486 research outputs found
Electronic structure of the muonium center as a shallow donor in ZnO
The electronic structure and the location of muonium centers (Mu) in
single-crystalline ZnO were determined for the first time. Two species of Mu
centers with extremely small hyperfine parameters have been observed below 40
K. Both Mu centers have an axial-symmetric hyperfine structure along with a
[0001] axis, indicating that they are located at the AB_{O,//} and BC_{//}
sites. It is inferred from their small ionization energy (~6 meV and 50 meV)
and hyperfine parameters (~10^{-4} times the vacuum value) that these centers
behave as shallow donors, strongly suggesting that hydrogen is one of the
primary origins of n type conductivity in as-grown ZnO.Comment: 4 pages, 4 figures, submitted to PR
Bowel Preparation for Colonoscopy with Sodium Phosphate Solution versus Polyethylene Glycol-Based Lavage: A Multicenter Trial
Background: Adequate bowel preparation is essential for
accurate colonoscopy. Both oral sodium phosphate (NaP) and
polyethylene glycol-based lavage (PEG-ELS) are used predominantly
as bowel cleansing modalities. NaP has gained popularity due to
low drinking volume and lower costs. The purpose of this
randomized multicenter observer blinded study was to compare
three groups of cleansing (NaP, NaP + sennosides, PEG-ELS +
sennosides) in reference to tolerability, acceptance, and
cleanliness. Patient and Methods: 355 outpatients between 18 and
75 years were randomized into three groups (A, B, C) receiving NaP =
A, NaP, and sennosides = B or PEG-ELS and sennosides = C.
Gastroenterologists performing colonoscopies were blinded to the
type of preparation. All patients documented tolerance and adverse
events. Vital signs, premedication, completeness, discomfort, and
complications were recorded. A quality score (0–4) of cleanliness
was generated. Results: The three groups were similar
with regard to age, sex, BMI, indication for colonoscopy, and
comorbidity. Drinking volumes (L) (A = 4.33 + 1.2, B = 4.56 + 1.18, C = 4.93 + 1.71) were in favor of NaP
(P = .005). Discomfort from
ingested fluid was recorded in A = 39.8% (versus C: P = .015),
B = 46.6% (versus C: P = .147), and C = 54.6%. Differences in tolerability and acceptance between the three groups were
statistically not significant. No differences in adverse events
and the cleanliness effects occurred in the three groups (P = .113).
The cleanliness quality scores 0–2 were calculated in A:
77.7%, B: 86.7%, and C: 85.2%. Conclusions:
These data fail to demonstrate significant differences in
tolerability, acceptance, and preparation quality between the
three types of bowel preparation for colonoscopy. Cleansing with
NaP was not superior to PEG-ELS
Identification of evolutionary and kinetic drivers of NAD-dependent signaling
Nicotinamide adenine dinucleotide (NAD) provides an important link between metabolism and signal transduction and has emerged as central hub between bioenergetics and all major cellular events. NAD-dependent signaling (e.g., by sirtuins and poly-adenosine diphosphate [ADP] ribose polymerases [PARPs]) consumes considerable amounts of NAD. To maintain physiological functions, NAD consumption and biosynthesis need to be carefully balanced. Using extensive phylogenetic analyses, mathematical modeling of NAD metabolism, and experimental verification, we show that the diversification of NAD-dependent signaling in vertebrates depended on 3 critical evolutionary events: 1) the transition of NAD biosynthesis to exclusive usage of nicotinamide phosphoribosyltransferase (NamPT); 2) the occurrence of nicotinamide N-methyltransferase (NNMT), which diverts nicotinamide (Nam) from recycling into NAD, preventing Nam accumulation and inhibition of NAD-dependent signaling reactions; and 3) structural adaptation of NamPT, providing an unusually high affinity toward Nam, necessary to maintain NAD levels. Our results reveal an unexpected coevolution and kinetic interplay between NNMT and NamPT that enables extensive NAD signaling. This has implications for therapeutic strategies of NAD supplementation and the use of NNMT or NamPT inhibitors in disease treatment
Julie Williams crowned Miss OBU 2019
Ouachita Baptist University hosted the 51st annual Miss Ouachita Baptist University Pageant on Saturday, Feb. 2, and crowned Arkadelphia, Ark., native Julie Williams as Miss OBU 2019
MutDB: update on development of tools for the biochemical analysis of genetic variation
Understanding how genetic variation affects the molecular function of gene products is an emergent area of bioinformatic research. Here, we present updates to MutDB (http://www.mutdb.org), a tool aiming to aid bioinformatic studies by integrating publicly available databases of human genetic variation with molecular features and clinical phenotype data. MutDB, first developed in 2002, integrates annotated SNPs in dbSNP and amino acid substitutions in Swiss-Prot with protein structural information, links to scores that predict functional disruption and other useful annotations. Though these functional annotations are mainly focused on nonsynonymous SNPs, some information on other SNP types included in dbSNP is also provided. Additionally, we have developed a new functionality that facilitates KEGG pathway visualization of genes containing SNPs and a SNP query tool for visualizing and exporting sets of SNPs that share selected features based on certain filters
Misty, Spellbound and the lost Gothic of British girls’ comics.
This article is a case study of the 1970s British girls’ comics Spellbound (DC Thomson, 1976–1977) and Misty (IPC, 1978–1980). These mystery anthology comics followed the more famous American horror comics from publishers like EC Comics - but were aimed at pre-teen girls. The article situates these comics with respect to Gothic critical theory and within the wider landscape of British girls’ comics. Firstly, it closely considers and compares the structure and content of their stories with respect to theories of the terror and horror Gothic. It discovers that both comics offer similar fare, with a subversive streak that undercuts established horror archetypes. The article then looks closely at both titles’ aesthetics and their use of the page to draw comparisons. It uses comics theory and Gothic cinematic theory to demonstrate that the appearance of Misty is more strongly Gothic than the aesthetic of Spellbound. Finally, it considers a selection of stories from both comics and analyses their common themes using Gothic critical theory. It argues that both comics rework Gothic themes into new forms that are relevant to their pre-teen and teenage readers. It concludes by summarising the study’s findings and suggesting that these comics offer a “Gothic for Girls” that is part cautionary tale and part bildungsroman. This article is published as part of a collection on Gothic and horror
Evaluation and reduction of magnetic resonance imaging artefacts induced by distinct plates for osseous fixation: an in vitro study @ 3 T
Objectives: To analyze MRI artefacts induced at 3 T by bioresorbable, titanium (TI) and glass fibre reinforced composite (GFRC) plates for osseous reconstruction.Methods: Fixation plates including bioresorbable polymers (Inion CPS, Inion Oy, Tampere, Finland; Rapidsorb, DePuy Synthes, Umkirch, Germany; Resorb X, Gebrueder KLS Martin GmbH, Tuttlingen, Germany), GFRC (Skulle Implants Oy, Turku, Finland) and TI plates of varying thickness and design (DePuy Synthes, Umkirch, Germany) were embedded in agarose gel and a 3 T MRI was performed using a standard protocol for head and neck imaging including T1W and T2W sequences. Additionally, different artefact reduction techniques (slice encoding for metal artefact reduction & ultrashort echo time) were used and their impact on the extent of artefacts evaluated for each material.Results: All TI plates induced significantly more artefacts than resorbable plates in T1W and T2W sequences. GFRCs induced the least artefacts in both sequences. The total extent of artefacts increased with plate thickness and height. Plate thickness had no influence on the percentage of overestimation in all three dimensions. TI-induced artefacts were significantly reduced by both artefact reduction techniques.Conclusions: Polylactide, GFRC and magnesium plates produce less susceptibility artefacts in MRI compared to TI, while the dimensions of TI plates directly influence artefact extension. Slice encoding for metal artefact reduction and ultrashort echo time significantly reduce metal artefacts at the expense of scan time or image resolution
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