A review on cesium desorption at the freshwater-seawater interface.

Understanding the processes governing the behavior of radiocesium in the sea is still essential to make accurate assessments of its potential impacts on marine ecosystems. One of the most important of this process is the desorption that may occur at the river-sea interface due to changes in physico-chemical conditions, including ionic strength and solution composition. It has been the subject of many studies using field measurements or laboratory experiments, but there was no global interpretation of these works and their results. The present review summarizes relevant laboratory experiments studying desorption of Cs (stable or radioactive) from particles in sea or brackish waters. To date, 32 experimental studies have been carried out on 68 Cs-bearing samples since 1964. A wide range of desorbed fraction (0-86%) was observed, partly depending on the experimental design. For particles containing radiocesium issued from a contamination in the environment, the desorption ranges from 0 to 64% of the particulate activity, with a median at only 3%. Particles contaminated in laboratory show a range between 6 and 86% with a multimodal distribution. The desorption initiates at low salinity (3-4) and rapidly reaches a threshold around 10-15. Laboratory experiments show that two first-order reactions govern the kinetics of the process, with half-life reaction times of 1 h and a few days. These two reactions are probably linked to the adsorption of Cs onto different particles sites. Also, the dynamic of Cs desorption depends on its initial distribution on these different sites, in relation with the history of its contamination and an aging effect.

[Epileptic seizures and hematemesis in a young patient with sickle cell disease]. / Épilepsie puis hématémèse chez une jeune patiente drépanocytaire.

INTRODUCTION: Sickle cell disease is a multi-faceted disease, which can affect all organs. Here, we report the case of a young woman whose clinical presentation was confusing. CASE REPORT: An 18-year-old patient from Martinique in Caribbean area presented to the emergency room with widespread pain, as part of a vaso-occlusive crisis. She reported being followed for SS sickle cell anemia, with a history of vaso-occlusive crises and exchange transfusions in the past. Her hemoglobin rate was 83g/L. She was treated with opioid analgesics. Then, she presented several generalized tonic-clonic seizures and major episodes of hematemesis, which proved to be simulated by the patient, whose hemoglobin electrophoresis result was finally AS. CONCLUSION: This patient had therefore the Münchausen syndrome, mimicking sickle cell anemia, like eight other cases reported in the literature.

Perfusion defects after pulmonary embolism: risk factors and clinical significance.

BACKGROUND: Little is known about residual abnormalities after pulmonary embolism (PE). OBJECTIVES: To assess risk factors and the clinical significance of perfusion defects in patients with PE. PATIENTS/METHODS: Consecutive patients receiving at least 3 months of anticoagulant for an acute PE were included in a prospective cohort study. Ventilation/perfusion lung scan, echocardiography, 6-min walk test, thrombophilia and hemostatic variables were performed 6-12 months after PE. Perfusion defect was defined as a perfusion defect in at least two segments. RESULTS: Seventy-three out of 254 patients (29%) had perfusion defects during follow-up (median 12 months) and were more likely to have dyspnea, had a higher systolic pulmonary arterial pressure [39 mmHg (SD) (12) vs. 31 mmHg (8); P < 0.001] and walked a shorter distance during the 6-min walk test [374 m (122) vs. 427 m (99); P = 0.004]. Age [odds ratio (OR) 1.35; 95% confidence interval (CI), 1.11-1.63], the time interval between symptom onset and diagnosis (OR, 1.17; 95% CI, 1.04-1.31), pulmonary vascular obstruction at the onset of PE (OR, 1.34; 95% CI, 1.16-1.55) and previous venous thromboembolism (OR 2.06; 95% CI, 1.03-4.11) were independent predictors of perfusion defect after treatment of acute PE. Total tissue factor pathway inhibitor concentration was associated with perfusion defects. CONCLUSIONS: Perfusion defects are associated with an increase in pulmonary artery pressure (PAP) and functional limitation. Age, longer times between symptom onset and diagnosis, initial pulmonary vascular obstruction and previous venous thromboembolism were associated with perfusion defects.

Place of human amniotic membrane immunoblotting in the diagnosis of autoimmune bullous dermatoses.

BACKGROUND: Fine analysis of antiskin autoantibodies can contribute to the differential diagnosis of autoimmune bullous dermatoses. OBJECTIVES: To develop a high-performance immunoblotting method using human amniotic membrane as the antigen source, and to compare it with current laboratory methods. METHODS: Sera from 113 patients were tested by immunoblotting (IB), rat and monkey oesophagus and salt-split skin indirect immunofluorescence (IIF), and enzyme-linked immunosorbent assay (ELISA) quantification of anti-BP180-NC16a and anti-BP230, or antidesmoglein (Dsg) 1 and 3 antibodies. There were 56 cases of bullous pemphigoid (BP), 22 cases of mucous membrane pemphigoid (MMP), eight cases of epidermolysis bullosa acquisita (EBA), two cases of bullous systemic lupus erythematosus (BSLE), 17 cases of pemphigus vulgaris (PV), and four cases each of pemphigus foliaceus (PF) and paraneoplastic pemphigus (PNP). RESULTS: In BP, the three methods had similar sensitivity (84-89%) for both anti-BP180-NC16a and anti-BP230 antibody detection. In MMP, autoantibodies (mainly directed against BP180 or laminin 332 subunits) were detected in 77% of patients by IB, compared with only 9% by IIF on rat and monkey oesophagus and 36% on salt-split skin, and 14% by anti-BP180-NC16a and anti-BP230 ELISA. In patients with pemphigus, ELISA had 92% sensitivity for anti-Dsg1 and 3, but IB and rat bladder IIF were necessary to confirm PNP by revealing specific and rare patterns (antidesmoplakin I/II, antienvoplakin and antiperiplakin antibodies). IB also revealed anticollagen VII antibodies in 60% of patients with EBA and BSLE, and antibodies to BP180, BP230 and Dsg3 in a few patients who were negative using the other two techniques. CONCLUSION: Amniotic membrane immunoblotting is an interesting diagnostic tool for bullous diseases, as the entire panel of autoantibodies can be detected with a single extract. This method improves the identification of complex and heterogeneous autoimmune processes in conjunction with IIF and ELISA, and is particularly useful for MMP characterization.

Four-Element Receiver for Pulsed 10-mum Heterodyne Doppler Lidar.

A four-element photomixer receiver has been tested in a 10-mum heterodyne Doppler lidar. It addresses a reduction of the variance of the power scattered off distributed aerosols targets at ranges as long as 8 km. An improvement in performance is expected when the four independent signals recorded on every single shot are combined. Two summation techniques of the four signals have been implemented: a coherent summation of signal amplitude and an incoherent summation of intensities. A phasing technique for the four signals is proposed. It is based on a more suitable correlation time with discernible self-consistent packets (SCP's). The SCP technique has been successfully tested, and the results obtained with a coherent summation of the four signals, i.e., variance reduction, carrier-to-noise ratio improvement, and velocity accuracy improvement, are in agreement with theory.