A non-FRET DNA reporter that changes fluorescence colour upon nuclease digestion.

Fluorescence resonance energy transfer (FRET) reporters are commonly used in the final stages of nucleic acid amplification tests to indicate the presence of nucleic acid targets, where fluorescence is restored by nucleases that cleave the FRET reporters. However, the need for dual labelling and purification during manufacturing contributes to the high cost of FRET reporters. Here we demonstrate a low-cost silver nanocluster reporter that does not rely on FRET as the on/off switching mechanism, but rather on a cluster transformation process that leads to fluorescence color change upon nuclease digestion. Notably, a 90 nm red shift in emission is observed upon reporter cleavage, a result unattainable by a simple donor-quencher FRET reporter. Electrospray ionization-mass spectrometry results suggest that the stoichiometric change of the silver nanoclusters from Ag13 (in the intact DNA host) to Ag10 (in the fragments) is probably responsible for the emission colour change observed after reporter digestion. Our results demonstrate that DNA-templated silver nanocluster probes can be versatile reporters for detecting nuclease activities and provide insights into the interactions between nucleases and metallo-DNA nanomaterials.

Assessing the efficacy of coproduction to better understand the barriers to achieving sustainability in NHS chronic kidney services and create alternate pathways.

CONTEXT: Too many people living with chronic kidney disease are opting for and starting on hospital-based dialysis compared to a home-based kidney replacement therapy. Dialysis services are becoming financially unsustainable. OBJECTIVE: This study aimed to assess the efficacy of coproductive research in chronic kidney disease service improvement to achieve greater sustainability. DESIGN: A 2-year coproductive service improvement study was conducted with multiple stakeholders with the specific intention of maximizing engagement with the national health kidney services, patients and public. SETTING AND PARTICIPANTS: A national health kidney service (3 health boards, 18 dialysis units), patients and families (n = 50), multidisciplinary teams including doctors, nurses, psychologists, social workers, and so forth (n = 68), kidney charities, independent dialysis service providers and wider social services were part of this study. FINDINGS: Coproductive research identified underutilized resources (e.g., patients on home dialysis and social services) and their potential, highlighted unmet social care needs for patients and families and informed service redesign. Education packages were reimagined to support the home dialysis agenda including opportunities for wider service input. The impacts of one size fits all approaches to dialysis on specialist workforce skills were made clearer and also professional, patient and public perceptions of key sustainability policies. DISCUSSION AND CONCLUSIONS: Patient and key stakeholders mapped out new ways to link services to create more sustainable models of kidney health and social care. Maintaining principles of knowledge coproduction could help achieve financial sustainability and move towards more prudent adult chronic kidney disease services. PATIENT OR PUBLIC CONTRIBUTION: Involved in developing research questions, study design, management and conduct, interpretation of evidence and dissemination.

Factors affecting evaporation rates of tear film components measured in vitro.

OBJECTIVES: With increasing age and in patients affected with dry-eye symptoms, the human tear film becomes more unstable and exhibits shorter tear break-up times. We examined whether the inclusion of proteins and lipids to water affected the evaporation rates measured in vitro and could account for the lower rates reported previously from in vivo measurements. The impact of temperature, air flow, and humidity on the evaporation rate of tears was measured in vitro. METHODS: Lipid-protein interactions were measured using fluorescence spectroscopy and in vitro rates of evaporation were performed gravimetrically. RESULTS: Human reflex tears evaporated at a rate similar to that of water. A temperature increase from 25 degrees C to 34 degrees C caused a threefold increase in the evaporation rates of tears in still air. Further increases were observed under a current of dry air. Wax, mucin, lysozyme, or beta-lactoglobulin did not influence significantly the rates of evaporation measured in vitro. In contrast, lipid layered on the surface resulted in a 23% decrease in the rates. CONCLUSIONS: Environmental factors affect evaporation rates significantly and should be carefully controlled when performing in vivo measurements. The presence of a lipid layer lowers evaporation rates. The significantly lower rates of evaporation of tears measured in vivo suggest that with the lipid layer intact, the high reserve capacity of the lacrimal gland to provide both unstimulated and stimulated tear flow is more than enough to compensate for evaporative loss. However, with dry eye, increased rates of evaporation and decreased lacrimal tear flow could result in decreased break-up times.