Ultrathin and lightweight organic solar cells with high flexibility

Application-specific requirements for future lighting, displays and photovoltaics will include large-area, low-weight and mechanical resilience for dual-purpose uses such as electronic skin, textiles and surface conforming foils. Here we demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2 μm thick, with equal power conversion efficiency to their glass-based counterparts. They can reversibly withstand extreme mechanical deformation and have unprecedented solar cell-specific weight. Instead of a single bend, we form a random network of folds within the device area. The processing methods are standard, so the same weight and flexibility should be achievable in light emitting diodes, capacitors and transistors to fully realize ultrathin organic electronics. These ultrathin organic solar cells are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date

Diagnostic Testing of Pediatric Fevers: Meta-Analysis of 13 National Surveys Assessing Influences of Malaria Endemicity and Source of Care on Test Uptake for Febrile Children under Five Years.

In 2010, the World Health Organization revised guidelines to recommend diagnosis of all suspected malaria cases prior to treatment. There has been no systematic assessment of malaria test uptake for pediatric fevers at the population level as countries start implementing guidelines. We examined test use for pediatric fevers in relation to malaria endemicity and treatment-seeking behavior in multiple sub-Saharan African countries in initial years of implementation. We compiled data from national population-based surveys reporting fever prevalence, care-seeking and diagnostic use for children under five years in 13 sub-Saharan African countries in 2009-2011/12 (n = 105,791). Mixed-effects logistic regression models quantified the influence of source of care and malaria endemicity on test use after adjusting for socioeconomic covariates. Results were stratified by malaria endemicity categories: low (PfPR2-10<5%), moderate (PfPR2-10 5-40%), high (PfPR2-10>40%). Among febrile under-fives surveyed, 16.9% (95% CI: 11.8%-21.9%) were tested. Compared to hospitals, febrile children attending non-hospital sources (OR: 0.62, 95% CI: 0.56-0.69) and community health workers (OR: 0.31, 95% CI: 0.23-0.43) were less often tested. Febrile children in high-risk areas had reduced odds of testing compared to low-risk settings (OR: 0.51, 95% CI: 0.42-0.62). Febrile children in least poor households were more often tested than in poorest (OR: 1.63, 95% CI: 1.39-1.91), as were children with better-educated mothers compared to least educated (OR: 1.33, 95% CI: 1.16-1.54). Diagnostic testing of pediatric fevers was low and inequitable at the outset of new guidelines. Greater testing is needed at lower or less formal sources where pediatric fevers are commonly managed, particularly to reach the poorest. Lower test uptake in high-risk settings merits further investigation given potential implications for diagnostic scale-up in these areas. Findings could inform continued implementation of new guidelines to improve access to and equity in point-of-care diagnostics use for pediatric fevers

The World-Wide Web Gateway to Hyper-G: Using a Connectionless Protocol to Access Session-Oriented Services

In this thesis, possibilities are studied how session-oriented services on the Internet can be made accessible to users of client programs that use a connectionless application-level protocol. The concepts and properties of two Hypermedia Information Systems, the World-Wide Web (WWW) and Hyper-G, are described and a comparison between these two systems is given. A gateway program was developed which is used as a protocol converter between the sessionoriented Hyper-G client-server protocol and the connectionless Hypertext Transfer Protocol (HTTP). A mechanism was implemented that allows to differentiate HTTP requests and to assign them to Hyper-G sessions. The gateway provides users of World-Wide Web clients with session-oriented access to information residing on Hyper-G servers. Table of Contents 1. Introduction...............................................................................................................1 2. The World-Wide Web .........................................

The World-Wide Web Gateway to Hyper-G: Using a Connectionless Protocol to Access Session-Oriented Services

In this thesis, possibilities are studied how session-oriented services on the Internet can be made accessible to users of client programs that use a connectionless application-level protocol. The concepts and properties of two Hypermedia Information Systems, the World-Wide Web (WWW) and Hyper-G, are described and a comparison between these two systems is given. A gateway program was developed which is used as a protocol converter between the sessionoriented Hyper-G client-server protocol and the connectionless Hypertext Transfer Protocol (HTTP). A mechanism was implemented that allows to differentiate HTTP requests and to assign them to Hyper-G sessions. The gateway provides users of World-Wide Web client