Synthesis and Characterisation of Nanocomposite Mo-Fe-B Thin Films Deposited by Magnetron Sputtering

Several ternary phases are known in the Mo-Fe-B system. Previous ab initio calculations have predicted that they should exhibit a tempting mix of mechanical and magnetic properties. In this study, we have deposited Mo-Fe-B films with a Fe-content varying from 0–37 at.% using non-reactive DC (direct current) magnetron sputtering. The phase composition, microstructure, and mechanical properties were investigated using X-ray diffraction, scanning transmission electron microscopy, and nanoindentation measurements. Films deposited at 300 °C and with >7 at.% Fe are nanocomposites consisting of two amorphous phases: a metal-rich phase and a metal-deficient phase. Hardness and elastic modulus were reduced with increasing Fe-content from ~29 to ~19 GPa and ~526 to ~353 GPa, respectively. These values result in H³/E² ratios of 0.089–0.052 GPa, thereby indicating brittle behaviour of the films. Also, no indication of crystalline ternary phases was observed at temperatures up to 600 °C, suggesting that higher temperatures are required for such films to form.     

Cysteine-Induced Hybridization of 2D Molybdenum Disulfide Films for Efficient and Stable Hydrogen Evolution Reaction

The noble, metal-free materials capable of efficiently catalyzing water splitting reactions currently hold a great deal of promise. In this study, we reported the structure and electrochemical performance of new MoS₂-based material synthesized with L-cysteine. For this, a facile one-pot hydrothermal process was developed and an array of densely packed nanoplatelet-shaped hybrid species directly on a conductive substrate were obtained. The crucial role of L-cysteine was determined by numerous methods on the structure and composition of the synthesized material and its activity and stability for hydrogen evolution reaction (HER) from the acidic water. A low Tafel slope of 32.6 mV dec⁻¹, close to a Pt cathode, was registered for the first time. The unique HER performance at the surface of this hybrid material in comparison with recently reported MoS₂-based electrocatalysts was attributed to the formation of more defective 1T, 2H-MoS₂/MoO_x, C nanostructures with the dominant 1T-MoS₂ phase and thermally degraded cysteine residues entrapped. Numerous stacks of metallic (1T-MoS₂ and MoO₂) and semiconducting (2H-MoS₂ and MoO₃) fragments relayed the formation of highly active layered nanosheets possessing a low hydrogen adsorption free energy and much greater durability, whereas intercalated cysteine fragments had a low Tafel slope of the HER reaction. X-ray photoelectron spectroscopy, scanning electron microscopy, thermography with mass spectrometry, high-resolution transmission electron microscopy, Raman spectroscopy techniques, and linear sweep voltammetry were applied to verify our findings.     

The Role of Brain Tumor Advocacy Groups

The brain tumor community is a unique, underserved population that has not seen significant improvements in survival over the last four decades. In the search for effective treatments for brain tumors, nonprofit patient advocacy organizations identify and fill the gaps that the for-profit sector and the government have not addressed or cannot address. Although many articles have been written on the roles of patient advocacy groups in general, or in targeted areas such as clinical trial recruitment, none have looked at the brain tumor community specifically. This review looks at the literature on patient advocacy groups and provides specific examples of brain tumor advocacy organizations that offer these services. It examines the evolution of the role of these organizations over time, and how that has been reflected in the programs and services provided. This is a collaborative effort to highlight programs and services across multiple patient advocacy organizations.     

Indoor air quality in a middle school, Part I: Use of CO2 as a tracer for effective ventilation

The overall objective of the study was to evaluate the indoor air quality at a middle school with an emphasis on characterizing baseline conditions. The focus of this article is on the relationship between occupancy and measured concentrations of carbon dioxide, and an evaluation of the use of carbon dioxide as a tracer for ventilation in the school. The school was characterized as having no health complaints, good maintenance schedules, no carpeting within the classrooms or hallways, and no significant remodeling, and its officials had agreed to allow the sampling to take place during school hours. Monitoring followed the guidelines recommended in the "Preliminary Draft: Conceptual Standardized EPA Protocol For Characterizing Indoor Air Quality in School Buildings." Four indoor locations including the cafeteria, a science classroom, an art classroom, and the lobby outside the main office, and one outdoor location were sampled for various environmental comfort and pollutant parameters for one week in February 1997. A consistent relationship between hourly occupancy and corresponding carbon dioxide concentrations was seen. Carbon dioxide concentrations in the cafeteria, art room, and lobby were within specified American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) guidelines for comfort (< 1000 ppm). The science room had the highest concentrations (frequently exceeding 1000 ppm) due to high occupancy and non-functioning unit ventilators. Measured ventilation rates were within specified ASHRAE guidelines for the art room, cafeteria, and lobby. The science room, which relied on natural ventilation only, was not able to meet the ASHRAE guideline on one of the three days studied. The use of a completely mixed space, one compartment mass balance model with estimated CO2 generation rates and measured CO2 concentrations is shown to be a useful method for evaluating ventilation. Modeled effective ventilation, air changes per hour, and mixing factors reflected measured carbon dioxide concentrations and measured ventilation in each room. Mechanical ventilation afforded better mixing than natural ventilation. This study demonstrates the usefulness of collecting indoor CO2 and occupancy data when carrying out indoor air quality evaluations in schools.     

High work disability rate among rheumatoid arthritis patients in Lithuania

OBJECTIVE: To evaluate labor force characteristics among patients with rheumatoid arthritis (RA) in Lithuania. To assess if Lithuania's transition from a state-planned to a free-market economy after 1990 changed the employment perspectives of patients with RA. METHODS: RA patients, age 16-65 years (n = 238), were randomly selected from the RA register in Vilnius. They completed questions about sociodemographics, working status, and disease characteristics, they underwent a clinical examination, and they completed the modified Health Assessment Questionnaire and the Short Form 36. RESULTS: Age- and sex-adjusted employment was 24.2% lower and work disability 51.7% higher in patients compared with the general population in Lithuania. After 10 years of disease, 48% of the patients had withdrawn from the labor force. In those with a paid job, the average sick leave in the past year was 31.9 days compared with the national average of 10.8 days. Although disease activity was not significantly different in employed compared with work-disabled patients, physical function and perceived quality of life (except general health) were worse among patients with work disability. The change in economic organization in 1990 was noted to increase the risk for work withdrawal by a factor of 2.75 (95% confidence interval 1.68-4.53). CONCLUSION: In Lithuania, the impact of RA on work disability is important. Although work disability in Lithuanian patients with RA seems more pronounced compared with reports from Western societies, variables associated with work disability are comparable. The transition to a market-orientated economy in 1990 increased the risk of becoming work disabled.     

The impact of systemic sclerosis on arterial wall stiffness parameters and endothelial function

Systemic sclerosis (SSc) is characterized by thickening and fibrosis of skin and internal organs that is associated with vascular damage. SSc may lead to arterial dysfunction and premature aging of the arteries. However, its relationship with parameters of arterial wall dysfunction has not been fully explored. To determine if carotid–radial pulse wave velocity (PWV), aortic augmentation index (AIx) and endothelial function are altered in SSc patients, 17 consecutive patients with SSc and 34 age- and gender-matched controls were included in our study. PWV and AIx were assessed non-invasively by applanation tonometry. The endothelium-dependent flow-mediated dilatation (FMD) test in a brachial artery was performed by the ultrasound system. The blood investigations included serum lipid profile, glucose, and high-sensitivity CRP (hsCRP) measurements. As compared to controls, SSc patients had significantly higher medians of the AIx (p = 0.002) and the PWV (p = 0.04) and the median of the FMD was significantly lower (p = 0.001). Stepwise linear regression including comorbid factors showed that SSc was a significant independent predictor of all arterial wall parameters measures. SSc patients have increased AIx and PWV and lower FMD as compared to control subjects. The relationship between SSc and measures of arterial wall parameters still remains unclear. Though replication of the results presented here is required, we conclude that SSc has a great impact on large and conduit arteries damage.