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Oxygen functional groups (OFGs) in graphene oxide (GO) are responsible for the unique optical, electrical, magnetic as well as ionic, liquid and gaseous transport properties. In the present study, we have discovered reversible epoxide opening/closing reactions in GO upon alkaline and acid treatments, respectively, under ambient conditions. We suggest that unique properties of GO including stability of the carbocation and fast proton migration on the surfaces enable the unusual pH-driven epoxide ring opening/closing reactions. Our experimental results indicate that an irreversible epoxy formation observed in base-treated GO under flux conditions is due to the decomposition of the vic-diol groups formed by epoxy ring opening in alkaline solutions. A high concentration of basal plane epoxides is a remarkable feature of GO. Thus, the reversible epoxy formation should be an important part of our understanding of reactivity and properties of GO. For example, the epoxy ring opening can be a mechanism for anomalous photoluminescent (PL) quenching of GO dispersions in alkaline conditions.

To establish a biotechnological system to convert CO2 into methane, we are trying to develop a new CO2 bio-conversion technology based on “electromethanogenesis”, a new bio-electrolysis reaction using microbially-catalyzed electrode. In this study, we characterized bio-electrochemical properties of electromethanogenic reaction by Methanothermobacter thermautotrophicus strain AH, a thermophilic methanogen. The methanogen can electromethanogenically produce methane without exogenously-supplied hydrogen. In the reaction, the methanogen utilized molecular hydrogen, which was evolved by the abiotic electrochemical reaction, for the hydrogenotrophic methanogenesis. The current-to-methane conversion efficiency was 20% and the hydrogen evolution reaction was the rate-limiting step of the reaction.

Sialolipoma is a new variant of salivary gland lipoma, which was first described in 2001. We report a rare case of sialolipoma of the palate, and review another 10 cases affecting the minor salivary gland and 13 affecting the major salivary gland, together with details of the clinical and histopathological findings.

We have investigated transport in a network of narrow two-dimensional electron gas (2DEG) channel under a gradient magnetic field which is generated by a network of cobalt film deposited on the surface. Resistance of the 2DEG network changed with the magnetization of the cobalt network. The gradient magnetic field breaks the symmetry of the system with respect to the direction along the channel. We have found that the differential resistance under a finite DC bias current depends on the current direction. Magnetoresistance as a function of uniform perpendicular magnetic field while keeping the gradient field constant exhibits an overall shift and modulation of Shubnikov de-Haas oscillations.

We have studied the transport in 2DEG subjected to two different types of magnetic barrier. Excess resistivities due to those magnetic barriers increase as T2. The resistance as a function of the uniform component of the magnetic field exhibits a positive magnetoresistance and a beating pattern of the Shubnikov–de Haas oscillations.

The retinoid X receptor (RXR) is a member of the nuclear hormone receptor superfamily and heterodimerizes with a variety of other family members such as the thyroid hormone receptor (TR),1 retinoic acid receptor, vitamin D receptor, and peroxisome proliferator-activated receptor. Therefore, RXR is supposed to play a key role in a ligand-dependent regulation of gene transcription by nuclear receptors. In this study, we have identified the octamer-binding transcription factor-1 (Oct-1) as a novel interaction factor of RXR. In vitro pull-down assays using RXR deletion mutants showed that the interaction surfaces were located in the region encompassing the DNA binding domain (C domain) and the hinge domain (D domain) of RXR. We also showed that RXR interacted with the POU homeodomain but not with the POU-specific domain of Oct-1. Gel shift analysis revealed that Oct-1 reduced the binding of TR/RXR heterodimers to the thyroid hormone response element (TRE). In transient transfection assays using COS1 cells, Oct-1 repressed the T3-dependent transcriptional activity of TR/RXR heterodimers, consistent with in vitro DNA binding data; however, transcriptional activation by Gal4-TR(LBD) (LBD, ligand binding domain), which lacks its own DNA binding domain but retains responsiveness to T3, was not influenced by Oct-1. These results suggest that Oct-1 functionally interacts with RXR and negatively regulates the nuclear receptor signaling pathway by altering the DNA binding ability of the receptors.

Very late antigen-4 (VLA-4) is the complex with alpha4 and beta1 integrins, which is the receptors to fibronectin and VCAM-1. We evaluate the effect of 1,25(OH)2D3 on the expression of VLA-4 in human leukemic HL-60, U937 cells and human melanoma A375 cells. Flow cytometric analysis demonstrate that the expression of alpha4 integrin is negatively regulated in the cell lines we studied. The expression of beta1 integrin is also decreased in HL-60 and U937 cells. The mRNA expression of alpha4 integrin is significantly decreased by the treatment with 1,25(OH)2D3, whereas 1,25(OH)2D3 does not alter the expression of beta1 mRNA. The adhesion assay demonstrate that the number of adherent cells treated with 1, 25(OH)2D3 is significantly lower than that untreated on VCAM-1-coated wells. Because VCAM-1 is highly expressed in the endothelial cells, it is possible that 1,25(OH)2D3 prevents the attachment of the cells from the endothelial cells in vivo.

Melanocytes synthesize melanin and transfer it to keratinocytes via dendritic processes. Keratinocytes are known to produce constitutively several factors, including endothelin-1 (ET-1), that together affect melanocyte proliferation, migration, melanogenesis, and dendrite formation. After ultraviolet (UV) irradiation, synthesis and secretion of ET-1 are up-regulated in keratinocytes. Because UV irradiation of skin is known to be associated with increased melanocyte dendricity, and because medium conditioned by UV-irrdiated keratinocytes (UV-KCM) induces melanocyte dendricity to a greater degree than does baseline keratinocyte-conditioned medium (KCM), we investigated whether ET-1 promotes melanocyte dendricity. ET-1, originally recognized as a vasoconstricitive peptide, has recently been shown to stimulate melanocyte proliferation and tyrosinase activity. We now report that ET-1 supplementation of cultured melanocytes significantly increases the percentage of dendritic melanocytes, as well as dendrite length, in a dose-dependent manner. Moreover, UV-KCM was found to contain over 25-fold more ET-1 than KCM, and ET-1 supplementation of KCM induced melanocyte dendricity comparable to that induced by UV-KCM. Further, melanocyte dendricity induced by UV-KCM was significantly inhibited by the addition of anti-ET-1 monoclonal antibody to the medium, suggesting that the UV-KCM effect on melanocyte dendricity is mediated largely through ET-1. Our findings suggested that in the skin, ET-1 of keratinocyte origin promotes melanocyte dendricity in response to UV irradiation.

We have established a dermal fibroblast-like stromal cell line, DFB-1, and a clone, 12E2, from epidermal sheets prepared from the skin of BALB/c mouse ears by trypsin digestion. They were suggested to be fibroblasts or myofibroblasts, as 1) they were polygonal or spindle-shaped under the phasecontrast microscope, 2) they did not possess any tonofilaments or desmosomes, and 3) they did not express any marker for bone marrow-derived cells or macrophages. Interestingly, these cells showed a unique phenomenon of "pseudoemperiporesis," which was first recognized in the interaction between thymic nurse cells and thymocytes. Namely, two T-cell clones and one T-cell hybridoma migrated beneath the cytoplasmic projections of the fibroblastlike cutaneous stromal cells in culture. Furthermore, secretion of interleukin 7 by these cells was confirmed by bioassay using an IL-7-dependent cell line and by inhibition with anti-interleukin 7 antibody, and the expression of interleukin 7 mRNA was also demonstrated in these cells by a combination of reverse-transcriptase polymerase chain reaction and Southern blot analysis. These data strongly suggest the presence of unique stromal cells even in the skin, probably at the upper dermis, which can function like the nurse cells in the thymus. These stromal cells may play a crucial role in cutaneous immunophysiology.

When HMV-II cells (a human malignant melanoma cell line) infected with a newly isolated influenza C strain (Yamagata/1/88) were examined by simple light microscopy, it was found that a large number of cord-like structures which had lengths up to about 500 microns or greater were emerging from the cell surface. The existence of viral glycoproteins (hemagglutinin-esterase, HE) on the surface of these huge structures was confirmed by hemadsorption experiments with erythrocytes from a variety of species as well as by immunofluorescent staining with anti-HE monoclonal antibody. Furthermore, electron microscopy revealed that numerous filamentous particles in the process of budding, each covered with a layer of surface projections approximately 13 nm in length, aggregated with their long axes parallel to form a cord-like structure visible under a light microscope. An electron-dense layer, which presumably consists of membrane protein (M), was seen in cross-sections of all filamentous virions whereas internal nucleocapsids were rarely seen. SDS-polyacrylamide gel electrophoresis of the purified cords also showed that they contained HE and M polypeptides but not nucleoprotein, confirming that long filamentous particles are mostly devoid of nucleocapsids. The emergence of cords on the cell surface was observed in various cell cultures infected with C/Yamagata/1/88 though their number and length varied markedly depending on cell type. The production of cord-like structures was also evident in HMV-II cells infected with any of several different influenza C strains, which suggests that the cord formation is a common feature of influenza C virus group.

Some pigmentary disorders such as unilateral lentiginosis and vitiligo have a dermatomal or quasidermatomal distribution. This distribution may be the result of abnormalities during fetal skin formation or disturbances in regional peripheral nerves. We describe a case of a previously unreported acquired unilateral pigmentary skin disorder with a dermatomal distribution, in which we found unique degenerative changes in the underlying peripheral nerves as well as at the dermoepidermal junction.

Kinematically complete measurements of the 2 (α, pα)n reaction at 18 MeV lab energy have been performed at various pairs of angles θ p and θ α . The p-α quasi-free scattering peak cross sections show an angular dependence similar to that predicted in the plane wave impulse approximation. From the analysis in a modified impulse approximation, it is found that two correction terms reflecting the effects of the three-nucleon transfer reaction and 6 Li resonances are necessary to reproduce the data, as was the case for the 15 MeV 2 H(α, pα)n reaction.

An analysis of the scattering 16 O- 19 F measured at the energies E lab = 21.4, 25.8 and 32.0 MeV has been carried out by using the core-exchange model. The value of cfp 〈 19 F|} 16 O, triton〉 obtained in the present analysis is consistent with that obtained from the analysis of 19 F ( 3 He, 6 Li) 16 O when the recoil effects are included.

Absolute cross sections of the 2 H(α, pα)n reaction have been measured at an incident energy and angle suitable for observing the effects of the n-p final state interaction (n-p FSI). The data are analysed by a semi-phenomenological modified impulse approximation (MIA). In the energy range E np ⪅ 0.6 MeV, destructive interference is clearly seen between the MIA matrix elements and n-p FSI.

With the aim of characterizing photoreceptor outer segments and obtaining in situ observation of macromolecular variations due to cell types as well as adaption, we counted the number of outer segment disk membranes using electron micrographs of ultrathin sections as well as intramembrane particles on the complementary replicas of the retina of Lampetra japonica. Long photoreceptor cells (LPCs, cone-type cells) numbered 10,000/mm2 in the central as well as peripheral regions, while short ones (SPCs, rod-type cells) numbered 30,000/mm2 in the same regions. The LPC outer segment exhibited 306 disks on average during the light cycle versus 364 during the dark cycle. 12.0% of the LPC disks during the light cycle versus 13.4% during the dark cycle represented the "open" disks. The SPC outer segment exhibited 470 disks on average during the light cycle versus 507 during the dark cycle. 11.1% of the SPC disks during the light cycle versus 13.6% during the dark cycle represented the "open" disks. The LPC disk membrane contained 44.3 particles/0.01 microns 2 during the light cycle versus 39.5 particles during the dark cycle, 95% of which were derived from the protoplasmic fracture (PF) face. The SPCs contained 36.0 particles/0.01 micron 2 during the light cycle versus 43.6 during the dark cycle, 90% of which were derived from the PF-face. The present findings contradict the frequently cited hypothesis that an "open" disk, retaining continuity with the plasmalemma, is preserved characteristically into later stages by the cone outer segment. The significance of the intramembrane particles for the activity of the photoreceptor membrane is discussed.