Revascularization and tissue regeneration of an empty root canal space is enhanced by a direct blood supply and stem cells

Background Regenerative endodontics is an innovative treatment concept aiming to regenerate pulp, dentin and root structures. In the diseased or necrotic tooth, the limitation in vascular supply renders successful tissue regeneration/generation in a whole tooth challenging. The aim of this study is to evaluate the ability of vascularized tissue to develop within a pulpless tooth using tissue engineering techniques. Materials and methods A pulpless tooth chamber, filled with collagen I gel containing isolated rat dental pulp cells (DPC) and angiogenic growth factors, was placed into a hole created in the femoral cortex or into its own tooth socket, respectively. The gross, histological and biochemical characteristics of the de novo tissue were evaluated at 4 and 8weeks post-transplantation. Results Tooth revascularization and tissue generation was observed only in the femur group, confirming the important role of vascular supply in tissue regeneration. The addition of cells and growth factors significantly promoted connective tissue production in the tooth chamber. Conclusion Successful revascularization and tissue regeneration in this model demonstrate the importance of a direct vascular supply and the advantages of a stem cell approach. © 2012 John Wiley & Sons A/S.

Assessing resilience of water supply systems under the impacts of climate change

This project was a step forward in developing the scientific basis for a methodology to assess the resilience of water supply systems under the impacts of climate change. The improved measure of resilience developed in this project provides an approach to assess the ability of water supply systems to absorb the pressure due changing climate while sustaining supply, and their speed of recovery in case of failure. The approach developed can be applied to any generic water supply system.

When supply does not meet demand-ER stress and plant programmed cell death

The endoplasmic reticulum (ER) is the central organelle in the eukaryotic secretory pathway. The ER functions in protein synthesis and maturation and is crucial for proper maintenance of cellular homeostasis and adaptation to adverse environments. Acting as a cellular sentinel, the ER is exquisitely sensitive to changing environments principally via the ER quality control machinery. When perturbed, ER-stress triggers a tightly regulated and highly conserved, signal transduction pathway known as the unfolded protein response (UPR) that prevents the dangerous accumulation of unfolded/misfolded proteins. In situations where excessive UPR activity surpasses threshold levels, cells deteriorate and eventually trigger programmed cell death (PCD) as a way for the organism to cope with dysfunctional or toxic signals. The programmed cell death that results from excessive ER stress in mammalian systems contributes to several important diseases including hypoxia, neurodegeneration, and diabetes. Importantly, hallmark features and markers of cell death that are associated with ER stress in mammals are also found in plants. In particular, there is a common, conserved set of chaperones that modulate ER cell death signaling. Here we review the elements of plant cell death responses to ER stress and note that an increasing number of plant-pathogen interactions are being identified in which the host ER is targeted by plant pathogens to establish compatibility.

Semiparametric estimates of the supply and demand effects of disability on labor force participation

This paper modifies and uses the semiparametric methods of Ichimura and Lee (1991) on standard cross-section data to decompose the effect of disability on labor force participation into a demand and a supply effect. It shows that straightforward use of Ichimura and Lee leads to meaningless results while imposing monotonicity on the unknown function leads to substantial results. The paper finds that supply effects dominate the demand effects of disability.

Supply, demand, and equilibrium in the market for CRNAs

This study determined the current trends in supply, demand, and equilibrium (ie, the level of employment where supply equals demand) in the market for Certified Registered Nurse Anesthetists (CRNAs). It also forecasts future needs for CRNAs given different possible scenarios. The impact of the current availability of CRNAs, projected retirements, and changes in the demand for surgeries are considered in relation to CRNAs needed for the future. The study used data from many sources to estimate models associated with the supply and demand for CRNAs and the relationship to relevant community and policy characteristics such as per capita income of the community and managed care. These models were used to forecast changes in surgeries and in the supply of CRNAs in the future. The supply of CRNAs has increased in recent years, stimulated by shortages of CRNAs and subsequent increases in the number of CRNAs trained. However, the increases have not offset the number of retiring CRNAs to maintain a constant age in the CRNA population. The average age will continue to increase for CRNAs in the near future despite increases in CRNAs trained. The supply of CRNAs in relation to surgeries will increase in the near future.

Tuning of magnetization in vertical graphenes by plasma-enabled chemical conversion of organic precursors with different oxygen content

Different magnetization in vertical graphenes fabricated by plasma-enabled chemical conversion of organic precursors with various oxygen atom contents and bonding energies was achieved. The graphenes grown from fat-like precursors exhibit magnetization up to 8 emu g−1, whereas the use of sugar-containing precursors results in much lower numbers. A relatively high Curie temperature exceeding 600 K was also demonstrated.

3-Orders-of-magnitude density control of single-walled carbon nanotube networks by maximizing catalyst activation and dosing carbon supply

Tailoring the density of random single-walled carbon nanotube (SWCNT) networks is of paramount importance for various applications, yet it remains a major challenge due to the insufficient catalyst activation in most growth processes. Here we report on a simple and effective method to maximise the number of active catalyst nanoparticles using catalytic chemical vapor deposition (CCVD). By modulating short pulses of acetylene into a methane-based CCVD growth process, the density of SWCNTs is dramatically increased by up to three orders of magnitude without increasing the catalyst density and degrading the nanotube quality. In the framework of a vapor-liquid-solid model, we attribute the enhanced growth to the high dissociation rate of acetylene at high temperatures at the nucleation stage, which can be effective in both supersaturating the larger catalyst nanoparticles and overcoming the nanotube nucleation energy barrier of the smaller catalyst nanoparticles. These results are highly relevant to numerous applications of random SWCNT networks in next-generation energy, sensing and biomedical devices. © 2011 The Royal Society of Chemistry.

Control of morphology and nucleation density of iron oxide nanostructures by electric conditions on iron surfaces exposed to reactive oxygen plasmas

The possibility to control the morphology and nucleation density of quasi-one-dimensional, single-crystalline α -Fe2 O3 nanostructures by varying the electric potential of iron surfaces exposed to reactive oxygen plasmas is demonstrated experimentally. A systematic increase in the oxygen ion flux through rf biasing of otherwise floating substrates and then an additional increase of the ion/neutral density resulted in remarkable structural transformations of straight nanoneedles into nanowires with controlled tapering/aspect ratio and also in larger nucleation densities. Multiscale numerical simulations relate the microscopic ion flux topographies to the nanostructure nucleation and morphological evolution. This approach is applicable to other metal-oxide nanostructures.

Reactive oxygen plasma-enabled synthesis of nanostructured CdO : tailoring nanostructures through plasma–surface interactions

Plasma-assisted synthesis of nanostructures is one of the most precise and effective approaches used in nanodevice fabrication. Here we report on the innovative approach of synthesizing nanostructured cadmium oxide films on Cd substrates using a reactive oxygen plasma-based process. Under certain conditions, the surface morphology features arrays of crystalline CdO nano/micropyramids. These nanostructures grow via unconventional plasma-assisted oxidation of a cadmium foil exposed to inductively coupled plasmas with a narrow range of process parameters. The growth of the CdO pyramidal nanostructures takes place in the solid-liquid-solid phase, with the rates determined by the interaction of plasma-produced oxygen atoms and ions with the surface. It is shown that the size of the pyramidal structures can be effectively controlled by the fluxes of oxygen atoms and ions impinging on the cadmium surface. The unique role of the reactive plasma environment in the controlled synthesis of CdO nanopyramidal structures is discussed as well.

Reactive Oxygen Species and Reactive Nitrogen Species in Epigenetic Modifications

For the normal homeostasis of a cell, there must be a balance between radical oxygen species/radical nitrogen species (ROS/RNS) production and the neutralization of these species by antioxidant scavenging. In times of stress, this balance is not maintained, and the result is oxidative stress. This stress can affect many pathways in the body and result in pathological consequences. Recent evidence suggests that ROS/RNS can affect the epigenetic regulation of genes by affecting the function of histone and DNA modifying enzymes, thus affecting phenotypic changes within the cellular environment. In the following chapter, we provide a broad overview of how oxidative stress induced by ROS/RNS can affect epigenetics, and using lung disease as our model we link the connection between these processes.

The use of supply chain management to reduce delays as result of pre-construction deficiencies in Malaysian public sector construction projects

This thesis examined the delay causes of Malaysian public sector projects. Using a systematic approach, the researcher identified the main delay factors and categorised them into pathogens. The pathogens were matched with beneficial Supply Chain Management (SCM) tools and developed into a holistic SCM framework to facilitate improvements in Malaysian public sector projects. The researcher concluded that SCM is the potential saviour for the delay dilemma and that it is necessary for the Malaysian government to initiate the revolutionary practice.

Calculation of the oxygen isotope discrimination factor for studying plant respiration

Measurement of discrimination against 18O during dark respiration in plants is currently accepted as the only reliable method of estimating the partitioning of electrons between the cytochrome and alternative pathways. In this paper, we review the theory of the technique and its application to a gas-phase system. We extend it to include sampling effects and show that the isotope discrimination factor, D, is calculated as –dln(1 + δ)/dlnO*, where δ is isotopic composition of the substrate oxygen and O*=[O2]/[N2] in a closed chamber containing tissue respiring in the dark. It is not necessary to integrate the expression but, if the integrated form is used, the resultant regression should not be constrained through the origin. This is important since any error in D will have significant effects on the estimation of the flux of electrons through the two pathways.

Regulating supply chains to improve health and safety

The fragmentation of previously integrated systems of production and service delivery has been an important feature of organisational restructuring over the last three decades. This article highlights the adverse implications of this development for the health and safety of workers, examines the extent to which current British health and safety law provides an adequate framework for addressing these outcomes and explores whether its capacity to do so could be enhanced through the introduction of new statutory provisions on the regulation of supply chains. It concludes that, in terms of both structure and operation, the present framework of law is problematic. It further argues that recent international initiatives show that it is feasible to develop such statutory provisions and that existing evidence suggests that provisions of this type could usefully be introduced in respect of a number of areas of activity where the implications of the externalisation of production and service delivery seem particularly problematic.

Regulating supply-chains to address the occupational health and safety problems associated with precarious employment: The case of home-based clothing workers in Australia

Over the past 20 years the labour market, workforce and work organisation of most if not all industrialised countries have been significantly refashioned by the increased use of more flexible work arrangements, variously labelled as precarious employment or contingent work. There is now a substantial and growing body of international evidence that many of these arrangements are associated with a significant deterioration in occupational health and safety (OHS), using a range of measures such as injury rates, disease, hazard exposures and work-related stress. Moreover, there is an emerging body of evidence that these arrangements pose particular problems for conventional regulatory regimes. Recognition of these problems has aroused the concern of policy makers - especially in Europe, North America and Australia - and a number of responses have been adopted in terms of modifying legislation, producing new guidance material and codes of practice and revised enforcement practices. This article describes one such in itiative in Australia with regard to home-based clothing workers. The regulatory strategy developed in one Australian jurisdiction (and now being ‘exported’ into others) seeks to counter this process via contractual tracking mechanisms to follow the work, tie in liability and shift overarching legal responsibility to the top of the supply chain. The process also entails the integration of minimum standards relating to wages, hours and working conditions; OHS and access to workers’ compensation. While home-based clothing manufacture represents a very old type of ‘flexible’ work arrangement, it is one that regulators have found especially difficult to address. Further, the elaborate multi-tiered subcont racting and diffuse work locations found in this industry are also characteristic of newer forms of contingent work in other industries (such as some telework) and the regulatory challenges they pose (such as the tendency of elaborate supply chains to attenuate and fracture statutory responsibilities, at least in terms of the attitudes and behaviour of those involved).

Supply chain regulation to protect the occupational health and safety of vulnerable workers

The last two decades have witnessed a fragmentation of previously integrated systems of production and service delivery with the advent of boundary-less, networked and porous organisational forms. This trend has been associated with the growth of outsourcing and increased use of contingent workers. One consequence of these changes is the development of production/service delivery systems based on complex national and international networks of multi-tiered subcontracting increasingly labelled as supply chains. A growing body of research indicates that subcontracting and contingent work arrangements affect design and decision-making processes in ways that can seriously undermine occupational health and safety (OHS). Elaborate supply chains also present a regulatory challenge because legal responsibility for OHS is diffused amongst a wider array of parties, targeting key decision-makers is more difficult, and government agencies encounter greater logistical difficulties trying to safeguard contingent workers. In a number of industries these problems have prompted new forms of regulatory intervention, including mechanisms for sheeting legal responsibility to the top of supply chains, contractual tracking devices and increasing industry, union and community involvement in enforcement. After describing the problems just alluded to this paper examines recent efforts to regulate supply chains to safeguard OHS in the United Kingdom and Australia.