An economic historian argues that privately funded space exploration is not a new development, but a trend beginning with the astronomical observatories of the nineteenth centuryOver the last ...half-century there has been a rapid expansion in commerce off the surface of our planet. Nations and corporations have placed hundreds of satellites that provide billions of dollars' worth of communications, scientific, global positioning, and commercial services, while construction has been completed on humanity's ninth and largest space station. On the planet itself, government agencies, corporations, and individuals plan for the expansion of economic development to the lunar surface, asteroids, and Mars. The future of space exploration seems likely to include a mix of large government funded missions as well as independent private-sector missions.The Long Space Ageexamines the economic history of American space exploration and spaceflight, from early astronomical observatories to the International Space Station, and argues that the contemporary rise of private-sector efforts is the re-emergence of a long-run trend not a new phenomenon.
In this study, an implantable stereo-electroencephalography (sEEG) depth electrode was functionalised with an enzyme coating for enzyme-based biosensing of glucose and L-glutamate. This was done ...because personalised medicine could benefit from active real-time neurochemical monitoring on small spatial and temporal scales to further understand and treat neurological disorders. To achieve this, the sEEG depth electrode was characterised using cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) using several electrochemical redox mediators (potassium ferri/ferrocyanide, ruthenium hexamine chloride, and dopamine). To improve performance, the Pt sensors on the sEEG depth electrode were coated with platinum black and a crosslinked gelatin-enzyme film to enable enzymatic biosensing. This characterisation work showed that producing a useable electrode with a good electrochemical response showing the expected behaviour for a platinum electrode was possible. Coating with Pt black improved the sensitivity to H
2
O
2
over unmodified electrodes and approached that of well-defined Pt macro disc electrodes. Measured current showed good dependence on concentration, and the calibration curves report good sensitivity of 29.65 nA/cm
2
/μM for glucose and 8.05 nA/cm
2
/μM for L-glutamate with a stable, repeatable, and linear response. These findings demonstrate that existing clinical electrode devices can be adapted for combined electrochemical and electrophysiological measurement in patients and obviate the need to develop new electrodes when existing clinically approved devices and the associated knowledge can be reused. This accelerates the time to use and application of in vivo and wearable biosensing for diagnosis, treatment, and personalised medicine.
Graphical abstract
Lake Urmia (LU) once was the second largest hypersaline lake in the world, covering up to 6000km2, but has undergone catastrophic desiccation in recent years resulting in loss of 90% of its area and ...extensive coverage by playas and marshlands that represent a source of salt and dust. This study examines daily Aerosol Optical Depth (AOD) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2001 and 2015 over northwestern Iran, which encompasses LU. Intriguingly, salt emissions from the LU surface associated with ongoing desiccation do not drive the study region's AOD profile, whereas pollution transported from other regions and emissions around LU are more important. Signatures of increasing local crustal emissions are most evident outside of the peak dust season (January, February, and October) and on the periphery of LU. AOD has generally increased in the latter half of the study period with the onset of the AOD ramp-up starting a month earlier in the spring season when comparing 2009–2015 versus earlier years. Results indicate that suppression of emissions on the LU border is critical as the combined area of salt and salty soil bodies around LU have increased by two orders of magnitude in the past two decades, and disturbing these areas via activities such as grazing and salt harvesting on the lake surface can have more detrimental impacts on regional pollution as compared to benefits. These results have important implications for public health, climate, the hydrological cycle, and pollution control efforts.
Display omitted
•AOD characteristics examined over Lake Urmia in northwestern Iran between 2001 and 2015.•No significant relationship found between lake water level and AOD.•Interannual AOD variability driven mainly by transport from upwind regions.•Enhanced emissions from salty/soil areas around the lake in the latter years•Activities like grazing can disturb the remaining playa and lead to salt emissions.
This work examines particulate chloride (Cl–) and bromide (Br–) depletion in marine aerosol particles influenced by wildfires at a coastal California site in the summers of 2013 and 2016. Chloride ...exhibited a dominant coarse mode due to sea salt influence, with substantially diminished concentrations during fire periods as compared to nonfire periods. Bromide exhibited a peak in the submicrometer range during fire and nonfire periods, with an additional supermicrometer peak in the latter periods. Chloride and Br– depletions were enhanced during fire periods as compared to nonfire periods. The highest observed %Cl– depletion occurred in the submicrometer range, with maximum values of 98.9% (0.32–0.56 μm) and 85.6% (0.56–1 μm) during fire and nonfire periods, respectively. The highest %Br– depletion occurred in the supermicrometer range during fire and nonfire periods with peak depletion between 1.8–3.2 μm (78.8% and 58.6%, respectively). When accounting for the neutralization of sulfate by ammonium, organic acid particles showed the greatest influence on Cl– depletion in the submicrometer range. These results have implications for aerosol hygroscopicity and radiative forcing in areas with wildfire influence owing to depletion effects on composition.
This paper presents novel results from size-resolved particulate matter (PM)
mass, composition, and morphology measurements conducted during the 2018
southwest monsoon (SWM) season in Metro Manila, ...Philippines. Micro-orifice
uniform deposit impactors (MOUDIs) were used to collect PM sample sets
composed of size-resolved measurements at the following aerodynamic cut-point
diameters (Dp): 18, 10, 5.6, 3.2, 1.8, 1.0, 0.56, 0.32, 0.18, 0.10, and
0.056 µm. Each sample set was analyzed for composition of the
water-soluble fraction. Analysis for mass was carried out on two sample sets, whereas
black carbon (BC) and morphology analysis were analyzed on a single sample set.
The bulk of the PM mass was between 0.18 and 1.0 µm with a dominant mode
between 0.32 and 0.56 µm. Similarly, most of the black carbon (BC) mass
was found between 0.10 and 1.0 µm, peaking between 0.18 and 0.32 µm.
These peaks are located in the Greenfield gap, or the size range between
0.10 and 1.0 µm, where wet scavenging by rain is relatively inefficient.
In the range between 0.10 and 0.18 µm, BC constituted 78.1 % of the
measured mass. Comparable contributions of BC (26.9 %) and the
water-soluble fraction (33.4 %) to total PM were observed and most of the
unresolved mass, which amounted to 39.6 % in total, was for diameters
exceeding 0.32 µm. The water-soluble ions and elements exhibited an
average combined concentration of 8.53 µg m−3, with
SO42-, NH4+, NO3-, Na+, and Cl− as
the major contributors. Positive matrix factorization (PMF) was applied to
identify the possible aerosol sources and estimate their contribution to the
water-soluble fraction of collected PM. The factor with the highest
contribution was attributed to “aged aerosol” (48.0 %), while “sea
salt” (22.5 %) and “combustion” emissions (18.7 %) had comparable
contributions. “Vehicular/resuspended dust” (5.6 %) and “waste
processing” emissions (5.1 %) were also identified. Microscopy analysis
highlighted the ubiquity of nonspherical particles regardless of size,
which is significant when considering calculations of parameters such as
single scattering albedo, the asymmetry parameter, and the extinction efficiency. The significant influence from aged aerosol to Metro Manila during the SWM
season indicates that local sources in this megacity do not fully govern
this coastal area's aerosol properties. The fact that the majority of the regional
aerosol mass burden is accounted for by BC and other insoluble components
has important downstream effects on the aerosol hygroscopic properties,
which depend on composition. The results are relevant for understanding the
impacts of monsoonal features on size-resolved aerosol properties, notably
aqueous processing and wet scavenging. Finally, the results of this work
provide contextual data for future sampling campaigns in Southeast Asia such
as the airborne component of the Cloud, Aerosol, and Monsoon Processes
Philippines Experiment (CAMP2Ex) planned for the SWM season in 2019.
Abstract Background Adult surgical patient safety literature is plentiful; however, there is a disproportionate paucity of published safety work in the children's surgical literature. We sought to ...systematically evaluate the nature and quality of patient safety evidence pertaining to pediatric surgical practice. Methods Systematic search of MEDLINE and EMBASE databases and gray literature identified 1399 articles. Data pertaining to demographics, methodology, interventions, and outcomes were extracted. Study quality was assessed utilizing formal criteria. Results 20 studies were included. 14 (70%) comprised peer-reviewed articles. 18 (90%) were published in the last 4 years. 13 (65%) described a novel intervention, and 7 (35%) described a modification of an existing intervention. Median patient sample size was 79 (29–1210). A large number (n = 55) and variety (n = 35) of measures were employed to evaluate the effect of interventions on patient safety. 15 (75%) studies utilized a checklist tool as a component of their intervention. 9 (45%) studies comprising handoff tools (n = 7); checklists (n = 1); and multidimensional quality improvement initiatives (n = 1) reported a positive effect on patient safety. Quality assessment was undertaken on 14 studies. Quantitative studies had significantly higher quality scores than qualitative studies (61 0–89 vs 44 11–78, p = 0.03). Conclusions Pediatric surgical patient safety evidence is in its early stages. Successful interventions that we identified were typically handoff tools. There now ought to be an onus on pediatric surgeons to develop and apply bespoke pediatric surgical safety interventions and generate an evidence base to parallel the adult literature. Level of Evidence Level IV, Case series with no comparison group.
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT
• Receptor antagonists that block the binding of chemokines such as CXCL8 (IL‐8) are effective in animals models of neutrophil‐mediated inflammation.
• It has ...been hypothesized that selective inhibition of neutrophil trafficking and activation may be a useful adjunct for the treatment of inflammatory airway diseases such as chronic obstructive pulmonary disease or cystic fibrosis. A CXCR1/2 receptor antagonist has shown activity in an ozone challenge model in humans.
WHAT THIS STUDY ADDS
• SB‐656933, a selective CXCR2 antagonist, is safe and well‐tolerated at single doses and is shown to inhibit agonist (CXCL1)‐mediated expression of the CD11b on peripheral blood neutrophils as well as ozone‐induced airway neutrophilia in healthy subjects.
AIMS To determine the safety and tolerability of a novel selective CXCR2 antagonist and assess its pharmacodynamic effects using measures of neutrophil activation and function, including CD11b expression in whole blood and ozone‐induced airway inflammation in healthy subjects.
METHODS Flow cytometric determination of ex vivo CXCL1‐induced CD11b expression on peripheral blood neutrophils was performed following single dose oral administration of SB‐656933 (dose range 2–1100 mg). A subsequent randomized study (placebo, 50 mg and 150 mg) was performed to explore the dose–response for ozone‐induced airway inflammation, as measured by sputum biomarkers.
RESULTS Oral administration of SB‐656933 resulted in significant inhibition of CXCL1‐induced CD11b expression on peripheral blood neutrophils at single doses greater than or equal to 50 mg. Maximum inhibition (70%) relative to placebo was observed following administration of SB‐656933 400 mg (95% CI 60%, 77%). This was sustained up to a dose of 1100 mg. Single doses of SB‐656933 reduced ozone‐induced airway inflammation in a dose‐dependent manner. Relative to placebo, there were 55% (95% CI 20%, 75%) and 74% (95% CI 55%, 85%) fewer neutrophils in the sputum of subjects after a single dose of 50 mg or 150 mg, respectively. There was a corresponding reduction in myeloperoxidase concentrations in the sputum supernatant of 32.8% (95% CI 9.2, 50.3) and 50.5% (95% CI 33.3, 63.3). SB‐656933 was safe and well‐tolerated at all doses.
CONCLUSIONS SB‐656933 is a CXCR2 antagonist that demonstrates dose‐dependent effects on neutrophil activation and recruitment within a well‐tolerated dose range. These data suggest that SB‐656933 may be an effective agent in neutrophil‐predominant diseases.
This study analyzes long-range transport of aerosol and aerosol chemical characteristics based on instances of high- and low-aerosol-loading events determined via ground-based size-resolved aerosol ...measurements collected at the Manila Observatory in Metro Manila, Philippines, from July to October 2018. Multiple data sources, including models, remote sensing, and in situ measurements, are used to analyze the impacts of long-range aerosol transport on Metro Manila and the conditions at the local and synoptic scales facilitating this transport. Through the use of case studies, evidence of long-range transport of biomass burning aerosol and continental emissions is identified in Metro Manila. Long-range transport of biomass burning aerosol from the Maritime Continent, bolstered by southwesterly flow and permitted by low rainfall, was identified through model results and the presence of biomass burning tracers (e.g., K, Rb) in the ground-based measurements. The impacts of emissions transported from continental East Asia on the aerosol characteristics in Metro Manila are also identified; for one of the events analyzed, this transport was facilitated by the nearby passage of a typhoon. Changes in the aerosol size distributions, water-soluble chemical composition, and contributions of various organic aerosol species to the total water-soluble organic aerosol were examined for the different cases. The events impacted by biomass burning transport had the overall highest concentration of water-soluble organic acids, while the events impacted by long-range transport from continental East Asia showed high percent contributions from shorter-chain dicarboxylic acids (i.e., oxalate) that are often representative of photochemical and aqueous processing in the atmosphere. The low-aerosol-loading event was subject to a larger precipitation accumulation than the high-aerosol events, indicative of wet scavenging as an aerosol sink in the study region. This low-aerosol event was characterized by a larger relative contribution from supermicrometer aerosols and had a higher percent contribution from longer-chain dicarboxylic acids (i.e., maleate) to the water-soluble organic aerosol fraction, indicating the importance of both primary aerosol emissions and local emissions.
This study examines major wildfires in the western United States between 2005 and 2015 to determine which species exhibit the highest percent change in mass concentration on day of peak fire ...influence relative to preceding nonfire days. Forty‐one fires were examined using the Environmental Protection Agency (EPA) Interagency Monitoring of Protected Visual Environments (IMPROVE) data set. Organic carbon (OC) and elemental carbon (EC) constituents exhibited the highest percent change increase. The sharpest enhancements were for the volatile (OC1) and semivolatile (OC2) OC fractions, suggestive of secondary organic aerosol formation during plume transport. Of the noncarbonaceous constituents, Cl, P, K, NO3−, and Zn levels exhibited the highest percent change. Dust was significantly enhanced in wildfire plumes, based on significant enhancements in fine soil components (i.e., Si, Ca, Al, Fe, and Ti) and PMcoarse (i.e., PM10–PM2.5). A case study emphasized how transport of wildfire plumes significantly impacted downwind states, with higher levels of fine soil and PMcoarse at the downwind state (Arizona) as compared to the source of the fires (California). A global model (Navy Aerosol Analysis and Prediction System, NAAPS) did not capture the dust influence over California or Arizona during this case event because it is not designed to resolve dust dynamics in fires, which motivates improved treatment of such processes. Significant chloride depletion was observed on the peak EC day for almost a half of the fires examined. Size‐resolved measurements during two specific fires at a coastal California site revealed significant chloride reductions for particle aerodynamic diameters between 1 and 10 μm.
Key Points
Dust (i.e., fine soil and coarse mass) levels are enhanced in wildfire plumes across the western United States
Chloride levels drop significantly on peak fire influence days for nearly a half of the wildfires examined
Cl, P, K, nitrate, and Zn exhibit the highest percent change in concentration on peak fire days after carbonaceous constituents of PM2.5
PDF
