ABSTRACT
A new upper limit on the 21 cm signal power spectrum at a redshift of z ≈ 9.1 is presented, based on 141 h of data obtained with the Low-Frequency Array (LOFAR). The analysis includes ...significant improvements in spectrally smooth gain-calibration, Gaussian Process Regression (GPR) foreground mitigation and optimally weighted power spectrum inference. Previously seen ‘excess power’ due to spectral structure in the gain solutions has markedly reduced but some excess power still remains with a spectral correlation distinct from thermal noise. This excess has a spectral coherence scale of 0.25–0.45 MHz and is partially correlated between nights, especially in the foreground wedge region. The correlation is stronger between nights covering similar local sidereal times. A best 2-σ upper limit of $\Delta ^2_{21} \lt (73)^2\, \mathrm{mK^2}$ at $k = 0.075\, \mathrm{h\, cMpc^{-1}}$ is found, an improvement by a factor ≈8 in power compared to the previously reported upper limit. The remaining excess power could be due to residual foreground emission from sources or diffuse emission far away from the phase centre, polarization leakage, chromatic calibration errors, ionosphere, or low-level radiofrequency interference. We discuss future improvements to the signal processing chain that can further reduce or even eliminate these causes of excess power.
Abstract
Wide-field surveys for transiting planets are well suited to searching diverse stellar populations, enabling a better understanding of the link between the properties of planets and their ...parent stars. We report the discovery of HAT-P-69 b (TOI 625.01) and HAT-P-70 b (TOI 624.01), two new hot Jupiters around A stars from the Hungarian-made Automated Telescope Network (HATNet) survey that have also been observed by the
Transiting Exoplanet Survey Satellite
. HAT-P-69 b has a mass of
M
Jup
and a radius of
R
Jup
and resides in a prograde 4.79 day orbit. HAT-P-70 b has a radius of
R
Jup
and a mass constraint of
M
Jup
and resides in a retrograde 2.74 day orbit. We use the confirmation of these planets around relatively massive stars as an opportunity to explore the occurrence rate of hot Jupiters as a function of stellar mass. We define a sample of 47,126 main-sequence stars brighter than
T
mag
= 10 that yields 31 giant planet candidates, including 18 confirmed planets, 3 candidates, and 10 false positives. We find a net hot Jupiter occurrence rate of 0.41 ± 0.10% within this sample, consistent with the rate measured by
Kepler
for FGK stars. When divided into stellar mass bins, we find the occurrence rate to be 0.71 ± 0.31% for G stars, 0.43 ± 0.15% for F stars, and 0.26 ± 0.11% for A stars. Thus, at this point, we cannot discern any statistically significant trend in the occurrence of hot Jupiters with stellar mass.
Background
The present interdisciplinary consensus review proposes clinical considerations and recommendations for anaesthetic practice in patients undergoing gastrointestinal surgery with an ...Enhanced Recovery after Surgery (ERAS) programme.
Methods
Studies were selected with particular attention being paid to meta‐analyses, randomized controlled trials and large prospective cohort studies. For each item of the perioperative treatment pathway, available English‐language literature was examined and reviewed. The group reached a consensus recommendation after critical appraisal of the literature.
Results
This consensus statement demonstrates that anaesthesiologists control several preoperative, intraoperative and postoperative ERAS elements. Further research is needed to verify the strength of these recommendations.
Conclusions
Based on the evidence available for each element of perioperative care pathways, the Enhanced Recovery After Surgery (ERAS ®) Society presents a comprehensive consensus review, clinical considerations and recommendations for anaesthesia care in patients undergoing gastrointestinal surgery within an ERAS programme. This unified protocol facilitates involvement of anaesthesiologists in the implementation of the ERAS programmes and allows for comparison between centres and it eventually might facilitate the design of multi‐institutional prospective and adequately powered randomized trials.
Abstract
The relative rarity of giant planets around low-mass stars compared with solar-type stars is a key prediction from the core-accretion planet formation theory. In this paper we report on the ...discovery of four gas giant planets that transit low-mass late K and early M dwarfs. The planets HATS-74Ab (TOI 737b), HATS-75b (TOI 552b), HATS-76b (TOI 555b), and HATS-77b (TOI 730b) were all discovered from the HATSouth photometric survey and follow-up using TESS and other photometric facilities. We use the new ESPRESSO facility at the VLT to confirm systems and measure their masses. We find that these planets have masses of 1.46 ± 0.14
M
J, 0.491 ± 0.039
M
J, 2.629 ± 0.089
M
J, and
1.374
−
0.074
+
0.100
M
J, respectively, and radii of 1.032 ± 0.021
R
J, 0.884 ± 0.013
R
J, 1.079 ± 0.031
R
J, and 1.165 ± 0.021
R
J, respectively. The planets all orbit close to their host stars with orbital periods ranging from 1.7319 days to 3.0876 days. With further work, we aim to test core-accretion theory by using these and further discoveries to quantify the occurrence rate of giant planets around low-mass host stars.
The analgesic efficacy and adverse effects of a single perioperative dose of dexamethasone are unclear. We performed a systematic review to evaluate the impact of a single i.v. dose of dexamethasone ...on postoperative pain and explore adverse events associated with this treatment.
MEDLINE, EMBASE, CINAHL, and the Cochrane Register were searched for randomized, controlled studies that compared dexamethasone vs placebo or an antiemetic in adult patients undergoing general anaesthesia and reported pain outcomes.
Forty-five studies involving 5796 patients receiving dexamethasone 1.25–20 mg were included. Patients receiving dexamethasone had lower pain scores at 2 h {mean difference (MD) −0.49 95% confidence interval (CI): −0.83, −0.15} and 24 h MD −0.48 (95% CI: −0.62, −0.35) after surgery. Dexamethasone-treated patients used less opioids at 2 h MD −0.87 mg morphine equivalents (95% CI: −1.40 to −0.33) and 24 h MD −2.33 mg morphine equivalents (95% CI: −4.39, −0.26), required less rescue analgesia for intolerable pain relative risk 0.80 (95% CI: 0.69, 0.93), had longer time to first dose of analgesic MD 12.06 min (95% CI: 0.80, 23.32), and shorter stays in the post-anaesthesia care unit MD −5.32 min (95% CI: −10.49 to −0.15). There was no dose–response with regard to the opioid-sparing effect. There was no increase in infection or delayed wound healing with dexamethasone, but blood glucose levels were higher at 24 h MD 0.39 mmol litre−1 (95% CI: 0.04, 0.74).
A single i.v. perioperative dose of dexamethasone had small but statistically significant analgesic benefits.
We present a simple experiment to demonstrate the concept of propagation of errors by measuring resistors on printed circuit boards (PCBs). We devise a method for connecting the resistors on a PCB ...that allows a relatively quick measurement of 200 resistor pairs to show that the distributions of the measurement of individual resistances, as well as the total resistance, are Gaussian-distributed, as expected from the central limit theorem. The measurement demonstrates how individual uncertainties propagate to the total uncertainty. The experiment is part of a laboratory course on statistics for physics students that emphasizes the application of statistics in data analysis.
Antibody-Drug Conjugates for Cancer Therapy Hafeez, Umbreen; Parakh, Sagun; Gan, Hui K ...
Molecules (Basel, Switzerland),
10/2020, Letnik:
25, Številka:
20
Journal Article
Recenzirano
Odprti dostop
Antibody-drug conjugates (ADCs) are novel drugs that exploit the specificity of a monoclonal antibody (mAb) to reach target antigens expressed on cancer cells for the delivery of a potent cytotoxic ...payload. ADCs provide a unique opportunity to deliver drugs to tumor cells while minimizing toxicity to normal tissue, achieving wider therapeutic windows and enhanced pharmacokinetic/pharmacodynamic properties. To date, nine ADCs have been approved by the FDA and more than 80 ADCs are under clinical development worldwide. In this paper, we provide an overview of the biology and chemistry of each component of ADC design. We briefly discuss the clinical experience with approved ADCs and the various pathways involved in ADC resistance. We conclude with perspectives about the future development of the next generations of ADCs, including the role of molecular imaging in drug development.
Initial Observations by the GOLD Mission Eastes, R. W.; McClintock, W. E.; Burns, A. G. ...
Journal of geophysical research. Space physics,
July 2020, Letnik:
125, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The NASA Global‐scale Observations of the Limb and Disk (GOLD) mission has flown an ultraviolet‐imaging spectrograph on SES‐14, a communications satellite in geostationary orbit at 47.5°W longitude. ...That instrument observes the Earth's far ultraviolet (FUV) airglow at ~134–162 nm using two identical channels. The observations performed include limb scans, stellar occultations, and images of the sunlit and nightside disk from 6:10 to 00:40 universal time each day. Initial analyses reveal interesting and unexpected results as well as the potential for further studies of the Earth's thermosphere‐ionosphere system and its responses to solar‐geomagnetic forcing and atmospheric dynamics. Thermospheric composition ratios for major constituents, O and N2, temperatures near 160 km, and exospheric temperatures are retrieved from the daytime observations. Molecular oxygen (O2) densities are measured using stellar occultations. At night, emission from radiative recombination in the ionospheric F region is used to quantify ionospheric density variations in the equatorial ionization anomaly (EIA). Regions of depleted F region electron density are frequently evident, even during the current solar minimum. These depletions are caused by the “plasma fountain effect” and are associated with the instabilities, scintillations, or “spread F” seen in other types of observations, and GOLD makes unique observations for their study.
Plain Language Summary
The NASA Global‐scale Observations of the Limb and Disk (GOLD) mission has flown a dual‐channel, ultraviolet‐imaging spectrograph on SES‐14, a communications satellite in geostationary orbit at 47.5°W longitude. That instrument observes the Earth's far ultraviolet (FUV) airglow at ~134–162 nm. The observations performed include images of the Earth's sunlit and nightside disk, limb scans, and stellar occultations, from 6:10 to 00:40 universal time each day. Initial analyses reveal interesting and unexpected results as well as the potential for further studies of the Earth's thermosphere‐ionosphere system and its responses to solar‐geomagnetic forcing and atmospheric dynamics. Thermospheric temperatures and composition ratios for major constituents, O and N2, near 160‐km altitude and exospheric temperatures are retrieved from the daytime observations. Molecular oxygen (O2) densities are measured using stellar occultations. At night, emission from radiative recombination in the ionospheric F region is used to quantify ionospheric density variations in the equatorial ionization anomaly (EIA). Regions of depleted F region electron density are frequently evident in the EIA, even during the current solar minimum.
Key Points
GOLD makes global‐scale, synoptic measurements of the temperature, composition, and densities in the thermosphere‐ionosphere system
Most measurements by the GOLD instrument are made in one of four modes
The observations are providing new and surprising insights into the characteristics and behavior of the thermosphere and ionosphere
Many pharmaceutical and personal care products (PPCPs) and endocrine-disrupting chemicals (EDCs) are present in reclaimed water, leading to concerns of human health risks from the consumption of food ...crops irrigated with reclaimed water. This study evaluated the potential for plant uptake and accumulation of four commonly occurring PPCP/EDCs, i.e., bisphenol A (BPA), diclofenac sodium (DCL), naproxen (NPX), and 4-nonylphenol (NP), by lettuce (Lactuca sativa) and collards (Brassica oleracea) in hydroponic culture, using 14C-labeled compounds. In both plant species, plant accumulation followed the order of BPA > NP > DCL > NPX and accumulation in roots was much greater than in leaves and stems. Concentrations of 14C-PPCP/EDCs in plant tissues ranged from 0.22 ± 0.03 to 927 ± 213 ng/g, but nearly all 14C-residue was non-extractable. PPCP/EDCs, particularly BPA and NP, were also extensively transformed in the nutrient solution. Dietary uptake of these PPCP/EDCs by humans was predicted to be negligible.
•Accumulation of bisphenol A, diclofenac, naproxen, and 4-nonylphenol by lettuce and collards was examined.•Plant accumulation had the order of BPA > NP > DCL > NPX.•Accumulation in roots was greater than in new leaves, original leaves, and stems.•Nearly all accumulated analyte was non-extractable.
Four commonly occurring PPCP/EDCs were taken up into roots of lettuce and collards, but translocation into edible leaves was limited and nearly all residue was non-extractable.
Magnetic skyrmions are nanoscale topological spin structures offering great promise for next-generation information storage technologies. The recent discovery of sub-100-nm room-temperature (RT) ...skyrmions in several multilayer films has triggered vigorous efforts to modulate their physical properties for their use in devices. Here we present a tunable RT skyrmion platform based on multilayer stacks of Ir/Fe/Co/Pt, which we study using X-ray microscopy, magnetic force microscopy and Hall transport techniques. By varying the ferromagnetic layer composition, we can tailor the magnetic interactions governing skyrmion properties, thereby tuning their thermodynamic stability parameter by an order of magnitude. The skyrmions exhibit a smooth crossover between isolated (metastable) and disordered lattice configurations across samples, while their size and density can be tuned by factors of two and ten, respectively. We thus establish a platform for investigating functional sub-50-nm RT skyrmions, pointing towards the development of skyrmion-based memory devices.
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