Primary Damage Research Articles

Molecular dynamic simulations of displacement cascades in Molybdenum and Molybdenum-Rhenium alloys

Molybdenum-Rhenium (Mo-Re) alloys are considered core materials for advanced nuclear reactor components due to their excellent mechanical properties, machinability, and resistance to irradiation damage. However, irradiation-induced embrittlement and phase precipitation at high temperatures, along with transmutation nuclides, have hindered their broader application. To address this, we developed a Mo-Re interatomic potential using the Finnis-Sinclair formalism, facilitating molecular dynamics simulations to study primary irradiation damage. Systemically primary irradiation damage simulations for Mo and Mo-Re alloys have been performed. It’s found that there were more Frenkel-pair defects produced during the stage of thermal spike in Mo-Re alloys but fewer defects survived at the end of the cascade compared to Mo. In addition, the number of large-size interstitial clusters and dislocation loops was higher in Mo-Re alloys than in pure Mo with the same PKA energy. This is mainly attributed to the fact that Mo-Re alloys have lower thermal conductivity, while the binding energies of interstitial clusters and dislocation loops with sizes less than 100 in Mo-Re alloys are comparable to those of pure Mo, resulting in higher defect composites and larger defect sizes in Mo-Re alloys. These findings provide valuable insights into the primary damage mechanisms in Mo-Re alloys under irradiation, offering a foundation for developing kinetic models to simulate radiation-induced microstructural evolution.

Systematic study of displacement threshold and the near-threshold primary radiation damage model

Radiation damage is a critical concern for materials employed in radiation environments such as space, radiotherapy centers, and nuclear energy systems. Numerous models have been developed to estimate the primary radiation damage. The slightly modified Athermal Recombination-Corrected (mARC)-Displacement per Atom (DPA) model proposes a simple function to describe the atomic displacement near the Threshold Displacement Energy (TDE). The present work systematically investigates the global minimum TDE and the near-TDE mARC-DPA model against experimental electron irradiation damage data for 26 materials. The determined high-accuracy global minimum TDE values are generally consistent with previous studies. The corresponding theoretical calculations agree well with experimental measurements, implying the applicability of the mARC model. Renormalization of certain experimental data is required due to the potential issues related to experimental measurements, the value of resistivity change per Frenkel pair (ρFP), or average TDE (Ed). Nevertheless, while some experimental data are supposed to be adjusted, the analysis shows that the ratio of ρFP/Ed can be definitively determined if assuming the experimental data for the remainders.

Investigation of rice debranning mechanism based on tribological behaviour between rice grains

Frictional debranning between rice grains is a fragile and energy-consuming process. Understanding the mechanism of this frictional debranning is the key to achieving moderate debranning, yet the mechanisms involved remain poorly understood. In this work, the mechanism of rice grain debranning was investigated through rice milling experiments, SEM analysis of the rice surface, and rice wear experiments. The results showed that the bran layer of rice grains exhibited different removal patterns at different milling pressures. During frictional debranning between rice grains, adhesive wear and bulk stripping of the bran layer occurred. The bran layer of the rice grain initially experiences primary damage due to adhesive wear, followed by bulk stripping at the edges of the existing damage. Pre-milling can effectively improve the debranning efficiency of rice grains. These findings should provide a theoretical reference for the design of grain milling equipment and the process improvement of grain moderate milling.

Identification of a New Role of miR-199a-5p as Factor Implied in Neuronal Damage: Decreasing the Expression of Its Target X-Linked Anti-Apoptotic Protein (XIAP) After SCI

Spinal cord injury (SCI) results in a cascade of primary and secondary damage, with apoptosis being a prominent cause of neuronal cell death. The X-linked inhibitor of apoptosis (XIAP) plays a critical role in inhibiting apoptosis, but its expression is reduced following SCI, contributing to increased neuronal vulnerability. This study investigates the regulatory role of miR-199a-5p on XIAP expression in the context of SCI. Using bioinformatic tools, luciferase reporter assays, and in vitro and in vivo models of SCI, we identified miR-199a-5p as a post-transcriptional regulator of XIAP. Overexpression of miR-199a-5p significantly reduced XIAP protein levels, although no changes were observed at the mRNA level, suggesting translational repression. In vivo, miR-199a-5p expression was upregulated at 3 and 7 days post-injury, while XIAP expression inversely decreased in both neurons and oligodendrocytes, being particularly significant in the latter at 7 dpi. These findings suggest that miR-199a-5p contributes to the downregulation of XIAP and may exacerbate neuronal apoptosis after SCI. Targeting miR-199a-5p could offer a potential therapeutic strategy to modulate XIAP levels and reduce apoptotic cell death in SCI.

Atomistic Simulation of Primary Radiation Damage Profiles in Fluorine-Doped Tin Oxide Thin Film Target Using SRIM Code

In this study, we investigated the discrepancy between the numbers of atomic displacements obtained from the Vac.txt method and those obtained from the Vac.dam method using SRIM-2013 operated in full cascade mode. The SRIM simulations also calculated energy partitioning, damage dose and distribution profiles of the implanted He, C and O ions at three different ion energies of 10 keV, 100 keV and 1 MeV. In all the simulations and at each ion energy value, the target thickness was increased until the entire ion beam was absorbed within the target. The simulated fluorine-doped tin oxide (FTO) thin film target stoichiometrically comprised 78.6% Sn, 16.4% O and 5.0% F, and a 6.013 g/cm3 bulk density. To achieve relatively good statistics with compromised computational time, each run followed 10 000 ion histories. The results indicated that, with increasing ion energies, the peaks of vacancy concentrations moved deeper into the material. For He ions, the vacancy profiles have peaks at ∼0.04, ~0.45 and ~2.9 µm at 10 keV, 100 keV and 1 MeV, respectively. Meanwhile, for C and O ions, the peaks were at ∼0.012, ~0.15 and ~1.23 µm for C ions and ∼0.01, 0.12 and 1.2 µm for O ions at 10 keV, 100 keV and 1 MeV, respectively. We also observed that for all the ions and at all ion energies considered, the Vac.txt method predicted more vacancies than the Vac.dam method, and the discrepancies generally increased with increasing Z by an average value of ∼1.21, ∼1.45 and 1.48 for He, C and O ions respectively. In addition, the electronic and nuclear partitioning profiles revealed that most of the energies of the ions were lost in collision with atomic electrons due to ionisation and excitations, and little to nuclear events. The simulations also revealed that nuclear stopping powers increase at low ion energies. This study also indicated that damage dose profiles strongly depend on the type of incident particle and its energy. A comparison of SRIM and iradina calculated vacancies and incident ion distribution profiles generally indicated perfect agreements between the two codes. FTO thin film remains a promising material for thermal control applications in future spacecraft. However, further analyses are still necessary to comprehensively understand its evolution under intense radiation environments comprising various ions and at different energies.

Irradiation damage evolution dependence on misorientaton angle for ∑ 5 grain boundary of Nb: An atomistic simulation-based study

Abstract Niobium as refractory element holds ability to arrest the primary radiation damage in reactor's fissionable conditions and can withstand high temperature applications. We have inclined the investigation of irradiated Nb ∑ 5 symmetric tilt angled-grain boundary (STGB) models at two high-angled grain boundary misorientation: 53.13 ° (∑ 5(2-10)/ (120)) and 36.87 ° (∑ 5(3-10)/ (130)) respectively. A hybrid of Ziegler-Biersack-Littmark (ZBL) and embedded atom method (EAM) potentials were superimposed to simulate radiation damage. Statistical averaging of the displacement cascades were conducted to study dynamic evolution of the point defects and interstitial clusters at varying magnitudes of primary knock-on atom (PKA) energies, irradiation temperatures and PKA directions respectively. The irradiated GB models were compared with a irradiated bulk Nb specimen and the results of the study indicate that the irradiated Nb system with greater misorientation angle i.e., Nb ∑ 5 (θ = 53.13 ° ) survived with lower number Frenkel pair defects as well as the population small-sized interstitial clusters. The cluster analysis indicated the highest population of interstitial clusters survived in Nb STGB models were irradiated along <1 3 5> PKA direction and 100 keV recoil energies respectively.

REHABILITATION IN NEPHROLOGY: HISTORY, CURRENT STATE, PROSPECTS

Rehabilitation assistance at healthcare institutions is a comprehensive package of measures designed to enhance the functional abilities of individuals who experience or may potentially experience limitations in their daily functioning within their surrounding environment. Nephrology is a branch of medical science that studies the etiology and pathogenesis of kidney damage, develops and improves diagnostic methods, treatments, and prevention strategies for congenital and acquired primary and secondary kidney damage at all stages of development. Pediatric urological disorders remain a signifi cant concern due to their high prevalence among children. Chronic kidney disease (CKD) is a particularly worrisome complication, as it is characterized by a relapsing nature and the potential for severe complications. The current system of healthcare is regarded as a costly branch of medical services, with expenditures on therapeutic and rehabilitative care (inpatient and outpatient stages) constituting a signifi cant proportion of the overall costs.The article presents the results of an analysis and a summary of the recommendations set forth in international and Ukrainian medicaltechnologicaldocuments based on evidence- based medicine with regard to rehabilitation care in pediatric nephrology. The methodology for establishing a clinical and rehabilitation patient pathway, comprising an individual rehabilitation patient plan, is presented. This pathway considers the most common urinary diseases among children at the hospital district level. The scientifi c research was conducted within the scientifi c focus of the Department of Pediatrics, Neonatology and Perinatal Medicine of Bukovinian State Medical University and the research project entitled «Chronobiological and Adaptive Aspects and Features ofAutonomic Regulation in Pathological Conditions in Children of Diff erent Age Groups.» The registration number is 0122U002245, and the project will run from January 1, 2022, to December 31, 2026.

Prepatellar bursa mucosa: An unreported postoperative complication of patellar fracture.

Patellar fracture is a common injury caused by overstrain of the extensor mechanism or a direct trauma to the knee. The most common complications after patellar fracture are nonunion, infection, post-traumatic arthritis, joint fibrosis, symptomatic hardware, and extensor mechanism failure. These are attributed to the post-fracture flexion and extension movements, the primary damage to the articular cartilage, and the thin soft tissue coverage over the knee. To our knowledge, prepatellar bursa mucosa is an unreported postoperative complication of patellar fracture. We describe a case of a 58-year-old woman with a left patellar fracture from a fall. Complete healing was achieved after in 2 months postoperatively using the improved Kirschner wire tension band and a cable grip system; however, at 7 months postoperatively, a prepatellar skin mass appeared. The patient reported prepatellar discomfort with no pain and influence of movement of the knee and daily life. One year postoperatively, we surgically removed the implants and mass. The pathological result showed bursa mucosa. The literature review shows that pain, secondary knee dysfunction, fracture nonunion, and malunion are postoperative complications of patellar fractures. However, prepatellar bursa mucosa have not been previously reported as a postoperative complication. This case highlights the need for appropriate placement of the intraoperative implant in adults with patellar fractures.

Plasma neurofilament light chain in fibromyalgia: A case control study exploring correlation with clinical and cognitive features.

Plasma neurofilament light chain (NFL) has been measured as a biomarker of neuronal damage in various neurological disorders. Elevated tau and β-amyloid levels have been found in patients with fibromyalgia (FM). The aim of the present study was to compare plasma neurofilament levels in fibromyalgia patients with normal controls and to investigate the correlation with clinical features and cognitive tests. Plasma NFL levels were assessed in 33 FM patients and compared with 22 age-matched controls. All patients were also assessed with clinical scales examining fibromyalgia disability, sleep quality and duration, fatigue, anxiety, and depression, and a neuropsychological battery examining executive function, verbal short-term memory, and working memory, as well as attentional executive function and selective attention, interference sensitivity, and inhibition of automatic responses. NFL levels were higher in FM patients (controls 6.19± 1.92; FM 17.28± 15.94 pg/mL ANOVA p 0.002). Working memory was the most impaired cognitive function significantly correlated with high NFL scores (Pearson p 0.034). Short sleep times also correlated with higher NFL scores (Pearson p 0.02) and poorer working memory performance (Pearson p 0.02). No correlation was found with indices of disease severity and duration. Plasma NFL levels are elevated in fibromyalgia patients, suggesting neuronal damage and correlating with a slight decrease in working memory and short sleep duration. Plasma neurofilament levels are elevated in patients with fibromyalgia, regardless of disease severity and duration. Neurofilament levels are higher in patients with mild working memory impairment and sleep disorders. Subgroups of patients with primary neuronal damage phenomena could be individualized for prospective evaluation with regard to the possible development of cognitive decline and sleep disturbances, which would justify a tailored therapeutic approach.

Synergistic effects of curcumin and stem cells on spinal cord injury: a comprehensive review.

Spinal cord injury (SCI) is damage to the spinal cord that permanently or temporarily disrupts its function, causing considerable autonomic, sensory, and motor disorders, and involves between 10 and 83 cases per million yearly. Traumatic SCI happens following primary acute mechanical damage, leading to injury to the spinal cord tissue and worsening clinical outcomes. The present therapeutic strategies for this complex disease fundamentally rely on surgical approaches and conservative remedies. However, these modalities are not effective enough for neurological recovery. Therefore, it is necessary to discover more efficient methods to treat patients with SCI. Today, considerable attention has been drawn to bioactive compounds-based remedies and stem cell therapy for curing various ailments and disorders, such as neurological diseases. Some researchers have recommended that harnessing curcumin, a polyphenol obtained from turmeric, in combination with stem cells, like mesenchymal stem cells, neural stem cells, and ependymal stem cells, can remarkably improve neurological recovery-related parameters more effective than the treatment with these two methods separately in experimental models. Hereby, this literature review delves into the functionality of curcumin combined with stem cells in treating SCI with a focus on cellular and molecular mechanisms.

Molecular Dynamics Assessment of Primary Damage Efficiency for Fusion Relevant Elements

Molecular Dynamics Assessment of Primary Damage Efficiency for Fusion Relevant Elements

Why is therapeutic exercise the best treatment for knee osteoarthritis?

Osteoarthritis (OA) of the knee joints (KJ) has a high social significance and is therefore a relevant pathology for scientific research. The authors have proposed an original hydraulic theory for the pathogenesis of OA in KJ. This approach is based on the notion of primary mechanical damage to the internal ligamentous structures and synovial membrane accompanied by posttraumatic edema, synovial hypervolemia, and hypertension. The authors demonstrated that regular physical activity at all stages of the disease is pathogenetically justified and allows the patient to improve lymphatic and venous outflow and thus resist increasing fibrosis. Improved arterial blood flow will reduce tissue hypoxia. Any type of symptom-modifying therapy can be harmful because it reduces the protective role of pain reflexes in protecting the KJ from excessive loads, leading to injury. The necessity of maintaining a walking speed of more than 4.3 km/h with an increase in cadence is emphasized from the perspective of reducing static stress during walking and extending life expectancy.

Molecular Dynamic Simulation of Primary Damage with Electronic Stopping in Indium Phosphide.

Indium phosphide (InP) is an excellent material used in space electronic devices due to its direct band gap, high electron mobility, and high radiation resistance. Displacement damage in InP, such as vacancies, interstitials, and clusters, induced by cosmic particles can lead to the serious degradation of InP devices. In this work, the analytical bond order potential of InP is modified with the short-range repulsive potential, and the hybrid potential is verified for its reliability to simulate the atomic cascade collisions. By using molecular dynamics simulations with the modified potential, the primary damage defects evolution of InP caused by 1-10 keV primary knock-on atoms (PKAs) are studied. The effects of electronic energy loss are also considered in our research. The results show that the addition of electronic stopping loss reduces the number of point defects and weakens the damage regions. The reduction rates of point defects caused by electronic energy loss at the stable state are 32.2% and 27.4% for 10 keV In-PKA and P-PKA, respectively. In addition, the effects of electronic energy loss can lead to an extreme decline in the number of medium clusters, cause large clusters to vanish, and make the small clusters dominant damage products in InP. These findings are helpful to explain the radiation-induced damage mechanism of InP and expand the application of InP devices.

Local delivery of soluble fractalkine (CX3CL1) peptide restores ribbon synapses after noise-induced cochlear synaptopathy.

Cochlear ribbon synapses between sensory inner hair cells (IHCs) and spiral ganglion neurons (SGNs) are vulnerable to rapid and primary damage and/or loss due to noise overexposure. Such damaged ribbon synapses can repair spontaneously in mouse and guinea pig. However, the mechanisms for synaptic repair are unclear. Previously, we have demonstrated a critical role for the fractalkine signaling axis (CX3CL1-CX3CR1) in synaptic repair, wherein noise-damaged ribbon synapses are spontaneously repaired in the presence of fractalkine receptor (CX3CR1) expressed by cochlear macrophages. Here, we examined whether local administration of chemokine fractalkine ligand (CX3CL1 or FKN) in the form of a peptide is effective in restoring synapses and hearing loss after noise-induced cochlear synaptopathy (NICS). Specifically, the efficacy of different isoforms of FKN was evaluated for restoration of loss of IHC ribbon synapses and hearing after NICS. A single transtympanic injection of soluble isoform of FKN (sFKN) peptide at 1 day after synaptopathic noise trauma for 2 hours at 93 decibel sound pressure level led to significant recovery of auditory brainstem response (ABR) thresholds, ABR peak I amplitudes and ribbon synapses in FKN knockout mice when compared to mice injected with membrane-bound FKN peptide (mFKN). Likewise, local treatment with sFKN peptide in FKN wild type mice restored synaptopathic noise-damaged ribbon synapses and ABR peak I amplitudes. Mechanistically, FKN regulates macrophage numbers in the damaged cochlea and in the absence of macrophages, sFKN failed to restore loss of synapses and hearing after NICS. Furthermore, sFKN treatment attenuated cochlear inflammation after NICS without altering the expression of CX3CR1. Finally, injected sFKN peptide was detectable inside the cochlea for 24 h localized to the basilar membrane and spiral lamina near the sensory epithelium. These data provide a proof-of-principle that local delivery of an immune factor, sFKN is effective in restoring ribbon synapses and hearing loss after NICS in a macrophage-dependent manner and highlights the potential of sFKN as an immunotherapy for cochlear synaptopathy due to noise.

Balance of Antioxidants vs. Oxidants in Perinatal Asphyxia

Perinatal asphyxia refers to an acute event of cerebral ischemia and hypoxia during the perinatal period, leading to various degrees of brain injury. The mechanisms involved in perinatal asphyxia include the production of reactive oxygen species (ROS), accumulation of intracellular calcium, lipid peroxidation, excitatory amino acid receptor overactivation, energy failure, and caspase-mediated cell death. Both primary and secondary neuronal damage are caused by the overproduction of ROS following a hypoxic/ischemic event. ROS can react with nearly any type of molecule, including lipids, proteins, polysaccharides, and DNA. Neonates who suffer from perinatal asphyxia are prone to oxidative stress, which is characterized by a disruption in the oxidant/antioxidant balance, favoring oxidants over the intracellular and extracellular antioxidant scavenging mechanisms. Current research has focused on developing treatment strategies that potentially improve the endogenous antioxidant neuroprotective mechanisms or minimize injury resulting from hypoxia/ischemia. In this narrative review, we aim to present evidence regarding the contribution of oxidant/antioxidant balance to the pathogenesis and progression of perinatal asphyxia. Also, we aim to explore the role of potential antioxidant therapies as promising treatment strategies for perinatal asphyxia, especially as an adjunct to therapeutic hypothermia in infants with perinatal asphyxia. The current literature on antioxidant treatments in newborns is limited; however, allopurinol, melatonin, and erythropoietin have shown some positive effects in clinical trials. Inhibitors of nitric oxide synthase, N-acetylcysteine, and docosahexaenoic acid have shown promising neuroprotective effects in preclinical studies. Finally, nanotherapeutics could potentially modulate oxidative stress in hypoxemic/ischemic brain injury by targeted medication delivery. Future research on neuroprotectants and their processes is warranted to develop innovative treatments for hypoxia/ischemia in clinical practice.

FEATURES OF FUNCTIONAL DIAGNOSTICS OF OPTIC NERVE DAMAGE IN CASE OF HEAD INJURY

Introduction. Traumatic optic nerve damage is a rare complication of a head injury. Symptoms of primary damage appear at the time of first diagnostic in the early period and mask TON’s signs. Understanding of visual disturbances for the patient comes in a later period, when recovery is limited due to the irreversibility of the received injuries. Difficulties of early diagnosis of optic nerve damage in case of head trauma encourage the search for new, more informative methods. The aim of the study was to analyze the functional manifestations of the optic nerve damage in case of head injuries with different localization. Materials and methods. 366 cases (732 eyes) of patients with traumatic optic neuropathy (TON) were studied according to archival data in the period from 2014 to 2019. The control group consisted of 58 practically healthy persons (116 eyes). All patients were divided into three groups: A group - patients with traumatic brain injury (TBI) was 120 persons, B group - patients with craniofacial injury (CFI) - 118 persons and C group - with combined injuries - 128 injured. The degree of optic nerve damage was assessed using visometry, pupillometry, and perimetry. Results. In case of craniocerebral injury, decrease of visual acuity with an average value of 0.92±0.06 corresponded to degrees 0 (93%) and I (7%). In the case of craniofacial trauma, according to the research, visual acuity decreased to 0.76±0.13 (by 0.24, 24% compared to the control group, p<0.05). The first degree (23%) and the second degree (7%) were determined. With a combined primary head injury, visual acuity decreased to 0.42±0.21 (by 0.58, 58%, compared to the control group, p<0.05). One third were patients with I, II and III degrees of visual impairment. The use of static perimetry made it possible to detect damage to the optic nerve in patients with 0 degrees of reduced visual acuity. At the same time, 88% of patients of A group (n=120) had 0A class, 23% of B group (n=118) had 0B class, and in C group (n=122) there was almost no. The relative afferent pupillary defect’s test was negative at 0A group of vision loss, but the pupil cycle speed (PSC) was reduced in all patients. This confirms damage to the optic nerve in patients with high visual acuity This study showed that patients with TBI had high visual acuity in 93% of cases, The visual acuity was around 0.5-1.0, but sensitivity in the central part of the visual field decreased by 12 times, and the pupil reaction rate decreased by 55% compared to the control group. In case of craniofacial trauma (B group), visual acuity decreased to 0.76±0.13 (by 0.24, 24% compared to the control group, p<0.05). I degree (23%) and II degree (7%) decrease of visual acuity was determined. As for the sensitivity in the central part of the visual field, it was 46.59% lower than in the A group. In patients with a combined injury of the head and face, a third of the injured had visual acuity less than 0.1, which is not found in other variants of injury. Conclusions. Analysis showed that severity of optic nerve damage depends on localization of the head injury. The use of static perimetry and pupillometry is important for the early diagnosis of TON in conditions with high visual acuity when other symptoms are weak or not amenable to examination.

Damage features and mechanism of prestressed hollow square piles subjected to non-contact underwater explosion

Critical hydraulic structures are increasingly vulnerable to underwater explosion attacks, with the supporting piles being prime targets for terrorist activities. This study investigates the damage effects and mechanisms of prestressed concrete hollow square (PCHS) piles under non-contact underwater explosions. A series of underwater explosion experiments was conducted on four PCHS piles. The dynamic response of PCHS piles throughout the underwater explosion process was simulated using a coupled fluid-solid numerical model. The mechanisms of dynamic damage to the PCHS piles were elucidated through an integrated analysis of both experimental and numerical results. The research indicates that the damage characteristics of PCHS piles include longitudinal and oblique cracks on the lateral surfaces, transverse cracks on the rear side, and localized fragmentation of concrete. Three primary damage modes have been identified: bending failure(L¯c= 0.59 m/kg1/3), combined bending-shear failure(L¯c= 0.36 m/kg1/3), and punching failure(L¯c= 0.24 m/kg1/3). The local and global responses induced by shock waves are the primary causes of structural damage. Furthermore, as the stand-off distance decreases, the impact of explosive bubbles increases the magnitude of the overall response. A comparative analysis also examined the impact of prestress and axial load on the damage behavior of hollow square piles.

Seismic behaviour and design of a tall mixed reinforced concrete–steel structure supporting an oil refinery reactor

AbstractThis study investigates the seismic behaviour of a special mixed reinforced concrete-steel structure that supports an oil refinery reactor. The structure is 64.90 m tall and consists of three parts: (a) a reinforced concrete frame basement; (b) a steel braced frame that supports the oil reactor and (c) the steel reactor itself. A three-dimensional model of the structure is created to perform static non-linear (pushover) analyses in order to obtain the capacity curves and understand the overall inelastic behavior of the structure. The results of the pushover analyses reveal that the structure exhibits similar inelastic behavior in both horizontal directions and satisfies the capacity design principles. The structure exhibits limited ductility considering the fact that has been designed with a behavior factor of q = 1.5 and primary damages are expected mainly in concrete members. Subsequently, dynamic non-linear time-history (NLTH) analyses are performed utilizing the three translational components of three seismic motions recorded during past earthquakes. These results involve: (i) the maximum values for displacements, accelerations and base shears; (ii) the maximum stresses at critical points of the oil refining reactor and (iii) the formation of plastic hinges at columns, beams and braces of the structure. Contrary to pushover analyses, NLTH analyses revealed the development of plastic hinges, hence seismic damage, that do not follow the desirable formation pattern. Moreover, the accelerations and displacements observed are expected to cause failure of the piping and mechanical equipment, while local failure of the high-stress areas of the shell of the reactor may be possible. Localized strengthening might be necessary to avoid repair works and downtime after such seismic event.

Cover Image

The cover image is based on the Article Imaging Hypoxia to Predict Primary Neuronal Cell Damage in Branch Retinal Artery Occlusion by Sara Z. Jamal et al., https://doi.org/10.1111/micc.12883. Created in BioRender. Uddin, M. (2023) BioRender.com/p53i167. image

MORPHOLOGY OF THE HEART IN THE DELAYED PERIOD OF EXPOSURE TO LOW DOSES OF LEAD

The aim of this study was to investigate the delayed effects of low doses of lead exposure on the hart using an original experimental model for studying the delayed effects. Analysis of the obtained morphological picture revealed structural abnormalities affecting both the muscular and stromal-vascular components. The degree of damage is in direct correlation with the received dose of lead. The above indicates that lead loading, even in low doses, is accompanied by structural abnormalities in the heart even after a long time. Most likely, this is due to the ability of lead to accumulate in the body and remain there for a long time. Vascular disorders play a certain, if not the main, role in the damage to muscle cells. However, the presence of a complex mechanism, which also implies primary damage to cardiomyocytes under the influence of lead, cannot be ruled out. Due to the properties of lead and its impact on the body, and also due to the fact that it is impossible to stop the spread of lead in nature, it is important, along with the study of the mechanisms and results of lead exposure, to find prophylactic means that displace lead ions from the body and regulate metabolism, which is affected by their activity.