Pallado-Catalyzed Cascade Synthesis of 2-Alkoxyquinolines from 1,3-Butadiynamides.

A novel synthesis strategy to access 2-alkoxyquinoline derivatives via a palladium-driven cascade reaction is disclosed. Unlike classic methods based on the alkylation of 2-quinolones with alkyl halides, the present method benefits from the de novo assembly of the quinoline core starting from 1,3-butadiynamides. Palladium-catalyzed reaction cascades with -(2-iodophenyl)--tosyl-1,3-butadiynamides and primary alcohols as external nucleophiles proceed under mild reaction conditions and selectively deliver a variety of differently functionalized 4-alkenyl 2-alkoxyquinolines in a single batch transformation.

Persistent Organic Pollutants and Suspended Particulate Matter in Snow of Eastern Siberia in 2009-2023: Temporal Trends and Effects of Meteorological Factors and Recultivation Activities at Former Industrial Area.

Suspended particulate matter (SPM), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCP) were studied in the snow cover at urban and suburban localities in the Irkutsk region, Eastern Siberia for their temporal variations in 2009-2023, daily deposition fluxes (DDFs), and effects of some meteorological factors, as well as the effects of different technogenic activities in the industrial area of the former organochlorine enterprises of Usol'ekhimprom. SPM loads at both stations were found to be at a low level of pollution. The levels of HCB, α + γ-HCH, and ∑,'-DDX were lower than Russian maximum permissible levels (MPLs) in drinking water, groundwater, and surface water for household drinking and cultural purposes.

Iron Catalyzed Dearomatization of Pyridines into Annelated Azepine Derivatives in a One-Step, Three-Component Reaction.

Commercially available Fe(TTP)Cl catalyzes three-component dearomative formal cycloaddition reactions between pyridines, diazo compounds, and coumalates. Diversely substituted annelated seven-membered N-heterocycles could be generated in less than 10 min in one step at room temperature. The reaction is compatible to gram scale.

Antigenic Characterization of Neuraminidase of Influenza A/H7N9 Viruses Isolated in Different Years.

Influenza outbreaks caused by A/H7N9 viruses have occurred since 2013. After 2016, A/H7N9 influenza viruses underwent evolutionary changes. In this study, we examined the antigenic properties of influenza neuraminidase (NA) of A/H7N9 viruses as part of a live influenza vaccine (LAIV).

Media-Driven Pd-Catalyzed Reaction Cascades with 1,3-Diynamides Leading Selectively to Either Indoles or Quinolines.

Divergent Pd-catalyzed reaction cascades with various 1,3-diynamides yielding either 2-amino-3-alkynylindoles or 2-amino-4-alkenylquinolines were established. Omitting or adding TBAF (tetrabutylammonium fluoride) to the reaction of N,N-(2-iodophenyl)(4-toluenesulfonyl)-1,3-diynamides with secondary or primary amines in the presence of KOH in THF and catalytic amounts of Pd(PPh ) completely changed the outcome of the reaction. In the absence of TBAF, 2-amino-3-alkynylindoles were the sole products, while the presence of TBAF switched the product formation to 2-amino-4-alkenylquinolines.

Study of Antibody-Dependent Reactions of Mast Cells and in a Model of Severe Influenza Infection in Mice.

We investigated the reaction of mouse peritoneal mast cells (MCs) after IgG-containing immune complex introduction using A/H5N1 and A/H1N1pdm09 influenza viruses as antigens. The sera of immune mice served as a source of IgG antibodies. The concentration of histamine in the supernatants was determined at 4 hours after incubation with antisera and virus.

Mast cell degranulation and histamine release during A/H5N1 influenza infection in influenza-sensitized mice.

Here we evaluate the role of mast cells in infection with influenza A/H5N1 virus in immunized mice. CBA mice were immunized intramuscularly with formalin-inactivated A/Vietnam/1194/2004 (H5N1)NIBRG-14 (H5N1). Serum samples were obtained on days 7, 12, 14, 21 after immunization.

Complementary Site-Selective Halogenation of Nitrogen-Containing (Hetero)Aromatics with Superacids.

Site-selective functionalization of arenes that is complementary to classical aromatic substitution reactions remains a long-standing quest in organic synthesis. Exploiting the generation of halenium ion through oxidative process and the protonation of the nitrogen containing function in HF/SbF , the chlorination and iodination of classically inert Csp -H bonds of aromatic amines occurs. Furthermore, the superacid-promoted (poly)protonation of the molecules acts as a protection, favoring the late-stage selective halogenation of natural alkaloids and active pharmaceutical ingredients.

Mucosal vaccine based on attenuated influenza virus and the group B Streptococcus recombinant peptides protected mice from influenza and S. pneumoniae infections.

Although many influenza-related deaths are attributable to secondary bacterial infection with S. pneumoniae, vaccines that simultaneously protect against influenza and pneumococcal infection are currently not developed. The aim of our study was to evaluate the possibility to prevent post-influenza pneumococcal infection using an associated vaccine based on live influenza vaccine (LAIV) combined with recombinant polypeptides derived from superficial factors of Group B streptococcus (GBS) determining pathogenicity.

PCBs and OCPs in human milk in Eastern Siberia, Russia: Levels, temporal trends and infant exposure assessment.

The aim of our study is to investigate the spatial distribution of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolites, α- and γ-isomers of hexachlorocyclohexane (HCH) in 155 samples of human milk (HM) from Eastern Siberia (six towns and seven villages in Irkutsk Region, one village of the Republic of Buryatia and one town in Zabaikal'sk Region, Russia), and to examine the dietary and social factors influencing the human exposure to the organochlorines. The median and range of the concentration of six indicator PCBs in HM in 14 localities in Eastern Siberia (114 (19-655) ng g lipids respectively) are similar to levels in the majority of European countries. However, in one village, Onguren, the median and range of levels of six indicator PCBs (1390 (300-3725) ng g lipids) were comparable to levels measured in highly contaminated populations.

Signs of Selection in Synonymous Sites of the Mitochondrial Cytochrome b Gene of Baikal Oilfish (Comephoridae) by mRNA Secondary Structure Alterations.

Studies over the past decade have shown a significant role of synonymous mutations in posttranscriptional regulation of gene expression, which is particularly associated with messenger RNA (mRNA) secondary structure alterations. Most studies focused on prokaryote genomes and the nuclear genomes of eukaryotes while little is known about the regulation of mitochondrial DNA (mtDNA) gene expression. This paper reveals signs of selection in synonymous sites of the mitochondrial cytochrome b gene (Cytb) of Baikal oilfish or golomyankas (Comephoridae) directed towards altering the secondary structure of the mRNA and probably altering the character of mtDNA gene expression.

Access to pyridyl-substituted 1,3,5-triazines from 4H-pyrido[1,3]oxazin-4-ones via a cyclocondensation process.

Pyridyl-substituted 1,3,5-triazines were synthesized in good to excellent yields via an unprecedented one-step cyclocondensation of 4H-pyrido[1,3]oxazin-4-ones with amidines at room temperature or under microwave irradiations. The broad applicability was demonstrated by 33 examples with a variety of amidines and three different 4H-pyrido[1,3]oxazin-4-one chemical series. In addition, a one-pot process from 4H-pyrido[1,3]oxazin-4-one precursors (imide sodium salts) was developed and led to the desired triazines compounds, thus allowing a one-step economy in their global synthetic preparation.

Polychlorinated biphenyls in surface soil in urban and background areas of Mongolia.

Polychlorinated biphenyls (PCBs) were measured in soil in some industrial towns (Ulaanbaatar, Suhbaatar, Erdenet, Darhan, Tsetserleg, Hovd, Ulaangom, Altay, Bayanhongor, Arvayheer, Saynshand, Choybalsan) and in background and rural areas of Mongolia. The average sum of all investigated PCB congeners in soil of Mongolia comes to 7.4 ng/g dry weight (DW) and varies from 0.

[The levels of stable organic pollutants in the breast milk of women living in the Irkutsk region].

The concentrations of stable organic chlorine pollutants (SOCP) in the breast milk of women living in Irkutsk, Baikalsk, and the settlement of Kachug are lower than those in the increased SOCP-burdened areas of the Irkutsk Region (the town of Usolye-Sibirskoye, settlements on the shore of the Baikal Lake) and comparable with those in Russia and industrially developed countries of the world. The content of SOPC is much lower than those in the developing countries where this pesticide continues to be applied. The breast milk levels of OCP, TEQ (polychlorinated dibento-para-dioxines and polychlorinated dibenzofurans) in all towns and individual indicator polychlorinated biphenyls (PCB) in Irkutsk significantly decreased as compared with those in the 1980s.

The influence of soil contamination on the concentrations of PCBs in milk in Siberia.

Although atmospheric deposition is generally the dominant pathway of PCBs into agricultural food chains, soil ingestion by livestock can be important in some cases. The relationship between PCB levels in cow's milk and in pasture soil was studied in the Irkutsk region in Siberia where an historical atmospheric source(s) of PCBs has led to widespread contamination of soil. Milk samples were collected in spring and again in autumn from 18 different farms and analyzed for PCBs.

Sulfation of extracellular polysaccharides of red microalgae: preparation, characterization and properties.

Polysaccharides are natural polymers with a variety of properties that may be translated into significant commercial applications. A program of chemical modifications of the extracellular polysaccharides of red microalgae, such as Porphyridium sp. and Rhodella reticulata, has been undertaken by our group in order to tailor new properties and hence to broaden the spectrum of potential applications.

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in Baikal seal.

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were determined in blubber tissue of one 3 month and two adult female seals from Lake Baikal. High PCDD and PCDF concentrations were found in the Baikal seal. The levels are comparable with those reported for ringed seals (phoca hispida) living in the Baltic sea, and Barrow Strait and Admiralty Inlet in the Canadian Arctic.

[Intraoperative radiation therapy: its technological support, potentials and prospects].

The authors' experience with intraoperative radiotherapy (IORT) in 129 patients with a tumorous process at various sites has demonstrated that in most clinical events, single radiation doses of 10-20 Gy is insufficient to have a persistent local effect and requires additional pre- or postoperative remote irradiation. The use of IORT as a single component of radiation exposure does not lead to significant radiation damages to normal tissues. When IORT is combined with remote irradiation (the latter using doses of 30-60 Gy), 30% of patients develop radiation-induced normal tissue lesions.

[Potentialities of CT with densitometry in the assessment of local diffusion of esophageal cancer].

Computer-aided tomographic (CT) examination of 94 patients with esophageal cancer was carried out. Densitometric analysis of computer image of esophageal tumors making use of profile density histograms is presented for the first time. Objective graphic criteria for assessment of the depth of tumor invasion have been developed.

[Methods for increasing graft survival in esophagogastroplasty].

From their own clinical material the authors revealed that insufficient venous outflow was the main link in the pathogenesis of impaired viability of the pedicle formed from the greater curvature in esophagoplasty. This leads to circulatory disorders in the graft: venous hypertension of up to 34.4 +/- 2.

[Specifics of endocrine regulation of digestion in patients with esophageal neoplasms after esophagogastroplasty].

In 67 patients with esophageal cancer, the peculiarities of endocrine regulation of alimentation after resection and plasty of the esophagus, using an isoperistaltic gastric tube were studied. Of these patients, 15 underwent correction of the disorders revealed. Accelerated evacuation of the content from a gastric transplant is accompanied by atony of the pylorus and is due to relative incompetence of neuroendocrine elements in gastric and duodenal mucosa (presence of a small amount of EC- and P-cells).

Combined therapy of thoracic esophageal cancer.

High rates of esophageal cancer in advanced stages and poor short- and long-term results with surgical treatment have led to the use of combined treatment regimens. There is, however, no unanimity as to the most effective preoperative therapy or the most effective therapeutic tactics. In combined therapy we are in favor of strict compliance with the sequence of abdominal exploration, radiotherapy, and finally surgery.