476 research outputs found

    Technical Note: Evaluation of a Crucible Furnace Retort for Laboratory Torrefactions of Wood Chips

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    Torrefaction is a thermal process that improves biomass performance as a fuel by property enhancements such as decreased moisture uptake and increased carbon density. Most studies to date have used very small amounts of finely ground biomass. This study reports the testing of a crucible furnace retort that was fabricated to produce intermediate quantities of torrefied material and to allow processing of wood chips. Yields ranging from 51 to 96% were impacted to a greater extent by differences in temperature than time of treatment. Although temperature-control issues (gradients, slow heating) were experienced with the crucible furnace retort, this equipment proved to be useful for its intended purpose

    Evaluation of a semiquantitative SNAP test for measurement of bile acids in dogs

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    Background. Serum bile acids (SBA) are used as a routine screening tool of liver function in dogs. Serum samples are usually shipped to a referral laboratory for quantitative analysis with an enzymatic chemistry analyzer. The canine SNAP Bile Acids Test (SNAP-BAT) provides an immediate, semi-quantitative measurement of bile acid concentrations in-house. With the SNAP-BAT, bile acids concentrations of 5–30 µmol/L are quantified, and results outside of that range are classified as 30 µmol/L. Agreement of the SNAP-BAT with the enzymatic method has not been extensively investigated.Objectives. The purposes of this prospective clinical study were to assess the precision of the SNAP-BAT and determine agreement of SNAP-BAT with results from an in-house chemistry analyzer.Methods. After verifying intra-assay precision of the SNAP-BAT, a prospective analysis was performed using blood samples collected from 56 dogs suspected to have liver disease. Each sample was analyzed with an enzymatic, in-house chemistry analyzer and the SNAP-BAT. Agreement between the two methods was statistically assessed using the κ index of agreement.Results. Intra-assay variability was minimal. The κ index for agreement between the SNAP-BAT and routine chemistry analyzer was between 0.752 and 0.819, indicating substantial to near perfect agreement.Conclusions. The SNAP-BAT is a highly accurate, semi-quantitative test that yields immediate results, and has very little intra-assay variability, particularly for results >30 µmol/L

    Healthcare professionals' preferences for surgery or primary endocrine therapy to treat older women with operable breast cancer

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    Introduction : Primary endocrine therapy (PET) is an alternative treatment to surgery for oestrogen receptor (ER) positive operable breast cancer in older women. However, there is variable use of PET in the UK, with up to 40% of patients aged over 70 receiving PET instead of surgery in some regions. Treatment options offered to patients rely heavily on healthcare professional (HCP) assessment and opinion on which treatments are appropriate. Materials and methods : This was a mixed methods study combining semi-structured interviews with HCPs working in high and low PET regions in the UK, followed by a postal questionnaire survey distributed via the Association of Breast Surgery (ABS). Results : Thirty-four HCPs (20 breast surgeons; 13 nurse specialists; 1 geriatrician) were interviewed from 14 sites across the UK and 252/641 questionnaires returned (39%). There was an overriding view that PET is not suitable for patients under the age of 80 unless there are significant comorbidities. Opinion was split regarding the best way to treat patients with dementia. Patient preference was generally stated to be the most important factor when considering treatment, however only around a quarter 65/244 (26.6%) felt that all patients over the age of 70 should be offered PET as an alternative treatment option. Conclusions : Opinions differ on the best way to treat women over 70 with operable breast cancer, especially if they have co-existing dementia, as well as whether they should be offered PET as a treatment option. This may be a significant cause of treatment variation in the UK. Keywords : Breast cancer; Primary endocrine therapy; Surgery; Elderly; Older; Mixed methods.</p

    Sufficient conditions for two-dimensional localization by arbitrarily weak defects in periodic potentials with band gaps

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    We prove, via an elementary variational method, 1d and 2d localization within the band gaps of a periodic Schrodinger operator for any mostly negative or mostly positive defect potential, V, whose depth is not too great compared to the size of the gap. In a similar way, we also prove sufficient conditions for 1d and 2d localization below the ground state of such an operator. Furthermore, we extend our results to 1d and 2d localization in d dimensions; for example, a linear or planar defect in a 3d crystal. For the case of D-fold degenerate band edges, we also give sufficient conditions for localization of up to D states.Comment: 9 pages, 3 figure

    The decision-making process for senior cancer patients: treatment allocation of older women with operable breast cancer in the UK.

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    Objective: Up to 40% of women over 70 years with primary operable breast cancer in the UK are treated with primary endocrine therapy (PET) as an alternative to surgery. A variety of factors are important in determining treatment for older breast cancer patients. This study aimed to identify the patient and tumor factors associated with treatment allocation in this population. Methods: Prospectively collected data on treatment received (surgery vs. PET) were analysed with multivariable logistic regression using the variables age, modified Charlson Comorbidity Index (CCI), activities of daily living (ADL) score, Mini-Mental State Examination (MMSE) score, HER2 status, tumour size, grade and nodal status. Results: Data were available for 1,122 cancers in 1,098 patients recruited between February 2013 and June 2015 from 51 UK hospitals. About 78% of the population were treated surgically, with the remainder being treated with PET. Increasing patient age at diagnosis, increasing CCI score, large tumor size (5 cm or more) and dependence in one or more ADL categories were all strongly associated with non-surgical treatment (P<0.05). Conclusion: Increasing comorbidity, large tumor size and reduced functional ability are associated with reduced likelihood of surgical treatment of breast cancer in older patients. However, age itself remains a significant factor for non-surgical treatment; reinforcing the need for evidence-based guidelines

    KELT-8b: A highly inflated transiting hot Jupiter and a new technique for extracting high-precision radial velocities from noisy spectra

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    We announce the discovery of a highly inflated transiting hot Jupiter discovered by the KELT-North survey. A global analysis including constraints from isochrones indicates that the V = 10.8 host star (HD 343246) is a mildly evolved, G dwarf with Teff=575455+54T_{\rm eff} = 5754_{-55}^{+54} K, logg=4.0780.054+0.049\log{g} = 4.078_{-0.054}^{+0.049}, [Fe/H]=0.272±0.038[Fe/H] = 0.272\pm0.038, an inferred mass M=1.2110.066+0.078M_{*}=1.211_{-0.066}^{+0.078} M_{\odot}, and radius R=1.670.12+0.14R_{*}=1.67_{-0.12}^{+0.14} R_{\odot}. The planetary companion has mass MP=0.8670.061+0.065M_P = 0.867_{-0.061}^{+0.065} MJM_{J}, radius RP=1.860.16+0.18R_P = 1.86_{-0.16}^{+0.18} RJR_{J}, surface gravity loggP=2.7930.075+0.072\log{g_{P}} = 2.793_{-0.075}^{+0.072}, and density ρP=0.1670.038+0.047\rho_P = 0.167_{-0.038}^{+0.047} g cm3^{-3}. The planet is on a roughly circular orbit with semimajor axis a=0.045710.00084+0.00096a = 0.04571_{-0.00084}^{+0.00096} AU and eccentricity e=0.0350.025+0.050e = 0.035_{-0.025}^{+0.050}. The best-fit linear ephemeris is T0=2456883.4803±0.0007T_0 = 2456883.4803 \pm 0.0007 BJDTDB_{\rm TDB} and P=3.24406±0.00016P = 3.24406 \pm 0.00016 days. This planet is one of the most inflated of all known transiting exoplanets, making it one of the few members of a class of extremely low density, highly-irradiated gas giants. The low stellar logg\log{g} and large implied radius are supported by stellar density constraints from follow-up light curves, plus an evolutionary and space motion analysis. We also develop a new technique to extract high precision radial velocities from noisy spectra that reduces the observing time needed to confirm transiting planet candidates. This planet boasts deep transits of a bright star, a large inferred atmospheric scale height, and a high equilibrium temperature of Teq=167555+61T_{eq}=1675^{+61}_{-55} K, assuming zero albedo and perfect heat redistribution, making it one of the best targets for future atmospheric characterization studies.Comment: Submitted to ApJ, feedback is welcom

    Quaternary Structure Defines a Large Class of Amyloid-β Oligomers Neutralized by Sequestration

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    SummaryThe accumulation of amyloid-β (Aβ) as amyloid fibrils and toxic oligomers is an important step in the development of Alzheimer’s disease (AD). However, there are numerous potentially toxic oligomers and little is known about their neurological effects when generated in the living brain. Here we show that Aβ oligomers can be assigned to one of at least two classes (type 1 and type 2) based on their temporal, spatial, and structural relationships to amyloid fibrils. The type 2 oligomers are related to amyloid fibrils and represent the majority of oligomers generated in vivo, but they remain confined to the vicinity of amyloid plaques and do not impair cognition at levels relevant to AD. Type 1 oligomers are unrelated to amyloid fibrils and may have greater potential to cause global neural dysfunction in AD because they are dispersed. These results refine our understanding of the pathogenicity of Aβ oligomers in vivo

    Pharmacokinetics of Clindamycin in Obese and Nonobese Children

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    ABSTRACT Although obesity is prevalent among children in the United States, pharmacokinetic (PK) data for obese children are limited. Clindamycin is a commonly used antibiotic that may require dose adjustment in obese children due to its lipophilic properties. We performed a clindamycin population PK analysis using data from three separate trials. A total of 420 samples from 220 children, 76 of whom had a body mass index greater than or equal to the 95th percentile for age, were included in the analysis. Compared to other metrics, total body weight (TBW) was the most robust measure of body size. The final model included TBW and a sigmoidal maturation relationship between postmenstrual age (PMA) and clearance (CL): CL (liters/hour) = 13.8 × (TBW/70) 0.75 × [PMA 2.83 /(39.5 2.83 +PMA 2.83 )]; volume of distribution ( V ) was associated with TBW, albumin (ALB), and alpha-1 acid glycoprotein (AAG): V (liters) = 63.6 × (TBW/70) × (ALB/3.3) −0.83 × (AAG/2.4) −0.25 . After accounting for differences in TBW, obesity status did not explain additional interindividual variability in model parameters. Our findings support TBW-based dosing for obese and nonobese children

    Potential Cost-effectiveness of Early Identification of Hospital-acquired Infection in Critically Ill Patients

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    Limitations in methods for the rapid diagnosis of hospital-acquired infections often delay initiation of effective antimicrobial therapy. New diagnostic approaches offer potential clinical and cost-related improvements in the management of these infections. We developed a decision modeling framework to assess the potential cost-effectiveness of a rapid biomarker assay to identify hospital-acquired infection in high-risk patients earlier than standard diagnostic testing. The framework includes parameters representing rates of infection, rates of delayed appropriate therapy, and impact of delayed therapy on mortality, along with assumptions about diagnostic test characteristics and their impact on delayed therapy and length of stay. Parameter estimates were based on contemporary, published studies and supplemented with data from a four-site, observational, clinical study. Extensive sensitivity analyses were performed. The base-case analysis assumed 17.6% of ventilated patients and 11.2% of nonventilated patients develop hospital-acquired infection and that 28.7% of patients with hospital-acquired infection experience delays in appropriate antibiotic therapy with standard care. We assumed this percentage decreased by 50% (to 14.4%) among patients with true-positive results and increased by 50% (to 43.1%) among patients with false-negative results using a hypothetical biomarker assay. Cost of testing was set at 110/d.Inthebasecaseanalysis,amongventilatedpatients,dailydiagnostictestingstartingonadmissionreducedinpatientmortalityfrom12.3to11.9110/d. In the base-case analysis, among ventilated patients, daily diagnostic testing starting on admission reduced inpatient mortality from 12.3 to 11.9% and increased mean costs by 1,640 per patient, resulting in an incremental cost-effectiveness ratio of 21,389perlifeyearsaved.Amongnonventilatedpatients,inpatientmortalitydecreasedfrom7.3to7.121,389 per life-year saved. Among nonventilated patients, inpatient mortality decreased from 7.3 to 7.1% and costs increased by 1,381 with diagnostic testing. The resulting incremental cost-effectiveness ratio was 42,325perlifeyearsaved.Thresholdanalysesrevealedtheprobabilitiesofdevelopinghospitalacquiredinfectioninventilatedandnonventilatedpatientscouldbeaslowas8.4and9.842,325 per life-year saved. Threshold analyses revealed the probabilities of developing hospital-acquired infection in ventilated and nonventilated patients could be as low as 8.4 and 9.8%, respectively, to maintain incremental cost-effectiveness ratios less than 50,000 per life-year saved. Development and use of serial diagnostic testing that reduces the proportion of patients with delays in appropriate antibiotic therapy for hospital-acquired infections could reduce inpatient mortality. The model presented here offers a cost-effectiveness framework for future test development

    Using Interactive Simulation to Extend Access to Learning Along the Historic Tour Route of Mammoth Cave National Park

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    This poster presentation displays work of a current project to address the problem of limited inclusion to field-based learning experiences for students with physical disabilities. Led by researchers at Georgia State University, Ohio State University and Mammoth Cave International Center for Science and Learning, the overall objective of the project is through integration of emerging simulation technologies and techniques, to provide a rich virtual environment of a geological field site for students with mobility impairments. Through the development of a synthetic field-based module that employs a virtual environment that interchangeably uses two and three-dimensional representation for presenting an alternative to field experience, this project will assess the effectiveness in engaging the student community and its efficacy in the curriculum when used as an alternative representation of field experience. The expected outcome is that the emulation would preclude the need for physical presence within the traditional field site, and provide adequate pedagogical representation for content transfer. Additionally, creating such an environment will impact all able-bodied students by providing supplemental resources that can both precede a traditional field experience and allow for visitors to re-examine a field site long after a field trip, in both current formal and informal educational settings. Based on the identified need to accommodate students with mobility impairments in field-based instructional experiences, this talk will present a virtual recreation of Mammoth Cave National Park, describing the potential for including all students in remotely accessing cave and karst field studies, regardless of their physical abilities
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