Single-molecule DNA sequencing of widely varying GC-content using nucleotide release, capture and detection in microdroplets.

Despite remarkable progress in DNA sequencing technologies there remains a trade-off between short-read platforms, having limited ability to sequence homopolymers, repeated motifs or long-range structural variation, and long-read platforms, which tend to have lower accuracy and/or throughput. Moreover, current methods do not allow direct readout of epigenetic modifications from a single read. With the aim of addressing these limitations, we have developed an optical electrowetting sequencing platform that uses step-wise nucleotide triphosphate (dNTP) release, capture and detection in microdroplets from single DNA molecules. Each microdroplet serves as a reaction vessel that identifies an individual dNTP based on a robust fluorescence signal, with the detection chemistry extended to enable detection of 5-methylcytosine. Our platform uses small reagent volumes and inexpensive equipment, paving the way to cost-effective single-molecule DNA sequencing, capable of handling widely varying GC-bias, and demonstrating direct detection of epigenetic modifications.

The effectiveness and cost-effectiveness of assistive technology and telecare for independent living in dementia: a randomised controlled trial.

OBJECTIVES: The use of assistive technology and telecare (ATT) has been promoted to manage risks associated with independent living in people with dementia but with little evidence for effectiveness. METHODS: Participants were randomly assigned to receive an ATT assessment followed by installation of all appropriate ATT devices or limited control of appropriate ATT. The primary outcomes were time to institutionalisation and cost-effectiveness. Key secondary outcomes were number of incidents involving risks to safety, burden and stress in family caregivers and quality of life. RESULTS: Participants were assigned to receive full ATT (248 participants) or the limited control (247 participants). After adjusting for baseline imbalance of activities of daily living score, HR for median pre-institutionalisation survival was 0.84; 95% CI, 0.63 to 1.12; P = 0.20. There were no significant differences between arms in health and social care (mean -£909; 95% CI, -£5,336 to £3,345, P = 0.678) and societal costs (mean -£3,545; 95% CI, -£13,914 to £6,581, P = 0.499). ATT group members had reduced participant-rated quality-adjusted life years (QALYs) at 104 weeks (mean - 0.105; 95% CI, -0.204 to -0.007, P = 0.037) but did not differ in QALYs derived from proxy-reported EQ-5D. DISCUSSION: Fidelity of the intervention was low in terms of matching ATT assessment, recommendations and installation. This, however, reflects current practice within adult social care in England. CONCLUSIONS: Time living independently outside a care home was not significantly longer in participants who received full ATT and ATT was not cost-effective. Participants with full ATT attained fewer QALYs based on participant-reported EQ-5D than controls at 104 weeks.

Thermal-driven domain and cargo transport in lipid membranes.

Domain migration is observed on the surface of ternary giant unilamellar vesicles held in a temperature gradient in conditions where they exhibit coexistence of two liquid phases. The migration localizes domains to the hot side of the vesicle, regardless of whether the domain is composed of the more ordered or disordered phase and regardless of the proximity to chamber boundaries. The distribution of domains is explored for domains that coarsen and for those held apart due to long-range repulsions. After considering several potential mechanisms for the migration, including the temperature preferences for each lipid, the favored curvature for each phase, and the thermophoretic flow around the vesicle, we show that observations are consistent with the general process of minimizing the system's line tension energy, because of the lowering of line interface energy closer to mixing. DNA strands, attached to the lipid bilayer with cholesterol anchors, act as an exemplar "cargo," demonstrating that the directed motion of domains toward higher temperatures provides a route to relocate species that preferentially reside in the domains.

Directed tubule growth from giant unilamellar vesicles in a thermal gradient.

We demonstrate experimental control over tubule growth in giant unilamellar vesicles with liquid-liquid phase coexistence, using a thermal gradient to redistribute lipid phase domains on the membrane. As studied previously, the domains of the less abundant phase always partition towards hotter temperatures, depleting the cold side of the vesicle of domains. We couple this mechanism of domain migration with the inclusion of negative-curvature lipids within the membrane, resulting in control of tubule growth direction towards the high temperature. Control of composition determines the interior/exterior growth of tubules, whereas the thermal gradient regulates the length of the tubule relative to the vesicle radius. Maintaining lipid membranes under non-equilibrium conditions, such as thermal gradients, allows the creation of thermally-oriented protrusions, which could be a key step towards developing functional materials or artificial tissues. Interconnected vesicle compartments or ejected daughter vesicles as transport intermediaries towards hot/cold are just two possibilities.

Assistive technology and telecare to maintain independent living at home for people with dementia: the ATTILA RCT.

BACKGROUND: Assistive technology and telecare have been promoted to manage the risks associated with independent living for people with dementia, but there is limited evidence of their effectiveness. OBJECTIVES: This trial aimed to establish whether or not assistive technology and telecare assessments and interventions extend the time that people with dementia can continue to live independently at home and whether or not they are cost-effective. Caregiver burden, the quality of life of caregivers and of people with dementia and whether or not assistive technology and telecare reduce safety risks were also investigated. DESIGN: This was a pragmatic, randomised controlled trial. Blinding was not undertaken as it was not feasible to do so. All consenting participants were included in an intention-to-treat analysis. SETTING: This trial was set in 12 councils in England with adult social services responsibilities. PARTICIPANTS: Participants were people with dementia living in the community who had an identified need that might benefit from assistive technology and telecare. INTERVENTIONS: Participants were randomly assigned to receive either assistive technology and telecare recommended by a health or social care professional to meet their assessed needs (a full assistive technology and telecare package) or a pendant alarm, non-monitored smoke and carbon monoxide detectors and a key safe (a basic assistive technology and telecare package). MAIN OUTCOME MEASURES: The primary outcomes were time to admission to care and cost-effectiveness. Secondary outcomes assessed caregivers using the 10-item Center for Epidemiological Studies Depression Scale, the State-Trait Anxiety Inventory 6-item scale and the Zarit Burden Interview. RESULTS: Of 495 participants, 248 were randomised to receive full assistive technology and telecare and 247 received the limited control. Comparing the assistive technology and telecare group with the control group, the hazard ratio for institutionalisation was 0.76 (95% confidence interval 0.58 to 1.01; p = 0.054). After adjusting for an imbalance in the baseline activities of daily living score between trial arms, the hazard ratio was 0.84 (95% confidence interval 0.63 to 1.12; p = 0.20). At 104 weeks, there were no significant differences between groups in health and social care resource use costs (intervention group - control group difference: mean -£909, 95% confidence interval -£5336 to £3345) or in societal costs (intervention group - control group difference: mean -£3545; 95% confidence interval -£13,914 to £6581). At 104 weeks, based on quality-adjusted life-years derived from the participant-rated EuroQol-5 Dimensions questionnaire, the intervention group had 0.105 (95% confidence interval -0.204 to -0.007) fewer quality-adjusted life-years than the control group. The number of quality-adjusted life-years derived from the proxy-rated EuroQol-5 Dimensions questionnaire did not differ between groups. Caregiver outcomes did not differ between groups over 24 weeks. LIMITATIONS: Compliance with the assigned trial arm was variable, as was the quality of assistive technology and telecare needs assessments. Attrition from assessments led to data loss additional to that attributable to care home admission and censoring events. CONCLUSIONS: A full package of assistive technology and telecare did not increase the length of time that participants with dementia remained in the community, and nor did it decrease caregiver burden, depression or anxiety, relative to a basic package of assistive technology and telecare. Use of the full assistive technology and telecare package did not increase participants' health and social care or societal costs. Quality-adjusted life-years based on participants' EuroQol-5 Dimensions questionnaire responses were reduced in the intervention group compared with the control group; groups did not differ in the number of quality-adjusted life-years based on the proxy-rated EuroQol-5 Dimensions questionnaire. FUTURE WORK: Future work could examine whether or not improved assessment that is more personalised to an individual is beneficial. TRIAL REGISTRATION: Current Controlled Trials ISRCTN86537017. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 19. See the NIHR Journals Library website for further project information.

Many people with dementia living at home are recommended assistive technology and telecare to help them remain living safely and independently in the community. These devices are meant to assist and support activities such as taking medication or cooking, or to raise an alert when there is an issue, such as a fire; however, there is currently little evidence to support such claims. This trial investigated whether or not assistive technology and telecare could delay people moving into residential care and keep them any safer than alternatives, and whether or not they were cost-effective. We recruited 495 people with dementia and their unpaid caregivers, who were randomly assigned to receive either a package of assistive technology and telecare recommended by a health or social care professional or alternative support involving only basic assistive technology and telecare. We monitored the residential status, the use of health-care services and the health and well-being of participants with dementia and their caregivers over a 2-year period. Researchers also spent time with participants to see how they were living with the technology. The trial found no difference in the time that people with dementia with full assistive technology and telecare remained at home, nor any reduction in the number of safety incidents, compared with the participants who received basic assistive technology and telecare only. Full assistive technology and telecare did not increase health and social care costs. It did not improve the well-being of people with dementia or that of their caregivers. People with dementia who had full assistive technology and telecare rated their quality of life poorer than those with basic assistive technology and telecare did, but their caregivers rated their quality of life as about the same as caregivers of people with basic assistive technology and telecare. The technology sometimes averted crises but also disrupted people's everyday lives. These results suggest that assistive technology and telecare for people with dementia provided in real-world conditions may not be as beneficial as previously claimed. The way that assistive technology and telecare services are organised bears further investigation to see how these services could be improved.

The impact of assistive technology on burden and psychological well-being in informal caregivers of people with dementia (ATTILA Study).

INTRODUCTION: Assistive technology and telecare (ATT) may alleviate psychological burden in informal caregivers of people with dementia. This study assessed the impact of ATT on informal caregivers' burden and psychological well-being. METHODS: Individuals with dementia and their informal caregivers were recruited to a randomized-controlled trial assessing effectiveness of ATT. Caregivers were allocated to two groups according to their cared-for person's randomization to a full or basic package of ATT and were assessed on caregiver burden, state anxiety, and depression. Caregivers' data from three assessments over 6 months of the trial were analyzed. RESULTS: No significant between- or within-group differences at any time point on caregivers' burden, anxiety, and depression levels were found. DISCUSSION: Full ATT for people with dementia did not impact caregivers' psychological outcomes compared to basic ATT. The length of follow up was restricted to 6 months.

Assessment of need and practice for assistive technology and telecare for people with dementia-The ATTILA (Assistive Technology and Telecare to maintain Independent Living At home for people with dementia) trial.

INTRODUCTION: The objective of this study was to define current assistive technology and telecare (ATT) practice for people with dementia living at home. METHODS: This is a randomized controlled trial (N = 495) of ATT assessment and ATT installation intervention, compared with control (restricted ATT package). ATT assessment and installation data were collected. Qualitative work identified value networks delivering ATT, established an ATT assessment standard. RESULTS: ATT was delivered by public and not-for-profit telecare networks. ATT assessments showed 52% fidelity to the ATT assessment standard. Areas of assessment most frequently leading to identifying ATT need were daily activities (93%), memory (89%), and problem-solving (83%). ATT needs and recommendations were weakly correlated (τ = 0.242; P < .000), with ATT recommendations and installations moderately correlated (τ = -0.470; P < .000). Half (53%) of recommended technology was not installed. Safety concerns motivated 38% of installations. DISCUSSION: Assessment recommendations were routinely disregarded at the point of installation. ATT was commonly recommended for safety and seldom for supporting leisure.

Thermophoretic migration of vesicles depends on mean temperature and head group chemistry.

A number of colloidal systems, including polymers, proteins, micelles and hard spheres, have been studied in thermal gradients to observe and characterize their driven motion. Here we show experimentally the thermophoretic behaviour of unilamellar lipid vesicles, finding that mobility depends on the mean local temperature of the suspension and on the structure of the exposed polar lipid head groups. By tuning the temperature, vesicles can be directed towards hot or cold, forming a highly concentrated region. Binary mixtures of vesicles composed of different lipids can be segregated using thermophoresis, according to their head group. Our results demonstrate that thermophoresis enables robust and chemically specific directed motion of liposomes, which can be exploited in driven processes.

Printing small dots from large drops.

Printing of droplets of pure solvents containing suspended solids typically leads to a ring stain due to convective transport of the particles toward the contact line during evaporation of the solvent. In mixtures of volatile solvents, recirculating cells driven by surface tension gradients are established that lead to migration of colloidal particles toward the center of the droplet. In favorable cases, a dense disk of particles forms with a diameter much smaller than that of the droplet. In the latter stages of drying, convective transport of the particles radially toward the contact line still occurs. Two strategies are described to fix the distribution of particles in a compact disk much smaller than the initial diameter of the drying droplet. First, a nanoparticulate clay is added to induce an evaporation-driven sol-gel transition that inhibits convective flow during the latter stages of drying. Second, a nonadsorbing polymer is added to induce depletion flocculation that restricts particle motion after the particles have been concentrated near the center of the droplet. The area of the resulting deposit can be as little as 10% of the footprint of the printed droplet.

Control of the particle distribution in inkjet printing through an evaporation-driven sol-gel transition.

A ring stain is often an undesirable consequence of droplet drying. Particles inside evaporating droplets with a pinned contact line are transported toward the periphery by radial flow. In this paper, we demonstrate how suspensions of laponite can be used to control the radial flow inside picoliter droplets and produce uniform deposits. The improvement in homogeneity arises from a sol-gel transition during evaporation. Droplets gel from the contact line inward, reducing the radial motion of particles and thus inhibiting the formation of a ring stain. The internal flows and propagation of the gelling front were followed by high-speed imaging of tracer particles during evaporation of the picoliter droplets of water. In the inkjet nozzle, the laponite network is broken down under high shear. Recovery of the low shear viscosity of laponite suspensions was shown to be fast with respect to the lifetime of the droplet, which was instrumental in controlling the deposit morphology. The radial and vertical particle distributions within dried deposits were measured for water droplets loaded with 1 and 5 wt % polystyrene spheres and various concentrations of laponite. Aggregation of the polystyrene spheres was suppressed by the addition of colloidal silica. The formulation can be tuned to vary the deposit profile from a ring to a pancake or a dome.