Nearly half of care home residents with advanced dementia have clinically significant agitation. Little is known about costs associated with these symptoms toward the end of life. We calculated ...monetary costs associated with agitation from UK National Health Service, personal social services, and societal perspectives.
Prospective cohort study.
Thirteen nursing homes in London and the southeast of England.
Seventy-nine people with advanced dementia (Functional Assessment Staging Tool grade 6e and above) residing in nursing homes, and thirty-five of their informal carers.
Data collected at study entry and monthly for up to 9 months, extrapolated for expression per annum. Agitation was assessed using the Cohen-Mansfield Agitation Inventory (CMAI). Health and social care costs of residing in care homes, and costs of contacts with health and social care services were calculated from national unit costs; for a societal perspective, costs of providing informal care were estimated using the resource utilization in dementia (RUD)-Lite scale.
After adjustment, health and social care costs, and costs of providing informal care varied significantly by level of agitation as death approached, from £23,000 over a 1-year period with no agitation symptoms (CMAI agitation score 0-10) to £45,000 at the most severe level (CMAI agitation score >100). On average, agitation accounted for 30% of health and social care costs. Informal care costs were substantial, constituting 29% of total costs.
With the increasing prevalence of dementia, costs of care will impact on healthcare and social services systems, as well as informal carers. Agitation is a key driver of these costs in people with advanced dementia presenting complex challenges for symptom management, service planners, and providers.
The idea of carbide-free bainitic (CFB) microstructure, a mixture of bainitic ferrite and retained austenite (RA), in high-silicon steels has been recently thoroughly investigated by numerous ...researchers. In this research, two medium-carbon steel grades were tested in a wear tumbling machine to investigate microstructural changes under wet sliding abrasive wear conditions and to benchmark their performance against conventional tempered martensitic steels. The nature and type of defects responsible for material removal were analysed using scanning electron microscopy. To observe microstructural evolution of heavily deformed top layers of test specimens, special layer-by-layer X-ray diffraction methodology was applied. This technique allows accurate quantification of the volume fraction of RA transformed into untempered martensite at different depths from the worn surface. The results suggest that better performance is achieved in specimens heat treated to carbide-free bainitic microstructure containing higher volume fraction of RA, however with blocks of RA thermally stable at room temperature. The improved wear resistance is due to the increased surface hardness caused by stress-induced transformation of RA into untempered martensite during wear, while maintaining good toughness in the subsurface zones, which prevent brittle cracking.
•A bespoke wear tumbling machine is used to test steel performance under abrasive wear conditions.•Carbide-free bainitic steels outperformed martensitic ones due to greater hardening of top layer.•Layer-by-layer X-ray diffraction methodology was used to quantify microstructural evolution.
We present a novel design of fine segmented low gain avalanchediodes ('GAD) based on trench-isolation technique. The proposed design reduces the width of the no-gain inter-pad region down to less ...than 10 μm, from the 20-80 μm of the current 'GAD technology, enabling the production of sensors with small pixel pitch and high fill-factor. Prototypes of this new technologywere produced in the FBK laboratories. Their electrical characterization in terms of I-V, gain measurement and response to a focused laser, indicates that the trenches provide electrical isolation among pixels without any increase in the dark current level and without affecting the gain of the sensor. In addition, I-V measurements of p-i-n diodes with the same trench-isolation structure demonstrate that such termination scheme can withstand more than 500 Volts without reaching breakdown. This is well above the typical operating bias voltage of 'GADs, thus confirming that trench-isolation is a promising solution for finely pixelated 'GAD sensors.
The potential of photon detectors to achieve precise timing information is of increasing importance in many domains, PET and CT scanners in medical imaging and particle physics detectors, amongst ...others. The goal to increase by an order of magnitude the sensitivity of PET scanners and to deliver, via time-of-flight (TOF), true space points for each event, as well as the constraints set by future particle accelerators require a further leap in time resolution of scintillator-based ionizing radiation detectors, reaching eventually a few picoseconds resolution for sub MeV energy deposits. In spite of the impressive progress made in the last decade by several manufacturers, the Single Photon Time Resolution (SPTR) of SiPMs is still in the range of 70–120 ps FWHM, whereas a value of 10 ps or even less would be desirable. Such a step requires a break with traditional methods and the development of novel technologies. The possibility of combining the extraordinary potential of nanophotonics with new approaches offered by modern microelectronics and 3D electronic integration opens novel perspectives for the development of a new generation of metamaterial-based SiPMs with unprecedented photodetection efficiency and timing resolution.
Abstract
One of the major drawback of Genetic Algorithm (GA) based solutions to many optimization problems is the difficulty to obtain convergence to an optimal solution. One of the possible reason ...for not obtaining good convergence is due to the improper encoding of chromosomes. Many techniques were proposed in some previous researches for improving the convergence of GA based solutions. However, no consideration regarding the role of chromosome encoding in achieving convergence and optimality both has been discussed in the past. In the present work, a can volume optimization problem is solved with the help of two types of chromosome encoding techniques that are proposed and evaluated in GA environment. First, based on single random gene selection and second based on mean value of genes of the encoded chromosome. A numerical example with an objective function and constraints has been solved and the results for each of the scheme is being discussed.
Coincidence time resolution (CTR) of scintillation detectors based on Ce- and Mg-codoped Gd 3 Al 2 Ga 3 O 12 (GAGG) scintillation crystals and high-density silicon photomultipliers (SiPMs) is shown ...to be 165 ps (full width at half maximum) for 511-keV <inline-formula> <tex-math notation="LaTeX">\gamma </tex-math></inline-formula>-quanta, approaching that achieved by using LSO scintillators. To study the prospective for further improvement of the time resolution, the population of the emitting Ce centers was investigated by optical pump and probe technique using selective photoexcitation and probing by a white light continuum with subpicosecond time resolution. The importance of free electron trapping for excitation transfer to emitting Ce ions was revealed. The influence of transfer delay on the scintillation response time is described, and the dynamics of electron relaxation to the lowest excited level of Ce ion is studied experimentally and analyzed by taking into account intracenter relaxation and relaxation via conduction band. The influence of electron diffusivity on the rise time of the population of the emitting level is described. It is shown that codoping of GAGG:Ce by magnesium even at the level as low as 10 ppm efficiently decreases the scintillator response time by enhancing the electron diffusivity.
A large number of particle detectors employ liquid argon as their target material owing to its high scintillation yield and its ability to drift ionization charge over large distances. Scintillation ...light from argon is peaked at 128 nm and a wavelength shifter is required for its efficient detection. In this work, we directly compare the light yield achieved in two identical liquid argon chambers, one of which is equipped with polyethylene naphthalate (PEN) and the other with tetraphenyl butadiene (TPB) wavelength shifter. Both chambers are lined with enhanced specular reflectors and instrumented with SiPMs with a coverage fraction of approximately 1%, which represents a geometry comparable to the future large scale detectors. We measured the light yield of the PEN chamber to be 39.4
±
0.4(stat)
±
1.9(syst)% of the yield of the TPB chamber. Using a Monte Carlo simulation this result is used to extract the wavelength shifting efficiency of PEN relative to TPB equal to 47.2
±
5.7%. This result paves the way for the use of easily available PEN foils as a wavelength shifter, which can substantially simplify the construction of future liquid argon detectors.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Time of flight (TOF) in positron emission tomography (PET) has experienced a revival of interest after its first introduction in the eighties. This is due to a significant progress in solid state ...photodetectors (SiPMs) and newly developed scintillators (LSO and its derivatives). Latest developments at Fondazione Bruno Kessler (FBK) lead to the NUV-HD SiPM with a very high photon detection efficiency of around 55%. Despite the large area of 4x4 mm super(2) it achieves a good single photon time resolution (SPTR) of 180+ or -5ps FWHM. Coincidence time resolution (CTR) measurements using LSO:Ce codoped with Ca scintillators yield best values of 73+ or -2ps FWHM for 2x2x3 mm super(3) and 117+ or -3ps for 2x2x20 mm super(3) crystal sizes. Increasing the crystal cross-section from 2x2 mm super(2) to 3x3 mm super(2) a non negligible CTR deterioration of approximately 7ps FWHM is observed. Measurements with LSO:Ce codoped Ca and LYSO:Ce scintillators with various cross-sections (1x1 mm super(2)- 4x4 mm super(2)) and lengths (3mm - 30mm) will be a basis for discussing on how the crystal geometry affects timing in TOF-PET. Special attention is given to SiPM parameters, e.g. SPTR and optical crosstalk, and their measured dependency on the crystal cross-section. Additionally, CTR measurements with LuAG:Ce, LuAG:Pr and GGAG:Ce samples are presented and the results are interpreted in terms of their scintillation properties, e.g. rise time, decay time, light yield and emission spectra.
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