Highly polarized compounds exhibiting intramolecular charge transfer (ICT) are used widely as nonlinear optical (NLO) materials and red emitters and in organic light emitting diodes. ...Low-molecular-weight donor/acceptor (D/A)-substituted ICT compounds are ideal candidates for use as the building blocks of hierarchically structured, multifunctional self-assembled supramolecular systems. This Account describes our recent studies into the development of functional molecular systems with well-defined self-assembled structures based on charge-transfer (CT) interactions. From solution (sensors) to the solid state (assembled structures), we have fully utilized intrinsic and stimulus-induced CT interactions to construct these functional molecular systems. We have designed some organic molecules capable of ICT, with diversity and tailorability, that can be used to develop novel self-assembled materials. These ICT organic molecules are based on a variety of simple structures such as perylene bisimide, benzothiadiazole, tetracyanobutadiene, fluorenone, isoxazolone, BODIPY, and their derivatives. The degree of ICT is influenced by the nature of both the bridge and the substituents. We have developed new methods to synthesize ICT compounds through the introduction of heterocycles or heteroatoms to the π-conjugated systems or through extending the conjugation of diverse aromatic systems via another aromatic ring. Combining these ICT compounds featuring different D/A units and different degrees of conjugation with phase transfer methodologies and solvent-vapor techniques, we have self-assembled various organic nanostructures, including hollow nanospheres, wires, tubes, and ribbonlike architectures, with controllable morphologies and sizes. For example, we obtained a noncentrosymmetric microfiber structure that possessed a permanent dipole along its fibers’ long axis and a transition dipole perpendicular to it; the independent NLO responses of this material can be separated and tuned spectroscopically and spatially. The ready processability and intrinsically high NLO efficiency of these microfibers offer great opportunities for applications in photonic devices. We have also designed molecular sensors based on changes in the efficiency of the ICT process upon complexation of an analyte with the D or A moieties in the ICT compounds. Such sensors, which display evident Stokes shifts or changes in quantum yields or fluorescence lifetimes, have promise for applications in chemical and biological recognition and sensing. In this Account, we shed light on the structure–function relationships of these functional molecular systems with well-defined self-assembled structures based on ICT interactions. The encouraging results that we have obtained suggest that such self-assembled ICT molecular materials can guide the design of new nanostructures and materials from organic systems, and that these materials, across a range of compositions, sizes, shapes, and functionalities, can potentially be applied in the fields of electronics, optics, and optoelectronics.
We revisit the computation of particle number fluctuations and the Rényi entanglement entropy of a two-dimensional Fermi gas using multidimensional bosonization. In particular, we compute these ...quantities for a circular Fermi surface and a circular entangling surface. Both quantities display a logarithmic violation of the area law, and the Rényi entropy agrees with the Widom conjecture. Lastly, we compute the symmetry-resolved entanglement entropy for the two-dimensional circular Fermi surface and find that, while the total entanglement entropy scales as R ln R , the symmetry-resolved entanglement scales as √ R ln R , where R is the radius of the subregion of our interest.
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bstract
We consider the logarithmic negativity and related quantities of time evolution operators. We study free fermion, compact boson, and holographic conformal field theories (CFTs) as well as ...numerical simulations of random unitary circuits and integrable and chaotic spin chains. The holographic behavior strongly deviates from known non- holographic CFT results and displays clear signatures of maximal scrambling. Intriguingly, the random unitary circuits display nearly identical behavior to the holographic channels. Generically, we find the “line-tension picture” to effectively capture the entanglement dynamics for chaotic systems and the “quasi-particle picture” for integrable systems. With this motivation, we propose an effective “line-tension” that captures the dynamics of the logarithmic negativity in chaotic systems in the spacetime scaling limit. We compare the negativity and mutual information leading us to find distinct dynamics of quantum and classical information. The “spurious entanglement” we observe may have implications on the “simulatability” of quantum systems on classical computers. Finally, we elucidate the connection between the operation of partially transposing a density matrix in conformal field theory and the entanglement wedge cross section in Anti-de Sitter space using geodesic Witten diagrams.
Time-reversed evolution has substantial implications in physics, including applications in refocusing of classical waves or spins and fundamental studies such as quantum information scrambling. In ...quantum metrology, nonlinear interferometry based on time-reversal protocols supports entanglement-enhanced measurements without requiring low-noise detection. Despite the broad interest in this topic, it remains challenging to reverse the quantum dynamics of an interacting many-body system, which is typically realized by an (effective) sign flip of the system’s Hamiltonian. Here we present an approach that is broadly applicable to cyclic systems for implementing nonlinear interferometry without invoking time reversal. As time-reversed dynamics drives a system back to its starting point, we propose to accomplish the same by forcing the system to travel along a ‘closed loop’ instead of explicitly tracing back its antecedent path. Utilizing the quasiperiodic spin mixing dynamics in a three-mode 87Rb atomic spinor condensate, we implement such a closed-loop nonlinear interferometer and achieve a metrological gain of 5.01−0.76+0.76 decibels over the classical limit for a total of 26,500 atoms. Our approach unlocks the potential of nonlinear interferometry by allowing the dynamics to penetrate into the deep nonlinear regime, which gives rise to highly entangled non-Gaussian states.Nonlinear interferometry based on time reversal enables entanglement-enhanced measurements without the need for low-noise detection. An alternative approach now exploits cyclic dynamics and shows performance beyond the standard quantum limit.
Characterized by low cost, flame resistance and mild processing procedure, freeze-dried clay aerogel is an ideal alternative for thermal insulation in building sector. However, the negatively charged ...surface of clay platelet and high freezing rate require the addition of a high amount of polymer to ensure the integrity of aerogel during freezing stage, which inevitably increases the density as well as the thermal conductivity of aerogel. Herein, we reported a green and versatile strategy to fabricate crack-free yet thermal insulative aerogel by introducing cellulose nanofibrils (CNFs) into starch/clay system. Owing to the abundant hydroxyl groups, high aspect ratio and excellent mechanical strength of CNFs, the CNF/starch/clay aerogels prepared exhibit enhanced crack resistance and compressive strength, enabling the reduction of starch content from 4 to 2% while maintaining the integrity of aerogel in the process of freezing. As a result, the density and thermal conductivity of aerogel significantly decrease from 0.12 to 0.05 g/cm
3
and 48.3 to 41.5 mW/mK respectively. Further crosslinked by glutaraldehyde, the CNF/starch/clay aerogels display improved moisture resistance, shape recovery and thermal stability. Being versatile and cost-effective, the present approach is thought-provoking for the up-scale production of freeze-dried clay aerogel for thermal insulation.
Graphical abstract
Neurodegenerative diseases (NDs) are incurable and can develop progressively debilitating disorders, including dementia and ataxias. Alzheimer's disease and Parkinson's disease are the most common ...NDs that mainly affect the elderly people. There is an urgent need to develop new diagnostic tools so that patients can be accurately stratified at an early stage. As a common post‐translational modification, protein glycosylation plays a key role in physiological and pathological processes. The abnormal changes in glycosylation are associated with the altered biological pathways in NDs. The pathogenesis‐related proteins, like amyloid‐β and microtubule‐associated protein tau, have altered glycosylation. Importantly, specific glycosylation changes in cerebrospinal fluid, blood and urine are valuable for revealing neurodegeneration in the early stages. This review describes the emerging biomarkers based on glycoproteomics in NDs, highlighting the potential applications of glycoprotein biomarkers in the early detection of diseases, monitoring of the disease progression, and measurement of the therapeutic responses. The mass spectrometry‐based strategies for characterizing glycoprotein biomarkers are also introduced.
Neurodegenerative disease (ND) may lead to aberrant changes in glycoenzymes, including glycosyltransferases and glycosidases, which further regulate the key ND‐related molecules, such as amyloid precursor protein, nicastrin, β‐site APP‐cleaving enzyme 1β‐site APP‐cleaving enzyme 1, a disintegrin and metallopeptidase domain 10 (ADAM10), neprilysin, etc.
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We explore non-equilibrium processes in two-dimensional conformal field theories (2d CFTs) due to the growth of operators induced by inhomogeneous and homogeneous Hamiltonians by ...investigating the time dependence of the partition function, energy density, and entanglement entropy. The non-equilibrium processes considered in this paper are constructed out of the Lorentzian and Euclidean time evolution governed by different Hamiltonians. We explore the effect of the time ordering on entanglement dynamics so that we find that in a free boson CFT and RCFTs, this time ordering does not affect the entanglement entropy, while in the holographic CFTs, it does. Our main finding is that in the holographic CFTs, the non-unitary time evolution induced by the inhomogeneous Hamiltonian can retain the initial state information longer than in the unitary time evolution.
Abstract
The gravitational coupling between large-scale perturbations and small-scale perturbations leads to anisotropic distortions of the small-scale matter distribution. The measured local ...small-scale power spectrum can thus be used to infer the large-scale matter distribution. In this paper, we present a new tidal reconstruction algorithm for reconstructing large-scale modes using the full three-dimensional tidal shear information. We apply it to simulated dark matter halo fields and find the reconstructed large-scale density field correlates well with the original matter density field on large scales, improving upon the previous tidal reconstruction method, which only uses two transverse shear fields. This has profound implications for recovering lost 21 cm radial modes due to foreground subtraction and constraining primordial non-Gaussianity using the multitracer method with future cosmological surveys.
Viral infection triggers induction of type I interferons (IFNs), which are critical mediators of innate antiviral immune response. Mediator of IRF3 activation (MITA, also called STING) is an adapter ...essential for virus-triggered IFN induction pathways. How post-translational modifications regulate the activity of MITA is not fully elucidated. In expression screens, we identified RING finger protein 26 (RNF26), an E3 ubiquitin ligase, could mediate polyubiquitination of MITA. Interestingly, RNF26 promoted K11-linked polyubiquitination of MITA at lysine 150, a residue also targeted by RNF5 for K48-linked polyubiquitination. Further experiments indicated that RNF26 protected MITA from RNF5-mediated K48-linked polyubiquitination and degradation that was required for quick and efficient type I IFN and proinflammatory cytokine induction after viral infection. On the other hand, RNF26 was required to limit excessive type I IFN response but not proinflammatory cytokine induction by promoting autophagic degradation of IRF3. Consistently, knockdown of RNF26 inhibited the expression of IFNB1 gene in various cells at the early phase and promoted it at the late phase of viral infection, respectively. Furthermore, knockdown of RNF26 inhibited viral replication, indicating that RNF26 antagonizes cellular antiviral response. Our findings thus suggest that RNF26 temporally regulates innate antiviral response by two distinct mechanisms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Epilepsy is a common chronic neurological disorder characterized by widespread neuronal death. The purpose of this study was to investigate the role of nuclear factor erythroid 2‐related factor 2 ...(Nrf2) m6A methylation in epilepsy. To create epileptic models, the rats were given Lithium chloride and pilocarpine, and isolated primary rat hippocampal neurons were cultured in an Mg2+‐free medium. The frequency of seizures was recorded in the epilepsy group of rats. The functional tests included TUNEL, MTT, and flow cytometry. Mechanistically, RNA degradation assay, RNA immunoprecipitation, and methylated RNA immunoprecipitation were performed. In epileptic models, Nrf2 and fat mass and obesity‐associated (FTO) levels were downregulated, whereas YT521‐B homology (YTH) domain family protein 2 (YTHDF2) was upregulated. Additionally, in epileptic models, there was a rise in the m6A methylation level of Nrf2 mRNA. Overexpressing FTO increased cell viability and reduced apoptosis, but Nrf2 interference reversed these effects. Meanwhile, FTO overexpression decreased the m6A methylation of Nrf2 mRNA. Moreover, YTHDF2 bound to Nrf2 mRNA and decreased its stability. Furthermore, FTO overexpression reduced seizure frequency in rats and inhibited hippocampal neuron apoptosis via lowering the m6A methylation level of Nrf2 mRNA. Overexpressing FTO reduced m6A methylation of Nrf2 mRNA, increased cell viability, suppressed apoptosis, and slowed the progression of epileptic diseases, which is linked to YTHDF2 binding to m6A‐modified Nrf2 and promoting its degradation, as well as downregulating Nrf2 expression in hippocampal neurons.
The downregulation of the eraser protein FTO expression leads to the upregulation of the m6A methylation level of Nrf2, and the m6A reader YTHDF2 directly binds to the m6A methylated Nrf2 mRNA and promotes its degradation, leading to the decrease of neuronal cell vitality and the increase of cell apoptosis.
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