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S-Adenosyl-l-methionine (SAM)-mediated methylation of biomolecules controls their function and regulates numerous vital intracellular processes. Analogs of SAM with a reporter group in place of the S-methyl group are widely used to study these processes. However, many of these analogs are chemically unstable that largely limits their practical application. We have developed a new compound, SAM-PH, which contains an H-phosphinic group (-P(O)(H)OH) instead of the SAM carboxylic group. SAM-PH is significantly more stable than SAM, retains functional activity in catechol-O-methyltransferase and methyltransferase WBSCR27 reactions. The last is associated with Williams–Beuren syndrome. Rac-SAM-PH was synthesized chemically, while (R,S)-SAM-PH and its analogs were prepared enzymatically either from H-phosphinic analogs of methionine (Met-PH) or H-phosphinic analog of S-adenosyl-l-homocysteine (SAH-PH) using methionine adenosyltransferase 2A or halide methyltransferases, respectively. SAH-PH undergoes glycoside bond cleavage in the presence of methylthioadenosine nucleosidase like natural SAH. Thus, SAM-PH and its analogs are promising new tools for investigating methyltransferases and incorporating reporter groups into their substrates.

Abstract Background Pregnenolone and progesterone are the life-important steroid hormones regulating essential vital functions in mammals, and widely used in different fields of medicine. Microbiological production of these compounds from sterols is based on the use of recombinant strains expressing the enzyme system cholesterol hydroxylase/C20-C22 lyase (CH/L) of mammalian steroidogenesis. However, the efficiency of the known recombinant strains is still low. New recombinant strains and combination approaches are now needed to produce these steroid hormones. Results Based on Mycolicibacterium smegmatis, a recombinant strain was created that expresses the steroidogenesis system (CYP11A1, adrenodoxin reductase, adrenodoxin) of the bovine adrenal cortex. The recombinant strain transformed cholesterol and phytosterol to form progesterone among the metabolites. When 3-methoxymethyl ethers of sterols were applied as bioconversion substrates, the corresponding 3-ethers of pregnenolone and dehydroepiandrosterone (DHEA) were identified as major metabolites. Under optimized conditions, the recombinant strain produced 85.2 ± 4.7 mol % 3-methoxymethyl-pregnenolone within 48 h, while production of 3-substituted DHEA was not detected. After the 3-methoxymethyl function was deprotected by acid hydrolysis, crystalline pregnenolone was isolated in high purity (over 98%, w/w). The structures of steroids were confirmed using TLC, HPLC, MS and 1H- and 13C-NMR analyses. Conclusion The use of mycolicybacteria as a microbial platform for the expression of systems at the initial stage of mammalian steroidogenesis ensures the production of valuable steroid hormones—progesterone and pregnenolone from cholesterol. Selective production of pregnenolone from cholesterol is ensured by the use of 3-substituted cholesterol as a substrate and optimization of the conditions for its bioconversion. The results open the prospects for the generation of the new microbial biocatalysts capable of effectively producing value-added steroid hormones.

Abstract The MEG II experiment, based at the Paul Scherrer Institut in Switzerland, reports the result of a search for the decay $$\upmu ^+ \rightarrow {\textrm{e}}^+ \upgamma $$ μ + → e + γ from data taken in the first physics run in 2021. No excess of events over the expected background is observed, yielding an upper limit on the branching ratio of $${\mathcal {B}} (\upmu ^+ \rightarrow {\textrm{e}}^+ \upgamma ) < 7.5 \times 10^{-13}$$ B ( μ + → e + γ ) < 7.5 × 10 - 13 (90% CL). The combination of this result and the limit obtained by MEG gives $${\mathcal {B}} (\upmu ^+ \rightarrow {\textrm{e}}^+ \upgamma ) < 3.1 \times 10^{-13}$$ B ( μ + → e + γ ) < 3.1 × 10 - 13 (90% CL), which is the most stringent limit to date. A ten-fold larger sample of data is being collected during the years 2022–2023, and data-taking will continue in the coming years.

Abstract Snyder–Robinson syndrome (SRS) results from mutations in spermine synthase (SMS), which converts the polyamine spermidine into spermine. Affecting primarily males, common manifestations of SRS include intellectual disability, osteoporosis, hypotonia, and seizures. Symptom management is the only treatment. Reduced SMS activity causes spermidine accumulation while spermine levels are reduced. The resulting exaggerated spermidine:spermine ratio is a biochemical hallmark of SRS that tends to correlate with symptom severity. Our studies aim to pharmacologically manipulate polyamine metabolism to correct this imbalance as a therapeutic strategy for SRS. Here we report the repurposing of 2‐difluoromethylornithine (DFMO), an FDA‐approved inhibitor of polyamine biosynthesis, in rebalancing spermidine:spermine ratios in SRS patient cells. Mechanistic in vitro studies demonstrate that, while reducing spermidine biosynthesis, DFMO also stimulates the conversion of spermidine into spermine in hypomorphic SMS cells and induces uptake of exogenous spermine, altogether reducing the aberrant ratios. In a Drosophila SRS model characterized by reduced lifespan, DFMO improves longevity. As nearly all SRS patient mutations are hypomorphic, these studies form a strong foundation for translational studies with significant therapeutic potential.

Background: Cervical cancer is the most common type of female genital malignancies. In Russia, its incidence is 17 to 19 cases per 100,000 of female population. Cervical cancer is characterized by high activity, rapid development of radio/chemoresistance and unfavorable prognosis. To assess the risk of recurrence, metastasis and choice of the optimal treatment strategy, factors related to the disease progression are under study. Vascular endothelial growth factor (VEGF) overexpression is related to tumor angiogenesis and poor outcome in various cancer types, including cervical cancer. Aim: To study an association between the rs2010963 polymorphism of the VEGFA gene and risk of development and progression of cervical cancer. Materials and methods: This case-control study included 120 women (aged 49 [42; 65] years) with cervical cancer stage I-II and 112 women without cervical or other types of cancer. Based on the results of histological examination, two subgroups were formed: the one with tumor emboli (TE+) in the tumor vasculature and surrounding tissues (n = 41, 34.17%) and the other without tumor emboli (TE-) (n = 79, 65.83%). The polymorphic DNA loci of the rs2010963 VEGFA gene were analyzed by real time polymerase chain reaction. Results: In the patients, cervical cancer has associated with the VEGFA gene allelic polymorphism rs2010963 (χ2 = 5.47; p = 0.021). The minor C allele increased risk of cervical cancer by 1.6-fold (odds ratio (OR) 1.58, 95% confidence interval (CI) 1.08-2.31), and the ancestral G allele reduced the cervical cancer probability (OR 0.63, 95% CI 0.43-0.93). The genotypes distribution in the dominant model (GG and GC + CC) confirmed the association of the rs2010963 VEGFA gene polymorphism with cervical cancer (χ2 = 4.73; p = 0.031), specifically, if there was a minor C allele in the genotype (GC + CC). We found that the association of the rs2010963 VEGFA gene polymorphism with TE in the tumor vessels and surrounding tissues was a predictor of unfavorable progression and metastasis of cervical cancer (χ2 = 3.94; p = 0.049). The minor C allele increased the risk of TE by 1.7-fold (OR 1.72, 95% CI 1.004-2.98), whereas the ancestral G allele reduced this chance (OR 0.58, 95% CI 0.34-0.996). Conclusion: The C allele of the rs2010963 polymorphism of the VEGFA gene is a risk factor for cervical cancer, as well as a risk factor for the development of tumor emboli.

The effect of an erbium alloying on the hot deformation behavior of the crossover Al3Zn3Mg3Cu0.2Zr alloy was investigated in detail. First of all, Er increases the solidus temperature of the alloy. This allows hot deformation at a higher temperature. The precipitates resulting from the Er alloying of the Al3Zn3Mg3Cu0.2Zr alloy were analyzed using transmission electron microscopy. Erbium addition to the alloy produces the formation of more stable and fine L12-(Al3(Zr, Er)) precipitates with a size of 20–60 nm. True stress tends to increase with a decline in the temperature and an increase in the deformation rate. The addition of Er leads to decreases in true stress at the strain rates of 0.01–1 s−1 due to particle-stimulated nucleation softening mechanisms. The effective activation energy of the alloy with the Er addition has a lower value, enabling an easier hot deformation process in the alloy with an elevated volume fraction of the intermetallic particles. The addition of Er increases the strain rate sensitivity, which makes the failure during deformation less probable. The investigated alloys have a significant difference in the dependence of the activation volume on the temperature. The flow instability criterion allows better deformability of Er-doped alloys and enables the alloys to be formed more easily. The evenly distributed particles prevent the formation of shear bands with elevated storage energy and decrease the probability of crack initiation during the initial stages of hot deformation when only one softening mechanism (dynamic recovery) is working. The microstructure analysis proves that dynamic recovery is the main softening mechanism.

Oligoarginine peptides, known mostly for their cell-penetrating properties, are also inhibitors of the nicotinic acetylcholine receptors (nAChRs). Since octa-arginine (R8) inhibits α9α10 nAChR and suppresses neuropathic pain, we checked if other polycationic compounds containing amino and/or guanidino groups could be effective and tested the activity of the disulfide-fixed “cyclo”R8, a series of biogenic polyamines (putrescine, spermidine, and spermine), C-methylated spermine analogs, agmatine and its analogs, as well as acylpolyamine argiotoxin-636 from spider venom. Their inhibitory potency on muscle-type, α7 and α9α10 nAChRs was determined using radioligand analysis, electrophysiology, and calcium imaging. “Cyclo”R8 showed similar activity to that of R8 against α9α10 nAChR (IC50 ≈ 60 nM). Biogenic polyamines as well as agmatine and its analogs displayed low activity on muscle-type Torpedo californica, as well as α7 and α9α10 nAChRs, which increased with chain length, the most active being spermine and its C-methylated derivatives having IC50 of about 30 μM against muscle-type T. californica nAChR. Argiotoxin-636, which contains a polyamine backbone and terminal guanidino group, also weakly inhibited T. californica nAChR (IC50 ≈ 15 μM), but it revealed high potency against rat α9α10 nAChR (IC50 ≈ 200 nM). We conclude that oligoarginines and similar polycationic compounds effectively inhibiting α9α10 nAChR may serve as a basis for the development of analgesics to reduce neuropathic pain.

The Ukrainian Danube region is characterized by a high level of self-regulation of interethnic issues. In the two hundred years since the last colonization of the region, there have been no ethnic conflicts. The conflicts that did take place were purely domestic in nature. Socio-cultural boundary of the region, which is caused by centuries-old historical and geographical processes in the Northern Black Sea region, is a direct catalyst for modern geopolitical and geoeconomic changes. The relations between Ukraine and Romania have the greatest influence on these processes. With the beginning of the intensive phase of Russian aggression, the geopolitical position of the Ukrainian Danube region has changed significantly. This region became the main center of export-import operations of our state. After the end of the war, a flow of goods and people will go through the Ukrainian Danube region to restore public life. In such a situation, it is necessary to develop comprehensive plans for sustainable development of the region, which will take into account all its competitive advantages. It is of particular importance to use the multiculturalism of the region for the development of tourism and obtaining working capital for economic entities and territorial communities. The main attention should be paid to the ethnic tourism oriented to the citizens of the countries that have their diasporas in the south-western part of the Odessa region.

When synthesizing systems for railway interlocking, it is recommended to use automated models to implement the logic of railway automation and remote control units. Finite-state machines (FSMs) can be implemented on any hardware component. When using relay technology, the functional safety of electrical interlocking is achieved by using uncontrolled (safety) relays with a high coefficient of asymmetry of failures in types 1 → 0 and 0 → 1. When using programmable components, the use of backup and diverse protection methods is required. This paper presents a flexible approach to synthesizing FSMs for railway automation and remote control units that offer both individual and route-based control. Unlike existing solutions, this proposal considers the pre-failure states of railway automation and remote control units during the finite-state machine synthesis stage. This enables the implementation of self-checking and self-diagnostic modules to manage automation units. By increasing the number of states for individual devices and considering the states of interconnected objects, the transition graphs can be expanded. This expansion allows for the synthesis of the transition graph of the control subsystem and other systems. The authors used a field-programmable gate array (FPGA) to implement a finite-state machine. In this case, the proposal is to encode the states of a finite-state machine using weight-based sum codes in the residue class ring based on a given modulus. The best coverage of errors occurring at the outputs of the logic converter in the structure of the FSM can be ensured by selecting the weighting coefficients and the value of the module. This paper presents an example of synthesizing an FPGA-based FSM using state encoding through modular weight-based sum codes. The operation of the synthesized device was modeled. It was found to operate according to the same algorithm as the real devices. When synthesizing self-checking and self-controlled train control devices, it is recommended to consider the solutions proposed in this paper.

Hepatitis C virus (HCV) is an oncogenic virus that causes chronic liver disease in more than 80% of patients. During the last decade, efficient direct-acting antivirals were introduced into clinical practice. However, clearance of the virus does not reduce the risk of end-stage liver diseases to the level observed in patients who have never been infected. So, investigation of HCV pathogenesis is still warranted. Virus-induced changes in cell metabolism contribute to the development of HCV-associated liver pathologies. Here, we studied the impact of the virus on the metabolism of polyamines and proline as well as on the urea cycle, which plays a crucial role in liver function. It was found that HCV strongly suppresses the expression of arginase, a key enzyme of the urea cycle, leading to the accumulation of arginine, and up-regulates proline oxidase with a concomitant decrease in proline concentrations. The addition of exogenous proline moderately suppressed viral replication. HCV up-regulated transcription but suppressed protein levels of polyamine-metabolizing enzymes. This resulted in a decrease in polyamine content in infected cells. Finally, compounds targeting polyamine metabolism demonstrated pronounced antiviral activity, pointing to spermine and spermidine as compounds affecting HCV replication. These data expand our understanding of HCV’s imprint on cell metabolism.

Background. Insight into blood viscosity in terms of its physical and biochemical properties carries significant clinical value. By understanding the relationship between the physical properties of blood and physiology, a potentially powerful tool for diagnosing early signs of many diseases can be discovered. Purpose. To identify the effect of fibrinogen on tensio- and rheometric characteristics of blood plasma and serum in patients with coronary heart disease and with mitral and/or aortic valve disease. Materials and methods. Prospective non-randomized study. The study of dynamic, equilibrium surface tension and viscoelastic modulus was performed by the pendant drop method using a PAT-1 device (Sinterface Technologies, Germany). We measured parameters characterizing the surface tension and dilatation rheology of blood serum such as: dynamic surface tension at an adsorption time of 100 s (γ), equilibrium surface tension (γ ∞) (adsorption time 2500 s), viscoelastic modulus |E|, and phase angle (φ) at frequencies of 0.1 and 0.01 Hz. All patients under study were divided into 3 groups. The healthy volunteers (30 subjects) without chronic diseases and active complaints aged 49 to 78 years (mean age, 61.1±1.1 years) comprised the comparison group (group 1). Group 2 - 40 patients with coronary heart disease (CHD) aged 49 to 77 years (mean age 62.2±1.3 years) who underwent bypass surgery to treat atherosclerotic coronary vessels (2 to 5 bypasses). Group 3 - 30 patients with cardiac mitral and/or aortic valve lesions aged 52 to 78 years (mean age 61.3±1.2 years). They underwent mitral and/or aortic valve replacement with mechanical prostheses. The most common pathophysiological syndrome in patients due to coronary artery or heart valve lesions was chronic heart failure (CHF) (stage 2A-2B according to Vasilenko-Strazhesko classification). Results. Characteristic γ100s of blood serum and plasma had significant difference in both patients’ groups, possibly due to the role of coagulation and anti-coagulation system proteins’ role in dynamic surface tension of plasma in a shorter timeframe (up to 100 s.). The increase in Δγ100s in both patients’ groups by day 7 of the postoperative period indicates an increasing dynamic surface tension of serum compared to plasma. Plasma of perioperative patients does not differ from the comparison group by its surface-equilibrium properties. Accordingly, the Δγ∞s values in groups 1 and 2 both before surgery and on days 1 and 7 of the postoperative period are almost identical, pointing to no difference in the amount of surfactants tending to adsorb on the droplet surface. Alterations of viscoelastic modulus |E| and phase angle (φ) at 0.1 and 0.01 Hz in the perioperative period indicate changes in qualitative and quantitative characteristics of circulating blood with variation in individual homeostasis characteristics, resulting in an increase in surface elasticity combined with an almost unchanged surface viscosity. Conclusion. Dynamic and equilibrium surface tension parameters in patients’ plasma differ from those in serum due to the presence of fibrinogen and other proteins of the blood coagulation system.

The effect of 0.2%Cr addition on the structure, phase composition, and mechanical properties of the novel cast and wrought Al-2.5Zn-2.5Mg-2.5Cu-0.2Zr-Er(Y) alloys were investigated in detail. Chromium is distributed between primary crystals (5.7–6.8%) of the intermetallic phase and the aluminum solid solution (0.2%) (Al). The primary crystals contain for the main part Cr, Ti, Er(Y). The experimental phase composition is in good correlation with the thermodynamic computation data. The micron-sized solidification origin phases (Al8Cu4Er(or Y) and Mg2Si) and supersaturated (Al) with nano-sized Al3(Zr,Ti) and E (Al18Mg3Cr2) precipitates are presented in the microstructure of the novel alloys after solution treatment. The nucleation of η (MgZn2) (0.5%), S (Al2CuMg) (0.4%), and T (Al,Zn,Mg,Cu) (8.8%) phase precipitates at 180 °C, providing the achievement of a maximum hardness of 135 HV in the Al2.5Zn2.5Mg2.5CuYCr alloy. The corrosion potential of the novel alloy is similar to the Ecor of the referenced alloy, but the corrosion current density (0.68–0.98 µA/sm2) is still significantly lower due to the formation of E (Al18Mg3Cr2) precipitates and S phase precipitates of the aging origin, in addition to the T phase. The formation of E (Al18Mg3Cr2) precipitates under the solution treatment provides a lower proportion of recrystallized grains (2.5–5% vs. 22.4–25.1%) and higher hardness (110 HV vs. 85–95 HV) in the Cr-rich alloys compared to the referenced alloys. Solution treated, hot and cold rolled, recrystallized, water quenched and aged at 210 °C alloys demonstrate an excellent microstructure stability and tensile properties: YS = 299–300 MPa, UTS = 406–414 MPa, and El. = 9–12.3%.

Background and Objectives: Despite the fact that the methods of dynamic interfacial tensiometry and rheology are used to study blood and other biological fluids, in medicine there is no unified approach in the methodology of analysis and interpretation of the results. However, in some cases, the obtained numerical characteristics do not have a simple physical meaning and do not allow to evaluate the contribution of individual components and, as a consequence, it is impossible to identify the main link. Taking into account the multidirectional and nongeneralized data on rheology and due to the multicomponent and uncertain composition, there have been no successful attempts so far to create models to determine the real contribution of individual blood components. The purpose of this study is to develop a model, based on which one could obtain information about physical constants and parameters of individual plasma and/or blood serum components for medical diagnostics. Materials and Methods: The study is performed on blood samples of two human groups: group 1) 15 patients with coronary heart disease aged from 51 to 76 years; group 2) conditionally healthy volunteers (15 people) aged from 50 to 75 years. Results: For serum/plasma fractionation, a protein “desalting” method is used to obtain a fraction of low-molecular-weight metabolites. Further determination of interphase tensiometry is performed by the hanged drop method using hardware-software complex PAT-1 (“Sinterface Technologies”, Germany). The curves of the dynamic interfacial tension of the studied groups differ significantly throughout the entire time of the experiment. The average values of the dynamic interfacial tension of native serum in group 1 are noticeably lower than in the group 2 (the group of healthy volunteers). The detected change in the value of the dynamic interfacial tension may indicate an accumulation of surfactants in the serum of patients with coronary heart disease. The data obtained are in satisfactory agreement withthemathematicalmodel proposed bythe authors. Ifthe adsorption atthe beginning of the experiment is due mainly to low molecular weight compounds, then the value of the sum of the concentrations of high molecular weight compounds (after protein precipitation) should be slightly lower than the values of the corresponding indicators of the native blood samples. Conclusion: Using the obtained data of dynamic surface tension and the proposed mathematical model the following conclusions have been formulated: 1) tensiometric characteristics of blood serum for group 1 and 2 differ in dynamic and equilibrium surface tension; 2) the quantitative and qualitative contribution of the coagulation system to surface tension and the sum of concentrations of low molecular weight compounds; 3) the contribution of low molecular weight metabolites in the formation of surface tension of plasma and serum has been estimated; 4) the heterogeneity of the qualitative composition of low-molecular substances fractions in the studied groups has been shown.

New antibiotics are unquestionably needed to fight the emergence and spread of multidrug-resistant bacteria. To date, antibiotics targeting bacterial central metabolism have been poorly investigated. By determining the minimal inhibitory concentration (MIC) of desmethylphosphinothricin (Glu-γ-PH), an analogue of glutamate with a phosphinic moiety replacing the γ-carboxyl group, we previously showed its promising antibacterial activity on Escherichia coli. Herein, we synthetized and determined the growth inhibition exerted on E. coli by an L-Leu dipeptide derivative of Glu-γ-PH (L-Leu-D,L-Glu-γ-PH). Furthermore, we compared the growth inhibition obtained with this dipeptide with that exerted by the free amino acid, i.e., Glu-γ-PH, and by their phosphonic and non-desmethylated analogues. All the tested compounds were more effective when assayed in a chemically-defined minimal medium. The dipeptide L-Leu-D,L-Glu-γ-PH had a significantly improved antibacterial activity (2 μg/mL), at a concentration between the non-desmethytaled (0.1 μg/mL) and the phosphonic (80 μg/mL) analogues. Also, in Bacillus subtilis, the dipeptide L-Leu-D,L-Glu-γ-PH displayed an activity comparable to that of the antibiotic amoxicillin. This work highlights the antibacterial relevance of the phosphinic pharmacophore and proposes new avenues for the development of novel antimicrobial drugs containing the phosphinic moiety.

The article is devoted to the socio-geographical characteristics of the territorial recreational complex of Odesa. The article gives a historical review of establishment and development of recreational activity, gives a description of natural recreational resources and historical and cultural potential of the city. It gives a description of certain types of recreational activities, in particular, sanatorium treatment, medical rehabilitation and tourism, resort areas, formed within the city limits, the problems and prospects of development of Odesa recreational complex are considered here.