1,090 research outputs found
Preparation of C2-Symmetric Biaryl Bisiminium Salts and Their Use as Organocatalysts for Asymmetric Epoxidation
Two C2-symmetric bisiminium salt species containing biphenylazepinium units and derived from two chiral diamines were prepared and tested as organocatalysts for asymmetric epoxidation
Epidemiology of Cardiopulmonary Resuscitation in Critically Ill Children Admitted to Pediatric Intensive Care Units Across England: A Multicenter Retrospective Cohort Study
Background Cardiopulmonary arrests are a major contributor to mortality and morbidity in pediatric intensive care units (PICUs). Understanding the epidemiology and risk factors for CPR may inform national quality improvement initiatives. Methods and Results A retrospective cohort analysis using prospectively collected data from the Paediatric Intensive Care Audit Network database. The Paediatric Intensive Care Audit Network contains data on all PICU admissions in the United Kingdom. We identified children who received cardiopulmonary resuscitation (CPR) in 23 PICUs in England (2013-2017). Incidence rates of CPR and associated factors were analyzed. Logistic regression was used to estimate the size and precision of associations. Cumulative incidence of CPR was 2.2% for 68 114 admissions over 5 years with an incidence rate of 4.9 episodes/1000 bed days. Cardiovascular diagnosis (odds ratio [OR], 2.30; 95% CI, 2.02-2.61), age <1 year (OR, 1.84; 95% CI, 1.65-2.04), the Paediatric Index of Mortality 2 score on admission (OR, 1.045; 95% CI, 1.042-1.047) and longer length of stay (OR, 1.013; 95% CI, 1.012-1.014) were associated with increased odds of receiving CPR. We also found a higher risk of CPR associated with a history of preadmission cardiac arrest (OR, 20.69; [95% CI, 18.16-23.58) and for children with a cardiac condition admitted to a noncardiac PICU (OR, 2.75; 95% CI, 1.91-3.98). Children from Black (OR, 1.68; 95% CI, 1.36-2.07) and Asian (OR, 1.49; 95% CI, 1.28-1.74) racial/ethnic backgrounds were at higher risk of receiving CPR in PICU than White children. Conclusions Data from this first multicenter study from England provides a foundation for further research and evidence for benchmarking and quality improvement for prevention of cardiac arrests in PICU
Optogenetic Control of Subcellular Protein Location and Signaling in Vertebrate Embryos.
This chapter describes the use of optogenetic heterodimerization in single cells within whole-vertebrate embryos. This method allows the use of light to reversibly bind together an "anchor" protein and a "bait" protein. Proteins can therefore be directed to specific subcellular compartments, altering biological processes such as cell polarity and signaling. I detail methods for achieving transient expression of fusion proteins encoding the phytochrome heterodimerization system in early zebrafish embryos (Buckley et al., Dev Cell 36(1):117-126, 2016) and describe the imaging parameters used to achieve subcellular light patterning
In the eye of the storm: impact of COVID-19 pandemic on admission patterns to paediatric intensive care units in the UK and Eire
Background
The coronavirus disease-19 (COVID-19) pandemic had a relatively minimal direct impact on critical illness in children compared to adults. However, children and paediatric intensive care units (PICUs) were affected indirectly. We analysed the impact of the pandemic on PICU admission patterns and patient characteristics in the UK and Ireland.
Methods
We performed a retrospective cohort study of all admissions to PICUs in children < 18 years during Jan–Dec 2020, using data collected from 32 PICUs via a central database (PICANet). Admission patterns, case-mix, resource use, and outcomes were compared with the four preceding years (2016–2019) based on the date of admission.
Results
There were 16,941 admissions in 2020 compared to an annual average of 20,643 (range 20,340–20,868) from 2016 to 2019. During 2020, there was a reduction in all PICU admissions (18%), unplanned admissions (20%), planned admissions (15%), and bed days (25%). There was a 41% reduction in respiratory admissions, and a 60% reduction in children admitted with bronchiolitis but an 84% increase in admissions for diabetic ketoacidosis during 2020 compared to the previous years. There were 420 admissions (2.4%) with either PIMS-TS or COVID-19 during 2020. Age and sex adjusted prevalence of unplanned PICU admission reduced from 79.7 (2016–2019) to 63.1 per 100,000 in 2020. Median probability of death [1.2 (0.5–3.4) vs. 1.2 (0.5–3.4) %], length of stay [2.3 (1.0–5.5) vs. 2.4 (1.0–5.7) days] and mortality rates [3.4 vs. 3.6%, (risk-adjusted OR 1.00 [0.91–1.11, p = 0.93])] were similar between 2016–2019 and 2020. There were 106 fewer in-PICU deaths in 2020 (n = 605) compared with 2016–2019 (n = 711).
Conclusions
The use of a high-quality international database allowed robust comparisons between admission data prior to and during the COVID-19 pandemic. A significant reduction in prevalence of unplanned admissions, respiratory diseases, and fewer child deaths in PICU observed may be related to the targeted COVID-19 public health interventions during the pandemic. However, analysis of wider and longer-term societal impact of the pandemic and public health interventions on physical and mental health of children is required
Interleaved Parton Showers and Tuning Prospects
General-purpose Monte Carlo event generators have become important tools in
particle physics, allowing the simulation of exclusive hadronic final states.
In this article we examine the Pythia 8 generator, in particular focusing on
its parton-shower algorithms. Some relevant new additions to the code are
introduced, that should allow for a better description of data. We also
implement and compare with 2 to 3 real-emission QCD matrix elements, to check
how well the shower algorithm fills the phase space away from the soft and
collinear regions. A tuning of the generator to Tevatron data is performed for
two PDF sets and the impact of first new LHC data is examined
Measuring the Meltdown: Drivers of Global Amphibian Extinction and Decline
Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species) to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545) or had increased (n = 28). These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation
First observations of separated atmospheric nu_mu and bar{nu-mu} events in the MINOS detector
The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of nuµ and [overline nu ]µ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field nuµ and [overline nu ]µ interactions are separated. The ratio of [overline nu ]µ to nuµ events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving R[overline nu ][sub mu]/nu[sub mu]data/R[overline nu ][sub mu]/nu[sub mu]MC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for nuµ and [overline nu ]µ
On the effects of the fix geometric constraint in 2D profiles on the reusability of parametric 3D CAD models
[EN] In order to be reusable, history-based feature-based parametric CAD models must reliably allow for modifications while maintaining their original design intent. In this paper, we demonstrate that relations that fix the location of geometric entities relative to the reference system produce inflexible profiles that reduce model reusability. We present the results of an experiment where novice students and expert CAD users performed a series of modifications in different versions of the same 2D profile, each defined with an increasingly higher number of fix geometric constraints. Results show that the amount of fix constraints in a 2D profile correlates with the time required to complete reusability tasks, i.e., the higher the number of fix constraints in a 2D profile, the less flexible and adaptable the profile becomes to changes. In addition, a pilot software tool to automatically track this type of constraints was developed and tested. Results suggest that the detection of fix constraint overuse may result in a new metric to assess poor quality models with low reusability. The tool provides immediate feedback for preventing high semantic level quality errors, and assistance to CAD users. Finally, suggestions are introduced on how to convert fix constraints in 2D profiles into a negative metric of 3D model quality.The authors would like to thank Raquel Plumed for her support in the statistical analysis. This work has been partially funded by Grant UJI-A02017-15 (Universitat Jaume I) and DPI201784526-R (MINECO/AEI/FEDER, UE), project CAL-MBE. The authors also wish to thank the editor and reviewers for their valuable comments and suggestions that helped us improve the quality of the paper.González-Lluch, C.; Company, P.; Contero, M.; Pérez Lopez, DC.; Camba, JD. (2019). On the effects of the fix geometric constraint in 2D profiles on the reusability of parametric 3D CAD models. 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Dataset of manually measured QT intervals in the electrocardiogram
BACKGROUND: The QT interval and the QT dispersion are currently a subject of considerable interest. Cardiac repolarization delay is known to favor the development of arrhythmias. The QT dispersion, defined as the difference between the longest and the shortest QT intervals or as the standard deviation of the QT duration in the 12-lead ECG is assumed to be reliable predictor of cardiovascular mortality. The seventh annual PhysioNet/Computers in Cardiology Challenge, 2006 addresses a question of high clinical interest: Can the QT interval be measured by fully automated methods with accuracy acceptable for clinical evaluations? METHOD: The PTB Diagnostic ECG Database was given to 4 cardiologists and 1 biomedical engineer for manual marking of QRS onsets and T-wave ends in 458 recordings. Each recording consisted of one selected beat in lead II, chosen visually to have minimum baseline shift, noise, and artifact. In cases where no T wave could be observed or its amplitude was very small, the referees were instructed to mark a 'group-T-wave end' taking into consideration leads with better manifested T wave. A modified Delphi approach was used, which included up to three rounds of measurements to obtain results closer to the median. RESULTS: A total amount of 2*5*548 Q-onsets and T-wave ends were manually marked during round 1. To obtain closer to the median results, 8.58 % of Q-onsets and 3.21 % of the T-wave ends had to be reviewed during round 2, and 1.50 % Q-onsets and 1.17 % T-wave ends in round 3. The mean and standard deviation of the differences between the values of the referees and the median after round 3 were 2.43 ± 0.96 ms for the Q-onset, and 7.43 ± 3.44 ms for the T-wave end. CONCLUSION: A fully accessible, on the Internet, dataset of manually measured Q-onsets and T-wave ends was created and presented in additional file: 1 (Table 4) with this article. Thus, an available standard can be used for the development of automated methods for the detection of Q-onsets, T-wave ends and for QT interval measurements
Direct and indirect interactions between ants ( Pheidole megacephala ), scales ( Coccus viridis ) and plants ( Pluchea indica )
This study investigated direct and indirect interactions between the ant, Pheidole megacephala (Fabr.), the green scale, Coccus viridis (Green), and the scale's host plant, Pluchea indica (L.). To examine the influence of ants on scales and host plants, scale population densities, scale mortality rates, and plant performance were studied on control host plants with ants and host plants from which ants had been removed. Plants with ants present had significantly greater scale population densities and scale reproductive rates than did plants without ants. Scale mortality from both parasitism and other causes was increased on plants without ants relative to plants with ants. Predator introduction experiments showed that P. megacephala removes predatory coccinellid larvae, even when they are covered with a protective coating. Host plants from which ants had been removed had significantly higher degrees of honeydew accumulation, which resulted in greater colonization by sooty mold and greater rates of leaf death and abscission. Ants also removed herbivorous lepidopteran larvae from plants. Results are discussed in terms of the potential of P. megacephala to exert direct and indirect positive effects on scale populations and an indirect positive effect on Pluchea indica .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47790/1/442_2004_Article_BF00325261.pd
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