1,935 research outputs found
Cosmic Rays Induced Background Radiation on Board of Commercial Flights
The aim of this work is to determine the total integrated flux of cosmic
radiation which a commercial aircraft is exposed to along specific flight
trajectories. To study the radiation background during a flight and its
modulation by effects such as altitude, latitude, exposure time and transient
magnetospheric events, we perform simulations based on Magnetocosmics and
CORSIKA codes, the former designed to calculate the geomagnetic effects on
cosmic rays propagation and the latter allows us to simulate the development of
extended air showers in the atmosphere. In this first work, by considering the
total flux of cosmic rays from 5 GeV to 1 PeV, we obtained the expected
integrated flux of secondary particles on board of a commercial airplane during
the Bogot\'a-Buenos Aires trip by point-to-point numerical integration.Comment: 5 pages, 2 figures, Proceedings X SILAFAE Medellin-2014. To appear in
Nuclear Physics B - Proceedings Supplement
Development and application of two novel monoclonal antibodies against overexpressed CD26 and integrin α3 in human pancreatic cancer.
Monoclonal antibody (mAb) technology is an excellent tool for the discovery of overexpressed cell surface tumour antigens and the development of targeting agents. Here, we report the development of two novel mAbs against CFPAC-1 human pancreatic cancer cells. Using ELISA, flow cytometry, immunoprecipitation, mass spectrometry, Western blot and immunohistochemistry, we found that the target antigens recognised by the two novel mAbs KU44.22B and KU44.13A, are integrin α3 and CD26 respectively, with high levels of expression in human pancreatic and other cancer cell lines and human pancreatic cancer tissue microarrays. Treatment with naked anti-CD26 mAb KU44.13A did not have any effect on the growth and migration of cancer cells nor did it induce receptor downregulation. In contrast, treatment with anti-integrin α3 mAb KU44.22B inhibited growth in vitro of Capan-2 cells, increased migration of BxPC-3 and CFPAC-1 cells and induced antibody internalisation. Both novel mAbs are capable of detecting their target antigens by immunohistochemistry but not by Western blot. These antibodies are excellent tools for studying the role of integrin α3 and CD26 in the complex biology of pancreatic cancer, their prognostic and predictive values and the therapeutic potential of their humanised and/or conjugated versions in patients whose tumours overexpress integrin α3 or CD26
Scattered light images of spiral arms in marginally gravitationally unstable discs with an embedded planet
Scattered light images of transition discs in the near-infrared often show
non-axisymmetric structures in the form of wide-open spiral arms in addition to
their characteristic low-opacity inner gap region. We study self-gravitating
discs and investigate the influence of gravitational instability on the shape
and contrast of spiral arms induced by planet-disc interactions.
Two-dimensional non-isothermal hydrodynamical simulations including viscous
heating and a cooling prescription are combined with three-dimensional dust
continuum radiative transfer models for direct comparison to observations. We
find that the resulting contrast between the spirals and the surrounding disc
in scattered light is by far higher for pressure scale height variations, i.e.
thermal perturbations, than for pure surface density variations. Self-gravity
effects suppress any vortex modes and tend to reduce the opening angle of
planet-induced spirals, making them more tightly wound. If the disc is only
marginally gravitationally stable with a Toomre parameter around unity, an
embedded massive planet (planet-to-star mass ratio of ) can trigger
gravitational instability in the outer disc. The spirals created by this
instability and the density waves launched by the planet can overlap resulting
in large-scale, more open spiral arms in the outer disc. The contrast of these
spirals is well above the detection limit of current telescopes.Comment: Accepted for publication in MNRAS; 13 pages, 8 figure
Carbon nanotube net as a conductive and transparent film for solar energy conversion
Vertically aligned silicon nanowires arrays have been grown through a metal-assisted chemical etching method, giving a heavily absorbing surface. Over this surface, a transparent and conductive net of carbon nanotubes has been formed by chemical vapour deposition. The optical characterisation of the net has been performed by the study of its hemispherical reflectance, and the electrical properties have been obtained by four-point probe method. A high transmittance of the net (over 99%) in the 300-900 nm range is reported. Also, a good sheet resistance value has been obtained (around 3 kΩ/□) for such a thin carbon nanotube netThis work was supported by MINECO research Project ENE2014-57977-C2-1-
Probabilistic trend detection in different levels of consciousness
We aimed to explore how alertness modulates the management of probabilistic information in order to accurately detect changing patterns in a stream of conflicting evidence. We hypothesized that a decreased level of alertness might disrupt the strategy deployed to approach a probabilistic reversal learning task by impairment of working memory, of integration and value-updating of each piece of evidence, and decreased cognitive control. Our results showed that performance in probabilistic reversal learning is altered in decreased alertness, in relation to a higher frequency of spontaneous switching between patterns. Besides, response time and type suggest an impaired ability to generate a stable evidence-based strategy, although evidence-driven responses are present even in heavy drowsiness
Molecular Dynamics Simulation of Polymer-Metal Bonds
Molecular simulation is becoming a very powerful tool for studying dynamic phenomena in materials. The simulation yields information about interaction at length and time scales unattainable by experimental measurements and unpredictable by continuum theories. This is especially meaningful when referring to bonding between a polymer and a metal substrate. A very important characteristic of polymers is that their physical properties do not rely on the detailed chemical structure of the molecular chains but only on their flexibility, and accordingly they will be able to adopt different conformations. In this paper, a molecular simulation of the bonding between vinyl ester polymer and steel is presented. Four different polymers with increasing chain lengths have been studied. Atomic co-ordinates are adjusted in order to reduce the molecular energy. Conformational changes in the macromolecules have been followed to obtain the polymer pair correlation function. Radius of gyration and end-to-end distance distributions of the individual chains have been used as a quantitative measurement of their flexibility. There exists a correlation between flexibility of the molecular chains and the energy of adhesion between the polymer and the metal substrate. Close contacts between the two materials are established at certain points but every atom up to a certain distance from the interface contributes to the total value of the adhesion energy of the system
A longitudinal retrospective study on intracranial arterial pulsatility index: its evolution in ten years' time and how it relates to the occurrence of cerebral and systemic ischemic disease
BACKGROUND AND AIMS: Intracranial arterial pulsatility index (PI) has been related to old age, hypertension, diabetes and small vessel disease. However, the cross- sectional design of most studies prevents a proper assessment of causality and evolution. We sought to explore how this index changes through time, which conditions affect this evolution and whether or not it can predict the occurrence of future ischemic events. METHODS: Between the years 2001-2006, 1288 patients underwent a transcranial Doppler evaluation in the Department of Neurology of the Hospital Universitario Central de Asturias. PI values for the middle cerebral and basilar arteries were systematically annotated. After exclusion of deceased patients and significant large artery stenoses, 89 patients were recruited for a re-evaluation in 2012. Afterwards, the sample was expanded up to 150 patients, with 61 randomly selected patients –either alive or deceased- who did not undergo a second exploration. Both groups had their clinical files reviewed, with special attention to vascular risk factors and brain or coronary ischemic events. RESULTS AND DISCUSSION: Our results pointed to the following conclusions: • Intracranial arterial PI works as a dynamic measure of both cerebral and systemic vascular disease. • Age is the main factor influencing PI value and variation, but, within a certain age group, PI is able to point subjects at higher long-term risk of future ischemic events. • Basilar artery PI seems to be a better predictor of future cerebral and coronary ischemic disease than middle cerebral artery PI
Workplace wellbeing programmes and their impact on employees and their employing organisations: a scoping review of the evidence base
This report constitutes a scoping literature review that identifies and critically examines the evidence base surrounding health and wellbeing programmes conducted in the workplace and their impact on employees and their employing organisations. The review drew on a broad range of sources covering multiple sectors. However, the report additionally highlights evidence that relates specifically to the retail and construction industries. The review offers an analysis of the current evidence base and discusses the implications of implementing different types of workplace health and wellbeing schemes. Some recommendations for supporting and promoting the health and wellbeing of employees in organisations are made on the basis of this review and, where gaps in knowledge are identified, recommendations for further research are made
- …