96 research outputs found

    A conformable active matrix LED display

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    Conformable and stretchable displays can be integrated on complex surfaces. Such a display can assume the shape of a conformed surface by simultaneous multi-dimensional stretching and bending. Such technology provides new opportunities in the field of display applications, for example wearable displays integrated or embedded in a textile or onto complex surfaces in automotive interiors. In this work we present a conformable active matrix display using LEDs mounted on an amorphous Indium-Gallium-Zinc Oxide (a-IGZO) TFT backplane. A two-transistor and one capacitor (2T-1C) pixel engine based backplane, fabricated on polyimide substrate, is used to drive LEDs. Rigid LED pixels are connected via meandered copper film. The meander interconnections have been optimized with respect to their electrical and mechanical properties to provide a display with a 2 mm pitch between the pixels and good conformability. At an operating supply voltage of 7 V, the average brightness of the display exceeds 170 cd/m2

    High-sensitivity high-resolution X-ray imaging with soft-sintered metal halide perovskites

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    To realize the potential of artificial intelligence in medical imaging, improvements in imaging capabilities are required, as well as advances in computing power and algorithms. Hybrid inorganic–organic metal halide perovskites, such as methylammonium lead triiodide (MAPbI3), offer strong X-ray absorption, high carrier mobilities (”) and long carrier lifetimes (τ), and they are promising materials for use in X-ray imaging. However, their incorporation into pixelated sensing arrays remains challenging. Here we show that X-ray flat-panel detector arrays based on microcrystalline MAPbI3 can be created using a two-step manufacturing process. Our approach is based on the mechanical soft sintering of a freestanding absorber layer and the subsequent integration of this layer on a pixelated backplane. Freestanding microcrystalline MAPbI3 wafers exhibit a sensitivity of 9,300 ”C Gyair–1 cm–2 with a Ότ product of 4 × 10–4 cm2 V–1, and the resulting X-ray imaging detector, which has 508 pixels per inch, combines a high spatial resolution of 6 line pairs per millimetre with a low detection limit of 0.22 nGyair per frame

    Positive health effects of the natural outdoor environment in typical populations in different regions in Europe (PHENOTYPE): a study programme protocol

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    Introduction Growing evidence suggests that close contact with nature brings benefits to human health and well-being, but the proposed mechanisms are still not well understood and the associations with health remain uncertain. The Positive Health Effects of the Natural Outdoor environment in Typical Populations in different regions in Europe (PHENOTYPE) project investigates the interconnections between natural outdoor environments and better human health and well-being. Aims and methods The PHENOTYPE project explores the proposed underlying mechanisms at work (stress reduction/restorative function, physical activity, social interaction, exposure to environmental hazards) and examines the associations with health outcomes for different population groups. It implements conventional and new innovative high-tech methods to characterise the natural environment in terms of quality and quantity. Preventive as well as therapeutic effects of contact with the natural environment are being covered. PHENOTYPE further addresses implications for land-use planning and green space management. The main innovative part of the study is the evaluation of possible short-term and long-term associations of green space and health and the possible underlying mechanisms in four different countries (each with quite a different type of green space and a different use), using the same methodology, in one research programme. This type of holistic approach has not been undertaken before. Furthermore there are technological innovations such as the use of remote sensing and smartphones in the assessment of green space. Conclusions The project will produce a more robust evidence base on links between exposure to natural outdoor environment and human health and well-being, in addition to a better integration of human health needs into land-use planning and green space management in rural as well as urban areas

    Haploinsufficiency for ANKRD11-flanking genes makes the difference between KBG and 16q24.3 microdeletion syndromes:12 new cases

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    16q24 deletion involving the ANKRD11 gene, ranging from 137 kb to 2 Mb, have been associated with a microdeletion syndrome characterized by variable cognitive impairment, autism spectrum disorder, facial dysmorphisms with dental anomalies, brain abnormalities essentially affecting the corpus callosum and short stature. On the other hand, patients carrying either deletions encompassing solely ANKRD11 or its loss-of-function variants were reported in association with the KBG syndrome, characterized by a very similar phenotype, including mild-to-moderate intellectual disability, short stature and macrodontia of upper incisors, with inter and intrafamilial variability. To assess whether the haploinsufficiency of ANKRD11-flanking genes, such as ZFPM1, CDH15 and ZNF778, contributed to either the severity of the neurological impairment or was associated with other clinical features, we collected 12 new cases with a 16q24.2q24.3 deletion (de novo in 11 cases), ranging from 343 kb to 2.3 Mb. In 11 of them, the deletion involved the ANKRD11 gene, whereas in 1 case only flanking genes upstream to it were deleted. By comparing the clinical and genetic features of our patients with those previously reported, we show that the severity of the neurological phenotype and the frequency of congenital heart defects characterize the deletions that, besides ANKRD11, contain ZFPM1, CDH15 and ZNF778 as well. Moreover, the presence of thrombocytopenia and astigmatism should be taken into account to distinguish between 16q24 microdeletion syndrome and KBG syndrome. The single patient not deleted for ANKRD11, whose phenotype is characterized by milder psychomotor delay, cardiac congenital malformation, thrombocytopenia and astigmatism, confirms all this dat

    Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

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    [This corrects the article DOI: 10.1186/s13054-016-1208-6.]

    Scalable electronic ratchet with over 10% rectification efficiency

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    Electronic ratchets use a periodic potential with broken inversion symmetry to rectify undirected (electromagnetic, EM) forces and can in principle be a complement to conventional diode-based designs. Unfortunately, ratchet devices reported to date have low or undetermined power conversion efficiencies, hampering applicability. Combining experiments and numerical modeling, field-effect transistor-based ratchets are investigated in which the driving signal is coupled into the accumulation layer via interdigitated finger electrodes that are capacitively coupled to the field effect transistor channel region. The output current–voltage curves of these ratchets can have a fill factor >> 0.25 which is highly favorable for the power output. Experimentally, a maximum power conversion efficiency well over 10% at 5 MHz, which is the highest reported value for an electronic ratchet, is determined. Device simulations indicate this number can be increased further by increasing the device asymmetry. A scaling analysis shows that the frequency range of optimal performance can be scaled to the THz regime, and possibly beyond, while adhering to technologically realistic parameters. Concomitantly, the power output density increases from ≈4 W m−2 to ≈1 MW m−2. Hence, this type of ratchet device can rectify high-frequency EM fields at reasonable efficiencies, potentially paving the way for actual use as energy harvester

    Exact algorithms for procurement under a total quantity discount problems structure

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    In this paper, we study the procurement problem faced by a buyer who needs to purchase a variety of goods from suppliers applying a so-called total quantity discount policy. This policy implies that every supplier announces a number of volume intervals and that the volume interval in which the total amount ordered lies determines the discount. Moreover, the discounted prices apply to all goods bought from the supplier, not only to those goods exceeding the volume threshold. We refer to this cost-minimization problem as the total quantity discount (tqd) problem. We give a mathematical formulation for this problem and argue that not only it is np-hard, but also that there exists no polynomial-time approximation algorithm with a constant ratio (unless p = np). Apart from the basic form of the tqd problem, we describe four variants. In a first variant, the market share that one or more suppliers can obtain is constrained. Another variant allows the buyer to procure more goods than strictly needed, in order to reach a lower total cost. We also consider a setting where the buyer needs to pay a disposal cost for the extra goods bought. In a third variant, the number of winning suppliers is limited, both in general and per product. Finally, we investigate a multi-period variant, where the buyer not only needs to decide what goods to buy from what supplier, but also when to do this, while considering the inventory costs. We show that the tqd problem and its variants can be solved by solving a series of min-cost flow problems. Finally, we investigate the performance of three exact algorithms (min-cost flow based branch-and-bound, linear programming based branch-and-bound, and branch-and-cut) on randomly generated instances involving 50 suppliers and 100 goods. It turns out that even the large instances of the basic problem are solved to optimality within a limited amount of time. However, we find that different algorithms perform best in terms of computation time for different variants
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