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951.
Woo Chang Kim Min Jeong Kim Jang Ho Kim Frank J. Fabozzi 《European Journal of Operational Research》2014
Robust portfolios reduce the uncertainty in portfolio performance. In particular, the worst-case optimization approach is based on the Markowitz model and form portfolios that are more robust compared to mean–variance portfolios. However, since the robust formulation finds a different portfolio from the optimal mean–variance portfolio, the two portfolios may have dissimilar levels of factor exposure. In most cases, investors need a portfolio that is not only robust but also has a desired level of dependency on factor movement for managing the total portfolio risk. Therefore, we introduce new robust formulations that allow investors to control the factor exposure of portfolios. Empirical analysis shows that the robust portfolios from the proposed formulations are more robust than the classical mean–variance approach with comparable levels of exposure on fundamental factors. 相似文献
952.
In this paper we prove that there does not exist any Hopf real hypersurface in complex hyperbolic two‐plane Grassmannians with parallel Ricci tensor. 相似文献
953.
Kim SH Kwon SW Chu SY Lee JH Narsaiah B Kim CH Kang SK Kang NS Rhee SD Bae MA Ahn SH Ha DC Kim KY Ahn JH 《Chemical & pharmaceutical bulletin》2011,59(1):46-52
In the continuation of our 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitor research, cyclic sulfonamide derivatives with an acetamide group at the 2-position were synthesized and evaluated for their abilities to inhibit 11β-HSD1. Among this series, Compound 34 showed good in vitro activity toward human 11β-HSD1, selectivity against 11β-HSD2, microsomal stability, good pharmacokinetic and safety profiles human ether-a-go-go related gene (hERG and cytochrome P450 (CYP)). Also, a docking study explained the activity difference between human and mouse 11β-HSD1. 相似文献
954.
This article investigates the impact of elastic liposomes on enhancing the skin delivery of genistein and the influences of skin tissues with or without hair follicles on permeation and accumulation properties of genistein from liposomal suspensions. The greater permeation rate and deposition values of genistein were observed from the elastic liposomes than conventional liposomes in haired skin. When measured with hairless skin, the flux and skin deposition values of genistein in elastic liposomes were significantly decreased compared to conventional liposomes, indicating that the percutaneous delivery of elastic liposomes was considerably influenced by existence of hair follicles in the skin tissue. 相似文献
955.
It has been demonstrated that dialkyl, diaryl, and aryl alkyl sulfoxides can be efficiently converted into the corresponding sulfides by the reaction with a MoCl5/In system in good to excellent yields under mild conditions. 相似文献
956.
Jaewoo Lee Jooyoung Chung Sang Moon Byun B. Moon Kim Chulbom Lee 《Tetrahedron》2013,69(27-28):5660-5664
The direct C–H arylation of a heteroarene with aryl bromides has been achieved under the catalysis of magnetic nanoparticles. In the presence of bimetallic Pd–Fe3O4 heterodimer nanocrystals (1 mol % in palladium), the reaction of imidazo[1,2-a]pyridine with various aryl bromides gives the corresponding arylated products with exclusive C3-selectivity. The highly regioselective method is applicable to a wide range of aryl bromides with varying electronic and steric properties. The Pd–Fe3O4 nanocrystals can be recoverable by simple magnetic separation and have been recycled ten times without loss of catalytic activity. 相似文献
957.
Jooyoung Chung Jinju Kim Youngjin Jang Sangmoon Byun Taeghwan Hyeon B. Moon Kim 《Tetrahedron letters》2013
We have developed a convenient Pd–Fe3O4 heterodimeric nanocrystal catalyst system for Heck and Sonogashira reactions. This catalyst offers an environment-friendly, atom-efficient, and robust catalytic system for both reactions. Furthermore the nanocrystal catalyst could be easily separated by an external magnet and recycled six times without losing its catalytic activity. 相似文献
958.
Ji Hong Hwang Hyemin Choi In-sok Hwang A. Ryun Kim Eun-Rhan Woo Dong Gun Lee 《Applied biochemistry and biotechnology》2013,170(8):1934-1941
In this study, antibacterial effects of (+)-Medioresinol isolated from stem bark of Sambucus williamsii and its synergistic activities in combination with antibiotics such as ampicillin, cefotaxime, and chloramphenicol were tested by antibacterial susceptibility testing and checkerboard assay. (+)-Medioresinol possessed antibacterial effects against antibiotics-susceptible- or antibiotics-resistant strains. Most of combinations between (+)-Medioresinol and each antibiotic showed synergistic interaction (fractional inhibitory concentration index ≤0.5) against bacterial strains including antibiotics-resistant Pseudomonas aeruginosa. Furthermore, the antibiofilm effect of (+)-Medioresinol alone or in combination with each antibiotic was investigated. The results indicated that not only (+)-Medioresinol but also its combination with each antibiotic had antibiofilm activities. It concludes that (+)-Medioresinol has potential as a therapeutic agent and adjuvant for treatment of bacterial infection. 相似文献
959.
Soon Mo Choi Deepti Singh Yong Woo Cho Tae Hwan Oh Sung Soo Han 《Colloid and polymer science》2013,291(5):1121-1133
The aim of this work is to develop a novel biocompatible drug delivery carrier and tissue engineering scaffold with the ability of controlled drug release and also tissue regeneration. We have synthesized N-(2-hydroxypropyl)methacrylamide and 2-(dimethylamino)ethyl methacrylate copolymer-based hydrogels loaded with doxorubicin and tested in vitro. The manifestation of temperature sensitivity is noted with a sharp decrease or increase in hydrogel optical transparency that happens with the temperature exceeding a critical transition value. The drug release profile exhibited pH-sensitive behavior of the hydrogel. The hydrolytic degradation of gel and in vitro studies of polymer–doxorubicin conjugate and doxorubicin release from hydrogel matrix indicated that hydrogels were stable under acidic conditions (in buffers at pH 4.64 and 6.65). In both drug forms, polymer–doxorubicin conjugate and free doxorubicin could be released from the hydrogel scaffold at a rate depending directly on either the rate of drug diffusion from the hydrogel or rate of hydrogel degradation or at rate controlled by a combination of the both processes. In vitro analysis showed homogenous cell attachment and proliferation on synthesized hydrogel matrix. In vivo implantation demonstrated integration of the gel with the surrounding tissue of mice within 2 weeks and prominent neo-angiogenesis observed in the following weeks. This multifunctional hydrogels can easily overcome biological hurdles in the in vivo conditions where the pH range changes drastically and could attain higher site-specific drug delivery improving the efficacy of the treatment in various therapeutical applications, especially in cancer therapy, and could also be used as tissue engineering scaffold due to its porous interconnected and biocompatible behavior. 相似文献
960.
In Taek Choi Dr. Myung Jong Ju Sang Hyun Song Sang Gyun Kim Dr. Dae Won Cho Prof. Dr. Chan Im Prof. Dr. Hwan Kyu Kim 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(46):15545-15555
The Y‐shaped, low molecular mass, hole‐conductor (HC), acidic coadsorbents 4‐{3,7‐bis[4‐(2‐ethylhexyloxy)phenyl]‐10H‐phenothiazin‐10‐yl}benzoic acid ( PTZ1 ) and 4‐{3,7‐bis[4‐(2‐ethylhexyloxy)phenyl]‐10H‐phenothiazin‐10‐yl}biphenyl‐4‐carboxylic acid ( PTZ2 ) were developed. Owing to their tuned and negative‐shifted HOMO levels (vs. NHE), they were used as HC coadsorbents in dye‐sensitized solar cells (DSSCs) to improve cell performance through desired cascade‐type hole‐transfer processes. Their detailed functions as HC coadsorbents in DSSCs were investigated to obtain evidence for the desired cascade‐type hole‐transfer processes. They have multiple functions, such as preventing π–π stacking of dye molecules, harvesting light of shorter wavelengths, and faster dye regeneration. By using PTZ2 as the tailor‐made HC coadsorbent on the TiO2 surface with the organic dye NKX2677, an extremely high conversion efficiency of 8.95 % was achieved under 100 mW cm?2 AM 1.5G simulated light (short‐circuit current JSC=16.56 mA cm?2, open‐circuit voltage VOC=740 mV, and fill factor of 73 %). Moreover, JSC was increased by 13 %, VOC by 27 % and power‐conversion efficiency by 49 % in comparison to an NKX2677‐based DSSC without an HC coadsorbent. This is due to the HC coadsorbent having a HOMO energy level well matched to that of the NKX‐2677 dye to induce the desired cascade‐type hole‐transfer processes, which are associated with a slower charge recombination, fast dye regeneration, effective screening of liquid electrolytes, and an induced negative shift of the quasi‐Fermi level of the electrode. Thus, this new class of Y‐shaped, low molecular weight, organic, HC coadsorbents based on phenothiazine carboxylic acid derivatives hold promise for highly efficient organic DSSCs. 相似文献