An assessment of contamination pickup on ground robotic vehicles for nuclear surveying application.

Ground robotic vehicles are often deployed to inspect areas where radioactive floor contamination is a prominent risk. However, the accuracy of detection could be adversely affected by enhanced radiation signal through self-contamination of the robot occurring over the course of the inspection. In this work, it was hypothesised that a six-legged robot could offer advantages over the more conventional ground robotic devices such as wheeled and tracked rovers. To investigate this, experimental contamination testing and computational Monte Carlo simulation techniques (GEANT4) were employed to understand how radioactive contamination pick-up on three different robotic vehicles would affect their detection accuracy. Two robotic vehicles were selected for comparison with the hexapod robot based on their type of locomotion; a wheeled rover and a tracked rover. With the aid of a non-toxic fluorescent tracer dust, the contamination received by the all three vehicles when traversing a contaminated area was initially compared through physical inspection using high definition cameras. The parametric results from these tests where used in the computational study carried out in GEANT4. A cadmium zinc telluride detector was simulated at heights ranging from 10 to 50 cm above each contaminated vehicle, as if it were mounted on a plinth. Assuming a uniform activity of 60 Bq cm-2on all contaminated surfaces, the results suggested that due to the hexapod's small ground-contacting surface area and geometry, radiation detection rates using an uncollimated detector are likely to be overestimated by between only 0.07%-0.12%, compared with 3.95%-8.43% and 1.75%-14.53% for the wheeled and tracked robot alternatives, respectively.

The kinetics and mechanism of the uranium hydride - water vapour system under ambient conditions.

This work investigated the reaction of uranium hydride powder with saturated water vapour at 25 °C. Two corrosion experiments were conducted one with deionised water (H2O) and one with deuterated water (D2O). The kinetics of the reaction were measured through gas generation method while concurrent residual gas analysis (RGA) allowed better understanding of the oxidation mechanism governing the system. From the analysis, it was found that the kinetics of the reaction are robust initially, followed by quasi-linear decelerating regime indicative of a 'shrinking core' type oxidation behaviour. The extent of the reaction (conversion to UO2) was lower in comparison to other works. The reaction remained incomplete bolstering the case of UH3 persistence in legacy wastes. Through interpretation of the gas analysis data, a mechanism for the uranium hydride water reaction was suggested.

A review of the reaction rates of uranium corrosion in water.

This work conducts a review on the kinetics of the uranium and water reaction system by gathering all available kinetic data and across a wide range of reaction conditions. Temperature and pressure dependent kinetic equations that describe the reaction are derived for the uraniumwater vapour and uranium-liquid water systems. Detailed tables which provide information about the reaction conditions and other parameters for each rate point are constructed. From evaluation of the tables, the effects of underlying parameters on the reaction kinetics are discussed. It is suggested that these parameters contribute to the reported discrepancies between reaction rate values under similar conditions. Better prediction of the corrosion rate and rate behaviour can be achieved by combining the kinetic rate equations with the effect of these underlying parameters.

Evolving phenotype of systemic lupus erythematosus in Caucasians: low incidence of lupus nephritis, high burden of neuropsychiatric disease and increased rates of late-onset lupus in the 'Attikon' cohort.

OBJECTIVE: This study aimed to analyse the phenotype of systemic lupus erythematosus (SLE) at first presentation and during follow-up in a newly established SLE cohort based at 'Attikon' University Hospital. The hospital combines primary, secondary and tertiary care for the region of Western Attica, Greece. METHODS: This study comprised a mixed prevalent and incident cohort of 555 Caucasian patients diagnosed with SLE according to American College of Rheumatology 1997 criteria and/or the Systemic Lupus Erythematosus International Collaborating Clinics (SLICC) 2012 criteria. Demographic and clinical characteristics, patterns of severity, treatments and SLICC damage index were recorded for each patient at the time of diagnosis and at last evaluation. RESULTS: The mean age at lupus diagnosis was 38.3 years (standard deviation = 15.6 years), with a median disease duration at last follow-up of two years (interquartile range 1-11). At initial presentation, the most common 'classification' manifestations were arthritis (73.3%), acute cutaneous lupus (65%) and unexplained fever (25%), while among symptoms not included in any criteria set, Raynaud's phenomenon (33%) was the most common. Kidney and neuropsychiatric involvement as presenting manifestations were present in 10.3% and 11.5% cases, respectively. Irreversible damage accrual was present in 17.8% within six months of disease diagnosis, attributed mainly to thrombotic and neuropsychiatric disease. At last evaluation, 202 (36.4%) patients had developed severe disease, of whom more than half were treated with pulse cyclophosphamide. CONCLUSION: In this cohort of Caucasian patients, lupus nephritis is not as common as in older cohorts, while neuropsychiatric disease is emerging as a major frontier in lupus prevention and care. These data may help to document changes in the natural history and treatment of SLE over time and may have implications for its early recognition and management.

Interstitial sodium and lithium doping effects on the electronic and mechanical properties of silicon nanowires: a DFT study.

In this work, we present a theoretical study of the electronic band structure and the Young's modulus of hydrogen-passivated silicon nanowires (H-SiNWs), grown along the [110] crystallographic direction, as a function of the concentration of interstitial sodium (Na) and lithium (Li) atoms. The study is performed using the supercell scheme and the density functional theory (DFT), within the local density approximation (LDA). The results show that the presence of Na or Li atoms closes the former semiconducting band gap of the H-SiNWs and shifts the Fermi energy into the conduction band. The transition from semiconductor to metal occurs as soon as a single Na or Li atom is added to the nanowire and the number of occupied states near the Fermi level is larger for the H-SiNWs with Li atoms in comparison with those nanowires with the same concentration of Na atoms. The calculated formation energies reveal that the system becomes less stable when the concentration of Na and Li atoms augments. Moreover, the obtained binding energies indicate that Si-Li and Si-Na bonds are formed. It is worth mentioning that the binding energies of H-SiNWs with interstitial Li atoms are larger than those corresponding to the H-SiNWs with interstitial Na atoms. On the other hand, the Young's moduli of H-SiNWs with Na atoms are lower than those of pure H-SiNWs and their values diminish when the concentration of Na atoms increases. In contrast, Young's moduli of H-SiNWs present a non-monotonic behavior as a function of the concentration of interstitial Li atoms and for the largest studied concentration the nanowire fractures. These results give insight into the changes that electronic and mechanical properties of H-SiNWs suffer during the charge-discharge process, which should be taken into account in the design of electrodes of Na or Li-ion batteries.

Sexual dimorphism in SLE: above and beyond sex hormones.

Systemic lupus erythematosus (SLE) is characterized by aberrant production of auto-antibodies and a sexual dimorphism both in the phenotypic expression and frequency of the disease between males and females. The striking female predominance was initially attributed primarily to sex hormones. However, recent data challenge this simplistic view and point more towards genetic and epigenetic factors accounting for this difference. More specifically, several SLE-associated single-nucleotide polymorphisms (SNPs) have been found to play an important role in the gender predilection in SLE. Their effect is mediated through their involvement in sex-hormone and immune system signalling and dysregulation of the expression of genes and miRNAs pertinent to the immune system. Additionally, the genetic factors are interchangeably associated with epigenetic modifications such as DNA methylation and histone modification, thus revealing a highly complex network of responsible mechanisms. Of importance, disturbance in the epigenetic process of X chromosome inactivation in females as well as in rare X chromosome abnormalities leads to increased expression of X-linked immune-related genes and miRNAs, which might predispose females to SLE. Microbiota dysbiosis has also been implicated in the sexual dimorphism by the production of oestrogens within the gut and the regulation of oestrogen-responsive immune-related genes. Sexual dimorphism in SLE is an area of active research, and elucidation of its molecular basis may facilitate ongoing efforts towards personalized care.

Epidemiologia de la hipertensión pulmonar en Colombia / Epidemiology of pulmonary hypertension in Colombia

Resumen Objetivo: Estimar la prevalência e incidencia de la hipertensión pulmonar (HTP) en Colombia entre el periodo comprendido entre 2010 y 2014. Metodologia: Estudio de corte transversal utilizando la Bodega de Datos del Sistema Integral de Información de la Protección Social (SISPRO) del Ministerio de Salud y Protección Social (MSPS). Se incluyeron todas las personas atendidas a nivel nacional que tenían registrado los diagnósticos de Hipertensión Pulmonar Primaria (Clasificación Internacional de Enfermedades CIE-101270), durante el periodo establecido para el estudio. Resultados: Se estimó que la prevalencia e incidencia de HTP es de aproximadamente 52 y 20 casos por cada millón de habitantes, respectivamente. Predomina en el sexo femenino y en los grupos de edad mayores de 60 años. Conclusión: Las estimaciones epidemiológicas de la HTP en Colombia son compatibles con la definición de enfermedades huérfanas o raras.

Abstract Objective: To estimate the prevalence and incidence of pulmonary hypertension (PH) in Colombia between the period between 2010 and 2014. Methodology: Cross-sectional study using the Data Warehouse of the Social Protection Information System (SISPRO) of the Ministry of Health and Social Protection (MSPS). We included all the nationwide patients who had registered the diagnoses of Primary Pulmonary Hypertension (ICD-101270) during the period established for the study. Results: It was estimated that the prevalence and incidence of PH is approximately 52 and 20 cases per million inhabitants, respectively. It predominates in the female sex and in the age groups over 60 years. Conclusion: Epidemiological estimates of PH in Colombia are consistent with the definition of orphan or rare diseases.

In-situ, time resolved monitoring of uranium in BFS:OPC grout. Part 2: Corrosion in water.

To reflect potential conditions in a geological disposal facility, uranium was encapsulated in grout and submersed in de-ionised water for time periods between 2-47 weeks. Synchrotron X-ray Powder Diffraction and X-ray Tomography were used to identify the dominant corrosion products and measure their dimensions. Uranium dioxide was observed as the dominant corrosion product and time dependent thickness measurements were used to calculate oxidation rates. The effectiveness of physical and chemical grout properties to uranium corrosion and mobilisation is discussed and Inductively Coupled Plasma Mass Spectrometry was used to measure 238U(aq) content in the residual water of several samples.

Lithium effects on the mechanical and electronic properties of germanium nanowires.

Semiconductor nanowire arrays promise rapid development of a new generation of lithium (Li) batteries because they can store more Li atoms than conventional crystals due to their large surface areas. During the charge-discharge process, the electrodes experience internal stresses that fatigue the material and limit the useful life of the battery. The theoretical study of electronic and mechanical properties of lithiated nanowire arrays allows the designing of electrode materials that could improve battery performance. In this work, we present a density functional theory study of the electronic band structure, formation energy, binding energy, and Young's modulus (Y) of hydrogen passivated germanium nanowires (H-GeNWs) grown along the [111] and [001] crystallographic directions with surface and interstitial Li atoms. The results show that the germanium nanowires (GeNWs) with surface Li atoms maintain their semiconducting behavior but their energy gap size decreases when the Li concentration grows. In contrast, the GeNWs can have semiconductor or metallic behavior depending on the concentration of the interstitial Li atoms. On the other hand, Y is an indicator of the structural changes that GeNWs suffer due to the concentration of Li atoms. For surface Li atoms, Y stays almost constant, whereas for interstitial Li atoms, the Y values indicate important structural changes in the GeNWs.

In-situ, time resolved monitoring of uranium in BFS:OPC grout. Part 1: Corrosion in water vapour.

Uranium encapsulated in grout was exposed to water vapour for extended periods of time. Through synchrotron x-ray powder diffraction and tomography measurements, uranium dioxide was determined the dominant corrosion product over a 50-week time period. The oxide growth rate initiated rapidly, with rates comparable to the U + H2O reaction. Over time, the reaction rate decreased and eventually plateaued to a rate similar to the U + H2O + O2 reaction. This behaviour was not attributed to oxygen ingress, but instead the decreasing permeability of the grout, limiting oxidising species access to the metal surface.

Development of PLA films containing oregano essential oil (Origanum vulgare L. virens) intended for use in food packaging.

Consumers' concerns about the environment and health have led to the development of new food packaging materials avoiding petroleum-based matrices and synthetic additives. The present study has developed polylactic acid (PLA) films containing different concentrations of essential oil from Origanum vulgare L. virens (OEO). The effectiveness of this new active packaging was checked for use in ready-to-eat salads. A plasticising effect was observed when OEO was incorporated in PLA films. The rest of the mechanical and physical properties of developed films did not show much change when OEO was included in the film. An antioxidant effect was recorded only for films containing the highest percentages of the active agent (5% and 10%). In addition, films exhibited in vitro antibacterial activity against Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Enterococcus faecalis and Staphylococcus carnosus. Moreover, in ready-to-eat salads, antimicrobial activity was only observed against yeast and moulds, where 5% and 10% of OEO was the most effective.

Safe and prolonged survival with long-term exposure to pomalidomide in relapsed/refractory myeloma.

BACKGROUND: The IFM2009-02 trial studied pomalidomide (4 mg daily, 21/28 versus 28/28) and dexamethasone in very advanced relapsed or refractory multiple myeloma (RRMM). We observed that 40% of patients had a prolonged progression-free survival (PFS) and subsequently overall survival (OS). We sought to analyze the characteristics of these patients and study the effect of long exposure to pomalidomide. DESIGN: We separated the studied population into two groups: 3 months to 1 year (<1 year) and more than 1 year (≥1 year) of treatment with pomalidomide and dexamethasone based on clinical judgment and historical control studies. We then analyzed the characteristics of patients according to duration of treatment. RESULTS: The overall response rate (ORR) for the <1-year group was 43%, the median PFS 4.6 months [95% confidence interval (95% CI) 3.8-6.4] with only 6% at 12 months, and the median OS was 15 months (11.7-20.3) and 40% at 18 months. For the ≥1-year group, the response rate and survival were strikingly different, ORR at 83%, median PFS 20.7 months (14.7-35.4), median OS not reached, and 91% at 18 months. CONCLUSION: Pomalidomide and dexamethasone favored prolonged and safe exposure to treatment in 40% of heavily treated and end-stage RRMM, a paradigm shift in the natural history of RRMM characterized with a succession of shorter disease-free intervals and ultimately shorter survival. Although an optimization of pomalidomide-dexamethasone regimen is warranted in advanced RRMM, we claim that pomalidomide has proven once more to change the natural history of myeloma in this series, which should be confirmed in a larger study.

Lenalidomide with or without erythropoietin in transfusion-dependent erythropoiesis-stimulating agent-refractory lower-risk MDS without 5q deletion.

After failure of erythropoiesis-stimulating agents (ESAs), lenalidomide (LEN) yields red blood cell (RBC) transfusion independence (TI) in 20-30% of lower-risk non-del5q myelodysplastic syndrome (MDS). Several observations suggest an additive effect of ESA and LEN in this situation. We performed a randomized phase III study in 131 RBC transfusion-dependent (TD, median transfusion requirement six RBC units per 8 weeks) lower-risk ESA-refractory non-del5q MDS. Patients received LEN alone, 10 mg per day, 21 days per 4 weeks (L arm) or LEN (same schedule) + erythropoietin (EPO) beta, 60,000 U per week (LE arm). In an intent-to-treat (ITT) analysis, erythroid response (HI-E, IWG 2006 criteria) after four treatment cycles (primary end point) was 23.1% (95% CI 13.5-35.2) in the L arm and 39.4% (95% CI 27.6-52.2) in the LE arm (P=0.044), while RBC-TI was reached in 13.8 and 24.2% of the patients in the L and LE arms, respectively (P=0.13). Median response duration was 18.1 and 15.1 months in the L and LE arms, respectively (P=0.47). Side effects were moderate and similar in the two arms. Low baseline serum EPO level and a G polymorphism of CRBN gene predicted HI-E. Combining LEN and EPO significantly improves erythroid response over LEN alone in lower-risk non-del5q MDS patients with anemia resistant to ESA.

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages.

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed.

Achalasia--An Autoimmune Inflammatory Disease: A Cross-Sectional Study.

Idiopathic achalasia is a disease of unknown etiology. The loss of myenteric plexus associated with inflammatory infiltrates and autoantibodies support the hypothesis of an autoimmune mechanism. Thirty-two patients diagnosed by high-resolution manometry with achalasia were included. Twenty-six specimens from lower esophageal sphincter muscle were compared with 5 esophagectomy biopsies (control). Immunohistochemical (biopsies) and flow cytometry (peripheral blood) analyses were performed. Circulating anti-myenteric autoantibodies were evaluated by indirect immunofluorescence. Herpes simplex virus-1 (HSV-1) infection was determined by in situ hybridization, RT-PCR, and immunohistochemistry. Histopathological analysis showed capillaritis (51%), plexitis (23%), nerve hypertrophy (16%), venulitis (7%), and fibrosis (3%). Achalasia tissue exhibited an increase in the expression of proteins involved in extracellular matrix turnover, apoptosis, proinflammatory and profibrogenic cytokines, and Tregs and Bregs versus controls (P < 0.001). Circulating Th22/Th17/Th2/Th1 percentage showed a significant increase versus healthy donors (P < 0.01). Type III achalasia patients exhibited the highest inflammatory response versus types I and II. Prevalence of both anti-myenteric antibodies and HSV-1 infection in achalasia patients was 100% versus 0% in controls. Our results suggest that achalasia is a disease with an important local and systemic inflammatory autoimmune component, associated with the presence of specific anti-myenteric autoantibodies, as well as HSV-1 infection.

Dual Intragastric Balloon: Single Ambulatory Center Spanish Experience with 60 Patients in Endoscopic Weight Loss Management.

BACKGROUND: Many obese patients fail conventional medical management and decline bariatric surgery. Less invasive weight loss options such as intragastric balloons may provide an opportunity to reach this large number of untreated patients. The aim of this study was to investigate the safety and effectiveness of the Dual Intragastric Balloon (DIGB) in the treatment of obese patients, as well as the impact of degree of obesity, age, and gender. METHODS: The study was conducted at the Bariatric Endoscopy Unit of the Madrid Sanchinarro University Hospital. Sixty patients (11 men, 49 women) underwent endoscopic placement of a DIGB filled with a total of 900 cc of saline (450 cc in each balloon) for at least 6 months, along with regular counseling from a multidisciplinary team. Study outcomes included: change in body weight (TBWL), % of loss of initial body weight (%TBWL), % of excess body weight loss (%EWL), and adverse events. RESULTS: Initial BMI 38.8 kg/m(2) decreased 6.1 units, with mean TBWL, %TBWL, and %EWL of 16.6 kg, 15.4 %, and 47.1 %, respectively. We found no difference in %TBWL between grade of obesity, age or sex, but morbidly obese patients demonstrated greater TBWL, and women and less obese subjects obtained higher %EWL. The DIGB was generally well tolerated, with one early removal for patient intolerance, one early deflation without migration, and one gastric perforation. Fourteen patients had small, clinically insignificant ulcers or erosions noted at the time of removal. CONCLUSIONS: The present study shows that the DIGB was easy to use, resulted in significant weight loss, safe, and well tolerated.

Endoscopic Sleeve Gastroplasty: How I Do It?

BACKGROUND: Primary endoscopic weight loss therapies are of interest for access, simplicity, and economy. The objective of this manuscript is to describe the endoscopic sleeve gastroplasty used in 50 patients. METHODS: The goal of this procedure is to reduce the gastric lumen into a tubular configuration, with the greater curvature modified by a line of sutured plications. General anesthesia with endotracheal intubation is needed. An endoscopic suturing system requiring a specific double-channel endoscope delivers full-thickness sets of running sutures from the antrum to the fundus. Patients are admitted and observed, with discharge planned within 24 h. Post-procedure outpatient care includes diet instruction with intensive follow-up by a multidisciplinary team. Voluntary oral contrast and endoscopy studies are scheduled to assess the gastroplasty at 3, 6, and 12 months. RESULTS: The technique was applied in 50 patients (13 men) with an average body mass index (BMI) of 37.7 kg/m(2) (range 30-47) with 13 having reached 1 year. Procedure duration averaged 66 min during which six to eight sutures on average were placed. All patients were discharged in less than 24 h. There were no major intra-procedural, early, or delayed adverse events. Weight loss parameters were satisfactory, mean BMI changes from 37.7 ± 4.6 to 30.9 ± 5.1 kg/m(2) at 1 year, and mean %TBWL was 19.0 ± 10.8. Oral contrast studies and endoscopy revealed sleeve gastroplasty configuration at least until 1 year of follow-up. CONCLUSION: Endoscopic sleeve gastroplasty is a safe, effective, and reproducible primary weight loss technique.

Nuclear waste viewed in a new light; a synchrotron study of uranium encapsulated in grout.

How do you characterise the contents of a sealed nuclear waste package without breaking it open? This question is important when the contained corrosion products are potentially reactive with air and radioactive. Synchrotron X-rays have been used to perform micro-scale in-situ observation and characterisation of uranium encapsulated in grout; a simulation for a typical intermediate level waste storage packet. X-ray tomography and X-ray powder diffraction generated both qualitative and quantitative data from a grout-encapsulated uranium sample before, and after, deliberately constrained H2 corrosion. Tomographic reconstructions provided a means of assessing the extent, rates and character of the corrosion reactions by comparing the relative densities between the materials and the volume of reaction products. The oxidation of uranium in grout was found to follow the anoxic U+H2O oxidation regime, and the pore network within the grout was observed to influence the growth of uranium hydride sites across the metal surface. Powder diffraction analysis identified the corrosion products as UO2 and UH3, and permitted measurement of corrosion-induced strain. Together, X-ray tomography and diffraction provide means of accurately determining the types and extent of uranium corrosion occurring, thereby offering a future tool for isolating and studying the reactions occurring in real full-scale waste package systems.