299 research outputs found
Some Aspects of Oxidation-Reduction Reactions under Carbon-Bearing Flux Welding
The authors have completed thermodynamic calculations of oxidation-reduction processes under submerged arc welding with application of carbon containing additive. The calculations have shown that carbon, due to its high reducing properties under Т=1950-2200 K, introduced into the system can significantly decrease the amount of non-metallic inclusions in the weld metal and so improve its mechanical properties
Improvement of bait method for isolation of entomopathogenic fungi from soil
An increase of the sensitivity of the bait method of entomopathogenic fungi isolation from the soil was registered under the use of larvae Galleria mellonella envenomated by ectoparasitoid Habrobracon hebetor. Further, modified method will allow to isolate fungi from soil with low titer of colony forming unit, particularly from steppes soils.Работа выполнена при финансовой поддержке РФФИ (проект 15–04–02322_а) и Президента РФ (МК–6278.2015.4.)
Comparison of the Endoscopic Picture in Case of Complications of the upper Gastrointestinal Tract Caused by the Use of Antithrombotic Agents and Non-Steroidal Anti-Inflammatory Drugs
Intaking antithrombotic funds (ATA) and non-steroidal anti-inflammatory drugs (NSAIDs) is one of the most frequent causes of pathology in gastrointestinal (GI) tract.The purpose of the study: comparison of pathological changes of the mucous membrane in the upper GI tract, that occur against the background of ATA and NSAIDs admission.Material and methods. Endoscopic data of two groups of patients taking ATA and NSAIDS have been compared. The first group of 448 patients from the 10th Gastrointestinal Department in N.N. Burdenko Main Military Clinical Hospital was on record from 2013 to 2017. The patients had erosive ulcerous changes of gastrointestinal mucosa, occurred against the background of the ATA admission. The second group comprised 6431 patients with rheumatic diseases. They were hospitalized in the clinic of V.A. Nasonova Research Institute of Rheumatology in the period from 2007 to 2016 and took NSAIDs regularly.Results. Duodenal and gastric ulcer changes in gastric mucosa and duodenal ulcers were identified in 168 (37.5 %) patients taking ATA and in 1691 (26.3 %) patient treated with NSAIDS. Structure of pathology varied. So, against the background of ATA and NSAIDS admission, the number of acute gastric ulceration amounted to 6.5 % and 15.5 % (p < 0.001); acute ulcers duodenal was 2.9 % and 4.9 %; combined ulcerative lesions of gastric and duodenal was 2.9 % and 2.0 %; multiple erosions of gastroduodenal mucosa were 52.4 % and 15.7 % (p < 0.001); single erosion was 35. 1% and 61.6 %. The factor of ulcer history and age ≥ 65 years old increased significantly the risk of duodenal and gastric ulcer changes in patients taking ATA and NSAIDs: OR 5.182 (95% CI 2.701–9.942) and 3.24 (95% CI 2.19–5.34), 4.537 (95% CI 2.036–10.11) and 2.016 (95% CI 1.230–2.917) respectively. Intaking of proton pump inhibitor (PPI) reduced significantly the risk of complications for both ATA and NSAIDs: OR 0.329 (95% CI 0.199–0.546) and 0.317 (95% CI 0.210–0.428) respectively.Conclusion. The structure of pathology of mucous in the upper gastrointestinal tract that arose against the backdrop of ATA and NSAIDs admission is different. The first is characterized by a multiple erosion, while the second one has single acute distal gastric ulcers. The ulcerative history and advanced age of patients increase significantly the risk of complications concerning the gastroduodenal mucosa when using ATA and NSAIDs. PPI is the effective means of preventing this pathology
Links between soil bacteriobiomes and fungistasis toward fungi infecting the Colorado potato beetle
Entomopathogenic fungi can be inhibited by different soil microorganisms, but the effect of a soil microbiota on fungal growth, survival, and infectivity toward insects is insufficiently understood. We investigated the level of fungistasis toward Metarhizium robertsii and Beauveria bassiana in soils of conventional potato fields and kitchen potato gardens. Agar diffusion methods, 16S rDNA metabarcoding, bacterial DNA quantification, and assays of Leptinotarsa decemlineata survival in soils inoculated with fungal conidia were used. Soils of kitchen gardens showed stronger fungistasis toward M. robertsii and B. bassiana and at the same time the highest density of the fungi compared to soils of conventional fields. The fungistasis level depended on the quantity of bacterial DNA and relative abundance of Bacillus, Streptomyces, and some Proteobacteria, whose abundance levels were the highest in kitchen garden soils. Cultivable isolates of bacilli exhibited antagonism to both fungi in vitro. Assays involving inoculation of nonsterile soils with B. bassiana conidia showed trends toward elevated mortality of L. decemlineata in highly fungistatic soils compared to low-fungistasis ones. Introduction of antagonistic bacilli into sterile soil did not significantly change infectivity of B. bassiana toward the insect. The results support the idea that entomopathogenic fungi can infect insects within a hypogean habitat despite high abundance and diversity of soil antagonistic bacteria
Efficient laser pumping of a Co:MgF2 crystal by radiation with the wavelength 1.3 μm
A Co:MgF2 crystal laser was pumped with radiation (λ = 1.35 μm) from a neodymium glass laser. This resulted in generation of radiation of 1.6 J energy with a quantum efficiency of 67%. The Co:MgF2 crystal could thus be used for efficient conversion of λ = 1.3 μm laser beams, such as those from iodine photodissociation and chemical oxygen-iodine lasers
Fungus Metarhizium robertsii and neurotoxic insecticide affect gut immunity and microbiota in Colorado potato beetles
Fungal infections and toxicoses caused by insecticides may alter microbial communities and immune responses in the insect gut. We investigated the effects of Metarhizium robertsii fungus and avermectins on the midgut physiology of Colorado potato beetle larvae. We analyzed changes in the bacterial community, immunity- and stress-related gene expression, reactive oxygen species (ROS) production, and detoxification enzyme activity in response to topical infection with the M. robertsii fungus, oral administration of avermectins, and a combination of the two treatments. Avermectin treatment led to a reduction in microbiota diversity and an enhancement in the abundance of enterobacteria, and these changes were followed by the downregulation of Stat and Hsp90, upregulation of transcription factors for the Toll and IMD pathways and activation of detoxification enzymes. Fungal infection also led to a decrease in microbiota diversity, although the changes in community structure were not significant, except for the enhancement of Serratia. Fungal infection decreased the production of ROS but did not affect the gene expression of the immune pathways. In the combined treatment, fungal infection inhibited the activation of detoxification enzymes and prevented the downregulation of the JAK-STAT pathway caused by avermectins. The results of this study suggest that fungal infection modulates physiological responses to avermectins and that fungal infection may increase avermectin toxicosis by blocking detoxification enzymes in the gut
Perspectives of using Illumina MiSeq for identification of arbuscular mycorrhizal fungi
Arbuscular mycorrhiza fungi (AMF) form one of the most common symbiosis with the majority of land plants. AMF supply the plant with various mineral elements, primarily phosphorus, and improve the water supply. The search for the most effective AMF strains for symbiosis and the creation of microbial preparations on that basis is an important task for modern biology. Owing to the difficulties of cultivation without a host plant and their high genetic polymorphism, identifying AMF is very difficult. The high number of cryptic species often also makes morphological identification unreliable. Recent years have seen growth in the number of AMF biodiversity studies performed by modern NGS-based methods, Illumina MiSeq in particular. Currently, there are still many questions that remain for the identification of AМF. The most important are whether conservative or variable sequences should be used to select a marker for barcoding and whether universal primers or those specific to AMF should be used. In our work, we have successfully used universal primers ITS3 and ITS4 for the sequencing in Illumina MiSeq of the 5.8S rDNA – ITS2 region of the 35S rRNA genes, which contain both a conservative and variable regions. The molecular genetic approach for AMF identification was quite effective and allowed us to reliably identify eight of nine isolates to the species level: five isolates of Rhizophagus irregularis, and one isolate of R. invermaius, Paraglomus laccatum, and Claroideoglomus etunicatum, respectively. For all five R. irregularis isolates high variability in the ITS region and the absence of ecotopic-related molecular characters in the ITS2 region were demonstrated. The NCBI data is still insufficient for accurate AMF identification of Acaulospora sp. isolates from the genus to the species level
Tunka Advanced Instrument for cosmic rays and Gamma Astronomy
The paper is a script of a lecture given at the ISAPP-Baikal summer school in
2018. The lecture gives an overview of the Tunka Advanced Instrument for cosmic
rays and Gamma Astronomy (TAIGA) facility including historical introduction,
description of existing and future setups, and outreach and open data
activities.Comment: Lectures given at the ISAPP-Baikal Summer School 2018: Exploring the
Universe through multiple messengers, 12-21 July 2018, Bol'shie Koty, Russi
Horizontal transmission of entomopatho genic fungi by ectoparasitoid Habrobra conhebetor
Experiments were carried out on the laboratory system Galleria mellonella (Lepidoptera, Piraliidae) — Habrobracon hebetor (Hymenopera, Braconidae) — Beauveria bassiana (Hypocreales, Cordycipitaceae). We found that contamination of H. hebetor ovipositor with low titers of conidia B. bassiana and following envenomation of G. mellonella larvae led to mycoses followed by host colonization and conidia formation. In addition H. hebetor females transmitted fungal conidia from infected (6 hours post inoculation with conidia) to native G. mellonella larvae, and this transmission led to successful mycosis of native host larvae. The decreasing of cellular and humoral immune reactions, significant increasing of adhesion and germination of fungus on cuticle of envenomated larvae were registered. As result susceptibility of envenomated G. mellonella larvae to fungal infection was increased in thousands times compared with native control. Thus the paralyzation and strong inhibition of immune reactions of larvae by venom of H. hebetor allow minimize quantity of transmitting with parasitoid fungal inoculum. We assumed that «paralyzing» parasitoids can take part in transmission of entomopathogenic fungi particularly in out-of-the-way places (shelters) as well as disperse of fungal infection under low density of hosts.Работа выполнена при финансовой поддержке РФФИ (проект 15–04–02322_а) и Президента РФ (МК–6278.2015.4.)
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