ABSTRACT
Ground-based near-infrared (NIR) astronomy is severely hampered by the forest of atmospheric emission lines resulting from the rovibrational decay of OH molecules in the upper atmosphere. ...The extreme brightness of these lines, as well as their spatial and temporal variability, makes accurate sky subtraction difficult. Selectively filtering these lines with OH suppression instruments has been a long standing goal for NIR spectroscopy. We have shown previously the efficacy of fibre Bragg gratings (FBGs) combined with photonic lanterns for achieving OH suppression. Here we report on PRAXIS, a unique NIR spectrograph that is optimized for OH suppression with FBGs. We show for the first time that OH suppression (of any kind) is possible with high overall throughput (18 per cent end-to-end), and provide examples of the relative benefits of OH suppression.
Aims/hypothesis
Insulin resistance (IR) improves with weight loss, but this response is heterogeneous. We hypothesised that metabolomic profiling would identify biomarkers predicting changes in IR ...with weight loss.
Methods
Targeted mass spectrometry-based profiling of 60 metabolites, plus biochemical assays of NEFA, β-hydroxybutyrate, ketones, insulin and glucose were performed in baseline and 6 month plasma samples from 500 participants who had lost ≥4 kg during Phase I of the Weight Loss Maintenance (WLM) trial. Homeostatic model assessment of insulin resistance (HOMA-IR) and change in HOMA-IR with weight loss (∆HOMA-IR) were calculated. Principal components analysis (PCA) and mixed models adjusted for race, sex, baseline weight, and amount of weight loss were used; findings were validated in an independent cohort of patients (
n
= 22).
Results
Mean weight loss was 8.67 ± 4.28 kg; mean ∆HOMA-IR was −0.80 ± 1.73, range −28.9 to 4.82). Baseline PCA-derived factor 3 (branched chain amino acids BCAAs and associated catabolites) correlated with baseline HOMA-IR (
r
= 0.50,
p
< 0.0001) and independently associated with ∆HOMA-IR (
p
< 0.0001). ∆HOMA-IR increased in a linear fashion with increasing baseline factor 3 quartiles. Amount of weight loss was only modestly correlated with ∆HOMA-IR (
r
= 0.24). These findings were validated in the independent cohort, with a factor composed of BCAAs and related metabolites predicting ∆HOMA-IR (
p
= 0.007).
Conclusions/interpretation
A cluster of metabolites comprising BCAAs and related analytes predicts improvement in HOMA-IR independent of the amount of weight lost. These results may help identify individuals most likely to benefit from moderate weight loss and elucidate novel mechanisms of IR in obesity.
A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A ...solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.
GaAs-on-Si epitaxial crystal quality has historically been limited by a number of growth-related defects. In particular, antiphase domain boundaries (APBs) can nucleate at the GaAs/Si interface and ...propagate throughout the entire GaAs layer. Still little is known about how thermal processing can affect the APB density in GaAs. In this study, GaAs was grown on nominally on-axis Si(001) by metal–organic chemical vapor deposition. The effect of ex situ post-growth annealing was evaluated for a temperature range of 550–700 °C. It was found that upon annealing the APB density was decreased significantly. The rate of APB density decrease was found to be temperature dependent. At annealing temperatures of 650 °C and above, the APB density was reduced from 0.10 μm
−1
to approximately 0.010 μm
−1
in less than 10 min. The activation energy for APB dissolution was determined to be 3.8 eV. The mechanism of APB dissolution is discussed.
We present results from the first on-sky demonstration of a prototype astronomical integrated photonic spectrograph (IPS) using the Anglo-Australian Telescope near-infrared imaging spectrometer ...(IRIS2) at Siding Spring Observatory to observe atmospheric molecular OH emission lines. We have succeeded in detecting upwards of 27 lines, and demonstrated the practicality of the IPS device for astronomy. Furthermore, we present a laboratory characterization of the device, which is a modified version of a commercial arrayed-waveguide grating multiplexer. We measure the spectral resolution full-width-half-maximum to be 0.75 +/- 0.05 nm (giving R = lambda/deltalambda = 2100 +/- 150 at 1500 nm). We find the free spectral range to be 57.4 +/- 0.6 nm and the peak total efficiency to be approximately 65%. Finally, we briefly discuss the future steps required to realize an astronomical instrument based on this technology concept.
CONTEXT Endotracheal intubation (ETI) is widely used for airway management of
children in the out-of-hospital setting, despite a lack of controlled trials
demonstrating a positive effect on survival ...or neurological outcome. OBJECTIVE To compare the survival and neurological outcomes of pediatric patients
treated with bag-valve-mask ventilation (BVM) with those of patients treated
with BVM followed by ETI. DESIGN Controlled clinical trial, in which patients were assigned to interventions
by calendar day from March 15, 1994, through January 1, 1997. SETTING Two large, urban, rapid-transport emergency medical services (EMS) systems. PARTICIPANTS A total of 830 consecutive patients aged 12 years or younger or estimated
to weigh less than 40 kg who required airway management; 820 were available
for follow-up. INTERVENTIONS Patients were assigned to receive either BVM (odd days; n = 410) or
BVM followed by ETI (even days; n = 420). MAIN OUTCOME MEASURES Survival to hospital discharge and neurological status at discharge
from an acute care hospital compared by treatment group. RESULTS There was no significant difference in survival between the BVM group
(123/404 30%) and the ETI group (110/416 26%) (odds ratio OR, 0.82;
95% confidence interval CI, 0.61-1.11) or in the rate of achieving a good
neurological outcome (BVM, 92/404 23% vs ETI, 85/416 20%) (OR, 0.87; 95%
CI, 0.62-1.22). CONCLUSION These results indicate that the addition of out-of-hospital ETI to a
paramedic scope of practice that already includes BVM did not improve survival
or neurological outcome of pediatric patients treated in an urban EMS system.
The use of biologics targeted to the human epidermal growth factor receptor 2 (HER2) protein is the latest addition to the armamentarium used to fight advanced gastric or gastro-oesophageal junction ...adenocarcinoma. The decision to treat with the biologic trastuzumab is completely dependent on HER2 testing of tumour tissue. In 2017, the College of American Pathologists, American Society for Clinical Pathology and the American Society of Clinical Oncology jointly published guidelines for HER2 testing and clinical decision making in gastro-oesophageal adenocarcinoma. The Association of Clinical Pathologists Molecular Pathology and Diagnostics Committee has issued the following document as a commentary of these guidelines and, in parallel, to provide guidance on HER2 testing in National Health Service pathology departments within the UK. This guidance covers issues related to case selection, preanalytical aspects, analysis and interpretation of such HER2 testing.
Despite the success of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) vaccines, there remains a clear need for new classes of preventatives for respiratory viral infections due to ...vaccine hesitancy, lack of sterilizing immunity, and for at‐risk patient populations, including the immunocompromised. While many neutralizing antibodies have been identified, and several approved, to treat COVID‐19, systemic delivery, large doses, and high costs have the potential to limit their widespread use, especially in low‐ and middle‐income countries. To use these antibodies more efficiently, an inhalable formulation is developed that allows for the expression of mRNA‐encoded, membrane‐anchored neutralizing antibodies in the lung to mitigate SARS‐CoV‐2 infections. First, the ability of mRNA‐encoded, membrane‐anchored, anti‐SARS‐CoV‐2 antibodies to prevent infections in vitro is demonstrated. Next, it is demonstrated that nebulizer‐based delivery of these mRNA‐expressed neutralizing antibodies potently abrogates disease in the hamster model. Overall, these results support the use of nebulizer‐based mRNA expression of neutralizing antibodies as a new paradigm for mitigating respiratory virus infections.
Despite the success of vaccination, severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) remains an ongoing threat worldwide. Monoclonal antibody therapies have proven useful but are expensive and require high systemic doses. This study reports mRNA‐expressed membrane‐anchored antibodies along with an inhalable polymeric nanoparticle formulation that prevent SARS‐CoV‐2 infection in the stringent hamster model.
The stratospheric climate and variability from simulations of sixteen chemistry‐climate models is evaluated. On average the polar night jet is well reproduced though its variability is less well ...reproduced with a large spread between models. Polar temperature biases are less than 5 K except in the Southern Hemisphere (SH) lower stratosphere in spring. The accumulated area of low temperatures responsible for polar stratospheric cloud formation is accurately reproduced for the Antarctic but underestimated for the Arctic. The shape and position of the polar vortex is well simulated, as is the tropical upwelling in the lower stratosphere. There is a wide model spread in the frequency of major sudden stratospheric warnings (SSWs), late biases in the breakup of the SH vortex, and a weak annual cycle in the zonal wind in the tropical upper stratosphere. Quantitatively, “metrics” indicate a wide spread in model performance for most diagnostics with systematic biases in many, and poorer performance in the SH than in the Northern Hemisphere (NH). Correlations were found in the SH between errors in the final warming, polar temperatures, the leading mode of variability, and jet strength, and in the NH between errors in polar temperatures, frequency of major SSWs, and jet strength. Models with a stronger QBO have stronger tropical upwelling and a colder NH vortex. Both the qualitative and quantitative analysis indicate a number of common and long‐standing model problems, particularly related to the simulation of the SH and stratospheric variability.
A new chiral tertiary aminonaphthol ligand 3b served as a highly efficient ligand for the asymmetric catalytic phenyl transfer to aromatic aldehydes and a variety of chiral diarylmethanols was ...prepared in high ee values (ee up to 99%) and chemical yields. The straightforward syntheses of both 3b and its enantiomer provide an excellent opportunity for large-scale applications.
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