Highly sensitive electrochemiluminescent nanobiosensor for the detection of palytoxin

Marine toxins appear to be increasing in many areas of the world. An emerging problem in the Mediterranean Sea is represented by palytoxin (PlTX), one of the most potent marine toxins, frequently detected in seafood. Due to the high potential for human toxicity of PlTX, there is a strong and urgent need for sensitive methods toward its detection and quantification. We have developed an ultrasensitive electrochemiluminescence-based sensor for the detection of PlTX, taking advantage of the specificity provided by anti-PlTX antibodies, the good conductive properties of carbon nanotubes, and the excellent sensitivity achieved by a luminescence-based transducer. The sensor was able to produce a concentration-dependent light signal, allowing PlTX quantification in mussels, with a limit of quantification (LOQ = 2.2 μg/kg of mussel meat) more than 2 orders of magnitude more sensitive than that of the commonly used detection techniques, such as LC-MS/MS.

Decision-making criteria among national policymakers in five countries: a discrete choice experiment eliciting relative preferences for equity and efficiency

BACKGROUND

Worldwide, there is a need for formalization of the priority setting processes in health. Recent research has used the term multicriteria decision analysis for methods that systematically include preferences for both equity and efficiency. The present study compares decision-makers' preferences at the country level for a set of equity and efficiency criteria according to a multicriteria decision analysis framework.

METHODS

Discrete choice experiments were conducted for Brazil, Cuba, Nepal, Norway, and Uganda. By using standardized methods, we elicited preferences for intervention attributes using a individual choice questionnaire. A multinomial logistic regression was applied to estimate the coefficients for all single-policy criteria, per country. Attributes were assigned to an equity group or to an efficiency group. After testing for scale variance, predicted probabilities for interventions with both types of attributes were compared across countries.

RESULTS

The Norway and Nepal groups showed considerable preferences for efficiency criteria over equity criteria with percent change in respective predicted sum probabilities of [10%, -84%] and [6%, -79%]. Brazil and Uganda also showed preference for the efficiency criteria though less convincingly ([-34%, -93%], [-18%, -63%], respectively). The Cuban group showed the strongest preferences with equity attributes dominating efficiency ([-52%, 213%]).

CONCLUSIONS

Group preferences of policymakers show explicit but varying trade-offs of efficiency and equity in these diverse settings. This multicriteria decision analysis approach, using discrete choice experiments, indicates that systematic setting of health priorities is possible across a variety of countries. It may be a valuable tool to guide health reform initiatives.

Health care priority setting in Norway a multicriteria decision analysis

Background

Priority setting in population health is increasingly based on explicitly formulated values. The Patients Rights Act of the Norwegian tax-based health service guaranties all citizens health care in case of a severe illness, a proven health benefit, and proportionality between need and treatment. This study compares the values of the country's health policy makers with these three official principles.

Methods

In total 34 policy makers participated in a discrete choice experiment, weighting the relative value of six policy criteria. We used multi-variate logistic regression with selection as dependent valuable to derive odds ratios for each criterion. Next, we constructed a composite league table - based on the sum score for the probability of selection - to rank potential interventions in five major disease areas.

Results

The group considered cost effectiveness, large individual benefits and severity of disease as the most important criteria in decision making. Priority interventions are those related to cardiovascular diseases and respiratory diseases. Less attractive interventions rank those related to mental health.

Conclusions

Norwegian policy makers' values are in agreement with principles formulated in national health laws. Multi-criteria decision approaches may provide a tool to support explicit allocation decisions.

Large conductance modulation of gold thin films by huge charge injection via electrochemical gating

By using an electrochemical gating technique with a new combination of polymer and electrolyte, we were able to inject surface charge densities n(2D) as high as 3.5×10(15)  e/cm(2) in gold films and to observe large relative variations in the film resistance, ΔR/R', up to 10% at low temperature. ΔR/R' is a linear function of n(2D)-as expected within a free-electron model-if the film is thick enough (≥25  nm); otherwise, a tendency to saturation due to size effects is observed. The application of this technique to 2D materials might allow extending the field-effect experiments to a range of charge doping where large conductance modulations and, in some cases, even the occurrence of superconductivity are expected.

Providing and financing aged care in Australia

This article focuses on the provision and financing of aged care in Australia. Demand for aged care will increase substantially as a result of population aging, with the number of Australians aged 85 and over projected to increase from 400,000 in 2010 to over 1.8 million in 2051. Meeting this demand will greatly strain the current system, and makes it important to exploit opportunities for increased efficiency. A move to greater beneficiary co-payments is also likely, though its extent may depend on whether aged care insurance and other forms of pre-payment can develop.

Toward Quantum-dot Cellular Automata units: thiolated-carbazole linked bisferrocenes

Quantum-dot Cellular Automata (QCA) exploit quantum confinement, tunneling and electrostatic interaction for transistorless digital computing. Implementation at the molecular scale requires carefully tailored units which must obey several structural and functional constraints, ranging from the capability to confine charge efficiently on different 'quantum-dot centers'-in order to sharply encode the Boolean states-up to the possibility of having their state blanked out upon application of an external signal. In addition, the molecular units must preserve their geometry in the solid state, to interact electrostatically in a controlled way. Here, we present a novel class of organometallic molecules, 6-3,6-bis(1-ethylferrocen)-9H-carbazol-9-yl-6-hexan-1-thiols, which are engineered to satisfy all such crucial requirements at once, as confirmed by electrochemistry and scanning tunneling microscopy measurements, and first principles density functional calculations.

Raman doping profiles of polyelectrolyte SWNTs in solution

We present a resonance Raman study of electrochemical charge transfer doping on polyelectrolyte single-walled carbon nanotubes (SWNTs) in solution. Changes in the intensity of the radial breathing modes of well-identified SWNTs are measured as a function of the electrochemical potential. The intensity is maximum when the nanotubes are neutral. Unexpectedly, the Raman signal decreases as soon as charges are transferred to the nanotubes, leading to intensity profiles that are triangular for metallic and trapezoidal for semiconducting nanotubes. A key result is that the width in energy of the plateaus for the semiconducting nanotubes is roughly equal to the optical gap (rather than the free carrier gap). While these experiments can be used to estimate the energy levels of individual nanotubes, strong dynamical screening appears to dominate in individual SWNT polyelectrolytes so that only screened energy levels are being probed.

Electrochemical study of hydrogen peroxide formation in isolated mitochondria

Mitochondrial respiration generates reactive oxygen species that are involved in physiological and pathological processes. The majority of methods, with exception of electron paramagnetic resonance, used to evaluate the identity, the rate and the conditions of the reactive oxygen species produced by mitochondria, are mainly based on oxidation sensitive markers. Following latest electrochemical methodology, we implemented a novel electrochemical assay for the investigation of aerobic metabolism in preparations of isolated mitochondria through simultaneous measurement of O₂ consumption and reactive species production. This electrochemical assay reveals active H₂O₂ production by respiring mouse liver mitochondria, and shows that ATP synthase activation and moderate depolarization increase the rate of H₂O₂ formation, suggesting that ATP synthesizing (state 3) mitochondria might contribute to oxidative stress or signaling.

Graphene solutions

Thermodynamics drive the sonication-free spontaneous dissolution of a KC₈ graphite intercalation compound in N-methyl-pyrrolidinone and subsequent obtention of graphene solutions at 0.7 mg ml⁻¹. Reduction potential of graphene has been measured at +22 mV vs. SCE.

The global financial crisis and Australian general practice

Objective. To explore the potential effects of the global financial crisis (GFC) on the market for general practitioner (GP) services in Australia. Design. We estimate the impact of changes in unemployment rates on demand for GP services and the impact of lost asset values on GP retirement plans and work patterns. Combining these supply and demand effects, we estimate the potential effect of the GFC on the market for GP services under various scenarios. Results. If deferral of retirement increases GP availability by 2%, and historic trends to reduce GP working hours are halved, at the current level of ~5.2% unemployment average fees would decline by $0.23 per GP consultation and volumes of GP services would rise by 2.53% with almost no change in average GP gross earnings over what would otherwise have occurred. With 8.5% unemployment, as initially predicted by Treasury, GP fees would increase by $0.91 and GP income by nearly 3%. Conclusions. The GFC is likely to increase activity in the GP market and potentially to reduce fee levels relative to the pre-GFC trends. Net effects on average GP incomes are likely to be small at current unemployment levels. What is known about the topic? Although the broad directions of the impact of the global financial crisis on the demand for and supply of GP services have been the subject of public discussion, the overall impact on the GP market has not been formally assessed. What does this paper add? Drawing on existing supply and demand models, we estimate the likely effect of the global financial crisis on GP activity levels, GP earnings, and the fees to be faced by patients. What are the implications for practitioners? Practitioners on average are likely to work harder to recover losses in the investments they have made for their retirements. They may face lower fees than would have been the case due to the increasing supply of GPs as some defer retirement, but average incomes are likely to be minimally affected.

Risk equalisation in voluntary health insurance markets: A three country comparison

The paper summarises the conclusions for health policy from the experience of three countries who have introduced risk equalisation subsidies, in their voluntary health insurance (VHI) markets. The countries chosen are Australia, Ireland and South Africa. All of these countries have developed VHI markets and have progressed towards introducing risk equalisation. The objective of such subsidies is primarily to make VHI affordable while encouraging efficiency in health care production. The paper presents a conceptual framework to understand and compare risk equalisation subsidies in VHI markets. The paper outlines how such subsidies are organised in each of the countries and identifies problems that arise in their implementation. We conclude that the objectives of risk equalisation, in VHI markets are no different to those in countries with mandatory insurance systems. We find that the introduction of risk equalisation subsidies is complex and that countries seeking to introduce risk equalisation in VHI markets must carefully consider how such subsidies advance their overall health policy goals. Furthermore, we conclude that such subsidies must be structured correctly as otherwise incentives exist for risk selection which may threaten affordability and efficiency. Our overall conclusion is that also in voluntary health insurance markets risk equalisation has a role in meeting the related public policy objectives of risk solidarity and affordability, and without it these objectives are severely undermined.

Risk equalisation and voluntary health insurance markets: The case of Australia

In April 2007, Australia introduced a risk equalisation (RE) scheme (de facto a claims equalisation scheme), which replaced an extant reinsurance scheme that had operated since 1976. This scheme is one of a number of policy measures that the Australian Government has instituted to support the voluntary private health insurance (PHI) market which is subject to mandatory community rating and the attendant problem of selection. The latter has been a persistent concern in the Australian PHI market since the introduction of Australia's universal, compulsory national health insurance scheme Medicare. This paper presents a brief overview of Australia's health care financing arrangements and, in particular, focuses on the history, structure and functioning of the RE scheme. It provides an exposition of the operation of the scheme and empirical evidence of the scheme's effects in its first full year of operation, 2007-08. The paper makes three contributions: first, it provides the only detailed overview of the functioning of the Australian RE scheme published to date; second, it presents the first empirical measures of the scheme's operation at the level of the 38 individual PHI funds; and third, it describes the systematic differences in the scheme's operation with respect to large and small funds. Thus, this paper provides a number of insights into the operation and outcomes of the Australian RE scheme following its first year of operation.