Routine high-precision Nd isotope analyses: an optimized chromatographic purification scheme

We present an optimized α-HIBA column chromatography method for Nd for high-precision isotope analyses (±2–5 ppm). It produces consistently high yields (>95%) and extremely good separation of Ce, Pr and Sm from Nd.

Updating technological modes for concentrated sugar-containing solutions purification

Existing technological schemes of lime-carbon dioxide purification of diffusion juice include lime treatment (defecation) and two-stage treatment with carbon dioxide (saturation) with sediment separation. Improving cleaning methods aimed at increasing its efficiency is an urgent task. Lime-carbon dioxide purification of the concentrated sugar-containing solution before boiling allows to improve the quality of sugar, reducing the syrup color and increasing its natural alkalinity. The proposed purification scheme, which includes overcarbonation to low syrup pH values (8 and below), its mixing with carbonated syrup and adding activated suspension of II saturation sediment, makes it possible to obtain a purified solution with an increased effect of adsorption purification, with a significantly low content of high-molecular compounds and their calcium salts. The results of the study of various schemes for the purification of syrups in a laboratory setup have been presented. A method for purification of concentrated sugar-containing solutions, protected by a patent of the Russian Federation for the invention, has been developed, which provides for the reduction in the consumption of calcium hydroxide by 0,10–0,12% of CaO by weight of the product or by 0,04% by weight of beet.

Photonic hybrid state entanglement swapping using cat state superpositions

We propose the use of hybrid entanglement in an entanglement swapping protocol, as means of distributing a Bell state with high fidelity to two parties. The hybrid entanglement used in this work is described as a discrete variable (Fock state) and a continuous variable (cat state super- position) entangled state. We model equal and unequal levels of photonic loss between the two propagating continuous variable modes, before detecting these states via a projective vacuum-one-photon measurement, and the other mode via balanced homodyne detection. We investigate homodyne measurement imperfections, and the associated success probability of the measurement schemes chosen in this protocol. We show that our entanglement swapping scheme is resilient to low levels of photonic losses, as well as low levels of averaged unequal losses between the two propagating modes, and show an improvement in this loss resilience over other hybrid entanglement schemes using coherent state superpositions as the propagating modes. Finally, we conclude that our protocol is suitable for potential quantum networking applications which require two nodes to share entanglement separated over a distance of 5 -- 10 km , when used with a suitable entanglement purification scheme.

DESIGNING THE DESORPTION COLUMN FOR THE INSTALLATION OF WATER WASHING OF TECHNOLOGICAL GASES FROM AMMONIA AND AMINES

The paper proposes the reconstruction of the technological scheme of water washing of the gas mixture from ammonia and amines, a desorption column has been designed for a new purification scheme.

The method of purification of N-cyclohexyl maleimide - comonomer for heat-resistant optical methacrylic copolymers

Experimental evaluation of various methods for the synthesis of purified N-cyclohexylmaleimide was carried out. It was shown that the monomer obtained by the combined purification scheme, including steam distillation and sequential recrystallization in organic solvents of diff erent polarities, allows to obtain N-cyclohexylmaleimide with the content of the main substance of at least 99.5 wt.% and with a yield of 70–80 wt.%.The monomer synthesized according to the proposed scheme does not contain polymerization-active and coloring impurities. It makes it possible to obtain unpainted methacrylic copolymers on its base with high heat resistance.

The young and the restless: Isolating the dynamic mammalian preribosomes

Despite the advances in understanding the assembly of yeast preribosomes using affinity purification and structural analysis, studies on mammalian ribosome biogenesis have lagged behind. Using an unbiased method to purify native mammalian preribosomal complexes from the nucleus, Abetov et al. now uncover two types of premature ribonucleoprotein complexes that are nutrient- and mTOR-dependent. This purification scheme, combined with genome-editing techniques, could be exploited to untangle the complexities underlying human ribosome biogenesis and ribosomopathies.

A library of structurally homogeneous human N-glycans synthesized from microbial oligosaccharide precursors

Synthesis of homogenous glycans in quantitative yields represents a major bottleneck to the production of molecular tools for glycoscience, such as glycan microarrays, affinity resins, and reference standards. Here, we describe a combined biological/enzymatic method termed bioenzymatic synthesis that is capable of efficiently converting microbially-derived precursor oligosaccharides into structurally uniform human-type N-glycans. Unlike starting material obtained by chemical synthesis or direct isolation from natural sources, which can be time consuming and costly to generate, bioenzymatic synthesis involves precursors derived from renewable sources including wild-type Saccharomyces cerevisiae glycoproteins and lipid-linked oligosaccharides from glycoengineered Escherichia coli. Following deglycosylation of these biosynthetic precursors, the resulting microbial oligosaccharides are subjected to a greatly simplified purification scheme followed by structural remodeling using commercially available and recombinantly produced glycosyltransferases including key N- acetylglucosaminyltransferases (e.g., GnTI, GnTII, and GnTIV) involved in early remodeling of glycans in the mammalian glycosylation pathway. Using this approach, preparative quantities of hybrid and complex-type N-glycans including asymmetric multi-antennary structures were generated all without the need of a specialized skillset. Collectively, our results reveal bioenzymatic synthesis to be a user-friendly methodology for rapidly supplying homogeneous oligosaccharide structures that can be used to understand the human glycome and probe the biological roles of glycans in health and disease.