68 research outputs found
New experimental insights into magneto-mechanical rate dependences of magnetorheological elastomers
Magnetorheological elastomers (MREs), consisting of an elastomeric matrix filled with magnetic particles,
are one of the most promising multifunctional composites. The main advantage of these materials is their
response to external magnetic fields by mechanically deforming and/or changing their magnetorheological
properties. This multi-physical nature makes them ideal candidates for timely applications in soft robotics and
bioengineering. Although several works have addressed the magneto-mechanical coupling in these composites
from both experimental and modelling approaches, there is still a big gap of knowledge preventing the
full understanding of their underlying physics. In this regard, there is no experimental work addressing
a comprehensive magneto-mechanical characterisation combining different MRE configurations, mechanical
deformation modes and magnetic conditions. Furthermore, the interplays of rate dependences into such
magnetorheological behaviour still remain elusive. In this work, we provide an unprecedented experimental
characterisation of a soft MRE considering more than 100 different experimental conditions involving more
than 600 tests. The experiments include monotonous uniaxial compression at different deformation rates
and magnetic conditions, magneto-mechanical DMA tests, relaxation tests, oscillatory shear tests at different
deformation rates and magnetic conditions, magneto-mechanical shear frequency sweep tests, and novel
magneto-mechanical experiments. The results obtained in this work provide full characterisation of soft MREs
with a special focus on rate dependences, forming the basis to explain novel multifunctional mechanisms
identified behind their coupled response. In addition, it opens the door to new constitutive and modelling
approaches.The authors acknowledge support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 947723, project: 4D-BIOMAP). MAM acknowledges support from the Ministerio de Ciencia, Innovacion y Universidades, Spain (FPU19/03874) and DGG acknowledges support from the Talent Attraction grant (CM 2018 - 2018-T2/IND-9992) from the Comunidad de Madri
Evaluation of different methodologies for primary human dermal fibroblast spheroid formation: automation through 3D bioprinting technology
Cell spheroids have recently emerged as an effective tool to recapitulate native microenvironments of living organisms in an in vitro scenario, increasing the reliability of the results obtained and broadening their applications in regenerative medicine, cancer research, disease modeling and drug screening. In this study the generation of spheroids containing primary human dermal fibroblasts was approached using the two-widely employed methods: hanging-drop and U-shape low adhesion plate (LA-plate). Moreover, extrusion-based three-dimensional (3D) bioprinting was introduced to achieve a standardized and scalable production of cell spheroids, decreasing considerably the possibilities of human error. This was ensured when U-shape LA-plates were used, showing an 85% formation efficiency, increasing up to a 98% when it was automatized using the 3D bioprinting technologies. However, sedimentation effect within the cartridge led to a reduction of 20% in size of the spheroid during the printing process. Hyaluronic acid (HA) was chosen as viscosity enhancer to supplement the bioink and overcome cell sedimentation within the cartridge due to the high viability values exhibited by the cells -around 80%- at the used conditions. Finally, (ANCOVA) of spheroid size over time for different printing conditions stand out HA 0.4% (w/v) 60 kDa as the viscosity-improved bioink that exhibit the highest cell viability and spheroid formation percentages. Besides, not only did it ensure cell spheroid homogeneity over time, reducing cell sedimentation effects, but also wider spheroid diameters over time with less variability, outperforming significantly manual loading.We kindly thank Daniel García for their guidance with the rheological experiments. This work was supported by Programa de Actividades de I + D entre Grupos de Investigación de la Comunidad de Madrid, S2018/ BAA-4480, Biopieltec-CM, Programa Estatal de I + D + i Orientada a los Retos de la Sociedad, RTI2018-101627-B-I00 and Cátedra Fundación Ramón Areces. The experimental techniques used during this study were performed in the CleanRooms of Bioengineering, Universidad Carlos III de Madrid, Madrid, Spain
Natural Enzootic Vectors of Venezuelan equine encephalitis virus in the Magdalena Valley, Colombia
To characterize the transmission cycle of enzootic Venezuelan equine encephalitis virus (VEEV) strains believed to represent an epizootic progenitor, we identified natural vectors in a sylvatic focus in the middle Magdalena Valley of Colombia. Hamster-baited traps were placed into an active forest focus, and mosquitoes collected from each trap in which a hamster became infected were sorted by species and assayed for virus. In 18 cases, a single, initial, high-titered mosquito pool representing the vector species was identified. These vectors included Culex (Melanoconion) vomerifer (11 transmission events), Cx. (Mel.) pedroi (5 transmissions) and Cx. (Mel.) adamesi (2 transmissions). These results extend the number of proven enzootic VEEV vectors to 7, all of which are members of the Spissipes section of the subgenus Melanoconion. Our findings contrast with previous studies, which have indicated that a single species usually serves as the principal enzootic VEEV vector at a given location
Bioética. El final de la vida y las voluntades anticipadas
Esta obra contiene textos elaborados por investigadores de diferentes áreas del conocimiento: medicina, filosofía, derecho, entre otras especialidades, pertenecientes a distintos países: España, Chile y México. El objetivo principal de este libro es servir de referente teórico a otros investigadores de bioética, y especialmente a los que son o desean estar especializados en la comprensión del final de la vida y las voluntades anticipadas en el ámbito sanitario en cualquier país del mundo
Recent developments for the linguistic linked open data infrastructure
In this paper we describe the contributions made by the European H2020 project “Pret-a-LLOD” (‘Ready-to-use Multilingual Linked Language Data for Knowledge Services across Sectors’) to the further development of the Linguistic Linked Open Data (LLOD) infrastructure. Pret-a-LLOD aims to develop a new methodology for building data value chains applicable to a wide range of sectors and applications and based around language resources and language technologies that can be integrated by means of semantic technologies. We describe the methods implemented for increasing the number of language data sets in the LLOD. We also present the approach for ensuring interoperability and for porting LLOD data sets and services to other infrastructures, as well as the contribution of the projects to existing standards
Molecular characterization of multidrug resistant Enterobacterales strains isolated from liver and kidney transplant recipients in Spain
The objective of this study was to analyse the mechanisms of resistance to carbapenems and other extended-spectrum-?-lactams and to determine the genetic relatedness of multidrug-resistant Enterobacterales (MDR-E) causing colonization or infection in solid-organ transplantation (SOT) recipients. Prospective cohort study in kidney (n= 142), liver (n= 98) or kidney/pancreas (n= 7) transplant recipients between 2014 and 2018 in seven Spanish hospitals. We included 531 MDR-E isolates from rectal swabs obtained before transplantation and weekly for 4?6 weeks after the procedure and 10 MDR-E from clinical samples related to an infection. Overall, 46.2% Escherichia coli, 35.3% Klebsiella pneumoniae, 6.5% Enterobacter cloacae, 6.3% Citrobacter freundii and 5.7% other species were isolated. The number of patients with MDR-E colonization post-transplantation (176; 71.3%) was 2.5-fold the number of patients colonized pre-transplantation (71; 28.7%). Extended spectrum ?-lactamases (ESBLs) and carbapenemases were detected in 78.0% and 21.1% of MDR-E isolates respectively. In nine of the 247 (3.6%) transplant patients, the microorganism causing an infection was the same strain previously cultured from surveillance rectal swabs. In our study we have observed a low rate of MDR-E infection in colonized patients 4?6 weeks post-transplantation. E. coli producing blaCTX-M-G1 and K. pneumoniae harbouring blaOXA-48 alone or with blaCTX-M-G1 were the most prevalent MDR-E colonization strains in SOT recipients.Acknowledgements The authors thank Mª Jesús Lecea and Laura Álvarez for technical assistance. Tis research was supported by ‘Plan Nacional de I+D+i and Instituto de Salud Carlos III (Fondo de Investigaciones Sanitarias 13/01191), Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, and the Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0007, RD16/0016/0010, RD16/0016/0012, RD16/0016/0011, RD16/0016/0008, RD16/0016/0002). Te study was co-fnanced by the European Development Regional Fund “A way to achieve Europe” and the Operative Program Intelligent Growth 2014‐2020
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A Holistic Solution to Icing by Acoustic Waves: De-Icing, Active Anti-Icing, Sensing with Piezoelectric Crystals, and Synergy with Thin Film Passive Anti-Icing Solutions
Icing has become a hot topic both in academia and in the industry given its implications in transport, wind turbines, photovoltaics, and telecommunications. Recently proposed de-icing solutions involving the propagation of acoustic waves (AWs) at suitable substrates may open the path for a sustainable alternative to standard de-icing or anti-icing procedures. Herein, the fundamental interactions are unraveled that contribute to the de-icing and/or hinder the icing on AW-activated substrates. The response toward icing of a reliable model system consisting of a piezoelectric plate activated by extended electrodes is characterized at a laboratory scale and in an icing wind tunnel under realistic conditions. Experiments show that surface modification with anti-icing functionalities provides a synergistic response when activated with AWs. A thoughtful analysis of the resonance frequency dependence on experimental variables such as temperature, ice formation, or wind velocity demonstrates the application of AW devices for real-time monitoring of icing processes
Impact of late presentation of HIV infection on short-, mid- and long-term mortality and causes of death in a multicenter national cohort: 2004–2013
SummaryObjectivesTo analyze the impact of late presentation (LP) on overall mortality and causes of death and describe LP trends and risk factors (2004–2013).MethodsCox models and logistic regression were used to analyze data from a nation-wide cohort in Spain. LP is defined as being diagnosed when CD4 < 350 cells/ml or AIDS.ResultsOf 7165 new HIV diagnoses, 46.9% (CI95%:45.7–48.0) were LP, 240 patients died.First-year mortality was the highest (aHRLP.vs.nLP = 10.3[CI95%:5.5–19.3]); between 1 and 4 years post-diagnosis, aHRLP.vs.nLP = 1.9(1.2–3.0); and >4 years, aHRLP.vs.nLP = 1.5(0.7–3.1).First-year's main cause of death was HIV/AIDS (73%); and malignancies among those surviving >4 years (32%). HIV/AIDS-related deaths were more likely in LP (59.2% vs. 25.0%; p < 0.001). LP declined from 55.9% (2004–05) to 39.4% (2012–13), and reduced in 46.1% in men who have sex with men (MSM) and 37.6% in heterosexual men, but increased in 22.6% in heterosexual women.Factors associated with LP: sex (ORMEN.vs.WOMEN = 1.4[1.2–1.7]); age (OR31–40.vs.<30 = 1.6[1.4–1.8], OR41–50.vs.<30 = 2.2[1.8–2.6], OR>50.vs.<30 = 3.6[2.9–4.4]); behavior (ORInjectedDrugUse.vs.MSM = 2.8[2.0–3.8]; ORHeterosexual.vs.MSM = 2.2[1.7–3.0]); education (ORPrimaryEducation.vs.University = 1.5[1.1–2.0], ORLowerSecondary.vs.University = 1.3[1.1–1.5]); and geographical origin (ORSub-Saharan.vs.Spain = 1.6[1.3–2.0], ORLatin-American.vs.Spain = 1.4[1.2–1.8]).ConclusionsLP is associated with higher mortality, especially short-term- and HIV/AIDS-related mortality. Mid-term-, but not long-term mortality, remained also higher in LP than nLP. LP decreased in MSM and heterosexual men, not in heterosexual women. The groups most affected by LP are low educated, non-Spanish and heterosexual women
Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial
Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie
Joint Observation of the Galactic Center with MAGIC and CTA-LST-1
MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes (IACTs), designed to detect very-high-energy gamma rays, and is operating in stereoscopic mode since 2009 at the Observatorio del Roque de Los Muchachos in La Palma, Spain. In 2018, the prototype IACT of the Large-Sized Telescope (LST-1) for the Cherenkov Telescope Array, a next-generation ground-based gamma-ray observatory, was inaugurated at the same site, at a distance of approximately 100 meters from the MAGIC telescopes. Using joint observations between MAGIC and LST-1, we developed a dedicated analysis pipeline and established the threefold telescope system via software, achieving the highest sensitivity in the northern hemisphere. Based on this enhanced performance, MAGIC and LST-1 have been jointly and regularly observing the Galactic Center, a region of paramount importance and complexity for IACTs. In particular, the gamma-ray emission from the dynamical center of the Milky Way is under debate. Although previous measurements suggested that a supermassive black hole Sagittarius A* plays a primary role, its radiation mechanism remains unclear, mainly due to limited angular resolution and sensitivity. The enhanced sensitivity in our novel approach is thus expected to provide new insights into the question. We here present the current status of the data analysis for the Galactic Center joint MAGIC and LST-1 observations
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