Thermo-fluidic Transport Process in a Novel M-shaped Cavity Packed with Non-Darcian Porous Medium and Hybrid Nanofluid: Application of Artificial Neural Network (ANN)

In this work, an attempt has been made to explore numerically the thermo-fluidic transport process in a novel M-shaped enclosure filled with permeable material along with Al2O3-Cu hybrid nanoparticles suspended in water under the influence of a horizontal magnetizing field. To exercise the influence of geometric parameters, a classical trapezoidal cavity is modified with an inverted triangle at the top to construct an M-shaped cavity. The cavity is heated isothermally from the bottom and cooled from the top, whereas the inclined sidewalls are insulated. The role of geometric parameters on the thermal performance is scrutinized thoroughly by changing the sidewall inclination, number, and height of the top inverted triangular undulation under similar boundary conditions. The governing equations transformed into dimensionless form are solved by using a computing code written in the finite volume approach. The analysis is conducted by considering a wide range of parametric influences like sidewall angles (γ), number (n), and height (δ) of the top triangular undulations, modified Rayleigh number (Ram), Darcy number (Da), Hartmann number (Ha), and hybrid nanoparticle concentrations (φ). Furthermore, the artificial neural network (ANN) technique is implemented and tested to predict the overall thermal behavior of the novel cavity to predict new cases. The results revealed that the design of sidewall inclination (γ) is an important parameter for modulating the thermo-flow physics. The M-shaped cavity (compared to trapezoidal) reveals either a rise or drop in the fluid circulation strength depending upon the magnitude of δ, but the heat transfer rate always increases due to an increase in the cooling length. The heat transfer increment is ∼61.01% as δ increases. Single undulation with higher depth is the optimum choice for achieving improved heat transfer (which may go up to ∼355.75% for δ = 0.5 and γ  = 45°). A decrease in Da or Ha causes a drop in the flow strength, which consequently leads to a drop in the heat transfer rate. Furthermore, the concepts of ANN will help researchers predict the behavior for such complicated cavity shapes with a multiphysics approach. This will save efforts as well as computing time for exploring the thermal behavior of any range of a dataset

Giant cells: multiple cells unite to survive

Multinucleated Giant Cells (MGCs) are specialized cells that develop from the fusion of multiple cells, and their presence is commonly observed in human cells during various infections. However, MGC formation is not restricted to infections alone but can also occur through different mechanisms, such as endoreplication and abortive cell cycle. These processes lead to the formation of polyploid cells, eventually resulting in the formation of MGCs. In Entamoeba, a protozoan parasite that causes amoebic dysentery and liver abscesses in humans, the formation of MGCs is a unique phenomenon and not been reported in any other protozoa. This organism is exposed to various hostile environmental conditions, including changes in temperature, pH, and nutrient availability, which can lead to stress and damage to its cells. The formation of MGCs in Entamoeba is thought to be a survival strategy to cope with these adverse conditions. This organism forms MGCs through cell aggregation and fusion in response to osmotic and heat stress. The MGCs in Entamoeba are thought to have increased resistance to various stresses and can survive longer than normal cells under adverse conditions. This increased survival could be due to the presence of multiple nuclei, which could provide redundancy in case of DNA damage or mutations. Additionally, MGCs may play a role in the virulence of Entamoeba as they are found in the inflammatory foci of amoebic liver abscesses and other infections caused by Entamoeba. The presence of MGCs in these infections suggests that they may contribute to the pathogenesis of the disease. Overall, this article offers valuable insights into the intriguing phenomenon of MGC formation in Entamoeba. By unraveling the mechanisms behind this process and examining its implications, researchers can gain a deeper understanding of the complex biology of Entamoeba and potentially identify new targets for therapeutic interventions. The study of MGCs in Entamoeba serves as a gateway to exploring the broader field of cell fusion in various organisms, providing a foundation for future investigations into related cellular processes and their significance in health and disease

Nuclear Factor Y (NF-Y) Modulates Encystation in Entamoeba via Stage-Specific Expression of the NF-YB and NF-YC Subunits

The human parasite Entamoeba histolytica is an important pathogen with significant global impact and is a leading cause of parasitic death in humans. Since only the cyst form can be transmitted, blocking encystation would prevent new infections, making the encystation pathway an attractive target for the development of new drugs. Identification of the genetic signals and transcriptional regulatory networks that control encystation would be an important advance in understanding the developmental cascade. We show that the Entamoeba NF-Y complex plays a crucial role in regulating the encystation process in Entamoeba.Nuclear factor Y (NF-Y) is a heterotrimeric transcription factor composed of three subunits, namely, NF-YA, NF-YB, and NF-YC, which are conserved throughout evolution. In higher eukaryotes, NF-Y plays important roles in several cellular processes (development, cell cycle regulation, apoptosis, and response to growth, stress, and DNA damage) by controlling gene expression through binding to a CCAAT promoter motif. We demonstrated that NF-Y subunits in the protist Entamoeba, while significantly divergent from those of higher eukaryotes, have well-conserved domains important for subunit interactions and DNA binding and that NF-YB and NF-YC are developmentally expressed during encystation. Electrophoretic mobility shift assays confirmed that the NF-Y protein(s) from Entamoeba cysts binds to a CCAAT motif. Consistent with a role as a transcription factor, the NF-Y proteins show nuclear localization during development. Additionally, we demonstrated that NF-YC localizes to the chromatoid body (an RNA processing center) during development, indicating that it may have a role in RNA processing. Finally, silencing of the NF-YC subunit resulted in reduced stability of the NF-Y complex and decreased encystation efficiency. We demonstrated that the NF-Y complex functions at a time point subsequent to the NAD+ flux and expression of the transcription factor encystation regulatory motif-binding protein, both of which are early regulators of Entamoeba development. Taken together, our results demonstrate that the NF-Y complex plays an important role in regulating encystation in Entamoeba and add to our understanding of the transcriptional networks and signals that control this essential developmental pathway in an important human pathogen

Recent advances in Entamoeba biology: RNA interference, drug discovery, and gut microbiome [version 1; referees: 4 approved]

In recent years, substantial progress has been made in understanding the molecular and cell biology of the human parasite Entamoeba histolytica, an important pathogen with significant global impact. This review outlines some recent advances in the Entamoeba field in the last five years, focusing on areas that have not recently been discussed in detail: (i) molecular mechanisms regulating parasite gene expression, (ii) new efforts at drug discovery using high-throughput drug screens, and (iii) the effect of gut microbiota on amoebiasis

A Novel Galacto-Glycerolipid from Oxalis corniculata Kills Entamoeba histolytica and Giardia lamblia▿ †

Oxalis corniculata is a naturally occurring weed that has been used in traditional medicine for the cure of dysentery and diarrhea in India. One of the common causes of dysentery is due to infection by the protist pathogen Entamoeba histolytica. Bioactivity profiling of extracts from O. corniculata identified several compounds that showed antiamoebic activity in axenic cultures of E. histolytica. These were characterized by nuclear magnetic resonance, infrared, and mass spectrometry as (i) Oc-1, a mixture of saturated fatty acids C24 to C28; (ii) Oc-2, a mixture of long-chain alcohols C18 to C28; and (iii) Oc-3, a single compound that was a galacto-glycerolipid (GGL). Of the different compounds that were obtained, the strongest antiamoebic activity was found in GGL. The addition of GGL to E. histolytica xenic cultures containing other microbial flora from the large intestine did not affect its antiamoebic activity. Amoebicidal concentrations of GGL had no effect on intestinal microbial flora or on the mammalian cell line HEK-293. GGL was also found to be equally effective in killing another protist pathogen, Giardia lamblia, that causes diarrhea in humans. The importance of this study is based on the identification of novel natural products and the possibility of developing these compounds as active agents to treat at least two pathogenic parasitic intestinal infections endemic to tropical regions

Pecularities in the distribution of produced particles emission in ²⁴Mg-Ag/Br interactions at 4.5 A GeV*

156-160The angular sub-structures of particle produced within dense and dilute groups along the rapidity axis in 24Mg induced interaction of Ag/Br nuclei in an emulsion detector at 4.5 A GeV/c have been investigated. The experimental results have been compared with the results simulated by Monte Carlo method. Non-statistical jet-like sub-structures have been found in the data. However, when the parameter S2 is used in the analysis there seems to be definite jet-structure for the dilute groups which cannot be accounted for independent emission model (MC). The average behaviour of the S parameters strongly favours the presence of jet-like sub-structures

Exciton Dynamics in Anthracene Nanoaggregates

Anthracene nanoaggregates (NA), synthesized using a well-known reprecipitation method, have shapes of nanodisks with the average diameter and height of about 260 and 50 nm, respectively. Following photoexcitation of the anthracene nanoaggregate, we have observed population of two different types of singlet excitonic states, namely, free exciton and self-trapped exciton or excimeric state. Our investigation reveals that the presence of defect conditions in the molecular aggregates reduces the free exciton lifetime and slows the exciton diffusion process marginally. Both the exciton diffusion coefficient and exciton diffusion length in the nanoaggregate and in crystals are comparable. Comparable values of the diffusion lengths in the case of the singlet exciton in the nanoaggregate and crystals suggest that the nanoaggreagates may also be considered as materials for efficient optoelectronic and photovoltaic devices. However, drastic reduction in triplet exciton diffusion coefficient in the nanoaggregate as compared to that in the crystalline form is explained by considering the triplet energy transfer mechanism via spin exchange, which is a slow process

ANALYSIS OF WALL SHEAR PARAMETERS OF PHYSIOLOGICAL PULSATILE FLOW THROUGH MILD AND SEVERE ARTERIAL STENOSIS AND CORRELATION TO ATHEROSCLEROSIS

Numerical simulations of physiological pulsatile flow through mild and severe arterial stenosis are carried out to analyze wall shear stress parameters. The governing equations are solved by finite volume method. The study shows that the distribution patterns of time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI) and relative residence time (RRT) are same forboth mild stenosis and severe stenosis. The magnitude of peak TAWSS and low TAWSS and extent of negative TAWSS of severe stenosis is higher than those of mild stenosis. The OSI value of severe stenosis is higher at distal to throat of stenosis in comparison to mild stenosis. The size of recirculation zone of severe stenosis is lager than that of mild stenosis. The abnormally high peak value of RRT of severe stenosis is concentrated and located at far away from stenosis when it is compared with mild stenosis