bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Compaction State and Position of the Cold Joints on the Flexural Capacity of RC Beams
Authors: Aziz Maysaa Mahdi , Abd Sultan Ali
Published: December 2024

تعتبر الوصلات الباردة بمثابة توقفات في عملية صب الخرسانة وهي ضرورية لأنه من غير العملي صب الخرسانة في عملية واحدة مستمرة في العديد من الهياكل. تحدد قوة القوالب وقدرات الخلط والخلط كمية الخرسانة التي يمكن وضعها مرة واحدة. يجب أن تتمتع وصلة البناء جيدة الصنع بقدرة كافية على القص واستمرارية الانحناء عبر الواجهة. في هذه الدراسة تم دراسة تأثير وضع الوصلات الباردة الأفقية وعملية الدمك على سلوك الانحناء للخرسانة المسلحة. تم اختبار خمس عينات من العتبات بأبعاد 160×100×1200 ملم. المتغيرات التي تم فحصها هي موضع الوصلات الباردة (التي تم وضعها أفقيًا عند ألياف الانضغاط وعند ألياف الشد للعتبات)، وما إذا كانت الطبقة الخرسانية المصبوبة الأولى قد تم ضغطها أو تم تركها غير مضغوطة حتى يتم وضع الصب الثاني. أشارت نتائج البحث إلى أن الحمل النهائي، والانحراف النهائي، والليونة، والمتانة قد تم تقليلها جميعًا نتيجة لوجود مثل هذه المفاصل الباردة. كانت مؤشرات السلوك هذه تعتمد بشكل أساسي على موقع المفصل البارد والطبقة الأولى المضغوطة. إن دمك الطبقة الأولى وموقع الوصلة الباردة له تأثير كبير على قدرة حمل الحمولة والانحراف المقابل للعتبات المختبرة، وانخفاض الحمل النهائي، والانحراف النهائي، والمرونة والمتانة للعتبات التي تم دمكها ووضعها أفقياً في ألياف الشد كانت 13.78%، 34.95%، 32.1% و 84.04% على التوالي، بينما بالنسبة للعتبة التي كانت طبقة أولى غير مضغوطة كان الانخفاض 31.35%، 29.52%، 31.6% و 61.03%. كان الانخفاض في الحمل النهائي والانحراف النهائي والمرونة والمتانة للعتبات التي تم ضغطها ووضعها أفقيًا عند ألياف الضغط 15.50%، 37.95%، 35.1% و85.575 على التوالي، بينما بالنسبة للعتبات التي كانت الطبقة الأولى غير المضغوطة كان الانخفاض 40.91%. 43.76،33.9% و72.7% على التوالي.
CONVERSION OSTEOSYNTHESIS TECHNIQUE FOR LIMB COMBAT INJURIES
Authors: Tanasiienko P.V. , Guriev S.O. , Vasylov V.V.
Published: December 2024

To achieve optimal treatment outcomes in complex cases involving severe mine-explosive injuries, a staged approach has been developed worldwide. This approach involves external fixation for initial stabilization followed by definitive reconstruction using internal fixators.
The purpose of this study was to evaluate the effectiveness of conversion osteosynthesis in providing medical care to victims of modern warfare. The study analyzed 174 cases of long bone injuries sustained during the full-scale invasion of Russia between 2022 and 2024.
The treatment outcomes in the main group demonstrated an increase in the average consolidation time, characteristic of closed fractures, but a lower incidence of nonunion and malunion with segmental deformities. The frequency of delayed fusion of fragments was 7.7% less compared to the victims of the control group. Fusion of bone fragments with deformation in patients of the main group was 8.6% of cases, and in the control group in 13.8% of cases. False bone joints in the victims of the main group developed 4.8% less often than in the wounded of the control group.
Infectious complications occurred in 5.4% of patients in the main group, with superficial infections accounting for 80.0% of these cases. Deep infections with osteomyelitis were observed in one patient, representing 1.1% of the main group.
The study confirmed the effectiveness of conversion osteosynthesis in treating combat-related limb injuries. Transitioning from external fixation to internal osteosynthesis significantly reduced inpatient treatment time for patients with long bone fractures and improved treatment outcomes. However, the specific indications, methods, and timing for implementing conversion osteosynthesis in such cases require further development.
PREOPERATIVE PLANNING OF ARTHROSCOPIC SYNOVECTOMY IN PATIENTS WITH KNEE INJURIES AND CONCOMITANT PATHOLOGY
Authors: Boskina M.H. , Pelypenko O.V.
Published: December 2024

Knee joint pathology poses a significant challenge in modern orthopaedics, driven by the rising incidence of traumatic injuries and their frequent association with comorbid conditions. Epidemiological data report an annual knee injury incidence of 5.3 per 1,000 population, with approximately 40% of cases progressing to synovitis. The presence of comorbidities significantly influences disease progression and treatment outcomes, underscoring their clinical importance.
This study aimed to identify key factors affecting the quality of preoperative planning for arthroscopic synovectomy, with a focus on individual patient characteristics and the specific nature of concomitant pathologies.
This study included 97 patients (2020–2024), categorized into two groups: traumatic pathology (n = 50) and degenerative pathology (n = 47). The assessment protocol comprised clinical evaluation using the Knee Injury and Osteoarthritis Outcome Score, magnetic resonance imaging analysis based on the Whole-Organ Magnetic Resonance Imaging Score and the Boston Knee Osteoarthritis Scoring System, inflammatory marker measurements, and comorbidity profiling.
Statistical analysis revealed significant variations in synovitis severity and functional parameters correlating with comorbidity patterns. The concurrent presence of grade II- III hypertension and diabetes mellitus demonstrated the most adverse clinical profile, characterized by maximum synovitis scores (2.0 points by the Whole-Organ Magnetic Resonance Imaging Score) and severely compromised functional parameters (35.9±1.2 points by the Pain subscale of Knee Injury and Osteoarthritis Outcome Score).
The study has established key risk factors for severe synovitis and developed a comprehensive risk stratification system, categorizing patients into low-, moderate-, and high-risk groups, facilitating the implementation of individualized preoperative management strategies tailored to their comorbidity profiles.
CHRONIC RECURRENT HERPETIC STOMATITIS: STRATEGIES FOR COMPREHENSIVE PATIENT’S EXAMINATION
Authors: Zadorozhnaya S.
Published: December 2024

Introduction. This research paper highlights the diagnosis and treatment of patients with chronic recurrent herpetic stomatitis, a condition caused by herpes simplex virus type 1. This disease is marked by frequent relapses, often triggered by stress, illness, or dental procedures. The aim of this study is to assess the effectiveness of using questionnaires and modern diagnostic tests to improve the accuracy of diagnosis and treatment outcomes.
Subjects and materials. A total of 40 patients aged 20 to 45 were evaluated using a questionnaire and an initial clinical assessment. Recurrences were confirmed in 67.5% of the patients, with four individuals exhibiting clinical manifestations of the disease at the time of examination. Additional laboratory tests were prescribed for those presenting symptoms of chronic recurrent herpetic stomatitis. These tests included a complete blood count, IgG testing for herpes simplex virus, vitamin D level assessment, and a biochemical blood analysis focusing on liver function. Patients were also referred to relevant specialists, including an internist, a neurologist, and an infectious disease expert.
Results. Based on the laboratory results, personalized treatment plans were developed, which included Valtrex (an antiviral medication), essential phospholipids, Ibuprofen (as needed), and local diode laser therapy. This approach yielded positive results, with patients reporting reduced itching and pain, and noticeable healing beginning as early as the fourth day of treatment. The author concludes that stress is a significant factor contributing to the recurrence of herpetic stomatitis. The use of advanced diagnostic techniques, such as immunological tests with molecular markers (including polymerase chain reaction, immunofluorescence methods, and enzyme-linked immunosorbent assays), enables highly accurate detection of the virus’s activity. Furthermore, a comprehensive patient history and questionnaire can help refine treatment strategies and enhance prevention efforts through the application of the latest physiotherapeutic methods.
EFFECT OF CHROMIUM PICOLINATE ADMINISTRATION ON OXIDATIVE STRESS IN RAT MUSCLES UNDER METABOLIC SYNDROME CONDITIONS
Authors: Akimov O.Y. , Mykytenko A.O. , Mischenko A.V. , Kostenko V.O.
Published: December 2024

Introduction. Over 1 billion people worldwide are affected by obesity, including approximately 650 million adults, 340 million adolescents, and 39 million children. According to WHO projections, 167 million individuals are expected to be overweight or obese by 2025. Obesity is a major risk factor for metabolic syndrome, cardiovascular disease, stroke, type 2 diabetes, and certain types of cancer.
The aim of this study is to investigate the impact of a transcription factor p38 activation inducer on antioxidant enzyme activity, superoxide anion radical production, oxidatively modified protein levels, and malondialdehyde concentration in the biceps femoris muscle of rats under experimental metabolic syndrome conditions.
Materials and methods. The study involved 24 sexually mature male Wistar rats weighing 200–260 g, divided into four groups: a control group; a metabolic syndrome model group, which was formed by providing a 20% fructose solution as the sole drinking source alongside a standard vivarium diet for 60 days; a chromium picolinate administration group, where chromium picolinate was administered orally at a dose of 80 μg/kg daily for 60 days; and a combined group subjected to both chromium picolinate administration and metabolic syndrome modeling. In a 10% homogenate of the biceps femoris muscle, the following parameters were analyzed: superoxide production, superoxide dismutase activity, catalase activity, malondialdehyde content, and levels of oxidatively modified proteins.
Results. The administration of chromium picolinate during metabolic syndrome modeling significantly reduced oxidative stress in the biceps femoris muscle of rats. Basal superoxide production decreased by 25.7%, while superoxide production by microsomes and mitochondria decreased by 18.8% and 24.4%, respectively, compared to the metabolic syndrome group. Additionally, superoxide dismutase activity increased by 60.5%, and catalase activity rose by 52.6%. The concentration of malondialdehyde decreased by 41.2%, and the content of oxidatively modified proteins was reduced by 34.3%.
Conclusion. Chromium picolinate administration under metabolic syndrome conditions effectively mitigates oxidative damage to lipids and proteins in rat skeletal muscle. This is achieved through a reduction in reactive oxygen species production and the restoration of antioxidant enzyme activity.
EFFECT OF TRANSCRIPTION FACTOR MODULATORS ON THE NITRIC OXIDE SYSTEM PARAMETERS IN THE BLOOD OF RATS UNDER LIPOPOLYSACCHARIDE-INDUCED SYSTEMIC INFLAMMATORY RESPONSE
Authors: Morhun Ye.O. , Kostenko V.O.
Published: December 2024

The study aimed to investigate the effect of transcription factor modulators on nitric oxide (NO) system parameters in the blood of rats under lipopolysaccharide (LPS)-induced systemic inflammatory response (SIR). The experiment was conducted on 42 male Wistar rats weighing 180–220 g, divided into 6 groups (7 animals per group): Group 1 included intact rats (Control I); Group 2 involved rats, which underwent LPS-induced systemic inflammatory response (SIR) modeling (Control II). In the remaining groups, transcription factor modulators were administered under SIR modeling: Group 3 received the anticancer drug bortezomib (used to treat multiple myeloma and mantle cell lymphoma), an NF-κB inhibitor (via proteasome suppression); Group 4 received the anticancer agent SR 11302 (investigated as a potential treatment for lung cancer), an inhibitor of the transcription factor AP-1; Group 5 received dimethyl fumarate, a specific activator of the Nrf2–ARE signaling pathway; Group 6 was administered with quercetin, a flavonoid that acts as an NF-κB inhibitor and an Nrf2 pathway activator.
The results showed that LPS-induced SIR significantly increased total NOS and iNOS activity while reducing cNOS and arginase activity in blood serum. This indicates the development of nitrosative stress and impaired L-arginine metabolism in rats. The use of NF-κB inhibitors (bortezomib) and AP-1 inhibitors (SR 11302), as well as Nrf2 activators (dimethyl fumarate and quercetin) reduced iNOS activity and partially normalized cNOS activity, demonstrating their anti-inflammatory and metabolic effects. The most effective agents for correcting nitrosative stress in SIR were bortezomib and SR 11302, which reduced iNOS activity to near-intact levels and partially restored the functional activity of cNOS.
Most transcription factor modulators (bortezomib, dimethyl fumarate, quercetin) partially restored arginase activity, highlighting their potential role in correcting impaired L-arginine metabolism. However, the AP-1 inhibitor (SR 11302) further decreased arginase activity compared to the LPS-induced group, suggesting possible inhibition of compensatory enzyme mechanisms and an exacerbation of metabolic imbalance.
The findings confirm the key roles of the NF-κB, AP-1, and Nrf2 signaling pathways in regulating nitrosative stress, offering promising pharmacological targets for correcting inflammatory and metabolic disturbances.
PERCEPTION OF THE EDUCATIONAL ENVIRONMENT BY MEDICAL STUDENTS AT POLTAVA STATE MEDICAL UNIVERSITY
Authors: Fedorchenko I. L. , Lytovka V. V. , Stryzhenok V. P. , Severyn Yu. M.
Published: December 2024

Іntroduction. The educational environment comprises a complex set of external factors essential for a successful educational process, fostering conditions for personal growth and development.
The study of the educational environment is a priority for higher education institutions globally due to its significant impact on learning outcomes and overall student success.
The purpose of this study is to analyze indicators of students’ perception of the educational environment at Poltava State Medical University among those pursuing second-level (Master's) education.
Materials and Methods. Materials and Methods. This study analyzes the results of a survey conducted among 220 students in their 1st to 3rd years of the second (Master's) level of higher education at Poltava State Medical University. A questionnaire consisting of 93 questions was developed to examine medical students’ adaptation to learning and the factors influencing their choices. The questionnaire incorporated the Johns Hopkins Learning Environment Scale and the Medical School Learning Environment Scale. The survey was conducted using Google Forms (https://docs.google.com/forms), and the results were processed using Google Sheets and MS Office 2019. Statistical significance was set at p < 0.05.
Results. According to the Spielberg-Hanin subscale of situational anxiety, the mean score of the participants was 53.44 [51.0–56.0], while the mean score for reactive anxiety was 51.77 ± 0.44. The combined scores for situational and reactive anxiety in women averaged 106.91 [105.0–129.0], and in men, 106.0 [99.0–113.0] (p < 0.0001); no significant differences were found between medical and dental students for these scales (p = 0.7145).
Respondents rated their overall perception of the educational environment as 1.0 [0–1.0]. A weak correlation was observed between their perception of the educational environment and scores on the situational anxiety scale (ρ = 0.13; p = 0.0048). No correlation was found with reactive anxiety scores (ρ = -0.016; p = 0.78), the Johns Hopkins Learning Environment Scale (R = -0.02; p = 0.88), or the Medical School Learning Environment Scale (R = -0.16; p = 0.18).
Gender differences were not observed on the Johns Hopkins Learning Environment Scale (U = 4774, p = 0.24). However, on the Medical School Learning Environment Scale, the average score was higher for women (0.46 ± 0.04) compared to men (0.44 ± 0.06) (U = 2.272, p = 0.0262). A moderate correlation was identified between the Johns Hopkins Learning Environment Scale and the Medical School Learning Environment Scale (R = 0.73; p < 0.05).
Conclusion. The scales are relevant and reliable tools for assessing medical students’ perception of the educational environment, particularly in terms of satisfaction with the psychological microclimate of learning. Evaluating medical students’ perception of the educational environment should consider gender, age, and social and living conditions.
CURRENT PERSPECTIVES ON THE EFFECTS OF MAIN TYPES OF CARRAGEENANS ON THE HUMAN BODY
Authors: Bachynskyi R. , Nakonechna О. , Stetsenko S. , Bondareva А. , Yarmish N. , Vasylieva I. , Denysenko S.
Published: December 2024

The relevance of studying carrageenans (red seaweed extracts) stems from the need to address a medical and scientific issue concerning the limited depth of understanding regarding their effects on the human body. The purpose of this study is to analyze current scientific literature on the effects of the primary types of carrageenans—kappa, iota, and lambda—and to evaluate the safety and efficacy of these food additives in the food industry. Results and discussion. Due to their hydrocolloidal properties, carrageenans contribute to the formation of stable structures in various food matrices, making them a key ingredient in the production of dairy and meat products, as well as in products made from plant ingredients. On the other hand, due to their structural and functional diversity, carrageenans are used in the cosmetics and pharmaceutical industries. According to modern scientific research, the external use of these biopolymers is considered safe. Moreover, experimental studies have shown that carrageenans have antioxidant properties, demonstrate a wide range of antiviral effects, and are effective against various viruses, including SARS-CoV-2, dengue virus, herpes simplex virus, cytomegalovirus, HIV, rabies virus, papillomavirus, influenza virus, and rhinoviruses. It has been established that different types of dietary undegraded carrageenans can significantly affect the gastrointestinal tract, namely, digestion processes - proteolysis. In vitro results have demonstrated that carrageenans can inhibit the activity of key gastrointestinal enzymes such as gastric pepsin and pancreatic trypsin. One of the potential toxic effects of orally consuming food additives E407 and E407a is the disruption of protein digestion in the gastrointestinal tract, leading to a deficiency in essential amino acids due to the inhibition of proteolysis. To gain a deeper understanding of these effects, further in-depth studies are needed to explore the biochemical mechanisms by which different types of carrageenans affect the gastrointestinal tract, as well as to investigate the dose-dependent nature of these changes.
CHANGES IN NEUROHUMORAL STATUS OF PATIENTS WITH COMMUNITY-ACQUIRED PNEUMONIA IN ASSOCIATION WITH CORONAVIRUS INFECTION COVID-19
Authors: Dotsenko S. Ya.
Published: December 2024

The aim of this study was to analyze and summarize the available data on changes in neurohumoral status in patients with community-acquired pneumonia associated with COVID-19, as well as to identify the main mechanisms explaining these changes.
Materials and methods. For a systematic review of the literature, scientific articles published in leading scientific databases, including PubMed, Scopus, Google Scholar and Web of Science, which provide access to peer-reviewed articles and other scientific publications, were selected.
Results. Among patients with community-acquired pneumonia caused by COVID-19, the most common forms of involvement were bilateral multisegmental and right-sided lower lobe pneumonia. The localization of pneumonia varies significantly by gender and age group, with right-sided lower lobe pneumonia more common in men aged 20-30 and 51-60 years, and right-sided upper lobe pneumonia in women aged 20-30 years and left-sided lower lobe pneumonia in women aged 31-50 years. The most common forms in mild disease are left-sided and right-sided lower lobe pneumonia, while in severe disease, bilateral multisegmental pneumonia is the most common.
Changes in the levels of immunoinflammatory markers (CRP, IL-6), the stress hormone cortisol, and the thrombosis marker D-dimer were important prognostic markers of disease severity. In patients with severe pneumonia, a significant increase in these parameters was observed, which is associated with a high risk of developing thromboembolic complications and required intensive care. Elevated levels of CRP, IL-6, D-dimer and cortisol in patients with severe COVID-19 are prognostic markers for assessing the severity of the disease and the development of complications such as thromboembolism.
Conclusion. Thus, early detection of changes in the levels of inflammatory and stress markers allows predicting the severity of the disease, assessing the risk of complications, and timely applying treatment strategies to reduce mortality and improve treatment outcomes.
Properties evaluation of terrazzo tiles produced for external use using a fine aggregate from a domestic waste incineration plant
Authors: Huynh Trong-Phuoc , Van-Pham Dan-Thuy , Lam Tri-Khang , Tran Van-Linh , Bui Quoc-Trung
Published: December 2024

The increasing amount of incineration ash raised significant environmental concerns, particularly regardingwaste disposal and pollution. To address these issues and promote sustainable development, this study explored the production of terrazzo tiles using a fine aggregate of waste incineration bottom ash (WIBA) and aternary binder of cement, fly ash, and hydrated lime. The findings revealed that the substitution of cement withhydrated lime at an optimal level (i.e., 1% by weight) enhanced the flexural and compressive strengths whilereducing the surface water absorption of the terrazzo tiles. The surface abrasion resistance remained relativelyunchanged due to the consistent use of the same surface material across samples. Observation of scanningelectron microscope images further confirmed the obtained engineering properties of the terrazzo tiles. As aresult, the terrazzo tiles met the Vietnamese National standard requirements for external use, further indicatingtheir suitability for various applications in construction. This study found that the terrazzo tiles produced usinga mixture of 13% cement, 1% hydrated lime, 10% fly ash, and 76% WIBA earned the lowest surface waterabsorption of 2.56% and the highest flexural and compressive strengths of 3.86 and 21.37 MPa, respectively.Whereas, the surface abrasion of the sample was recorded at 0.241 g/cm2, making it an optimal choice for practical use in construction.
Analysis of the effect of construction technology factors on controlling thermal cracking in mass concrete
Authors: Minh Le Van , Duc Nguyen Anh , Khoa Ho Ngoc , Ha Le Hong , Thuc Luu Van
Published: December 2024

A comprehensive numerical study was conducted in this study to evaluate the effects of construction technology factors including curing temperature, initial temperature of fresh concrete mixture, type of formwork, type of cement, and cement content on controlling thermal cracking in mass concrete. The probability of cracking will also be included in the analysis to align with the trend of thermal cracking control planning in some countries today. Stress-temperature field analysis will be performed using the finite element heat flow analysis tool of Midas/Civil software. The reliability and accuracy of the proposed method are verified by comparing the analysis results with a experimental result of a mass concrete sample with dimensions of 2.5 × 2.5 × 2.5 m. Based on the validated numerical model, a parametric study was conducted on a typical mass concrete block with dimensions 5.0 × 5.0 × 5.0 m to investigate the impact of construction technology parameters on temperature development in mass concrete. The obtained results demonstrate that construction technology factors significantly affect thermal cracking in mass concrete. An effective construction solution will contribute significantly to the overall plan for controlling thermal cracking in mass concrete.
Improvement of biofilm activities in sequencing batch reactor via polyvinyl alcohol (PVA) granules addition
Authors: Lan Nguyen Xuan , Huyen Dang Thi Thanh , Thuy Pham Thi , Khai Nguyen Manh
Published: December 2024

Polyvinyl alcohol (PVA) (C2H4O)n is a synthetic polymer material commercially available on an industrial scale. In this study, two formulas were tested for preparing biofilm carriers in spherical shape from PVA/H3BO3 (formula 1) and PVA/NaNO3 (formula 2) crosslink bonds without activated sludge entrapment. Formula 2 gave better results with white, round, gel-textured, flexible, and firm carriers. The PVA/NaNO3 granules continued to be used as moving-bed biofilm carriers at a ratio of 10% of the working volume to evaluate the wastewater treatment capacity in the sequencing batch reactor (SBR). After five weeks of operation, the results showed that the PVA/NaNO3 granules turned light yellow due to the presence and development of aerobic biomass. The surface of PVA/NaNO3 granules was plump, elastic, not cracked, and settled well. The amount of biomass attached to the PVA/NaNO3 granules was 0.4 gTSS/g granules. The hydraulic settling velocity of the PVA/NaNO3 granules was 56 mm/s. The wastewater treatment efficiency of the SBR system using moving-bed biofilm activity developed on the PVA/NaNO3 granular carriers was evaluated according to the TSS, COD, and NH4+– N parameters at 88%, 90%, and 92%, respectively. The experimental results have demonstrated the potential of developing a new type of biofilm carriers from PVA polymer materials that offer good settling ability and resistance to hydraulic shear force during aeration. Therefore, PVA granules can be easily applied in the column SBR configuration.
Causes of crane safety risk in the Vietnamese construction industry
Authors: Long Ngo Thanh , Giang Nguyen Hoang
Published: December 2024

Crane is one of the most important machineries in the construction field. They are used to move large or heavy loads on most construction sites. However, crane operations in construction are very dangerous activities and contribute to a big ratio of serious accidents around the world and in Vietnam. The paper aimed to identify and evaluate crane safety risk causes as well as groups of causes in the Vietnamese construction industry. The paperevaluated from the perspective of various related people involved in crane activities, namely drivers, managers,and workers. A well-structured questionnaire using a five-point Likert scale was produced and sent to collectdata from 60 valid crane-related practitioners. The paper finds 59 specific causes that give rise to crane safety risks in the Vietnamese construction industry. However, there are noteworthy differences in answers from managers, drivers, and workers. The managers, drivers, and workers showed the most common safety risks“Stress of crane workers due to time pressure”, “Insufficient safety awareness and behavior of crane workers”, and “Subcontractor does not establish safety funds for the construction safety”, respectively. They pointed out that “Crane manufacturers with bad manufacturing quality” are the most severe cause of safety risk. The managers, drivers, and workers also showed the highest safety risk level of cause “Stress of crane workers due to time pressure”, “Insufficient supervise of main contractor for the crane foundation and installation task”, and “Government lacks a good implementation of certificate management and graduation for crane operators”,respectively. Crane management of construction site-related causes is the most common safety risk and the highest safety risk level. Regulatory bodies and stakeholders-related causes have the highest degree of severity.
Ensemble learning methods for the mechanical behavior prediction of tri-directional functionally graded plates
Authors: Do Dieu T. T
Published: December 2024

This paper aims to enhance computational performance for behavior prediction of tri-directional functionallygraded plates using ensemble learning methods such as random forest, extreme gradient boosting, and lightgradient boosting machine. Furthermore, the effectiveness of these methods is verified by comparing theirresults with those of artificial neural networks. The present investigation focuses on the buckling problem of tridirectional functionally graded plates. In this study, data pairs consisting of input and output data are generated using a combination of isogeometric analysis and generalized shear deformation theory to ensure the accuracy of the dataset. The input data in this case are eighteen control points used to characterize material distribution; the output data are total ceramic volume fraction and non-dimensional buckling load. Based on this dataset, the effect of hyperparameters in machine learning models on accuracy and computational cost is investigated to determine models with optimal hyperparameters, referred to as optimal models. The performance of the optimal models in predicting plate behavior is compared to each other. Furthermore, in terms of computational time and accuracy, the light gradient boosting machine model gives the best results compared to the others.
Assessing the social costs of public transport in a mixed traffic environment with endogenous demand
Authors: Vu Tam
Published: December 2024

In reality, public transport (PT) passenger demand levels are influenced by internal factors rather than external ones, as they are shaped by the performance of public transport services such as price, service frequency and travel time. This paper develops a calculation process for PT endogenous demand with respect to social costs in motorcycle-dominated mixed transport systems, based on the total social cost of public transport in previous research. The incremental elasticity analysis is used to estimate the endogenous passenger demand for dedicated PT technologies. A case study of Quang Trung – Tran Phu – Nguyen Trai corridor in Hanoi is presented, highlighting the incremental elasticity analysis (IEA) of PT modes, including conventional buses,bus rapid transit (BRT), monorail and urban rail transit (URT), with a focus on passenger waiting and invehicle times. The findings reveal that conventional buses are most cost-effective for daily demands below 31,000 passengers per direction per day (pdd), while BRT is preferable for demands ranging from 31,000 to 55,000 pdd. The Monorail emerges as the most efficient option for demand between 55,000 and 165,000 pdd, with Urban Rail Transit (URT) becoming optimal when demand exceeds 165,000 pdd. These insights provide urban transport planners and policymakers with valuable guidance for strategic decision-making regarding new PT projects in mixed transport environments with a dominance of motorcycles
Enhancing programevaluation and review technique (PERT) for construction project scheduling with Bayesian updating and appropriate probability distributions
Authors: Duc Nguyen Anh
Published: December 2024

The Program Evaluation and Review Technique (PERT) is a popular scheduling technique that takes advantage of the Beta distribution to present uncertainty in activity durations. This study presents an advanced PERT method with an improved Bayesian updating and improved assumed prior distributions, which better represent real-world projects. The method is backed with detailed mathematical proofs and derivations for a solid theoretical foundation. A numerical case study involving a 30-floor building construction project is used to compare the performance of traditional PERT, the Beta-improved Bayesian PERT, and the Log-Normal Bayesian PERT methods. In the example, the activities considered are Formwork, Rebar and Construction, Masonry, Mechanical-Electrical-Plumbing (MEP), and Finishing, which are the main activities in a construction project. The results show that the Beta-improved and the Log-Normal distributions are constructed successfully in the models with converging variance – an observation that delineates the uncertainty reduced along a real project’s course. With enhanced functions, the PERT method can be utilized to support project decision-makers in scheduling and managing complex projects in reality.
Migración climática: una visión desde la vulnerabilidad social y la transgresión a los derechos humanos
Authors: Gran Castro Juan Alberto , Ramos de Robles S. Lizette
Published: December 2024

En este ensayo se analiza la relación entre el cambio climático, la migración y los derechos humanos, partiendo de la premisa de que los desastres son eventos socialmente construidos. Asimismo, se explora la incidencia de la vulnerabilidad y la exposición a desastres en los procesos de migración climática. A través de un análisis narrativo de la audiencia de la Comisión Interamericana de Derechos Humanos (CIDH) sobre “Derechos humanos de las personas en movilidad humana por efectos del cambio climático”, llevada a cabo el 29 de febrero del 2024, se sostiene que la migración climática es tanto una consecuencia de los impactos directos del cambio climático como de las condiciones preexistentes de vulnerabilidad. Estas narrativas revelan que, por falta de una adecuada respuesta gubernamental frente al cambio climático, se perdieron los medios de vida necesarios para disfrutar de derechos humanos fundamentales, como el ambiente sano, el agua, la alimentación, la salud y la vida. Se concluye que los casos de desplazamiento humano por cambio climático representan situaciones de violación a los derechos humanos de las poblaciones afectadas. Esta afirmación es crucial porque permite abordar concretamente los desafíos de la migración climática, planteando acciones dirigidas a garantizar y proteger los derechos humanos.
Trends in the critical frequency foF2 at stations of the Northern and Southern hemispheres
Authors: Danilov A. D. , Konstantinova A. V. , Berbeneva N. A.
Published: December 2024

A search for long-term trends in the F2 layer critical frequency foF2 is performed based on vertical sounding observations at three stations of the Northern Hemisphere (Juliusruh, Boulder, and Moscow) and three stations of the Southern Hemisphere (Townsville, Hobart, and Canberra). A method developed and extensively described by the authors is used. The data for two winter months in each hemisphere for five near-noon LT moments were analyzed. Three solar activity (SA) proxies (F30, Ly-α, and MgII) were used to eliminate SA effects. Negative trends are obtained for all considered situations (station, month, LT moment, SA proxy). The trends agree well with each other both if stations of the Northern and Southern hemispheres are compared individually or in aggregate.
Seasonal-diurnal features of the medium-scale traveling ionospheric disturbances characteristics in the Asian Region of Russia During years of moderate solar activity
Authors: Kurkin V. I. , Podlesnyi A. V. , Cedrik M. V. , Sofyin A. V.
Published: December 2024

Based on data from a network of oblique-incidence sounding radio paths at mid-latitudes in the Asian region of Russia, a high (up to 40−50%) average-daily recording probability of the medium-scale traveling ionospheric disturbances in years of moderate solar activity has been identified. The daily variation in the recording probability of these disturbances at mid-latitude radio paths in the Asian region of Russia has a pronounced seasonal dependence. For the winter season, there is a daily maximum probability, reaching 100% on some days. In the summer season, it occurs at night hours of local time at the midpoint of the corresponding radio path. The most likely reason for this is the transition from winter to summer pattern of the atmosphere zonal circulation.
Low-energy excited singlet states of para-aminothiophenol in methanol and n-hexane solutions
Authors: Tseplina S. N. , Tseplin E. E.
Published: December 2024

Optical absorption spectra of para-aminothiophenol in n-hexane and methanol solutions have been obtained. The calculation has been carried out using the TDDFT B3LYP/6-311+G(d,p) method taking into account the polarizable continuum model of the electronic spectra of the p-aminothiophenol molecule in n-hexane and its hydrogen-bonded complex with two methanol molecules in a methanol solution. Based on these calculations, the main absorption bands are interpreted and it is shown that the second excited singlet state is formed by a π → σ* electronic transition, which makes a significant contribution to the first absorption band of p-aminothiophenol in these solutions.
Functionalization of polypropylene subjected to gamma-irradiation and postradiation high-temperature shear grinding and its toxic properties
Authors: Allayarova U. Y. , Allayarov S. R. , Demidov S. V. , Baimuratova R. K. , Chekalina S. D. , Mishchenko D. V. , Klimanova E. N. , Abdusalamov A. B. , Dixon D. A.
Published: December 2024

The results of FT-IR spectral study of polypropylene (PP) subjected to gamma irradiation and postradiation high-temperature shear milling are presented. Absorption peaks of hydroxyl and oxygen-containing groups appear in the IR spectra of air-irradiated PP pellets, the intensity of which decreases markedly in the powder obtained after grinding of irradiated polymer pellets. Toxic properties of PP obtained by grinding by high-temperature shear milling of irradiated polymer pellets were investigated. It was shown that gamma-irradiation of polymer pellets in air has no effect on toxic properties of its powder obtained by grinding of irradiated pellets with 700–4500 kGy dose. It was found that when administered intragastrically to BDF mice1 PP powder from non-irradiated and irradiated granules is moderately toxic.
Kinetics of radiation-oxidative aging of polyamide fibers and composites based on them
Authors: Dalinkevich A. A. , Piskakev I. M. , Fomin L. V. , Nenasheva T. A.
Published: December 2024

Kinetics of the decrease in the strength of polyamide PA-6 (poly-ε-caprolactam) fibers by X-ray irradiation in air at absorbed dose rates ranging within 0.16–10 Gy/s has been studied. It has been shown that strength of irradiated polyamide PA-6 fibers decreases to a certain limiting value depending on the dose rate and can be described by the kinetics of a reversible pseudo-first-order reaction. The proposed structural-kinetic model of radiation–oxidative aging of fibers takes into account the opposite effects of destruction and crosslinking of tie macromolecules on the strength of the oriented polymer (fiber),and structural features of the oriented polymer. The model agrees well with experiment and allows us to describe the change in the strength of an oriented polymer (fibers PA-6) and a unidirectional composite (impregnated strands) based on them during the simultaneous occurrence of processes of radiation–oxidative degradation and crosslinking of macromolecular chains.
What actin and myosin do in the nucleus: new functions of the well-known proteins
Authors: Saidova A. A. , Vorobjev I. A.
Published: December 2024

The functions of actin and its motor proteins myosins in the cytoplasm have been the subject of research for more than 100 years, but the existence and function of these proteins in the nucleus has been a matter of debate until recently. Recent data has clarified the role of actin and myosin molecules in controlling the dynamics of processes in the cell nucleus, chromatin organization and genome integrity. New microscopy techniques and the use of modified actin-binding probes have made it possible for the first time to directly visualize the polymerization of actin filaments in the nucleus of living cells. Here we discuss the processes that control the dynamic balance of actin and myosins between the nucleus and the cytoplasm, as well as the role of these proteins in the regulation of transcription, DNA repair, chromatin reorganization, tumor transformation and cell differentiation.
Zebrafish xenographs in oncology and personalized medicine
Authors: Lunina N. A. , Safina D. R. , Kostrov S. V.
Published: December 2024

The bony fish Danio rerio (zebrafish) has become one of the important vertebrate model organisms in biomedical cancer research and is used, among other things, for the development of anticancer drugs using xenotransplantation approaches. The ex utero development of zebrafish, optically transparent tissues in the first month of growth, as well as the immature adaptive immune system during this period greatly facilitate the manipulation of embryos. For highly aggressive cancers where patient survival may be expected to be only a few months, the zebrafish xenograft assay may be the only appropriate method as it requires only 4 to 7 days. Thousands of embryos can be implanted with biopsy tissue from a patient to produce zebrafish xenografts and use them to automatically screen a large number of drugs and compounds to develop an effective treatment regimen for a specific patient. The review examines the advantages and disadvantages of the zebrafish model in oncology research. The main focus is on the use of zebrafish xenografts to study metastasis and create avatars in personalized medicine.
ArdA Protein Specificity to Type I Restriction–Modification Systems
Authors: Kudryavtseva A. A. , Vlasov A. V. , Zinovev E. V. , Yanovskaya D. D. , Utkina A. A. , Rastorguev S. M. , Manukhov I. V.
Published: December 2024

ArdA are DNA-mimic proteins which inhibit type I restriction-modification (RMI) systems by binding to them instead of DNA. The question of specificity to DNA methylation sites recognized by RMI complexes remains to be answered: is ArdA able to mimic a specific DNA site? In this work, we cloned ardA genes from three Gram-positive bacteria Agrobacterium tumefaciens, Pseudomonas monteilii and Xanthomonas sp. Antirestriction abilities of these genes were tested against three RMI systems of Escherichia coli, differing in DNA recognition/methylation sites. It was shown that despite the similarity of predicted structures of the studied ArdA proteins, they have significant specificity for three RMI systems. The results obtained may indicate the ability of DNA-mimetics to imitate specific DNA sites.
Uniqueness and phylogenesis of the plague microbe Yersinia pestis
Authors: Suntsov V. V.
Published: December 2024

The phylogenies of the plague microbe (Yersinia pestis), reconstructed on the basis of an advanced molecular genetic (MG) approach, are not congruent with the facts accumulated by classical scientific areas: ecology, biogeography, paleontology, epizootiology, and others. The MG approach cannot name the original host of the plague pathogen and reliably characterize the root of the phylogenetic tree. This deficiency is compensated by the ecologic in a broad sense (ECO) approach, which operates with such ecological, phylogeographic and biogeographic categories as geographical population, subspecies, range, ecological niche, direct kinship. Y. pestis, the “blood dweller” of warm-blooded rodent hosts, is transmitted through flea bites and is unique in the family of predominantly intestinal bacteria Yersiniaceae (Enterobacteriaceae). According to the ECO approach, its uniqueness is associated with the origin in the populations of its primary host – Mongolian marmot (Marmota sibirica) in unique circumstances – when the marmot population was infected with pseudotuberculosis not by the traditional alimentary way in grasslands, but in a traumatic way during hibernation. The identification of the original host of the plague pathogen opens up broad prospects for studying its evolutionary history (speciation and intraspecific diversification) and improving the methodology of ecologic, geographic, phylogeographic and phylogenetic studies of this especially dangerous pathogen.
Influence of different lighting and feeding regimes on the expression of the fadsd5, fadsd6, elovl2, elovl5a desaturase and elongase genes in the liver of juvenile Atlantic Salmon Salmo salar L. under aquaculture conditions
Authors: Khurtina S. N. , Murzina S. А. , Kuznetsova М. V. , Nemova N. N.
Published: December 2024

The relative gene expression of enzymes – desaturases and elongases (fadsd5, fadsd6, elovl2, elovl5a, elovl4), which play a key role in the biosynthesis of long-chain polyunsaturated fatty acids, was studied in the liver of juvenile Atlantic salmon Salmo salar Linnaeus, 1758, reared under different lighting and feeding regimes in aquaculture conditions. The expression level of the fadsd5 desaturase gene was higher in Atlantic salmon smolts (0+), reared under round-the-clock lighting and feeding regime, compared to smolts from experimental group with natural photoperiod and daylight feeding. Changes in the level of gene expression (elovl2, elovl5a, fadsd5) in juvenile Salmo salar reflect adaptive processes at the molecular genetic level during the growth and development of fish and in response to changes in environmental conditions. The obtained results make it possible to assess the ability/requirement to the biosynthesis of PUFAs in juvenile salmon during its growth and development.
Distribution of Lemna at the Range Boundary in the North-West of the Murmansk Region as a result of anthropogenic changes in water bodies
Authors: Zueva N. V. , Grishutkin О. G. , Efimov D. Yu. , Bobrov А. А.
Published: December 2024

Data on the new localities of Lemna minor, L. trisulca, and hybrid between L. minor and L. turionifera (L. × japonica) (Lemnaceae) in the north-west of the Murmansk Region (north of 68.5° N), i.e., in the Pasvik State Nature Reserve and neighboring territories in the drainage basin of the Paz River, are presented. Lemna minor and L. trisulca were previously known for the region by several reports. In the north-west of the Murmansk Region, 2 new localities of Lemna minor, 1 locality of L. × japonica, and 10 localities of L. trisulca were found. In total, representatives of Lemna occurred in 18 studied sites: L. minor in 2, L. × japonica in 2, and L. trisulca in 16 (L. minor and L. trisulca grew together in 2 sites). In the studied rivers and lakes, the pH range of water varied from 6.0 to 7.6, i.e., was mainly neutral (the average value was 6.9). TDS varied in the range from 17 to 251 ppm (on average, 53 ppm). The localities of L. minor in the unnamed lake near Zapolyarnyi town and in Kuetsjarvi Lake are probably the northernmost in the world, while locality of L. trisulca in the Paz River in Klistervatn Lake is the northernmost in European Russia. In the north of the Murmansk Region, L. minor and L. × japonica were associated only with anthropogenic eutrophicated water bodies with increased TDS in comparison to the background value. These taxa can be considered an indicator of high trophicity in this region. The localities of L. trisulca are mainly anthropogenic transformed water bodies. The maximum abundance of this species is also recorded in the areas of increased trophic level.