GATE : a simulation toolkit for PET and SPECT

Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols, and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. A public release of GATE licensed under the GNU Lesser General Public License can be downloaded at the address http://www-lphe.epfl.ch/GATE/

Humidity resistant MoSx films prepared by pulsed magnetron sputtering

It is well known that MoS2 is a good lubricant, but the lubricity of MoSx thin films is greatly affected by the deposition parameters, especially when used under environmental conditions of high relative humidity. In this work, MoSx films were prepared by magnetron sputtering using a bipolar pulsed power supply. Several deposition parameters such as argon pressure, substrate temperature, substrate bias voltage, cathode power and deposition time were varied. Composition, morphology and structure were investigated by a number of techniques including energy dispersive spectroscopy (EDS), Rutherford back scattering (RBS), scanning electron microscopy(SEM) and X-ray diffraction (XRD). Tribological properties were measured with a ball-on-disk fretting tester. The results show that MoSx films prepared at low argon pressure (below 0.4 Pa) and low substrate temperature (room temperature) have a low friction coefficient and long wear life. These films have a remarkable low sulfur content (x approximate to 1 and even smaller, in contrast to frequently reported values of x = 1.2 similar to 1.8), a featureless morphology and only a strong basal plane (002) diffraction peak The relative humidity, up to values of 90%, has only a small effect on the friction coefficient and wear life. The structure of the films and the friction and wear mechanism are discussed in view of the low sulfur content. (C) 2000 Elsevier Science B.V. All rights reserved.status: publishe

The Gut-Lung Axis in Health and Respiratory Diseases: A Place for Inter-Organ and Inter-Kingdom Crosstalks.

The gut and lungs are anatomically distinct, but potential anatomic communications and complex pathways involving their respective microbiota have reinforced the existence of a gut-lung axis (GLA). Compared to the better-studied gut microbiota, the lung microbiota, only considered in recent years, represents a more discreet part of the whole microbiota associated to human hosts. While the vast majority of studies focused on the bacterial component of the microbiota in healthy and pathological conditions, recent works have highlighted the contribution of fungal and viral kingdoms at both digestive and respiratory levels. Moreover, growing evidence indicates the key role of inter-kingdom crosstalks in maintaining host homeostasis and in disease evolution. In fact, the recently emerged GLA concept involves host-microbe as well as microbe-microbe interactions, based both on localized and long-reaching effects. GLA can shape immune responses and interfere with the course of respiratory diseases. In this review, we aim to analyze how the lung and gut microbiota influence each other and may impact on respiratory diseases. Due to the limited knowledge on the human virobiota, we focused on gut and lung bacteriobiota and mycobiota, with a specific attention on inter-kingdom microbial crosstalks which are able to shape local or long-reached host responses within the GLA

Non-specific symptoms and post-treatment Lyme disease syndrome in patients with Lyme borreliosis: a prospective cohort study in Belgium (2016–2020)

Background: Patients with Lyme borreliosis (LB) may report persisting non‑specific symptoms such as fatigue, widespread musculoskeletal pain or cognitive difficulties. When present for more than 6 months and causing a reduction in daily activities, this is often referred to as post‑treatment Lyme disease syndrome (PTLDS). This study aimed to compare the occurrence of symptoms between LB patients and controls, to estimate the proportion of LB patients developing PTLDS and to identify risk factors. Methods: A prospective cohort study was set up including three subpopulations: patients with an erythema migrans (EM) (i) or disseminated/late LB (ii) and a non‑LB control group (iii). At 6‑ and 12‑months follow‑up, the occurrence of several symptoms, including six symptoms used to define PTLDS, i.e. muscle pain, joint pain, fatigue, memory problems, difficulties concentrating and problems finding words, and impact on daily activities, was compared between LB patients and controls. Finally, the proportion of LB patients developing PTLDS as defined by the Infectious Disease Society of America was estimated, including a time frame for symptoms to be present. Results: Although the risk of presenting PTLDS‑related symptoms was significantly higher in EM patients (n = 120) compared to controls (n = 128) at 6 months follow‑up, the risk of presenting at least one of these symptoms combined with impact on daily activities was not significantly higher in EM patients, at either 6‑ or 12‑months follow‑up. A significant association was found between disseminated/late LB (n = 15) and the occurrence of any PTLDS‑symptom with an impact on daily activities at both time points. The proportion of patients with PTLDS was estimated at 5.9% (95% CI 2.7–12.9) in EM patients and 20.9% (95% CI 6.8–64.4) in patients with disseminated/late LB (RR = 3.53, 95% CI 0.98–12.68, p = 0.053). No significant risk factors were identified, which may be explained by small sample sizes. Conclusions: In our study, PTLDS was present in both LB cohorts, yet with a higher percentage in disseminated/late LB patients. Additional research is needed into risk factors for and causes of this syndrome. In addition, development and validation of standardized methods to assess the PTLDS case definition, easily applicable in practice, is of great importance