Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 204
Filter
1.
Environ Pollut ; 243(Pt A): 582-590, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30216890

ABSTRACT

The clean-up effort that is occurring across the region affected by the 2011 Fukushima Daiichi Nuclear Power Plant accident is unprecedented in its magnitude as well as the financial cost that will eventually result. A major component of this remediation is the stripping of large volumes of material from the land surface, depositing this into large waste storage bags before placing these 1 cubic meter bags into specially constructed stores across Fukushima Prefecture. In this work, using an unmanned aerial vehicle to perform radiological surveys of a site, the time-resolved distribution of contamination during the construction of one of these waste storage sites was assessed. The results indicated that radioactive material was progressively leaching from the store into the surrounding environment. A subsequent survey of the site conducted eight months later revealed that in response to this survey and remedial actions, the contamination issue once existing on this site had been successfully resolved. Such results highlight the potential of low-altitude unmanned aerial systems to easily and rapidly assess site-wide changes over time - providing highly-visual results; therefore, permitting for prompt remedial actions to be undertaken as required. Use of UAV radiation mapping and airborne photogrammetry to produce a time-resolved assessment of remediation efforts within a Fukushima temporary storage facility.


Subject(s)
Hazardous Waste Sites , Radioactive Waste , Cesium Radioisotopes/analysis , Fukushima Nuclear Accident , Japan , Radiation Monitoring
2.
Sci Rep ; 8(1): 9282, 2018 Jun 18.
Article in English | MEDLINE | ID: mdl-29915385

ABSTRACT

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.

3.
J Environ Radioact ; 183: 102-111, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29331769

ABSTRACT

Whilst prior nuclear forensic studies have focused on identifying signatures to distinguish between different uranium deposit types, this paper focuses on providing a scientific basis for source identification of materials from different uranium mine sites within a single region, which can then be potentially used within nuclear forensics. A number of different tools, including gamma spectrometry, alpha spectrometry, mineralogy and major and minor elemental analysis, have been utilised to determine the provenance of uranium mineral samples collected at eight mine sites, located within three different uranium provinces, in Portugal. A radiation survey was initially conducted by foot and/or unmanned aerial vehicle at each site to assist sample collection. The results from each mine site were then compared to determine if individual mine sites could be distinguished based on characteristic elemental and isotopic signatures. Gamma and alpha spectrometry were used to differentiate between samples from different sites and also give an indication of past milling and mining activities. Ore samples from the different mine sites were found to be very similar in terms of gangue and uranium mineralogy. However, rarer minerals or specific impurity elements, such as calcium and copper, did permit some separation of the sites examined. In addition, classification rates using linear discriminant analysis were comparable to those in the literature.


Subject(s)
Radiation Monitoring/methods , Soil Pollutants, Radioactive/analysis , Uranium/analysis , Mining , Portugal
4.
BMC Psychiatry ; 18(1): 19, 2018 01 24.
Article in English | MEDLINE | ID: mdl-29361921

ABSTRACT

BACKGROUND: An increased awareness of the health benefits of walking has emerged with the development and refinement of accelerometer equipment. Evidence is beginning to highlight the value of promoting walking, particularly focusing on the Japanese mark of obtaining 10,000 steps per day. Workplace based step challenges have become popular to engage large cohorts in increasing their daily physical activity in a sustainable and enjoyable way. Findings are now highlighting the positive health effects of these medium-term programs (typically conducted over a few months) in terms of cardiovascular health, reducing diabetes risk and improving lifestyle factors such as weight and blood pressure. As yet, research has not focused on whether similar improvements in psychological health and wellbeing are present. METHODS: This study investigated the impact of a 100-day, 10,000 step program on signs of depression, anxiety and stress as well as general wellbeing using standardised psychological scales. RESULTS: The results indicated a small but consistent effect on all of these measures of mental health over the term of the program. This effect appeared irrespective of whether a person reached the 10,000 step mark. CONCLUSIONS: These results highlight improved mental health and wellbeing in people undertaking this 100-day 10,000 step program and indicates the efficacy and potential of these programs for a modest, yet important improvement in mental health. Notably, targets reached may be less important than participation itself.


Subject(s)
Depressive Disorder/psychology , Exercise Therapy , Health Status Indicators , Walking , Accelerometry , Adolescent , Adult , Aged , Depressive Disorder/therapy , Female , Humans , Male , Middle Aged , Psychometrics , Young Adult
5.
Sci Rep ; 7(1): 7999, 2017 08 11.
Article in English | MEDLINE | ID: mdl-28801638

ABSTRACT

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.

6.
Eur Psychiatry ; 31: 20-8, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26655594

ABSTRACT

BACKGROUND: Cognitive deficits have been reported during the early stages of bipolar disorder; however, the role of medication on such deficits remains unclear. The aim of this study was to compare the effects of lithium and quetiapine monotherapy on cognitive performance in people following first episode mania. METHODS: The design was a single-blind, randomised controlled trial on a cohort of 61 participants following first episode mania. Participants received either lithium or quetiapine monotherapy as maintenance treatment over a 12-month follow-up period. The groups were compared on performance outcomes using an extensive cognitive assessment battery conducted at baseline, month 3 and month 12 follow-up time-points. RESULTS: There was a significant interaction between group and time in phonemic fluency at the 3-month and 12-month endpoints, reflecting greater improvements in performance in lithium-treated participants relative to quetiapine-treated participants. After controlling for multiple comparisons, there were no other significant interactions between group and time for other measures of cognition. CONCLUSION: Although the effects of lithium and quetiapine treatment were similar for most cognitive domains, the findings imply that early initiation of lithium treatment may benefit the trajectory of cognition, specifically verbal fluency in young people with bipolar disorder. Given that cognition is a major symptomatic domain of bipolar disorder and has substantive effects on general functioning, the ability to influence the trajectory of cognitive change is of considerable clinical importance.


Subject(s)
Antimanic Agents/therapeutic use , Antipsychotic Agents/therapeutic use , Bipolar Disorder/drug therapy , Bipolar Disorder/psychology , Cognition/drug effects , Lithium Compounds/therapeutic use , Quetiapine Fumarate/therapeutic use , Adolescent , Adult , Dibenzothiazepines/therapeutic use , Female , Follow-Up Studies , Humans , Intelligence , Male , Memory , Single-Blind Method , Time Factors , Treatment Outcome , Verbal Learning , Young Adult
7.
Eur Psychiatry ; 30(8): 975-82, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26485297

ABSTRACT

BACKGROUND: Treatment strategies for mental disorders may vary according to illness stage. However no data currently exist to guide treatment in first episode psychotic mania. The aim of this study was to compare the safety and efficacy profile of chlorpromazine and olanzapine, as add-on to lithium, in patients with a first episode of psychotic mania, expecting better safety profile and adherence to olanzapine but similar efficacy for both treatments. METHODS: Data from 83 patients were collected in an 8-week randomised controlled trial on clinical variables, side effects, vital signs, and weight. Analyses of treatment differences over time were based on intent-to-treat principles. Kaplan-Meier estimated survival curves were used to analyse time-to-event data and mixed effects models repeated measures analysis of variance were used to determine treatment group differences over time on safety and efficacy measures. RESULTS: Ethics committee approval to delay informed consent procedure until recovery from the acute episode allowed the inclusion of 83 patients highly representative of those treated in the public sector. Contrary to our hypotheses, safety profile of both medications was similar. A signal for higher rate (P=.032) and earlier occurrence (P=.043) of mania remission was observed in the olanzapine group which did not survive correction for multiple comparisons. CONCLUSIONS: Olanzapine and chlorpromazine have a similar safety profile in a uniquely representative cohort of patients with first episode psychotic mania. The possibility for a greater impact of olanzapine on manic symptoms leading to earlier remission of the episode needs exploration in a large sample.


Subject(s)
Benzodiazepines , Bipolar Disorder/drug therapy , Chlorpromazine , Adult , Antipsychotic Agents/administration & dosage , Antipsychotic Agents/adverse effects , Benzodiazepines/administration & dosage , Benzodiazepines/adverse effects , Bipolar Disorder/diagnosis , Bipolar Disorder/psychology , Chlorpromazine/administration & dosage , Chlorpromazine/adverse effects , Diagnostic and Statistical Manual of Mental Disorders , Drug Monitoring , Female , Humans , Lithium/therapeutic use , Male , Olanzapine , Psychotic Disorders/drug therapy , Treatment Outcome
8.
PLoS One ; 10(7): e0132284, 2015.
Article in English | MEDLINE | ID: mdl-26176551

ABSTRACT

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.


Subject(s)
Radioactive Waste/analysis , Uranium/analysis , Waste Management , Powders , Time Factors , X-Ray Diffraction
9.
J Hazard Mater ; 285: 221-7, 2015 Mar 21.
Article in English | MEDLINE | ID: mdl-25497037

ABSTRACT

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.


Subject(s)
Radioactive Waste , Uranium Compounds/chemistry , Uranium/chemistry , Waste Management/methods , Construction Materials , Corrosion , Industrial Waste , Powder Diffraction , Synchrotrons , Tomography, X-Ray , X-Ray Diffraction
10.
J Affect Disord ; 112(1-3): 212-8, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18501434

ABSTRACT

While ECT is widely used for the management of severe and refractory depression, its utility in bipolar disorder is not extensively studied. The aim of this study was to examine the reported effectiveness of ECT in patients with unipolar and bipolar depression as reported by psychiatrists, nurses and patients (i.e. using objective and subjective measures). The records of 787 consecutive inpatient admissions to the Geelong Clinic, a private psychiatric centre based outside Melbourne, Victoria were reviewed in this file audit. Routine assessment measures were completed at admission and discharge, and included patient rated measures (Medical Outcomes Short Form SF-14 and Depression Anxiety and Stress Scale, DASS), nurse rated measures, (The Health of the Nation Outcome Scale, HoNOS) and a psychiatrist rated measure, the Clinical Global impression scale (CGI). In contrast to individuals with unipolar depression, where improvement was seen on all measures, in bipolar disorder, while improvement in clinician rated measures was seen (CGI, HoNOS), there was an absence of improvement in subjective measures of mood (DASS, SF14). This study suggests that in bipolar disorder, there is a poorer subjective response to ECT than in unipolar disorder.


Subject(s)
Bipolar Disorder/therapy , Depressive Disorder/therapy , Electroconvulsive Therapy/methods , Health Status , Psychiatric Status Rating Scales/statistics & numerical data , Attitude of Health Personnel , Attitude to Health , Bipolar Disorder/diagnosis , Depressive Disorder/diagnosis , Diagnostic and Statistical Manual of Mental Disorders , Female , Hospitalization , Humans , Male , Middle Aged , Personality Inventory/statistics & numerical data , Predictive Value of Tests , Psychiatry/statistics & numerical data , Quality of Life , Surveys and Questionnaires , Treatment Outcome , Victoria
11.
Exp Lung Res ; 33(5): 259-75, 2007.
Article in English | MEDLINE | ID: mdl-17620187

ABSTRACT

Increasing the extravascular fluid of the airways acutely by obstructing pulmonary lymph drainage causes a reflex diuresis mediated by neuronal nitric oxide synthase in the renal medulla. The authors examined this reflex in rabbits with a chronic increase in extravascular fluid of the airways resulting from surgically induced mitral regurgitation. Intact rabbits served as controls. Renal neuronal (nNOS) and endothelial (eNOS) nitric oxide synthase expressions were also examined. The reflex was absent in rabbits with mitral regurgitation. There were significant increases in medullary and cortical nNOS mRNA compared to controls. The observed changes in mRNA levels correlated with nNOS protein levels. eNOS mRNA was unaffected.


Subject(s)
Airway Obstruction/physiopathology , Diuresis/physiology , Extravascular Lung Water/physiology , Lymphatic System/physiopathology , Mitral Valve Insufficiency/physiopathology , Reflex/physiology , Animals , Gene Expression Regulation, Enzymologic , Kidney Cortex/blood supply , Kidney Cortex/enzymology , Kidney Cortex/innervation , Kidney Medulla/blood supply , Kidney Medulla/enzymology , Kidney Medulla/innervation , Mitral Valve/physiopathology , Nitric Oxide Synthase Type I/metabolism , Nitric Oxide Synthase Type III/metabolism , RNA, Messenger/metabolism , Rabbits , Regional Blood Flow/physiology , Renin-Angiotensin System/physiology
12.
Hum Psychopharmacol ; 22(4): 223-30, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17487935

ABSTRACT

BACKGROUND: Atypical antipsychotics may be beneficial in treating the core psychopathology of anorexia nervosa (AN). METHODS: An 8 week open-label study of quetiapine was conducted in eight severely ill DSM-IV AN patients consecutively admitted to a specialist eating disorders unit. Participants were assessed by EDE-12, MADRS, YBOCS, SAPS-delusions and CDR neuropsychological battery at baseline, 4 weeks and 8 weeks, and by weekly body mass index (BMI), CGI and extrapyramidal scores. Quetiapine doses ranged from 50 mg to 800 mg per day, according to efficacy and tolerability. RESULTS: Seven participants completed 4 weeks and five participants completed 8 weeks. All participants had clinically significant levels of specific eating disorders psychopathology, and mild to moderately severe depressive symptomatology. Apart from initial mild sedation, no subjects experienced any significant adverse events. Over 4 weeks there was no significant difference in BMI, but a significant difference in the EDE-12 restraint score. There were significant differences on BMI and EDE-12 restraint subscale scores over 8 weeks. CONCLUSIONS: A double-blind placebo controlled study is required to further evaluate the therapeutic utility of quetiapine in severely ill AN patients beyond multidisciplinary specialist intervention.


Subject(s)
Anorexia Nervosa/drug therapy , Antipsychotic Agents/therapeutic use , Dibenzothiazepines/therapeutic use , Adult , Anorexia Nervosa/psychology , Antipsychotic Agents/adverse effects , Arousal/drug effects , Body Mass Index , Delusions/psychology , Depression/psychology , Dibenzothiazepines/adverse effects , Dyskinesia, Drug-Induced/epidemiology , Humans , Male , Neuropsychological Tests , Obsessive Behavior/psychology , Psychiatric Status Rating Scales , Quetiapine Fumarate , Reaction Time/drug effects , Weight Gain
13.
J Orthop Res ; 24(8): 1587-96, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16779825

ABSTRACT

Physical wear of orthopedic implants is inevitable. CoCr alloy samples, typically used in joint reconstruction, corrode rapidly after removal of the protective oxide layer. The behavior of CoCr pellets immersed in human serum, foetal bovine serum (FBS), synovial fluid, albumin in phosphate-buffered saline (PBS), EDTA in PBS, and water were studied using X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS). The difference in the corrosive nature of human serum, water, albumin in PBS and synovial fluid after 5 days of immersion was highlighted by the oxide layer, which was respectively 15, 3.5, 1.5, and 1.5 nm thick. The thickness of an additional calcium phosphate deposit from human serum and synovial fluid was 40 and 2 nm, respectively. Co and Cr ions migrated from the bulk metal surface and were trapped in this deposit by the phosphate anion. This may account for the composition of wear debris from CoCr orthopedic implants, which is known to consist predominantly of hydroxy-phosphate compounds. Known components of synovial fluid including proteoglycans, pyrophosphates, phospholipids, lubricin, and superficial zone protein (SZP), have been identified as possible causes for the lack of significant calcium phosphate deposition in this environment. Circulation of these compounds around the whole implant may inhibit calcium phosphate deposition.


Subject(s)
Calcium Phosphates/chemistry , Chromium Alloys/chemistry , Fetal Blood/chemistry , Prosthesis Failure , Synovial Fluid/chemistry , Albumins/chemistry , Animals , Buffers , Cattle , Corrosion , Edetic Acid/chemistry , Humans , In Vitro Techniques , Sodium Chloride , Spectrometry, Mass, Secondary Ion , Spectrometry, X-Ray Emission , Stress, Mechanical , Water/chemistry
14.
Behav Brain Res ; 153(2): 481-6, 2004 Aug 31.
Article in English | MEDLINE | ID: mdl-15265646

ABSTRACT

The olfactory bulbectomised (OB) rat is being increasingly used as a model of impaired learning and mnemonic functioning. In this study the model has been utilised to determine the effect of the acetylcholinesterase inhibiting compounds tacrine and physostigmine on spatial working memory deficits associated with the OB rat. One-hundred and twenty male rats were randomly allocated to OB or sham operated groups and received chronic i.p. treatment with either saline, physostigmine (0.1 mg/kg) or tacrine (0.1 and 0.3 mg/kg). Two weeks after beginning treatment animals were tested on the Morris water maze and open field test. The results indicated that the OB surgery was associated with spatial working memory disturbances that were effectively attenuated with both doses of tacrine, but not physostigmine. Increased hyperactivity and defecation was observed in OB animals in the Open-field test, however, these changes were not ameliorated by either drug treatment. The ability for tacrine but not physostigmine to attenuate OB cognitive deficits may be associated with the different half-life of these compounds. This study provides further support for the use of the OB rat as a drug discovery model for the investigation of novel therapeutic compounds that target the cholinergic system.


Subject(s)
Cholinesterase Inhibitors/pharmacology , Escape Reaction/drug effects , Maze Learning/drug effects , Memory, Short-Term/physiology , Olfactory Bulb/drug effects , Olfactory Bulb/physiology , Orientation/physiology , Physostigmine/pharmacology , Tacrine/pharmacology , Alzheimer Disease/physiopathology , Animals , Arousal/drug effects , Arousal/physiology , Basal Nucleus of Meynert/drug effects , Basal Nucleus of Meynert/physiology , Cholinergic Fibers/drug effects , Cholinergic Fibers/physiology , Defecation/drug effects , Defecation/physiology , Escape Reaction/physiology , Injections, Intraperitoneal , Maze Learning/physiology , Memory, Short-Term/drug effects , Motor Activity/drug effects , Motor Activity/physiology , Orientation/drug effects , Rats , Rats, Sprague-Dawley , Social Environment
15.
Environ Pollut ; 120(2): 415-22, 2002.
Article in English | MEDLINE | ID: mdl-12395856

ABSTRACT

The bandgap of solid-state TiO2 (3.2 eV) enables it to be a useful photocatalyst in the ultraviolet (lambda < 380 nm) region of the spectrum. A clean TiO2 surface in the presence of sunlight therefore enables the removal of harmful NOx gases from the atmosphere by oxidation to nitrates. These properties, in addition to the whiteness, relative cheapness and non-toxicity, make TiO2 ideal for the many de-NOX catalysts that are currently being commercially exploited both in the UK and Japan for concrete paving materials in inner cities. There is need, however, for further academic understanding of the surface reactions involved. Hence, we have used surface specific techniques, including X-ray photoelectron spectroscopy and Raman spectroscopy, to investigate the NOx adsorbate reaction at the TiO2 substrate surface.


Subject(s)
Air Pollutants/chemistry , Environmental Health , Nitrogen Oxides/chemistry , Titanium/chemistry , Adsorption , Ammonia/chemistry , Catalysis , Microscopy, Electron, Scanning , Spectrometry, X-Ray Emission , Spectrum Analysis, Raman , Ultraviolet Rays
17.
Mod Healthc ; 30(14): 2, 16, 2000 Apr 03.
Article in English | MEDLINE | ID: mdl-11066403

ABSTRACT

Call it selective prosecution. Last week's disclosure of several alleged "sweetheart deals" involving the settlement of Medicare billing disputes has HCFA officials concerned that other healthcare providers could start demanding more favorable treatment. Former HCFA Administrator Bruce Vladeck (left) was among those testifying on those cases last week in Washington. Meanwhile, a look at data on federal fraud investigations shows big geographic disparities in those probes. See story on p. 36.


Subject(s)
Centers for Medicare and Medicaid Services, U.S./legislation & jurisprudence , Insurance, Health, Reimbursement/legislation & jurisprudence , Medicare/legislation & jurisprudence , Negotiating , United States
20.
SELECTION OF CITATIONS
SEARCH DETAIL