211 research outputs found

    Synthesis of novel azo compounds containing 5(4H)-oxazolone ring as potent tyrosinase inhibitors

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    Six new azo dyes containing of 5(4H)-oxazolone ring were prepared by diazotization of 4-aminohippuric acid and coupling with N,N-dimethylaniline, 1-naphthol and 2-naphthol and condensation with 4-fluoro benzaldehyde or 4-trifluoromethoxy benzaldehyde. The new compounds were fully characterized by spectroscopic techniques. All synthesized compounds exhibited high tyrosinase inhibitory behavior. The results of mushroom tyrosinase inhibition assays indicate that the 4-trifluoromethoxy derivatives have high degrees of inhibition and N,N-dimethylaniline derivatives are better for tyrosinase inhibition than 1-naphthol and 2-naphthol derivatives. All synthesized azo compounds (4a-4f) showed the most potent mushroom tyrosinase inhibition, comparable to that of Kojic acid and l-mimosine, as reference standard inhibitors. © 2013 Elsevier Ltd. All rights reserved

    Commensurate 4a04a_0 period Charge Density Modulations throughout the Bi2Sr2CaCu2O8+xBi_2Sr_2CaCu_2O_{8+x} Pseudogap Regime

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    Theories based upon strong real space (r-space) electron electron interactions have long predicted that unidirectional charge density modulations (CDM) with four unit cell (4a0a_0) periodicity should occur in the hole doped cuprate Mott insulator (MI). Experimentally, however, increasing the hole density p is reported to cause the conventionally defined wavevector QAQ_A of the CDM to evolve continuously as if driven primarily by momentum space (k-space) effects. Here we introduce phase resolved electronic structure visualization for determination of the cuprate CDM wavevector. Remarkably, this new technique reveals a virtually doping independent locking of the local CDM wavevector at Q0=2π/4a0|Q_0|=2\pi/4a_0 throughout the underdoped phase diagram of the canonical cuprate Bi2Sr2CaCu2O8Bi_2Sr_2CaCu_2O_8. These observations have significant fundamental consequences because they are orthogonal to a k-space (Fermi surface) based picture of the cuprate CDM but are consistent with strong coupling r-space based theories. Our findings imply that it is the latter that provide the intrinsic organizational principle for the cuprate CDM state

    CenoDerm vs. fascia lata for the prevention of dorsal nasal irregularities in rhinoplasty

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    Introduction: Dorsal nasal irregularity is a complication of rhinoplasty surgery, mostly seen in patients with thin skin. Acellular dermis (CenoDerm) and homologous fascia lata covering the nasal bone cartilage structure have been used to achieve a smooth surface. In this study, we aimed to investigate clinical outcomes using these two materials. Materials and Methods: After a standard rhinoplasty procedure, a layer of the acellular dermis or homologous fascia lata was placed in the pocket of the dorsum. Patients were evaluated for clinical outcomes at 3, 6, and 12 months after the procedure. Results Forty-two of 68 patients completed the follow-up period. Patient satisfaction was higher in the homologous fascia lata group. Similarly, nasal dorsum inspection and palpation results were better in the homologous fascia lata group compared with the CenoDerm group but was significant in palpation (P=0.00). There was no complete absorption in the homologous fascia lata group 6 months after surgery (P= 0.04 vs. CenoDerm) but no significant difference was observed at 12 months. Conclusion: Homologous fascia lata is better than acellular dermis in preventing dorsal nasal irregularity after rhinoplasty in thin-skinned patients

    CenoDerm vs. fascia lata for the prevention of dorsal nasal irregularities in rhinoplasty

    Get PDF
    Introduction: Dorsal nasal irregularity is a complication of rhinoplasty surgery, mostly seen in patients with thin skin. Acellular dermis (CenoDerm) and homologous fascia lata covering the nasal bone cartilage structure have been used to achieve a smooth surface. In this study, we aimed to investigate clinical outcomes using these two materials. Materials and Methods: After a standard rhinoplasty procedure, a layer of the acellular dermis or homologous fascia lata was placed in the pocket of the dorsum. Patients were evaluated for clinical outcomes at 3, 6, and 12 months after the procedure. Results Forty-two of 68 patients completed the follow-up period. Patient satisfaction was higher in the homologous fascia lata group. Similarly, nasal dorsum inspection and palpation results were better in the homologous fascia lata group compared with the CenoDerm group but was significant in palpation (P=0.00). There was no complete absorption in the homologous fascia lata group 6 months after surgery (P= 0.04 vs. CenoDerm) but no significant difference was observed at 12 months. Conclusion: Homologous fascia lata is better than acellular dermis in preventing dorsal nasal irregularity after rhinoplasty in thin-skinned patients

    Infra-Red Stable Supersymmetry in Chern-Simons Theories with Matter and Quenched Disorder

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    We study Abelian Chern-Simons field theories with matter fields and global SU(N) symmetry in the presence of random weak quenched disorder. In the absence of disorder these theories possess N=2 supersymmetric fixed points and N=1 supersymmetric fixed lines in the infra-red limit. We show that although the presence of disorder forbids any supersymmetry of the bare action, infra-red stable supersymmetric fixed points and fixed lines are realized in the disorder-averaged effective theories.Comment: 8 pp., LaTeX. Explanatory remarks and references added. Version to appear in Phys. Rev. Let

    Gauged Yukawa Matrix Models and 2-Dimensional Lattice Theories

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    We argue that chiral symmetry breaking in three dimensional QCD can be identified with N\'eel order in 2-dimensional quantum antiferromagnets. When operators which drive the chiral transition are added to these theories, we postulate that the resulting quantum critical behavior is in the universality class of gauged Yukawa matrix models. As a consequence, the chiral transition is typically of first order, although for a limited class of parameters it can be second order with computable critical exponents.Comment: LaTeX, 11 page
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