The Mobile Analyzer of Radioactive Gases OuTflows (MARGOT): A promising environmental xenon radionuclides detection system.

An ultra-compact and unshielded spectrometer for analysis of atmospheric xenon radionuclides has been developed: the MARGOT system. This system works at ambient temperature and high pressure, and has a 54.3 cm3 inner active volume. Atmospheric xenon radionuclide activities are determined with the electron-photon coincidence technique using both NaI(Tl) detectors and large pixellized Si-PIN detectors. The MARGOT system integrates an enhanced version of the PIPSBox™, Geant4 simulation and first calibration results are discussed.

Introducing the MARGOT prototype: An ultra-compact and mobile gas detection system for nuclear explosion monitoring.

An ultra-compact and unshielded spectrometer for analysis of atmospheric radioxenons has been developed. This system works at ambient temperature and has a 58 cm3 inner active volume. Atmospheric radioxenons activities are determined with electron/photon coincidence technique using both NaI(Tl) detector and large pixellized Si-PIN detector. The performances of the detection system without shielding in terms of Minimal Detectable Activities are below 65 mBq for a 12 h acquisition, for all radioxenons of interest. An enhanced version of the prototype presented here is already under development: the Mobile Analyzer for Radioactive Gases OuTflows (MARGOT) system.

Credentialing for robotic lobectomy: what is the learning curve? A retrospective analysis of 272 consecutive cases by a single surgeon.

Credentialing processes for surgeons seeking robotic thoracic surgical privileges are not evidence-based, and the learning curve has not been reported. The goal of this study is to review our experience with robotic lobectomies and provide evidence for the development of a more uniform credentialing process. We performed a retrospective review of the first 272 consecutive robotic lobectomies performed between 2011 and 2017 by a single surgeon with prior video-assisted thoracoscopic (VATS) experience. Primary outcomes were operative duration, blood loss, chest tube duration, length of hospital stay, intraoperative complication, and conversion to thoracotomy. The patients were subdivided by surgical date into two cohorts of 120 consecutive patients to compare differences in outcomes, thereby illustrating the learning curve. Between 2011 and 2017, 272 patients (median age 67.5 years) underwent a robotic lobectomy by a single surgeon. The majority of patients (157/272) had early stage (T1N0) adenocarcinoma. For the entire cohort, median operative time was 160 min (83-317 min). The median blood loss was 75 mL (10-4000 mL). Median chest tube duration was 2 days (1-23 days) and median hospital stay was 3 days (1-25 days). Intraoperative complications occurred in seven patients. Only six patients required conversion to thoracotomy. Using multivariable logistic regression, it was found that the age, gender, and stage do not factor into conversion to thoracotomy, but BMI was found to be a significant covariate (p 0.043). As the surgeon performs more surgeries, there is a significantly shorter operative time (p < 0.001), decreased blood loss (p < 0.001), and shorter hospital stay (p < 0.014). When the first 120 and last 120 surgeries were compared, there was significantly less blood loss (234.6 vs 78.69 cc, p < 0.001), shorter operative time (181.9 vs 147.4 min, p < 0.001), shorter tube duration (3.49 vs 3.11 days, p 0.007), and shorter length of stay (4.03 vs 3.48 days, p < 0.001), respectively. More intraoperative complications were observed during the first 120 surgeries (6/120) compared to the last 120 surgeries (0/120; Fischer exact p = 0.029). Regression model plots did not show any apparent and significant change points, but rather a steady improvement. The more cases the surgeon does, the better is the outcome in terms of operative duration, blood loss, post-operative length of stay and intraoperative complications. The learning curve for robotic surgery for a surgeon with prior VATS experience is that of a continuous improvement with experience instead of a particular change point. Since most thoracic surgeons who perform robotic-assisted surgery have already gotten past their VATS learning curves, they no longer have a definable learning curve for robotic surgery. Hence, if a surgeon is already proficient and credentialed to perform VATS lung resections, he or she is no longer faced with a significant learning curve for robotic lung resections, and should be credentialed to do so once he or she has undergone the appropriate training with the equipment and technology.

Low-level laboratory measurement of xenon radionuclides: Electron-photon versus photon measurements.

Radioactive xenon (mainly 131mXe, 133Xe, 133mXe and 135Xe) are tracked as markers of nuclear weapons testing. The CEA has developed the PIPSBox, a measurement cell able to detect electrons emitted by xenon nuclides. Combined with an ultra-low background γ spectrometer, electron detection capacities allow reaching minimum detectable activities (MDA) for a 3-day long measurement of about 0.5mBq for the four xenon radionuclides. Compared to a classical measurement cell, MDAs are improved by a factor of 2-4.

Dose escalated neoadjuvant chemoradiotherapy with dose-painting intensity-modulated radiation therapy and improved pathologic complete response in locally advanced esophageal cancer.

We compared pathologic complete response (pCR) rate, toxicity, and postoperative complications between patients treated preoperatively with 50.4 Gy versus dose escalation with dose-painting intensity-modulated radiation therapy (dp-IMRT) to 56 Gy in locally advanced esophageal cancer. We evaluated esophageal cancer patients treated between 2006 and 2014 with preoperative IMRT chemoradiation to a dose of 50.4 Gy versus 56 Gy. The endpoints were pCR and toxicity. We identified 113 patients (50.4 Gy: n = 40; 56 Gy: n = 73). There were no significant differences in tumor or patient characteristics. Patients treated with 56 Gy demonstrated a higher pCR rate (56.2% vs. 30.0%) and lower pathologic nonresponse rate (4.1% vs. 20.0%) compared to patients treated to 50.4 Gy (P = 0.008). This remained significant on multivariate analysis (OR 3.375 95%CI 1.3-8.8, P = 0.013). Patients treated to 56 Gy also had an improved 3-year locoregional control rate compared to those treated to 50.4 Gy (93.8% vs. 78.5%; P = 0.022). The estimated 3-year freedom from failure was also superior in the 56 Gy arm (73.7% vs. 52.2%; P = 0.051), approaching significance. There were no differences in treatment related grade ≥3 toxicities, hospital admissions, feeding tube, esophageal stent placement, or dilation. There was, however, a statistically significant increase in postoperative atrial fibrillation in patients treated with 56 Gy (30.1% vs. 12.5%; P = 0.036). There was no difference in postoperative 30 or 60 day mortality. Dose escalation to 56 Gy with dp-IMRT is safe and results in significantly higher complete pathologic response rates in esophageal cancer without an increase in treatment-related toxicity. Prospective trials using dp-IMRT are needed to address the role of dose escalation on pCR rate and survival in esophageal cancer.

Prevalence, risk factors, and impact on clinical outcome of extended-spectrum beta-lactamase-producing Escherichia coli bacteraemia: a five-year study.

BACKGROUND: The impact of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) bacteraemia on outcome remains controversial. METHODS: A retrospective analysis of the prevalence, risk factors, clinical features, and outcomes of all ESBL-EC bacteraemia in one French hospital over a 5-year period was performed. A case-control study was undertaken: cases had at least one ESBL-EC bacteraemia and controls a positive non-ESBL-EC bacteraemia. RESULTS: The prevalence of ESBL-EC bacteraemia increased from 5.2% of all positive E. coli blood cultures in 2005 to 13.5% in 2009 (p<0.003). CTX-M represented 70% of ESBL-EC bacteraemia strains, and strains were not clonally related. On adjusted analysis, the only significant risk factor for ESBL-EC bacteraemia was a previous ESBL-EC colonization (odds ratio 11.3, 95% confidence interval 1.2-107; p=0.003). Initial antimicrobial therapy was less frequently adequate in the ESBL-EC group (48% vs. 85%; p=0.003). The presence of ESBL-EC bacteraemia was not associated with a longer hospital stay (p=0.088). Day 30 mortality was high, but not significantly different in the two groups (30% vs. 27%; p=0. 82). CONCLUSION: The prevalence of ESBL-EC bacteraemia has been increasing dramatically. Previous colonization with ESBL-EC was a strong risk factor for ESBL-EC bacteraemia. More inadequate initial antimicrobial therapy was noted in the ESBL-EC group, but mortality and length of hospital stay were not significantly different from those of patients with non-ESBL-EC bacteraemia.

Spalax™ new generation: A sensitive and selective noble gas system for nuclear explosion monitoring.

In the context of the verification regime of the Comprehensive nuclear Test ban Treaty (CTBT), CEA is developing a new generation (NG) of SPALAX™ system for atmospheric radioxenon monitoring. These systems are able to extract more than 6cm(3) of pure xenon from air samples each 12h and to measure the four relevant xenon radioactive isotopes using a high resolution detection system operating in electron-photon coincidence mode. This paper presents the performances of the SPALAX™ NG prototype in operation at Bruyères-le-Châtel CEA centre, integrating the most recent CEA developments. It especially focuses on an innovative detection system made up of a gas cell equipped with two face-to-face silicon detectors associated to one or two germanium detectors. Minimum Detectable activity Concentrations (MDCs) of environmental samples were calculated to be approximately 0.1 mBq/m(3) for the isotopes (131m)Xe, (133m)Xe, (133)Xe and 0.4 mBq/m(3) for (135)Xe (single germanium configuration). The detection system might be used to simultaneously measure particulate and noble gas samples from the CTBT International Monitoring System (IMS). That possibility could lead to new capacities for particulate measurements by allowing electron-photon coincidence detection of certain fission products.

An introduction to γ(3) a new versatile ultralow background gamma spectrometer. Background description and analysis.

The γ(3) setup has been designed as a versatile, high sensitivity spectrometry platform. State-of-the art techniques have been implemented to reduce its background to minimum level even though the system is installed at ground level. The shield design and background performance of the setup are presented. The spectrometer is composed of three identical HPGe detectors for high detection efficiency or coincidence measurement and can accommodate several sample geometries. Its shield includes three layers of increasing purity lead, a cosmic veto, an inner borated polyethylene layer, and a radon-free gas injection system. The spectrometer normalized background count rate is 4.4 counts per minutekgGe(-1) (in the 40-2500keV energy range). Its background characteristics, cosmic veto efficiency, and radon-free gas injection performances are discussed.

On the use of (127)Xe standards for the quality control of CTBTO noble gas stations and support laboratories.

(127)Xe has a longer half-life than (131m)Xe, it can be easily purely produced and it is present in the environment at very low level. For these reasons, (127)Xe is supposed to be a convenient quality control radionuclide for remote noble gas stations of the International Monitoring System (IMS) network. As CEA/DAM has recently developed two new photon/electron setups for low-level detection of (131m)Xe, (133m)Xe, (133)Xe and (135)Xe, we took the opportunity to test these setups for the measurement of a (127)Xe standard. The results and a detailed description of these measurements are presented in this paper. They illustrate the complexity of (127)Xe decay, emitting simultaneously several γ, X-rays, conversion electrons and Auger electrons; this results in highly summated coincidence spectra. The measurements performed provide precise electron energy calibration of the setups. The count rate of electrons in coincidence with iodine Kα X-rays was found to be surprisingly low, leading to the study of electron-gated photon spectrum. Finally, a comparison of three photon/electron coincidence spectra obtained with three different setups is given. The use of (127)Xe as a standard for energy calibration of IMS noble gas station is possible, but it appears to be quite complicated for efficiency check of noble gas station equipped with ß/γ detectors.

Improvements of low-level radioxenon detection sensitivity by a state-of-the art coincidence setup.

The ability to quantify isotopic ratios of 135, 133 m, 133 and 131 m radioxenon is essential for the verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT). In order to improve detection limits, CEA has developed a new on-site setup using photon/electron coincidence (Le Petit et al., 2013. J. Radioanal. Nucl. Chem., DOI : 10.1007/s 10697-013-2525-8.). Alternatively, the electron detection cell equipped with large silicon chips (PIPS) can be used with HPGe detector for laboratory analysis purpose. This setup allows the measurement of ß/γ coincidences for the detection of (133)Xe and (135)Xe; and K-shell Conversion Electrons (K-CE)/X-ray coincidences for the detection of (131m)Xe, (133m)Xe and (133)Xe as well. Good energy resolution of 11 keV at 130 keV and low energy threshold of 29 keV for the electron detection were obtained. This provides direct discrimination between K-CE from (133)Xe, (133m)Xe and (131m)Xe. Estimation of Minimum Detectable Activity (MDA) for (131m)Xe is in the order of 1mBq over a 4 day measurement. An analysis of an environmental radioxenon sample using this method is shown.

Correlation between urine ketones (acetoacetate) and capillary blood ketones (3-beta-hydroxybutyrate) in hyperglycaemic patients.

AIMS: To facilitate the transition from urine ketones (acetoacetate) to capillary blood ketones (3-beta-hydroxybutyrate), we studied the correlation between these two tests. METHODS: Retrospective study of all patients with blood glucose greater than or equal to 2.5 g/l on arrival in the Emergency Department. We studied the correlation between urine ketones (Clinitek 50, Bayer) and capillary blood ketones (Optium, Abbott). We then compared the relative risks (RR) of ketoacidosis and hospitalization associated with each of these tests. RESULTS: In 33 months, 529 adult patients with both urine and blood testing for ketones were enrolled (ketoacidosis 8%, admission rate 49%). Urine ketones scored as +, ++ and +++ corresponded to median capillary blood ketone levels of 0.5 mmol/l (IQR: 0.1-0.9), 0.7 mmol/l (IQR: 0.2-1.8) and 3 mmol/l (IQR: 1.4-5.2), respectively. RRs of ketoacidosis or hospitalization associated with blood ketones greater than or equal to 3 mmol/l were higher than those associated with +++ urine ketones: 74 (95% confidence interval [CI]: 48-88) and 2.9 (95% CI: 2.5-3) versus 31 (95% CI: 18-45) and 2 (95% CI: 1.7-2.1), respectively. CONCLUSIONS: In hyperglycaemic patients in the Emergency Department, a good correlation was observed between urine ketones and capillary blood ketones for low values, but a poor correlation was observed for high values. Either test can therefore be used to exclude ketosis, but the capillary blood ketones test is more accurate to confirm ketoacidosis.

Automated radioxenon monitoring for the comprehensive nuclear-test-ban treaty in two distinctive locations: Ottawa and Tahiti.

In preparation for verification of the Comprehensive Nuclear-Test-Ban-Treaty, automated radioxenon monitoring is performed in two distinctive environments: Ottawa and Tahiti. These sites are monitored with SPALAX (Systeme de Prelevement d'air Automatique en Ligne avec l'Analyse des radioXenons) technology, which automatically extracts radioxenon from the atmosphere and measures the activity concentrations of (131m,133m,133,135)Xe. The resulting isotopic concentrations can be useful to discern nuclear explosions from nuclear industry xenon emissions. Ambient radon background, which may adversely impact analyser sensitivity, is discussed. Upper concentration limits are reported for the apparently radioxenon free Tahiti environment. Ottawa has a complex radioxenon background due to proximity to nuclear reactors and medical isotope facilities. Meteorological models suggest that, depending on the wind direction, the radioxenon detected in Ottawa can be characteristic of the normal radioxenon background in the Eastern United States, Europe, and Japan or distinctive due to medical isotope production.

Esophagectomy in a patient with AIDS.

As the life expectancy of AIDS patients continues to increase due to improved anti-retroviral therapy less of these patients die of HIV-related illnesses. Dysphagia is a common complaint in AIDS patients and usually results from a fungal esophagitis. While cancer of the esophagus is occasionally found in AIDS patients, we report our experience with an AIDS patient diagnosed with a squamous cell esophageal malignancy who received pre-operative radiation and chemotherapy, followed by transhiatal esophagectomy. The patient is alive 16 months post-operatively. The transition of HIV/AIDS from an acute fulminant disease to a chronic condition mandates that these patients should receive full and standard therapy for their esophageal malignancies.

Atmospheric xenon radioactive isotope monitoring.

The Comprehensive Nuclear Test Ban Treaty (CTBT) organisation is implementing a world-wide monitoring network in order to check that the State Signatories comply with the treaty. One of the monitoring facilities consists of an atmospheric noble gas monitoring equipment. According to the requirements annexed in the treaty, the French Atomic Energy Commission (CEA) developed a device, called SPALAX, which automatically extracts xenon from ambient air and makes in situ measurements of the activities of four xenon radioisotopes (131mXe, 133mXe, 133Xe, 135Xe). The originality of this device is noticeable essentially in the gas sample processing method: thanks to the coupling of a gas permeator and of a noble gas specific adsorbent, it can selectively extract and concentrate xenon to more than 3 x 10 E6. This process is carried out continuously without cryogenic cooling, without any regeneration time. The detection of the xenon radioactive isotopes is done automatically by high spectral resolution gamma spectrometry, a robust technology well-suited for on-field instrumentation. In the year 2000, a prototype was involved in an international evaluation exercise directed by the CTBT organisation (CTBTO). This exercise demonstrated that the SPALAX equipment perfectly met the requirements of the CTBTO for such systems. On the basis of the continuous 24-h resolution record of the atmospheric xenon radioactive isotopes concentrations, the SPALAX system also demonstrated that ambient levels of 133Xe can fluctuate quickly from less than the detection limit to over 40 x 10(-3) Bq m(-3). In order to build an industrial version of this equipment, the CEA entered into a partnership with a French engineering company (S.F.I., Marseille, France), which is now able to produce an industrial version of SPALAX, i.e. more compact and more efficient than the prototypes. The 133Xe minimum detectable concentration is 0.15 x 10(-3) Bq m(-3) air per 24 h sampling cycle.

Intercomparison experiments of systems for the measurement of xenon radionuclides in the atmosphere.

Radioactive xenon monitoring is one of the main technologies used for the detection of underground nuclear explosions. Precise and reliable measurements of (131m)Xe, (133g)Xe, (133m)Xe, and (135g)Xe are required as part of the International Monitoring System for compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). For the first time, simultaneous testing of four highly sensitive and automated fieldable radioxenon measurement systems has been performed and compared to established laboratory techniques. In addition to an intercomparison of radioxenon monitoring equipment of different design, this paper also presents a set of more than 2000 measurements of activity concentrations of radioactive xenon made in the city of Freiburg, Germany in 2000. The intercomparison experiment showed, that the results from the newly developed systems agree with each other and the equipment fulfills the fundamental requirements for their use in the verification regime of the CTBT. For 24-h measurements, concentrations as low as 0.1 mBqm(-3) were measured for atmospheric samples ranging in size from 10 to 80 m(3). The (133)Xe activity concentrations detected in the ambient air ranged from below 1 mBqm(-3) to above 100 mBqm(-3).

Inelastic neutron-scattering study of the proton transfer dynamics in polyglycine I at 20 K.

Inelastic neutron-scattering (INS) spectra of three isotopic derivatives of polyglycine I (-COCH2NH-)n, (-COCD2NH-)n, and (-COCH2ND-)n at 20 K are presented from 30 to 4000 cm(-1). The band frequencies are compared to those observed in the infrared and Raman. Assignments in terms of group vibrations are proposed. These mostly resemble previous assignment schemes, except for the amide bands. The INS intensities reveal that the proton dynamics for the (N)H proton are totally different from those proposed previously. They are independent of the molecular frame and the valence bond approach is not consistent with observation. A phenomenological approach is proposed in terms of localized modes. The calculated intensities reveal that the (N)H stretching mode has two components at approximately 1377 and 1553 cm(-1). This is a dramatic change compared to all former assignments at approximately 3280 cm(-1) based on infrared and Raman data. These proton-dynamics are associated with a weakening of the NH bond due to the ionic character of the hydrogen bond (N(delta-)...H+...O(delta'-)) and proton transfer. The infrared and Raman spectra are re-examined and a new assignment scheme is proposed for the amide bands; the amide A and B bands are re-assigned to the overtones of the stretching modes. A symmetric double-minimum potential for the proton is consistent with all the observations.

[Epidemiology of giardiasis]. / Sur l'épidémiologie de la giardiase.

Prevalence analysis in the Gard; fluctuations according to seasons, age and sex. Statement a excystation method after passage in a induction solution; observations and excystation rate. Cysts resistance study in exterior middle at various temperature: at dry from -5 degrees C to 40 degrees C, in fresh water from -5 degrees C to 20 degrees C and in sea water at 10 degrees and 20 degrees C. Epidemiologic consequences.