Array Of Channels Research Articles

Mitigating Pass Gate Effect in Buried Channel Array Transistors Through Buried Oxide Integration: Addressing Interference Phenomenon Between Word Lines

As semiconductor devices become smaller, their performance and integration density improve, but new negative effects emerge due to the reduced distance between structures. In DRAM, these effects can lead to data loss or require additional refresh cycles, causing performance degradation. Specifically, in the 6F2 DRAM structure, activating a word line (WL) lowers the energy barrier of adjacent WLs, leading to the Pass Gate Effect (PGE). This study investigates the use of buried oxide beneath the WL to mitigate the PGE through simulation. Using SILVACO TCAD, we analyzed the impact of varying the size and position of the buried oxide on the PGE. The results showed that increasing the oxide size or reducing the distance to the WL effectively reduced the PGE. However, the presence of interface traps, which increase with the addition of buried oxide, was found to exacerbate the PGE, indicating that minimizing interface traps is crucial when incorporating buried oxide.

Combining array-assisted SERS microfluidic chips and machine learning algorithms for clinical leukemia phenotyping

The disease progression and treatment options of leukemia between different subtypes vary considerably, emphasizing the importance of phenotyping. However, early typing of leukemia remains challenging due to the lack of highly sensitive and specific analytical tools. Herein, we propose a SERS-based platform for the classification of acute lymphoblastic T-cell leukemia (T-ALL) and chronic myeloid leukemia (CML) through the combination of machine learning and microfluidic chips. The ordered arrays in microfluidic channels reshape the microscopic flow field and contacting interfaces, facilitating the uniform and efficient capture of tumor cells. To enable phenotypic analysis, spectrally orthogonal SERS aptamer nanoprobes were applied, providing composite spectral signatures of individual cells in accordance with surface protein expression. Further, machine learning algorithms were employed to analyze the SERS signatures automatically, resulting in an accuracy of 98.6 % for 73 clinical blood samples. The results demonstrate that this platform holds promising potential for clinical leukemia diagnosis and precision medicine.

Axon Initial Segment Structure and Function in Health and Disease.

At the simplest level, neurons are structured to integrate synaptic input and perform computational transforms on that input, converting it into an action potential (AP) code. This process-converting synaptic input into AP output-typically occurs in a specialized region of axon termed the axon initial segment (AIS). The AIS, as its name implies, is often contained to the first section of axon abutted to the soma and is home to a dizzying array of ion channels, attendant scaffolding proteins, intracellular organelles, extracellular proteins, and, in some cases, synapses. The AIS serves multiple roles as the final arbiter for determining if inputs are sufficient to evoke APs, as a gatekeeper that physically separates the somatodendritic domain from the axon proper, and as a regulator of overall neuronal excitability, dynamically tuning its size to best suit the needs of parent neurons. These complex roles have received considerable attention from experimentalists and theoreticians alike. Here, we review recent advances in our understanding of the AIS and its role in neuronal integration and polarity in health and disease.

Large improvement in RF magnetic fields and imaging SNR with whole-head high-permittivity slurry helmet for human-brain MRI applications at 7 T.

To optimize the design and demonstrate the integration of a helmet-shaped container filled with a high-permittivity material (HPM) slurry with RF head coil arrays to improveRF coil sensitivity and SNR for human-brain proton MRI. RF reception magneticfields ( ) of a 32-channel receive-only coil array with various geometries and permittivity values of HPM slurry helmet are calculated with electromagnetic simulation at 7 T. A 16-channel transmit-only coil array, a 32-channel receive-only coil array, and a 2-piece HPM slurry helmet were constructed and assembled. RF transmission magnetic field ( ), , and MRI SNR maps from the entire human brain were measured and compared. Simulations showed that averaged improvement with the HPM slurry helmet increased from 57% to 87% as the relative permittivity (εr) of HPM slurry increased from 110 to 210. In vivo experiments showed that the average improvement over the human brain was 14.5% with the two-piece HPM slurry (εr ≈ 170) helmet, and the average and SNR were improved 63% and 34%, respectively, because the MRI noise level was increased by the lossy HPM. The RF coil sensitivity and MRI SNR were largely improved with the two-piece HPM slurry helmet demonstrated by both electromagnetic simulations and in vivo human head experiments at 7 T. The findings demonstrate that incorporating an easily producible HPM slurry helmet into the RF coil array significantly enhances human-brain MRI SNRhomogeneity and quality at ultrahigh field. Greater SNR improvement is anticipated using the less lossy HPM and optimal design.

Phase-cancellation of velocity oscillations in a flow duct using a slow-sound metamaterial

Self-sustained acoustic oscillations in industrial systems with mean flow can cause unwanted vibrations or noise pollution. Acoustic metamaterials can be engineered and integrated in such systems to prevent these limit cycles. In this study, an acoustic metamaterial is proposed for decreasing the acoustic admittance at the outlet of a contraction in a pipe. It can reduce velocity oscillations by more than 50%, without requiring an enlargement of the pipe or increasing the static resistance to the mean flow significantly. The acoustic metamaterial consists of an array of slow-sound and regular channels, which form a contraction in a pipe. The slow-sound effect shifts the resonances of the respective slow-sound channels. For the frequency of interest, the velocity oscillations of these two types of channels are out of phase, which reduces the spatially averaged velocity oscillations at the outlet of the contraction and therefore decreases its acoustic admittance. The effect is demonstrated experimentally, using impedance measurements and particle image velocimetry. A key achievement of this work is the demonstration of a device that is nearly lossless for the mean (steady) flow, i.e. having a low pressure drop, while being very stiff for the acoustic (oscillating) flow at its nominal working frequency, i.e. low admittance, which was so far a difficult challenge to address.

Multi-Cluster Approaches to Radio Sensor Array Channel Modeling and Simulation.

In this paper, we explore the physical propagation environment of radio waves by describing it in terms of distant scattering clusters. Each cluster consists of numerous scattering objects that may exhibit certain statistical properties. By utilizing geometry-based methods, we can study the channel second-order statistics (CSOS), where each distant scattering cluster corresponds to a CSOS, contributes a portion to the Doppler spectrum, and is associated with a state-space multiple-input and multiple-output (MIMO) radio channel model. Consequently, the physical propagation environment of radio waves can be modeled by summing multiple state-space MIMO radio channel models. This approach offers three key advantages: simplicity, the ability to construct the entire Doppler power spectrum from multiple uncorrelated distant scattering clusters, and the capability to obtain the channels contributed by these clusters by summing the individual channels. This methodology enables the reconstruction of the radio wave propagation environment in a simulated manner and is crucial for developing massive MIMO channel models.

Cu2Cl(OH)3 nanozyme-based colorimetric sensor array for phosphates discrimination and disease identification

The identification of phosphates holds significant importance in many physiological processes and disease diagnosis, and traditional detection techniques struggle to simultaneously detect and distinguish phosphates. The complexity of synthesizing sensing units restricts the construction of sensor arrays as well. In this study, a bifunctional dicopper chloride trihydroxide (Cu2Cl(OH)3) nanozyme with conspicuous laccase- and peroxidase-like activities has been synthesized in basic deep eutectic solvents (DES). Exploiting the various regulatory impacts of multiple phosphates on the dual-enzyme mimicking activities, the sensor array based on the laccase mimic and peroxidase mimic properties of Cu2Cl(OH)3 was designed, which has been successfully harnessed for the identification of eight phosphates (ATP, ADP, AMP, PPi, Pi, GTP, GDP, and GMP). This approach streamlines the creation of sensor arrays. Besides, the three simulated actual samples (healthy individuals, moderately ill patients, and severely ill patients) have been accurately distinguished. This work makes a substantial contribution to enhancing the highly effective construction of array channels and promoting discrimination of phosphates in intricate samples.

Enhanced 3D Magnetic Resonance Cholangiopancreatography with Fast Gradient and Spin Echo Sequence: Technical Advancements and Clinical Implications

Objective: The application of fast gradient and spin echo (GRASE) sequence in 3D magnetic resonance cholangiopancreatography (MRCP) was investigated. Methods: Sixty patients who underwent 3D MRCP examination using the Philips Ingenia 3.0T superconducting MR imaging system and a 32-channel phased array direct digital RF receiving coil in the hospital from June 2021 to June 2023 were selected. The acquisition times of the two sequences were compared, and the scanned images of the two sequences were subjectively and objectively evaluated, with the scanning sequence including turbo spin echo (TSE) sequence and GRASE sequence. Results: The display scores, image artifact scores, and overall image quality scores of the GRASE sequence on the common bile duct, gallbladder duct, main pancreatic duct, left and right hepatic ducts were higher than those of the TSE sequence, and the differences were statistically significant (P<0.05). The acquisition time of GRASE sequence was 16 seconds, which was about 96% shorter than that of TSE sequence (399.06±84.53) seconds. The contrast to noise ratio (CNR) of the GRASE sequence was higher than that of the TSE sequence, and the difference was statistically significant (P < 0.05); The signal to noise ratio (SNR) of the GRASE sequence was slightly higher than that of the TSE sequence, but the difference was not statistically significant (P > 0.05). Conclusion: The use of the GRASE sequence in 3D MRCP examinations can improve image quality, shorten acquisition time, and ensure CNR.

Nanofibrous textured silk aerogel with 3D channel arrays and adjustable mechanical properties for bone tissue regeneration

Bone tissue engineering scaffolds are an important means of repairing bone defects, but current solutions do not adequately simulate complex extracellular microenvironment fibrous structures and adjustable mechanical properties. We use template-assisted fiber freeze-shaping technology to construct silk fibroin nanofiber aerogels (SNFAs) with nanofibrous textures and adjustable mechanical properties. The parallel arranged channels, the pores, electrospun nanofibers, and silk protein conformation together constitute the hierarchical structure of SNFAs. Especially, the introduced electrospun nanofibers formed a biomimetic nanofibrous texture similar to the extracellular matrix, providing favorable conditions for cell migration and tissue regeneration. In addition, Young's modulus of SNFAs can be adjusted freely between 7 and 88 kPa. The rationally designed 3D architecture makes SNFAs perfectly mimic the fiber structure of the extracellular matrix and can adjust its mechanical properties to match the bone tissue perfectly. Finally, fiber-containing SNFAs observably promoted cell adhesion, proliferation, and differentiation, accelerating the bone repair process. The bone density in the defect area reached 0.53 g/cm3 and the bone volume/total volume (BV/TV) ratio reached 57 % at 12 weeks, respectively. It can be expected that this kind of tissue engineering scaffold with highly simulating extracellular matrix microenvironment and adjustable mechanical properties will possess broad prospects in the field of bone repair.

Si Nanorod Array Integrated Microfluidic Device for Enhanced Extracellular Vesicle Isolation

AbstractTumor‐derived extracellular vesicles (EVs) have attracted tremendous interest as one of the early cancer diagnostic markers. The major obstacle preventing EV‐based liquid biopsy is the efficient collection of EVs from the complex body fluid environment. This paper introduces a nanorod‐integrated microfluidic chip capable of immunoaffinity‐isolating EVs. Periodic silicon nanorod arrays in zigzag channels are prepared by nanosphere lithography. Nanorod sidewalls provide larger binding sites for antibodies, and their close interspacing to the EV sizes improves the binding probability. The fluid simulation results show that the significant increase in isolation efficiency also comes from the liquid perturbation enhanced by the particular nanorod arrangement. Under optimal operating conditions, plasma samples from patients (n = 14) with different types of cancers (hepatocellular carcinoma, colorectal cancer, and pancreatic adenocarcinoma) to the chip for EV isolation is applied. In this proof‐of‐concept study, the expression level of the epidermal growth factor receptor (EGFR) in isolated EVs is then quantified using droplet digital PCR, showing good diagnostic performance in cancer detection.

Three-dimensional MXene/carbon nanotube composite electrodes in flexible 64-channel arrays for noninvasive electromyography signal acquisition

Three-dimensional MXene/carbon nanotube composite electrodes in flexible 64-channel arrays for noninvasive electromyography signal acquisition

Central vein sign and trigeminal lesions of multiple sclerosis visualised by 7T MRI

BackgroundAlthough trigeminal nerve involvement is a characteristic of multiple sclerosis (MS), its prevalence across studies varies greatly due to MRI resolution and cohort selection bias. The mechanism behind the site...

Aptamer Encapsulated Inside the Array Channel of Ni‐MOF for Bisphenol A Determination in Multi‐interference System

AbstractAs an endocrine disruptor, bisphenol A (BPA) has many adverse effects on environmental safety and human health. Aiming at the existing problems at the current detection methods, herein, a 3D metal‐organic framework (Ni‐MOF) was fabricated as a carrier to achieve BPA aptamers immobilization inside its array channels under Mg2+ regulation. Based on the reversible quenching of 6‐FAM (6‐carboxyfluorescein) fluorescence labeled on the BPA aptamers during the encapsulation process, a fluorescent aptamer sensing platform was constructed for the quantitative detection of BPA in water. Morphology analysis, VASP (Vienna ab‐initio simulation package) and other kinetic simulations were performed to elaborate the mechanism of the influence of pore size, medium ions, etc. on the recognition process. Due to the in‐hole fixation strategy of aptamers, Ni‐MOF played an obvious protection aptamers. Not only the activity of BPA aptamer@MOF composite was maintained more than 50 % in complex environments such as pH 3.0–11.0, 30–70 °C and organic solvents, but also the aptamer was protected from nuclease hydrolysis under physiological conditions. The stability and application range of the sensor are greatly improved, detection limit of 0.34 μM. The result was expected to provide theoretical guidance for the rapid detection of pollutants in complex environments.

Pressurized water reactor fuel corrosion-related unidentified deposit and its related safety issues – I. Corrosion product deposition and heat transfer

CRUD depositions on fuel cladding are the main cause of power shift and localized corrosion in nuclear power plants. This paper is the first of a three-part study concerning the formation mechanism of CRUD depositions and its related heat transfer issues. In this paper, CRUD depositions are obtained under subcooled boiling conditions in 2 × 2 rod array channels via accelerated deposition method to explore corrosion product deposition and its feedback on heat transfer. Imbalance of deposition and erosion at initial stage causes fouling resistance to increase first and then decrease. CRUD growth is proposed as a relatively pure fouling process combining soluble precipitation and particulate aggregation. Through high-resolution characterizations, boiling chimney diameters span from 3 μm to a dozen microns. Principal components are nickel ferrite and nickel elemental with Fe/Ni ratio of 1.9:1. Static contact angle decreases to less than 30°. Effective CRUD thermal conductivity decreases with the increase of heat flux with 1.3866 W/(m × K) on average. The results of this study provide a precise method for understanding corrosion product deposition and its impact on heat transfer to further establish accurate CRUD-related models and predict CRUD-related safety issues.

Multiphoton parallel transmission (MP-pTx): Pulse design methods and numerical validation.

We propose and evaluate multiphoton parallel transmission (MP-pTx) to mitigate flip angle inhomogeneities in high-field MRI. MP-pTx is an excitation method that utilizes a single, conventional birdcage coil supplemented with low-frequency (kHz) irradiation from a multichannel shim array and/or gradient channels. SAR analysis is simplified to that of a conventional birdcage coil, because only the radiofrequency (RF) field from the birdcage coil produces significant SAR. MP-pTx employs an off-resonance RF pulse from a conventional birdcage coil supplemented with oscillating -directed fields from a multichannel shim array and/or the gradient coils. We simulate the ability of MP-pTx to create uniform nonselective brain excitations at 7 T using realistic and field maps. The RF, shim array, and gradient waveform's amplitudes and phases are optimized using a genetic algorithm followed by sequential quadratic programming. A 1 ms MP-pTx excitation using a 32-channel shim array with current constrained to less than 50 Amp-turns reduced the transverse magnetization's normalized root-mean-squared error from 29% for a conventional birdcage excitation to 6.6% and was nearly 40% better than a 1 ms birdcage coil 5 kT-point excitation with optimized kT-point locations and comparable pulse power. The MP-pTx method resembles conventional pTx in its goals and approach but replaces the parallel RF channels with cheaper, low-frequency shim channels. The method mitigates high-field flip angle inhomogeneities to a level better than 3 T CP-mode and comparable to 7 T pTx while retaining the straightforward SAR characteristics of conventional birdcage excitations, as low-frequency shim array fields produce negligible SAR.

Stakeholders' views on the global guidelines for the sustainable use of non‐native trees

Abstract A large number of non‐native trees (NNTs) have been introduced globally and widely planted, contributing significantly to the world's economy. Although some of these species present a limited risk of spreading beyond their planting sites, a growing number of NNTs are spreading and becoming invasive leading to diverse negative impacts on biodiversity, ecosystem functions and human well‐being. To help minimize the negative impacts and maximize the economic benefits of NNTs, Brundu et al. developed eight guidelines for the sustainable use of NNTs globally—the Global Guidelines for the Use of NNTs (GG‐NNTs). Here, we used an online survey to assess perceptions of key stakeholders towards NNTs, and explore their knowledge of and compliance with the GG‐NNTs. Our results show that stakeholders are generally aware that NNTs can provide benefits and cause negative impacts, often simultaneously and they consider that their organization complies with existing regulations and voluntary agreements concerning NNTs. However, they are not aware of or do not apply most of the eight recommendations included in the GG‐NNTs. We conclude that effectively managing invasions linked to NNTs requires both more communication efforts using an array of channels for improving stakeholder awareness and implementation of simple measures to reduce NNT impacts (e.g. via GG‐NNTs), and a deeper understanding of the barriers and reluctance of stakeholders to manage NNT invasions. Read the free Plain Language Summary for this article on the Journal blog.

Indirect 1H-[13C] MRS of the human brain at 7 T using a 13C-birdcage coil and eight transmit-receive 1H-dipole antennas with a 32-channel 1H-receive array.

The neuronal tricarboxylic acid and glutamate/glutamine (Glu/Gln) cycles play important roles in brain function. These processes can be measured in vivo using dynamic 1H-[13C] MRS during administration of 13C-labeled glucose. Proton-observed carbon-edited (POCE) MRS enhances the signal-to-noise ratio (SNR) compared with direct 13C-MRS. Ultra-high field further boosts the SNR and increases spectral dispersion; however, even at 7 T, Glu and Gln 1H-resonances may overlap. Further gain can be obtained with selective POCE (selPOCE). Our aim was to create a setup for indirect dynamic 1H-[13C] MRS in the human brain at 7 T. A home-built non-shielded transmit-receive 13C-birdcage head coil with eight transmit-receive 1H-dipole antennas was used together with a 32-channel 1H-receive array. Electromagnetic simulations were carried out to ensure that acquisitions remained within local and global head SAR limits. POCE-MRS was performed using slice-selective excitation with semi-localization by adiabatic selective refocusing (sLASER) and stimulated echo acquisition mode (STEAM) localization, and selPOCE-MRS using STEAM. Sequences were tested in a phantom containing non-enriched Glu and Gln, and in three healthy volunteers during uniformly labeled 13C-glucose infusions. In one subject the voxel position was alternated between bi-frontal and bi-occipital placement within one session. [4-13C]Glu-H4 and [4-13C]Gln-H4 signals could be separately detected using both STEAM-POCE and STEAM-selPOCE in the phantom. In vivo, [4,5-13C]Glx could be detected using both sLASER-POCE and STEAM-POCE, with similar sensitivities, but [4,5-13C]Glu and [4,5-13C]Gln signals could not be completely resolved. STEAM-POCE was alternately performed bi-frontal and bi-occipital within a single session without repositioning of the subject, yielding similar results. With STEAM-selPOCE, [4,5-13C]Glu and [4,5-13C]Gln could be clearly separated. We have shown that with our setup indirect dynamic 1H-[13C] MRS at 7 T is feasible in different locations in the brain within one session, and by using STEAM-selPOCE it is possible to separate Glu from Gln in vivo while obtaining high quality spectra.

Method for measuring radiation patterns of digital antenna arrays

Formulation of the problem. The Digital Beamforming Antenna Arrays (DBAA) are widely used as the directional antennas in radio systems today. However, such arrays typically do not have a radiofrequency output. Consequently, the standard methods for measuring the Radiation Patterns (RP), based on the transmitting of a monochromatic probing signals, reception of the signals in the far field, as well as measuring the output power of the antenna array, cannot be used to measure the RP of the DBAA. The method considered in this work involves the transmitting a probing signal modulated by a pseudonoise sequence and processing the DBAA output signal at the zero intermediate frequency (base-band) using a matched filter or a correlator. Target. A method for measuring the radiation pattern of the DBAA is considered, based on the correlation processing of its output signal. Results. The paper presents a description of the setup for measuring the DBAA RP, as well as a mathematical explanation of the measurement procedure. It is shown that the accuracy of the RP measurement depends on the Signal-to-Noise Ratio (SNR) at the outputs of the receivers of the DBAA channels, and the number of array channels and the number of symbols of the pseudonoise sequence used for the modulation of the radiated signal. The error in the RP measurement decreases by 3 dB each time as the number of the DBAA channels or the number of symbols of the pseudonoise sequence used in the measurements is doubled. This result is confirmed by simulation the measurement of RP of the eight- and sixteen-channel linear DBAA using pseudo-noise sequences of maximum length (M-sequences) with a number of symbols equal to 1023 and 2047. Practical significance. The proposed method does not require the usage of the up-converter to convert the base-band DBAA output signal from the base-band to a carrier frequency, and it also does not require the usage of a power meter for measurement the analog signal at the output of this converter.

α-Latrotoxin Tetramers Spontaneously Form Two-Dimensional Crystals in Solution and Coordinated Multi-Pore Assemblies in Biological Membranes.

α-Latrotoxin (α-LTX) was found to form two-dimensional (2D) monolayer arrays in solution at relatively low concentrations (0.1 mg/mL), with the toxin tetramer constituting a unit cell. The crystals were imaged using cryogenic electron microscopy (cryoEM), and image analysis yielded a ~12 Å projection map. At this resolution, no major conformational changes between the crystalline and solution states of α-LTX tetramers were observed. Electrophysiological studies showed that, under the conditions of crystallization, α-LTX simultaneously formed multiple channels in biological membranes that displayed coordinated gating. Two types of channels with conductance levels of 120 and 208 pS were identified. Furthermore, we observed two distinct tetramer conformations of tetramers both when observed as monodisperse single particles and within the 2D crystals, with pore diameters of 11 and 13.5 Å, suggestive of a flickering pore in the middle of the tetramer, which may correspond to the two states of toxin channels with different conductance levels. We discuss the structural changes that occur in α-LTX tetramers in solution and propose a mechanism of α-LTX insertion into the membrane. The propensity of α-LTX tetramers to form 2D crystals may explain many features of α-LTX toxicology and suggest that other pore-forming toxins may also form arrays of channels to exert maximal toxic effect.

Experiment study on focusing pattern prediction of particles in asymmetric contraction-expansion array channel.

Contraction-expansion array (CEA) microchannel is a typical structure applied on particle/cell manipulation. The prediction of the particle focusing pattern in CEA microchannel is worthwhile to be investigate deeply. Here, we demonstrated a virtual boundary method by flow field analysis and theoretical derivation. The calculating method of the virtual boundary location, related to the Reynolds number (Re) and the structure parameter RW, was proposed. Combining the approximate Poiseuille flow pattern based on the virtual boundary method with the simulation results of Dean flow, the main line pattern and the main/lateral lines pattern were predicted and validated in experiments. The transformation from the main line pattern to the main/lateral lines pattern can be facilitated by increasing Re, decreasing RW , and decreasing α. An empirical formula was derived to characterize the critical condition of the transformation. The virtual boundary method can provide a guidance for asymmetric CEA channel design and contribute to the widespread application of microfluidic particle focusing.