Localised tuneable composition single crystal silicon-germanium-on-insulator for low cost devices

The realisation of high quality silicon-germanium-on-insulator (SGOI) is a major goal for the field of silicon photonics because it has the potential to enable extremely low power active devices functioning at the communication wavelengths of 1.3 µm and 1.55 µm. In addition, SGOI has the potential to form faster electronic devices such as BiCMOS transistors, and could also form the backbone of a new silicon photonics platform that extends into the mid-IR wavelengths for applications in, amongst others, sensing and telecoms. In this paper, we present a novel method of forming single crystal, defect free SGOI using a rapid melt growth technique. We use tailored structures to form localised uniform composition SGOI strips, which are suitable for state of the art device fabrication. This technique could pave the way for the seamless integration of electronic and photonic devices using only a single, low cost Ge deposition step

Costs and Outcomes of Increasing Access to Bariatric Surgery: Cohort Study and Cost-Effectiveness Analysis Using Electronic Health Records

Objectives: To estimate costs and outcomes of increasing access to bariatric surgery in obese adults and in population subgroups of age, sex, deprivation, comorbidity, and obesity category. Methods: A cohort study was conducted using primary care electronic health records, with linked hospital utilization data, for 3,045 participants who underwent bariatric surgery and 247,537 participants who did not undergo bariatric surgery. Epidemiological analyses informed a probabilistic Markov model to compare bariatric surgery, including equal proportions with adjustable gastric banding, gastric bypass, and sleeve gastrectomy, with standard nonsurgical management of obesity. Outcomes were quality-adjusted life-years (QALYs) and net monetary benefits at a threshold of £30,000 per QALY. Results: In a UK population of 250,000 adults, there may be 7,163 people with morbid obesity including 1,406 with diabetes. The immediate cost of 1,000 bariatric surgical procedures is £9.16 million, with incremental discounted lifetime health care costs of £15.26 million (95% confidence interval £15.18–£15.36 million). Patient-years with diabetes mellitus will decrease by 8,320 (range 8,123–8,502). Incremental QALYs will increase by 2,142 (range 2,032–2,256). The estimated cost per QALY gained is £7,129 (range £6,775–£7,506). Net monetary benefits will be £49.02 million (range £45.72–£52.41 million). Estimates are similar for subgroups of age, sex, and deprivation. Bariatric surgery remains cost-effective if the procedure is twice as costly, or if intervention effect declines over time. Conclusions: Diverse obese individuals may benefit from bariatric surgery at acceptable cost. Bariatric surgery is not cost-saving, but increased health care costs are exceeded by health benefits to obese individuals

\u27Vitamin D and cognition in older adults\u27: updated international recommendations.

BACKGROUND: Hypovitaminosis D, a condition that is highly prevalent in older adults aged 65 years and above, is associated with brain changes and dementia. Given the rapidly accumulating and complex contribution of the literature in the field of vitamin D and cognition, clear guidance is needed for researchers and clinicians. METHODS: International experts met at an invitational summit on \u27Vitamin D and Cognition in Older Adults\u27. Based on previous reports and expert opinion, the task force focused on key questions relating to the role of vitamin D in Alzheimer\u27s disease and related disorders. Each question was discussed and voted using a Delphi-like approach. RESULTS: The experts reached an agreement that hypovitaminosis D increases the risk of cognitive decline and dementia in older adults and may alter the clinical presentation as a consequence of related comorbidities; however, at present, vitamin D level should not be used as a diagnostic or prognostic biomarker of Alzheimer\u27s disease due to lack of specificity and insufficient evidence. This population should be screened for hypovitaminosis D because of its high prevalence and should receive supplementation, if necessary; but this advice was not specific to cognition. During the debate, the possibility of \u27critical periods\u27 during which vitamin D may have its greatest impact on the brain was addressed; whether hypovitaminosis D influences cognition actively through deleterious effects and/or passively by loss of neuroprotection was also considered. CONCLUSIONS: The international task force agreed on five overarching principles related to vitamin D and cognition in older adults. Several areas of uncertainty remain, and it will be necessary to revise the proposed recommendations as new findings become available

Visual impairment, eye diseases and dementia risk: A systematic review and meta-analysis

This is the author accepted manuscript. The final version is available from IOS Press via the DOI in this recordBackground: Visual impairment and eye diseases have been associated with dementia, though with mixed findings and often in cross-sectional studies. Objective: To identify prospective studies investigating associations between visual impairment or common eye diseases and risk of all-cause dementia or key dementia subtypes. Methods: We searched Medline, PsycINFO, and Embase from inception to January 2020. We also conducted backward and forward citation searches of included studies and set up alerts to identify studies published after the search date. Random-effects meta-analysis was used to combine adjusted estimates across studies. Results: Thirty studies met our eligibility criteria. For visual impairment, pooled estimates indicated an increased risk of all-cause dementia (37,705 participants, 3,415 cases, risk ratio [RR] = 1.38, 95% confidence interval [CI]: 1.19-1.59, I2 = 28.6%). Pooled estimates also suggested an increased dementia risk associated with cataract (6,659 participants, 1,312 cases, hazard ratio [HR] = 1.17, 95% CI 1.00-1.38, I2= 0.0%) and diabetic retinopathy (43,658 participants, 7,060 cases, HR= 1.34, 95% CI 1.11-1.61, I2= 63.9%), respectively. There was no evidence of an association between glaucoma (175,357 participants, 44,144 cases, HR= 0.97, 95% CI 0.90-1.04, I2= 51.5%) or age-related macular degeneration (7,800,692 participants, >2,559 cases, HR= 1.15, 95% CI 0.88-1.50, I2= 91.0%) and risk of dementia, respectively. Conclusion: As visual impairment, cataract and diabetic retinopathy are associated with an increased likelihood of developing dementia, early diagnosis may help identify those at risk of dementia. Given most causes of visual impairment are treatable or preventable, the potential for dementia prevention warrants further investigation.Nicolaus and Margrit Langbehn FoundationMoorfields Eye CharityUKRIAlzheimer’s Research UKNational Health and Medical Research Council (NHMRC)JP Moulton FoundationNational Institute on AgingNational Institutes of Health (NIH)Alan Turing InstituteEngineering and Physical Sciences Research Council (EPSRC)Federal Ministry of Education and Research (BMBF)Federal Joint Committee (G-BA) Innovation Fun

The advantages of UK Biobank's open access strategy for health research

Ready access to health research studies is becoming more important as researchers, and their funders, seek to maximize the opportunities for scientific innovation and health improvements. Large‐scale population‐based prospective studies are particularly useful for multidisciplinary research into the causes, treatment and prevention of many different diseases. UK Biobank has been established as an open‐access resource for public health research, with the intention of making the data as widely available as possible in an equitable and transparent manner. Access to UK Biobank's unique breadth of phenotypic and genetic data has attracted researchers worldwide from across academia and industry. As a consequence, it has enabled scientists to perform world‐leading collaborative research. Moreover, open access to an already deeply characterized cohort has encouraged both public and private sector investment in further enhancements to make UK Biobank an unparalleled resource for public health research and an exemplar for the development of open‐access approaches for other studies

High-speed 4 ×{\times} 4 silicon photonic electro-optic switch, operating at the 2 {\mu}m waveband

The escalating need for expansive data bandwidth, and the resulting capacity constraints of the single mode fiber (SMF) have positioned the 2-${\mu}$m waveband as a prospective window for emerging applications in optical communication. This has initiated an ecosystem of silicon photonic components in the region driven by CMOS compatibility, low cost, high efficiency and potential for large-scale integration. In this study, we demonstrate a plasma dispersive, 4 ${\times}$ 4 electro-optic switch operating at the 2-${\mu}$m waveband with the shortest switching times. The demonstrated switch operates across a 45-nm bandwidth, with 10-90% rise and 90-10% fall time of 1.78 ns and 3.02 ns respectively. In a 4 ${\times}$ 4 implementation, crosstalk below -15 dB and power consumption below 19.15 mW across all 16 ports are indicated. The result brings high-speed optical switching to the portfolio of devices at the promising waveband

Health technology reassessment: the art of the possible

BACKGROUND: Health technology reassessment (HTR) is "a structured, evidence-based assessment of the clinical, social, ethical, and economic effects of a technology currently used in the healthcare system, to inform optimal use of that technology in comparison to its alternatives." The purpose of this study is to describe the key themes in the context of current HTR activities and propose a way forward for this newly emerging field. METHODS: Data were gathered from a workshop held as part of the 2012 Canadian Agency for Drugs and Technology in Health (CADTH) symposium. The workshop consisted of two panel presentations followed by discussion; data gathered, including presentations and rich audience discussion transcripts, were analyzed for key themes emerging in the field of HTR using constant comparative analysis. RESULTS: The language chosen to describe HTR will set the tone for engagement. The identification of champions at multiple levels and political will are essential. Key lessons from international experience are: disinvestment is difficult, focus on clinical areas not specific technologies, identify clear goals of the HTR agenda. Six key themes were identified to move the HTR agenda forward: emphasize integration over segregation, focus on development of HTR methods and processes, processes are context-specific but lessons must be shared, build capacity in synergistic interdisciplinary fields, develop meaningful stakeholder engagement, strengthen postimplementation monitoring and evaluation. CONCLUSIONS: To move this field forward, we must continue to build on international experiences with a focus on developing novel methodological approaches to generating, incorporating, and implementing evidence into policy and practice.Gail MacKean, Tom Noseworthy, Adam G. Elshaug, Laura Leggett, Peter Littlejohns, Joan Berezanski and Fiona Clemen