Intrinsic Channel Research Articles

Identifying legitimacy: Experimental evidence on compliance with authority.

To what extent do individuals’ perceptions of legitimacy affect their intrinsic motivations to comply with an authority? Answering this question has critical implications for law enforcement but is challenging because actions or institutions that affect intrinsic motivations typically also affect extrinsic, material ones. To disentangle these, we propose an experimental approach that separately identifies the effect of an authority’s costly action to improve enforcement fairness on citizen behavior through both intrinsic and extrinsic channels. In experiment 1, the authority’s simple attempt to institute fairer enforcement increases prosocial behavior by 10 to 12 percentage points via the intrinsic channel. A follow-up experiment demonstrates that this is not motivated by citizen attempts to “pay back” authorities. Our findings provide causally credible evidence that an authority’s actions can directly shape citizens’ behavior by enhancing her legitimacy and have important implications in policy domains where this conflicts with other incentives.

Synthesis and Photophysics of Phenylene Based Triplet Donor–Acceptor Dyads: ortho vs. para Positional Effect on Intramolecular Triplet Energy Transfer

Two phenylene based geometrical/isomeric triplet ortho - and para –dyads ( o – 3 and p – 3 , respectively) were synthesized and fully characterized using advanced photophysical tools and computations. In dyad o – 3 , the through-space donor-acceptor interactions led to simultaneous triplet energy transfer and charge transfer with identical kinetics. On the other hand, in the dyad p – 3 , it was found that the phenylene spacer favors a fast triplet energy delocalization over the charge transfer process. Furthermore, analysis of the results from the present investigation indicates that the deactivation of the photo-excited species ( o – 3 )* occurs through both the intrinsic channel viz. S 0 ←S 1 and charge recombination. In the case of dyad p – 3 , the results indicate that the primary deactivation pathway is self-quenching or triplet-triplet annihilation involving the acceptor unit(s).

The disordered C-terminal tail of TRPA1 is required for calmodulin binding and desensitization

TRPA1 is a non-selective cation channel that has been Identified as a potential drug target for persistent pain since it is required for thermal and mechanical hypersensitivity. While TRPA1 channel gating by direct agonists has been resolved, the pathways that control TRPA1 channel regulation are not well characterized. Increases in intracellular calcium control both TRPA1 potentiation and desensitization, but the mechanisms that govern these processes are poorly understood. Our research shows that calmodulin is required for TRPA1 channel desensitization, and TRPA1 lacks intrinsic channel desensitization capability unlike other ion channels.

Robustness of structural superlubricity beyond rigid models

Structural superlubricity is a theoretical concept stating that the friction force is absent between two rigid, incommensurate crystalline surfaces. However, elasticity of the contact pairs could modify the lattice registry at interfaces by nucleating local slips, favoring commeasure. The validity of structural superlubricity is thus concerned for large-scale systems where the energy cost of elastic distortion to break the lattice registry is low. In this work, we study the size dependence of superlubricity between single-crystal graphite flakes. Molecular dynamics simulations show that with nucleation and propagation of out-of-plane dislocations and strained solitons at Bernal interfaces, the friction force is reduced by one order of magnitude. Elastic distortion is much weaker for non-Bernal or incommensurate ones, remaining notable only at the ends of contact. Lattice self-organization at small twist angles perturbs the state of structural superlubricity through a reconstructed potential energy surface. Theoretical models are developed to illustrate and predict the interfacial elastoplastic behaviors at length scales beyond those in the simulations. These results validate the rigid assumption for graphitic superlubricity systems at microscale, and reveal the intrinsic channels of mechanical energy dissipation. The understandings lay the ground for the design of structural superlubricity applications.

Analysis of modified P-I-N tunnel FET architecture for applications in low power domain

Tunnel FET with a few modifications is studied here for use in low power VLSI circuits as a worthy replacement of MOS based devices. The conventional TFET structure with P-I-N architecture is modified in the present work with dual gates, front and back, to give better control over the tunnelling current passing through the channel. In the proposed architecture asymmetrical lengths are utilised for the back and front gates, which improves the control even further. An SiGe based highly doped P + pocket is inserted in the intrinsic channel near the source end to rise the ON current and to increase the ION/IOFF ratio. In this device low subthreshold slope (SS) and lower DIBL values are also observed. The oxide layer below both the gates are engineered to optimise the combination of high and low k dielectric, lengths, to obtain performance improvement. Device Simulation Tool Silvaco Atlas is used to design and simulate the proposed device. Optimisation is done for the device with regards to length of channel, dimensions of the channel pocket, underlap and overlap lengths of the gates. The device is also tested over a wide range of temperatures to come to the best possible architecture, which is described here. The proposed device is proven to be a worthy contender to replace MOSFET in future ultra-low power, CMOS compatible VLSI circuits.

A phosphonated phenol-formaldehyde-based high-temperature proton exchange membrane with intrinsic protonic conductors and proton transport channels

Phosphonated phenol-formaldehyde was first introduced into polybenzimidazole to obtain a high-temperature proton exchange membrane which synchronously has sufficient intrinsic protonic conductors and long-range proton transport channels.

Intrinsic background of the beta channel of the aerosol volumetric activity monitor

The work is devoted to the study of the features of generation of the intrinsic background of the measuring beta channel of the aerosol monitor in real conditions of measuring the volumetric activity of aerosols, caused by radionuclides of technogenic origin.
 The influence of external factors on the generation of the level of the intrinsic background of the measuring channel of the monitor and its metrological characteristics is investigated.
 The reliability of the results of measurements of the volumetric activity of air aerosols substantially depends on the correct accounting of external factors, parameters of the monitored environment and the specified operating mode of the monitor.
 Aerosol volumetric activity monitors, as a rule, operate in a continuous mode, in which the aspiration method of aerosol accumulation is implemented, followed by measuring the volumetric activity of aerosols by alpha radiation and (or) beta radiation generated by technogenic radionuclides.
 This article describes the results of experiments on measuring the iCAM aerosol monitor’s intrinsic beta channel background under real operating conditions, and its dependence on external factors.
 The studies were carried out on iCAM aerosol monitors (iCAM/D and iCAM/MF modifications) manufactured by Canberra Industries Inc. in a laboratory room in normal climatic conditions with a radon volumetric activity of 35±10 Bq·m-3 and an equivalent dose rate of gamma radiation of 0.13±0.02 μSv·h-1.
 In modern aerosol monitors, software and hardware solutions are implemented that allow to significantly reduce the background level and, as a result, to expand the measurement range of the volumetric activity of aerosols towards low values.

New apatite‐type oxide ion conductors Ce9.33+xSi6O26+δ: Structures, phase stabilities, electrical properties, and conducting mechanisms

AbstractApatite‐type rare earth silicate with high oxygen ion conductivity are attractive materials for their wide potential applications, such as being used in solid oxide fuel cells as electrolytes. Herein, a series of new apatite‐type oxide ion conductors Ce9.33+xSi6O26+δ (x = 0.43, 0.67, 1.03) have been prepared, with their phases, stabilities, electrical properties, and conducting mechanisms been thoroughly studied. The results reveal that these materials are stable under inert or reducing atmospheres, but decomposed under an oxidizing environment at elevated temperatures. The combined alternative current and directive current techniques reveal dominating oxide ion conductions and minor electronic conductions in them. The bond‐valence‐based method is applied to investigate the possible oxide ion migration pathways and disclose the main contribution from interstitial oxygens, which locate between two neighboring tetrahedral SiO4 units and enable the oxide ion transporting among them along the c‐axis direction, whereas the intrinsic channel oxygens show an inferior responsibility for the oxide ion conductivities.

Microscopic Understanding of Ultrafast Charge Transfer in van der Waals Heterostructures.

Van der Waals heterostructures show many intriguing phenomena including ultrafast charge separation following strong excitonic absorption in the visible spectral range. However, despite the enormous potential for future applications in the field of optoelectronics, the underlying microscopic mechanism remains controversial. Here we use time- and angle-resolved photoemission spectroscopy combined with microscopic many-particle theory to reveal the relevant microscopic charge transfer channels in epitaxial WS_{2}/graphene heterostructures. We find that the timescale for efficient ultrafast charge separation in the material is determined by direct tunneling at those points in the Brillouin zone where WS_{2} and graphene bands cross, while the lifetime of the charge separated transient state is set by defect-assisted tunneling through localized sulphur vacancies. The subtle interplay of intrinsic and defect-related charge transfer channels revealed in the present work can be exploited for the design of highly efficient light harvesting and detecting devices.

Emerging Mechanisms Underpinning Neurophysiological Impairments in C9ORF72 Repeat Expansion-Mediated Amyotrophic Lateral Sclerosis/Frontotemporal Dementia

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are characterized by degeneration of upper and lower motor neurons and neurons of the prefrontal cortex. The emergence of the C9ORF72 hexanucleotide repeat expansion mutation as the leading genetic cause of ALS and FTD has led to a progressive understanding of the multiple cellular pathways leading to neuronal degeneration. Disturbances in neuronal function represent a major subset of these mechanisms and because such functional perturbations precede degeneration, it is likely that impaired neuronal function in ALS/FTD plays an active role in pathogenesis. This is supported by the fact that ALS/FTD patients consistently present with neurophysiological impairments prior to any apparent degeneration. In this review we summarize how the discovery of the C9ORF72 repeat expansion mutation has contributed to the current understanding of neuronal dysfunction in ALS/FTD. Here, we discuss the impact of the repeat expansion on neuronal function in relation to intrinsic excitability, synaptic, network and ion channel properties, highlighting evidence of conserved and divergent pathophysiological impacts between cortical and motor neurons and the influence of non-neuronal cells. We further highlight the emerging association between these dysfunctional properties with molecular mechanisms of the C9ORF72 mutation that appear to include roles for both, haploinsufficiency of the C9ORF72 protein and aberrantly generated dipeptide repeat protein species. Finally, we suggest that relating key pathological observations in C9ORF72 repeat expansion ALS/FTD patients to the mechanistic impact of the C9ORF72 repeat expansion on neuronal function will lead to an improved understanding of how neurophysiological dysfunction impacts upon pathogenesis.

An Empirical Modeling of Gate Voltage-Dependent Behaviors of Amorphous Oxide Semiconductor Thin-Film Transistors including Consideration of Contact Resistance and Disorder Effects at Room Temperature.

In this paper, we present an empirical modeling procedure to capture gate bias dependency of amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) while considering contact resistance and disorder effects at room temperature. From the measured transfer characteristics of a pair of TFTs where the channel layer is an amorphous In-Ga-Zn-O (IGZO) AOS, the gate voltage-dependent contact resistance is retrieved with a respective expression derived from the current–voltage relation, which follows a power law as a function of a gate voltage. This additionally allows the accurate extraction of intrinsic channel conductance, in which a disorder effect in the IGZO channel layer is embedded. From the intrinsic channel conductance, the characteristic energy of the band tail states, which represents the degree of channel disorder, can be deduced using the proposed modeling. Finally, the obtained results are also useful for development of an accurate compact TFT model, for which a gate bias-dependent contact resistance and disorder effects are essential.

A conveniently synthesized redox-active fluorescent covalent organic framework for selective detection and adsorption of uranium

Uranium is a key element in the nuclear industry and also a global environmental contaminant with combined highly toxic and radioactive. Currently, the materials based on post-modification of amidoxime have been developed for uranium detection and adsorption. However, the affinity of amidoxime group for vanadium is stronger than that of uranium, which is the main challenge hindering the practical application of amidoxime-based adsorbents. Herein, we synthesized a fluorescent covalent organic framework (TFPPy-BDOH) through integrating biphenyl diamine and pyrene unit into the π-conjugated framework. TFPPy-BDOH has an excellent selectivity to uranium due to the synergistic effect of nitrogen atom in the imine bond and hydroxyl groups in conjugated framework. It can achieve ultra-fast fluorescence response time (2 s) and ultra-low detection limit (8.8 nM), which may be attributed to its intrinsic regular porous channel structures and excellent hydrophilicity. More excitingly, TFPPy-BDOH can chemically reduce soluble U (VI) to insoluble U (IV), and release the binding site to adsorb additional U (VI), achieving high adsorption capacity of 982.6 ± 49.1 mg g−1. Therefore, TFPPy-BDOH can overcome the challenges faced by current amidoxime-based adsorbents, making it as a potential adsorbent in practical applications.

Hierarchical micro- and mesoporous ZIF-8 with core–shell superstructures using colloidal metal sulfates as soft templates for enzyme immobilization

Metal–organic frameworks (MOFs), with large specific surface area and tunable porosity, have gained lots of attention for immobilizing enzymes. However, the intrinsic open channels of most reported MOFs are generally smaller than 2 nm, which significantly prevents the passage of enzymes, and the diffusion efficiency of substrates and products. Here we report a new hierarchical micro-mesoporous zeolitic imidazolate framework-8 (ZIF-8) with core–shell superstructure (HZIF-8) using colloidal hydrated zinc sulfate (ZnSO4·7H2O) as a soft template for enzyme immobilization. The ZnSO4·7H2O forms an aggregation of colloids due to the self-conglobation effect in methanol, which affords a soft template for the formation of HZIF-8. Cytochrome C (Cyt C) was immobilized in interior of HZIF-8 through entrapment during the formation of HZIF-8. The resultant immobilized Cyt C (Cyt C@HZIF-8) exhibited 4-fold and 3-fold higher activity than free Cyt C and Cyt C encapsulated in conventional microporous ZIF-8 (Cyt C@ZIF-8), respectively. Meanwhile, the Km value of Cyt C@HZIF-8 significantly decreased due to the presence of mesopores compared with Cyt C@ZIF-8, indicating enhanced substrate affinity. After 7 cycles, Cyt C@HZIF-8 still maintained 70% of its initial activity whereas Cyt C@ZIF-8 only retained 10% of its initial activity. Moreover, the obtained HZIF-8 showed outstanding performance in co-immobilization of multi-enzyme for the detection of glucose.

Hybrid membranes with 2D vertical continuous channels from layered double hydroxides array for high-efficiency ethanol dehydration

Hybrid membranes with 2D vertical continuous channels are expected to achieve high separation performance, but remain unexplored. In this study, 2D vertical continuous channels from layered double hydroxide (LDH) array were constructed in hybrid membranes for pervaporation dehydration. Vertically aligned LDH array that anchored onto the polyacrylonitrile substrate via in situ hydrothermal synthesis was employed to provide intrinsic continuous channels with an interlayer distance between water and ethanol. Sodium alginate impregnated into interstitial space of LDH array ensured a leakage-free and mechanical strength of membranes. The height of LDH array within hybrid membranes could be facilely manipulated from 1.5 μm to 3.6 μm through altering the hydrothermal reaction time and Co2+/Al3+ ratio. Comparing hybrid membranes with randomly oriented LDH, the hybrid membrane with vertically aligned LDH array exhibites optimal water permeability of 7742 Barrer together with a desirable selectivity of 1903 when the reaction time is 10 h, and Co2+/Al3+ ratio is 2. This study provided an innovative avenue to fabricating high-performance hybrid membranes with 2D vertical continuous channels.

Analysis of barrier distributions data for16O + 64Zn reaction at sub-barrier energies

The barrier distribution data for the 16O + 64Zn reaction at energies spanning around the no minal barrier are examined by employing symmetric-asymmetric Gaussian barrier distribution (SAGBD) approach. The cumulative role of dominant channel couplings in the SAGBD method are determined in terms of the channel coupling parameter λ and percentage decrease of fusion barrier VCBRED with reference to nominal Coulomb barrier. The non-zero and positive values of these parameters for the studied system quantitively measure the influences of dominant intrinsic channels originated from the structure of the participants. The barrier distribution data of 16O + 64Zn reaction is quantitatively as well as qualitatively explained by SAGBD outcomes.

Bias-Dependent Intrinsic RF Thermal Noise Modeling and Characterization of Single-Layer Graphene FETs

In this article, the bias dependence of intrinsic channel thermal noise of single-layer (SL) graphene field-effect transistors (GFETs) is thoroughly investigated by experimental observations and compact modeling. The findings indicate an increase of the specific noise as drain current increases, whereas a saturation trend is observed at very high carrier density regime. Besides, short-channel effects, such as velocity saturation (VS) also result in an increment of noise at higher electric fields. The main goal of this work is to propose a physics-based compact model that accounts for and accurately predicts the above experimental observations in short-channel GFETs. In contrast to long-channel MOSFET-based models adopted previously to describe thermal noise in graphene devices without considering the degenerate nature of graphene, in this work, a model for short-channel GFETs embracing the 2-D material’s underlying physics and including a bias dependence is presented. The implemented model is validated with deembedded high-frequency data from two short-channel devices at quasi-static (QS) region of operation. The model precisely describes the experimental data for a wide range of low-to-high drain current values without the need of any fitting parameter. Moreover, the consideration of the degenerate nature of graphene reveals a significant decrease of noise in comparison with the nondegenerate case and the model accurately captures this behavior. This work can also be of utmost significance from the circuit designers’ aspect since noise excess factor, a very important figure of merit for RF circuits implementation, is defined and characterized for the first time in graphene transistors.

Coronary Large Conductance Ca2+-Activated K+ Channel Dysfunction in Diabetes Mellitus.

Diabetes mellitus (DM) is an independent risk of macrovascular and microvascular complications, while cardiovascular diseases remain a leading cause of death in both men and women with diabetes. Large conductance Ca2+-activated K+ (BK) channels are abundantly expressed in arteries and are the key ionic determinant of vascular tone and organ perfusion. It is well established that the downregulation of vascular BK channel function with reduced BK channel protein expression and altered intrinsic BK channel biophysical properties is associated with diabetic vasculopathy. Recent efforts also showed that diabetes-associated changes in signaling pathways and transcriptional factors contribute to the downregulation of BK channel expression. This manuscript will review our current understandings on the molecular, physiological, and biophysical mechanisms that underlie coronary BK channelopathy in diabetes mellitus.

Simulation-Based Analysis of Ultra Thin-Body Double Gate Ferroelectric TFET for an Enhanced Electric Performance

The ultra thin body double gate FE layer TFET (UTB-DG-FE-TFET) is proposed and investigated in this work. Electrical performance parameters such as surface potential ψ (x), electrical field, drain current, sub-threshold swing, threshold voltage, and Ion/Ioff ratio are further analyzed using simulation-based analysis. Integration of Si: HFO2 ferroelectric layer on top and bottom surfaces make the structure that provides negative capacitance, higher on current, enormous surface potential, peak electric field, and improvement in SS with degradation in off Current. The suggested design is evaluated in comparison with FE-TFET and standard TFET structures. Finally, the impact of device geometry variants like ferroelectric layer thickness (tfe), intrinsic channel thickness tsi, interfacial layer types, interfacial layer thickness (tox) and channel length Lc on transfer characteristics are investigated through 2D TCAD Sentaurus Simulator for a clear validation of its optimization. The recommended work demonstrates that it is a suitable device enabling superior performance and helpful in ultra-low-power applications.

A Low Strain A‐Site Deficient Perovskite Lithium Lanthanum Niobate Anode for Superior Li+ Storage

AbstractThe oxide perovskite family holds great promise for diverse applications on account of their unique chemical and physical properties. However, owing to the inadequate Li+‐storage sites, the insertion‐type perovskite anodes for lithium‐ion batteries (LIBs) are limited. A‐site deficient perovskites with rich intrinsic vacancies and ion transport channels are believed to be the desirable hosts of superior Li+ storage. Herein, the perovskite Li0.1La0.3NbO3 (LLNO) is designed and demonstrated as the remarkable anode for LIBs with a high specific capacity, a safe operating voltage, an excellent rate performance, and a long cycling life. More importantly, the outstanding cycling stability of LLNO is originated from its low strain characteristic with a maximum volume change of only 1.17%. The exceptional rate performance can be explained by the unconventional Li+ transport pathways with external → grain boundaries → lattice deficiencies. These results not only reveal that A‐site deficient perovskite LLNO is a promising anode for LIBs but also provide fundamental insights into the Li+ ions transport mechanism, facilitating the development of high‐performance perovskite anodes.

Glycine receptors in GtoPdb v.2021.3

The inhibitory glycine receptor (nomenclature as agreed by the NC-IUPHAR Subcommittee on Glycine Receptors) is a member of the Cys-loop superfamily of transmitter-gated ion channels that includes the zinc activated channels, GABAA, nicotinic acetylcholine and 5-HT3 receptors and Zn2+- activated channels. The receptor is expressed either as a homo-pentamer of α subunits, or a complex now thought to harbour 2α and 3β subunits [33, 7], that contain an intrinsic anion channel. Four differentially expressed isoforms of the α-subunit (α1-α4) and one variant of the β-subunit (β1, GLRB, P48167) have been identified by genomic and cDNA cloning. Further diversity originates from alternative splicing of the primary gene transcripts for α1 (α1INS and α1del), α2 (α2A and α2B), α3 (α3S and α3L) and β (βΔ7) subunits and by mRNA editing of the α2 and α3 subunit [83, 93, 21]. Both α2 splicing and α3 mRNA editing can produce subunits (i.e., α2B and α3P185L) with enhanced agonist sensitivity. Predominantly, the adult form of the receptor contains α1 (or α3) and β subunits whereas the immature form is mostly composed of only α2 subunits. The &a;pha;4 subunit is a pseudogene in humans. High resolution molecular structures are available for the α1 and α3 homomeric receptors [50, 20]. As in other Cys-loop receptors, the orthosteric binding site for agonists and the competitive antagonist strychnine is formed at the interfaces between the subunits’ extracellular domains. Inclusion of the β-subunit in the pentameric glycine receptor contributes to agonist binding, reduces single channel conductance and alters pharmacology. The β-subunit also anchors the receptor, via an amphipathic sequence within the large intracellular loop region, to gephyrin. This a cytoskeletal attachment protein that binds to a number of subsynaptic proteins involved in cytoskeletal structure and thus clusters and anchors hetero-oligomeric receptors to the synapse [56, 54, 88]. G protein βγ subunits enhance the open state probability of native and recombinant glycine receptors by association with domains within the large intracellular loop [124, 123]. Intracellular chloride concentration modulates the kinetics of native and recombinant glycine receptors [96]. Intracellular Ca2+ appears to increase native and recombinant glycine receptor affinity, prolonging channel open events, by a mechanism that does not involve phosphorylation [27]. Extracellular Zn2+ potentiates GlyR function at nanomolar concentrations [86]. and causes inhibition at higher micromolar concentrations (17).