Understanding ordered structure in hematite nanowhiskers synthesized via thermal oxidation of iron-based substrates

Hematite (α-Fe₂O₃) nanowhiskers (NWs) with (001) basal faces synthesized via thermal oxidation of iron-based substrates are known to contain an ordered structure. The ordered structure has been identified to be related to oxygen vacancy ordering. However, the cause of its formation remains a mystery. In this study, with a high-resolution transmission electron microscopy (HR-TEM) investigation based on negative-Cs imaging (NCSI) and atomic-column position analysis, we observed tensile strain in the above-mentioned α-Fe₂O₃ NWs and revealed that the ordered structure was actually periodic interplanar gap expansions induced by oxygen vacancy accumulations. These findings were further confirmed in a monochromated electron energy loss spectroscopy (EELS) analysis of the α-Fe₂O₃ NWs. The EELS data indicated that, in comparison to pristine α-Fe₂O₃, the α-Fe₂O₃ NWs possessed expanded average Fesingle bondO and Osingle bondO interatomic distances and were oxygen-deficient. Clarifying oxygen deficiency in the α-Fe₂O₃ NWs was not attributed to an insufficient oxygen supply during the NW growth, we concluded the ordered structure formed to accommodate tensile strain in the α-Fe₂O₃ NWs. This work demonstrates the applicability of integrating NCSI and monochromated EELS for the examination of strain-induced microstructural and microchemical variations in lightly strained metal oxides

Phase segregated Cu₂₋ₓSe/Ni₃Se₄ bimetallic selenide nanocrystals formed through the cation exchange reaction for active water oxidation precatalysts

Control over the composition and nanostructure of solid electrocatalysts is quite important for drastic improvement of their performance. The cation exchange reaction of nanocrystals (NCs) has been reported as the way to provide metastable crystal structures and complicated functional nanostructures that are not accessible by conventional synthetic methods. Herein we demonstrate the cation exchange-derived formation of metastable spinel Ni₃Se₄NCs (sp-Ni₃Se₄) and phase segregated berzelianite Cu₂₋ₓSe (ber-Cu₂₋ₓSe)/sp-Ni₃Se₄ heterostructured NCs as active oxygen evolution reaction (OER) catalysts. A rare sp-Ni₃Se₄ phase was formed by cation exchange of ber-Cu₂₋ₓSe NCs with Ni²⁺ ions, because both phases have the face-centered cubic (fcc) Se anion sublattice. Tuning the Ni : Cu molar ratio leads to the formation of Janus-type ber-Cu₂₋ₓSe/sp-Ni₃Se₄ heterostructured NCs. The NCs of sp-Ni₃Se₄ and ber-Cu₂₋ₓSe/sp-Ni₃Se₄ heterostructures exhibited high catalytic activities in the OER with small overpotentials of 250 and 230 mV at 10 mA cm⁻² in 0.1 M KOH, respectively. They were electrochemically oxidized during the OER to give hydroxides as the real active species. We anticipate that the cation exchange reaction could have enormous potential for the creation of novel heterostructured NCs showing superior catalytic performance

Two cases of breast carcinoma with osteoclastic giant cells: Are the osteoclastic giant cells pro-tumoural differentiation of macrophages?

Breast carcinoma with osteoclastic giant cells (OGCs) is characterized by multinucleated OGCs, and usually displays inflammatory hypervascular stroma. OGCs may derive from tumor-associated macrophages, but their nature remains controversial. We report two cases, in which OGCs appear in common microenvironment despite different tumoural histology. A 44-year-old woman (Case 1) had OGCs accompanying invasive ductal carcinoma, and an 83-year-old woman (Case 2) with carcinosarcoma. Immunohistochemically, in both cases, tumoural and non-tumoural cells strongly expressed VEGF and MMP12, which promote macrophage migration and angiogenesis. The Chalkley count on CD-31-stained sections revealed elevated angiogenesis in both cases. The OGCs expressed bone-osteoclast markers (MMP9, TRAP, cathepsin K) and a histiocyte marker (CD68), but not an MHC class II antigen, HLA-DR. The results indicate a pathogenesis: regardless of tumoural histology, OGCs derive from macrophages, likely in response to hypervascular microenvironments with secretion of common cytokines. The OGCs have acquired bone-osteoclast-like characteristics, but lost antigen presentation abilities as an anti-cancer defense. Appearance of OGCs may not be anti-tumoural immunological reactions, but rather pro-tumoural differentiation of macrophage responding to hypervascular microenvironments induced by breast cancer

Low-fat Elemental Enteral Nutrition in the Management of Pediatric Acute Pancreatitis

Acute pancreatitis（AP）in childhood is rare, but is starting to be recognized more often. However, optimal enteral nutrition formulas for children with AP have not been determined. This report describes the successful management of AP, with low-fat elemental enteral nutrition, in a 5-year-old boy. The patient had been diagnosed with mild AP and started oral feeding after about 3 days of fasting, but his pancreatic enzyme levels subsequently became elevated. Therefore, to allow the pancreas to rest, total parenteral nutrition（TPN）was started. After starting TPN, there was no improvement in his pancreatic enzyme levels but, because his clinical symptoms were stable, a small amount of elemental diet was initiated. Elemental diet therapy was safely performed without return of any clinical symptoms and the patient’s pancreatic enzyme levels slowly improved. Elemental diet was both safe and beneficial, providing clinical remission and improvement in quality of life. Early elemental diet therapy may therefore be a useful treatment strategy for pediatric patients with AP

Discovery of Self‐Assembling Small Molecules as Vaccine Adjuvants

自己集合性ワクチンアジュバントの発見. 京都大学プレスリリース. 2020-10-07.Vaccine ingredients could be hiding in small molecule libraries. 京都大学プレスリリース. 2020-10-07.Immune potentiators, termed adjuvant, trigger early innate immune responses to ensure the generation of robust and long‐lasting adaptive immune responses of vaccines. Here we present study that takes advantage of a self‐assembling small molecule library for the development of a novel vaccine adjuvant. Cell‐based screening of the library and subsequent structural optimization led to the discovery of a simple, chemically tractable deoxycholate derivative (molecule 6 , also named cholicamide) whose well‐defined nano‐assembly potently elicits innate immune responses in macrophages and dendritic cells. Functional and mechanistic analyses indicate that the virus‐like assembly is engulfed inside cells and stimulates the innate immune response through toll‐like receptor 7 (TLR7), an endosomal TLR that detects single‐stranded viral RNA. As an influenza vaccine adjuvant in mice, molecule 6 was as potent as Alum, a clinically used adjuvant. The studies described here paves the way for a new approach to discovering and designing self‐assembling small‐molecule adjuvants against pathogens, including emerging viruses

High-performance liquid chromatography separation of unsaturated organic compounds by a monolithic silica column embedded with silver nanoparticles.

Article first published online: 15 JUL 2015The optimization of a porous structure to ensure good separation performances is always a significant issue in high-performance liquid chromatography column design. Recently we reported the homogeneous embedment of Ag nanoparticles in periodic mesoporous silica monolith and the application of such Ag nanoparticles embedded silica monolith for the high-performance liquid chromatography separation of polyaromatic hydrocarbons. However, the separation performance remains to be improved and the retention mechanism as compared with the Ag ion high-performance liquid chromatography technique still needs to be clarified. In this research, Ag nanoparticles were introduced into a macro/mesoporous silica monolith with optimized pore parameters for high-performance liquid chromatography separations. Baseline separation of benzene, naphthalene, anthracene, and pyrene was achieved with the theoretical plate number for analyte naphthalene as 36, 000 m(-1). Its separation function was further extended to cis/trans isomers of aromatic compounds where cis/trans stilbenes were chosen as a benchmark. Good separation of cis/trans-stilbene with separation factor as 7 and theoretical plate number as 76, 000 m(-1) for cis-stilbene was obtained. The trans isomer, however, is retained more strongly, which contradicts the long- established retention rule of Ag ion chromatography. Such behavior of Ag nanoparticles embedded in a silica column can be attributed to the differences in the molecular geometric configuration of cis/trans stilbenes

Retrospective Study of the Correlation Between Pathological Tumor Size and Survival After Curative Resection of T3 Pancreatic Adenocarcinoma: Proposal for Reclassification of the Tumor Extending Beyond the Pancreas Based on Tumor Size

BackgroundEven though most patients who undergo resection of pancreatic adenocarcinoma have T3 disease with extra-pancreatic tumor extension, T3 disease is not currently classified by tumor size. The aim of this study was to modify the current TNM classification of pancreatic adenocarcinoma to reflect the influence of tumor size.MethodsA total of 847 consecutive pancreatectomy patients were recruited from multiple centers. Optimum tumor size cutoff values were calculated by receiver operating characteristics analysis for tumors limited to the pancreas (T1/2) and for T3 tumors. In our modified TNM classification, stage II was divided into stages IIA (T3aN0M0), IIB (T3bN0M0), and IIC (T1-3bN1M0) using tumor size cutoff values. The usefulness of the new classification was compared with that of the current classification using Akaike’s information criterion (AIC).ResultsThe optimum tumor size cutoff value distinguishing T1 and T2 was 2 cm, while T3 was divided into T3a and T3b at a tumor size of 3 cm. The median survival time of the stages IIA, IIB, and IIC were 44.7, 27.6, and 20.3 months, respectively. There were significant differences of survival between stages IIA and IIB (P = 0.02) and between stages IIB and IIC (P = 0.03). The new classification showed better performance compared with the current classification based on the AIC value.ConclusionsThis proposed new TNM classification reflects the influence of tumor size in patients with extra-pancreatic tumor extension (T3 disease), and the classification is useful for predicting mortality