Although the cardiovascular benefits of an increased urinary potassium excretion have been suggested, little is known about the potential cardiac association of urinary potassium excretion in patients with chronic kidney disease. In addition, whether the cardiac association of urinary potassium excretion was mediated by serum potassium levels has not been studied yet. We reviewed the data of 1633 patients from a large-scale multicentre prospective Korean study (2011–2016). Spot urinary potassium to creatinine ratio was used as a surrogate for urinary potassium excretion. Cardiac injury was defined as a high-sensitivity troponin T ≥ 14 ng/l. OR and 95 % (CI for cardiac injury were calculated using logistic regression analyses. Of 1633 patients, the mean spot urinary potassium to creatinine ratio was 49·5 (sd 22·6) mmol/g Cr and the overall prevalence of cardiac injury was 33·9 %. Although serum potassium levels were not associated with cardiac injury, per 10 mmol/g Cr increase in the spot urinary potassium to creatinine ratio was associated with decreased odds of cardiac injury: OR 0·917 (95 % CI 0·841, 0·998), P = 0·047) in multivariate logistic regression analysis. In mediation analysis, approximately 6·4 % of the relationship between spot urinary potassium to creatinine ratio and cardiac injury was mediated by serum potassium levels, which was not statistically significant (P = 0·368). Higher urinary potassium excretion was associated with lower odds of cardiac injury, which was not mediated by serum potassium levels.

Modern electronics have been geared toward exploring novel electronic materials that can encompass a broad set of unusual functionalities absent in conventional platforms. In this regard, two-dimensional (2D) transition metal dichalcogenide (TMD) semiconductors are highly promising, owing to their large mechanical resilience coupled with superior transport properties and van der Waals (vdW) attraction-enabled relaxed assembly. Moreover, 2D TMD heterolayers based on chemically distinct constituent layers exhibit even more intriguing properties beyond their mono-component counterparts, which can materialize only when they are manufactured on a technologically practical wafer-scale. This mini-review provides a comprehensive overview of recent progress in exploring wafer-scale 2D TMD heterolayers of various kinds. It extensively surveys a variety of manufacturing strategies and discusses their scientific working principles, resulting 2D TMD heterolayers, their material properties, and device applications. Moreover, it offers extended discussion on remaining challenges and future outlooks toward further improving the material quality of 2D TMD heterolayers in both material and manufacturing aspects.

In this study, the effect of simple shearing on microstructure evolution and mechanical properties of 316L austenitic stainless steel were investigated. Two different shear strain routes were obtained by twisting cylindrical specimens in the forward and backward directions. The strain-induced martensite phase was effectively obtained by alteration of the routes. Formation of the martensite phase clearly resulted in significant hardening of the steel. Grain-size reduction and strain-induced martensitic transformation within the deformed structures of the strained specimens were characterized by scanning electron microscopy – electron back-scattered diffraction, X-ray diffraction, and the TEM-ASTAR (transmission electron microscopy – analytical scanning transmission atomic resolution, automatic crystal orientation/phase mapping for TEM) system. Significant numbers of twin networks were formed by alteration of the shear strain routes, and the martensite phases were nucleated at the twin interfaces.

To ascertain whether aromatase (CYP19A1) expression is linked to sperm fertility of pigs, the present study determined the expression of the CYP19A1 gene in porcine sperm and its relationship with fertilization in vitro. First, to investigate its role in fertility, the presence of CYP19A1 of mRNA and protein expression in porcine sperm were confirmed by real-time (RT) or quantitative polymerase chain reaction (q-PCR) and by western blots. The expression levels were determined quantitatively using two sperm groups recovered by a Percoll gradient, which revealed that the sperm group with a low density had a higher penetration rate than that of the high-density group (P < 0.05). However, the expression level of CYP19A1 was not significantly different between the two groups. Secondly, to examine the effect of aromatase activity on fertilization, fresh semen was treated with a steroidal inhibitor, exemestane (50 μM for 0.5 h), followed by the dose- and time-dependent viability test. Our results clearly showed that an exemestane treatment effect (P < 0.05) was found for both the sperm-penetration rate and the oocyte cleavage rate. These results indicated that CYP19A1 could be involved in sperm fertility and its expression in sperm plays an important role in fertilization.

The dehydrogenated microstructure of the lithium borohydride-yttrium hydride (LiBH4-YH3) composite obtained at 350°C under 0.3 MPa of hydrogen and static vacuum was investigated by transmission electron microscopy combined with a focused ion beam technique. The dehydrogenation reaction between LiBH4 and YH3 into LiH and YB4 takes place under 0.3 MPa of hydrogen, which produces YB4 nano-crystallites that are uniformly distributed in the LiH matrix. This microstructural feature seems to be beneficial for rehydrogenation of the dehydrogenation products. On the other hand, the dehydrogenation process is incomplete under static vacuum, leading to the unreacted microstructure, where YH3 and YH2 crystallites are embedded in LiBH4 matrix. High resolution imaging confirmed the presence of crystalline B resulting from the self-decomposition of LiBH4. However, Li2B12H12, which is assumed to be present in the LiBH4 matrix, was not clearly observed.

Dynamic recrystallization (DRX) of 99.9999% aluminum single crystal at room temperature was examined under frictionless deformation mode. To exclude the self-heating of the specimen due to applied high strain, a microcrack that localizes the stress at a very small region was intentionally introduced by controlled local necking. For the in situ observation of DRX, a specially designed in situ microdeformation device was positioned inside an electron backscattered diffraction system chamber. Recrystallized grains showed relatively random texture and preferred growth direction. The subgrains with low-angle grain boundaries formed by dynamic recovery transformed into small grains with high-angle grain boundaries, acting as nuclei for discontinuous dynamic recrystallization and growing by further deformation. The DRX in pure aluminum can take place under frictionless tensile deformation conditions at room temperature, and the stress localization and high purity are key issues for the DRX of aluminum at room temperature.

Cast AZ31B-H24 magnesium alloy, comprising Mg with 3.27 wt% Al and 0.96 wt% Zn, was cold rolled and subsequently annealed. Global texture evolutions in the specimens were observed by X-ray diffractometry after the thermomechanical processing. Image-based microstructure and texture for the deformed, recrystallized, and grown grains were observed by electron backscattered diffractometry. Recrystallized grains could be distinguished from deformed ones by analyzing grain orientation spread. Split basal texture of ca. ±10–15° in the rolling direction was observed in the cold-rolled sample. Recrystallized grains had widely spread basal poles at nucleation stage; strong {0001} basal texture developed with grain growth during annealing.

Band contrast (BC) is a qualitative measure of electron back-scattered diffraction (EBSD), which is derived from the intensity of the Kikuchi bands. The BC is dependent upon several factors including scanning electron microscope measurement parameters, EBSD camera setup, and the specimen itself (lattice defect and grain orientation). In this study, the effective factors for BC variations and the feasibility of using BC variations for the quantification of microstructure evolutions have been investigated. In addition, the effects of the lattice defect and the grain orientation on the BC variations are studied. Next, a shear-deformed microstructure of 316L stainless steel, which contains nanosized grains and a large portion of twin boundaries, is revealed by BC map and histogram. Recovery and recrystallization of shear-deformed 316L stainless steel are displayed by BC variations during isothermal annealing at 700 and 800°C, respectively. It is observed that the BC turns bright as the shear-deformed crystal structure is recovered or recrystallized.

12Cr ODS steel samples were prepared by mechanical alloying of the metal powders with 20-30 nm Y2O3 particles followed by isostatic pressing, hot rolling and final heat treatment. Evolutions of oxide particles such as YTaO4 and YCrO3 after each fabrication step were investigated by using TEM with EDS. Crystallographic correlation between oxide particles and the matrix was investigated in a HIPped sample, and interactions between dislocations and oxide particles were observed in hot rolled or heat treated sample. Size distributions of oxide particles were measured by carbon replica samples and it was found that coarsening of oxide particles from 9 to 12 nm occurred during hot rolling process. Additional isothermal annealing at 1250 ˚C revealed that phase transformation of oxide particles from monoclinic YTaO4 to face centered cubic Y3TaO7 was observed.

For a flexible electronic device integrating inorganic materials on a polymer substrate, the polymer can deform substantially, but the inorganic materials usually fracture at small strains. This paper describes an approach to make such a device highly stretchable. A polyimide substrate is first coated with a thin layer of an elastomer, on top of which SiNx islands are fabricated. When the substrate is stretched to a large strain, the SiNx islands remain intact. Calculations confirm that the elastomer reduces the strain in the SiNx islands by orders of magnitude.

During the self-annealing in the copper electrodeposits for the copper metallization, an in-situ observation of grain growth of the copper at room temperature was performed by using EBSD (electron backscatter diffraction). The thin film structure of the copper electrodeposits after annealing was columnar. New twin was initiated at the front surface of growing twin and grew along the normal direction of the twin boundary between the new and parent twins. It was confirmed that the annealing twin in the copper electrodeposits during the self-annealing have an {111} growth front surface.

In a crystallographic study of stress induced voiding of copper interconnect, the planar electron backscattered diffraction analysis showed that the void was initiated at the triple junction of the grain boundaries, not at the junction of the twin boundary and grain boundary. By using stepwise cross-sectional crystalline investigation for the void, it was possible to rebuild 3D crystalline structure near the void. From the stress calculation based on the measured crystalline structures, the hydrostatic stress was highly concentrated at the triple junction of the twin boundary and grain boundary, but experimentally, there was no voiding at that. The voiding in the copper interconnect may depend mainly on the boundary instability.

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

In this paper, we investigate the structure of Ariki–Koike algebras and their Specht modules using Gröbner–Shirshov basis theory and combinatorics of Young tableaux. For a multipartition $\lambda$, we find a presentation of the Specht module $S^{\lambda}$ given by generators and relations, and determine its Gröbner–Shirshov pair. As a consequence, we obtain a linear basis of $S^{\lambda}$ consisting of standard monomials with respect to the Gröbner–Shirshov pair. We show that this monomial basis can be canonically identified with the set of cozy tableaux of shape $\lambda$.

We have investigated the development of erbium(III)-cored supramolecular complexes containing metalloporphyrins to circumvent the solubility problem and improve the optical amplification property. The new synthetic methodology was accomplished through the ligand-exchange model reaction using ErCl3 to optimize its synthetic condition We have designed and synthesized the model complexes to investigate coordination property between the ligand and the erbium ion. Highly coordinated erbium(III)-cored model complexes (at least 8 to 10 coordination) showed the strong near infrared(IR) emission at 1520 nm, corresponding to the 4I13/2 → 4I15/2 transition. Also, with these synthetic results, erbium(III)-cored supramolecular complexes based on metalloporphyrins were synthesized and characterized. They also showed the infrared emission of the 4I13/2 → 4I15/2 transition at 1520 nm.

We studied on the thermal annealing effect on the residual stress and the mechanical properties in thin compressive stressed diamond-like carbon film on Si substrate. Annealing experiments were carried out with Rapid Thermal Procedure system at 200–600 °C, and the stress change with annealing temperature was investigated by in-situ stress measurement system. The apparent stress reduction occurred with minimal structure changes. In order to measure the change of chemical structure of diamond-like carbon film by annealing, we used Raman spectrometer. The adhesion deterioration in interface has been detected as annealing temperature increased. In the compressive stressed DLC film, we observed the dramatic evolution of interface delamination at certain high temperature using in-situ heating stage built in Environment SEM. The quantitative change of adhesion affected by annealing process was also measured with scratch testing. For exploring the interface structure affected by the thermal annealing process at high temperature, the cross section of annealed film has been observed with HR TEM.

Various Cu films were fabricated using sputtering and electroplating with and without additive, and their surface damages after annealing were investigated. After annealing at 435°C, the difference between damage morphologies of the films was observed. In some films stressinduced grooves along the grain boundaries were observed, while in the others voids at the grain boundary triple junctions were observed. It was also observed that the stress-induced groove was formed along the high energy grain boundaries. To explain the morphological difference of surface damages, a simple parameter considering the contributions of grain structures and grain boundary characteristics to surface and grain boundary diffusions is suggested. The effective grain boundary area, which is a function of grain size, film thickness and the fraction of high energy grain boundaries, played a key role in the morphological difference.

The role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.

The topology of telephone cord buckles that form beneath compressed diamond-like carbon films (DLC) on glass substrates has been characterized with Atomic Force Microscopy (AFM) and with the Focused Ion Beam (FIB). Using AFM with 2nm resolution, the wavelength and amplitude of the buckles and their profiles have been measured. It has been found that, within each wavelength, the profile has symmetric and asymmetric segments. These changes have been related to differences in local mode mixity around the periphery of each repeat unit along the buckle, resulting in a fundamental rationale for the factors governing the wavelength. Sections made through various segments of the buckle by using the FIB imaging system result in local changes in the shape and size of the buckles that provide further insight into the buckle propagation criterion.