Nonreciprocal Wavefront Engineering with Time-Modulated Gradient Metasurfaces

We propose a paradigm to realize nonreciprocal wavefront engineering using time-modulated gradient metasurfaces. The essential building block of these surfaces is a subwavelength unit cell whose reflection coefficient oscillates at low frequency. We demonstrate theoretically and experimentally that such modulation permits tailoring the phase and amplitude of any desired nonlinear harmonic and determines the behavior of all other emerging fields. By appropriately adjusting the phase delay applied to the modulation of each unit cell, we realize time-modulated gradient metasurfaces that provide efficient conversion between two desired frequencies and enable nonreciprocity by (i) imposing drastically different phase gradients during the up/down conversion processes and (ii) exploiting the interplay between the generation of certain nonlinear surface and propagative waves. To demonstrate the performance and broad reach of the proposed platform, we design and analyze metasurfaces able to implement various functionalities, including beam steering and focusing, while exhibiting strong and angle-insensitive nonreciprocal responses. Our findings open an alternative direction in the field of gradient metasurfaces, in which wavefront control and magnetic-free nonreciprocity are locally merged to manipulate the scattered fields

Anterior segment changes following intravitreal bevacizumab injection for treatment of neovascular glaucoma

The purpose of this study was to describe anterior segment changes in a prospective, interventional, noncomparative case series of patients with neovascular glaucoma secondary to proliferative diabetic retinopathy treated with intravitreal bevacizumab. Five consecutive patients with neovascular glaucoma and a refractory, symptomatic elevation of intraocular pressure and pronounced anterior segment congestion received intravitreal bevacizumab 1.25 mg/0.05 mL. Follow-up examinations were performed at 4-16 weeks by the same specialists, with testing performed at hour 48, week 1, and months 1, 3, and 6 after intravitreal bevacizumab. We observed a significant difference (P = 0.021) between initial and mean neovascularization at three months in all the quadrants. At three months, median intraocular pressure was 19 ± 5.38 (range 12-26) mmHg. In three of the five cases, diode laser cyclophotocoagulation was required, and in one case a trabeculectomy was performed. One patient showed complete synechial angle closure 48 hours after treatment which required cyclodestructive procedures to normalize intraocular pressure. Intravitreal bevacizumab achieves complete regression of neovascularization in neovascular glaucoma secondary to proliferative diabetic retinopathy, and this regression is stable when associated with treatment of the underlying disease and should be investigated more thoroughly as an adjunct in the management of neovascular glaucoma

Lithium-ion battery degradation: how to model it

Predicting lithium-ion battery degradation is worth billions to the global automotive, aviation and energy storage industries, to improve performance and safety and reduce warranty liabilities. However, very few published models of battery degradation explicitly consider the interactions between more than two degradation mechanisms, and none do so within a single electrode. In this paper, the first published attempt to directly couple more than two degradation mechanisms in the negative electrode is reported. The results are used to map different pathways through the complicated path dependent and non-linear degradation space. Four degradation mechanisms are coupled in PyBaMM, an open source modelling environment uniquely developed to allow new physics to be implemented and explored quickly and easily. Crucially it is possible to see 'inside' the model and observe the consequences of the different patterns of degradation, such as loss of lithium inventory and loss of active material. For the same cell, five different pathways that can result in end-of-life have already been found, depending on how the cell is used. Such information would enable a product designer to either extend life or predict life based upon the usage pattern. However, parameterization of the degradation models remains as a major challenge, and requires the attention of the international battery community

Description of the BRIGHTLIGHT cohort: the evaluation of teenage and young adult cancer services in England

Objective International recognition of the unique needs of young people with cancer is growing. Many countries have developed specialist age-appropriate cancer services believing them to be of value. In England, 13 specialist principal treatment centres (PTCs) deliver cancer care to young people. Despite this expansion of specialist care, systematic investigation of associated outcomes and costs has, to date, been lacking. The aim of this paper is to describe recruitment and baseline characteristics of the BRIGHTLIGHT cohort and the development of the bespoke measures of levels of care and disease severity, which will inform the evaluation of cancer services in England. Design Prospective, longitudinal, observational study. Setting Ninety-seven National Health Service hospitals in England. Participants A total of 1114 participants were recruited and diagnosed between July 2012 and December 2014: 55% (n=618) were men, mean age was 20.1 years (SD=3.3), most (86%) were white and most common diagnoses were lymphoma (31%), germ cell tumour (19%) and leukaemia (13%). Results At diagnosis, median quality of life score was significantly lower than a published control threshold (69.7 points); 40% had borderline to severe anxiety, and 21% had borderline to severe depression. There was minimal variation in other patient-reported outcomes according to age, diagnosis or severity of illness. Survival was lower in the cohort than for young people diagnosed during the same period who were not recruited (cumulative survival probability 4 years after diagnosis: 88% vs 92%). Conclusions Data collection was completed in March 2018. Longitudinal comparisons will determine outcomes and costs associated with access/exposure to PTCs. Findings will inform international intervention and policy initiatives to improve outcomes for young people with cancer

Climate impacts of energy technologies depend on emissions timing

Energy technologies emit greenhouse gases with differing radiative efficiencies and atmospheric lifetimes. Standard practice for evaluating technologies, which uses the global warming potential (GWP) to compare the integrated radiative forcing of emitted gases over a fixed time horizon, does not acknowledge the importance of a changing background climate relative to climate change mitigation targets. Here we demonstrate that the GWP misvalues the impact of CH[subscript 4]-emitting technologies as mid-century approaches, and we propose a new class of metrics to evaluate technologies based on their time of use. The instantaneous climate impact (ICI) compares gases in an expected radiative forcing stabilization year, and the cumulative climate impact (CCI) compares their time-integrated radiative forcing up to a stabilization year. Using these dynamic metrics, we quantify the climate impacts of technologies and show that high-CH[subscript 4]-emitting energy sources become less advantageous over time. The impact of natural gas for transportation, with CH[subscript 4] leakage, exceeds that of gasoline within 1–2 decades for a commonly cited 3 W m[superscript −2] stabilization target. The impact of algae biodiesel overtakes that of corn ethanol within 2–3 decades, where algae co-products are used to produce biogas and corn co-products are used for animal feed. The proposed metrics capture the changing importance of CH[subscript 4] emissions as a climate threshold is approached, thereby addressing a major shortcoming of the GWP for technology evaluation.New England University Transportation Center (DOT Grant DTRT07-G-0001

Specialist cancer services for teenagers and young adults in England: BRIGHTLIGHT research programme

Background: When cancer occurs in teenagers and young adults, the impact is far beyond the physical disease and treatment burden. The effect on psychological, social, educational and other normal development can be profound. In addition, outcomes including improvements in survival and participation in clinical trials are poorer than in younger children and older adults with similar cancers. These unique circumstances have driven the development of care models specifically for teenagers and young adults with cancer, often focused on a dedicated purpose-designed patient environments supported by a multidisciplinary team with expertise in the needs of teenagers and young adults. In England, this is commissioned by NHS England and delivered through 13 principal treatment centres. There is a lack of evaluation that identifies the key components of specialist care for teenagers and young adults, and any improvement in outcomes and costs associated with it. / Objective: To determine whether or not specialist services for teenagers and young adults with cancer add value. / Design: A series of multiple-methods studies centred on a prospective longitudinal cohort of teenagers and young adults who were newly diagnosed with cancer. / Settings: Multiple settings, including an international Delphi study of health-care professionals, qualitative observation in specialist services for teenagers and young adults, and NHS trusts. / Participants: A total of 158 international teenage and young adult experts, 42 health-care professionals from across England, 1143 teenagers and young adults, and 518 caregivers. / Main outcome measures: The main outcomes were specific to each project: key areas of competence for the Delphi survey; culture of teenagers and young adults care in the case study; and unmet needs from the caregiver survey. The primary outcome for the cohort participants was quality of life and the cost to the NHS and patients in the health economic evaluation. / Data sources: Multiple sources were used, including responses from health-care professionals through a Delphi survey and face-to-face interviews, interview data from teenagers and young adults, the BRIGHTLIGHT survey to collect patient-reported data, patient-completed cost records, hospital clinical records, routinely collected NHS data and responses from primary caregivers. / Results: Competencies associated with specialist care for teenagers and young adults were identified from a Delphi study. The key to developing a culture of teenage and young adult care was time and commitment. An exposure variable, the teenagers and young adults Cancer Specialism Scale, was derived, allowing categorisation of patients to three groups, which were defined by the time spent in a principal treatment centre: SOME (some care in a principal treatment centre for teenagers and young adults, and the rest of their care in either a children’s or an adult cancer unit), ALL (all care in a principal treatment centre for teenagers and young adults) or NONE (no care in a principal treatment centre for teenagers and young adults). The cohort study showed that the NONE group was associated with superior quality of life, survival and health status from 6 months to 3 years after diagnosis. The ALL group was associated with faster rates of quality-of-life improvement from 6 months to 3 years after diagnosis. The SOME group was associated with poorer quality of life and slower improvement in quality of life over time. Economic analysis revealed that NHS costs and travel costs were similar between the NONE and ALL groups. The ALL group had greater out-of-pocket expenses, and the SOME group was associated with greater NHS costs and greater expense for patients. However, if caregivers had access to a principal treatment centre for teenagers and young adults (i.e. in the ALL or SOME groups), then they had fewer unmet support and information needs. / Limitations: Our definition of exposure to specialist care using Hospital Episode Statistics-determined time spent in hospital was insufficient to capture the detail of episodes or account for the variation in specialist services. Quality of life was measured first at 6 months, but an earlier measure may have shown different baselines. / Conclusions: We could not determine the added value of specialist cancer care for teenagers and young adults as defined using the teenage and young adult Cancer Specialism Scale and using quality of life as a primary end point. A group of patients (i.e. those defined as the SOME group) appeared to be less advantaged across a range of outcomes. There was variation in the extent to which principal treatment centres for teenagers and young adults were established, and the case study indicated that the culture of teenagers and young adults care required time to develop and embed. It will therefore be important to establish whether or not the evolution in services since 2012–14, when the cohort was recruited, improves quality of life and other patient-reported and clinical outcomes. / Future work: A determination of whether or not the SOME group has similar or improved quality of life and other patient-reported and clinical outcomes in current teenage and young adult service delivery is essential if principal treatment centres for teenagers and young adults are being commissioned to provide ‘joint care’ models with other providers. / Funding: This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 12. See the NIHR Journals Library website for further project information

Trends in HbA1c thresholds for initiation of hypoglycemic agents:Impact of changed recommendations for older and frail patients

Aims: Less strict glycated hemoglobin (HbA1c) thresholds have been recommended in older and/or frail type 2 diabetes (T2D) patients than in younger and less frail patients for initiating hypoglycemic agents since 2011. We aimed to assess trends in HbA1c thresholds at initiation of a first hypoglycemic agent(s) in T2D patients and the influence of age and frailty on these trends. Materials and methods: The groningen initiative to analyze type 2 diabetes treatment (GIANTT) database was used, which includes primary care T2D patients from the north of the Netherlands. Patients initiating a first non-insulin hypoglycemic agent(s) between 2008 and 2014 with an HbA1c measurement within 120 days before initiation were included. The influence of calendar year, age, or frailty and the interaction between calendar year and age or frailty were assessed using multilevel regression analyses adjusted for confounders. Results: We included 4588 patients. The mean HbA1c threshold at treatment initiation was 7.4% up to 2010, decreasing to 7.1% in 2011 and increasing to 7.4% in 2014. This quadratic change over the years was significant (P 0.05). Conclusions: HbA1c thresholds at initiation of a first hypoglycemic agent(s) changed significantly over time, showing a decrease after 2010 and an increase after 2012. The HbA1c threshold at initiation was not influenced by age or frailty, which is in contrast with recommendations for more personalized treatment

10 simple rules to create a serious game, illustrated with examples from structural biology

Serious scientific games are games whose purpose is not only fun. In the field of science, the serious goals include crucial activities for scientists: outreach, teaching and research. The number of serious games is increasing rapidly, in particular citizen science games, games that allow people to produce and/or analyze scientific data. Interestingly, it is possible to build a set of rules providing a guideline to create or improve serious games. We present arguments gathered from our own experience ( Phylo , DocMolecules , HiRE-RNA contest and Pangu) as well as examples from the growing literature on scientific serious games

New use of global warming potentials to compare cumulative and short-lived climate pollutants

Parties to the United Nations Framework Convention on Climate Change (UNFCCC) have requested guidance on common greenhouse gas metrics in accounting for Nationally determined contributions (NDCs) to emission reductions1. Metric choice can affect the relative emphasis placed on reductions of ‘cumulative climate pollutants’ such as carbon dioxide versus ‘short-lived climate pollutants’ (SLCPs), including methane and black carbon2, 3, 4, 5, 6. Here we show that the widely used 100-year global warming potential (GWP100) effectively measures the relative impact of both cumulative pollutants and SLCPs on realized warming 20–40 years after the time of emission. If the overall goal of climate policy is to limit peak warming, GWP100 therefore overstates the importance of current SLCP emissions unless stringent and immediate reductions of all climate pollutants result in temperatures nearing their peak soon after mid-century7, 8, 9, 10, which may be necessary to limit warming to “well below 2 °C” (ref. 1). The GWP100 can be used to approximately equate a one-off pulse emission of a cumulative pollutant and an indefinitely sustained change in the rate of emission of an SLCP11, 12, 13. The climate implications of traditional CO2-equivalent targets are ambiguous unless contributions from cumulative pollutants and SLCPs are specified separately