High-uniformity atomic layer deposition of superconducting niobium nitride thin films for quantum photonic integration

Atomic layer deposition (ALD) has been identified as a promising growth method for high-uniformity superconducting thin films for superconducting quantum photonic applications, offering superior uniformity, thickness control and conformality to techniques such as reactive sputtering. The potential scalability of ALD makes this method especially appealing for fabrication of superconducting nanowires and resonators across large areas. We report on the growth of highly uniform superconducting NbN thin films via plasma-enhanced atomic layer deposition (PEALD) with radio frequency (RF) substrate biasing, on a 200 mm (8-inch) Si wafer, specifically for superconducting nanowire single-photon detector (SNSPD) applications. Niobium nitride films were grown using (tert-butylimido)-tris(diethylamido)-niobium(V) (TBTDEN) precursor and a H2/Ar plasma. The superconducting properties of a variable thickness series of films (5 – 30 nm) show critical temperature (Tc) of 13.5 K approaching bulk thickness (30 nm) with low suppression down to the ultrathin regime (5 nm) with Tc > 11 K. Tc across the 200 mm wafer with 8 nm thick NbN, measured in 15 mm intervals, exhibits minimal variation (< 7%). Microbridge structures fabricated on 8 nm thick NbN films also exhibit high critical current densities (Jc), > 10 MA/cm2 at 2.6 K. PEALD could therefore be a pivotal technique in enabling large-scale fabrication of integrated quantum photonic devices across a variety of applications

Long-term weight loss following a randomised controlled trial of a weight management programme for men delivered through professional football clubs: the Football Fans in Training follow-up study

Background: Rising levels of obesity require interventions that support people in long-term weight loss. The Football Fans in Training (FFIT) programme uses loyalty to football teams to engage men in weight loss. In 2011/12, a randomised controlled trial (RCT) found that the FFIT programme was effective in helping men lose weight up to 12 months. Objectives: To investigate the long-term weight, and other physical, behavioural and psychological outcomes up to 3.5 years after the start of the RCT; the predictors, mediators and men’s qualitative experiences of long-term weight loss; cost-effectiveness; and the potential for long-term follow-up via men’s medical records. Design: A mixed-methods, longitudinal cohort study. Setting: Thirteen professional Scottish football clubs from the RCT and 16 additional Scottish football clubs that delivered the FFIT programme in 2015/16. Participants: A total of 665 men who were aged 35–65 years at the RCT baseline measures and who consented to follow-up after the RCT (intervention group, n = 316; comparison group, n = 349), and 511 men who took part in the 2015/16 deliveries of the FFIT programme. Interventions: None as part of this study. Main outcome measures: Objectively measured weight change from the RCT baseline to 3.5 years. Results: In total, 488 out of 665 men (73.4%) attended 3.5-year measurements. Participants in the FFIT follow-up intervention group sustained a mean weight loss from baseline of 2.90 kg [95% confidence interval (CI) 1.78 to 4.02 kg; p Additional co-authors: Colin McCowan, Alice McLean, Nanette Mutri

Long-term weight loss trajectories following participation in a randomised controlled trial of a weight management programme for men delivered through professional football clubs:a longitudinal cohort study and economic evaluation

Background: Obesity is a major public health concern requiring innovative interventions that support people to lose weight and keep it off long term. However, weight loss maintenance remains a challenge and is under-researched, particularly in men. The Football Fans in Training (FFIT) programme engages men in weight management through their interest in football, and encourages them to incorporate small, incremental physical activity and dietary changes into daily life to support long term weight loss maintenance. In 2011/12, a randomised controlled trial (RCT) of FFIT demonstrated effectiveness and cost-effectiveness at 12 months. The current study aimed to investigate long-term maintenance of weight loss, behavioural outcomes and lifetime cost-effectiveness following FFIT. Methods: A longitudinal cohort study comprised 3.5-year follow-up of the 747 FFIT RCT participants. Men aged 35-65 years, BMI≥28 kg/m2 at RCT baseline who consented to long-term follow-up (n=665) were invited to participate: those in the FFIT Follow-Up Intervention group (FFIT-FU-I) undertook FFIT in 2011 during the RCT; the FFIT Follow-Up Comparison group (FFIT-FU-C) undertook FFIT in 2012 under routine (non-research) conditions. The primary outcome was objectively-measured weight loss (from baseline) at 3.5 years. Secondary outcomes included changes in self-reported physical activity and diet at 3.5 years. Cost-effectiveness was estimated at 3.5 years and over participants’ lifetime. Results: Of 665 men invited, 488 (73%; 65% of the 747 RCT participants) attended 3.5-year measurements. The FFIT-FU-I group sustained a mean weight loss of 2.90 kg (95% CI 1.78, 4.02; p<0.001) 3.5 years after starting FFIT; 32.2% (75/233) weighed ≥5% less than baseline. The FFIT-FU-C group had lost 2.71 kg (1.65, 3.77; p<0.001) at the 3.5-year measurements (2.5 years after starting FFIT); 31.8% (81/255) weighed ≥5% less than baseline. There were significant sustained improvements in self-reported physical activity and diet in both groups. The estimated incremental cost-effectiveness of FFIT was £10,700-£15,300 per QALY gained at 3.5 years, and £1,790-£2,200 over participants’ lifetime. Conclusions: Participation in FFIT under research and routine conditions leads to long-term weight loss and improvements in physical activity and diet. Investment in FFIT is likely to be cost-effective as part of obesity management strategies in countries where football is popular

Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

Femtosecond wavevector overtone spectroscopy of anharmonic lattice dynamics in ferroelectric crystals

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1997.Includes bibliographical references.by Ciaran Joseph Brennan.Ph.D

Lower back pain in physically demanding college academic programs : a questionnaire based study

Background: Lower back pain (LBP) is ranked first as a cause of disability and inability to work, and is expected to affect up to 90% of the worlds population at some point in their lifetime. The annual first time incidence of LBP is 5%, and the annual prevalence (i.e. those suffering at time of questioning) is between 15 and 63%. Prospective studies demonstrate that low back problems do not display a six-week spontaneous recovery pattern, as was once believed. The condition is regularly seen to worsen over time, becoming a chronic disorder, influenced by both physical and psychosocial factors. Methods: The current study assessed the level of LBP amongst students engaged in educational programs that were physically demanding, and its influence on lower back problems. A 1-year retrospective questionnaire consisting of 37 closed, open and multi-choice questions was designed to ascertain self-reported information on the occurrence, cause and type of LBP. Treatment, care seeking and general knowledge regarding LBP were also recorded. Students were enrolled in BSc Equine Science, BSc Physical Education and BSc Sports & Exercise Science degree programs and a total number of 188 valid questionnaires were collected. Results: The self reported, anthropometrical data for participants in this study are: age 20.9 ± 2.7 yrs; height 171.8 ± 9.3 cm; weight 66.7 ± 10.4 kg; female 64% (n = 120), male 36% (n = 68). The overall self reported prevalence of LBP was 32% (n = 61). Within the LBP population, 77% reported their problem as recurring. Two factors showed significance as having an influence on LBP. They were age (21.6 ± 3.5 yrs, p = 0.005) and hours of personal training physical activity (14.0 ± 8.2 hrs per week, p = 0.02). LBP sufferers also displayed poor management of their condition and an interest in education and treatment of their problem. Conclusion: The current study revealed high prevalence of LBP consistent with that of the literature, and unveiled a recurrence rate and behavioral habits of sufferers, which are warning signs of a more chronic state to come. Novel data presented here offers strong support for the need for prospective injury tracking, plus educational intervention and treatment aimed at prevention of LBP

Is Bigger Better? Living Donor Kidney Volume as Measured by the Donor CT Angiogram in Predicting Donor and Recipient eGFR after Living Donor Kidney Transplantation

Background. The role of kidney volume measurement in predicting the donor and recipient kidney function is not clear. Methods. We measured kidney volume bilaterally in living kidney donors using CT angiography and assessed the association with the donor remaining kidney and recipient kidney (donated kidney) function at 1 year after kidney transplantation. Donor volume was categorized into tertiles based on lowest, middle, and highest volume. Results. There were 166 living donor and recipient pairs. The mean donor age was 44.8 years (SD ± 10.8), and donor mean BMI was 25.5 (SD ± 2.9). The recipients of living donor kidneys were 64% male and had a mean age of 43.5 years (SD ± 13.3). Six percent of patients experienced an episode of cellular rejection and were maintained on dialysis for a mean of 18 months (13–32) prior to transplant. Kidney volume was divided into tertiles based on lowest, middle, and highest volume. Kidney volume median (range) in tertiles 1, 2, and 3 was 124 (89–135 ml), 155 (136–164 ml), and 184 (165–240 ml) with donor eGFR ml/min (adjusted for body surface area expressed as ml/min/1.73 m2) at the time of donation in each tertile, 109 (93–129), 110 (92–132), and 101 ml/min (84–117). The median (IQR) eGFR in tertiles 1 to 3 in kidney recipients at 1 year after donation was 54 (44–67), 62 (50–75), and 63 ml/min (58–79), respectively. The median (IQR) eGFR in tertiles 1 to 3 in the remaining kidney of donors at 1 year after donation was 59 (53–66), 65 (57–72), and 65 ml/min (56–73), respectively. Conclusion. Bigger kidney volume was associated with better eGFR at 1 year after transplant in the recipient and marginally in the donor remaining kidney

Tantalum on Sapphire and Silicon Substrates for Superconducting Quantum Circuits

Materials science of superconducting circuits is considered with increasing importance, particularly as it directly affects qubit coherence. Appropriate nanofabrication and film growth techniques need to be developed to incorporate quality-factor engineered components. One emerging structure for superconductor ground planes and feedlines is tantalum (Ta) on a sapphire substrate, for which high coherence times were achieved for transmon qubits. The oxide formation and stoichiometry of α-phase Ta films leads to fewer sources of noise for the qubit to incoherently exchange energy with. In this presentation, we demonstrate growth techniques for deposition of Ta on heated sapphire substrates, and deposition of Ta on Si substrates using a Nb seed layer. We will also present different recipes that were used to dry etch Ta films into resonator structures, and discuss the extracted internal quality factors from these film. We discuss our investigations into fabricating Ta resonators on Si at room temperature which opens up a way to fabricate highly coherent circuits on systems without heating capabilities, and avoids thermally induced diffusion of pre-deposited materials. Finally, we detail the different dry etch chemistries that can be used and which one we have found to be optimal