Merging parallel-plate and levitation actuators to enable linearity and tunability in electrostatic MEMS

In this study, a linear electrostatic MEMS actuator is introduced. The system consists of a MEMS cantilever beam with combined parallel-plate and electrostatic levitation forces. By using these two forcing methods simultaneously, the static response and natural frequency can be made to vary linearly with the voltage. The static response shows a linear increase of 90 nm/V and is maintained for more than 12μm of the tip displacement. The natural frequency shows a linear increase of 16 Hz/V and is maintained throughout a 2.9 kHz shift in the natural frequency. This wide range of linear displacement and frequency tunability is extremely useful for MEMS sensors and actuators, which suffer from the inherent nonlinearity of electrostatic forces. A theoretical model of the system is derived and validated with experimental data. Static response, natural frequency, and frequency response calculations are performed. Merging these two mechanisms enables high oscillation branches for a wide range of frequencies with potential applications in MEMS filters, oscillators, and sensors

Predictors of interest in psychological treatment for insomnia among older primary care patients with disturbed sleep.

In this study, we examined whether the common sense model of illness representation (CSMIR) could be successfully used to predict interest in cognitive-behavioral treatment for insomnia (CBT-I) among older primary care patients with disturbed sleep. The Sleep Impairment Index (C. M. Morin, 1993) was used to assess sleep disturbance and the constructs of the CSMIR in primary care patients ages 55 and older. Statistical analyses showed that the CSMIR constructs of consequences (perceived adverse consequences of sleep disturbance to functioning), causes (attributing one\u27s insomnia to bad sleeping habits), and emotion (concern about one\u27s sleep problem) predicted interest in CBT-I. These data provided encouraging support for the ability of the CSMIR to accurately predict patient interest in treatment for insomnia. Implications for assessment and treatment of insomnia in primary care are discussed

Fiblast (trafermin) in acute stroke: results of the European-Australian phase II/III safety and efficacy trial.

BACKGROUND: Trafermin (basic fibroblast growth factor) has been shown to reduce infarct volume in acute ischemic stroke models, and to promote functional recovery and new synapse formation when given to animals with completed cerebral infarction. A previous study in acute stroke patients suggested that trafermin was safe and well tolerated when given over a 3-hour period over a wide dose range. METHODS AND RESULTS: Double-blind, parallel group, placebo-controlled trial of a single 24-hour intravenous infusion of trafermin. Patients having onset of stroke symptoms within 6 h and a baseline score of >/=7 on the NIH Stroke Scale (>/=2 motor) were randomized to receive 5 or 10 mg of trafermin or placebo intravenously infused over 24 h. The primary efficacy outcome was a categorized combination of the Barthel and Rankin scales assessed at 90 days. A total of 286 patients had been enrolled at 55 sites in 11 countries when the sponsor directed that enrollment be stopped because an interim analysis of efficacy data predicted too small a chance of demonstrating a statistically significant benefit after recruitment of the planned 900 patients. The 5-mg group showed a slight but nonsignificant advantage over placebo (OR 1.2, 95% CI 0.72-2.00, p = 0.48); the 10-mg group showed a nonsignificant disadvantage (OR 0.74, 95% CI 0.44-1.22, p = 0.24). Mortality rates at 90 days were 17% in the 5-mg group, 24% in the 10-mg group and 18% in the placebo group. Treatment with trafermin was associated with an increased leukocytosis and a decrease in blood pressure: mean decrease in systolic blood pressure from baseline was 19 mm Hg in the 5-mg group, 22 mm Hg in the 10-mg group and 8 mm Hg in the placebo group. In a post hoc subgroup analysis, patients in the 5-mg group treated more than 5 h after the onset of symptoms showed an apparent advantage over placebo (OR 2.1, 95% CI 1.00-4.41, p = 0.044; after age adjustment: OR 1.9, 95% CI 0.91-4.13, p = 0.08). CONCLUSIONS: With the proper treatment regimen, trafermin can likely be given safely to stroke patients. The 5-mg dose showed a trend toward a treatment advantage. The ideal time window for this agent may exceed 5 h. This may open new avenues for acute stroke therapy, aiming at enhancing recovery mechanisms rather than immediate neuroprotection

Intramedullary tissue cultures from the Reamer-Irrigator-Aspirator system for diagnosing fracture-related infection

Fracture-related infection (FRI) is a serious complication following musculoskeletal trauma. Accurate diagnosis and appropriate treatment depend on retrieving adequate deep tissue biopsies for bacterial culture. The aim of this cohort study was to compare intraoperative tissue cultures obtained by the Reamer-Irrigator-Aspirator system (RIA)-system against standard tissue cultures obtained during the same surgical procedure. All patients had long bone fractures of the lower limbs and were assigned to the FRI or Control group based on the FRI consensus definition. The FRI group consisted of 24 patients with confirmed FRI and the Control group consisted of 21 patients with aseptic nonunion or chronic pain (in the absence of other suggestive/confirmatory criteria). Standard tissue cultures and cultures harvested by the RIA-system showed similar results. In the FRI group, standard tissue cultures and RIA cultures revealed relevant pathogens in 67% and 71% of patients, respectively. Furthermore, in four FRI patients, cultures obtained by the RIA-system revealed additional relevant pathogens that were not found by standard tissue culturing, which contributed to the optimization of the treatment plan. In the Control group, there were no false-positive RIA culture results. As a proof-of-concept, this cohort study showed that the RIA-system could have a role in the diagnosis of FRI as an adjunct to standard tissue cultures. Since scientific evidence on the added value of the RIA-system in the management of FRI is currently limited, further research on this topic is required before its routine application in clinical practice