Liquid crystals for luminescent concentrators: a review

Luminescent optical concentrators are thin films containing fluorescent dyes that enable light collection over a wide field of view without the need to track the path of the Sun. However, a disadvantage when using luminescent concentrators is that the performance is often impeded by surface losses through these films. Liquid-crystal (LC) hosts are attractive for luminescent concentrators, as they impart, at the very least, an orientational ordering to the transition dipole moment of the dyes dispersed within these films. This enables the directivity of both the absorption and emission and can reduce surface losses by, for example, adopting the homeotropic alignment of the LC director. This article reviews the developments and applications of LCs to luminescent optical concentrators and describes the strategies that have been introduced to further combat losses by decoupling the absorption and emission processes through Förster energy transfer, the approaches employed to enhance the chemical structures of the dyes, and the methods of using alternative LC phases and external configurations. The review presents a comprehensive summary of the material combinations and the techniques that have been considered in the development of LC-based concentrator films and concludes with a discussion about the future perspectives for these exciting optical concentrators

Socioeconomic status is associated with symptom severity and sickness absence in people with infectious intestinal disease in the UK

BACKGROUND: The burden of infectious intestinal disease (IID) in the UK is substantial. Negative consequences including sickness absence are common, but little is known about the social patterning of these outcomes, or the extent to which they relate to disease severity. METHODS: We performed a cross-sectional analysis using IID cases identified from a large population-based survey, to explore the association between socioeconomic status (SES) and symptom severity and sickness absence; and to assess the role of symptom severity on the relationship between SES and absence. Regression modelling was used to investigate these associations, whilst controlling for potential confounders such as age, sex and ethnicity. RESULTS: Among 1164 cases, those of lower SES versus high had twice the odds of experiencing severe symptoms (OR 2.2, 95%CI;1.66-2.87). Lower SES was associated with higher odds of sickness absence (OR 1.8, 95%CI;1.26-2.69), however this association was attenuated after adjusting for symptom severity (OR 1.4, 95%CI;0.92-2.07). CONCLUSIONS: In a large sample of IID cases, those of low SES versus high were more likely to report severe symptoms, and sickness absence; with greater severity largely explaining the higher absence. Public health interventions are needed to address the unequal consequences of IID identified

A saturated red color converter for visible light communication using a blend of star-shaped organic semiconductors

Authors would like to acknowledge the EPSRC for financial support for the UP-VLC (EP/K00042X/1). PJS and IDWS also acknowledge Royal Society Wolfson Research Merit Awards.We report a study of blends of semiconducting polymers as saturated red color converters to replace commercial phosphors in hybrid LEDs for visible light communication (VLC). By blending two star-shaped organic semiconductor molecules, we found a near complete energy transfer (> 90% efficiency) from the green-emitting truxene-cored compound T4BT-B to the red-emitting boron dipyrromethene (BODIPY) cored materials. Furthermore, we have demonstrated the capability of these materials as fast color converters for VLC by measuring their intrinsic optical modulation bandwidth and data rate. The measured 3 dB modulation bandwidth of blends (~55 MHz) is more than 10 times higher than commercially available LED phosphors and also higher than the red-emitting BODIPY color converter alone in solution. The data rate achieved with this blend is 20 times higher than measured with a commercially available phosphor based color converter.PostprintPeer reviewe

Garden varieties: how attractive are recommended garden plants to butterflies?

One way the public can engage in insect conservation is through wildlife gardening, including the growing of insect-friendly flowers as sources of nectar. However, plant varieties differ in the types of insects they attract. To determine which garden plants attracted which butterflies, we counted butterflies nectaring on 11 varieties of summer-flowering garden plants in a rural garden in East Sussex, UK. These plants were all from a list of 100 varieties considered attractive to British butterflies, and included the five varieties specifically listed by the UK charity Butterfly Conservation as best for summer nectar. A total of 2659 flower visits from 14 butterfly and one moth species were observed. We performed a principal components analysis which showed contrasting patterns between the species attracted to Origanum vulgare and Buddleia davidii. The “butterfly bush” Buddleia attracted many nymphalines, such as the peacock, Inachis io, but very few satyrines such as the gatekeeper, Pyronia tithonus, which mostly visited Origanum. Eupatorium cannibinum had the highest Simpson’s Diversity score of 0.75, while Buddleia and Origanum were lower, scoring 0.66 and 0.50 respectively. No one plant was good at attracting all observed butterfly species, as each attracted only a subset of the butterfly community. We conclude that to create a butterfly-friendly garden, a variety of plant species are required as nectar sources for butterflies. Furthermore, garden plant recommendations can probably benefit from being more precise as to the species of butterfly they attract

Cladribine with cyclophosphamide and prednisone in the management of low-grade lymphoproliferative malignancies

The feasibility of combining cladribine with cyclophosphamide and prednisone in the management of indolent lymphoid malignancies was determined. Nineteen patients [nine chronic lymphocytic leukaemia (CLL), seven non-Hodgkin's lymphoma (NHL) and three macroglobulinaemia (M))] received cladribine 0.1 mg kg−1 per day as a subcutaneous bolus injection on days 1–3 (up to 5 injections) with intravenous cyclophosphamide 500 mg m−2 on day 1 and oral prednisone 40 mg m−2 on days 1–5 at 4-weekly intervals up to a maximum of six courses. A total of 80 courses were given. Overall response rate was 88%, with four patients achieving a complete clinical and haematological response and 12 achieving a partial response. Neutropenia WHO grade 4 in two patients and WHO grade 3 infection in one patient were the limiting toxicities on treatment. During the follow-up, WHO grade ≥3 haematological complications occurred in five patients and WHO grade ≥3 non-haematological complications in five patients. There were no treatment-related deaths. This study demonstrates the feasibility of the cladribine/cyclophosphamide/prednisone (CCP) combination that appears highly active and safe in the management of indolent lymphoid malignancies. © 1999 Cancer Research Campaig

An Integrated-Photonics Optical-Frequency Synthesizer

Integrated-photonics microchips now enable a range of advanced functionalities for high-coherence applications such as data transmission, highly optimized physical sensors, and harnessing quantum states, but with cost, efficiency, and portability much beyond tabletop experiments. Through high-volume semiconductor processing built around advanced materials there exists an opportunity for integrated devices to impact applications cutting across disciplines of basic science and technology. Here we show how to synthesize the absolute frequency of a lightwave signal, using integrated photonics to implement lasers, system interconnects, and nonlinear frequency comb generation. The laser frequency output of our synthesizer is programmed by a microwave clock across 4 THz near 1550 nm with 1 Hz resolution and traceability to the SI second. This is accomplished with a heterogeneously integrated III/V-Si tunable laser, which is guided by dual dissipative-Kerr-soliton frequency combs fabricated on silicon chips. Through out-of-loop measurements of the phase-coherent, microwave-to-optical link, we verify that the fractional-frequency instability of the integrated photonics synthesizer matches the $7.0*10^{-13}$ reference-clock instability for a 1 second acquisition, and constrain any synthesis error to $7.7*10^{-15}$ while stepping the synthesizer across the telecommunication C band. Any application of an optical frequency source would be enabled by the precision optical synthesis presented here. Building on the ubiquitous capability in the microwave domain, our results demonstrate a first path to synthesis with integrated photonics, leveraging low-cost, low-power, and compact features that will be critical for its widespread use.Comment: 10 pages, 6 figure

Reduction of the ATPase inhibitory factor 1 (IF1) leads to visual impairment in vertebrates

In vertebrates, mitochondria are tightly preserved energy producing organelles, which sustain nervous system development and function. The understanding of proteins that regulate their homoeostasis in complex animals is therefore critical and doing so via means of systemic analysis pivotal to inform pathophysiological conditions associated with mitochondrial deficiency. With the goal to decipher the role of the ATPase inhibitory factor 1 (IF1) in brain development, we employed the zebrafish as elected model reporting that the Atpif1a−/− zebrafish mutant, pinotage (pnttq209), which lacks one of the two IF1 paralogous, exhibits visual impairment alongside increased apoptotic bodies and neuroinflammation in both brain and retina. This associates with increased processing of the dynamin-like GTPase optic atrophy 1 (OPA1), whose ablation is a direct cause of inherited optic atrophy. Defects in vision associated with the processing of OPA1 are specular in Atpif1−/− mice thus confirming a regulatory axis, which interlinks IF1 and OPA1 in the definition of mitochondrial fitness and specialised brain functions. This study unveils a functional relay between IF1 and OPA1 in central nervous system besides representing an example of how the zebrafish model could be harnessed to infer the activity of mitochondrial proteins during development

Developing a digital intervention for cancer survivors: an evidence-, theory- and person-based approach

This paper illustrates a rigorous approach to developing digital interventions using an evidence-, theory- and person-based approach. Intervention planning included a rapid scoping review which identified cancer survivors’ needs, including barriers and facilitators to intervention success. Review evidence (N=49 papers) informed the intervention’s Guiding Principles, theory-based behavioural analysis and logic model. The intervention was optimised based on feedback on a prototype intervention through interviews (N=96) with cancer survivors and focus groups with NHS staff and cancer charity workers (N=31). Interviews with cancer survivors highlighted barriers to engagement, such as concerns about physical activity worsening fatigue. Focus groups highlighted concerns about support appointment length and how to support distressed participants. Feedback informed intervention modifications, to maximise acceptability, feasibility and likelihood of behaviour change. Our systematic method for understanding user views enabled us to anticipate and address important barriers to engagement. This methodology may be useful to others developing digital interventions

Neuronal pentraxin II is highly upregulated in Parkinson’s disease and a novel component of Lewy bodies

Neuronal pentraxin II (NPTX2) is the most highly upregulated gene in the Parkinsonian substantia nigra based on our whole genome expression profiling results. We show here that it is a novel component of Lewy bodies and Lewy neurites in sporadic Parkinson’s disease (PD). NPTX2 is also known as the neuronal activity-regulated protein (Narp), which is secreted and involved in long-term neuronal plasticity. Narp further regulates AMPA receptors which have been found to mediate highly selective non-apoptotic cell death of dopaminergic neurons. NPTX2/Narp is found in close association with alpha-synuclein aggregates in both substantia nigra and cerebral cortex in PD but unlike alpha-synuclein gene expression, which is down-regulated in the Parkinsonian nigra, NPTX2 could represent a driver of the disease process. In view of its profound (>800%) upregulation and its established role in synaptic plasticity as well as dopaminergic nerve cell death, NPTX2 is a very interesting novel player which is likely to be involved in the pathway dysregulation which underlies PD