78 research outputs found

    Temperature-sensitive Tien Shan tree ring chronologies show multi-centennial growth trends

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    Two millennia-length juniper ring width chronologies, processed to preserve multi-centennial growth trends, are presented for the Alai Range of the western Tien Shan in Kirghizia. The chronologies average the information from seven near-timberline sampling sites, and likely reflect summer temperature variation. For comparison, chronologies are also built using standard dendrochronological techniques. We briefly discuss some qualities of these "inter-decadal” records, and show the low frequency components removed by the standardization process include a long-term negative trend in the first half of the last millennium and a long-term positive trend since about AD 1800. The multi-centennial scale Alai Range chronologies, where these trends are retained, are both systematically biased (but in an opposite sense) in their low frequency domains. Nevertheless, they represent the best constraints and estimates of long-term summer temperature variation, and reflect the Medieval Warm Period, the Little Ice Age, and a period of warming since about the middle of the nineteenth centur

    Geminal systems 64.*N-Alkoxy-N-chloroureas and N,N-dialkoxyureas

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    Molecular and crystal structures of N-alkoxy-N-chloroureas and N,N-dialkoxyureas were studied together with those of N-alkoxyureas as reference compounds. N-Alkoxy-N-chloroureas were found to have an elongated N—Cl bond and a shortened N—O(Alk) bond due to the nO(Alk)*N—Cl anomeric effect. Alcoholysis of N-alkoxy-N-chloro derivatives of urea, N´-arylureas, and carbamates in the presence of silver trifluoroacetate leads to sterically hindered N,N-dialkoxyureas, N,N-dialkoxy-N´-arylureas, and N,N-dialkoxycarbamates, respectively

    N-Chloro-N-alkoxyureas: synthesis, structure and properties

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    The XRD studies of N-chloro-N-alkoxyureas 1, 2 have revealed the high pyramidality of the amide nitrogen in the O–N–Cl group caused by nO–s*N–Cl anomeric effect, the other sequence of this effect is anionic lability of the chlorine atom; nucleophilic substitution at the nitrogen depends on the N'-substitutent nature: chlorine atoms in ureas 1 and 5 are replaced by outer nucleophile whereas, under the same conditions, ureas 2–4 undergo cyclization into 1-alkoxybenzimidazolin-2-ones 10–12

    ДІАГНОСТИКА СИНДРОМУ ПРОФЕСІЙНОГО ВИГОРАННЯ ЛІКАРІВ БАГАТОПРОФІЛЬНОГО ЗАКЛАДУ ОХОРОНИ ЗДОРОВ’Я

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    The articlre presents a brief theoretical review of professional burnout problem, highlights its structure forms of influence on psychosomatic health of workers (distinguishing the probessions in risk group) and effectiveness of their work the posibble results were deterinined. The article also adduces the results of conducted research among the doctors of multidisciplinary public healt establishment with detailed explanation of the obtained results. В статье приводится краткий теоретический обзор проблемы профессионального выгорания, освещаются структура, формы воздействия на психосоматическое здоровье работников (с выделением профессий, которые находятся в группе риска) и эффективность их труда, определены возможные последствия. Также в статье описаны результаты проведенного исследования среди врачей многопрофильного учреждения здравоохранения с подробным объяснением полученных результатов.У статті надається стислий теоретичний огляд проблеми професійного вигорання, висвітлюються його структура, форми впливу на психосоматичне здоров’я працівників (з виділенням професій, які знаходяться в групі ризику) та ефективність їхньої праці, визначені можливі наслідки. Також у статті описані результати проведеного дослідження серед лікарів багатопрофільного закладу охорони здоров’я з детальним поясненням отриманих результатів

    Synthesis and structure of new N-alkoxy-N-(1-pyridinium)urea chlorides

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    New N-[1-(4-amino)pyridinium]-N-methoxyurea chloride, N-[1-(2-amino)pyridinium]-N-methoxyurea chloride and their analogs were synthesized by N-alkoxy-N-chloroureas reaction with the proper pyridines in acetonitrile or ether solution by improved procedure. XRD study of N-[1-(4-amino)pyridinium]-N-methoxyurea and N-[1-(2 amino)pyridinium]-N-methoxyurea revealed the elongation of N-N+ bonds and some shortening of MeO-N bonds, qunonoid deformation of pyridine rings compare to it unsubstituted analog. The substantial pyramidality of central nitrogen atom in O-N-N+ moiety and N-C carbamoyl bonds difference were established too. The structure summary of N-alkoxy-N-(1-pyridinium)ureas salts and other derivatives of 1-(N-alkoxyamino)pyridinium salts has been done

    The Effectiveness of MALDI ToF Mass Spectrometry in Identification of <i>Francisella tularensis</i> Strains

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    The aim of the study was to evaluate the effectiveness of MALDI‑ToF mass spectrometry in the identification of collection and newly isolated strains of tularemia pathogen using the database “Protein profiles of mass spectra of microorganisms belonging to I–II pathogenicity groups for the MALDI Biotyper software”.Materials and methods. We investigated 142 strains of Francisella tularensis, including 59 collection strains and 83 newly isolated ones. Bacteriological, molecular-genetic and proteomic research methods were used to identify them. The acquisition of mass spectra, analysis, generation and expansion of reference libraries were performed on a mass analyzer “Microflex LT” using FlexControl v. 3.3, FlexAnalysis v. 3.3, and MALDI Biotyper 3.0 software packages. The cluster analysis was performed using the BioNumerics 7.6 software.Results and discussion. The possibility of identifying tularemia pathogen has been assessed using the extended database for MALDI Biotyper 3.0 “Protein profiles of mass spectra of microorganisms belonging to I–II pathogenicity groups for the MALDI Biotyper software”. During identification to the species level, the significance of mass spectrometry results for collection strains and newly isolated ones was 91.5 % and 97.6 %, respectively. In determining the genus appurtenance, the reliability of identification was 100 %. Thus, the MALDI‑ToF mass spectrometry method allows for accurate species and genus identification of F. tularensis strains. Based on the cluster analysis of 66 F. tularensis strains in BioNumerics 7.6 software using «Pearson correlation» and the UPGMA algorithm, the possibility of subspecies differentiation has been evaluated. Due to the similarity of protein profiles of F. tularensis strains, a clear differentiation into subspecies could not be achieved. It is necessary to use other options for sample preparation, new generation devices with higher resolution, as well as apply additional approaches and analysis tools for successful subspecific differentiation
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