Rugged miniaturized mass sensors for use in plutonium conversion processes

Ionization is produced either through Plasma Desorption, in the case of a solid, using fission fragments from a Cf-252 source; or in the case of a gas, via an electron avalanche from the impact on a microsphere detector of {alpha} particles from a radioactive source. The gaseous compound analysis yielded multiple peaks on parent ion and molecular fragments. In the solid compound analysis, the results indicated that solid-state mass spectrometry will provide important information about the degradation of materials by measured changes in molecular weight

On the nucleation of ikaite (CaCO3x6H2O) – A comparative study in the presence and absence of mineral surfaces

The formation of ikaite (CaCO3x6H2O) was studied in the presence and absence of quartz and mica surfaces using desupersaturation curves from cryo-mixed-batch-reactor experiments. Upon nucleation and growth within the reactor, the solution approached solubility of the precipitating carbonate phase. For ikaite, a solubility constant of log Ksp ikaite = -7.3 ± 0.1 was found (T = 0 °C). At supersaturations Ωikaite < 15, the nucleation of ikaite was significantly promoted by the presence of quartz or mica. This promotion prevented a competing nucleation of anhydrous calcium carbonates. In the presence of quartz or mica, therefore, ikaite forms over a much broader supersaturation range than in the absence. Similarly strong promotors of ikaite nucleation rather than anhydrous carbonate nucleation were previously attributed to calcite-inhibiting substances only. At supersaturations Ωikaite ≥ 8, application of classical nucleation theory on induction periods of ikaite formation yielded an effective interfacial energy of 15 ± 3 mJ/m2. Compared to data of anhydrous CaCO3 phases, this interfacial energy is low and expresses the highly hydrated character of ikaite. At supersaturations Ωikaite ≥ 18, a transient amorphous phase appeared besides ikaite. Our results show that a comprehensive understanding of ikaite formation in natural settings requires consideration not only of supersaturation and presence of calcite-inhibitors but also of the presence or absence of mineral surfaces capable of promoting heterogeneous nucleation of ikaite

Assessing quality of life in a clinical study on heart rehabilitation patients: how well do value sets based on given or experienced health states reflect patients' valuations?

Background: Quality of life as an endpoint in a clinical study may be sensitive to the value set used to derive a single score. Focusing on patients' actual valuations in a clinical study, we compare different value sets for the EQ-5D-3L and assess how well they reproduce patients' reported results. Methods: A clinical study comparing inpatient (n = 98) and outpatient (n = 47) rehabilitation of patients after an acute coronary event is re-analyzed. Value sets include: 1. Given health states and time-trade-off valuation (GHS-TTO) rendering economic utilities;2. Experienced health states and valuation by visual analog scale (EHS-VAS). Valuations are compared with patient-reported VAS rating. Accuracy is assessed by mean absolute error (MAE) and by Pearson's correlation.. External validity is tested by correlation with established MacNew global scores. Drivers of differences between value sets and VAS are analyzed using repeated measures regression. Results: EHS-VAS had smaller MAEs and higher. in all patients and in the inpatient group, and correlated best with MacNew global score. Quality-adjusted survival was more accurately reflected by EHS-VAS. Younger, better educated patients reported lower VAS at admission than the EHS-based value set. EHS-based estimates were mostly able to reproduce patient-reported valuation. Economic utility measurement is conceptually different, produced results less strongly related to patients' reports, and resulted in about 20 % longer quality-adjusted survival. Conclusion: Decision makers should take into account the impact of choosing value sets on effectiveness results. For transferring the results of heart rehabilitation patients from another country or from another valuation method, the EHS-based value set offers a promising estimation option for those decision makers who prioritize patient-reported valuation. Yet, EHS-based estimates may not fully reflect patient-reported VAS in all situations

Adiposity has differing associations with incident coronary heart disease and mortality in the Scottish population: cross-sectional surveys with follow-up

Objective: Investigation of the association of excess adiposity with three different outcomes: all-cause mortality, coronary heart disease (CHD) mortality and incident CHD. Design: Cross-sectional surveys linked to hospital admissions and death records. Subjects: 19 329 adults (aged 18–86 years) from a representative sample of the Scottish population. Measurements: Gender-stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause mortality, CHD mortality and incident CHD. Separate models incorporating the anthropometric measurements body mass index (BMI), waist circumference (WC) or waist–hip ratio (WHR) were created adjusted for age, year of survey, smoking status and alcohol consumption. Results: For both genders, BMI-defined obesity (greater than or equal to30 kg m−2) was not associated with either an increased risk of all-cause mortality or CHD mortality. However, there was an increased risk of incident CHD among the obese men (hazard ratio (HR)=1.78; 95% confidence interval=1.37–2.31) and obese women (HR=1.93; 95% confidence interval=1.44–2.59). There was a similar pattern for WC with regard to the three outcomes; for incident CHD, the HR=1.70 (1.35–2.14) for men and 1.71 (1.28–2.29) for women in the highest WC category (men greater than or equal to102 cm, women greater than or equal to88 cm), synonymous with abdominal obesity. For men, the highest category of WHR (greater than or equal to1.0) was associated with an increased risk of all-cause mortality (1.29; 1.04–1.60) and incident CHD (1.55; 1.19–2.01). Among women with a high WHR (greater than or equal to0.85) there was an increased risk of all outcomes: all-cause mortality (1.56; 1.26–1.94), CHD mortality (2.49; 1.36–4.56) and incident CHD (1.76; 1.31–2.38). Conclusions: In this study excess adiposity was associated with an increased risk of incident CHD but not necessarily death. One possibility is that modern medical intervention has contributed to improved survival of first CHD events. The future health burden of increased obesity levels may manifest as an increase in the prevalence of individuals living with CHD and its consequences

CARDIOVASCULAR MEDICINE C reactive protein concentration and recurrence of atrial fibrillation after electrical cardioversion

Background: To test the hypothesis that a high C reactive protein (CRP) concentration would predict recurrence of atrial fibrillation (AF) after cardioversion in patients taking antiarrhythmic drugs. Methods: 111 patients who underwent direct current cardioversion for symptomatic AF were enrolled. Blood was drawn for CRP determination before cardioversion on the same day. All patients were taking antiarrhythmic drugs before and after electrical cardioversion. Results: After a mean follow up of 76 days, 75 patients had recurrence of AF. In univariate analysis, the median CRP concentration was significantly higher in patients with AF recurrence (3.95 mg/l v 1.81 mg/l, p = 0.002). Among the 55 patients with CRP in the upper 50th centile, 44 (80%) experienced recurrence of AF over a total follow up of 8.98 patient years, whereas among the 56 patients with CRP in the lower 50th centile, 31 (55%) experienced recurrence of AF over a total follow up of 14.3 patient years (p , 0.001). The adjusted hazard ratio comparing the upper 50th centile of CRP with the lower 50th centile of CRP was 2.0 (95% confidence interval 1.2 to 3.2, p = 0.007). Conclusions: CRP is independently associated with recurrence of AF after electrical cardioversion among patients taking antiarrhythmic drugs. These results suggest that inflammation may have a role in the pathogenesis of AF resistant to antiarrhythmic drugs

Patient-rated health status predicts prognosis following percutaneous coronary intervention with drug-eluting stenting

Purpose: In patients treated with percutaneous coronary intervention (PCI) with the paclitaxel-eluting stent, we examined whether patient-rated health status predicts adverse clinical events. Methods: Consecutive PCI patients treated with drug-eluting stenting (N = 870; 72.2% men; mean age = 62.6 ± 11.5) completed the EQ-5D post-PCI. The EQ-5D levels were dichotomized into 'no problems' (level 1) versus 'problems' (levels 2, 3); the visual analogue scale (VAS) was dichotomized using the 25th percentile (cut-off ≤60) indicating poor health status. Patients were followed up for 1-year clinical events (death or non-fatal myocardial infarction (MI)). Results: There were 53 deaths/MIs at follow-up. The EQ-5D health status dimensions mobility (HR:2.23; 95% CI:1.25-3.97), self-care (HR:3.09; 95% CI:1.54-6.20), and self-reported health status as measured with the EQ-VAS (HR:2.94; 95% CI:1.65-5.25) were independent predictors of death/MI and added to the predictive value of a model comprised of demographic and clinical characteristics. The EQ-5D dimensions usual activities, pain/discomfort, and anxiety/depression were not associated with adverse clinical events in adjusted analysis. Conclusions: Patient-rated health status predicted adverse clinical events at 1-year follow-up in PCI patients treated with drug-eluting stenting, with the risk being more than 2-fold indepe

Chronic non-specific low back pain - sub-groups or a single mechanism?

Copyright 2008 Wand and O'Connell; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain is a substantial health problem and has subsequently attracted a considerable amount of research. Clinical trials evaluating the efficacy of a variety of interventions for chronic non-specific low back pain indicate limited effectiveness for most commonly applied interventions and approaches. Discussion: Many clinicians challenge the results of clinical trials as they feel that this lack of effectiveness is at odds with their clinical experience of managing patients with back pain. A common explanation for this discrepancy is the perceived heterogeneity of patients with chronic non-specific low back pain. It is felt that the effects of treatment may be diluted by the application of a single intervention to a complex, heterogeneous group with diverse treatment needs. This argument presupposes that current treatment is effective when applied to the correct patient. An alternative perspective is that the clinical trials are correct and current treatments have limited efficacy. Preoccupation with sub-grouping may stifle engagement with this view and it is important that the sub-grouping paradigm is closely examined. This paper argues that there are numerous problems with the sub-grouping approach and that it may not be an important reason for the disappointing results of clinical trials. We propose instead that current treatment may be ineffective because it has been misdirected. Recent evidence that demonstrates changes within the brain in chronic low back pain sufferers raises the possibility that persistent back pain may be a problem of cortical reorganisation and degeneration. This perspective offers interesting insights into the chronic low back pain experience and suggests alternative models of intervention. Summary: The disappointing results of clinical research are commonly explained by the failure of researchers to adequately attend to sub-grouping of the chronic non-specific low back pain population. Alternatively, current approaches may be ineffective and clinicians and researchers may need to radically rethink the nature of the problem and how it should best be managed

Characterization of the Testicular Abnormality in 5a-Reductase Deficiency

The testes of five phenotypic women (from four families) with 5ª-reductase deficiency were studied. In one of the patients, the enzyme deficiency was similar in the testis and epididymis and in fibroblasts cultured from the labia majora. In testes from four of the patients, the concentrations of the 55ªreduced steroids dihydrotestosterone and 3ª-androstanediol were less than 10% of those in normal subjects. We conclude that the testis is involved in 55ª-reductase deficiency. Impaired spermatogenesis was evident in testicular biopsies from all five subjects, and in two, sperm production, as estimated in testicular homogenates, was less than 10% of normal. The extent to which spermatogenic arrest is due to 55ª-reductase deficiency or testicular maldescent is not clear

Cardiac rehabilitation in Austria: long term health-related quality of life outcomes

<p>Abstract</p> <p>Background</p> <p>The goal of cardiac rehabilitation programs is not only to prolong life but also to improve physical functioning, symptoms, well-being, and health-related quality of life (HRQL). The aim of this study was to document the long-term effect of a 1-month inpatient cardiac rehabilitation intervention on HRQL in Austria.</p> <p>Methods</p> <p>Patients (N = 487, 64.7% male, age 60.9 ± 12.5 SD years) after myocardial infarction, with or without percutaneous interventions, coronary artery bypass grafting or valve surgery underwent inpatient cardiac rehabilitation and were included in this long-term observational study (two years follow-up). HRQL was measured with both the MacNew Heart Disease Quality of Life Instrument [MacNew] and EuroQoL-5D [EQ-5D].</p> <p>Results</p> <p>All MacNew scale scores improved significantly (p < 0.001) and exceeded the minimal important difference (0.5 MacNew points) by the end of rehabilitation. Although all MacNew scale scores deteriorated significantly over the two year follow-up period (p < .001), all MacNew scale scores still remained significantly higher than the pre-rehabilitation values. The mean improvement after two years in the MacNew social scale exceeded the minimal important difference while MacNew scale scores greater than the minimal important difference were reported by 40-49% of the patients.</p> <p>Two years after rehabilitation the mean improvement in the EQ-5D Visual Analogue Scale score was not significant with no significant change in the proportion of patients reporting problems at this time.</p> <p>Conclusion</p> <p>These findings provide a first indication that two years following inpatient cardiac rehabilitation in Austria, the long-term improvements in HRQL are statistically significant and clinically relevant for almost 50% of the patients. Future controlled randomized trials comparing different cardiac rehabilitation programs are needed.</p

The impact of type 2 diabetes on health related quality of life in Bangladesh: results from a matched study comparing treated cases with non-diabetic controls

Background Little is known about the association between diabetes and health related quality of life (HRQL) in lower-middle income countries. This study aimed to investigate HRQL among individuals with and without diabetes in Bangladesh. Methods The analysis is based on data of a case-control study, including 591 patients with type 2 diabetes (cases) who attended an outpatient unit of a hospital in Dhaka and 591 age -and sex-matched individuals without diabetes (controls). Information about socio-demographic characteristics, health conditions, and HRQL were assessed in a structured interview. HRQL was measured with the EuroQol (EQ) visual analogue scale (VAS) and the EQ five-dimensional (5D) descriptive system. The association between diabetes status and quality of life was examined using multiple linear and logistic regression models. Results Mean EQ-VAS score of patients with diabetes was 11.5 points lower (95 %-CI: −13.5, −9.6) compared to controls without diabetes. Patients with diabetes were more likely to report problems in all EQ-5D dimensions than controls, with the largest effect observed in the dimensions ‘self-care’ (OR = 5.9; 95 %-CI: 2.9, 11.8) and ‘mobility’ (OR = 4.5; 95 %-CI: 3.0, −6.6). In patients with diabetes, male gender, high education, and high-income were associated with higher VAS score and diabetes duration and foot ulcer associated with lower VAS scores. Other diabetes-related complications were not significantly associated with HRQL. Conclusions Our findings suggest that the impact of diabetes on HRQL in the Bangladeshi population is much higher than what is known from western populations and that unlike in western populations comorbidities/complications are not the driving factor for this effect