2,546 research outputs found
Time and dose dependency of bone-sarcomas in patients injected with radium-224
The time course and dose dependency of the incidence of bone-sarcomas among 900 German patients treated with high doses of radium-224 is analysed in terms of a proportional hazards model with a log-normal dependency of time to tumor and a linear-quadratic dose relation. The deduced dose dependency agrees well with a previous analysis in terms of a non-parametric proportional hazards model, and confirms the temporal distribution which has been used in the Radioepidemiological Tables of NIH. However, the linear-quadratic dose-response model gives a risk estimate for low doses which is somewhat less than half that obtained under the assumption of linearity.
Dedicated to Prof. W. Jacobi on the occasion of his 60th birthday
Work performed under Euratom contracts BI6-D-083-D, BI6-F-111-D, U.S. Department of Energy contract DE-AC 02-76 EV-00119, the U.S. National Cancer Institut
Design and assembly of a catalyst bed gas generator for the catalytic decomposition of high concentration hydrogen peroxide propellants and the catalytic combustion of hydrocarbon/air mixtures
A method for designing and assembling a high performance catalyst bed gas generator for use in decomposing propellants, particularly hydrogen peroxide propellants, for use in target, space, and on-orbit propulsion systems and low-emission terrestrial power and gas generation. The gas generator utilizes a sectioned catalyst bed system, and incorporates a robust, high temperature mixed metal oxide catalyst. The gas generator requires no special preheat apparatus or special sequencing to meet start-up requirements, enabling a fast overall response time. The high performance catalyst bed gas generator system has consistently demonstrated high decomposition efficiency, extremely low decomposition roughness, and long operating life on multiple test articles
Comparison of the impact of two national health and social care integration programmes on emergency hospital admissions
Background: Policy-makers expect that integration of health and social care will improve user and carer experience and reduce avoidable hospital use. [We] evaluate the impact on emergency hospital admissions of two large nationally-initiated service integration programmes in England: the Pioneer (November 2013 to March 2018) and Vanguard (January 2015 to March 2018) programmes. The latter had far greater financial and expert support from central agencies. Methods: Of the 206 Clinical Commissioning Groups (CCGs) in England, 51(25%) were involved in the Pioneer programme only, 22(11%) were involved in the Vanguard programme only and 13(6%) were involved in both programmes. We used quasi-experimental methods to compare monthly counts of emergency admissions between four groups of CCGs, before and after the introduction of the two programmes. Results: CCGs involved in the programmes had higher monthly hospital emergency admission rates than non-participants prior to their introduction [7.9 (95% CI:7.8–8.1) versus 7.5 (CI: 7.4–7.6) per 1000 population]. From 2013 to 2018, there was a 12% (95% CI:9.5–13.6%) increase in emergency admissions in CCGs not involved in either programme while emergency admissions in CCGs in the Pioneer and Vanguard programmes increased by 6.4% (95% CI: 3.8–9.0%) and 8.8% (95% CI:4.5–13.1%), respectively. CCGs involved in both initiatives experienced a smaller increase of 3.5% (95% CI:-0.3–7.2%). The slowdown largely occurred in the final year of both programmes. Conclusions: Health and social care integration programmes can mitigate but not prevent rises in emergency admissions over the longer-term. Greater financial and expert support from national agencies and involvement in multiple integration initiatives can have cumulative effects
The organisational and human resource challenges facing primary care trusts : protocol of a multiple case study
BACKGROUND: The study is designed to assess the organisational and human resource challenges faced by Primary Care Trusts (PCTs). Its objectives are to: specify the organisational and human resources challenges faced by PCTs in fulfilling the roles envisaged in government and local policy; examine how PCTs are addressing these challenges, in particular, to describe the organisational forms they have adopted, and the OD/HR strategies and initiatives they have planned or in place; assess how effective these structures, strategies and initiatives have been in enabling the PCTs to meet the organisational and human resources challenges they face; identify the factors, both internal to the PCT and in the wider health community, which have contributed to the success or failure of different structures, strategies and initiatives. METHODS: The study will be undertaken in three stages. In Stage 1 the key literature on public sector and NHS organisational development and human resources management will be reviewed, and discussions will be held with key researchers and policy makers working in this area. Stage 2 will focus on detailed case studies in six PCTs designed to examine the organisational and human resources challenges they face. Data will be collected using semi-structured interviews, group discussion, site visits, observation of key meetings and examination of local documentation. The findings from the case study PCTs will be cross checked with a Reference Group of up to 20 other PCG/Ts, and key officers working in organisational development or primary care at local, regional and national level. In Stage 3 analysis of findings from the preparatory work, the case studies and the feedback from the Reference Group will be used to identify practical lessons for PCTs, key messages for policy makers, and contributions to further theoretical development
Application of a mixed metal oxide catalyst to a metallic substrate
A method for applying a mixed metal oxide catalyst to a metallic substrate for the creation of a robust, high temperature catalyst system for use in decomposing propellants, particularly hydrogen peroxide propellants, for use in propulsion systems. The method begins by forming a prepared substrate material consisting of a metallic inner substrate and a bound layer of a noble metal intermediate. Alternatively, a bound ceramic coating, or frit, may be introduced between the metallic inner substrate and noble metal intermediate when the metallic substrate is oxidation resistant. A high-activity catalyst slurry is applied to the surface of the prepared substrate and dried to remove the organic solvent. The catalyst layer is then heat treated to bind the catalyst layer to the surface. The bound catalyst layer is then activated using an activation treatment and calcinations to form the high-activity catalyst system
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