Promotion of Adventitious Roots in Chrysanthemum Cuttings by Soaking in Ozonated Water

To examine the effect of soaking in ozonated water (OW) on development of adventitious roots, basal ends of chrysanthemum cuttings (Chrysanthemum morifolium Ramat.) were soaked in 1, 3 or 5 mg L^?1 OW, in an indol-3-butyric acid (IBA) solution prepared from a commercial root promoting agent or in distilled water (DW). At 20 day after transplanting (DAT), a significant increase in adventitious root number (ARN) was observed in the IBA-treated cuttings but early root elongation was delayed. When soaked in the 5 mg L^?1 OW, ARN and total root length (TRL) grown over 40 mm were increased with a decrease in soaking duration (from 50 to 5 min). Lateral root number (LRN) of the cuttings soaked in the 3 mg L^?1 OW for 1 h showed four times higher than that of the DW treatment at 19 DAT. Optimal combination of dissolved ozone concentration and soaking duration can promote early root elongation and LRN of chrysanthemum cuttings. From a comprehensive standpoint, a high DOC of OW with a short soaking duration (3 mg L^?1 × 1 h and 5 mg L^?1 × 5 min) worked as well as IBA for adventitious rooting of chrysanthemum cuttings. These findings indicate that ozonated water can be an alternative to root promotion agents for adventitious rooting of chrysanthemum cuttings.     

Multicolor emission and thin film transistor properties of 1,8-diethynylcarbazole-based conjugated copolymers

1,8-Carbazole-based conjugated copolymers are synthesized by the Sonogashira polycondensation between the 1,8-diethynylcarbazole derivative and dibromo comonomers. The resulting polymers are fully characterized by GPC, and ¹H NMR and IR spectroscopies, and their high thermal stability with the 5% decomposition temperature exceeding 350 °C by thermogravimetric analyses. The optical properties of the carbazole polymers reveal that the comonomer structures significantly affect the absorption and emission spectra. For example, a bathochromic shift of the spectra is achieved when electron-accepting comonomers are selected, finally leading to the production of additive primaries. The mixtures of three carbazole polymers with red, green, and blue emission colors provide a white light emission both in solutions and in thin solid films. In addition, the thin film transistor properties of the carbazole polymers are investigated. The 1,8-carbazole-based polymers display an intermediate mobility between the 2,7-carbazole and 3,6-carbazole-based counter polymers. All these results suggest the potential application possibilities of the 1,8-carbazole-based conjugated polymers in optoelectronic devices.     

Engine for brain development: similarity between engine and brain

A theoretical model that simulates the developmental process of the human brain, including the blood vessels, is proposed. Observations of the development of the human brain with a high-speed camera show that the bones of the skull become increasingly large over the neck, and that a lot of soup-like fluid for generating brain cells enters the skull from the body. This process is essentially similar to the intake process of an internal combustion engine, because the volume of the engine cylinder, which increases according to the descent of the piston, corresponds geometrically to the development of the skull, and also because the human neck resembles the intake port that serves as the throat of the engine. A higher-order numerical computation of the Navier-Stokes equation reveals the similarity between the convexo-concave forms inside the brain and the flow structure in the internal combustion engine at very low Reynolds numbers. Further, we examine the similarity between the main blood vessels in the brain and the path lines in the engine.     

Morphological and functional behaviors of rat hepatocytes cultured on single-walled carbon nanotubes

This study describes the morphological and functional behaviors of rat hepatocytes on single-walled carbon nanotube (CNT)-coated surfaces. Although the hydrophobic characteristics of CNT-coated surfaces increased with increasing CNT density, hepatocyte adhesion decreased, indicating that the interaction between hepatocytes and CNTs is weak. We found that hepatocytes on a CNT-coated surface gradually gather together and form spheroids (spherical multicellular aggregates). These spheroids exhibit compact spherical morphology with a smooth surface and express connexin-32, an intracellular communication molecule. In contrast, collagen treatment in conjunction with the CNT-coated surface improved hepatocyte adhesion, and the cells maintained a monolayer configuration throughout the culture period. The albumin secretion and ammonia removal activities of hepatocyte spheroids were maintained at elevated levels for at least 15 days of culturing as compared with hepatocyte monolayers. These results indicate that CNTs can be used for the formation and long-term culture of hepatocyte spheroids.     

The Aneugenicity of Ketone Bodies in Colon Epithelial Cells Is Mediated by Microtubule Hyperacetylation and Is Blocked by Resveratrol

Diabetes mellitus (DM) is considered to be associated with an increased risk of colorectal cancer. Recent studies have also revealed that tubulin hyperacetylation is caused by a diabetic status and we have reported previously that, under microtubule hyperacetylation, a microtubule severing protein, katanin-like (KL) 1, is upregulated and contributes to tumorigenesis. To further explore this phenomenon, we tested the effects of the ketone bodies, acetoacetate and β-hydroxybutyrate, in colon and fibroblast cells. Both induced microtubule hyperacetylation that responded differently to a histone deacetylase 3 knockdown. These two ketone bodies also generated intracellular reactive oxygen species (ROS) and hyperacetylation was commonly inhibited by ROS inhibitors. In a human fibroblast-based microtubule sensitivity test, only the KL1 human katanin family member showed activation by both ketone bodies. In primary cultured colon epithelial cells, these ketone bodies reduced the tau protein level and induced KL1- and α-tubulin acetyltransferase 1 (ATAT1)-dependent micronucleation. Resveratrol, known for its tumor preventive and tubulin deacetylation effects, inhibited this micronucleation. Our current data thus suggest that the microtubule hyperacetylation induced by ketone bodies may be a causal factor linking DM to colorectal carcinogenesis and may also represent an adverse effect of them that needs to be controlled if they are used as therapeutics.     

Synthesis of Cycloparaphenylenes and Related Carbon Nanorings: A Step toward the Controlled Synthesis of Carbon Nanotubes

Since their discovery in 1991, carbon nanotubes (CNTs) have attracted significant attention because of their remarkable mechanical, electronic, and optical properties. Structural uniformity of the CNT is critically important because the sidewall structures (armchair, zigzag, and chiral) determine many of the significant properties of CNTs. Ideally researchers would synthesize CNTs with a defined target sidewall structure and diameter, but the current synthetic methods, such as arc discharge and chemical vapor deposition, only provide CNTs as the mixtures of various structures. Purification of these mixtures does not allow researchers to isolate a structurally uniform CNT, which is the bottleneck for fundamental studies and advanced applications of these materials. Therefore, the selective and predictable synthesis of structurally uniform CNTs would represent a critical advance in both nanocarbon science and synthetic chemistry. This Account highlights our efforts toward the bottom-up synthesis of structurally uniform carbon nanotubes (CNTs). We envisioned a bottom-up synthesis of structurally uniform CNTs through a controlled growth process from a short carbon nanoring (template) that corresponds to the target structure of CNTs. Our simple retrosynthetic analysis led to the identification of cycloparaphenylenes (CPPs), acene-inserted CPPs, and cyclacenes as the shortest sidewall segments of armchair, chiral, and zigzag CNTs, respectively. With this overall picture in mind, we initiated our synthetic studies of aromatic rings/belts as an initial step toward structurally uniform CNTs in 2005. This research has led to (i) a general strategy for the synthesis of CPPs and related carbon nanorings using cyclohexane derivatives as a benzene-convertible L-shaped unit, (ii) a modular, size-selective, and scalable synthesis of [n]CPPs (a shortest segment of armchair CNTs), (iii) the X-ray crystal structure analysis of CPPs, (iv) the design and synthesis of acene-inserted CPPs as the shortest segment of chiral CNTs, and (v) the first synthesis of cyclo-1,4-naphthylene, a π-extended CPP. We believe this work will serve as important initial steps toward a controlled synthesis of CNTs.     

A Covalent Inhibitor for Glutathione S-Transferase Pi (GSTP1-1) in Human Cells

Glutathione S-transferase π (GSTP_1-1) is overexpressed in many types of cancer and is involved in drug resistance. Therefore, GSTP_1-1 is an important target in cancer therapy, and many GST inhibitors have been reported. We had previously developed an irreversible inhibitor, GS-ESF, as an effective GST inhibitor; however, its cellular permeability was too low for it to be used in inhibiting intracellular GST. We have now developed new irreversible inhibitors by introducing sulfonyl fluoride (SF) into chloronitrobenzene (CNB). The mechanism of action was revealed to be that CNBSF first reacts with glutathione (GSH) through an aromatic substitution in the cell, then the sulfonyl group on the GSH conjugate with CNBSF reacts with Tyr108 of GST to form a sulfonyl ester bond. Our new inhibitor irreversible inhibited GSTP_1-1 both in vitro and in cellulo with a long duration of action.     

Adhesion of ultrahigh molecular weight polyethylene plates photografted with hydrophilic monomers and evaluation of failure location by X‐ray photoelectron spectroscopy

In this study, methacrylic acid (MAA) and acrylic acid (AA) were photografted onto the ultrahigh molecular weight polyethylene (UHMWPE) plates at different monomer concentrations and temperatures, and the grafted UHMWPE plates were bonded with aqueous polyvinyl alcohol (PVA) solutions. The tensile shear adhesive strength of both grafted UHMWPE plates was also discussed in relation to wettability and water absorptivity. The location of failure was also estimated by X‐ray photoelectron spectroscopy (XPS). Wettability of the MAA‐grafted UHMWPE plates became constant, when the UHMWPE surface was fully covered with grafted PMAA chains. Conversely, wettability of the AA‐grafted UHMWPE plates passed through the maximum value and then gradually decreased against the grafted amount probably due to aggregation of grafted PAA chains. Water absorptivity of the grafted layers formed at lower monomer concentrations or temperatures sharply increased at lower grafted amounts. The adhesive strength increased with the grafted amount and substrate breaking was observed at higher grafted amounts, indicating that a main factor to increase the adhesive strength is the formation of a grafted layer by shorter grafted polymer chains and/or the restriction of the location of photografting to the outer surface region. In addition, surface analysis by XPS showed that failure occurred in the boundary between the layer composed of grafted polymer chains and PVA chains and the ungrafted layer at a low adhesive strength, and the location of failure was shifted to the grafted layer containing PVA chains at the grafted amount increased. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40133.     

Diacylglycerol Kinase η Activity in Cells Using Protein Myristoylation and Cellular Phosphatidic Acid Sensor

Diacylglycerol kinase (DGK) phosphorylates diacylglycerol to produce phosphatidic acid (PtdOH) and regulates the balance between two lipid second messengers: diacylglycerol and PtdOH. Several lines of evidence suggest that the η isozyme of DGK is involved in the pathogenesis of bipolar disorder. However, the detailed molecular mechanisms regulating the pathophysiological functions remain unclear. One reason is that it is difficult to detect the cellular activity of DGKη. To overcome this difficulty, we utilized protein myristoylation and a cellular PtdOH sensor, the N-terminal region of α-synuclein (α-Syn-N). Although DGKη expressed in COS-7 cells was broadly distributed in the cytoplasm, myristoylated (Myr)-AcGFP-DGKη and Myr-AcGFP-DGKη-KD (inactive (kinase-dead) mutant) were substantially localized in the plasma membrane. Moreover, DsRed monomer-α-Syn-N significantly colocalized with Myr-AcGFP-DGKη but not Myr-AcGFP-DGKη-KD at the plasma membrane. When COS-7 cells were osmotically shocked, all DGKη constructs were exclusively translocated to osmotic shock-responsive granules (OSRG). DsRed monomer-α-Syn-N markedly colocalized with only Myr-AcGFP-DGKη at OSRG and exhibited a higher signal/background ratio (3.4) than Myr-AcGFP-DGKη at the plasma membrane in unstimulated COS-7 cells (2.5), indicating that α-Syn-N more effectively detects Myr-AcGFP-DGKη activity in OSRG. Therefore, these results demonstrated that the combination of myristoylation and the PtdOH sensor effectively detects DGKη activity in cells and that this method is convenient to examine the molecular functions of DGKη. Moreover, this method will be useful for the development of drugs targeting DGKη. Furthermore, the combination of myristoylation (intensive accumulation in membranes) and α-Syn-N can be applicable to assays for various cytosolic PtdOH-generating enzymes.