1,622 research outputs found
An acoustically-driven biochip - Impact of flow on the cell-association of targeted drug carriers
The interaction of targeted drug carriers with epithelial and endothelial
barriers in vivo is largely determined by the dynamics of the body fluids. To
simulate these conditions in binding assays, a fully biocompatible in vitro
model was developed which can accurately mimic a wide range of physiological
flow conditions on a thumbnail-format cell-chip. This acoustically-driven
microfluidic system was used to study the interaction characteristics of
protein-coated particles with cells. Poly(D,L-lactide-co-glycolide) (PLGA)
microparticles (2.86 {\pm} 0.95 {\mu}m) were conjugated with wheat germ
agglutinin (WGA-MP, cytoadhesive protein) or bovine serum albumin (BSA-MP,
nonspecific protein) and their binding to epithelial cell monolayers was
investigated under stationary and flow conditions. While mean numbers of 1500
{\pm} 307 mm-2 WGA-MP and 94 {\pm} 64 mm-2 BSA-MP respectively were detected to
be cell-bound in the stationary setup, incubation at increasing flow velocities
increasingly antagonized the attachment of both types of surface-modified
particles. However, while binding of BSA-MP was totally inhibited by flow,
grafting with WGA resulted in a pronounced anchoring effect. This was indicated
by a mean number of 747 {\pm} 241 mm-2 and 104 {\pm} 44 mm-2 attached particles
at shear rates of 0.2 s-1 and 1 s-1 respectively. Due to the compactness of the
fluidic chip which favours parallelization, this setup represents a highly
promising approach towards a screening platform for the performance of drug
delivery vehicles under physiological flow conditions. In this regard, the
flow-chip is expected to provide substantial information for the successful
design and development of targeted micro- and nanoparticulate drug carrier
systems.Comment: 19 page
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Visible Wavelength Astro-Comb
We demonstrate a tunable laser frequency comb operating near 420 nm with mode spacing of 20-50 GHz, usable bandwidth of 15 nm and output power per line of ~20 nW. Using the TRES spectrograph at the Fred Lawrence Whipple Observatory, we characterize this system to an accuracy below 1m/s, suitable for calibrating high-resolution astrophysical spectrographs used, e.g., in exoplanet studies.AstronomyPhysic
Association of amino acids and parameters of bone metabolism with endothelial dysfunction and vasculopathic changes in limited systemic sclerosis
ObjectivesPathways contributing to endothelial dysfunction in patients with limited cutaneous systemic sclerosis (lcSSc) are largely unknown. The aim of this study was to investigate potential associations of amino acids and parameters of bone metabolism with endothelial dysfunction and vasculopathy-related changes in patients with lcSSc and early-stage vasculopathy.MethodsAmino acids, calciotropic parameters, including 25-hydroxyvitamin D and parathyroid hormone (PTH), and bone turnover parameters, including osteocalcin and N-terminal peptide of procollagen-3 (P3NP), were measured in 38 lcSSc patients and 38 controls. Endothelial dysfunction was assessed by biochemical parameters, pulse-wave analysis, flow-mediated and nitroglycerine-mediated dilation. Additionally, vasculopathy-related and SSc-specific clinical changes including capillaroscopic, skin, renal, pulmonary, gastrointestinal and periodontal parameters were recorded.ResultsNo significant differences in amino acids, calciotropic and bone turnover parameters were observed between lcSSc patients and controls. In patients with lcSSc, several significant correlations were found between selected amino acids, parameters of endothelial dysfunction, vasculopathy-related and SSc-specific clinical changes (all with p < 0.05). In addition, significant correlations were observed between PTH and 25-hydroxyvitamin D with homoarginine, and between osteocalcin, PTH and P3NP with modified Rodnan skin score and selected periodontal parameters (all with p < 0.05). Vitamin D deficiency defined as 25-hydroxyvitamin D < 20 ng/ml was associated with the presence of puffy finger (p = 0.046) and early pattern (p = 0.040).ConclusionSelected amino acids may affect endothelial function and may be associated to vasculopathy-related and clinical changes in lcSSc patients, while the association with parameters of bone metabolism seems to be minor
AIM2 recognizes cytosolic dsDNA and forms a caspase-1-activating inflammasome with ASC
The innate immune system senses nucleic acids by germline-encoded pattern recognition receptors. RNA is sensed by Toll-like receptor members TLR3, TLR7 and TLR8, or by the RNA helicases RIG-I (also known as DDX58) and MDA-5 (IFIH1). Little is known about sensors for cytoplasmic DNA that trigger antiviral and/or inflammatory responses. The best characterized of these responses involves activation of the TANK-binding kinase (TBK1)-interferon regulatory factor 3 (IRF3) signalling axis to trigger transcriptional induction of type I interferon genes. A second, less well-defined pathway leads to the activation of an 'inflammasome' that, via caspase-1, controls the catalytic cleavage of the pro-forms of the cytokines IL1beta and IL18 (refs 6, 7). Using mouse and human cells, here we identify the PYHIN (pyrin and HIN domain-containing protein) family member absent in melanoma 2 (AIM2) as a receptor for cytosolic DNA, which regulates caspase-1. The HIN200 domain of AIM2 binds to DNA, whereas the pyrin domain (but not that of the other PYHIN family members) associates with the adaptor molecule ASC (apoptosis-associated speck-like protein containing a caspase activation and recruitment domain) to activate both NF-kappaB and caspase-1. Knockdown of Aim2 abrogates caspase-1 activation in response to cytoplasmic double-stranded DNA and the double-stranded DNA vaccinia virus. Collectively, these observations identify AIM2 as a new receptor for cytoplasmic DNA, which forms an inflammasome with the ligand and ASC to activate caspase-1
Quantum theta functions and Gabor frames for modulation spaces
Representations of the celebrated Heisenberg commutation relations in quantum
mechanics and their exponentiated versions form the starting point for a number
of basic constructions, both in mathematics and mathematical physics (geometric
quantization, quantum tori, classical and quantum theta functions) and signal
analysis (Gabor analysis).
In this paper we try to bridge the two communities, represented by the two
co--authors: that of noncommutative geometry and that of signal analysis. After
providing a brief comparative dictionary of the two languages, we will show
e.g. that the Janssen representation of Gabor frames with generalized Gaussians
as Gabor atoms yields in a natural way quantum theta functions, and that the
Rieffel scalar product and associativity relations underlie both the functional
equations for quantum thetas and the Fundamental Identity of Gabor analysis.Comment: 38 pages, typos corrected, MSC class change
\emph{In-situ} determination of astro-comb calibrator lines to better than 10 cm s
Improved wavelength calibrators for high-resolution astrophysical
spectrographs will be essential for precision radial velocity (RV) detection of
Earth-like exoplanets and direct observation of cosmological deceleration. The
astro-comb is a combination of an octave-spanning femtosecond laser frequency
comb and a Fabry-P\'erot cavity used to achieve calibrator line spacings that
can be resolved by an astrophysical spectrograph. Systematic spectral shifts
associated with the cavity can be 0.1-1 MHz, corresponding to RV errors of
10-100 cm/s, due to the dispersive properties of the cavity mirrors over broad
spectral widths. Although these systematic shifts are very stable, their
correction is crucial to high accuracy astrophysical spectroscopy. Here, we
demonstrate an \emph{in-situ} technique to determine the systematic shifts of
astro-comb lines due to finite Fabry-P\'erot cavity dispersion. The technique
is practical for implementation at a telescope-based spectrograph to enable
wavelength calibration accuracy better than 10 cm/s.Comment: 11 pages, 7 figure
European Society of Cardiology: Cardiovascular Disease Statistics 2017
Background: The European Society of Cardiology (ESC) Atlas has been compiled by the European Heart Agency to document cardiovascular disease (CVD) statistics of the 56 ESC member countries. A major aim of this 2017 data presentation has been to compare high income and middle income ESC member countries, in order to identify inequalities in disease burden, outcomes and service provision. Methods: The Atlas utilizes a variety of data sources, including the World Health Organization, the Institute for Health Metrics and Evaluation, and the World Bank to document risk factors, prevalence and mortality of cardiovascular disease and national economic indicators. It also includes novel ESC sponsored survey data of health infrastructure and cardiovascular service provision provided by the national societies of the ESC member countries. Data presentation is descriptive with no attempt to attach statistical significance to differences observed in stratified analyses. Results: Important differences were identified between the high income and middle income member countries of the ESC with regard to CVD risk factors, disease incidence and mortality. For both women and men, the age-standardised prevalence of hypertension was lower in high income countries (18.3% and 27.3%) compared with middle income countries (23.5% and 30.3%). Smoking prevalence in men (not women) was also lower (26% vs 41.3%), and together these inequalities are likely to have contributed to the higher CVD mortality in middle income countries. Declines in CVD mortality have seen cancer becoming a more common cause of death in a number of high income member countries, but in middle income countries declines in CVD mortality have been less consistent where CVD remains the leading cause of death. Inequalities in CVD mortality are emphasised by the smaller contribution they make to potential years of life lost in high income compared with middle income countries both for women (13% vs. 23%) and men (20% vs. 27%). The downward mortality trends for CVD may, however, be threatened by the emerging obesity epidemic that is seeing rates of diabetes increasing across all ESC member countries. Survey data from the National Cardiac Societies (n=41) showed that rates of cardiac catheterization and coronary artery bypass surgery, as well as the number of specialist centres required to deliver them, were greatest in the high income member countries of the ESC. The Atlas confirmed that these ESC member countries, where the facilities for the contemporary treatment of coronary disease were best developed, were often those in which declines in coronary mortality have been most pronounced. Economic resources were not the only driver for delivery of equitable cardiovascular healthcare, as some middle income ESC member countries reported rates for interventional procedures and device implantations that matched or exceeded the rates in wealthier member countries. Conclusion: In documenting national CVD statistics, the Atlas provides valuable insights into the inequalities in risk factors, healthcare delivery and outcomes of CVD across ESC member countries. The availability of these data will underpin the ESC’s ambitious mission “to reduce the burden of cardiovascular disease” not only in its member countries, but also in nation states around the world
Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC
Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe
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