5,040 research outputs found

    Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer

    Get PDF
    CONTEXT: In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer. OBJECTIVES: To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial. METHODS: Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made. RESULTS: The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients. CONCLUSIONS: This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions

    Overview of PIER-Funded Existing Building Commissioning and Diagnostics Research

    Get PDF
    The California Energy Commission's Public Interest Energy Research (PIER) Program supports research and development that helps improve the quality of life in California by bringing environmentally safe, affordable, and reliable energy services and products to the marketplace. The PIER Program awards up to $62 million annually and has funded some of the most promising energy research in the U.S. The PIER Buildings program area seeks to decrease building energy use through research that develops or improves energy efficient technologies, strategies, tools, and building performance evaluation methods. This paper summarizes the accomplishments of projects within the PIER Buildings Program related to existing building commissioning and diagnostics between 1999 and 2003

    Does Neck Strength in Male and Female Youth Soccer Players Affect Head Velocity During Goal-Directed Heading: A Proposal

    Get PDF
    Introduction: Head impact research in soccer (e.g., during heading) has increased recently, with the intent to reduce the risk of play-related injuries such as concussions. Low neck strength and head kinematics (e.g., velocity) in players have been proposed as risk factors for concussion1. However, previous research has primarily focused on collegiate athletes1, despite the possible increased risk for youth players due to crucial neurodevelopment occurring in this group2. Therefore, the purpose of this study is to determine neck strength differences between male and female youth soccer players, and to quantify the relationship between heading velocities and neck strength. Methods: Participants will include male and female youth soccer players (11 - 13 years old). Neck strength will be quantified while supine during lateral flexion, cervical flexion, and extension using a prone push test with a hand-held dynamometer. Participants will also complete five headers in the lab in each of three directions: balls tossed to them from their right, left, and in front. Three retroreflective markers on each participant’s head will be recorded using five GoPro Hero 9 cameras. ProAnalyst (Xcitex) motion capture analysis software will be used to determine head velocities. Pearson correlations will be completed to assess the strength of the relationship between neck strength and head velocities, and between sex and head velocities. Expected results: Youth with lower neck strength will have increased head velocities during purposeful heading. Moreover, females will have lower neck strength, and therefore, higher head velocities in comparison to their male counterparts. Keywords: youth soccer, neck strength, head velocities, sex differences References: Dezman, Z. D., Ledet, E. H., & Kerr, H. A. (2013). Neck strength imbalance correlates with increased head acceleration in soccer heading. Sports Health, 5(4), 320-326. Patel, D. R., Shivdasani, V., & Baker, R. J. (2005). Management of sport-related concussion in young athletes. Sports Medicine, 35(8), 671-84

    A Comparison of Deep Inelastic Scattering Monte Carlo Event Generators to HERA Data

    Get PDF
    The Monte Carlo models ARIADNE, HERWIG and LEPTO are compared to deep-inelastic scattering data measured at the ep-collider HERA

    Quality of the Literacy Environment in Inclusive Early Childhood Special Education ECSE Classrooms

    Get PDF
    The purpose of this study was to examine the quality of the literacy environment in inclusive early childhood special education (ECSE) classrooms (N = 54). The first aim was to describe the quality of the literacy environment in terms of structure (i.e., book materials and print/writing materials) and instruction (i.e., instructional support). The second aim was to examine the interrelationships among teacher and classroom characteristics and the quality of the literacy environment. Results showed that, on average, the quality of the structural literacy environment was low to moderate, and the quality of the instructional literacy environment was generally low. The number of children who were Dual Language Learners related to the quality of the structural literacy environment. The quality of the instructional literacy environment was positively associated with two teacher variables (teacher education and self-efficacy) and was negatively associated with one teacher variable (the number of language and literacy workshops attended). Implications are discussed

    Exposure to Household Air Pollution from Biomass-Burning Cookstoves and HbA1c and Diabetic Status Among Honduran Women

    Full text link
    Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middle‐income countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This cross‐sectional study of 142 women (72 with traditional stoves and 70 with cleaner‐burning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24‐hour average kitchen and personal fine particulate matter [PM2.5] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84 μg/m3 increase in personal PM2.5, 1.49; 95% confidence interval [CI], 1.11‐2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated

    A Search for Instantons at HERA

    Get PDF
    A search for QCD instanton (I) induced events in deep-inelastic scattering (DIS) at HERA is presented in the kinematic range of low x and low Q^2. After cutting into three characteristic variables for I-induced events yielding a maximum suppression of standard DIS background to the 0.1% level while still preserving 10% of the I-induced events, 549 data events are found while 363^{+22}_{-26} (CDM) and 435^{+36}_{-22} (MEPS) standard DIS events are expected. More events than expected by the standard DIS Monte Carlo models are found in the data. However, the systematic uncertainty between the two different models is of the order of the expected signal, so that a discovery of instantons can not be claimed. An outlook is given on the prospect to search for QCD instanton events using a discriminant based on range searching in the kinematical region Q^2\gtrsim100\GeV^2 where the I-theory makes safer predictions and the QCD Monte Carlos are expected to better describe the inclusive data.Comment: Invited talk given at the Ringberg Workshop on HERA Physics on June 19th, 2001 on behalf of the H1 collaboratio

    Antenatal atazanavir: a retrospective analysis of pregnancies exposed to atazanavir.

    Get PDF
    INTRODUCTION: There are few data regarding the tolerability, safety, or efficacy of antenatal atazanavir. We report our clinical experience of atazanavir use in pregnancy. METHODS: A retrospective medical records review of atazanavir-exposed pregnancies in 12 London centres between 2004 and 2010. RESULTS: There were 145 pregnancies in 135 women: 89 conceived whilst taking atazanavir-based combination antiretroviral therapy (cART), "preconception" atazanavir exposure; 27 started atazanavir-based cART as "first-line" during the pregnancy; and 29 "switched" to an atazanavir-based regimen from another cART regimen during pregnancy. Gastrointestinal intolerance requiring atazanavir cessation occurred in five pregnancies. Self-limiting, new-onset transaminitis was most common in first-line use, occurring in 11.0%. Atazanavir was commenced in five switch pregnancies in the presence of transaminitis, two of which discontinued atazanavir with persistent transaminitis. HIV-VL < 50 copies/mL was achieved in 89.3% preconception, 56.5% first-line, and 72.0% switch exposures. Singleton preterm delivery (<37 weeks) occurred in 11.7% preconception, 9.1% first-line, and 7.7% switch exposures. Four infants required phototherapy. There was one mother-to-child transmission in a poorly adherent woman. CONCLUSIONS: These data suggest that atazanavir is well tolerated and can be safely prescribed as a component of combination antiretroviral therapy in pregnancy
    corecore