2,315 research outputs found

    SPECIAL VALUES OF THE BELL POLYNOMIALS OF THE SECOND KIND FOR SOME SEQUENCES AND FUNCTIONS: Special values of Bell polynomials of second kind

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    In the paper, the authors concisely review some closed formulas and applications of special values of the Bell polynomials of the second kind for some special sequences and elementary functions, explicitly present closed formulas for those sequences investigated in [F. T. Howard, A special class of Bell polynomials, Math. Comp. 35 (1980), no. 151, 977–989; Available online at https://doi.org/10.2307/2006208], and newly establish some closed formulas for some special values of the Bell polynomials of the second kind

    Green purchasing: an effective integrated process of supply chain perspective in mtt priority

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    Green purchasing has become a significant priority for organizations and related parties to ensure a sustainable environment and future. Organizations should practise green purchasing because it provides a lot of benefits to the internal part of organization and to the external environment. The objective of this research is to examine the significant effectiveness of green fundamentals of purchasing and supply management, purchasing administration and materials management in enhancing the integrated purchasing and supply management process (green purchasing). This research focuses on a company that practising best in green purchasing that is Malaysia Trade and Transport Priority (MTT Priority). 20 Questionnaires were distributed to the employees and interviews were conducted with the Chief Executive Officer (CEO) and General Manager (GM) in the company. Green fundamentals of purchasing and supply management, purchasing administration and materials management are the independent variables for the green purchasing. Theoretically, it contributes an insight study on how the independent variables will affect green purchasing and benefit the company. Practically, this research is applicable for organizations in various industries, especially those who are operating business, in making important decisions to improve sustainable operations. Based on this research, it is found that there is positive outcome to promote Green Purchasing in the business organizations

    Green purchasing: An effective integrated process of supply chain perspective

    Get PDF
    Green purchasing has become a significant priority for organizations and related parties to ensure a sustainable environment and future.Organizations should practise green purchasing because it provides a lot of benefits to the internal part of organization and to the external environment.The objective of this research is to examine the significant effectiveness of green fundamentals of purchasing and supply management, purchasing administration and materials management in enhancing the integrated purchasing and supply management process (green purchasing).This research focuses on a company that practising best in green purchasing-Malaysia Trade and Transport Priority (MTT Priority).Questionnaires (20 questions) were distributed to the employees and interview was conducted with the CEO and GM in the company.Green fundamentals of purchasing and supply management, purchasing administration and materials management are the independent variables for the green purchasing.Theoretically, it contributes an insight study on how the independent variables will affect green purchasing and benefit the company.Practically, this research is applicable for organizations in various industries, especially those who are operating business, in making important decisions to improve sustainable operations.Based on this research, it is found that there is positive outcome to promote Green Purchasing in the business organization

    Pyrite nanocrystals: shape-controlled synthesis and tunable optical properties via reversible self-assembly

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    Nanocrystals from non-toxic, earth abundant materials have recently received great interest for their potential large-scale application in photovoltaics and photocatalysis. Here, we report for the first time on the shape-controlled and scalable synthesis of phase-pure pyrite (FeS2) nanocrystals employing the simple, inexpensive, thermal reaction of iron–oleylamine complexes with sulfur in oleylamine. Either dendritic nanocrystals (nanodendrites) or nanocubes are obtained by adjusting the iron-oleylamine concentration and thereby controlling the nucleus concentration and kinetics of the nanocrystal growth. Pyrite nanodendrites are reversibly assembled by washing with toluene and redispersed by adding the ligand oleylamine. The assembly–redispersion-process is accompanied by an increased absorption in the red/near-infrared spectral region for the aggregated state. This increased low-energy absorption is due to interactions between the closed-packed nanocrystals. High-concentration nanodendrite dispersions are used to prepare pyrite thin films with strong broadband extinction in the visible and near-infrared. These films are attractive candidates for light harvesting in all inorganic solar cells based on earth abundant, non-toxic materials as well as for photocatalytic applications

    Ethnicity and COVID-19 cardiovascular complications: a multi-center UK cohort

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    BACKGROUND: Recent reports suggest an association between ethnicity and COVID-19 mortality. In the present multi-center study, we aimed to assess the differences underlying this association, and ascertain whether ethnicity also mediates other aspects of COVID-19 like cardiovascular complications. METHODS: Data were collected from a mixed-ethnicity UK cohort of 613 patients admitted and diagnosed COVID-19 positive, across six hospitals in London during the second half of March 2020: 292 were White Caucasian ethnicity, 203 were Asian and 118 were of Afro-Caribbean ethnicity. RESULTS: Caucasian patients were older (P<0.001) and less likely to have hypertension (P=0.038), while Afro-Caribbean patients had higher prevalence of diabetes mellitus (P<0.001). Asian patients were more likely to present with venous thromboembolic disease (adj.OR=4.10, 95% CI 1.49-11.27, P=0.006). On the other hand, Afro-Caribbean had more heart failure (adj.OR=3.64, 95% CI 1.50-8.84, P=0.004) and myocardial injury (adj.OR=2.64, 95% CI 1.10-6.35, P=0.030). Importantly, our adjusted multi-variate Cox regression analysis revealed significantly higher all-cause mortality both for Asian (adj.HR=1.89, 95% CI 1.23-2.91, P=0.004) and Afro-Caribbean ethnicity (adj.HR=2.09, 95% CI 1.30-3.37, P=0.002). CONCLUSIONS: Our data show that COVID-19 may have different presentations and follow different clinical trajectories depending on the ethnicity of the affected subject. Awareness of complications more likely to arise in specific ethnicities will allow a more timely diagnosis and preventive measures for patients at risk. Due to increased mortality, individuals of Afro-Caribbean and Asian ethnicity should be considered as high-risk groups. This may have an impact on health-resource allocation and planning, definition of vulnerable groups, disease management, and the protection of healthcare workers at the frontline

    High sensitivity troponin and COVID-19 outcomes

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    Background: Recent reports have demonstrated high troponin levels in patients affected with COVID-19. In the present study, we aimed to determine the association between admission and peak troponin levels and COVID-19 outcomes. / Methods: This was an observational multi-ethnic multi-centre study in a UK cohort of 434 patients admitted and diagnosed COVID-19 positive, across six hospitals in London, UK during the second half of March 2020. / Results: Myocardial injury, defined as positive troponin during admission was observed in 288 (66.4%) patients. Age (OR: 1.68 [1.49–1.88], p <.001), hypertension (OR: 1.81 [1.10–2.99], p =.020) and moderate chronic kidney disease (OR: 9.12 [95% CI: 4.24–19.64], p <.001) independently predicted myocardial injury. After adjustment, patients with positive peak troponin were more likely to need non-invasive and mechanical ventilation (OR: 2.40 [95% CI: 1.27–4.56], p =.007, and OR: 6.81 [95% CI: 3.40–13.62], p <.001, respectively) and urgent renal replacement therapy (OR: 4.14 [95% CI: 1.34–12.78], p =.013). With regards to events, and after adjustment, positive peak troponin levels were independently associated with acute kidney injury (OR: 6.76 [95% CI: 3.40–13.47], p <.001), venous thromboembolism (OR: 11.99 [95% CI: 3.20–44.88], p <.001), development of atrial fibrillation (OR: 10.66 [95% CI: 1.33–85.32], p =.026) and death during admission (OR: 2.40 [95% CI: 1.34–4.29], p =.003). Similar associations were observed for admission troponin. In addition, median length of stay in days was shorter for patients with negative troponin levels: 8 (5–13) negative, 14 (7–23) low-positive levels and 16 (10–23) high-positive (p <.001). / Conclusions: Admission and peak troponin appear to be predictors for cardiovascular and non-cardiovascular events and outcomes in COVID-19 patients, and their utilisation may have an impact on patient management

    Hospitalization for permanent pacemaker implantation in the context of isolated sinus node dysfunction is associated with increased mortality compared with an outpatient strategy

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    Background: Permanent pacemaker (PPM) implantation is a well-established treatment for symptomatic sinus node dysfunction (SND). The optimal timing of this intervention is unclear, with atrioventricular blocks often prioritized in resource stressed waiting lists due to mortality concerns. Methods: Mortality data was compared between patients receiving elective outpatient (OP) PPM implantation, and those presenting to hospital for urgent inpatient (IP) management for symptomatic SND. Survival analysis was conducted using Kaplan-Meier plots and compared using the log-rank test. Univariable and multivariable Cox regression, as well as propensity score matching analyses were performed to assess the prognostic effect on 30-day and 1-year all-cause mortality of inpatient implant. Results: Of the 1269 patients identified with isolated SND, 740 (58%) had PPMs implanted on an OP and 529 (42%) on an IP basis. Mortality was significantly worse in patients where management was driven by hospital admission on an urgent basis (Log-Rank χ2 = 21.6, p < 0.001) and remained an independent predictor of 1-year all-cause mortality (HR 3.40, 95% CI 1.97–5.86, p < 0.001) on multivariable analysis. Conclusions: SND is predominantly a disease associated with ageing and comorbid populations, where avoidance of deconditioning, hospitalization acquired infections, and polypharmacy is advantageous. Admission avoidance is therefore the preferable strategy
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