-99, HBB, PBEB and Dechlorane-604 were not detected in any sample.

Intracellular distribution of Tankyrases as detected by multicolor immunofluorescence techniques.

Poly(ADP-ribose) polymerases are a family of enzymes that catalyze the conversion of NAD+ into ADP-ribose. Among them, Tankyrases have been found to bind to centrosome, mitotic spindle and microsome proteins, in the cytoplasm, and to telomeres in the nucleus, where they play a relevant role in telomere metabolism. However, their precise intracellular localization during interphase has not been so far fully elucidated. We investigated this aspect in situ by double immunofluorescence experiments using antibodies recognizing Tankyrases 1-2 or other proteins residing in specific organelles (Golgi apparatus, mitochondria, lysosomes, endoplasmic reticulum). We used HeLa cells as a model system in vitro, before and after treatment with either actinomycin D or etoposide, to also investigate the possible relocation of Tankyrases during apoptosis. We observed that Tankyrases are distributed both in the nucleus and in the cytoplasm; in this latter compartment, they were found to colocate with the Golgi apparatus but never with the mitochondria; a pool of Tankyrases also colocates with the endoplasmic reticulum and lysosomes. Interestingly, in cells with clear signs of apoptosis, Tankyrases were detectable in the cytoplasmic blebs: this suggests that they are not massively cleaved during apoptosis and persist in the largely heterogeneous apoptotic remnants which are known to contain components of cytoplasmic and nuclear origin.

Hypocrellin-B acetate as a fluorogenic substrate for enzyme-assisted cell photosensitization.

Photosensitizing molecules (PSs) undergo chemico-physical changes upon addition of suitable substituents, influencing both their photophysical properties and their ability to accumulate into cells. Once inside the cells, the modified PS acts as a fluorogenic substrate: the added substituent is removed by a specific enzyme, restoring the native PS in subcellular sensitive sites. We investigated the photophysical properties and interaction with HeLa cells of Hypocrellin-B (HypB), as native molecule and upon acetate-group addition (HypB-Ac). Chemical modification alters both absorption and fluorescence features of HypB; consequently, the dynamics of the enzyme hydrolysis of HypB-Ac can be monitored through restoring the native HypB spectral properties. At the cellular level, only the HypB emission signal was detected within 5 min of incubation with either HypB or HypB-Ac, allowing a direct comparison of the time courses of their intracellular accumulation. Plateau values were reached within 15 min of incubation with both compounds, the emission signals being significantly higher in HypB-Ac than in HypB treated cells. Consistently, imaging showed a rapid appearance of red fluorescence in the cytoplasm, with more abundant bright spots in HypB-Ac treated cells. Both compounds did not induce dark toxicity at concentrations up to 1 × 10(-6) M, while upon irradiation at 480 nm phototoxicity was significantly higher for cells exposed to HypB-Ac than for HypB-loaded cells. These findings suggest an improved efficacy of acetylated HypB to be internalized by cells through membrane trafficking, with a preferential interaction of the photoactive molecules on sensitive intracellular sites. After irradiation, in HypB-Ac treated cells, prominent disorganization of several cytoplasmic organelles such as the endoplasmic reticulum, Golgi apparatus, lysosomes, microfilaments and microtubules were observed.

Different patterns of apoptosis in response to cisplatin in B50 neuroblastoma rat cells.

Cisplatin (cisPt) is a chemotherapeutic drug used for several human malignancies. CisPt cytotoxicity is primarily mediated by its ability to cause DNA damage and subsequent apoptotic cell death. DNA is the primary target of cisPt; however, recent data have shown that cisPt may have important direct interactions with mitochondria, which can induce apoptosis and may account for a significant part of the clinical activity associated with this drug. We have previously demonstrated that in the rat neuronal cell line B50, at 20 h-treatment with cisPt activates apoptosis through an intrinsic pathway involving an alteration of mitochondrial membrane permeability and the release of cytochrome c. The present study investigates different death pathways induced in the same cell line by a prolonged treatment with 40 µM cisPt for 48 h. To address this issue, we focused on caspases-8 and -12, and on the mitochondrial apoptosis inducing factor (AIF), which translocates to the nucleus and induces cell death via caspase-independent pathway. We found that cisPt activates different forms of cell death, i.e. the receptor-mediated apoptotic extrinsic pathway and a death process mediated by endoplasmic reticulum stress. Moreover, we demonstrated that AIF-mediated death occurs, being characterized by the translocation of AIF from mitochondria to the nucleus. On the whole, we provided evidence that prolonged cisPt treatment is able to activate both caspase-dependent and caspase-independent apoptotic pathways in B50 rat neuronal cells.

Developing central nervous system and vulnerability to platinum compounds.

Comparative studies on the effects of the platinum complexes in use or in clinical trials are carried out in order to discover differences in the neurotoxic potential and the reversibility of neurotoxicity. In this paper, we summarized the current literature on neurotoxicity and chemoresistance of cisplatin (cisPt) and discussed our recent efforts on the interference of cisPt and a new platinum compound [Pt(O,O'-acac)(γ-acac)(DMS)] (PtAcacDMS), with high specific reactivity with sulphur ligands instead of nucleobases as cisPt, on some crucial events of rat postnatal cerebellum development. The acute effects of drug treatments on cell proliferation and death in the external granular layer and granule cell migration and the late effects on the dendrite growth of Purkinje cells were evaluated. Together with the demonstrated antineoplastic effectiveness in vitro, compared with cisPt, data suggest a lower neurotoxicity of PtAcacDMS, in spite of its presence in the brain that involves considerations on the blood brain barrier permeability.

[Suicide and occupation in France]. / Suicide et activité professionnelle en France.

BACKGROUND: Suicide is a complex and multifactorial phenomenon. The number of work-related suicides is difficult to assess in France. There are nevertheless some data available to document this problem. The aim of this study is to describe suicide attempts (SA) and suicide mortality according to occupation in France. METHODS: The description of SA relies on the "Baromètre Santé 2005", a cross-sectional representative survey conducted by the Inpes in France. The study population includes 6264 men and 7389 women in employment at the time of the survey. The prevalence of all life SA is described according to occupational category (one and two digits). Data on suicide mortality before the age of 65 comes from the Cosmop project, conducted by the Department of Occupational Health/InVS, and based on data from the "Echantillon démographique permanent"/Insee linked to medical causes of death from the French national death registry (CepiDc/Inserm). People included was born in France, employed at one of censuses (1968, 1975, 1982 and 1990, 187,938 men, 150,683 women). Relative risks for suicide mortality were estimated for the last known occupational category and economic sector. RESULTS: The prevalence of life course SA was higher among women than among men (6.6% vs 3.1%); an opposite situation was observed for mortality. Regarding salaried people, categories of manual workers and clerks are the most affected by SA and mortality from suicide whereas executives are the least concerned. Farmers were little affected by SA (0.4% men, 4.1% women) but experienced the highest rate of mortality by suicide (RR=3.1 men, RR=2.2 women). Among women, compared to non market sectors, the agricultural and equipment goods sectors exhibited an excessive risk of mortality from suicide. CONCLUSION: This study points out SA and mortality from suicide inequalities by occupational categories and to a lesser extent by economic sector. These results provide a first assessment on suicide according to occupation in France.

Monte Carlo simulation of the radiation environment encountered by a biochip during a space mission to Mars.

Simulations with a Monte Carlo tool kit have been performed to determine the radiation environment a specific device, called a biochip, would face if it were placed into a rover bound to explore Mars' surface. A biochip is a miniaturized device that can be used to detect organic molecules in situ. Its specific detection part is constituted of proteins whose behavior under cosmic radiation is completely unknown and must be investigated to ensure a good functioning of the device under space conditions. The aim of this study is to define particle species and energy ranges that could be relevant to investigate during experiments on irradiation beam facilities. Several primary particles have been considered for galactic cosmic ray (GCR) and solar energetic particle (SEP) contributions. Ionizing doses accumulated in the biochip and differential fluxes of protons, alphas, neutrons, gammas, and electrons have been established for both the Earth-Mars transit and the journey at Mars' surface. Neutrons and gammas appear as dominant species on martian soil, whereas protons dominate during the interplanetary travel. Depending on solar event occurrence during the mission, an ionizing dose of around a few Grays (1 Gy = 100 rad) is expected.

Hepatoma tissue culture (HTC) cells as a model for investigating the effects of low concentrations of herbicide on cell structure and function.

Previous studies on mice fed genetically modified (GM) soybean demonstrated modifications of the mitochondrial functions and of the transcription/splicing pathways in hepatocytes. The cause(s) of these alterations could not be conclusively established but, since the GM soybean used is tolerant to glyphosate and was treated with the glyphosate-containing herbicide Roundup , the possibility exists that the effects observed may be due to herbicide residues. In order to verify this hypothesis, we treated HTC cells with 1-10mM Roundup and analysed cellular features by flow cytometry, fluorescence and electron microscopy. Under these experimental conditions, the death rate and the general morphology of HTC cells were not affected, as well as most of the cytoplasmic organelles. However, in HTC-treated cells, lysosome density increased and mitochondrial membranes modified indicating a decline in the respiratory activity. Moreover, nuclei underwent morpho-functional modifications suggestive of a decreased transcriptional/splicing activity. Although we cannot exclude that other factors than the presence of the herbicide residues could be responsible for the cellular modifications described in GM-fed mice, the concordance of the effects induced by low concentrations of Roundup on HTC cells suggests that the presence of Roundup residues could be one of the factors interfering with multiple metabolic pathways.

Peribulbar and retrobulbar combined anesthesia for vitreoretinal surgery using ropivacaine.

PURPOSE: To evaluate the efficacy and clinical effects of local retrobulbar anesthesia using ropivacaine in vitreoretinal surgery. METHODS: Prospective study. A total of 919 vitreoretinal operations were followed. The operations were divided into three groups, depending on the degree of anesthesia needed. Group A: Vitrectomies with episcleral procedures (208 vitrectomies for detached retina or perforating trauma). Group B: Episcleral procedures only (410 operations for detached retina without vitrectomy). Group C: Vitrectomies without episcleral surgery (301 operations for macular pucker or hole, proliferative diabetic retinopathy, or silicone oil removal). Anesthesia was administered using a 23-gauge Atkinson-type retrobulbar needle, after topical anesthesia. Six mL of the solution containing 7.5 mg ropivacaine/mL were injected into the peribulbar space, and the other 4 mL deeper, into the retrobulbar space. The degree of infiltration of the palpebral region, the motor block in the extrinsic ocular muscles, and pain felt were checked and rated. RESULTS: Swelling of lids was seen in 885 patients (96%); in 21 (2%) swelling was partial. In 13 patients (1%) there were no signs of infiltration. The motor block was total in 801 (87%) eyes, while 118 (12%) had reduced ocular movements. The degree of anesthesia was as follows, considering the three groups together: no pain = 855 (93%) patients; moderate pain = 44 (4%) patients; very strong pain = 20 (2%) patients. No adverse events or side effects were observed. CONCLUSIONS: Ropivacaine used for retrobulbar-peribulbar combined anesthesia in vitreoretinal surgery showed excellent clinical efficacy as regards analgesia and muscle akinesia.

GATE: a simulation toolkit for PET and SPECT.

Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort is also invested in the ability and the flexibility to model novel detection systems or systems still under design. A public release of GATE licensed under the GNU Lesser General Public License can be downloaded at http:/www-lphe.epfl.ch/GATE/. Two benchmarks developed for PET and SPECT to test the installation of GATE and to serve as a tutorial for the users are presented. Extensive validation of the GATE simulation platform has been started, comparing simulations and measurements on commercially available acquisition systems. References to those results are listed. The future prospects towards the gridification of GATE and its extension to other domains such as dosimetry are also discussed.

Validation of the GATE Monte Carlo simulation platform for modelling a CsI(Tl) scintillation camera dedicated to small-animal imaging.

Monte Carlo simulations are increasingly used in scintigraphic imaging to model imaging systems and to develop and assess tomographic reconstruction algorithms and correction methods for improved image quantitation. GATE (GEANT4 application for tomographic emission) is a new Monte Carlo simulation platform based on GEANT4 dedicated to nuclear imaging applications. This paper describes the GATE simulation of a prototype of scintillation camera dedicated to small-animal imaging and consisting of a CsI(Tl) crystal array coupled to a position-sensitive photomultiplier tube. The relevance of GATE to model the camera prototype was assessed by comparing simulated 99mTc point spread functions, energy spectra, sensitivities, scatter fractions and image of a capillary phantom with the corresponding experimental measurements. Results showed an excellent agreement between simulated and experimental data: experimental spatial resolutions were predicted with an error less than 100 microns. The difference between experimental and simulated system sensitivities for different source-to-collimator distances was within 2%. Simulated and experimental scatter fractions in a [98-182 keV] energy window differed by less than 2% for sources located in water. Simulated and experimental energy spectra agreed very well between 40 and 180 keV. These results demonstrate the ability and flexibility of GATE for simulating original detector designs. The main weakness of GATE concerns the long computation time it requires: this issue is currently under investigation by the GEANT4 and the GATE collaborations.