Potential-Regulated Design for Direct Recycling of Degraded LiFePO4 Cathode.

The rapid proliferation of power sources equipped with lithium-ion batteries poses significant challenges in terms of post-scrap recycling and environmental impacts, necessitating urgent attention to the development of sustainable solutions. The cathode direct regeneration technologies present an optimal solution for the disposal of degraded cathodes, aiming to non-destructively re-lithiate and straightforwardly reuse degraded cathode materials with reasonable profits and excellent efficiency. Herein, a potential-regulated strategy is proposed for the direct recycling of degraded LiFePO4 cathodes, utilizing low-cost Na2SO3 as a reductant with lower redox potential in the alkaline systems. The aqueous re-lithiation approach, as a viable alternative, not only enables the re-lithiation of degraded cathode while ignoring variation in Li loss among different feedstocks but also utilizes the rapid sintering process to restore the cathode microstructure with desirable stoichiometry and crystallinity. The regenerated LiFePO4 exhibits enhanced electrochemical performance with a capacity of 144 mA h g-1 at 1 C and a high retention of 98% after 500 cycles at 5 C. Furthermore, this present work offers considerable prospects for the industrial implementation of directly recycled materials from lithium-ion batteries, resulting in improved economic benefits compared to conventional leaching methods.

Investigating the proliferative inhibition of HepG2 cells by exosome-like nanovesicles derived from Centella asiatica extract through metabolomics.

Nano-particles demonstrating excellent anticancer properties have gradually found application in cancer therapy. However, their widespread use is impeded by their potential toxicity, high cost, and the complexity of the preparation process. In this study, we achieved exosome-like Centella asiatica-derived nanovesicles (ADNVs) through a straightforward juicing and high-speed centrifugation process. We employed transmission electron microscopy and nanoparticle flow cytometry to characterize the morphology, diameter, and stability of the ADNVs. We evaluated the in vitro anticancer effects of ADNVs using Cell Counting Kit-8 and apoptosis assays. Through sequencing and bicinchoninic acid protein analysis, we discovered the abundant presence of proteins and microRNAs in ADNVs. These microRNAs can target various diseases such as cancer and infection. Furthermore, we demonstrated the effective internalization of ADNVs by HepG2 cells, resulting in an increase in reactive oxygen species levels, mitochondrial damage, cell cycle arrest at the G1 phase, and apoptosis. Finally, we analyzed changes in cellular metabolites post-treatment using cell metabolomics techniques. Our findings indicated that ADNVs primarily influence metabolic pathways such as amino acid metabolism and lipid biosynthesis, which are closely associated with HepG2 treatment. Our results demonstrate the potential utility of ADNVs as anticancer agents.

Enzymatic mechanism of MlrB for catalyzing linearized microcystins by Sphingopyxis sp. USTB-05.

Microcystins (MCs) are the most widespread cyanobacterial toxins in eutrophic water body. As high toxic intermediate metabolites, linearized MCs are further catalyzed by linearized microcystinase (MlrB) of Sphingopyxis sp. USTB-05. Here MlrB structure was studied by comprizing with a model representative of the penicillin-recognizing enzyme family via homology modeling. The key active sites of MlrB were predicted by molecular docking, and further verified by site-directed mutagenesis. A comprehensive enzymatic mechanism for linearized MCs biodegradation by MlrB was proposed: S77 transferred a proton to H307 to promote a nucleophilic attack on the peptide bond (Ala-Leu in MC-LR or Ala-Arg in MC-RR) of linearized MCs to form the amide intermediate. Then water was involved to break the peptide bond and produced the tetrapeptide as product. Meanwhile, four amino acid residues (K80, Y171, N173 and D245) acted synergistically to stabilize the substrate and intermediate transition states. This study firstly revealed the enzymatic mechanism of MlrB for biodegrading linearized MCs with both computer simulation and experimental verification.

Ultrasensitive label-free electrochemical aptasensor for Pb2+ detection exploiting Exo III amplification and AgPt/GO nanocomposite-enhanced transduction.

Lead ion pollution has become a serious public health concern worldwide. Therefore, sensitive detection of Pb2+ is critical to control lead pollution, assess risks, and safeguard the health of vulnerable populations. This study reports a highly sensitive labelling-free electrochemical aptasensor for Pb2+ detection. The aptasensor employs silver-platinum nanoparticles/graphene oxide (AgPt/GO) and Exonuclease III (Exo III) for signal amplification. GO provides high surface area and conductivity for immobilizing AgPt NPs, facilitating the immobilization of aptamer (Apt) probes on the electrode surface. Exo III enzymatically cleaves DNA strands on the electrode surface, releasing DNA segments to amplify the signal further. The synergistic amplification by AgPt/GO and ExoIII enables an extremely wide linear detection range of 0.05 pM-5 nM for Pb2+, with a low detection limit of 0.019 pM. Additionally, the G-quadruplex structure ensures excellent selectivity for Pb2+ detection, resulting in high reproducibility and stability of the aptasensor. The aptasensor was successfully applied to detect spiked Pb2+ in tap water samples, achieving recovery rates ranging from 96 to 108.4 %. By integrating nanomaterials, aptamers and enzymatic amplification, the aptasensor facilitates highly sensitive and selective detection of Pb2+, demonstrating potential for practical applications in environmental monitoring.

Soft yet mechanically robust injectable alginate hydrogels with processing versatility based on alginate/hydroxyapatite hybridization.

The salient gelling feature of alginate via forming the egg-box structure with calcium ions has received extensive interests for different applications. Owing to the interfacial incompatibility of rigid inorganic solids with soft polymers, the requirement of overall stereocomplexation with calcium released from uniformly distributed solids in alginate remains a challenge. In this study, a novel alginate-incorporated calcium source was proposed to tackle the intractable dispersion for the preparation of injectable alginate hydrogels. Calcium phosphate synthesis in alginate solution yielded CaP-alginate hybrids as a calcium source. The physicochemical characterization confirmed the CaP-alginate hybrid was a nano-scale alginate-hydroxyapatite complex. The colloidally stable CaP-alginate hybrids were uniformly dispersed in alginate solutions even under centrifugation. The calcium-induced gelling of the CaP-alginate hybrids-loaded alginate solutions formed soft yet tough hydrogels including transparent sheets and knittable threads, confirming the homogeneous gelation of the hydrogel. The gelation time, injectability and mechanical properties of the hydrogels could be adjusted by changing preparation parameters. The prepared hydrogels showed uniform porous structure, excellent swelling, wetting properties and cytocompatibility, showing a great potential for applications in different fields. The present strategy with organic/inorganic hybridization could be exemplarily followed in the future development of functional hydrogels especially associated with the interface integration.

Multidimensional biomarker approach integrating tumor markers, inflammatory indicators, and disease activity indicators may improve prediction of rheumatoid arthritis-associated interstitial lung disease.

INTRODUCTION: Rheumatoid arthritis (RA) often leads to interstitial lung disease (ILD), significantly affecting patient outcomes. This study explored the diagnostic accuracy of a multi-biomarker approach to offer a more efficient and accessible diagnostic strategy for RA-associated ILD (RA-ILD). METHODS: Patients diagnosed with RA, with or without ILD, at Beijing Tiantan Hospital from October 2019 to October 2023 were analyzed. A total of 125 RA patients were included, with 76 diagnosed with RA-ILD. The study focused on three categories of indicators: tumor markers, inflammatory indicators, and disease activity measures. The heatmap correlation analysis was employed to analyze the correlation among these indicators. Logistic regression was used to determine odds ratios (OR) for indicators linked to RA-ILD risk. Receiver-operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic potential of these indicators for RA-ILD. RESULTS: The results of logistic regression analysis showed that tumor markers (carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), and cytokeratin 19 fragment (CYFRA21-1)), as well as inflammatory indicators (neutrophil, neutrophil-to-lymphocyte ratio (NLR), platelet, C-reactive protein (CRP)) and disease activity measures (disease activity score-28-CRP (DAS28-CRP), rheumatoid factor (RF), and anti-cyclic peptide containing citrulline (anti-CCP)), were significantly associated with RA-ILD. The correlation coefficients among these indicators were relatively low. Notably, the combination indicator 4, which integrated the aforementioned three categories of biomarkers, demonstrated improved diagnostic accuracy with an AUC of 0.857. CONCLUSION: The study demonstrated that combining tumor markers, inflammatory indicators, and disease activity measures significantly enhanced the prediction of RA-ILD. Key Points • Multidimensional strategy: Integrated tumor markers, inflammatory indicators, and disease activity measures to enhance early detection of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). • Diagnostic accuracy: Employed heatmap correlation and logistic regression, identifying significant associations and improving diagnostic accuracy with a multidimensional biomarker combination. • Superior performance: The combined multidimensional biomarker strategy demonstrated higher diagnostic precision compared to individual or dual-category indicators. • Clinical relevance: Offers a promising, accessible approach for early detection of RA-ILD in clinical settings, potentially improving patient outcomes.

Microstructure, Mechanical Property and Thermal Conductivity of Porous TiCO Ceramic Fabricated by In Situ Carbothermal Reduction of Phenolic Resin and Titania.

The porous TiCO ceramic was synthesized through a one-step sintering method, utilizing phenolic resin, TiO2 powder, and KCl foaming agent as raw materials. Ni(NO3)2·6H2O was incorporated as a catalyst to facilitate the carbothermal reaction between the pyrolytic carbon and TiO2 powder. The influence of Ni(NO3)2·6H2O catalyst content (0, 5, 10 wt.% of the TiO2 powder) on the microstructure, compressive strength, and thermal conductivity of the resultant porous TiCO ceramic was examined. X-ray diffraction and X-ray photoelectron spectroscopy results confirmed the formation of TiC and TiO in all samples, with an increase in the peak of TiC and a decrease in that of TiO as the Ni(NO3)2·6H2O content increased from 0% to 10%. Scanning electron microscopy results demonstrated a morphological change in the pore wall, transforming from a honeycomb-like porous structure composed of well-dispersed carbon and TiC-TiO particles to rod-shaped TiC whiskers, interconnected with each other as the catalyst content increased from 0% to 10%. Mercury intrusion porosimetry results proved a dual modal pore-size distribution of the samples, comprising nano-scale pores and micro-scale pores. The micro-scale pore size of the samples minorly changed, while the nano-scale pore size escalated from 52 nm to 138 nm as the catalyst content increased from 0 to 10%. The morphology of the pore wall and nano-scale pore size primarily influenced the compressive strength and thermal conductivity of the samples by affecting the load-bearing capability and solid heat-transfer conduction path, respectively.

Effectiveness of tofacitinib monotherapy for patients with IgG4-RD or idiopathic retroperitoneal fibrosis.

OBJECTIVES: To explore the effectiveness of tofacitinib for immunoglobulin G4-related disease (IgG4-RD) and idiopathic retroperitoneal fibrosis (IRF), and investigate the expression of JAKs in the lesion of these diseases. METHODS: Clinical data of patients with IgG4-RD or IRF who were administered with tofacitinib monotherapy were collected. IgG4-RD responder index (IgG4-RD RI) was assessed. The expression of JAK1, JAK2, JAK3, and TYK2 were analysed with immunohistochemistry staining in three salivary glands specimens of IgG4-RD and one retroperitoneal tissue of IRF. RESULTS: Two patients with IRF and two patients with IgG4-RD used tofacitinib monotherapy. Two patients with IRF achieved complete remission with diminished retroperitoneal mass and decreased CRP, as IgG4-RD RI decreased from 6 to 1 in both of them. One with IgG4-RD achieved complete remission with alleviated enlargement of pancreas and IgG4 level decreased from 13.7 g/L to 2.4 g/L, as IgG4-RD RI decreased from 12 to 1. One with IgG4-RD achieved partial response with IgG4 level decreased from 77.1g/L to 25.8g/L as IgG4-RD RI from 18 to 6. JAK1, JAK2, JAK3, and TYK2 expression were detected in biopsy tissues. The staining intensity of the JAK family on the lesion from one IRF patient was similar to those from IgG4-RD patients. CONCLUSIONS: Tofacitinib is a potentially effective treatment for IgG4-RD and IRF and it is reasonable to conduct clinical trial to validate its efficacy. The JAKs were expressed in the inflammatory lesions of IgG4-RD and IRF and they may share a common pathogenesis pathway that is independent of IgG4 production.

Enhancing Iodine Capture of Porous Organic Cages through N-Heteroatom Engineering.

Iodine radioisotopes, produced or released during nuclear-related activities, severely affect human health and the environment. The efficient removal of radioiodine from both aqueous and vapor phases is crucial for the sustainable development of nuclear energy. In this study, we propose an "N-heteroatom engineering" strategy to design three porous organic cages with N-containing functional groups for efficient iodine capture. Among the molecular cages investigated, FT-Cage incorporating tertiary amine groups and RT-Cage with secondary amine groups show higher adsorption capacity and much faster iodine release compared to IT-Cage with imine groups. Detailed investigations demonstrate the superiority of amine groups, along with the influence of crystal structures and porosity, for iodine capture. These findings provide valuable insights for the design of porous organic cages with enhanced capabilities for capturing iodine.

Xianglian Pill combined with 5-fluorouracil enhances antitumor activity and reduces gastrointestinal toxicity in gastric cancer by regulating the p38 MAPK/NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Perioperative or postoperative adjuvant chemotherapy based on 5-fluorouracil (5-FU) is a common first-line adjuvant therapy for gastric cancer (GC). However, drug resistance and the side effects of 5-FU have reduced its efficacy. Among these side effects, gastrointestinal (GI) toxicity is one of the most common. Xianglian Pill (XLP) is a Chinese patent medicine that is commonly used for the treatment of diarrhoea. It can reduce inflammation and has a protective effect on the intestinal mucosa. Recent studies have shown that many components of XLP can inhibite tumor cell growth. However, the therapeutic effect of XLP in combination with 5-FU on GC is unclear. AIM OF THE STUDY: To investigate whether the combination of XLP and 5-FU can enhance anti-GC activity while reducing GI toxicity. MATERIALS AND METHODS: XLP was administered orally during intraperitoneal injection of 5-FU in GC mice model. Mice were continuously monitored for diarrhea and xenograft tumor growth. After 2 weeks, the mice were sacrificed and serum was collected to determine interleukin-6 levels. Pathological changes, the expression of pro-inflammatory factors and p38 mitogen-activated protein kinase (MAPK) in GI tissue were determined by Western blot analysis. Pathological changes, apoptosis levels and p38 MAPK expression levels in xenograft tissues were also determined. RESULTS: The results showed that XLP could alleviate GI mucosal injury caused by 5-FU, alleviated diarrhea, and inhibited the expression of nuclear factor (NF)-κB and myeloid differentiation primary response-88. Besides, XLP could promote the 5-FU-induced apoptosis of GC cells and enhance the inhibitory effect of 5-FU on tumor xenografts. Further study showed that XLP administration could regulate the expression of p38 MAPK. CONCLUSIONS: XLP in combination with 5-FU could alleviate its GI side effects and enhance its inhibitory effect on xenograft tumor. Moreover, these effects were found to be related to the regulation of the p38 MAPK/NF-κB pathway.

Clinical characteristics of Guillain-Barré syndrome in patients with primary Sjögren's syndrome.

To investigate the clinical characteristics of Guillain-Barré syndrome (GBS) in patients with primary Sjögren's syndrome (SS). Records of patients with positive anti-SSA antibodies hospitalized in the Beijing Tiantan Hospital between December 2011 and May 2020 were retrieved. Patients who fulfilled the criteria for diagnosis of GBS and primary SS were included, and their clinical data were analyzed. Among the 785 patients with positive anti-SSA, 52 patients were identified in this study. They were 27 males and 25 females with median age of 59 years old. Besides anti-SSA antibodies, multiple autoantibodies were detected in these patients including antinuclear antibody, anti-Ro52, anti-mitochondrial M2, anti-thyroid peroxidase and anti-thyroglobulin autoantibodies. Preceding infection was reported in 42 patients. Hyporeflexia/areflexia and limbs weakness were the most common manifestation and 35 patients presented cranial nerve injuries. GBS disability score of 3, 4 and 5 was scaled in 28 (53.8%), 15 (28.8%) and 3 (5.8%) patients respectively. Forty-six patients received intravenous immunoglobulin (IVIG) monotherapy, 5 patients were treated by IVIG plus glucocorticoids, and 51 patients improved during hospitalization. The frequency of male gender among the patients with both GBS and primary SS suggests an independent onset of GBS and the co-existence of these autoimmune diseases in patients with multiple autoantibodies. Majority of patients with GBS and primary SS experience benign disease course.

Negatively Curved Octagon-Incorporated Aza-nanographene and its Assembly with Fullerenes.

A negatively curved aza-nanographene (NG) containing two octagons was synthesized by a regioselective and stepwise cyclodehydrogenation procedure, in which a double aza[7]helicene was simultaneously formed as an intermediate. Their saddle-shaped structures with negative curvature were unambiguously confirmed by X-ray crystallography, thereby enabling the exploration of the structure-property relationship by photophysical, electrochemical and conformational studies. Moreover, the assembly of the octagon-embedded aza-NG with fullerenes was probed by fluorescence spectral titration, with record-high binding constants (Ka=9.5×103 M-1 with C60, Ka=3.7×104 M-1 with C70) found among reported negatively curved polycyclic aromatic compounds. The tight association of aza-NG with C60 was further elucidated by X-ray diffraction analysis of their co-crystal, which showed the formation of a 1 : 1 complex with substantial concave-convex interactions.

pH-Responsive Carrier-Free Polyphenol Nanoparticles Assembled by Oxidative Polymerization with Enhanced Stability and Antioxidant Activity for Improved Bioaccessibility.

Encapsulation of plant polyphenols with micro-/nano-carriers for enhanced bioavailability has been well documented, but the preparation of these carriers and subsequent loading of polyphenols is a multiple process, which is generally complicated with potentially unexpected negative effects on the bioactivity of the polyphenols. Here, we reported a convenient method to assemble carrier-free polyphenol nanoparticles (NPs) based on oxidative coupling polymerization. The effectiveness was assessed with five different polyphenols including pyrocatechol (PY), catechin (CA), epigallocatechin gallate (EGCG), tannic acid (TA), and proanthocyanidin (PC). The structural characteristics of these assembled nanoparticles (PY NPs, CA NPs, EG NPs, TA NPs, and PC NPs) were systematically analyzed with dynamic light scattering (DLS), transmission electron microscopy (TEM), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR). All NPs were colloidally stable with varying NaCl concentrations from 0 to 300 mM, were acid-resistant and alkali-intolerant, and were suitable for oral administration. An array of antioxidant assays further confirmed the superior antioxidant capabilities of NPs over Trolox and polyphenol monomers, indicating that the oxidative polymerization of polyphenols did not compromise the polyphenol activity of NPs. The in vitro simulated digestion studies validated that these responsive NPs were actually gastrointestinal pH-responsive and applicable to the gastrointestinal physiological environment. The bioaccessibility assessments by using a static in vitro digestion model revealed that better results were achieved with NPs than polyphenol monomers, with TA NPs showing about 1.5-fold higher bioaccessibility than other polyphenol nanoparticles. The present study with five polyphenols demonstrated that the oxidative polymerization of polyphenols provides an effective platform to assemble various carrier-free NPs with enhanced antioxidant activity, favorable stability, and improved bioaccessibility, which could be used promisingly as a functional food ingredient in food matrices or as oral drug delivery candidates for helping to manage human health or treating various gastrointestinal disorders in both the pharmaceutical and nutritional fields.

Molecular Face-Rotating Polyhedra: Chiral Cages Inspired by Mathematics.

ConspectusMolecular polyhedral cages, notable for their enclosed inner cavities, can possess varying degrees of symmetry, spanning from regular Platonic polyhedra to lower symmetry forms that may display chirality. Crafting chiral molecular cages typically involves using building blocks containing stereogenic elements or arranging achiral components in a manner that lacks mirror and inversion symmetries. Achieving precise control over their chirality poses both significance and challenges.In this Account, we present an overview of our research endeavors in the realm of chiral molecular polyhedral cages, drawing inspiration from Buckminster Fuller's "Face-Rotating Polyhedra (FRP)". Mathematically, FRP introduce a unique form of chirality distinguished by a rotating pattern around the center of each face, setting it apart from regular polyhedra.Molecular FRP can be constructed using two types of facial building blocks. The first includes rigid, planar molecules such as truxene and triazatruxene, which exhibit either clockwise or counterclockwise rotations in two dimensions. The second category involves propeller-like molecules, e.g., tetraphenylethylene, 1,2,3,4,5-penta(4-phenylaldehyde)pyrrole, and tridurylborane, displaying dynamic stereochemistry.The synthesis of FRP may potentially yield a diverse array of stereoisomers. Achieving high stereoselectivity becomes feasible through the selection of building blocks with specific substitution patterns and rigidity. Prominent noncovalent repulsive forces within the resulting cages often play a pivotal role in the dynamic covalent assembly process, ultimately leading to the formation of thermodynamically stable FRP products.The capacity to generate a multitude of stereoisomers, combined with the integration of chiral vertices, has facilitated investigations into phenomena such as chiral self-sorting and the "sergeant and soldiers" chiral amplification effect in FRP. Even the inclusion of one chiral vertex significantly impacts the stereochemical configuration of the entire cage. While many facial building blocks establish a stable rotational pattern in FRP, other units, such as tridurylborane, can dynamically transition between P and M configurations within the cage structures. The kinetic characteristics of such stereolabile FRP can be elucidated through physicochemical investigations.Our research extends beyond the FRP concept to encompass mathematical analysis of these structures. Graph theory, particularly the coloring problem, sheds light on the intricate facial patterns exhibited by various FRP stereoisomers and serves as an efficient tool to facilitate the discovery of novel FRP structures. This approach offers a fresh paradigm for designing and analyzing chiral molecular polyhedral cages, showcasing in our work the synergy between mathematics and molecular design.

Influences of carboxymethyl chitosan upon stabilization and gelation of O/W Pickering emulsions in the presence of inorganic salts.

The objective of this study was to investigate the effects of carboxymethyl chitosan (CMCS) on the stabilization and gelation of oil-in-water (O/W) Pickering emulsions (PEs) with polyphenol-amino acid particles in the presence of inorganic salts. The results revealed that the CMCS-induced depletion interactions contributed to improving the emulsification ability and interfacial adsorption efficiency of polyphenol-amino acid particles as well as constructing the network structures in the continuous phase. These relevant changes collectively resulted in elevating stability, viscosity and moduli of PEs. The additional effects of different inorganic salts with varying additions were further investigated, and the addition-dependent phenomena were observed. At low additions of inorganic salts, the occurrence of the chelation of inorganic salts with CMCS consolidated the constructed network structure, favorable to the gelation of PEs. With increasing additions, this chelation effect became stronger which compromised the CMCS-induced depletion, gradually leading to destabilization of PEs. In terms of ion species, the more pronounced effect on emulsion stability was achieved with calcium ions than with potassium and iron ions. This study expects to provide a new perspective on the extending application of cationic CMCS for improving the stability of O/W PEs in the food industry.

Collagen Scaffolds Functionalized by Cu2+-Chelated EGCG Nanoparticles with Anti-Inflammatory, Anti-Oxidation, Vascularization, and Anti-Bacterial Activities for Accelerating Wound Healing.

Skin injury is a common health problem worldwide, and the highly complex healing process poses critical challenges for its management. Therefore, wound dressings with salutary effects are urgently needed for wound care. However, traditional wound dressing with a single function often fails to meet the needs of wound repair, and the integration of multiple functions has been required for wound repair. Herein, Cu2+-chelated epigallocatechin gallate nanoparticles (EAC NPs), with radical scavenging, inflammation relieving, bacteria restraining, and vascularization accelerating capacities, are adopted to functionalize collagen scaffold, aiming to promote wound healing. Radical scavenging experiments verify that EAC NPs could efficiently scavenge radicals. Additionally, EAC NPs could effectively remove Escherichia coli and Staphylococcus aureus. H2O2 stimuli-responsive EAC NPs show slow and sustained release properties of Cu2+. Furthermore, EAC NPs exhibit protective effects against H2O2-induced oxidative-stress damage and anti-inflammatory activity in vivo. Physicochemical characterizations show that the introduction of EAC NPs does not disrupt the gelation behavior of collagen, and the composite scaffolds (CS) remain porous structure similar to collagen scaffold. Animal experiments demonstrate that CS could promote wound healing through improving the thickness of renascent epidermis and number of new vessels. CS with multiple salutary functions is a promising dressing for wound care.

Enantioselective Self-Assembly of a Homochiral Tetrahedral Cage Comprising Only Achiral Precursors.

How Nature synthesizes enantiomerically pure substances from achiral or racemic resources remains a mystery. In this study, we aimed to emulate this natural phenomenon by constructing chiral tetrahedral cages through self-assembly, achieved by condensing two achiral compounds-a trisamine and a trisaldehyde. The occurrence of intercomponent CH⋅⋅⋅π interactions among the phenyl building blocks within the cage frameworks results in twisted conformations, imparting planar chirality to the tetrahedrons. In instances where the trisaldehyde precursor features electron-withdrawing ester side chains, we observed that the intermolecular CH⋅⋅⋅π forces are strong enough to prevent racemization. To attain enantioselective self-assembly, a chiral amine was introduced during the imine formation process. The addition of three equivalents of chiral amino mediator to one equivalent of the achiral trisaldehyde precursor formed a trisimino intermediate. This chiral compound was subsequently combined with the achiral trisamino precursor, leading to an imine exchange reaction that releasing the chiral amino mediator and formation of the tetrahedral cage with an enantiomeric excess (ee) of up to 75 %, exclusively composed of achiral building blocks. This experimental observation aligns with theoretical calculations based on the free energies of related cage structures. Moreover, since the chiral amine was not consumed during the imine exchange cycle, it enabled the enantioselective self-assembly of the tetrahedral cage for multiple cycles when new batches of the achiral trisaldehyde and trisamino precursors were successively added.

What can molecular assembly learn from catalysed assembly in living organisms?

Molecular assembly is the process of organizing individual molecules into larger structures and complex systems. The self-assembly approach is predominantly utilized in creating artificial molecular assemblies, and was believed to be the primary mode of molecular assembly in living organisms as well. However, it has been shown that the assembly of many biological complexes is "catalysed" by other molecules, rather than relying solely on self-assembly. In this review, we summarize these catalysed-assembly (catassembly) phenomena in living organisms and systematically analyse their mechanisms. We then expand on these phenomena and discuss related concepts, including catalysed-disassembly and catalysed-reassembly. Catassembly proves to be an efficient and highly selective strategy for synergistically controlling and manipulating various noncovalent interactions, especially in hierarchical molecular assemblies. Overreliance on self-assembly may, to some extent, hinder the advancement of artificial molecular assembly with powerful features. Furthermore, inspired by the biological catassembly phenomena, we propose guidelines for designing artificial catassembly systems and developing characterization and theoretical methods, and review pioneering works along this new direction. Overall, this approach may broaden and deepen our understanding of molecular assembly, enabling the construction and control of intelligent assembly systems with advanced functionality.

Self-assembled soft alloy with Frank-Kasper phases beyond metals.

Soft building blocks, such as micelles, cells or soap bubbles, tend to adopt near-spherical geometry when densely packed together. As a result, their packing structures do not extend beyond those discovered in metallic glasses, quasicrystals and crystals. Here we report the emergence of two Frank-Kasper phases from the self-assembly of five-fold symmetric molecular pentagons. The µ phase, an important intermediate in superalloys, is indexed in soft matter, whereas the ϕ phase exhibits a structure distinct from known Frank-Kasper phases in metallic systems. We find a broad size and shape distribution of self-assembled mesoatoms formed by molecular pentagons while approaching equilibrium that contribute to the unique packing structures. This work provides insight into the manipulation of soft building blocks that deviate from the typical spherical geometry and opens avenues for the fabrication of 'soft alloy' structures that were previously unattainable in metal alloys.

Experimental quantum e-commerce.

E-commerce, a type of trading that occurs at a high frequency on the internet, requires guaranteeing the integrity, authentication, and nonrepudiation of messages through long distance. As current e-commerce schemes are vulnerable to computational attacks, quantum cryptography, ensuring information-theoretic security against adversary's repudiation and forgery, provides a solution to this problem. However, quantum solutions generally have much lower performance compared to classical ones. Besides, when considering imperfect devices, the performance of quantum schemes exhibits a notable decline. Here, we demonstrate the whole e-commerce process of involving the signing of a contract and payment among three parties by proposing a quantum e-commerce scheme, which shows resistance of attacks from imperfect devices. Results show that with a maximum attenuation of 25 dB among participants, our scheme can achieve a signature rate of 0.82 times per second for an agreement size of approximately 0.428 megabit. This proposed scheme presents a promising solution for providing information-theoretic security for e-commerce.