Imaging Assessment of Cardiovascular Disease in Systemic Lupus Erythematosus

Systemic lupus erythematosus is a multisystem, autoimmune disease known to be one of the strongest risk factors for atherosclerosis. Patients with SLE have an excess cardiovascular risk compared with the general population, leading to increased cardiovascular morbidity and mortality. Although the precise explanation for this is yet to be established, it seems to be associated with the presence of an accelerated atherosclerotic process, arising from the combination of traditional and lupus-specific risk factors. Moreover, cardiovascular-disease associated mortality in patients with SLE has not improved over time. One of the main reasons for this is the poor performance of standard risk stratification tools on assessing the cardiovascular risk of patients with SLE. Therefore, establishing alternative ways to identify patients at increased risk efficiently is essential. With recent developments in several imaging techniques, the ultimate goal of cardiovascular assessment will shift from assessing symptomatic patients to diagnosing early cardiovascular disease in asymptomatic patients which will hopefully help us to prevent its progression. This review will focus on the current status of the imaging tools available to assess cardiac and vascular function in patients with SLE

THE OPTIMAL RELATIONSHIP BETWEEN ACTUATOR STIFFNESS AND ACTUATION TIMING FOR A PASSIVE ANKLE EXOSKELETON: AN OPENSIM SIMULATION

Introduction The passive ankle exoskeleton developed by Collins et al. (2015) reduced the metabolic cost of walking with an actuation-timing of ~16% of stance [1]; however, other actuation timings have not been extensively investigated. Therefore, the purpose of this study was to determine the optimal relationship between actuator-stiffness and actuation-timing for a passive ankle exoskeleton by using musculoskeletal modeling. Methods Kinematics and ground reaction forces were recorded while a healthy-young male walked on overground force-plates, and these data were exported to a musculoskeletal modeling software (OpenSim) for simulation. A passive ankle exoskeleton model was designed and integrated with a default OpenSim lower-limb model. A total of 2000 simulations were performed to test all combinations of 20 actuator stiffnesses (5.5-17.5 kN/m) and 10 actuation timings (15-60% stance) across 10 walking steps. The Umberger probe [2] was used to estimate the metabolic rate of each muscle and the integrals of the metabolic rates for all the lower extremity muscles were used to estimate the total metabolic cost of walking. Results and Discussion The greatest reduction in metabolic cost (Δ -2.67% ± 0.83%, p References [1] Collins et al., “Reducing the energy cost of human walking using an unpowered exoskeleton,” Nature., vol. 522, no. 7555, pp. 212–215, 2015, doi:10.1038/nature14288. [2] Umberger BR. Stance and swing phase costs in human walking. J R Soc Interface. 2010;7(50):1329-1340. doi:10.1098/rsif.2010.008

Interplay between Fe-Titanate Nanotube Fragmentation and Catalytic Decomposition of C2H4: Formation of C/TiO2 Hybrid Interfaces

This paper reports the synthesis of Fe-titanate nanotubes by means of the conventional ion-exchange method with iron nitrate solutions. As the iron-rich nanotubes were found to contain the catalyst precursor intrinsically dispersed in their structures, the unprecedented possibility of using this kind of materials for building carbon nanostructures, firmly attached at the surface of the forming TiO2 nanoparticles, was verified. The catalytic decomposition of ethylene, used as a carbon source, was performed at a relatively high temperature (750 °C) when the nanotubes undergo an irreversible phase transformation to form anatase and rutile nanoparticles. Due to the different amounts of Fe ions in the nanotubes, distinct types of carbon/TiO2 hybrid interfaces were formed, ranging from amorphous (lower Fe3+ concentration) to the more crystalline graphitic domains (higher Fe3+ concentrations), as documented by the microstructure of the treated samples. The present approach is of potential interest for (photo)catalytic and energy conversion/transport applications

Current knowledge and future perspectives of barrier membranes: A biomaterials perspective

Periodontal regenerations and bone augmentations are common procedures practiced on a daily basis worldwide. This had led to the introduction of a wide number of barrier membranes, all aiming at regenerating a sufficient amount of bone while being safe, cost effective and easy to handle. Membranes have different characteristics that may influence their clinical properties and the result obtained. The article aims at presenting an overview of the different barrier membranes commonly used in the oral surgery field, while shedding light on the new advances in the third generation membranes

Turnaround Arts Initiative Final Evaluation Report

This final evaluation report provides a description and analysis of program impacts in the pilot cohort of Turnaround Arts schools at the end of their second year, including summaries of: 1) the theory of action and program pillars, 2) the evaluation design and research questions, 3) program operation and implementation in the arts, and 4) outcomes and trends in school reform indicators and student achievement data

Which domains of the theoretical domains framework should be targeted in interventions to increase adherence to antihypertensives? A systematic review

Nonadherence to antihypertensives is prevalent and is associated with poorer health outcomes. This study aimed to identify psychological factors associated with adherence in patients taking antihypertensives as these are potentially modifiable, and can, therefore, inform the development of effective interventions to increase adherence. PubMed, EMBASE and PsychINFO were searched to identify studies that tested for significant associations between psychological domains and adherence to antihypertensives. The domains reported were categorized according to the Theoretical Domains Framework. The quality of included studies was evaluated using the National Institute for Clinical Excellence critical appraisal of questionnaire checklist. Thirty-one studies were included. Concerns about medicines (a subdomain of 'beliefs about consequences') and 'beliefs about capabilities' consistently showed association with adherence in over five studies. Healthcare professionals should actively ask patients if they have any concerns about their antihypertensives and their belief in their ability to control their blood pressure through taking antihypertensives

EFFICACY OF THE OPENSIM SIMULATOR AS A TOOL TO DETECT CHANGES IN GAIT: A PERIPHERAL ARTERY DISEASE MODEL

INTRODUCTION Peripheral Artery Disease (PAD) is characterized by atherosclerotic plaques in the leg arteries. A common treatment for PAD is supervised exercise training [1]. However, gait is not fully restored following supervised exercise training (SET). Musculoskeletal simulation may provide insight into how muscle activation changes following SET contributed to persistent gait alterations. METHODS Kinematic and kinetic data from overground walking of patients with PAD (n=12), before and after a 6-month exercise intervention, was used as input for musculoskeletal modeling (OpenSim). The subjects in our sample were subdivided based on the location of ischemic muscle pain, as reported on the San Diego Claudication Questionnaire. Virtual models were scaled to match the anthropometry of the subjects before muscle parameters were derived. Muscle activation was analyzed across the stance phase of gait and the output was analyzed across subjects and conditions. RESULTS AND DISCUSSION The subset of subjects that reported an attenuation of thigh pain as a result of SET (pain-free, n=4) showed a significant increase in late-stance knee flexor force, whereas the group that experienced no difference in thigh pain following SET (pain, n=8) did not demonstrate a significant change in knee flexor force. A significant positive association exists between the difference in absolute claudication distance and the difference in maximum knee flexor force. CONCLUSIONS This study demonstrated that a subset of patients with PAD experienced a significant increase in knee flexor force as a result of SET. Simulations may be an effective tool for understanding gait changes in a PAD model

MUSCLE OXYGENATION IN PATIENTS WITH PERIPHERAL ARTERY DISEASE DURING WALKING WITH AND WITHOUT AN ANKLE FOOT ORTHOSIS

Peripheral artery disease (PAD) is a cardiovascular disease caused by blockages in the arteries that reduce blood flow to the peripheral limbs. Claudication, a prominent symptom of PAD is a condition in which the lack of blood flow causes an inability to meet the metabolic demands of the muscle tissue, causes severe cramping pain. Previous studies have shown muscle oxygenation starts significantly lower and declines faster in patients with PAD compared to healthy controls. An ankle foot orthosis (AFO) can provide walking assistance by absorbing and returning the mechanical force during walking. We hypothesized oxygenation levels would be higher in patients with PAD walking with the AFO. Our research included seven subjects with PAD, patients performed a standardized graded treadmill test until claudication pain made them stop for both the AFO and non-ankle foot orthosis condition (NAF). Muscle oxygenation values were recorded before, during and directly following the trials for both conditions. PAD patients using the AFO significantly improved muscle oxygenation in the calf muscles. Our study only included seven patients, larger trials will be needed to increase the statistical strength