42 research outputs found
A submarine volcanic eruption leads to a novel microbial habitat
Submarine volcanic eruptions are major catastrophic events that allow investigation of the colonization mechanisms of newly
formed seabed. We explored the seafloor after the eruption of the Tagoro submarine volcano off El Hierro Island, Canary
Archipelago. Near the summit of the volcanic cone, at about 130 m depth, we found massive mats of long, white filaments that we
named Venus’s hair. Microscopic and molecular analyses revealed that these filaments are made of bacterial trichomes enveloped
within a sheath and colonized by epibiotic bacteria. Metagenomic analyses of the filaments identified a new genus and species
of the order Thiotrichales, Thiolava veneris. Venus’s hair shows an unprecedented array of metabolic pathways, spanning from
the exploitation of organic and inorganic carbon released by volcanic degassing to the uptake of sulfur and nitrogen compounds.
This unique metabolic plasticity provides key competitive advantages for the colonization of the new habitat created by the submarine eruption. A specialized and highly diverse food web thrives on the complex three-dimensional habitat formed by these
microorganisms, providing evidence that Venus’s hair can drive the restart of biological systems after submarine volcanic eruption
Neutron radiobiology studies with a pure cold neutron beam
Data on the radiobiological effects of thermal neutrons are usually obtained from irradiations in a mixed field of
neutrons of different energies and gamma rays or from conversion of proton data with similar energies to those
created in the neutron capture on nitrogen. Experimental data from irradiations in a pure thermal or cold
neutron beam can help to find new values for neutron relative biological effectiveness (RBE) factors, which are
useful for BNCT (Boron Neutron Capture Therapy) and radiation protection applications. We present a new
experimental setup for radiobiological studies at a cold neutron beam at Institut Laue-Langevin, a beam without
fast neutron component and almost no gamma ray contribution. After the irradiation, survival assays are performed
to obtain the survival curves. Finally, comparing with a reference photon irradiation, the thermal
neutron RBE factors can be calculated. The methodology is outlined at the example of A375 melanoma cells for
which new radiobiological data were obtained.We acknowledge financial support for this work from the Fundación
Científica de la Asociación Española Contra el Cáncer (AECC) under
grant PS16163811PORR, Junta de Andalucía (Andalusian Regional
Government), under contract P11-FQM-8229, Spanish MINECO and
FEDER funds under contract FIS2015-69941-C2-1-P, the grant agreement
ILL-UGR and the founders of the University of Granada Chair
Neutrons for Medicine: Spanish Fundación ACS and Capitán Antonio.
M.P. acknowledges a grant under the program Becas de Iniciación a la Investigación from the Universidad de Granada (Plan Propio de
Investigación). The open access fee was covered by FILL2030, a
European Union project within the European Commission’s
Horizon 2020 Research and Innovation programme under grant
agreement N°731096
Thermal Neutron Relative Biological Effectiveness Factors for Boron Neutron Capture Therapy from In Vitro Irradiations
The experimental determination of the relative biological effectiveness of thermal neutron
factors is fundamental in Boron Neutron Capture Therapy. The present values have been obtained
while using mixed beams that consist of both neutrons and photons of various energies. A common
weighting factor has been used for both thermal and fast neutron doses, although such an approach has
been questioned. At the nuclear reactor of the Institut Laue-Langevin a pure low-energy neutron beam
has been used to determine thermal neutron relative biological effectiveness factors. Different cancer
cell lines, which correspond to glioblastoma, melanoma, and head and neck squamous cell carcinoma,
and non-tumor cell lines (lung fibroblast and embryonic kidney), have been irradiated while using
an experimental arrangement designed to minimize neutron-induced secondary gamma radiation.
Additionally, the cells were irradiated with photons at a medical linear accelerator, providing reference
data for comparison with that from neutron irradiation. The survival and proliferation were studied
after irradiation, yielding the Relative Biological Effectiveness that corresponds to the damage of
thermal neutrons for the different tissue types.Asociacion Espanola Contra el Cancer (AECC)
PS16163811PORRSpanish MINECO
FIS2015-69941-C2-1-PJunta de Andalucia
P11-FQM-8229Campus of International Excellence BioTic
P-BS-64University of Granada Chair Neutrons for Medicine: the Spanish Fundacion ACSAsociacion Capitan AntonioFundacion ACSLa Kuadrilla de IznallozSonriendo Se Puede Gana
Radiobiology data of melanoma cells after low-energy neutron irradiation and boron compound administration
The cold neutron beam at the PF1b line at the Institut Laue-Langevin (ILL), without fast neutrons and a low contribution of gamma rays, is a very suitable facility to measure cell damage following low-energy neutron irradiation. The biological damage associated with the thermal and the boron doses can be obtained in order to evaluate the relative biological effectiveness (RBE) for Boron Neutron Capture Therapy. Three different experiments were carried out on the A375 melanoma cell line: the first one in a hospital LINAC, to obtain the reference radiation data, and the other two at the ILL, in which the damage to cells with and without boron compounds added was measured
Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites
The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions.
The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness
of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence
were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density
and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that
the wood in the starch composites did not prevent water loss from the samples.Peer reviewe
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
Consensus guidelines for the use and interpretation of angiogenesis assays
The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference