查找使用阿拉丁产品的科研文献

A structure–activity relationship study of flavonoids as inhibitors of E. coli by membrane interaction effect

Ting Wu,Mengying He,Xixi Zang,Ying Zhou,Tianfu Qiu,Siyi Pan,Xiaoyun Xu

Flavonoids exhibit a broad range of biological activities including antibacterial activity. However, the mechanism of their antibacterial activity has not been fully investigated. The antibacterial activity and membrane interaction of 11 flavonoids (including 2 polymethoxyflavones and 4 isoflavonoids) against Escherichia coli were examined in this study. The antibacterial capacity was determined as flavonoids   >   polymethoxyflavones   >   isoflavonoids. Using fluorescence, it was observed that the 5 flavonoids rigidified the liposomal membrane, while the polymethoxyflavones and isoflavonoids increased membrane fluidity. There was a significant positive correlation between antibacterial capacity and membrane rigidification effect of the flavonoids. A quantitative structure–activity relationship (QSAR) study demonstrated that the activity of the flavonoid compounds can be related to molecular hydrophobicity (CLogP) and charges on C atom at position3 (C3). The QSAR model could be used to predict the antibacterial activity of flavonoids which could lead to natural compounds having important use in food and medical industry.

Dynamic Cu–Fe Dual Sites Steering Tandem e–/H+ Delivery for Efficient NH3 Electrosynthesis in Acid

Yuan Ma,Yongli Li,Lan Jiang,Xin Kong,Xin You,Liang Liu,Rui Bao,Zhenhua Ge,Hao Cui,Feng Liu,Jianhong Yi

The energy-intensive Haber-Bosch process for ammonia synthesis necessitates sustainable alternatives, electrochemical nitrate reduction (eNO3RR) is emerging as a promising route to address nitrate pollution. However, it faces a critical bottleneck: the low ammonia selectivity arising from competitive hydrogen evolution. Herein, we introduce copper carbon dots-supported iron phthalocyanine (Cu-CDs/FePc) - a electrocatalyst featuring dynamic Cu–Fe dual sites that steer tandem e–/H+ delivery for efficient NH3 electrosynthesis. It achieves an outstanding ammonia yield of 17.69 mg h–1 mgcat.–1 with a remarkable Faradaic efficiency of 91.0% at −0.7 V vs RHE in acid conditions, which surpasses many reported transition metal-based electrocatalysts for eNO3RR. In-situ FTIR spectroscopy and density functional theory (DFT) calculations elucidate that dynamic Cu–Fe dual sites orchestrate directional electron–proton relay chains through electronic complementarity: Electron-deficient Cu2+ centers intensify NO3– adsorption/activation, while electron-enriched Fe2+ sites drive *NO2 protonation, and interfacial charge shuttling initiates valence oscillations (Cu+/Cu2+ and Fe2+/Fe3+) effectively lower rate-determining step energy barrier, thereby boosting ammonia selectively while simultaneously suppressing hydrogen evolution. Furthermore, the catalyst exhibits robust stability over 100 h and practical versatility in zinc-air battery systems. This work presents a rational design strategy for high-performance eNO3RR catalysts, offering a significant advance toward efficient green ammonia synthesis and environmental remediation.

Fabrication, characterization, and bioactivity assessment of chitosan microemulsion containing lauric acid-vitamin E against foodborne pathogens

Chen Li,Peipei Ma,Xiaoyue Sui,Aminu Abdullahi Mahmoud,Xinyu Liao,Tian Ding,Runrun Zhang

The stable food-grade lauric acid emulsions were developed. • Emulsions showed homogeneous structure and good viscoelastic stability. • The emulsions exhibited notable antioxidant activity and activity against S. aureus . • Antibacterial activity linked to membrane damage and energy disruption. Lauric acid (LA) is an antimicrobial medium-chain fatty acid, but its poor aqueous solubility limits its application in food matrices. To address this, ultrasound-assisted emulsion was developed using LA in vitamin E (VE) oil and chitosan-polyvinyl alcohol (CS-PVA) aqueous matrix. The emulsion exhibited uniformly dispersed oil droplets forming a compact network structure, along with superior stability and viscoelastic properties. No phase separation was observed during storage except for the 5 CP/VL system after 30 days, where CP/VL refers to the CS-PVA/VE-LA. Functionally, the emulsion disrupted bacterial membrane integrity and interfered with cellular energy metabolism. The 10 CP/VL formulation achieved a favorable balance between stability and bioactivity, with DPPH scavenging rate of 26.57% and 2.8 log CFU/mL reduction of Staphylococcus aureus after 2 h at 1% concentration. Overall, this study provides a feasible strategy for enhancing the dispersion and function of LA in aqueous systems for food-related applications. Download: Download high-res image (399KB) Download: Download full-size image

Dual-Dynamic Polyurethane Elastomers Integrating High Strength and Room-Temperature Self-Healing for an E-Skin

Yufei Cao,Pengyu Zhu,Shuo Yang,Wenwen Wu,Dongli Fan,Peng Zhu,Haiyan Ma,Hongbin Lu,Jie Liu,Yufeng Cao,Tao Qian

Conventional flexible sensors often face a compromise between mechanical properties and self-healing ability, which severely limits their long-term usability and functional reliability. In this work, we report a series of polyurethane elastomers synergistically reinforced by multiple hydrogen bonds and disulfide bonds, which integrates high mechanical strength and autonomous self-healing ability. The optimized composition, PU-BHO0.3-BHDS0.7, achieved an excellent breaking strength of ∼39.73 MPa, an elongation at break of ∼1568.61%, and a fracture energy of ∼157.75 kJ·m–2. It also exhibited an ultrahigh self-healing efficiency of ∼99.29% at room-temperature, retaining ∼85.90% even at −18 °C. Based on this elastomer, we fabricated a multilayer resistive sensor using liquid gallium (LG) and carbon black (CB) as conductive electrodes. The healed sensor maintained a gauge factor and resistance response nearly identical to its original state, demonstrating complete functional restoration. This work provides a feasible strategy for developing high-performance self-healing materials suitable for durable flexible electronic devices, such as human motion sensors.

Bio-derived protein-based E-skin: Ionic liquid-enhanced hydrogel sensors with high conductivity and biocompatibility

Yanyan Lu,Yuhui Zhao,Guo Zhao,Xinglian Xu,Xue Zhao

An MP-IL dual-network hydrogel sensor is developed from chicken by-products. • It offers skin-matched modulus, high conductivity, and wide-range dmotion monitoring. • The hydrogel shows high biocompatibility with no inflammatory response. • The hydrogel shows negligible IL leakage and stable 200-cycle performance. • This MP-based e-skin uniquely integrates biosafety and and biodegradability. Biocompatible sensors with tissue-like mechanical properties are urgently needed for individuals with communication and movement disorders. Conductive hydrogels are promising candidates, yet conventional synthetic versions face biosafety and degradability challenges for long-term wearable use. In this work, we developed a biocompatible dual-network hydrogel sensor for high-performance epidermal sensing, integrating the skin-homologous myofibrillar proteins (MP) with ionic liquid (IL) through unique molecular design. The hydrogel network is constructed via Schiff-base crosslinking between MP and oxidized dextran (ODex), interpenetrated with an ionically cross-linked sodium alginate (SA) network. This unique design achieves skin-matched mechanical properties (tensile strength 440.4 ± 16.6 kPa, elastic modulus 342.5 ± 12.2 kPa) and high ionic conductivity (9.1 mS/cm). The resulting sensor exhibits excellent strain response (0.4 s) and recovery (0.2 s) times, high sensitivity (gauge factor ~ 1.55), and stable resistance variation under both tensile and compressive deformation, showing potential for monitoring a wide range of motions from subtle physiological signals (e.g., frowning, swallowing, and smiling) to large-scale joint movements, speaking, and handwriting signal monitoring, with possible relevance to throat motion monitoring and assistive communication. The ionic liquid shows negligible leakage (<5% cumulative release over 7 days), and the hydrogel maintains stable mechanical performance over 200 cyclic loading-unloading tests, supporting long-term wearable reliability. In vitro cytotoxicity, in vivo skin patch, and implantation tests confirm excellent biocompatibility (cell viability ≥94.2%) with no significant inflammatory response. Sourced from low-cost chicken meat by-products, this hydrogel provides an alternative platform for next-generation epidermal electronics that harmonizes biosafety and biodegradability. Download: Download high-res image (160KB) Download: Download full-size image

Immobilization of mutated xylanase from Neocallimastix patriciarum in E. coli and application for kraft pulp biobleaching

Huang Y.,Zhang N.-J.,Zhao Z.

As an important enzyme, xylanase is widely used in the food, pulp, and textile industry. Different applications of xylanase warrant specific conditions including temperature and pH. This study aimed to carry out sodium alginate beads as carrier to immobilize previous reported mutated xylanase from Neocallimastix patriciarum which expressed in E. coli, the activity of immobilization of mutated xylanase was elevated about 4% at pH 6 and 13% at 62 °C. Moreover, the immobilized mutated xylanase retained a greater proportion of its activity than the wide type in thermostability. These properties suggested that the immobilization of mutated xylanase has potential to apply in biobleaching industry.

Direct RBS Engineering of the biosynthetic gene cluster for efficient productivity of violaceins in E. coli

Zhang Yuyang,Chen Hongping,Zhang Yao,Yin Huifang,Zhou Chenyan,Wang Yan

Background Violaceins have attracted much attention as potential targets used in medicines, food additives, insecticides, cosmetics and textiles, but low productivity was the key factor to limit their large-scale applications. This work put forward a direct RBS engineering strategy to engineer the violacein biosynthetic gene cluster cloned from Chromobacterium violaceum ATCC 12,472 to efficiently improve the fermentation titers.Results Through four-rounds of engineering of the native RBSs within the violaceins biosynthetic operon vioABCDE, this work apparently broke through the rate-limiting steps of intermediates conversion, resulting in 2.41-fold improvement of violaceins production compared to the titers of the starting strain Escherichia coli BL21(DE3) (Vio12472). Furthermore, by optimizing the batch-fermentation parameters including temperature, concentration of IPTG inducer and fermentation time, the maximum yield of violaceins from (BCDE)m (tnaA−) reached 3269.7 µM at 2 mM tryptophan in the medium. Interestingly, rather than previous reported low temperature (20 ℃), we for the first time found the RBS engineered Escherichia coli strain (BCDE)m worked better at higher temperature (30 ℃ and 37 ℃), leading to a higher-level production of violaceins.Conclusion sTo our knowledge, this is the first time that a direct RBS engineering strategy is used for the biosynthesis of natural products, having the potential for a greater improvement of the product yields within tryptophan hyperproducers and simultaneously avoiding the costly low temperature cultivation for large-scale industrial production of violaciens. This direct RBS engineering strategy could also be easily and helpfully used in engineering the native RBSs of other larger and value-added natural product biosynthetic gene clusters by widely used site-specific mutagenesis methods represented by inverse PCR or CRISPR-Cas9 techniques to increase their fermentation titers in the future.

E-jet 3D printed drug delivery implants to inhibit growth and metastasis of orthotopic breast cancer

Yikun Yang,Xiaoyin Qiao,Ruiying Huang,Haoxiang Chen,Xuelei Shi,Jian Wang,Weihong Tan,Zhikai Tan

Drug-loaded implants have attracted considerable attention in cancer treatment due to their precise delivery of drugs into cancer tissues. Contrary to injected drug delivery, the application of drug-loaded implants remains underutilized given the requirement for a surgical operation. Nevertheless, drug-loaded implants have several advantages, including a reduction in frequency of drug administration, minimal systemic toxicity, and increased delivery efficacy. Herein, we developed a new, precise, drug delivery device for orthotopic breast cancer therapy able to suppress breast tumor growth and reduce pulmonary metastasis using combination chemotherapy. Poly-lactic-co-glycolic acid scaffolds were fabricated by 3D printing to immobilize 5-fluorouracil and NVP-BEZ235. The implantable scaffolds significantly reduced the required drug dosages and ensured curative drug levels near tumor sites for prolonged period, while drug exposure to normal tissues was minimized. Moreover, long-term drug release was achieved, potentially allowing one-off implantation and, thus, a major reduction in the frequency of drug administration. This drug-loaded scaffold has great potential in anti-tumor treatment, possibly paving the way for precise, effective, and harmless cancer therapy.

Efficient photocatalytic inactivation of E. coli by Mn-CdS/ZnCuInSe/CuInS2 quantum dots-sensitized TiO2 nanowires

Hongchao Geng,Ning Jiang,Chenyi Li,Xingqi Zhu,Yan Qiao,Qingyun Cai

A novel visible light-driven photocatalyst (represented as Mn-CdS/ZCISe/CIS/TiO2) for the passivation of E. coli was prepared with TiO2 nanowires as support and using CuInS2 (CIS) and ZnCuInSe (ZCISe) quantum dots (QDs), as well as Mn-doped CdS (Mn-CdS) nanoparticles (NPs) as sensitizers. The use of CIS and ZCISe QDs and Mn-CdS NPs extends the light harvest region to visible light. The photoelectric conversion efficiency was consequently improved, with a photocurrent density of 12.5 mA cm−2, about 60 times that of pure TiO2 nanowires. The germicidal efficiency of the photocatalyst was assessed by passivation of E. coli, 96% bacteria in 50 ml 105 colony forming units (CFU) ml−1 solution were killed within 50 min. Besides the high efficiency, the composite has good stability and satisfactory recycling performance. The antibiotic mechanism was also performed by using photoluminescence and a scavenging agent of different active matter, revealing that the photo-generated holes play a major role in the sterilization process.

Bimodal Thermoelectric/AIE E-Skin Decouples Contact-Area Ambiguity for Concurrent Pain Perception and Injury Mapping

Bingchen Huo,Fengxia Kuang,Chunyu Du,Chengzhi Chen,Qi Sun,Wanqiang Li,Lirong Liang,Hanfu Wang,Cun-Yue Guo,Guangming Chen

Thermoreceptive electronic skins face fundamental limitations due to signal ambiguity caused by the contact-area effect in thermoelectric devices. Since electrical output depends on total heat flux, localized high-temperature stimuli generate indistinguishable signals from widespread low-temperature stimuli, leading to unreliable thermal hazard assessment. To address this challenge, we developed a dual-modality bilayer e-skin integrating a single-walled carbon nanotube-based thermoelectric layer and an aggregation-induced emission luminogen-based photoluminescent layer. The bottom thermoelectric layer functions as a fast-response nociceptor, converting temperature gradients into voltage-encoded “pain” signals. The top AIE layer provides contact-area-independent optical mapping of thermal fields through photoluminescence quenching, enabling direct visual decoupling of temperature from contact area without computational processing. This integrated platform achieves real-time injury visualization, accurate temperature recognition (>97% accuracy), and reliable nociceptive-like sensing. Validated by a biomimetic robotic reflex system, the e-skin offers a robust solution for intelligent safety protection and enhanced human-machine interaction in dynamic thermal environments.

Synthesis of (E)-β-iodovinyl sulfones via DTBP/I2 promoted difunctionalization of alkynes with sodium benzenesulfinates

Wenzhu Bi,Chunyan Ren,Linguo Jia,Xiaoyi Xia,Xi Chen,Xiaolan Chen,Yufen Zhao

Enhanced hydrophilicity and antibacterial activity of PVDF ultrafiltration membrane using Ag3PO4/TiO2 nanocomposite against E. coli

Xiaoting Hong,Yumei Zhou,Zhuoliang Ye,Haifeng Zhuang,Wanpeng Liu,K.S. Hui,Zhi Zeng,Xianhuan Qiu

Ag 3 PO 4 /TiO 2 nanocomposite was fabricated by an in situ precipitation method and then blended into poly(vinylidene fluoride) (PVDF) casting solution to prepare the ultrafiltration membrane via wet phase inversion technique. The water flux and bovine serum albumin (BSA) rejection rate of membrane were investigated; meanwhile, the ultrafiltration membrane morphologies and structural properties were analyzed using scanning electron microscope (SEM) and X-ray diffraction. Compared with the control membrane, the permeate performance of blended membranes was improved while possessing a steady BSA retention due to enhanced hydrophilicity. Mechanical tests revealed that the modified membranes exhibited a larger tensile strength and breakage elongation. SEM images and the halo zone testing were employed to assess the antibacterial performances of the nanocomposite membranes against Escherichia coli. The antibacterial tests confirmed that the modified membranes showed an effective antibacterial property against E. coli.