307 research outputs found
The Present Position & Future of the Manganese Industry with Special Reference to Indian Resources
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
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
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
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
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
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
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
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
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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