Completion of Partial Reaction Equations

We present a deep-learning model for inferring missing molecules in reaction equations. Such an algorithm features multiple interesting behaviors. First, it can infer the necessary reagents and solvents in chemical transformations specified only in terms of main compounds, as often resulting from retrosynthetic analyses. The completion with necessary reagents ensures that reaction equations are compatible with deep-learning models relying on a complete reaction specification. Second, it can cure existing datasets by detecting missing compounds, such as reagents that are essential for given classes of reactions. Finally, this model is a generalization of models for forward reaction prediction and retrosynthetic analysis, as both can be formulated in terms of incomplete reaction equations. We illustrate that a single trained model, based on the transformer architecture and acting on reaction SMILES strings, can address all three points.<br><br>Workshop paper at the Machine Learning for Molecules Workshop at NeurIPS 2020.<br>

Completion of Partial Reaction Equations

We present a deep-learning model for inferring missing molecules in reaction equations. Such an algorithm features multiple interesting behaviors. First, it can infer the necessary reagents and solvents in chemical transformations specified only in terms of main compounds, as often resulting from retrosynthetic analyses. The completion with necessary reagents ensures that reaction equations are compatible with deep-learning models relying on a complete reaction specification. Second, it can cure existing datasets by detecting missing compounds, such as reagents that are essential for given classes of reactions. Finally, this model is a generalization of models for forward reaction prediction and retrosynthetic analysis, as both can be formulated in terms of incomplete reaction equations. We illustrate that a single trained model, based on the transformer architecture and acting on reaction SMILES strings, can address all three points.<br><br>Workshop paper at the Machine Learning for Molecules Workshop at NeurIPS 2020.<br>

Succinate Coenzyme A Ligase Beta-Like Protein from Trichinella spiralis Suppresses the Immune Functions of Rat PBMCs in Vitro and Inhibits the Secretions of Interleukin-17 in Vivo

: Succinate Coenzyme A ligase beta-like protein (SUCLA-β) is a subunit of Succinyl-coenzyme A synthetase, which is involved in substrate synergism, unusual kinetic reaction in which the presence of SUCLA-β for one partial reaction stimulates another partial reaction. Trichinella spiralis is a parasitic nematode, which may hinder the development of autoimmune diseases. Immunomodulatory effects of SUCLA-β from Trichinella spiralis in the parasite-host interaction are unidentified. In this study the gene encoding T. spiralis SUCLA-β was cloned and expressed. Binding activities of recombinant T. spiralis SUCLA-β (rTs-SUCLA-β) to rat peripheral blood mononuclear cells (PBMCs) were checked by immunofluorescence assay (IFA) and the immuno-regulatory effects of rTs-SUCLA-β on cell migration, cell proliferation, nitric oxide (NO) production and apoptosis were observed by co-incubation of rTs-SUCLA-β with rat PBMCs in vitro, while cytokine secretions in rTs-SUCLA-β treated rats were evaluated in vivo. Furthermore, phagocytosis of monocytes was detected by flow cytometry and effects of rTs-SUCLA-β-induced protective immunity on T. spiralis adult worms and muscle larva were evaluated in rats. The IFA results revealed that rTs-SUCLA-β could bind to rat PBMCs. Treatment of PBMCs with rTs-SUCLA-β significantly decreased the monocyte phagocytosis, cell migration and cell proliferation, while NO production and apoptosis of PBMCs were unaffected. Results of the in vivo study showed that the IL-17 secretion decreased significantly after rTs-SUCLA-β administration in rats, while no significant effects were observed on the secretions of IFN-γ, IL-9, TGF-β and IL-4. Moreover, significant reduction of T. spiralis muscle larvae burden and significant increase in anti-rTs-SUCLA-β immunoglobulin level of IgG, IgG1 and IgG2a was observed in rTs-SUCLA-β-administered rats. The results indicated that rTs-SUCLA-β may be a potential target for controlling T. spiralis infection by suppressing the immune functions of the rat PBMCs and by reducing the parasite burden. Additionally it may also contribute to the treatment of autoimmune diseases and graft rejection by suppressing IL-17 immune response in the host.

The Influence of Al2O3 and TiO2 Additions on the Sintering Behavior of Partial Reaction Bonding Silicon Nitride

To compare the influence of Al2O3 and TiO2 on the sintering behavior of partial reaction bonding silicon nitride (RBSN) and post densification behavior, different amounts of Al2O3 or TiO2 have been added into Si-Si3N4-Y2O3 system. The results indicated that a high amount of Al2O3 addition inhibited the reaction bonding process, a lower nitridation degree was obtained, while TiO2 has limited influence on nitridation, only slightly decreased nitration degree with increasing TiO2 addition. After post sintered at 1800 °C, a density ranging from 2.31 to 3.09g/cm3 were obtained with additions of Al2O3 and TiO2, much larger than the one without them. The linear shrinkage of post-sintered samples was strongly promoted with high Al2O3 content, but it was irrelevant with the amount of TiO2. The highest bending strength of 523MPa can be obtained with addition of 6wt% Al2O3. TiO2 transformed into TiN which located at grain boundary interfaces, restraining the grain growth of β-Si3N4 and leading to an inferior flexural strength after post sintered at 1800 °C.

Reclaiming Protection as a Humanitarian Goal: Fodder for the Faint-Hearted Aid-Worker

Humanitarian action is under pressure on two fronts. On one side, western nations seek to use aid as a foreign policy tool, threatening the neutral image of humanitarian actors and placing them under suspicion. On the other, and in partial reaction to this, host states are re-asserting sovereignty and imposing new limits on humanitarian action in their territory. In many contexts, organisations are being limited by law or practice from addressing abuse of the populations they seek to assist. This is not a surprising reaction from states whose actions are scrutinised; but it is making inroads on the confidence of humanitarian actors themselves. Some are beginning to question not only the feasibility but also the appropriateness of the protection work they have taken on since the 1990s. The article seeks to reinforce the importance and legitimacy of humanitarian protection by showing that both assistance and protection are key goals of humanitarian action as defined by international law. It urges organisations to fight for the space the law has granted, in order to most effectively help the victims of armed conflict.

Microstructure Control of Ceramic-Intermetallic Composites by Heat-Treatment before Combustion Synthesis

When mixtures of Fe, Al, Ti and B powders were heated, the combustion synthesis, or SHS, reaction occurred and produced a TiB2 particle dispersed FeAl-based composite. The TiB2 particle size increased with increasing TiB2 volume fraction from 0.3 to 0.8, which was considered to be due to the fact that the adiabatic temperature of the reaction increases with the increase in TiB2 concentration in the composite due to the large formation enthalpy of TiB2. The TiB2 particle size decreased with increasing preheating time, temperature and pressure before the SHS reaction. It was suggested that partial reaction between elemental powders before the SHS reaction reduced the adiabatic temperature and hence the TiB2 particle size. The Vickers hardness of the composite varied from 500 to 2000 depending on the microstructure. This method was applied to the production of TiC-FeAl, TiC-Fe, TiB2-Fe composites.