Biomimetic pheomelanin to unravel the electronic, molecular and supramolecular structure of the natural product.

Herein, we investigate synthetic routes to a close mimic of natural pheomelanin. Three different oxidative polymerization routes were attempted to generate synthetic pheomelanin, each giving rise to structurally dissimilar materials. Among them, the route employing 5-cysteinyl-dihydroxyphenylalanine (5-CD) as a monomer was verified as a close analogue of extracted pheomelanin from humans and birds. The resulting biomimetic and natural pheomelanins were compared via various techniques, including solid-state Nuclear Magnetic Resonance (ssNMR) and Electron Paramagnetic Resonance (EPR). This synthetic pheomelanin closely mimics the structure of natural pheomelanin as determined by parallel characterization of pheomelanin extracted from multiple biological sources. With a good synthetic biomimetic material in hand, we describe cation-π interactions as an important driving force for pheomelanogenesis, further advancing our fundamental understanding of this important biological pigment.

Is Eriocnemis luciani meridae (Aves: Trochilidae) a diagnosable taxon and does it come from Venezuela, with remarks on the collectors Salomn Briceo and Walther Frederick Henninger.

Eriocnemis luciani meridae was originally described from a single specimen collected in the late 19th century in western Venezuela. Subsequently a second specimen of E. luciani, also labelled Venezuela, has been taken as additional proof for a highly disjunct population of this hummingbird, which otherwise ranges from southwest Colombia to southern Peru (taxonomy-dependent). Eriocnemis l. meridae has been accepted by all of the global checklists of birds, but has been routinely ignored by Venezuelan sources. In an effort to resolve this dichotomy of treatment, we re-examined the specimens plumage in comparison with relevant material in two major European bird collections. We found that the characters used to erect E. l. meridae are only doubtfully or weakly expressed in the holotype and appear invisible in the Ohio specimen, but both are clearly referrable to the species E. luciani. Evidence that the second specimen was definitely collected in Venezuela is weak and its overall provenance is unclear. In contrast, an extensive historical investigation of the relevant collectors indicates that the holotype does appear to have been taken in Venezuela, although perhaps not in the precise locality indicated for it. This leaves an unusual situation whereby we consider the case for a separate Venezuelan endemic taxon to be unproven, but there is no incontrovertible reason to exclude the species from the countrys avifauna; according to recent niche modelling data it is best searched for in the Sierra Nevada of Mrida state. In contrast, a second subspecies of E. luciani, E. l. baptistae, described by the same authors as endemic to part of western Ecuador is, according to our reappraisal, clearly diagnosable and is upheld.

The use of trained volunteers in the response to out-of-hospital cardiac arrest - the GoodSAM experience.

In England, fewer than 1 in 10 out-of-hospital cardiac arrest victims survive to hospital discharge. This could be substantially improved by increasing bystander cardiopulmonary resuscitation and Automated External Defibrillator use. GoodSAM is a mobile-phone, app-based system alerting trained individuals to nearby cardiac arrests. 'Responders' can be notified by bystanders using the GoodSAM 'Alerter' function. In London, when a 999 call-handler identifies cardiac arrest, in addition to dispatching the usual professional resources, London Ambulance Service automatically activates nearby GoodSAM responders. This article discusses the development of GoodSAM, its integration with London Ambulance Service, and the plans for future expansion.

Barriers and facilitators to public access defibrillation in out-of-hospital cardiac arrest: a systematic review.

Public access defibrillation initiatives make automated external defibrillators available to the public. This facilitates earlier defibrillation of out-of-hospital cardiac arrest victims and could save many lives. It is currently only used for a minority of cases. The aim of this systematic review was to identify barriers and facilitators to public access defibrillation. A comprehensive literature review was undertaken defining formal search terms for a systematic review of the literature in March 2017. Studies were included if they considered reasons affecting the likelihood of public access defibrillation and presented original data. An electronic search strategy was devised searching MEDLINE and EMBASE, supplemented by bibliography and related-article searches. Given the low-quality and observational nature of the majority of articles, a narrative review was performed. Sixty-four articles were identified in the initial literature search. An additional four unique articles were identified from the electronic search strategies. The following themes were identified related to public access defibrillation: knowledge and awareness; willingness to use; acquisition and maintenance; availability and accessibility; training issues; registration and regulation; medicolegal issues; emergency medical services dispatch-assisted use of automated external defibrillators; automated external defibrillator-locator systems; demographic factors; other behavioural factors. In conclusion, several barriers and facilitators to public access defibrillation deployment were identified. However, the evidence is of very low quality and there is not enough information to inform changes in practice. This is an area in urgent need of further high-quality research if public access defibrillation is to be increased and more lives saved. PROSPERO registration number CRD42016035543.

LaFe x Co(1-x)O3 Thin-Film Oxygen Reduction Catalysts Prepared Using Spray Pyrolysis without Conductive Additives.

LaFe x Co(1-x)O3 thin films were prepared on fluorine-doped tin oxide conducting glass substrates by spray pyrolysis without any conductive additives and evaluated for their ability to catalyze the oxygen reduction reaction. Onset potential and current density were found to be comparable to platinum, and the resulting crystallite size was on the order of 20 nm. Coordination of the precursor metal ions by citrate was found not to be advantageous. Results from multiple scan linear sweep voltammetry suggest lattice oxide saturation during reduction of oxygen and lattice oxide depletion upon water oxidation. The color of the best-performing composition changes dramatically between 1.2 and -1.15 V versus saturated calomel electrode, so X-ray photoelectron spectra of the fully oxidized and reduced films were compared, demonstrating that cobalt in the film changes oxidation state. Performance of the films as a function of iron-to-cobalt ratio is consistent with what others have reported in the literature, indicating that spray pyrolysis is an efficient method to prepare and evaluate new catalytic materials.

Novel web-based real-time dashboard to optimize recycling and use of red cell units at a large multi-site transfusion service.

BACKGROUND: Effective blood inventory management reduces outdates of blood products. Multiple strategies have been employed to reduce the rate of red blood cell (RBC) unit outdate. We designed an automated real-time web-based dashboard interfaced with our laboratory information system to effectively recycle red cell units. The objective of our approach is to decrease RBC outdate rates within our transfusion service. METHODS: The dashboard was deployed in August 2011 and is accessed by a shortcut that was placed on the desktops of all blood transfusion services computers in the Capital District Health Authority region. It was designed to refresh automatically every 10 min. The dashboard provides all vital information on RBC units, and implemented a color coding scheme to indicate an RBC unit's proximity to expiration. RESULTS: The overall RBC unit outdate rate in the 7 months period following implementation of the dashboard (September 2011-March 2012) was 1.24% (123 units outdated/9763 units received), compared to similar periods in 2010-2011 and 2009-2010: 2.03% (188/9395) and 2.81% (261/9220), respectively. The odds ratio of a RBC unit outdate postdashboard (2011-2012) compared with 2010-2011 was 0.625 (95% confidence interval: 0.497-0.786; P < 0.0001). CONCLUSION: Our dashboard system is an inexpensive and novel blood inventory management system which was associated with a significant reduction in RBC unit outdate rates at our institution over a period of 7 months. This system, or components of it, could be a useful addition to existing RBC management systems at other institutions.

Cerebral venous thrombosis during pregnancy in the setting of type I antithrombin deficiency: case report and literature review.

Inherited antithrombin deficiency is estimated to carry a 50% risk of a venous thrombotic complication during each pregnancy and puerperium. We present a case of a female with heterozygous type I antithrombin deficiency who presented with a central nervous system transverse sinus thrombosis in the third trimester of pregnancy despite the use of therapeutic doses of low molecular weight heparin, as venous thromboembolic prophylaxis, since conception. A successful pregnancy outcome was achieved with the combined use of therapeutic anticoagulation and regular plasma-derived antithrombin concentrate infusions to normalize her antithrombin levels. This case lends further debate to the issue of whether antithrombin concentrate, in addition to anticoagulation, should be routinely administered for venous thromboembolic prophylaxis during pregnancy and the puerperium to women with inherited antithrombin deficiency. This point may become more relevant as further experience is gained with the use of recombinant human antithrombin.

Calcitonin plays a critical role in regulating skeletal mineral metabolism during lactation.

The maternal skeleton rapidly demineralizes during lactation to provide calcium to milk, responding to the stimuli of estrogen deficiency and mammary-secreted PTH-related protein. We used calcitonin/calcitonin gene-related peptide-alpha (Ctcgrp) null mice to determine whether calcitonin also modulates lactational mineral metabolism. During 21 d of lactation, spine bone mineral content dropped 53.6% in Ctcgrp nulls vs. 23.6% in wild-type (WT) siblings (P < 0.0002). After weaning, bone mineral content returned fully to baseline in 18.1 d in Ctcgrp null vs. 13.1 d in WT (P < 0.01) mice. Daily treatment with salmon calcitonin from the onset of lactation normalized the losses in Ctcgrp null mice, whereas calcitonin gene-related peptide-alpha or vehicle was without effect. Compared with WT, Ctcgrp null mice had increased circulating levels of PTH and up-regulation of mammary gland PTH-related protein mRNA. In addition, lactation caused the Ctcgrp null skeleton to undergo more trabecular thinning and increased trabecular separation compared with WT. Our studies confirm that an important physiological role of calcitonin is to protect the maternal skeleton against excessive resorption and attendant fragility during lactation and reveal that the postweaning skeleton has the remarkable ability to rapidly recover even from losses of over 50% of skeletal mineral content.

Identification and partial characterization of two inducible gelatin-cleavage activities localized to the sea urchin extraembryonic matrix, the hyaline layer.

We have identified two inducible, gelatin-cleaving activities in the sea urchin extraembryonic matrix, the hyaline layer. Isolated hyaline layers, incubated in the presence of benzamidine, were devoid of gelatin-cleavage activities with apparent molecular mass less then 80k. However, when layers were incubated for 9-11 h in the absence of benzamidine, gelatin-cleavage activities, with apparent molecular mass 40- and 50k, were detected. Induction required the presence of NaCl and CaCl(2) at concentrations similar to those found in seawater and readdition of the reversible serine protease inhibitor benzamidine prevented induction. Both gelatin-cleaving activities were activated by calcium at a concentration similar to the calcium concentration found in seawater. Magnesium, also a major cationic species present in seawater, could not replace calcium as the activating ion. In addition, magnesium could not compete with calcium for binding to the gelatinases. Both cleavage activities showed substrate specificity and each failed to cleave bovine serum albumin, bovine hemoglobin or casein. Cleavage activity towards gelatin was inhibited by benzamidine and aminoethyl benzenesulfonyl fluoride, indicating that both activities belonged to the serine class of proteases. The induced 40-kDa activity displayed similar properties to those of a comigrating, gelatin-cleaving activity present in 69-h-old embryos.