171 research outputs found

    Night Eating Syndrome, circadian rhythms and seasonality. A study in a population of Italian university students

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    PURPOSE: The aim of this research was to assess the prevalence of Night Eating Syndrome (NES) in a university student population and to clear up the relationship between NES, depression and chronotype. The relation between NES and seasonality was also investigated. METHODS: The data were collected from a sample of 1136 students of the L'Aquila University, Italy. All subjects were invited to answer to the Sociodemographic Information Form and to take a self-report battery composed by four questionnaires: the Night Eating Questionnaire (NEQ), the Morningness Eveningness Questionnaire (MEQ), the Seasonal Pattern Assessment Questionnaire (SPAQ) and the Beck Depression Inventory (BDI). RESULTS: The 5.3% of our population (60 subjects) reached the criteria for NES. The distribution of chronotypes in the sample was: Morning Type 15.3%, Intermediate 64.3% and Evening Type 20.4%. The 36.7% of the participants reaching the criteria for NES, obtained low scores on the MEQ. The data indicated that NEQ and MEQ scores are significantly inversely correlated (r=-.22; p<.01, two-tailed test). The 3.6% of our population (41 subjects) reached the criteria for Seasonal Affective Disorder (SAD) and 10.7% for subclinical SAD (121 subjects). Furthermore, the 11.7% of subjects with NES presented SAD and the 5% presented Subclinical SAD. The data demonstrated that NES and Global Seasonality Score (GSS) are significantly associated (r=.22; p<0.01, two-tailed test). CONCLUSIONS: The main finding of this study is the strong relation between NES and eveningness dimension. Our results help to clear up the literature debate about the role of eveningness dimension in the night eating, suggesting that subjects with NES present a circadian delay, not only in the food intake, but in the entire functioning. At the best of one knowledge this study is the first one to examine the relationship between NES and seasonality. This research found preliminary evidence that, similarly to the findings of previous studies in subjects with Bulimia Nervosa (BN) and Binge Eating Disorder (BED), night eating symptoms may vary significantly across the seasons; subjects with NES experience seasonal variation in their mood and in their eating patterns

    Design, realization, and characterization of a novel diamond detector prototype for FLASH radiotherapy dosimetry

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    Purpose: FLASH radiotherapy (RT) is an emerging technique in which beams with ultra-high dose rates (UH-DR) and dose per pulse (UH-DPP) are used. Commercially available active real-time dosimeters have been shown to be unsuitable in such conditions, due to severe response nonlinearities. In the present study, a novel diamond-based Schottky diode detector was specifically designed and realized to match the stringent requirements of FLASH-RT. Methods: A systematic investigation of the main features affecting the diamond response in UH-DPP conditions was carried out. Several diamond Schottky diode detector prototypes with different layouts were produced at Rome Tor Vergata University in cooperation with PTW-Freiburg. Such devices were tested under electron UH-DPP beams. The linearity of the prototypes was investigated up to DPPs of about 26 Gy/pulse and dose rates of approximately 1 kGy/s. In addition, percentage depth dose (PDD) measurements were performed in different irradiation conditions. Radiochromic films were used for reference dosimetry. Results: The response linearity of the diamond prototypes was shown to be strongly affected by the size of their active volume as well as by their series resistance. By properly tuning the design layout, the detector response was found to be linear up to at least 20 Gy/pulse, well into the UH-DPP range conditions. PDD measurements were performed by three different linac applicators, characterized by DPP values at the point of maximum dose of 3.5, 17.2, and 20.6 Gy/pulse, respectively. The very good superimposition of three curves confirmed the diamond response linearity. It is worth mentioning that UH-DPP irradiation conditions may lead to instantaneous detector currents as high as several mA, thus possibly exceeding the electrometer specifications. This issue was properly addressed in the case of the PTW UNIDOS electrometers. Conclusions: The results of the present study clearly demonstrate the feasibility of a diamond detector for FLASH-RT applications

    Application of a novel diamond detector for commissioning of FLASH radiotherapy electron beams

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    Purpose: A diamond detector prototype was recently proposed by Marinelli et al. (Medical Physics 2022, https://doi.org/10.1002/mp.15473) for applications in ultrahigh-dose-per-pulse (UH-DPP) and ultrahigh-dose-rate (UH-DR) beams, as used in FLASH radiotherapy (FLASH-RT). In the present study, such so-called flashDiamond (fD) was investigated from the dosimetric point of view, under pulsed electron beam irradiation. It was then used for the commissioning of an ElectronFlash linac (SIT S.p.A., Italy) both in conventional and UH-DPP modalities. Methods: Detector calibration was performed in reference conditions, under 60 Co and electron beam irradiation. Its response linearity was investigated in UH-DPP conditions. For this purpose, the DPP was varied in the 1.2-11.9 Gy range, by changing either the beam applicator or the pulse duration from 1 to 4 Î¼s. Dosimetric validation of the fD detector prototype was then performed in conventional modality, by measuring percentage depth dose (PDD) curves, beam profiles, and output factors (OFs). All such measurements were carried out in a motorized water phantom. The obtained results were compared with the ones from commercially available dosimeters, namely, a microDiamond, an Advanced Markus ionization chamber, a silicon diode detector, and EBT-XD GAFchromic films. Finally, the fD detector was used to fully characterize the 7 and 9 MeV UH-DPP electron beams delivered by the ElectronFlash linac. In particular, PDDs, beam profiles, and OFs were measured, for both energies and all the applicators, and compared with the ones from EBT-XD films irradiated in the same experimental conditions. Results: The fD calibration coefficient resulted to be independent from the investigated beam qualities. The detector response was found to be linear in the whole investigated DPP range. A very good agreement was observed among PDDs, beam profiles, and OFs measured by the fD prototype and reference detectors, both in conventional and UH-DPP irradiation modalities. Conclusions: The fD detector prototype was validated from the dosimetric point of view against several commercial dosimeters in conventional beams. It was proved to be suitable in UH-DPP and UH-DR conditions, for which no other commercial real-time active detector is available to date. It was shown to be a very useful tool to perform fast and reproducible beam characterizations in standard clinical motorized water phantom setups. All of the previously mentioned demonstrate the suitability of the proposed detector for the commissioning of UH-DR linac beams for preclinical FLASH-RT applications

    Compact S-band linear accelerator system for ultrafast, ultrahigh dose-rate radiotherapy

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    Radiation therapy is currently the most utilized technique for the treatment of tumors by means ofionizing radiation, such as electrons, protons and x/gamma rays, depending on the type, size and depth ofthe cancer mass. Radiation therapy has in general fulfilled the main requirement of targeting thus damagingthe malignant cells and sparing the healthy tissues as best as possible. In this scenario, electron linearaccelerators have been operated as viable tools for the delivery of both high-energetic electrons and x-raybeams, which are obtained via the bremsstrahlung process of the electrons hitting on a high-Z material.Recently, it has been experimentally demonstrated that ultrahigh dose-rate bursts of electrons and x-raybeams increase the differential response between healthy and tumor tissues. This beneficial response isreferred to as the FLASH effect. For this purpose, we have developed the first dedicated compactS-bandlinear accelerator for FLASH radiotherapy. This linac is optimized for a nominal energy of 7 MeV and apulsed electron beam current of 100 mA and above. The accelerator is mounted on a remote-controlledsystem for preclinical research studies in the FLASH regime. We will show the rf and beam dynamicsdesign of theS-band linac as well as the commissioning and high-power rf tests. Furthermore, the results ofthe dosimetric measurements will be illustrate

    Corrigendum: FLASH Radiotherapy With Electrons: Issues Related to the Production, Monitoring, and Dosimetric Characterization of the Beam

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    In the original article, the following authors were missing: Luigi Faillace, Lucia Giuliano, Mauro Migliorati, Luigi Palumbo. The corrected Author Contributions statement appears below. Affiliation 3, ‘Sapienza University of Rome, Rome, Italy’, is also added for authors LF, LG, MM, and LP. The authors apologize for these errors and state that this does not change the scientific conclusions of the article in any way. The original article has been updated

    Interplay Among Psychopathologic Variables, Personal Resources, Context-Related Factors, and Real-life Functioning in Individuals With Schizophrenia: A Network Analysis

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    Enhanced understanding of factors associated with symptomatic and functional recovery is instrumental to designing personalized treatment plans for people with schizophrenia. To date, this is the first study using network analysis to investigate the associations among cognitive, psychopathologic, and psychosocial variables in a large sample of community-dwelling individuals with schizophrenia

    Changing expression of vertebrate immunity genes in an anthropogenic environment: a controlled experiment

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    Background: The effect of anthropogenic environments on the function of the vertebrate immune system is a problem of general importance. For example, it relates to the increasing rates of immunologically-based disease in modern human populations and to the desirability of identifying optimal immune function in domesticated animals. Despite this importance, our present understanding is compromised by a deficit of experimental studies that make adequately matched comparisons between wild and captive vertebrates. Results: We transferred post-larval fishes (three-spined sticklebacks), collected in the wild, to an anthropogenic (captive) environment. We then monitored, over 11 months, how the systemic expression of immunity genes changed in comparison to cohort-matched wild individuals in the originator population (total n = 299). We found that a range of innate (lyz, defbl2, il1r-like, tbk1)and adaptive (cd8a, igmh) immunity genes were up-regulated in captivity, accompanied by an increase in expression of the antioxidant enzyme, gpx4a. For some genes previously known to show seasonality in the wild, this appeared to be reduced in captive fishes. Captive fishes tended to express immunity genes, including igzh, foxp3b, lyz, defbl2, and il1r-like, more variably. Furthermore, although gene co-expression patterns (analyzed through gene-by-gene correlations and mutual information theory based networks) shared common structure in wild and captive fishes, there was also significant divergence. For one gene in particular, defbl2, high expression was associated with adverse health outcomes in captive fishes. Conclusion: Taken together, these results demonstrate widespread regulatory changes in the immune system in captive populations, and that the expression of immunity genes is more constrained in the wild. An increase in constitutive systemic immune activity, such as we observed here, may alter the risk of immunopathology and contribute to variance in health in vertebrate populations exposed to anthropogenic environments

    Swelling-Activated Ca2+ Channels Trigger Ca2+ Signals in Merkel Cells

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    Merkel cell-neurite complexes are highly sensitive touch receptors comprising epidermal Merkel cells and sensory afferents. Based on morphological and molecular studies, Merkel cells are proposed to be mechanosensory cells that signal afferents via neurotransmission; however, functional studies testing this hypothesis in intact skin have produced conflicting results. To test this model in a simplified system, we asked whether purified Merkel cells are directly activated by mechanical stimulation. Cell shape was manipulated with anisotonic solution changes and responses were monitored by Ca2+ imaging with fura-2. We found that hypotonic-induced cell swelling, but not hypertonic solutions, triggered cytoplasmic Ca2+ transients. Several lines of evidence indicate that these signals arise from swelling-activated Ca2+-permeable ion channels. First, transients were reversibly abolished by chelating extracellular Ca2+, demonstrating a requirement for Ca2+ influx across the plasma membrane. Second, Ca2+ transients were initially observed near the plasma membrane in cytoplasmic processes. Third, voltage-activated Ca2+ channel (VACC) antagonists reduced transients by half, suggesting that swelling-activated channels depolarize plasma membranes to activate VACCs. Finally, emptying internal Ca2+ stores attenuated transients by 80%, suggesting Ca2+ release from stores augments swelling-activated Ca2+ signals. To identify candidate mechanotransduction channels, we used RT-PCR to amplify ion-channel transcripts whose pharmacological profiles matched those of hypotonic-evoked Ca2+ signals in Merkel cells. We found 11 amplicons, including PKD1, PKD2, and TRPC1, channels previously implicated in mechanotransduction in other cells. Collectively, these results directly demonstrate that Merkel cells are activated by hypotonic-evoked swelling, identify cellular signaling mechanisms that mediate these responses, and support the hypothesis that Merkel cells contribute to touch reception in the Merkel cell-neurite complex

    Preliminary study on the correlation between accelerated current and dose in water for an electron-based LINAC

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    Purpose: Intraoperative electron radiotherapy (IOeRT) is considered the first clinical translation of FLASH with electrons. A crucial aspect is represented by the precise dose monitoring and measurement; to this aim, we propose a method fully based on Monte Carlo (MC) simulation that uses as input the beam current measurement and the beam optics simulation. To validate this approach, we chose the NOVAC11 (produced by Sordina IORT Technologies SpA) accelerator, which provides a well-studied model.Methods: We used FLUKA and FRED MC software to simulate in detail the geometry of the NOVAC11 and the coupled applicator usually adopted in clinical practice to deliver the dose in the surgical bed. The simulation results of the longitudinal and off-axis profiles and dose per pulse obtained in a water phantom with different applicators are compared to the experimental data.Results: A very good agreement not only for the relative dosimetry in both the longitudinal and off-axis profiles, with a gamma index pass rate of 100% with 3%/3 mm acceptance criteria, but also for the absolute dosimetry was obtained.Conclusion: The results completely validate the MC description of the system and provide a reliable evaluation of the dose per pulse and output factor with an accuracy of the order of few % for different sets of applicator diameters and lengths
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