The acoustic levitation of liquid drops has been a key phenomenon for more than 40 years, driven partly by the ability to mimic a microgravity environment. It has seen more than 700 research articles published in this time and has seen a recent resurgence in the past 5 years thanks to low cost developments. As well as investigating the basic physics of levitated drops, acoustic levitation has been touted for container free delivery of samples to a variety of measurements systems, most notably in various spectroscopy techniques including Raman, Fourier Transform InfraRed (FTIR) in addition to numerous X-Ray techniques. For 30 years the workhorse of the acoustic levitation apparatus was a stack comprising a piezoelectric transducer coupled to a horn shaped radiative element often referred to as the Langevin horn. Decades of effort have been dedicated to such devices, paired with a matching and opposing device or a reflector, but they have a significant dependence on temperature and require precision alignment. The last decade has seen a significant shift away from these in favour of arrays of digitally driven, inexpensive transducers, giving a new dynamic to the topic which we review herein.
Macromolecular Crystallography is a powerful and valuable technique to assess protein structures. Samples are commonly cryogenically cooled to minimise radiation damage effects from the X-ray beam, but low temperatures hinder normal protein functions and this procedure can introduce structural artefacts. Previous experiments utilising acoustic levitation for beamline science have focused on Langevin horns which deliver significant power to the confined droplet and are complex to set up accurately. In this work, the low power, portable TinyLev acoustic levitation system is used in combination with an approach to dispense and contain droplets, free of physical sample support to aid protein crystallography experiments. This method facilitates efficient X-ray data acquisition in ambient conditions compatible with dynamic studies. Levitated samples remain free of interference from fixed sample mounts, receive negligible heating, do not suffer significant evaporation and since the system occupies a small volume, can be readily installed at other light sources.
Parenteral and enteral nutrition support are key components of care for various medical and physiological conditions in infants, children, and adults. Nutrition support practices have advanced over time, driven by the goals of safe and sufficient delivery of needed nutrients and improved patient outcomes. These advances have been, and continue to be, dependent on research and development studies. Such studies address aspects of enteral and parenteral nutrition support: formulations, delivery devices, health outcomes, cost-effectiveness, and related metabolism. The studies are supported by public funding from the government and by private funding from foundations and from the nutrition support industry.To build public trust in nutrition support research findings, it is important to underscore ethical research conduct and reporting of results for all studies, including those with industry sponsors. In 2019, American Society for Parenteral and Enteral Nutrition's (ASPEN's) Board of Directors established a task force to ensure integrity in nutrition support research that is done as collaborative partnerships between the public (government and individuals) and private groups (foundations, academia, and industry).
Magnetic Resonance (MR) sensors are an area of increasing interest for the measurement and monitoring of material properties. There are two relaxation times associated with samples that can be measured with MR sensors: The spin-lattice and spin-spin relaxations. When developing new sensors, it is desirable to have a series of standards by which instruments can be assessed. The standard calibration materials available typically comprise different concentrations of Nickel Sulphate which is carcinogenic and toxic. In this work we report the use of solutions containing full fat milk powder as a safe and inexpensive material that shortens the longitudinal relaxation time of water over a wide range of values. We demonstrate that concentrations in distilled water from 5% w/v to 64% w/v give T1 values from 1.7 s down to 469 ms respectively in a 1.5T clinical MRI, while within an MR sensor these times were from 1.6 s down to 431 ms. In addition, both systems have the same exponential coefficient (−0.022× concentration) that demonstrates the effectiveness of the NMR sensor in comparison to the clinical MRI.
W.G. Sebald's 1997 lectures, Luftkrieg und Literatur, sparked intense debate in the German media over the supposed taboo surrounding the literary depiction of German civilian victims of Allied attacks and the potential blurring of the already problematic ‘Täter’/‘Opfer’ complex. On its publication, Grass's most recent work Im Krebsgang either fuelled or became embroiled in this dispute and became front‐ page news. It is contended that such a media frenzy led to literary reviews at the time ignoring the aesthetic merits and failures of the novella and thus overlooking the complexities of its narratological structure, giving rise to over‐simplistic interpretations of Grass's contribution to the ‘Täter’/‘Opfer’ debate. The following article attempts to redress the journalistic imbalance by undertaking a detailed analysis of the various narrative strategies employed within the work and relating this to the generational and familial framework with which Grass addresses the issue of German suffering. This serves to illuminate further the topic of memory and memorialising the past which lies at the heart of Sebald's essay and of Grass's novella.
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