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Taking into account the fact that since the 1970s frontal polymerization (FP) reactors in flow have been the subject of our study, the work gives a brief chronology of the development of FP reactors for the synthesis of high molecular polymers, polymeric hydrogels with cross-linked structure, their advantages and drawbacks. The reasons for the impossibility of the practical implementation of tubular FP reactors in flow for the synthesis of polymers are established. The possibility of implementation of tubular FP reactors for the synthesis of polyacrylamide hydrogels (PAH) capable of absorbing and releasing large amount of water is presented. The paper also presents some data on the methods for the synthesis of PAHs with prescribed properties in tubular continuous FP reactors by way of using nano-additives and regulating the kinetics of the synthesis process. As a result, the synthesis process of PAHs with the required properties both in the absorption and release of water, and in the physical-mechanical properties was carried out in frontal tubular-type reactors in flow, and the water absorption kinetic curves and physical-mechanical properties of the obtained hydrogels are presented.

The purpose of this work was to study the causes of the formation of nonlinear and spin modes in the process of frontal polymerization (FP). The latter is an autowave process of the propagation of polymerization heat waves, and is a nontraditional method for the synthesis of various polymers and polymeric composites. Monomers of metal-complexes of acrylamide with and without additions of inert and nano-fillers were chosen as objects of study. Research data on dilatometric analysis, as well as on kinetics and macrokinetics of the polymerization processes of the monomers in frontal mode are presented. On the basis of the results obtained, a conclusion was drawn on the stability loss and transition boundary from a stationary mode to nonstationary one during FP. It was shown that, during the polymerization processes, shrinkage of the resulting polymer composites occurs, commensurate with the phase of the heat wave oscillations, which disturbs the propagating heat waves from layer to layer and violates the stationarity of the process. This, in turn, results in the formation of spin-like rings and a nonstationary mode of FP.

The excimer-pumped alkali laser (XPAL) system has recently been demonstrated in several different mixtures of alkali vapor and rare gas. Without special preventive measures, plasma formation during operation of XPAL is unavoidable. Recent advancements in the availability of reliable data for electron impact collisions with atoms and molecules have enabled development of a complete reaction mechanism to investigate XPAL-induced plasmas. We report on pathways leading to plasma formation in an Ar/C_2H_6/Cs XPAL sustained at different cell temperatures. We find that depending on the operating conditions, the contribution of electron impact processes can be as little as bringing the excitation of Cs(P2) states to higher level Cs^** states, and can be as high as bringing Cs(P2) excited states to a full ionization. Increasing the input pumping power or cell temperature, or decreasing the C_2H_6 mole fraction leads to electron impact processes dominating in plasma formation over the energy pooling mechanisms previously reported in literature.

Many ischemic strokes or transient ischemic attacks are labeled cryptogenic but may have undetected atrial fibrillation (AF). We sought to identify those most likely to have subclinical AF.

AbstractLet kbe a positive integer, and let G be a simple graph with vertex set V(G). A k-distance Roman dominating functionon Gis a labeling f: V(G) → {0, 1, 2} such that every vertex with label 0 has a vertex with label 2 within distance kfrom each other. A set {f1, f2, …, fdd} of k-distance Roman dominating functions on Gwith the property that eqfi(v) ≤ 2 for each v∊ V(G), is called a k-distance Roman dominating family(of functions) on G. The maximum number of functions in a k-distance Roman dominating family on Gis the k-distance Roman domatic numberof G, denoted by . In this paper we initiate the study of k-distance Roman domatic number in graphs and we present some sharp bounds for . In addition, we determine the k-distance Roman domatic number of some graphs.

Soft tissue sarcomas remain one of the rarest malignancies with numerous subtypes that go undiagnosed. The PDGFRα antagonist Olaratumab (Lartruvo) was withdrawn from the market due to disappointing findings in the phase III studies. We share our experience with this medication in a tertiary care center in the Middle East and North Africa region. Monitor the effect of Olaratumab on sarcomas when it was used prior to its withdrawal, and compare our findings with the literature. We performed a retrospective analysis of adult patients with advanced-/metastatic soft tissue sarcomas treated with at least two cycles of Olaratumab at a tertiary care center in Lebanon during the period from January 1, 2017 to December 31, 2018. Fifteen patients were included in the study. The mean age was 49 with a range of 26–75 years. The median duration of the use of Olaratumab was 21.3 months with a range of 7.3–37 months. The average number of number of cycles received per patient was four. Five patients were deceased. Median PFS was 7.87 months (95% CI 5.28–10.45), and mean OS was 12.26 months (95% CI 8.47–16.05) Median OS was 9.8 months (95% CI 6.07–13.53). Olaratumab has been withdrawn from the market, and it is currently being investigated as part of the phase II ANNOUNCE 2 trial. Our experience from a tertiary care center shows results similar to those reported in the literature. The immunogenicity and heterogeneity of soft tissue sarcomas pose a challenge to the treatment of soft tissue sarcomas, but they also allow a wide array of possible management solutions.