Cellular Element Research Articles

Electromagnetic responses on microstructures of duplex stainless steels based on 3D cellular and electromagnetic sensor finite element models

Electromagnetic responses on microstructures of duplex stainless steels based on 3D cellular and electromagnetic sensor finite element models

Towards a Direct Consideration of Microstructure Deformation during Dynamic Recrystallisation Simulations with the Use of Coupled Random Cellular Automata-Finite Element Model.

Dynamic recrystallisation (DRX) is one of the fundamental phenomena in materials science, significantly impacting the microstructure and mechanical properties of components subjected to large plastic deformations. Experimental research on that topic carried out for a wide range of new metallic materials is often supported by computational materials science. A direct consideration and detailed understanding of this phenomenon are possible with a class of full-field numerical models based on the cellular automata (CA) method. However, the classical CA approach is based on a regular, fixed computational space and has limitations in capturing large deformations of the computational domain. Therefore, the main goal of the work is to develop and implement an alternative solution to overcome this limitation. The proposed solution is based on coupling the finite element (FE) method with the random cellular automata (RCA) approach. Such a model can directly consider the influence of geometrical changes in microstructure during large plastic deformation on recrystallisation progress. Details of the developed RCA DRX model assumptions and coupling issues with FE mesh are discussed. Particular attention is also paid to increasing model efficiency and robustness studies.

Modelling the Charpy Impact Ductile-Brittle Transition of a Ship Plate Steel with CAFE Modelling

In the present work, a cellular automata finite element model (CAFE) was developed to model the ductile-brittle transition of a Grade A ship plate steel. Therefore, ductile and brittle cellular automata (CA) arrays of cells were created in the model to integrate material data at microstructural level, along with the ductile and brittle fracture processes. Microstructural data was analysed with Weibull distributions and incorporated in CAFE model using random number generators, along with ductile and brittle fracture parameters. Ductile fracture was modelled with Rousselier damage model; hence damage model parameters were calibrated with experimental data. Brittle fracture was modelled with Beremin model, and four different cleavage particles, found in a Grade A ship plate steel, were incorporated in CAFE model in order to model a competition of particles nucleating microcracks of critical size in the damage regions of Impact Charpy tests and four-point double-notch bend tests performed at low temperature. The mechanical properties the plate steel was measured in the transition region and incorporated in CAFE model, along with ductile-brittle transition rules. The present CAFE model was able to simulate distributions of microcracks in the notch region of four-point double-notch bend models (in the transition region), which correlated with experimental data. CAFE model was also able to simulate microvoids in the notch region of Charpy specimens along with the load-displacement Charpy curve for room test temperature, with very good agreement with experimental data. Once CAFE model was validated at micro and structural level, it was applied to model the typical scatter of impact Charpy energy values in the transition region of Grade A ship plate steel with good agreement with the measured ductile-brittle transition curved of the plate steel. Keywords: cellular automata, finite element modelling, ductile-brittle transition, damage modelling.

Low-dose aspirin increases olfactory sensitivity in association with enhanced neurogenesis and reduced activity of AChE in the experimental aging mice

This study examined the effect of aspirin on olfactory discrimination and neurogenesis in experimental aging mice. The results from the buried food test (BFT) and odour preference test (OPT) indicated that aspirin treatment enhanced the olfactory functions in the experimental animals. The immunohistochemical assessment revealed increased amounts of doublecortin (DCX)-positive immature neurons and bromodeoxyuridine (BrdU)/neuronal nuclei (NeuN) double-positive new neurons in the olfactory bulb (OB) of aspirin-treated animals compared to the control group. Besides, aspirin treatment resulted in a decreased number of ionized calcium-binding adaptor molecule (Iba)-1 positive microglia, a main cellular element of neuroinflammation in the brain compared to the control group. In addition, the increased activities of key antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in OB of the aspirin-treated mice were evident. Acetylcholinesterase (AChE) is a key enzyme that hydrolyses acetylcholine (ACh), an important neurotransmitter, involved in cognition, and olfaction. While the enhanced activity of AChE has been linked to the severity of dementia and OB defects, the biochemical assessments indicated reduced activity of AChE in OB-derived homogenates of the aspirin-treated experimental animals than that of the control group. Taken together, this study validates the proneurogenic, cholinergic, and anti-neuroinflammatory properties of aspirin in the OB which can be considered in boosting neural regeneration and management of olfactory deficits in aging and various disorders.

Simulation and Study of Influencing Factors on the Solidification Microstructure of Hazelett Continuous Casting Slabs Using CAFE Model.

The Hazelett continuous casting and rolling process represents a leading-edge production method for cold-rolled aluminum sheet and strip billets in the world. Its solidification microstructure significantly influences the quality of billets produced for cold rolling of aluminum sheets and strips. In this study, employing the CAFE (Cellular Automaton-Finite Element) method, we developed a coupled computational model to simulate the solidification microstructure in the Hazelett continuous casting process. We investigated the impact of nucleation parameters, casting temperature, and continuous casting speed on the microstructural evolution of the continuous casting billet. Through integrated metallographic analyses, we aimed to elucidate the controlling mechanisms underlying the Hazelett continuous casting process and its resultant microstructure. The results demonstrate that the equiaxed rate of grains increases with an increase in nucleation density, and the grain size decreases under constant cooling strength. With other nucleation parameters held constant, the grain size decreases as undercooling increases, and the columnar crystal zone expands. The nucleation density of the Hazelett continuous casting aluminum alloy has been determined to range between 1011 m-3 and 1013 m-3, and the undercooling ranges between 1 °C and 2.5 °C. The solidified grain structure can be controlled between 35 μm and 72 μm. The grain size of the continuous casting billet increases with an increase in pouring temperature and decreases as the casting speed increases. Elevating the pouring temperature positively impacts the fraction of high-angle grain boundaries and promotes the dendritic to equiaxed grain transition. Moreover, there exists potential for further optimization of continuous casting process parameters.

Cell viability and cytotoxicity assays: Biochemical elements and cellular compartments.

Cell viability and cytotoxicity assays play a crucial role in drug screening and evaluating the cytotoxic effects of various chemicals. The quantification of cell viability and proliferation serves as the cornerstone for numerous in vitro assays that assess cellular responses to external factors. In the last decade, several studies have developed guidelines for defining and interpreting cell viability and cytotoxicity based on morphological, biochemical, and functional perspectives. As this domain continues to experience ongoing growth, revealing new mechanisms orchestrating diverse cell cytotoxicity pathways, we suggest a revised classification for multiple assays employed in evaluating cell viability and cell death. This classification is rooted in the cellular compartment and/or biochemical element involved, with a specific focus on mechanistic and essential aspects of the process. The assays are founded on diverse cell functions, encompassing metabolic activity, enzyme activity, cell membrane permeability and integrity, adenosine 5'-triphosphate content, cell adherence, reduction equivalents, dye inclusion or exclusion, constitutive protease activity, colony formation, DNA fragmentation and nuclear splitting. These assays present straightforward, reliable, sensitive, reproducible, cost-effective, and high-throughput approaches for appraising the effects of newly formulated chemotherapeutic biomolecules on the cell survival during the drug development process.

Integrated vehicle chassis fabricated by wire and arc additive manufacturing: structure generation, printing radian optimisation, and performance prediction

ABSTRACT In the automotive industry, the extended design and iteration cycles for integrated chassis typically span 2–3 years, creating a misalignment with swiftly changing market demands. Wire arc additive manufacturing (WAAM) technology presents a viable alternative, overcoming the limitations of conventional chassis production. Our holistic framework significantly condenses the design, optimisation, and validation stages for automotive chassis. Initially, a ground structure method is utilised to outline and generate a skeleton chassis. We then utilise the OpenCV image processing method to select a hollow skeleton chassis with minimal material occupancy (0.476) and suspension printing. Subsequently, we assess the influence of printing radian variations by the robotic arm on the microstructure and stress, employing a cellular automaton-finite element (CA-FE) model at the 150th and 200th layer benchmarks. A Kalman filter (KF) is also implemented to fine-tune the printing radian in regions with coarse grain structures and elevated solute concentrations. The process concludes with collision and modal simulation verifications of the skeleton chassis, affirming the optimisation's success. This streamlined methodology allows the completion of the chassis design and manufacturing cycle within a remarkably condensed time frame of one week, accelerating the development process by a factor of 120.

Content and ultrastructure of natural killer cells in the blood of patients with newly diagnosed type 2 diabetes mellitus

Background. In patients with newly diagnosed type 2 diabetes mellitus (T2DM), a small but statistically significant decrease in absolute number of natural killer (NK) cells (CD56+) in the peripheral blood (PB) was found, especially pronounced with concomitant obesity. In connection with the above, one of the main aims of the present report was to further study the role of NK cells in patients with newly diagnosed T2DM, including those with obesity. For this purpose, a combination of flow cytometry methods with scanning and transmission electron microscopy was used to determine the number and function of CD56+ cells in the PB of patients with T2DM. Materials and methods. We examined 144 patients of both sexes with newly diagnosed T2DM aged 40–70 years who had no other acute or chronic diseases and had not previously taken any hypoglycemic drugs. The control group consisted of 50 healthy individuals with normoglycemia aged 40–65 years who had not COVID-19 disease. Results. Our studies have found that in untreated patients with newly diagnosed T2DM compared to healthy controls, there is a very small statistically significant decrease in the absolute number of CD56+ cells in the PB. When combining flow cytometry (FACS method), transmission and scanning electron microscopy in patients with T2DM, a significant change in the ultrastructure of CD56+ cells was revealed, indicating a decrease in their function (an increase in the number of cells with a smoother surface of the cell membrane, a sharp decrease in the number of azurophilic granules in the cytoplasm considered the main producer of cytokines and perforins, the appearance of parallel tubular structures, biomarkers of decreased cell function, a disruption of the Golgi apparatus structure, granular endoplasmic reticulum, etc.). The data obtained indicate that at the initial stage of T2DM development in humans, there is a pronounced weakening in the function of NK cells and, consequently, the natural immune defense of the body and explain the increased susceptibility of diabetics to various viruses and infections, including COVID-19, and also more severe clinical course and increased mortality. Conclusions. The conducted studies show that in patients with T2DM who are at the initial stage of T2DM, there is a sharp disturbance in the submicroscopic organization of CD56+ cells, the most important cellular element of natural immunity, which suggests a weakening of the function of natural immune defense. It is the main cause of increased sensitivity of diabetic patients to infection with various pathogens, including the SARS-CoV-2, as well as more severe clinical course and increased mortality rate.

Mild Cognitive Impairment and Astrocytic Influences Affecting Network Communication

Amnestic mild cognitive impairment (MCI) is generally understood to mean an age-related impairment in cognition beyond that normally observed in the elderly, where amnestic refers to a loss of the ability to recall stored information. The significance of this classification has traditionally rested on a presumptive clinical indication of dementia, based on a documented 5% to 10% annual rate of progression to dementia, a rate much higher than the 1% to 2% incidence observed within the general population. Because recollection mechanisms have been shown to center on the hippocampal cortical network (HCN), amnestic MCI is likely to entail an interruption of this network. Accumulating evidence indicates that a crucial cellular element regulating information flow in the HCN is the astrocyte. By extension, astrocytic mechanisms involved in regulating information flow within the HCN are likely to be disrupted in MCI. Consistent with this, astrocyte influence in memory networks is multimodally affected in MCI and AD patients, with impairments seen, for example, in interregional oscillatory coupling. Astrocyte pathologies thus appear to drive clinically relevant phenotypes of MCI and could represent novel and significant therapeutic targets for MCI treatment. Understanding the mechanisms astrocytes employ to enable communication within the HCN may not only advance our understanding of how and which processes are likely to go awry in MCI, but how they may be treated to arrest the loss of this most iconic MCI symptom.

Modeling the Evolution of Grain Texture during Solidification of Laser-Based Powder Bed Fusion Manufactured Alloy 625 Using a Cellular Automata Finite Element Model

The grain texture of the as-printed material evolves during the laser-based powder bed fusion (PBF-LB) process. The resulting mechanical properties are dependent on the obtained grain texture and the properties vary depending on the chosen process parameters such as scan velocity and laser power. A coupled 2D Cellular Automata and Finite Element model (2D CA-FE) is developed to predict the evolution of the grain texture during solidification of the nickel-based superalloy 625 produced by PBF-LB. The FE model predicts the temperature history of the build, and the CA model makes predictions of nucleation and grain growth based on the temperature history. The 2D CA-FE model captures the solidification behavior observed in PBF-LB such as competitive grain growth plus equiaxed and columnar grain growth. Three different nucleation densities for heterogeneous nucleation were studied, 1 × 1011, 3 × 1011, and 5 × 1011. It was found that the nucleation density 3 × 1011 gave the best result compared to existing EBSD data in the literature. With the selected nucleation density, the aspect ratio and grain size distribution of the simulated grain texture also agrees well with the observed textures from EBSD in the literature.

The role of cellular immunity and systemic inflammation indices in the pathogenetic mechanisms of mental disorders

To date, inflammatory mechanisms are known to be involved in neuronal damage and increased risk of associated mental disorders, but most previous work has focused primarily on cytokines and other inflammatory markers that are difficult to replicate and not economically feasible for use in routine clinical practice. Other extremely important indicators of the systemic inflammatory process are circulating blood cells and changes in their number, composition, and ratio. Hematologic indices of systemic inflammation (HISI) are already used in somatic specialties: neutrophil-lymphocyte (NLR), monocyte-lymphocyte (MLR) and platelet-lymphocyte (PLR) ratios, as well as the Systemic Immune Inflammation Index (SII) and the System Inflammation Response Index (SIRI). In the context of psychopathology, the HISI require additional investigation, which makes it necessary to pay more attention to the possible mechanisms underlying their changes. The article provides data on the contribution of each cellular element to the mechanism of neuroinflammation and neurodegeneration and on their role in the development of psychopathological processes.

Effect of transurethral resection of prostate on Uroflowmetry parameters on patients having benign prostatic hyperplasia

Objective: To determine improvement in uroflowmetry after Transurethral resection ofprostateStudy design: A prospective observational Study Place and Duration of the Study: January 2014 to June 2016 Department at urology POF HospitalWah Cantt, Pakistan INTRODUCTION:Lower urinary tract problems affect 15%–60% of men over 40. Complex symptoms include frequency, urgency, nocturia, problems commencing urination, insufficient bladder emptying, low steam force, and steam stoppage. BPH frequently causes male LUTS. Benign prostatic enlargement Chronic BOO may induce urine retention, renal insufficiency, recurrent UTIs, extensive hematuria, and bladder calculi. It involves prostate histopathological cellular element proliferation. BPH and LUTS rise considerably with age. BPH affects 70% of US men aged 60–69 and 80% over 70. Autopsy examinations indicated 8%, 50%, and 80% histological frequency in the 4". and 9*decades. LUTS risk factors and larger prostates cause benign prostatic enlargement. Formerly, TURP was the best BPH procedure. Higher disease pathophysiology knowledge and digital rectal examination, transabdominal, and transrectal ultrasounds are the second most prevalent interventions in adult male patients worldwide. Urodynamic and serum PSA tests may misdiagnose the condition and require surgery. Uroflowmetry records voiding time from urinal pee. It would assess average flow and obstruction severity. For boys 14–45, the average flow rate is 21 mL/s, 46–65 mL/s, and 66–80 mL/s. Uroflowmetry in post-TURP benign hypertrophic hyperplasia patients will be examined after transurethral prostate removal. keywords: transurethral resection , prostate Uroflowmetry parameters, prostatic hyperplasia

Selenium alleviates lead-induced CIK cells pyroptosis and inflammation through IRAK1/TAK1/IKK pathway

The toxic heavy metal lead is widely found in rivers and soils as an environmental pollutant, posing a threat to the health of aquatic organisms. Selenium is an essential trace element and a powerful antioxidant that has been shown to have anti-inflammatory and antioxidant properties as well as alleviating heavy metal poisoning. Many studies have shown that lead poisoning produces inflammatory responses and damage to the kidneys of a wide range of animals, but the effects on cellular pyroptosis and immune function and selenium antagonism in CIK cells are not clear. In this study, 500 μM Pb and 20 nM Se were applied to grass carp kidney cells, and the results showed that Pb exposure to CIK cells resulted in oxidative stress, activation of the IRAK1/TAK1/IKK pathway, up-regulation of the expression of cellular pyroptosis markers GSDMD and NLRP3, and cellular pyroptosis of CIK cells, as well as up-regulation of IL-1β and IL-18, and the generation of cellular inflammatory response. In contrast, Se treatment significantly reduced the ROS level, the expression of cellular pyroptosis markers GSDMD, NLRP3 and inflammatory element IL-1β and IL-18. Taken together, Se alleviated cellular pyroptosis and immune dysfunction caused by Pb exposure through oxidative stress and activation of the IRAK1/TAK1/IKK pathway. This study complements the harmful effects of the heavy metal Pb on fish and the real-life application of selenium in the healthy culture of fish as a reference will be provided.

Parametric Modelling of Rousselier ́s Damage Model Parameters with Instrumented Charpy Tests

This work presents Rousselier´s damage model parameters effect and their physical meaning on Charpy fracture propagation curves. Therefore, instrumented Charpy tests were performed at room test temperature to measure the load-displacement curve. The parameters were measured from a Grade A ship plate steel, employed for the construction of merchant ships. The effect of Rousselier´s model parameter was done by performing cellular automata finite element (CAFE) modelling, where Rousselier’s damage model was coded, and therefore Rousselier´s model parameters were incorporated using random number generators in the ductile arrays of cells, using Weibull distributions. Consequently, in each CAFE simulation, the model evaluates random values of Rousselier´s damage model parameters performing a more physically based modelling. The results showed that the present CAFE modelling was able to reproduce the hardening and fracture propagation regions of instrumented Charpy data. Furthermore, the present work showed a suitable Rousselier´s damage model parameters calibration procedure with Charpy data, and how each Rousselier´s model parameter can affect the hardening and fracture propagations regions when they are not properly calibrated, producing unrealistic results. Additionally, it can be observed that the present results can be used as a template for a better calibration of Rousselier´s damage model parameters in CAFE modelling.

A framework for predicting residual mechanical response fields for laser powder bed fusion at the polycrystalline length scale

A framework is developed to directly model the effect of processing parameters utilized during laser powder bed fusion additive manufacturing (LPBF AM) on material thermomechanical response during solidification in order to predict residual stress and strain development at the microstructure-resolved polycrystalline length scale. Specifically, a workflow is established where the processing parameters serve as input to a cellular automata finite element (CAFE) model that simulates the microstructure solidification evolution via a thermally driven empirical solidification law. The CAFE’s output microstructures serve as representative volume elements which are input to a Multiphysics finite element solver, which solves the thermally driven mechanical response during solidification based on the crystal plasticity finite element formulation. A model validation study is presented, which demonstrates that the modeling framework accurately predicts various features of intragrain misorientation when compared to electron backscatter diffraction data of an LBPF 316L thin wall part built using a GE/Concept Laser M2 SLM system. Following model validation, four variations of processing parameters are chosen to investigate the influence of scan strategy and laser scan velocity on the manufacturing of an LPBF 316L thin wall. Also included is an analogous simulation that treats the microstructure as isotropic and homogeneous, which allows for quantifying the contribution of microstructural heterogeneity on residual stress and strain distribution and magnitudes. Correlations between processing parameters, temperature fields, texture and grain morphology, and the resulting as-built mechanical response are determined and discussed. The current research has the potential to provide valuable insights and guidance for designing AM build conditions to optimize residual mechanical response together with grain structures and textures.

Pericytes as an Essential Cellular Element in Transwell Blood–Brain Barrier Models In Vitro

Pericytes as an Essential Cellular Element in Transwell Blood–Brain Barrier Models In Vitro

Coronary cardiovascular Disease and the Treatment of Atherosclerosis A REVIEW

Coronary cardiovascular disease could be a disorder of the center sometimes causeby a condition known as induration of the arteries. induration of the arteries is one among the main and most frequent causes of Heart arrest. illness|arteriosclerosis|arterial sclerosis|hardening of the arteries|induration of the arteries|coronary-artery disease} is that the disease that affects the massive arteries and it's the condition during which development of plaque happens within these arteries. This causes the narrowing of arteries. Plaque is created of fatty substances, cholesterin, cellular waste product, metallic element and protein (a natural process material within the blood). medicine studies have exhibited many vital risk factors related to induration of the arteries. induration of the arteries} plaque among the coronary arteries is chargeable for arteria coronaria disease, heart muscle misdemeanour and Acute coronary syndromes. Induration of the arteries will cause serious issues, together with heart failure, stroke, or maybe death. This study in the main discusses the mechanism of development of induration of the arteries within the arteries, their risk issue and also the recent advancements to treat the induration of the arteries

Cancer-associated fibroblasts in gynecological malignancies: are they really allies of the enemy?

Molecular and cellular components of the tumor microenvironment are essential for cancer progression. The cellular element comprises cancer cells and heterogeneous populations of non-cancer cells that satisfy tumor needs. Immune, vascular, and mesenchymal cells provide the necessary factors to feed the tumor mass, promote its development, and favor the spread of cancer cells from the primary site to adjacent and distant anatomical sites. Cancer-associated fibroblasts (CAFs) are mesenchymal cells that promote carcinogenesis and progression of various malignant neoplasms. CAFs act through the secretion of metalloproteinases, growth factors, cytokines, mitochondrial DNA, and non-coding RNAs, among other molecules. Over the last few years, the evidence on the leading role of CAFs in gynecological cancers has notably increased, placing them as the cornerstone of neoplastic processes. In this review, the recently reported findings regarding the promoting role that CAFs play in gynecological cancers, their potential use as therapeutic targets, and the new evidence suggesting that they could act as tumor suppressors are analyzed and discussed.

Identification of the Vibrational Optical Coherence Tomography Corneal Cellular Peak.

Our team previously identified the presence of five corneal resonant frequency (RF) peaks in healthy volunteers using vibrational optical coherence tomography (VOCT). Prior studies have suggested that the ≤100 Hz RF peak represents the cellular element of tissue. The aim of this study was to confirm that this peak reflects the human corneal cellular component using VOCT and histological analysis. Two human research globes were obtained from the same donor, and VOCT measurements were collected from the full-thickness corneas. A microkeratome was then used to create serial-free corneal caps from each cornea, with VOCT performed on the residual stromal bed after each excision. All lamellar sections from both globes were sent for histological analysis to determine cellularity. Cell counts on the specimens were performed by two independent observers. The average of the normalized ≤100 Hz peak values before lamellar sectioning was significantly higher than the average of this peak values after the first, second, and third cuts (P = 0.023), which was 33.9% less than before any cuts. The cell count values in the first slice were significantly higher than the average cell count values of the three deeper slices (P < 0.001), and the cell count dropped 84.4% after the first slice was removed. The findings of this study suggest that the ≤100 Hz corneal peak identified by VOCT corresponds to the cellular component of the cornea. This work furthers our understanding of the origin of the corneal ≤100 Hz peak identified using VOCT.

Eosinophils in normal and pathological conditions. Structure, mediators, development

Eosinophils are the most important cell type. They have a variety of functions. Eosinophil as a separate cellular element was first described by Paul Ehrlich in 1879. Their number usually ranges from 1–4% of the total number of circulating leukocytes. The presence of large specific (secondary) granules is a characteristic feature that distinguishes eosinophils from other granulocytes. Primary granules, lipid bodies are also determined in the cell. Charcot — Leiden crystals are registered in the cytoplasm and granules. Eosinophils are the effector cells of natural immunity. Eosinophils have an ability to rapidly release a vast number of tissue mediators such as granule proteins, cytokines, neuromediators, enzymes and others. It should be noted that some of them are determined only in these cells. The concentrations of many mediators in eosinophils is much higher than in neutrophils. The development of eosinophils is determined by the interaction of a whole complex of transcription factors and cytokines. It is shown that new transcription factors and other molecules involved in the differentiation of these cells to be determined in the future. A more detailed characterization of eosinophil mediators will also be carried out.