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The continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which caused the recent pandemic, has generated countless new variants with varying fitness. Mutations of the spike glycoprotein play a particularly vital role in shaping its evolutionary trajectory, as they have the capability to alter its infectivity and antigenicity. We present a time-resolved statistical method, Dynamic Expedition of Leading Mutations (deLemus), to analyze the evolutionary dynamics of the SARS-CoV-2 spike glycoprotein. The proposed L-index of the deLemus method is effective in quantifying the mutation strength of each amino acid site and outlining evolutionarily significant sites, allowing the comprehensive characterization of the evolutionary mutation pattern of the spike glycoprotein. © 2024 The Author(s)

Mixed-halide perovskite nanocrystals (PeNCs) featuring bandgap-tunable luminescence with narrow bandwidth have emerged as promising electroluminescent materials for light-emitting diodes (LEDs) to satisfy the color standard of Rec. 2100. However, the phase segregation of mixed-halide perovskites severely restricts the spectral stability and lifetime of perovskite LEDs (PeLEDs). Here, we report that the introduction of multifunctional side-chain-promoted polymer architectures in the synthesis of I/Br-mixed PeNCs to suppress halide segregation and enable electroluminescent stability of the PeLEDs up to ∼2500 min, which is the longest to our knowledge. Meanwhile, the PeLEDs exhibit the pure-red electroluminescence spectrum with Commission Internationale de l’Eclairage coordinates (0.705, 0.292) at one of the highest external quantum efficiencies reported to date, 23.6%. Fundamentally, the as-proposed polymer ligand architecture simultaneously offers long-term nanocrystal dispersion, good charge transport, defect elimination, and phase segregation suppression. Overall, the work demonstrates the potential of the multifunctionalized polymer ligands for developing high-performance PeLEDs toward practical applications. © 2024 American Chemical Society.

It is generally difficult to achieve high quality in low-n-value (MA-free) FA-based Dion-Jacobson (DJ) 2D perovskites due to their low crystallinity, random well-width distribution of multiple quantum wells (QWs) with disordered orientation, which has seriously hindered further advances in photovoltaics. Meanwhile, pure-phase DJ 2D perovskites with uniform QWs width and fixed low-n values are highly desirable for high efficiency and stability. Herein a novel 4APP(FA)3Pb4I13-based quasi-DJ-2D perovskite is presented first, where 4APP is 4-aminopiperidinium. The remarkable rigidity of 4APP and its strong hydrogen bonding with the perovskites prolong the perovskite intrinsic stability. the tri-solvent engineering approach is further established by matching solvent properties to achieve pure-phase DJ-2D perovskites with uniform QWs width structure and finely oriented crystal grains, which enhance the power conversion efficiency of unencapsulated solar cells by 48%, representing one of the highest values in MA-free DJ 2D perovskite with n <= 4. Remarkably, the unencapsulated devices retain 95% of their initial PCE after 2000 h of operation under 1-sun illumination at 40 degrees C, and 3000 h exposure in the air at 85 degrees C and 60-90% relative humidity (RH). The simultaneous control of rigidity and phase purity in DJ-2D perovskites will open up new directions for fundamental research and application exploration. This work presents a novel 4APP(FA)3Pb4I13-based quasi-DJ-2D perovskite, where 4APP is 4-aminopiperidinium. The remarkable rigidity of 4APP prolongs the perovskite intrinsic stability. It also establishes tri-solvent engineering to achieve pure-phase DJ-2D perovskites that improve solar cell efficiency by 48%. It is concluded that controlling rigidity and phase purity simultaneously in 2D perovskites will lead to new directions for fundamental research.image

Perovskite light-emitting diodes (PeLEDs) have recently achieved a great breakthrough in external quantum efficiency (EQE). However, the operational stability of pure primary color PeLEDs lags far behind because of serious ion migration. Herein, a self-stabilized quasi-2D perovskite is constructed with a strategically synthesized ion-migration-inhibition ligand ((IMI)ligand) to realize highly stable and efficient pure green PeLEDs approaching the standard green light of Rec. 2020. The( IMI)ligand takes the role to not only eliminate migration pathways and anchor halide ions to suppress the ion migration but to also further enhance the crystalline orientation and energy transfer in quasi-2D perovskites. Meanwhile, the self-stabilized quasi-2D perovskite overcomes the degradation of electrical performance caused by conventional exogenous passivation additives. Ultimately, the figure of merit of the pure green quasi-2D PeLEDs is at least double that of previous works. The devices achieve an EQE of 26.2% and operational stability of 920 min at initial luminance of 1000 cd m(-2).

Solution-processed top electrodes using metallic nanoparticles have great potential in the high-throughput large-scale industrialization of organic solar cells (OSCs). To overcome poor reflectance, severe conditions of post-treatments, and unclear bottom-up formation mechanisms from nanoscale materials to bulk electrode films, we propose a compact-packing-enabled fabrication approach for stacking and then sintering metallic nanoparticles to become very efficient top electrodes with high conductivity and high broadband reflectance. We establish the formation mechanism in which spray-coated silver nanoparticle (AgNP) electrodes ligated by gallic acid (GA) form well-dispersed compactly packed structures during the stacking. Featuring the self-packing ability of AgNPs and a much higher space proportion of silver, GA-assisted AgNPs with a uniform distribution of particle size and superior storage stability form high-quality AgNP films in low-temperature sintering. Finally, attributing to the superior electrical and optical properties, and facile post-treatment of electrodes, the fully solution-processed OSCs with the GA-assisted AgNP electrodes achieve a record high efficiency of 14.69% for large-area devices (≥1 cm2).

Machine learning has revolutionized information processing for large datasets across various fields. However, its limited interpretability poses a significant challenge when applied to chemistry. In this study, we developed a set of simple molecular representations to capture the structural information of ligands in palladium-catalyzed Sonogashira coupling reactions of aryl bromides. Drawing inspiration from human understanding of catalytic cycles, we used a graph neural network to extract structural details of the phosphine ligand, a major contributor to the overall activation energy. We combined these simple molecular representations with an electronic descriptor of aryl bromide as inputs for a fully connected neural network unit. The results allowed us to predict rate constants and gain mechanistic insights into the rate-limiting oxidative addition process using a relatively small dataset. This study highlights the importance of incorporating domain knowledge in machine learning and presents an alternative approach to data analysis.

The nucleation-growth process is a crucial component of crystallization. While previous theoretical models have focused on nucleation events and postnucleation growth, such as the classical nucleation theory and Lifshitz-Slyozov-Wagner model, recent advancements in experiments and simulations have highlighted the inability of classical models to explain the transient dynamics during the early development of nanocrystals. To address these shortcomings, we present a model that describes the nucleation-growth dynamics of individual nanocrystals as a series of reversible chain reactions, with the free energy landscape extended to include activation-adsorption-relaxation reaction pathways. By using the Monte Carlo method based on the transition state theory, we simulate the crystallization dynamics. We derive a Fokker-Planck formalism from the master equation to describe the nucleation-growth process as a heterogeneous random walk on the extended free energy landscape with activated states. Our results reveal the transient quasiequilibrium of the prenucleation stage before nucleation starts, and we identify a postnucleation crossover regime where the dynamic growth exponents asymptotically converge towards classical limits. Additionally, we generalize the power laws to address the dimension and scale effects for the growth of large crystals.

Despite extensive studies of supercooled water, it remains challenging to understand its peculiar dynamic anomalous properties. In this work, we integrated full atomistic simulations of supercooled water over the temperature range of room temperature to 200 K using a quantum-mechanics-based polarizable force field with the dressed dynamics method that couples fast collision events and slow reorganization dynamics of hydrogen-bond networks. Our analysis unveils the salient multiscale features in the transient relaxation dynamics of supercooled water. A classical Langevin behavior dominates at fast timescales, while long-time relaxations unveil two different activation barriers in two temperature regions: below and above 230 K. The modulation of the entropy spectrum by temperature is elucidated in terms of a three-state model underlined by the complexity of the water dynamics associated with a topological transition of a strong hydrogen-bond network. This state-dependent network topology is quantitatively characterized by power-law exponents of inverse network connectivity from 200 to 298 K. This work provides valuable guidance for further studies on the transient relaxation dynamics of supercooled water. © 2023 The Royal Society of Chemistry.

Understanding prokaryotic cell growth requires a multiscale modeling framework from the kinetics perspective. The detailed kinetics pathway of ribosomes exhibits features beyond the scope of the classical Hopfield kinetics model. The complexity of the molecular responses to various nutrient conditions poses additional challenge to elucidate the cell growth. Herein, a kinetics framework is developed to bridge ribosomal synthesis to cell growth. For the ribosomal synthesis kinetics, the competitive binding between cognate and near-cognate tRNAs for ribosomes can be modulated by Mg2+. This results in distinct patterns of the speed – accuracy relation comprising “trade-off” and “competition” regimes. Furthermore, the cell growth rate is optimized by varying the characteristics of ribosomal synthesis through cellular responses to different nutrient conditions. In this scenario, cellular responses to nutrient conditions manifest by two quadratic scaling relations: one for nutrient flux versus cell mass, the other for ribosomal number versus growth rate. Both are in quantitative agreement with experimental measurements. © 2022 Biophysical Society

Perovskite light-emitting diodes (PeLEDs) based on 3D mixed Br-Cl compositions have shown good color stability and efficiency in the sky-blue color range. However, when the Cl/Br ratio increases to reach deep-blue emission, the performance of the PeLEDs decreases drastically, with the external quantum efficiency (EQE) typically below 1%. Such performance decay is due largely to the poor morphology of the emissive layer. Herein, theoretical and experimental approach is combined to investigate the evolution of solvated lead complexes in the precursor solution of mixed Br-Cl perovskites. It is found that the energetically favorable exchange of halide ions in the lead complexes drives the precipitation of CsCl, leading to extremely low precursor solubility at high Cl/Br ratios and consequently poor perovskite film coverage. Based on the findings, a metastable dissolution strategy for perovskite film preparation is proposed and deep-blue PeLEDs with a record high EQE of 4% in 3D-based PeLEDs and excellent spectral stability is achieved.

Electron donors and acceptors in organic solar cells (OSCs) shall strike a favorable vertical phase separation that acceptors and donors have sufficient contact and gradient accumulation near the cathodes and anodes, respectively. Random mixing of donors/acceptors at surface will result in charge accumulation and severe recombination for low carrier-mobility organic materials. However, it is challenging to tune the vertical distribution in bulk-heterojunction films as they are usually made from a well-mixed donor/acceptor solution. Here, for the first time, it presents with solid evidence that the commonly used 1-chloronaphthalene (CN) additive can tune the donor/acceptor vertical distribution and establish the mechanism. Different from the previous understanding that ascribed the efficiency enhancement brought by CN to the improved molecular stacking/crystallization, it is revealed that the induced vertical distribution is the dominant factor leading to the significantly increased performance. Importantly, the vertical distribution tunability is effective in various hot nonfullerene OSC systems and creates more channels for the collection of dissociated carriers at corresponding organic/electrode interfaces, which contributes the high efficiency of 18.29%. This study of the material vertical distribution and its correlation with molecular stacking offers methods for additives selection and provides insights for the understanding and construction of high-performance OSCs. © 2022 Wiley-VCH GmbH

Many researchers have examined the desalination performance of various kinds of two-dimensional (2D) porous nanosheets prepared by top-down approaches such as forming pores on the plain based on molecular dynamics (MD) simulations. In contrast, it is rare to find MD simulations addressing the desalination performance of a 2D porous nanosheet prepared by bottom-up approaches. We investigated the desalination performance of a 2D porous nanosheet prepared by the assembly of cucurbit[6]uril (CB[6]) via MD simulation. The model 2D CB[6] nanosheet features CB[6] with the carbonyl-fringed portals of 3.9 Å and the interstitial space filled with hydrophobic linkers and dangling side chains. Our MD simulation demonstrated that the 2D porous CB[6] nanosheet possesses a 70 to 140 times higher water permeance than commercial reverse osmosis membranes while effectively preventing salt passage. The extremely high water permeance and perfect salt rejection stem from not only CB[6]’s nature (hydrophilicity, negative charge, and the right dimension for size exclusion) but also the hydrophobic and tightly filled interstitial space. We also double-checked that the extremely high water permeance was attributable to only CB[6]’s nature, not water leakage, by contrasting it with a 2D nanosheet comprising CB[6]-spermine complexes. Lastly, this paper provides a discussion on a better cucurbituril homologue to prepare a next-generation desalination membrane possessing great potential to such an extent to surpass the 2D porous CB[6] nanosheet based on quantum mechanics calculations.

Electron donors and acceptors in organic solar cells (OSCs) shall strike a favorable vertical phase separation that acceptors and donors have sufficient contact and gradient accumulation near the cathodes and anodes, respectively. Random mixing of donors/acceptors at surface will result in charge accumulation and severe recombination for low carrier-mobility organic materials. However, it is challenging to tune the vertical distribution in bulk-heterojunction films as they are usually made from a well-mixed donor/acceptor solution. Here, for the first time, it presents with solid evidence that the commonly used 1-chloronaphthalene (CN) additive can tune the donor/acceptor vertical distribution and establish the mechanism. Different from the previous understanding that ascribed the efficiency enhancement brought by CN to the improved molecular stacking/crystallization, it is revealed that the induced vertical distribution is the dominant factor leading to the significantly increased performance. Importantly, the vertical distribution tunability is effective in various hot nonfullerene OSC systems and creates more channels for the collection of dissociated carriers at corresponding organic/electrode interfaces, which contributes the high efficiency of 18.29%. This study of the material vertical distribution and its correlation with molecular stacking offers methods for additives selection and provides insights for the understanding and construction of high-performance OSCs. © 2022 Wiley-VCH GmbH

Identification and classification are important application areas of surface-enhanced Raman spectroscopy (SERS). Substance is identified via the chemical finger-print function of Raman spectroscopy. Diseases can be diagnosed through biofluidic Raman spectrum analysis and classification accordingly. Since bio-fluidic, such as serumurineand tissue fluid contains various substances, Raman spectrum is too complex to be classified manually. The optimization of deep learning classification model is critical in diagnosis accuracy improvement. Here we propose, for the first, applying DARSHN algorithm in automatic diagnosis model design and optimization. DARSHN was applied to serialize the discrete search space. Optimal structural solution was generated through approximate gradient descent subsequently. This research suggested that DARSHN can be used in the optimization of classification models automatically and effectively. Its advantages in the application of serum SERS-based cancer diagnosis compared to residual network spectral classification models were shown in this paper. © 2022 IEEE.

Many researchers have examined the desalination performance of various kinds of two-dimensional (2D) porous nanosheets prepared by top-down approaches such as forming pores on the plain based on molecular dynamics (MD) simulations. In contrast, it is rare to find MD simulations addressing the desalination performance of a 2D porous nanosheet prepared by bottom-up approaches. We investigated the desalination performance of a 2D porous nanosheet prepared by the assembly of cucurbit[6]uril (CB[6]) via MD simulation. The model 2D CB[6] nanosheet features CB[6] with the carbonyl-fringed portals of 3.9 Å and the interstitial space filled with hydrophobic linkers and dangling side chains. Our MD simulation demonstrated that the 2D porous CB[6] nanosheet possesses a 70 to 140 times higher water permeance than commercial reverse osmosis membranes while effectively preventing salt passage. The extremely high water permeance and perfect salt rejection stem from not only CB[6]’s nature (hydrophilicity, negative charge, and the right dimension for size exclusion) but also the hydrophobic and tightly filled interstitial space. We also double-checked that the extremely high water permeance was attributable to only CB[6]’s nature, not water leakage, by contrasting it with a 2D nanosheet comprising CB[6]-spermine complexes. Lastly, this paper provides a discussion on a better cucurbituril homologue to prepare a next-generation desalination membrane possessing great potential to such an extent to surpass the 2D porous CB[6] nanosheet based on quantum mechanics calculations.

The peptidyl transferase center (PTC) in the large subunit of the ribosome plays a critical role in protein synthesis by catalyzing the formation of peptide bonds with an astounding speed of about 15 to 20 peptide bonds per second. The ribosome coordinates the nucleophilic attack and deprotonation in the rate-limiting step at the PTC. However, the details of peptide bond formation within the ribosome, particularly the precise role of the two water molecules in the PTC, remain unclear. Here, we propose a novel stepwise "proton shuttle" mechanism which corroborates all the reported experimental measurements so far. In this mechanism, a water molecule close to A76 of peptidyl-tRNA 2′- and 3′-O stabilizes the transition state. The other one adjacent to the carbonyl oxygen of peptidyl-tRNA actively participates in the proton shuttle, playing the catalytic role of ribosome-catalyzed peptide bond formation.

With the development of state-of-the-art techniques in biological systems, many previous inaccessible data now has become massive. To understanding this unprecedented data is the key to discover new principles underlying the biological behaviour. The application of statistical methods, which contains mathematical formulation and physical thinking, could extract the hidden information from research data and shed light to the major research direction. The evolution is essentially variation, namely mutation, in its genetic material, which leads to the variation in the product, protein. Most of mutations at amino acid level come from non-synonymous single nucleotide polymorphism (nsSNP). The functions of protein could thus be altered. As a result, propagation of mutations and competitions between different sub-types together, is regarded as evolution. In this dissertation, two chapters are included under the title statistical methods for protein function and evolution analysis. In the first chapter, a statistical method, deLemus, is constructed for the time-resolved track of mutation trajectories, and the robustness of deLemus is verified by mapping the SOI with sites with structural and functional significance.In the second chapter, the mechanisms of CRISPR Cas9 were firstly introduced. Then a model with consideration of confrontational changes is proposed to link the mutation and off-target effects. During the ongoing CoVID-19 epidemic, the continuous genomic evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been generating new variants with enhanced transmissibility and immune escape. Being one key target of antibodies, mutations of the spike glycoprotein play a vital role in the trajectory of virus evasion. Here, we present a time-resolved statistical method, dynamic expedition of leading mutations (deLemus), to analyze the evolution dynamics of the spike protein. Together with analysis on single amino-acid polymorphism (SAP), we proposed

Low-dimensional copper halides having nontoxic elements are attracting increasing attention for their peculiar emission properties. Self-trapped excitons (STEs) account for their high photoluminescence quantum yields (PLQYs) with emission that can stretch across the entire visible spectrum. However, intrinsic factors that influence the formation or loss of the emissive species in low-dimensional copper halides remain elusive. Here, a comprehensive study on the STE formation dynamics of one-dimensional CsCu2I3 and zero-dimensional Cs3Cu2I5 is presented. It is found from STE kinetic analysis that a slower STE formation demonstrated by the 1D structure is not hindered by a potential barrier, but instead related to the number of phonons released in the self-trapping process. It is further revealed that in 1D CsCu2I3, the non-radiative recombination of STEs mainly occurs via the intersection between the STE state and the ground state in the configuration coordinate diagram, placing an intrinsic limit on the PLQY at room temperature. These findings show that the STE formation is affected by both the self-trapping depth and the phonon energy as opposed to a potential barrier in low-dimensional copper halides. The better understanding of STE formation and recombination processes provide basis for improving design and performance for broadband light emitting devices.

Introducing ionic liquids (ILs) into ultra-high molecular polyethylene (UHMWPE) is a promising approach to improving the processibility of UHMWPE. To have a comprehensive understanding of the role of ILs in affecting the properties and molecular structures of UHWMPE, we conducted a systematic study on the viscoelastic behaviours of UHMWPE/IL composites with various ILs content at room temperature. Stress relaxation tests were performed under constant tensile strain (epsilon(0) = 0.47%). Constant strain-rate tests were also performed at five strain rates over the range of 2 x 10(-3) s(-1) to 1.7 x10(-1) s(-1). To have deeper insights into the phenomena and the structure-property relationship, theoretical modelling based on the generalized Maxwell model was employed to study the time-dependent relaxation modulus. The modelling results suggest decreased elasticity and viscosity by the addition of ILs, indicating weakened bonding and enhanced motions of chain segments. Moreover, experimental yield stresses from the constant strain-rate tests were modelled by the cooperative model, which is based on the Eyring's activation theory and takes the cooperative motion of chain segments into accounts. Analysis of the modelling results also shows that ILs increased the effective volume and decreased the energy barrier required to activate chain motions, confirming the enhanced mobilities of chain segments of UHMWPE by the addition of ILs.

Solid atomic catalysts with well-defined and complex structures are believed to effectively bridge homogeneous and heterogeneous catalysis. Nonetheless, the current limited capacity of “precise engineering” in solid atomic catalysts has led to structural heterogeneity and thus unsatisfactory catalytic selectivity. Here, we show that late 3d metal cations, such as Co2+, Ni2+, Cu2+, and Zn2+, can be assembled to afford combinations of “dual atoms” within zeolitic micropores, and this clearly avoids issues like uncontrolled metal aggregation during synthesis. In this work, by the quantitative evaluation of the structural descriptors over a probe superoxide dismutation reaction, we demonstrate the unique synergistic advantage between (i) neighboring bimetallic active motifs, (ii) tertiary structure around the zeolitic support, and (iii) the local coordination environment. The identification and tunability of the structural descriptors shown in this work unravel a reliable approach to the precise engineering of next-generation solid dual-atom catalysts. © 2022 Elsevier Inc.

The electrochemical reduction (ECR) of CO2 is a powerful strategy to reduce the world's carbon footprint by converting CO2 to useful products such as CH3OH and CO. Recent techno-economic analysis has found that for the electro-conversion of CO2 to be adapted for practical use, the main products formed from this reaction need to be low-order, such as CO. This review summarizes recent progress in the ECR of CO2 to CO on nano-electrocatalysts (noble, non-noble metals and carbon nanomaterials) and provides the limitations and challenges that each electrocatalyst faces. It discusses the mechanism behind the performance of the electrocatalysts and offers the potential future prospects of the ECR process.

Electron donors and acceptors in organic solar cells (OSCs) shall strike a favorable vertical phase separation that acceptors and donors have sufficient contact and gradient accumulation near the cathodes and anodes, respectively. Random mixing of donors/acceptors at surface will result in charge accumulation and severe recombination for low carrier-mobility organic materials. However, it is challenging to tune the vertical distribution in bulk-heterojunction films as they are usually made from a well-mixed donor/acceptor solution. Here, for the first time, it presents with solid evidence that the commonly used 1-chloronaphthalene (CN) additive can tune the donor/acceptor vertical distribution and establish the mechanism. Different from the previous understanding that ascribed the efficiency enhancement brought by CN to the improved molecular stacking/crystallization, it is revealed that the induced vertical distribution is the dominant factor leading to the significantly increased performance. Importantly, the vertical distribution tunability is effective in various hot nonfullerene OSC systems and creates more channels for the collection of dissociated carriers at corresponding organic/electrode interfaces, which contributes the high efficiency of 18.29%. This study of the material vertical distribution and its correlation with molecular stacking offers methods for additives selection and provides insights for the understanding and construction of high-performance OSCs. © 2022 Wiley-VCH GmbH

Layered phosphorus materials hold great potential in a wide range of applications. Although tremendous efforts have been made to investigate energetics of monolayer phosphorus structures, the insight into better understanding their stability from a structure and bonding perspective remains elusive. In this work, the gauche conformation is identified to play an important role in the energetics of reported monolayer phosphorus allotropes via a proposed potential energy function. This study sheds light on the importance of delicate lone pairs' interactions manifested by gauche effect in understanding the stability of phosphorene allotropes. © 2022 American Chemical Society. All rights reserved.

We study halide perovskites materials, which have lately emerged as potential materials for low-cost, high-efficiency solar cells due to their ease of synthesis and relatively abundant constituent elements, as well as their intriguing photo-physical features. Increasing evidences has showed that the drivers of their remarkable properties is related to a temperature-activated symmetry-lowering distortion effect, which was originally named emphanisis in the context of compounds like rock-salt group IV chalcogenides. Here we study a class of ABX3 compounds [A+ = Cs or CH3NH3 (MA) or CH(NH2)2 (FA); B2+ = Sn or Pb; X- = Br or I] to understand the driving forces behind emphanisis or dynamical off-centering instability. We show that electron-phonon interaction is the driving force with the covalency of BX3 framework and the dipole fluctuations of the A-site cation plays an essential role in determining the off-center temperature. We propose a general formula that capture the observed off-centering temperature dependence on aforementioned factors. Our theory suggests that A-site driven polaron-like model might be beneficial to understand the off-centering phenomenon in halide perovskites.

The need to understand chemistry through data-driven analysis from a comprehensive collection of reaction data has long been recognized, and the development of chemical reaction databases has been conducted for decades, including commercial databases such as Reaxys, Scifinder, or Web of Science and open-source database like the Open Reaction Database. As a result, exploiting information in this large-scale database could accelerate the process of addressing challenging chemistry problems. Recent developments in big data and machine learning have revolutionized approaches for analyzing chemical data, and successful applications of these techniques have significantly advanced the research in chemical reactions, including reaction classification, product prediction, yield estimation, and synthesis planning. In recent years, homogeneous nickel catalysis has been extensively studied in academia and industry. Remarkable advances have been made for many valuable reactions by using nickel as an effective catalyst, owing to its unique reactivity and cost efficiency. It would be beneficial to prepare a dataset to analyze this field from a fundamental point of view and provide more insight into the nickel-catalyzed reactions. We collected and analyzed a comprehensive dataset containing important papers in the field of C-O bond activation cross-coupling reactions and developed data mining tools to accelerate similar studies in the future.

Quantum geometric tensor, including a symmetric real part defined as quantum metric and an antisymmetric part defined as Berry curvature, is essential for understanding many phenomena. In this study, we investigated the photogalvanic effect of semiconductors with time-reversal-invariant and spatial inversion symmetries using the quantum kinetic equation. We concluded that the integral of the symmetric (antisymmetric) part of quantum geometric tensor on the equal energy surface in momentum space, satisfying the resonance condition, is related to the generation rate of carriers in semiconductors under linearly (circularly) polarized light. Under additional bias voltage, the dc photocurrent is proportional to the bias voltage. Our study provided an alternative interpretation for the photogalvanic effect in the view of quantum geometric tensor. Additionally, it classified the intrinsic difference between linearly and circularly polarized optical fields.

Atomistic modeling of energy and charge transfer at the heterojunction of organic solar cells is an active field with many remaining outstanding questions owing, in part, to the difficulties in performing reliable photodynamics calculations on very large systems. One approach to being able to overcome these difficulties is to design and apply an appropriate simplified method. Density-functional tight binding (DFTB) has become a popular form of approximate density-functional theory based on a minimal valence basis set and neglect of all but two center integrals. We report the results of our tests of a recent long-range correction (lc) [A. Humeniuk and R. Mitri, J. Chem. Phys. 143, 134120 (2015)] for time-dependent (TD) lc-DFTB by carrying out TD-lc-DFTB fewest switches surface hopping calculations of energy and charge transfer times using the relatively new DFTBABY [A. Humeniuk and R. Mitri, Comput. Phys. Commun. 221, 174 (2017)] program. An advantage of this method is the ability to run enough trajectories to get meaningful ensemble averages. Our interest in the present work is less in determining exact energy and charge transfer rates than in understanding how the results of these calculations vary with the value of the range-separation parameter (R-lc = 1/mu) for a model organic solar cell heterojunction consisting of a gas-phase van der Waals complex P/F made up of a single pentacene (P) molecule together with a single buckminsterfullerene (F) molecule. The default value of R-lc = 3.03 a(0) is found to be much too small as neither energy nor charge transfer is observed until R-lc approximate to 10 a(0). Tests at a single geometry show that the best agreement with high-quality ab initio spectra is obtained in the limit of no lc (i.e., very large R-lc). A plot of energy and charge transfer rates as a function of R-lc is provided, which suggests that a value of R-lc approximate to 15 a(0) yields the typical literature (condensed-phase) charge transfer time of about

In spite of many efforts to grasp the nature of porous nanomaterials, it is hard to find research work addressing empirical evidence for selective water permeation through their channels or pores. Herein, we report the experimental proof of selective water permeation through cucurbit[6]uril (CB[6]) with a portal diameter of 3.9 Å along with quantum mechanics calculation results elucidating the mechanisms underlying the selective water transport. CB[6] improved the water/salt permselectivity of CB[6]-polyamide thin-film nanocomposite (CB[6]-TFN) membranes since ion passage was inhibited by a high energy barrier imposed by the CB[6]’s portals while the portals are energetically favorable from the perspective of water transport. This difference in water and salt's permeabilities stems from its carbonyl-fringed portals, which are cut out for size exclusion and negatively charged for charge repulsion. Due to the rigidity, CB[6]-TFN membranes were found to be more resistant to compaction under elevated pressures. Such unique characteristics of CB[6] allowed CB[6]-TFN membranes to outperform newly developed TFN membranes as well as commercial RO membranes. © 2020 Elsevier B.V.

Motivated by the controversial bright exciton splittings in inorganic cesium lead halide perovskite nanocrystals, we studied excitation state of perovskite CsPbBr3 by four-band model Hamiltonian. With spin-orbit coupling, the calculated band structure shows that the double degeneracy of each band around (0, 0, 0) point is removed because of broken spatial inversion symmetry (SIS). With broken SIS, ring-shaped valence band maximum is formed in the band structure of ground state, and SU(2) vector potential in momentum is created with the excitation of one electron from valence band to conduction band by photon absorption. In the case of low density carrier, our theory also predicts that the energy splitting between the four binding electron-hole states by the vector potential is proportional to the power of laser light which certainly stimulates further experimental work in this intriguing topic. © 2021 World Scientific Publishing Company.

Introducing ionic liquid (ILs) into ultra-high molecular polyethylene (UHMWPE) to form composites is a promising approach in enhancing the processability of UHMWPE and thus broaden its applications in industries. In order to have a comprehensive understanding of the effect of ILs, we conducted a systematic study on the UHMWPE/ILs composites with various ILs content under different applied tensile strains (0.28, 0.47 and 0.94 %) and room temperature. Constant strain-rate tests are also performed at five constant strain rates over the range of 2 × 10−3 s−1 to 1.7 × 10−1 s−1. The generalized Maxwell model was employed to model the time-dependent relaxation modulus, and the modelling results agree well with the experimental measurements. Moreover, experimental yield stress were modelled by the cooperative model based on Eyring’s activation theory and collective motion of chain segments under a fixed temperature. Analysis of the modelling results suggests that both the activation volume and the energy barrier are reduced by the addition of ILs, resulting in enhanced mobilities of chain segments and processibility of the UHMWPE.

Quantum geometric tensor, including a symmetric real part defined as quantum metric and an antisymmetric part defined as Berry curvature, is essential for understanding many phenomena. In this study, we investigated the photogalvanic effect of semiconductors with time-reversal-invariant and spatial inversion symmetries using the quantum kinetic equation. We concluded that the integral of the symmetric (antisymmetric) part of quantum geometric tensor on the equal energy surface in momentum space, satisfying the resonance condition, is related to the generation rate of carriers in semiconductors under linearly (circularly) polarized light. Under additional bias voltage, the dc photocurrent is proportional to the bias voltage. Our study provided an alternative interpretation for the photogalvanic effect in the view of quantum geometric tensor. Additionally, it classified the intrinsic difference between linearly and circularly polarized optical fields.

In spite of many efforts to grasp the nature of porous nanomaterials, it is hard to find research work addressing empirical evidence for selective water permeation through their channels or pores. Herein, we report the experimental proof of selective water permeation through cucurbit[6]uril (CB[6]) with a portal diameter of 3.9 Å along with quantum mechanics calculation results elucidating the mechanisms underlying the selective water transport. CB[6] improved the water/salt permselectivity of CB[6]-polyamide thin-film nanocomposite (CB[6]-TFN) membranes since ion passage was inhibited by a high energy barrier imposed by the CB[6]’s portals while the portals are energetically favorable from the perspective of water transport. This difference in water and salt's permeabilities stems from its carbonyl-fringed portals, which are cut out for size exclusion and negatively charged for charge repulsion. Due to the rigidity, CB[6]-TFN membranes were found to be more resistant to compaction under elevated pressures. Such unique characteristics of CB[6] allowed CB[6]-TFN membranes to outperform newly developed TFN membranes as well as commercial RO membranes. © 2020 Elsevier B.V.

Motivated by the controversial bright exciton splittings in inorganic cesium lead halide perovskite nanocrystals, we studied excitation state of perovskite CsPbBr3 by four-band model Hamiltonian. With spin-orbit coupling, the calculated band structure shows that the double degeneracy of each band around (0, 0, 0) point is removed because of broken spatial inversion symmetry (SIS). With broken SIS, ring-shaped valence band maximum is formed in the band structure of ground state, and SU(2) vector potential in momentum is created with the excitation of one electron from valence band to conduction band by photon absorption. In the case of low density carrier, our theory also predicts that the energy splitting between the four binding electron-hole states by the vector potential is proportional to the power of laser light which certainly stimulates further experimental work in this intriguing topic. © 2021 World Scientific Publishing Company.

Background and aims: genetic predisposition to autoimmune hepatitis (AIH) in adults is associated with possession of human leukocyte antigen (HLA) class I (A*01, B*08) and class II (DRB1*03, -04, -07, or -13) alleles, depending on geographic region. Juvenile autoimmune liver disease (AILD) comprises AIH-1, AIH-2, and autoimmune sclerosing cholangitis (ASC), which are phenotypically different from their adult counterparts. We aimed to define the relationship between HLA profile and disease course, severity, and outcome in juvenile AILD. Approach and results: we studied 236 children of European ancestry (152 female [64%], median age 11.15 years, range 0.8-17), including 100 with AIH-1, 59 with AIH-2, and 77 with ASC. The follow-up period was from 1977 to June 2019 (median 14.5 years). Class I and II HLA genotyping was performed using PCR/sequence-specific primers. HLA B*08, -DRB1*03, and the A1-B8-DR3 haplotype impart predisposition to all three forms of AILD. Homozygosity for DRB1*03 represented the strongest risk factor (8.8). HLA DRB1*04, which independently confers susceptibility to AIH in adults, was infrequent in AIH-1 and ASC, suggesting protection; and DRB1*15 (DR15) was protective against all forms of AILD. Distinct HLA class II alleles predispose to the different subgroups of juvenile AILD: DRB1*03 to AIH-1, DRB1*13 to ASC, and DRB1*07 to AIH-2. Possession of homozygous DRB1*03 or of DRB1*13 is associated with fibrosis at disease onset, and possession of these two genes in addition to DRB1*07 is associated with a more severe disease in all three subgroups. Conclusions: unique HLA profiles are seen in each subgroup of juvenile AILD. HLA genotype might be useful in predicting responsiveness to immunosuppressive treatment and course.

Quantum geometric tensor, including a symmetric real part defined as quantum metric and an antisymmetric part defined as Berry curvature, is essential for understanding many phenomena. In this study, we investigated the photogalvanic effect of semiconductors with time-reversal-invariant and spatial inversion symmetries using the quantum kinetic equation. We concluded that the integral of the symmetric (antisymmetric) part of quantum geometric tensor on the equal energy surface in momentum space, satisfying the resonance condition, is related to the generation rate of carriers in semiconductors under linearly (circularly) polarized light. Under additional bias voltage, the dc photocurrent is proportional to the bias voltage. Our study provided an alternative interpretation for the photogalvanic effect in the view of quantum geometric tensor. Additionally, it classified the intrinsic difference between linearly and circularly polarized optical fields.

Atomistic modeling of energy and charge transfer at the heterojunction of organic solar cells is an active field with many remaining outstanding questions owing, in part, to the difficulties in performing reliable photodynamics calculations on very large systems. One approach to being able to overcome these difficulties is to design and apply an appropriate simplified method. Density-functional tight binding (DFTB) has become a popular form of approximate density-functional theory based on a minimal valence basis set and neglect of all but two center integrals. We report the results of our tests of a recent long-range correction (lc) [A. Humeniuk and R. Mitri, J. Chem. Phys. 143, 134120 (2015)] for time-dependent (TD) lc-DFTB by carrying out TD-lc-DFTB fewest switches surface hopping calculations of energy and charge transfer times using the relatively new DFTBABY [A. Humeniuk and R. Mitri, Comput. Phys. Commun. 221, 174 (2017)] program. An advantage of this method is the ability to run enough trajectories to get meaningful ensemble averages. Our interest in the present work is less in determining exact energy and charge transfer rates than in understanding how the results of these calculations vary with the value of the range-separation parameter (R-lc = 1/mu) for a model organic solar cell heterojunction consisting of a gas-phase van der Waals complex P/F made up of a single pentacene (P) molecule together with a single buckminsterfullerene (F) molecule. The default value of R-lc = 3.03 a(0) is found to be much too small as neither energy nor charge transfer is observed until R-lc approximate to 10 a(0). Tests at a single geometry show that the best agreement with high-quality ab initio spectra is obtained in the limit of no lc (i.e., very large R-lc). A plot of energy and charge transfer rates as a function of R-lc is provided, which suggests that a value of R-lc approximate to 15 a(0) yields the typical literature (condensed-phase) charge transfer time of about

Motivated by the controversial bright exciton splittings in inorganic cesium lead halide perovskite nanocrystals, we studied excitation state of perovskite CsPbBr3 by four-band model Hamiltonian. With spin-orbit coupling, the calculated band structure shows that the double degeneracy of each band around (0, 0, 0) point is removed because of broken spatial inversion symmetry (SIS). With broken SIS, ring-shaped valence band maximum is formed in the band structure of ground state, and SU(2) vector potential in momentum is created with the excitation of one electron from valence band to conduction band by photon absorption. In the case of low density carrier, our theory also predicts that the energy splitting between the four binding electron-hole states by the vector potential is proportional to the power of laser light which certainly stimulates further experimental work in this intriguing topic. © 2021 World Scientific Publishing Company.

In spite of many efforts to grasp the nature of porous nanomaterials, it is hard to find research work addressing empirical evidence for selective water permeation through their channels or pores. Herein, we report the experimental proof of selective water permeation through cucurbit[6]uril (CB[6]) with a portal diameter of 3.9 Å along with quantum mechanics calculation results elucidating the mechanisms underlying the selective water transport. CB[6] improved the water/salt permselectivity of CB[6]-polyamide thin-film nanocomposite (CB[6]-TFN) membranes since ion passage was inhibited by a high energy barrier imposed by the CB[6]’s portals while the portals are energetically favorable from the perspective of water transport. This difference in water and salt's permeabilities stems from its carbonyl-fringed portals, which are cut out for size exclusion and negatively charged for charge repulsion. Due to the rigidity, CB[6]-TFN membranes were found to be more resistant to compaction under elevated pressures. Such unique characteristics of CB[6] allowed CB[6]-TFN membranes to outperform newly developed TFN membranes as well as commercial RO membranes. © 2020 Elsevier B.V.

Introducing ionic liquid (ILs) into ultra-high molecular polyethylene (UHMWPE) to form composites is a promising approach in enhancing the processability of UHMWPE and thus broaden its applications in industries. In order to have a comprehensive understanding of the effect of ILs, we conducted a systematic study on the UHMWPE/ILs composites with various ILs content under different applied tensile strains (0.28, 0.47 and 0.94 %) and room temperature. Constant strain-rate tests are also performed at five constant strain rates over the range of 2 × 10−3 s−1 to 1.7 × 10−1 s−1. The generalized Maxwell model was employed to model the time-dependent relaxation modulus, and the modelling results agree well with the experimental measurements. Moreover, experimental yield stress were modelled by the cooperative model based on Eyring’s activation theory and collective motion of chain segments under a fixed temperature. Analysis of the modelling results suggests that both the activation volume and the energy barrier are reduced by the addition of ILs, resulting in enhanced mobilities of chain segments and processibility of the UHMWPE.

Background and aims: genetic predisposition to autoimmune hepatitis (AIH) in adults is associated with possession of human leukocyte antigen (HLA) class I (A*01, B*08) and class II (DRB1*03, -04, -07, or -13) alleles, depending on geographic region. Juvenile autoimmune liver disease (AILD) comprises AIH-1, AIH-2, and autoimmune sclerosing cholangitis (ASC), which are phenotypically different from their adult counterparts. We aimed to define the relationship between HLA profile and disease course, severity, and outcome in juvenile AILD. Approach and results: we studied 236 children of European ancestry (152 female [64%], median age 11.15 years, range 0.8-17), including 100 with AIH-1, 59 with AIH-2, and 77 with ASC. The follow-up period was from 1977 to June 2019 (median 14.5 years). Class I and II HLA genotyping was performed using PCR/sequence-specific primers. HLA B*08, -DRB1*03, and the A1-B8-DR3 haplotype impart predisposition to all three forms of AILD. Homozygosity for DRB1*03 represented the strongest risk factor (8.8). HLA DRB1*04, which independently confers susceptibility to AIH in adults, was infrequent in AIH-1 and ASC, suggesting protection; and DRB1*15 (DR15) was protective against all forms of AILD. Distinct HLA class II alleles predispose to the different subgroups of juvenile AILD: DRB1*03 to AIH-1, DRB1*13 to ASC, and DRB1*07 to AIH-2. Possession of homozygous DRB1*03 or of DRB1*13 is associated with fibrosis at disease onset, and possession of these two genes in addition to DRB1*07 is associated with a more severe disease in all three subgroups. Conclusions: unique HLA profiles are seen in each subgroup of juvenile AILD. HLA genotype might be useful in predicting responsiveness to immunosuppressive treatment and course., Fifth Medical Center of PLA General Hospital; Roger Dobson Funds; King's College Hospital Charity; Medical Research Council Clinician Scientist Fellowship; Medical Research Council PhD Studentship; Alex Mowat PhD Studentship; King's College Hospital Charity; National Institute for Health Research University College London Hospital/University College London Biomedical Research Centre

Concentrated lithium solvated electron solutions (LiSESs) consisting of p-terphenyl (TER) in tetrahydrofuran (THF) prepared using suspensions of TER in THF, exhibit a more than twelve times increase in conductivity compared to more dilute solutions. The temperature dependent conductivity of LiSES has metallic-like characteristics, i.e. linear decrease of conductivity with increasing temperature, except for the solution of higher concentration (less THF) with the ratio of lithium to TER being 2 which conductivity increases as raising temperature due to the higher contribution of ionic conductivity. From temperature dependent open circuit voltage temperature measurement, the values of changes in entropy (ΔS) and enthalpy (ΔH) were determined. Unlike lithium-intercalated graphite, the ΔS decreases linearly as the ratio of lithium to TER increases, which demonstrates fundamental differences in the lithium charging/discharging processes between solution and solid state. The TER based LiSES with higher concentrations (less THF) show deviations from the ΔS and ΔH values of solutions with lower concentrations. The ΔS values for the TER based LiSES are higher than for naphthalene and biphenyl based Li SES having the same composition, but lower than those for solid lithium ion battery anode materials. LiSES with the maximum ratio of lithium to TER is 2.4 to 1 exhibits minimum conductivity which indicates the formation of a dimeric structure under these conditions. The LiSES provides higher energy density comparing to vanadium redox batteries, which demonstrates that LiSES holds good promise as anolytes in liquid-based refuelable batteries.

High electron mobility is pivotal in engineering oxide interfaces for electronic devices. Here, interfacial structure and physical behaviors of gamma-A1(2)O(3)/SrTiO3 spinel/perovskite heterostructure are explored to understand the microscopic origin of its extremely high electron mobility (1.4 x 10(5) cm(2) V(-1 )s(-1) at 2 K). Lattice mismatch at interface and intrinsic Al cation vacancies result in unexpected interfacial reconstruction and anisotropic electronic behavior. The spontaneous polarization in the gamma-A1(2)O(3) part leads to an insulator-metal transition observed experimentally, even if the thickness of gamma-A1(2)O(3) is only one unit cell, and a strong internal electric field can be as large as 142 mV/angstrom roughly 1.8 times the experimentally observed value of 80.1 mV/angstrom in LaA1O(3)/SrTiO3. As a result, unlike only in-plane slightly occupied Ti-d(xy) subbands in the conventional SrTiO3-based perovskite/perovskite heterostructure, all three t(2g) orbitals have charge exchange with the surfacial O-2p orbitals in gamma-A1(2)O(3)/SrTiO3; especially, the preferential orbital occupation is out-of-plane Ti-d(xz)/Ti-d(yz) at the interface. Nontrivial orbital occupation and complicated interfacial reconstruction result in large group velocity and a high density of states at the Fermi level and therefore serve as the origins of extremely high electron mobility and high carrier concentration. The physical mechanism revealed in our work offers insight into the creation of high-mobility nanoscale electronic devices.

The mainstream approach to antiviral drugs against COVID-19 is to focus on key stages of the SARS-CoV-2 life cycle. The vast majority of candidates under investigation are repurposed from agents of other indications. Understanding protein-inhibitor interactions at the molecular scale will provide crucial insights for drug discovery to stop this pandemic. In this article, we summarize and analyze the most recent structural data on several viral targets in the presence of promising inhibitors for COVID-19 in the context of the perspective of modes of action (MOA) to unravel insightful mechanistic features with atomistic resolution. The targets include spike glycoprotein and various host proteases mediating the entry of the virus into the cells, viral chymotrypsin- and papain-like proteases, and RNA-dependent RNA polymerase. The main purpose of this review is to present detailed MOA analysis to inspire fresh ideas for both de novo drug design and optimization of known scaffolds to combat COVID-19.

In the original publication of the article, in the Appendix section, under the heading “Calculations by density functional theory-based methods” the ionization potential (IP) equation incorrectly appears as IP=IP=EM+−EM. The correct equation is as below: IP=EM+−EM

As-grown AgF2 has an electronic structure remarkably similar to insulating cuprates, but it is extremely electronegative, which makes it hard to handle and dope. Furthermore, buckling of layers reduces magnetic interactions and enhances unwanted self-trapping lattice effects. We argue that epitaxial engineering can solve all these problems. By using a high-throughput approach and first-principle computations, we find a set of candidate substrates which can sustain the chemical aggressiveness of AgF2 and at the same time have good lattice parameter matching for heteroepitaxy, enhancing AgF2 magnetic and transport properties, and opening the possibility of field-effect carrier injection to achieve a unique generation of high-Tc superconductors. Assuming magnetic mechanism and extrapolating from cuprates we predict that the superconducting critical temperature of a single layer can reach 195 K.

Herein, we report a smart coating with autonomous self-healing and self-reporting functions by simple integration of one-component microcapsules into the matrix without external intervention. The microcapsules containing hexamethylene diisocyanate (HDI) solution of aggregation-induced emission luminogens (AIEgens) were synthesized, and their properties, such as their composition, thermal stability, morphology, and damage-indicating ability, were investigated systematically. The AIEgen/HDI microcapsule-embedded coatings display adaptive self-repair of scratches and simultaneous high-contrast indication of the healed damage. Two commercialized AIEgens, tetraphenylethylene (TPE) and its derivative with dimethoxyl and benzylidene-methyloxazolone moieties (DM-TPE-BMO), were utilized as examples to demonstrate the feasibility of this concept in diverse polymer matrixes (including blue autofluorescent matrixes). It was found that the content of AIEgens can even be lowered to 0.05 wt %. This facile, economical, and feasible strategy toward the dual functions of self-repairing and self-sensing provides a new route for enhancing the longevity and reliability of polymer coatings, which is appealing and of great importance in practical applications. Copyright © 2019 American Chemical Society.

Adsorption of globular proteins at liquid-liquid interface results in compromised structures and functionalities to maintain a thermodynamically favorable state. However, the structural behavior of highly symmetrical supramolecular protein assemblies, adsorbed at the liquid-liquid interface, is not well understood. In this study, a model supramolecular protein assembly, E2 protein nanocage, a dodecahedral cage-structured protein, is studied upon adsorption at the oil-water interface by both theoretical and experimental analyses. Molecular dynamics simulations and force estimation reveal that noncovalent interactions between E2 subunits dominate over the tangential force experienced by E2 at the interface allowing it to retain its structural integrity. Experimental analyses confirm the adsorption of E2 on the liquid-liquid interface with negligible penetration depth. Molecular structural analyses further suggest the structural integrity of the caged structure of E2 at the oil-water interface with minimal change in the tertiary and secondary structures. In conclusion, this study brings new insights into the behavior of highly symmetrical supramolecular protein assemblies at liquid-liquid interface which is important in preserving their functionalities.

Recent experimental data reveal the complexity of diffusion dynamics beyond the scope of classical Brownian dynamics. The particles exhibit diverse diffusive motions from the anomalous toward classical diffusion over a wide range of temporal scales. Here a dressed diffusion model is developed to account for non-Brownian phenomena. By coupling the particle dynamics with a local field, the dressed diffusion model generalizes the Langevin equation through coupled damping kernels and generates the salient feature of time-dependent diffusion dynamics reported in the experimental measurements of biomolecules. The dressed diffusion model provides one quantitative aspect for future endeavors in this rapid-growing field. Copyright © 2019 American Chemical Society.

In the original publication of the article, in the Appendix section, under the heading “Calculations by density functional theory-based methods” the ionization potential (IP) equation incorrectly appears as IP=IP=EM+−EM. The correct equation is as below: IP=EM+−EM

Transparent ceramics have various potential applications such as infrared (IR) windows/domes, lamp envelopes, opto-electric components/devices, composite armors, and screens for smartphones and they can be used as host materials for solid-state lasers. Transparent ceramics were initially developed to replace single crystals because of their simple processing route, variability in composition, high yield productivity, and shape control, among other factors. Optical transparency is one of the most important properties of transparent ceramics. In order to achieve transparency, ceramics must have highly symmetric crystal structures; therefore, the majority of the transparent ceramics have cubic structures, while tetragonal and hexagonal structures have also been reported in the open literature. Moreover, the optical transparency of ceramics is determined by their purity and density; the production of high-purity ceramics requires high-purity starting materials, and the production of high-density ceramics requires sophisticated sintering techniques and optimized sintering aids. Furthermore, specific mechanical properties are required for some applications, such as window materials and composite armor. This review aims to summarize recent progress in the fabrication and application of various transparent ceramics. © 2019 The Authors