Interfacial Engineering of Binder-Free Janus Separator with Ultra-Thin Multifunctional Layer for Simultaneous Enhancement of Both Metallic Li Anode and Sulfur Cathode.

Exploring a scalable strategy to fabricate a multifunctional separator is of great significance to overcome the challenges of lithium polysulfides (LiPSs) and dendritic growth in lithium-sulfur batteries (LSBs). Herein, a binder-free Janus separator is constructed by interfacial engineering. At the cathode interface, an ultra-thin covalent triazine piperazine film containing tailorable micropores and adsorption sites is decorated on polyacrylonitrile (PAN) membrane by in situ interfacial polymerization, building a triple barrier for LiPSs. The combination of steric hindrance and chemical adsorption reduces LiPS's migration by 81.85%. Meanwhile, at the anode interface, a fast-ionic conductor Li6.4 La3 Zr1.4 Ta0.6 O12  (LLZTO) is created on the surface of PAN nanofiber by magnetron sputtering to suppress dendrite growth. Even though there is no binder between the ceramic layer and the fibrous separator, sputtering creates an inter-embedded structure that ensures no depowering after cycling. Furthermore, the PAN-based separator displays a high temperature tolerance of 180 °C. Consequently, the cell delivers a high capacity of 1287.9 mAh g-1 at 0.5 C and stable cycling performance with an ultra-low capacity decay rate of 0.059% per cycle over 500 cycles. This work provides a scalable strategy for functionalizing separators to tackle the challenges in LSBs, which is binder-free, stripping-free, and essentially thickening-free.

A fast hemostatic and enhanced photodynamic 2-dimensional metal-organic framework loaded aerogel patch for wound management.

Achieving rapid hemostasis and highly effective antibacterial holds significant importance in the early-stage treatment of wounds. In this study, a hybrid aerogel patch comprising carbon quantum dots (CQDs) modified 2-dimensional (2D) porphyrinic metal-organic framework (MOF) nanosheets was designed by incorporating gelatin methacrylate (GelMA) and polyacrylamide (PAM) based matrix. On one hand, CQDs were stably doped onto the surface of the 2D MOF nanosheets, thereby enhancing the photodynamic activity through fluorescence resonance energy transfer (FRET) process. After the preparation of hybrid aerogel patch, the patch loaded with CQDs-doped 2D MOF exhibited excellent photodynamic bactericidal activity against Gram-positive Staphylococcus aureus (>99.99 %) and Gram-negative Escherichia coli (>99.99 %). On the other hand, the hybrid patch with highly porous and absorbent structure can rapidly absorb blood to aggregate clotting components and form a hydration barrier covering the wound to enhance hemostasis. Besides, the hemolysis and cytotoxicity assays demonstrated a good biocompatibility of this designed patch. In summary, this 2D MOF-loaded aerogel patch holds a potential to achieve rapid hemostasis and effective anti-infection in the early-stage treatment of traumatic wounds.

Room Temperature Phosphorescent Nanofiber Membranes by Bio-Fermentation.

Stimuli-responsive materials exhibiting exceptional room temperature phosphorescence (RTP) hold promise for emerging technologies. However, constructing such systems in a sustainable, scalable, and processable manner remains challenging. This work reports a bio-inspired strategy to develop RTP nanofiber materials using bacterial cellulose (BC) via bio-fermentation. The green fabrication process, high biocompatibility, non-toxicity, and abundant hydroxyl groups make BC an ideal biopolymer for constructing durable and stimuli-responsive RTP materials. Remarkable RTP performance is observed with long lifetimes of up to 1636.79 ms at room temperature. Moreover, moisture can repeatedly quench and activate phosphorescence in a dynamic and tunable fashion by disrupting cellulose rigidity and permeability. With capabilities for repeatable moisture-sensitive phosphorescence, these materials are highly suitable for applications such as anti-counterfeiting and information encryption. This pioneering bio-derived approach provides a reliable and sustainable blueprint for constructing dynamic, scalable, and processable RTP materials beyond synthetic polymers.

Photodynamic activity enhanced by in situ biosynthetic BC/CQDs@PCN-224 membranes through FRET strategy.

Porphyrin-based metal organic frameworks (MOFs) with efficient bactericidal performance have increasingly attracted attention in photodynamic inactivation materials. However, low reactive oxygen species (ROS) yield and drug residue hazards of current porphyrin-MOFs materials lead to unsatisfactory clinical therapeutic effects. In this paper, carbon quantum dots (CQDs) were encapsulated into PCN-224, which enhanced the photodynamic activity of the MOFs through fluorescence resonance energy transfer (FRET) process. Singlet oxygen (1O2) detection confirmed that the photodynamic activity of CQDs-doped PCN-224 (CQDs@PCN-224) was enhanced than that of pristine PCN-224 under illumination. Furthermore, the CQDs@PCN-224 were firmly embedded into bacterial cellulose (BC) nanofibrous membranes by using an eco-friendly biosynthetic approach, efficiently preventing MOFs leakage during use. The results of bactericidal assays demonstrated that BC/CQDs@PCN-224 membrane with higher photodynamic activity causes more severe disruption to bacterial structure and possesses better antibacterial efficiency (>99.99 % reduction of both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli O157:H7 within 30 min) than BC/PCN-224 membrane under visible light illumination (500 W, 15 cm height, λ ≥ 420 nm). In addition, the biosynthesized BC/CQDs@PCN-224 membrane showed good hemocompatibility and low cytotoxicity, revealing that the BC- and MOFs-based material with enhanced PDI efficiency and satisfying safety has great potential in medical fields.

Phase transition of DNA knotting in spherical space.

Knots have been discovered in various biological systems, such as DNA. The knotting probability of DNA in free space depends non-monotonically on its bending rigidity and has a prominent peak. The current work aims to understand the underlying mechanism of the non-monotonic dependence of DNA knotting probability on bending rigidity. Monte Carlo simulations are performed on a closed DNA molecule confined in spherical space described by a worm-like chain model and a flexible kink model, respectively. The closed DNA's contour length and the spherical space radius both increase knotting probability, but also alter the unimodal dependence of knotting probability on bending rigidity. This is generalized using universal phase diagrams based on the two models. Under the flexible kink model, the total knotting probability of closed DNA is obviously increased at a relatively high excited energy. This supports the expectation that the entropy effect of knot size favours knot formation at a relatively low bending rigidity. In a given spherical space, the increasing contour length of closed DNA described by the worm-like chain model results in a visible shift in the knotting probability distribution. At the same time, the gyration radius of non-trivial closed DNA becomes comparable to that of trivial closed DNA, so that their ratio is not anti-correlated with average knot length. For closed DNA of various contour lengths, the relationship between average knot length and bending rigidity has a universal behaviour: the average knot length decreases to a local minimum at a bending rigidity of ∼5 and then gradually increases to a constant value. The existence of the local minimum is determined by the cut-off distance in repulsive Lennard-Jones potential. The bending rigidity corresponding to the beginning of the constant average knot length is consistent with that at the peak in the knotting distribution. At this point, the knot-size effect balances with the fragment free-energy effect and, at an even greater bending rigidity, knot length breathes around the average knot length value.

Multi-duties for one post: Biodegradable bacterial cellulose-based separator for lithium sulfur batteries.

High-energy density lithium sulfur battery containing highly active materials is more prone to safety hazards. Besides, the infamous shuttle effect of lithium polysulfides (LiPSs) and listless redox kinetic limit its practical applications. Here, a "one-for-all" design concept for separator enabled by interfacial engineering is proposed to relieve the bottlenecks. For one thing, porous bacterial cellulose (PBC) membrane with high thermostability (no shrinking at 200 °C) and puncture resistance was employed to ensure the battery's safety. For another, a difunctional Ti3C2Tx-SnS2 modified layer could capture LiPSs through lewis-acid interaction and promoted the redox kinetics by catalytically active sites. The symmetric cell with anchoring-electrocatalysis Ti3C2Tx-SnS2-PBC separator infiltrated with the electrolyte delivered an ionic conductivity of 2.171 mS/cm at a high temperature of 180 °C. And a capacity retention is improved by 71.2% compared with PP separator. This work furnishes a facial engineering strategy for manufacturing a multifunctional separator for lithium sulfur batteries.

Lexicon and attention-based named entity recognition for kiwifruit diseases and pests: A Deep learning approach.

Named Entity Recognition (NER) is a crucial step in mining information from massive agricultural texts, which is required in the construction of many knowledge-based agricultural support systems, such as agricultural technology question answering systems. The vital domain characteristics of Chinese agricultural text cause the Chinese NER (CNER) in kiwifruit diseases and pests to suffer from the insensitivity of common word segmentation tools to kiwifruit-related texts and the feature extraction capability of the sequence encoding layer being challenged. In order to alleviate the above problems, effectively mine information from kiwifruit-related texts to provide support for agricultural support systems such as agricultural question answering systems, this study constructed a novel Chinese agricultural NER (CANER) model KIWINER by statistics-based new word detection and two novel modules, AttSoftlexicon (Criss-cross attention-based Softlexicon) and PCAT (Parallel connection criss-cross attention), proposed in this paper. Specifically, new words were detected to improve the adaptability of word segmentation tools to kiwifruit-related texts, thereby constructing a kiwifruit lexicon. The AttSoftlexicon integrates word information into the model and makes full use of the word information with the help of Criss-cross attention network (CCNet). And the PCAT improves the feature extraction ability of sequence encoding layer through CCNet and parallel connection structure. The performance of KIWINER was evaluated on four datasets, namely KIWID (Self-annotated), Boson, ClueNER, and People's Daily, which achieved optimal F1-scores of 88.94%, 85.13%, 80.52%, and 92.82%, respectively. Experimental results in many aspects illustrated that methods proposed in this paper can effectively improve the recognition effect of kiwifruit diseases and pests named entities, especially for diseases and pests with strong domain characteristics.

PCN-224 Nanoparticle/Polyacrylonitrile Nanofiber Membrane for Light-Driven Bacterial Inactivation.

Increasing issues of pathogen drug resistance and spreading pose a serious threat to the ability to treat common infectious diseases, which encourages people to explore effective technology to meet the challenge. Photodynamic antibacterial inactivation (aPDI) is being explored for inactivating pathogens, which could be used as a novel approach to prevent this threat. Here, porphyrin-embedded MOF material (PCN-224) with photodynamic effect was synthesized, then the PCN-224 nanoparticles (NPs) were embedded into PAN nanofibers with an electrospinning process (PAN-PCN nanofiber membrane). On the one hand, polyacrylonitrile (PAN) nanofibers help to improve the stability of PCN-224 NPs, which could avoid their leakage. On the other, the PAN nanofibers are used as a support material to load bactericidal PCN-224 NPs, realizing recycling after bacterial elimination. An antibacterial photodynamic inactivation (aPDI) study demonstrated that the PAN-PCN 0.6% nanofiber membrane processed 3.00 log unit elimination towards a E. coli bacterial strain and 4.70 log unit towards a S. aureus strain under illumination. A mechanism study revealed that this efficient bacterial elimination was due to singlet oxygen (1O2). Although the materials are highly phototoxic, an MTT assay showed that the as fabricated nanofiber membranes had good biocompatibility in the dark, and the cell survival rates were all above 85%. Taken together, this work provided an application prospect of nanofibers with an aPDI effect to deal with the issues of pathogen drug resistance and spreading.

Smart Textiles with Self-Disinfection and Photothermochromic Effects.

Self-disinfecting textile materials employing combined photodynamic/photothermal effects enable the prevention of microbial infections, a property that has great potential in healthcare applications. However, smart textiles with stimulus responses to ambient temperature are marvelous materials for enhancing their photothermal applications with additional functions. It is still challenging to realize vivid and contrasting color changes as temperature indicators. Herein, through the in situ growth of PCN-224 metal-organic frameworks (MOFs), the electrospraying of a Ti3C2 MXene colloid, and the screen printing of a thermochromic dye, a smart photothermochromic self-disinfecting textile has been fabricated. An antibacterial inactivation study revealed 99.9999% inactivation toward gram-negative (Escherichia coli ATCC 8099) and gram-positive (Staphylococcus aureus ATCC 6538) bacteria in 30 min. A mechanism study revealed that light-driven singlet oxygen and heat are the main reasons for bacterial inactivation. Interestingly, the fabrics presented photothermal effects not only under a handheld 780 nm NIR laser but also under visible Xe lamp (λ ≥ 420 nm) illumination. The color of the fabrics (S-CF@PCN0.08) changed completely from dark green to dark red when the temperature exceeded 45 °C under Xe lamp illumination. Furthermore, the photothermochromic effect occurred in just 1 s under a 780 nm laser. Taken together, this smart photothermochromic self-disinfecting textile permits a new way to feedback the timely signal of temperature by color change and provides novel insights into the development of self-disinfecting textiles.

Light-driven self-disinfecting textiles functionalized by PCN-224 and Ag nanoparticles.

Toward the goal of preventing microbial infections in hospitals or other healthcare institutions, here we developed a self-disinfecting textile with synergistic photodynamic/photothermal antibacterial property. Porphyrinic Metal-organic frameworks (PCN-224) and Ag nanoparticles (NPs) were in situ grown on knitted cotton textile (KCT) successively to achieve rapid photodynamic antibacterial and durable bacteriostatic effect. Light-driven singlet oxygen (1O2) generated from PCN-224 and heat generated from Ag could function synergistically to realize rapid bacterial inactivation. Interestingly, 1O2 could promote Ag NPs to be degraded to release more Ag+ ions, achieving durable bacteriostatic effect. Antibacterial assay demonstrated 6 and 4.49 log unit inactivation toward two typical bacterial strains (E. coli and S. aureus) under Xe arc lamp in 30 min, respectively. Even after ten washes, the textile still maintained 6 log unit bacterial inactivation. Mechanism study proved light-driven 1O2 and heat are main factors causing bacterial inactivation, they could work synergistically to enhance bacterial inactivation efficiency. Photothermal study revealed that the textile could reach to 69 â„ƒ under visible light and 79.1 â„ƒ under 780-nm light-laser, which showed much potential in photothermal material applications. Taken together, our findings demonstrated a synergistic self-disinfecting cotton textile that exhibited constructive significance for preventing microbial infections and transmissions.

Circulating purification of cutting fluid: an overview.

Cutting fluid has cooling and lubricating properties and is an important part of the field of metal machining. Owing to harmful additives, base oils with poor biodegradability, defects in processing methods, and unreasonable emissions of waste cutting fluids, cutting fluids have serious pollution problems, which pose challenges to global carbon emissions laws and regulations. However, the current research on cutting fluid and its circulating purification technique lacks systematic review papers to provide scientific technical guidance for actual production. In this study, the key scientific issues in the research achievements of eco-friendly cutting fluid and waste fluid treatment are clarified. First, the preparation and mechanism of organic additives are summarized, and the influence of the physical and chemical properties of vegetable base oils on lubricating properties is analyzed. Then, the process characteristics of cutting fluid reduction supply methods are systematically evaluated. Second, the treatment of oil mist and miscellaneous oil, the removal mechanism and approach of microorganisms, and the design principles of integrated recycling equipment are outlined. The conclusion is concluded that the synergistic effect of organic additives, biodegradable vegetable base oils and recycling purification effectively reduces the environmental pollution of cutting fluids. Finally, in view of the limitations of the cutting fluid and its circulating purification technique, the prospects of amino acid additive development, self-adapting jet parameter supply system, matching mechanism between processing conditions and cutting fluid are put forward, which provides the basis and support for the engineering application and development of cutting fluid and its circulating purification.

Carbon quantum dots embedded electrospun nanofibers for efficient antibacterial photodynamic inactivation.

Faced with the emergence and proliferation of antibiotic resistant pathogens, novel nonspecific materials and approaches are required. Herein, we employed electrospinning technology to fabricate nanofibers with antibacterial photodynamic inactivation. This material combines polyacrylonitrile, as a photostable polymer, and biocompatible carbon quantum dots. The resulted nanofibers were successfully characterized by physical and spectroscopic methods. The microbicidal reactive oxygen species (i.e., singlet oxygen) upon illumination was confirmed, and cytotoxicity assay demonstrated that the nanofibers had low cytotoxicity and good biocompatibility. Antibacterial photodynamic inactivation studies demonstrated broad antibacterial efficacy of Gram-negative Escherichia coli ATCC-8099 (99.9999+%, 6 log units inactivation), Gram-negative Pseudomonas aeruginosa CMCC (B) 10104 (99.9999+%, 6 log units inactivation), and Gram-positive Bacillus subtilis CMCC (B) 63501 (99.9999+%, 6 log units inactivation) upon illumination with visible light (Xe lamp, 500 W, 12 cm sample distance, λ ≥ 420 nm, 1.5 h). However modest inactivation results were observed against Gram-positive Staphylococcus aureus ATCC-6538 (98.3%, 1.8 log units inactivation). Owing to the prepared nanofibers exhibiting efficient antibacterial activity against Gram-negative and Gram-positive bacteria, such materials could be potentially used in anti-infective therapy.

Insight into light-driven antibacterial cotton fabrics decorated by in situ growth strategy.

Development of ease-fabricated and effectively self-disinfecting textile materials for antimicrobial and infection prevention has been urgently desired by both consumers and industry. However, some nonresponsive antibacterial agents finished fabrics may be harmful to human. To address this issue, we developed a facile finishing method to endow woven cotton fabrics (WCF) with light-driven antibacterial property. Here in, porphyrinic metal-organic frameworks (PCN-224) were in situ synthesized on WCF (termed PCN-224/WCF) and PCN-224/WCF was proven to be used for antibacterial photodynamic inactivation (aPDI). aPDI studies indicated no difference in bacterial inactivation, the inactivation was 99.9999% of Gram-negative Escherichia coli 8099 and Pseudomonas aeruginosa CMCC (B) 10104 as well as Gram-positive Staphylococcus aureus ATCC-6538 and Bacillus subtilis CMCC (B) 63501 under visible light illumination (500 W, 15 cm vertical distance, λ ≥ 420 nm, 45 min). Cytotoxicity tests revealed PCN-224/WCF had low biological toxicity and good biocompatibility. Mechanism study revealed that singlet oxygen (1O2) was produced by PCN-224/WCF and caused severe damage to bacteria which was observed from the SEM images. This study provided a facile guideline to functionalize cotton fabrics with responsive bactericidal property which showed great potential for new generation of textiles with practical applications.

Carbon quantum dots: A bright future as photosensitizers for in vitro antibacterial photodynamic inactivation.

Carbon nanomaterials have increasingly gained the attention of the nano-, photo- and biomedical communities owing to their unique photophysical properties. Here, we facilely synthesized carbon quantum dots (CQDs) in a one-pot solvothermal reaction, and demonstrated their utility as photosensitizers for in vitro antibacterial photodynamic inactivation (aPDI). The bottom-up synthesis employed inexpensive and sustainable starting materials (citric acid), used ethanol as an environmentally-friendly solvent, was relatively energy efficient, produced minimal waste, and purification was accomplished simply by filtration. The CQDs were characterized by both physical (TEM, X-ray diffraction) and spectroscopic (UV-visible, fluorescence, and ATR-FTIR) methods, which together confirmed their nanoscale dimensions and photophysical properties. aPDI studies demonstrated detection limit inactivation (99.9999 + %) of Gram-negative Escherichia coli 8099 and Gram-positive Staphylococcus aureus ATCC-6538 upon visible light illumination (λ ≥ 420 nm, 65 ± 5 mW/cm2; 60 min). Post-illumination SEM images of the bacteria incubated with the CQDs showed perforated and fragmented cell membranes consistent with damage from reactive oxygen species (ROS), and mechanistic studies revealed that the bacteria were inactivated by singlet oxygen, with no discernable roles for other ROS (e.g., superoxide or hydroxyl radicals). These findings demonstrated that CQDs can be facilely prepared, operate via a Type II mechanism, and are effective photosensitizers for in vitro aPDI.