| 1. |
- Rauer, H., et al.
(author)
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The PLATO 2.0 mission
- 2014
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In: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 38:1-2, s. 249-330
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Journal article (peer-reviewed)abstract
- PLATO 2.0 has recently been selected for ESA's M3 launch opportunity (2022/24). Providing accurate key planet parameters (radius, mass, density and age) in statistical numbers, it addresses fundamental questions such as: How do planetary systems form and evolve? Are there other systems with planets like ours, including potentially habitable planets? The PLATO 2.0 instrument consists of 34 small aperture telescopes (32 with 25 s readout cadence and 2 with 2.5 s cadence) providing a wide field-of-view (2232 deg(2)) and a large photometric magnitude range (4-16 mag). It focuses on bright (4-11 mag) stars in wide fields to detect and characterize planets down to Earth-size by photometric transits, whose masses can then be determined by ground-based radial-velocity follow-up measurements. Asteroseismology will be performed for these bright stars to obtain highly accurate stellar parameters, including masses and ages. The combination of bright targets and asteroseismology results in high accuracy for the bulk planet parameters: 2 %, 4-10 % and 10 % for planet radii, masses and ages, respectively. The planned baseline observing strategy includes two long pointings (2-3 years) to detect and bulk characterize planets reaching into the habitable zone (HZ) of solar-like stars and an additional step-and-stare phase to cover in total about 50 % of the sky. PLATO 2.0 will observe up to 1,000,000 stars and detect and characterize hundreds of small planets, and thousands of planets in the Neptune to gas giant regime out to the HZ. It will therefore provide the first large-scale catalogue of bulk characterized planets with accurate radii, masses, mean densities and ages. This catalogue will include terrestrial planets at intermediate orbital distances, where surface temperatures are moderate. Coverage of this parameter range with statistical numbers of bulk characterized planets is unique to PLATO 2.0. The PLATO 2.0 catalogue allows us to e. g.: - complete our knowledge of planet diversity for low-mass objects, - correlate the planet mean density-orbital distance distribution with predictions from planet formation theories,- constrain the influence of planet migration and scattering on the architecture of multiple systems, and - specify how planet and system parameters change with host star characteristics, such as type, metallicity and age. The catalogue will allow us to study planets and planetary systems at different evolutionary phases. It will further provide a census for small, low-mass planets. This will serve to identify objects which retained their primordial hydrogen atmosphere and in general the typical characteristics of planets in such a low-mass, low-density range. Planets detected by PLATO 2.0 will orbit bright stars and many of them will be targets for future atmosphere spectroscopy exploring their atmospheres. Furthermore, the mission has the potential to detect exomoons, planetary rings, binary and Trojan planets. The planetary science possible with PLATO 2.0 is complemented by its impact on stellar and galactic science via asteroseismology as well as light curves of all kinds of variable stars, together with observations of stellar clusters of different ages. This will allow us to improve stellar models and study stellar activity. A large number of well-known ages from red giant stars will probe the structure and evolution of our Galaxy. Asteroseismic ages of bright stars for different phases of stellar evolution allow calibrating stellar age-rotation relationships. Together with the results of ESA's Gaia mission, the results of PLATO 2.0 will provide a huge legacy to planetary, stellar and galactic science.
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| 2. |
- Lueftinger, T., et al.
(author)
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Surface structure of the CoRoT CP2 target star HD50773
- 2010
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 509:1, s. A43-
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Journal article (peer-reviewed)abstract
- Aims. We compare surface maps of the chemically peculiar star HD50773 produced with a Bayesian technique and based on high quality CoRoT photometry with those derived from rotation phase resolved spectropolarimetry. The goal is to investigate the correlation of surface brightness with surface chemical abundance distribution and the stellar magnetic surface field. Methods. The rotational period of the star was determined from a nearly 60 days long continuous light curve obtained during the initial run of CoRoT. Using a Bayesian approach to star-spot modelling, which in this work is applied for the first time for the photometric mapping of a CP star, we derived longitudes, latitudes and radii of four different spot areas. Additional parameters like stellar inclination and the spot's intensities were also determined. The CoRoT observations triggered an extensive ground-based spectroscopic and spectropolarimetric observing campaign and enabled us to obtain 19 different high resolution spectra in Stokes parameters I and V with NARVAL, ESPaDOnS, and SemelPol spectropolarimeters. Doppler and Magnetic Doppler imaging techniques allowed us to derive the magnetic field geometry of the star and the surface abundance distributions of Mg, Si, Ca, Ti, Cr, Fe, Ni, Y, and Cu. Results. We find a dominant dipolar structure of the surface magnetic field. The CoRoT light curve variations and abundances of most elements mapped are correlated with the aforementioned geometry: Cr, Fe, and Si are enhanced around the magnetic poles and coincide with the bright regions on the surface of HD50773 as predicted by our light curve synthesis and confirmed by photometric imaging.
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| 3. |
- Pavel, Marianne E, et al.
(author)
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Everolimus plus octreotide long-acting repeatable for the treatment of advanced neuroendocrine tumours associated with carcinoid syndrome (RADIANT-2) : a randomised, placebo-controlled, phase 3 study
- 2011
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In: The Lancet. - 0140-6736 .- 1474-547X. ; 378:9808, s. 2005-2012
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Journal article (peer-reviewed)abstract
- Background Everolimus, an oral inhibitor of the mammalian target of rapamycin (mTOR), has shown antitumour activity in patients with advanced pancreatic neuroendocrine tumours. We aimed to assess the combination of everolimus plus octreotide long-acting repeatable (LAR) in patients with low-grade or intermediate-grade neuroendocrine tumours (carcinoid). Methods We did a randomised, double-blind, placebo-controlled, phase 3 study comparing 10 mg per day oral everolimus with placebo, both in conjunction with 30 mg intramuscular octreotide LAR every 28 days. Randomisation was by interactive voice response systems. Participants were aged 18 years or older, with low-grade or intermediate-grade advanced (unresectable locally advanced or distant metastatic) neuroendocrine tumours, and disease progression established by radiological assessment within the past 12 months. Our primary endpoint was progression-free survival. Adjusted for two interim analyses, the prespecified boundary at final analysis was p <= 0.0246. This study is registered at ClinicalTrials.gov, number NCT00412061. Findings 429 individuals were randomly assigned to study groups; 357 participants discontinued study treatment and one was lost to follow-up. Median progression-free survival by central review was 16.4 (95% CI 13.7-21.2) months in the everolimus plus octreotide LAR group and 11.3 (8.4-14.6) months in the placebo plus octreotide LAR group (hazard ratio 0.77, 95% CI 0.59-1.00; one-sided log-rank test p=0.026). Drug-related adverse events (everolimus plus octreotide LAR vs placebo plus octreotide LAR) were mostly grade 1 or 2, and adverse events of all grades included stomatitis (62% vs 14%), rash (37% vs 12%), fatigue (31% vs 23%), and diarrhoea (27% vs 16%). Interpretation Everolimus plus octreotide LAR, compared with placebo plus octreotide LAR, improved progression-free survival in patients with advanced neuroendocrine tumours associated with carcinoid syndrome.
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| 6. |
- Fassnacht, Martin, et al.
(author)
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Combination chemotherapy in advanced adrenocortical carcinoma
- 2012
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In: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 366:23, s. 2189-2197
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Journal article (peer-reviewed)abstract
- BACKGROUND:Adrenocortical carcinoma is a rare cancer that has a poor response to cytotoxic treatment.METHODS:We randomly assigned 304 patients with advanced adrenocortical carcinoma to receive mitotane plus either a combination of etoposide (100 mg per square meter of body-surface area on days 2 to 4), doxorubicin (40 mg per square meter on day 1), and cisplatin (40 mg per square meter on days 3 and 4) (EDP) every 4 weeks or streptozocin (streptozotocin) (1 g on days 1 to 5 in cycle 1; 2 g on day 1 in subsequent cycles) every 3 weeks. Patients with disease progression received the alternative regimen as second-line therapy. The primary end point was overall survival.RESULTS:For first-line therapy, patients in the EDP-mitotane group had a significantly higher response rate than those in the streptozocin-mitotane group (23.2% vs. 9.2%, P<0.001) and longer median progression-free survival (5.0 months vs. 2.1 months; hazard ratio, 0.55; 95% confidence interval [CI], 0.43 to 0.69; P<0.001); there was no significant between-group difference in overall survival (14.8 months and 12.0 months, respectively; hazard ratio, 0.79; 95% CI, 0.61 to 1.02; P=0.07). Among the 185 patients who received the alternative regimen as second-line therapy, the median duration of progression-free survival was 5.6 months in the EDP-mitotane group and 2.2 months in the streptozocin-mitotane group. Patients who did not receive the alternative second-line therapy had better overall survival with first-line EDP plus mitotane (17.1 month) than with streptozocin plus mitotane (4.7 months). Rates of serious adverse events did not differ significantly between treatments.CONCLUSIONS:Rates of response and progression-free survival were significantly better with EDP plus mitotane than with streptozocin plus mitotane as first-line therapy, with similar rates of toxic events, although there was no significant difference in overall survival.
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| 7. |
- Kerkhofs, Tm, et al.
(author)
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Comparison of Two Mitotane Starting dose Regimens in Patients with Advanced Adrenocortical Carcinoma
- 2013
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 98:12, s. 2281-
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Journal article (peer-reviewed)abstract
- Context:Mitotane is the only approved drug for treatment of adrenocortical carcinoma(ACC). Its pharmacokinetic properties are not fully elucidated and different dosing regimens have never been compared head-to-head.Objective:To investigate the relationship between mitotane dose and plasma concentration comparing two dosing regimens.Design/Setting:Prospective open-label multicenter trial of a predefined duration of twelve weeks.Patients/Interventions:Forty mitotane-naïve patients with metastatic ACC were assigned to a predefined low- or high-dose regimen by the local investigator. Thirty-two could be evaluated in detail.Main Outcome Measure:Difference in median mitotane plasma levels between both treatment groups.Results:Despite a difference in mean cumulative dose (440±142g versus 272±121g), median maximum plasma levels were not significantly different between the two groups (high-dose 14.3mg/L (6.3-29.7,n=20) versus 11.3mg/L (5.5-20.0,n=12), p=0.235). Ten out of twenty patients on the high-dose regimen reached plasma concentrations ≥14mg/L after 46 days (18-81 days) compared to four of twelve patients on the low-dose regimen after 55 days (46-74 days,p=0.286). All patients who reached 14mg/L at 12 weeks displayed a level ≥4.1 mg/L on day 33 (100% sensitivity). There were no significant differences in frequency and severity of adverse events. Among patients not receiving concomitant chemotherapy mitotane exposure was higher in the high-dose group: 1013±494mg.d/L versus 555±168mg.d/L, p=0.080.Conclusions:The high-dose starting regimen did neither result in significantly different mitotane levels nor in a different rate of adverse events, but concomitant chemotherapy influenced these results. Thus, for mitotane monotherapy the high-dose approach is favorable, whereas for combination therapy a lower dose seems reasonable.
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