bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral and general health quality of life following a subtemporal preauricular infratemporal approach with condylar fossa osteotomy in surgical skull base tumor resection
Authors: Taniguchi Seika , Kam Jeremy , Castle-Kirszbaum Mendel , Akagami Ryojo
Published: October 2024

OBJECTIVE

With the capacity to provide maximal lesion exposure, the subtemporal preauricular infratemporal (SPI) approach with condylar fossa osteotomy is highly utilized in radical resection of skull base tumors. While this approach requires disruption of the temporomandibular joint (TMJ) for access, the effects of this maneuver are poorly appreciated in neurosurgery. The aim of this study was to assess the morbidity of condylar fossa osteotomies by comparing oral health quality of life (OHQOL) and general health quality of life (GHQOL) outcomes after TMJ-involving and TMJ-sparing skull base approaches.

METHODS

A retrospective review of the medical records of patients who underwent surgery with the SPI approach (TMJ-involving approach) for skull base chondrosarcoma (CS) by a single senior surgeon at Vancouver General Hospital between 2002 and 2022 was performed. Patients undergoing TMJ-sparing anterolateral approaches for trigeminal schwannoma (TS) during the same study period by the same surgeon were included as controls. GHQOL was evaluated using the 36-item Short Form Health Survey from preoperative and postoperative periods. Postoperative OHQOL was evaluated using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Axis I/II screening instrument.

RESULTS

Data regarding quality of life were available for 13 of 19 CS patients and 12 of 15 TS patients surgically managed between 2002 and 2022. CS patients demonstrated less jaw dysfunction in all parameters of the DC/TMD Axis I/II components when specifically assessing OHQOL. CS patients had a lower likelihood of temporomandibular disorder (TMD) presence on the TMD pain screener than TS patients (25% vs 45%, p = 0.40). Chronic pain scores were higher in the TS group, with significantly more patients with grade 2 or higher pain (36.4% vs 0%, p = 0.01). The mean Jaw Functional Limitation Scale (JFLS) scores were lower in CS patients than in TS patients. Both CS and TS patients demonstrated lower mean JLFS scores (0.50 and 0.81, respectively) than patients with chronic TMD (1.76), but higher mean JLFS scores than patients without TMD (0.16).

CONCLUSIONS

The authors report novel findings regarding the impact of the SPI approach with a condylar fossa osteotomy on OHQOL and GHQOL among skull base tumor patients. Anatomical disruption of the TMJ was not associated with significant clinical TMJ dysfunction. Compared with TS patients, CS patients had even lower mean scores in TMJ-related morbidity, and both groups had lower TMJ morbidity than patients diagnosed with chronic TMJ dysfunction. Condylar fossa osteotomies can therefore be considered without concern of significant additional morbidity.
Natural history and management outcomes of patients with ruptured Spetzler-Martin grade IV and V brain arteriovenous malformations
Authors: Sattari Shahab Aldin , Yang Wuyang , Feghali James , Antar Albert , Hung Alice , Xu Risheng , Tamargo Rafael J. , Huang Judy
Published: October 2024

OBJECTIVE

The natural history of ruptured high Spetzler-Martin grade IV and V brain arteriovenous malformations (bAVMs) is underreported given the scarcity of this pathology, and decision-making for patients with bAVMs remains unclarified. In this study, the authors sought to shed light on this topic.

METHODS

Patients harboring ruptured high-grade bAVMs were identified from an institutional database spanning from 1990 to 2020. The authors examined outcomes of annual hemorrhagic risk in natural history and after treatment, follow-up hemorrhage rate, bAVM obliteration, follow-up modified Rankin Scale (mRS) score > 2, worsened mRS score, and mortality.

RESULTS

After reviewing the charts of 1066 patients without hereditary hemorrhagic telangiectasia, 84 patients with ruptured high-grade bAVMs were included in the study for analysis. For cortical bAVMs, the annual risk of hemorrhage during natural history was 2.68%. Surgery decreased the risk to 0.74%, while radiosurgery increased the risk to 5.35%, and embolization only increased the risk to 16.96%. For deep-seated high-grade bAVMs, the annual risk of hemorrhage during natural history was 8.37%. Radiosurgery decreased the risk to 3.11%, surgery decreased the risk to 5.25%, and embolization only increased the risk to 22.33%. Poisson regression analysis demonstrated that embolization only increased the risk of hemorrhage in cortical bAVMs (rate ratio 4.745, 95% CI 1.365–12.819; p = 0.005) and deep-seated bAVMs (rate ratio 6.290, 95% CI 0.997–21.932; p = 0.013). Logistic regression analysis showed that surgery (OR 52.000, 95% CI 8.083–1046.127; p = 0.004) and radiosurgery (OR 11.142, 95% CI 1.804–217.650; p = 0.029) were predictors of obliteration in cortical and deep-seated bAVMs, respectively. The proportions of patients experiencing a worsened mRS score, a follow-up mRS score > 2, and mortality were similar between conservative and treatment groups.

CONCLUSIONS

The natural history of cortical ruptured high-grade bAVMs bears a risk similar to that of incidental bAVMs, whereas deep-seated ruptured high-grade bAVMs have an increased risk of hemorrhage. With extremely prudent patient selection, surgery might be a viable option for cortical bAVMs to obliterate the bAVM and reduce hemorrhagic risk, while preserving functional status. Radiosurgery might be beneficial to lower hemorrhagic risk in deep-seated bAVMs. Embolization as a single modality should be avoided as it provides no benefit to reduce hemorrhagic risk.
Defining pediatric neurosurgery in low-income countries: a cross-sectional study in Ethiopia
Authors: Asfaw Zerubabbel K. , Abdi Hodan , Moges Kaleab Tesfaye , Akililu Yemisirach B. , Barthélemy Ernest J. , Laeke Tsegazeab , Germano Isabelle M. , Tirsit Abenezer
Published: October 2024

OBJECTIVE

Pediatric neurosurgical practice is prevalent in most low- and lower-middle-income countries but lacks comprehensive documentation of practice patterns, demographics, and case variety. This study aimed to present the current state of pediatric neurosurgery in Ethiopia, including workforce characterization, case variety, and relevant procedures.

METHODS

A survey was developed and distributed to all Ethiopian fully trained neurosurgeons (n = 50). Survey questions assessed sociodemographic variables, level of training, case variety, and neurosurgical practice. Statistical analysis was conducted to describe the current practice of pediatric neurosurgery.

RESULTS

A total of 45 neurosurgeons responded (90%). Three respondents (7%) were women. There was only 1 fellowship-trained pediatric neurosurgeon, while most neurosurgeons were general neurosurgeons who served a pediatric patient population. Most neurosurgeons (56%) worked in the capital city, Addis Ababa, while another 13% worked in other urban settings. The top three indications for a pediatric neurosurgical procedure were neural tube defects (NTDs) (96%), hydrocephalus (93%), and trauma (60%). NTD-associated hydrocephalus was the most common hydrocephalus type seen (71%). The most common procedure for hydrocephalus was shunt insertion (96%). A prenatal diagnosis of NTD was made in < 10% of cases, as reported by 84% of respondents.

CONCLUSIONS

The study highlights Ethiopia’s need for more pediatric neurosurgeons. Suggested strategies to facilitate subspecialty training include the establishment of a fellowship program facilitated by the implementation of a nationwide pediatric neurosurgery registry. Promoting efforts for early diagnosis and treatment of pediatric conditions coupled with NTD prevention initiatives could improve pediatric neurosurgical care in Ethiopia.
The impact of smoking on patient-reported outcomes following lumbar decompression: an analysis of the Quality Outcomes Database
Authors: Djurasovic Mladen , Owens R. Kirk , Carreon Leah Y. , Gum Jeffrey L. , Bisson Erica F. , Bydon Mohamad , Glassman Steven D.
Published: October 2024

OBJECTIVE

Smoking has been shown to negatively impact spinal health, as well as the outcomes of spinal fusion. Published reports show conflicting data regarding whether smoking negatively impacts patient outcomes following lumbar decompression. The objective of this study was to investigate whether smoking affects the outcomes of patients undergoing lumbar decompression for spinal stenosis or herniated disc.

METHODS

The Quality Outcomes Database was queried for patients with spinal stenosis or lumbar disc herniation who underwent one- or two-level lumbar decompression without fusion. All patients had preoperative and 12-month outcome measures and were divided into groups of nonsmokers and current smokers. Outcomes were compared between the two groups, as well as the percentage of patients reaching the minimal clinically important difference (MCID) threshold for numeric rating scale (NRS) back and leg pain scores and the Oswestry Disability Index (ODI).

RESULTS

Of 17,271 patients, 14,233 were nonsmokers and 3038 were current smokers. Smokers had worse baseline NRS back and leg pain, ODI, and EQ-5D scores and experienced slightly less improvement in all measures following lumbar decompression (p ≤ 0.009), although changes were largely similar, and a high percentage of patients achieved the MCID thresholds for NRS back pain (78% nonsmokers vs 75% smokers), NRS leg pain (79% nonsmokers vs 73% smokers), and ODI (74% nonsmokers vs 68% smokers). Comparison of propensity-matched cohorts did not identify any difference in outcomes in smokers versus nonsmokers.

CONCLUSIONS

In patients undergoing lumbar decompression for spinal stenosis or herniated disc, smokers demonstrated slightly less improvement in outcomes compared with nonsmokers, and a high proportion of both groups achieved meaningful improvement with surgery. While smoking cessation should be strongly encouraged in all patients, lumbar decompression procedures for spinal stenosis and herniated disc should not be denied to smokers.
Posterior aggressive debulking versus minimal decompression surgery in patients with metastatic spinal cord compression: propensity-score–matching analysis from a multicenter study cohort
Authors: Park Se-Jun , Park Jin-Sung , Kang Dong-Ho , Lee Chong-Suh , Chang Bong-Soon , Kim Hyoungmin , Chang Sam Yeol , Lee Jiyong
Published: October 2024

OBJECTIVE

The goal of this study was to evaluate the comparative outcomes of aggressive debulking (AD) and minimal decompression (MD) surgeries for metastatic spinal cord compression based on surgical burden, functional improvement, and symptomatic local recurrence (SLR).

METHODS

In this retrospective analysis from 2 tertiary hospitals, the authors assessed patients with metastatic spinal cord compression treated via AD and MD surgeries between 2010 and 2022. The evaluation included patient demographics, Eastern Cooperative Oncology Group performance status (ECOG-PS), primary tumor type, modified Tokuhashi scores, surgical burden, and SLR. Propensity-score matching (1:1 ratio) was conducted based on oncological status for intergroup comparisons. Survival analysis and logistic regression analyses were conducted.

RESULTS

A total of 264 patients were included in the study. After 1:1 propensity-score matching, a total of 156 matched patients were analyzed (78 patients each in the AD and MD groups). Operation time, estimated blood loss, transfused red blood cell units, and inpatient medical complications were significantly higher in the AD group compared to the MD group (p = 0.001, p = 0.002, p = 0.006, and p = 0.035, respectively). There was no significant difference in distribution of postoperative ECOG-PS between the AD and MD groups (OR 1.461, 95% CI 0.821–2.599, p = 0.197). In initially nonambulatory patients (ECOG-PS of grade 3 or 4), the AD group showed a higher proportion of patients regaining ambulatory function compared to the MD group (56.5% vs 36.2%; OR 2.294, p = 0.049). In cases with a preoperative ECOG-PS of grade 3, the difference in ambulation recovery between AD and MD was not statistically significant (60.0% vs 53.3%, p = 0.577). However, for severely impaired patients (ECOG-PS of grade 4), the AD group showed a higher proportion of patients regaining ambulatory function compared to the MD group (33.3% vs 5.9%, p = 0.086). Symptomatic SLR-free survival showed no significant differences at final follow-up (p = 0.095). Multivariate analysis identified the modified Tokuhashi score as the sole predictor of SLR (OR 1.871, p = 0.001).

CONCLUSIONS

This study found that MD surgery significantly reduced surgical burden compared to AD. AD surgery led to slightly better functional recovery showing greater rescue ratios, especially in patients with a preoperative ECOG-PS of grade 4. However, no difference in rescue ratio was observed in patients with a preoperative ECOG-PS of grade 3. There was no significant difference in SLR rates between the AD and MD groups.
Arteriovenous malformation–associated aneurysms in the pediatric population: the University of Pittsburgh Medical Center experience
Authors: Jacobs Rachel C. , Chilukuri Akanksha , Abou-Al-Shaar Hussam , Garcia Joseph H. , Agarwal Prateek , McDowell Michael M. , Al-Bayati Alhamza R. , Greene Stephanie
Published: October 2024

OBJECTIVE

Arteriovenous malformations (AVMs) are the most common cause of spontaneous intracranial hemorrhage (ICH) in children, often leading to devastating complications. The current literature from the adult AVM population suggests that both younger age and associated aneurysms carry an increased risk of hemorrhagic presentation. However, detailed analysis of pediatric AVM-associated aneurysms and their link to ICH is relatively unknown, with the literature largely consisting of case reports. This study aimed to determine whether AVM-associated aneurysms predispose pediatric patients to ICH.

METHODS

A retrospective cohort study of 238 pediatric patients with AVMs who presented to the Children’s Hospital of Pittsburgh from 1988 to 2023 was performed. Hospital records, patient charts, and radiographic imaging studies were reviewed for patient demographic characteristics, presentation status, and AVM architecture.

RESULTS

Of the 238 total patients, 44 (18.5%) children with AVM had associated aneurysms. There were 19 (38.8%) feeding artery aneurysms, 8 (16.3%) intranidal aneurysms, 21 (42.9%) postnidal aneurysms, and 1 (2.0%) unrelated aneurysm of 49 aneurysms. Five patients had venous varices. One hundred forty (58.8%) children presented with hemorrhage. Twenty-one of 44 (47.7%) patients with an AVM-associated aneurysm presented with hemorrhage, whereas 119 of 194 (61.3%) with a solitary AVM presented with hemorrhage (p = 0.10). On multivariate analysis, postnidal aneurysm (OR 0.36, p = 0.037) and an increased number of draining veins (OR 0.66, p = 0.049) were significantly associated with a decreased likelihood of hemorrhagic presentation. Deep venous drainage was associated with an increase in hemorrhagic presentation (OR 2.25, p = 0.0045) on multivariate analysis.

CONCLUSIONS

Approximately one-fifth of children with AVMs in this study had accompanying aneurysms, and in this patient population, those with postnidal aneurysms and increased number of draining veins had a decreased incidence of hemorrhage on presentation. Feeding artery and intranidal aneurysms were not associated with an elevated risk of hemorrhagic presentation.
A two-institution pilot study on the psychological burden and distress of parents caring for children with shunted hydrocephalus
Authors: Knerlich-Lukoschus Friederike , Cohrs Gesa , Mehdorn H. Maximilian , Synowitz Michael , Messing-Jünger Martina , Goebel Simone
Published: October 2024

OBJECTIVE

Little is known about the emotional health of parents caring for children with shunted hydrocephalus. The aim of this pilot study was to find out whether parents caring for shunt-treated hydrocephalic children experience serious psychological problems and psychosocial distress and whether these problems are related to the sociodemographic background of the caregivers, the clinical characteristics of their children, and parents’ illness-related concerns and perceived burden of their children’s illness.

METHODS

This pilot study was performed in an outpatient setting at two German hospitals. The following questionnaires were handed out to parents of children with shunted hydrocephalus (< 21 years of age): the Patient Health Questionnaire (PHQ-9) for depression, the Generalized Anxiety Disorder Scale (GAD-7) for anxiety, the Distress Thermometer (DT) for psychosocial distress, the Hydrocephalus Concerns Questionnaire (HCQ) for assessment of parents’ illness-related concerns, and the Hydrocephalus Outcome Questionnaire (HOQ) for assessment of perceived children’s disease burden. Clinical data of the respective children were collected from electronic charts. Parents’ demographic data were evaluated via questionnaires. Parents’ psychological variables were correlated with demographic and clinical data and HCQ and HOQ scores. Regression analyses of HCQ and HOQ scores with psychological items were performed.

RESULTS

Sixty-three parents were included in this study. Of these, 60% reported clinically relevant levels of either depression (11%), anxiety (10%), and/or psychosocial distress (57%). There were no associations between parental sociodemographic or children’s clinical characteristics with parents’ psychosocial well-being or psychosocial distress. Depression, anxiety, and DT scores were highly intercorrelated and significantly correlated with HCQ scores (r = 0.508, r = 0.516, r = 0.442; p < 0.01). Thereby, worries about shunt-related complications were the most reported concern in the HCQ. Depression and anxiety correlated with the scores of some HOQ subcategories. In preliminary regression analyses, higher illness-related concerns predicted occurrence of parents’ anxiety.

CONCLUSIONS

The authors’ results support the notion that there is a need for psychosocial support for a proportion of parents who care for shunted hydrocephalic children. Perceived child symptom burden and parental illness concerns were identified as relevant correlates of parental psychological well-being. Thus, concerns specific to shunt-related problems could be a first starting point for the development of individual support measures.
Sol-gel synthesis and research of inorganic compounds, hybrid functional materials and disperse systems
Authors: Simonenko E. P. , Ivanov V. K.
Published: October 2024

The results are summarised of the Seventh International Conference of CIS countries “Sol-gel synthesis and research of inorganic compounds, hybrid functional materials and disperse systems “Sol-gel 2023”, the key reports are discussed within the scientific sections: Theoretical aspects of sol-gel process; Films, coatings and membranes obtained using sol-gel technology; Hybrid organic-inorganic sol-gel materials; Xerogels, glasses and bulk ceramic materials synthesized by sol-gel method; Nano- and microstructured materials, nanotechnology; Methods of research of structure and properties of materials obtained using sol-gel synthesis.
Preparation of New Hybrid Materials SiO2@Melamine-Cyanurate as Precursors of Graphite-Like Carbon Nitride
Authors: Lebedev М. D. , Goncharenko A. A. , Skvortsov I. A. , Kuzmikov M. S. , Vashurin A. S.
Published: October 2024

This work describes the use of silica particles obtained by sol-gel method as a templat for deposition of supramolecular complexes of melamine cyanurate. To obtain SiO2@melamine-cyanurate (SiO2@MCA) material, the method of covalent modification of silica surface by melamine molecules (SiO2-mel) was applied and the method of its further functionalization by hydrogen-bonded organic framework of melamine-cyanurate (HOF, MCA) was proposed. One of the promising directions of using SiO2@melamine-cyanurate is obtaining SiO2@g-C3N4 material on its basis. Control of the amount of applied melamine-cyanurate allows to potentially obtain g-C3N4 layers of different thicknesses on the silica surface.
Electronic Structure Of Cobalt Phosphates Co1-xmxpo4 Doped With Iron And Nickel Atoms
Authors: Pecherskaya M. D. , Galkina O. A. , Ruzimuradov O. N. , Mamatkulov Sh. I.
Published: October 2024

In this research, the electronic states, band structures, and bond properties of the framework compounds of CoPO4, Co1-xFexPO4, and Co1–xNixPO4 were investigated by the density functional theory calculations. The potential capabilities of these systems in the photocatalytic water splitting to produce hydrogen were analyzed. The spin-up electron densities of states for the CoPO4, Co1–xFexPO4, and Co1–xNixPO4 systems have band gaps of 2.7, 3.4, and 3.45 eV, respectively. The band of spin-down electron states has several energy gaps above the Fermi level. The density of states of electron with spin up near the Fermi level is obviously greater than that of electrons with spin down. In this case, localized states of electrons appear in the band gap of doped semiconductors due to impurity atoms. The calculated value of the energy at the lower edge of the conduction band for CoPO4 was –0.7 eV, which is more negative than the energy required for water splitting. Meanwhile, the calculated value of the energy at the upper edge of the valence band was 2.01 eV, which is more positive than the oxygen evolution energy of 1.23 eV.
Stability of Supramolecular β-Cyclodextrin-Pyrene Complexes in A Silicate Hydrogel Matrix
Authors: Kondakova A. V. , Medvedeva A. A. , Koshkin A. V.
Published: October 2024

In order to use the β-cyclodextrin-pyrene complex as a fluorescent receptor center, its stability in the solid phase of a water-soluble silicate gel was investigated. For this purpose, a technique for obtaining a silicate matrix with a high content of supramolecular complexes was developed and the temperature stability of the resulting material was investigated. Optimal conditions for working with complexes in the silica gel matrix have been identified. Comparative studies of the fluorescence spectra of complexes in liquid and solid phases were carried out by the method of fluorescence spectroscopy. As a result of the work done, it was possible to determine the main patterns of behavior of the supramolecular complex in the silicate hydrogel matrix and to conclude about the influence of the matrix structure on its stability.
Application Of Vanadyl Alkoxoacetylacetonate In Formation Of v2O5 Electrochromic Films
Authors: Gorobtsov P. Y. , Simonenko N. P. , Mokrushin A. S. , Simonenko E. P. , Kuznetsov N. T.
Published: October 2024

Crystal structure, morphology and electrochromic properties of V2O5 film, prepared using vanadyl alkoxoacetylacetonate as precursor, were studied. We have shown that the obtained vanadium pentoxide contains significant amount of V4+ cations, which is indicated by low electron work function among other things. This results in material possessing anodic electrochromism – coloring upon oxidation – with rapid bleaching process (1 s upon necessary potential application). Anodic coloration is observed in the whole visible light spectrum, as well as in near IR region up to 1100 nm. Obtained data show high prospects for approach to formation of V2O5-based films using vanadyl acetylacetonate as precursor and application of such films as components of smart windows and displays, optical properties of which could be controlled by electrical current application.
The diversity of commercial marine bivalves in the Nha Phu Lagoon, Khanh Hoa Province, south-central Vietnam
Authors: Lan N. T. , Dgebuadze P. Yu. , Huan P. T.
Published: October 2024

The study was conducted as part of the Joint Vietnam–Russia Tropical Science and Technology Research Center’s project on indicator organisms in the marine environment of south-central Vietnam. The research focused on coastal areas with significant anthropogenic impacts, revealing that biological resources directly affect the livelihood and activities of coastal populations. These resources are dynamic and subject to both human and natural factors. The material from the soft-bottom zone was collected using a grab rake with a mesh bag at the end. Scuba diving equipment was used in areas with a hard substrate and mudflats. In addition, during sample collection, several mollusc specimens were acquired from fishermen who cought marine organisms in that lagoon. Comparing the results with previous studies on bivalve resources in the area, the Nha Phu Lagoon was found to harbour a wide range of economically valuable bivalve species. A total of twenty-seven bivalve species from thirteen families were identified, with the family Veneridae having the highest number of species (eight). The most abundant catches were from the families Ostreidae and Mytilidae, primarily consisting of Magallana gigas (Thunberg 1793) and Perna viridis (Linnaeus 1758), both cultured in the lagoon. Apart from their economic value, these two species also play crucial roles in the ecosystem by filtering water and retaining organic debris in the environment.
First record of Canthocamptus (Canthocamptus) microstaphylinus Wolf 1905 (Harpacticoida, Copepoda) from a shallow coastal area of Lake Baikal
Authors: Alekseeva T. M. , Fefilova E. B. , Sheveleva N. G. , Timoshkin O. A.
Published: October 2024

Female and male specimens of the Palearctic species, Canthocamptus (Canthocamptus) microstaphylinus Wolf 1905, were found in the coastal zone of Lake Baikal, Siberia. This was the first record of the species in Lake Baikal and the Baikal region. A general description and brief morphological characteristics were made using scanning electron microscopy. The authors compared the principal diagnostic morphological traits of C. (C.) microstaphylinus from Lake Baikal and some water bodies from the European part of Russia (within the Syktyvkar City, Republic of Komi). As a result, specimens from Lake Baikal and the Syktyvkar area were shown to be similar in the structure of their thoracic appendages and caudal rami.
The East Asian species Thermocyclops taihokuensis (Harada 1931) (Crustacea, Copepoda, Cyclopoida) in the Taganrog Bay of Azov Sea
Authors: Lazareva V. I. , Sabitova R. Z.
Published: October 2024

In August–September 2021–2023, the composition and abundance of pelagic Copepoda in the Don River delta and in the eastern part of the Taganrog Bay of Azov Sea were studied. The East Asian copepod, Thermocyclops taihokuensis (Harada 1931) was recorded for the first time from the eastern part of the bay at a water salinity of 3.5–5.8‰. The species must have entered the Taganrog Bay with water from the Don River. The largest population of the invader was registered in the Don River delta in August 2021 ( 7.000 ind./m3); in the bay in September 2023 it reached 4.000 ind./m3. The body size and fertility of the invader were close to those in the Tsimlyansk Reservoir and the Don River. In 2023, the reproduction of T. taihokuensis was noted in the bay with an extremely low (about 1%) proportion of mature individuals in the population. The species seems to have not yet been fully naturalized in the bay, its population still being supported by bioflow from the Don River delta. The potential consequences of the introduction of this alien copepod for the zooplankton of Taganrog Bay are discussed.
Inheritance of signs of parent species by hybrids of Russet, Yellow and Speckled ground squirrels (Spermophilus, Sciuridae, Rodentia)
Authors: Titov S. V. , Chernyshova O. V. , Simakov M. D. , Kartavov N. A. , Kuzmin A. A.
Published: October 2024

The inheritance of size, color and bioacoustic characteristics of Russet (Spermophilus major), Yellow (S. fulvus) and Speckled (S. suslicus) ground squirrels in hybrids differing in their genetic status were studied. In a hybrid population of Russet and Yellow ground squirrels, 10 individuals of S. major, 10 individuals of S. fulvus and 40 hybrids of S. major × S. fulvus were analyzed; in a hybrid population of Russet and Speckled ground squirrels, 11 individuals of S. major, 11 individuals of S. suslicus and 24 hybrids of S. major × S. suslicus were analyzed. Hybrid individuals different in genetic status have been shown to demonstrate differentiation in the vector space of the variability range of the parental species. At the same time, both a shift in some categories of hybrids towards one of the hybridizing species and a significant deviation are noted. The results obtained indicate an increase in the level of variability in size, color and bioacoustic characters in hybrid populations, associated with the erosion of the divergent hiatus of specific features of the parental forms due to the formation of a differentiated hybrid population. As hybrid individuals with different combinations of parental traits accumulate in the population, the situation arises when a sufficient number of hybrids with an overall combination of parental traits (Hcomb) appear in the hybridogenic population. In the hybrid population of the Russet and Yellow ground squirrels, the proportion of such hybrids, according to our data, is 22.5% (n = 40), and in the hybrid population of the Russet and Speckled ground squirrels it is 12.5% (n = 24). This category of hybrid individuals can be considered as possible material for further microevolutionary events and the process of speciation.
Usage of Volumetric Reflectors for Adjusting Ultrasonic Testing Parameters
Authors: Mogilner L. Yu. , Smorodinsky Ya. G. , Tishkin V. V.
Published: October 2024

In ultrasonic flaw detection, lateral cylindrical drillings are traditionally used to adjust and check the parameters of equipment. Other volumetric reflectors, such as vertical drillings or spherical pores, are rarely used. This article notes that such models of internal and surface defects of welded seams are convenient to use and easy to manufacture. For a long time, a limitation to the use of drillings for modeling in ultrasonic flaw detection was the use of these effects not only on defect models in the form of noise associated with the diffraction effects of elastic waves running around cylindrical cavities. It is noted that these effects are currently well studied and are used to identify the type of defects and measure their sizes. Based on the results of experiments on observing the scattering of longitudinal waves and transverse waves with different polarization on cylinders and spheres, typical examples of the manifestation and use of these diffraction effects are given. The expediency of using not only drillings, but also spherical pores is noted. Experiments of the ultrasonic waves scattering on pores are performed on transparent glass samples for clarity. Comparative data on the manifestation of diffraction effects on various volume cavities are presented. In particular, it is noted that there is a focusing of signals enveloping spherical pores. Limitations on the duration of ultrasonic wave pulses are noted, at which diffraction signals can be used to increase the information content when detecting defects. It is recommended to expand the use of 2 mm diameter side drillings in samples to adjust sensitivity during ultrasonic testing using the echo method.
Comparative Analysis of Experimental Methods for Determining the Curie Temperature of Ferrite Materials
Authors: Bobuyok S. A. , Surzhikov A. P. , Nikolaev E. V. , Malyshev A. V. , Lysenko E. N.
Published: October 2024

Magnetic phase transformations in the Curie temperature region of a ferrite material with the composition Ni0,4Zn0,6Fe2O4 were studied using thermomagnetometric analysis and methods for recording the temperature dependence of the initial magnetic permeability μ0(T) and electrical resistivity ρ(T). The description of the equipment utilized and the key characteristics of the application of the experimental methods under review are provided. During thermomagnetometry at the cooling stage, it was found that the temperature at which the material completes the transition to the ferrimagnetic state corresponds to the inflection point temperature on the µ0(T) curve and the breakpoint on the lnρ(T) plot. The established interaction between the parameters of transients can be useful for more correct determination of the Curie temperature in ferrites.
Measuring the Viscosity of Sulphur Melt by the Proton Microscopy Method
Authors: Khurchiev A. O. , Gavrilin R. O. , Skoblyakov A. V. , Kantsyrev A. V. , Golubev A. A. , Mintsev V. B. , Nikolaev D. N. , Shilkin N. S. , Belikov R. S.
Published: October 2024

Sulfur is a substance with an abnormal dependence of viscosity on temperature. An experimental setup was created to study the viscosity of sulfur at pressures up to 100 bar and temperatures up to 500 °C. To visualize the process of falling of a tungsten carbide ball located in molten sulfur, the proton radiography method was used. The experiment was carried out on a PRIOR-II proton microscope (Institute for Heavy Ion Research, GSI, Darmstadt, Germany). In this experiment, the operating mode of the SIS-18 accelerator with slow beam extraction was used for the first time for proton radiography. The viscosity of the sulfur melt was measured at a pressure of 90 bar and temperatures of 190—320 °C. It has been shown that the viscosity of sulfur is greatly influenced by impurities, including hydrogen sulfide, which appears in the molten sulfur at high temperatures.
Deep Learning Method of Precious Wood Image Classification Based on Microscopic Computed Tomography
Authors: Yang Xiaoxia , Zheng Zhishuai , Zheng Huanqi , Liu Xiaoping
Published: October 2024

Correctly identifying precious wood species is crucial for import and export trade and furniture material identification. This study utilizes nondestructive testing (Microscopic Computed Tomography, Micro-CT) to capture microscopic images of the transverse, radial, and tangential sections of 24 precious wood species, creating a comprehensive dataset. The SLConNet deep learning model is developed, enhancing recognition accuracy through multi-scale convolution and an improved residual block structure. The experiment results show that the classification accuracy of the transverse, radial and tangential sections is 98.72, 96.75 and 95.36 % respectively when the gain value is 0.8. The model outperforms traditional models like Alexnet, ResNet50, Inception-V3, and Xception. This research highlights the efficiency of nondestructive testing in obtaining a large number of microscopic wood images, compared to traditional anatomical methods. The SLConNet model showcases high accuracy in precision, recall, and specificity, suggesting its potential for widespread applications in wood classification.
The Role of DNA Methylation in Zebrafish Models of CNS Diseases
Authors: Yushko L. V. , Shevlyakov A. D. , Romazeva M. A. , Apukhtin K. V. , Volgin A. D. , Abramov D. A. , Kotova M. M. , Kalueff A. V.
Published: October 2024

DNA methylation plays an important role in the regulation of gene expression. Disturbances in this process in the brain cause various neurological diseases, including autism, schizophrenia and mood disorders. Zebrafish (Danio rerio) are a promising model organism in biomedicine. Given high genetic and physiological homology with humans, studying genome methylation deficits in zebrafish can help to clarify the molecular processes underlying etiology and pathogenesis of various neurological diseases, as well as to develop novel therapies. Here, we discuss the mechanisms of DNA methylation in the brain and the diseases associated with its dysregulation in humans, as well as their genetic and pharmacological models in zebrafish. We also evaluate the limitations of zebrafish models and possible directions for further research in this field. Mounting evidence summarized here supports zebrafish as an effective model for elucidating the molecular mechanisms of brain pathologies associated with impaired DNA methylation.
Olfactory Dysfunction in Obesity and Type 2 Diabetes
Authors: Bigday E. V. , Zuykova A. A. , Pozdnyakov A. V.
Published: October 2024

The article analyzes literature data on the close relationship between energy balance and sense of smell. Olfaction is one of the main modalities of hedonic evaluation of food. Odor is one of the most important sensory signals predicting food quality and plays a key role in food selection and consumption. Appetite can be stimulated by various stimuli, but the leading role belongs to olfactory signals (tasty smells) and levels of hormones that signal hunger and satiety. Olfactory perception is subject to hormonal modulation. In this regard, special attention in the article is paid to the modulating function of insulin. Insulin, one of the main metabolic hormones that controls food intake, has an anorexigenic effect not only at the level of the hypothalamus, but also at the level of the olfactory pathway, especially strong in the olfactory bulb. It has a rate of insulin transport two to eight times higher than in other parts of the brain, and it contains the highest concentration of insulin and the highest density of insulin receptor kinase. Thus, insulin is not only able to penetrate to the site of olfactory information processing, but do so quickly. At the same time, insulin and its receptors are localized in the olfactory epithelium, namely in mature olfactory sensory neurons. Therefore, insulin affects the primary stage of perception of an odorous molecule – odor detection, which occurs at the level of the olfactory epithelium. The sense of smell is impaired up to its complete loss in obesity and type 2 diabetes, worsening the quality of life of such patients. The paper examines the effectiveness of intranasal insulin administration to restore olfactory function in metabolic disorders and other diseases.
Synergic Trio of Metabolic Regulators Supporting the Vicious Circle of Pathological Processes in Post-Traumatic Stress Disorder
Authors: Kondashevskaya M. V. , Artemyeva K. A. , Mikhaleva L. M.
Published: October 2024

Post-traumatic stress disorder (PTSD) is a maladaptive response to exposure of extreme intensity stressor. The body of animals and humans reacts at the systemic and cellular levels, as with any response to external challenges. Disorder of the collective work of stress-realizing and stress-limiting systems causes transformation of behavior, cognitive abilities and other functions of the central nervous system in stress-sensitive individuals. Currently, it has been proven that in the pathogenesis of PTSD, an important place is occupied by changes in the number and composition of the intestinal microbiota. In this regard, methods of improving the microflora are being considered. Analyzing data of Russian and foreign researchers, the authors came to the conclusion, that metabolic, somatic and mental health largely depends on the coordinated functioning of the main interdependent components of metabolism: hepatobiliary system, intestinal microbiota and, according to the authors, on the state of mast cells. A close study of the interaction of these components will allow us to identify new therapeutic targets and the most effective methods of treating PTSD.
Maternal Methyl-Enriched Diet Improves Episodic Memory and Does Not Affect the Conditioned Fear Memory in Offspring of WAG/RIJ Rats
Authors: Fedosova E. A. , Shatskova A. B. , Sarkisova K. Yu.
Published: October 2024

The purpose of this study is to find out what effect the maternal methyl-enriched diet (MED) in the perinatal period exerts on cognitive functions in adult offspring of WAG/Rij rats, a genetic model of absence epilepsy with comorbid depression. Cognitive functions (learning and memory) were evaluated in tests of a novel object recognition (NOR) and a conditioning of fear memory (fear conditioning). The experiments were carry out on 6-months old male WAG/Rij rats. The mothers of the experimental group fed MED, and the mothers of the control group fed the control diet. The NOR test was used to assess episodic memory. This test is based on innate exploratory motivation (novelty preference motivation), which is usually reduced in depression. The conditioning of fear memory is the classic Pavlovian defensive conditioned reflex, manifested in the form of freezing reactions in response to negative reinforcement (electrical stimulation of paws). In the NOR test, in rats of the experimental group the recognition index (a measure of episodic memory), as well as the number of entries to the center of the arena (a measure of explorative motivation) were significantly higher compared with corresponding measures in the control group. However, no intergroup differences were found in the manifestation of the conditioned fear memory (% of freezing reactions) to the context and sound signal. The results indicate that the maternal MED improves episodic memory in the NOR test, but does not affect the conditioned fear memory associated with context and sound signal in adult offspring of WAG/Rij rats.
Application of lactoferrin for the prevention and restoration of bone tissue in Wistar rats under conditions of hindlimb unloading
Authors: Gordienko K. V. , Lukicheva N. A. , Akhmetzyanova A. I. , Kolupaev A. K. , Sachenkov O. A. , Baltina T. V. , Sadchikova E. R. , Vassilieva G. Yu.
Published: October 2024

The influence of gravitational unloading (antiorthostatic suspension) and subsequent recovery on the mineral density and mechanical properties of the femoral and tibial bones of Wistar rats was studied with oral administration of a biotechnological analog of human lactoferrin (200 mg/kg) derived from the milk of producer goats. Bone mineral density was determined by dual-energy X-ray absorptiometry, and strength and stiffness were assessed through three-point bending tests.
It was shown that gravitational unloading for 21 days led to a decrease in the mineral density of the tibial and femoral bones. The administration of lactoferrin did not significantly affect the mineral density or projected area of the studied bones. No statistically significant differences in mechanical stiffness were found between the experimental groups, but after readaptation, the ultimate strength was significantly higher in the groups that received lactoferrin. Thus, the obtained results may indicate the potential of lactoferrin preparations as prophylactic agents for maintaining bone strength. At the same time, maintaining bone mineral density under deficit-stimulating conditions requires consideration of alternative dosages and delivery methods of the drug.
Conscious and Unconscious Processes in the Arithmetic Priming Task Depend on the Arithmetic Skill
Authors: Knyazeva V. M. , Polyakova N. V. , Fedorov D. G. , Sitnikova D. D. , Aleksandrov A. A.
Published: October 2024

The study examined the role of conscious and unconscious processes depending on the level of arithmetic skill. The participants were divided into two groups according to their arithmetic skill based on the calculation fluency test results. Masked and unmasked single-digit addition problems (primes) followed by correct and incorrect results were presented on the screen. In a conscious perception task (unmasked priming), when large and small problem results were presented, an arithmetic N400 and LPC effects were observed in both groups. In the case of unconscious perception (masked priming), when small problem results were presented, the LPC effect was observed in the group with low arithmetic skill. The fact that the LPC arithmetic effect was discovered during the unconscious presentation may indicate the automatic nature of the encoding and retrieving information processes, reflecting neurophysiological characteristics associated with the level of arithmetic skill.
Estimate of the onset of laminar-turbulent transition on a plate in flight in the Mars atmosphere
Authors: Grigor’ev Yu. N. , Ershov I. V.
Published: October 2024

Comparative calculations of the location of the onset of the laminar-turbulent transition zone are performed using the eN-method for two points on the Mars "Pathfinder" entry trajectory. A three-component model of thermochemically nonequilibrium CO2–CO–O mixture is used in the calculations. The set of spatial disturbance frequencies is found using neutral curves for the first unstable modes of temporary disturbances. The transition Reynolds number ReδTis determined from the envelopes of families ofN-factor curves atNT= 8. In the hypersonic regime at M = 12.6, taking into account the developed thermochemical nonequilibrium leads to a significant decrease in the static temperature of gas in the lower part of the boundary layer. As a result, the onset of the laminarturbulent transition zone is displaced downstream by approximately 9% as compared to the case of a perfect gas.
Development of the wave motion induced by near-bottom periodic disturbances in a two-layer shear current
Authors: Sturova I. V.
Published: October 2024

The behavior of wave motion arising in an ideal incompressible homogeneous fluid under switching-on periodic bottom disturbances is studied in the linear approximation for the two-dimensional non-stationary problem. In the undisturbed state, the velocities of two-layer fluid flow are linear functions of the vertical coordinate in each of the layers with different gradients and coincide on the boundary of the layers. The upper boundary of fluid can be either free or bounded by the rigid cover. The dispersion dependences and the group velocities of the appearing wave modes are determined. The vertical displacements of the free surface and the interface between the layers are calculated. A comparison with the solution for a single-layer fluid is carried out.
Linear waves in shallow water over an uneven bottom, slowing down near the shore
Authors: Melnikov I. E. , Pelinovsky E. N.
Published: October 2024

The exact solutions of the system of equations of the linear theory of shallow water are discussed, representing traveling waves with specific properties for the time propagation, which is infinite when approaching the shore and finite when leaving for deep water. These solutions are obtained by reducing one-dimensional shallow water equations to the Euler–Poisson–Darboux equation with a negative integer coefficient before the lower derivative. The analysis of the wave field dynamics is carried out. It is shown that the shape of a wave approaching the shore will be differentiated a certain number of times, which is illustrated by a number of examples. When a wave moves away from the shore, its profile is integrated. The solutions obtained in the framework of linear theory are valid only for a finite interval of depth variation.
Gas suction effect on the crossflow instability in flow past a swept wing
Authors: Novikov A. V. , Obraz A. O. , Timokhin D. A.
Published: October 2024

The results of the swept wing boundary layer stability investigation are presented for the case, when the wing surface has a region of gas suction through the wall normal to the surface, while the wing is in Mach number 2 flow. In the flow regime considered the predominant boundary layer instability type is the crossflow instability. The gas suction effect on the development of unstable modes in the boundary layer is investigated using the linear stability theory and direct numerical modeling. The numerical modeling of laminar (undisturbed) flow fields with regions of gas suction and disturbed flow fields is carried out by integrating Navier–Stokes equations. An analysis within the framework of the linear stability theory is performed using theeN-method. The suction region location is varied with conservation of the integral intensity. It is shown that the mode instability growth can be considerably suppressed at the expense of an optimal disposition of the suction region.