104,899 research outputs found
Comparison of the mesomorphic behaviour of 1:1 and 1:2 mixtures of charged gay-berne GB(4.4,20.0,1,1) and lennard-jones particles
No full textWe present a Molecular Dynamics study of mixtures of charged Gay-Berne (GB) ellipsoids and spherical Lennard-Jones (LJ) particles as models of ionic liquids and ionic liquid crystals. The GB system is highly anisotropic (GB(4.4,20.0,1,1)) and we observe a rich mesomorphism, with ionic nematic and smectic phases in addition to the isotropic mixed phase and crystalline phases with honeycomb structure. The systems have been investigated by analyzing the orientational and translational order parameters, as well as radial distribution functions. We have directly compared 1:1 mixtures, where the GB and LJ particles have a charge equal in magnitude and opposite in sign, and 1:2 mixtures where the number of LJ particles is twice as large compared to the GB and their charge half in magnitude. The results highlight the role of the long-range isotropic electrostatic interaction compared to the short-range van der Waals anisotropic contribution, and the effect of the stoichiometry on the stability of ionic mesophases
MD simulations of mixtures of charged Gay-Berne and Lennard-Jones particles as models of ionic liquid crystals
No full textWe use a simple model of Ionic Liquid Crystals represented by mixtures of positively charged ellipsoidal Gay-Berne particles and negatively charged spherical Lennard-Jones particles. This system will model common ionic liquid crystals, for example those based on symmetrically substituted imidazolium halide salts. The system has been studied using Molecular Dynamics simulations for three different values of the scaled charge (0.0, 0.5, 2.0) at two different number densities (0.30, 0.36) in the NVT ensemble. Radial distribution functions and orientational order parameters have been calculated in order to get more insights on the phase segregation and organization of domains together with a comparison of the van der Waals and coulombic terms of the total interaction energy
Tuning Coulombic interactions to stabilize nematic and smectic ionic liquid crystal phases in mixtures of charged soft ellipsoids and spheres
No full textWe have investigated the effect of electrostatic interactions in mixtures of soft ellipsoids and spheres based on the well-known Gay-Berne (GB) and Lennard-Jones (LJ) potential, respectively. These model systems, in their original version, that is without any electrostatic charge, have been thoroughly investigated in the literature both as pure components and mixtures. In particular, mixtures of particles of different shapes, such as spheres and ellipsoids, tend to phase separate because of the excluded volume effects. Common ionic liquid crystals, based on imidazolium or other quaternary ammonium salts, are usually composed of roughly elongated (although flexible) cations and roughly spherical anions, that is, particles with a similar shape such as the GB and LJ models. Therefore, in this work, we present the results of molecular dynamics simulations of mixtures of positively charged GB and negatively charged LJ particles as models of ionic liquid crystals. Interestingly, by modulating the charge of the particles it is possible to stabilize isotropic, nematic, smectic and crystalline ionic phases. The relative weight of Coulomb (a radial, therefore isotropic interaction) and van der Waals (an anisotropic interaction) contributions is a key parameter to tune the stability of various mesophases. The Royal Society of Chemistry 2017
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Handwritten biographical information on Paulina T. McClung Merritt
No full textA handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Effect of Intraocular Lens Power Calculation Formula Optimization in the Sum-of-Segments Optical Biometer
No full textTakashi Kojima,1,2 Akeno Tamaoki,2 Kazuo Ichikawa,3 Yuya Satoh,4 Ryota Tomemori,5 Keizo Watanabe,6 Asato Hasegawa,2 Ayako Sawaki,2 Tatsushi Kaga2 1Department of Ophthalmology, Nagoya Eye Clinic, Nagoya, Aichi, Japan; 2Department of Ophthalmology, Japanese Community Healthcare Organization Chukyo Hospital, Nagoya, Aichi, Japan; 3Department of Ophthalmology, Chukyo Eye Clinic, Nagoya, Aichi, Japan; 4Department of Ophthalmology, Satoh Yuya Eye Clinic, Sendai, Miyagi, Japan; 5Department of Ophthalmology, Tomemori Eye Clinic, Hashimoto, Wakayama, Japan; 6Department of Ophthalmology, Minami Osaka Eye Clinic, Sennangun, Osaka, JapanCorrespondence: Takashi Kojima, Email [email protected]: We evaluated the effect of optimization of the intraocular lens (IOL) power calculation formula SRK/T and Barrett Universal II (BU II) in long eyes (≥ 26 mm: group L) and short eyes (≤ 22 mm: group S) using axial length calculated from segmented refractive indices (SRI).Setting: Multicenter study at five sites in Japan.Design: Retrospective observational study.Methods: This study included 461 eyes of 461 patients (mean age 73.8 ± 8.4 years) who underwent cataract surgery. The predicted refractive error (PRE) was compared between the SRI (ARGOS) and the equivalent refractive index (ERI) biometers (IOLMasterTM 700). The patients were randomly divided into two groups, a learning group and a validation group. The optimization constants were determined in the learning group, and the optimization constants were subsequently applied to the validation group and compared with the ERI biometer results.Results: Using both SRK/T and BU II, the validation group’s PRE using optimization constants for the SRI biometer in group L was significantly smaller than that using the ERI biometer (p< 0.001, p< 0.01). In group L, the arithmetic PRE of Barrett UII formula with SRI showed a significant improvement after optimization compared to before optimization (p< 0.0001). In group S, the arithmetic PRE of SRK/T and Barrett UII formula with SRI showed a significant improvement (p< 0.0001, p< 0.0001).Conclusion: In long and short eyes, the current study revealed that optimization of the SRK/T and Barrett formula constants for the SRI biometer was beneficial to achieve accurate refractive outcomes after cataract surgery.Keywords: segmented refractive index, intraocular lens power calculation, Sanders-Retzlaff-Kraff theoretic, Barrett universal II, optimizatio
Pelevin’s Trinity in the novel “t”: author – protagonist – reader
No full textThe article attempts to interpret Pelevin's artistic strategy in the novel "T" by exploring its subject organization and addressing the key problems of the author, the protagonist, and the reader as they are seen by the researcher. The article analyzes the peculiarities of constructing the narrative reality in the novel "T", and goes on to discuss Pelevin's philosophic models of the development of the humankind, and the emergence of his new anthropology
Measuring industry-science links through inventor-author relations: A profiling method
No full textIn this pilot study we examine the performance of text-based profiling in recovering a set of validated inventor-author links. In a first step we match patents and publications solely based on their similarity in content. Next, we compare inventor and author names on the highest ranked matches for the occurrence of name matches. Finally, we compare these candidate matches with the names listed in a validated set of inventor-author names. Our text-based profile methodology performs significantly better than a random matching of patents and publications, suggesting that text-based profiling is a valuable complementary tool to the name searches used in previous studies.innovation; industry-science links; text-based profiling;
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