Application of palladium complexes bearing acyclic amino(hydrazido)carbene ligands as catalysts for copper-free Sonogashira cross-coupling

Metal-mediated coupling of one isocyanide in cis-[PdCl2(CNR1)2] (R1 = C6H11 (Cy) 1, tBu 2, 2,6-Me2C6H3 (Xyl) 3, 2-Cl-6-MeC6H34) and various carbohydrazides R2CONHNH2 [R2 = Ph 5, 4-ClC6H46, 3-NO2C6H47, 4-NO2C6H48, 4-CH3C6H49, 3,4-(MeO)2C6H310, naphth-1-yl 11, fur-2-yl 12, 4-NO2C6H4CH213, Cy 14, 1-(4-fluorophenyl)-5-oxopyrrolidine-3-yl 15, (pyrrolidin-1-yl)C(O) 16, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propane-1-yl 17, EtNHC(O) 18] or sulfohydrazides R3SO2NHNH2 [R3 = Ph 19, 4-MeC6H420] led to a series of (hydrazido)(amino)carbene complexes cis-[PdCl2{C(NHNHX)double bond; length as m-dashN(H)R1}(CNR1)]; X = COR2, SO2R3 (21–48, isolated yields 60–96%). All prepared species were characterized by elemental analyses (C, H, N), HR ESI+-MS, IR, 1H and 13C{1H} NMR spectroscopy, and by a single-crystal X-ray diffraction for 38. Complexes 21–48 demonstrated excellent activity as catalysts in copper-free Sonogashira coupling of aryl iodides and a variety of aromatic terminal alkynes. Catalytic system runs in environmentally benign EtOH ensuring product yields of up to 75–96% and TONs of up to 104. Mechanism of the copper-free Sonogashira catalytic cycle involving 21–48 as catalysts was proposed upon identification of key intermediates using HRESI-mass

Synthesis, structures, and reactivity of isomers of [RuCp*(1,4- (Me2N)2C6H4)]2

[RuCp*(1,3,5-R3C6H3)]2 {Cp* = &eta;5-pentamethylcyclopentadienyl, R = Me, Et} have previously been found to be moderately air stable, yet highly reducing, with estimated D+/0.5D2 (where D2 and D+ represent the dimer and the corresponding monomeric cation, respectively) redox potentials of ca. &minus;2.0 V vs. FeCp2+/0. These properties have led to their use as n-dopants for organic semiconductors. Use of arenes substituted with &pi;-electron donors is anticipated to lead to even more strongly reducing dimers. [RuCp*(1-(Me2N)-3,5-Me2C6H3)]+PF6&minus; and [RuCp*(1,4-(Me2N)2C6H4)]+PF6&minus; have been synthesized and electrochemically and crystallographically characterized; both exhibit D+/D potentials slightly more cathodic than [RuCp*(1,3,5-R3C6H3)]+. Reduction of [RuCp*(1,4-(Me2N)2C6H4)]+PF6&minus; using silica-supported sodium&ndash;potassium alloy leads to a mixture of isomers of [RuCp*(1,4-(Me2N)2C6H4)]2, two of which have been crystallographically characterized. One of these isomers has a similar molecular structure to [RuCp*(1,3,5-Et3C6H3)]2; the central C&ndash;C bond is exo,exo, i.e., on the opposite face of both six-membered rings from the metals. A D+/0.5D2 potential of &minus;2.4 V is estimated for this exo,exo dimer, more reducing than that of [RuCp*(1,3,5-R3C6H3)]2 (&minus;2.0 V). This isomer reacts much more rapidly with both air and electron acceptors than [RuCp*(1,3,5-R3C6H3)]2 due to a much more cathodic D2˙+/D2 potential. The other isomer to be crystallographically characterized, along with a third isomer, are both dimerized in an exo,endo fashion, representing the first examples of such dimers. Density functional theory calculations and reactivity studies indicate that the central bonds of these two isomers are weaker than those of the exo,exo isomer, or of [RuCp*(1,3,5-R3C6H3)]2, leading to estimated D+/0.5D2 potentials of &minus;2.5 and &minus;2.6 V vs. FeCp2+/0. At the same time the D2˙+/D2 potentials for the exo,endo dimers are anodically shifted relative to those of [RuCp*(1,3,5-R3C6H3)]2, resulting in much greater air stability than for the exo,exo isomer. &nbsp;</p

The adaptive potential of North American subtype H7N2 avian influenza viruses to mammals

Introduction. H7 subtype avian influenza viruses causing severe epizootics among birds are phylogenetically different in the Eastern and Western hemispheres. Numerous human infections caused by these viruses in the Eastern hemisphere indicate that H7 viruses can overcome the interspecies barrier and pose a potential threat of a new pandemic.The H7N2 viruses with deletion of amino acids 221–228 (H3 numbering) in hemagglutinin (HA) had been circulating among poultry in the Western Hemisphere during 1996–2006, and had once again been detected in 2016 in an animal shelter, where they caused cat diseases. The objective of this study is to elucidate the mechanism of adaptation to mammals of North American H7N2 influenza viruses with deletion in HA. Materials and methods. The A/chicken/New Jersey/294598-12/2004 (H7N2) virus was adapted to mice by the lung passages. Complete genomes of original and mouse-adapted viruses were analyzed. The receptor specificity and thermostability of viruses, HA activation pH and virulence for mice were determined. Results. The non-pathogenic H7N2 avian influenza virus became pathogenic after 10 passages in mice. Amino acid substitutions occurred in five viral proteins: one in PB2 (E627K), NA (K127N), NEP (E14Q), four in HA and six in NS1. Mutations in HA slightly changed receptor specificity but increased the pH of HA activation by 0.4 units. The NS1 protein undergone the greatest changes in the positions (N73T, S114G, K118R, G171A, F214L and G224R), where amino acid polymorphisms were observed in the original virus, but only minor amino acid variants have been preserved in the mouse adapted variant. Conclusion. The results show that H7N2 viruses have the potential to adapt to mammals. The increase in virulence is most likely due to the adaptive E627K mutation in PB2 and possibly in HA

Моделирование функциональных кист яичников путем введения фолликулостимулирующего гормона

Aim. To study the morphofunctional state of ovaries after the introduction of recombinant FSH. Materials and methods. Two groups of mature female Wistar rats were used in the study. The experimental group consisted of 35 rats with a model of follicular ovarian cysts, while 25 rats were in the control group.Rats were taken out of the experiment on days 3, 7, 15, 30 and 60. Paraffin slides of ovaries were stained with hematoxylin and eosin by Van Gieson. Histological and morphometric investigations were performed.Results. On day 7 of FSH administration, the maximum increase in the size of the ovaries was observed due to the formation of single-cell follicular cysts. Rats in the experimental group showed a marked decrease in the number of growing follicles on day 7 and 15. The increase in atretic bodies and follicles in comparison with the control group was observed on day 7 and lasted until the end of the experiment. Additionally, on day 7 of the experiment, hyperemia and vasoconstriction were noted. The number of yellow bodies decreased during the experiment, and an increase in collagen formation occurred starting from day 15 of the experiment.Conclusion. The introduction of follicle-stimulating hormone for 7 days leads to disruption of folliculogenesis, strengthening of atresia in the ovaries, and the formation of functional cysts.Цель исследования. Изучить морфологические изменения яичников при введении рекомбинантного фолликулостимулирующего гормона.Материал и методы. Эксперимент проведен на половозрелых белых самках крыс линии Wistar. Основную группу составили 35 животных с моделью функциональных кист яичников, контрольную – 25 интактных животных. Крысы выводились из эксперимента на 3-и, 7-е, 15-, 30- и 60-е сут. Проведены гистологическое и морфометрическое исследования на депарафинированных срезах яичников, окрашенных гематоксилином и эозином и по Ван Гизону.Результаты. На 7-е сут введения фолликулостимулирующего гормона наблюдалось максимальное увеличение размеров яичников за счет формирования однокамерных функциональных кист. У животных основной группы отмечалось выраженное снижение количества растущих фолликулов на 7- и 15-е сут.Увеличение количества атретических фолликулов и тел по сравнению с таковым в группе контроля наблюдалось с 7-х сут и продолжалось до 60-х сут эксперимента. На 7-е сут эксперимента отмечались гиперемия и полнокровие сосудов. Количество желтых тел уменьшалось в ходе эксперимента. Отмечалось усиление процессов коллагенообразования, начиная с 15-х сут эксперимента.Заключение. Введение фолликулостимулирующего гормона в течение 7 сут приводит к нарушению процессов фолликулогенеза, усилению процессов атрезии в яичниках и формированию функциональных кис

Fine-mapping analysis including over 254,000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes

Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development

Foreign War Prisoners in the Astrakhan Province in the Years of the First World War and the Russian Revolution

The article is devoted to the study of various aspects of military captivity, which became a mass phenomenon (“mass experience”) in the years of the First World War and the revolutionary events in Russia and which influenced both the individual fate of war prisoners and different sides of the development of society. The article presents data on the number of war prisoners located in the years of war and revolution on the territory of the Astrakhan province, their categories and ethnic composition. The majority of war prisoners were soldiers of the German, Austro-Hungarian armies. The largest number of war prisoners on the territory of the province was recorded in May 1918. On the basis of documentary material, most of which is first introduced in the scientific use, the war prisoners’ accommodation, provision of clothing, food, medical care is researched. The placement of the contingent of war prisoners and their number depended on the needs of the region in labour force. War prisoners were sent to work on the municipal facilities in the provincial center and district towns, were attached to joint-stock and private enterprises, worked as doctors and paramedics in hospitals. The situation of war prisoners fully depended on socio-economic and political situation in the country. The problems of supply of war prisoners with clothing and food aggravated with the economic and political crisis in the country as well as rising prices and were common to all categories of population who needed support. The deterioration of living conditions led to increase in diseases, epidemics and deaths among the prisoners. Local authorities made efforts to supply war prisoners with food and provide with higher wages and hospitals. After the events of February 1917 there were hopes for mitigation of the regime of war prisoners, but visible improvement did not follow and the weakening supervision of war prisoners resulted in the growth of prison breaks

In Situ EXAFS-Derived Mechanism of Highly Reversible Tin Phosphide/Graphite Composite Anode for Li-Ion Batteries

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim A novel Sn4P3/graphite composite anode material with superior capacity and cycling performance (651 mA h g−1 after 100 cycles) is investigated by in situ X-ray absorption spectroscopy. Extended X-ray absorption fine structure modeling and detailed analysis of local environment changes are correlated to the cell capacity and reveal the mechanism of lithiation/delithiation process. Results show that in the first two lithiation/delithiation cycles crystalline Sn4P3 is fully converted to an amorphous SnPx phase, which in further cycles participates in reversible conversion and alloying reactions. The superior reversibility of this material is attributed to the highly dispersed SnPx in the graphite matrix, which provides enhanced electrical conductivity and prevents aggregation of Sn clusters during the lithiation/delithiation process. The gradual capacity fading in long-term cycling is attributed to the observed increase in the size and the amount of metallic Sn clusters in the delithiated state, correlated to the reduced recovery of the SnPx phase. This paper reveals the mechanism responsible for the highly reversible tin phosphides and provides insights for improving the capacity and cycle life of conversion and alloying materials