Topological Gap States of Rectangular Armchair Ribbon.

We consider a rectangular graphene armchair ribbon with an excitation gap. The boundary of this system consists of two short zigzag edges and two long armchair edges. Within such a ribbon, topological gap states exist that are localized along the zigzag edges. The end charge of these states is an integer, which can be related to the Zak phase of the periodic armchair ribbon constructed from the rectangular armchair ribbon by connecting its zigzag edges together. In this paper, we provide an explicit analytical computation of the Zak phase of a periodic armchair ribbon, and show that its value is consistent with the integer end charges that are computed numerically. In the presence of a staggered potential, non-integer end charges are possible. We discuss its relation to the Zak phase.

Relationships between Single Nucleotide Polymorphism Markers and Meat Quality Traits of Duroc Breeding Stocks in Korea.

This study was conducted to determine the relationships of five intragenic single nucleotide polymorphism (SNP) markers (protein kinase adenosine monophosphate-activated γ3 subunit [PRKAG3], fatty acid synthase [FASN], calpastatin [CAST], high mobility group AT-hook 1 [HMGA1], and melanocortin-4 receptor [MC4R]) and meat quality traits of Duroc breeding stocks in Korea. A total of 200 purebred Duroc gilts from 8 sires and 40 dams at 4 pig breeding farms from 2010 to 2011 reaching market weight (110 kg) were slaughtered and their carcasses were chilled overnight. Longissimus dorsi muscles were removed from the carcass after 24 h of slaughter and used to determine pork properties including carcass weight, backfat thickness, moisture, intramuscular fat, pH24h, shear force, redness, texture, and fatty acid composition. The PRKAG3, FASN, CAST, and MC4R gene SNPs were significantly associated with the meat quality traits (p<0.003). The meats of PRKAG3 (A 0.024/G 0.976) AA genotype had higher pH, redness and texture than those from PRKAG3 GG genotype. Meats of FASN (C 0.301/A 0.699) AA genotype had higher backfat thickness, texture, stearic acid, oleic acid and polyunsaturated fatty acid than FASN CC genotype. While the carcasses of CAST (A 0.373/G 0.627) AA genotype had thicker backfat, and lower shear force, palmitoleic acid and oleic acid content, they had higher stearic acid content than those from the CAST GG genotype. The MC4R (G 0.208/A 0.792) AA genotype were involved in increasing backfat thickness, carcass weight, moisture and saturated fatty acid content, and decreasing unsaturated fatty acid content in Duroc meat. These results indicated that the five SNP markers tested can be a help to select Duroc breed to improve carcass and meat quality properties in crossbred pigs.

Magnetic transition and long-time relaxation behavior induced by selective injection of guest molecules into clathrate hydrates.

Magnetic molecules physisorbed into low-dimensional nanostructures of microporous materials such as graphite and metal-organic frameworks have been verified to exhibit an unusual magnetic behavior. We demonstrate that the selective injection of both magnetic and nonmagnetic guest molecules into the water-ice cages of clathrate hydrates to form a 3D superstructure with tetrahedral and diamond-like sublattices can modify the inherent magnetism.

Soliton fractional charge of disordered graphene nanoribbon.

We investigate the properties of the gap-edge states of half-filled interacting disordered zigzag graphene nanoribbons, and find that the midgap states can display a quantized fractional charge of 1/2. These gap-edge states can be represented by topological kinks with their site probability distribution divided between the left and right zigzag edges with different chiralities. In addition, there are numerous spin-split gap-edge states, similar to those in a Mott-Anderson insulator.

Stability of Anomalous States of a Local Potential in Graphene.

Graphene Landau levels have discrete energies consisting zero energy chiral states and non-zero energy states with mixed chirality. Each Landau level splits into discrete energies when a localized potential is present. A simple scaling analysis suggests that a localized potential can act as a strong perturbation, and that it can be even more singular in graphene than in ordinary two-dimensional systems of massful electrons. Parabolic, Coulomb, and Gaussian potentials in graphene may have anomalous boundstates whose probability density has a sharp peak inside the potential and a broad peak of size magnetic length l outside the potential. The n = 0 Landau level with zero energy has only one anomalous state while the n = ±1 Landau levels with non-zero energy have two (integer quantum number n is related to the quantized Landau level energies). These anomalous states can provide a new magnetospectroscopic feature in impurity cyclotron resonances of graphene. In the present work we investigate quantitatively the conditions under which the anomalous states can exist. These results may provide a guide in searching for anomalous states experimentally.

Follistatin-like 3 is a mediator of exercise-driven bone formation and strengthening.

Exercise is vital for maintaining bone strength and architecture. Follistatin-like 3 (FSTL3), a member of follistatin family, is a mechanosensitive protein upregulated in response to exercise and is involved in regulating musculoskeletal health. Here, we investigated the potential role of FSTL3 in exercise-driven bone remodeling. Exercise-dependent regulation of bone structure and functions was compared in mice with global Fstl3 gene deletion (Fstl3-/-) and their age-matched Fstl3+/+ littermates. Mice were exercised by low-intensity treadmill walking. The mechanical properties and mineralization were determined by µCT, three-point bending test and sequential incorporation of calcein and alizarin complexone. ELISA, Western-blot analysis and qRT-PCR were used to analyze the regulation of FSTL3 and associated molecules in the serum specimens and tissues. Daily exercise significantly increased circulating FSTL3 levels in mice, rats and humans. Compared to age-matched littermates, Fstl3-/- mice exhibited significantly lower fracture tolerance, having greater stiffness, but lower strain at fracture and yield energy. Furthermore, increased levels of circulating FSTL3 in young mice paralleled greater strain at fracture compared to the lower levels of FSTL3 in older mice. More significantly, Fstl3-/- mice exhibited loss of mechanosensitivity and irresponsiveness to exercise-dependent bone formation as compared to their Fstl3+/+ littermates. In addition, FSTL3 gene deletion resulted in loss of exercise-dependent sclerostin regulation in osteocytes and osteoblasts, as compared to Fstl3+/+ osteocytes and osteoblasts, in vivo and in vitro. The data identify FSTL3 as a critical mediator of exercise-dependent bone formation and strengthening and point to its potential role in bone health and in musculoskeletal diseases.

Continuous culture of immobilized streptomyces cells for kasugamycin production.

Continuous cultures of immobilized Streptomyces kasugaensis, a kasugamycin producer, were carried out on Celite beads. When using a prototype separator for immobilized-cell separation and recycling, the continuous operation could not be sustained for an extended period as a result of an excessive loss of immobilized cells caused by the poor performance of the separator. Accordingly, the immobilized-cell separator was revised to provide better immobilized-cell settling and thus recycling into the reactor. In a subsequent culture using the revised separator, a stable operation was maintained for over 820 h with a high kasugamycin productivity. The kasugamycin productivity ranged from 9.8 to 16.1 mg/L/h, which was about 14- to 23-fold higher than that in a batch suspended-cell culture. When the original feeding medium concentration was doubled at the end of the continuous culture, the productivity became severely impaired for several reasons, which will be discussed. An excessive formation of free cells and loss of immobilized cells through the separator were also observed.

Ammonia removal using hepatoma cells in mammalian cell cultures.

It was examined whether hepatocyte cell lines can be used for ammonia removal in mammalian cell cultures. It was found that there exists a critical ammonium concentration level for each hepatocyte cell to remove ammonia. Among the cells tested in this work, primary hepatocytes showed the strongest ammonia removal capability if ammonium concentration is higher than the critical level. However, primary hepatocytes lost the liver function gradually and finally died after 2-3 weeks. Because of this limitation, primary hepatocytes were not appropriate to be used for ammonia removal in long-term cultures. Hep G2 cells, which are immortal, also showed a strong ammonia removal activity. The ammonia removal activity of Hep G2 cells depended on the concentration of ammonium in the medium, as in the case of primary hepatocytes. However, urea could not be detected in the course of ammonia removal by Hep G2 cells. Instead of urea, Hep G2 cells secreted glutamine into the culture medium. The capacity for ammonia removal was higher in the absence than in the presence of glutamine. Thus we checked the activity of glutamine synthetase in the Hep G2 cells. The level of glutamine synthetase activity increased with the addition of ammonium chloride. This result accounts for the ammonium concentration dependency of Hep G2 cells in ammonia removal and glutamine synthesis. Furthermore Hep G2 cells could grow well in the absence of glutamine, which was necessarily required in mammalian cell cultures. These results prove that glutamine formation serves as the primary mechanism of detoxifying ammonia in hepatocyte cell lines as expected. In addition, it was demonstrated that ammonium level could be reduced 38% and that erythropoietin production increased 2-fold in the mixed culture of Hep G2 and recombinant CHO cells.

The design of original antimalarial drugs. An example of phospholipid metabolism.

The aim of our program was to find an original chemotherapeutical treatment (and eventually a preventive treatment) of malaria, an illness largely predominant in developing countries, by interfering on an essential metabolism developed by Plasmodium during its erythrocytic phase. Apart from what has been learnt about metabolism and the pharmacological target, a crucial step has been taken during this contract by passing from micromolar in vitro active concentrations (during 1986-1990) to nanomolar ones (during 1990). These compounds should naturally short-circuit resistance phenomena already established against drugs in current use, as has already been verified on polypharmacoresistant strains or isolates of P. falciparum. The administration of a therapeutic dose of our molecules would now appear to be possible in all cases.

Effect of adjunctive dipyridamole to DAPT on platelet function profiles in stented patients with high platelet reactivity. The result of the ACCEL-DIP Study.

Adjunctive use of phosphodiesterase (PDE) inhibitor can enhance antiplatelet and vasoprotective properties in patients with cardiovascular disease. The aim of this study was to evaluate the impact of PDE5 inhibitor dipyridamole on platelet function in stented patients with high platelet reactivity (HPR) during dual antiplatelet therapy (DAPT) with aspirin and clopidogrel. Patients with HPR after 600-mg clopidogrel loading were randomly assigned to adjunctive dipyridamole 75 mg twice daily to standard DAPT (DIP group; n = 45) or double-dose clopidogrel of 150 mg daily (DOUBLE group; n = 46) for 30 days. Platelet function was assessed at baseline and 30-day follow-up with platelet reactivity index (PRI) by vasodilator-stimulated phosphoprotein-phosphorylation (VASP-P) assay and platelet aggregation (PA) by light transmittance aggregometry (LTA). Primary endpoint was PRI at 30-day follow-up. HPR was defined as PRI > 50%. Baseline platelet function did not differ between the groups. Following 30-day therapy, platelet function was significantly reduced in the DIP and DOUBLE groups (all p-values ≤ 0.004 and ≤ 0.068, respectively). PRI values were not significantly different between the two groups (mean difference: 3.1%; 95% confidence interval: -2.8% to 9.0%: p = 0.295). PA values and prevalence of HPR were similar between the groups. However, a significant number of patients still exhibited HPR in the DIP (75.6%) and DOUBLE (67.4%) groups. In conclusion, among stented HPR patients, adding dipyridamole to DAPT does not reduce platelet reactivity and prevalence of HPR compared with double-dose clopidogrel therapy, and therefore both strategies are inadequate to overcome HPR.

Superfine saengshik improves liver protecting effect compared with fine saengshik in an animal model.

This study was performed to compare the effect of liver protection of fine saengshik (FS) and superfine saengshik (SS) and uncooked and powdered grains and vegetables, produced by the different mill technique on the acute hepatotoxicity induced by CCl(4) in mouse. As the result of particle size distribution in number, particles included under 0.955 microm dia were 7.02% and 68.92% respectively. Hematological and serological examination showed that AST (P < 0.05) and ALT (P < 0.05) of SS + CCl(4) group decreased significantly compared with those of FS + CCl(4) group. On the examination of antioxidant effect, water extract of SS showed a higher superoxide dismutase (SOD)-like activity on the condition of the HX/XOD system than that of FS (P < 0.001). Also, the glutathione peroxidase (P < 0.01) and glutathione reductase (P < 0.05) activities in liver showed a significant difference between FS + CCl(4) and SS + CCl(4) groups. On the histological observation of liver, SS + CCl(4) group showed a mild reversible hepatocytic change and infiltration of inflammatory cells around the central veins, whereas FS + CCl(4) group showed severe agglutination necrosis by CCl(4) toxicity. These results suggest that superfine saengshik significantly improves liver protection effect compared with fine saengshik; its major mechanism is supposed to be the improved antioxidant effect of saengshik by reduced size of particles.

Presenilin enhancer-2 (PSENEN), a component of the gamma-secretase complex, is involved in adipocyte differentiation.

This study was conducted to identify genes expressed during adipocyte differentiation of bovine intramuscular fibroblast-like cells using differential display reverse-transcriptase polymerase chain reaction. The presenilin enhancer-2 (PSENEN) gene was found to be down-regulated during adipocyte differentiation of bovine intramuscular fibroblast-like cells. The ectopic expression of bovine PSENEN in 3T3-L1 reduced adipogenesis and the inhibition of endogenous PSENEN by siRNA induced adipogenesis on d 4 of adipocyte differentiation of 3T3-L1 cells. Interestingly, the expression of gamma-secretase complex gene-related Notch signaling was decreased at d 2 and d 4 during adipocyte differentiation. In addition, expression of the Notch-signaling genes (Notch-1, Hes-1, Pref-1, adipsin) was regulated during adipocyte differentiation by regulation of PSENEN expression. These results suggest that PSENEN plays an important role in adipocyte differentiation and that Notch signaling is involved in adipogenesis.

Non-resonant and resonant x-ray scattering studies on multiferroic TbMn2O5.

Comprehensive x-ray scattering studies, including resonant scattering at Mn L, Tb L, and M edges, were performed on single crystals of TbMn2O5 for crystallographic data to elucidate the nature of its commensurate and incommensurate phases. The scattering results provide direct evidence of symmetry lowering to the ferroelectric phase driven by magnetically induced lattice modulations and show the presence of multiple magnetic orders. The competing orders under spin-frustrated geometry are believed to cause discommensuration and result in the commensurate-to-incommensurate phase transition around 24 K. It is proposed that the low temperature incommensurate phase consists of commensurate domains separated by antiphase domain walls which change both signs of spontaneous polarizations and x-ray scattering amplitudes for forbidden reflections.

Coherent manipulation of electronic States in a double quantum dot.

We investigate coherent time evolution of charge states (pseudospin qubit) in a semiconductor double quantum dot. This fully tunable qubit is manipulated with a high-speed voltage pulse that controls the energy and decoherence of the system. Coherent oscillations of the qubit are observed for several combinations of many-body ground and excited states of the quantum dots. Possible decoherence mechanisms in the present device are also discussed.