456 research outputs found

    Phase behavior of hard spheres confined between parallel hard plates: Manipulation of colloidal crystal structures by confinement

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    We study the phase behavior of hard spheres confined between two parallel hard plates using extensive computer simulations. We determine the full equilibrium phase diagram for arbitrary densities and plate separations from one to five hard-sphere diameters using free energy calculations. We find a first-order fluid-solid transition, which corresponds to either capillary freezing or melting depending on the plate separation. The coexisting solid phase consists of crystalline layers with either triangular or square symmetry. Increasing the plate separation, we find a sequence of crystal structures from n triangular to (n+1) square to (n+1) triangular, where n is the number of crystal layers, in agreement with experiments on colloids. At high densities, the transition between square to triangular phases are intervened by intermediate structures, e.g., prism, buckled, and rhombic phases.Comment: 9 pages, 4 figures. Accepted for publication in J. Phys.: Condens. Matte

    Stable crystalline lattices in two-dimensional binary mixtures of dipolar particles

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    The phase diagram of binary mixtures of particles interacting via a pair potential of parallel dipoles is computed at zero temperature as a function of composition and the ratio of their magnetic susceptibilities. Using lattice sums, a rich variety of different stable crystalline structures is identified including AmBnA_mB_n structures. [AA (B)(B) particles correspond to large (small) dipolar moments.] Their elementary cells consist of triangular, square, rectangular or rhombic lattices of the AA particles with a basis comprising various structures of AA and BB particles. For small (dipolar) asymmetry there are intermediate AB2AB_2 and A2BA_2B crystals besides the pure AA and BB triangular crystals. These structures are detectable in experiments on granular and colloidal matter.Comment: 6 pages - 2 figs - phase diagram update

    First report on the lipid composition of milk from livestock in Cuba Primer informe de la composición lipídica de la leche en ganado de interés económico en Cuba

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    In the framework of the project IBEROFUN «Incorporation of new functional ingredients to food as a contribution to health promotion and/or prevention of diseases of the Latin American population», Ref: 110AC0386, a collaborative work on the lipid composition of milk from cows, buffaloes and goats was carried out by the National Center for Animal and Plant Health (CENSA) and the Research Institute of Food Science (CIAL) in Spain

    901-5 Intravenous Amiodarone Restores Sinus Rhythm in Acute Myocardial Infarction Complicated with Atrial Fibrillation

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    The effectiveness and tolerance of intravenous (IV) amiodarone (Am) in atrialfibrillation (AF) complicated acute myocardial infarction (AMI) is not well studied. Thus, twenty patients (Pts) with AMI complicated with AF occurring within 30h (11.9 ± 10) of the onset of AMI symptoms were treated with IV administration of digitalis (d, 0.5mg and an additional 0.25mg later) followed by IV Am 300mg over 2h (starting 2h after the initial dose of d) and followed by 44mg/h for up to 3 days, if sinus rhythm (SR) was not restored. Intravenous d restored SR within 2h in 5/20pts. AF relapsed in 2 of them. Subsequent administration of Am for 2 h restored SR in the remaining 15/20pts and in the 2pts in whom AF had relapsed after the initial restoration of SR by d. Am restored SR within an average of 12.8 (range 0.5–56) h of infusion. Total dose of Am was 1922 ± 720mg in 4pts and 425 ± 241mg in the remaining 13. Am was well tolerated by all pts including 1 with cardiogenic shock assisted with the intraaortic balloon pump. In conclusion, IV Am administration ishighly effective in restoring sinusrhythm in AF complicating AMI and is well tolerated

    Nanocrystalline tin oxide nanofibers deposited by a novel focused electrospinning method. Application to the detection of TATP precursors

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    A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP) in air in the ppm range. High and fast responses to these gases have been obtained. © 2014 by the authors; licensee MDPI, Basel, Switzerland.This work has been supported by the Spanish Science and Innovation Ministry under the projects TEC2010-21357-C05-04 and TEC2013-48147-C6-4-R. Authors want to thank University of Extremadura for SEM and XRD analysis. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe

    Surface-charge-induced freezing of colloidal suspensions

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    Using grand-canonical Monte Carlo simulations we investigate the impact of charged walls on the crystallization properties of charged colloidal suspensions confined between these walls. The investigations are based on an effective model focussing on the colloids alone. Our results demonstrate that the fluid-wall interaction stemming from charged walls has a crucial impact on the fluid's high-density behavior as compared to the case of uncharged walls. In particular, based on an analysis of in-plane bond order parameters we find surface-charge-induced freezing and melting transitions

    Love-Wave Sensors Combined with Microfluidics for Fast Detection of Biological Warfare Agents

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    The following paper examines a time-efficient method for detecting biological warfare agents (BWAs). The method is based on a system of a Love-wave immunosensor combined with a microfluidic chip which detects BWA samples in a dynamic mode. In this way a continuous flow-through of the sample is created, promoting the reaction between antigen and antibody and allowing a fast detection of the BWAs. In order to prove this method, static and dynamic modes have been simulated and different concentrations of BWA simulants have been tested with two immunoreactions: phage M13 has been detected using the mouse monoclonal antibody anti-M13 (AM13), and the rabbit immunoglobulin (Rabbit IgG) has been detected using the polyclonal antibody goat anti-rabbit (GAR). Finally, different concentrations of each BWA simulants have been detected with a fast response time and a desirable level of discrimination among them has been achieved.This work was supported by the Spanish Science and Innovation Ministry under the project TEC2010-21357-C05-04, and a postdoctoral fellowship at the National Autonomous University of Mexico.We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer reviewe

    Preclinical Efficacy of Cabazitaxel Loaded Poly (2-alkyl cyanoacrylate) Nanoparticle Variants

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    \ua9 2024 Valsalakumari et al. This work is published and licensed by Dove Medical Press Limited.Background: Biodegradable poly(alkyl cyanoacrylate) (PACA) nanoparticles (NPs) are receiving increasing attention in anti-cancer nanomedicine development not only for targeted cancer chemotherapy, but also for modulation of the tumor microenvironment. We previously reported promising results with cabazitaxel (CBZ) loaded poly(2-ethylbutyl cyanoacrylate) NPs (PEBCA-CBZ NPs) in a patient derived xenograft (PDX) model of triple-negative breast cancer, and this was associated with a decrease in M2 macrophages. The present study aims at comparing two endotoxin-free PACA NP variants (PEBCA and poly(2-ethylhexyl cyanoacrylate); PEHCA), loaded with CBZ and test whether conjugation with folate would improve their effect. Methods: Cytotoxicity assays and cellular uptake of NPs by flow cytometry were performed in different breast cancer cells. Biodistribution and efficacy studies were performed in PDX models of breast cancer. Tumor associated immune cells were analyzed by multiparametric flow cytometry. Results: In vitro studies showed similar NP-induced cytotoxicity patterns despite difference in early NP internalization. On intravenous injection, the liver cleared the majority of NPs. Efficacy studies in the HBCx39 PDX model demonstrated an enhanced effect of drug-loaded PEBCA variants compared with free drug and PEHCA NPs. Furthermore, the folate conjugated PEBCA variant did not show any enhanced effects compared with the unconjugated counterpart which might be due to unfavorable orientation of folate on the NPs. Finally, analyses of the immune cell populations in tumors revealed that treatment with drug loaded PEBCA variants affected the myeloid cells, especially macrophages, contributing to an inflammatory, immune activated tumor microenvironment. Conclusion: We report for the first time, comparative efficacy of PEBCA and PEHCA NP variants in triple negative breast cancer models and show that CBZ-loaded PEBCA NPs exhibit a combined effect on tumor cells and on the tumor associated myeloid compartment, which may boost the anti-tumor response
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