1,435 research outputs found
Photoacoustic Signal Enhancement by Localized Surface Plasmon of Gold Nanoparticles
Photoacoustic imaging has been widely studied as a deep biological tissue imaging modality combining
optical absorption and ultrasonic detection. It enables multi-scale high resolution imaging of optical absorbing
intrinsic molecules as well as exogenous molecules. Gold nanoparticles have the primary advantages
of large absorption cross section and bioconjugation capability for the imaging contrast agents. In
order to design the photoacoustic imaging agents for enhancing the contrast with high specificity to targeted
molecules and / or cell, we measured and analyzed time-of-flight photoacoustic signals of aqueous solutions
of various shapes and sizes of gold nanoparticles. The signal intensities were sensitive to the shapes
and sizes of the gold nanoparticles. We found a strong photoacoustic signal of the polyhedral gold nanoparticle
due to the localized surface plasmon resonance. The experimental results derive the strategy of designing
the optimum photoacoustic contrast agents.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3543
Exceeding classical capacity limit in quantum optical channel
The amount of information transmissible through a communications channel is
determined by the noise characteristics of the channel and by the quantities of
available transmission resources. In classical information theory, the amount
of transmissible information can be increased twice at most when the
transmission resource (e.g. the code length, the bandwidth, the signal power)
is doubled for fixed noise characteristics. In quantum information theory,
however, the amount of information transmitted can increase even more than
twice. We present a proof-of-principle demonstration of this super-additivity
of classical capacity of a quantum channel by using the ternary symmetric
states of a single photon, and by event selection from a weak coherent light
source. We also show how the super-additive coding gain, even in a small code
length, can boost the communication performance of conventional coding
technique.Comment: 4 pages, 3 figure
Kinetic modeling and microbial assessment by fluorescent in situ hybridization in anaerobic sequencing batch biofilm reactors treating sulfate-rich wastewater
This paper reports the results of applying anaerobic sequencing batch biofilm reactors (AnSBBR) for treating sulfate-rich wastewater. The reactor was filled with polyurethane foam matrices or with eucalyptus charcoal, used as the support for biomass attachment. Synthetic wastewater was prepared with two ratios between chemical oxygen demand (COD) and sulfate concentration (COD/SO4(2-)) of 0.4 and 3.2. For a COD/SO4(2-) ratio of 3.2, the AnSBBR performance was influenced by the support material used; the average levels of organic matter removal were 67% and 81% in the reactors filled with polyurethane foam and charcoal, respectively, and both support materials were associated with similar levels of sulfate reduction (above 90%). In both reactors, sulfate-reducing bacteria (SRB) represented more than 65% of the bacterial community. The kinetic model indicated equilibrium between complete- and incomplete-oxidizing SRB in the reactor filled with polyurethane foam and predominantly incomplete-oxidizing SRB in the reactor filled with charcoal. Methanogenic activity seems to have been the determining factor to explain the better performance of the reactor filled with charcoal to remove organic matter at a COD/SO4(2-) ratio of 3.2. For a COD/SO4(2-) ratio of 0.4, low values of sulfate reduction (around 32%) and low reaction rates were observed as a result of the small SRB population (about 20% of the bacterial community). Although the support material did not affect overall performance for this condition, different degradation pathways were observed; incomplete oxidation of organic matter by SRB was the main kinetic pathway and methanogenesis was negligible in both reactors.This work was funded by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and the Financiadora de Estudos e Projetos (FINEP), Brazil. The authors acknowledge the grants received from FAPESP and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazi
Large mass dileptons from the passage of jets through quark gluon plasma
We calculate the emission of large mass dileptons originating from the
annihilation of quark jets passing through quark gluon plasma. Considering
central collisions of heavy nuclei at SPS, RHIC and LHC energies, we find that
the yield due to the jet-plasma interaction gets progressively larger as the
collision energy increases. We find it to be negligible at SPS energies, of the
order of the Drell-Yan contribution and much larger than the normal thermal
yield at RHIC energies and up to a factor of ten larger than the Drell-Yan
contribution at LHC energies. An observation of this new dilepton source would
confirm the occurrence of jet-plasma interactions and of conditions suitable
for jet-quenching to take place.Comment: 9 pages, 11 figures; references added, improved calculation,
conclusions unchange
Vasorelaxant activity of indole alkaloids from Tabernaemontana dichotoma.
The aim of this study was to search for bioactive natural products from medicinal plants targeting vasorelaxant activity and we found the methanol extract from bark of Tabernaemontana dichotoma showed vasorelaxant activity on rat aorta. We isolated eight indole alkaloids including 10-methoxyalstonerine (1), a new macroline type indole alkaloid, from bark of T. dichotoma. These were respectively identified as 10-methoxyaffinisine (2), lochnerine (3), cathafoline (4), (−)-alstonerine (5), 19,20-dehydro-10-methoxytalcarpine (6), alstonisine (7), and alstonal (8) based on spectroscopic analysis. Among them, sarpagine type (2 and 3), akuammiline type (4), and macroline oxindole type (7 and 8) showed potent vasorelaxant activity. Mechanism of action on vasorelaxant activity of 10-methoxyaffinisine (2), cathafoline (4), and alstonisine (7) was clarified. Effects of 10-methoxyaffinisine (2), cathafoline (4), and alstonisine (7) were partially mediated the NO release from endothelial cells. Furthermore, 10-methoxyaffinisine (2) and alstonisine (7) attribute to the inhibitory effect of VDC and ROC, and cathafoline (4) have inhibitory effect on Ca2+ influx via ROC. In addition, 10-methoxyaffinisine (2) as a major compound from bark of T. dichotoma showed hypotensive effect on normotensive rats in vivo
Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.
The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
Male antene: postupci smanjivanja izmjera i primjene
The paper presents research results in the field of small antennas obtained at the Department of Wireless Communications, Faculty of Electrical Engineering and Computing, University of Zagreb. A study comparing the application of several miniaturization techniques on a shorted patch antenna is presented. Single and dual band shorted patch antennas with notches and/or slot are introduced. A PIFA designed for application in mobile GSM terminals is described. The application of stacked shorted patches as array elements for a mobile communication base station as well as for electromagnetic field sensor is presented. The design of single and dual band folded monopoles is described. Prototypes of the presented antennas have been manufactured and their characteristics were verified by measurements.U radu su prikazani rezultati istraživanja u području malih antena ostvareni na Zavodu za Radiokomunikacije, Sveučilišta u Zagrebu Fakulteta elektrotehnike i računarstva. Prikazana je primjena više postupaka za smanjivanje izmjera skraćene mikrotrakaste antene. Opisane su izvedbe skraćenih mikrotrakastih antena s urezima i prorezom za rad u jednom i u dva frekvencijska područja. Prikazana je izvedba planarne invertirane F-antene (PIFA) za primjenu u ručnim terminalima sustava pokretnih komunikacija GSM. Višeslojne skraćene mikrotrakaste antene uporabljene su za izvedbu antenskog niza za baznu postaju sustava pokretnih komunikacija te kao elementi osjetila za mjerenje jakosti elektromagnetskog polja. Prikazana je izvedba savijenih monopolnih antena za rad u jednom te u dva frekvencijska pojasa. Izrađeni su prototipovi opisanih antena i mjerenjima su ispitane njihove osobine
The Formation and Evolution of the First Massive Black Holes
The first massive astrophysical black holes likely formed at high redshifts
(z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations.
These black holes grow by mergers and gas accretion, evolve into the population
of bright quasars observed at lower redshifts, and eventually leave the
supermassive black hole remnants that are ubiquitous at the centers of galaxies
in the nearby universe. The astrophysical processes responsible for the
formation of the earliest seed black holes are poorly understood. The purpose
of this review is threefold: (1) to describe theoretical expectations for the
formation and growth of the earliest black holes within the general paradigm of
hierarchical cold dark matter cosmologies, (2) to summarize several relevant
recent observations that have implications for the formation of the earliest
black holes, and (3) to look into the future and assess the power of
forthcoming observations to probe the physics of the first active galactic
nuclei.Comment: 39 pages, review for "Supermassive Black Holes in the Distant
Universe", Ed. A. J. Barger, Kluwer Academic Publisher
Analysis of ground reaction force and electromyographic activity of the gastrocnemius muscle during double support
O documento em anexo encontra-se na versão post-print (versão corrigida pelo editor).Purpose: Mechanisms associated with energy expenditure during gait have been extensively researched and studied. According to the double-inverted pendulum model energy expenditure is higher during double support, as lower limbs need to work to redirect the centre of mass velocity. This study looks into how the ground reaction force (GRF) of one limb affects the muscle activity required by the medial gastrocnemius (MG) of the contralateral limb during step-to-step transition. Methods: Thirty-five subjects were monitored as to the MG electromyographic activity (EMGa) of one limb and the GRF of the contralateral limb during double support. Results: After determination of the Pearson correlation coefficient (r), a moderate correlation was observed between the MG EMGa of the dominant leg and the vertical (Fz) and anteroposterior (Fy) components of GRF of the non-dominant leg (r=0.797, p<0.0001; r=-0.807, p<0.0001) and a weak and moderate correlation was observed between the MG EMGa of the non-dominant leg and the Fz and Fy of the dominant leg, respectively (r=0.442, p=0.018; r=-0.684 p<0.0001). Conclusions: The results obtained suggest that during double support, GRF is
associated with the EMGa of the contralateral MG and that there is an increased dependence between the GRF of the non-dominant leg and the EMGa of the dominant MG
Immunotherapy: is a minor god yet in the pantheon of treatments for lung cancer?
Immunotherapy has been studied for many years in lung cancer without significant results, making the majority of oncologists quite skeptical about its possible application for non-small cell lung cancer treatment. However, the recent knowledge about immune escape and subsequent 'cancer immunoediting' has yielded the development of new strategies of cancer immunotherapy, heralding a new era of lung cancer treatment. Cancer vaccines, including both whole-cell and peptide vaccines have been tested both in early and advanced stages of non-small cell lung cancer. New immunomodulatory agents, including anti-CTLA4, anti-PD1/PDL1 monoclonal antibodies, have been investigated as monotherapy in metastatic lung cancer. To date, these treatments have shown impressive results of efficacy and tolerability in early clinical trials, leading to testing in several large, randomized Phase III trials. As these results will be confirmed, these drugs will be available in the near future, offering new exciting therapeutic options for lung cancer treatment
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