595 research outputs found

    Spectrum and Franck-Condon factors of interacting suspended single-wall carbon nanotubes

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    A low energy theory of suspended carbon nanotube quantum dots in weak tunnelling coupling with metallic leads is presented. The focus is put on the dependence of the spectrum and the Franck-Condon factors on the geometry of the junction including several vibronic modes. The relative size and the relative position of the dot and its associated vibrons strongly influence the electromechanical properties of the system. A detailed analysis of the complete parameters space reveals different regimes: in the short vibron regime the tunnelling of an electron into the nanotube generates a plasmon-vibron excitation while in the long vibron regime polaron excitations dominate the scenario. The small, position dependent Franck-Condon couplings of the small vibron regime convert into uniform, large couplings in the long vibron regime. Selection rules for the excitations of the different plasmon-vibron modes via electronic tunnelling events are also derived.Comment: 23 pages, 8 figures, new version according to the published on

    The Economic Impact of Lower Extremity Amputations in Diabetics. a Retrospective Study From a Tertiary Care Hospital of Faisalabad, Pakistan

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    Background: Among the various complications of diabetes, lower-extremity amputation due to diabetic foot is a common problem. In Pakistan, 6-7% of patients with diabetes suffer from diabetic foot ulceration. Objectives: Our primary objective was to explore the frequency of diabetic foot amputations, and the secondary objective was to calculate the economic burden of these preventable surgeries on the health budget of the provincial government. Materials & Methods: It was a retrospective cross-sectional observational study conducted after obtaining approval from the Ethical Review Committee of Allied hospital, Faisalabad Medical University. The data of diabetic foot patients who underwent amputations between July 2017 and December 2017 were retrieved from three Surgical Units (I, II & III), using a purposive sampling technique. All amputations carried out for reasons other than diabetic foot were excluded. The direct medical cost of one diabetic foot amputation was calculated via a local survey of the various private hospitals of Faisalabad. The indirect costs in terms of loss of productivity and disability costs, transport costs, rehabilitation costs were not included in this study. The data were evaluated by using SPSS Version 23. Results: A total of 85 patients were included in our study. The male to female ratio was 2.7 to 1. The mean direct treatment cost for minor amputation was PKR 46926.00 ± 11730.90 (382.35±95.58),andthemeandirecttreatmentcostformajoramputationwasPKR53720.00±12401.24(382.35 ± 95.58), and the mean direct treatment cost for major amputation was PKR 53720.00 ± 12401.24 (437.71 ± 101.40). Out of 85 amputations, 63 (74%) were major amputations, and the remaining 22 (26%) were minor amputations. The total cost for 63 major amputations was PKR 3,384,360 (27568.91)andfor22minoramputationwasPKR1,032,372(27568.91) and for 22 minor amputation was PKR 1,032,372 (8409.67). The net cost came out to be PKR 4,416,732 ($35978.59) for all the 85 cases being reported in a tertiary care hospital of Faisalabad for six months. Conclusion: Diabetic foot, a preventable complication of long-term diabetes mellitus, has an economic burden on the hospital budget, which, if adequately addressed via primary prevention programme, can yield not just economical but medical benefits as well

    Impact of pulsed plasma beam on the thermal erosion and the surface structure of graphite

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    Among materials prospective as plasmaface materials for first wall of fusion reactor a priority is given to the materials with low atomic number, high threshold for physical sputtering, high thermal conductivity, low chemical activity to hydrogen, high thermal resistance and melting point. According to modern point of view, preferred plasma-face materials for tokamaks and future Generation IV reactors should be based on the carbon, beryllium and tungsten. Tungsten is one of the most promising materials for protection of tokamaks diverter plates

    Case Studies on the Exploitation of Crowd-Sourcing with Web 2.0 Functionalities

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    Crowd-sourcing appears more promising with Web 2.0 functionality and businesses have started using it for a wide range of activities, that would be better completed by a crowd rather than any specific pool of knowledge workers. However, relatively little is known about how a business can leverage on collective intelligence and capture the user- generated value for competitive advantage. This empirical study uses the principle of interpretive field research to validate the case findings with a descriptive multiple case study methodology. An extended theoretical framework to identify the important considerations at strategic and functional levels for the effective use of crowd-sourcing is proposed. The analytic framework uses five Business Strategy Components: Vision and Strategy, Human Capital, Infrastructure, Linkage and Trust, and External Environment. It also uses four Web 2.0 Functional Components: Social Networking, Interaction Orientation, Customization & Personalization, and User- added Value. By using these components as analytic lenses, the case research examines how successful e-commerce firms may deploy Web 2.0 functionalities for effective use of crowd-sourcing. Prioritization of these functional considerations might be favorable in some cases for the best fit of situations and limitations. In conclusion, it is important that the alignment between strategy and functional components is maintained

    Impact of pulsed plasma beam on the thermal erosion and the surface structure of graphite

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    Among materials prospective as plasmaface materials for first wall of fusion reactor a priority is given to the materials with low atomic number, high threshold for physical sputtering, high thermal conductivity, low chemical activity to hydrogen, high thermal resistance and melting point. According to modern point of view, preferred plasma-face materials for tokamaks and future Generation IV reactors should be based on the carbon, beryllium and tungsten. Tungsten is one of the most promising materials for protection of tokamaks diverter plates

    Hypermetabolism and Coronavirus Disease 2019

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    A natural histone H2A variant lacking the Bub1 phosphorylation site and regulated depletion of centromeric histone CENP-A foster evolvability in Candida albicans.

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    Eukaryotes have evolved elaborate mechanisms to ensure that chromosomes segregate with high fidelity during mitosis and meiosis, and yet specific aneuploidies can be adaptive during environmental stress. Here, we identify a chromatin-based system required for inducible aneuploidy in a human pathogen. Candida albicans utilizes chromosome missegregation to acquire tolerance to antifungal drugs and for nonmeiotic ploidy reduction after mating. We discovered that the ancestor of C. albicans and 2 related pathogens evolved a variant of histone 2A (H2A) that lacks the conserved phosphorylation site for kinetochore-associated Bub1 kinase, a key regulator of chromosome segregation. Using engineered strains, we show that the relative gene dosage of this variant versus canonical H2A controls the fidelity of chromosome segregation and the rate of acquisition of tolerance to antifungal drugs via aneuploidy. Furthermore, whole-genome chromatin precipitation analysis reveals that Centromere Protein A/ Centromeric Histone H3-like Protein (CENP-A/Cse4), a centromeric histone H3 variant that forms the platform of the eukaryotic kinetochore, is depleted from tetraploid-mating products relative to diploid parents and is virtually eliminated from cells exposed to aneuploidy-promoting cues. We conclude that genetically programmed and environmentally induced changes in chromatin can confer the capacity for enhanced evolvability via chromosome missegregation

    Post impact evaluation of an E-learning cross-infection control CD-ROM provided to all general dental practitioners in England

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    Aim To carry out a post-impact evaluation of a cross-infection control CD-ROM, developed for NHS dental teams as a continuing professional development e-learning tool. The program was commissioned by the Department of Health and developed by a project team through the UK Committee of Postgraduate Dental Deans. The Dental Practice Boardhad originally sent one copy of the CD-ROM to each dental practice in England in 2004. Method A quantitative statistical analysis of the results of 326 online respondents to the learning package and a survey of 118 dental practitioners drawn from the Dental Practice Board database. Results Practitioners felt the CD-ROM in this instance was well designed and appropriate for their needs. It is inclusive and accessible to a wide range of dental professionals including nurses and hygienists. Conclusions This form of continuing professional development is popular with dental practitioners, although it should not be the only form of continuing professional development available. However, whilst the project was generally regarded as successful, there were problems with the distribution of the CD-ROM. This suggests that anonline resource should be made available in the future

    Design of a structurally optimized bioinspired structural arrangement of а polymer composite regional aircraft tail fin

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    Aircraft frame elements are highly responsible elements. They are subject to stringent requirements for strength, stability, resource. Often these requirements contradict each other, especially if it is necessary to ensure the minimum mass of the product. However, it is necessary to improve the characteristics of aircraft. Nevertheless, the optimization of the frame has almost exhausted itself. The power frame consists of longitudinal and transverse elements. It is possible to improve the characteristics of structural arrangement by using polymer composite materials based on glass and carbon fibers. This will improve the design characteristics due to high specific properties. In addition, one of the directions is the development of new bioinspired structural layout based on natural analogues. The work is devoted to the actual task of searching and choosing new structural arrangement for the aircraft tail. The paper considers five variants of structural layout, including the classical original design. The advantage of the bioinspired variant in terms of mass and displacement is shown
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