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At least 1,369 records · Page 76

In-depth study of the H - T phase diagram of Sr 4 Ru 3 O 10 by magnetization experiments

Here, we present magnetization measurements on Sr 4 Ru 3 O 10 as a function of temperature and magnetic field applied perpendicular to the magnetic easy c-axis inside the ferromagnetic phase. Peculiar metamagnetism evolves in Sr 4 Ru 3 O 10 below the ferromagnetic transition T C as a double step in the magnetization at two critical fields H c1 and H c2 . We map the Sr 4 Ru 3 O 10 - T phase diagram with special focus on the temperature range 50 K ≤ T ≤ T C . We find that the critical field H c1 ( T ) connects the field and temperature axes of the phase diagram, whereas the Sr 4 Ru 3 O 10 c2 boundary starts at 2.8 T for the lowest temperatures and ends in a critical endpoint at (1 T; 80 K). We also conclude from the temperature dependence of the ratio H c1/ H c2( T ) that the double metamagnetic transition is an intrinsic effect of the material and it is not caused by sample stacking faults such as twinning or partial in-plane rotation between layers.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Photon counting with intensified charge coupled device (ICCD) – I. In-depth detector characterization

While the adsorption properties of transition metal catalysts have been widely studied, leading to the discovery of various scaling relations, descriptors of catalytic activity, and well-established computational models, a similar understanding of semiconductor catalysts has not yet been achieved. In this work, we present a high-throughput density functional theory investigation into the adsorption properties of 5 oxides of interest to the photocatalytic CO 2 reduction reaction: TiO 2 (rutile and anatase), SrTiO 3 , NaTaO 3 , and CeO 2 . Using a systematic approach, we exhaustively identify unique surfaces and construct adsorption structures to undergo geometry optimizations. We then perform a data-driven analysis, which reveals the presence of weak adsorption energy scaling relations, the propensity of adsorbates of interest to interact with oxygen surface sites, and the importance of slab deformation upon adsorption. Our findings are presented in the context of experimental observations and in comparison to previously studied classes of catalysts, such as pure metals and tellurium-containing semiconductors, and reinforce the need for a comprehensive approach to the study of site-specific surface phenomena on semiconductors.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Depth profile of a time-reversal focus in an elastic solid

The out-of-plane velocity component is focused on the flat surface of an isotropic solid sample using the principle of time reversal. This experiment is often reproduced in the context of nondestructive testing for imaging features near the surface of the sample. However, it is not clear how deep the focus extends into the bulk of the sample and what its profile is. In this paper, this question is answered using both numerical simulations and experimental data. The profiles of the foci are expressed in terms of the wavelengths of the dominant waves, based on the interpretation of the Lamb’s problem and the use of the diffraction limit.

36 MATERIALS SCIENCE↗

In-depth evaluation of commercially available human vascular smooth muscle cells phenotype: Implications for vascular tissue engineering

In vitro research on vascular tissue engineering has extensively used isolated primary human or animal smooth muscle cells (SMC). Research programs that lack such facilities tend towards commercially available primary cells sources. Here, we aim to evaluate the capacity of commercially available human SMC to maintain their contractile phenotype, and determine if dedifferentiation towards the synthetic phenotype occurs in response to conventional cell culture and passaging without any external biochemical or mechanical stimuli. Lower passage SMC adopted a contractile phenotype marked by a relatively slower proliferation rate, higher expression of proteins of the contractile apparatus and smoothelin, elongated morphology, and reduced deposition of collagen types I and III. As the passage number increased, migratory capacity was enhanced, average cell speed, total distance and net distance travelled increased up to passage 8. Through the various assays, corroborative evidence pinpoints SMC at passage 7 as the transition point between the contractile and synthetic phenotypes, while passage 8 distinctly and consistently exhibited characteristics of synthetic phenotype. This knowledge is particularly useful in selecting SMC of appropriate passage number for the target vascular tissue engineering application, for example, a homeostatic vascular graft for blood vessel replacement versus recreating atherosclerotic blood vessel model in vitro. - Highlights: • Ability of human smooth muscle cells to alter phenotype in culture is evaluated. • Examined the effect of passaging human smooth muscle cells on phenotype. • Phenotype is assessed based on morphology, proliferation, markers, and migration. • Multi-resolution assessment methodology, single-cell and cell-population. • Lower and higher passages than P7 adopted a contractile and synthetic phenotype respectively.

60 APPLIED LIFE SCIENCES↗

Rescuing Those Left Behind: Recovering and Characterizing Underdigested Membrane and Hydrophobic Proteins To Enhance Proteome Measurement Depth

The marine archaeon Nanoarchaeum equitans is dependent on direct physical contact with its host, the hyperthermophile Ignicoccus hospitalis. It is thought that this interaction is membrane-associated, involving a myriad of membrane-anchored proteins; proteomic efforts to better characterize this difficult to analyze interface are paramount to uncovering the mechanism of their association. By extending multienzyme digestion strategies that use sample filtration to recover underdigested proteins for reprocessing/consecutive proteolytic digestion, we applied chymotrypsin to redigest the proteinaceous material left over after initial proteolysis with trypsin of sodium dodecyl sulfate (SDS)-extracted I. hospitalis-N. equitansproteins. We show that proteins with increased hydrophobic character, including membrane proteins with multiple transmembrane helices, are enriched and recovered in the underdigested fraction. Chymotryptic reprocessing provided significant sequence coverage gains in both soluble and hydrophobic proteins alike, with the latter benefiting more so in terms of membrane protein representation. Moreover, these gains were despite a large proportion of high-quality peptide spectra remaining unassigned in the underdigested fraction suggesting high levels of protein modification on these often surface-exposed proteins. Importantly, these gains were achieved without applying extensive fractionation strategies usually required for thorough characterization of membrane-associated proteins and were facilitated by the generation of a distinct, complementary set of peptides that aid in both the identification and quantitation of this important, under-represented class of proteins.

59 BASIC BIOLOGICAL SCIENCES↗

Long-Term Cyclability of NCM-811 at High Voltages in Lithium-Ion Batteries: an In-Depth Diagnostic Study

High-nickel layered oxides, such as LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM-811), offer higher energy density than their low-nickel counterparts at a given voltage and are gaining major traction in automotive lithium-ion batteries for electric vehicles. Besides high-Ni content, higher charging voltages above 4.3 V vs Li + /Li boost the energy and represent another focus in battery development. Here, we investigate the long-term cyclability of NCM-811 in graphite pouch cells over 1000 deep cycles between 2.5–4.2, 2.5–4.4, and 2.5–4.5 V through a suite of sensitive characterization techniques. The NCM-811 full cells show severely deteriorated cyclability with higher charging voltages, from 78% at 4.2 V to 52 and 32% at 4.4 and 4.5 V, respectively. At 4.2 V, minor parasitic electrolyte oxidation as well as cathode Li/Ni mixing and cracking are revealed after cycling, while transition-metal dissolution and surface reconstruction into rock-salt NiO are virtually undetectable. At 4.4 and 4.5 V, transition-metal dissolution and crossover to the anode become much more pronounced and a primary contributor to the capacity fade, while significant surface NiO formation causes substantial voltage polarization, which is less noticeable at 4.2 V. Meanwhile, more severe electrolyte oxidation, Li/Ni mixing, and particle pulverization exacerbate the voltage and capacity fade. Finally, these results outline distinct challenges for stable high-Ni layered oxide cathodes in high-voltage Li-ion batteries.

25 ENERGY STORAGE↗

In-Depth Proteome Profiling of Small Extracellular Vesicles Isolated from Cancer Cell Lines and Patient Serum

Extracellular Vesicle (EV) secretion has been observed from most types of normal and tumor cells. These EVs contain a variety of distinctive cargo where tumor-derived serum proteins in EVs secreted into the bloodstream can be used to provide a minimally invasive method for clinical monitoring. We have therefore undertaken a comprehensive study of the protein content of the EVs from several cancer cell lines using direct Data Independent Analysis (DIA). Further, several thousand proteins were detected including many of the classic EV markers such as CD9, CD81, CD63, TSG101 and Syndecan-1 among others. Many distinctive cancer related proteins were detected and some of them are known to be potential markers of cancer detection and monitoring of cancer progression. We have further studied the protein content of EVs from patient serum for both normal controls and pancreatic (PC) and Hepatocellular Carcinoma (HCC) cancers. The EVs for these studies have been isolated by various methods for comparison including ultracentrifugation (UC) and CD9 immunoaffinity column (CD9-IC). Typically, 500-1,000 proteins were identified where most of them overlapped with the EV proteins identified from the cell lines studied. Many of the EV protein markers were identified in these serum EVs and large numbers of proteins related to pancreatic and HCC cancers were identified.

60 APPLIED LIFE SCIENCES↗