307 research outputs found

    The Present Position & Future of the Manganese Industry with Special Reference to Indian Resources

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    Statistics are quoted which show that manganese ore production is tied directly with world steel production, but fluctuations in steel output affect Indian ore production much more than production from other sources. A steady and increased demand for manganese is likely to result from research and development into: 1'. Improvement of quality of the end product and concentration of the manganese metal content to reduce freight charges. 2. The technical advantages of manganese as an alloying constituent in steel and the replacement of the more expensive alloying constituents, such as nickel, by manganese in alloy steels. 3. The use of manganese in non-ferrous alloys with particular reference to alloying constituent which increase the stability of the ductile gammaphase of manganese. 4. Manganese as a coating to provide corrosion and abrasion resistance to steel and non-ferrous metals, particularly in those fields in which zinc and nickel are at present used. The formation of a research and development organization to promote the use of manganese is advocated

    Nanoparticle-infused-biodegradable-microneedles as drug-delivery systems: preparation and characterisation

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    For almost two decades, scientists were exploring the use of nanoparticles as drug vesicles capable of protecting their cargo and deliver it to the target site while evading detection by the body. However, their translation to clinical use has been slower than expected. To a large degree, this is due to the difficulty to formulate the nanomaterial into a usable form, in which they retain their unique, size-dependent properties without aggregating into a bulk material. In this work, we describe a simple methodology for synthesising novel biodegradable microneedle systems infused with silica nanoparticles (SiNP). SiNP were doped with small library of model anti-cancer drugs or drug surrogates before being characterised and encapsulated into biodegradable microneedles. Detailed preparation and characterisation methods for both the nanoparticles and the microneedles-infused with nanoparticles is presented here. We demonstrated the distribution of the nanoparticles within the microneedle matrix in a uniform, un-aggregated form, which enabled the release of the nanoparticles in a sustained manner. Formulating nanomaterial into biodegradable, hydrogel-like microneedles showed to be effective in preserving their colloidal properties, whilst simultaneously enabling the transdermal delivery of the nanomaterial into the body. Although the concepts of nanoparticles and biodegradable microneedles have been researched individually, the combination of the two, to the best of our knowledge, offers a new pathway to nanomedicine-related applications

    Nanomedicines and microneedles: a guide to their analysis and application

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    The fast-advancing progress in the research of nanomedicine and microneedles application in the past two decades have suggested that the combination of the two concepts could help to overcome some of the challenges we are facing in healthcare. These include poor patient compliance with medication and the lack of appropriate administration forms that enable the optimal dose to reach the target site. Nanoparticles as drug vesicles can protect their cargo and deliver it to the target site, while evading the body’s defence mechanisms. Unfortunately, despite intense research on nanomedicine in the past 20 years, we still haven’t answered some crucial questions, e.g. about their colloidal stability in solution and their optimal formulation, which makes the translation of this exciting technology from lab bench to a viable product difficult. Dissolvable microneedles could be an effective way to maintain and stabilise nano-sized formulations, whilst enhancing the ability of nanoparticles to penetrate the stratum corneum barrier. Both concepts have been individually investigated fairly well and many analytical techniques for tracking the fate of the nanomaterial with their precious cargo, both in vitro and in vivo, have been established. Yet, to the best of our knowledge, a comprehensive overview of the analytical tools encompassing the concepts of microneedles and nanoparticles with specific and successful examples is missing. In this review, we have attempted to briefly analyse the challenges associated with nanomedicine itself but crucially, we provide an easy-to-navigate scheme of methods, suitable for characterisation and imaging the physico-chemical properties of the material matrix

    More Holography from Conformal Field Theory

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    We extend the work of [4] to support the conjecture that any conformal field theory with a large N expansion and a large gap in the spectrum of anomalous dimensions has a local bulk dual. We count to O(1/N^2) the solutions to the crossing constraints in conformal field theory for a completely general scalar four-point function and show that, to this order, the counting matches the number of independent interactions in a general scalar theory on Anti-de Sitter space. We introduce parity odd conformal blocks for this purpose.Comment: 19 page

    Proactivity with image in mind: How employee and manager characteristics affect evaluations of proactive behaviours

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    This paper investigates image cost as a potential downside of proactivity. Drawing on attribution theory, we examine how people construct subjective evaluations of one manifestation of proactivity, feedback-seeking behaviour. Using a scenario methodology, we examined how employees' performance history, their manager's implicit person theory (IPT), and the frequency of their feedback-seeking affect how managers evaluate employees' feedback seeking. Results indicate that manager attribute average performers' feedback seeking significantly less to performance-enhancement motives than superior performers' seeking. Results further show that the frequency of feedback seeking and a manager's IPT interact in influencing managers' attributions for feedback seeking, with more entity oriented managers attributing frequent feedback seeking significantly more to impression-management motives than infrequent feedback requests. These results highlight the importance of not only the instrumental benefits of employee proactivity, but also its potential costs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79279/1/096317909X479529.pd

    Holography from Conformal Field Theory

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    The locality of bulk physics at distances below the AdS length is one of the remarkable aspects of AdS/CFT duality, and one of the least tested. It requires that the AdS radius be large compared to the Planck length and the string length. In the CFT this implies a large-N expansion and a gap in the spectum of anomalous dimensions. We conjecture that the implication also runs in the other direction, so that any CFT with a planar expansion and a large gap has a local bulk dual. For an abstract CFT we formulate the consistency conditions, most notably crossing symmetry, and show that the conjecture is true in a broad range of CFT's, to first nontrivial order in 1/N^2: any CFT with a gap and a planar expansion is generated via the AdS/CFT dictionary from a local bulk interaction. We establish this result by a counting argument on each side, and also investigate various properties of some explicit solutions.Comment: 49 pages. Minor corrections. Figure and references adde

    Nanoparticle-infused-biodegradable-microneedles as drug-delivery systems: preparation and characterisation

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    For almost two decades, scientists were exploring the use of nanoparticles as drug vesicles capable of protecting their cargo and deliver it to the target site while evading detection by the body. However, their translation to clinical use has been slower than expected. To a large degree, this is due to the difficulty to formulate the nanomaterial into a usable form, in which they retain their unique, size-dependent properties without aggregating into a bulk material. In this work, we describe a simple methodology for synthesising novel biodegradable microneedle systems infused with silica nanoparticles (SiNP). SiNP were doped with small library of model anti-cancer drugs or drug surrogates before being characterised and encapsulated into biodegradable microneedles. Detailed preparation and characterisation methods for both the nanoparticles and the microneedles-infused with nanoparticles is presented here. We demonstrated the distribution of the nanoparticles within the microneedle matrix in a uniform, un-aggregated form, which enabled the release of the nanoparticles in a sustained manner. Formulating nanomaterial into biodegradable, hydrogel-like microneedles showed to be effective in preserving their colloidal properties, whilst simultaneously enabling the transdermal delivery of the nanomaterial into the body. Although the concepts of nanoparticles and biodegradable microneedles have been researched individually, the combination of the two, to the best of our knowledge, offers a new pathway to nanomedicine-related applications

    Peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) restores carbapenem susceptibility to NDM-1-positive pathogens in vitro and in vivo

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    The objective of this study was to test the efficacy of an inhibitor of the New Delhi metallo-β- lactamase (NDM-1). Inhibiting expression of this type of antibiotic-resistance gene has the potential to restore antibiotic susceptibility in all bacteria carrying the gene.Methods: We have constructed a peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) that selectively inhibits the expression of NDM-1 and examined its ability to restore susceptibility to meropenem in vitro and in vivo.Results:In vitro, the PPMO reduced the MIC of meropenem for three different genera of pathogens that express NDM-1. In a murine model of lethal E. coli sepsis, the PPMO improved survival (92%) and reduced systemic bacterial burden when given concomitantly with meropenem.Conclusions: These data show that a PPMO can restore antibiotic susceptibility in vitro and in vivo and that the combination of PPMO and meropenem may have therapeutic potential against certain class B carbapenem- resistant infections in multiple genera of Gram-negative pathogens

    Perceived senior leadership opportunities in MNCs: The effect of social hierarchy and capital

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    Drawing on the structural perspective in organizational theory, this study develops a conceptual framework of the social hierarchy within the multinational corporation (MNC). We suggest that parent country nationals (PCNs), host country nationals (HCNs), and third country nationals (TCNs) occupy distinctively different positions in the social hierarchy, which are anchored in their differential control or access to various forms of capital or strategically valuable organizational resources. We further suggest that these positions affect employees’ perceptions of senior leadership opportunities, defined as the assessment of the extent to which nationality and location influence access to senior leadership opportunities. Using multilevel analysis of survey data from 2039 employees in seven MNCs, the study reveals two significant findings. First, HCNs and TCNs perceive that nationality and location influence access to senior leadership opportunities more than PCNs. Second, three moderating factors – gender, tenure, and education – increase the perception gaps between PCNs on the one hand and HCNs and TCNs on the other, although these results are inconsistent. These findings indicate that the structural position of PCNs, HCNs, and TCNs in the social hierarchy affect sense-making and perceptions of access to senior leadership opportunities
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