This study describes the capabilities and limitations of carrying out total scattering experiments on the Powder Diffraction (PD) beamline at the Australian Synchrotron, ANSTO. A maximum instrument ...momentum transfer of 19 Å−1 can be achieved if the data are collected at 21 keV. The results detail how the pair distribution function (PDF) is affected by Qmax, absorption and counting time duration at the PD beamline, and refined structural parameters exemplify how the PDF is affected by these parameters. There are considerations when performing total scattering experiments at the PD beamline, including (1) samples need to be stable during data collection, (2) highly absorbing samples with a μR > 1 always require dilution and (3) only correlation length differences >0.35 Å may be resolved. A case study comparing the PDF atom–atom correlation lengths with EXAFS‐derived radial distances of Ni and Pt nanocrystals is also presented, which shows good agreement between the two techniques. The results here can be used as a guide for researchers considering total scattering experiments at the PD beamline or similarly setup beamlines.
Total scattering data can be obtained on the PD beamline although there are constraints to the capabilities offered including longer acquisition times and necessary dilution of highly absorbing samples. This work details the considerations needed to successfully carry out total scattering studies on this bending‐magnet beamline, which has not been specifically designed for total scattering experiments.
Nothing trumps good data Pinkerton, A. Alan
Acta crystallographica. Section A, Foundations and advances,
March 2021, Volume:
77, Issue:
2
Journal Article
Peer reviewed
Open access
The advantages of a powerful new tool for determining the electron density of small inorganic systems using high‐quality powder diffraction data from the MYTHEN microstrip detector Svane et al. ...(2021). Acta Cryst. A77, 85–95 are considered.
The advantages of a powerful new tool for determining the electron density of small inorganic systems using high‐quality powder diffraction data from the MYTHEN microstrip detector Svane et al. (2021). Acta Cryst. A77, 85–95 are considered.
This book greatly enhances our knowledge of the interrelationship of Greek religion & culture and the Ancient Near East by offering important analyses of Greek myths, divinities and terms like ...'magic' and 'paradise', but also of the Greek contribution to the Christian notion of atonement.
A facile usage of a MYTHEN 1K detector with a Huber 5021 six‐circle diffractometer is described in detail. A mechanical support has been custom designed for the first time to combine the MYTHEN 1K ...detector with a point detector, which can be used as a reference point for each individual pixel of the MYTHEN 1K during measurements. The MYTHEN 1K is mounted on the arm of the 2θ circle of the Huber diffractometer with an intrinsic angular resolution of ∼0.0038°, and its pitch angle can be automatically adjusted with an accuracy of 0.0072°. Standard procedures are discussed for its calibration. Programs have been written in the SPEC environment for simultaneous data conversion, integration and acquisition. The X‐ray powder diffraction patterns of standard samples were measured in the Debye–Scherrer geometry and matched well with those of references. The angular shift due to sample‐to‐center displacement in the `flat‐plate transmission' geometry, which is frequently employed in operando experiments, has been successfully investigated and can be efficiently corrected. One operando experiment using the MYTHEN 1K is presented. This work provides a straightforward procedure to use the MYTHEN 1K detector properly in Debye–Scherrer geometry, and could facilitate its application at other synchrotron facilities.
A mechanical assembly has been successfully designed to combine a MYTHEN 1K with a point detector, and is proved facile for the angular calibration of individual pixels. In `flat‐plate transmission' geometry, which is frequently used in various operando experiments, straightforward corrections can be efficiently made to compensate for sample displacement away from the diffractometer center.
Advances in instrumentation, as well as the development of powerful crystallographic software have significantly facilitated the collection of high‐resolution diffraction data and have made X‐ray ...powder diffraction (XRPD) particularly useful for the extraction of structural information; this is true even for complex molecules, especially when combined with synchrotron radiation. In this study, in‐line with past instrumental profile studies, an improved data collection strategy exploiting the MYTHEN II detector system together with significant beam focusing and tailored data collection options was introduced and optimized for protein samples at the Material Science beamline at the Swiss Light Source. Polycrystalline precipitates of octreotide, a somatostatin analog of particular pharmaceutical interest, were examined with this novel approach. XRPD experiments resulted in high angular and d‐spacing (1.87 Å) resolution data, from which electron‐density maps of enhanced quality were extracted, revealing the molecule's structural properties. Since microcrystalline precipitates represent a viable alternative for administration of therapeutic macromolecules, XRPD has been acknowledged as the most applicable tool for examining a wide spectrum of physicochemical properties of such materials and performing studies ranging from phase identification to complete structural characterization.
The complete structure of a pharmaceutical molecule, octreotide (PDB code 6vc1), obtained by X‐ray powder diffraction data at 1.87 Å resolution, using a MYTHEN II detector system at the Swiss Light Source, is reported.
Eating disorder mental health literacy (ED-MHL) refers to knowledge about the symptoms, causes, and treatment of eating disorders (EDs) and is an important factor in people's attitudes towards ...individuals with EDs and help-seeking for EDs. Associations between ED-MHL, stigma, ED symptomatology, and gender were investigated in a sample of N = 194 German high school students. Knowledge and myths about EDs were assessed with 18 factual statements about EDs and agreement/disagreement with common myths about ED. Students also completed the Universal Stigma Scale (USS), the Weight Concerns Scale (WCS), and demographic items. Students judged M = 8.39 (SD = 3.40) statements correctly, while the average agreement with all ED myths was low (M = 0.19, SD = 0.14). Greater ED-MHL was associated with lower stigmatization of EDs. Male participants were less knowledgeable and more likely to agree with the ED myths. Participants displayed moderate ED-MHL; however, certain aspects such as ED risk factors or symptoms of specific disorders such as anorexia nervosa and bulimia nervosa were less well known. These results can inform the design of future MHL interventions for adolescents.
Empirische Studien zeigen, dass Studierende über ihr Stu-dium hinweg an Fehlvorstellungen zum Thema Gehirn und Lernen (Neuromythen) und transmissiven Lehr-Lern-Überzeugungen festhalten. Derartige ...Befunde stellen ein Gelingen des allgemeinen Studienziels in Frage, angehenden Lehrkräften ein angemessenes Konzept von Lernen nahezubringen. Mit dem Ziel, Biologielehramtsstu-dierende besser bei der Konstruktion wissenschaftlich angemessener Lehr-Lern-Vorstellungen zu unterstützen, wurde in dem im Rahmen dieses Beitrags beschriebenen Projekt das Modell der Didaktischen Rekonstruktion auf den Hochschulbereich übertragen und als Planungs- und Forschungsrahmen für die Gestaltung und Evaluation der universitären Lehrveranstaltung Gehirngerechtes Lernen – Konzept oder Mythos? verwendet. Im Beitrag wird das Modell der Didaktischen Rekonstruktion für die Hochschulbildung (MDRH) in seinen Unterschieden zu anderen Modellen vorgestellt. Erläutert wird, wie sich eine fachliche Klärung mit fachwissenschaftlicher, fachdidaktischer und bildungswissenschaftlicher Analyse gestaltete und wie sie zur theoretischen Fundierung der Lehrveranstaltung genutzt wurde. Beschrieben wird weiterhin, wie sich die drei Lehrveranstaltungselemente (1) Verschachteltes Lehren von Seminarinhalten, (2) Erfahrungen stiften mit Methoden nachhaltigen Lernens, Lernversuchen und neurodidaktischen Prinzipien sowie (3) Einsatz von Konzeptwechseltexten gestalten, die mittels didaktischer Strukturierung konzipiert wurden. Erläuterungen übertragbarer Konzepte, Durchführungshinweise sowie Onlinematerial sollen einen Transfer ermöglichen. Ein Erfahrungsbericht fasst Evaluationsergebnisse zusammen und diskutiert Praktikabilität und Innovationskraft des MDRH für konstruktivistisches Lehren an Universitäten. Zusammengefasst zeigt sich am Beispiel des Themas Gehirn und Lernen, dass sich das MDRH in der Hochschulbildung anwenden lässt, die didaktisch rekonstruierte Lehrveranstaltung Gehirn und Lernen – Konzept oder Mythos? positive Wirkungen auf Professionswissen, Lehr-Lern-Überzeugungen und Fehlvorstellungen Biologielehramtsstudierender erzielt und die fachliche Klärung zur Theoriebildung in Bezug auf Neuromythen, Professionsforschung und Hochschuldidaktik beitragen kann.
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