2,760 research outputs found

    Topological Quantum Phase Transition in Synthetic Non-Abelian Gauge Potential

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    The method of synthetic gauge potentials opens up a new avenue for our understanding and discovering novel quantum states of matter. We investigate the topological quantum phase transition of Fermi gases trapped in a honeycomb lattice in the presence of a synthetic non- Abelian gauge potential. We develop a systematic fermionic effective field theory to describe a topological quantum phase transition tuned by the non-Abelian gauge potential and ex- plore its various important experimental consequences. Numerical calculations on lattice scales are performed to compare with the results achieved by the fermionic effective field theory. Several possible experimental detection methods of topological quantum phase tran- sition are proposed. In contrast to condensed matter experiments where only gauge invariant quantities can be measured, both gauge invariant and non-gauge invariant quantities can be measured by experimentally generating various non-Abelian gauges corresponding to the same set of Wilson loops

    The preparation, characterization, and pharmacokinetic studies of chitosan nanoparticles loaded with paclitaxel/dimethyl-β-cyclodextrin inclusion complexes.

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    A novel biocompatible and biodegradable drug-delivery nanoparticle (NP) has been developed to minimize the severe side effects of the poorly water-soluble anticancer drug paclitaxel (PTX) for clinical use. PTX was loaded into the hydrophobic cavity of a hydrophilic cyclodextrin derivative, heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD), using an aqueous solution-stirring method followed by lyophilization. The resulting PTX/DM-β-CD inclusion complex dramatically enhanced the solubility of PTX in water and was directly incorporated into chitosan (CS) to form NPs (with a size of 323.9–407.8 nm in diameter) using an ionic gelation method. The formed NPs had a zeta potential of +15.9–23.3 mV and showed high colloidal stability. With the same weight ratio of PTX to CS of 0.7, the loading efficiency of the PTX/DM-β-CD inclusion complex-loaded CS NPs was 30.3-fold higher than that of the PTX-loaded CS NPs. Moreover, it is notable that PTX was released from the DM-β-CD/CS NPs in a sustained-release manner. The pharmacokinetic studies revealed that, compared with reference formulation (Taxol(®)), the PTX/DM-β-CD inclusion complex-loaded CS NPs exhibited a significant increase in AUC(0→24h) (the area under the plasma drug concentration–time curve over the period of 24 hours) and mean residence time by 2.7-fold and 1.4-fold, respectively. Therefore, the novel drug/DM-β-CD inclusion complex-loaded CS NPs have promising applications for the significantly improved delivery and controlled release of the poorly water-soluble drug PTX or its derivatives, thus possibly leading to enhanced therapeutic efficacy and less severe side effects

    Comparison of the Accuracy of HSV1 and HSV2 Antibody Tests with PCR in the Diagnosis of Recurrent Genital Herpes

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    Jia Deng, Yu-Jian Ye, Qiu-Ping Chen, Yi-Jin Zhang, Ji-Feng Liu Department of Dermatology, Hangzhou Third People’s Hospital, Hangzhou, People’s Republic of ChinaCorrespondence: Ji-Feng Liu, Department of Dermatology, Hangzhou Third People’s Hospital, No. 38 of West Lake Road, Shangcheng District, Hangzhou, Zhejiang, 310009, People’s Republic of China, Tel/Fax +86 0571-87827514, Email [email protected]: To assess the accuracy of HSV1and HSV2 antibody testing in identifying genital herpes infection.Methods: A cohort of 299 patients previously diagnosed with recurrent genital herpes, confirmed via PCR, were tested using ELISA for HSV1 and HSV2 IgM and IgG antibodies. The study compared the accuracy of HSV1 and HSV2 antibody tests in diagnosing genital herpes.Results: Among 299 patients, 14 tested positives for HSV1 DNA. Of these, 9 had HSV1 IgG antibodies, but none had HSV2 IgG antibody. Among 278 patients with HSV2 DNA, 149 had HSV1 IgG, 9 had HSV2 IgG, and 97 had both. Seven patients had both HSV1 and HSV2 DNA; 3 had HSV1 IgG, 1 had HSV2 IgG, and 3 had both. The accuracy of HSV1 IgG for HSV1 infection was 64.2%, and for HSV1 and HSV2 co-infection, 85.7%. The accuracy of HSV2 IgG for HSV2 infection was 38.1%, and for HSV1 and HSV2 co-infection, 57.1%. The combined antibody positivity accuracy was 34.9%.Conclusion: Genital herpes is primarily caused by HSV2 (92.98%). A smaller percentage is HSV1 (4.67%) or co-infection (2.34%). Despite relatively low diagnostic accuracy (34.9– 85.7%) for antibody detection, combined antibody testing is necessary. Herpes DNA testing is recommended for accurate diagnosis. Absence of antibodies does not rule out genital herpes and clinical assessment is essential.Keywords: antibody test, DNA test, genital herpes, HSV-1, HSV-

    Design of arbitrarily shaped planar microstrip antenna arrays with improved efficiency

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    A design technique is described for an arbitrarily shaped planar microstrip antenna array with improved radiation efficiency. In order to fully utilize the limited antenna aperture, several basic modules are proposed from which we construct the array. A consideration of the aperture shape shows that with several practical examples a proper combination of these basic modules not only allows the convenient design of arbitrarily-shaped microstrip array, but also helps to improve the aperture radiation efficiency. To confirm the feasibility of the approach, a circular array with 256 elements was constructed and fabricated. Both computed and measured aperture radiation results are compared and these demonstrate that the design technique is effective for arbitrarily-shaped planar microstrip arrays. © 2013 Sheng Ye et al

    Extent of Safety Database in Pediatric Drug Development: Types of Assessment, Analytical Precision, and Pathway for Extrapolation through On-Target Effects

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    Pediatric patients should have access to medicines that have been appropriately evaluated for safety and efficacy. Given this goal of revised labelling, the adequacy of the pediatric clinical development plan and resulting safety database must inform a favorable benefit-risk assessment for the intended use of the medicinal product. While extrapolation from adults can be used to support efficacy of drugs in children, there may be a reluctance to use the same approach in safety assessments, wiping out potential gains in trial efficiency through a reduction of sample size. To address this reluctance, we explore safety review in pediatric trials, including factors affecting these data, specific types of safety assessments, and precision on the estimation of event rates for specific adverse events (AEs) that can be achieved. In addition, we discuss the assessments which can provide a benchmark for the use of extrapolation of safety that focuses on on-target effects. Finally, we explore a unified approach for understanding precision using Bayesian approaches as the most appropriate methodology to describe/ascertain risk in probabilistic terms for the estimate of the event rate of specific AEs

    Mining features of products from Chinese customer online reviews

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    2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Computational Complexity of Atomic Chemical Reaction Networks

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    Informally, a chemical reaction network is "atomic" if each reaction may be interpreted as the rearrangement of indivisible units of matter. There are several reasonable definitions formalizing this idea. We investigate the computational complexity of deciding whether a given network is atomic according to each of these definitions. Our first definition, primitive atomic, which requires each reaction to preserve the total number of atoms, is to shown to be equivalent to mass conservation. Since it is known that it can be decided in polynomial time whether a given chemical reaction network is mass-conserving, the equivalence gives an efficient algorithm to decide primitive atomicity. Another definition, subset atomic, further requires that all atoms are species. We show that deciding whether a given network is subset atomic is in NP\textsf{NP}, and the problem "is a network subset atomic with respect to a given atom set" is strongly NP\textsf{NP}-Complete\textsf{Complete}. A third definition, reachably atomic, studied by Adleman, Gopalkrishnan et al., further requires that each species has a sequence of reactions splitting it into its constituent atoms. We show that there is a polynomial-time algorithm\textbf{polynomial-time algorithm} to decide whether a given network is reachably atomic, improving upon the result of Adleman et al. that the problem is decidable\textbf{decidable}. We show that the reachability problem for reachably atomic networks is Pspace\textsf{Pspace}-Complete\textsf{Complete}. Finally, we demonstrate equivalence relationships between our definitions and some special cases of another existing definition of atomicity due to Gnacadja

    Chromosome 1p13 genetic variants antagonize the risk of myocardial infarction associated with high ApoB serum levels

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    PMCID: PMC3480949This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
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