Dublin City University

About: Dublin City University is a education organization based out in Dublin, Ireland. It is known for research contribution in the topics: Context (language use) & Machine translation. The organization has 5904 authors who have published 17178 publications receiving 389376 citations. The organization is also known as: National Institute for Higher Education, Dublin & DCU.

Characterisation of porosity and sensor response times of sol–gel-derived thin films for oxygen sensor applications

Abstract: In recent years, sol–gel-derived films have played a significant role in optical sensor development. This paper focuses on the characterisation of oxygen-sensitive tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS)-based films. Film porosity and sensor response times are reported for a range of films fabricated under different conditions. Porosity data are correlated with predicted film behaviour and also with previous characterisation studies. Oxygen diffusion coefficients are estimated from the response times. The enhanced diffusion coefficient of MTEOS films compared to TEOS films is discussed in terms of the relative oxygen solubility of the films. Comparisons are made with data for oxygen-sensitive polymer films, indicating an enhanced solubility for sol–gel films compared with typical polymer films.

Microglial P2X4R-evoked pain hypersensitivity is sexually dimorphic in rats.

Abstract: Microglia-neuron signalling in the spinal cord is a key mediator of mechanical allodynia caused by peripheral nerve injury. We recently reported sex differences in microglia in pain signalling in mice: spinal mechanisms underlying nerve injury-induced allodynia are microglial dependent in male but not female mice. Whether this sex difference in pain hypersensitivity mechanisms is conserved in other species is unknown. Here, we show that in rats, the spinal mechanisms of nerve injury-induced hypersensitivity in males differ from those in females, with microglial P2X4 receptors (P2X4Rs) being a key point of divergence. In rats, nerve injury produced comparable allodynia and reactive microgliosis in both sexes. However, inhibiting microglia in the spinal cord reversed allodynia in male rats but not female rats. In addition, pharmacological blockade of P2X4Rs, by an intrathecally administered antagonist, attenuated pain hypersensitivity in male rats only. Consistent with the behavioural findings, nerve injury increased cell surface expression and function of P2X4Rs in acutely isolated spinal microglia from male rats but not from female rats. Moreover, in microglia cultured from male rats, but not in those from female rats, stimulating P2X4Rs drove intracellular signalling through p38 mitogen-activated protein kinase. Furthermore, chromatin immunoprecipitation-qPCR revealed that the transcription factor IRF5 differentially binds to the P2rx4 promoter region in female rats vs male rats. Finally, mechanical allodynia was produced in otherwise naive rats by intrathecally administering P2X4R-stimulated microglia from male rats but not those from female rats. Together, our findings demonstrate the existence of sexually dimorphic pain signalling in rats, suggesting that this sex difference is evolutionarily conserved, at least across rodent species.

Barriers and facilitators to the access to and use of formal dementia care: Findings of a focus group study with people with dementia, informal carers and health and social care professionals in eight European countries

Abstract: People with dementia and informal carers often access formal care late in the process of dementia. The barriers and facilitators to service use from the perspectives of different stakeholders involved are not well understood. Thus, we aimed to explore the barriers and facilitators of access to and utilisation of formal care from the perspectives of people with dementia, their informal carers and health and social care professionals. Focus groups with people with dementia, informal carers and professionals were conducted in eight European countries. Recruitment targeted people with dementia, informal carers with experience of formal care and professionals involved in providing (access to) formal care. Qualitative content analysis using open coding was used on a national level. Cross-national synthesis was based on the translated national reports. Overall, 55 focus groups with 261 participants were conducted, involving 51 people with dementia, 96 informal carers and 114 professionals. Sixteen categories describing barriers and facilitators were identified, referring to three global themes: Aspects related to 1) individuals involved, 2) the system or 3) overarching aspects. The attitudes and beliefs of people with dementia and their carers may have a major impact, and they often serve as barriers. Formal care was perceived as a threat to the individual independence of people with dementia and was thus avoided as long as possible. A healthcare professional serving as a constant key contact person could be an essential facilitator to overcome these barriers. Contact should be initiated proactively, as early as possible, and a trusting and consistent relationship needs to be established. Beyond that, the findings largely confirm former research and show that barriers to accessing and using formal care still exist across Europe despite a number of national and European initiatives. Further investigations are needed to elaborate how the concept of a key contact person could be integrated with existing case management approaches and how the independence and autonomy of people with dementia can be strengthened when formal care needs to be accessed and used. These may be meaningful facilitators regarding enhanced access to formal care for people with dementia and their families.

Retarding field analyzer for ion energy distribution measurements at a radio-frequency biased electrode

Abstract: A retarding field energy analyzer designed to measure ion energy distributions impacting a radio-frequency biased electrode in a plasma discharge is examined. The analyzer is compact so that the need for differential pumping is avoided. The analyzer is designed to sit on the electrode surface, in place of the substrate, and the signal cables are fed out through the reactor side port. This prevents the need for modifications to the rf electrode—as is normally the case for analyzers built into such electrodes. The capabilities of the analyzer are demonstrated through experiments with various electrode bias conditions in an inductively coupled plasma reactor. The electrode is initially grounded and the measured distributions are validated with the Langmuir probe measurements of the plasma potential. Ion energy distributions are then given for various rf bias voltage levels, discharge pressures, rf bias frequencies—500kHzto30MHz, and rf bias waveforms—sinusoidal, square, and dual frequency.