3,606 research outputs found

    Albumin-heparin microspheres as carriers for cytostatic agents

    Get PDF
    Much work has been done on adriamycin-loaded albumin microspheres (Alb-MS) for chemoembolization [1–4], the rationale being that site-specific drug delivery may increase the therapeutic efficacy of the drug. Alb-Ms are being investigated because of their biocompatibility and because the degradation products of these microspheres are non-toxic. However, these microspheres have some disadvantages (i.e. drug loading during the microsphere preparation, low payloads, large burst effects). These disadvantages can be overcome by the incorporation of heparin (a highly negatively charged mucopolysaccharide). Albumin-heparin microspheres were prepared (i) by crosslinking of soluble albumin and heparin first using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and subsequently glutaraldehyde (Alb-Hep-MS) and (ii) by crosslinking a preformed soluble conjugate of heparin and albumin with glutaraldehyde (Alb-Hep-Conj-MS). Albumin-heparin microspheres could be loaded with adriamycin after microsphere preparation giving payloads of 15–30%. Preliminary in vitro adriamycin release experiments showed that Alb-Hep-Conj-MS exhibit sustained release properties. Furthermore ion-exchange properties could be observed both with Alb-Hep-MS and Alb-Hep-Conj-MS. In vitro and in vivo toxicity experiments with Alb-Hep-MS showed no adverse effects

    Wormhole phase in the RST model

    Full text link
    We show that the RST model describing the exactly soluble black hole model can have a dynamical wormhole solution along with an appropriate boundary condition. The necessary exotic matter which is usually negative energy density is remarkably produced by the quantization of the infalling matter fields. Then the asymptotic geometry in the past is two-dimensional anti-de Sitter(AdS2_2), which implies the exotic matter is negative. As time goes on, the wormhole eventually evolves into the black hole and its Hawking radiation appears. The throat of the static RST wormhole is lower-bounded but in the presence of infalling matter it collapses to a black hole.Comment: v1. REVTeX3, 12 pages and 1 figure; v2. JHEP3, 10 pages and 1 figure, version published in JHE

    Observation of correlated-photon statistics using a single detector

    Full text link
    We report experimental observations of correlated-photon statistics in the single-photon detection rate. The usual quantum interference in a two-photon polarization interferometer always accompanies a dip in the single detector counting rate, regardless of whether a dip or peak is seen in the coincidence rate. This effect is explained by taking into account all possible photon number states that reach the detector, rather than considering just the state post-selected by the coincidence measurement. We also report an interferometeric scheme in which the interference peak or dip in coincidence corresponds directly to a peak or dip in the single-photon detection rate.Comment: 4 pages, two-column (minor errors corrected.

    Helicobacter pylori-derived extracellular vesicles increased in the gastric juices of gastric adenocarcinoma patients and induced inflammation mainly via specific targeting of gastric epithelial cells

    Get PDF
    Evidence indicates that Helicobacter pylori is the causative agent of chronic gastritis and perhaps gastric malignancy. Extracellular vesicles (EVs) play an important role in the evolutional process of malignancy due to their genetic material cargo. We aimed to evaluate the clinical significance and biological mechanism of H. pylori EVs on the pathogenesis of gastric malignancy. We performed 16S rDNA-based metagenomic analysis of gastric juices either from endoscopic or surgical patients. From each sample of gastric juices, the bacteria and EVs were isolated. We evaluated the role of H. pylori EVs on the development of gastric inflammation in vitro and in vivo. IVIS spectrum and confocal microscopy were used to examine the distribution of EVs. The metagenomic analyses of the bacteria and EVs showed that Helicobacter and Streptococcus are the two major bacterial genera, and they were significantly increased in abundance in gastric cancer (GC) patients. H. pylori EVs are spherical and contain CagA and VacA. They can induce the production of tumor necrosis factor-��, interleukin (IL)-6 and IL-1�� by macrophages, and IL-8 by gastric epithelial cells. Also, EVs induce the expression of interferon gamma, IL-17 and EV-specific immunoglobulin Gs in vivo in mice. EVs were shown to infiltrate and remain in the mouse stomach for an extended time. H. pylori EVs, which are abundant in the gastric juices of GC patients, can induce inflammation and possibly cancer in the stomach, mainly via the production of inflammatory mediators from gastric epithelial cells after selective uptake by the cells. ? 2017 KSBMB. All rights reserved.115Ysciescopuskc

    Strings on type IIB pp-wave backgrounds with interacting massive theories on the worldsheet

    Full text link
    We consider superstring theories on pp-wave backgrounds which result in an integrable N=(2,2){\cal N}=(2,2) supersymmetric Landau-Ginzburg theory on the worldsheet. We obtain exact eigenvalues of the light-cone gauge superstring hamiltonian in the massive and interacting world-sheet theory with superpotential Z3ZZ^3-Z. We find the modes of the supergravity part of the string spectrum, and their space-time interpretation. Because the system is effectively at strong coupling on the worldsheet, these modes are not in one-to-one correspondence with the usual type IIB supergravity modes in the p0p_{-} \to 0 limit. However, the above correspondence holds in the α0\alpha'\to 0 limit.Comment: 20 pages, 1 figure; minor changes, comments adde

    Perturbation-minimized triangular bunch for high-transformer ratio using a double dogleg emittance exchange beam line

    Get PDF
    The longitudinal shape, i.e., the current profile, of an electron bunch determines the transformer ratio in a collinear wakefield accelerator and thus methods are sought to control the longitudinal bunch shape. The emittance exchange (EEX) appears to be promising for creating a precisely controlled longitudinal bunch shapes. The longitudinal shape is perturbed by two sources: higher-order terms in the beam line optics and collective effects and these perturbations can lead to a significant drop of the transformer ratio. In this paper, we analytically and numerically investigate the perturbation to an ideal triangular longitudinal bunch shape and propose methods to minimize it.1153Ysciescopu

    Interferometric Bell-state preparation using femtosecond-pulse-pumped Spontaneous Parametric Down-Conversion

    Full text link
    We present theoretical and experimental study of preparing maximally entangled two-photon polarization states, or Bell states, using femtosecond pulse pumped spontaneous parametric down-conversion (SPDC). First, we show how the inherent distinguishability in femtosecond pulse pumped type-II SPDC can be removed by using an interferometric technique without spectral and amplitude post-selection. We then analyze the recently introduced Bell state preparation scheme using type-I SPDC. Theoretically, both methods offer the same results, however, type-I SPDC provides experimentally superior methods of preparing Bell states in femtosecond pulse pumped SPDC. Such a pulsed source of highly entangled photon pairs is useful in quantum communications, quantum cryptography, quantum teleportation, etc.Comment: 11 pages, two-column format, to appear in PR

    Vortex pinning in high-Tc materials via randomly oriented columnar defects, created by GeV proton-induced fission fragments

    Full text link
    Extensive work has shown that irradiation with 0.8 GeV protons can produce randomly oriented columnar defects (CD's) in a large number of HTS materials, specifically those cuprates containing Hg, Tl, Pb, Bi, and similar heavy elements. Absorbing the incident proton causes the nucleus of these species to fission, and the recoiling fission fragments create amorphous tracks, i.e., CD's. The superconductive transition temperature Tc decreases linearly with proton fluence and we analyze how the rate depends on the family of superconductors. In a study of Tl-2212 materials, adding defects decreases the equilibrium magnetization Meq(H) significantly in magnitude and changes its field dependence; this result is modeled in terms of vortex pinning. Analysis of the irreversible magnetization and its time dependence shows marked increases in the persistent current density and effective pinning energy, and leads to an estimate for the elementary attempt time for vortex hopping, tau ~ 4x10^(-9) s.Comment: Submitted to Physica C; presentation at ISS-2001. PDF file only, 13 pp. tota

    Modeling of Rotational Nonequilibrium in Post-Normal Shock Flow Analyses

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106447/1/AIAA2013-191.pd
    corecore