251 research outputs found
Three planets around HD 27894. A close-in pair with a 2:1 period ratio and an eccentric Jovian planet at 5.4 AU
Aims. Our new program with HARPS aims to detect mean motion resonant
planetary systems around stars which were previously reported to have a single
bona fide planet, often based only on sparse radial velocity data. Methods.
Archival and new HARPS radial velocities for the K2V star HD 27894 were
combined and fitted with a three-planet self-consistent dynamical model. The
best-fit orbit was tested for long-term stability. Results. We find clear
evidence that HD 27894 is hosting at least three massive planets. In addition
to the already known Jovian planet with a period 18 days
we discover a Saturn-mass planet with 36 days, likely in
a 2:1 mean motion resonance with the first planet, and a cold massive planet
( 5.3 ) with a period 5170
days on a moderately eccentric orbit ( = 0.39). Conclusions. HD
27894 is hosting a massive, eccentric giant planet orbiting around a tightly
packed inner pair of massive planets likely involved in an asymmetric 2:1 mean
motion resonance. HD 27894 may be an important milestone for probing planetary
formation and evolution scenarios.Comment: 4 pages, 2 tables, 3 figures. Accepted for publication in A&A Letters
to the Edito
Polyethylene glycol-coated collagen patch (hemopatch®) in open partial nephrectomy
PURPOSE To describe the results of a polyethylene glycol-coated collagen patch, Hemopatch® on blood loss, surgical time and renal function in partial nephrectomy (PN) for renal cell carcinoma (RCC). METHODS Out of a single surgeon cohort of n = 565 patients undergoing conventional open PN (CPN) between 01/2015 and 12/2017 at the University of Munich a consecutive subgroup (n = 42) was operated on using a polyethylene glycol-coated collagen-based sealant Hemopatch® (Baxter International Inc., Deerfield, IL, USA) (HPN). RESULTS Median age was 65.2~years (range 12.7-95.2) with median follow-up of 9.43~months (0.03-49.15). Baseline renal function (CKD-EPI) was 78.56~ml/min/1.73~m2 (range 20.38-143.09) with a non-significant decline to 74.78~ml/min/1.73~m2 (range 3.75-167.74) at follow-up. In CPN 46% had low complexity, 33% moderate complexity and 20% high complexity lesions with 33% low, 40% moderate and 27% high complexity masses in HPN. Median tumor size was 4.3~cm (range 1-38~cm) in CPN with 4.8~cm (range 3.8-18.3~cm) with HPN, p = 0.293. Median blood loss and duration of surgery was significantly lower in the HPN group vs. CPN (146~ml ± 195 vs. 114~ml ± 159~ml; p = 0.021; 43~min ± 27 for HPN vs. 53~min ± 49; p = 0.035) with no difference in clamping time (12.6~min ± 8.6 for HPN vs. 12.0~min ± 9.5; p = 0.701). CONCLUSIONS Hemopatch® supported renoraphy shows promising results compared to standard renoraphy in PN. No side effects were seen. Further studies should evaluate the prevention of arterio-venous or urinary fistulas. In complex partial nephrectomies Hemopatch® supported renoraphy should be considered
Astrometric search for a planet around VB 10
We observed VB 10 in August and September 2009 using the FORS2 camera of the
VLT with the aim of measuring its astrometric motion and of probing the
presence of the announced planet VB 10b. We used the published STEPS
astrometric positions of VB 10 over a time-span of 9 years, which allowed us to
compare the expected motion of VB 10 due to parallax and proper motion with the
observed motion and to compute precise deviations. The achieved single-epoch
precisions of our observations are about 0.1 mas and the data showed no
significant residual trend, while the presence of the planet should have
induced an apparent proper motion larger than 10 mas/yr. Subtraction of the
predicted orbital motion from the observed data produces a large trend in
position residuals of VB 10. We estimated the probability that this trend is
caused by random noise. Taking all the uncertainties into account and using
Monte-Carlo resampling of the data, we are able to reject the existence of VB
10b with the announced mass of 6.4 M_J with the false alarm probability of only
0.0005. A 3.2 M_J planet is also rejected with a false alarm probability of
0.023.Comment: 6 pages, 6 figures, 2 tables, accepted for publication in A&
New HARPS and FEROS observations of GJ1046
In this paper we present new precise Doppler data of GJ1046 taken between
November 2005 and July 2018 with the HARPS and the FEROS high-resolution
spectographs. In addition, we provide a new stellar mass estimate of GJ1046 and
we update the orbital parameters of the GJ1046 system. These new data and
analysis could be used together with the GAIA epoch astrometry, when available,
for braking the degeneracy and revealing the true mass of the GJ1046
system.Comment: 2 pages, 1 figure, 1 table with RV data (available only in the
Astro-PH version of the paper), Accepted by RNAA
The EBLM project. II. A very hot, low-mass M dwarf in an eccentric and long period eclipsing binary system from SuperWASP
In this paper, we derive the fundamental properties of
1SWASPJ011351.29+314909.7 (J0113+31), a metal-poor (-0.40 +/- 0.04 dex),
eclipsing binary in an eccentric orbit (~0.3) with an orbital period of ~14.277
d. Eclipsing M dwarfs orbiting solar-type stars (EBLMs), like J0113+31, have
been identified from WASP light curves and follow-up spectroscopy in the course
of the transiting planet search. We present the first binary of the EBLM sample
to be fully analysed, and thus, define here the methodology. The primary
component with a mass of 0.945 +/- 0.045 Msun has a large radius (1.378 +/-
0.058 Rsun) indicating that the system is quite old, ~9.5 Gyr. The M-dwarf
secondary mass of 0.186 +/- 0.010 Msun and radius of 0.209 +/- 0.011 Rsun are
fully consistent with stellar evolutionary models. However, from the
near-infrared secondary eclipse light curve, the M dwarf is found to have an
effective temperature of 3922 +/- 42 K, which is ~600 K hotter than predicted
by theoretical models. We discuss different scenarios to explain this
temperature discrepancy. The case of J0113+31 for which we can measure mass,
radius, temperature and metallicity, highlights the importance of deriving
mass, radius and temperature as a function of metallicity for M dwarfs to
better understand the lowest mass stars. The EBLM Project will define the
relationship between mass, radius, temperature and metallicity for M dwarfs
providing important empirical constraints at the bottom of the main sequence.Comment: 13 pages, 7 figures. Accepted for publication in A&
ROPS: A New Search for Habitable Earths in the Southern Sky
We present the first results from our Red Optical Planet Survey (ROPS) to
search for low mass planets orbiting late type dwarfs (M5.5V - M9V) in their
habitable zones (HZ). Our observations, with the red arm of the MIKE
spectrograph (0.5 - 0.9 microns) at the 6.5 m Magellan Clay telescope at Las
Campanas Observatory indicate that >= 92 per cent of the flux lies beyond 0.7
microns. We use a novel approach that is essentially a hybrid of the
simultaneous iodine and ThAr methods for determining precision radial
velocities. We apply least squares deconvolution to obtain a single high S/N
ratio stellar line for each spectrum and cross correlate against the
simultaneously observed telluric line profile, which we derive in the same way.
Utilising the 0.62 - 0.90 micron region, we have achieved an r.m.s. precision
of 10 m/s for an M5.5V spectral type star with spectral S/N ~160 on 5 minute
timescales. By M8V spectral type, a precision of ~30 m/s at S/N = 25 is
suggested, although more observations are needed. An assessment of our errors
and scatter in the radial velocity points hints at the presence of stellar
radial velocity variations. Of our sample of 7 stars, 2 show radial velocity
signals at 6-sigma and 10-sigma of the cross correlation uncertainties. If the
signals are planetary in origin, our findings are consistent with estimates of
Neptune mass planets that predict a frequency of 13 - 27 per cent for early M
dwarfs.Our current analysis indicates the we can achieve a sensitivity that is
equivalent to the amplitude induced by a 6 M_Earth planet orbiting in the
habitable zone. Based on simulations, we estimate that <10 M_Earth habitable
zone planets will be detected in a new stellar mass regime, with <=20 epochs of
observations.Comment: MNRAS accepted: 14 pages, 8 figures, 3 table
18F-PSMA-1007 PET/CT for response assessment in patients with metastatic renal cell carcinoma undergoing tyrosine kinase or checkpoint inhibitor therapy: preliminary results
INTRODUCTION Tyrosine kinase (TKI) and checkpoint inhibitors (CI) prolonged overall survival in metastatic renal cell carcinoma (mRCC). Early prediction of treatment response is highly desirable for the individualization of patient management and improvement of therapeutic outcome; however, serum biochemistry is unable to predict therapeutic efficacy. Therefore, we compared 18F-PSMA-1007 PET imaging for response assessment in mRCC patients undergoing TKI or CI therapy compared to CT-based response assessment as the current imaging reference standard.
METHODS 18F-PSMA-1007 PET/CT was performed in mRCC patients prior to initiation of systemic treatment and 8~weeks after therapy initiation. Treatment response was evaluated separately on 18F-PSMA-PET and CT. Changes on PSMA-PET (SUVmean) were assessed on a per patient basis using a modified PERCIST scoring system. Complete response (CRPET) was defined as absence of any uptake in all target lesions on posttreatment PET. Partial response (PRPET) was defined as decrease in summed SUVmean of > 30%. The appearance of new, PET-positive lesions or an increase in summed SUVmean of > 30% was defined as progressive disease (PDPET). A change in summed SUVmean of ± 30% defined stable disease (SDPET). RECIST 1.1 criteria were used for response assessment on CT. Results of radiographic response assessment on PSMA-PET and CT were compared.
RESULTS Overall, 11 mRCC patients undergoing systemic treatment were included. At baseline PSMA-PET1, all mRCC patients showed at least one PSMA-avid lesion. On follow-up PET2, 3 patients showed CRPET, 3 PRPET, 4 SDPET, and 1 PDPET. According to RECIST 1.1, 1 patient showed PRCT, 9 SDCT, and 1 PDCT. Overall, concordant classifications were found in only 2 cases (2 SDCT + PET). Patients with CRPET on PET were classified as 3 SDCT on CT using RECIST 1.1. By contrast, the patient classified as PRCT on CT showed PSMA uptake without major changes during therapy (SDPET). However, among 9 patients with SDCT on CT, 3 were classified as CRPET, 3 as PRPET, 1 as PDPET, and only 2 as SDPET on PSMA-PET. CONCLUSION On PSMA-PET, heterogeneous courses were observed during systemic treatment in mRCC patients with highly diverging results compared to RECIST 1.1. In the light of missing biomarkers for early response assessment, PSMA-PET might allow more precise response assessment to systemic treatment, especially in patients classified as SD on CT
Investigating the provenance of Egyptian blue pigments in ancient Roman polychromy
Egyptian blue is a copper-based blue pigment that was widely used across the Mediterranean from ca. 3300 BC
up to late antiquity and even later. For this case study, we analyzed the provenance of Egyptian blue from a
Campana relief from the collection of the Ny Carlsberg Glyptotek, Denmark. Campana reliefs are terracotta
plaques, which were named after the Italian collector Gampietro Campana, who published the first collection in
1851. These mould-made plaques were used as ornaments in central Italy from ca. 60 BC to 50 AD – a time
when Egyptian blue production is attested at several sites in the Bay of Naples, Italy. The provenance of copper
raw materials that were used for producing this pigment could provide clues about the distribution of production
centers and trade contacts. A previous investigation of the provenance of a single bulk Egyptian blue sample of
this artefact by Rodler et al. (2017) indicated a possible long-distance transport of (Iberian) copper ore or
mixing of distant (Iberian) and Italian copper. Our new data are based on the lead isotope analysis of four
individual Egyptian blue samples. The refined sampling resolution emphasizes the Italian South-Eastern Alps as
the most likely source area of copper raw materials. This copper could have been processed in local Egyptian
blue production workshops or brought to the contemporary Egyptian blue production hub in the Bay of Naples
and transported from there to the workshop where the artefact was painted
Assembly of the Inner Perivitelline Layer, a Homo log of the Mammalian Zona Pellucida: An Immunohistochemical and Ultrastructural Study
The avian inner perivitelline layer (IPVL), a homologous structure to the mammalian zona pellucida, is deposited between the granulosa cells and the oocyte cell membrane during folliculogenesis. The glycoprotein meshwork of the IPVL forms a 3-dimensional matrix and possesses important functions in the fertilization process: it contributes to the binding of avian spermatozoa to the oocyte and induces acrosomal exocytosis. In contrast to the zona pellucida of mammals, the IPVL does not prevent the physiological polyspermy found in birds. Previous studies have shown that in the Japanese quail (Cotumix japonica) at least 5 glycoproteins are constituents of the IPVL (ZP1, ZP2, ZP3, ZP4, and ZPD). In this study, we investigated the spatiotennporal assembly pattern of the IPVL during folliculogenesis using immunohistochemical and ultrastructural methods. The obtained results clearly show that these glycoproteins are incorporated into the IPVL at distinct points during follicular development, supporting the hypothesis that ZP2 and ZP4 form a type of prematrix into which ZP1, ZP3, and ZPD are integrated at a later stage of development. Copyright (C) 2011 S. Karger AG, Base
- …