High-Temperature Cycling of Plasma Sprayed Multilayered NiCrAlY/YSZ/GZO/YAG Thermal Barrier Coatings Prepared from Liquid Feedstocks.

High-enthalpy hybrid water/argon-stabilized plasma (WSP-H) torch may be used for efficient deposition of coatings from dry powders, suspensions, and solutions. WSP-H torch was used to deposit two complete thermal barrier coatings (TBCs) with multilayered top-coat. NiCrAlY was used as bond-coat and deposited on nickel-based superalloy substrates. Top-coat consisted of up to three sublayers: (i) yttria-stabilized zirconia (ZrO2-8 wt.%Y2O3-YSZ) deposited from solution, (ii) gadolinium zirconate (Gd2Zr2O7-GZO) deposited from suspension, and (iii) optional yttrium aluminum garnet (Y3Al5O12-YAG) overlayer deposited from suspension. Each of the sublayers was intended to provide different functionalities, namely improved fracture toughness, low thermal conductivity, and high erosion resistance, respectively. High-temperature performance and thermal shock resistance of the deposited coatings were tested by thermal cycling fatigue "TCF" test (maximum temperature 1100 °C, 1 h dwell per cycle) and "laser-rig" test (maximum temperature ~ 1530 °C, 5 min dwell per cycle) exposing samples to isothermal and gradient thermal conditions, respectively. In both tests, coatings endured around 800 test cycles which shows great potential for further development of these layers and their application in demanding thermal conditions. Analysis of the samples after the test showed microstructural changes and identified reason of ultimate coating failure.

The Influence of Plasma Composition in the Thermal Cyclic Performance of Yttria-Stabilized Zirconia (8YSZ) Thermal Barrier Coatings (TBCs).

In the combustion chambers of gas turbine engines, ZrO2-8wt.%Y2O3 (YSZ) TBCs are commonly applied by air plasma spray (APS) using Ar-/H2-based plasmas via legacy torches. Alternatively, N2/H2 plasmas could be used with the potential of increasing overall deposition efficiency (DE) and hence reduce the consumption of high-value feedstock powder. Also, by increasing DE, spraying time would be reduced, thereby providing another contribution to bring down production costs. In this work, TBCs were prepared with Ar- and N2-based plasmas with different YSZ powders using Metco 9MB legacy torch. The use of N2-based plasma resulted in higher particle temperature and lower particle velocity values than those provided by the Ar-based plasma. The measured DEs were between 41-43 and 53-60% for the Ar- and N2-based plasmas, respectively. This represents a ~ 40% increase in the DE. The coatings produced with the two different plasmas exhibited equivalent porosity levels ~ 11-13%. On average, the lowest thermal conductivity values were given by a N2-based LD-B YSZ TBC. In the furnace cycle test, the performance of the TBCs prepared with the N2-based plasma was superior to that of the TBCs prepared with the Ar plasma, and also exceeding that of an industrial APS TBC benchmark.

National prevalence survey in Brazil to evaluate the quality of microbiology laboratories: the importance of defining priorities to allocate limited resources.

This report describes a survey of microbiology laboratories (n = 467) serving Brazilian hospitals with ≥10 intensive care beds and/or involved in the government health care adverse event reporting system. Coordinators were interviewed and laboratories classified as follows: Level 0 (no minimal functioning conditions-85.4% of laboratories); Level 1 (minimal functioning conditions but inadequate execution of basic routine-6.7%); Level 2 (minimal functioning conditions and adequate execution of basic routine but no adequate procedures for quality control-5.8%); Level 3 (minimal functioning conditions, adequate execution of basic routine, and adequate procedures for quality control, but no direct communication with the infection control department-0.9%); Level 4 (minimal functioning conditions, adequate execution of basic routine, adequate procedures for quality control, and direct communication with infection control, but no available advanced resources-none); and Level 5 (minimal functioning conditions, adequate execution of basic routine, adequate procedures for quality control, direct communication with infection control, and available advanced resources-0.9%). Twelve laboratories did not perform Ziehl-Neelsen staining; 271 did not have safety cabinets; and >30% without safety cabinets had automated systems. Low quality was associated with serving hospitals not participating in government adverse-event program; private hospitals; nonteaching hospitals; and those outside state capitals. Results may reflect what occurs in many other countries where defining priorities is important due to limited resources.

National prevalence survey in Brazil to evaluate the quality of microbiology laboratories: the importance of defining priorities to allocate limited resources / Encuesta de prevalencia nacional para evaluar la calidad de los laboratorios de microbiología en el Brasil: importancia de la definición de prioridades para asignar recursos limitados

This report describes a survey of microbiology laboratories (n = 467) serving Brazilian hospitals with >10 intensive care beds and/or involved in the government health care adverse event reporting system. Coordinators were interviewed and laboratories classified as follows: Level 0 (no minimal functioning conditions-85.4% of laboratories); Level 1 (minimal functioning conditions but inadequate execution of basic routine-6.7%); Level 2 (minimal functioning conditions and adequate execution of basic routine but no adequate procedures for quality control-5.8%); Level 3 (minimal functioning conditions, adequate execution of basic routine, and adequate procedures for quality control, but no direct communication with the infection control department-0.9%); Level 4 (minimal functioning conditions, adequate execution of basic routine, adequate procedures for quality control, and direct communication with infection control, but no available advanced resources-none); and Level 5 (minimal functioning conditions, adequate execution of basic routine, adequate procedures for quality control, direct communication with infection control, and available advanced resources-0.9%). Twelve laboratories did not perform Ziehl-Neelsen staining; 271 did not have safety cabinets; and >30% without safety cabinets had automated systems. Low quality was associated with serving hospitals not participating in government adverse-event program; private hospitals; nonteaching hospitals; and those outside state capitals. Results may reflect what occurs in many other countries where defining priorities is important due to limited resources.

Este artículo describe una encuesta realizada en Brasil en laboratorios de microbiología (n = 467) que prestaban servicio a hospitales que contaban al menos con 10 camas de cuidados intensivos. Se entrevistó a los coordinadores y los laboratorios se clasificaron de la siguiente manera: nivel 0 (sin condiciones de funcionamiento mínimas: 85,4% de los laboratorios), nivel 1 (condiciones de funcionamiento mínimas pero ejecución inadecuada del trabajo habitual básico: 6,7%), nivel 2 (condiciones de funcionamiento mínimas y ejecución adecuada del trabajo habitual básico, pero sin procedimientos de control de calidad apropiados: 5,8%), nivel 3 (condiciones de funcionamiento mínimas, ejecución adecuada del trabajo habitual básico y procedimientos de control de calidad apropiados, pero sin comunicación directa con el departamento de control de infecciones: 0,9%), nivel 4 (condiciones de funcionamiento mínimas, ejecución adecuada del trabajo habitual básico, procedimientos de control de calidad apropiados y comunicación directa con el departamento de control de infecciones, pero sin recursos avanzados disponibles: ningún laboratorio) y nivel 5 (condiciones de funcionamiento mínimas, ejecución adecuada del trabajo habitual básico, procedimientos de control de calidad apropiados, comunicación directa con el departamento de control de infecciones y recursos avanzados disponibles: 0,9%). Doce laboratorios no realizaban la tinción de Ziehl-Neelsen, 271 no contaban con cámaras de seguridad biológica, y más de 30% de los laboratorios que carecían de cámaras de seguridad biológica tenían sistemas automatizados. La escasa calidad se asoció a la falta de participación en el programa gubernamental de notificación de acontecimientos adversos, a los hospitales privados, a los hospitales no docentes y a la ubicación de los hospitales fuera de las capitales de los estados. Los resultados pueden reflejar lo que ocurre en muchos otros países con recursos limitados, donde es importante definir las prioridades.

Titania-hydroxyapatite nanocomposite coatings support human mesenchymal stem cells osteogenic differentiation.

In addition to mechanical and chemical stability, the third design goal of the ideal bone-implant coating is the ability to support osteogenic differentiation of mesenchymal stem cells (MSCs). Plasma-sprayed TiO(2)-based bone-implant coatings exhibit excellent long-term mechanical properties, but their applications in bone implants are limited by their bioinertness. We have successfully produced a TiO(2) nanostructured (grain size <50 nm) based coating charged with 10% wt hydroxyapatite (TiO(2)-HA) sprayed by high-velocity oxy-fuel. On Ti64 substrates, the novel TiO(2)-HA coating bond 153× stronger and has a cohesive strength 4× higher than HA coatings. The HA micro- and nano-sized particles covering the TiO(2)-HA coating surface are chemically bound to the TiO(2) coating matrix, producing chemically stable coatings under high mechanical solicitations. In this study, we elucidated the TiO(2)-HA nanocomposite coating surface chemistry, and in vitro osteoinductive potential by culturing human MSCs (hMSCs) in basal and in osteogenic medium (hMSC-ob). We assessed the following hMSCs and hMSC-ob parameters over a 3-week period: (i) proliferation; (ii) cytoskeleton organization and cell-substrate adhesion; (iii) coating-cellular interaction morphology and growth; and (iv) cellular mineralization. The TiO(2) -HA nanocomposite coatings demonstrated 3× higher hydrophilicity than HA coatings, a TiO(2)-nanostructured surface in addition to the chemically bound HA micron- and nano-sized rod to the surface. hMSCs and hMSC-ob demonstrated increased proliferation and osteoblastic differentiation on the nanostructured TiO(2)-HA coatings, suggesting the TiO(2)-HA coatings nanostructure surface properties induce osteogenic differentiation of hMSC and support hMSC-ob osteogenic potential better than our current golden standard HA coating.