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Hepatic tissue engineering may be an effective approach for the treatment of liver disease; however, its practical application requires hepatic cell separation technologies that do not involve cell surface modification and maintain cell activity. In this study, we developed hepatocyte cell separation materials using a thermoresponsive polymer and a polymer with high affinity to hepatocytes. A block copolymer of poly(N-p-vinylbenzyl-O-β- D -galactopyranosyl-(1→4)- D -gluconamide) (PVLA) and poly(N-isopropylacrylamide) (PNIPAAm) [PVLA-b-PNIPAAm] was prepared through two steps of atom transfer radical polymerization. On the prepared PVLA-b-PNIPAAm brush, HepG2 cells (model hepatocytes) adhered at 37 °C and detached at 20 °C, attributed to the temperature-modulated affinity between PVLA and HepG2. Cells from the immortalized human hepatic stellate cell line (TWNT-1) did not adhere to the copolymer brush, and RAW264.7 cells (mouse macrophage; model Kupffer cells) adhered to the copolymer brush, regardless of temperature. Using the difference in cell adhesion properties on the copolymer brush, temperature-modulated cell separation was successfully demonstrated. A mixture of HepG2, RAW264.7, and TWNT-1 cells was seeded on the copolymer brush at 37 °C for adherence. By reducing the temperature to 20 °C, adhered HepG2 cells were selectively recovered with a purity of approximately 85% and normal activity. In addition, induced pluripotent stem (iPS) cell-derived hepatocytes adhered on the PVLA-b-PNIPAAm brush at 37 °C and detached from the copolymer brush at 20 °C, whereas the undifferentiated iPS cells did not adhere, indicating that the prepared PVLA-b-PNIPAAm brush could be utilized to separate hepatocyte differentiated and undifferentiated cells. These results indicated that the newly developed PVLA-b-PNIPAAm brush can separate hepatic cells from contaminant cells by temperature modulation, without affecting cell activity or modifying the cell surface. Thus, the copolymer brush is expected to be a useful separation tool for cell therapy and tissue engineering using hepatocytes. [ABSTRACT FROM AUTHOR]

This article describes the synthesis of a novel C(sub)2-symmetric bis-sulfoxide and its application to asymmetric desymmetrization of cyclic meso-1,2-diols. Data indicate that the desymmetrization occurs via acetalization followed by highly diastereoselective acetal fission. The synthesis of the heterocyclic compound involves three steps via asymmetric oxidation of the 1,2-benzenedithiol.

We have developed for heat-assisted magnetic recording a novel write head in which a magnetic writer and a near-field optical lens system are integrated. The single-pole type (SPT) write head is embedded in the hemispherical lens of a solid immersion lens (SIL) system, which has an effective NA of 1.44 at a wavelength of 405 nm. The SPT head, which has high magnetic efficiency and minimizes light scattering, consists of a main pole and vertical-turns type (VTT) coils. With an FWHM spot diameter of 130 nm and a main pole 2 [micro]m wide, the head is estimated to be capable of small-spot writing. Index Terms--Heat-assisted magnetic recording (HAMR), perpendicular magnetic recording, single-pole-type (SPT) head, solid-immersion lens (SIL).

The enantioselective total synthesis of (+)-hexachlorosulfolipid, a cytotoxin isolated from the Adriatic mussel Mytilus galloprovincialis, is presented. The total synthesis has allowed the conformation of the absolute configuration of the natural cytotoxic (+)-hexachlorosulfolipid.

Presents a proposed design of a 50% shaped rail negative pressure air bearing slider, the Papillon slider disk drive. Design's attainment of constant fly height and near-zero roll characteristics across the disk; Steady-state analysis.

Previously we synthesized JCI-20679, a novel thiophene-3-carboxamide analog of annonaceous acetogenins which have shown potent antitumor activity, with no serious side effects, in mouse xenograft models. In this study, we investigated the antitumor mechanism of JCI-20679. The growth inhibition profile (termed “fingerprint”) of this agent across a panel of 39 human cancer cell lines (termed “JFCR39”) was measured; this fingerprint was analyzed by the COMPARE algorithm utilizing the entire drug sensitivity database for the JFCR39 panel. The JCI-20679-specific fingerprint exhibited a high similarity to those of two antidiabetic biguanides and a natural rotenoid deguelin which were already known to be mitochondrial complex I inhibitors. In addition, the fingerprint exhibited by JCI-20679 was not similar to that displayed by any typical anticancer drugs within the database, suggesting that it has a unique mode of action. In vitro experiments using bovine heart-derived mitochondria showed direct inhibition of mitochondrial complex I by JCI-20679 and associated derivatives. This inhibition of enzymatic activity positively correlated with tumor cell growth inhibition. Furthermore, a fluorescently labeled derivative of JCI-20679 localized to the mitochondria of live cancer cells in vitro. These results suggest that JCI-20679 can inhibit cancer cell growth by inhibiting mitochondrial complex I. Our results show that JCI-20679 is a novel anticancer drug lead with a unique mode of action. [ABSTRACT FROM AUTHOR]

SUMMARY With an increase in renewable energy source installations in the domestic field, bidirectional ac/dc converters are attracting attention. Efficiency, power density improvement, and EMI reduction are necessary for converters in this field. Using high-frequency switching can reduce the size of passive components and help to achieve a high-power-density converter; however, the switching losses and EMI can increase. In this study, we propose a new bidirectional ac/dc converter circuit topology that can reduce the switching losses and EMI with soft-switching operation. The soft-switching operation is based on discontinuous current mode (DCM) operation and a magnetic energy recovery switch (MERS)-type turn-off snubber. This paper focuses on a modulation technique applied to this converter. Experiments with a fabricated 1-kW converter were conducted and the principles of operation were confirmed. Loss analysis indicates that inductor design is the key design issue for the proposed converter. [ABSTRACT FROM AUTHOR]

The prognosis of glioblastoma, which is the most frequent type of adult-onset malignant brain tumor, is extremely poor. Therefore, novel therapeutic strategies are needed. Previous studies report that JCI-20679, which is synthesized based on the structure of naturally occurring acetogenin, inhibits mitochondrial complex I and suppresses the growth of various types of cancer cells. However, the efficacy of JCI-20679 on glioblastoma stem cells (GSCs) is unknown. The present study demonstrated that JCI-20679 inhibited the growth of GSCs derived from a transposon system-mediated murine glioblastoma model more efficiently compared with the growth of differentiation-induced adherent cells, as determined by a trypan blue staining dye exclusion test. The inhibition of proliferation was accompanied by the blockade of cell-cycle entry into the S-phase, as assessed by a BrdU incorporation assay. JCI-20679 decreased the mitochondrial membrane potential, suppressed the oxygen consumption rate and increased mitochondrial reactive oxygen species generation, indicating that JCI-20679 inhibited mitochondrial activity. The mitochondrial inhibition was revealed to increase phosphorylated (phospho)-AMPKα levels and decrease nuclear factor of activated T-cells 2 (NFATc2) expression, and was accompanied by a decrease in calcineurin phosphatase activity. Depletion of phospho-AMPKα by knockdown of AMPKβ recovered the JCI-20679-mediated decrease in NFATc2 expression levels, as determined by western blotting and reverse transcription-quantitative PCR analysis. Overexpression of NFATc2 recovered the JCI-20679-mediated suppression of proliferation, as determined by a trypan blue staining dye exclusion test. These results suggest that JCI-20679 inhibited mitochondrial oxidative phosphorylation, which activated AMPK and reduced NFATc2 expression levels. Moreover, systemic administration of JCI-20679 extended the event-free survival rate in a mouse model transplanted with GSCs. Overall, these results suggested that JCI-20679 is a potential novel therapeutic agent against glioblastoma. [ABSTRACT FROM AUTHOR]

This paper proposes a new single-phase dc/ac converter topology with soft-switching operation. The proposed converter achieves soft-switching by using DCM (discontinuous current mode) operation and a common turn-off snubber capacitor connected to the dc terminals of a full-bridge configuration. One additional semiconductor switch is used to disconnect the snubber capacitor from the dc side, and allows the snubber capacitor to be discharged. The DCM operation realizes zero-current turn-on and the snubber capacitor achieves zero-voltage turn-off. The proposed converter can be applied to a grid-connected converter for domestic renewable energy and energy storage, including Photovoltaic and battery energy storage devices. This paper describes operation principles, control and modulation techniques as a grid-connecting converter. Experimental verification including loss analysis with a 1-kW pilot device is provided. [ABSTRACT FROM AUTHOR]

An efficient synthesis of 6-substituted 3-(alkoxycarbonyl)- 5-aryl-α-pyrones is reported. This methodology consists of the successive manipulation of an addition-elimination reaction between benzyl ketone derivatives and dimethyl methoxymethylenemalonate, and an acid-catalyzed condensation reaction. The synthesis is applicable to various 5-p-substituted-aryl 6-substituted α-pyrones and good to excellent yields were obtained over two steps from benzyl ketone derivatives that were easily prepared from phenylacetic acid by the Negishi coupling or the Claisen decarboxylation reaction. [ABSTRACT FROM AUTHOR]

A one-pot convenient access to chiral 2-oxazolidinones is described. Diethylzinc-mediated asymmetric alkynylation of aldehydes with propiolates in the presence of ?-sulfonamide alcohol as the chiral ligand, followed by treatment with isocyanates, yielded chiral 4-alkylidene-2-oxazolidinones. [ABSTRACT FROM AUTHOR]

Most Annonaceous acetogenins are characterized by between one and three THF ring(s) with one or two flanking hydroxyl group(s) in the center of a C32/34 fatty acid, and the terminal carboxylic acid is combined with a 2-propanol unit to form an α,β-unsaturated γ-lactone. While many studies have addressed the properties and synthesis of natural acetogenins due to their attractive biological activities and unique structural features, a number of analogues have also been described. This review covers the design, synthesis, and biological evaluation of acetogenin analogues. [ABSTRACT FROM AUTHOR]