823 research outputs found

    SWAS observations of comet 9P/Tempel 1 and Deep Impact

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    On 4 July 2005 at 1:52 UT the Deep Impact mission successfully completed its goal to hit the nucleus of 9P/Tempel 1 with an impactor, forming a crater on the nucleus and ejecting material into the coma of the comet. The 370 kg impactor collided with the sunlit side of the nucleus with a relative velocity of 10.2 km/s. NASA's Submillimeter Wave Astronomy Satellite (SWAS) observed the 1(10)-1(01) ortho-water ground-state rotational transition in comet 9P/Tempel 1 before, during, and after the impact. No excess emission from the impact was detected by SWAS. However, the water production rate of the comet showed large natural variations of more than a factor of three during the weeks before the impact.Comment: to appear in the proceedings of the IAU Symposium No. 231: "Astrochemistry - Recent Successes and Current Callenges". Typo corrected in author affiliation lis

    Safety and Efficacy of Extended Interval Dosing for Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer During the COVID-19 Pandemic

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    INTRODUCTION: Extended interval (EI) dosing for immune checkpoint inhibitor (ICI) mono- or consolidation therapy initiated due to the COVID-19 pandemic led to a significant reduction in ICI-related site visits for patients with stage III and IV non-small cell lung cancer (NSCLC). Here we report the safety and efficacy compared to standard dose (SD) schedules. METHOD: In this retrospective analysis patients who received ICI mono- or consolidation therapy, or adjuvant ICI therapy were assessed. Safety and efficacy of EI dosing with data of SD schedules were compared. RESULTS: One hundred seventeen patients received EI dosing for ICI and 88 patients SD. Patient characteristics were comparable. We observed 237 adverse events in the EI dosing cohort versus 118 in the SD group (p = 0.02). Overall, there was no difference in the occurrence of grade ≥3 adverse events (EI dosing: 21/237 [8.9%]; SD group: 20/118 [17.0%], p = 0.42), except for the pembrolizumab EI dosing cohort. Of all patients who received an EI dosing schedule, however, only 8 (6.8%) were reduced to SD because of toxicity. In 5 (4.3%) patients ICI was permanently stopped because of severe toxicity compared to 11 (12.5%) discontinuations in the SD group. Short-term treatment interruption occurred with similar frequencies in both groups. PFS and OS were comparable in patients receiving pembrolizumab and in those receiving adjuvant durvalumab. Progression-free survival and OS were better in the EI dosing cohort of nivolumab. CONCLUSION: EI dosing for ICI did not lead to an increase of clinically relevant toxicities resulting in dose reduction and/or treatment discontinuation. Efficacy of EI dosing of pembrolizumab and durvalumab were comparable to SD. Based on our safety and efficacy data EI dosing for ICI seems a safe and effective strategy. MICRO ABSTRACT: Aim Retrospective analysis of the safety and efficacy of extended interval dosing (EI) ICI compared to standard dose (SD) schedules. Results 117 patients received EI dosing and 88 SD. In the EI dosing cohort was no increase in toxicity leading to dose reduction and/or discontinuation of treatment. Furthermore, efficacy of EI dosing of pembrolizumab and durvalumab were comparable to SD. Based on our safety and efficacy data EI dosing for ICI seem a safe and effective strategy and should be continued also beyond the COVID-19 pandemic

    Preparation, Structure and Spectroscopic Properties of NH 4 [Ln(S 2 CNH 2 ) 4 ] ⋅ H 2 O (Ln=La, Eu)

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    The title compounds were prepared under mild ambient conditions by a facile co-precipitation route. NH4[Eu(S2CNH2)4] ⋅ H2O (a) and NH4[La(S2CNH2)4] ⋅ H2O (b) crystallize isotypically in the monoclinic space group P21/c with a=8.4461(3), b=13.6367(3), c=16.2945(5) Å, β=103.759(2)° (for (a)), and a=8.50484(9), b=13.84476(16), c=16.20816(17) Å, β=103.7644(11)° for (b), respectively. The spectroscopic data reveal the presence of a ligand-to-metal charge transfer (LMCT) process of low energy in a and in the solid solutions NH4[La1−xEux(S2CNH2)4] ⋅ H2O (x=0.016 and 0.05). Despite of the consequent efficient luminescent quenching, it was possible to recorded excitation and emission spectra at room temperature. These spectra are characterized by narrow bands due to intraconfigurational-4f transitions of the Eu3+ ion. However, broad bands associated to the LMCT state were also observed, mainly for the solid solutions NH4[La1−xEux(S2CNH2)4] ⋅ H2O (x=0.016 and 0.05). Consequently, an intramolecular energy transfer mechanism is proposed, taking into account the role of the LMCT on the spectroscopic properties of dithiocarbamate complexes

    Blunt cerebrovascular injuries in the craniofacial fracture population - Are we screening the right patients?

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    Current knowledge of blunt cerebrovascular injuries (BCVIs) in craniomaxillofacial fracture (CMF) patients is limited. The purpose of this study was to determine the occurrence of BCVIs in patients with all types of CMF. This retrospective study included CMF patients in a level 1 trauma centre during a 3-year period. Patients who were not imaged with computed tomography angiography and patients with mechanisms other than blunt injury were excluded. The primary outcome variable was BCVI. A total of 753 patients were included in the analysis. A BCVI was detected in 4.4% of the patients screened. BCVIs occurred in 8.7% of cranial fracture patients, 7.1% of combined craniofacial fracture patients, and 3.1% of facial fracture patients. The risk of BCVI was significantly increased in patients with isolated cranial fractures (odds ratio (OR) 2.55, 95% confidence interval (CI) 1.18?5.50; P = 0.017), those involved in motor vehicle accidents (OR 3.42, 95% CI 1.63?7.17; P = 0.001), and those sustaining high-energy injuries (OR 3.17, 95% CI 1.57?6.40; P = 0.001). BCVIs in CMF patients are relatively common in highenergy injuries. However, these injuries also occur in minor traumas. Imaging thresholds should be kept low in this patient population when BCVIs are suspected.Peer reviewe

    The host of the Type I SLSN 2017egm: A young, sub-solar metallicity environment in a massive spiral galaxy

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    Here we present an integral-field study of the massive, high-metallicity spiral NGC 3191, the host of SN 2017egm, the closest SLSN Type I to date. We use data from PMAS/CAHA and the public MaNGA survey to shed light on the properties of the SLSN site and the origin of star-formation in this non-starburst spiral galaxy. We map the physical properties different \ion{H}{II} regions throughout the galaxy and characterize their stellar populations using the STARLIGHT fitting code. Kinematical information allows to study a possible interaction with its neighbouring galaxy as the origin of recent star formation activity which could have caused the SLSN. NGC 3191 shows intense star-formation in the western part with three large SF regions of low metallicity. The central regions of the host have a higher metallicity, lower specific star-formation rate and lower ionization. Modeling the stellar populations gives a different picture: The SLSN region has two dominant stellar populations with different ages, the youngest one with an age of 2-10 Myr and lower metallicity, likely the population from which the SN progenitor originated. Emission line kinematics of NGC 3191 show indications of interaction with its neighbour MCG+08-19-017 at \sim45 kpc, which might be responsible for the recent starburst. In fact, this galaxy pair has in total hosted 4 SNe, 1988B (Type Ia), SN 2003ds (Type Ic in MCG+08-19-017), PTF10bgl (SLSN-Type II) and 2017egm, underlying the enhanced SF in both galaxies due to interaction. Our study shows that one has to be careful interpreting global host and even gas properties without looking at the stellar population history of the region. SLSNe seem to still be consistent with massive stars (>> 20 M_\odot) requiring low (<0.6Z< 0.6Z_{\odot}) metallicity and those environments can also occur in massive, late-type galaxies but not necessarily starbursts.Comment: Accepted for publication in A&A, 13 pages, 11 figures, 7 tables. Abstract has been reduced to match arXiv form requirement

    A method for detection of structure

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    Context. In order to understand the evolution of molecular clouds it is important to identify the departures from self-similarity associated with the scales of self-gravity and the driving of turbulence. Aims. A method is described based on structure functions for determining whether a region of gas, such as a molecular cloud, is fractal or contains structure with characteristic scale sizes. Methods. Using artificial data containing structure it is shown that derivatives of higher order structure functions provide a powerful way to detect the presence of characteristic scales should any be present and to estimate the size of such structures. The method is applied to observations of hot H2 in the Kleinman-Low nebula, north of the Trapezium stars in the Orion Molecular Cloud, including both brightness and velocity data. The method is compared with other techniques such as Fourier transform and histogram techniques. Results. It is found that the density structure, represented by H2 emission brightness in the K-band (2-2.5micron), exhibits mean characteristic sizes of 110, 550, 1700 and 2700AU. The velocity data show the presence of structure at 140, 1500 and 3500AU. Compared with other techniques such as Fourier transform or histogram, the method appears both more sensitive to characteristic scales and easier to interpret.Comment: Astronomy and Astrophysics, in pres

    The provision of solar energy to rural households through a fee-for-service system

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    This baseline report is part of an evaluation commissioned by the Policy and Operations Evaluation Department (IOB) of the Netherlands Ministry of Foreign Affairs. It belongs to a series of impact evaluations of renewable energy and development programmes supported by the Netherlands, with a focus on the medium and long term effects of these programmes on end-users or final beneficiaries. A characteristic of these studies is the use of mixed methods, being quantitative research techniques, in combination with qualitative techniques, to get insight in the magnitude of effects. The purpose of the impact evaluations is to account for assistance provided and to draw lessons from the findings for improvement of policy and policy implementation. The results of these impact evaluations will be input to a policy evaluation of the “Promoting Renewable Energy Programme” (PREP) to be concluded in 2014
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