760 research outputs found
Analysis of Medication Errors in the Pediatric Population: Assessment of Age, Error Types, Time to Error Discovery, and Clinical Severity
Context: Medication errors are a significant source of iatrogenic morbidity and mortality in the hospital inpatient setting. The pediatric population is especially vulnerable to medication errors because of the need to dose medications by weight and their inability to control and understand their medical condition. There are currently few epidemiological studies regarding medication errors in the pediatric inpatient setting. Objectives: To determine 1) the relationship between certain error types and the pediatric age at which these errors occur, 2) the relationship between the time to discovering medication errors and the pediatric age at which these errors occur, and 3) to integrate these findings into a model to determine if age is an independent predictor of clinical severity. Design: Quantitative analysis of database of self-reported medication errors spanning 2 years from February 2000 to May 2002 at the University of North Carolina. Results: We reviewed 6247 medication error reports classified into one of 16 error types. We discovered that certain error types involving incorrect IV/TPN solutions, incorrect IV/TPN rate, and IV incompatibility occurred in a significantly younger age population, and that other error types such as allergy due to medication and medications given at an incorrect time or frequency occurred in a significantly older age population. Younger patients on average experienced errors discovered during the same shift than older patients. Age was found to be an independent predictor of clinical severity in a limited regression model. Conclusions: Age is a significant predictor of medication errors regarding certain clinical error types, time to discovery, and clinical severity.Master of Public Healt
Inducing Metallicity in Graphene Nanoribbons via Zero-Mode Superlattices
The design and fabrication of robust metallic states in graphene nanoribbons
(GNRs) is a significant challenge since lateral quantum confinement and
many-electron interactions tend to induce electronic band gaps when graphene is
patterned at nanometer length scales. Recent developments in bottom-up
synthesis have enabled the design and characterization of atomically-precise
GNRs, but strategies for realizing GNR metallicity have been elusive. Here we
demonstrate a general technique for inducing metallicity in GNRs by inserting a
symmetric superlattice of zero-energy modes into otherwise semiconducting GNRs.
We verify the resulting metallicity using scanning tunneling spectroscopy as
well as first-principles density-functional theory and tight binding
calculations. Our results reveal that the metallic bandwidth in GNRs can be
tuned over a wide range by controlling the overlap of zero-mode wavefunctions
through intentional sublattice symmetry-breaking.Comment: The first three authors listed contributed equall
Topological Band Engineering of Graphene Nanoribbons
Topological insulators (TIs) are an emerging class of materials that host
highly robust in-gap surface/interface states while maintaining an insulating
bulk. While most notable scientific advancements in this field have been
focused on TIs and related topological crystalline insulators in 2D and 3D,
more recent theoretical work has predicted the existence of 1D
symmetry-protected topological phases in graphene nanoribbons (GNRs). The
topological phase of these laterally-confined, semiconducting strips of
graphene is determined by their width, edge shape, and the terminating unit
cell, and is characterized by a Z2 invariant (similar to 1D solitonic systems).
Interfaces between topologically distinct GNRs characterized by different Z2
are predicted to support half-filled in-gap localized electronic states which
can, in principle, be utilized as a tool for material engineering. Here we
present the rational design and experimental realization of a
topologically-engineered GNR superlattice that hosts a 1D array of such states,
thus generating otherwise inaccessible electronic structure. This strategy also
enables new end states to be engineered directly into the termini of the 1D GNR
superlattice. Atomically-precise topological GNR superlattices were synthesized
from molecular precursors on a Au(111) surface under ultra-high vacuum (UHV)
conditions and characterized by low temperature scanning tunneling microscopy
(STM) and spectroscopy (STS). Our experimental results and first-principles
calculations reveal that the frontier band structure of these GNR superlattices
is defined purely by the coupling between adjacent topological interface
states. This novel manifestation of 1D topological phases presents an entirely
new route to band engineering in 1D materials based on precise control of their
electronic topology, and is a promising platform for future studies of 1D
quantum spin physics.Comment: Contains main manuscript and supplemental informatio
Engineering Robust Metallic Zero-Mode States in Olympicene Graphene Nanoribbons
Metallic graphene nanoribbons (GNRs) represent a critical component in the
toolbox of low-dimensional functional materials technolo-gy serving as 1D
interconnects capable of both electronic and quantum information transport. The
structural constraints imposed by on-surface bottom-up GNR synthesis protocols
along with the limited control over orientation and sequence of asymmetric
monomer building blocks during the radical step-growth polymerization has
plagued the design and assembly of metallic GNRs. Here we report the
regioregular synthesis of GNRs hosting robust metallic states by embedding a
symmetric zero-mode superlattice along the backbone of a GNR. Tight-binding
electronic structure models predict a strong nearest-neighbor electron hopping
interaction between adjacent zero-mode states resulting in a dispersive
metallic band. First principles DFT-LDA calculations confirm this prediction
and the robust, metallic zero-mode band of olympicene GNRs (oGNRs) is
experimentally corroborated by scanning tunneling spectroscopy.Comment: 8 pages, 4 figure
Prevalence and demographics of methicillin resistant Staphylococcus aureus in culturable skin and soft tissue infections in an urban emergency department
<p>Abstract</p> <p>Background</p> <p>The rising incidence of methicillin resistant <it>Staph. aureus </it>(MRSA) infections is a concern for emergency practitioners. While studies have examined MRSA in inpatients, few have focused on emergency department populations. We sought to describe predictors of MRSA skin infections in an emergency department population.</p> <p>Methods</p> <p>This was a prospective observational cohort study conducted over three months in 2005. A convenience sample of patients with culturable skin infections presenting to a busy, urban emergency department was enrolled. Demographic and risk factor information was collected by structured interview. The predictive value of each risk factor for MRSA, as identified by culture, was tested using univariable logistic regression, and a multivariable predictive model was developed.</p> <p>Results</p> <p>Patients were 43% black, 40% female and mean age was 39 years (SD 14 years). Of the 182 patients with cultures, prevalence of MRSA was 58% (95%CI 50% to 65%). Significant predictors of MRSA were youth, lower body mass index, sexual contact in the past month, presence of an abscess cavity, spontaneous infection, and incarceration. The multivariable model had a C-statistic of 0.73 (95%CI 0.67 to 0.79) with four significant variables: age, group living, abscess cavity, and sexual contact within one month.</p> <p>Conclusion</p> <p>In this population of emergency department patients, MRSA skin infection was related to youth, recent sexual contact, presence of abscess, low body mass index, spontaneity of infection, incarceration or contact with an inmate, and group home living.</p
Metabolic Network Analysis Reveals Altered Bile Acid Synthesis and Metabolism in Alzheimer\u27s Disease.
Increasing evidence suggests Alzheimer\u27s disease (AD) pathophysiology is influenced by primary and secondary bile acids, the end product of cholesterol metabolism. We analyze 2,114 post-mortem brain transcriptomes and identify genes in the alternative bile acid synthesis pathway to be expressed in the brain. A targeted metabolomic analysis of primary and secondary bile acids measured from post-mortem brain samples of 111 individuals supports these results. Our metabolic network analysis suggests that taurine transport, bile acid synthesis, and cholesterol metabolism differ in AD and cognitively normal individuals. We also identify putative transcription factors regulating metabolic genes and influencing altered metabolism in AD. Intriguingly, some bile acids measured in brain tissue cannot be explained by the presence of enzymes responsible for their synthesis, suggesting that they may originate from the gut microbiome and are transported to the brain. These findings motivate further research into bile acid metabolism in AD to elucidate their possible connection to cognitive decline
Risk Categorization Using New American College of Cardiology/American Heart Association Guidelines for Cholesterol Management and Its Relation to Alirocumab Treatment Following Acute Coronary Syndromes
BACKGROUND: The 2018 US cholesterol management guidelines recommend
additional lipid-lowering therapies for secondary prevention in patients with lowdensity lipoprotein cholesterol ≥70 mg/dL or non−high-density lipoprotein cholesterol
≥100 mg/dL despite maximum tolerated statin therapy. Such patients are considered
at very high risk (VHR) based on a history of >1 major atherosclerotic cardiovascular
disease (ASCVD) event or a single ASCVD event and multiple high-risk conditions.
We investigated the association of US guideline-defined risk categories with the
occurrence of ischemic events after acute coronary syndrome and reduction of
those events by alirocumab, a PCSK9 (proprotein convertase subtilisin/kexin type 9)
inhibitor.
METHODS: In the ODYSSEY OUTCOMES trial (Evaluation of Cardiovascular
Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab),
patients with recent acute coronary syndrome and residual dyslipidemia despite
optimal statin therapy were randomly assigned to alirocumab or placebo. The primary
trial outcome (major adverse cardiovascular events, ie, coronary heart disease death,
nonfatal myocardial infarction, is
Multi-ethnic GWAS and meta-analysis of sleep quality identify MPP6 as a novel gene that functions in sleep center neurons
Poor sleep quality can have harmful health consequences. Although many aspects of sleep are heritable, the understandings of genetic factors involved in its physiology remain limited. Here, we performed a genome-wide association study (GWAS) using the Pittsburgh Sleep Quality Index (PSQI) in a multi-ethnic discovery cohort (n = 2868) and found two novel genome-wide loci on chromosomes 2 and 7 associated with global sleep quality. A meta-analysis in 12 independent cohorts (100 000 individuals) replicated the association on chromosome 7 between NPY and MPP6. While NPY is an important sleep gene, we tested for an independent functional role of MPP6. Expression data showed an association of this locus with both NPY and MPP6 mRNA levels in brain tissues. Moreover, knockdown of an orthologue of MPP6 in Drosophila melanogaster sleep center neurons resulted in decreased sleep duration. With convergent evidence, we describe a new locus impacting human variability in sleep quality through known NPY and novel MPP6 sleep genes.Peer reviewe
Bile acids targeted metabolomics and medication classification data in the ADNI1 and ADNIGO/2 cohorts
Alzheimer’s disease (AD) is the most common cause of dementia. The mechanism of disease development and progression is not well understood, but increasing evidence suggests multifactorial etiology, with a number of genetic, environmental, and aging-related factors. There is a growing body of evidence that metabolic defects may contribute to this complex disease. To interrogate the relationship between system level metabolites and disease susceptibility and progression, the AD Metabolomics Consortium (ADMC) in partnership with AD Neuroimaging Initiative (ADNI) is creating a comprehensive biochemical database for patients in the ADNI1 cohort. We used the Biocrates Bile Acids platform to evaluate the association of metabolic levels with disease risk and progression. We detail the quantitative metabolomics data generated on the baseline samples from ADNI1 and ADNIGO/2 (370 cognitively normal, 887 mild cognitive impairment, and 305 AD). Similar to our previous reports on ADNI1, we present the tools for data quality control and initial analysis. This data descriptor represents the third in a series of comprehensive metabolomics datasets from the ADMC on the ADNI
Digenic inheritance and genetic modifiers
Digenic inheritance (DI) concerns pathologies with the simplest form of multigenic etiology, implicating more than 1 gene (and perhaps the environment). True DI is when biallelic or even triallelic mutations in 2 distinct genes, in cis or in trans, are necessary and sufficient to cause pathology with a defined diagnosis. In true DI, a heterozygous mutation in each of 2 genes alone is not associated with a recognizable phenotype. Well-documented diseases with true DI are so far rare and follow non-Mendelian inheritance. DI is also encountered when by serendipity, pathogenic mutations responsible for 2 distinct disease entities are co-inherited, leading to a mixed phenotype. Also, we can consider many true monogenic Mendelian conditions, which show impressively broad spectrum of phenotypes due to pseudo-DI, as a result of co-inheriting genetic modifiers (GMs). I am herewith reviewing examples of GM and embark on presenting some recent notable examples of true DI, with wider discussion of the literature. Undeniably, the advent of high throughput sequencing is bound to unravel more patients suffering with true DI conditions and elucidate many important GM, thus impacting precision medicine. - 2017 John Wiley & Sons A/S. Published by John Wiley & Sons LtdCyprus Research Promotion Foundation (co-funded by the European Regional Development Fund and the Republic of Cyprus), Grant/Award number: NEW INFRASTRUCTURE/STRATEGIC/0308/24 ; Republic of Cyprus; European Regional Development Fund. The work of Prof Deltas presented here was partly supported by the Cyprus Research Promotion Foundation through the grant NEW INFRASTRUCTURE/STRATEGIC/0308/24 (co-funded by the European Regional Development Fund and the Republic of Cyprus).Scopu
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