An Insight into Slag Structure from Sulphide Capacities

The molar sulphide capacities $ C_{\text{S}}^{'} $ ?=?(mol?pct?S) ( $ P_{{{\text{O}}_{2} }} /P_{{{\text{S}}_{2} }} $ )^1/2 on four binary systems, MgO-SiO₂, CaO-SiO₂, MnO-SiO₂ and FeO-SiO₂ are elucidated so as to compare the magnitudes of the basicities of four metallic oxides and to estimate the temperature dependencies of the basicities of metallic oxides. The enthalpy changes of the reaction?2O^??=?O?+?O^2?, viz. the silicate polymerization reaction (denoted as $ \Updelta H_{(8)}^{^\circ } $ ) have been calculated from the slopes of the log $ C_{\text{S}}^{'} $ vs 1/T curves for four binary silicates. The $ \Updelta H_{(8)}^{^\circ } $ value is considered in the present work to be an index of the basicity of silicate melts. The basicities obtained on the basis of the $ \Updelta H_{(8)}^{^\circ } $ values are in the order MgO?<?CaO?<?MnO?<?FeO, which are determined by two effects; (i) ionicity of chemical bonds between metallic and oxygen ions and (ii) clustering of metallic oxides in silicates. It is also found that the basicity of the FeO-SiO₂ system is larger at higher temperatures.     

Identification and analysis of specific chromosomal region adjacent to exogenous Dhfr-amplified region in Chinese hamster ovary cell genome

Chinese hamster ovary (CHO) cells are widely used for the stable production of recombinant proteins. Gene amplification techniques are frequently used to improve of protein production, and the dihydrofolate reductase (DHFR) gene amplification system is most widely used in the CHO cell line. We previously constructed a CHO genomic bacterial artificial chromosome (BAC) library from a mouse Dhfr-amplified CHO DR1000L-4N cell line and one BAC clone (Cg0031N14) containing the CHO genomic DNA sequence adjacent to Dhfr was selected. To identify the specific chromosomal region adjacent to the exogenous Dhfr-amplified region in the CHO cell genome, we performed further screening of BAC clones to obtain other Dhfr-amplified regions in the CHO genome. From the screening by high-density replica filter hybridization using a digoxigenin-labeled pSV2-dhfr/hGM-CSF probe, we obtained 8 new BAC clones containing a Dhfr-amplified region. To define the structures of the 8 BAC clones, Southern blot analysis, BAC end sequencing and fluorescence in situ hybridization (FISH) were performed. These results revealed that all the selected BAC clones contained a large palindrome structure with a small inverted repeat in the junction region. This suggests that the obtained amplicon structure in the Dhfr-amplified region in the CHO genome plays an important role in exogenous gene amplification.     

Thermal conductivity enhancement of liquid crystalline epoxy/MgO composites by formation of highly ordered network structure

To develop a high thermal conductive composite, an MgO filler was incorporated into a liquid crystalline (LC) epoxy containing a mesogenic moiety. The thermal conductivity of the obtained composite was 1.41 W/(m∙K) at 33 vol% content, which was remarkably higher than the value predicted using Bruggeman's model. To investigate the reason for this significant enhancement of the thermal conductivity in the LC epoxy composites, the LC phase structure of the composite was analyzed by a polarized optical microscope, an X-ray diffractometry (XRD) and a polarized IR mapping measurement. An XRD analysis indicated the local formation of a highly ordered smectic phase structure, even in the high-loading composite. This result indicated the promotion of the self-assembly of the mesogenic network polymer chains by the MgO filler loading. We considered that this highly ordered structural formation can lead to an increase in the matrix resin's thermal conductivity, which can result in the effective enhancement of the thermal conductivity in the LC epoxy/MgO composite.     

Structural Analyses of Hydrated Crystals in Mixed Green Surfactant Systems: α‐Sulfonated Fatty Acid Methyl Ester Salt and Fatty Acid Soap Mixtures

α‐Sulfonated fatty acid methyl ester salts (MES), synthesized from renewable plant resources, are an example of green surfactants used in eco‐friendly washing detergents because of their excellent detergent properties, biodegradability, and enzyme stability. Although various physicochemical properties of MES crystals and micelles have been studied, mixed systems composed of MES and other surfactants have not been well studied. We investigated the crystalline structures of hydrated solids in mixed systems containing MES and soaps, which have been utilized as detergents, using small‐ and wide‐angle X‐ray scattering (SWAXS), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy techniques. The minimum dissolution temperature, determined by visual observation, of a 4:1 M ratio of the sodium salt of α‐sulfonated palmitic acid methyl ester (C₁₆MES‐Na) and sodium palmitate (C₁₆‐Na), is indicative of a eutectic mixture. SWAXS measurements reveal that C₁₆MES‐Na and C₁₆‐Na crystals are formed separately in this system. Eutectic mixtures were also observed for the C₁₆MES‐Na/C₁₆MES‐K (α‐sulfonated palmitic acid methyl ester potassium salt) system and in the C₁₆MES‐K/C₁₆‐Na system. Furthermore, in addition to C₁₆MES‐K and C₁₆‐Na crystals, C₁₆MES‐Na crystals were also formed in the C₁₆MES‐K/C₁₆‐Na system, through counterion exchange during crystallization.     

Spatial and Quantitative Analysis of Tumor-Associated Macrophages: Intratumoral CD163-/PD-L1+ TAMs as a Marker of Favorable Clinical Outcomes in Triple-Negative Breast Cancer

Tumor-associated macrophages (TAMs) and abnormalities in cancer cells affect cancer progression and response to therapy. TAMs are a major component of the tumor microenvironment (TME) in breast cancer, with their invasion affecting clinical outcomes. Programmed death-ligand 1 (PD-L1), a target of immune checkpoint inhibitors, acts as a suppressive signal for the surrounding immune system; however, its expression and effect on TAMs and the clinical outcome in breast cancer are unknown. In this study, we used high-throughput multiple immunohistochemistry to spatially and quantitatively analyze TAMs. We subjected 81 breast cancer specimens to immunostaining for CD68, CD163, PD-1, PD-L1, CD20, and pan-CK. In both stromal and intratumoral areas, the triple-negative subtype had significantly more CD68/CD163, CD68/PD-L1, and CD163/PD-L1 double-positive cells than the estrogen receptor (ER)/progesterone receptor (PR) subtype. Interestingly, a higher number of CD68+/PD-L1+/CK-/CD163- TAMs in the intratumoral area was correlated with a favorable recurrence rate (p = 0.048). These findings indicated that the specific subpopulation and localization of TAMs in the TME affect clinical outcomes in breast cancer.     

Flame retardancy and thermomechanical properties of the poly‐(glycidyloxypropyl) phenyl silsesquioxane/layered titanate nanocomposites

Poly‐(glycidyloxypropyl) phenyl silsesquioxane (PGPSQ) was combined with an organo‐layered titanate filler. The phase structure of the obtained composite was evaluated by XRD and TEM observations. Moreover, a burning test was carried out according to the UL‐94 test method. The extinguishing time of the nanocomposites was classified V‐0 even for the 1 wt % layered titanate content. Based on the results, it was clarified that the frame retardancy of the PGPSQ/organo‐layered titanate system was superior to the poly‐(glycidyloxypropyl) silsesquioxane (PGSQ)/organo‐layered titanate system, which was reported in a previous paper. In addition, the layered titanate as a filler also improved the ductility of the PGPSQ. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Cooperative formation of a substrate binding pocket by alpha- and beta-subunits of mitochondrial processing peptidase

Mitochondrial processing peptidase (MPP) specifically recognizes a large variety of mitochondrial precursor proteins and cleaves off N-terminal extension peptides. The enzyme is a metalloprotease and forms a heterodimer consisting of structurally related alpha- and beta-subunits. To investigate the responsibility of MPP subunits for substrate recognition, we monitored interaction of the fluorescent-labeled peptide substrates with the MPP and its subunits. The specific binding of the peptide to the MPP was confirmed by findings of the direct participation of arginine residues in the binding, which are located at position -2 and the position distal to the cleavage site and are essential for the cleavage reaction. MPP bound the substrate peptides with high affinity only in the dimeric complex, and each subunit monomer had about a 30-fold less affinity than the complex. The individual subunit required arginines at different positions in the peptide for binding, although their affinities were much lower than that of MPP. Fluorescence quenching analysis showed that the peptide bound to MPP was buried in the enzyme. Thus, both subunits of MPP might be required for formation of a substrate binding pocket with multiple subsites lying across them.