The simultaneous analysis of the molecular positions and their recognition functions of immobilized molecules presents a significant challenge. We investigated an analytical method using a Co-saloph complex as a model molecule. By employing frequency modulation atomic force microscopy with an amino-terminated tip, we examined the positions and their recognition functions at the single-molecular level. The results reveal that the specific coordination bond formations between the amino group on the tip and the Co-saloph complex is detectable as an increase in the dissipation signal, which occurs concurrently with the detection of the positions of the Co-saloph complexes.

1-Ethyl-3-methylimidazolium acetate ([C2mim]OAc) is the most commonly used cellulose-dissolving ionic liquid and has been extensively studied for biorefinery applications. Although [C2mim]OAc had been considered to be a liquid, we here found [C2mim]OAc crystals at room temperature (around 25 °C) with a melting point of 44 °C. A plausible reason for the crystallization is shearing stress. [C2mim]OAc seed crystals led to the crystallization of liquid [C2mim]OAc.

Self-aligned Si-quantum-dots (Si-QDs) with an areal density as high as similar to 1011 cm-2 have been fabricated on ultrathin SiO2 by using a similar to 4.5 nm thick poly-Si on insulator (SOI) substrate, and controlling low-pressure CVD using monosilane (SiH4), and followed by thermal oxidation. By controlling the thermal oxidation processes of Si-QDs and the poly-Si layer, we have successfully demonstrated the vertical alignment of Si-QDs, where the Si-QDs are also used as a shadow mask of the underlying poly-Si layer. We also demonstrated in-plane alignment of the one-dimensionally self-aligned Si-QDs on line-patterned SiO2. In addition, from surface potential measurements by using atomic force microscopy/Kelvin probe force microscopy, we confirmed that the initial surface potential change caused by valence electron extraction from the dots to the tip was stably maintained until similar to 120 min, implying the quantum confinement effect at discrete energy levels of the upper and lower-QDs.

In this paper, we proposed a thermodynamic procedure to evaluate binary surfactant mixed adsorbed film and mixed micelle compositions above critical micelle concentrations. This theory first calculates the change in the molar ratio of two surfactants in monomer and micelle states based on the phase-separation model and then imposes the chemical equilibrium between the mixed adsorbed film and mixed micelle of known composition and concentration. We applied this theory to a cationic-nonionic surfactant mixed system, and the relationship between the calculated mixed adsorbed film composition and foam film stability was discussed using the DLVO theory.

We investigated the effects of a HCl-based cleaning (SC2) and post-deposition annealing (PDA) on an Al 2 O 3 /GaN interface and electrical properties. X-ray photoelectron spectroscopy revealed the existence of the Cl atoms near the interface after the Al 2 O 3 deposition and subsequent PDA, resulting in a band bending at the GaN surface. A C–V curve of a MOS capacitor with the Al 2 O 3 /GaN interface with SC2 was shifted toward the positive bias direction compared with that without SC2. It was found that PDA induced negative shifts of the C–V curves, and that the SC2 treatment increases interface trap density at the Al 2 O 3 /GaN interface. These results indicate that the Cl termination of the GaN surface has clear impacts on the interface and electrical properties.

We have demonstrated the formation of ultrathin Ni silicide on SiO2 by annealing Si/Ni/Si structures and have systematically evaluated the impacts of the Si layer thickness on oxidation, surface roughening and the silicidation reaction. X-ray photoelectron spectroscopy analyses revealed that suppression of Ni oxidation due to the top Si layer makes it possible to form an ultrathin Ni silicide layer with a thickness of around 2 nm. Then, it turned out that the composition ratio of Ni and Si depends on not only the annealing temperature but also the initial thickness ratio of the top and bottom Si layers. Furthermore, this work clarified that the ultra-thin top Si layer has a large impact on the surface morphology during Ni silicide formation with diffusion and preferential oxidation.

We have demonstrated the formation of one-dimensionally aligned self-assembling silicon quantum dots (Si-QDs) by low-pressure (LP) CVD using pure monosilane (SiH4) gas. Formation of Si-QDs on line-patterned SiO2 formed on p-Si(100) after low-temperature oxidation was carried out. From AFM images taken after LPCVD, we confirmed high-density Si-QDs formation with an areal density as high as-1011 cm-2 on the OH-terminated SiO2-line while dot density as low as-1010 cm-2 on as-grown SiO2. We also confirmed that, with a decreasing the SiO2 line width, the number of Si-QDs on the SiO2-line was decreased evidently. Based on the results, we have succeeded in the one-dimensional arrangement of Si-QDs on the-30 nm-width SiO2 line-patterns.

The PD-1 receptor triggers a negative immunoregulatory mechanism that prevents overactivation of immune cells and subsequent inflammatory diseases. Because of its biological significance, PD-1 has been a drug target for modulating immune responses. Immunoenhancing anti–PD-1 blocking antibodies have become a widely used cancer treatment; however, little is known about the required characteristics for anti–PD-1 antibodies to be capable of stimulating immunosuppressive activity. Here, we show that PD-1 agonists exist in the group of anti–PD-1 antibodies recognizing the membrane-proximal extracellular region in sharp contrast to the binding of the membrane-distal region by blocking antibodies. This trend was consistent in an analysis of 81 anti-human PD-1 monoclonal antibodies. Because PD-1 agonist antibodies trigger immunosuppressive signaling by cross-linking PD-1 molecules, Fc engineering to enhance FcγRIIB binding of PD-1 agonist antibodies notably improved human T cell inhibition. A PD-1 agonist antibody suppressed inflammation in murine disease models, indicating its clinical potential for treatment of various inflammatory disorders, including autoimmune diseases.

Effects of the surface modification by O-2 plasma exposure on the Al/Ge(111) structure have been investigated in order to get an insight into a layer transfer technique of the ultrathin Ge layer segregated on the Al/Ge(111) structure toward the device fabrication, and then the wafer bonding of the Al/Ge(111) structure to the thermally-grown SiO2/Si structure has been demonstrated. The O-2 plasma treatment and the subsequent pure water rinse were found to be effective to form the hydrophilic surface of the Al/Ge(111) structure with a suppression of the segregated Ge layer oxidation. The Al/Ge(111) structure with the hydrophilic surface was then bonded to the SiO2/Si substrate, and its bonding strength was enough to perform Ge thinning by the chemical mechanical polishing and the wet-chemical etching using H2O2-based solutions. Ohmic contact of the ring-type device pattern with the segregated Ge/Al stack was achieved by using the remaining p-type Ge substrate as the contact pads.

Two-dimensional sheets of ultra-thin germanium with the lattice parameter of free-standing germanene, i.e., 0.41 nm, are formed by atomic segregation epitaxy on face-centered-cubic Ag0.9Al0.1(111) thin films grown on a Ge(111) template. Low-energy electron diffraction clearly shows a square-like (root 13 x root 13)R +/- 46(degrees) super-structure, expressed as ( (4 1)(1 4)) in Matrix form, whose 92(degrees) angle between the two vectors is clearly observed, as well as incommensurate (1.41 x 1.41)R +/- 27(degrees) spots. Scanning tunneling microscopy (STM) images show the square-like superstructure and a defective honeycomb-like arrangement with this characteristic 0.41 nm lattice constant, corresponding to LEED patterns. Complimentary high-resolution synchrotron radiation photoemission spectroscopy measurements reveal the electronic structure of the honeycomb-like germanene sheet and further demonstrate that it overlays the surface of the Ag0.9Al0.1(111) alloy.

Control of diffusion and segregation of Si atoms through a thin metal layer from a stacked Si structure is one of the effective techniques to grow two-dimensional (2D) or ultrathin Si crystals. We have studied the formation of the Al layer with a flat surface and high crystallinity on a wet-cleaned Si(111) wafer by thermal evaporation in order to use it as a growth template for ultrathin Si crystals. Then, the impacts of the annealing in N-2 ambient on the surface flatness, the Al crystallinity, and the chemical bonding features for the Al/Si(111) structure were investigated. A formation of a sub-nanometer Si layer on the Al(111) surface using Si segregation with keeping surface flatness was demonstrated by the control of annealing temperature.

During the long-term storage of cells, it is necessary to inhibit ice crystal formation by adding cryoprotectants. Non-cell-permeable cryoprotectants have high osmotic pressure which dehydrates cells, indirectly suppressing intracellular ice crystal formation. However, the high osmotic pressure and dehydration often damage cells. Emerging polymer-type non-cell-permeable cryoprotectants form matrices surrounding cells. These matrices inhibit the influx of extracellular ice nuclei that trigger intracellular ice crystal formation. However, these polymer-type cryoprotectants also require high osmotic pressure to exert an effective cryoprotecting effect. In this study, we designed a poly(zwitterion) (polyZI) that forms firm matrices around cells based on their high affinity to cell membranes. The polyZI successfully cryopreserved freeze-vulnerable cells under isotonic conditions. These matrices also controlled osmotic pressure by adsorbing and desorbing NaCl depending on the temperature, which is a suitable feature for isotonic cryopreservation. Although cell proliferation was delayed by the cellular matrices, washing with a sucrose solution improved proliferation.

The effect of Mg channeled implantation into epitaxially grown gallium nitride (GaN) was studied using Hall-effect measurements, photoluminescence (PL), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) and Rutherford backscattering spectroscopy (RBS). In the channeled implantation, deeper profiles were obtained with lower implantation energy and less damage compared to random implantation. The donor–acceptor pair signal at ∼3.28 eV, suggesting that Mg is activated, was confirmed by PL measurement when the ion dose and implantation energy are 1 × 10 14 cm −2 and 20 keV, respectively. However, even with channeled implantation, several types of defects including point defects and oblong defects as seen in the random implantation were observed by TEM/STEM analysis. RBS analysis showed slightly worse crystal qualities in channeled implantation compared to non-implanted samples. Mg channeled implantation is useful to achieve deeper profiles (>1 μ m), but further condition tuning of process will be necessary for practical application.

We fabricated Fe-silicide nanodots (NDs) on an ultrathin SiO2 layer and evaluated changes in electron transport properties with and without magnetic field application. High-density NDs with an areal density as high as similar to 1011 cm-2 were formed on thermally grown SiO2 by exposing ultrathin Fe/Si-NDs structures to a remote H2 plasma without external heat-ing. In electron transport properties related to current-time characteristics for a diode with Fe electrode and charging energy to NDs, clear changes in current levels through NDs and electron injection modulation of NDs depending on intensity of magnetic fields were observed.

We have characterized charged states of a self-aligned Si quantum dot (QD) structure with an areal density as high as ∼1013 cm−2 by surface potential measurements by using atomic force microscopy (AFM)/Kelvin probe force microscopy (KFM). By line scanning with the electrically-biased AFM tip with respect to the substrate in a contact mode, the corresponding area was negatively charged caused by electron injection from the tip into QDs. Cross-sectional profiles of the surface potential were clearly changed, which depends on the tip bias voltages. Also, a stepwise shape in a relationship between the change of the surface potential (ΔV) and the tip bias voltages was observed, reflecting electron charging into the discrete energy levels due to the quantum confinement effect. By assuming a simple equivalent circuit model for KFM measurements of the self-aligned Si-QDs, calculated results for ΔV are in good agreement with the measured results. The agreements precisely clarified the charged states in Si-QDs.

The antioxidant (AOX) activities of alanyl tyrosine dipeptide-type surfactants with several chain lengths were investigated. The critical micelle concentration decreased exponentially with the carbon number of the hydrophobic chain of the surfactant. The antioxidative property was investigated using the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS) assay and the oxygen radical absorbance capacity (ORAC) assay. The AOX activity was found to be strongly dependent on the chain length in the monomer solution. Therefore, an increase in the molecular size negatively influenced the AOX ability of the tyrosine residue. However, it was almost independent of the chain length of the surfactant in the micellar solution. The micelle particles acted as a catalyst for the reduction of the radicals in the ORAC assay.

We formed FePt magnetic nanodots (NDs) by exposing an ultrathin bilayer metal stack on ∼3.0 nm SiO 2 /Si(100) substrates to a remote H 2 plasma (H 2 -RP) and studied the effect of external heating during the exposure to H 2 -RP on the formation and magnetic properties of NDs. The ultrathin bilayer with a uniform surface coverage drastically changed to NDs with an areal density as high as ∼3.5 × 10 11 cm −2 by exposing to H 2 -RP with external heating. We also found that NDs formed by the exposure to H 2 -RP at 400 °C exhibited a perpendicular anisotropy with a perpendicular coercivity of ∼1.5 kOe, reflecting the magneto-crystalline anisotropy of (001)-oriented L1 0 phase FePt.