Impact of Central Venous Catheter Type and Methods on Catheter-Related Colonization and Bacteraemia

A prospective, randomized, controlled, multi-centre clinical trial was performed to test the effectiveness of an antimicrobial central venous catheter (CVC) made of polyurethane integrated with silver, platinum and carbon black (Vantex). Adults expected to require a CVC for more than 60 h were eligible, and were randomized to receive the test or control catheter. All CVCs were inserted with new venipunctures using full aseptic technique. Following catheter removal, the distal tip and an intracutaneous segment were removed and cultured using semiquantitative and quantitative methods. Peripheral blood samples were obtained and cultured to confirm cases of catheter-related bloodstream infection (CRBSI). Bacterial and fungal organisms were identified by standard microbiological methods. Catheter placement was performed primarily in the intensive care unit (50%) or operating theatre (42%). Complete data could be evaluated for 539 patients (77%). The mean duration of CVC placement was 149.3h (six days). There were no significant differences in colonization or bacteraemia rates between the test and control catheters. The overall colonization rate was not particularly low (24.5%), and yet CVC-related bacteraemia occurred in only 1.4% of patients, and CRBSI occurred in only one patient from the control group (0.2%). Insertion site and dressing change frequency were significantly associated with the colonization rate. Although CVCs with antimicrobial features have been associated with a decrease in catheter-related colonization and bacteraemia, this study demonstrated that infection rates may depend more on non-catheter-related factors, such as adherence to infection control standards, selection of insertion site, duration of CVC placement, and dressing change frequency. As microbial resistance increases, clinicians should make maximal use of these processes to reduce catheter-related infections

Impact of Central Venous Catheter Type and Methods on Catheter-Related Colonization and Bacteraemia

A prospective, randomized, controlled, multi-centre clinical trial was performed to test the effectiveness of an antimicrobial central venous catheter (CVC) made of polyurethane integrated with silver, platinum and carbon black (Vantex). Adults expected to require a CVC for more than 60 h were eligible, and were randomized to receive the test or control catheter. All CVCs were inserted with new venipunctures using full aseptic technique. Following catheter removal, the distal tip and an intracutaneous segment were removed and cultured using semiquantitative and quantitative methods. Peripheral blood samples were obtained and cultured to confirm cases of catheter-related bloodstream infection (CRBSI). Bacterial and fungal organisms were identified by standard microbiological methods. Catheter placement was performed primarily in the intensive care unit (50%) or operating theatre (42%). Complete data could be evaluated for 539 patients (77%). The mean duration of CVC placement was 149.3h (six days). There were no significant differences in colonization or bacteraemia rates between the test and control catheters. The overall colonization rate was not particularly low (24.5%), and yet CVC-related bacteraemia occurred in only 1.4% of patients, and CRBSI occurred in only one patient from the control group (0.2%). Insertion site and dressing change frequency were significantly associated with the colonization rate. Although CVCs with antimicrobial features have been associated with a decrease in catheter-related colonization and bacteraemia, this study demonstrated that infection rates may depend more on non-catheter-related factors, such as adherence to infection control standards, selection of insertion site, duration of CVC placement, and dressing change frequency. As microbial resistance increases, clinicians should make maximal use of these processes to reduce catheter-related infections

Efficient Certified Resolution Proof Checking

We present a novel propositional proof tracing format that eliminates complex processing, thus enabling efficient (formal) proof checking. The benefits of this format are demonstrated by implementing a proof checker in C, which outperforms a state-of-the-art checker by two orders of magnitude. We then formalize the theory underlying propositional proof checking in Coq, and extract a correct-by-construction proof checker for our format from the formalization. An empirical evaluation using 280 unsatisfiable instances from the 2015 and 2016 SAT competitions shows that this certified checker usually performs comparably to a state-of-the-art non-certified proof checker. Using this format, we formally verify the recent 200 TB proof of the Boolean Pythagorean Triples conjecture

Direct, biomimetic synthesis of (+)-artemone via a stereoselective, organocatalytic cyclization

We present a four-step synthesis of (+)-artemone from (–)- linalool, featuring iminium organocatalysis of a doubly diastereoselective conjugate addition reaction. The strategy follows a proposed biosynthetic pathway, rapidly generates stereochemical complexity, uses no protecting groups, and minimizes redox manipulations

Microscopic description of anisotropic flow in relativistic heavy ion collisions

Anisotropic flow of hadrons is studied in heavy ion collisions at SPS and RHIC energies within the microscopic quark-gluon string model. The model was found to reproduce correctly many of the flow features, e.g., the wiggle structure of direct flow of nucleons at midrapidity, or centrality, rapidity, and transverse momentum dependences of elliptic flow. Further predictions are made. The differences in the development of the anisotropic flow components are linked to the freeze-out conditions, which are quite different for baryons and mesons.Comment: Proceedings of the Erice School on Nuclear Physics (Erice, Italy, September 16-24, 2003

On being a memory expert witness: Three cases

I describe three legal cases in which I acted as a memory expert witness. The cases contain remarkable accounts of memories. Such memories are by no means unusual in legal cases, are often over retention intervals measured in decades, and contain details the specificity of which is highly unusual. For example, recalling from childhood verbatim conversations, clothes worn by self and others, the weather, actions that at the time could not have been understood, details that could not have been known, precise durations and calendar dates, and much more. I show how our scientific understanding of memory can help courts reach more informed decisions about such fantastical "memories" and how these memories constitute data that as researchers we should seek to understand

Distinct gene signatures in aortic tissue from ApoE-/- mice exposed to pathogens or Western diet

BACKGROUND: Atherosclerosis is a progressive disease characterized by inflammation and accumulation of lipids in vascular tissue. Porphyromonas gingivalis (Pg) and Chlamydia pneumoniae (Cp) are associated with inflammatory atherosclerosis in humans. Similar to endogenous mediators arising from excessive dietary lipids, these Gram-negative pathogens are pro-atherogenic in animal models, although the specific inflammatory/atherogenic pathways induced by these stimuli are not well defined. In this study, we identified gene expression profiles that characterize P. gingivalis, C. pneumoniae, and Western diet (WD) at acute and chronic time points in aortas of Apolipoprotein E (ApoE-/-) mice. RESULTS: At the chronic time point, we observed that P. gingivalis was associated with a high number of unique differentially expressed genes compared to C. pneumoniae or WD. For the top 500 differentially expressed genes unique to each group, we observed a high percentage (76%) that exhibited decreased expression in P. gingivalis-treated mice in contrast to a high percentage (96%) that exhibited increased expression in WD mice. C. pneumoniae treatment resulted in approximately equal numbers of genes that exhibited increased and decreased expression. Gene Set Enrichment Analysis (GSEA) revealed distinct stimuli-associated phenotypes, including decreased expression of mitochondrion, glucose metabolism, and PPAR pathways in response to P. gingivalis but increased expression of mitochondrion, lipid metabolism, carbohydrate and amino acid metabolism, and PPAR pathways in response to C. pneumoniae; WD was associated with increased expression of immune and inflammatory pathways. DAVID analysis of gene clusters identified by two-way ANOVA at acute and chronic time points revealed a set of core genes that exhibited altered expression during the natural progression of atherosclerosis in ApoE-/- mice; these changes were enhanced in P. gingivalis-treated mice but attenuated in C. pneumoniae-treated mice. Notable differences in the expression of genes associated with unstable plaques were also observed among the three pro-atherogenic stimuli. CONCLUSIONS: Despite the common outcome of P. gingivalis, C. pneumoniae, and WD on the induction of vascular inflammation and atherosclerosis, distinct gene signatures and pathways unique to each pro-atherogenic stimulus were identified. Our results suggest that pathogen exposure results in dysregulated cellular responses that may impact plaque progression and regression pathways

Nonexistence Certificates for Ovals in a Projective Plane of Order Ten

In 1983, a computer search was performed for ovals in a projective plane of order ten. The search was exhaustive and negative, implying that such ovals do not exist. However, no nonexistence certificates were produced by this search, and to the best of our knowledge the search has never been independently verified. In this paper, we rerun the search for ovals in a projective plane of order ten and produce a collection of nonexistence certificates that, when taken together, imply that such ovals do not exist. Our search program uses the cube-and-conquer paradigm from the field of satisfiability (SAT) checking, coupled with a programmatic SAT solver and the nauty symbolic computation library for removing symmetries from the search.Comment: Appears in the Proceedings of the 31st International Workshop on Combinatorial Algorithms (IWOCA 2020

Inclusive production of charged pions in p+C collisions at 158 GeV/c beam momentum

The production of charged pions in minimum bias p+C interactions is studied using a sample of 377000 inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The data cover a phase space area ranging from 0 to 1.8 GeV/c in transverse momentum and from -0.1 to 0.5 in Feynman x. Inclusive invariant cross sections are given on a grid of 270 bins per charge thus offering for the first time a dense coverage of the projectile hemisphere and of the cross-over region into the target fragmentation zone.Comment: 31 pages, 30 figures, submitted to European Journal of Physic

Results on correlations and fluctuations from NA49

The large acceptance and high momentum resolution as well as the significant particle identification capabilities of the NA49 experiment at the CERN SPS allow for a broad study of fluctuations and correlations in hadronic interactions. In the first part recent results on event-by-event charge and p_t fluctuations are presented. Charge fluctuations in central Pb+Pb reactions are investigated at three different beam energies (40, 80, and 158 AGeV), while for the p_t fluctuations the focus is put on the system size dependence at 158 AGeV. In the second part recent results on Bose Einstein correlations of h-h- pairs in minimum bias Pb+Pb reactions at 40 and 158 AGeV, as well as of K+K+ and K-K- pairs in central Pb+Pb collisions at 158 AGeV are shown. Additionally, other types of two particle correlations, namely pi p, Lambda p, and Lambda Lambda correlations, have been measured by the NA49 experiment. Finally, results on the energy and system size dependence of deuteron coalescence are discussed.Comment: 10 pages, 12 figures, Presented at Quark Matter 2002, Nantes, France, Corrected error in Eq.