Search Results (18)

Background/Objectives: Obesity and related metabolic diseases arise from an interplay of lipid overload, insulin resistance and oxidative stress. Acetyl-CoA carboxylase 2 (ACC2) controls malonyl-CoA production and thereby gates mitochondrial fatty-acid oxidation, placing it at the intersection of lipid handling and redox-sensitive metabolic dysfunction. Dietary antioxidants such as polyphenols, flavonoids and terpenoids are increasingly studied as modulators of these pathways, yet systematic prioritization of food-derived antioxidant compounds against defined metabolic targets remains challenging. We developed an integrated deep learning and structure-based workflow to prioritize FooDB compounds with predicted ACC2-binding potential. Methods: A curated set of 3983 ACC2 bioactivity records from ChEMBL 36 was used to train scaffold-split models, including graph neural-network and graph–Morgan fingerprint-fusion architectures. The calibrated ensemble screened 139,988 FooDB compounds; 200 candidates with predicted activity probability above 0.70 were docked against the ACC2 carboxyltransferase domain (PDB ID: 3FF6), and six prioritized complexes underwent 500 ns molecular dynamics and MM/GBSA analysis. Results: Redocking of the co-crystallized ligand reproduced the experimental pose (RMSD 1.2 Å). Although the highest-ranked screening hits were antioxidant terpenoids and alkaloids, docking-based prioritization from the top candidates selected six larger, more polar food-derived compounds, including glycosides and two nucleotide/cofactor-like conjugates, which showed docking scores from −7.47 to −6.65 kcal/mol versus −6.21 kcal/mol for the reference ligand. Glu539 emerged as a recurrent interaction hotspot. All candidates gave more favourable MM/GBSA binding free energies than the reference (ΔG = −22.52 kcal/mol), led by FDB029596 (−35.65), FDB021568 (−34.14) and FDB017807 (−33.87 kcal/mol). Conclusions: This workflow provides a reproducible framework for prioritizing food-derived compounds as candidate ACC2 binders relevant to obesity and metabolic disease, generating structurally supported hypotheses for biochemical and nutritional validation. The prioritized compounds are computational candidates only and require biochemical and cellular (experimental) validation before any ACC2-related biological relevance can be established. Full article

The development of novel information-functional devices based on emergent physical phenomena is crucial for integrated circuit technology in the post-Moore era. Two-dimensional magnetic materials present an ideal platform for spintronic devices; however, regulating their room temperature magnetism poses significant challenges. Traditional methods like ionic liquid gating and strain control face issues such as poor stability and complex processes, complicating compatibility with standard silicon technology. Here, we demonstrate a straightforward and robust approach for dielectric layer-engineered room temperature ferromagnetism in 2D metallic magnets by leveraging metal–insulator–semiconductor (MIS) structures. Using surface-oxidized Fe₃GeTe₂ as a model system, we systematically investigate how SiO_x dielectric layer thickness (50–300 nm) modulates magnetic properties. Thin dielectric layers significantly enhance room temperature ferromagnetism through boosted interfacial charge transfer, whereas thick layers maintain the material near its intrinsic state due to dielectric screening effects. Furthermore, reversible optical modulation of magnetism is achieved under ultraviolet illumination, with photoresponse capability diminishing as dielectric thickness increases. This work establishes a scalable, silicon-compatible strategy for controlling 2D magnetism and provides critical insights for developing optically tunable spintronic devices and non-volatile memory applications. Full article

Electrochemical sensing arrays enable the spatial study of dopamine levels throughout brain slices, the diffusion of electroactive molecules, as well as neurotransmitter secretion from single cells. The integration of complementary metal-oxide semiconductor (CMOS) devices in the development of electrochemical sensing devices enables large-scale parallel recordings, providing beneficial high-throughput for drug screening studies, brain–machine interfaces, and single-cell electrophysiology. In this paper, an electrochemical sensor capable of recording at 40,000 frames per second using a CMOS sensor array with 1024 electrochemical detectors and a custom field-programmable gate array data acquisition system is detailed. A total of 1024 on-chip electrodes are monolithically integrated onto the designed CMOS chip through post-CMOS fabrication. Each electrode is paired with a dedicated transimpedance amplifier, providing 1024 parallel electrochemical sensors for high-throughput studies. To support the level of data generated by the electrochemical device, a powerful data acquisition system is designed to operate the sensor array as well as digitize and transmit the output of the CMOS chip. Using the presented electrochemical sensing system, both dopamine and hydrogen peroxide diffusions across the sensor array are successfully recorded at 40,000 frames per second across the 32 × 32 electrochemical detector array. Full article

This paper presents a method to recover the negative threshold voltage shift during high field gate oxide screening of 1.2 kV 4H-SiC MOSFETs with an additional adjustment gate voltage pulse. To reduce field failure rates of the MOSFETs in operation, manufacturers perform a screening treatment to remove devices with extrinsic defects in the oxide. Current gate oxide screening procedures are limited to oxide fields at or below ~9 MV/cm for short durations (<1 s), which is not enough to remove all the devices with extrinsic defects. The results show that by implementing a lower field gate pulse, the threshold voltage shift can be partially recovered, and therefore the maximum screening field and time can be increased. However, both the initial screening pulse and the adjustment pulse require careful calibration to prevent significant degradation of the device threshold voltage, on-resistance, interface state density, or intrinsic lifetime. With a well calibrated set of pulses, higher screening fields can be utilized without significantly damaging the devices. This leads to an improvement in the overall screening efficiency of the process, reducing the number of devices with extrinsic oxide defects entering the field, and improving the reliability of the SiC MOSFETs in operation. Full article

This work introduces a novel temperature-triggered threshold voltage shift (T3VS) method to study the energy-dependent $D_{it}$ distribution close to the conduction band edge in commercial 1.2 kV 4H-SiC MOSFETs with planar and trench gate structures. Traditional $D_{it}$ extraction methodologies are complicated and require sophisticated instrumentation, complex analysis, and/or prior information related to the device design and fabrication, which is generally unavailable to the consumers of commercial devices. This methodology merely utilizes the transfer characteristics of the device and is straightforward to implement. The $D_{it}$ analysis using the T3VS method shows that trench devices have significantly lower $D_{it}$ in comparison to the planar devices, making them more reliable and efficient in practical applications. Furthermore, this study examines the impact of a novel room temperature gate oxide screening methodology called screening with adjustment pulse (SWAP) on the $D_{it}$ distribution in commercial planar MOSFETs, utilizing the proposed T3VS method. The result demonstrates that the SWAP technique is aggressive in nature and can introduce new defect states close to the conduction band edge. Hence, additional care is needed during screening optimization to ensure the reliability and usability of the screened devices in the consequent applications. Full article

In medium- and high-power-density applications, silicon carbide (SiC) metal-oxide semiconductor field effect transistors (MOSFETs) are often connected in parallel increasing the current capability. However, the current sharing of paralleled SiC MOSFETs is affected by the mismatched technical parameters of devices and the deviated power circuit parasitic inductances, even if power devices are controlled by a single gate driver. This leads to unevenly distributed power losses causing different stress between SiC MOSFETs. As a result, unbalanced current sharing increases the probability of severe power switch(es) and system failures. For over a decade, the current imbalance issue between parallel-connected SiC MOSFETs has concerned the scientific community, and many methods and techniques have been proposed. However, most of these solutions are impossible to realize without the necessity of screening power devices to measure their technical parameters. Consequently, system costs significantly increase due to the expensive equipment for screening SiC MOSFETs. Also, transient current imbalance is the main concern of most papers, without addressing static imbalance. In this paper, an innovative approach is proposed, capable of suppressing both static and transient current imbalance between paralleled SiC MOSFETs, under both symmetrical and asymmetrical layouts, through an improved active gate driver and without the requirement for any power device screening process. Additionally, the proposed solution employs a self-sustaining algorithmic approach utilizing current sensors and a field-programmable gate array (FPGA). The functionality of the proposed solution is verified through experimental tests, achieving current imbalance suppression between two paralleled SiC MOSFETs, actively and autonomously. Full article

The availability of yeast surface display nanobody (Nb) libraries offers a convenient way to acquire antigen-specific nanobodies that may be useful for protein structure–function studies and/or therapeutic applications, complementary to the conventional method of acquiring nanobodies through immunization in camelids. In this study, we developed a general approach to select nanobodies for cytochrome P450 enzymes from a highly diverse yeast display library. We tested our method on three P450 enzymes including CYP102A1, neuronal nitric oxide synthase (nNOS), and the complex of CYP2B4:POR, using a novel streamlined approach where biotinylated P450s were bound to fluorescent-labeled streptavidin for Nb screening. The Nb–antigen binders were selectively enriched using magnetic-activated cell sorting (MACS) and fluorescence-activated cell sorting (FACS). After two rounds of MACS, the population of positive binders was enriched by >5-fold compared to the naïve library. The subsequent FACS selection, with a gating of 0.1%, identified 634, 270, and 215 positive binders for CYP102A1, nNOS, and CYP2B4:POR, respectively. The positive binders for CYP102A1 were further triaged based on EC₅₀ determined at various antigen concentrations. DNA sequencing of the top 30 binders of CYP102A1 resulted in 26 unique clones, 8 of which were selected for over-expression and characterization. They were found to inhibit CYP102A1-catalyzed oxidation of omeprazole with IC₅₀ values in the range of 0.16–2.8 µM. These results validate our approach and may be applied to other protein targets for the effective selection of specific nanobodies. Full article

Due to the lower cost compared to screen-printed silver contacts, the Ni/Cu/Ag contacts formed by plating have been continuously studied as a potential metallization technology for solar cells. To address the adhesion issue of backside grid lines in electroplated n-Tunnel Oxide Passivating Contacts (n-TOPCon) solar cells and reduce ohmic contact, we propose a novel approach of adding a Ni/Si alloy seed layer between the Ni and Si layers. The metal nickel layer is deposited on the backside of the solar cells using electron beam evaporation, and excess nickel is removed by H₂SO₄:H₂O₂ etchant under annealing conditions of 300–425 °C to form a seed layer. The adhesion strength increased by more than 0.5 N mm⁻¹ and the contact resistance dropped by 0.5 mΩ cm² in comparison to the traditional direct plating Ni/Cu/Ag method. This is because the resulting Ni/Si alloy has outstanding electrical conductivity, and the produced Ni/Si alloy has higher adhesion over direct contact between the nickel–silicon interface, as well as enhanced surface roughness. The results showed that at an annealing temperature of 375 °C, the main compound formed was NiSi, with a contact resistance of 1 mΩ cm⁻² and a maximum gate line adhesion of 2.7 N mm⁻¹. This method proposes a new technical solution for cost reduction and efficiency improvement of n-TOPCon solar cells. Full article

Although the 20S core particle (CP) of the proteasome is an important component of the 26S holoenzyme, the stand-alone 20S CP acts directly on intrinsically disordered and oxidized/damaged proteins to degrade them in a ubiquitin-independent manner. It has been postulated that some structural features of substrate proteins are recognized by the 20S CP to promote substrate uptake, but the mechanism of substrate recognition has not been fully elucidated. In this study, we screened peptides that bind to the 20S CP from a random eight-residue pool of amino acid sequences using complementary DNA display an in vitro molecular evolution technique. The identified 20S CP-binding amino acid sequence was chemically synthesized and its effects on the 20S CP were investigated. The 20S CP-binding peptide stimulated the proteolytic activity of the inactive form of 20S CP. The peptide bound directly to one of the α-subunits, opening a gate for substrate entry on the α-ring. Furthermore, the attachment of this peptide sequence to α-synuclein enhanced its degradation by the 20S CP in vitro. In addition to these results, docking simulations indicated that this peptide binds to the top surface of the α-ring. These peptides could function as a key to control the opening of the α-ring gate. Full article

We propose a novel silicon carbide (SiC) self-aligned N-type ion implanted trench MOSFET (NITMOS) device. The maximum electric field in the gate oxide could be effectively reduced to below 3 MV/cm with the introduction of the P-epi layer below the trench. The P-epi layer is partially counter-doped by a self-aligned N-type ion implantation process, resulting in a relatively low specific on-resistance (R_on,sp). The lateral spacing between the trench sidewall and N-implanted region (W_sp) plays a crucial role in determining the performance of the SiC NITMOS device, which is comprehensively studied through the numerical simulation. With the W_sp increasing, the SiC NITMOS device demonstrates a better short-circuit capability owing to the reduced saturation current. The gate-to-drain capacitance (C_gd) and gate-to-drain charge (Q_gd) are also investigated. It is observed that both C_gd and Q_gd decrease as the W_sp increases, owing to the enhanced screen effect. Compared to the SiC double-trench MOSFET device, the optimal SiC NITMOS device exhibits a 79% reduction in C_gd, a 38% decrease in Q_gd, and a 41% reduction in Q_gd × R_on,sp. A higher switching speed and a lower switching loss can be achieved using the proposed structure. Full article

Rapid, highly sensitive, and accurate detection of tumor biomarkers in serum is of great significance in cancer screening, early diagnosis, and postoperative monitoring. In this study, an electrochemiluminescence (ECL) immunosensing platform was constructed by enhancing the ECL signal through in situ growth of platinum nanoparticles (PtNPs) in a nanochannel array, which can achieve highly sensitive detection of the tumor marker carcinoembryonic antigen (CEA). An inexpensive and readily available indium tin oxide (ITO) glass electrode was used as the supporting electrode, and a layer of amino-functionalized vertically ordered mesoporous silica film (NH₂-VMSF) was grown on its surface using an electrochemically assisted self-assembly method (EASA). The amino groups within the nanochannels served as anchoring sites for the one-step electrodeposition of PtNPs, taking advantage of the confinement effect of the ultrasmall nanochannels. After the amino groups on the outer surface of NH₂-VMSF were derivatized with aldehyde groups, specific recognition antibodies were covalently immobilized followed by blocking nonspecific binding sites to create an immunorecognition interface. The PtNPs, acting as nanocatalysts, catalyzed the generation of reactive oxygen species (ROS) with hydrogen peroxide (H₂O₂), significantly enhancing the ECL signal of the luminol. The ECL signal exhibited high stability during continuous electrochemical scanning. When the CEA specifically bound to the immunorecognition interface, the resulting immune complexes restricted the diffusion of the ECL emitters and co-reactants towards the electrode, leading to a reduction in the ECL signal. Based on this immune recognition-induced signal-gating effect, the immunosensor enabled ECL detection of CEA with a linear range of 0.1 pg mL⁻¹ to 1000 ng mL⁻¹ with a low limit of detection (LOD, 0.03 pg mL⁻¹). The constructed immunosensor demonstrated excellent selectivity and can achieve CEA detection in serum. Full article

In this study, we use NEGF quantum transport simulations to study the fundamental detection limit of ultra-scaled Si nanowire FET (NWT) biosensors. A N-doped NWT is found to be more sensitive for negatively charged analytes as explained by the nature of the detection mechanism. Our results predict threshold voltage shifts due to a single-charge analyte of tens to hundreds of mV in air or low-ionic solutions. However, with typical ionic solutions and SAM conditions, the sensitivity rapidly drops to the mV/q range. Our results are then extended to the detection of a single 20-base-long DNA molecule in solution. The impact of front- and/or back-gate biasing on the sensitivity and limit of detection is studied and a signal-to-noise ratio of 10 is predicted. Opportunities and challenges to reach down to single-analyte detection in such systems are also discussed, including the ionic and oxide-solution interface-charge screening and ways to recover unscreened sensitivities. Full article

Instead of molecularly imprinting a whole protein molecule, imprinting protein epitopes is gaining popularity due to cost and solubility issues. Belonging to the matrix metalloproteinase protein family, MMP-1 is an interstitial collagenase that degrades collagen and may be involved in cell migration, cell proliferation, the pro-inflammatory effect, and cancer progression. Hence, it can serve as a disease protein biomarker and thus be useful in early diagnosis. Herein, epitopes of MMP-1 were identified by screening its crystal structure. To identify possible epitopes for imprinting, MMP-1 was cleaved in silico with trypsin, pepsin at pH = 1.3, and pepsin at pH > 2.0 using Peptide Cutter, generating peptide fragments containing 8 to 12 amino acids. Five criteria were applied to select the peptides most suitable as potential epitopes for MMP-1. The triphenylamine rhodanine-3-acetic acid (TPARA) functional monomer was synthesized to form a stable pre-polymerization complex with a selected template epitope. The complexed functional monomer was then copolymerized with 3,4-ethoxylenedioxythiophene (EDOT) using potentiodynamic electropolymerization onto indium–tin–oxide (ITO) electrodes. The composition of the molecularly imprinted poly(TPARA-co-EDOT) (MIP) was optimized by maximizing the film’s electrical conductivity. Cyclic voltammetry was used to determine MMP-1 concentration in the presence of the Fe(CN)₆³⁻/Fe(CN)₆⁴⁻ redox probe actuating the “gate effect.” A calibration curve was constructed and used to determine the usable concentration range and the limit of detection as ca. 0.001 to 10.0 pg/mL and 0.2 fg/mL MMP-1, respectively. Finally, the MMP-1 concentration in the A549 human lung (carcinoma) culture medium was measured, and this determination accuracy was confirmed using an ELISA assay. Full article

Sensitive determination of C-reactive protein (CRP) is of great significance because it is an early indicator of inflammation in cardiovascular disease and acute myocardial infarction. A disposable electrode with an integrated three-electrode system (working, reference, and counter electrodes) has great potential in the detection of biomarkers. In this work, an electrochemical immunosensing platform was fabricated on disposable and integrated screen-printed carbon electrode (SPCE) by introducing nanochannel arrays and gated electrochemical signals, which can achieve the sensitive detection of CRP in serum. To introduce active reactive groups for the fabrication of immuno-recognitive interface, vertically-ordered mesoporous silica-nanochannel film (VMSF) with rich amino groups (NH₂-VMSF) was rapidly grown by electrochemical assisted self-assembly (EASA). The electrochemically reduced graphene oxide (ErGO) synthesized in situ during the growth of NH₂-VMSF was used as a conductive adhesive glue to achieve stable bonding of the nanochannel array (NH₂-VMSF/ErGO/SPCE). After the amino group on the outer surface of NH₂-VMSF reacted with bifunctional glutaraldehyde (GA/NH₂-VMSF/ErGO/SPCE), the converted aldehyde surface was applied for covalent immobilization of the recognitive antibody (Ab) followed with the blocking of the non-specific sites. The fabricated immunosensor, Ab/GA/NH₂-VMSF/ErGO/SPCE, enables sensitive detection of CRP in the range from 10 pg/mL to 100 ng/mL with low limit of detection (LOD, 8 pg/mL, S/N = 3). The immunosensor possessed high selectivity and can realize reliable determination of CRP in human serum. Full article

This article provides a detailed study of performance and reliability issues and trade-offs in silicon carbide (SiC) power MOSFETs. The reliability issues such as threshold voltage variation across devices from the same vendor, instability of threshold voltage under positive and negative gate bias, long-term reliability of gate oxide, screening of devices with extrinsic defects by means of gate voltage, body diode degradation, and short circuit withstand time are investigated through testing of commercial devices from different vendors and two-dimensional simulations. Price roadmap and foundry models of SiC MOSFETs are discussed. Future development of mixed-mode CMOS circuits with high voltage lateral MOSFETs along with 4−6× higher power handling capability compared to silicon circuits has been described. Full article