Challenges and Opportunities at the Dawn of the New Space Age

As space technology evolves due to increased private- and publicsector investments and due to the accelerated pace of innovation, Perry World House hosted a oneday workshop to discuss the novel challenges and opportunities that have emerged at this  critical point in the "New Space Age." This new age is characterized by a diversity of actors beyond the nation-state— actors that have greater accessibility and fewer barriers  to acquiring a footprint in space. As participant Xavier Pasco of Fondation pour la Recherche Stratégique wrote in his workshop contribution, "Space was born from the Cold War and from the promotion of national interests with the prevalence of foreign  policy considerations." The New Space Age has expanded the map to include private  actors and "new technological processes and innovative modes of industrialization and commercial exploitation.

Impact of Backbone fluorination on -conjugated polymers in organic photovoltaic devices: a review

Solution-processed bulk heterojunction solar cells have experienced a remarkable acceleration in performances in the last two decades, reaching power conversion efficiencies above 10%. This impressive progress is the outcome of a simultaneous development of more advanced device architectures and of optimized semiconducting polymers. Several chemical approaches have been developed to fine-tune the optoelectronics and structural polymer parameters required to reach high efficiencies. Fluorination of the conjugated polymer backbone has appeared recently to be an especially promising approach for the development of efficient semiconducting polymers. As a matter of fact, most currently best-performing semiconducting polymers are using fluorine atoms in their conjugated backbone. In this review, we attempt to give an up-to-date overview of the latest results achieved on fluorinated polymers for solar cells and to highlight general polymer properties’ evolution trends related to the fluorination of their conjugated backbone

Impact of Backbone fluorination on -conjugated polymers in organic photovoltaic devices: a review

Solution-processed bulk heterojunction solar cells have experienced a remarkable acceleration in performances in the last two decades, reaching power conversion efficiencies above 10%. This impressive progress is the outcome of a simultaneous development of more advanced device architectures and of optimized semiconducting polymers. Several chemical approaches have been developed to fine-tune the optoelectronics and structural polymer parameters required to reach high efficiencies. Fluorination of the conjugated polymer backbone has appeared recently to be an especially promising approach for the development of efficient semiconducting polymers. As a matter of fact, most currently best-performing semiconducting polymers are using fluorine atoms in their conjugated backbone. In this review, we attempt to give an up-to-date overview of the latest results achieved on fluorinated polymers for solar cells and to highlight general polymer properties’ evolution trends related to the fluorination of their conjugated backbone

Insights into nitromethane combustion from detailed kinetic modeling – Pyrolysis experiments in jet-stirred and flow reactors

International audienceThe pyrolysis of nitromethane highly diluted in helium was studied in a plug flow reactor and in a jet-stirred reactor at 1.07 bar and over the temperature range from 500 to 1100 K. Mole fraction profiles of major products and of intermediates were identified with gas chromatography and Fourier transform infrared spectroscopy. Using these experimental data, as well as published ones, we have developed a newly compiled model for the prediction of the pyrolysis and of the oxidation of nitromethane in jet-stirred and flow reactors, freely propagating, and burner-stabilized premixed flames, as well as in shock-tubes. The experimental results from the present work and from the literature are interpreted with the help of the kinetic model derived here. This study mainly focuses on the analysis of speciation in different reactors. Among the nitrogenous species, NO is found to be a major product for pyrolysis and oxidation. The model suggests that for nitromethane pyrolysis and oxidation the thermal dissociation channel to CH3 and NO2 is the main reaction path for the nitromethane degradation followed by the H-atom abstraction channel. The most sensitive reactions for nitromethane pyrolysis in a flow reactor and during pyrolysis and oxidation in a jet-stirred reactor are found to be CH3NO2(+M) ⇋ CH3 + NO2(+M) and CH3 + NO2 ⇋ CH3O + NO. The reaction CH3 + NO2 ⇋ CH3O + NO is found to be the most important reaction for all conditions studied. In a burner-stabilized premixed flame, as the mixture gets richer, the thermal dissociation channel CH3NO2(+M) ⇋ CH3 + NO2(+M) becomes more important as the contribution of the H-atom abstraction channel is decreased. Furthermore, in the burner-stabilized premixed flames, it was found that NO is mainly formed via NO2: NO2 + H ⇋ NO + OH, NO2 + CH3 ⇋ CH3O + NO. The model provided an overall reasonable agreement with the experimental data. However, for pyrolysis conditions, future work is desirable to improve predictions of intermediate species. This work extends the kinetic database and helps to improve the understanding of nitromethane chemistry. The kinetic model presented in this work can serve as a base model for hydrocarbons and oxygenated fuels higher than C2 and nitrogen-containing compounds higher than C1 as well as for pure nitrogen compounds

Correlation with basic differentiation processes of neurons

The development of the spinal cord involves the proliferation of neurons, their migration to well-defined areas, fiber outgrowth and synapse formation. The present study was designed to correlate the spatiotemporal pattern of expression of synaptophysin, an integral membrane protein of small synaptic vesicles, with these basic processes occurring during the embryonic development of the rat spinal cord. Thoracic segments of spinal cords from embryonic days 12, 14, 16, 18, 20 and of adult spinal cords were studied. S1 nuclease protection assays and immunoblots revealed minute amounts of specific mRNA and synaptophysin at embryonic day 12. There was a steep increase of mRNA between embryonic days 14 and 16, after which levels reached a plateau. A rise in the amount of synaptophysin in the spinal cord occurred between embryonic days 12 and 14, and the levels changed only slightly until the end of embryonic development. Even higher levels of synaptophysin, found in the adult spinal cord, may indicate that its biosynthesis continued after birth. In situ hybridization histochemistry revealed the localization of specific synaptophysin mRNA in the neuroepithelium. However, immunocytochemistry failed to detect synaptophysin in the neuroepithelial cells. Following migration of the neuroblasts, synaptophysin was found in neurons concomitantly with the onset of fiber outgrowth. Thus, already at embryonic day 12, outgrowing fibers of the dorsal root sensory neurons and of motoneurons were synaptophysin positive. From embryonic day 14 throughout the prenatal period, strong synaptophysin immunoreactivity was seen in the ventrolateral and dorsal parts of the marginal layer. Most likely this staining pattern indicates transient functional synaptic contacts because, in the adult spinal cord, the corresponding region, the white matter, exhibited only faint synaptophysin immunoreactivity. In the intermediate layer of the embryonic spinal cord, which corresponds to the gray matter of the adult spinal cord, synaptophysin-positive fibers were observed prior to the formation of functional synapses. The latter are most likely permanent, since synaptophysin in the adult spinal cord is mainly confined to the gray matter. Our data (i) show transcription and translation of synaptophysin within the neurons of the spinal cord and correlate these processes with proliferation, migration, fiber outgrowth and the formation of transient or permanent synapses, and (ii) prove that synaptophysin is a marker for fiber outgrowth in addition to synapse formation

Crystal isomorphisms in Fock spaces and Schensted correspondence in affine type A

We are interested in the structure of the crystal graph of level $l$ Fock spaces representations of $\mathcal{U}_q (\widehat{\mathfrak{sl}_e})$. Since the work of Shan [26], we know that this graph encodes the modular branching rule for a corresponding cyclotomic rational Cherednik algebra. Besides, it appears to be closely related to the Harish-Chandra branching graph for the appropriate finite unitary group, according to [8]. In this paper, we make explicit a particular isomorphism between connected components of the crystal graphs of Fock spaces. This so-called "canonical" crystal isomorphism turns out to be expressible only in terms of: - Schensted's classic bumping procedure, - the cyclage isomorphism defined in [13], - a new crystal isomorphism, easy to describe, acting on cylindric multipartitions. We explain how this can be seen as an analogue of the bumping algorithm for affine type $A$. Moreover, it yields a combinatorial characterisation of the vertices of any connected component of the crystal of the Fock space

Recommendations for burns care in mass casualty incidents: WHO Emergency Medical Teams Technical Working Group on Burns (WHO TWGB) 2017-2020

Health and logistical needs in emergencies have been well recognised. The last 7 years has witnessed improved professionalisation and standardisation of care for disaster affected communities – led in part by the World Health Organisation Emergency Medical Team (EMT) initiative. Mass casualty incidents (MCIs) resulting in burn injuries present unique challenges. Burn management benefits from specialist skills, expert knowledge, and timely availability of specialist resources. With burn MCIs occurring globally, and wide variance in existing burn care capacity, the need to strengthen burn care capability is evident. Although some high-income countries have well-established disaster management plans, including burn specific plans, many do not – the majority of countries where burn mass casualty events occur are without such established plans. Developing globally relevant recommendations is a first step in addressing this deficit and increasing preparedness to deal with such disasters. Global burn experts were invited to a succession of Technical Working Group on burns (TWGB) meetings to: 1) review literature on burn care in MCIs; and 2) define and agree on recommendations for burn care in MCIs. The resulting 22 recommendations provide a framework to guide national and international specialist burn teams and health facilities to support delivery of safe care and improved outcomes to burn patients in MCIs.publishedVersio

Challenge of material haemocompatibility for microfluidic blood-contacting applications

Biological applications of microfluidics technology is beginning to expand beyond the original focus of diagnostics, analytics and organ-on-chip devices. There is a growing interest in the development of microfluidic devices for therapeutic treatments, such as extra-corporeal haemodialysis and oxygenation. However, the great potential in this area comes with great challenges. Haemocompatibility of materials has long been a concern for blood-contacting medical devices, and microfluidic devices are no exception. The small channel size, high surface area to volume ratio and dynamic conditions integral to microchannels contribute to the blood-material interactions. This review will begin by describing features of microfluidic technology with a focus on blood-contacting applications. Material haemocompatibility will be discussed in the context of interactions with blood components, from the initial absorption of plasma proteins to the activation of cells and factors, and the contribution of these interactions to the coagulation cascade and thrombogenesis. Reference will be made to the testing requirements for medical devices in contact with blood, set out by International Standards in ISO 10993-4. Finally, we will review the techniques for improving microfluidic channel haemocompatibility through material surface modifications—including bioactive and biopassive coatings—and future directions