Clinical significance of HER2-low expression in early breast cancer: a nationwide study from the Korean Breast Cancer Society

There is an increasing interest in HER2-low breast cancer with promising data from clinical trials using novel anti-HER2 antibody–drug conjugates. We explored the differences in clinicopathological characteristics and survival outcomes between HER2-low and HER2-IHC 0 breast cancer. Using nationwide data from the Korean Breast Cancer Registry between 2006 and 2011, 30,491 patients with stages I to III breast cancer were included in the analysis: 9,506 (31.2%) in the HER2-low group and 20,985 (68.8%) in the HER2-IHC 0 group. Kaplan–Meier and Cox proportional hazards regression survival analysis were used to compare breast cancer-specific survival between the two groups. HER2-low breast cancer was more frequent in patients with hormone receptor-positive breast cancer than in those with triple-negative breast cancer. In patients with hormone receptor-positive breast cancer, HER2-low breast cancer was associated with fewer T4 tumors, higher histological grade, and a negative lymphatic invasion. In patients with triple-negative breast cancer, HER2-low breast cancer was associated with a high lymph node ratio and positive lymphatic invasion. HER2-low breast cancer was significantly associated with a lower Ki-67 labeling index. No significant difference was observed in overall survival between the two groups. HER2-low breast cancer showed significantly better breast cancer-specific survival than HER2-IHC 0 breast cancer, regardless of the hormone receptor status. In multivariate analysis, the impact of low HER2 expression on breast cancer-specific survival was significant only in triple-negative breast cancer (HRs, 0.68; 95% CI, 0.49–0.93; P = 0.019). These findings suggest that the biology and clinical impact of low HER2 expression can differ according to the hormone receptor status and support the need for further investigation on the understanding of the biology of HER2-low breast cancer

Fundamental understanding on catalytic behavior of single-atom catalysts supported on CeO2

School of Energy and Chemical Engineering (Chemical Engineering)ope

First-principles investigation of the effect of Co in stabilizing the structures of layer-structured cathodes in delithiated state

The structural and chemical features of delithiated layer-structured cathodes (Li _0.333 TMO _2 , TM = Ni and Co) are investigated. Energetically stable structures are evaluated by combing particle swarm optimization algorithm and density functional theory calculations. The concentration of defects is calculated assuming that the entire crystal is the statistical combination of the lowest-energy structures. TM antisites that occupy Li sites and interstitial Li ions at tetrahedral sites are the major defect types in Li _0.333 TMO _2 ; their prevalence decreases with increase in Co content. The oxidation state of Ni ions increases in the presence of Co, because the Co ions sustain low oxidation numbers, which results in decrease in the possibility of Ni ^2+ formation. In addition, the covalent bond of Co–O appears to be stronger than that of Ni–O. Therefore, the suppression of Ni ^2+ formation and the strong covalent bonding are proposed as the mechanisms underlying the stabilizing effect of Co

Point Defects in Layer-Structured Cathode Materials for Lithium-Ion Batteries

The structural characteristics related to point defects within layer-structured cathode materials for lithium-ion batteries were investigated. Crystal models containing certain types of defects were designed, and phase diagrams of Li–Co–O and Li–Ni–O systems were simulated by assuming these crystal models were independent phases based on first-principle methods, enabling the thermodynamic examination of the stability and formation probability of point defects. From the formation energy and mixing entropy of a defect phase in the thermodynamically stable phase, a quantitative calculation equation was designed to predict the concentration of defects. By combining the equation with the simulated phase diagrams, the equilibrium concentrations of every defect in LiCoO₂ and LiNiO₂ systems were calculated. Point defects in LiCoO₂ were predicted to form below 0.1%, whereas the formation of several percent of Li-deficiency and Li–Ni cation mixing appeared to be thermodynamically unavoidable in LiNiO₂. The reliability of the theoretical study was confirmed by good agreement with experimental features, and thus this theoretical approach is expected to be utilized to interpret defect formation and related properties in various material systems

Lithium Nickel Cobalt Manganese Oxide Synthesized Using Alkali Chloride Flux: Morphology and Performance As a Cathode Material for Lithium Ion Batteries

Li­(Ni_0.8Co_0.1Mn_0.1)­O₂ (NCM811) was synthesized using alkali chlorides as a flux and the performance as a cathode material for lithium ion batteries was examined. Primary particles of the powder were segregated and grown separately in the presence of liquid state fluxes, which induced each particle to be composed of one primary particle with well-developed facet planes, not the shape of agglomerates as appears with commercial NCMs. The new NCM showed far less gas emission during high temperature storage at charged states, and higher volumetric capacity thanks to its high bulk density. The material is expected to provide optimal performances for pouch type lithium ion batteries, which require high volumetric capacity and are vulnerable to deformation caused by gas generation from the electrode materials

Synthesis of High-Density Nickel Cobalt Aluminum Hydroxide by Continuous Coprecipitation Method

Spherical nickel cobalt aluminum hydroxide (Ni_0.80Co_0.15Al_0.05-hydroxide, NCA) was prepared by a continuous coprecipitation method. A new design of the Al solution and the feeding method was applied, which enabled to prevent rapid precipitation of Al­(OH)₃ and to obtain spherical NCA with large enough particle size and high density. The active material (LiNi_0.80Co_0.15Al_0.05O₂ or LNCA) prepared from it showed higher tap-density than that made from NCA prepared by general processes, and homogeneity of Al-distribution was also improved. It is expected that the electrode density of lithium ion batteries adopting LNCA could be improved with the new process proposed in this study

Mechanism of CO Oxidation on Pd/CeO2(100): The Unique Surface-Structure of CeO2(100) and the Role of Peroxide

Understanding the atomic mechanism of low-temperature CO oxidation on a heterogeneous catalyst is challenging. We performed density functional theory (DFT) calculations to identify the surface structure and reaction mechanism responsible for low-temperature CO oxidation on Pd/CeO2(100) surfaces. DFT calculations reveal the formation of a unique zigzag chain structure by the oxygen and Ce atoms of the topmost surface of CeO2(100) with Pd atoms located between the zigzag chains. O(2)adsorbed on such Pd atoms is stable in the presence of CO but plays a very important role in lowering the activation barrier for low-temperature CO oxidation by forming a square-planar PdO(4)structure and facilitating further O(2)adsorption.In-situRaman spectroscopy studies confirm the adsorbed oxygen species to be peroxides. The calculated activation barrier for CO oxidation, based on the mechanism suggested by these unique structures and peroxides, is 31.2 kJ/mol, in excellent agreement with our experimental results

Defects on the Surface of Ti-Doped MgAl2O4 Nanophosphor

Abstract Ti-doped nano MgAl2O4 for white emission was synthesized by combustion method. Extrinsic Schottky defects, Al vacancies and Ti4+ dopant in Al sites, which are considered to be responsible for bluish-white emission, were observed by STEM on the surface of Ti-doped nano MgAl2O4 powder. The stabilities of the Schottky defect associates, (TiAl ·–VAl′′′)′′, were demonstrated by DFT calculation. The emission behavior was interpreted with these results

Is Gross Extrathyroidal Extension to Strap Muscles (T3b) Only a Risk Factor for Recurrence in Papillary Thyroid Carcinoma? A Propensity Score Matching Study

The presence of extrathyroidal extension (ETE) is associated with locoregional recurrence and distant metastases in papillary thyroid carcinoma (PTC). This study was designed to compare the recurrence risk between minimal ETE (mETE) and gross ETE (gETE) in patients with PTC using propensity score matching. In this study, 4452 patients with PTC who underwent thyroid surgery in a single center were retrospectively analyzed, and clinicopathological characteristics were compared according to the ETE status. Disease-free survival (DFS) and recurrence risk were compared between mETE and gETE after propensity score matching. The mean follow-up duration was 122.7 ± 22.5 months. In multivariate analysis, both mETE and gETE were not associated with recurrence risk before propensity score matching (p = 0.154 and p = 0.072, respectively). After propensity score matching, no significant difference in recurrence rates was observed between the two groups (p = 0.668). DFS of the gETE group did not significantly differ from that of the mETE group (log-rank p = 0.531). This study revealed that both mETE and gETE are not independent risk factors for the risk of recurrence in PTC. Our findings suggest that gETE invading strap muscles only might not be associated with worse oncological outcomes in PTC

Luminescent properties and energy transfer of Eu2+/Mn2+ codoped Na(Sr,Ba)PO4 and Ba2Mg(BO3)2 phosphors

Two series of the phosphors Na(Sr,Ba)PO4 and Ba2Mg(BO3)2 codoped with different concentrations of Eu2+ and Mn2+ were synthesized using a solid-state reaction method. The energy transfer between Eu2+ and Mn2+ in both host crystals was investigated by steady-state and time-resolved photoluminescence measurements. For Na(Sr,Ba)PO4, Eu2+ has an emission centered at 460 nm which overlaps with multiple excitation transition of Mn2+. In contrast, for Ba2Mg(BO3)2, Eu2+ emission is red-shifted to 612 nm, which causes a single spectral overlap between Eu2+ and Mn2+ energy levels. As a result, the energy transfer efficiency is improved between Eu2+ and Mn2+ in Ba2Mg(BO3)2 with a maximum energy transfer efficiency of 91% compared to that in Na(Sr,Ba)PO4 with that of 57%