Design, fabrication and characterization of resonant waveguide grating based optical biosensors

The absence of rapid, low cost and highly sensitive biodetection platform has hindered the implementation of next generation cheap and early stage clinical or home based point-of-care diagnostics. Label-free optical biosensing with high sensitivity, throughput, compactness, and low cost, plays an important role to resolve these diagnostic challenges and pushes the detection limit down to single molecule. Optical nanostructures, specifically the resonant waveguide grating (RWG) and nano-ribbon cavity based biodetection are promising in this context. The main element of this dissertation is design, fabrication and characterization of RWG sensors for different spectral regions (e.g. visible, near infrared) for use in label-free optical biosensing and also to explore different RWG parameters to maximize sensitivity and increase detection accuracy. Design and fabrication of the waveguide embedded resonant nano-cavity are also studied. Multi-parametric analyses were done using customized optical simulator to understand the operational principle of these sensors and more important the relationship between the physical design parameters and sensor sensitivities. Silicon nitride (SixNy) is a useful waveguide material because of its wide transparency across the whole infrared, visible and part of UV spectrum, and comparatively higher refractive index than glass substrate. SixNy based RWGs on glass substrate are designed and fabricated applying both electron beam lithography and low cost nano-imprint lithography techniques. A Chromium hard mask aided nano-fabrication technique is developed for making very high aspect ratio optical nano-structure on glass substrate. An aspect ratio of 10 for very narrow (~60 nm wide) grating lines is achieved which is the highest presented so far. The fabricated RWG sensors are characterized for both bulk (183.3 nm/RIU) and surface sensitivity (0.21nm/nm-layer), and then used for successful detection of Immunoglobulin-G (IgG) antibodies and antigen (~1μg/ml) both in buffer and serum. Widely used optical biosensors like surface plasmon resonance and optical microcavities are limited in the separation of bulk response from the surface binding events which is crucial for ultralow biosensing application with thermal or other perturbations. A RWG based dual resonance approach is proposed and verified by controlled experiments for separating the response of bulk and surface sensitivity. The dual resonance approach gives sensitivity ratio of 9.4 whereas the competitive polarization based approach can offer only 2.5. The improved performance of the dual resonance approach would help reducing probability of false reading in precise bio-assay experiments where thermal variations are probable like portable diagnostics.

Diagnosing primary ciliary dyskinesia: an international patient perspective

Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterised by progressive sinopulmonary disease, with symptoms starting soon after birth. A European Respiratory Society (ERS) Task Force aims to address disparities in diagnostics across Europe by providing evidence-based clinical practice guidelines. We aimed to identify challenges faced by patients when referred for PCD diagnostic testing. A patient survey was developed by patient representatives and healthcare specialists to capture experience. Online versions of the survey were translated into nine languages and completed in 25 countries. Of the respondents (n=365), 74% were PCD-positive, 5% PCD-negative and 21% PCD-uncertain/inconclusive. We then interviewed 20 parents/patients. Transcripts were analysed thematically. 35% of respondents visited their doctor more than 40 times with PCD-related symptoms prior to diagnostic referral. Furthermore, the most prominent theme among interviewees was a lack of PCD awareness among medical practitioners and failure to take past history into account, leading to delayed diagnosis. Patients also highlighted the need for improved reporting of results and a solution to the “inconclusive” diagnostic status. These findings will be used to advise the ERS Task Force guidelines for diagnosing PCD, and should help stakeholders responsible for improving existing services and expanding provision for diagnosis of this rare disease.

Home birth in Ireland 1993-1997: a review of community midwifery practice

To date little is known about the practices of domiciliary midwives and the outcomes of home birth in Ireland. The purpose of this review is to provide some background information on the situation for women seeking a home birth and to document the outcomes of home births in Ireland between 1993 -1997. Design: Descriptive analysis of prospective data collected from domiciliary midwives regarding women who requested a home birth between 1993 and 1997. Participants: The questionnaire was distributed to 15 domiciliary midwives; this included all the domiciliary midwives known to the authors to be practising in Ireland at that time. Findings: During this period, 585 women planned to give birth in their home with the assistance of midwives, 500 women achieved this. The spontaneous vaginal delivery rate for women who commenced their labour at home was 96.9% (n = 554). These women gave birth without medications or other interventions. 544 (93%) of the women breastfed their babies and 538 (92%) were still breastfeeding at 6 weeks. This is the first review of domiciliary midwifery practice in Ireland in recent years. They obtained data from 11 independent midwives on 585 women who planned home births. Findings showed high rates of spontaneous vaginal delivery and breastfeeding. There were 500 babies born at home with three perinatal deaths, including one undiagnosed breech delivery, one infant with abnormal lungs on post-mortem and one infant with Potter's Syndrome who was stillborn.

Practice-based film education for children: teaching and learning for creativity, citizenship and participation

Practice-oriented film education aimed at children has been hailed for various reasons: at a personal level, as a means of providing tools for self-expression, for developing creativity and communication skills. And at a social level, it is argued that children must now become competent producers, in addition to critical consumers, of audiovisual content so they can take part in the global public sphere that is arguably emerging. This chapter discusses how the challenges posed by introducing children to filmmaking (i.e. digital video) are being met at three civil associations in Mexico: La Matatena AC, which seeks to enrich the children’s lives by means of the aesthetic experience filmmaking can bring them. Comunicaciòn Comunitaria, concerned with the impact filmmaking can have on the community, preserving cultural memory and enabling participation. And Juguemos a Grabar, with a focus on urban regeneration through the cultural industries.

Time-limited home-care reablement services for maintaining and improving the functional independence of older adults

Background: Reablement, also known as restorative care, is one possible approach to home-care services for older adults at risk of functional decline. Unlike traditional home-care services, reablement is frequently time-limited (usually six to 12 weeks) and aims to maximise independence by offering an intensive multidisciplinary, person-centred and goal-directed intervention. Objectives: To assess the effects of time-limited home-care reablement services (up to 12 weeks) for maintaining and improving the functional independence of older adults (aged 65 years or more) when compared to usual home-care or wait-list control group. Search methods: We searched the following databases with no language restrictions during April to June 2015: the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (OvidSP); Embase (OvidSP); PsycINFO (OvidSP); ERIC; Sociological Abstracts; ProQuest Dissertations and Theses; CINAHL (EBSCOhost); SIGLE (OpenGrey); AgeLine and Social Care Online. We also searched the reference lists of relevant studies and reviews as well as contacting authors in the field. Selection criteria: We included randomised controlled trials (RCTs), cluster randomised or quasi-randomised trials of time-limited reablement services for older adults (aged 65 years or more) delivered in their home; and incorporated a usual home-care or wait-list control group. Data collection and analysis: Two authors independently assessed studies for inclusion, extracted data, assessed the risk of bias of individual studies and considered quality of the evidence using GRADE. We contacted study authors for additional information where needed. Main results: Two studies, comparing reablement with usual home-care services with 811 participants, met our eligibility criteria for inclusion; we also identified three potentially eligible studies, but findings were not yet available. One included study was conducted in Western Australia with 750 participants (mean age 82.29 years). The second study was conducted in Norway (61 participants; mean age 79 years). We are very uncertain as to the effects of reablement compared with usual care as the evidence was of very low quality for all of the outcomes reported. The main findings were as follows. Functional status: very low quality evidence suggested that reablement may be slightly more effective than usual care in improving function at nine to 12 months (lower scores reflect greater independence; standardised mean difference (SMD) -0.30; 95% confidence interval (CI) -0.53 to -0.06; 2 studies with 249 participants). Adverse events: reablement may make little or no difference to mortality at 12 months' follow-up (RR 0.97; 95% CI 0.74 to 1.29; 2 studies with 811 participants) or rates of unplanned hospital admission at 24 months (RR 0.94; 95% CI 0.85 to 1.03; 1 study with 750 participants). The very low quality evidence also means we are uncertain whether reablement may influence quality of life (SMD -0.23; 95% CI -0.48 to 0.02; 2 trials with 249 participants) or living arrangements (RR 0.92, 95% CI 0.62 to 1.34; 1 study with 750 participants) at time points up to 12 months. People receiving reablement may be slightly less likely to have been approved for a higher level of personal care than people receiving usual care over the 24 months' follow-up (RR 0.87; 95% CI 0.77 to 0.98; 1 trial, 750 participants). Similarly, although there may be a small reduction in total aggregated home and healthcare costs over the 24-month follow-up (reablement: AUD 19,888; usual care: AUD 22,757; 1 trial with 750 participants), we are uncertain about the size and importance of these effects as the results were based on very low quality evidence. Neither study reported user satisfaction with the service. Authors' conclusions: There is considerable uncertainty regarding the effects of reablement as the evidence was of very low quality according to our GRADE ratings. Therefore, the effectiveness of reablement services cannot be supported or refuted until more robust evidence becomes available. There is an urgent need for high quality trials across different health and social care systems due to the increasingly high profile of reablement services in policy and practice in several countries.