Channel Surface Research Articles

Exploring the Role of Surface and Mitochondrial ATP-Sensitive Potassium Channels in Cancer: From Cellular Functions to Therapeutic Potentials.

ATP-sensitive potassium (KATP) channels are found in plasma membranes and mitochondria. These channels are a type of ion channel that is regulated by the intracellular concentration of adenosine triphosphate (ATP) and other nucleotides. In cell membranes, they play a crucial role in linking metabolic activity to electrical activity, especially in tissues like the heart and pancreas. In mitochondria, KATP channels are involved in protecting cells against ischemic damage and regulating mitochondrial function. This review delves into the role of KATP channels in cancer biology, underscoring their critical function. Notably responsive to changes in cellular metabolism, KATP channels link metabolic states to electrical activity, a feature that becomes particularly significant in cancer cells. These cells, characterized by uncontrolled growth, necessitate unique metabolic and signaling pathways, differing fundamentally from normal cells. Our review explores the intricate roles of KATP channels in influencing the metabolic and ionic balance within cancerous cells, detailing their structural and operational mechanisms. We highlight the channels' impact on cancer cell survival, proliferation, and the potential of KATP channels as therapeutic targets in oncology. This includes the challenges in targeting these channels due to their widespread presence in various tissues and the need for personalized treatment strategies. By integrating molecular biology, physiology, and pharmacology perspectives, the review aims to enhance the understanding of cancer as a complex metabolic disease and to open new research and treatment avenues by focusing on KATP channels. This comprehensive approach provides valuable insights into the potential of KATP channels in developing innovative cancer treatments.

A salty snapshot: extreme variations in basal erosion patterns preserved in a submarine channel

The bases of active submarine channels are marked by large erosional features, such as knickpoints and plunge pools. However, their presence in ancient channel-fills has rarely been documented, so their importance in submarine channel morphodynamics requires investigation. Using seismic reflection data calibrated by wells from a buried submarine channel-fill, we document erosional features hundreds of metres long and tens of metres deep, here interpreted as knickpoints and a plunge pool, and provide a mechanistic process for their transfer into the stratigraphic record. Channel incision patterns are interpreted to record a transient uplift in an otherwise subsiding depocentre. Local structural complexities in the channel slope formed zones of preferential scouring. A switch to a depositional regime preserved the irregular channel base, inhibiting both the upstream migration of scours and smoothing of the channel base. The formation and preservation of these scours record the responses to salt tectonics and provide a unique snapshot of the formative processes of an ancient submarine channel. The presence of these exceptional basal scours indicates that headward erosion processes did not operate rapidly, challenging the paradigm that knickpoint migration controls channel evolution. Our results show that the primary erosion of the main channel surface and long-term channel evolution are both dominated by far more gradual processes.

Molecularly Reconfigurable Neuroplasticity of Layered Artificial Synapse Electronics

AbstractBrain‐inspired electronics with multimodal signal processing have been investigated as the next‐generation semiconductor platforms owing to the limitations of von Neumann architecture, which limits data processing and energy consumption efficiencies. This study demonstrates the molecular reconfiguration of plasticity of artificial synaptic devices with tunable electric conductance based on molecular dynamics at the channel surfaces for realizing chemical multimodality. Carrier transport dynamics are adjusted using the density of trapped carriers for the molecular adsorption of HS in the MoSe2 channel, and the results are consistent with the molecular simulations. In molecular dynamics‐controlled devices, enhanced hysteresis enables the engineering of artificial neuroplasticity, mimicking the neurotransmitter release of biological synapses. Owing to the molecular reconfigurability of MoSe2 devices, the synaptic weights of excitatory and inhibitory synapse modes are significantly enhanced. Thus, this study can potentially contribute to the creation of the next generation of multimodal interfaces and artificial intelligence hardware realization.

Doxorubicin-Loaded Microalgal Delivery System for Combined Chemotherapy and Enhanced Photodynamic Therapy of Osteosarcoma.

Osteosarcoma (OS) is considered the most frequent type of primary malignant bone tumor. Currently, radiotherapy, photodynamic (PDT), and other therapies for osteosarcoma are limited by tumor hypoxia and single efficacy and serve side-effects. Herein, we reported a microalgal drug delivery system (SpiD), doxorubicin (DOX)-loaded Spirulina platensis (Spi) for OS therapy. The specific surface of Spirulina platensis allowed for effective loading of DOX via surface channels and electrostatic interactions. Under 650 nm laser irradiation, SpiD enabled high oxygen production by photosynthesis and enhanced reactive oxygen species (ROS) generation via chlorophyll-assisted photosensitization, synergistically killing tumor cells with the released DOX. Combined chemotherapy and enhanced PDT mediated by SpiD exerted synergic antitumor effects and resulted in potent therapeutic efficacy in orthotopic osteosarcoma mice. Furthermore, SpiD could reduce the side-effects of chemotherapy, showing excellent blood and tissue safety. Taken together, this microalgal drug delivery system provided a natural, efficient, safe, and inexpensive strategy for OS treatment.

Salt-resistant solar water desalination system via surface modification and configuration engineering

Floating solar water desalination systems have received a lot of attention since they are portable, low cost, environmentally friendly, and highly efficient. However, salt accumulation on the evaporation surface and water transfer channels is one of the main obstacle to the development of these systems. In this work, two strategies of surface modification and configuration engineering are focused on to make the devices salt-resistant. First, the system becomes salt-resistant by formation of a hydration layer on the water manager and light absorber surface through cross-linking of polyethylene glycol diacrylate. Remarkably, the surface-modified device shows a water evaporation rate of 1.34 kg.m−2.h−1 and a conversion efficiency of 91.75 % in artificial seawater. There is no salt accumulation on the evaporation surface of surface-modified devices after desalination in the simulated seawater. In the second strategy, the water transferring to the evaporation surface and water evaporation rate are balanced by tuning the number of water transport channels and location. The engineered device shows an evaporation rate of 0.98 kg.m−2.h−1 and an efficiency of 75.5 % in a high saline solution (20 wt% NaCl). Simultaneous surface modification and configuration engineering improve the salt resistivity, showing that the configuration should be engineered according to the water salinity.

Intrinsically Antifouling, soft and conformal bioelectronic from scalable fabrication of Thin-Film OECT arrays by zwitterionic polymers

Thin-film bioelectronic arrays, emerging as a new medical tool, offers significant opportunities for health monitoring, medical diagnosis, medical treatment, life science studies, etc. Thin film devices face several challenges, including biofouling which hinders targeted electrocoupling in complex biological environments, high surface Young's modulus that causes mechanical mismatches with biological matter, and poor surface adhesion that makes it difficult to conform to undeveloped biosurfaces. Here, we developed a universal lithography fabrication platform with high yield, uniformity, and precision to prepare a biomimetic thin-film organic electrochemical transistor (OECT) array featuring intrinsic biofouling resistance, tissue-like surface softness, and strong adhesion to undeveloped surfaces. This fabrication platform is based on the photolithography fabrication of zwitterionic-polymer-based conducting channels and hermetic encapsulation systems without compromising their electrical properties and low permeability. The all-zwitterionic feature softens the surface and helps prevent proteins and cells from approaching the encapsulation and channel surface, thus protecting the OECT array from interference from nonspecific protein and cell interactions. The strong capillary force from the hydrated zwitterions drives the thin-film device to conform well on nonplanar surfaces. Utilizing this biomimetic device, we successfully demonstrated cell-selective electrocoupling in the presence of white blood cells (WBCs) and simultaneously realized close and stable on-skin electrocardiogram (ECG) monitoring via good skin contact and robust epidermal surface lipid resistance. We envision that our process would provide a versatile platform for producing antifouling and flexible bioelectronic devices that seamlessly integrate with biological systems, and promote the practical application of thin-film bioelectronic arrays in real-life scenarios.

Research on Crack Propagation Mechanism of Silicon Nitride Ceramic Ball Bearing Channel Surface Based on Rolling Friction Experiment

The application feedback on existing silicon nitride ceramic bearings and RCF experimental research all indicate that the primary failure mode of silicon nitride ceramic bearings is material spalling on the contact surface. Spalling failure occurs due to the initiation and propagation of cracks under rolling contact. However, silicon nitride ceramic bearings, owing to their unique manufacturing method, inevitably exhibit defects and cracks. Therefore, as silicon nitride ceramic bearings are increasingly prevalent, reducing the probability of spalling failure is crucial for extending their service life. This can only be achieved by gaining a clear understanding of the crack initiation and expansion mechanisms in silicon nitride ceramic bearings. This paper is based on silicon nitride rolling friction experiments. It involves the joint simulation of Franc3D-V8.4 and ABAQUS2020, wherein the crack front SIFs are calculated for each load contact position of the surface crack on the silicon nitride ceramic bearing ring during cyclic movement. The study also delves into the determination of the maximum effective stress intensity factors and explores the influence of the initial crack depth on the cycle life and direction of crack propagation. The research yields several valuable conclusions. The findings of this research offer theoretical guidance for formulating grinding technologies for silicon nitride rings and adjusting and controlling working parameters of silicon nitride ceramic ball bearings. These insights are crucial for enhancing the reliability and longevity of silicon nitride ceramic bearings in practical applications.

Channel engineering strategy of precisely modified MOF/nanofiber composite separator for advanced aqueous zinc ion batteries

As the combination of metal-organic framework (MOF) materials with adjustable channels and flexible polymeric matrix, MOF/nanofiber composite separators enable the controllable ion transport behavior, which offers promising candidates for developing novel battery separators. In this study, series MOF functionalized electrospun polyacrylonitrile nanofiber separators were successfully developed via a precisely surface grafting strategy and then served as the separators for highly efficient aqueous zinc (Zn)-ion batteries (ZIBs). Moreover, channel engineering was developed by placing amino (MOF-N) and sulfonic acid groups (MOF-NS) on the channel surface of UIO-66, which then effectively promoted the ion transport progress. In particular, the resultant MOF-NS shows an excellent ionic conductivity (22.81 mS cm−1), improved Zn2+ transference number (0.78), and outstanding cyclic durability. These enhanced properties can be contributed by the effectively promoted dissociation of zinc salts and desolvation processes of hydrated Zn ions through strong ion-dipole interactions, as confirmed by the theoretical simulations. Our work demonstrates the great importance of channel engineering in modifying porous MOFs materials and the strong power of the precisely modified MOF/nanofiber separators in regulating ion transmission behavior and thus offers a promising separator candidate for high performance aqueous ZIBs.

On grazing scattering of a charged particle by a flat solid surface

The sliding motion of a quantum nonrelativistic charged particle near a flat surface of a solid body is considered within the framework of the effective potential approach, which consists of the interaction of the particle with surface atoms and excitations, i.e. within the framework of the so-called surface channeling formalism. We have demonstrated that the imaginary part of this potential is amenable to classical interpretation. A detailed analysis of the angular scattering of a positively charged particle is presented, including surface channeling requirements.

Numerical Study on Thermal Hydraulic and Flow-Induced Noise in Triply Periodic Minimal Surface (TPMS) Channels

Abstract Mini-channel heat exchanger are widely used due to their compact structures and high efficiency. Integrating heat exchangers with triply periodic minimal surfaces (TPMS) has shown great potential to optimize the flow and heat transfer performance. In this study, Gyroid (G), Diamond (D) and IWP type TPMS based heat exchangers are constructed in three dimensions. The thermal hydraulic, entropy production and flow-induced noise characteristics of TPMS based heat exchangers are numerically investigated. The results indicate that the TPMS channels with larger viscosity entropy production have smaller thermal entropy production due to the greater flow disturbance. The G-channel has the highest friction factor and the lowest sound source intensity, while the D-channel obtains the strongest sound source intensity due to frequent cross-collisions of the fluid. The sound source intensity of the IWP channel is 10% lower than the D-channel. The wall dipole sound source plays a dominant role in TPMS channels. This study provides different perspectives to evaluate the performance of a TPMS heat exchanger, and provides references for the design and optimization of TPMS heat exchangers.

Effect of Erosion on Surface Roughness and Hydromechanical Characteristics of Abrasive-Jet Machining

The article contains the fundamental results of the experimental and numerical investigations for pneumo-abrasive unit nozzles with different geometries. The research was purposed by the pressing need to develop an inexpensive and effective working nozzle design of the air-abrasive unit which can be applied for surface processing before some technological processes are performed, as well as for surface coating, descaling after thermal treatment, processing of hollow holes of the crankshafts, smoothing of the inner surfaces of the narrow channels between the impeller blades after electric discharge machining for ultrahigh-pressure combination compressors. Several designs were considered, ranging from the simplest to those with a complicated inner channel geometry. The impact of the nozzle material and challenging inner surface application on its characteristics has also been studied. The research was done using the application of modern CFD complexes for numerical modeling of the air-abrasive mixture discharge from the working nozzle of the pneumo-abrasive unit. In addition, physical experimentation was provided. The methods applied in the research allow for profound, systematic research of spraying units operating on the air-abrasive mixture within a wide range of geometrical and mode parameters. The novelty of the gained results lies in the development of the mathematical model of the pneumo-abrasive nozzle operating process, the working out of a cheaper nozzle design, getting information about air-abrasive mixture distribution along the nozzle length, giving practical recommendations for calculation and designing a working nozzle for the jet-abrasive unit.

Peristaltic flow of Williamson nanofluid on a rough surface

The aim of this current research is to investigate the peristaltic flow of Williamson nanofluid across a rough surface in a non-uniform channel under the influence of inclined magnetic field. The Joule heating and viscous dissipation effects are also retained in the current scrutiny. The objective of studying peristaltic flow of Williamson nanofluid on a rough surface is to gain insights into the complex fluid dynamics and heat transfer phenomena occurring in such systems. This knowledge can be used to design more efficient and effective nanofluid-based devices and processes. In the context of mathematical modeling, the appropriate dimensional nonlinear equations for momentum, heat and mass transport are simplified into dimensionless equation by applying the essential estimation of long wavelength and low Reynolds number. The equations subjected to boundary conditions have solved numerically by the Mathematica software built-in numerical Solver ND_solve method. Various essential physical characteristics on velocity, temperature and concentration are presented graphically in the end. It can be seen that fluid velocity decreases at the central part of the channel for the escalting values Hartman number M. As Darcy number Da increases then velocity profile increases at the core part of the channel and the walls of the channel experiencing an opposite behavior. It is noticed that Higher value of Eckert number Ec enhances the temperature profile. When Weissenberg number We gets stronger then temperature profile decreases. It is observed that the temperature and concentration profiles show an opposite behavior for the rising values of thermophoresis parameter [Formula: see text].

Increasing in technology of turbine channels by combined method

In this paper, we will talk about complex technological processes that combine the combined finishing and hardening treatment of the surfaces of the interblade channel of solid cast turbines with a second-order curvature and a twist along the radius. This method allows to improve manufacturability and achieve the desired design parameters.

Absolute calibration method of electron cyclotron emission imaging system on EAST tokamak

<sec>Electron cyclotron emission imaging (ECEI) system can provide the poloidal two-dimensional (2D) relative electron temperature perturbation profile of the core plasma with high spatial and temporal resolution. After absolute calibration of ECEI system, 2D absolute electron temperature profile and its perturbation can be provided. It can provide experimental data support for studying the local heat transport and the evolution of magnetic surface of macro magneto-hydro-dynamics instability. However, due to a large number of measurement channels and the wide measuring area of ECEI diagnostic system, the absolute calibration method in which a blackbody radiation source is used as a standard source, still has technical difficulties.</sec><sec>This paper provides an absolute calibration method of ECEI diagnostic system on EAST tokamak, which can cover all the channels of ECEI system. Firstly, the sawtooth inversion surface can be determined by measuring the relative electron temperature change before and after the collapse of the sawtooth. The magnetic surface position and the shape (<inline-formula><tex-math id="M1">\begin{document}${S_{{\text{inv}}}}$\end{document}</tex-math><alternatives><graphic specific-use="online" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20240497_M1.jpg"/><graphic specific-use="print" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="13-20240497_M1.png"/></alternatives></inline-formula>) of the ECEI measuring area are fitted based on the position and shape of the inversion surface. Then, the one-to-one mapping relationship between laboratory coordinates of each ECEI channel and magnetic surface is obtained. Secondly, according to the assumption that the electron temperature is the same on each magnetic surface in equilibrium, the electron temperature of each magnetic surface is fitted by the electron cyclotron emission (ECE) system result, while the ECE system is absolutely calibrated. The calibration coefficient <i>k</i>(<i>i</i>, <i>j</i>) of each ECEI channel is obtained by comparing with the signal amplitude and the electron temperature on the magnetic surface. The relative error of absolute electron temperature between ECEI and ECE is no more than 6% at the same location.</sec><sec>Based on the absolute electron temperature profile provided by ECEI, the motion of the magnetic axis during sawtooth instability can be tracked. It is found that the radial displacement of the magnetic axis occurs followed by the poloidal displacement during sawtooth collapse. This result indicates that after absolute calibration, the ECEI system can provide more abundant information about experimental research.</sec>

Analysis of GAAFET’s transient heat transport process based on phonon hydrodynamic equations

Compared to the classical Fourier’s law, the phonon hydrodynamic model has demonstrated significant advantages in describing ultrafast phonon heat transport at the nanoscale. The gate-all-around field-effect transistor (GAAFET) greatly optimizes its electrical performance through its three-dimensional channel design, but its nanoscale characteristics also lead to challenges such as self-heating and localized overheating. Therefore, it is of great significance to study the internal heat transport mechanism of GAAFET devices to obtain the thermal process and heat distribution characteristics. Based on this, this paper conducts theoretical and numerical simulation analyses on the phonon heat transfer characteristics within nanoscale GAAFET devices. Firstly, based on the phonon Boltzmann equation, the phonon hydrodynamic model and boundary conditions are rigorously derived, establishing a numerical solution method based on finite elements. For the novel GAAFET devices, the effects of factors such as surface roughness, channel length, channel radius, gate dielectric, and interface thermal resistance on their heat transfer characteristics are analyzed. The research results indicate that the larger the surface roughness, the smaller the channel length and the channel radius, the larger the interface thermal resistance leads to the higher hot spot peak temperature. The non-Fourier heat analysis method based on the phonon hydrodynamic model and temperature jump condition within the continuous medium framework constructed in this paper can accurately predict the non-Fourier phonon heat conduction process inside GAAFET and reveal the mechanisms of resistive scattering and phonon/interface scattering. This work provides important theoretical support for further optimizing the thermal reliability design of GAAFET, improving its thermal stability, and operational performance.

Diffusioosmotic flow reversals due to ion-ion electrostatic correlations.

Existing theories of diffusioosmosis have neglected ion-ion electrostatic correlations, which are important in concentrated electrolytes. Here, we develop a mathematical model to numerically compute the diffusioosmotic mobilities of binary symmetric electrolytes across low to high concentrations in a charged parallel-plate channel. We use the modified Poisson equation to model the ion-ion electrostatic correlations and the Bikerman model to account for the finite size of ions. We report two key findings. First, ion-ion electrostatic correlations can cause a unique reversal in the direction of diffusioosmosis. Such a reversal is not captured by existing theories, occurs at ≈ 0.4 M for a monovalent electrolyte, and at a much lower concentration of ≈ 0.003 M for a divalent electrolyte in a channel with the same surface charge. This highlights that diffusioosmosis of a concentrated electrolyte can be qualitatively different from that of a dilute electrolyte, not just in its magnitude but also its direction. Second, we predict a separate diffusioosmotic flow reversal, which is not due to electrostatic correlations but the competition between the underlying chemiosmosis and electroosmosis. This reversal can be achieved by varying the magnitude of the channel surface charge without changing its sign. However, electrostatic correlations can radically change how this flow reversal depends on the channel surface charge and ion diffusivity between a concentrated and a dilute electrolyte. The mathematical model developed here can be used to design diffusioosmosis of dilute and concentrated electrolytes, which is central to applications such as species mixing and separation, enhanced oil recovery, and reverse electrodialysis.

Investigation of Motor Units Activity: Comparison of Single Channel Surface EMG Deconvolution and Blind Source Separation of Multichannel Data

Investigation of Motor Units Activity: Comparison of Single Channel Surface EMG Deconvolution and Blind Source Separation of Multichannel Data

Evaluation of Side Spillway Cavitation of Krueng Kluet Dam Using Computational Fluid Dynamic

Dam construction provides benefits to improve socio-economic status through the availability of food self-sufficiency, irrigation, conservation efforts, hydropower, flood control, and many other benefits to the community around the development. Before the construction process is carried out, a study is needed to present the flow behavior at side spillway of the dam to be safe against hydraulic failure, namely cavitation. The safety evaluation of this dam was carried out on the Krueng Kluet Dam located in South Aceh Regency, Aceh Province, using computational fluid dynamics. The method used in this study is a calculation of analysis from the results of numerical modeling at Krueng Kluet Dam with a discharge flow of Q1000. Cavitation analysis takes flow velocity and pressure data on the side spillway. Results show that crest of the spillway, side channels, and transition channels are safe from cavitation damage. In chute channel, cavitation damage occurs at distances of 450-465 m, 485-505 m, and 560-580 m. This cavitation arises due to a considerable negative static pressure value that can erode the channel surface slowly. A design to prevent cavitation is installing an aerator on chute channel or building a sill on transition channel at a distance of 430 m.

Advances in nanofluidic field-effect transistors: external voltage-controlled solid-state nanochannels for stimulus-responsive ion transport and beyond.

Ion channels, intricate protein structures facilitating precise ion passage across cell membranes, are pivotal for vital cellular functions. Inspired by the remarkable capabilities of biological ion channels, the scientific community has ventured into replicating these principles in fully abiotic solid-state nanochannels (SSNs). Since the gating mechanisms of SSNs rely on variations in the physicochemical properties of the channel surface, the modification of their internal architecture and chemistry constitutes a powerful strategy to control the transport properties and, consequently, render specific functionalities. In this framework, both the design of the nanofluidic platform and the subsequent selection and attachment of different building blocks gain special attention. Similar to biological ion channels, functional SSNs offer the potential to finely modulate ion transport in response to various stimuli, leading to innovations in a variety of fields. This comprehensive review delves into the intricate world of ion transport across stimuli-responsive SSNs, focusing on the development of external voltage-controlled nanofluidic devices. This kind of field-effect nanofluidic technology has attracted special interest due to the possibility of real-time reconfiguration of the ion transport with a non-invasive strategy. These properties have found interesting applications in drug delivery, biosensing, and nanoelectronics. This document will address the fundamental principles of ion transport through SSNs and the construction, modification, and applications of external voltage-controlled SSNs. It will also address future challenges and prospects, offering a comprehensive perspective on this evolving field.

Grazing incidence fast atom diffraction: general considerations, semiclassical perturbation theory and experimental implications.

Using semiclassical methods, an analytical approach to describe grazing incidence scattering of fast atoms (GIFAD) from surfaces is described. First, we consider a model with a surface corrugated in the scattering plane, which includes the surface normal and the incidence direction. The treatment uses a realistic, Morse potential, within a perturbation approach, and correctly reproduces the basic GIFAD phenomenology, whereby the scattering is directed primarily in the specular direction. Second, we treat the more general case of scattering from a surface corrugated in two-dimensions. Using time averaging along the direction of fast motion in the incidence direction, we derive a time dependent potential for the GIFAD scattering away from a low index direction. The results correctly describe the observation that diffraction is seen only when the scattering plane is aligned close to a low-index direction in the surface plane. For the case of helium scattering from LiF(001) we demonstrate that the resulting theoretical predictions agree well with experiment and show that the analysis provides new information on the scattering time and the length scale of the interaction. The analysis also gives insights into the validity of the axial surface channeling approximation (ASCA) and shows that within first order perturbation theory, along a low-index direction, the full 3-dimensional problem can be represented accurately by an equivalent 2-dimensional problem with a potential averaged along the third dimension. In contrast, away from low-index directions, the effective 2-dimensional potential in the projectile frame is time-dependent.