This investigation identifies 4 host- and pathogen-related risk factors for hematogenous bacterial seeding and reaffirms the importance of prompt catheter removal.

Ascorbic acid is among the most abundant antioxidants in the lung, where it likely plays a key role in the mechanism by which particulate air pollution initiates a biological response. Because ascorbic acid is a highly redox active species, it engages in a far more complex web of reactions than a typical organic molecule, reacting with oxidants such as the hydroxyl radical as well as redox-active transition metals such as iron and copper. The literature provides a solid outline for this chemistry, but there are large disagreements about mechanisms, stoichiometries and reaction rates, particularly for the transition metal reactions. Here we synthesize the literature, develop a chemical kinetics model, and use seven sets of laboratory measurements to constrain mechanisms for the iron and copper reactions and derive key rate constants. We find that micromolar concentrations of iron(III) and copper(II) are more important sinks for ascorbic acid (both AH2 and AH−) than reactive oxygen species. The iron and copper reactions are catalytic rather than redox reactions, and have unit stoichiometries: Fe(III)/Cu(II) + AH2/AH−  + O2 → Fe(III)/Cu(II) + H2O2 + products. Rate constants are 5.7 × 104 and 4.7 × 104 M−2 s−1 for Fe(III) + AH2/AH− and 7.7 × 104 and 2.8 × 106 M−2 s−1 for Cu(II) + AH2/AH−, respectively.

The impact of bacterial genetic characteristics on the outcome of patients with Staphylococcus aureus infections is uncertain. This investigation evaluated potential associations between bacterial genotype and clinical outcome using isolates collected as part of an international phase 2 clinical trial (FAST II) evaluating telavancin for the treatment of complicated skin and skin structure infections (cSSSI). Ninety S. aureus isolates from microbiologically evaluable patients with cSSSI enrolled in the FAST II trial from 11 sites in the United States (56 isolates, or 62%) and 7 sites in South Africa (34 isolates, or 38%) were examined for staphylococcal cassette chromosome mec, agr, and the presence of 31 virulence genes and subjected to pulsed-field gel electrophoresis (PFGE). South African methicillin-susceptible S. aureus (MSSA) isolates were more likely to carry certain virulence genes, including sdrD (P ‫؍‬ 0.01), sea (P < 0.01), and pvl (P ‫؍‬ 0.01). All 44 (49%) methicillin-resistant S. aureus (MRSA) isolates were from the United States; 37 (84%) were strain USA 300 by PFGE. In the United States, MRSA isolates were more likely than MSSA isolates to carry genes for sdrC (P ‫؍‬ 0.03), map/eap (P ‫؍‬ 0.05), fnbB (P ‫؍‬ 0.11), tst (P ‫؍‬ 0.02), sea (P ‫؍‬ 0.04), sed (P ‫؍‬ 0.04), seg (P ‫؍‬ 0.11), sej (P ‫؍‬ 0.11), agr (P ‫؍‬ 0.09), V8 (P ‫؍‬ 0.06), sdrD, sdrE, eta, etb, and see (P < 0.01 for all). MRSA isolates were more often clonal than MSSA isolates by PFGE. Isolates from patients who were cured were significantly more likely to contain the pvl gene than isolates from patients that failed or had indeterminate outcomes (79/84 [94%] versus 3/6 [50%]; P ‫؍‬ 0.01). S. aureus strains from different geographic regions have different distributions of virulence genes.

The paper will draw on practice-based research, highlighting the differences and similarities of CC against the more established FCC. Arguments will be presented to show that rather than competing with FCC, CCC has the potential to complement or extend traditional FCC, by placing children in a more prominent and central position than that which they currently hold within health care.

No abstract

Biogenic alkenes, which are among the most abundant volatile organic compounds in the atmosphere, are readily oxidized by ozone. Characterizing the reactivity and kinetics of the first-generation products of these reactions, carbonyl oxides (often named Criegee intermediates), is essential in defining the oxidation pathways of organic compounds in the atmosphere but is highly challenging due to the short lifetime of these zwitterions. Here, we report the development of a novel online method to quantify atmospherically relevant Criegee intermediates (CIs) in the gas phase by stabilization with spin traps and analysis with proton-transfer reaction mass spectrometry. Ozonolysis of α-pinene has been chosen as a proof-of-principle model system. To determine unambiguously the structure of the spin trap adducts with α-pinene CIs, the reaction was tested in solution, and reaction products were characterized with high-resolution mass spectrometry, electron paramagnetic resonance, and nuclear magnetic resonance spectroscopy. DFT calculations show that addition of the Criegee intermediate to the DMPO spin trap, leading to the formation of a six-membered ring adduct, occurs through a very favorable pathway and that the product is significantly more stable than the reactants, supporting the experimental characterization. A flow tube set up has been used to generate spin trap adducts with α-pinene CIs in the gas phase. We demonstrate that spin trap adducts with α-pinene CIs also form in the gas phase and that they are stable enough to be detected with online mass spectrometry. This new technique offers for the first time a method to characterize highly reactive and atmospherically relevant radical intermediates in situ.

The chemical composition and evolution of secondary organic aerosol (SOA) in the atmosphere represents one of the largest uncertainties in our current understanding of air quality. Despite vast research, the toxicological mechanisms relating to adverse human health effects upon exposure to particulate matter are still poorly understood. Particle-bound reactive oxygen species (ROS) may substantially contribute to observed health effects by influencing aerosol oxidative potential (OP). The role of radicals in both the formation and aging of aerosol, as well as their contribution to aerosol OP, remains highly uncertain. The profluorescent spin trap BPEAnit (9,10-bis-(phenylethynyl)anthracenenitroxide), previously utilized to study combustion-generated aerosol, has been applied to provide the first estimate of particle-bound radical concentrations in SOA. We demonstrate that SOA from different atmospherically important VOC precursors have different particle-bound radical concentrations, estimated for the ozonolysis of α-pinene (0.020 ± 0.0050 nmol/μg), limonene (0.0059 ± 0.0010 nmol/μg), and β-caryophyllene (0.0025 ± 0.00080 nmol/μg), highlighting the potential importance of OH-initiated formation of particlebound organic radicals. Additionally, the lifetime of particle-bound radical species in α-pinene SOA was estimated, and a pseudo-first-order rate constant of k = 7.3 ± 1.7 × 10 −3 s −1 was derived, implying a radical lifetime on the order of minutes.

Review question/objective: The objective of this scoping review is to identify and evaluate the concept of child-centered care (CCC) in healthcare in order to achieve greater clarity on the concept and its applicability, benefits and potential to inform the evidence base of children's health care, policy and practice. The questions of this review are:What constitutes the concept of CCC in healthcare?How has the concept developed?What is the applicability of CCC and what are its limitations?How does the concept of CCC benefit and inform children's healthcare?