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2.
J Phys Condens Matter ; 33(31)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34038894

RESUMO

The titanomagnetites (Fe2-xTixO4,x⩽ 1) are a family of reducible spinel-structure oxides of interest for their favorable magnetic, catalytic, and electrical transport properties. To understand the stability of the system during low temperature deposition, epitaxial thin films of Fe2TiO4were deposited by molecular beam epitaxy (MBE) on MgO(001) at 250-375 °C. The homogeneous incorporation of Ti, Fe valence state, and film morphology were all found to be strongly dependent on the oxidation conditions at the low substrate temperatures employed. More oxidizing conditions led to phase separation into epitaxial, faceted Fe3O4and rutile TiO2. Less oxidizing conditions resulted in polycrystalline films that exhibited Ti segregation to the film surface, as well as mixed Fe valence (Fe3+, Fe2+, Fe0). A narrow window of intermediate oxygen partial pressure during deposition yielded nearly homogeneous Ti incorporation and a large fraction of Fe2+. However, these films were poorly crystallized, and no occupation of tetrahedral sites in the spinel lattice by Fe2+was detected by x-ray magnetic circular dichroism at the Fe L-edge. After vacuum annealing, a small fraction of Fe2+was found to occupy tetrahedral sites. Comparison of these results with previous work suggests that the low temperature deposition conditions imposed by use of MgO substrates limits the incorporation of Ti into the spinel lattice. This work suggests a path towards obtaining stoichiometric, well-crystallized Fe2TiO4by MBE by utilizing high substrate temperature and low oxygen partial pressure during deposition on thermally stable substrates.

3.
Lancet Glob Health ; 9(3): e267-e279, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33333015

RESUMO

BACKGROUND: Progress in reducing maternal and neonatal deaths and stillbirths is impeded by data gaps, especially regarding coverage and quality of care in hospitals. We aimed to assess the validity of indicators of maternal and newborn health-care coverage around the time of birth in survey data and routine facility register data. METHODS: Every Newborn-BIRTH Indicators Research Tracking in Hospitals was an observational study in five hospitals in Bangladesh, Nepal, and Tanzania. We included women and their newborn babies who consented on admission to hospital. Exclusion critiera at admission were no fetal heartbeat heard or imminent birth. For coverage of uterotonics to prevent post-partum haemorrhage, early initiation of breastfeeding (within 1 h), neonatal bag-mask ventilation, kangaroo mother care (KMC), and antibiotics for clinically defined neonatal infection (sepsis, pneumonia, or meningitis), we collected time-stamped, direct observation or case note verification data as gold standard. We compared data reported via hospital exit surveys and via hospital registers to the gold standard, pooled using random effects meta-analysis. We calculated population-level validity ratios (measured coverage to observed coverage) plus individual-level validity metrics. FINDINGS: We observed 23 471 births and 840 mother-baby KMC pairs, and verified the case notes of 1015 admitted newborn babies regarding antibiotic treatment. Exit-survey-reported coverage for KMC was 99·9% (95% CI 98·3-100) compared with observed coverage of 100% (99·9-100), but exit surveys underestimated coverage for uterotonics (84·7% [79·1-89·5]) vs 99·4% [98·7-99·8] observed), bag-mask ventilation (0·8% [0·4-1·4]) vs 4·4% [1·9-8·1]), and antibiotics for neonatal infection (74·7% [55·3-90·1] vs 96·4% [94·0-98·6] observed). Early breastfeeding coverage was overestimated in exit surveys (53·2% [39·4-66·8) vs 10·9% [3·8-21·0] observed). "Don't know" responses concerning clinical interventions were more common in the exit survey after caesarean birth. Register data underestimated coverage of uterotonics (77·9% [37·8-99·5] vs 99·2% [98·6-99·7] observed), bag-mask ventilation (4·3% [2·1-7·3] vs 5·1% [2·0-9·6] observed), KMC (92·9% [84·2-98·5] vs 100% [99·9-100] observed), and overestimated early breastfeeding (85·9% (58·1-99·6) vs 12·5% [4·6-23·6] observed). Inter-hospital heterogeneity was higher for register-recorded coverage than for exit survey report. Even with the same register design, accuracy varied between hospitals. INTERPRETATION: Coverage indicators for newborn and maternal health care in exit surveys had low accuracy for specific clinical interventions, except for self-report of KMC, which had high sensitivity after admission to a KMC ward or corner and could be considered for further assessment. Hospital register design and completion are less standardised than surveys, resulting in variable data quality, with good validity for the best performing sites. Because approximately 80% of births worldwide take place in facilities, standardising register design and information systems has the potential to sustainably improve the quality of data on care at birth. FUNDING: Children's Investment Fund Foundation and Swedish Research Council.


Assuntos
Países em Desenvolvimento , Serviços de Saúde Materno-Infantil/organização & administração , Indicadores de Qualidade em Assistência à Saúde/organização & administração , Inquéritos e Questionários/normas , Antibacterianos/provisão & distribuição , Antibacterianos/uso terapêutico , Aleitamento Materno/estatística & dados numéricos , Humanos , Recém-Nascido , Doenças do Recém-Nascido/tratamento farmacológico , Método Canguru/estatística & dados numéricos , Serviços de Saúde Materno-Infantil/normas , Hemorragia Pós-Parto/prevenção & controle , Indicadores de Qualidade em Assistência à Saúde/normas , Qualidade da Assistência à Saúde/normas , Reprodutibilidade dos Testes
4.
J Glob Health ; 9(1): 010902, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30863542

RESUMO

BACKGROUND: To achieve Sustainable Development Goals and Universal Health Coverage, programmatic data are essential. The Every Newborn Action Plan, agreed by all United Nations member states and >80 development partners, includes an ambitious Measurement Improvement Roadmap. Quality of care at birth is prioritised by both Every Newborn and Ending Preventable Maternal Mortality strategies, hence metrics need to advance from health service contact alone, to content of care. As facility births increase, monitoring using routine facility data in DHIS2 has potential, yet validation research has mainly focussed on maternal recall surveys. The Every Newborn - Birth Indicators Research Tracking in Hospitals (EN-BIRTH) study aims to validate selected newborn and maternal indicators for routine tracking of coverage and quality of facility-based care for use at district, national and global levels. METHODS: EN-BIRTH is an observational study including >20 000 facility births in three countries (Tanzania, Bangladesh and Nepal) to validate selected indicators. Direct clinical observation will be compared with facility register data and a pre-discharge maternal recall survey for indicators including: uterotonic administration, immediate newborn care, neonatal resuscitation and Kangaroo mother care. Indicators including neonatal infection management and antenatal corticosteroid administration, which cannot be easily observed, will be validated using inpatient records. Trained clinical observers in Labour/Delivery ward, Operation theatre, and Kangaroo mother care ward/areas will collect data using a tablet-based customised data capturing application. Sensitivity will be calculated for numerators of all indicators and specificity for those numerators with adequate information. Other objectives include comparison of denominator options (ie, true target population or surrogates) and quality of care analyses, especially regarding intervention timing. Barriers and enablers to routine recording and data usage will be assessed by data flow assessments, quantitative and qualitative analyses. CONCLUSIONS: To our knowledge, this is the first large, multi-country study validating facility-based routine data compared to direct observation for maternal and newborn care, designed to provide evidence to inform selection of a core list of indicators recommended for inclusion in national DHIS2. Availability and use of such data are fundamental to drive progress towards ending the annual 5.5 million preventable stillbirths, maternal and newborn deaths.


Assuntos
Serviços de Saúde Materno-Infantil/estatística & dados numéricos , Serviços de Saúde Materno-Infantil/normas , Indicadores de Qualidade em Assistência à Saúde , Bangladesh , Feminino , Humanos , Recém-Nascido , Nepal , Gravidez , Reprodutibilidade dos Testes , Tanzânia
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