Metastable Nanobubbles at the Solid–Liquid Interface Due to Contact Angle Hysteresis

Nanobubbles exist at solid–liquid interfaces between pure water and hydrophobic surfaces with very high stability, lasting in certain cases up to several days. Not only semispherical but also other shapes, such as micropancakes, are known to exist at such interfaces. However, doubt has been raised as to whether or not the nanobubbles are gas-phase entities. In this study, surface nanobubbles at a pure water–highly ordered pyrolytic graphite (HOPG) interface were investigated by peak force quantitative nanomechanics (PF-QNM). Multiple isolated nanobubbles generated by the solvent-exchange method were present on the terraced areas, avoiding the steps of the HOPG surface. Adjacent nanobubbles coalesced and formed metastable nanobubbles. Coalescence was enhanced by the PF-QNM measurement. We determined that nanobubbles can exist for a long time because of nanoscale contact angle hysteresis at the water–HOPG interface. Moreover, the hydrophilic steps of HOPG were avoided during coalescence, providing evidence that the nanobubbles are truly gas phase

Metastable Nanobubbles at the Solid–Liquid Interface Due to Contact Angle Hysteresis

Nanobubbles exist at solid–liquid interfaces between pure water and hydrophobic surfaces with very high stability, lasting in certain cases up to several days. Not only semispherical but also other shapes, such as micropancakes, are known to exist at such interfaces. However, doubt has been raised as to whether or not the nanobubbles are gas-phase entities. In this study, surface nanobubbles at a pure water–highly ordered pyrolytic graphite (HOPG) interface were investigated by peak force quantitative nanomechanics (PF-QNM). Multiple isolated nanobubbles generated by the solvent-exchange method were present on the terraced areas, avoiding the steps of the HOPG surface. Adjacent nanobubbles coalesced and formed metastable nanobubbles. Coalescence was enhanced by the PF-QNM measurement. We determined that nanobubbles can exist for a long time because of nanoscale contact angle hysteresis at the water–HOPG interface. Moreover, the hydrophilic steps of HOPG were avoided during coalescence, providing evidence that the nanobubbles are truly gas phase

Droplet Nucleation on a Well-Defined Hydrophilic–Hydrophobic Surface of 10 nm Order Resolution

Water condensation on a hybrid hydrophilic–hydrophobic surface was investigated to reveal nucleation mechanisms at the microscale. Focused ion beam (FIB) irradiation was used to change the wettability of the hydrophobic surface with 10 nm order spatial resolution. Condensation experiments were conducted using environmental scanning electron microscopy; droplets, with a minimum diameter of 800 nm, lined up on the FIB-irradiated hydrophilic lines. The heterogeneous nucleation theory was extended to consider the water molecules attracted to the hydrophilic area, thereby enabling explanation of the nucleation mechanism under unsaturated conditions. Our results showed that the effective surface coverage of the water molecules on the hydrophilic region was 0.1–1.1 at 0.0 °C and 560 Pa and was dependent on the width of the FIB-irradiated hydrophilic lines and hydrophobic area. The droplet nucleation mechanism unveiled in this work would enable the design of new surfaces with enhanced dropwise condensation heat transfer

Metastable Nanobubbles at the Solid–Liquid Interface Due to Contact Angle Hysteresis

Nanobubbles exist at solid–liquid interfaces between pure water and hydrophobic surfaces with very high stability, lasting in certain cases up to several days. Not only semispherical but also other shapes, such as micropancakes, are known to exist at such interfaces. However, doubt has been raised as to whether or not the nanobubbles are gas-phase entities. In this study, surface nanobubbles at a pure water–highly ordered pyrolytic graphite (HOPG) interface were investigated by peak force quantitative nanomechanics (PF-QNM). Multiple isolated nanobubbles generated by the solvent-exchange method were present on the terraced areas, avoiding the steps of the HOPG surface. Adjacent nanobubbles coalesced and formed metastable nanobubbles. Coalescence was enhanced by the PF-QNM measurement. We determined that nanobubbles can exist for a long time because of nanoscale contact angle hysteresis at the water–HOPG interface. Moreover, the hydrophilic steps of HOPG were avoided during coalescence, providing evidence that the nanobubbles are truly gas phase

Supplementary files for ``Late Cretaceous–Paleogene terrestrial sequence in the northern Kitakami Mountains, Northeast Japan: Depositional ages, clay mineral contents, and vitrinite reflectance.''

This includes supplementary files for the research article of "Late Cretaceous–Paleogene terrestrial sequence in the northern Kitakami Mountains, Northeast Japan: Depositional ages, clay mineral contents, and vitrinite reflectance."</p

Sorafenib enhanced expression of osteopontin, an AP-1 target gene, in human hepatoma cell lines.

<p>(A, B) Knockdown of c-Jun decreased expression of osteopontin after 48 hours of transfection into PLC/PRF/5 cells with siRNA against c-Jun (si-c-Jun) or si-control (si-C). Lysates from transfected cells were immunoblotted with antibodies against osteopontin or β-tubulin. β-tubulin was used as internal control. (C, D) Western blot analyses of osteopontin and β-tubulin expression in PLC/PRF/5 cells treated with or without 10 μM sorafenib for 12 hours. (E, F) Western blot analyses of osteopontin and β-tubulin expression in HepG2.2.15 cells treated with or without 10 μM sorafenib for 12 hours. Densitometric analyses were performed with ImageJ software. Data are presented as mean ± SD of triplicate samples. *<i>p < 0</i>.<i>05</i> between two groups.</p

Sorafenib enhances expression and phosphorylation of c-Jun in human hepatoma cell lines.

<p>(A)-(C) Western blot analyses of phosphorylated-c-Jun (p-c-Jun), c-Jun and GAPDH expression in PLC/PRF/5 cells treated with or without 10 μM sorafenib for 12 hours. (D)-(F) Western blot analyses of p-c-Jun, c-Jun and GAPDH expression in HepG2.2.15 cells treated with or without 10 μM sorafenib for 12 hours. (B, C, E, F) Densitometric analyses were performed using ImageJ software. Data are presented as mean ± SD of triplicate samples. *<i>p < 0</i>.<i>05</i> compared to untreated control.</p

Relationship between Mutations of the Pectin Methylesterase Gene in Soybean and the Hardness of Cooked Beans

Hardness of cooked soybeans [<i>Glycine max</i> (L). Merr.] is an important attribute in food processing. We found one candidate gene, <i>Glyma03g03360</i>, to be associated with the hardness of cotyledons of cooked soybeans, based on a quantitative trait locus and fine-scale mapping analyses using a recombinant inbred line population developed from a cross between two Japanese cultivars, “Natto-shoryu” and “Hyoukei-kuro 3”. Analysis of the DNA sequence of <i>Glyma03g03360</i>, a pectin methylesterase gene homologue, revealed three patterns of mutations, two of which result in truncated proteins and one of which results in an amino acid substitution. The truncated proteins are presumed to lack the enzymatic activity of Glyma03g03360. We classified 24 cultivars into four groups based on the sequence of <i>Glyma03g03360.</i> The texture analysis using the 22 cultivars grown in different locations indicated that protein truncation of Glyma03g03360 resulted in softer cotyledons of cooked soybeans, which was further confirmed by texture analysis performed using F₂ populations of a cross between “Enrei” and “LD00-3309”, and between “Satonohohoemi” and “Sakukei 98”. A positive correlation between hardness and calcium content implies the possible effect of calcium binding to pectins on the hardness of cooked soybean cotyledons

Effects of sorafenib on cell proliferation in human hepatoma cell lines.

<p>(A) PLC/PRF/5, (B) HepG2.2.15, (C) Huh6, (D) Hep3B, (E) HepG2 and (F) Huh7 cells. The cells were treated with sorafenib at the indicated concentrations for 12 hours, and cell proliferation was evaluated by MTS assay (Promega). Data are presented as mean ± SD of triplicate samples. *<i>p < 0</i>.<i>05</i> compared to the untreated control.</p

Changes of MAPK-signaling pathway-associated genes in human hepatoma cell lines treated with or without sorafenib.

<p>Six human hepatoma cell lines were treated with or without 10 μM sorafenib for 12 hours. (A) Total expression of 6 human hepatoma cells (PLC/PRF/5, HepG2.2.15, Huh6, Hep3B, HepG2 and Huh7). Expression of 2 genes significantly changed after 12 hours of treatment with sorafenib: Jun proto-oncogene (c-Jun) and MAP kinase interacting serine/threonine kinase 1 (MKNK1), which are shown in red. (B) Human hepatoma cells without HBV genome integration (Huh6, HepG2 and Huh7). Mitogen-activated protein kinase 10 (MAPK10) expression significantly changed after 12 hours of treatment with sorafenib. MAPK10 is shown in red, and c-Jun is shown in yellow. (C) Human hepatoma cells with HBV integration (PLC/PRF/5, HepG2.2.15 and Hep3B). Expression of 2 genes significantly changed after 12 hours of treatment of sorafenib: c-Jun and cell division cycle 42 (GTP binding protein, 25 kDa) (CDC42), which are shown in red.</p