85 research outputs found

    Towards Comparison of Ultrasound Dose Measurements - Current Capabilities and Open Challenges

    Get PDF
    open7sĂŹThe aim of this work is to evaluate measurement methods for dosimetry and exposimetry quantities that were developed in the EMRP project “Dosimetry for Ultrasound Therapy -DUTy” by comparing the measurement results for three common quantities from three national laboratories. It further aims to investigate the general feasibility of possible future (key) comparisons for dosimetry and exposimetry quantities and to identify possible open challenges towards this goal. The general format is similar to a metrological comparison, with which the National Metrological Institutes, NMIs, are already familiar. The first step involved the agreement of the protocol that was to specify the set of transducers to be circulated and the measurement conditions. Two transducers were circulated and different drive voltage levels and pulsing regimes were defined and tissue mimicking materials (TMMs) characteristics were specified. Each lab was asked to prepare the TMMs for their own measurements with the inclusion of formulations and preparation instructions specified in the protocol. Uncertainties of the input data were to be declared by the participating laboratories.openDurando, G.; Guglielmone, C.; Haller, J.; Georg, O.; Shaw, A.; Martin, E.; Karaböce, B.Durando, Giovanni; Guglielmone, CLAUDIO LUIGI DOME; Haller, J.; Georg, O.; Shaw, A.; Martin, E.; Karaböce, B

    Composite risk and benefit from adjuvant dose-dense chemotherapy in hormone receptor-positive breast cancer

    Get PDF
    The GIM2 phase III trial demonstrated the benefit of dose-dense chemotherapy in node-positive early breast cancer (eBC). To better define the dose-dense effect in the hormone receptor-positive subgroup, we evaluated its benefit through a composite measure of recurrence risk. We conducted an ancillary analysis of the GIM2 trial evaluating the absolute treatment effect through a composite measure of recurrence risk (CPRS) in patients with hormone receptor-positive HER2-negative eBC. CPRS was estimated through Cox proportional hazards models applied to the different clinicopathological features. The treatment effect was compared to the values of CPRS by using the Sub-population Treatment Effect Pattern Plot (STEPP) process. The Disease-Free Survival (DFS)-oriented STEPP analysis showed distinct patterns of relative treatment effect with respect to CPRS. Overall, 5-year DFS differed across CPRS quartiles ranging from 95.2 to 66.4%. Each CPRS quartile was characterized by a different patients\u2019 composition, especially for age, lymph node involvement, tumor size, estrogen and progesterone receptor expression, and Ki-67. A number needed to treat of 154 and 6 was associated with the lowest and the highest CPRS quartile, respectively. Dose-dense adjuvant chemotherapy showed a consistent benefit in node-positive eBC patients with hormone receptor-positive HER2-negative disease, but its effect varied according to CPRS

    Beam test results of 25 and 35 Ό m thick FBK ultra-fast silicon detectors

    Get PDF
    This paper presents the measurements on first very thin Ultra-Fast Silicon Detectors (UFSDs) produced by Fondazione Bruno Kessler; the data have been collected in a beam test setup at the CERN PS, using beam with a momentum of 12 GeV/c. UFSDs with a nominal thickness of 25 and 35 mu m and an area of 1 x 1 mm(2) have been considered, together with an additional HPK 50-mu m thick sensor, taken as reference. Their timing performances have been studied as a function of the applied voltage and gain. A time resolution of about 25 ps and of 22 ps at a voltage of 120 and 240 V has been obtained for the 25 and 35 mu m thick UFSDs, respectively

    Direct detection of charged particles with SiPMs

    Get PDF
    The direct response of Silicon PhotoMultipliers being traversed by a MIP charged particle have been studied in a systematic way for the first time. Using beam test data, time resolution and the crosstalk probability have been measured. A characterization of the SiPM by means of a laser beam is also reported. The results obtained for different sensors indicate a measured time resolution around 40-70 ps. Although particles are expected to traverse only one SPAD per event, crosstalk measurements on different sensors indicate an unexpected higher value with respect to the one related to the sensor noise

    National support to public health research: a survey of European ministries

    Get PDF
    Background: Within SPHERE (Strengthening Public Health Research in Europe), a collaborative study funded by the European Commission, we have assessed the support for public health research at ministry level in European countries. Methods: We surveyed the health and science ministries in 25 EU countries and 3 EEA countries, using a broad definition of public-health research at population level. We made over 600 phone calls and emails to identify respondents and to gain answers. We gained formal replies from 42 out of 56 ministries (73% response) in 25 countries. There were 22 completed questionnaires (from 25 ministries), 6 short answers and 11 contacts declaring that their ministries were not responsible for public health research, while in 14 ministries (both ministries in three countries) no suitable ministry contact could be found. Results: In most European countries, ministries of health, or their devolved agencies, were regarded as the leading organizations. Most ministries were able to specify thematic areas for public-health research (from three to thirty), and others ministries referred to policy documents, health plans or public-health plans to define research priorities. Ministries and their agencies led on decisions for financial support of public-health research, with less involvement of other external organisations compared with the process of identifying priorities. However, the actual funds available for public health were not easily identifiable. Most ministries relied on general academic means for dissemination of results of public-health research, while ministries get information on the use of public-health research usually through informal means. Ministries made suggestions for strengthening public-health research through initiatives of their own countries and of the European Union: as well as more resources, improving coordination was most frequently suggested. Conclusion: There is no common approach to support for public-health research across Europe, and significant gaps in organisation and funding. Health ministries and national agencies value exchange between researchers and policy-makers, civil society organizations, and academic and public authorities, and the application of public-health research results. There would be benefits from better processes of priority setting and improved coordination for research, at regional, national and European levels

    Measurements of the Cherenkov effect in direct detection of charged particles with SiPMs

    Full text link
    In this paper, different Silicon PhotoMultiplier (SiPM) sensors have been tested with charged particles to characterize the Cherenkov light produced in the sensor protection layer. A careful position scan of the SiPM response has been performed with different prototypes, confirming the large number of firing cells and proving almost full efficiency, with the SiPM filling factor essentially negligible. This study also allowed us to study the time resolution of such devices as a function of the number of firing cells, reaching values below 20 ps. These measurements provide significant insight into the capabilities of SiPM sensors in direct detection of charged particles and their potential for several applications

    Public health research systems in the European union

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Strengthening health research is an important objective for international health organisations, but there has been less attention to support for health research in Europe. We describe the public-health (population and organisational level) research systems in the 27 European Union countries.</p> <p>Methods</p> <p>We developed a typology for describing health research structures based on funding streams and strategies. We drew data from internet sources and asked country informants to review these for consistency and completeness. The structures were described as organograms and narratives in country profiles for each of the 27 EU member states. National public-health research structures included public and independent funding organisations, 'mixed' institutions (which receive funds, and both use and allocate them) and provider institutions.</p> <p>Results</p> <p>Most health research is funded through ministries of science or science councils (and sometimes foundations), while parliaments and regions may also contribute. National institutes of public health are usually funded by ministries of health. Many national research organisations both determine research programmes and undertake health research, but there is a move towards public-health sciences within the universities, and a transition from internal grants to competitive funding. Of 27 national research strategies, 17 referred to health and 11 to public health themes. Although all countries had strategies for public health itself, we found little coherence in public-health research programmes. The European Commission has country contact points for both EU research and health programmes, but they do not coordinate with national health-research programmes.</p> <p>Conclusions</p> <p>Public-health research is broadly distributed across programmes in EU countries. Better understanding of research structures, programmes and results would improve recognition for public health in Europe, and contribute to practice. EU ministries of health should give greater attention to national public-health research strategies and programmes, and the European Union and the World Health Organisation can provide coordination and support.</p

    Weight change during chemotherapy changes the prognosis in non metastatic breast cancer for the worse

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Weight change during chemotherapy is reported to be associated with a worse prognosis in breast cancer patients, both with weight gain and weight loss. However, most studies were conducted prior to the common use of anthracycline-base chemotherapy and on North American populations with a mean BMI classified as overweight. Our study was aimed to evaluate the prognostic value of weight change during anthracycline-based chemotherapy on non metastatic breast cancer (European population) with a long term follow-up.</p> <p>Methods</p> <p>Patients included 111 women diagnosed with early stage breast cancer and locally advanced breast cancer who have been treated by anthracycline-based chemotherapy regimen between 1976 and 1989. The relative percent weight variation (WV) between baseline and postchemotherapy treatment was calculated and categorized into either weight change (WV > 5%) or stable (WV < 5%). The median follow-up was 20.4 years [19.4 - 27.6]. Cox proportional hazard models were used to evaluate any potential association of weight change and known prognostic factors with the time to recurrence and overall survival.</p> <p>Results</p> <p>Baseline BMI was 24.4 kg/m2 [17.1 - 40.5]. During chemotherapy treatment, 31% of patients presented a notable weight variation which was greater than 5% of their initial weight.</p> <p>In multivariate analyses, weight change (> 5%) was positively associated with an increased risk of both recurrence (RR 2.28; 95% CI: 1.29-4.03) and death (RR 2.11; 95% CI: 1.21-3.66).</p> <p>Conclusions</p> <p>Our results suggest that weight change during breast-cancer chemotherapy treatment may be related to poorer prognosis with higher reccurence and higher mortality in comparison to women who maintained their weight.</p

    Effects of Topically Administered Neuroprotective Drugs in Early Stages of Diabetic Retinopathy:Results of the EUROCONDOR Clinical Trial

    Get PDF
    The primary objective of this study was to assess whether the topical administration of two neuroprotective drugs (brimonidine and somatostatin) could prevent or arrest retinal neurodysfunction in patients with type 2 diabetes. For this purpose, adults aged between 45 and 75 years with a diabetes duration ≄5 years and an Early Treatment of Diabetic Retinopathy Study (ETDRS) level of ≀35 were randomly assigned to one of three arms: placebo, somatostatin, or brimonidine. The primary outcome was the change in implicit time (IT) assessed by multifocal electroretinography between baseline and at the end of follow-up (96 weeks). There were 449 eligible patients allocated to brimonidine (n = 152), somatostatin (n = 145), or placebo (n = 152). When the primary end point was evaluated in the whole population, we did not find any neuroprotective effect of brimonidine or somatostatin. However, in the subset of patients (34.7%) with preexisting retinal neurodysfunction, IT worsened in the placebo group (P < 0.001) but remained unchanged in the brimonidine and somatostatin groups. In conclusion, the topical administration of the selected neuroprotective agents appears useful in preventing the worsening of preexisting retinal neurodysfunction. This finding points to screening retinal neurodysfunction as a critical issue to identify a subset of patients in whom neuroprotective treatment might be of benefit
    • 

    corecore