Aggregate (Hoboken, N.J.)最新文献

Muscle contraction and cellular motility depend on the complex interplay between myosin, actin, and associated proteins. Disruptions in these interactions are linked to various human diseases, including muscular dystrophies and cardiac conditions. In this study, we developed a tissue-extraction protocol to purify the actin–tropomyosin–myosin (ATM) complex and filamentous actin (F-actin) directly from human and mouse left ventricles, as well as from rat skeletal muscles. Utilizing cryo-electron microscopy (cryo-EM), we resolved the structures of the ATM complexes and F-actin derived from these tissues. Additionally, we extracted ATM complexes from mice carrying the hypertrophic cardiomyopathy (HCM) mutation R404Q and demonstrated how this mutation alters the formation of ATM complexes and the structural configuration in myosin. Our approach offers a general method for isolating intact ATM complexes directly from various mammalian tissues, providing insights into the structural basis of ATM complex formation and regulation in muscle function and disease.

Self-assembled monolayers (SAMs) have proven to be highly efficient hole-transporting layers (HTLs) due to their advantages, including low cost, minimal material consumption, ease of synthesis, negligible optical loss, and exceptional stability. Recently, carbazole-based SAM HTLs have considerably improved the power conversion efficiency (PCE) of organic solar cells (OSCs) and perovskite solar cells (PSCs)—with PCEs reaching 21% and 27%, respectively. This review begins with a concise overview of the chemical structure of SAMs, emphasizing the recent advancements achieved by carbazole-based SAMs in the photovoltaics (PVs) sector. We then systematically summarize the modifications made to the chemical structure of carbazole-based SAMs to optimize their interface dipole, surface wettability, and interface defects. Especially for functional group, the modification techniques are categorized into four main types: methoxylation, conjugation, halogenation, and asymmetrization. Finally, several challenges, including solubility, film quality, and stability, along with potential solutions for these issues are discussed. We hope this review serves as a valuable guide and source of inspiration for the design of SAM HTLs, ultimately enhancing the performance of PV devices.

Intrinsic milk photoluminescence (PL), though empirically observed, remains insufficiently explored in terms of mechanism and application. This work illustrates the general dual-emission characteristics of milk and elucidates their distinct origin: blue emission at 390–460 nm from casein and whey protein aggregates via clustering-triggered emission and yellow-green emission at around 530 nm from riboflavin. Crucially, microbial metabolism during spoilage induces pronounced physicochemical transformations: lactic acid accumulation that drops the pH from 6.69 to 4.79 within 72 h, extensive protein degradation with a 200-fold increase in free proline, and colloidal reorganization from uniform particles to polydisperse aggregates. These changes dynamically modulate PL signatures: early-stage (<12 h) riboflavin decay induces blueshifted emission, while advanced spoilage (24–72 h) disrupts protein aggregation, reducing quantum yield $��\left(�\Phi �\right)�$ by >80% and further blueshifting the emission toward the blue-violet region. Exploiting this correlation, we establish a dual-mode milk freshness assessment strategy: (1) visual colorimetry under 365 nm UV excitation, where fresh milk appears bright yellow-green and spoiled milk turns dim blue, and (2) quantitative $��\ln �(�\Phi �/�\%�)�$ scaling that differentiates fresh samples above 3.5 from spoiled samples below 2.4. Validated against physicochemical benchmarks, this noncontact strategy enables real-time, field-deployable milk quality visualization for supply chain and consumer applications. This study not only reveals the underlying mechanism of milk luminescence but also provides a facile dual-mode approach for rapid quality assessment.

To overcome the limitations of batch-to-batch variations and donor material robustness in polymer solar cells (PSCs), we designed quaternary (H1–H9), ternary (H10–H15), and binary (PM6, PBQ10, PBDS-T) polymer donors via precise monomer ratio modulation. Due to the synergistic coordination among multiple components, the H4-based blend film demonstrated enhanced intermolecular interactions and provides additional low-energy-barrier pathways for efficient charge carrier transport. After blending with L8-BO, the H4-based films displayed a more desirable morphology and effective charge carrier transport than the categories. As a result, the H4:L8-BO-based PSCs achieved impressive power conversion efficiency (PCE) of 19.66% for binary device and 20.34% for ternary device. Besides, the introduced functional groups disrupt the regularity of the matrix polymer main chain, leading to stable and robust film morphologies. Consequently, the H4:L8-BO-based blend film not only demonstrates improved mechanical robustness, with a crack onset strain (COS) of 17.8%, and maintains a PCE of 16.35% in flexible devices, but also exhibits excellent batch-to-batch stability with significant variations in molecular weight. This work presents a strategy to simultaneously enhance device performance, mechanical robustness, and reproducibility through quaternary copolymerization, enabling controlled crystallinity and additional multichannel charge transport.

To overcome the intrinsic drawbacks of conventional viologens, such as slow optical response and poor radical stability, we synthesized a series of viologen derivatives (BTV, NTV, and STV) by incorporating thiazolo[5,4-d]thiazole units into bipyridine cores, followed by N-substitution with benzyl, naphthylmethyl, and propanesulfonate groups. These derivatives self-assemble into donor–acceptor ion-pair charge-transfer organic nanoparticles (IPCT-ONs) that exhibit redshifted UV–Vis absorption and fluorescence emission, thereby extending the visible-light response. X-ray photoelectron spectroscopy (XPS) analysis and DFT results confirmed electron transfer from tetraphenylborate anions to viologen moieties. The IPCT-ONs display rapid and reversible photochromism, with distinct color transitions occurring within 30 s under 365 nm irradiation in an Ar atmosphere (BTV/NTV: yellow → green → blue; STV: yellow → purple), which remain effective even when embedded in polyvinyl alcohol (PVA) films. They demonstrate dual-mode amine sensing, wherein ethylenediamine induces both a colorimetric shift (yellow → blue–violet) and fluorescence quenching at 470 nm, enabling sensitive and selective detection of toxic amines. Additionally, this IPCT nanoparticle platform offers applications in real-time light intensity monitoring, anti-counterfeiting measures, and ink-free printing.

Coulomb's law predicts that like-charge ions repel and avoid dimerization. However, a class of dimers between like-charge ions is characterized. The [3,3’-Fe(1,2-C₂B₉H₁₁)₂]⁻ (abbreviated as [o-FESAN]⁻) represents an innovative non-classical inorganic anion apart from hydroxyanions that exhibits anion-anion stabilization via dihydrogen bonding. Experimental methods (nuclear magnetic resonance [NMR], dynamic light scattering [DLS], and X-ray diffraction) and theoretical approaches (density functional theory) reveal that [o-FESAN]⁻ clusters aggregate by overcoming long-range electrostatic repulsion. The synthesis of [H₃O][o-FESAN]•3H₂O and its crystal structure confirm the formation of stabilized anion-anion aggregates, with [H₃O]⁺ counterions residing freely in the channels rather than between the anionic clusters. The structure exhibits the cisoid rotamer, which facilitates the ability of the anionic [o-FESAN]⁻ cluster to form interactions stabilized by dihydrogen bonds (head-to-middle cluster) shorter than the sum of the Van der Waals radii. These shorter bonds are crucial for the formation of anion-anion interactions mediated by dihydrogen bonds. X-ray structures show that anions aggregate in the solid state, overcoming long-range electrostatic repulsion through dihydrogen bonds, which are distinct from the hydrogen bonds commonly observed in anion systems involving highly electronegative elements. Consistent with crystal structure evidence, ¹H NMR, transmission electron microscopy, and DLS confirm [o-FESAN]⁻ anion-anion aggregates in solution. Theoretical calculations support the formation of these anion-anion aggregates, primarily via C_cluster-H···H-B bonds. While individual B-H···H-B interactions are weakly attractive, their cumulative effect significantly enhances aggregate stability. Additionally, the crystal structure of Na(H₂O)₃[o-FESAN] is reported and analyzed, providing further evidence of unconventional interactions stabilized by dihydrogen bonds.

Protein aggregation is an important pathological feature of cardiovascular disease. Therein, thrombin-mediated fibrin aggregation is one of the mechanisms of thrombosis, accurate monitoring of which is significant for the research of thrombosis. In this study, the optical properties and theoretical calculations confirmed that the AIE probe could specifically illuminate fibrin aggregates without interference, and its signal response was positively correlated with thrombin activity. Therefore, the biosensing technique can realize in situ monitoring of the coagulation process and rapid identification of active substances in complex systems. Furthermore, to detect anticoagulant active monomers, a biosensing targeted affinity screening (BioSTAS) technology was established by combining the above biosensing technique with the affinity chromatography technique. The rapid identification of active substances was achieved through biosensing, and then active monomers were captured by affinity chromatography. As a result, two agents with anticoagulant activity, rhein and oleanolic acid, were discovered via the screening of more than 30 kinds of natural products and commercial preparations. This study not only provides a new idea for the application of AIE probes in the dynamic monitoring of protein aggregation but also establishes an innovative strategy for screening active agents from a complex system through the integration of biosensing and affinity chromatography technologies.

Lignin, as one of the most abundant natural aromatic polymers, holds significant promise for high-value applications; however, its inherent dark coloration poses a major constraint for such uses. In this review, we systematically examine the key factors contributing to lignin's color, with a focus on structural alterations during extraction, the formation of chromophores, and the influence of molecular weight and morphology. We then provide a comprehensive overview of current decolorization strategies, including oxidative bleaching, hydroxyl shielding modification, physical methods, and biomass fractionation techniques. This review offers a detailed summary of both the mechanisms underlying lignin coloration and recent advances in decolorization, thereby providing valuable guidance for the optimization of whitening processes and facilitating the advanced utilization of lignin.

The electronic spectra and luminescence decay measurements at room temperature (RT) and 77 K have been recorded for pristine hexagonal and cubic CsCdCl₃ and for this material doped with Mn²⁺ or Fe³⁺. First-principles calculations have been performed in order to rationalize the results. The RT visible emission broad band of hexagonal CsCdCl₃ is due to [MnCl₆]⁴⁻ emission at two different Cd²⁺ sites. On cooling below RT, the Mn²⁺ emission weakens in intensity, and variable intensity near-ultraviolet emission bands are assigned to spin-orbit coupling mixed singlet and triplet ¹D₂, ³D_3,2,1 (4d⁹5s¹) → ¹A_1g (4d¹⁰) (O_h) transitions at C_3v and D_3d sites of Cd²⁺. Pristine cubic CsCdCl₃ exhibits two weak RT emission bands associated with tetrahedral and octahedral Mn²⁺ impurity. Doping hexagonal CsCdCl₃ with Fe³⁺ does not produce additional visible emissions and leads to quenching of Cd²⁺ emissions below RT. Very weak infrared emission from Fe³⁺ is observed. The thermoluminescence of cubic and hexagonal CsCdCl₃ is weak, but long-lasting persistent luminescence is obtained upon Mn²⁺ doping at a several percent level. Optical applications for anti-counterfeiting and information encryption are suggested.