214 research outputs found

    Procjena in vitro protoskolicidne učinkovitosti metanolnih biljnih ekstrakata na hidatidne ciste

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    The present study aimed at an evaluation of the protoscolicidal potential of methanolic extracts of three herbs; Ferula asafoetida (dried latex), Trachyspermum ammi (fruits) and Hippophae salicifolia (leaves) at three different concentrations (10, 20 and 30 mg/mL) for 20, 40 and 60 minute treatment intervals, with respect to standard allopathic drug albendazole. The in-vitro viability of the protoscolices was assessed by the Eosin exclusion method. The slope of mortality and lethal concentration for 50% (LC50) was determined from the regression graphs of the probit mortality of protoscolices plotted against log values of increasing concentrations of herbal extracts for 60 minute treatment intervals. The percentage of mortality caused by various extracts at concentrations ranging from 10-30 mg/mL varied from 29.54-97.76% with maximum mortality of 97.76, 97.30 and 81.91% recorded with methanolic extracts of F. asafoetida, T. ammi and H. salicifolia, respectively. Among all the extracts, the highest protoscolicidal activity was exhibited by F. asafoetida at 20 and 30 mg/mL concentrations in the 60 (97.16%) and 40/60 minutes (97.20% and 97.76%) treatments, respectively, and it showed a minimum LC50 value of 0.204, followed by T. ammi at 0.933. As compared to the standard allopathic drug, albendazole, the methanolic extracts of F. asafoetida and T. ammi exhibited better or comparable protoscolicidal activities.Cilj je istraživanja bila procjena protoskolicidnog potencijala metanolnih ekstrakata triju biljaka: Ferula asafoetida (sušena smola), Trachyspermum ammi (voće) i Hippophae salicifolia (lišće) u trima različitim koncentracijama (10, 20 i 30 mg/mL) u 20, 40 i 60-minutnim pokusnim intervalima u odnosu na standardni alopatski lijek albendazol. In vitro vitalnost protoskoleksa procijenjena je metodom isključivanja eozina. Krivulja pomora i smrtonosne koncentracije za 50 % (LC50) određena je iz regresijskih grafikona mortaliteta protoskoleksa u odnosu na log vrijednosti rastućih koncentracija biljnih ekstrakata tijekom 60-minutnog intervala. Pomor uzrokovan različitim ekstraktima u koncentracijama od 10 do 30 mg/mL varirao je od 29,54 do 97,76 % s najvišim postotkom od 97,76, 97,30 i 81,91 % u slučaju metanolnih ekstrakata F. asafoetida, T. ammi i H. salicifolia. Od svih primijenjenih ekstrakata najvišu protoskolicidnu aktivnost imala je F. asafoetida u koncentracijama od 20 i 30 mg/mL tijekom tretmana od 60 (97,16 %) i 40/60 minuta (97,20 i 97,76%), te je pokazala minimalnu vrijednost LC50 od 0,204, praćenu s T. ammi od 0,933. Usporedbom sa standardnim antiparazitikom albendazolom, metanolni ekstrakti biljaka F. asafoetida i T. ammi ostvarili su bolji ili slični protoskolicidni učinak

    Dynamic correlations in symmetric electron-electron and electron-hole bilayers

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    The ground-state behavior of the symmetric electron-electron and electron-hole bilayers is studied by including dynamic correlation effects within the quantum version of Singwi, Tosi, Land, and Sjolander (qSTLS) theory. The static pair-correlation functions, the local-field correction factors, and the ground-state energy are calculated over a wide range of carrier density and layer spacing. The possibility of a phase transition into a density-modulated ground state is also investigated. Results for both the electron-electron and electron-hole bilayers are compared with those of recent diffusion Monte Carlo (DMC) simulation studies. We find that the qSTLS results differ markedly from those of the conventional STLS approach and compare in the overall more favorably with the DMC predictions. An important result is that the qSTLS theory signals a phase transition from the liquid to the coupled Wigner crystal ground state, in both the electron-electron and electron-hole bilayers, below a critical density and in the close proximity of layers (d <~ r_sa_0^*), in qualitative agreement with the findings of the DMC simulations.Comment: 13 pages, 11 figures, 2 table

    Pair distribution function in a two-dimensional electron gas

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    We calculate the pair distribution function, g(r)g(r), in a two-dimensional electron gas and derive a simple analytical expression for its value at the origin as a function of rsr_s. Our approach is based on solving the Schr\"{o}dinger equation for the two-electron wave function in an appropriate effective potential, leading to results that are in good agreement with Quantum Monte Carlo data and with the most recent numerical calculations of g(0)g(0). [C. Bulutay and B. Tanatar, Phys. Rev. B {\bf 65}, 195116 (2002)] We also show that the spin-up spin-down correlation function at the origin, g(0)g_{\uparrow \downarrow}(0), is mainly independent of the degree of spin polarization of the electronic system.Comment: 5 figures, pair distribution dependence with distance is calculate

    A dot enzyme immunoassay for detection of IgM antibodies against phenolic glycolipid-1 in sera from leprosy patients

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    A visual dipstick dot enzyme immunoassay (EIA) for diagnosis of leprosy is described. The assay is based on detection of IgM antibodies against phenolic glycolipid (PGL-I) in sera from leprosy patients. The antigen (PGL-1 or synthetic disaccharide of PGL-I) was dotted on a nitrocellulose pad stuck on a plastic strip (dipstick). Sera were used at a dilution of 1:200. Peroxidase coupled mouse anti-human IgM monoclonal antibodies were used as the conjugate. A positive test gave a blue dot against a white background. The test was highly specific for leprosy, and was quite sensitive for detection of bacilliferous (BL/LL) leprosy. The antigen dotted and preblocked dipsticks stored at room temperature upto 4 months of observation period, were unable in the assay

    Phonon thermal transport in alloyed and hybrid zigzag nanoribbons of gold and silver

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    53-55We have investigated phonon transport in alloyed (Au0.5Ag0.5) and hybrid (AumAgn; here m and n are indices for the width of respective nanoribbons) zigzag nanoribbons of gold and silver. To this endeavour, we have employed the non-equilibrium Green’s function approach integrated with force-field methods as implemented in the General Utility Lattice Program. The phonon thermal conductance kph has been computed and its dependence on width of nanoribbons and temperature has been explored. It has been found that kph increases linearly with the width for the alloyed nanoribbons. However, the hybrid nanoribbons exhibit the linear behavior only for the special case of m=n. The calculated results of kph are compared with the corresponding pristine nanoribbons. Interestingly, we find that both alloying and hybridization result in a significant reduction in kph. For a comparable width, the reduction is more in the alloyed nanoribbons. Thus, our study suggests that alloying may be exploited to suppress the phononic thermal conductance, and hence to enhance the thermoelectric efficiency of nanoribbons

    Multi-dye theranostic nanoparticle platform for bioimaging and cancer therapy

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    Amit K Singh,1,2 Megan A Hahn,2 Luke G Gutwein,3 Michael C Rule,4 Jacquelyn A Knapik,5 Brij M Moudgil,1,2 Stephen R Grobmyer,3 Scott C Brown,2,61Department of Materials Science and Engineering, College of Engineering, 2Particle Engineering Research Center, College of Engineering, 3Division of Surgical Oncology, Department of Surgery, College of Medicine, 4Cell and Tissue Analysis Core, McKnight Brain Institute, 5Department of Pathology, College of Medicine, University of Florida, Gainesville, FL, USA; 6DuPont Central Research and Development, Corporate Center for Analytical Science, Wilmington, DE, USABackground: Theranostic nanomaterials composed of fluorescent and photothermal agents can both image and provide a method of disease treatment in clinical oncology. For in vivo use, the near-infrared (NIR) window has been the focus of the majority of studies, because of greater light penetration due to lower absorption and scatter of biological components. Therefore, having both fluorescent and photothermal agents with optical properties in the NIR provides the best chance of improved theranostic capabilities utilizing nanotechnology.Methods: We developed nonplasmonic multi-dye theranostic silica nanoparticles (MDT-NPs), combining NIR fluorescence visualization and photothermal therapy within a single nanoconstruct comprised of molecular components. A modified NIR fluorescent heptamethine cyanine dye was covalently incorporated into a mesoporous silica matrix and a hydrophobic metallo-naphthalocyanine dye with large molar absorptivity was loaded into the pores of these fluorescent particles. The imaging and therapeutic capabilities of these nanoparticles were demonstrated in vivo using a direct tumor injection model.Results: The fluorescent nanoparticles are bright probes (300-fold enhancement in quantum yield versus free dye) that have a large Stokes shift (&amp;gt;110 nm). Incorporation of the naphthalocyanine dye and exposure to NIR laser excitation results in a temperature increase of the surrounding environment of the MDT-NPs. Tumors injected with these NPs are easily visible with NIR imaging and produce significantly elevated levels of tumor necrosis (95%) upon photothermal ablation compared with controls, as evaluated by bioluminescence and histological analysis.Conclusion: MDT-NPs are novel, multifunctional nanomaterials that have optical properties dependent upon the unique incorporation of NIR fluorescent and NIR photothermal dyes within a mesoporous silica platform.Keywords: bioluminescence, in vivo imaging, mesoporous silica nanoparticles, NIR fluorescence, photothermal ablation, theranosti

    Dynamical Properties and Plasmon Dispersion of a Weakly Degenerate Correlated One-Component Plasma

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    Classical Molecular Dynamics (MD) simulations for a one-component plasma (OCP) are presented. Quantum effects are included in the form of the Kelbg potential. Results for the dynamical structure factor are compared with the Vlasov and RPA (random phase approximation) theories. The influence of the coupling parameter Γ\Gamma, degeneracy parameter ρΛ3\rho \Lambda^3 and the form of the pair interaction on the optical plasmon dispersion is investigated. An improved analytical approximation for the dispersion of Langmuir waves is presented.Comment: 23 pages, includes 7 ps/eps-figures and 2 table

    Efficient light emission from inorganic and organic semiconductor hybrid structures by energy level tuning

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    The fundamental limits of inorganic semiconductors for light emitting applications, such as holographic displays, biomedical imaging and ultrafast data processing and communication, might be overcome by hybridization with their organic counterparts, which feature enhanced frequency response and colour range. Innovative hybrid inorganic/organic structures exploit efficient electrical injection and high excitation density of inorganic semiconductors and subsequent energy transfer to the organic semiconductor, provided that the radiative emission yield is high. An inherent obstacle to that end is the unfavourable energy level offset at hybrid inorganic/organic structures, which rather facilitates charge transfer that quenches light emission. Here, we introduce a technologically relevant method to optimize the hybrid structure's energy levels, here comprising ZnO and a tailored ladder-type oligophenylene. The ZnO work function is substantially lowered with an organometallic donor monolayer, aligning the frontier levels of the inorganic and organic semiconductors. This increases the hybrid structure's radiative emission yield sevenfold, validating the relevance of our approach

    Nebulization of the acidified sodium nitrite formulation attenuates acute hypoxic pulmonary vasoconstriction

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    <p>Abstract</p> <p>Background</p> <p>Generalized hypoxic pulmonary vasoconstriction (HPV) occurring during exposure to hypoxia is a detrimental process resulting in an increase in lung vascular resistance. Nebulization of sodium nitrite has been shown to inhibit HPV. The aim of this project was to investigate and compare the effects of nebulization of nitrite and different formulations of acidified sodium nitrite on acute HPV.</p> <p>Methods</p> <p><it>Ex vivo </it>isolated rabbit lungs perfused with erythrocytes in Krebs-Henseleit buffer (adjusted to 10% hematocrit) and <it>in vivo </it>anesthetized catheterized rabbits were challenged with periods of hypoxic ventilation alternating with periods of normoxic ventilation. After baseline hypoxic challenges, vehicle, sodium nitrite or acidified sodium nitrite was delivered via nebulization. In the <it>ex vivo </it>model, pulmonary arterial pressure and nitric oxide concentrations in exhaled gas were monitored. Nitrite and nitrite/nitrate were measured in samples of perfusion buffer. Pulmonary arterial pressure, systemic arterial pressure, cardiac output and blood gases were monitored in the <it>in vivo </it>model.</p> <p>Results</p> <p>In the <it>ex vivo </it>model, nitrite nebulization attenuated HPV and increased nitric oxide concentrations in exhaled gas and nitrite concentrations in the perfusate. The acidified forms of sodium nitrite induced higher levels of nitric oxide in exhaled gas and had longer vasodilating effects compared to nitrite alone. All nitrite formulations increased concentrations of circulating nitrite to the same degree. In the <it>in vivo </it>model, inhaled nitrite inhibited HPV, while pulmonary arterial pressure, cardiac output and blood gases were not affected. All nitrite formulations had similar potency to inhibit HPV. The tested concentration of appeared tolerable.</p> <p>Conclusion</p> <p>Nitrite alone and in acidified forms effectively and similarly attenuates HPV. However, acidified nitrite formulations induce a more pronounced increase in nitric oxide exhalation.</p
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