Metastable Nanostructured Metallized Fluoropolymer Composites for Energetics

Fluoropolymers have long served as potent oxidizers for metal-based pyrolant designs for the preparation of energetic materials. Commercial perfluoropolyethers (PFPEs), specifically known as Fomblins®, are well-known to undergo accelerated thermal degradation in the presence of native metals and Lewis acids producing energetically favorable metal fluoride species. This study employs the use of PFPEs to coat nano-aluminum (n-Al) and under optimized stoichiometric formulations, harness optimized energy output. The PFPEs serve as ideal oxidizers of n-Al because they are non-volatile, viscous liquids that coat the particles thereby maximizing surface interactions. The n-Al/PFPE blended combination is required to interface with an epoxy-based matrix in order to engineer a moldable/machinable, structurally viable epoxy composite without compromising bulk thermal/mechanical properties. Computational modeling/simulation supported by thermal experimental studies showed that the n-Al/PFPE blended epoxy composites produced an energetic material that undergoes latent thermal metal-mediated oxidation. Details of the work include the operationally simple, scalable synthetic preparation, thermal properties from DSC/TGA, and SEM/TEM of these energetic metallized nanocomposite systems. Post-burn analysis using powder XRD of this pyrolant system confirms the presence of the predominating exothermic metal-mediated oxidized AlF3 species in addition to the production of Al2O3 and Al4C3 during the deflagration reaction. Details of this first epoxy-based energetic nanocomposite entrained with a thermally reactive formulation of PFPE coated n-Al particles are presented herein

Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure

From Expert Discipline to Common Practice: A Vision and Research Agenda for Extending the Reach of Enterprise Modeling

The benefits of enterprise modeling (EM) and its contribution to organizational tasks are largely undisputed in business and information systems engineering. EM as a discipline has been around for several decades but is typically performed by a limited number of people in organizations with an affinity to modeling. What is captured in models is only a fragment of what ought to be captured. Thus, this research note argues that EM is far from its maximum potential. Many people develop some kind of model in their local practice without thinking about it consciously. Exploiting the potential of this “grass roots modeling” could lead to groundbreaking innovations. The aim is to investigate integration of the established practices of modeling with local practices of creating and using model-like artifacts of relevance for the overall organization. The paper develops a vision for extending the reach of EM, identifies research areas contributing to the vision and proposes elements of a future research Agenda

The Urban Environment and Childhood Asthma (URECA) birth cohort study: design, methods, and study population

<p>Abstract</p> <p>Background</p> <p>The incidence and morbidity of wheezing illnesses and childhood asthma is especially high in poor urban areas. This paper describes the study design, methods, and population of the Urban Environment and Childhood Asthma (URECA) study, which was established to investigate the immunologic causes of asthma among inner-city children.</p> <p>Methods and Results</p> <p>URECA is an observational prospective study that enrolled pregnant women in central urban areas of Baltimore, Boston, New York City, and St. Louis and is following their offspring from birth through age 7 years. The birth cohort consists of 560 inner-city children who have at least one parent with an allergic disease or asthma, and all families live in areas in which at least 20% of the population has incomes below the poverty line. In addition, 49 inner-city children with no parental history of allergies or asthma were enrolled. The primary hypothesis is that specific urban exposures in early life promote a unique pattern of immune development (impaired antiviral and increased Th2 responses) that increases the risk of recurrent wheezing and allergic sensitization in early childhood, and of asthma by age 7 years. To track immune development, cytokine responses of blood mononuclear cells stimulated <it>ex vivo </it>are measured at birth and then annually. Environmental assessments include allergen and endotoxin levels in house dust, pre- and postnatal maternal stress, and indoor air nicotine and nitrogen dioxide. Nasal mucous samples are collected from the children during respiratory illnesses and analyzed for respiratory viruses. The complex interactions between environmental exposures and immune development will be assessed with respect to recurrent wheeze at age 3 years and asthma at age 7 years.</p> <p>Conclusion</p> <p>The overall goal of the URECA study is to develop a better understanding of how specific urban exposures affect immune development to promote wheezing illnesses and asthma.</p

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

The 1.28 GHz MeerKAT DEEP2 Image

We present the confusion-limited 1.28 GHz MeerKAT DEEP2 image covering one qb » ¢ 68 FWHM primarybeam area with θ = 7 6 FWHM resolution and s = m - n 0.55 0.01 Jy beam 1 rms noise. Its J2000 center position α = 04h 13m 26 4, δ = −80° 00′ 00″ was selected to minimize artifacts caused by bright sources. We introduce the new 64-element MeerKAT array and describe commissioning observations to measure the primary-beam attenuation pattern, estimate telescope pointing errors, and pinpoint (u, v) coordinate errors caused by offsets in frequency or time. We constructed a 1.4 GHz differential source count by combining a power-law count fit to the DEEP2 confusion P(D) distribution from 0.25 to 10 μJy with counts of individual DEEP2 sources between 10 μJy and 2.5 mJy. Most sources fainter than S ∼ 100 μJy are distant star-forming galaxies (SFGs) obeying the far-IR/ radio correlation, and sources stronger than 0.25 μJy account for ∼93% of the radio background produced by SFGs. For the first time, the DEEP2 source count has reached the depth needed to reveal the majority of the star formation history of the universe. A pure luminosity evolution of the 1.4 GHz local luminosity function consistent with the Madau & Dickinson model for the evolution of SFGs based on UV and infrared data underpredicts our 1.4 GHz source count in the range -5 log Jy 4 [ ( )] S

South African Paediatric Surgical Outcomes Study : a 14-day prospective, observational cohort study of paediatric surgical patients

BACKGROUND : Children comprise a large proportion of the population in sub-Saharan Africa. The burden of paediatric surgical disease exceeds available resources in Africa, potentially increasing morbidity and mortality. There are few prospective paediatric perioperative outcomes studies, especially in low- and middle-income countries (LMICs). METHODS : We conducted a 14-day multicentre, prospective, observational cohort study of paediatric patients (aged <16 yrs) undergoing surgery in 43 government-funded hospitals in South Africa. The primary outcome was the incidence of in-hospital postoperative complications. RESULTS : We recruited 2024 patients at 43 hospitals. The overall incidence of postoperative complications was 9.7% [95% confidence interval (CI): 8.4–11.0]. The most common postoperative complications were infective (7.3%; 95% CI: 6.2–8.4%). In-hospital mortality rate was 1.1% (95% CI: 0.6–1.5), of which nine of the deaths (41%) were in ASA physical status 1 and 2 patients. The preoperative risk factors independently associated with postoperative complications were ASA physcial status, urgency of surgery, severity of surgery, and an infective indication for surgery. CONCLUSIONS : The risk factors, frequency, and type of complications after paediatric surgery differ between LMICs and high-income countries. The in-hospital mortality is 10 times greater than in high-income countries. These findings should be used to develop strategies to improve paediatric surgical outcomes in LMICs, and support the need for larger prospective, observational paediatric surgical outcomes research in LMICs. CLINICAL TRIAL REGISTRATION : NCT03367832.Jan Pretorius Research Fund; Discipline of Anaesthesiology and Critical Care, Nelson R Mandela School of Medicine, University of KwaZulu-Natal; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital and University of Cape Town; Department of Anaesthesia, University of the Witwatersrand; and the Paediatric Anaesthesia Community of South Africa (PACSA).https://bjanaesthesia.org2020-02-01gl2019Anaesthesiolog

Ценностные ориентации, как основа для формирования профессиональных компетенций учащихся специальности «Медико-профилактическое дело»

ОБРАЗОВАНИЕ МЕДИЦИНСКОЕМЕДИЦИНСКИЕ УЧЕБНЫЕ ЗАВЕДЕНИЯПРОФЕССИОНАЛЬНЫЕ КОМПЕТЕНЦИИСТУДЕНТЫ МЕДИЦИНСКИХ УЧЕБНЫХ ЗАВЕДЕНИЙКОМПЕТЕНТНОСТНЫЙ ПОДХОДЦЕННОСТНЫЕ ОРИЕНТАЦИИМЕДИКО-ПРОФИЛАКТИЧЕСКОЕ ДЕЛО (СПЕЦИАЛЬНОСТЬ