2,753 research outputs found
Compressive behaviour at High Temperatures of Fibre Reinforced Concretes
This paper summarizes the research that is being carried out at the Universities of Coimbra and Rio de Janeiro, on fibre reinforced concretes at high temperatures. Several high strength concrete compositions reinforced with fibres (polypropylene, steel and glass fibres) were developed. The results of compressive tests at high temperatures (300 °C, 500 °C and 600 °C) and after heating and cooling down of the concrete are presented in the paper. In both research studies, the results indicated that polypropylene fibers prevent concrete spalling.
The RoPES project with HARPS and HARPS-N. I. A system of super-Earths orbiting the moderately active K-dwarf HD 176986
We report the discovery of a system of two super-Earths orbiting the
moderately active K-dwarf HD 176986. This work is part of the RoPES RV program
of G- and K-type stars, which combines radial velocities (RVs) from the HARPS
and HARPS-N spectrographs to search for short-period terrestrial planets. HD
176986 b and c are super-Earth planets with masses of 5.74 and 9.18
M, orbital periods of 6.49 and 16.82 days, and distances of 0.063
and 0.119 AU in orbits that are consistent with circular. The host star is a
K2.5 dwarf, and despite its modest level of chromospheric activity (log(R'hk) =
- 4.90 +- 0.04), it shows a complex activity pattern. Along with the discovery
of the planets, we study the magnetic cycle and rotation of the star. HD 176986
proves to be suitable for testing the available RV analysis technique and
further our understanding of stellar activity.Comment: 21 pages, 24 figures, 7 table
A super-Earth orbiting the nearby M-dwarf GJ 536
We report the discovery of a super-Earth orbiting the star GJ 536 based on
the analysis of the radial-velocity time series from the HARPS and HARPS-N
spectrographs. GJ 536 b is a planet with a minimum mass M sin of 5.36 +-
0.69 Me with an orbital period of 8.7076 +- 0.0025 days at a distance of
0.066610(13) AU, and an orbit that is consistent with circular. The host star
is the moderately quiet M1 V star GJ 536, located at 10 pc from the Sun. We
find the presence of a second signal at 43 days that we relate to stellar
rotation after analysing the time series of Ca II H&K and H alpha spectroscopic
indicators and photometric data from the ASAS archive. We find no evidence
linking the short period signal to any activity proxy. We also tentatively
derived a stellar magnetic cycle of less than 3 years.Comment: 14 pages, 14 figures, 5 tables, Accepted in A&
Estudio de factibilidad de un sistema energético termo solar en la Región Caribe Colombiana
La investigación nace como una búsqueda para la ampliación de conocimiento en cuanto a las energías renovables en Colombia, tal así, surge el proceso de recolección de datos climatológicos, selección de equipos para la simulación basado en la evaluación técnica previamente realizada según los avances tecnológicos, su factible comercialización y adquisición. Los estudios técnicos se basan en el análisis de los componentes de localización y dimensionamiento del campo solar que se obtuvieron los siguientes lugares relevantes de radiación solar, ubicados en la región caribe de Colombia, según los datos del IDEAM se estima la radiación solar en los últimos cinco años [1] y un modelo solar representado por medio de una ecuación matemática; estos datos alimentaran la data necesaria del Programa de simulación (System Advisory Model o Homer), cuyos resultados nos permiten determinar la evaluación económica para complementar la viabilidad económica para la construcción de la Central Termo Solar en varios sectores del caribe Colombiano; serán seleccionados de acuerdo a sus condiciones óptimas de localización y radiación solar anual, y del resultado se inferirá si viable técnica y económicamente, siendo necesario se regulen los incentivos económicos y tarifarios para hacerla competitiva. El estudio surge como iniciativa de ampliar los conocimientos en cuanto a la generación de energía eléctrica a partir de energía termo solar y se pretende consolidar como una investigación de vanguardia en el sector del caribe en Colombia
Improved Performance of an Epoxy Matrix as a Result of Combining Graphene Oxide and Reduced Graphene
We present an easy and effective way to improve the mechanical properties of an epoxy matrix by reinforcing it with a combination of graphene oxide (GO) and reduced graphene oxide (RGO). These nanocomposites were prepared with different load of nanofillers: 0.1, 0.4, 0.7, 1.0 wt% and a neat epoxy. Ratios of graphene oxide and reduced graphene (GO : RGO) employed were: 0 : 1, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, and 1 : 0. Results show that with only 0.4 wt% and a ratio 0.2 : 0.75 of GO : RGO, tensile strength and tensile toughness are 52% and 152% higher than neat epoxy while modulus of elasticity was improved ~20%. The obtained results suggest that it is possible achieve advantageous properties by combining graphene in oxidized and reduced conditions as it shows a synergic effect by the presence of both nanofillers
An in vivo culture system for human embryos using an encapsulation technology: a pilot study
BACKGROUND Animal studies have demonstrated better embryo development in vivo than in vitro. This pilot study tested the feasibility of using a novel in utero culture system (IUCS) to obtain normal human fertilization and embryo development. METHODS The IUCS device comprised a perforated silicone hollow tube. The study included 13 patients (<36 years) undergoing a first intracytoplasmic sperm injection (ICSI) treatment and 167 metaphase II oocytes in three groups. In Group 1, 1-2 h after ICSI, sibling oocytes were assigned to IUCS or conventional in vitro culture. The device was retrieved on Day 1, and all zygotes were cultured in vitro till Day 5. In Group 2, fertilized oocytes were assigned on Day 1, embryos retrieved on Day 3 and all embryos cultured till Day 5. In Group 3, after Day 0 assignment, embryos were retrieved on Day 3 for blastomere biopsy and fluorescence in situ hybridization (FISH) and cultured until Day 5. The highest quality blastocysts were transferred on Day 5. RESULTS Fertilization and embryo development were comparable in the in vitro and IUCS arms, with a tendency towards better embryo quality in the IUCS. FISH analysis in Group 3 revealed more normal embryos using the IUCS (P = 0.049). Three clinical pregnancies and live births were obtained: two from the IUCS arm and one from the in vitro arm. CONCLUSIONS Our pilot study shows that this new IUCS appears to be feasible and safe, supporting normal fertilization, embryo development and normal chromosomal segregation. Furthermore, live births are possible after the transient presence of a silicone device in the uterus.Clinicaltrials.gov: NCT0048010
Polymorphisms associated with adalimumab and infliximab response in moderate-to-severe plaque psoriasis
Aims. This study evaluated the influence of pharmacogenetics in psoriatic patients treated with adalimumab and/or infliximab. Materials & methods: Prospective observational study evaluating the association of 124 polymorphisms with the response to adalimumab or infliximab (PASI75) in patients with moderate-to-severe plaque psoriasis at 3 months (n = 95) and 6 months of treatment (n = 90). Significant SNPs for univariate analysis were subjected to multivariate analysis. Results: Five SNPs were associated with PASI75 at 3 months: rs6661932 (IVL), rs2546890 (IL-12B), rs2145623 (NFKBIA), rs9304742 (ZNF816A) and rs645544 (SLC9A8). Furthermore, rs1061624 (TNFR1B) was associated with PASI75 at 6 months. Conclusion: Nevertheless, these biomarkers should be validated in large-scale studies before implementation in clinical practice
Global Equation of State of two-dimensional hard sphere systems
Hard sphere systems in two dimensions are examined for arbitrary density.
Simulation results are compared to the theoretical predictions for both the low
and the high density limit, where the system is either disordered or ordered,
respectively. The pressure in the system increases with the density, except for
an intermediate range of volume fractions , where a
disorder-order phase transition occurs. The proposed {\em global equation of
state} (which describes the pressure {\em for all densities}) is applied to the
situation of an extremely dense hard sphere gas in a gravitational field and
shows reasonable agreement with both experimental and numerical data.Comment: 4 pages, 2 figure
DNA copy number variation associated with anti-tumour necrosis factor drug response and paradoxical psoriasiform reactions in patients with moderate-to-severe psoriasis
Biological drugs targeting tumour necrosis factor are effective for psoriasis. However, 30–50% of patients do not respond to these drugs and may even develop paradoxical psoriasiform reactions. This study search-ed for DNA copy number variations that could predict anti-tumour necrotic factor drug response or the ap-pearance of anti-tumour necrotic factor induced pso-riasiform reactions. Peripheral blood samples were collected from 70 patients with anti-tumour necrotic factor drug-treated moderate-to-severe plaque pso-riasis. Samples were analysed with an Illumina 450K methylation microarray. Copy number variations were obtained from raw methylation data using conumee and Chip Analysis Methylation Pipeline (ChAMP) R packa-ges. One copy number variation was found, harbouring one gene (CPM) that was significantly associated with adalimumab response (Bonferroni-adjusted p-value < 0.05). Moreover, one copy number variation was identified harbouring 3 genes (ARNT2, LOC101929586 and MIR5572) related to the development of paradoxical psoriasiform reactions. In conclusion, this study has identified DNA copy number variations that could be good candidate markers to predict response to ada-limumab and the development of anti-tumour necrotic factor paradoxical psoriasiform reactions.This study was supported by Instituto de Salud Carlos III PI 13/01598 and the Ministry of Science and Innovation and the European Regional Development’s funds (FEDER).
Conflicts of interest. FA-S has been a consultant or investigator in clinical trials sponsored by the following pharmaceutical companies: Abbott, Alter, Chemo, Farmalíder, Ferrer, GlaxoSmithKline, Gilead, Janssen-Cilag, Kern, Normon, Novartis, Servier, Teva, and Zambon. ED has potential conflicts of interest (advisory board member, consultant, grants, research support, participation in clinical trials, honoraria for speaking, and research support) with the following pharmaceutical companies: AbbVie (Abbott), Amgen, Janssen-Cilag, Leo Pharma, Novartis, Pfizer, MSD, Lilly and Celgene. ML-V has potential conflicts of interest as she has participated in clinical trials or as consultant with Abbvie (Abbott), Galderma, Janssen-Cilag, Leo Pharma, Pfizer, Novarties, Lilly, Almirall and Celgene. MCO-B has potential conflicts of interest (honoraria for speaking and research support) with Janssen-Cilag and Leo Pharma. The other authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. AS-T has served as a consultant and/or paid speaker for and/or participated in clinical trials sponsored by companies that manufacture drugs used for the treatment of psoriasis, including AbbVie, Celgene, Janssen-Cilag, LEO Pharma, Lilly, Novartis and Pfizer. RB-E has served as a consultant and/or paid speaker for and/or participated in clinical trials sponsored by companies that manufacture drugs used for the treatment of psoriasis, including AbbVie, Celgene, Janssen-Cilag, LEO Pharma, Lilly, Novartis and Pfizer
- …