Development of methodology for identification and assessment of ecosystems with an underground source of tritium.

The article considers the issues of working out the suitable approaches for identifying zones with the presence of underground near-surface waters with increased concentrations of tritium discharged into a surface reservoir. The following methods were used as possible methods: determination of tritium content in snow cover, determination of tritium content in vegetation in the form of tritium of free water and organically bound tritium, determination of tritium content in river water and coastal vegetation. The studies were carried out at a previously identified site where groundwater with a tritium concentration of up to 6000 Bq/l is present, located in the vicinity of the city of Obninsk (Kaluga region, Russia). As a result of the conducted research, it was concluded that the analysis of the distribution of tritium in vegetation is an excellent methodological technique for identifying areas of location of near-surface underground waters contaminated with tritium. As a control parameter, both the concentration of tritium in the free water of plants and the content of organically bound tritium can be used. To detect underground tritium contamination the most promising use is the following indicator - the content of OBT in the shoots of woody plants. This parameter is very informative, and the sampling procedure for its determination has no seasonal restrictions, unlike such parameters as the content of tritium in grass and leaves, the content of tritium in snow cover, surface waters, which are preferably collected only in summer or winter. It should be noted that the control of surface waters of the groundwater discharge zone may not be a sufficiently informative indicator for identifying areas of polluted water inflow, since it depends on the ratio of the volumes of leaking polluted groundwater and the annual flow of the watercourse.

Limb salvage and functional recovery in infected nonunion of the distal tibia treated with the Ilizarov techniques.

Introduction: Treatment of infected nonunion of the distal juxta-articular tibia is a challenge due to a short distal fragment, deformity, thin soft-tissue envelope, and active infection. There is still no consensus on the approach that is able to maximally salvage the limb and ankle function. Material and methods: Infected juxta-articular nonunion of the distal tibia was managed with two Ilizarov techniques, monofocal compression (MC) used in 12 patients and bifocal compression-distraction (BCD) in 6 patients. The choice of the technique depended on the size of the postresection defect, ≥3 cm or ≤3 cm, respectively. The tactics of functional approach were careful debridement, insertion of wires in the distal fragment so that they do not penetrate the ankle joint, stable fixation, and temporary bridging of the ankle and forefoot. MSCT was used along with regular radiography to assess the union and regeneration. Ankle functions were evaluated with AOFAS ankle-hindfoot score system. Results: Bone consolidation, infection arrest and ankle function improvement were achieved in all patients. External fixation continued 221.7 ± 15.1 days for MC and 235 ± 25.8 days for BCD. Complications were wound divergence, wire-tract infection, premature consolidation of the fibula, and hypoplastic regeneration in one case. The mean functional AOFAS score after treatment was 90.7 ± 2.5 points in MC and 89.7 ± 1.3 in BCD patients. Residual limb discrepancy after MC ranged 0-4 cm. Bone shortening was compensated in BCD patients. Conclusion: Limb-salvage and functional approach to the treatment of infected nonunion of the juxta-articular distal tibia with the Ilizarov techniques achieves good outcomes. It provides bone infection arrest, consolidation, defect compensation and significantly improves the ankle joint function.

Optogenetic cytosol acidification of mammalian cells using an inward proton-pumping rhodopsin.

Ion gradients are a universal form of energy, information storage and conversion in living cells. Advances in optogenetics inspire the development of novel tools towards control of different cellular processes with light. Rhodopsins are perspective tools for optogenetic manipulation of ion gradients in cells and subcellular compartments, controlling pH of the cytosol and intracellular organelles. The key step of the development of new optogenetic tools is evaluation of their efficiency. Here, we used a high-throughput quantitative method for comparing efficiency of proton-pumping rhodopsins in Escherichia coli cells. This approach allowed us to show that an inward proton pump xenorhodopsin from Nanosalina sp. (NsXeR) is a powerful tool for optogenetic control of pH of mammalian subcellular compartments. Further, we demonstrate that NsXeR can be used for fast optogenetic acidification of the cytosol of mammalian cells. This is the first evidence of optogenetic cytosol acidification by an inward proton pump at physiological pH values. Our approach offers unique opportunities to study cellular metabolism at normal and pathological conditions and might help to understand the role of pH dysregulation in cellular dysfunctions.

[Possible changes in the electroencephalogram and electrocardiogram after the introduction of peripheral muscle relaxants]. / Vozmozhnye izmeneniya elektroentsefalogrammy i elektrokardiogrammy pri ispol'zovanii miorelaksantov perifericheskogo deistviya.

OBJECTIVE: To evaluate the changes in the electroencephalogram (EEG) parameters in time, coinciding with the changes recorded by the electrocardiogram (ECG) channel in patients after the introduction of peripheral muscle relaxants. MATERIAL AND METHODS: Twenty-four patients were examined in intensive care units on artificial lung ventilation (ALV). During the study, myographic artifacts were recorded in all patients in the EEG, the elimination of which was impossible without the use of pharmacological agents leading to relaxation of muscles - muscle relaxants of peripheral action. RESULTS: Complete suppression of myographic artifacts on the EEG was noted in all patients after the introduction of peripheral muscle relaxants. However, in 4 of them, EEG changes were noted in the period 2 to 3 minutes after the introduction of muscle relaxants and the disappearance of myographic artifacts on the EEG. These changes coincided in time with the changes recorded by the ECG channel. CONCLUSIONS: The EEG changes in time, coinciding with the changes in ECG indicators, suggest the presence of short-term disturbances of the functional state of the basic brain systems, probably due to changes in hemodynamics due to cardiac rhythm and conduction disturbances. It is advisable to record the EEG with the inclusion of an ECG channel in the wiring diagram for synchronous recording.

[The changes in electroencephalogram parameters in patients in the somatogenic phase of acute poisoning with opioid receptor agonists]. / Izmeneniya pokazatelei elektroentsefalogrammy u patsientov v somatogennuyu fazu ostrykh otravlenii agonistami opioidnykh retseptorov.

OBJECTIVE: To evaluate the parameters of the electroencephalogram (EEG) using the methods of computer processing of EEG data for an approach to the analysis of possible neurophysiological mechanisms underlying the fluctuations detected in the EEG in patients in the somatogenic phase of acute poisoning with opioid receptor agonists. MATERIAL AND METHODS: Thirty-one patients were examined in the somatogenic phase of acute poisoning with opioid receptor agonists with a wakefulness level 3 to 15 points on the Glasgow Coma Scale. The EEG was recorded in accordance with the recommendations of the International Federation of Clinical Neurophysiology. The indicators of electrical activity of the brain were analyzed; computer processing of EEG data, including spectral analysis, localization of equivalent dipole sources of pathological electrical activity of the brain localization of the maximum of the equivalent density of EEG oscillation currents in the neocortex, was performed. RESULTS: Delta-band oscillations dominated in the majority of patients (65%, 20 patients). EEG delta waves were localized mainly at the level of the thalamus; using the method of low-resolution electromagnetic tomography, the localization of the maximum of the equivalent current density of delta oscillations in the projection of the neocortex was noted. Possible neurophysiological mechanisms of «pathological¼ delta waves recorded in the EEG of these patients are discussed. CONCLUSIONS: The changes on the EEG in these patients arise as a result of a disturbance of the function of the generator mechanisms of both cortical and activating structures of the brain, while the recorded slow-wave, mainly delta activity, taking into account the recording time (somatogenic phase), may be due to the action of secondary alternating factors (hypoxia and cerebral edema).

[COMPREHENSIVE ASSESSMENT OF THE SPECIES COMPOSITION AND SENSITIVITY OF MICROFLORA IN PATIENTS WITH ODONTOGENIC MAXILLARY SINUSITIS].

Objective - to study the species composition of microflora and its sensitivity in patients with odontogenic maxillary sinusitis. The study included 230 patients of both sexes aged 18 to 70 years, who were treated at the Moscow Regional Scientifics Research and Clinical Institute named after M. F. Vladimirsky with a diagnosis of Odontogenic maxillary sinusitis. Of these, there were 155 patients with odontogenic sinusitis, complicated by perforation of the maxillary sinus and the presence of an oro-antral fistula, and 75 patients with maxillary aspergillosis. All patients underwent microbiological examination of smears and flushes from the maxillary sinus cavity with the determination of the species composition and antibiotic sensitivity. In the majority of the patients with perforative forms of odontogenic maxillary sinusitis, coccal flora (streptococci and various species) was detected, in a smaller number compared to it - facultative and obligate anaerobes, pathogenic fungi (Candida). A comparative analysis of the microflora, depending on the duration of the maxillary sinus perforation, showed that the rhinogenic microorganisms (Moraxella spp.) were found only in intraoperative perforations (up to 20% of cases). The presence of obligate anaerobes (Fusobacterium spp. Bacteroides spp.) was typical for long-existing perforations. In patients with maxillary aspergillosis facultative and obligate anaerobes were found less frequently and in a smaller variety than in patients with perforative maxillary sinusitis. There were no cases of sinus contamination by pathogenic fungi of the genus Candida in this group. At the same time, rhinogenic microgranisms (Moraxella spp.) were detected with a higher frequency (up to 27.3%) in this group of patients.

[The modern methods of evaluation of implementing personalized programs of prevention of age-associated diseases].

The development of preventive programs targeting specific groups of consumers of medical social services having age-related health and lifestyle characteristics is one of the most prospective methods to improve quality of medical care of the elderly and senile patients. The previously developed by Russian and foreign scientists programs of personalized prevention of age-related diseases make it possible to organize target groups of patients seeking medical services in both state and private health care organizations to be screened for conditions of medical and social significance from the point of view of preventive medicine. This permits to achieve a real integration of various components of preventive care that improves health of elderly and senile patients in terms of morphofunctional indices of patient's physical status, quality of life, degree of independence, and, as a result, quality and scope of implementation of preventive programs for elderly population. Therefore, the development of the basics of personalized programs preventing age-related diseases in elderly population is actual.

[Detection of markers of hepatitis B and D virus infection in biological media and dried blood spots.]

The aim of this study was to assess the rates of detection of the major markers of infection with hepatitis B and Delta (D) viruses in serum, saliva and dry blood dots (DBS) as a possible option for serological studies among the population of the endemic region in conditions of limited laboratory resources. For this purpose, paired samples of blood serum and DBS, blood serum and saliva from patients with chronic hepatitis B with Delta agent living in the Republic of Tyva, which is endemic for this disease. HBsAg was detected in 289 (100%) serum samples, in 88/92 (95.7%) saliva samples, in 60/80 (75%) DBS samples, stored three years at room temperature, and in 111/117 (94.9%) DBS stored one year at the same conditions. Anti-HBcore was detected in 209 (100%) serum samples, while in saliva and DBS samples this marker was detected in only 13.04% (12/92) and 19.7% (23/117), respectively. Anti-HDV antibodies in serum were detected in 209 (100%) samples collected from patients in 2017-2018. In saliva and DBS anti-HDV were not detected in any sample. This difference in the detection rates of anti-HBcore and anti-HDV might be accounted for the fact that the HBV core protein is a very strong immunogen, indusing the production of anti-HBcore in high concentrations. Probably, the concentration of anti-HDV is much lower, which explains its absence in saliva and DBS in patients with hepatitis B+D. Samples of biological media (saliva), as well as DBS can serve as an alternative material for the detection of HBsAg in screening and research prevalence studies. Meanwhile, the definition of anti-HDV in such media is not possible due to the false negative results. Due to the high probability of superinfection with HDV in patients with HBV in endemic areas, the detection of HBsAg in alternative media (saliva or DBS) should be followed by testing for anti-HDV in serum samples.

Dynamics of supernova bounce in laboratory.

We draw attention to recent high-explosive (HE) experiments which provide compression of macroscopic amount of matter to high, even record, values of pressure in comparison with other HE experiments. The observed bounce after the compression corresponds to processes in core-collapse supernova explosions after neutrino trapping. Conditions provided in the experiments resemble those in core-collapse supernovae, permitting their use for laboratory astrophysics. A unique feature of the experiments is compression at low entropy. The values of specific entropy are close to those obtained in numerical simulations during the process of collapse in supernova explosions, and much lower than those obtained at laser ignition facilities, another type of high-compression experiment. Both in supernovae and HE experiments the bounce occurs at low entropy, so the HE experiments provide a new platform to realize some supernova collapse effects in laboratory, especially to study hydrodynamics of collapsing flows and the bounce. Due to the good resolution of diagnostics in the compression of macroscopic amounts of material with essential effects of nonideal plasma in EOS, and observed development of 3D instabilities, these experiments may serve as a useful benchmark for astrophysical hydrodynamic codes.

Molecular Heterogeneity of Lectins in Wheat Seedlings under the Action of Stevioside and Heavy Metals.

The effect of the diterpene glycoside stevioside and high concentrations of heavy metals on the molecular heterogeneity of lectins was studied in seedlings of Kazanskaya 560 winter wheat cultivar. Stevioside induced the emergence of a new 45-kDa lectin. Cultivation of wheat seedlings in CdSO4 and ZnSO4 solutions resulted in the emergence of the protein with Mr = 88 kDa. We detected the presence of both lectins in seedlings during combined treatment with stevioside and heavy metals.

Determination of coal ash content by the combined x-ray fluorescence and scattering spectrum.

An alternative method is proposed for the determination of the inorganic constituent mass fraction (ash) in solid fuel by the ratio of Compton and Rayleigh X-ray scattering peaks IC/IR subject to the iron fluorescence intensity. An original X-ray optical scheme with a Ti/Mo (or Sc/Cu) double-layer secondary radiator allows registration of the combined fluorescence-and-scattering spectrum at the specified scattering angle. An algorithm for linear calibration of the Compton-to-Rayleigh IC/IR ratio is proposed which uses standard samples with two certified characteristics: mass fractions of ash (Ad) and iron oxide (WFe2O3 ). Ash mass fractions have been determined for coals of different deposits in the wide range of Ad from 9.4% to 52.7% mass and WFe2O3 from 0.3% to 4.95% mass. Due to the high penetrability of the probing radiation with energy E > 17 keV, the sample preparation procedure is rather simplified in comparison with the traditional method of Ad determination by the sum of fluorescence intensities of all constituent elements.

Mapping autosomal recessive intellectual disability: combined microarray and exome sequencing identifies 26 novel candidate genes in 192 consanguineous families.

Approximately 1% of the global population is affected by intellectual disability (ID), and the majority receive no molecular diagnosis. Previous studies have indicated high levels of genetic heterogeneity, with estimates of more than 2500 autosomal ID genes, the majority of which are autosomal recessive (AR). Here, we combined microarray genotyping, homozygosity-by-descent (HBD) mapping, copy number variation (CNV) analysis, and whole exome sequencing (WES) to identify disease genes/mutations in 192 multiplex Pakistani and Iranian consanguineous families with non-syndromic ID. We identified definite or candidate mutations (or CNVs) in 51% of families in 72 different genes, including 26 not previously reported for ARID. The new ARID genes include nine with loss-of-function mutations (ABI2, MAPK8, MPDZ, PIDD1, SLAIN1, TBC1D23, TRAPPC6B, UBA7 and USP44), and missense mutations include the first reports of variants in BDNF or TET1 associated with ID. The genes identified also showed overlap with de novo gene sets for other neuropsychiatric disorders. Transcriptional studies showed prominent expression in the prenatal brain. The high yield of AR mutations for ID indicated that this approach has excellent clinical potential and should inform clinical diagnostics, including clinical whole exome and genome sequencing, for populations in which consanguinity is common. As with other AR disorders, the relevance will also apply to outbred populations.

A new approach to improving the accuracy of elemental analysis in laser mass spectrometry.

It is shown that the main reason affecting the accuracy and reproducibility of the elemental analysis of solids with a laser source of ions is the difference in the ionization cross sections of different elements in the generation of laser plasma. Computer modeling was carried out for the evaporation of the sample and generation of laser plasma at different values of laser power density. The aim of modelling was to determine the cause of the low accuracy of analysis by direct selection of ions from the plasma. The researches have shown that we cannot get satisfactory accuracy of analysis using analytical signal formed only on the base of single-charged ions. At the same time, in the formation of an analytical signal, as a sum of the intensities of the mass peaks of all charges of each element, the accuracy of the analysis does not depend either on the ionization cross section or on the nonreproducibility of the laser radiation power. It is shown that this approach completely eliminates the "matrix effect."

Correlation between LC50 for Adult Fish and Fish Embryos.

Testing for substance toxicity for living organisms is an important step in the development and adaptation of new drugs for various purposes. Analysis of the dependences between toxicological parameters of chemical substances for various test objects and physicochemical properties of these agents is a promising trend. Partition coefficient logP (logKow) was chosen as the key physicochemical parameter determining the toxicological parameters of the same substance for hydrobionts at different developmental stages. We found a correlation between decimal logarithm of the ratio of LCe50 for fish embryos to LCa50 for adult fish and logP. This dependence was found as a liner combination of equations obtained by drawing a trend line between experimental points and calculation of Pearson's correlation coefficient R.

[Protective action of fish muscle extracts against cellular senescence induced by oxidative stress]. / Zashchitnoe deistvie ékstraktov iz myshts ryb ot indutsirovannogo okislitel'nym stressom kletochnogo stareniia.

Muscle extracts of some fish species, i.e. pike (Esox lucius), sterlet (Acipenser ruthenus), pink salmon (Oncorhynchus gorbuscha) and, to a lesser extent, perch (Perca fluviatilis) and Russian sturgeon, (Acipenser gueldenstaedtii) prevent the development of premature senescence of the human embryonic fibroblasts induced by the sublethal concentration of H2O2. Muscle extracts of other fish species tested, i.e. coho salmon (Oncorhynchus kisutch) and zander (Sander lucioperca), have not demonstrated this feature. Cell proliferation increased after the action of the senescence-inhibiting muscle extracts. Possible mechanisms of the action of nature biologically active compounds that interfere with the development of stress-induced cell senescence are discussed.

Dependence between LD50 for Rodents and LC50 for Adult Fish and Fish Embryos.

We revealed empirical dependences between common logarithm of a ratio of rat oral LD50 to LCa50 for adult fish and lgP for 50 different chemicals; and common logarithm of a ratio of the oral LD50 in rodents to LCe50 for fish embryos and lgP for 30 different chemicals. The dependences were obtained by constructing a trend line between experimental points and calculation of Pearson's R correlation coefficient as a measure of regression significance. These dependences can show the influence of substance lipophilicity on its toxicity for aquatic organisms comparing to mammals.

First experience of hematopoietic stem cell transplantation treatment of Shwachman-Diamond syndrome using unaffected HLA-matched sibling donor produced through preimplantation HLA typing.

The only proven cure for Shwachman-Diamond syndrome (SDS) bone marrow failure is allogeneic hematopoietic stem cell transplantation (HSCT). However HSCT with donors other than HLA-identical siblings is associated with high mortality and unfavorable prognosis. This paper presents the first experience of HSCT treatment of SDS using an unaffected HLA-identical sibling produced through preimplantation genetic diagnosis (PGD). The patient was a 6-year-old blood transfusion-dependent SDS baby girl with secondary myelodysplastic syndrome, for whom no HLA-identical donor was available. As a result of PGD, two unaffected HLA matched embryos were identified; one of them was randomly selected for transfer, resulting in a clinical pregnancy and birth of an apparently healthy child. The patient underwent allogeneic transplantation of cord blood hematopoietic stem cells, together with bone marrow from this sibling, resulting in complete hemopoietic recovery. The patient was no longer transfusion-dependent and had normal blood values 160 days after transplantation.

Rapid diagnostics of urinary iodine using a portable EDXRF spectrometer.

A method for urinary iodine diagnostics using a portable energy-dispersion X-ray fluorescent (EDXRF) spectrometer is proposed. The principle of the method consists in excitation of the sample atoms fluorescence by the energy spectrum intentionally formed from the spectrum of an X-ray tube using an optimized X-ray scheme. The optimization by the criterion of the minimum detection limit for L-series iodine fluorescence lines included the calculation of optimal atomic numbers for materials of a re-radiator and a filter, and their thicknesses, the collimation system parameters, and an X-ray tube voltage. Experimentally achieved detection limits were 45 and 75 µg/L by I-Lα and I-Lß lines, respectively, at the theoretically extreme value 30 µg/L. This sensitivity is found to be sufficient for urinary iodine diagnostics in the range from 50 to 200 µg/L. The results obtained from different patients have shown the satisfactory convergence for the iodine concentration determination by Lα and I-Lß fluorescence lines. The simple sample preparation procedure and comparably small sizes of the apparatus allows rapid researches directly in clinical settings.