46 research outputs found

    Infinitesimal sulfur fusion yields quasi-metallic bulk silicon for stable and fast energy storage

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    A fast-charging battery that supplies maximum energy is a key element for vehicle electrification. High-capacity silicon anodes offer a viable alternative to carbonaceous materials, but they are vulnerable to fracture due to large volumetric changes during charge???discharge cycles. The low ionic and electronic transport across the silicon particles limits the charging rate of batteries. Here, as a three-in-one solution for the above issues, we show that small amounts of sulfur doping (<1 at%) render quasi-metallic silicon microparticles by substitutional doping and increase lithium ion conductivity through the flexible and robust self-supporting channels as demonstrated by microscopy observation and theoretical calculations. Such unusual doping characters are enabled by the simultaneous bottom-up assembly of dopants and silicon at the seed level in molten salts medium. This sulfur-doped silicon anode shows highly stable battery cycling at a fast-charging rate with a high energy density beyond those of a commercial standard anode

    ESGAP inventory of target indicators assessing antibiotic prescriptions: A cross-sectional survey

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    Background A variety of indicators is commonly used to monitor antibiotic prescriptions as part of national antimicrobial stewardship (AMS) programmes. Objectives To make an inventory of indicators that assess antibiotic prescriptions and are linked to specific targets and incentives, at a national level. Methods A cross-sectional survey (three-item questionnaire) was conducted in 2017 among all ESGAP (ESCMID Study Group for Antimicrobial stewardshiP) members, coming from 23 European countries and 16 non-European countries. Results Almost all (20/23, 87%) European countries belonging to the ESGAP network participated, as well as one non-European country. Computerized systems routinely linking antibiotic prescriptions to clinical diagnoses were reported for only two countries (Turkey and Croatia). Only 6/21 (29%) countries had national indicators with both clear targets and incentives (Bulgaria, Croatia, France, the Netherlands, Norway and Portugal). We identified a total of 21 different indicators used in these countries, 16 concerning inpatients (9 quality indicators and 7 quantity metrics) and 8 concerning outpatients (all quantity metrics); some indicators were used in both settings. Three types of incentives were used: financing mechanism, hospitals' accreditation and public reporting. Some respondents reported that such indicators with both clear targets and incentives were used at a regional level in their country (e.g. Andalusia in Spain and England in the UK). Conclusions National indicators, with clear targets and incentives, are not commonly used in Europe and we observed wide variations between countries regarding the selected indicators, the units of measure and the chosen targets

    Antimicrobial consumption and resistance in adult hospital inpatients in 53 countries:results of an internet-based global point prevalence survey

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    Summary: Background: The Global Point Prevalence Survey (Global-PPS) established an international network of hospitals to measure antimicrobial prescribing and resistance worldwide. We aimed to assess antimicrobial prescribing and resistance in hospital inpatients. Methods: We used a standardised surveillance method to collect detailed data about antimicrobial prescribing and resistance from hospitals worldwide, which were grouped by UN region. The internet-based survey included all inpatients (adults, children, and neonates) receiving an antimicrobial who were on the ward at 0800 h on one specific day between January and September, 2015. Hospitals were classified as primary, secondary, tertiary (including infectious diseases hospitals), and paediatric hospitals. Five main ward types were defined: medical wards, surgical wards, intensive-care units, haematology oncology wards, and medical transplantation (bone marrow or solid transplants) wards. Data recorded included patient characteristics, antimicrobials received, diagnosis, therapeutic indication according to predefined lists, and markers of prescribing quality (eg, whether a stop or review date were recorded, and whether local prescribing guidelines existed and were adhered to). We report findings for adult inpatients. Findings: The Global-PPS for 2015 included adult data from 303 hospitals in 53 countries, including eight lower-middle-income and 17 upper-middle-income countries. 86 776 inpatients were admitted to 3315 adult wards, of whom 29 891 (34·4%) received at least one antimicrobial. 41 213 antimicrobial prescriptions were issued, of which 36 792 (89·3%) were antibacterial agents for systemic use. The top three antibiotics prescribed worldwide were penicillins with β-lactamase inhibitors, third-generation cephalosporins, and fluoroquinolones. Carbapenems were most frequently prescribed in Latin America and west and central Asia. Of patients who received at least one antimicrobial, 5926 (19·8%) received a targeted antibacterial treatment for systemic use, and 1769 (5·9%) received a treatment targeting at least one multidrug-resistant organism. The frequency of health-care-associated infections was highest in Latin America (1518 [11·9%]) and east and south Asia (5363 [10·1%]). Overall, the reason for treatment was recorded in 31 694 (76·9%) of antimicrobial prescriptions, and a stop or review date in 15 778 (38·3%). Local antibiotic guidelines were missing for 7050 (19·2%) of the 36 792 antibiotic prescriptions, and guideline compliance was 77·4%. Interpretation: The Global-PPS showed that worldwide surveillance can be accomplished with voluntary participation. It provided quantifiable measures to assess and compare the quantity and quality of antibiotic prescribing and resistance in hospital patients worldwide. These data will help to improve the quality of antibiotic prescribing through education and practice changes, particularly in low-income and middle-income countries that have no tools to monitor antibiotic prescribing in hospitals. Funding: bioMérieux

    Solution-processed semiconductors for next-generation photodetectors

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    Efficient light detection is central to modern science and technology.Current photodetectors mainly use photodiodes based on crystalline inorganic elementalsemiconductors, such as silicon, or compounds such as III–V semiconductors. Photodetectorsmade of solution-processed semiconductors — which include organic materials, metal-halideperovskites and quantum dots — have recently emerged as candidates for next-generation lightsensing. They combine ease of processing, tailorable optoelectronic properties, facile integrationwith complementary metal–oxide–semiconductors, compatibility with flexible substrates andgood performance. Here, we review the recent advances and the open challenges in the field ofsolution-processed photodetectors, examining the topic from both the materials and the deviceperspective and highlighting the potential of the synergistic combination of materials and deviceengineering. We explore hybrid phototransistorsand their potential to overcome trade-offsin noise, gain and speed, as well as the rapid advances in metal-halide perovskite photodiodesand their recent application in narrowband filterless photodetection
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