Search

Strontium ferromolybdate, Sr2FeMoO6, is an important member of the family of double perovskites with the possible technological applications in the field of spintronics and solid oxide fuel cells. Its preparation via a multi-step ceramic route or various wet chemistry-based routes is notoriously difficult. The present work demonstrates that Sr2FeMoO6 can be mechanosynthesized at ambient temperature in air directly from its precursors (SrO, α-Fe, MoO3) in the form of nanostructured powders, without the need for solvents and/or calcination under controlled oxygen fugacity. The mechanically induced evolution of the Sr2FeMoO6 phase and the far-from-equilibrium structural state of the reaction product are systematically monitored with XRD and a variety of spectroscopic techniques including Raman spectroscopy, 57Fe Mössbauer spectroscopy, and X-ray photoelectron spectroscopy. The unique extensive oxidation of iron species (Fe0 → Fe3+) with simultaneous reduction of Mo cations (Mo6+ → Mo5+), occuring during the mechanosynthesis of Sr2FeMoO6, is attributed to the mechanically triggered formation of tiny metallic iron nanoparticles in superparamagnetic state with a large reaction surface and a high oxidation affinity, whose steady presence in the reaction mixture of the milled educts initiates/promotes the swift redox reaction. High-resolution transmission electron microscopy observations reveal that the mechanosynthesized Sr2FeMoO6, even after its moderate thermal treatment at 923 K for 30 min in air, exhibits the nanostructured nature with the average particle size of 21(4) nm. At the short-range scale, the nanostructure of the as-prepared Sr2FeMoO6 is characterized by both, the strongly distorted geometry of the constituent FeO6 octahedra and the extraordinarily high degree of anti-site disorder. The degree of anti-site disorder ASD = 0.5, derived independently from the present experimental XRD, Mössbauer, and SQUID magnetization data, corresponds to the completely random distribution of Fe3+ and Mo5+ cations over the sites of octahedral coordination provided by the double perovskite structure. Moreover, the fully anti-site disordered Sr2FeMoO6 nanoparticles exhibit superparamagnetism with the blocking temperature T B = 240 K and the deteriorated effective magnetic moment μ = 0.055 μ B per formula unit.

ObjectivesEvidence of the impact electronic health records (EHRs) have on clinical outcomes remains mixed. The impact of EHRs likely depends on the organizational context in which they are used. This study focuses on one aspect of the organizational context: cohesion of primary care teams. We examined whether team cohesion among primary care team members changed the association between EHR use and changes in clinical outcomes for patients with diabetes.Study designRetrospective longitudinal study.MethodsWe combined provider-reported primary care team cohesion with lab values for patients with diabetes collected during the staggered EHR implementation (2005-2009). We used multivariate regression models with patient-level fixed effects to assess whether team cohesion levels changed the association between outpatient EHR use and clinical outcomes for patients with diabetes. Subjects were comprised of 80,611 patients with diabetes, in whom we measured changes in glycated hemoglobin (A1C) and low-density lipoprotein cholesterol (LDL-C).ResultsFor A1C, EHR use was associated with an average decrease of 0.11% for patients with higher-cohesion primary care teams compared with a decrease of 0.08% for patients with lower-cohesion teams (difference = 0.02% in A1C; 95% CI, 0.01%-0.03%). For LDL-C, EHR use was associated with a decrease of 2.15 mg/dL for patients with higher-cohesion primary care teams compared with a decrease of 1.42 mg/dL for patients with lower-cohesion teams (difference = 0.73 mg/dL; 95% CI, 0.41-1.11 mg/dL).ConclusionsPatients cared for by higher cohesion primary care teams experienced modest but statistically significantly greater EHR-related health outcome improvements, compared with patients cared for by providers practicing in lower cohesion teams.

ObjectivesThis study aimed to assess the effects of physically demanding work - measured as energy expenditure (EE) during occupational physical activities (OPA) - on risk of acute myocardial infarction (AMI) among men with and without preexisting ischemic heart disease (IHD).MethodsThe 20-year prospective study examined 1891 middle-aged working men using absolute (kcal/day) and relative (relative aerobic strain and percent oxygen uptake reserve) measures of EE. Linear and quadratic hazard models were explored in Cox regression analyses adjusting for 19 potential confounders and considering interactions with baseline IHD.ResultsRelative EE measures were positively associated with 20-year incidence of AMI in linear and quadratic hazard models and interacted with IHD. Each 10% increase of relative aerobic strain increased AMI risk by 18% among men without IHD [hazard ratio (HR) 1.18, 95% confidence interval (95% CI) 1.08-1.28, P=0.001] and by 8% among men with IHD (HR 1.08, 95% CI 0.98-1.20, P=0.129) in fully adjusted linear models. Results for quadratic models and percent oxygen uptake reserve were similar. Absolute EE did not predict AMI. Age, baseline IHD, systolic blood pressure, anti-hypertensive medication, body mass index, blood glucose, low-density lipoprotein cholesterol, cholesterol-lowering medication, mental stress, and smoking were independently associated with AMI, but not income, social support, alcohol, or conditioning leisure-time physical activity.ConclusionIn contrast to absolute EE, relative workload measures that take individual fitness into account were positively associated with AMI incidence among men without IHD. For men with IHD, associations were also positive but weaker possibly due to healthy worker selection effects. These findings provide evidence for a positive association between OPA and AMI among men.

BackgroundHealth information technology (HIT) may improve health care quality and outcomes, in part by making information available in a timelier manner. However, there are few studies documenting the changes in timely availability of data with the use of a sophisticated electronic medical record (EMR), nor a description of how the timely availability of data might differ with different types of EMRs. We hypothesized that timely availability of data would improve with use of increasingly sophisticated forms of HIT.MethodsWe used an historical observation design (2004-2006) using electronic data from office visits in an integrated delivery system with three types of HIT: Basic, Intermediate, and Advanced. We calculated the monthly percentage of visits using the various types of HIT for entry of visit diagnoses into the delivery system's electronic database, and the time between the visit and the availability of the visit diagnoses in the database.ResultsIn January 2004, when only Basic HIT was available, 10% of office visits had diagnoses entered on the same day as the visit and 90% within a week; 85% of office visits used paper forms for recording visit diagnoses, 16% used Basic at that time. By December 2006, 95% of all office visits had diagnoses available on the same day as the visit, when 98% of office visits used some form of HIT for entry of visit diagnoses (Advanced HIT for 67% of visits).ConclusionUse of HIT systems is associated with dramatic increases in the timely availability of diagnostic information, though the effects may vary by sophistication of HIT system. Timely clinical data are critical for real-time population surveillance, and valuable for routine clinical care.

IntroductionStudies of the relationship between work time and health have been inconclusive. Consequently, we sought to examine the effect of work time on progression of atherosclerosis.MethodsThis prospective study of 621 middle-aged Finnish men evaluated effects of baseline and repeat measures of work time on 11-year progression of ultrasonographically assessed carotid intima-media thickness (IMT) and interactions with cardiovascular disease. Multiple linear regression models adjusted for 21 biological, behavioral, and psychosocial risk factorsResultsWorking 3 (minimum), 5 (medium), or 7 (maximum) days per week at baseline was associated with 23%, 31%, and 40% 11-year increases in IMT, respectively. The relative change ratio (RCR) at maximum vs minimum was 1.14 for baseline days worked per week and 1.10 for hours worked per year of follow-up. Significant interactions existed between cardiovascular disease and work time. Men with ischemic heart disease (IHD) who worked the maximum of 14.5 hours per day experienced a 69% increase in IMT compared with a 29% increase in men without IHD. The RCR ratio for IHD (RCRIHD/RCRno IHD) was 1.44 for hours per day. Similarly, the RCR ratio for baseline carotid artery stenosis was 1.29 for hours per day and 1.22 for hours per year.ConclusionIncreases in work time are positively associated with progression of carotid atherosclerosis in middle-aged men, especially in those with preexisting cardiovascular disease. Our findings are consistent with the hemodynamic theory of atherosclerosis.

Objectives This study prospectively assessed the effects of occupational physical activity on atherosclerosis progression.Methods This population-based prospective study of ultrasonographically assessed carotid intima media thickness (IMT) used repeated measures of occupational physical activity during baseline, 4-year, and 11-year examinations of 612 Finnish men 42-60 years of age at baseline. The association between five measures of energy expenditure and the 11-year change in maximum IMT was evaluated in regression models adjusting for 21 potential confounders, including biological factors, leisure-time physical activity, smoking, socioeconomic status, psychosocial job factors, and baseline health status.Results At baseline, 31% of all the men and 51% of those with ischemic heart disease (IHD) exceeded the recommended maximum levels of relative aerobic strain. All five measures of energy expenditure were significantly associated with adjusted 11-year IMT change. Significant interactions were found between IHD and several measures of energy expenditure. Maximum relative aerobic strain resulted in a 90% increase in IMT among the men with IHD compared with a 46% increase among those without IHD. The men with preexisting carotid stenosis also had higher rates of IMT progression than the men without this condition.Conclusions This study shows that high energy expenditures at work are associated with an accelerated progression of atherosclerosis even after control for virtually all known cardiovascular risk factors, especially among older workers and workers with preexisting IHD or carotid artery stenosis. The findings support the hemodynamic theory of atherosclerosis and have important implications for workplace surveillance and disease prevention.