[«KCE Trials» : innovation based on practice oriented clinical trials]

Many questions in healthcare can only be answered after the conduct of clinical trials. For medicinal products and medical devices the industry finances most studies to bring their products to market. However, there is a need for further research in certain areas e.g. children, older people and comparative research of different treatment options (comparative effectiveness). In addition, interventions that are less industry-driven such as surgery, radiotherapy, psychotherapy, diet, physical medicine, needappropriately funded large scale clinical trials. Such clinical trials can be a good investment for the government and the healthcare payer. At the end of 2015 the Belgian Healthcare Knowledge Centre (KCE) received the mission and budget to run a programme of practice-oriented comparative clinical trials. Two years later the recruitment of patients in the first trials is ongoing. In addition to its yearly national calls for trial proposals, early in 2018 KCE launched its first international common call for comparative clinical trials with its Dutch counterpart ZonMw (BeNeFIT).

CHARACTERIZATION OF FLUORESCENT NUCLEAR TRACK DETECTORS AS CRITICALITY DOSIMETERS II

Fluorescent nuclear track detectors (FNTDs) as criticality dosimeters for both neutrons and gamma are further characterized in terms of angular dependence and quick dose assessment. The power spectrum integral depth profiles obtained from stacks of fluorescent images acquired within FNTDs exposed to a broad spectrum neutron field at various angles are analyzed to determine a calibration curve for angular dependence. MCNPX simulations were shown to be in good agreement with experimental results. A prototype triage reader was also designed and tested for quick assessment of dose. An unfolding technique incorporating both energy dependence and angular dependence is discussed. The advantages and shortcomings of using FNTDs in the event of a criticality excursion accident are analyzed.

COMPARISON BETWEEN PADC AND FNTD NEUTRON DETECTOR SYSTEMS IN BLIND TESTS

The objective of this study was to compare a neutron dosimetry system based on polyallyl diglycol carbonate (PADC) detectors with a new system based on Al2O3:C,Mg fluorescence nuclear track detectors (FNTD). The irradiations, performed as part of an intercomparison organized by the Physikalisch-Technische Bundesanstalt (PTB), Germany, were on a PMMA phantom with 252Cf or 241Am-Be source, usually with the phantom surface perpendicular to the radiation beam (0° angle), and with Hp(10) values between 0.3 and 7 mSv. One 252Cf irradiation was performed at 30° angle, and one with an additional 1 mSv gamma irradiation. The results showed an agreement between the two techniques with an average and maximum difference between PADCs and FNTDs of 1.5 and 22%, respectively, if one compares only cases of doses >1 mSv. For one of the irradiation conditions with dose of 0.9 mSv, use of the incorrect calibration factor for the FNTD (252Cf instead of 241Am-Be) led to reported values ~×2 larger than the given doses, due to low statistics in the determination of the ratio between 6Li-doped glass and polyethylene neutron converters. Although the FNTD track analysis algorithm may need further development, the results presented here demonstrate the feasibility of the FNTD technology and indicate areas requiring improvements.

ENERGY RESPONSE OF FLUORESCENT NUCLEAR TRACK DETECTORS OF VARIOUS COLORATIONS TO MONOENERGETIC NEUTRONS

The neutron-energy dependence of the track-counting sensitivity of fluorescent nuclear track detectors (FNTDs) at two ranges of Mg doping, resulting in different crystal colorations, was investigated. The performance of FNTDs was studied with the following converters: Li-glass for thermal to intermediate-energy neutrons, polyethylene for fast neutrons, and polytetrafluoroethylene (Teflon™) for photon- and radon-background subtraction. The irradiations with monoenergetic neutrons were performed at the National Physics Laboratory (NPL), UK. The energy range was varied from 144 keV to 16.5 MeV in the personal dose equivalent range from 1 to 3 mSv. Monte Carlo simulations were performed to model the response of FNTDs to monoenergetic neutrons. A good agreement with the experimental data was observed suggesting the development of a basic model for future MC studies. Further work will focus on increasing FNTD sensitivity to low-energy neutrons and developing a faster imaging technique for scanning larger areas to improve counting statistics.

Description of complex viewing geometries of fusion tomography diagnostics by ray-tracing

Ray-tracing techniques are applied to bolometry, a diagnostic where the finite collection volume is particularly sensitive to the machine and detector configuration. A technique is presented that can handle arbitrarily complex aperture and collimator geometries, neglecting reflection effects. Sight lines from the ASDEX Upgrade bolometer foils were ray-traced with a path tracing algorithm, where the optical path is represented by a statistical bundle of ray paths connecting the foil surface with the slit geometry. By using the full 3D machine model for the detector box and first wall, effects such as occlusion and vignetting were included in the calculation of the bolometer's étendue. Inversion matrices calculated with the ray-tracing technique were compared with the more conventional single-ray approach and shown to be naturally more constrained, requiring less regularisation. The two models were tested on a sample radiation scenario, and the common single-ray approximation is shown to be insufficient. These results are particularly relevant for the divertor where strong emission gradients may be present. The technique developed generalises well to arbitrarily complex viewing geometries and collimators, opening up a new design space for bolometer configurations that might not normally have been considered.

Measurement of the Ratio of the B^{0}→D^{*-}τ^{+}ν_{τ} and B^{0}→D^{*-}μ^{+}ν_{μ} Branching Fractions Using Three-Prong τ-Lepton Decays

The ratio of branching fractions R(D^{*-})≡B(B^{0}→D^{*-}τ^{+}ν_{τ})/B(B^{0}→D^{*-}μ^{+}ν_{μ}) is measured using a data sample of proton-proton collisions collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3  fb^{-1}. For the first time, R(D^{*-}) is determined using the τ-lepton decays with three charged pions in the final state. The B^{0}→D^{*-}τ^{+}ν_{τ} yield is normalized to that of the B^{0}→D^{*-}π^{+}π^{-}π^{+} mode, providing a measurement of B(B^{0}→D^{*-}τ^{+}ν_{τ})/B(B^{0}→D^{*-}π^{+}π^{-}π^{+})=1.97±0.13±0.18, where the first uncertainty is statistical and the second systematic. The value of B(B^{0}→D^{*-}τ^{+}ν_{τ})=(1.42±0.094±0.129±0.054)% is obtained, where the third uncertainty is due to the limited knowledge of the branching fraction of the normalization mode. Using the well-measured branching fraction of the B^{0}→D^{*-}μ^{+}ν_{μ} decay, a value of R(D^{*-})=0.291±0.019±0.026±0.013 is established, where the third uncertainty is due to the limited knowledge of the branching fractions of the normalization and B^{0}→D^{*-}μ^{+}ν_{μ} modes. This measurement is in agreement with the standard model prediction and with previous results.

An evaluation of a common elements treatment approach for youth in Somali refugee camps

BACKGROUND

This paper reports on: (1) an evaluation of a common elements treatment approach (CETA) developed for comorbid presentations of depression, anxiety, traumatic stress, and/or externalizing symptoms among children in three Somali refugee camps on the Ethiopian/Somali border, and (2) an evaluation of implementation factors from the perspective of staff, lay providers, and families who engaged in the intervention.

METHODS

This project was conducted in three refugee camps and utilized locally validated mental health instruments for internalizing, externalizing, and posttraumatic stress (PTS) symptoms. Participants were recruited from either a validity study or from referrals from social workers within International Rescue Committee Programs. Lay providers delivered CETA to youth (CETA-Youth) and families, and symptoms were re-assessed post-treatment. Providers and families responded to a semi-structured interview to assess implementation factors.

RESULTS

Children who participated in the CETA-Youth open trial reported significant decreases in symptoms of internalizing (d  =  1.37), externalizing (d  =  0.85), and posttraumatic stress (d  =  1.71), and improvements in well-being (d  =  0.75). Caregivers also reported significant decreases in child symptoms. Qualitative results were positive toward the acceptability and appropriateness of treatment, and its feasibility.

CONCLUSIONS

This project is the first to examine a common elements approach (CETA: defined as flexible delivery of elements, order, and dosing) with children and caregivers in a low-resource setting with delivery by lay providers. CETA-Youth may offer an effective treatment that is easier to implement and scale-up versus multiple focal interventions. A fullscale randomized clinical trial is warranted.

ICRP Task Group 95: internal dose coefficients

Internal doses are calculated using biokinetic and dosimetric models. These models describe the behaviour of the radionuclides after ingestion, inhalation, and absorption to the blood, and the absorption of the energy resulting from their nuclear transformations. The International Commission on Radiological Protection (ICRP) develops such models and applies them to provide dose coefficients and bioassay functions for the calculation of equivalent or effective dose from knowledge of intakes and/or measurements of activity in bioassay samples. Over the past few years, ICRP has devoted a considerable amount of effort to the revision and improvement of models to make them more physiologically realistic representations of uptake and retention in organs and tissues, and of excretion. Provision of new biokinetic models, dose coefficients, monitoring methods, and bioassay data is the responsibility of Committee 2 and its task groups. Three publications in a series of documents replacing the ICRP Publication 30 series and ICRP Publications 54, 68, and 78 have been issued [Occupational Intakes of Radionuclides (OIR) Parts 1-3]. OIR Part 1 describes the assessment of internal occupational exposure to radionuclides, biokinetic and dosimetric models, methods of individual and workplace monitoring, and general aspects of retrospective dose assessment. OIR Parts 2-5 provide data on individual elements and their radioisotopes. Work is also in progress on revision of dose coefficients for radionuclide intakes by members of the public.

The Mental Capacity Act 2005: review of mental capacity assessment in people with proximal femoral fracture

Aims and method

To ascertain whether patients with proximal femoral fractures were being correctly assessed in line with the Mental Capacity Act 2005. Fifty people admitted with proximal femoral fractures were audited to assess whether they had given consent to treatment in accordance with the Act. A Mental Capacity Act 2005 guidance and assessment form was then introduced accompanied by staff training. A re-audit was undertaken to assess the impact.

Results

The initial audit showed that only one person (2%) had been properly assessed. The re-audit demonstrated that the use of the Mental Capacity Act 2005 assessment form ensured correct assessment.

Clinical implications

Our findings suggest the form is a useful tool in the documentation and assessment of an individual's capacity under the Mental Capacity Act.

First Observation of the Rare Purely Baryonic Decay B^{0}→pp[over ¯]

The first observation of the decay of a B^{0} meson to a purely baryonic final state, B^{0}→pp[over ¯], is reported. The proton-proton collision data sample used was collected with the LHCb experiment at center-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3.0  fb^{-1}. The branching fraction is determined to be B(B^{0}→pp[over ¯])=(1.25±0.27±0.18)×10^{-8}, where the first uncertainty is statistical and the second systematic. The decay mode B^{0}→pp[over ¯] is the rarest decay of the B^{0} meson observed to date. The decay B_{s}^{0}→pp[over ¯] is also investigated. No signal is seen and the upper limit B(B_{s}^{0}→pp[over ¯])<1.5×10^{-8} at 90% confidence level is set on the branching fraction.

Updated search for long-lived particles decaying to jet pairs

A search is presented for long-lived particles with a mass between 25 and 50 GeV / c 2 and a lifetime between 2 and 500 ps, using proton-proton collision data corresponding to an integrated luminosity of 2.0 fb - 1 , collected by the LHCb detector at centre-of-mass energies of 7 and 8 TeV. The particles are assumed to be pair-produced in the decay of a 125 GeV / c 2 Standard-Model-like Higgs boson. The experimental signature is a single long-lived particle, identified by a displaced vertex with two associated jets. No excess above background is observed and limits are set on the production cross-section as a function of the mass and lifetime of the long-lived particle.

Observation of D^{0} Meson Decays to π^{+}π^{-}μ^{+}μ^{-} and K^{+}K^{-}μ^{+}μ^{-} Final States

The first observation of the D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays is reported using a sample of proton-proton collisions collected by LHCb at a center-of-mass energy of 8 TeV, and corresponding to 2  fb^{-1} of integrated luminosity. The corresponding branching fractions are measured using as normalization the decay D^{0}→K^{-}π^{+}[μ^{+}μ^{-}]_{ρ^{0}/ω}, where the two muons are consistent with coming from the decay of a ρ^{0} or ω meson. The results are B(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(9.64±0.48±0.51±0.97)×10^{-7} and B(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(1.54±0.27±0.09±0.16)×10^{-7}, where the uncertainties are statistical, systematic, and due to the limited knowledge of the normalization branching fraction. The dependence of the branching fraction on the dimuon mass is also investigated.

Search for Baryon-Number Violating Ξ_{b}^{0} Oscillations

A search for baryon-number violating Ξ_{b}^{0} oscillations is performed with a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3  fb^{-1}. The baryon number at the moment of production is identified by requiring that the Ξ_{b}^{0} come from the decay of a resonance Ξ_{b}^{*-}→Ξ_{b}^{0}π^{-} or Ξ_{b}^{'-}→Ξ_{b}^{0}π^{-}, and the baryon number at the moment of decay is identified from the final state using the decays Ξ_{b}^{0}→Ξ_{c}^{+}π^{-},Ξ_{c}^{+}→pK^{-}π^{+}. No evidence of baryon-number violation is found, and an upper limit at the 95% confidence level is set on the oscillation rate of ω<0.08  ps^{-1}, where ω is the associated angular frequency.

Improved limit on the branching fraction of the rare decay K S 0 → μ + μ -

A search for the decay K S 0 → μ + μ - is performed, based on a data sample of proton-proton collisions corresponding to an integrated luminosity of 3 fb - 1 , collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV . The observed yield is consistent with the background-only hypothesis, yielding a limit on the branching fraction of B ( K S 0 → μ + μ - ) < 0.8 ( 1.0 ) × 10 - 9 at 90 % ( 95 % ) confidence level. This result improves the previous upper limit on the branching fraction by an order of magnitude.