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To evaluate the association between novel pre- and post-operative biomarker levels and 30-day unplanned readmission or mortality after paediatric congenital heart surgery.
Children aged 18 years or younger undergoing congenital heart surgery (n = 162) at Johns Hopkins Hospital from 2010 to 2014 were enrolled in the prospective cohort. Collected novel pre- and post-operative biomarkers include soluble suppression of tumorgenicity 2, galectin-3, N-terminal prohormone of brain natriuretic peptide, and glial fibrillary acidic protein. A model based on clinical variables from the Society of Thoracic Surgery database was developed and evaluated against two augmented models.
Unplanned readmission or mortality within 30 days of cardiac surgery occurred among 21 (13%) children. The clinical model augmented with pre-operative biomarkers demonstrated a statistically significant improvement over the clinical model alone with a receiver-operating characteristics curve of 0.754 (95% confidence interval: 0.65–0.86) compared to 0.617 (95% confidence interval: 0.47–0.76; p-value: 0.012). The clinical model augmented with pre- and post-operative biomarkers demonstrated a significant improvement over the clinical model alone, with a receiver-operating characteristics curve of 0.802 (95% confidence interval: 0.72–0.89; p-value: 0.003).
Novel biomarkers add significant predictive value when assessing the likelihood of unplanned readmission or mortality after paediatric congenital heart surgery. Further exploration of the utility of these novel biomarkers during the pre- or post-operative period to identify early risk of mortality or readmission will aid in determining the clinical utility and application of these biomarkers into routine risk assessment.
Many important scientific and technical problems are best addressed using multiple, microscopy-based analytical techniques that combine the strengths of complementary methods. Here, we provide two examples from biomedical challenges: unravelling the attachment zone between dental implants and bone, and uncovering the mechanism of Alzheimer's disease. They combine synchrotron-based scanning transmission X-ray microscopy (STXM) with transmission electron microscopy ((S)TEM), electron tomography (ET), EELS tomography, and/or atom probe tomography (APT). STXM provides X-ray absorption based chemical sensitivity at mesoscale resolution (10–30 nm), which complements higher spatial resolution electron microscopy and APT.
An assessment of topsoil (5–20cm) metal/metalloid (hereafter referred to as metal) concentrations across Glasgow and the Clyde Basin reveals that copper, molybdenum, nickel, lead, antimony and zinc show the greatest enrichment in urban versus rural topsoil (elevated 1.7–2.1 times; based on median values). This is a typical indicator suite of urban pollution also found in other cities. Similarly, arsenic, cadmium and lead are elevated 3.2–4.3 times the rural background concentrations in topsoil from the former Leadhills mining area. Moorlands show typical organic-soil geochemical signatures, with significantly lower (P<0.05) concentrations of geogenic elements such as chromium, copper, nickel, molybdenum and zinc, but higher levels of cadmium, lead and selenium than most other land uses due to atmospheric deposition/trapping of these substances in peat. In farmland, 14% of nickel and 7% of zinc in topsoil samples exceed agricultural maximum admissible concentrations, and may be sensitive to sewage-sludge application. Conversely, 5% of copper, 17% of selenium and 96% of pH in farmland topsoil samples are below recommended agricultural production thresholds. Significant proportions of topsoil samples exceed the most precautionary (residential/allotment) human-exposure soil guidelines for chromium (18% urban; 10% rural), lead (76% urban; 45% rural) and vanadium (87% urban; 56% rural). For chromium, this reflects volcanic bedrock and the history of chromite ore processing in the region. However, very few soil types are likely to exceed new chromiumVI-based guidelines. The number of topsoil samples exceeding the guidelines for lead and vanadium highlight the need for further investigations and evidence to improve human soil-exposure risk assessments to better inform land contamination policy and regeneration.
Three collated geochemical surveys of surface water in the Clyde catchment have established the spatial variability in water composition, primarily under baseflow conditions. The waters are broadly pH-neutral to alkaline (maximum pH 8.7) in the lowlands, but mildly acidic in uplands on the catchment periphery. Electrical conductance is relatively high in lowland streams (maximum 8320μgL–1), with lower values in the uplands. Dissolved chromium (Cr; <0.05–971μgL–1) and lead (Pb; <0.05–19.4μgL–1) are of importance due to recognised pollution sources within the catchment. High aqueous Cr concentrations (>5μgL–1) are recorded in urban areas associated with the disposal of alkaline industrial chromite ore processing residue. Under such conditions, Cr probably occurs as Cr(VI). Numerous relatively high Pb values occur in the upland and urban areas. These are likely to be associated with a combination of soil reactions, diffuse pollution and contamination from Pb mineralisation/mining. Pb has a stronger correlation with water pH than with stream sediment Pb content, suggesting that pH has a greater control on Pb mobility than host-rock Pb. Exceedances of water-quality standards are <1% for both Cr and Pb across the catchment. Absolute exceedances are more extreme for Cr than for Pb, highlighting the scale of the Cr pollution problem for urban surface water within the catchment.
Paediatric hospital-associated venous thromboembolism is a leading quality and safety concern at children’s hospitals.
The aim of this study was to determine risk factors for hospital-associated venous thromboembolism in critically ill children following cardiothoracic surgery or therapeutic cardiac catheterisation.
We conducted a retrospective, case–control study of children admitted to the cardiovascular intensive care unit at Johns Hopkins All Children’s Hospital (St. Petersburg, Florida, United States of America) from 2006 to 2013. Hospital-associated venous thromboembolism cases were identified based on ICD-9 discharge codes and validated using radiological record review. We randomly selected two contemporaneous cardiovascular intensive care unit controls without hospital-associated venous thromboembolism for each hospital-associated venous thromboembolism case, and limited the study population to patients who had undergone cardiothoracic surgery or therapeutic cardiac catheterisation. Odds ratios and 95% confidence intervals for associations between putative risk factors and hospital-associated venous thromboembolism were determined using univariate and multivariate logistic regression.
Among 2718 admissions to the cardiovascular intensive care unit during the study period, 65 met the criteria for hospital-associated venous thromboembolism (occurrence rate, 2%). Restriction to cases and controls having undergone the procedures of interest yielded a final study population of 57 hospital-associated venous thromboembolism cases and 76 controls. In a multiple logistic regression model, major infection (odds ratio=5.77, 95% confidence interval=1.06–31.4), age ⩽1 year (odds ratio=6.75, 95% confidence interval=1.13–160), and central venous catheterisation (odds ratio=7.36, 95% confidence interval=1.13–47.8) were found to be statistically significant independent risk factors for hospital-associated venous thromboembolism in these children. Patients with all three factors had a markedly increased post-test probability of having hospital-associated venous thromboembolism.
Major infection, infancy, and central venous catheterisation are independent risk factors for hospital-associated venous thromboembolism in critically ill children following cardiothoracic surgery or cardiac catheter-based intervention, which, in combination, define a high-risk group for hospital-associated venous thromboembolism.
In the United States alone, ∼14,000 children are hospitalised annually with acute heart failure. The science and art of caring for these patients continues to evolve. The International Pediatric Heart Failure Summit of Johns Hopkins All Children’s Heart Institute was held on February 4 and 5, 2015. The 2015 International Pediatric Heart Failure Summit of Johns Hopkins All Children’s Heart Institute was funded through the Andrews/Daicoff Cardiovascular Program Endowment, a philanthropic collaboration between All Children’s Hospital and the Morsani College of Medicine at the University of South Florida (USF). Sponsored by All Children’s Hospital Andrews/Daicoff Cardiovascular Program, the International Pediatric Heart Failure Summit assembled leaders in clinical and scientific disciplines related to paediatric heart failure and created a multi-disciplinary “think-tank”. The purpose of this manuscript is to summarise the lessons from the 2015 International Pediatric Heart Failure Summit of Johns Hopkins All Children’s Heart Institute, to describe the “state of the art” of the treatment of paediatric cardiac failure, and to discuss future directions for research in the domain of paediatric cardiac failure.
The near infrared sky spectral brightness has been measured at the South Pole with the Near Infrared Sky Monitor (NISM) throughout the 2001 winter season. The sky is found to be typically more than an order of magnitude darker than at temperate latitude sites, consistent with previous South Pole observations. Reliable robotic operation of the NISM, a low power, autonomous instrument, has been demonstrated throughout the Antarctic winter. Data analysis yields a median winter value of the 2.4μm (Kdark) sky spectral brightness of ˜120μJy arcsec−2 and an average of 210 ± 80μJy arcsec−2. The 75%, 50%, and 25% quartile values are 270 ± 100, 155 ± 60, and 80 ± 30μJy arcsec−2, respectively.
We have observed a pyroelectric effect (PE) in reactively sputtered aluminum nitride (AlN) thin films that is typically a factor of twenty greater than commercial pyroelectric materials such as triglycine sulfate (TGS). This is most likely due to an extrinsic effect since the known crystalline structures of AlN are too symmetric to allow such high values for the PE response. Preliminary annealing studies support the assumption that residual strains remaining from the AlN thin film deposition are the most likely source of the anomalously high PE response. The results of these studies are presented along with some measurements that indicate a still higher PE response might be obtainable.
Pore structure development in portland cement/fly ash blends was investigated using mercury porosimetry and methanol exchange techniques. The progress of hydration was monitored using compressive strength tests. The specimens were made using four water-cement ratios and were hydrated over a one-year period in lime-saturated water. Mercury porosimetry results indicated that the blended cement pastes generally had higher total porosity than plain cement pastes. The major contribution to this increase in porosity was in the form of smaller pore sizes. With reactive fly ash at 20% replacement, the pore structure of mature paste consists mainly of pores nominally smaller than 0.05 μm in diameter. Diffusion parameters obtained from the methanol exchange results were found to be inversely related to the volume of large pores (nominally >0.05 μm) and also to the volume of small pores (nominally <0.05 μm). The effects of the physical and chemical properties of cements and fly ashes on pore structure development are discussed.
Pore structure development in portland/fly ash blends was investigated using mercury porosimetry and methanol exchange techniques. The progress of hydration was monitored using compressive strength tests. The specimens were made using four water-cement ratios and were hydrated over a one-year period in lime-saturated water. Mercury porosimetry results indicated that the blended cement pastes generally had higher total porosity than plain cement pastes. The major contribution to this increase in porosity was in the form of smaller pore sizes. With reactive fly ash at 20% replacement, the pore structure of mature paste consists mainly of pores nominally smaller than 0.05 μm in diameter. Diffusion parameters obtained from the methanol exchange results were found to be inversely related to the volume of large pores (nominally <0.05 μm) and also to the volume of small pores (nominally <0.05 μm). The effects of the physical and chemical properties of cements and fly ashes on pore structure development are discussed.
Experimental and numerical analyses were performed on porous aluminum samples to evaluate microstructure and mechanical properties. Experiments consisted of tensile tests on dog-bone specimens containing 9 to 17% porosity, which were instrumented with axial and transverse extensometers. Properties measured included Young's modulus, Poisson's ratio, proportional limit, 0.2% offset yield strength, and ultimate tensile strength. Results indicated that Young's modulus and all strengths decreased with increasing porosity, but Poisson's ratio remained constant with porosity. For the numerical simulations, 3-D, mesoscale, multilayer models were constructed to evaluate the effects of pore morphology and interactions on material properties. The models allowed systematic spatial positioning of the pore within the cell and the ability to form solid zones. Pore arrangement, the effect of constraint, and gradients on the stress state were investigated. By using different combinations of hex cells as building blocks, several complicated microstructural arrangements were simulated.
Several multilayer test coatings for hard X-ray telescopes were fabricated using DC magnetron sputtering. The process parameters were selected from a series of trials of single layer depositions. The samples were characterized using X-ray specular reflectivity scans, AFM, and cross-sectional TEM. Additional measurements (stylus profilometry, RBS, and Auger analysis) were used in the optimization of the deposition rate and of the thin film properties (density, composition, surface/interface microroughness). The X-ray reflectivity scans showed that the combinations of reflector and spacer materials tested so far (W/Si and W/C) are suited for graded d-spacing multilayer coatings that present a constant reflectivity bandpass up to 70 keV.
The THz spectral region includes a number of important transitions which
allow us to trace the evolution of the interstellar medium. Because of the
opacity of the atmosphere in this spectral range, the best sites for
ground-based THz observations are on the Antarctic Plateau; of these sites,
Dome A is expected to be the best. THz survey science can be carried out
with small telescopes, easing logistical constraints. By deploying a
submillimetre-wave tipper/ telescope to Dome A, we have trialled several
technologies for such an instrument, and we are able to test whether the
site quality is sufficient for THz surveys.
The Gattini-DomeC project, part of the IRAIT site testing campaign and ongoing since January 2006, consists of two cameras for the measurement of optical sky brightness, large area cloud cover, and auroral detection above the DomeC site, home of the French-Italian Concordia station. The cameras are transit in nature and are virtually identical except for the nature of the lenses. The cameras have operated throughout the past two Antarctic winter seasons and here we present the results obtained from the 2006 winter-time dataset of the wide field “All-sky camera".