Validation of predictive performance models for supersonic gas-jet nozzles at the Laboratory for Laser Energetics.

We present results characterizing the neutral-density distributions produced by the supersonic nozzles used in experiments on the OMEGA-60 and OMEGA-EP laser systems at the University of Rochester's Laboratory for Laser Energetics (LLE). Axisymmetric Fluent® simulations using LLE nozzle specifications capture the viscous effects, gas expansion, and shock waves that complicate flow predictions for offsets above the nozzle exit. These simulations show good agreement with neutral-density measurements obtained using a four-wave shearing interferometer.

Focal cone high harmonic generation driven by a 400 TW laser.

The generation of self-focusing beams of extreme ultraviolet (XUV) radiation using the focal cone high harmonic generation (FCHHG) technique is examined for high energy lasers. The FCHHG geometry is created by passing a focusing laser beam through a gas sheet prior to reaching focus and thus creating a converging beam of high harmonic radiation. This leads to a larger interaction area that increases the total area of XUV emission while not exceeding the saturation intensity of the target atoms or increasing the density of the atoms.

Improving hospital safety for patients with chronic kidney disease: a mixed methods study.

Background: People living with chronic kidney disease (CKD) require complex medical management and may be frequently hospitalized. Patient safety incidents during hospitalization can result in serious complications which may negatively affect health outcomes. There has been limited examination of how these patients perceive their own safety.

Evaluation of moving bed sand filter for denitrification, suspended solids removal and very low effluent total phosphorus concentrations.

Continuously flushing moving bed sand filter was operated in pilot scale for phosphorus (P) and nitrogen removal with simultaneous particle removal. The wastewater tested was either final effluent from a municipal wastewater treatment plant (WWTP) with nitrogen removal in moving bed biofilm reactors (MBBRs) followed by coagulation and dissolved air flotation (DAF) for P and suspended solids (SS) removal, or different mixtures of this final effluent and effluent from the MBBR-stage. The study focused on the applicability to achieve low total phosphorus (TP) concentrations (below 0.

Hemodynamic Response to Upper Airway Obstruction in Hypertensive and Normotensive Pregnant Women.

Mild obstructive sleep apnea is common in pregnancy and may have an exacerbating role in gestational hypertension, although currently the interaction between these two diseases is uncertain. We analyzed 43 pregnant subjects, 28 with gestational hypertension (GH) and 15 with normal healthy pregnancy, by level I polysomnography. Additionally, diastolic and systolic blood pressure changes in response to obstructive respiratory events were measured by noninvasive beat-by-beat monitoring.

Improvement in obstructive sleep apnea diagnosis and management wait times: A retrospective analysis of home management pathway for obstructive sleep apnea.

Obstructive sleep apnea is a common condition within the Canadian population. The current gold standard for diagnosis and management of patients is in-laboratory (in-lab) polysomnography; however, the limited availability of testing options for patients has led to long wait times and increased disease burden within the population. The Sleep Research Laboratory in Saskatoon (Saskatchewan) implemented a home management program to run in parallel with the in-lab system several years ago in an effort to increase their capacity and reduce wait times.

Increased nocturnal periodic limb movements in rheumatoid arthritis patients meeting questionnaire diagnostic criteria for restless legs syndrome.

Background: Based on questionnaire criteria, the sensorimotor disorder restless legs syndrome (RLS) has been reported to have a higher prevalence in rheumatoid arthritis (RA) patients than in the general population. There has been some speculation that peripheral arthritic symptoms may allow false positive responses to questionnaire criteria. This study evaluates whether RA patients meeting RLS questionnaire criteria also have objective evidence of increased periodic limb movements (PLMs) characteristic of RLS.

The association between obesity and outcomes in critically ill patients.

Background: Obesity rates are increasing worldwide, particularly in North America. The impact of obesity on the outcome of critically ill patients is unclear.

Methods: A prospective observational cohort study of consecutive patients admitted to a tertiary critical care unit in Canada between January 10, 2008 and March 31, 2009 was conducted.

Excessive daytime sleepiness among rural residents in Saskatchewan.

Background: Obstructive sleep apnea (OSA) is a common diagnosis in clinical practice. Excessive daytime sleepiness may be a warning for possible OSA.

Objectives: To assess the prevalence of excessive daytime sleepiness as measured by the Epworth Sleepiness Scale (ESS) in a rural community population; potential risk factors for OSA were also assessed.

The utility of the elbow sign in the diagnosis of OSA.

Background: Multiple questionnaires have been used to predict the diagnosis of OSA. Such models typically have multiple questions requiring cumulative scoring for interpretation. We wanted to determine whether a simple two-part questionnaire has predictive value in the pretest clinical evaluation for OSA.

Inter-observer reliability of candidate predictive morphometric measurements for women with suspected obstructive sleep apnea.

Objective: Obstructive sleep apnea (OSA) is increasingly recognized as a public health concern. Definitive diagnosis is by overnight polysomnographic (PSG) examination. Identification of clinical predictors would be beneficial in helping prioritize high-risk patients for assessment.

Restless legs syndrome as a comorbidity in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a multisystem disease with a complex immunologic pathophysiology. Likewise, sleep disorders can involve a complicated interplay between the neurologic pathways, immune system, and respiratory system. Recent studies have shown an elevated prevalence of sleep abnormalities in connective tissue disorders compared to the general population.

Sleep disordered breathing and gestational hypertension: postpartum follow-up study.

Background: Gestational hypertension (GH) is a newly recognized risk factor for adverse cardiovascular events later in life. Sleep disordered breathing (SDB) is an established risk factor for adverse cardiovascular events. Recent research has suggested that women with GH may have an increased rate of SDB during pregnancy, but it is not known if this higher rate of SDB persists into the postpartum state.

Relationship between the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale in a sleep laboratory referral population.

Background: Sleep health questionnaires are often employed as a first assessment step for sleep pathology. The Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI) are two commonly employed questionnaire instruments. Aspects of sleep health may be measured differently depending on choice of instrument.

Can gestational hypertension be modified by treating nocturnal airflow limitation?

Objective: Recent evidence suggests that women with gestational hypertension (GH) have a high rate of sleep disordered breathing (SDB), and treatment for even marginal SDB may improve blood pressure control in women with GH. We assessed whether the application SDB treatment could improve blood pressure in women with GH.

Methods: This was a single-center randomized study.

Thiopurine methyltransferase screening before azathioprine prescription: a physician survey.

Background: In patients treated with azathioprine, deficient thiopurine methyltransferase (TPMT) activity has been associated with haematologic toxicity.

Objectives: To determine how many Saskatchewan rheumatologists routinely pre-screen TPMT activity before prescribing azathioprine. Further, to retrospectively review TPMT activity levels from pre-screening in one patient cohort.

Obstructive sleep apnoea in relation to rheumatic disease.

Sleep problems are common concerns in rheumatology patients and have been independently linked to increased pain perception and fatigue severity. Evidence supports an increased prevalence of primary sleep disorders, including sleep apnoea, in some rheumatic disease populations, particularly RA. Obstructive sleep apnoea is a significant public health concern and contributes to increased cardiovascular morbidity and mortality.

Improved Sleep Efficiency after Anti-Tumor Necrosis Factor α Therapy in Rheumatoid Arthritis Patients.

Background: Poor sleep health is increasingly recognized as contributing to decreased quality of life, increased morbidity/mortality and heightened pain perception. Our purpose in this study was to observe the effect on sleep parameters, specifically sleep efficiency, in rheumatoid arthritis (RA) patients treated with anti-tumor necrosis factor alpha (anti-TNF-α) therapy.

Methods: This was a prospective observational study of RA patients with hypersomnolence/poor sleep quality as defined by the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI).

Do sleepy rheumatoid arthritis patients have a sleep disorder?

Objective: Subjective reports of sleep dysfunction are common in people with rheumatoid arthritis (RA). Our objective was to determine whether excess sleepiness in RA is associated with polysomnographic (PSG) abnormalities.

Methods: Twelve RA participants with abnormal sleep scores were identified in clinic and age/gender matched to RA participants with normal Epworth Sleepiness Scale (ESS) scores.

Prevalence of High Epworth Sleepiness Scale scores in a rural population.

Background: Increased daytime sleepiness is an important symptom of obstructive sleep apnea (OSA). OSA is frequently underdiagnosed, and the Epworth Sleepiness Scale (ESS) can be a useful tool in alerting physicians to a potential problem involving OSA.

Objective: To measure the prevalence and determinants of daytime sleepiness measured using the ESS in a rural community population.

Comparison of polysomnographic and portable home monitoring assessments of obstructive sleep apnea in Saskatchewan women.

Objectives: To compare a commercially available, level III in-home diagnostic sleep test (Embletta, Embletta USA) and in-laboratory polysomnography (PSG) in women with suspected obstructive sleep apnea (OSA).

Methods: Consecutive women scheduled for routine PSG testing for evaluation of clinically suspected OSA and who met inclusion⁄exclusion criteria, were invited to participate. An in-home Embletta portable monitor test was performed one week before or after diagnostic PSG.