6 research outputs found
The Transiting Multi-planet System HD15337: Two Nearly Equal-mass Planets Straddling the Radius Gap
We report the discovery of a super-Earth and a sub-Neptune transiting the star HD 15337 (TOI-402, TIC 120896927), a bright (V = 9) K1 dwarf observed by the Transiting Exoplanet Survey Satellite (TESS) in Sectors 3 and 4. We combine the TESS photometry with archival High Accuracy Radial velocity Planet Searcher spectra to confirm the planetary nature of the transit signals and derive the masses of the two transiting planets. With an orbital period of 4.8 days, a mass of and a radius of 1.64 ± 0.06 R ⊕, HD 15337 b joins the growing group of short-period super-Earths known to have a rocky terrestrial composition. The sub-Neptune HD 15337 c has an orbital period of 17.2 days, a mass of , and a radius of 2.39 ± 0.12 R ⊕, suggesting that the planet might be surrounded by a thick atmospheric envelope. The two planets have similar masses and lie on opposite sides of the radius gap, and are thus an excellent testbed for planet formation and evolution theories. Assuming that HD 15337 c hosts a hydrogen-dominated envelope, we employ a recently developed planet atmospheric evolution algorithm in a Bayesian framework to estimate the history of the high-energy (extreme ultraviolet and X-ray) emission of the host star. We find that at an age of 150 Myr, the star possessed on average between 3.7 and 127 times the high-energy luminosity of the current Sun
K2-280 b - a low density warm sub-Saturn around a mildly evolved star
Stars and planetary system
Modelo murino experimental de cáncer renal
[EN]Introduction: The objective of this study was to determine the reproducibility in a murine
model of renal tumors of various histological strains that could be useful for investigating the
response to target drugs.
Material and methods: Development and analysis of the ‘‘in vivo’’ model: tumor xenograft
of renal cell carcinomas with Balb/c nude athymic mice. Nontumourous human renal tissue
was implanted in the interscapular region of 5 mice, chromophobe renal cell carcinoma was
implanted in 5 mice (which, after checking its growth, was prepared for implantation in another
10 mice) and Fuhrman grade 2 clear cell renal cell carcinoma (CCRCC) was implanted in 5 mice
(which was also subsequently implanted in 10 mice).
We monitored the tumor size, onset of metastases and increase in size and number of tumors.
When the size had reached a point greater than or equal to locally advanced or metastatic
carcinoma, the animals were euthanised for a pathological and immunohistochemical study
and a second phase of implantation.
Results: The subcutaneous xenograft of the healthy tissue did not grow. The animals were
euthanised at 6 months and no renal tissue was found. The chromophobe renal cell carcinoma
cells grew in the initial phase (100%); however, in the second phase, we observed a chronic
lymphomonocyte inflammatory reaction and a foreign body reaction. The CCRCC grew at 5---8
months both in the first and second phase (100%), maintaining the tumor type and grade.
Conclusions: The model with athymic Balb/c nude mice is useful for reproducing CCRCC, with
the same histological characteristics and aggressiveness as native human tumors, promoting
the development of the second experimental phase
Greening of the brown-dwarf desert. EPIC 212036875b: a 51 MJ object in a 5-day orbit around an F7 V star
Context. Although more than 2000 brown dwarfs have been detected to date, mainly from direct imaging, their characterisation is difficult due to their faintness and model-dependent results. In the case of transiting brown dwarfs, however, it is possible to make direct high-precision observations. Aims: Our aim is to investigate the nature and formation of brown dwarfs by adding a new well-characterised object, in terms of its mass, radius and bulk density, to the currently small sample of less than 20 transiting brown dwarfs. Methods: One brown dwarf candidate was found by the KESPRINT consortium when searching for exoplanets in the K2 space mission Campaign 16 field. We combined the K2 photometric data with a series of multicolour photometric observations, imaging, and radial velocity measurements to rule out false positive scenarios and to determine the fundamental properties of the system. Results: We report the discovery and characterisation of a transiting brown dwarf in a 5.17-day eccentric orbit around the slightly evolved F7 V star EPIC 212036875. We find a stellar mass of 1.15 ± 0.08 M&sun;, a stellar radius of 1.41 ± 0.05 R&sun;, and an age of 5.1 ± 0.9 Gyr. The mass and radius of the companion brown dwarf are 51 ± 2 MJ and 0.83 ± 0.03 RJ, respectively, corresponding to a mean density of 108-13+15 g cm-3. Conclusions: EPIC 212036875 b is a rare object that resides in the brown-dwarf desert. In the mass-density diagram for planets, brown dwarfs, and stars, we find that all giant planets and brown dwarfs follow the same trend from 0.3 MJ to the turn-over to hydrogen burning stars at 73 MJ. EPIC 212036875 b falls close to the theoretical model for mature H/He dominated objects in this diagram as determined by interior structure models. We argue that EPIC 212036875 b formed via gravitational disc instabilities in the outer part of the disc, followed by a quick migration. Orbital tidal circularisation may have started early in its history for a brief period when the brown dwarf's radius was larger. The lack of spin-orbit synchronisation points to a weak stellar dissipation parameter (Q*' ≳ 108), which implies a circularisation timescale of ≳23 Gyr, or suggests an interaction between the magnetic and tidal forces of the star and the brown dwarf. Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/628/A64This work is done under the framework of the KESPRINT collaboration (http://kesprint.science). KESPRINT is an international consortium devoted to the characterisation and research of exoplanets discovered with space-based missions. Associated Articles Source Paper     Catalog Description    
Legume consumption is inversely associated with type 2 diabetes incidence in adults: A prospective assessment from the PREDIMED study
Background & aims: Legumes, a low-energy, nutrient-dense and low glycemic index food, have shown beneficial effects on glycemic control and adiposity. As such, legumes are widely recommended in diabetic diets, even though there is little evidence that their consumption protects against type 2 diabetes. Therefore the aim of the present study was to examine the associations between consumption of total legumes and specific subtypes, and type 2 diabetes risk. We also investigated the effect of theoretically substituting legumes for other protein- or carbohydrate-rich foods. Methods: Prospective assessment of 3349 participants in the PREvención con DIeta MEDiterránea (PREDIMED) study without type 2 diabetes at baseline. Dietary information was assessed at baseline and yearly during follow-up. We used Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for type-2 diabetes incidence according to quartiles of cumulative average consumption of total legumes, lentils, chickpeas, dry beans and fresh peas. Results: During a median follow-up of 4.3 years, 266 new cases of type 2 diabetes occurred. Individuals in the highest quartile of total legume and lentil consumption had a lower risk of diabetes than those in the lowest quartile (HR: 0.65; 95% CI: 0.43, 0.96; P-trend = 0.04; and HR: 0.67; 95% CI: 0.46–0.98; P-trend = 0.05, respectively). A borderline significant association was also observed for chickpeas consumption (HR 0.68; 95% CI: 0.46, 1.00; P-trend = 0.06). Substitutions of half a serving/day of legumes for similar servings of eggs, bread, rice or baked potato was associated with lower risk of diabetes incidence. Conclusions: A frequent consumption of legumes, particularly lentils, in the context of a Mediterranean diet, may provide benefits on type 2 diabetes prevention in older adults at high cardiovascular risk. Trial registration: The trial is registered at http://www.controlled-trials.com (ISRCTN35739639). Registration date: 5th October 2005.The authors disclose no conflict of interest related with the article.
Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBEROBN) is an initiative of the Instituto de Salud Carlos III (ISCIII) of Spain which is supported by FEDER funds (CB06/03). Supported by the official funding agency for biomedical research of the Spanish government, ISCIII, through grants provided to research networks specifically developed for the trial (RTIC G03/140 and RD 06/0045) through CIBEROBN, and by grants from Centro Nacional de Investigaciones Cardiovasculares (CNIC 06/2007), Fondo de Investigación Sanitaria–FondoEuropeo de Desarrollo Regional (PI04–2239, PI05/2584, CP06/00100, PI07/0240, PI07/1138, PI07/0954, PI 07/0473, PI10/01407, PI10/02658, PI11/01647, and PI11/02505; PI13/00462), Ministerio de Ciencia e Innovación (AGL-2009–13906-C02 and AGL2010–22319-C03), Fundación Mapfre 2010, Consejería de Salud de la Junta de Andalucía (PI0105/2007), Public Health Division of the Department of Health of the Autonomous Government of Catalonia, Generalitat Valenciana (ACOMP06109, GVA-COMP2010–181, GVACOMP2011–151, CS2010-AP-111, and CS2011-AP-042), and the Navarra Regional Government (27/2011). The Fundación Patrimonio Comunal Olivarero and Hojiblanca SA (Málaga, Spain), California Walnut Commission (Sacramento, CA), Borges SA (Reus, Spain), and Morella Nuts SA (Reus, Spain) donated the olive oil, walnuts, almonds, and hazelnuts, respectively, used in the study. None of the funding sources played a role in the design, collection, analysis or interpretation of the data or in the decision to submit the manuscript for publication.
Acknowledgements: The authors thank all the participants for their collaboration, all the PREDIMED personnel for their assistance and all the personnel of affiliated primary care centers for making the study possible. CIBEROBN is an initiative of ISCIII, Spain.Peer Reviewe