49 research outputs found

    Motivations and Needs of Older People for Work and Active Lifestyle

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    The article presents the results of a poll of older people on the example of a particular region (The Tomsk Region) to identify the need for an active lifestyle and penchant for productive work. The system ofhypotheses under article issues is tested. The aim of the work is to analyze problems of older people which affect their labor activity.The empirical base for the study was the results of the survey (sample frame 400 pers.). The respondents were older people living in urban and rural areas of the Tomsk Region. To test the generated hypothesesstatistical methods (analysis of variance, correlation analysis, etc.) are used. There are three main problems the elderly related to their needs and inclinations to work. It was determined that the formationof a stable demand of older people in productive work and active lifestyle will help to solve a number of problems of socio-psychological and economic nature at the present stage of social development inRussia and abroad

    Increasing striatal dopamine release through repeated bouts of theta burst transcranial magnetic stimulation of the left dorsolateral prefrontal cortex. A 18F-desmethoxyfallypride positron emission tomography study

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    IntroductionTranscranial Magnetic Stimulation (TMS) can modulate fronto-striatal connectivity in the human brain. Here Positron Emission Tomography (PET) and neuro-navigated TMS were combined to investigate the dynamics of the fronto-striatal connectivity in the human brain. Employing 18F-DesmethoxyFallypride (DMFP) – a Dopamine receptor-antagonist – the release of endogenous dopamine in the striatum in response to time-spaced repeated bouts of excitatory, intermittent theta burst stimulation (iTBS) of the Left-Dorsolateral Prefrontal Cortex (L-DLPFC) was measured.Methods23 healthy participants underwent two PET sessions, each one with four blocks of iTBS separated by 30 minutes: sham (control) and verum (90% of individual resting motor threshold). Receptor Binding Ratios were collected for sham and verum sessions across 37 time frames (about 130 minutes) in striatal sub-regions (Caudate nucleus and Putamen).ResultsVerum iTBS increased the dopamine release in striatal sub-regions, relative to sham iTBS. Dopamine levels in the verum session increased progressively across the time frames until frame number 28 (approximately 85 minutes after the start of the session and after three iTBS bouts) and then essentially remained unchanged until the end of the session.ConclusionResults suggest that the short-timed iTBS protocol performed in time-spaced blocks can effectively induce a dynamic dose dependent increase in dopaminergic fronto-striatal connectivity. This scheme could provide an alternative to unpleasant and distressing, long stimulation protocols in experimental and therapeutic settings. Specifically, it was demonstrated that three repeated bouts of iTBS, spaced by short intervals, achieve larger effects than one single stimulation. This finding has implications for the planning of therapeutic interventions, for example, treatment of major depression

    Dose-escalation using intensity-modulated radiotherapy for prostate cancer - evaluation of quality of life with and without 18F-choline PET-CT detected simultaneous integrated boost

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    <p>Abstract</p> <p>Background</p> <p>In comparison to the conventional whole-prostate dose escalation, an integrated boost to the macroscopic malignant lesion might potentially improve tumor control rates without increasing toxicity. Quality of life after radiotherapy (RT) with vs. without <sup>18</sup>F-choline PET-CT detected simultaneous integrated boost (SIB) was prospectively evaluated in this study.</p> <p>Methods</p> <p>Whole body image acquisition in supine patient position followed 1 h after injection of 178-355MBq <sup>18</sup>F-choline. SIB was defined by a tumor-to-background uptake value ratio > 2 (GTV<sub>PET</sub>). A dose of 76Gy was prescribed to the prostate (PTV<sub>prostate</sub>) in 2Gy fractions, with or without SIB up to 80Gy. Patients treated with (n = 46) vs. without (n = 21) SIB were surveyed prospectively before (A), at the last day of RT (B) and a median time of two (C) and 19 month (D) after RT to compare QoL changes applying a validated questionnaire (EPIC - expanded prostate cancer index composite).</p> <p>Results</p> <p>With a median cut-off standard uptake value (SUV) of 3, a median GTV<sub>PET </sub>of 4.0 cm<sup>3 </sup>and PTV<sub>boost </sub>(GTV<sub>PET </sub>with margins) of 17.3 cm<sup>3 </sup>was defined. No significant differences were found for patients treated with vs. without SIB regarding urinary and bowel QoL changes at times B, C and D (mean differences ≤3 points for all comparisons). Significantly decreasing acute urinary and bowel score changes (mean changes > 5 points in comparison to baseline level at time A) were found for patients with and without SIB. However, long-term urinary and bowel QoL (time D) did not differ relative to baseline levels - with mean urinary and bowel function score changes < 3 points in both groups (median changes = 0 points). Only sexual function scores decreased significantly (> 5 points) at time D.</p> <p>Conclusions</p> <p>Treatment planning with <sup>18</sup>F-choline PET-CT allows a dose escalation to a macroscopic intraprostatic lesion without significantly increasing toxicity.</p

    Simulation-based partial volume correction for dopaminergic PET imaging: Impact of segmentation accuracy

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    AimPartial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in 18F-FDOPA brain-PET, with a special focus on the accuracy degradation introduced by various MR-based segmentation approaches.MethodsFour PVC algorithms (M-PVC; MG-PVC; mMG-PVC; and R-PVC) were analyzed on simulated 18F-FDOPA brain-PET images. MR image segmentation was carried out using FSL (FMRIB Software Library) and SPM (Statistical Parametric Mapping) packages, including additional adaptation for subcortical regions (SPML). Different PVC and segmentation combinations were compared with respect to deviations in regional activity values and time-activity curves (TACs) of the occipital cortex (OCC), caudate nucleus (CN), and putamen (PUT). Additionally, the PVC impact on the determination of the influx constant (Ki) was assessed.ResultsMain differences between tissue-maps returned by three segmentation algorithms were found in the subcortical region, especially at PUT. Average misclassification errors in combination with volume reduction was found to be lowest for SPML (PUT 70%). Accurate recovery of activity data at OCC is achieved by M-PVC (apparent recovery coefficient varies between 0.99 and 1.10). The other three evaluated PVC algorithms have demonstrated to be more suitable for subcortical regions with MG-PVC and mMG-PVC being less prone to the largest tissue misclassification error simulated in this study. Except for M-PVC, quantification accuracy of Ki for CN and PUT was clearly improved by PVC.ConclusionsThe regional activity value of PUT was appreciably overcorrected by most of the PVC approaches employing FSL or SPM segmentation, revealing the importance of accurate MR image segmentation for the presented PVC framework. The selection of a PVC approach should be adapted to the anatomical structure of interest. Caution is recommended in subsequent interpretation of Ki values. The possible different change of activity concentrations due to PVC in both target and reference regions tends to alter the corresponding TACs, introducing bias to Ki determination. The accuracy of quantitative analysis was improved by PVC but at the expense of precision reduction, indicating the potential impropriety of applying the presented framework for group comparison studies
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