251 research outputs found

    Can a Home-based Cardiac Physical Activity Program Improve the Physical Function Quality of Life in Children with Fontan Circulation?

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    Objective Patients after Fontan operation for complex congenital heart disease (CHD) have decreased exercise capacity and report reduced health-related quality of life (HRQOL). Studies suggest hospital-based cardiac physical activity programs can improve HRQOL and exercise capacity in patients with CHD; however, these programs have variable adherence rates. The impact of a home-based cardiac physical activity program in Fontan survivors is unclear. This pilot study evaluated the safety, feasibility, and benefits of an innovative home-based physical activity program on HRQOL in Fontan patients. Methods A total of 14 children, 8–12 years, with Fontan circulation enrolled in a 12-week moderate/high intensity home-based cardiac physical activity program, which included a home exercise routine and 3 formalized in-person exercise sessions at 0, 6, and 12 weeks. Subjects and parents completed validated questionnaires to assess HRQOL. The Shuttle Test Run was used to measure exercise capacity. A Fitbit Flex Activity Monitor was used to assess adherence to the home activity program. Results Of the 14 patients, 57% were male and 36% had a dominant left ventricle. Overall, 93% completed the program. There were no adverse events. Parents reported significant improvement in their child\u27s overall HRQOL (P \u3c .01), physical function (P \u3c .01), school function (P = .01), and psychosocial function (P  \u3c .01). Patients reported no improvement in HRQOL. Exercise capacity, measured by total shuttles and exercise time in the Shuttle Test Run and calculated VO2max, improved progressively from baseline to the 6 and 12 week follow up sessions. Monthly Fitbit data suggested adherence to the program. Conclusion This 12-week home-based cardiac physical activity program is safe and feasible in preteen Fontan patients. Parent proxy-reported HRQOL and objective measures of exercise capacity significantly improved. A 6-month follow up session is scheduled to assess sustainability. A larger study is needed to determine the applicability and reproducibility of these findings in other age groups and forms of complex CHD

    The Prediction of Professional Success in Apprenticeship: The Role of Cognitive and Non-Cognitive Abilities, of Interests and Personality

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    Context: We addressed the issue of person-job-fit by focussing on both professional success and work satisfaction. Publications studying the predictive validity of (cognitive) ability, personality, or vocational interest alone have shown relationships with professional success or work satisfaction for each predictor separately. Nevertheless, these predictors have rarely been studied simultaneously. Methods: To this end we tested the incremental validity of abilities, traits, and interests in a sample from diverse occupations: In 648 apprentices and students from five different branches (Food, Tech, People, Office, Craft) the (incremental) contributions of 3 intelligence factors (verbal, numerical, spatial), 3 alternative abilities (social-emotional, creative, practical), 4 conscientiousness facets, other big five factors (O, E, A, N), and of 14 professional interests were analysed regarding prediction of GPA in professional schools and school/job satisfaction. Results: Intelligence and conscientiousness were best predictors, followed by social-emotional competence and interests, whereas other traits provided marginal contributions. Predictors varied between branches, mostly following expectations. The test battery allowed a very good prediction of apprenticeship success (max. 37%), but for some branches prediction was considerably lower. Conclusion: Criteria for person-job-fit are not swappable, neither are the predictors. Professional success was mostly predicted by a different predictor set -namely ability and the personality dimension of conscientiousness- then satisfaction, which was mostly predicted by non-interest in a certain occupation. As a practical implication, we conclude that choosing the right candidate for a certain branch one needs to use a broad set of predictor variables. Besides cognitive ability also personality and vocational interests had predictive validity for an individuals person-job-fit

    An eigenvalue approach to evaluating minors for weighing matrices W(n,n-1)

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    In the present paper we concentrate our study on the evaluation of minors for weighing matrices W(n,n-1). Theoretical proofs concerning their minors up to the order of (n-4) x (n-4) are derived introducing an eigenvalue approach. A general theorem specifying the analytical form of any (n-l) x (n-l) minor is developed. An application to the growth problem for weighing matrices is given

    Results of ASERTAA, a randomized prospective crossover pharmacogenetic study of immediate-release versus extended-release tacrolimus in African American kidney transplant recipients

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    BACKGROUND: Differences in tacrolimus dosing across ancestries is partly attributable to polymorphisms in CYP3A5 genes that encode tacrolimus-metabolizing cytochrome P450 3A5 enzymes. The CYP3A5*1 allele, preponderant in African Americans, is associated with rapid metabolism, subtherapeutic concentrations, and higher dose requirements for tacrolimus, all contributing to worse outcomes. Little is known about the relationship between CYP3A5 genotype and the tacrolimus pharmacokinetic area under the curve (AUC) profile in African Americans or whether pharmacogenetic differences exist between conventional twice-daily, rapidly absorbed, immediate-release tacrolimus (IR-Tac) and once-daily extended-release tacrolimus (LifeCycle Pharma Tac [LCPT]) with a delayed absorption profile. STUDY DESIGN: Randomized prospective crossover study. SETTING & PARTICIPANTS: 50 African American maintenance kidney recipients on stable IR-Tac dosing. INTERVENTION: Recipients were randomly assigned to continue IR-Tac on days 1 to 7 and then switch to LCPT on day 8 or receive LCPT on days 1 to 7 and then switch to IR-Tac on day 8. The LCPT dose was 85% of the IR-Tac total daily dose. OUTCOMES: Tacrolimus 24-hour AUC (AUC MEASUREMENTS: CYP3A5 genotype, 24-hour tacrolimus pharmacokinetic profiles. RESULTS: ∼80% of participants carried the CYP3A5*1 allele (CYP3A5 expressers). There were no significant differences in AUC LIMITATIONS: This was primarily a pharmacogenetic study rather than an efficacy study; the follow-up period was too short to capture clinical outcomes. CONCLUSIONS: Achieving therapeutic tacrolimus trough concentrations with IR-Tac in most African Americans results in significantly higher peak concentrations, potentially magnifying the risk for toxicity and adverse outcomes. This pharmacogenetic effect is attenuated by delayed tacrolimus absorption with LCPT. TRIAL REGISTRATION: Registered at ClinicalTrials.gov, with study number NCT01962922

    Accelerated Charged Particle Tracking with Graph Neural Networks on FPGAs

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    We develop and study FPGA implementations of algorithms for charged particle tracking based on graph neural networks. The two complementary FPGA designs are based on OpenCL, a framework for writing programs that execute across heterogeneous platforms, and hls4ml, a high-level-synthesis-based compiler for neural network to firmware conversion. We evaluate and compare the resource usage, latency, and tracking performance of our implementations based on a benchmark dataset. We find a considerable speedup over CPU-based execution is possible, potentially enabling such algorithms to be used effectively in future computing workflows and the FPGA-based Level-1 trigger at the CERN Large Hadron Collider.Comment: 8 pages, 4 figures, To appear in Third Workshop on Machine Learning and the Physical Sciences (NeurIPS 2020

    Localized rest and stress human cardiac creatine kinase reaction kinetics at 3 T.

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    Changes in the kinetics of the creatine kinase (CK) shuttle are sensitive markers of cardiac energetics but are typically measured at rest and in the prone position. This study aims to measure CK kinetics during pharmacological stress at 3 T, with measurement in the supine position. A shorter "stressed saturation transfer" (StreST) extension to the triple repetition time saturation transfer (TRiST) method is proposed. We assess scanning in a supine position and validate the MR measurement against biopsy assay of CK activity. We report normal ranges of stress CK forward rate (kfCK ) for healthy volunteers and obese patients. TRiST measures kfCK in 40 min at 3 T. StreST extends the previously developed TRiST to also make a further kfCK measurement during <20 min of dobutamine stress. We test our TRiST implementation in skeletal muscle and myocardium in both prone and supine positions. We evaluate StreST in the myocardium of six healthy volunteers and 34 obese subjects. We validated MR-measured kfCK against biopsy assays of CK activity. TRiST kfCK values matched literature values in skeletal muscle (kfCK  = 0.25 ± 0.03 s-1 vs 0.27 ± 0.03 s-1 ) and myocardium when measured in the prone position (0.32 ± 0.15 s-1 ), but a significant difference was found for TRiST kfCK measured supine (0.24 ± 0.12 s-1 ). This difference was because of different respiratory- and cardiac-motion-induced B0 changes in the two positions. Using supine TRiST, cardiac kfCK values for normal-weight subjects were 0.15 ± 0.09 s-1 at rest and 0.17 ± 0.15 s-1 during stress. For obese subjects, kfCK was 0.16 ± 0.07 s-1 at rest and 0.17 ± 0.10 s-1 during stress. Rest myocardial kfCK and CK activity from LV biopsies of the same subjects correlated (R = 0.43, p = 0.03). We present an independent implementation of TRiST on the Siemens platform using a commercially available coil. Our extended StreST protocol enables cardiac kfCK to be measured during dobutamine-induced stress in the supine position.Funded by: a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society [098436/Z/12/B] to CTR, the BHF Centre of Research Excellence (OJR), a BHF clinical research training fellowship [FS/15/80/31803] to MAP, a BHF fellowship [FS/14/54/30946] to JJR, an NIHR OBRC fellowship to BR, a BHF programme grant [RG/13/8/30266] to CAL and SN, and a DPhil studentship from the Medical Research Council to WTC. We acknowledge support from the Oxford NIHR Biomedical Research Centre

    Cardiac Energetics in Patients With Aortic Stenosis and Preserved Versus Reduced Ejection Fraction.

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    BACKGROUND: Why some but not all patients with severe aortic stenosis (SevAS) develop otherwise unexplained reduced systolic function is unclear. We investigate the hypothesis that reduced creatine kinase (CK) capacity and flux is associated with this transition. METHODS: We recruited 102 participants to 5 groups: moderate aortic stenosis (ModAS) (n=13), SevAS, left ventricular (LV) ejection fraction ≥55% (SevAS-preserved ejection fraction, n=37), SevAS, LV ejection fraction 0.99). Accompanying the fall in CK flux, total CK and citrate synthase activities and the absolute activities of mitochondrial-type CK and CK-MM isoforms were also lower (P<0.02, all analyses). Median mitochondria-sarcomere diffusion distances correlated well with CK total activity (r=0.86, P=0.003). CONCLUSIONS: Total CK capacity is reduced in SevAS, with median values lowest in those with systolic failure, consistent with reduced energy supply reserve. Despite this, in vivo magnetic resonance spectroscopy measures of resting CK flux suggest that ATP delivery is reduced earlier, at the moderate AS stage, where LV function remains preserved. These findings show that significant energetic impairment is already established in moderate AS and suggest that a fall in CK flux is not by itself a necessary cause of transition to systolic failure. However, because ATP demands increase with AS severity, this could increase susceptibility to systolic failure. As such, targeting CK capacity and flux may be a therapeutic strategy to prevent and treat systolic failure in AS.This study was principally funded by a British Heart Foundation Clinical Training Research Fellowship FS/15/80/31803 (to Dr Peterzan) with support from a British Heart Foundation Program Grant (RG/18/12/34040). Drs Neubauer and Rider acknowledge support from British Heart Foundation Center of Research Excellence. Dr Neubauer acknowledges support from the National Institute of Health Research Oxford Biomedical Research Center. Dr Rodgers receives funding from the Wellcome Trust and the Royal Society (grant no. 098436/Z/12/B) and supported by the National Institute of Health Research Cambridge Biomedical Research Center. Dr Rider is funded by the British Heart Foundation FS/16/70/32157. Dr Miller was supported by a Novo Nordisk Postdoctoral Fellowship run in conjunction with the University of Oxford. The Biotechnology and Biological Sciences Research Council provided Advanced Life Sciences Research Technology Initiative 13 funding for serial block-face scanning electron microscopy through grant BB/C014122/1 (to Prof Chris Hawes, Oxford Brookes University)

    Functional testing of a tissue-engineered vocal fold cover replacement

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    ABSTRACT OBJECTIVES: Tissue engineering may provide a treatment for severe vocal fold scars. This study quantifies mechanical properties and demonstrates vibration of a tissue-engineered vocal fold cover replacement. METHODS: Tissue-engineered constructs were produced from fibrin and adipose-derived stem cells. Optimized bilayered constructs contained epithelial and mesenchymal cell phenotypes in a stratified geometry. For comparison, homogeneous constructs did not have epithelial differentiation. Elastic modulus was determined using indentation. Immunohistochemical labeling for type I collagen was performed. A bilayered construct was also tested in phonation in an excised larynx model. RESULTS: Bilayered vocal fold cover replacements had indentation moduli similar to human vocal fold covers (mean construct modulus 6.8 kPa). Collagen deposition occurred in the middle of the construct. Homogeneous constructs had a mean modulus of 8.3 kPa, and collagen was concentrated at the surface. An excised larynx with unilateral vocal fold cover replacement phonated and exhibited mucosal waves at physiologic airflow. CONCLUSION: Bilayered tissue-engineered constructs were produced that exhibited indentation modulus, microstructure, and vibration similar to that exhibited by human vocal fold covers. © 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved. T issue engineering may provide treatment for vocal fold scarring. We propose that replacing the entire vocal fold cover may be more effective than addressing only the lamina propria in severe cases. We have produced a stratified tissue-engineered construct resembling the vocal fold epithelium and lamina propria using adipose-derived stem cells (ASC) in fibrin. 1 With epidermal growth factor (EGF) and an air interface, the ASC differentiate into epithelial cells near the surface and mesenchymal cells within the construct bulk. We now assess whether this candidate cover replacement has mechanical and vibratory properties similar to the native vocal fold. Methods Institutional Review The UCLA Institutional Review Board approved the use of donated human lipoaspirate, cryoprecipitate, and cadaveric larynges. Fibrin-ASC Constructs ASC were isolated from lipoaspirate and cultured. 2 For fibrin constructs, cryoprecipitate was mixed with ASC and thrombin. 1 Three hundred L was polymerized within Transwell inserts (Cole-Parmer, Vernon Hills, IL), then concentrated ASC were added to the surface. Half of the constructs were cultured with an air interface and were supplied 10 ng/mL EGF and 10% fetal bovine serum in the culture medium (bilayered group). The remaining constructs had EGF-free culture medium and were submerged under liquid (homogeneous group). All were harvested at two weeks. For immunohistochemistry, samples were frozen, sectioned, and fixed onto slides. After blocking with goat serum, a rabbit antibody to type I collagen (DAKO, Denmark) was applied and detected with a goat-anti-rabbit fluorescein isothyocyanate-conjugated antibody. For a phonating construct, a 3 ϫ 1 cm rectangular well was scored in the base of a sterile culture dish. Cryoprecipitate-ASC-thrombin mixture was pipetted into the well. After the mixture gelled, additional concentrated ASC were added to the surface. Culture medium containing EGF bathed the gel on all sides but not on the surface. The sample was harvested at three weeks. Indentation A 1-mm indenter tip mounted onto a force transducer indented the construct surface in 0.025-mm steps until reach

    Distributed automated manufacturing of pluripotent stem cell products

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    Establishing how to effectively manufacture cell therapies is an industry-level problem. Decentralised manufacturing is of increasing importance, and its challenges are recognised by healthcare regulators with deviations and comparability issues receiving specific attention from them. This paper is the first to report the deviations and other risks encountered when implementing the expansion of human pluripotent stem cells (hPSCs) in an automated three international site–decentralised manufacturing setting. An experimental demonstrator project expanded a human embryonal carcinoma cell line (2102Ep) at three development sites in France, Germany and the UK using the CompacT SelecT (Sartorius Stedim, Royston, UK) automated cell culture platform. Anticipated variations between sites spanned material input, features of the process itself and production system details including different quality management systems and personnel. Where possible, these were pre-addressed by implementing strategies including standardisation, cell bank mycoplasma testing and specific engineering and process improvements. However, despite such measures, unexpected deviations occurred between sites including software incompatibility and machine/process errors together with uncharacteristic contaminations. Many only became apparent during process proving or during the process run. Further, parameters including growth rate and viability discrepancies could only be determined post-run, preventing ‘live’ corrective measures. The work confirms the critical nature of approaches usually taken in Good Manufacturing Practice (GMP) manufacturing settings and especially emphasises the requirement for monitoring steps to be included within the production system. Real-time process monitoring coupled with carefully structured quality systems is essential for multiple site working including clarity of decision-making roles. Additionally, an over-reliance upon post-process visual microscopic comparisons has major limitations; it is difficult for non-experts to detect deleterious culture changes and such detection is slow
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