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We describe in this paper the experimental procedure, the data treatment and the quantification of the black body correction: an experimental approach to compensate for scattering and systematic biases in quantitative neutron imaging based on experimental data. The correction algorithm is based on two steps; estimation of the scattering component and correction using an enhanced normalization formula. The method incorporates correction terms into the image normalization procedure, which usually only includes open beam and dark current images (open beam correction). Our aim is to show its efficiency and reproducibility: we detail the data treatment procedures and quantitatively investigate the effect of the correction. Its implementation is included within the open source CT reconstruction software MuhRec. The performance of the proposed algorithm is demonstrated using simulated and experimental CT datasets acquired at the ICON and NEUTRA beamlines at the Paul Scherrer Institut.

The macroscopic properties of advanced engineering and functional materials are highly dependent on their overall grain orientation distribution, size, and morphology. Here we present Laue 3D neutron diffraction tomography providing reconstructions of the grains constituting a coarse-grained polycrystalline material. Reconstructions of the grain morphology of a highly pure Fe cylinder and a Cu cube sample are presented. A total number of 23 and 9 grains from the Fe and Cu samples, respectively, were indexed and reconstructed. Validation of the grain morphological reconstruction is performed by post-mortem EBSD of the Cu specimen.

This article presents a measurement technique and data analysis tool to perform 3D grain distribution mapping and indexing of oligocrystalline samples using neutrons: Laue three-dimensional neutron diffraction (Laue3DND). The approach builds on forward modelling used for correlation and multiple fitting of the measured diffraction spots relative to individual grains. This enables not only to identify individual grains, but also their position and orientation in the sample. The feasibility and performance of the Laue3DND approach are tested using multi-grain synthetic datasets from cubic ( α -Fe) and tetragonal (YBaCuFeO 5 ) symmetries. Next, experimental results from two data sets measured at the FALCON instrument of Helmholtz-Zentrum Berlin are presented: A cylindrical alpha iron ( α -Fe) reference sample with 5 mm diameter and 5 mm height, as well as a 2 mm 3 layered perovskite (YBaCuFeO 5 ). Using Laue3DND, we were able to retrieve the position and orientation of 97 out of 100 grains from a synthetic α -Fe data set, as well as 24 and 9 grains respectively from the α -Fe and YBaCuFeO 5 sample measured at FALCON. Results from the synthetic tests also indicate that Laue3DND is capable of indexing 10 out of 10 grains for both symmetries in two extreme scenarios: using only 6 Laue projections and using 360 projections with extremely noisy data. The precision achieved in terms of spatial and orientation resolution for the current version of the method is 430  μ m and 1° respectively. Based on these results obtained, we are confident to present a tool that expands the capabilities of standard Laue diffraction, providing the number, position, orientation and relative size of grains in oligocrystalline samples.

The intrinsic magnetic moment of a neutron, combined with its charge neutrality, is a unique property which allows the investigation of magnetic phenomena in matter. Here we present how the utilization of a cold polarized neutron beam in neutron grating interferometry enables the visualization and characterization of magnetic properties on a microscopic scale in macroscopic samples. The measured signal originates from the phase shift induced by the magnetic potential. Our method enables the detection of previously inaccessible magnetic field gradients, in the order of T cm −1 , extending the probed range by an order of magnitude. We visualize and quantify the phase shift induced by a well-defined square shaped uniaxial magnetic field and validate our experimental findings with theoretical calculations based on Hall probe measurements of the magnetic field distribution. This allows us to further extend our studies to investigations of inhomogeneous and anisotropic magnetic field distribution. The magnetic field imaging on microscopic scale is of great importance to fundamental research as well industrial applications. Here the authors show the capability to visualize and characterize the magnetic properties with 100-micrometer resolution in macroscopic samples using a cold polarized neutron beam in neutron grating interferometry.

La deriva, tal i com la va definir el teòric situacionista Guy Debord, és un procediment d'acció, més que de moviment. És un posicionament espacial dels surrealistes, un procediment dels situacionistes, un deixar-se anar en l'espai i en el temps i, en última instància, un mecanisme per a la investigació artística. El remot és un lloc proper i alhora llunyà, un lloc mental obert al coneixement, el domini de la realitat imaginada. Després d'un llarg procés d'investigació i un extens treball de camp, l'artista Marc Raventós explica com la pràctica de la deriva es converteix en una escola de la mirada, en un mecanisme de mirada per a l'artista, en una eina per a la recerca del remot. El fet de la deriva provoca una ampliació de temàtiques i llenguatges expressius. I, el més important, aquest procés es converteix en una eina extraordinària per a la creació artística.

The dérive, as defined by Situationist theorist Guy Debord, is a procedure of action, more than of movement. It was a way to position oneself in space for the Surrealists, a kind of movement for the Situationists, a way to get carreid away space and in time and, ultimately, a mechanism used for artistic research. The remote space is a place that is simultaneously nearby and far-away, a mental place open to the knowledge. It is the domain of an imagined reality. After a long process of research and extensive field work, artist Marc Raventós explains how the praxis of the dérive serves as a tool for the research of the remote space. The act of dérive leads to a widening of subject matters and expressive languages. And, most importantly, this process becomes an extraordinary tool for artistic creation. The dérive, as defined by Situationist theorist Guy Debord, is a procedure of action, more than of movement. It was a way to position oneself in space for the Surrealists, a kind of movement for the Situationists, a way to get carreid away space and in time and, ultimately, a mechanism used for artistic research. The remote space is a place that is simultaneously nearby and far-away, a mental place open to the knowledge. It is the domain of an imagined reality. After a long process of research and extensive field work, artist Marc Raventós explains how the praxis of the dérive serves as a tool for the research of the remote space. The act of dérive leads to a widening of subject matters and expressive languages. And, most importantly, this process becomes an extraordinary tool for artistic creation.

This article presents a measurement technique and data analysis tool to perform 3D grain distribution mapping and indexing of oligocrystalline samples using neutrons: Laue three-dimensional neutron diffraction (Laue3DND). The approach builds on forward modelling used for correlation and multiple fitting of the measured diffraction spots relative to individual grains.This enables not only to identify individual grains, but also their position and orientation in the sample. The feasibility and performance of the Laue3DND approach are tested using multi-grain synthetic datasets from cubic ({\\alpha}-Fe) and tetragonal(YBaCuFeO5) symmetries. Next, experimental results from two data sets measured at the FALCON instrument of Helmholtz-Zentrum Berlin are presented: A cylindrical alpha iron ({\\alpha}-Fe) reference sample with 5 mm diameter and 5 mm height, as well as a 2 mm3 layered perovskite (YBaCuFeO5). Using Laue3DND, we were able to retrieve the position and orientation of 97 out of 100 grains from a synthetic{\\alpha}-Fe data set, as well as 24 and 9 grains respectively from the{\\alpha}-Fe and YBaCuFeO5 sample measured at FALCON. Results from the synthetic tests also indicate that Laue3DND is capable of indexing 10 out of 10 grains for both symmetries in two extreme scenarios: using only 6 Laue projections and using 360 projections with extremely noisy data. The precision achieved in terms of spatial and orientation resolution for the current version of the method is 430{\\mu}m and 1 degree respectively. Based on these results obtained, we are confident to present a tool that expands the capabilities of standard Laue diffraction, providing the number, position, orientation and relative size of grains in oligocrystalline samples.

Background Incidental gallbladder cancer (GBC) is frequently discovered on the specimen when cholecystectomy for a benign disease is performed. The objective of the present study was to assess the management of incidental GBC patients in a French registry. Methods Data on patients with GBC treated between 1998 and 2008 were retrospectively collated in a French, multicenter database. Results The registry contained 218 patients with incidental GBC (67 men and 151 women; median age = 64 years; age range = 31-88). One hundred forty-eight (68%) patients underwent re-resection after a median time interval of 48 days (range = 2–245). The most common complete procedure (66% of cases) was 4b + 5 segmentectomy with lymphadenectomy but not bile duct resection. Port-site excision was performed in 54 patients. The mortality and morbidity rates were 3 and 37%, respectively. Resection of the common bile duct (43%) increased postoperative complications (60 vs. 23%, p  = 0.0001). Local residual tumor was found in 83 (56%) patients; it was significantly correlated with the T stage and influenced long-term survival. R0 was obtained in 143 (97%) patients and port-site invasion was histologically confirmed in one patient (1.8%). After a median follow-up period of 34 months, the 1-, 3-, and 5-year survival rates for the 148 patients with re-resection were 76, 54, and 41%, respectively. Re-resection significantly increased survival in patients with T2 ( p  = 0.0001) and T3 ( p  = 0.04) disease. Resection of the common bile duct increased neither R0 resection nor overall survival ( p  = 0.06). Conclusion This study validates the concept of re-resection in T2 and T3 GBC. Bile duct resection increases postoperative morbidity but does not improve survival. There is currently a modification in the surgical management of incidental GBC, with minor liver resection and no common bile duct resection.

Introduction: In the midst of a pandemic, apps can be used to provide close follow-up, ensure that patients are monitored at home, avoid excessive pressure on medical facilities, prevent the movement of people (both patients and health professionals), and reduce the risk of infection. Objective: To adapt and validate the use of a smartphone application for outpatient follow-up of COVID-19 patients after hospital discharge. Methods: We conducted an open-label clinical trial at Hospital Universitari Vall d’Hebron in Barcelona, Spain. Patients were randomly assigned in a 1:1 ratio to be followed by the Farmalarm app or by their primary care center. The primary endpoint was the reduction in the need for in-person return visits. Results: From 31 March to 4 May 2020, 150 patients were enrolled in the study at hospital discharge: 74 patients were randomized to the experimental group, and 76 to the control group. All patients in the control group and all except for six in the experimental group completed the study. During hospitalization, before study inclusion, all but 4 (97.3%) had viral pneumonia, 91 (60.7%) required supplemental oxygen, and 16 (10.7%) required intensive care unit (ICU) admission. COVID-19–related return visits to the emergency department were significantly higher in the control group (7.9% vs. 0%; p = 0.028) in the per-protocol analysis. Telephone consultations with the emergency department were performed by 12 (15.8%) patients in the control group and 0 (0%) in the experimental group (p < 0.001). Satisfaction with outpatient monitoring was rated higher by the experimental group (5 vs. 4 points; p < 0.001). Conclusions: Following COVID-19 hospital discharge, home follow-up via a mobile app was effective in reducing in-person return visits without undermining patient satisfaction or perception of health, compared with standard follow-up.

Leishmaniasis is considered a neglected disease that causes thousands of deaths annually in some tropical and subtropical countries. There are various techniques to diagnose leishmaniasis of which manual microscopy is considered to be the gold standard. There is a need for the development of automatic techniques that are able to detect parasites in a robust and unsupervised manner. In this paper we present a procedure for automatizing the detection process based on a deep learning approach. We train a U-net model that successfully segments leismania parasites and classifies them into promastigotes, amastigotes and adhered parasites.