A novel experience-based internet intervention for smoking cessation : feasibility randomised controlled trial

The iPEx programme presents independent research funded by the UK National Institute for Health Research (NIHR) under its Programme Grants for Applied Research funding scheme (RP-PG-0608-10147). The views expressed in this paper are those of the authors, representing iPEx, and not necessarily those of the NHS, the NIHR or the Department of Health.Peer reviewedPublisher PD

Generation of counterpropagating and spectrally uncorrelated photon-pair states by spontaneous four-wave mixing in photonic crystal waveguides

In this work, we propose and theoretically analyze a new scheme for generation of counterpropagating photon pairs in photonic crystal waveguides through the process of spontaneous four-wave mixing. Using the fundamental properties of periodic Bloch modes in a standard photonic crystal waveguide, we demonstrate how modal phase-matching can be reached between forward-propagating pump modes and counterpropagating signal and idler modes, for generation of degenerate and non-degenerate photon pairs. We then show how this scheme can be used for generation of photon pairs that are nearly uncorrelated in the spectral degree of freedom. Such a source will be highly interesting as a heralded source of single photons, especially as the spectrally separable signal and idler photons are also spatially separated directly at the source. We conduct our investigation based on a design in silicon, yet our design concept is general and can in principle be applied to any nanostructured material platform

Approximation Algorithms for Min-Distance Problems

We study fundamental graph parameters such as the Diameter and Radius in directed graphs, when distances are measured using a somewhat unorthodox but natural measure: the distance between u and v is the minimum of the shortest path distances from u to v and from v to u. The center node in a graph under this measure can for instance represent the optimal location for a hospital to ensure the fastest medical care for everyone, as one can either go to the hospital, or a doctor can be sent to help. By computing All-Pairs Shortest Paths, all pairwise distances and thus the parameters we study can be computed exactly in O~(mn) time for directed graphs on n vertices, m edges and nonnegative edge weights. Furthermore, this time bound is tight under the Strong Exponential Time Hypothesis [Roditty-Vassilevska W. STOC 2013] so it is natural to study how well these parameters can be approximated in O(mn^{1-epsilon}) time for constant epsilon>0. Abboud, Vassilevska Williams, and Wang [SODA 2016] gave a polynomial factor approximation for Diameter and Radius, as well as a constant factor approximation for both problems in the special case where the graph is a DAG. We greatly improve upon these bounds by providing the first constant factor approximations for Diameter, Radius and the related Eccentricities problem in general graphs. Additionally, we provide a hierarchy of algorithms for Diameter that gives a time/accuracy trade-off

Therapeutic targets and limits of minocycline neuroprotection in experimental ischemic stroke

<p>Abstract</p> <p>Background</p> <p>Minocycline, a second-generation tetracycline with anti-inflammatory and anti-apoptotic properties, has been shown to promote therapeutic benefits in experimental stroke. However, equally compelling evidence demonstrates that the drug exerts variable and even detrimental effects in many neurological disease models. Assessment of the mechanism underlying minocycline neuroprotection should clarify the drug's clinical value in acute stroke setting.</p> <p>Results</p> <p>Here, we demonstrate that minocycline attenuates both <it>in vitro </it>(oxygen glucose deprivation) and <it>in vivo </it>(middle cerebral artery occlusion) experimentally induced ischemic deficits by direct inhibition of apoptotic-like neuronal cell death involving the anti-apoptotic Bcl-2/cytochrome c pathway. Such anti-apoptotic effect of minocycline is seen in neurons, but not apparent in astrocytes. Our data further indicate that the neuroprotection is dose-dependent, in that only low dose minocycline inhibits neuronal cell death cascades at the acute stroke phase, whereas the high dose exacerbates the ischemic injury.</p> <p>Conclusion</p> <p>The present study advises our community to proceed with caution to use the minimally invasive intravenous delivery of low dose minocycline in order to afford neuroprotection that is safe for stroke.</p

Effectiveness and cost-effectiveness of a self-guided internet intervention for social anxiety symptoms in a general population sample : randomized controlled trial

Background: Many people are accessing digital self-help for mental health problems, often with little evidence of effectiveness.Social anxiety is one of the most common sources of mental distress in the population and many people with symptoms do not seek help for what represents a significant public health problem. Objective: Two group randomized controlled trial conducted in England between 11th May 2016 and 27th June 2018. Adults with social anxiety symptoms who were not receiving treatment for social anxiety were recruited using online advertisements. All participants had unrestricted access to usual care and were randomized in a 1:1 ratio to either a web-based unguided self-help intervention based on cognitive-behavioural principles, or to a waiting list control group. All outcomes were collected through self-report online questionnaires. The primary outcome was the change in 17-item self-report Social Phobia Inventory (SPIN-17) score from baseline to 6 weeks using a linear mixed-effect model that used data from all timepoints (6 weeks, 3, 6, 12 months). Methods: Two group randomized controlled trial conducted in England between 11th May 2016 and 27th June 2018. Adults with social anxiety symptoms who were not receiving treatment for social anxiety were recruited using online advertisements. All participants had unrestricted access to usual care and were randomized in a 1:1 ratio to either a web-based unguided self-help intervention based on cognitive-behavioural principles, or to a waiting list control group. All outcomes were collected through self-report online questionnaires. The primary outcome was the change in 17-item self-report Social Phobia Inventory (SPIN-17) score from baseline to 6 weeks using a linear mixed-effect model that used data from all timepoints (6 weeks, 3, 6, 12 months). Results: 2212 participants were randomized. Six were excluded from analyses as ineligible. Of the 2116 eligible randomized participants (mean age 37 years, 80% women), 70.1% (1484/2116) had follow-up data available for analysis, and 56.9% (1205/2116) had data on the primary outcome, although attrition was higher in the intervention arm. At 6 weeks the mean (95% CI, P value) adjusted difference in change in SPIN-17 score in the intervention group compared to control, was -1.94 (-3.13 to -0.75, P=0.0014), a standardised mean difference effect size of 0.2. The improvement was maintained at 12 months. Given the high drop-out, sensitivity analyses explored missing data assumptions and were consistent with the primary analysis finding. The economic evaluation demonstrated cost-effectiveness with a small health status benefit and a reduction in health service utilisation. Conclusions: For people with social anxiety symptoms who are not receiving other forms of help, this study suggests that an online self-help tool based on cognitive behavioural principles can provide a small improvement in social anxiety symptoms compared with no intervention, although drop-out rates were high. Clinical Trial: ClinicalTrials.gov NCT02451878. https://clinicaltrials.gov/ct2/show/NCT0245187

Effectiveness and cost-effectiveness of a fully self-guided internet-based intervention for sub-clinical social anxiety symptoms : protocol for a randomised controlled trial

Design and objective: This paper describes the protocol for a large-scale pragmatic, randomised controlled trial and economic evaluation to investigate the effectiveness and cost-effectiveness of the self-directed E-Couch social anxiety module versus a waiting list control condition, for reducing sub-clinical social anxiety symptoms in the general population. Study population: Community-based adults (aged 18+) with social anxiety symptoms that do not meet the criteria for social anxiety disorder recruited via a direct-to-consumer advertisement on national websites. Intervention and control: Intervention is the self-guided E-Couch social anxiety module. Control group participants are placed on a waiting list to receive the intervention at the end of the trial. Both groups receive email and text message reminders. Outcome measures: The primary outcome will be change in self-reported social anxiety score using the Social Phobia Inventory (SPIN). Secondary outcomes will be the changes in the following self-report measures: Brief Fear of Negative Evaluation scale (BFNE-S); depression (CES-D); mental wellbeing (SWEMWEBS); health status (SF36); use of health services; safety events; and adherence, retention, and attrition rates. All measures will be administered at baseline, 6 weeks, and 3, 6 and 12 months. Analysis: A mixed effects model will be used to analyse the effect of the intervention on the primary and secondary outcomes (intention to treat analysis). Secondary analyses will explore moderators and mediators of effect. A prospective economic evaluation, conducted from a NHS and social care perspective, will provide estimates of cost utility and cost-effectiveness. An interview study will be conducted with 20 participants to explore issues including acceptability, adherence, retention and attrition

Uptake Coefficients of Some Volatile Organic Compounds by Soot and Their Application in Understanding Particulate Matter Evolution in Aircraft Engine Exhaust Plumes

To assist microphysical modeling on particulate matter (PM) evolution emitted from aircraft engines, uptake coefficients of some volatile organic compounds on soot were experimentally determined in this study. The determined values vary from (1.0±0.1)×10⁻⁶ for water-miscible propylene glycol to (2.5±0.1)×10⁻⁵ for 2,6-dimethylnaphthalene, a polycyclic aromatic hydrocarbon. An inverse power-law correlation between uptake coefficient on soot and solubility in water was observed. Using the correlation, microphysical simulations were performed for the exhaust plume evolution from an idling aircraft, and we found that the model-predicted volatile PM composition on soot is comparable with those results from past field measurements.United States. Department of Defense (Contract W912HQ-08-C-0052