Filament Formation Research Articles

Rapid Semiconducting Supramolecular Mg(II)-Metallohydrogel: Exploring Its Potential in Nonvolatile Resistive Switching Applications and Antiseptic Wound Healing Properties.

An effective strategy was employed for the rapid development of a supramolecular metallohydrogel of Mg(II) ion (i.e., Mg@PEHA) using pentaethylenehexamine (PEHA) as a low-molecular-weight gelator in aqueous medium under ambient conditions. The mechanical stability of the synthesized Mg@PEHA metallohydrogel was characterized by using rheological analysis, which showed its robustness across different angular frequencies and oscillator stress levels. The metallohydrogel exhibited excellent thixotropic behavior, which signifies that Mg@PEHA has a self-healing nature. Field emission scanning electron microscopy and transmission electron microscopy images were utilized to explore the rectangular pebble-like hierarchical network of the Mg@PEHA metallohydrogel. Elemental mapping through energy-dispersive X-ray spectroscopy analysis confirmed the presence of primary chemical constituents in the metallohydrogel. Fourier transform infrared spectroscopy spectroscopy provided insights into the possible formation strategy of the metallohydrogel. In this work, Schottky diode structures in a metal-semiconductor-metal geometry based on a magnesium(II) metallohydrogel (Mg@PEHA) were constructed, and the charge transport behavior was observed. Additionally, a resistive random access memory (RRAM) device was developed using Mg@PEHA, which displayed bipolar resistive switching behavior at room temperature. The researchers investigated the switching mechanism, which involved the formation or rupture of conduction filaments, to gain insights into the resistive switching process. The RRAM device demonstrated excellent performance with a high ON/OFF ratio of approximately 100 and remarkable endurance of over 5000 switching cycles. RRAM devices exhibit good endurance, meaning they can endure a large number of read and write cycles without significant degradation in performance. RRAM devices have shown promising reliability in terms of long-term performance and stability, making them suitable for critical applications that require reliable memory solutions. Significant inhibitory activity against the drug-resistant Klebsiella pneumonia strain and its biofilm formation ability was demonstrated by Mg@PEHA. The minimum inhibitory concentration value of the metallohydrogel was determined to be 3 mg/mL when it was dissolved in 1% DMSO. To study the antibiofilm activity, an MTT assay was performed, revealing that biofilm inhibition (60%) commenced at 1 mg/mL of Mg@PEHA when dissolved in 1% DMSO. Moreover, in the mouse excisional wound model, Mg@PEHA played a crucial role in preventing postoperative wound infections and promoting wound healing.

Poly(L-co-D,L-lactic acid-co-trimethylene carbonate) for extrusion-based 3D printing: Comprehensive characterization and cytocompatibility assessment

Extrusion-based 3D printing is a well-established material processing technique that has shown promise in employing a variety of polymers. Poly(lactic acid) is the most studied and widely used raw material in 3D printing, which can be modified by copolymerization with trimethylene carbonate (TMC), for tissue engineering applications. In this study, the aim was to explore the characterization of Poly(L-co-D,L-lactic acid-co-trimethylene carbonate) (PLDLA-TMC) at different ratios (60/40, 70/30, 80/20, and 90/10), focusing on their physicochemical, thermal, and rheological characterization, as well as their cytocompatibility. The results demonstrated shear-thinning behavior and highlighted the influence of TMC content on viscoelastic properties. The printing speed of 4 mm s−1 allowed the obtaining of scaffolds with rectangular pores and controlling of extrusion temperature promoted the formation of uniform filaments with high print quality. Additionally, the cytocompatibility assessment of the scaffolds revealed the terpolymer's potential for tissue engineering across a wide range of applications.

Noncytotoxic WORM Memory Using Lysozyme with Ultrahigh Stability for Transient and Sustainable Electronics Applications.

Biocompatibility and transient nature of electronic devices have been the matter of attention in recent times due to their immense potential for sustainable solutions toward hazardous e-wastes. In order to fulfill the requirement of high-density data-storage devices due to explosive growth in digital data, a resistive switching (RS)-based memory device could be the promising alternative to the present Si-based electronics. In this research work, we employed a biocompatible enzymatic protein lysozyme (Lyso) as the active layer to design a RS memory device having a device structure Au/Lyso/ITO. Interestingly the device showed transient, WORM memory behavior. It has been observed that the WORM memory performance of the device was very good with high memory window (2.78 × 102), data retention (up to 300 min), device yield (∼73.8%), read cyclability, as well as very high device stability (experimentally >700 days, extrapolated to 3000 days). Bias-induced charge trapping followed by conducting filament formation was the key behind such switching behavior. Transient behavior analysis showed that electronic as well as optical behaviors completely disappeared after 10 s dissolution of the device in luke warm water. Cytotoxicity of the as-prepared device was tested by challenging two environmentally derived bacteria, S. aureus and P. aeruginosa, and was found to have no biocidal effects. Hence, the device would cause no harm to the microbial flora when it is discarded. As a whole, this work suggests that Lyso-based WORM memory device could play a key role for the design of transient WORM memory device for sustainable electronic applications.

Exploration of a wide bandgap semiconducting supramolecular Mg(II)-metallohydrogel derived from an aliphatic amine: a robust resistive switching framework for brain-inspired computing

A rapid metallohydrogelation strategy has been developed of magnesium(II)-ion using trimethylamine as a low molecular weight gelator in water medium at room temperature. The mechanical property of the synthesized metallohydrogel material is established through the rheological analysis. The nano-rose like morphological patterns of Mg(II)-metallohydrogel are characterized through field emission scanning electron microscopic study. The energy dispersive X-ray elemental mapping analysis confirms the primary gel forming elements of Mg(II)-metallohydrogel. The possible metallohydrogel formation strategy has been analyzed through FT-IR spectroscopic study. In this work, magnesium(II) metallohydrogel (Mg@TMA) based metal–semiconductor-metal structures have been developed and charge transport behaviour is studied. Here, it is confirmed that the magnesium(II) metallohydrogel (Mg@TMA) based resistive random access memory (RRAM) device is showing bipolar resistive switching behaviour at room temperature. We have also explored the mechanism of resistive switching behaviour using the formation (rupture) of conductive filaments between the metal electrodes. This RRAM devices exhibit excellent switching endurance over 10,000 switching cycles with a large ON/OFF ratio (~ 100). The easy fabrication techniques, robust resistive switching behaviour and stability of the present system makes these structures preferred candidate for applications in non-volatile memory design, neuromorphic computing, flexible electronics and optoelectronics etc.

Filamentation and biofilm formation are regulated by the phase-separation capacity of network transcription factors in Candida albicans.

The ability of the fungus Candida albicans to filament and form biofilms contributes to its burden as a leading cause of hospital-acquired infections. Biofilm development involves an interconnected transcriptional regulatory network (TRN) consisting of nine transcription factors (TFs) that bind both to their own regulatory regions and to those of the other network TFs. Here, we show that seven of the nine TFs in the C. albicans biofilm network contain prion-like domains (PrLDs) that have been linked to the ability to form phase-separated condensates. Construction of PrLD mutants in four biofilm TFs reveals that these domains are essential for filamentation and biofilm formation in C. albicans. Moreover, biofilm PrLDs promote the formation of phase-separated condensates in the nuclei of live cells, and PrLD mutations that abolish phase separation (such as the removal of aromatic residues) also prevent biofilm formation. Biofilm TF condensates can selectively recruit other TFs through PrLD-PrLD interactions and can co-recruit RNA polymerase II, implicating condensate formation in the assembly of active transcriptional complexes. Finally, we show that PrLD mutations that block the phase separation of biofilm TFs also prevent filamentation in an in vivo model of gastrointestinal colonization. Together, these studies associate transcriptional condensates with the regulation of filamentation and biofilm formation in C. albicans, and highlight how targeting of PrLD-PrLD interactions could prevent pathogenesis by this species.

Positive and negative regulators of RAD51/DMC1 in homologous recombination and DNA replication

RAD51 recombinase plays a central role in homologous recombination (HR) by forming a nucleoprotein filament on single-stranded DNA (ssDNA) to catalyze homology search and strand exchange between the ssDNA and a homologous double-stranded DNA (dsDNA). The catalytic activity of RAD51 assembled on ssDNA is critical for the DNA-homology-mediated repair of DNA double-strand breaks in somatic and meiotic cells and restarting stalled replication forks during DNA replication. The RAD51-ssDNA complex also plays a structural role in protecting the regressed/reversed replication fork. Two types of regulators control RAD51 filament formation, stability, and dynamics, namely positive regulators, including mediators, and negative regulators, so-called remodelers. The appropriate balance of action by the two regulators assures genome stability. This review describes the roles of positive and negative RAD51 regulators in HR and DNA replication and its meiosis-specific homolog DMC1 in meiotic recombination. We also provide future study directions for a comprehensive understanding of RAD51/DMC1-mediated regulation in maintaining and inheriting genome integrity.

The protein phosphatase EYA4 promotes homologous recombination (HR) through dephosphorylation of tyrosine 315 on RAD51.

Efficient DNA repair and limitation of genome rearrangements rely on crosstalk between different DNA double-strand break (DSB) repair pathways, and their synchronization with the cell cycle. The selection, timingand efficacy of DSB repair pathways are influenced by post-translational modifications of histones and DNA damage repair (DDR) proteins, such as phosphorylation. While the importance of kinases and serine/threonine phosphatases in DDR have been extensively studied, the role of tyrosine phosphatases in DNA repair remains poorly understood. In this study, we have identified EYA4 as the protein phosphatase that dephosphorylates RAD51 on residue Tyr315. Through its Tyr phosphatase activity, EYA4 regulates RAD51 localization, presynaptic filament formation, foci formation, and activity. Thus, it is essential for homologous recombination (HR) at DSBs. DNA binding stimulates EYA4 phosphatase activity. Depletion of EYA4 decreases single-stranded DNA accumulation following DNA damage and impairs HR, while overexpression of EYA4 in cells promotes dephosphorylation and stabilization of RAD51, and thereby nucleoprotein filament formation. Our data have implications for a pathological version of RAD51 in EYA4-overexpressing cancers.

Preparation of ZnO resistive switching film and its corrosion behavior in 3.5 wt.% NaCl solution

ZnO resistive switching films were prepared on the surface of SS304 using hydrothermal method combined with heat treatment. The surface and cross-sectional morphology, composition, oxygen vacancy content and semiconductor type of ZnO films were characterized. The corrosion resistance and resistance switching properties of ZnO films were determined by electrochemical methods. The oxygen vacancy formation energy, surface adsorption energy and diffusion barrier of ZnO system were calculated using first-principles. The results show that the samples with 0.5 mol/L Zn2+ and 4 mol/L NaOH have the best performance, and its corrosion resistance efficiency can reach more than 99.5 %. Calculations show that the ZnO film containing oxygen vacancies still prevents the entry of Cl−, and applied electric field promotes the formation of oxygen vacancies and conductive filaments. Thus, polarization-immersion treatment can adjust the oxygen vacancy content in film, which enables film to switch between high and low resistance states, realizing the cyclic resistance-switching performance of film and greatly extending service life.

Formation of Cluster-Structured Metallic Filaments in Organic Memristors for Wearable Neuromorphic Systems with Bio-Mimetic Synaptic Weight Distributions.

With increasing demand for wearable electronics capable of computing huge data, flexible neuromorphic systems mimicking brain functions have been receiving much attention. Despite considerable efforts in developing practical neural networks utilizing several types of flexible artificial synapses, it is still challenging to develop wearable systems for complex computations due to the difficulties in emulating continuous memory states in a synaptic component. In this study, polymer conductivity is analyzed as a crucial factor in determining the growth dynamics of metallic filaments in organic memristors. Moreover, flexible memristors with bio-mimetic synaptic functions such as linearly tunable weights are demonstrated by engineering the polymer conductivity. In the organic memristor, the cluster-structured filaments are grown within the polymer medium in response to electric stimuli, resulting in gradual resistive switching and stable synaptic plasticity. Additionally, the device exhibits the continuous and numerous non-volatile memory states due to its low leakage current. Furthermore, complex hardware neural networks including ternary logic operators and a noisy image recognitions system are successfully implemented utilizing the developed memristor arrays. This promising concept of creating flexible neural networks with bio-mimetic weight distributions will contribute to the development of a new computing architecture for energy-efficient wearable smart electronics.

Synaptic plasticity emulation by natural biomaterial honey-CNT-based memristors

Artificial synaptic devices made from natural biomaterials capable of emulating functions of biological synapses, such as synaptic plasticity and memory functions, are desirable for the construction of brain-inspired neuromorphic computing systems. The metal/dielectric/metal device structure is analogous to the pre-synapse/synaptic cleft/post-synapse structure of the biological neuron, while using natural biomaterials promotes ecologically friendly, sustainable, renewable, and low-cost electronic devices. In this work, artificial synaptic devices made from honey mixed with carbon nanotubes, honey-carbon nanotube (CNT) memristors, were investigated. The devices emulated spike-timing-dependent plasticity, with synaptic weight as high as 500%, and demonstrated a paired-pulse facilitation gain of 800%, which is the largest value ever reported. 206-level long-term potentiation (LTP) and long-term depression (LTD) were demonstrated. A conduction model was applied to explain the filament formation and dissolution in the honey-CNT film, and compared to the LTP/LTD mechanism in biological synapses. In addition, the short-term and long-term memory behaviors were clearly demonstrated by an array of 5 × 5 devices. This study shows that the honey-CNT memristor is a promising artificial synaptic device technology for applications in sustainable neuromorphic computing.

Tau and neurodegeneration.

First identified in 1975, tau was implicated in Alzheimer's disease 10 years later. Filamentous tangle inclusions were known to be made of hyperphosphorylated tau by 1991, with similar inclusions gaining recognition for being associated with other neurodegenerative diseases. In 1998, mutations in MAPT, the gene that encodes tau, were identified as the cause of a dominantly inherited form of frontotemporal dementia with abundant filamentous tau inclusions. While this result indicated that assembly of tau into aberrant filaments is sufficient to drive neurodegeneration and dementia, most cases of tauopathy are sporadic. More recent work in experimental systems showed that filamentous assemblies of tau may first form in one brain area, and then spread to others in a prion-like fashion. Beginning in 2017, work on human brains using high-resolution techniques has led to a structure-based classification of tauopathies, which has opened the door to a better understanding of the significance of tau filament formation.

Highly Reliable 3D Channel Memory and Its Application in a Neuromorphic Sensory System for Hand Gesture Recognition.

Brain-inspired neuromorphic computing systems, based on a crossbar array of two-terminal multilevel resistive random-access memory (RRAM), have attracted attention as promising technologies for processing large amounts of unstructured data. However, the low reliability and inferior conductance tunability of RRAM, caused by uncontrollable metal filament formation in the uneven switching medium, result in lower accuracy compared to the software neural network (SW-NN). In this work, we present a highly reliable CoOx-based multilevel RRAM with an optimized crystal size and density in the switching medium, providing a three-dimensional (3D) grain boundary (GB) network. This design enhances the reliability of the RRAM by improving the cycle-to-cycle endurance and device-to-device stability of the I-V characteristics with minimal variation. Furthermore, the designed 3D GB-channel RRAM (3D GB-RRAM) exhibits excellent conductance tunability, demonstrating high symmetricity (624), low nonlinearity (βLTP/βLTD ∼ 0.20/0.39), and a large dynamic range (Gmax/Gmin ∼ 31.1). The cyclic stability of long-term potentiation and depression also exceeds 100 cycles (105 voltage pulses), and the relative standard deviation of Gmax/Gmin is only 2.9%. Leveraging these superior reliability and performance attributes, we propose a neuromorphic sensory system for finger motion tracking and hand gesture recognition as a potential elemental technology for the metaverse. This system consists of a stretchable double-layered photoacoustic strain sensor and a crossbar array neural network. We perform training and recognition tasks on ultrasonic patterns associated with finger motion and hand gestures, attaining a recognition accuracy of 97.9% and 97.4%, comparable to that of SW-NN (99.8% and 98.7%).

TAF15 amyloid filaments in frontotemporal lobar degeneration.

Frontotemporal lobar degeneration (FTLD) causes frontotemporal dementia (FTD), the most common form of dementia after Alzheimer's disease, and is often also associated with motor disorders1. The pathological hallmarks of FTLD are neuronal inclusions of specific, abnormally assembled proteins2. In the majority of cases the inclusions contain amyloid filament assemblies of TAR DNA-binding protein 43 (TDP-43) or tau, with distinct filament structures characterizing different FTLD subtypes3,4. The presence of amyloid filaments and their identities and structures in the remaining approximately 10% of FTLD cases are unknown but are widely believed to be composed of the protein fused in sarcoma (FUS,also known as translocated in liposarcoma). As such, these cases are commonly referred to as FTLD-FUS. Here we used cryogenic electron microscopy (cryo-EM)to determine the structures of amyloid filaments extracted from the prefrontal and temporal cortices of four individuals with FTLD-FUS. Surprisingly, we found abundant amyloid filaments of the FUS homologue TATA-binding protein-associated factor 15 (TAF15,also known as TATA-binding protein-associated factor 2N) rather than of FUS itself. The filament fold is formed from residues 7-99 in the low-complexity domain (LCD)of TAF15 and was identical between individuals. Furthermore, we found TAF15 filaments with the same fold in the motor cortex and brainstem of two of the individuals, both showing upper and lower motor neuron pathology. The formation of TAF15 amyloid filaments with a characteristic fold in FTLD establishes TAF15 proteinopathy in neurodegenerative disease. The structure of TAF15 amyloid filaments provides a basis for the development of model systems of neurodegenerative disease, as well as for the design of diagnostic and therapeutic tools targeting TAF15 proteinopathy.

Analog Memory and Synaptic Plasticity in an InGaZnO-Based Memristor by Modifying Intrinsic Oxygen Vacancies.

This study focuses on InGaZnO-based synaptic devices fabricated using reactive radiofrequency sputtering deposition with highly uniform and reliable multilevel memory states. Electron trapping and trap generation behaviors were examined based on current compliance adjustments and constant voltage stressing on the ITO/InGaZnO/ITO memristor. Using O2 + N2 plasma treatment resulted in stable and consistent cycle-to-cycle memory switching with an average memory window of ~95.3. Multilevel resistance states ranging from 0.68 to 140.7 kΩ were achieved by controlling the VRESET within the range of -1.4 to -1.8 V. The modulation of synaptic weight for short-term plasticity was simulated by applying voltage pulses with increasing amplitudes after the formation of a weak conductive filament. To emulate several synaptic behaviors in InGaZnO-based memristors, variations in the pulse interval were used for paired-pulse facilitation and pulse frequency-dependent spike rate-dependent plasticity. Long-term potentiation and depression are also observed after strong conductive filaments form at higher current compliance in the switching layer. Hence, the ITO/InGaZnO/ITO memristor holds promise for high-performance synaptic device applications.

Physical Origin of Threshold Switching in Amorphous Chromium‐Doped V2O3

Devices made of amorphous thin films of the prototypical Mott‐insulator chromium‐doped V2O3 show a threshold and negative differential resistance effect after an electroforming step. Here, it is demonstrated that this effect is caused by the formation of a crystalline filament, in which a thermal runaway effect can occur. A compact model is developed that can describe the switching behavior as well as its inherent variability. The influence of the doping concentration and oxygen stoichiometry on the switching behavior is characterized and by fitting the model to the experimental data, the underlying physical changes are extracted.

Achieving Reliable and Ultrafast Memristors via Artificial Filaments in Silk Fibroin.

The practical implementation of memristors in neuromorphic computing and biomimetic sensing suffers from unexpected temporal and spatial variations due to the stochastic formation and rupture of conductive filaments (CFs). Here, the biocompatible silk fibroin (SF) is patterned with an on-demand nanocone array by using thermal scanning probe lithography (t-SPL) to guide and confine the growth of CFs in the silver/SF/gold (Ag/SF/Au) memristor. Benefiting from the high fabrication controllability, cycle-to-cycle (temporal) standard deviation of the set voltage for the structured memristor is significantly reduced by ≈95.5% (from 1.535 to 0.0686 V) and the device-to-device (spatial) standard deviation is also reduced to 0.0648 V. Besides, the statistical relationship between the structural nanocone design and the resultant performance is confirmed, optimizing at the small operation voltage (≈0.5 V) and current (100 nA), ultrafast switching speed (sub-100 ns), large on/off ratio (104 ), and the smallest switching slope (SS < 0.01 mV dec-1 ). Finally, the short-term plasticity and leaky integrated-and-fire behavior are emulated, and a reliable thermal nociceptor system is demonstrated for practical neuromorphic applications.

Partial Eruption of Solar Filaments. I. Configuration and Formation of Double-decker Filaments

Partial eruptions of solar filaments are the typical representatives of solar eruptive behavior diversity. Here we investigate a typical filament partial eruption event and present integrated evidence for the configuration of the pre-eruption filament and its formation. The Chinese Hα Solar Explorer Hα observations reveal a structured Doppler velocity distribution within the pre-eruption filament, where distinct redshift only appeared in the eastern narrow part of the southern filament region and then disappeared after the partial eruption, while the northern part dominated by blueshift remained. Combining the Solar Dynamics Observatory and Advanced Space-based Solar Observatory observations, together with nonlinear-force-free-field modeling results, we verify that there were two independent material flow systems within the preflare filament, whose magnetic topology is a special double-decker configuration consisting of two magnetic flux ropes (MFRs) with opposite magnetic twist. During the formation of this filament system, continuous magnetic flux cancellation and footpoint motion were observed around its northern end. Therefore, we propose a new double-decker formation scenario: that the two MFRs composing such a double-decker configuration originated from two magnetic systems with different initial connections and opposite magnetic twist. Subsequent magnetic reconnection with the surrounding newly emerging fields resulted in the motion of the footpoint of the upper MFR to the region around the footpoint of the lower MFR, thus leading to the eventual formation of the double-decker configuration consisting of two MFRs with similar footpoints but opposite signs of magnetic twist. These results provide a potential way to determine unambiguously the progenitor configuration of a partially eruptive filament and reveal a special type of double-decker MFR configuration and a new double-decker formation scenario.

Formation of a Long Filament Through the Connection of Two Filament Segments Observed by CHASE

We present imaging and spectroscopic diagnostics of a long filament during its formation with the observations from the Chinese Hα Solar Explorer and Solar Dynamics Observatory. The seed filament first appeared at about 05:00 UT on 2022 September 13. Afterward, it grew gradually and connected to another filament segment nearby, building up a long filament at about 20:00 UT on the same day. The CHASE Hα spectra show an obvious centroid absorption with mild broadening at the main spine of the long filament, which is interpreted as evidence of filament material accumulation. More interestingly, near the footpoints of the filament, persistent redshifts have been detected in the Hα spectra during the filament formation, indicating continuous drainage of filament materials. Furthermore, through inspecting the extreme-ultraviolet (EUV) images and magnetograms, it was found that EUV jets and brightenings appeared repeatedly at the junction of the two filament segments, where opposite magnetic polarities converged and canceled each other continuously. These results suggest the occurrence of intermittent magnetic reconnection that not only connects magnetic structures of the two filament segments but also supplies cold materials for the filament channel likely by the condensation of injected hot plasma, even though a part of the cold materials falls down to the filament footpoints at the same time.

The AI‐based AlphaFold 2 algorithm predicts an open structure for tauC3

AbstractBackgroundTauC3 is an especially noxious C‐terminal tau fragment produced by caspase‐3 cleavage at Asp421. Two decades of accumulating evidence support its importance in the pathogenesis of AD and other tauopathies, notably FTD and PSP. TauC3 promotes aggregation and filament formation, recruits full length tau (FLT) to incipient fibrils, and despite low concentration in AD brain tissue relative to total tau, has been reported to account for substantially all the seeding activity in AD brain extracts. TauC3 has also been shown to slow fast axonal transport (FAT), with deleterious consequences. Although tau’s largely disordered structure prevents analysis by X‐ray crystallography, FRET analysis suggested the existence of a hairpin conformation in which the N‐terminus folds over the C‐terminus close to the MTBR. In this model, Ser432 is the point of closest contact with Pro301. Opening of the hairpin has been hypothesized to 1) make FLT prone to aggregation by exposing the MTBR, and 2) impair FAT by overexposing the phosphatase activating domain near the N‐terminus. We postulated that tauC3 cannot form the hairpin because it lacks Ser432 and thus has an “open” conformation. This would explain tauC3’s substantially increased pathogenicity compared to FLT. The AI‐based tool AlphaFold 2 (AF2) is being used to predict the conformation of many proteins with great accuracy. Applying it to FLT and tauC3 could provide valuable data about the hairpin and whether caspase cleavage alters it.MethodWe tested AF2’s ability to predict the conformation of 4‐repeat FLT and tauC3 from FASTA sequences, aligning the models produced with the MTBR.ResultAF2 modeling revealed a dramatically different conformation for tauC3 compared to FLT, specifically, an open conformation with the MTBR and N‐terminus far apart (Figure). Interestingly, it also revealed that the entire C‐terminus region of FLT starting at Gln423 is composed of a single α‐helix.ConclusionAF2 predictions support the existence of the hairpin conformation for tau and underscore the critical importance of residue 432 in maintaining it. The extended C‐terminus α‐helix may have functional implications. TauC3’s open conformation is consistent with its slowing of FAT and its ability to seed aggregation even at low concentrations.

Improved Resistive Switching Behaviors of Al/Ag-Doped Fe2O3 Film/ITO Devices Fabricated with a Radio-Frequency Co-Sputtering System

We fabricated Fe2O3−x and Ag-doped Fe2O3−x devices with resistive switching behavior by using a radiofrequency cosputtering system. Our results indicated that doping Ag into Fe2O3−x can effectively improve device performance, increasing the data retention test time to beyond 104 s and resulting in switching cycles of approximately ∼3 × 102 times; resistance on/off ratios of approximately ∼103; and mean setting and reset voltages of 0.94 V and −1.35 V, respectively. The improvement in performance had several possible reasons. In our case, conductive filament formation was mainly induced by oxygen vacancies and Ag atoms. X-ray photoelectron spectroscopy showed that oxygen vacancies increased significantly with Ag doping. This phenomenon can improve device performance. Ag atoms served as trap centers, allowing for the easy trapping and release of charges. This effect facilitated the formation of conductive filaments. Ag-doped Fe2O3−x has significant potential for application in resistive switching random access memory devices.