CVD-Enabled Graphene Manufacture and Technology.

Integrated manufacturing is arguably the most challenging task in the development of technology based on graphene and other 2D materials, particularly with regard to the industrial demand for “electronic-grade” large-area films. In order to control the structure and properties of these materials at the monolayer level, their nucleation, growth and interfacing needs to be understood to a level of unprecedented detail compared to existing thin film or bulk materials. Chemical vapor deposition (CVD) has emerged as the most versatile and promising technique to develop graphene and 2D material films into industrial device materials and this Perspective outlines recent progress, trends, and emerging CVD processing pathways. A key focus is the emerging understanding of the underlying growth mechanisms, in particular on the role of the required catalytic growth substrate, which brings together the latest progress in the fields of heterogeneous catalysis and classic crystal/thin-film growth.Funding from the ERC (Grant No. 279342, InSituNANO) and EPSRC (Grant No. EP/K016636/1, GRAPHTED) is acknowledged. R.S.W. acknowledges a research fellowship from St. John’s College, Cambridge.This is the final version of the article. It first appeared from ACS via http://dx.doi.org/10.1021/acs.jpclett.5b0105

Distribution of the vasoconstrictor and vasorelaxant effects of norbormide along the vascular tree of the rat

Norbormide is a vasoconstrictor of rat peripheral arteries and a relaxant in rat aorta. To characterise norbormide actions within the rat vascular tree we have investigated its effects on the contractile function of rings from several arteries and veins. A maximal norbormide concentration (50 muM) failed to contract thoracic aorta and carotid artery, whereas in pulmonary artery, abdominal aorta, iliac, caudal, and femoral arteries it induced a contractile effect that was respectively 4.8 +/- 0.6, 18.4 +/- 1.5, 39 +/- 5, 144 +/- 7, and 260 +/- 22% of that induced by 90 MM KCl. In pulmonary, carotid, and iliac arteries, and in thoracic and abdominal aorta, 50 muM norbormide inhibited KCl-induced responses. Norbormide (50 muM) contracted all veins investigated. The effect, expressed as % of KCl-induced contraction, was 121 +/- 25, 154 +/- 14.5, 154 +/- 18.2, 203 +/- 19, and 267 +/- 33 for pulmonary vein, thoracic and abdominal vena cava, iliac and jugular veins, respectively. In jugular vein, as previously shown in rat caudal artery, norbormide contraction was abolished in Ca2+-free medium, was unaffected by the Ca2+ channel blocker nifedipine, and was relaxed by SK&F 96365, a blocker of store-operated Ca2+ channels. In conclusion: i) rat veins represent the main target for contractile norbormide action; ii) in both artery and veins norbormide contractions are generally inversely related, to the calibre of the vessel; iii) norbormide-induced contraction is mediated by the same mechanism/s in arteries and veins; iiii) in norbormide-contracted arteries the drug activates both contractile and relaxing mechanisms. (C) 2004 Elsevier Inc. All rights reserved

Postoperative Dehydration Is Associated with Frailty and Decreased Survival in Older Patients with Hip Fracture

Background: Hyperosmolar dehydration (HD) is a risk factor for severe complications in hip fracture in older patients. However, evidence for recommending screening of dehydration is insufficient and its relation with frailty and mortality is unclear. We tested the hypothesis that postoperative HD is associated with frailty and increased mortality. Methods: We recruited 625 older (>65 years) patients surgically treated for hip fracture and co-managed by an orthogeriatric team over one year in 2017. Pre-and postoperative HD (serum osmolarity > 300 mmol/L) was diagnosed. Frailty and associated mortality risk were assessed by the Multidimensional Prognostic Index (MPI). Results: The prevalence of preoperative HD was 20.4%. Compared with no-HD, MPI was similar in HD patients despite higher (p < 0.05) prevalence of polypharmacy, arterial hypertension, diabetes, chronic kidney disease and heart failure. After surgery the incidence of HD decreased to 16.5%, but increased (p = 0.003) in the MPI high-risk subgroup. Postoperative HD was associated with more complications and was an independent determinant of adjusted hospital length of stay (LOS) and of 60-to 365-days mortality. Conclusions: Older frail patients with hip fracture are prone to developing postoperative HD, which independently predicts prolonged hospital LOS and mortality. Systematically screening older patients for frailty and dehydration is advisable to customize hydration management in high-risk individuals

Oral health status as predictor of 1-year mortality after discharge from an acute geriatric unit

Purpose: Predicting mortality of older patients is a difficult, yet crucial task, which has lead to development of several prognostic tools. We hypothesized that the evaluation of oral health, which is often neglected, might be helpful to improve 1-year mortality prediction in a cohort of patients > 65\ua0years admitted to an acute geriatric unit. Methods: We assessed 200 patients using the Decayed, Missing or Filled Teeth tool, the Periodontal Screening and Recording tool and the Plaque Index. A comprehensive geriatric assessment was performed to measure functional, cognitive, nutritional and comorbidity status and to calculate the Multidimensional Prognostic Index (MPI). An age- and sex-adjusted regression model was used to identify independent predictors of 1-year mortality. Area under ROC curve (AUROC) was calculated to assess predictive accuracy of MPI risk groups before and after correction for dental examination results. Results: Plaque Index and Periodontal Screening and Recording tool were associated with 1-year mortality. Participants with periodontal disease had a fivefold higher risk of death (p < 0.001). Conversely, absence of periodontal disease identified with high specificity (96.6%) participants who were still alive 1\ua0year after discharge. Periodontal disease was an independent predictor of 1-year mortality in a regression model adjusted for age, sex and other variables of the comprehensive geriatric assessment. The correction of MPI according to results of Periodontal Screening and Recording tool significantly improved AUROC from 0.62 to 0.68 (p < 0.003). Conclusion: Oral health evaluation, if integrated in the comprehensive geriatric assessment, improves estimation of 1-year mortality in hospitalized patients

Ethylene decomposition on Ir(111): initial path to graphene formation.

The complete mechanism behind the thermal decomposition of ethylene (C2H4) on Ir(111), which is the first step of graphene growth, is established for the first time employing a combination of experimental and theoretical methods. High-resolution X-ray photoelectron spectroscopy was employed, along with calculations of core level binding-energies, to identify the surface species and their evolution as the surface temperature is increased. To understand the experimental results, we have developed a reaction sequence between the various CnHm species, from ethylene to C monomers and dimers, based on ab initio density functional calculations of all the energy barriers and the Arrhenius prefactors for the most important processes. The resulting temperature evolution of all species obtained from the simulated kinetics of ethylene decomposition agrees with photoemission measurements. The molecular dissociation mechanism begins with the dehydrogenation of ethylene to vinylidene (CH2C), which is then converted to acetylene (CHCH) by the removal and addition of an H atom. The C-C bond is then broken to form methylidyne (CH), and in the same temperature range a small amount of ethylidyne (CH3C) is produced. Finally methylidyne dehydrogenates to produce C monomers that are available for the early stage nucleation of the graphene islands