Developing highly efficient non-precious metal catalysts for the oxygen reduction reaction (ORR) in microbial fuel cells (MFCs) remains a critical challenge. Herein, we report a novel strategy to synthesize a highly active ORR catalyst (Co3O4-ZIF/Zn-MnO2) by embedding alpha-MnO2 and Co3O4 into a mesoporous N-doped carbon matrix. The synthesis initiates with the rational design of a bimetallic leaf-like Co-ZIF/Zn template, which integrates the advantageous properties of ZIF-8 and ZIF-67 to serve as a combined structural and electronic mediator. This template is transformed in situ into Co3O4-ZIF/Zn, followed by the uniform incorporation of alpha-MnO2 via a straightforward Co2+-mediated reaction that requires no expensive equipment. Our results reveal that the combined strategy of a Co-ZIF/Zn template and MnO2 incorporation facilitates the creation of a defective mesoporous NC architecture, where Zn etching generates abundant oxygen vacancies (Ov). Concurrently, the electronic interaction between alpha-MnO2 and Co3O4 optimizes the valence states of the metal centers, resulting in a synergistic enhancement. Consequently, the Co3O4-ZIF/Zn-MnO2 composite delivers exceptional ORR performance, surpassing control samples and Pt/C with a superior turnover frequency (TOF), enhanced power density and robust organic pollutant degradation efficiency. This study highlights the pivotal role of structural design and electronic engineering in developing high-performance ORR catalysts for sustainable energy applications.

Rational ligand functionalization offers an effective strategy to modulate Co3O4/CeO2 interfacial properties and construct active sites for styrene oxidation, a representative volatile organic compound (VOC) from organic waste recycling. Herein, lysine was employed to complex Co and Ce ions, generating a high-concentration Co3O4/CeO2 interface. The optimized catalyst L-CoCeOx exhibited superior catalytic activity, achieving 90% styrene conversion at 275 degrees C-- approximately 60 degrees C lower than that of unmodified CoCeOx. The energy consumed to heat the reactor to 90% styrene conversion was 661.5 kJ for L-CoCeOx and 850.0 kJ for CoCeOx, while the energy consumption of maintaining operation was 56.8 kJ h- 1 and 77.0 kJ h- 1, respectively. Amino groups act as a sigma-donor, stabilizing higher oxidation states, while the carboxyl group as a weak-field anionic ligand modulates electron density. This work presents a ligand-directed approach for engineering active catalyst interface, and provides an assessment of energy savings.

Despite considerable advancements in the synthesis of two-dimensional (2D) mesoporous nanomaterials, achieving precise control over their components, morphology, lateral dimension, and thickness remains a formidable challenge. Here, we report a rational interface-confined anisotropic assembly strategy that enables the synthesis of square-shaped 2D mesoporous nanosheets with finely tunable features including compositions (metal ion-doped mesoporous polydopamine or silica), lateral dimensions (100-200 nm), thicknesses (14-25 nm), and in-plane mesopore sizes (8-20 nm). In this strategy, truncated rhombic dodecahedral ZIF-8 metal-organic framework (MOF) nanoparticles serve as seeds to direct the selective assembly of mesoporous micelles onto their six {100} facets. The geometric confinement of these square facets guides the interfacial organization of micelles into 2D sheet-like structure, faithfully inheriting the square geometry. Following etching of the ZIF-8 seeds, the resulting nanosheets preserve their well-defined square-shaped 2D morphology and mesoporous architecture. This versatile approach enables the fabrication of diverse 2D mesoporous tunable structural attributes and metal-ion dopants. As a proof of concept, mPDA-Zn2+/Fe2+ nanosquares, featuring a uniform 2D architecture, near-infrared (NIR) photothermal properties, and Fenton-like catalytic activity, demonstrate synergistic therapeutic effects. Compared to conventional spherical analogs (1.08 × 10-8 M/s), these nanosquares (2.11 × 10-8 M/s) achieve nearly doubled maximum reaction rates and achieved remarkable tumor inhibition of up to 90%. Overall, this study establishes a novel approach for the precise engineering of 2D mesoporous nanosquares with controllable parameters, unlocking new opportunities for applications in biomedicine and beyond.

Diamond/copper composites have attracted wide attention owing to their exceptional thermal conductivity and favorable mechanical properties, making them promising materials for high-performance thermal management and electronic packaging. This review summarizes key fabrication strategies, including vacuum hot pressing, spark plasma sintering, high-temperature high-pressure techniques, and infiltration methods, with a comparative discussion of their advantages and limitations. Emphasis is placed on interfacial bonding mechanisms and regulation approaches, such as matrix alloying and diamond surface metallization, along with the influence of processing parameters on interfacial integrity. The roles of intrinsic material characteristics, processing conditions, and interfacial modifications in governing thermal and mechanical performance are systematically examined. Moreover, recent advances in numerical simulations for optimizing design and predicting properties are highlighted. Finally, the application potential of diamond/Cu composites in advanced thermal management is outlined, and future research directions are proposed.

Aqueous zinc-ion batteries (AZIBs) are promising for safe, low-cost, and environmentally friendly energy storage, yet their practical application is hindered by challenges such as dendrite growth, cathode dissolution, and side reactions. To meet the growing demand for wearable electronics, textile-based AZIBs have attracted considerable attention owing to their inherent flexibility, breathability, and seamless integration with garments. This review provides a comprehensive and critical overview of recent advances in textile-based AZIBs, with a focus on the rational design and fabrication of fibrous and fabric electrodes, the development of gel polymer electrolytes, and advanced manufacturing techniques including wet spinning, electrospinning, and 3D printing. We systematically evaluate the electrochemical and mechanical performance of these devices under realistic wearable conditions, and compare key metrics such as areal capacity, energy density, rate capability, cycling stability, and Coulombic efficiency. The underlying charge storage mechanisms of AZIBs are briefly summarized to provide a foundation for understanding the behavior of textile-based systems. The review concludes by critically addressing the current lack of standardized testing protocols for flexible batteries and outlines future research directions toward durable, high-performance smart textile energy systems that can withstand real-world deployment.

Hydrodeoxygenation (HDO) upgrading of biomass-derived fatty acids/esters into drop-in hydrocarbon fuels represents a vital pathway to replace fossil fuels. This study systematically investigates the influence of the ZrO2 crystal phase on catalytic performance and its underlying mechanisms. Catalysts with pure crystal phases-Ni/c- ZrO2 (cubic), Ni/t-ZrO2 (tetragonal), and Ni/m-ZrO2 (monoclinic)-were synthesized via solvothermal and reflux methods and were employed in the one-pot hydrothermal deoxygenation of palmitic acid to produce n-alkanes. Characterization results indicate that the ZrO2 crystal phase significantly affects the physicochemical properties of catalysts, such as BET surface area, metal-support interaction, and surface acidity/basicity. More importantly, as the crystal phase transitions from monoclinic to tetragonal and then to cubic, both the strength and number of acidic sites, whose desorption temperature overlaps with the reaction temperature range, gradually increase. These property variations lead to differences in catalytic performance, with activity and stability following the order: Ni/m-ZrO2 < Ni/t-ZrO2 < Ni/c-ZrO2. Wherein, Ni/c-ZrO2 achieved 100% palmitic acid conversion and a 97.7% n-alkanes yield of at 260 °C, surpassing commercial NiAl and Pt/C, and demonstrated excellent hydrothermal stability and substrate applicability. This study provides insights for the application of crystal-phase regulation strategies in oxide-based catalyst.

The rapid advancement of integrated electronic devices has intensified the demand for efficient heat dissipation technologies. Layered materials exhibiting high thermal conductivity are essential for enabling lateral heat spreading from localized hotspots and suppressing thermal accumulation in devices. However, there are still severe challenges in terms of highly ordered stacking and scalable large-area fabrication. Herein, highly anisotropic and flexible aramid nanofibers/boron nitride nanosheets (ANF/BNNS) film was fabricated using a tunable layer-by-layer cyclic (LbLC) blade shearing strategy. Precise control of the shearing gap and solvent evaporation rate enables layer-by-layer stacking that yields a dense, highly aligned lamellar architecture. The resulting ANF/BNNS film exhibited a high Herman’s orientation factor of up to 0.933 and an in-plane thermal conductivity of 15.96 W·m⁻¹·K⁻¹ at 50 wt% BNNS loading. Additionally, the highly oriented lamellar architecture of BNNS, coupled with its exceptional interfacial compatibility with the ANF matrix, synergistically enhances the mechanical properties of the ANF/BNNS film, achieving a tensile strength of 149.28 MPa. Therefore, the proposed LbLC blade shearing method and the obtained high-performance ANF/BNNS film has significant potential application for thermal management in high power electrical devices.

Heterojunction electrocatalysts have emerged as promising candidates for advancing lithium-sulfur battery cathodes due to their tunable electronic structures and abundant active sites, yet their performance is often compromised by the thermodynamic instability arising from excessive defect sites at the interface. We report a phosphorus doping strategy to stabilize pre-engineered sulfur vacancies in a carbon-coated CoS2-FeS2 heterojunction (P-VS-CFS@C). Partial occupancy of Vs by P3- not only passivates the vacancy structure and suppresses interfacial trap effects, but also strengthens lithium polysulfide (LiPSs) adsorption. Density functional theory calculations reveal that phosphorus incorporation modulates the local charge redistribution, generating spin-polarized states near the Fermi level and lowering the energy barrier for the critical Li2S2-to-Li2S conversion. The resulting P-VS-CFS@C/S cathode delivers a high-rate capacity of 784.1 mAh g-1 at 5 C and exceptional long-term cycling stability with 963.6 mAh g-1 retained after 1000 cycles at 1 C. This work presents a rational anion-doping approach for stabilizing heterointerface defects and offers new insights into interface engineering for durable electrocatalysis in energy-storage systems.

The synergistic integration of chemotherapy and immunotherapy represents the most promising strategy for enhancing therapeutic efficacy in cancer treatment. Chemotherapy initiates the therapeutic cascade by inducing immunogenic cell death (ICD), thereby releasing tumor antigens and prime immune sensitization. Subsequently, immunotherapy blocks immune evasion pathways, resulting in a coordinated relay-like antitumor response. This temporally coordinated sequence maximizes synergistic therapeutic efficacy. However, current clinical practice cannot support the sequential and sustained administration of chemotherapy and immunotherapy. This study innovatively integrates artificial intelligence (AI) with 3D printing technology to develop a dual-layer drug-loaded implant (LEH@OG) to achieve precise spatiotemporally controlled sequential drug release. The AI model precisely predicted exposure time of the inner gel layer in advance by optimizing parameters such as outer shell thickness and concentration, thereby realizing an on-demand sequential release process. This study demonstrates that combining AI with 3D printing enables precise sequential delivery of chemotherapy-immunotherapy agents, providing a core solution for establishing personalized colorectal cancer peritoneal metastasis (CCPM) therapeutic platforms, while also offering a new paradigm for synergistic treatment of other solid tumors.

In this study, nano‑manganese oxide@lignin-derived sulfur self-doped hierarchical porous carbon composites with distinct interfacial characteristics were constructed via three synthesis strategies, including in-situ growth (IG-nMnxOy@SLC), impregnation pyrolysis (IP-nMnxOy@SLC), and co-precipitation (CP-nMnxOy@SLC). Through comprehensive characterization, the systematic mechanism by which the synthesis pathway directionally regulated the structure and properties of nMnxOy@SLC composites was elucidated. IG-nMnxOy@SLC exhibited unique three-dimensional hierarchical pore structure that established efficient mass transfer channels, abundant surface functional groups that provided ample active sites, and high density of oxygen vacancies (Ov) that synergistically interacted with adjacent Mn(III)/Mn(IV) redox couples to establish a dynamic electron transfer network. The continuous redox gradient formed at the interface significantly enhanced the generation efficiency of reactive oxygen species and the conversion capability of Tl(I), thereby demonstrating excellent Tl(I) removal performance. In contrast, IP-nMnxOy@SLC suffered from insufficient chemical removal capacity due to its lower surface oxygen-containing functional group density. In the case of CP-nMnxOy@SLC, the dense layered stacking structure restricted mass transfer of Tl(I) by pore blockage and reduced specific surface area. Concurrently, the low Ov content suppressed the generation of reactive oxygen species and hindered interfacial oxidation reactions. Mechanistic investigations through XRD, FTIR, XPS, EPR, Zeta potential, and N2 adsorption-desorption isotherms demonstrated that Tl(I) removal depended on the synergistic effects of size-matched pore filling, coordination by surface functional groups, interfacial electrostatic attraction, and multiple oxidation pathways, including Ov-Mn(III)-driven catalytic oxidation, superoxide radical-driven hydroxyl radical chain catalytic oxidation, and Mn(IV)/Mn(III)-driven heterogeneous Fenton-like catalytic oxidation.

Sluggish kinetics coupled with parasitic shuttling reactions are pivotal challenges hindering the performance of lithium-sulfur (Li-S) batteries. Improving areal capacity and cyclability of Li-S batteries can be achieved by addressing these challenges. A composite sulfur host material is synthesized herein by in situ anchoring ultrafine cobalt-iron phosphide nanoparticles (5-7 nm) onto a hollow mesoporous carbon sphere (HMCS) framework. This strategy achieved exceptional spatial restriction and a high density of catalytically active sites through the encapsulation of sulfur within a hollow-structured framework. Specifically, HMCS expedites rapid Li2S nucleation kinetics, while CoFeP facilitates robust Li2S dissolution kinetics by mitigating decomposition barriers. This synergistic integration equips CoFeP@HMCS with robust bi-directional catalytic activity, significantly promoting interfacial charge-transfer, facilitate sulfur multistep catalytic conversion, and inhibiting shuttling. Consequently, the battery exhibits excellent rate performance (991 mA h g-1 at 5.0 C) and retains a high areal capacity of 6.06 mA h cm-2 after 200 cycles under a high areal sulfur loading of 8.2 mg cm-2 but a low electrolyte/sulfur ratio of 4.8 lL mg-1. This work contributes to enhancing the practical specific capacity of lithium-sulfur batteries and deepens the understanding of catalysts enabling bidirectional electrocatalytic sulfur conversion. (c) 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Hypochlorous acid (HClO) accumulation during ferroptosis plays a critical role in lipid peroxidation and cell death, yet its real-time detection remains challenging due to high reactivity and transient nature. Herein, we report two novel aurone-based fluorescent probes, WSA-1 and WSA-2, for selective HClO detection. Both probes incorporate a dimethylthiocarbamoyl recognition module that undergoes HClO-mediated oxidative cleavage, eliciting rapid fluorescence turn-on with detection limits of 39.9 nM and 54.6 nM, respectively. High-resolution mass spectrometry confirms the sensing mechanism proceeds via fragmentation to regenerate the emissive aurone scaffold. The probes exhibit excellent selectivity for HClO over reactive oxygen species, biological thiols, and metal ions, with stable performance across physiological pH ranges. Cellular imaging demonstrates their capability to detect exogenous HClO, endogenous HClO induced by tunicamycin or PMA, and elevated HClO levels during erastin-induced ferroptosis in HeLa cells. Notably, ferroptosis-associated fluorescence is abolished by co-treatment with fer-1 or vitamin E, confirming specificity. These results establish WSA-1 and WSA-2 as valuable tools for investigating HClO dynamics in ferroptosis.

Chronic diabetic foot infections are severely hindered by tough biofilms and a self-fueling hyperinflammatory microenvironment, primarily orchestrated by the synergistic interplay between extracellular DNA (eDNA) and lipopolysaccharides (LPS) which facilitates the assembly of impenetrable biofilm architectures while inducing cross-inflammatory activation through the TLR4/9 axis. Conventional therapies often fail to resolve these "dual traps" of structural resistance and immunological interference. Herein, we developed a multifunctional mesoporous nano-regulator composed of Colistin (CT) and m-aminophenol formaldehyde (mAPF) framework, hence termed CT/mAPF to implement a "triad-strategy": biofilm disruption, bacterial eradication, and debris neutralization. The CT/mAPF nano-regulator achieves potent bactericidal activity (99.99%) and initiates ROS-mediated oxidative fragmentation of eDNA to destroy the biofilm scaffold. Crucially, the platform effectively neutralizes LPS and degrades eDNA, leading to the simultaneous silencing of TLR4 and TLR9 signaling pathways. This dual-targeting approach weakens the eDNA/LPS-mediated synergistic inflammatory response, and suppresses pro-inflammatory cytokines (IL-6, IL-1β, TNF-α). In diabetic mouse models, CT/mAPF significantly accelerated bacterial clearance and wound closure through enhanced angiogenesis and collagen maturation. This integrated strategy resolves the cycle of chronic infection and inflammation, offering a robust strategy for Gram-negative bacteria-infected diabetic wound management.

The rapid evolution of intelligent electromagnetic systems has heightened the performance standards for observation windows, driving a demand for flexible, multifunctional, transparent EMI shielding films with robust environmental durability, while current progress remains a significant challenge. In this study, a multifunctional transparent EMI shielding film composed of silver nanowire (AgNW) and polydimethylsiloxane (PDMS) with an embedded conductive network was fabricated via a two-step process involving rotational spraying followed by infiltration transfer. The resulting AgNW/PDMS film exhibits high optical transmittance (71.1%) and low sheet resistance (11.3 Ω/sq), combined with average EMI shielding effectiveness (EMI SE) of 30.2 dB in the X-band, 32.6 dB in the Ku-band, and 34.5 dB in the K-band. The synergistic effect of PDMS-induced physical confinement and hydrogen bonding markedly enhances the interfacial adhesion and antioxidant capacity of the transparent shielding film, contributing to the reliability and durability in harsh environments. Simultaneously, the strain-induced reconfiguration of the AgNW network and the resultant adaptive conductivity modulation synergistically enable the film to exhibit exceptional strain-sensing performance and efficient Joule heating functionality. The multifunctional integration clearly demonstrates that transparent shielding films possess significant potential for enabling iterative improvements in observation window systems across aerospace, automotive, and next-generation electronic device applications.

The selective oxidation of methane to methanol or formaldehyde, using oxygen as sacrificial agent, offers an ideal sustainable pathway for synthesizing bulk chemicals under mild conditions. However, balancing high productivity with selective control of the reaction remains a significant challenge. Adjusting the oxygen vacancies concentration of supported metal oxides has proven to be an effective strategy for promoting the selective conversion of methane to liquid products. In this study, In2O3 with varying oxygen vacancies concentrations were prepared through crystal phase engineering with AuPd alloy. Rich oxygen vacancy AuPd/In2O3-P, with more M-OV-In interfaces, effectively promotes the activation of O2 to hydroxyl radicals. At room temperature, the yield and selectivity of liquid product reached to 14.6 mmol/gcat. and 98 %, and formaldehyde selectivity was 76 %. Mechanistic studies indicate that holes can activate methane to methyl radical, while hydroxyl radicals are crucial for liquid products formation. Increasing the concentration of oxygen vacancies facilitates the activation of methane and oxygen. This research elucidates the structure-activity relationship between oxygen vacancies content and catalytic performance. Through a series of in-situ characterizations and DFT calculations, oxygen vacancy plays a crucial role in promoting electron transfer and in enhancing catalytic performance were further clarified.

Photothermal catalysis is an innovative and efficient approach that integrates photo-and thermo-chemistry to enable an enhanced reaction rate under light irradiation. Therefore, it is of significance to develop highperformance photothermal catalyst with strong light absorbance and rich active sites. Here we report the preparation of a photothermal catalyst, in which single-atom Pd (Pd1) anchored on N, S co-doped holey graphene (Pd1/NSHG) with unsymmetrically N, S-coordinated Pd1-N3S1 active sites. As both the atomic Pd and NSHG are photothermal materials and catalytically active to nitroaromatics reduction reaction, the as-prepared Pd1/NSHG can be used as photothermal single-atom catalyst (PTSAC) and exhibits excellent catalytic activity for the reduction of nitroaromatic compounds. In the reduction reaction of a representative substrate (i.e., 4-nitrophe-nol), the turnover frequency of Pd1/NSHG is as high as 0.602 mmol/(mg cat.& sdot;min), which is much higher than that of commercial Pd/C catalyst (0.25 mmol/(mg cat.& sdot;min)) and most of the reported metal supported catalysts under near-infrared irradiation. A plausible reaction mechanism of the Pd1/NSHG PTSAC catalyzed nitroaromatics reduction was proposed based on the reaction intermediates detected in the reduction process as well as theoretic simulations. This study provides a versatile designing approach to efficient photothermal catalysts with atomic metal and carbocatalyst components.

Skin‐like robust materials with prominent sensing performance have potential applications in flexible bioelectronics. However, it remains challenging to achieve mutually exclusive properties simultaneously including low interfacial impedance, high stretchability, sensitivity, and electrical resilience. Herein, a material and structure design concept of mixed ion‐electron conduction and mechanical interlocking structure is adopted to fabricate high‐performance mechanical‐bioelectrical dual‐modal composites with large stretchability, excellent mechanoelectrical stability, low interfacial impedance, and good biocompatibility. Flower‐like conductive metal‐organic frameworks (cMOFs) with enhanced conductivity through the overlapped level of metal‐ligand orbital are assembled, which bridge carbon nanotubes (denoted as cMOFs‐ b ‐CNTs). Then, precursor of poly(styrene‐ block ‐butadiene ‐block ‐styrene)/ionic liquid penetrates the pores and cavities in cMOFs‐ b ‐CNTs‐based network fabricated via filtration process, creating a semi‐embedded structure via mechanical interlocking. Thus, the mixed ion‐electron conduction and semi‐embedded structure endow the as‐prepared composites with a low interfacial impedance (51.60/28.90 kΩ at 10/100 Hz), wide sensing range (473%), high sensitivity (2195.29), rapid response/recovery time (60/85 ms), low limit of detection (0.05%), and excellent durability (>5000 cycles to 50% strain). Demonstrations of multifunctional mechanical‐bioelectrical dual‐modal sensors for in vivo/vitro monitoring physiological motions, electrophysiological activities, and urinary bladder activities validate the possibility for practical uses in biomedical research areas. This concept creates opportunities for the construction of durable skin‐like sensing materials.

Nonmetallic heteroatom-doped graphene has become a promising anode material for sodium-ion batteries. However, there is a lack of an efficient method to control the distribution of heteroatoms (e.g. proportion, content and configuration) over a wide range and with high precision. Utilizing density functional theory calculations grounded in first-principles, we explore the impact of the co-doping of various heteroatoms on sodium ion storage across distinct carbon layer sites. A meticulously designed hydrogen-bonded supramolecular complex, consisting of pyrrole-phytic acid and partially reduced graphene oxide, has been synthesized. Within this assembly, the pyrrole-phytic acid structure serves a dual role: It acts as a 'spacer' to prevent graphene nanosheets from stacking during pyrolysis and also serves as a sacrificial dopant for the precise control of nitrogen and phosphorus doping levels. The high tunability of the building units allows for precise electronic control over the configuration and ratio of heteroatoms, enabling the preparation of graphene conjugated frameworks with varying nitrogen and phosphorus co-doping levels, enriched with multiple active sites and structural defects, thereby significantly enhancing the performance of sodium-ion batteries. G-4N2P has excellent rate performance and good cycling stability, with a capacity of 247 mAh g-1 for 1000 cycles at 10 A g-1.

To investigate the structure and pyrolysis free radical reaction of kerogens in oil shale with different densities from the same mining area, this study determined the concentration of main covalent bonds in Longkou oil shale with three different densities, investigated the quantity and types of active free radicals generated during pyrolysis, and identified the rules of forming stable free radicals after coupling of active radicals. The results indicate that the concentrations of C al-Cal and C al-H decrease linearly with a reduction in H/C, while the concentrations of C al- C ar , C ar- C ar , C ar-H, C a l-O, C ar-O, and Cal=O increase linearly as H/C decreases. The concentrations of the eight covalent bonds also exhibit regular changes with O/C, but the relationship is nonlinear, and the trend is inverse. The concentration of active free radicals generated initially increases rapidly, then rises more slowly over time. At 260-420 degrees C pyrolysis, kerogen mainly undergoes gradual cleavage of weak bonds, generating active free radicals primarily comprising oxygen radical linked to aromatic carbon (center dot O-Car), aliphatic carbon radical connected to aromatic carbon (center dot Cal-Car), aromatic carbon radical (center dot Car), aliphatic carbon radical (center dot Cal), and oxygen radical connected to aliphatic carbon (center dot O-Cal). Among these active free radicals, 99.9 % couple with one another and annihilate, leaving less than 0.1 % of stable free radicals. The concentration of stable free radicals initially increases linearly, then decreases linearly, and subsequently increases again with the rise in active free radical concentration. Aliphatic radical fragments are more prone to generating volatile pyrolysis products through coupling reactions than aromatic radical fragments.