Use of dimephosphon in pathogenetic therapy of experimental tuberculosis]

The results of a study of a new synthetic drug dimephosphon used as a pathogenetic means in the treatment of experimental tuberculosis are presented. Dimephosphon was found to be responsible for both the in vivo and in vitro decrease of the degree of MBT resistance to rifampicin. The findings of macroscopic, histologic and bacteriologic examinations demonstrated a significant increase in the effectiveness of antituberculous therapy. Dimephosphon monotherapy in mice elicited manifested stimulation of peritoneal macrophages: increase in O2- production, and decline in extracellular 5-nucleotidase activity. Nemolysine-synthetic cellular splenic activity in mice rose essentially. No direct stimulating influence of dimephosphon on functional macrophage activity in vitro was found.     

Effect of antibacterial chemotherapeutic preparations of the synthesis of p-aminohil'puric acid in rat liver slices

Summary The effect of chemotherapeutic preparations on the synthesis of peptide bonds was studied.The reaction of synthesis of para-aminohippuric acid (PAHA) in sections of a rat's liver from para-aminobenzoic acid (PABA) and glycine was used. This method was described by P. P. Cohen and R. W. Gilwery. It was established that antituberculous chemotherapeutic preparation Tubazid, Ftivazid, Tibon, and streptomycm do not disturb biosynthesis of para-aminohippuric acid by liver slices. Penicillin, chloramphenicol. syntomycin, dextromycetin and chlortetracyclin in low concentrations, which correspond to therapeutic, have no effect on the above reactions of biosynthesis. In high concentrations these drugs suppress this reaction up to complete inhibition. Depression of reaction of biosynthesis of PAHA by chloramphenicol and its stereolsomers, penicillin, and chlortetracyclin may be explained by similarity of the chemical structure of the depressing substances with the products of this reaction.Presented by V. V. Zakusov, Member AMS USSR     

Incidence of urination disorders and erectile dysfunction after surgical treatment of congenital anorectal defects in children

For assessment of the incidence and characteristics of urination disorders and erectile dysfunction after radical surgical treatment of anorectal congenital defects in children, 60 patients (12 girls, 48 boys) without urination disorders before operation, who have undergone 1-4 proctoplasties were examined. Their was Hirschsprung's disease in 20 patients, anorectal atresia in 40 patients. Iatrogenic urination disorders and erectile dysfunction were revealed in 38 (63.3%) patients, majority of them (24) underwent repeated proctoplasty. The main urination disorders were urinary incontinence (30 patients), infravesical obstruction (10), hyporeflexion of urinary bladder. Erectile dysfunction after operation was in 11 (34.4%) patients from 32. The combination of disorders was revealed in 17 (44.7%) patients. Primary radical operations in children with anorectal defects often cause iatrogenic urination disorders and erectile dysfunction. The number of complications increases progressively after repeated proctoplasty. It is necessary to improve the treatment and the methods of surgical correction bearing in mind the risk of iatrogenic disorders of genitourinary apparatus.     

The Influence of biotinylation of 2F5 antibody on peptide selection from the combinatorial phage library

The effect of biotinylation of monoclonal antibodies (MAbs) on the yield and repertoire of peptides selected by biopanning is discussed in the present study. A comparative analysis of peptides selected from a phage library using the biotinylated and nonbiotinylated MAb 2F5 was performed. The yield of the peptides homologous to the native epitope was observed to be 1.7 times higher for the biotinylated antibodies, whereas the use of the nonbiotinylated antibodies in the enzyme-linked immunoassay (ELISA) resulted in a greater binding capacity of the selected phages with MAb 2F5. It is notable that the phages, displaying peptides that have a fouror five-amino-acid sequence similarity with the native epitope, demonstrate the highest binding affinity to the antibodies. The phages exposing peptides with three-amino-acid sequence similarity exhibit various binding affinities. In summary, the results have revealed that a rational biopanning protocol should be chosen according to the aim of each particular study.     

Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf

The East Siberian Arctic Shelf holds large amounts of inundated carbon and methane (CH₄). Holocene warming by overlying seawater, recently fortified by anthropogenic warming, has caused thawing of the underlying subsea permafrost. Despite extensive observations of elevated seawater CH₄ in the past decades, relative contributions from different subsea compartments such as early diagenesis, subsea permafrost, methane hydrates, and underlying thermogenic/ free gas to these methane releases remain elusive. Dissolved methane concentrations observed in the Laptev Sea ranged from 3 to 1,500 nM (median 151 nM; oversaturation by ∼3,800%). Methane stable isotopic composition showed strong vertical and horizontal gradients with source signatures for two seepage areas of δ¹³C-CH₄ = (−42.6 ± 0.5)/(−55.0 ± 0.5) ‰ and δD-CH₄ = (−136.8 ± 8.0)/(−158.1 ± 5.5) ‰, suggesting a thermogenic/natural gas source. Increasingly enriched δ¹³C-CH₄ and δD-CH₄ at distance from the seeps indicated methane oxidation. The Δ¹⁴C-CH₄ signal was strongly depleted (i.e., old) near the seeps (−993 ± 19/−1050 ± 89‰). Hence, all three isotope systems are consistent with methane release from an old, deep, and likely thermogenic pool to the outer Laptev Sea. This knowledge of what subsea sources are contributing to the observed methane release is a prerequisite to predictions on how these emissions will increase over coming decades and centuries.

The East Siberian Arctic Shelf (ESAS) is the world’s largest and shallowest shelf sea system, formed through inundation of northeast Siberia during sea level transgression in the early Holocene. The ESAS holds substantial but poorly constrained amounts of organic carbon and methane (CH₄). These carbon/methane stores are contained in unknown partitions as gas hydrates, unfrozen sediment, subsea permafrost, gas pockets within and below the subsea permafrost, and as underlying thermogenic gas (1–3). Methane release to the atmosphere from these compartments could potentially have significant effects on the global climate (4, 5), yet there are large uncertainties regarding the size and the vulnerability toward remobilization of these inaccessible and elusive subsea carbon/methane pools. Conceptual development and modeling have predicted that warming of the ESAS system by a combination of geothermal heat and climate-driven Holocene heat flux from overlying seawater, recently further enhanced by Anthropocene warming, may lead to thawing of subsea permafrost (6, 7). Subsea permafrost drilling in the Laptev Sea, in part at the same sites as 30 y ago, has recently confirmed that the subsea permafrost has indeed come near the point of thawing (8). In addition to mobilization of the carbon/methane stored within the subsea permafrost, its degradation can also lead to the formation of pathways for gaseous methane from underlying reservoirs, allowing further methane release to the overlying water column (3, 9).Near-annual ship-based expeditions to the ESAS over the past two decades have documented widespread seep locations with extensive methane releases to the water column (3, 10). Methane levels are often found to be 10 to 100 times higher than the atmospheric equilibrium and are particularly elevated in areas of strong ebullition from subsea gas seeps (“methane hotspots”). Similarly, elevated dissolved methane concentrations in bottom waters appear to be spatially related to the thermal state of subsea permafrost as deduced from modeling results and/or geophysical surveys (7, 9). Currently, we lack critical knowledge on the quantitative or even relative contributions of the different subsea pools to the observed methane release, a prerequisite for robust predictions on how these releases will develop. An important distinction needs to be made between pools that release methane gradually, such as methane produced microbially in shallow sediments during early diagenesis or in thawing subsea permafrost, versus pools with preformed methane that may release more abruptly once pathways are available, such as from disintegrating methane hydrates and pools of thermogenic (natural) gas below the subsea permafrost. Multidimensional isotope analysis offers a useful means to disentangle the relative importance of these different subsea sources of methane to the ESAS: Stable isotope data (δ¹³C-CH₄ and δD-CH₄) provide useful information on methane formation and removal pathways, and the radiocarbon content of methane (Δ¹⁴C-CH₄) helps to determine the age and methane source reservoir (see SI Appendix, text S1 for details on these isotope systematics and typical isotopic signatures for the ESAS subsea system).Here, we present triple-isotope–based source apportionment of methane conducted as part of the Swedish–Russian–US investigation of carbon–climate–cryosphere interactions in the East Siberian Arctic Ocean (SWERUS-C3) program. To this end, the distribution of dissolved methane, its stable carbon and hydrogen isotope composition, as well as natural radiocarbon abundance signature, were investigated with a focus on the isotopic fingerprint of methane escaping the seabed to pinpoint the subsea sources of elevated methane in the outer Laptev Sea.     

Beyond bone biology: Lessons from team science

Today, research in biomedicine often requires the knowledge and technologies in diverse fields. Therefore, there is an increasing need for collaborative team science that crosses traditional disciplines. Here, we discuss our own lessons from both interdisciplinary and transdisciplinary teams, which ultimately ushered us to expand our research realm beyond bone biology.     

Concrete by Preplaced Aggregate Method Using Silica Fume and Polypropylene Fibres

Preplaced aggregate concrete (PAC) is prepared in two steps, with the coarse aggregate being initially laid down in the formwork, after which a specialised grout is injected into it. To enhance the properties of concrete and to reduce the emission of CO₂ produced during the production of cement, supplementary cementitious materials (SCMs) are used to partially substitute ordinary Portland cement (OPC). In this study, 100 mm × 200 mm (diameter x height) PAC cylinders were cast with 10 per cent of cement being substituted with silica fume; along with that, 1.5% dosage of Macro polypropylene fibres were also introduced into the coarse aggregate matrix. Compressive strength test, splitting tensile strength test, mass loss at 250 °C, and compressive strength at 250 °C were performed on the samples. PAC samples with 10% of cement replaced with Silica Fume (SPAC) were used as control samples. The primary objective of this study was to observe the effect of the addition of Polypropylene fibres to PAC having Silica fume as SCM (FRPAC). The aforementioned tests showed that FRPAC had a lower compressive strength than that of the control mix (SPAC). FRPAC had greater tensile strength than that of NPAC and SPAC. Mass loss at 250 °C was greater in SPAC compared to FRPAC. The compressive strength loss at 250 °C was significantly greater in FRPAC compared to SPAC. FRPAC exhibited a greater strain for the applied stress, and their stress-strain curve showed that FRPAC was more ductile than SPAC.     

A Step towards Concrete with Partial Substitution of Waste Glass (WG) in Concrete: A Review

The annual worldwide production rate of waste glass is a million tons; the waste glass is non-biodegradable, resulting in environmental pollution. However, the chemical composition of waste glass (WG) is promoted to be used as a partial substitution of binding or filler (aggregate) material in concrete production. Although significant research has been conducted in this area, the results of these studies are scattered, and it is difficult to judge the suitability of waste glass in concrete. This review looks at the effects of waste glass on concrete’s fresh, mechanical, and durability properties. It concludes that waste glass decreased the flowability of concrete. Furthermore, waste glass can be used as pozzolanic material, creating secondary cementitious compound (CSH) gel. CSH gel increased the cement paste’s binding properties, leading to increased mechanical performance. Moreover, this study reveals that the optimum dose of waste glass is important to minimize the possibility of an alkali–silica reactions. Based on this review, most researchers conclude that 20% substitution of waste glass as binding material is the optimum dose. The wide range of discussion provides the necessary guideline for the best research practice in the future.