Nuclear α-actinin-4 regulates breast cancer invasiveness and EMT.

Epithelial-to-mesenchymal transition (EMT) is a key process where cells lose their adhesion properties and augment their invasive properties. α-Actinin4 (ACTN4) is an actin crosslinking protein that responds to mechanical stimuli and is found to be elevated in breast cancer patients. While ACTN4 has been implicated in regulating cancer invasiveness by modulating cytoskeletal organization, its nuclear functions remain much less explored. Here we address this question by first establishing a correlation between nuclear localization and invasiveness in breast cancer cells. Using cancer databases, we then establish a correlation between ACTN4 expression and EMT in breast cancer. Interestingly, TGFß-induced EMT induction in MCF10A normal mammary epithelial cells leads to increased ACTN4 expression and nuclear enrichment. We then show that ACTN4 knockdown in MDA-MB-231 breast cancer cells, which harbor sizeable fraction of nuclear ACTN4, leads to reduced invasiveness and loss of mesenchymal traits. Similar behavior was observed in knockdown cells expressing K255E ACTN4, which is primarily localized to the cytosol. Together, our findings establish a role for nuclear ACTN4 in regulating invasiveness via modulation of EMT.

MHD free convection with Joule heating and entropy generation inside an H-shaped hollow structure.

In this research, a free convective flow of water inside an H-shaped hollow structure which is subjected to the existence of an exterior magnetic field and Joule heating is computationally investigated. The structure's right and left upright surfaces are maintained at invariant ambient thermal condition, while the top and bottom-most surfaces of the structure are in adiabatic condition. The rest of the inner walls are heated isothermally. Computational analysis is carried out for different configurations of the chamber by solving Navier-Stokes and heat energy equations via the finite element approach. Parametric computations are conducted by varying Hartmann numbers (0 ≤ Ha ≤ 20), Rayleigh numbers (103 ≤ Ra ≤ 106), width of the vertical sections (0.2 ≤ d/L ≤ 0.4, where L denotes the structure's reference dimension), and thickness of the horizontal middle section (0.2 ≤ t/L ≤ 0.4). To find out the impact of the governing parameters on thermal performance for different configurations, the mean Nusselt number along the hot walls, mean temperature of fluid, overall entropy generation, and thermal performance criterion are assessed. In addition, the variations in fluid motion and thermal patterns are reported in terms of streamlines, isotherms, and heatlines. With a larger mean Nusselt number and smaller thermal performance criterion, better heat transmission performance is found for thicker horizontal middle section and wider vertical sections. The maximum reduction in thermal performance criterion is found to be 87.8 % for increasing the width of the vertical sections. However, in the cases of Ha and d/L, there is an interesting transition in Nusselt number noticed for different Rayleigh numbers.

Revisiting thermo-physical property models of Al2O3-Water nanofluid for natural convective flow.

One of the comprehensive ways of heat transport performance augmentation of thermo-fluid systems is to use nanofluid over base fluid. This study mainly scrutinizes several existing models of thermal conduction coefficient and absolute viscosity of Al2O3-water nanofluid with the experimental data. A benchmark problem of natural convective flow is selected to test the performance of the available nanofluid models. The Rayleigh number varies between 103 and 109, while the solid-volume proportion (φ) changes from 0 to 4%. The governing mathematical model is numerically discretized via the Galerkin finite element procedure under appropriate auxiliary conditions. The results produced by the models are verified with the existing experimental findings based on the evaluation of the Prandtl number and average Nusselt number. It has been confirmed that the AH model (Azmi's viscosity and Ho's conductivity models) is suitable for lower nanoparticle concentration (φ = 0.01), the AM model (Azmi's viscosity and Maxwell's conductivity models) for moderate concentration (0.01 < φ < 0.04), and the NH model (Ngueyn's viscosity and Ho's conductivity models) for higher value of the solid-volume proportion (φ = 0.04).

Optimization of system parameters during conjugate mixed convective flow in a square domain with an oscillating spinning cylinder.

A computational analysis has been executed to analyze the combined conduction-mixed convection heat transfer of a rotationally oscillating solid cylinder in a differentially heated square box filled with air. The conjugate mixed convective flow initiates the heat transfer process, where the left-side boundary is isothermally kept to a higher temperature, and the right-side boundary is maintained at a lower temperature. Conduction heat transfer takes place inside the solid cylinder. Navier-Stokes and heat energy conservation equations model the system in the dimensionless pressure-velocity formulation. All these equations are solved via the Galerkin finite element approach. Three different combinations of Grashof (103-105), Reynolds (32-316), and Richardson (0.1-10) numbers are examined to systematically investigate the variations of governing parameters on instantaneous Nusselt numbers and the respective time-averaged values along the hot wall. In each combination, the impacts of the oscillating amplitude and frequency and the variation of cylinder diameter are examined to perform the optimization study. Power spectrum analysis is also done using the Fast Fourier Transform in the frequency domain to visualize the principal frequency of the system. The instantaneous values of the Nusselt number exhibit a wavering pattern over time owing to the recurrent waning and waxing of the thermal boundary layer. For all the cases, the maximum diameter and oscillating amplitude of the cylinder are found to maximize the heat transfer. However, the optimized frequency of the oscillation strongly depends on the selection of the governing parameters. In addition, the principal thermal frequency of the system is determined to be independent of the oscillation frequency.

Multi-scaling analysis of turbulent boundary layers over an isothermally heated flat plate with zero pressure gradient.

A meticulous investigation into turbulent boundary layers over an isothermally heated flat plate with zero pressure gradient has been conducted. Eight distinct turbulence models, including algebraic yPlus, standard k-ω, standard k-ε, length-velocity, Spalart-Allmaras, low Reynolds number k-ε, shear stress transport, and v2-f turbulence models, are carefully chosen for numerical simulation alongside thermal energy and Reynolds-Averaged Navier-Stokes equations. A comparative analysis has determined that the Spalart-Allmaras model exhibits remarkable agreement with the results from direct numerical simulation, making it a reliable tool for predicting turbulent heat transfer and fluid flow, particularly at higher Prandtl and Reynolds numbers. Subsequently, a multi-scale investigation employs a comprehensive four-layer structure scheme and encompasses various momentum thickness Reynolds numbers of 1432, 2522, and 4000, and Prandtl numbers of 0.71, 2, and 5. The subsequent investigation reveals the governing non-dimensional numbers' substantial impact on the distribution and magnitude of mean thermal and flow characteristics. Notably, the scaling of mean thermal and momentum fields discloses the existence of a meso or intermediate layer characterized by a logarithmic nature unique to itself. The multi-scaling analysis of the flow field demonstrates greater conformity with the selected scaling variables primarily relying on the Reynolds number. Furthermore, the scaling of the energy field yields compelling outcomes within the inner and intermediate layers. However, according to the four-layer theory, minor discrepancies are observed in the outer layer when using the current scaling.

CFD analysis of heat transfer enhancement by wall mounted flexible flow modulators in a channel with pulsatile flow.

The aim of the present study is to explore heat transfer and pressure drop characteristics in a pulsating channel flow due to wall-mounted flexible flow modulators (FFM). Cold air in pulsating fashion is forced to enter through the channel having isothermally heated top and bottom walls with one/multiple FFMs mounted on them. The dynamic conditions of pulsating inflow are characterized by Reynolds number, non-dimensional pulsation frequency and amplitude. Applying the Galerkin finite element method in an Arbitrary Lagrangian-Eulerian (ALE) framework, the present unsteady problem has been solved. Flexibility (10-4 ≤ Ca ≤ 10-7), orientation angle (60° ≤ Î¸ ≤ 120°), and location of FFM(s) have been considered in this study to find out the best-case scenario for heat transfer enhancement. The system characteristics have been analyzed by vorticity contours and isotherms. Heat transfer performance has been evaluated in terms of Nusselt number variations and pressure drop across the channel. Besides, power spectrum analysis of thermal field oscillation along with that of the FFM's motion induced by pulsating inflow has been performed. The present study reveals that single FFM having flexibility of Ca = 10-5 and an orientation angle of θ = 90° offers the best-case scenario for heat transfer enhancement.

ICT-based solution for efficient fecal sludge management: An experience from Bangladesh.

In Bangladesh, people primarily depend on on-site sanitation facilities (OSSF) with an immense challenge in achieving safe sanitation due to unplanned infrastructure development, improper management of fecal sludge, and inadequate monitoring. The commitment of attaining Sustainable Development Goals (SDG) 6.2 (ensuring safe sanitation for all) by 2030 requires immediate attention in the management of fecal sludge for low-middle income countries. This paper presented the findings, challenges, and possible ways forward from a study conducted to provide data for Information and Communication Technology (ICT)-based fecal sludge management (FSM) at a municipality in the northwest of Bangladesh. A total of 18,808 households and 407 institutions in Saidpur municipality, a non-sewered town in Nilphamari district, were studied to understand the type of containment structures and on-ground desludging practices. The study showed around 10% of containments were connected to the drains illegally, 95% of the people in Saidpur practiced unsafe disposal, and 7% still practiced open defecation. To identify these malpractices, the study also implemented an ICT-based sustainable solution through a web application that enabled the local administrator to have a global look at the sanitation scenario of the municipality. The dashboard was developed to create a total sanitation monitoring system, identify defaulters, allow target-based safe managed sanitation service strategies, and ensure sustainability in FSM. The study highlighted the accessibility of vacuum truck services projecting through a spatial map and identified methods to empty the septic tanks where Vacutag services are unavailable by engaging local pit emptiers. The innovative approach of fecal sludge management will help not only to improve the existing sanitation practices but also raise community awareness to ensure sustainable sanitation system. Altogether, the web system will work as a medium to manage the faecal sludge for the existing co-compost plant where the faeces is converted into organic soil conditioner, creating prospects for a green business mechanism.

Particle deposition and fluid flow characteristics in turbulent corrugated pipe flow using Eulerian-Lagrangian approach.

A numerical simulation of aerosol particle deposition in a horizontal circular pipe with a corrugated wall under turbulent flow has been carried out in this research. This paper uses the RNG k-ε turbulence model with Enhanced Wall Treatment to simulate fluid flow. Furthermore, the Lagrangian particle tracking model simulates particle deposition in the corrugated pipe. Air-particle interaction is influenced by Stokes number, surface roughness, flow velocity, particle diameter, and pipe diameter. For the parametric simulation, particle diameter varies from 1 to 30 µm, whereas the Reynolds number ranges from 5000 to 10,000. The effect of corrugation height and pipe diameter on deposition efficiency is also investigated. This study shows that corrugation height significantly increases particle deposition compared to the smooth wall pipe. As the pipe diameter decreases, keeping the corrugation ratio constant, deposition efficiency also increases. Moreover, high flow velocity enhances deposition efficiency for particle diameters lower than 5 µm.

Entropy generation and characteristics of mixed convection in lid-driven trapezoidal tilted enclosure filled with nanofluid.

The investigation of steady, incompressible, laminar mixed convective fluid flow within two different types of tilted lid-driven trapezoidal enclosures filled with nanofluid composed of water and Al2O3 nanoparticles has been carried out in this paper. The upper wall of the enclosure is an isothermal cold surface that travels at a constant speed, while the bottom surface of the cavity maintains a constant high temperature. Non-dimensional governing equations along with the appropriate boundary conditions are solved using Galerkin finite element technique. Parametric simulation has been conducted by varying tilt angle of the base wall from 0° to 45°, Reynolds number from 0.1 to 103, Grashof number from 10-2 to 106, and Richardson number between 0.1 and 10 for three different cases. The streamlines and the isotherms are used to describe the fluid flow and heat transfer characteristics within the enclosure. Besides, the quantitative evaluations of thermal enhancement in terms of the average Nusselt number, average fluid temperature, and Bejan number of the enclosure are presented. Effects of base wall tilt angle and the presence of nanofluid on convection heat transmission characteristics as well as Bejan number are also explored.

Conjugate mixed convection heat transfer with internal heat generation in a lid-driven enclosure with spinning solid cylinder.

The current study investigates conjugate mixed convection heat transmission with internal heat generation in a square enclosure driven by a sliding lid and a solid cylinder with a heat-conducting surface at its center. The enclosure has a stationary bottom wall that is kept at a constant hot temperature and a cold upper wall that moves consistently. The solid cylinder rotates both clockwise and counterclockwise at different angular speeds. Two-dimensional steady continuity, momentum, thermal energy equations, and boundary and interface conditions are solved using a commercial CFD tool based on the finite element method. By choosing Reynolds, Grashof, and Richardson numbers, as well as varying the rotating cylinder's speed and direction under three different scenarios incorporating volumetric heat generation, parametric modeling of the mixed convection regime is carried out. The streamline and isotherm plots are used to illustrate qualitative findings. In contrast, the average Nusselt number, normalized Nusselt number, average drag coefficient, and average fluid temperature are used to assess quantitative thermal performance measures. This study reveals that the system's thermal performance is less dependent on the solid cylinder's rotational speed and direction. It successfully depicts the heat transfer enhancement with increasing Reynolds and Grashof numbers. A thorough study of the current facts can lead to the best choice of regulating parameters.

Successful endovascular treatment of spontaneous intrarenal pseudoaneurysm in a case of tuberous sclerosis.

Tuberous sclerosis is a complex disorder which has multisystem involvement and varied clinical manifestations. Almost half of the patients have associated angiomyolipoma which contains fat, vascular and smooth muscle components. Spontaneous pseudoaneurysm formation is a complication of angiomyolipoma. Here we present a case of a female child presenting with hematuria who after thorough clinical and radiological investigations was diagnosed as a case of tuberous sclerosis with right intrarenal pseudoaneurysm. She was successfully treated with endovascular coil embolization.