THz-TDS of liquids in a temperature-controlled transmission flowcell

Precise temperature-control is necessary for many spectroscopic measurements. We present the temperature-dependent complex THz refractive index of liquid samples measured in a flowcell, analysed by a numerical method that allows simultaneous extraction of the sample's thickness to verify the temperature-stability of the cell

Predictors of recruitment and retention in randomized controlled trials of behavioural smoking cessation interventions: a systematic review and meta-regression analysis

AIM: To investigate predictors of participant eligibility, recruitment, and retention in behavioural randomised controlled trials (RCTs) for smoking cessation. METHOD: Systematic review and pre-specified meta-regression analysis of behavioural RCTs for smoking cessation including adult (≥18 years old) smokers. The pre-specified predictors were identified through a literature review and experts' consultation and included participant, trial and intervention characteristics and recruitment and retention strategies. Measurements included eligibility rates (proportion of people eligible for the trials), recruitment rates, retention rates, and differential retention rates. RESULTS: 172 RCTs with 89,639 participants. Eligibility [median 57.6%; IQR 34.7-83.7], recruitment [median 66.4%; IQR 42.7-85.2] and retention rates [median 80.5%; IQR 42.7-85.2] varied considerably across studies. For eligibility rates, the recruitment strategy appeared not to be associated with eligibility rates. For recruitment rates, use of indirect recruitment strategies (e.g., public announcements) [OR 0.30, 95% CI 0.11-0.82] and self-help interventions [OR 0.14, 95% CI 0.03-0.67] were associated with lower recruitment rates. For retention rates, higher retention was seen if the sample had ongoing physical health condition/s [OR 1.66, 95% CI 1.04-2.63] whereas lower retention was seen amongst primarily female samples [OR 0.83, 95% CI 0.71-0.98] and those motivated to quit smoking [OR 0.74, 95% CI 0.55-0.99], when indirect recruitment methods were used [OR 0.60, 95% CI 0.38-0.97], and at longer follow-up assessments [OR 0.83, 95% CI 0.79-0.87]. For differential retention, higher retention in the intervention group occurred when the intervention but not comparator group received financial incentives for smoking cessation [OR 1.35, 95% CI: 1.02-1.77]. CONCLUSIONS: In randomised controlled trials of behavioural smoking cessation interventions, recruitment and retention rates appear to be higher for smoking cessation interventions that include a person-to-person rather than at-a-distance contact; male participants, smokers with chronic conditions, smokers not initially motivated to quit and shorter follow-up assessments seems to be associated with improved retention; financial incentive interventions improve retention in groups receiving them relative to comparison groups

Tailoring CONSORT-SPI to improve the reporting of smoking cessation intervention trials: An expert consensus study

Background and Aims: Inadequate reporting of smoking cessation intervention trials is common and leads to significant challenges for researchers. The aim of this study was to tailor CONSORT (Consolidated Standards of Reporting Trials)-SPI (Social and Psychological Interventions) guidelines to improve reporting of trials of behavioural interventions to promote smoking cessation. Method: Informed by missing data from the IC-SMOKE (Intervention and Comparison group support provided in SMOKing cEssation) systematic review project, this study used a multi-stage Delphi process to examine which items could be added or modified to improve the reporting of smoking cessation trials. The first stage involved an on-line survey of 17 international experts in smoking cessation and trial methodology voting on the importance of items for inclusion in the updated guidelines. This was followed by a face-to-face expert consensus meeting attended by 15 of these experts, where the final inclusion and exclusion of new items and modifications were agreed upon. A nine-point Likert scale was used to establish consensus, with suggested modifications requiring agreement of 75% or more. Disagreements in the first stage were presented again at the second stage for discussion and a second round of voting. Only items which reached the threshold for agreement were included. Results: The experts agreed on the inclusion of 10 new items and the specification of 12 existing items. This included modifications that could apply to trials more widely (e.g. the rationale for the comparator), but also modifications that were very specific to smoking cessation trials (e.g. the reporting of smoking cessation outcomes). Conclusions: A Delphi study has developed a modified CONSORT-SPI guideline (CONSORT-SPI-SMOKE) to improve the reporting of trials of behavioural interventions to promote smoking cessation

Predictors of recruitment and retention in randomized controlled trials of behavioural smoking cessation interventions: a systematic review and meta-regression analysis

Aim: To investigate predictors of participant eligibility, recruitment and retention in behavioural randomized controlled trials (RCTs) for smoking cessation. Method: Systematic review and pre-specified meta-regression analysis of behavioural RCTs for smoking cessation including adult (≥ 18-year-old) smokers. The pre-specified predictors were identified through a literature review and experts’ consultation and included participant, trial and intervention characteristics and recruitment and retention strategies. Outcome measures included eligibility rates (proportion of people eligible for the trials), recruitment rates, retention rates and differential retention rates. Results: A total of 172 RCTs with 89 639 participants. Eligibility [median 57.6%; interquartile range (IQR) = 34.7–83.7], recruitment (median 66.4%; IQR = 42.7–85.2) and retention rates (median 80.5%; IQR = 68.5–89.5) varied considerably across studies. For eligibility rates, the recruitment strategy appeared not to be associated with eligibility rates. For recruitment rates, use of indirect recruitment strategies (e.g. public announcements) [odds ratio (OR) = 0.30, 95% confidence interval (CI) = 0.11–0.82] and self-help interventions (OR = 0.14, 95% CI = 0.03–0.67) were associated with lower recruitment rates. For retention rates, higher retention was seen if the sample had ongoing physical health condition/s (OR = 1.66, 95% CI = 1.04–2.63), whereas lower retention was seen amongst primarily female samples (OR = 0.83, 95% CI = 0.71–0.98) and those motivated to quit smoking (OR = 0.74, 95% CI = 0.55–0.99) when indirect recruitment methods were used (OR = 0.60, 95% CI = 0.38–0.97) and at longer follow-up assessments (OR = 0.83, 95% CI = 0.79–0.87). For differential retention, higher retention in the intervention group occurred when the intervention but not comparator group received financial incentives for smoking cessation (OR = 1.35, 95% CI = 1.02–1.77). Conclusions: In randomized controlled trials of behavioural smoking cessation interventions, recruitment and retention rates appear to be higher for smoking cessation interventions that include a person-to-person rather than at-a-distance contact; male participants, smokers with chronic conditions, smokers not initially motivated to quit and shorter follow-up assessments seems to be associated with improved retention; financial incentive interventions improve retention in groups receiving them relative to comparison groups

Improvdent: Improving dentures for patient benefit. A crossover randomised clinical trial comparing impression materials for complete dentures.

Background According to the UK Adult Dental Health Survey (2009) 15% of adults aged 65–74, 30% aged 75–84 and 47% aged >85 years are edentulous and require complete dentures. Patients’ quality of life and nutrition status are affected by poor dentures. The quality of the dental impression is the most important issue for improving the fit and comfort of new dentures. There is paucity of RCT evidence for which impression material is best for complete dentures construction. This study aims to compare two impression materials for effectiveness and cost effectiveness. Methods/Design IMPROVDENT is a double-blind crossover trial comparing the use of alginate and silicone, two commonly used denture impression materials, in terms of patient preference and cost-effectiveness. Eighty five edentulous patients will be recruited and provided with two sets of dentures, similar in all aspects except for the impression material used (alginate or silicone). Patients will try both sets of dentures for a two-week period, unadjusted, to become accustomed to the feel of the new dentures (habituation period). Patients will then wear each set of dentures for a period of 8 weeks (in random order) during which time the dentures will be adjusted for optimum comfort. Finally, patients will be given both sets of dentures for a further two weeks to wear whichever denture they prefer (confirmation period). Patients will be asked about quality of life and to rate dentures on function and comfort at the end of each trial period and asked which set they prefer at the end of the habituation period (unadjusted denture preference) and confirmation period (adjusted denture preference). A health economic evaluation will estimate incremental cost-effectiveness ratios of producing dentures from the two materials. A qualitative study will investigate the impact of dentures on behaviour and quality of life. Funding: IMPROVDENT is funded by NIHR RfPB (PB-PG-0408-16300). Discussion This trial aims to provide evidence on the costs and quality of dentures cast from two different commonly used impression materials; the intention is to significantly impact on the quality of denture production within NHS dentistry

Supporting Future Cannabis Policy - Developing a Standard Joint Unit: A Brief Back-Casting Exercise.

The standardization of cannabis doses is a priority for research, policy-making, clinical and harm-reduction interventions and consumer security. Scientists have called for standard units of dosing for cannabis, similar to those used for alcohol. A Standard Joint Unit (SJU) would facilitate preventive and intervention models in ways similar to the Standard Drink (SD). Learning from the SD experiences allows researchers to tackle emerging barriers to the SJU by applying modern forecasting methods. During a workshop at the Lisbon Addictions Conference 2019, a back-casting foresight method was used to address challenges and achieve consensus in developing an SJU. Thirty-two professionals from 13 countries and 10 disciplines participated. Descriptive analysis of the workshop was carried out by the organizers and shared with the participants in order to suggest amendments. Several characteristics of the SJU were defined: (1) core values: easy-to use, universal, focused on THC, accurate, and accessible; (2) key challenges: sudden changes in patterns of use, heterogeneity of cannabis compounds as well as in administration routes, variations over time in THC concentrations, and of laws that regulate the legal status of recreational and medical cannabis use); and (3) facilitators: previous experience with standardized measurements, funding opportunities, multi-stakeholder support, high prevalence of cannabis users, and widespread changes in legislation. Participants also identified three initial steps for the implementation of a SJU by 2030: (1) Building a task-force to develop a consensus-based SJU; (2) Expanded available national-level data; (3) Linking SJU consumption to the concept of "risky use," based on evidence of harms

Renewable, ethical? Assessing the energy justice potential of renewable electricity

Energy justice is increasingly being used as a framework to conceptualize the impacts of energy decision making in more holistic ways and to consider the social implications in terms of existing ethical values. Similarly, renewable energy technologies are increasingly being promoted for their environmental and social benefits. However, little work has been done to systematically examine the extent to which, in what ways and in what contexts, renewable energy technologies can contribute to achieving energy justice. This paper assesses the potential of renewable electricity technologies to address energy justice in various global contexts via a systematic review of existing studies analyzed in terms of the principles and dimensions of energy justice. Based on publications including peer reviewed academic literature, books, and in some cases reports by government or international organizations, we assess renewable electricity technologies in both grid integrated and off-grid use contexts. We conduct our investigation through the rubric of the affirmative and prohibitive principles of energy justice and in terms of its temporal, geographic, socio-political, economic, and technological dimensions. Renewable electricity technology development has and continue to have different impacts in different social contexts, and by considering the different impacts explicitly across global contexts, including differences between rural and urban contexts, this paper contributes to identifying and understanding how, in what ways, and in what particular conditions and circumstances renewable electricity technologies may correspond with or work to promote energy justice

Asymptotically single-mode small-core terahertz Bragg fibre with low loss and low dispersion

This paper presents a novel design concept, which is verified by analytical and simulation results, of a single-mode small-core terahertz Bragg fibre exhibiting the properties of low loss and low dispersion. Conventionally, a single-TE₀₁-mode Bragg fibre requires a large core and many cladding layer periods to achieve a significant propagation loss discrimination between the desired mode and other unwanted competing modes. The use of a second-order bandgap in this paper completely eliminates this requirement, and enhances propagation loss discrimination using just a small core with a diameter at least 50% smaller than the conventional design and only four cladding layer periods. Furthermore, a generalized half-wavelength condition is proposed, promoting the manipulation of photonic bandgap for Bragg fibre. The TE₀₁ mode has a null point in the electric field close to the boundary interface between the core and the cladding, and this phenomenon has been exploited to minimize the impact of support bridges, which mechanically maintain the air gaps, on the propagation loss of the fibre. Finally, we propose a novel design of a tightly confined single-TE₀₁-mode small-air-core Bragg fibre with propagation loss and group velocity dispersion less than 1.2 dB/m and -0.6 ps/THz/cm, respectively, between frequencies of 0.85 THz and 1.15 THz