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The antiquity of iron meteorites and the inferred early intense heating by the decay of 26Al suggest that many planetesimals were molten beneath a thin insulating cap at the same time as chondrules were being made. As those planetesimals were colliding and merging, it seems inevitable that impact plumes of droplets from their liquid interiors would have been launched into space and cooled to form chondrules. We call the process splashing; it is quite distinct from making droplets by jetting during hypervelocity impacts. Evidence both for the existence of molten planetesimals, and for the cooling of chondrules within a plume setting, is strong and growing. Detailed petrographic and isotopic features of chondrules, particularly in carbonaceous chondrites (that probably formed beyond the orbit of Jupiter), suggest that the chondrule plume would have been ‘dirty’ and the otherwise uniform droplets would have been contaminated with earlier-formed dust and larger grains from a variety of sources. The contamination possibly accounts for relict grains, for the spread of oxygen isotopes along the primitive chondrule mineral (PCM) line in carbonaceous chondrites, and for the newly recognized nucleosynthetic isotopic complementarity between chondrules and matrix in Allende.
Pb-based organometal halide perovskite solar cells have passed the threshold of 20 % power conversion efficiency (PCE). However, the main issues hampering commercialization are toxic Pb contained in these cells and their instability in ambient air. Therefore, great attention is devoted to replace Pb by Sn or Bi, which are less harmful and - in the case of Bi - also expected to yield enhanced stability. In literature, the most efficient hybrid organic-inorganic methylammonium bismuth iodide (MBI) perovskite solar cells reach PCE up to 0.2 %. In this work, we present spin-coated MBI perovskite solar cells and highlight the impact of the concentration of the perovskite solution on the layer morphology and photovoltaic (PV) characteristics. The solar cells exhibit open-circuit voltages of 0.73 V, which is the highest value published for this type of solar cell. The PCE increases from 0.004 % directly after processing to 0.17 % after 48 h of storage in air. 300 h after exposure to air, the cells still yield 56 % of their peak PCE and 84 % of their maximum open-circuit voltage.
We aimed to explore multiple perspectives regarding barriers to and facilitators of advance care planning (ACP) among African Americans to identify similarities or differences that might have clinical implications.
Qualitative study with health disparities experts (n = 5), community members (n = 9), and seriously ill African American patients and caregivers (n = 11). Using template analysis, interviews were coded to identify intrapersonal, interpersonal, and systems-level themes in accordance with a social ecological framework.
Participants identified seven primary factors that influence ACP for African Americans: religion and spirituality; trust and mistrust; family relationships and experiences; patient-clinician relationships; prognostic communication, care preferences, and preparation and control. These influences echo those described in the existing literature; however, our data highlight consistent differences by group in the degree to which these factors positively or negatively affect ACP. Expert participants reinforced common themes from the literature, for example, that African Americans were not interested in prognostic information because of mistrust and religion. Seriously ill patients were more likely to express trust in their clinicians and to desire prognostic communication; they and community members expressed a desire to prepare for and control the end of life. Religious belief did not appear to negate these desires.
Significance of results
The literature on ACP in African Americans may not accurately reflect the experience of seriously ill African Americans. What are commonly understood as barriers to ACP may in fact not be. We propose reframing stereotypical barriers to ACP, such as religion and spirituality, or family, as cultural assets that should be engaged to enhance ACP. Although further research can inform best practices for engaging African American patients in ACP, findings suggest that respectful, rapport-building communication may facilitate ACP. Clinicians are encouraged to engage in early ACP using respectful and rapport building communication practices, including open-ended questions.
Children with CHD and acquired heart disease have unique, high-risk physiology. They may have a higher risk of adverse tracheal-intubation-associated events, as compared with children with non-cardiac disease.
Materials and methods
We sought to evaluate the occurrence of adverse tracheal-intubation-associated events in children with cardiac disease compared to children with non-cardiac disease. A retrospective analysis of tracheal intubations from 38 international paediatric ICUs was performed using the National Emergency Airway Registry for Children (NEAR4KIDS) quality improvement registry. The primary outcome was the occurrence of any tracheal-intubation-associated event. Secondary outcomes included the occurrence of severe tracheal-intubation-associated events, multiple intubation attempts, and oxygen desaturation.
A total of 8851 intubations were reported between July, 2012 and March, 2016. Cardiac patients were younger, more likely to have haemodynamic instability, and less likely to have respiratory failure as an indication. The overall frequency of tracheal-intubation-associated events was not different (cardiac: 17% versus non-cardiac: 16%, p=0.13), nor was the rate of severe tracheal-intubation-associated events (cardiac: 7% versus non-cardiac: 6%, p=0.11). Tracheal-intubation-associated cardiac arrest occurred more often in cardiac patients (2.80 versus 1.28%; p<0.001), even after adjusting for patient and provider differences (adjusted odds ratio 1.79; p=0.03). Multiple intubation attempts occurred less often in cardiac patients (p=0.04), and oxygen desaturations occurred more often, even after excluding patients with cyanotic heart disease.
The overall incidence of adverse tracheal-intubation-associated events in cardiac patients was not different from that in non-cardiac patients. However, the presence of a cardiac diagnosis was associated with a higher occurrence of both tracheal-intubation-associated cardiac arrest and oxygen desaturation.
Between 1013 - 1017 Hz the continua of all PG quasars can be described in the most general terms by a model consisting of two broad peaks of thermal radiation. There is no evidence for energetically significant nonthermal radiation in this frequency range in the continua of the PG quasars. We have compiled continuum observations for PG quasars from 6 cm to 2 KeV, including IRAS data for all these objects and new ground-based infrared data at 10 μm for many of these quasars. Sixty-three of the PG quasars were detected by IRAS in at least one band. The overall energy distributions for these sixty-three PG quasars are shown in Figure 1.
We have investigated organic light emitting diode (OLED) backside contacting for the enhancement of luminance uniformity as a superior alternative to gridlines. In this approach, the low-conductivity OLED anode is supported by a high-conductivity auxiliary electrode and vertically contacted through via holes. Electrical simulations of large-area OLEDs have predicted that this method allows comparable luminance uniformity while sacrificing significantly less active area compared to the common gridline approach.
The method for fabricating backside contacts is comprised of five steps: (1) Thin-film encapsulation of the OLED, (2) Patterning of the OLED surface with lithography (resist mask defining via hole positions), (3) Via hole formation to the bottom anode by a plasma etching process, (4) Organic residues removal and sidewall insulation. (5) Contacting of the anode with a high-conductivity auxiliary electrode.
Backside-contacted OLEDs processed by organic vapor phase deposition show high luminance uniformity. Scanning electron microscopy pictures and electrical breakthrough measurements confirm efficient sidewall insulation.
Galactic background radiation has been observed in the 78-111 eV Be band using 5000 Å beryllium filters in front of a thin-window proportional counter collimated to a 15° full width at half maximum field of view. Be band data have been analyzed from two sounding rocket flights (Bloch et al. 1986, Juda 1988) that viewed seventeen different directions distributed over the northern galactic hemisphere. In Figure 1 the pointing directions of the two flights are indicated on a map from McCammon et al. (1983) of the 130-188 eV B band count rate.
Recently, organometal halide perovskite solar cells have passed the threshold of 20 % power conversion efficiency (PCE). While such PCE values of perovskite solar cells are already competitive to those of other photovoltaic technologies, processing of large-area devices is still a challenge. Most of the devices reported in literature are prepared by small-scale solution-based processing techniques (e.g. spin-coating). Perovskite solar cells processed by vacuum thermal evaporation (VTE), which show uniform layers and achieve higher PCE and better reproducibility, have also been presented. Regarding the co-evaporation of the perovskite constituents, this technology suffers from large differences in the thermodynamic characteristics of the two species. While the organic components evaporate instantaneously at room temperature at pressures in the range of 10−6 hPa, significantly higher temperatures are needed for reasonable deposition rates of the metal halide compound. In addition, hybrid vapor phase deposition techniques have been developed employing a carrier gas to deposit the organic compound on the previously solution-processed metal halide compound. Generally, vapor phase processes have proven to be a desirable choice for industrial large-area production. In this work, we present a setup for the direct chemical vapor phase deposition (CVD) of methylammonium lead iodide (MAPbI3) employing nitrogen as carrier gas. X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements are carried out to investigate the crystal quality and structural properties of the resulting perovskite. By optimizing the deposition parameters, we have produced perovskite films with a deposition rate of 30 nm/h which are comparable to those fabricated by solution processing. Furthermore, the developed CVD process can be easily scaled up to higher deposition rates and larger substrates sizes, thus rendering this technique a promising candidate for manufacturing large-area devices. Moreover, CVD of perovskite solar cells can overcome most of the limitations of liquid processing, e.g. the need for appropriate and orthogonal solvents.
Although financing represents a critical component of health system strengthening and also a defining concern of efforts to move towards universal health coverage, many countries lack the tools and capacity to plan effectively for service scale-up. As part of a multi-country collaborative study (the Emerald project), we set out to develop, test and apply a fully integrated health systems resource planning and health impact tool for mental, neurological and substance use (MNS) disorders.
A new module of the existing UN strategic planning OneHealth Tool was developed, which identifies health system resources required to scale-up a range of specified interventions for MNS disorders and also projects expected health gains at the population level. We conducted local capacity-building in its use, as well as stakeholder consultations, then tested and calibrated all model parameters, and applied the tool to three priority mental and neurological disorders (psychosis, depression and epilepsy) in six low- and middle-income countries.
Resource needs for scaling-up mental health services to reach desired coverage goals are substantial compared with the current allocation of resources in the six represented countries but are not large in absolute terms. In four of the Emerald study countries (Ethiopia, India, Nepal and Uganda), the cost of delivering key interventions for psychosis, depression and epilepsy at existing treatment coverage is estimated at US$ 0.06–0.33 per capita of total population per year (in Nigeria and South Africa it is US$ 1.36–1.92). By comparison, the projected cost per capita at target levels of coverage approaches US$ 5 per capita in Nigeria and South Africa, and ranges from US$ 0.14–1.27 in the other four countries. Implementation of such a package of care at target levels of coverage is expected to yield between 291 and 947 healthy life years per one million populations, which represents a substantial health gain for the currently neglected and underserved sub-populations suffering from psychosis, depression and epilepsy.
This newly developed and validated module of OneHealth tool can be used, especially within the context of integrated health planning at the national level, to generate contextualised estimates of the resource needs, costs and health impacts of scaled-up mental health service delivery.
This paper briefly describes the principle of operation and science goals of the AMANDA high energy neutrino telescope located at the South Pole, Antarctica. Results from an earlier phase of the telescope, called AMANDA-BIO, demonstrate both reliable operation and the broad astrophysical reach of this device, which includes searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, Gamma-Ray Bursts and diffuse sources. The predicted sensitivity and angular resolution of the telescope were confirmed by studies of atmospheric muon and neutrino backgrounds. We also report on the status of the analysis from AMANDA-II, a larger version with far greater capabilities. At this stage of analysis, details of the ice properties and other systematic uncertainties of the AMANDA-II telescope are under study, but we have made progress toward critical science objectives. In particular, we present the first preliminary flux limits from AMANDA-II on the search for continuous emission from astrophysical point sources, and report on the search for correlated neutrino emission from Gamma Ray Bursts detected by BATSE before decommissioning in May 2000. During the next two years, we expect to exploit the full potential of AMANDA-II with the installation of a new data acquisition system that records full waveforms from the in-ice optical sensors.
Recent studies have claimed the existence of very massive stars (VMS) up to 300 M⊙ in the local Universe. As this finding may represent a paradigm shift for the canonical stellar upper-mass limit of 150 M⊙, it is timely to discuss the status of the data, as well as the far-reaching implications of such objects. We held a Joint Discussion at the General Assembly in Beijing to discuss (i) the determination of the current masses of the most massive stars, (ii) the formation of VMS, (iii) their mass loss, and (iv) their evolution and final fate. The prime aim was to reach broad consensus between observers and theorists on how to identify and quantify the dominant physical processes.