Усовершенствованный метод получения гептилового эфира 4-трифторацетилбензойной кислоты

A convenient three-step method for synthesis of heptyl (4-trifluoroacetyl)benzoate, an important neutral anion carrier, has been developed. The key step of the method is acylation of toluene by trifluoroacetic anhydride in presence of aluminium chloride at –8 – –10 oC. The procedure gives high overall yield and, unlike the earlier methods, does not include any organometallic reagents, therefore allowing scaling it up to several hundred grams, that makes the target compound much more readily available.Усовершенствованный метод получения гептилового эфира 4-трифторацетилбензойной кислоты Разработан удобный трeхстадийный метод синтеза гептилового эфира 4-трифторацетилбензойной кислоты, широко применяющегося в потенциометрическом анализе в качестве нейтрального переносчика анионов. Ключевой стадией метода является ацилирование толуола трифторуксусным ангидридом в присутствии хлорида алюминия при –8 – –10 oC. Данная процедура позволяет получить высокий общий выход продукта и, в отличие от описанных в литературе методик, не требует использования металлоорганических реагентов, что позволяет увеличить масштаб синтеза до сотен граммов и сделать целевой продукт значительно более доступным

Phase diagram of superfluid 3He in "nematically ordered" aerogel

Results of experiments with liquid 3He immersed in a new type of aerogel are described. This aerogel consists of Al2O3 strands which are nearly parallel to each other, so we call it as a "nematically ordered" aerogel. At all used pressures a superfluid transition was observed and a superfluid phase diagram was measured. Possible structures of the observed superfluid phases are discussed.Comment: 6 pages, 8 figures. Submitted to Pis'ma v ZhETF (JETP Letters

Orbital glass and spin glass states of 3He-A in aerogel

Glass states of superfluid A-like phase of 3He in aerogel induced by random orientations of aerogel strands are investigated theoretically and experimentally. In anisotropic aerogel with stretching deformation two glass phases are observed. Both phases represent the anisotropic glass of the orbital ferromagnetic vector l -- the orbital glass (OG). The phases differ by the spin structure: the spin nematic vector d can be either in the ordered spin nematic (SN) state or in the disordered spin-glass (SG) state. The first phase (OG-SN) is formed under conventional cooling from normal 3He. The second phase (OG-SG) is metastable, being obtained by cooling through the superfluid transition temperature, when large enough resonant continuous radio-frequency excitation are applied. NMR signature of different phases allows us to measure the parameter of the global anisotropy of the orbital glass induced by deformation.Comment: 7 pages, 6 figures, Submitted to Pis'ma v ZhETF (JETP Letters

Complete genome sequence of the extremely acidophilic methanotroph isolate V4, Methylacidiphilum infernorum, a representative of the bacterial phylum Verrucomicrobia

<p>Abstract</p> <p>Background</p> <p>The phylum <it>Verrucomicrobia </it>is a widespread but poorly characterized bacterial clade. Although cultivation-independent approaches detect representatives of this phylum in a wide range of environments, including soils, seawater, hot springs and human gastrointestinal tract, only few have been isolated in pure culture. We have recently reported cultivation and initial characterization of an extremely acidophilic methanotrophic member of the <it>Verrucomicrobia</it>, strain V4, isolated from the Hell's Gate geothermal area in New Zealand. Similar organisms were independently isolated from geothermal systems in Italy and Russia.</p> <p>Results</p> <p>We report the complete genome sequence of strain V4, the first one from a representative of the <it>Verrucomicrobia</it>. Isolate V4, initially named "<it>Methylokorus infernorum</it>" (and recently renamed <it>Methylacidiphilum infernorum</it>) is an autotrophic bacterium with a streamlined genome of ~2.3 Mbp that encodes simple signal transduction pathways and has a limited potential for regulation of gene expression. Central metabolism of <it>M. infernorum </it>was reconstructed almost completely and revealed highly interconnected pathways of autotrophic central metabolism and modifications of C₁-utilization pathways compared to other known methylotrophs. The <it>M. infernorum </it>genome does not encode tubulin, which was previously discovered in bacteria of the genus <it>Prosthecobacter</it>, or close homologs of any other signature eukaryotic proteins. Phylogenetic analysis of ribosomal proteins and RNA polymerase subunits unequivocally supports grouping <it>Planctomycetes</it>, <it>Verrucomicrobia </it>and <it>Chlamydiae </it>into a single clade, the PVC superphylum, despite dramatically different gene content in members of these three groups. Comparative-genomic analysis suggests that evolution of the <it>M. infernorum </it>lineage involved extensive horizontal gene exchange with a variety of bacteria. The genome of <it>M. infernorum </it>shows apparent adaptations for existence under extremely acidic conditions including a major upward shift in the isoelectric points of proteins.</p> <p>Conclusion</p> <p>The results of genome analysis of <it>M. infernorum </it>support the monophyly of the PVC superphylum. <it>M. infernorum </it>possesses a streamlined genome but seems to have acquired numerous genes including those for enzymes of methylotrophic pathways <it>via </it>horizontal gene transfer, in particular, from <it>Proteobacteria</it>.</p> <p>Reviewers</p> <p>This article was reviewed by John A. Fuerst, Ludmila Chistoserdova, and Radhey S. Gupta.</p

Physics of Auroral Phenomena

Abstract. We have found that some largest deep faults of the lithosphere are manifested in the horizontal component of the Earth&apos;s magnetic field. We have compiled a databank of magnetic stations located outside the lithospheric deep faults using the geological data. Every two chosen magnetic stations must be located nearly on the same corrected geomagnetic latitude, but above different tectonic zones. One of them should be located above the lithospheric deep fault and the other -outside a zone of deep faults. The horizontal geomagnetic field components measured at these stations were compared with each other. It has been shown that horizontal geomagnetic field component at the magnetic station, located above the lithospheric deep fault is much larger, than the value measured at the station located outside the deep fault&apos;s zone. The analysis of the horizontal geomagnetic field components measured at a large number of the magnetic stations located over different tectonic regions has shown that the above mentioned characteristic is quite persistent

Sorting algorithms for single-particle imaging experiments at X-ray free-electron lasers

Modern X-ray free-electron lasers (XFELs) operating at high repetition ratesproduce a tremendous amount of data. It is a great challenge to classify thisinformation and reduce the initial data set to a manageable size for furtheranalysis. Here an approach for classification of diffraction patterns measured inprototypical diffract-and-destroy single-particle imaging experiments at XFELsis presented. It is proposed that the data are classified on the basis of a set ofparameters that take into account the underlying diffraction physics and specificrelations between the real-space structure of a particle and its reciprocal-spaceintensity distribution. The approach is demonstrated by applying principalcomponent analysis and support vector machine algorithms to the simulated andmeasured X-ray data sets

Diagnostic accuracy of swine echinococcosis cytopathological tests and challenges for a differential diagnosis: slaughterhouse data

Echinococcosis disease shows clinical signs similar to many diseases. Hence we report cases that need to be confirmed using appropriate tests. A confirmatory study has been conducted to assess the accuracy of two cytopathological tests, with the histopathology test as the reference standard. The first cytopathological test evaluates the Ziehl Neelsen staining with an epifluorescence microscope (cytopath 1). The second cytopathological test uses the same staining followed by a transmitted light microscope examination (cytopath 2). Of a total of 2524 inspected pigs, 101 suspected cases of echinococcosis were detected, of which 67 were found positive with the two cytopathological tests and the histopathological one. The specificity of cytopath 1 (100 % [95 % CI 100 – 100]) and cytopath 2 (100 % [95 % CI 100;100]) were similar, as well as their respective positive predictive values: 100 % [95 % CI 100 – 100] vs. 100 % [95 % CI 100 – 100]. The sensitivity of cytopath 1 is 79.66 % [95 % CI 69.39 – 89.93], while cytopath 2 equals 66.10 % [95 % CI 54.02 – 78.18]. The difference in sensitivity of both tests was not significant. Negative predictive values found for cytopath 1, and cytopath 2 were 40 [95 % CI 18.53 – 61.47] and 28.57 [95 % CI 11.84 – 45.3], leading to the Generalized Estimating Equations (GEE) Model estimate for an odds ratio of 1.4 [95 % CI 0.41 – 5.2], p = 0.06. Cytopath 1 and cytopath 2 are equivalent in terms of specificity (100 % [95 % CI 100 – 100] vs. 100 % [95 % CI 100;100]) and positive predictive value (100 % [95 % CI 100 – 100]. Cytopath 1 is more sensitive than cytopath 2 but not significant (79.66 % [ 95 % CI 69.39 – 89.93] vs. 66.10 % [95 % CI 54.02 – 78.18]). However, the negative predictive value of cytopath 1 is better than that of cytopath 2: 40 % [95 % CI 18.53 – 61.47] vs. 28.57 % [95 % CI 11.84 – 45.3]

Erratum to: Several Articles in Journal of Applied Mechanics and Technical Physics

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