RESUMO
Healthcare facilities in low-income and middle-income countries lack an objective measurement tool to assess emergency care capacity. The African Federation for Emergency Medicine developed the Emergency Care Assessment Tool (ECAT) to fulfil this function. The ECAT assesses the provision of key medical interventions (signal functions) that emergency units (EUs) should be able to perform to adequately treat six common, life-threatening conditions (sentinel conditions). We describe the piloting and refinement of the ECAT, to improve usability and context-appropriateness. We undertook iterative, multisite refinement of the ECAT. After pilot testing at a South African referral hospital, subsequent studies occurred at district, regional and central facilities across four countries representing the major regions of Africa: Cameroon, Uganda, Egypt and Botswana. At each site, the tool was administered to three participants: one senior physician, one senior nurse and one other clinical provider. Feedback informed refinements of the ECAT, and an updated tool was used in the next-studied country. Iteratively implementing refined versions of the tool in various contexts across Africa resulted in a final ECAT that uses signal functions, categorised by sentinel conditions and evaluated against discrete barriers to emergency care service delivery, to assess EUs. It also allowed for refinement of administration and data analysis processes. The ECAT has a total of 71 items. Advanced facilities are expected to perform all 71 signal functions, while intermediate facilities should be able to perform 53. The ECAT is the first tool to provide a standardised method for assessing facility-based emergency care in the African context. It identifies where in the maturation process a hospital or system is and what gaps exist in delivery of care, so that a comprehensive roadmap for development can be established. Although validity and feasibility testing have now occurred, reliability studies must be conducted prior to amplification across the region.
RESUMO
We report a systemic study of the stability of organic thin film transistors (OTFTs) both in storage and under operation. Apart from a thin polystyrene buffer layer spin-coated onto the gate dielectric, the constituent parts of the OTFTs were all prepared by vacuum evaporation. The OTFTs are based on the semiconducting small molecule dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) deposited onto the surface of a polystyrene-buffered in situ polymerized diacrylate gate insulator. Over a period of 9 months, no degradation of the hole mobility occurred in devices stored either in the dark in dry air or in uncontrolled air and normal laboratory fluorescent lighting conditions. In the latter case, rather than decreasing, the mobility actually increased almost 2-fold to 1.5 cm(2)/(V · s). The devices also showed good stability during repeat on/off cycles in the dark in dry air. Exposure to oxygen and light during the on/off cycles led to a positive shift of the transfer curves due to electron trapping when the DNTT was biased into depletion by the application of positive gate voltage. When operated in accumulation, negative gate voltage under the same conditions, the transfer curves were stable. When voltage cycling in moist air in the dark, the transfer curves shifted to negative voltages, thought to be due to the generation of hole traps either in the semiconductor or its interface with the dielectric layer. When subjected to gate bias stress in dry air in the dark for at least 144 h, the device characteristics remained stable.