Display omitted
•Systematic summary of guest effects in spin-crossover Hofmann clathrates.•Molecular volume calculated by a convenient formula is applied to explore the size effect.•Strategies are ...discussed for optimizing the sensor property.
The incorporation of spin-crossover (SCO) properties into metal-organic frameworks (MOFs) is an appealing subclass of multifunctional MOFs with potential applications in molecular sensing. This review focuses on the design of SCO Hofmann-type MOFs, with emphasis on the guest effect on their SCO properties. The influences of guest size, dielectric constant, π⋯π interaction, hydrogen bonding interactions, weak X⋯M′ covalent bonding, and chemical reaction on the SCO properties of Hofmann-type MOFs are systematically explored. Further enhancements of sensing properties are also illustrated.
•Fractional Hausdorff grey model is proposed.•The relationship between the error and the order is proved.•The proposed model has better forecasting capability.
The grey model with the fractional ...Hausdorff derivative is put forward to enhance the forecasting accuracy of traditional grey model. The proposed model will not be effect by the initial value x(0)(1). The relationship between the error and the order (r) is proved. We also make a comparison among the proposed model with the traditional fractional grey model and the traditional grey model. The comparison results show that the proposed model can improve the traditional grey model.
Mitocbondrial fusion is a highly coordinated process that mixes and unifies the mitochondrial compartment for normal mitochondrial functions and mitochondrial DNA inheritance. Dysregulated ...mitochondrial fusion causes mitochondrial fragmentation, abnormal mitochondrial physiology and inheritance, and has been causally linked with a number of neuronal diseases. Here, we identified a diterpenoid derivative 15-oxospiramilactone （$3） that potently induced mitochondrial fusion to restore the mitochondrial network and oxidative respiration in cells that are deficient in either Mfnl or Mfn2. A mitochondria-localized deubiquitinase USP30 is a target of $3. The inhibition of USP30 by $3 leads to an increase of non-degradative ubiquitination of Mfnl/2, which enhances Mfnl and Mfn2 activity and promotes mitochondrial fusion. Thus, through the use of an inhibitor of USP30, our study uncovers an unconventional function of non-degradative ubiquitination of Mfns in promoting mitochondrial fusion.
A simple and efficient electrochemical selenylation of uracils in the presence of NH4I for the synthesis of 5‐selenouracils has been developed. This transformation was performed in the transition ...metal‐free, oxidant‐free, and aerobic conditions, providing a rapid and practical protocol to 5‐selenouracil derivatives.
A simple and efficient electrochemical selenylation of uracils in the presence of NH4I for the synthesis of 5‐selenouracils has been developed. This transformation was performed in the transition metal‐free, oxidant‐free, and air conditions, providing a rapid and practical protocol to 5‐selenouracil derivatives.
Each year approximately 10 million high school seniors in China compete for 6 million seats through a centralized college admissions system. Within the last decade, many provinces have transitioned ...from a “sequential” to a “parallel” mechanism to make their admissions decisions. In this study, we characterize a parametric family of applicationrejection assignment mechanisms, including the sequential, deferred acceptance, and parallel mechanisms in a nested framework. We show that all of the provinces that have abandoned the sequential mechanism have moved toward less manipulable and more stable mechanisms. We also show that existing empirical evidence is consistent with our theoretical predictions.
Abstract
The quantum spin Hall effect lays the foundation for the topologically protected manipulation of waves, but is restricted to one-dimensional-lower boundaries of systems and hence limits the ...diversity and integration of topological photonic devices. Recently, the conventional bulk-boundary correspondence of band topology has been extended to higher-order cases that enable explorations of topological states with codimensions larger than one such as hinge and corner states. Here, we demonstrate a higher-order quantum spin Hall effect in a two-dimensional photonic crystal. Owing to the non-trivial higher-order topology and the pseudospin-pseudospin coupling, we observe a directional localization of photons at corners with opposite pseudospin polarizations through pseudospin-momentum-locked edge waves, resembling the quantum spin Hall effect in a higher-order manner. Our work inspires an unprecedented route to transport and trap spinful waves, supporting potential applications in topological photonic devices such as spinful topological lasers and chiral quantum emitters.
The folding of proteins is challenging in the highly crowded and sticky environment of a cell. Regulation of translation elongation may play a crucial role in ensuring the correct folding of ...proteins. Much of our knowledge regarding translation elongation comes from the sequencing of mRNA fragments protected by single ribosomes by ribo-seq. However, larger protected mRNA fragments have been observed, suggesting the existence of an alternative and previously hidden layer of regulation.
In this study, we performed disome-seq to sequence mRNA fragments protected by two stacked ribosomes, a product of translational pauses during which the 5'-elongating ribosome collides with the 3'-paused one. We detected widespread ribosome collisions that are related to slow ribosome release when stop codons are at the A-site, slow peptide bond formation from proline, glycine, asparagine, and cysteine when they are at the P-site, and slow leaving of polylysine from the exit tunnel of ribosomes. The structure of disomes obtained by cryo-electron microscopy suggests a different conformation from the substrate of the ribosome-associated protein quality control pathway. Collisions occurred more frequently in the gap regions between α-helices, where a translational pause can prevent the folding interference from the downstream peptides. Paused or collided ribosomes are associated with specific chaperones, which can aid in the cotranslational folding of the nascent peptides.
Therefore, cells use regulated ribosome collisions to ensure protein homeostasis.
Monolithic 3-D (M3-D) integrated circuits (ICs) provide vertical interconnects with comparable size to on-chip metal vias, and therefore, achieve ultra-high density device integration. This ...fine-grained connectivity enabled by monolithic inter-tier vias reduces the silicon area, overall wirelength, and power consumption. An open source standard cell library for design automation of large-scale transistor-level M3-D ICs is developed, thereby facilitating future research on the critical aspects of M3-D technology. The cell library is based on full-custom design of each standard cell and is fully characterized by using existing design automation tools. The proposed open source cell library is utilized to demonstrate the M3-D implementation of several benchmark circuits of various sizes ranging from 2.7-K gates to 1.6-M gates. Both power and timing characteristics of the M3-D ICs are quantified. Several versions of the cell library are developed with different number of routing tracks to better understand the issue of routing congestion in the M3-D ICs. The effect of the number of routing tracks on area, power, and delay characteristics is investigated. Finally, the primary clock tree characteristics of the M3-D ICs are discussed.
Combining Ising‐type magnetic anisotropy with collinear magnetic interactions in single‐molecule magnets (SMMs) is a significant synthetic challenge. Herein we report a Dy15‐MCCu‐5 (1‐Dy) SMM, where ...a DyIII ion is held in a central pseudo‐D5h pocket of a rigid and planar Cu5 metallacrown (MC). Linking two Dy15‐MCCu‐5 units with a single hydroxide bridge yields the double‐decker {Dy15‐MCCu‐5}2 (2‐Dy) SMM where the anisotropy axes of the two DyIII ions are nearly collinear, resulting in magnetic relaxation times for 2‐Dy that are approximately 200 000 times slower at 2 K than for 1‐Dy in zero external field. Whereas 1‐Dy and the YIII‐diluted Dy@2‐Y analogue do not show remanence in magnetic hysteresis experiments, the hysteresis data for 2‐Dy remain open up to 6 K without a sudden drop at zero field. In conjunction with theoretical calculations, these results demonstrate that the axial ferromagnetic Dy–Dy coupling suppresses fast quantum tunneling of magnetization (QTM). The relaxation profiles of both complexes curiously exhibit three distinct exponential regimes, and hold the largest effective energy barriers for any reported d–f SMMs up to 625 cm−1.
The magnetic hysteresis of a metallacrown magnet opens after introducing axial ferromagnetic by linking two mono‐decker Dy15‐MCCu‐5 units with a single hydroxide bridge to give the double‐decker {Dy15‐MCCu‐5}2 single‐molecule magnet in which the anisotropy axes of the two DyIII ions are nearly collinear and the magnetic relaxation times are approximately 200 000 times slower than for the mono‐decker unit.
Low‐dimensional lead halide perovskite materials recently have drawn much attention owing to the intriguing broadband emissions; however, the toxicity of lead will hinder their future development. ...Now, a lead‐free (C4H14N2)2In2Br10 single crystal with a unique zero‐dimensional (0D) structure constituted by InBr63− octahedral and InBr4− tetrahedral units is described. The single crystal exhibits broadband photoluminescence (PL) that spans almost the whole visible spectrum with a lifetime of 3.2 μs. Computational and experimental studies unveil that an excited‐state structural distortion in InBr63− octahedral units enables the formation of intrinsic self‐trapped excitons (STEs) and thus contributing the broad emission. Furthermore, femtosecond transient absorption (fs‐TA) measurement reveals that the ultrafast STEs formation together with an efficient intersystem crossing has made a significant contribution to the long‐lived and broad STE‐based emission behavior.
A lead‐free indium‐based (C4H14N2)2In2Br10 single crystal was synthesized and characterized; it has a unique 0D crystal structure. An intrinsic self‐trapped exciton‐based ultra‐broad photoluminescence has been observed as a result of an excited‐state structural distortion in InBr63− octahedrons.
PDF
