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The Pd40Cu30Ni10P20 and Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glasses exhibit extraordinary stability against crystallization. It is assumed, that this results from the complicate crystallization behavior, which requires strong decomposition of the glass in some cases already preceding to the crystallization. The crystallization behavior of both these glasses in its first stage is studied after different thermal treatments by means of differential scanning calorimetry, XRD, transmission electron microscopy, energy-filtered transmission electron microscopy and three-dimensional atom probe. During annealing for long times at temperatures above and below the calorimetric glass transition respectively both metallic glasses undergo decomposition. Nanometer-scaled amorphous regions are observed sporadic or homogeneously distributed in the respective glasses. They differ in composition from their amorphous environment. After extended annealing or short time heat treatment at higher temperatures nano-crystals form from these regions. The composition of these crystals resembles the compositions of the decomposed regions. In case of Pd–Cu–Ni–P the crystals accord with an intermetallic phase. In case of Zr–Ti–Cu–Ni–Be, they are quasicrystalline. Depending on the pre-annealing treatment of the Zr–Ti–Cu–Ni–Be glass three different types of quasicrystals are found. For both alloys long-range diffusion over a wide concentration range is one important factor which controls the decomposition kinetics. Thus diffusion contributes essentially to the stability of the glasses and effects the pathway of crystallization and the resulting microstructure. [Copyright &y& Elsevier]

During heat treatment of metallic bulk glasses at temperatures below the calorimetric glass transition temperature Tg, the glasses undergo microstructural alterations indicated by their thermal behavior as observed by DSC, but not discernible by X-ray diffraction (XRD). A reversible enthalpy recovery at Tg indicates a slow, reversible relaxation of the glass into a temperature dependent structural equilibrium state. After prolonged annealing times below Tg the crystallization is irreversibly affected, i.e. it starts at a lower temperature, takes a different pathway and ends up in a different crystalline microstructure. This behavior was studied in Zr46.8Ti8.2Ni10Cu7.5Be27.5—bulk glass (V4) after preceding long term annealing well below Tg=603 K by means of differential scanning calorimeter (DSC), XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and microhardness measurements. [Copyright &y& Elsevier]

The surface structure of the liquid phase of the Au72Ge28 eutectic alloy has been measured using resonant and nonresonant x-ray reflectivity and grazing incidence x-ray diffraction. In spite of the significant differences in the surface tension of liquid Ge and Au the Gibbs adsorption enhancement of Ge concentration at the surface is minimal. This is in striking contrast to all the other binary alloys with large differences in the respective surface tensions measured up to date. In addition there is no evidence of the anomalous strong surface layering or in-plane crystalline order that has been reported for the otherwise quite similar liquid Au82Si18 eutectic. Instead, the surface of eutectic Au72Ge28 is liquidlike and the layering can be explained by the distorted crystal model with only slight modifications to the first layer., Engineering and Applied Sciences

The formation of the quasicrystalline phase is observed as a first step of crystallization during isothermal annealing of the Zr[sub 46.7]Ti[sub 8.3]Cu[sub 7.5]Ni[sub 10]Be[sub 27.5] bulk glass. The structure of the quasicrystals and the sequence of phase formation have been investigated by x-ray powder diffraction and transmission electron microscopy. The structure of the quasicrystals is determined to be primitive icosahedral with a quasilattice constant of 4.779 Å. The quasicrystals decompose into several intermetallic compounds after prolonged annealing at lower temperatures or in a short time period (less than 5 min) at high temperatures above 683 K. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Background: Chimeric antigen receptor engineered T (CAR-T) cell therapy is a promising approach currently revolutionizing the field of cancer immunotherapy. However, data concerning clinical-grade CAR-T cell stability and functionality after months of cryopreservation have not been released by companies so far. To investigate the effect of cryopreservation on CAR-T cells and to further optimize the potency assays, we performed this study., Methods: A third generation of CD19 CAR-T cells was manufactured according to Good Manufacturing Practice (GMP) requirements, which is applied to patients in an ongoing clinical phase 1 study. Quality control tests for sterility, endotoxin and mycoplasma were performed for each batch. Stability in terms of viability, recovery, transduction efficiency and functional capacity was determined using microscopy, multiparametric flow cytometry as well as chromium-51 release tests., Results: Up to 90days of cryopreservation had no influence on viability, recovery and transduction efficiency of CAR-T cells. However, higher cell concentration for cryopreservation could alter the cell viability and recovery but not the transduction efficiency. Moreover, directly after thawing, both the quantity and quality of the functionality of CAR-T cells were transiently hampered by the negative effects of cryopreservation. Notably, the impaired functionality could be fully restored and even strengthened after an overnight resting process., Discussion: Cryopreservation is a challenge for the functional activity of CAR-T cells. However, CAR-T cells regain their potency by overnight incubation at 37°C, which mimics the clinical application setting. Therefore, an overnight resting step should be included in in vitro potency assays., (Copyright © 2019 International Society for Cell and Gene Therapy. Published by Elsevier Inc. All rights reserved.)

The structural and mechanical properties of 2D crystalline surface phases that form at the surface of liquid eutectic Au82Si18 are studied using synchrotron x-ray scattering over a large temperature range. In the vicinity of the eutectic temperature the surface consists of a 2D atomic bilayer crystalline phase that transforms into a 2D monolayer crystalline phase during heating. The latter phase eventually melts into a liquidlike surface on further heating. We demonstrate that the short wavelength capillary wave fluctuations are suppressed due to the bending rigidity of 2D crystalline phases. The corresponding reduction in the Debye-Waller factor allows for measured reflectivity to be explained in terms of an electron density profile that is consistent with the 2D surface crystals.