APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
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2012
·Vol. 97
·期 8
·3355-3362
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IF 3.425
Guo Fei,Xu Haoming,Xu Hongna,Yu Hongwei
Despite directed evolution being a practical and efficient method of improving the properties of enzymes, a trade-off between the targeted property and other essential properties often exists which hinders the efficiency of directed evolution. In our previous work, mutant CVH of an esterase from Rhodobacter sphaeroides with high enantioselectivity was obtained by directed evolution, unfortunately its activity cannot catch another mutant YH. To compensate the trade-off of mutant CVH, site-directed saturation mutagenesis was conducted on four residues, three (Asn62, Met121, and Leu145) were hot spots determined from directed evolution, and one (Tyr27) was introduced to make up the large distance between a mutation (Asn62) and the substrate. A new mutant (HMVY) with high enantioselectivity and comparable activity to YH was obtained. According to the kinetic analysis and molecular dynamics simulations, it was understood that the high enantioselectivity and poor activity of mutant CVH was caused by different decrement of efficiency constants to two isomers, ( R )-, ( S )-methyl mandelate, and the high enantioselectivity and activity of mutant HWVY was caused by improved activity towards the preferred substrate (( S )-methyl mandelate), which provided the interpretation of the trade-off compensation. This work could provide a way to compensate the trade-off of enantioselectivity and activity in the process of enzyme evolution.
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RESEARCH ON CHEMICAL INTERMEDIATES
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2025
·
IF 3.5
Yang Luyao,Zou Xuehua,Wang Hanlin,Chen Tianhu,Liu Haibo,Sun Fuwei,Chen Dong
Birnessite-type (δ-MnO 2 ) exhibits a high adsorption and catalytic performance to remove organic contaminants, but it still suffers from agglomerates, low specific surface area, and uneven distribution of active sites. Here, a novel birnessite-loaded biochar (δ-MnO 2 @BC, MBC) was prepared by chemical precipitation and used for the catalytic degradation of tetracycline under visible light. The biochar provides a large number of birnessite loading sites, which increases the specific surface area of the material, and reduces the electron–hole pair complexation rate. Photocatalytic results showed that under optimal conditions, 91.89% of TC could be degraded by 20% MBC(m(δ-MnO 2 )/m(BC) = 20%) at a pH value of 3.0, with a negligible effect by solid–liquid ratio and temperature. Our evidences demonstrate that photogenerated electrons and holes serve as the key active species, whereas superoxide radicals play a supplementary role. The MBC photocatalyst exhibits excellent stability, maintaining an 85% TC removal efficiency after five recycling cycles. In addition, the proposed degradation pathways of TC were presented, suggesting a partial mineralization by visible light photocatalysis using MBC. This study provides new ideas for the treatment of antibiotic wastewater with manganese oxides and biochar materials. Graphical abstract
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Nature Communications
·
2025
·Vol. 16
·期 1
·1-13
·
IF 15.7
Sun Xue,Li Haitao,Song Yajie,Liu Jiaxuan,Ji Pengxiang,Lei Xincheng,zhang Xiangzhi,Liu Qingsong,Li Menglu,Deng Biao,Su Dong,Wang Jiajun
Sodium (Na)-air batteries show significant potential as alternatives to lithium-air batteries due to their high theoretical energy density and the abundant availability of sodium reserves. Nevertheless, the formation of complex products, specifically NaO 2 , Na 2 O 2 , Na 2 CO 3 ·xH 2 O, during the multi-step reactions inevitably raises reconciled potential incompatibility that causes low efficiency and large overpotential. Here, we introduce a cascade electrocatalysis strategy that involves switchable metal and oxygen redox chemistry through electrochemical potential tuning. Leveraging the lithium ion spatial pinning effect, sodium ions trigger in the Na[Li 1/3 Ru 2/3 ]O 2 electrode system to toggle the geometric state at a low electrochemical potential and oscillate among different catalytic states to achieve sequential conversion of complicated multi-step intermediates. The Na[Li 1/3 Ru 2/3 ]O 2 catalyst effectively compartmentalizes the threshold potential that circumvents deactivating or competing pathways while coupling different catalytic cycles. As a result, the sodium-air battery employing this catalyst exhibits long-term reversibility over 1000 cycles with a decent catalysis efficiency exceeding 99%. Our results demonstrate that the cascade electrocatalysis strategy contributes to the design of integrated sodium-air batteries with long-term cycling stability.
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JOURNAL OF APPLIED ELECTROCHEMISTRY
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2025
·
IF 3
Shi Haijie,Hui Yuchen,Luo Li
An ultrasound-assisted electrodeposition method was employed to fabricate cobalt-nickel layered double hydroxide thin films on a carbon cloth substrate. The research delved into the effects of ultrasound power and time on the electrode’s morphology, chemical structure, lattice structure, and electrochemical kinetics. Compared to conventional electrodeposition, using the ultrasound-assisted method reduced the pore size on cobalt-nickel layered double hydroxide and enlarged the electroactive surface area. This led to a significant reduction in the Warburg impedance of cobalt-nickel layered double hydroxide and an enhancement in its electrochemical kinetic properties, which enhanced its sodium ion adsorption capability. The ultrasound-assisted method regulated the chemical and lattice structures of the electro-deposited cobalt-nickel layered double hydroxide. It increased the proportion of crystalline regions and accelerated the intercalation and deintercalation of sodium ions, and improved the electrode’s reversibility. By selecting appropriate ultrasound power and time, the electrochemical performance of cobalt-nickel layered double hydroxide was effectively enhanced. The pseudocapacitor constructed with the cobalt-nickel layered double hydroxide achieved a maximum specific capacitance of 2446.9 F g −1 and an energy density of up to 148.6 Wh kg −1 at a power density of 445.8 W kg −1 . The ultrasound-assisted electrodeposition method presented great potential for the development of new high-performance electrochemical energy storage materials.
Section
Graphical abstract
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Journal of the Iranian Chemical Society
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2025
·
IF 2.3
Yin Dawei,Chen Jiabao,Liu Yuting,Dang Chi,Zhou Yi,Zhang Zixu,Zheng Ruilin
Glutamic acid (Glu), aspartic acid (Asp), arginine (Arg) and ascorbic acid (AA) play an important role in the body’s protein anabolism, promoting tissue healing, improving disease resistance, as well as promoting bone growth, improving malnutrition, antioxidant and so on. Therefore, rapid detection of Glu, Asp, Arg and AA is of great significance. 2-methoxy-4-(((5-phenyl-1,3,4-thiadiazol-2-yl)imino)methyl)phenol (Probe A) was synthesized with deep eutectic solvent as catalyst under mild conditions. The Probe A was applied to the detection of Glu, Asp, Arg and AA, and the results showed that Probe A could well identify Glu, Asp, Arg and AA. Glu, Arg and AA are well recognized at pH = 6–12. Asp is well recognized at pH = 7–12. The binding ratios between Probe A and Glu, Asp, Arg, AA were 2:3, 2:3, 1:2 and 2:3, respectively. The association constants were 9.59 × 10 3 M −1 , 7.34 × 10 3 M −1 , 4.46 × 10 4 M −1 , 1.69 × 10 4 M −1 , respectively. The detection limits were 3.33 × 10 –5 M, 1.62 × 10 –5 M, 2.22 × 10 –4 M, and 1.69 × 10 –5 M, respectively. The probe solution quickly became colorless after adding Glu, Asp and AA, and orange-red after adding Arg. The identification mechanism of Probe A with Glu, Asp, Arg and AA was obtained by infrared titration and nuclear magnetic titration. This method provides an important way for rapid detection of Glu, Asp, Arg and AA.
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Nature Communications
·
2025
·Vol. 16
·期 1
·1-12
·
IF 15.7
Liu Xuan,Wang Yuhan,He Hu,Zhao Zhonglong,Luo Xuan,Zhang Siyang,Lu Gang,Su Dong,Wang Yucheng,Huang Yunhui,Li Qing
The long-standing challenges facing Pt-based alloy catalysts in oxygen reduction reactions (ORRs) are rapid oxidation and loss of transition metal/Pt in proton exchange membrane fuel cells (PEMFCs). In this work, we report a concept of “covalentization” in intermetallic L1 0 -PtMM’ (M = Fe, Co, Ni and M’ = one of the 4 th -period elements (from Ti to Ge)) alloys to enhance their electrochemical stability. Specifically, the formation of a quasi-covalent bond network in L1 0 -PtMM’ due to the less occupied antibonding states induced by high d -band positions of M’ elements (e.g., Ti, V, Cr) enhances atomic bond order and strength, diminishing Co anodic dissolution via strengthened Pt/Co-M’ bonds and reducing Co cathodic corrosion by inhibiting Pt oxidation through an electron buffering effect. The developed L1 0 -PtCoCr/C catalysts show a high mass activity (MA = 1.27 A mg Pt −1 ) and rated power (16.5 W mg Pt −1 ) in PEMFCs at a low total Pt loading of 0.075 mg Pt cm −2 . The catalysts also exhibit high electrochemical stability with ~3% and 5% loss of MA and rated power after 30,000 accelerated durability testing cycles and projects a lifetime of about 42,000 hours.
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RARE METALS
·
2025
·
IF 11
Ding Kaiwei,Zhao Guanfei,Qiu Tingsheng,Qiu Xianhui,Yan Huashan,Wu Hao,Yang Wenhui,Yan Shunde,Lin Liqiang
Silver is a crucial rare and valuable metal in industrial applications, primarily found in polymetallic sulfide deposits as sulfides. The adsorption compatibility between various types of associated silver ores and collectors has not been extensively studied. This research focuses on acanthite (Ag 2 S), the predominant mineral in such ores. The study systematically investigates the adsorption compatibility differences between dithiophosphate collectors with five distinct substituents and associated silver ores. This investigation combines computational chemistry simulations with experimental validations. The findings reveal that the −N 2 PS 2 − -type collector exhibits superior surface matching with acanthite (100) surface compared to the −O 2 PS 2 − -type collector. Moreover, the presence of −C−O−C− bonds and benzene rings enhances the effectiveness of dithiophosphate-type collectors for acanthite. In contrast, the compatibility of the −C 2 PS 2 − -type 3418A collector, lacking characteristic groups, is relatively poor. In high-alkali processes, the adsorption of Ca(OH) + hinders the reactivity of silver atoms with the collector. The presence of benzene rings and −NH− groups in the substituents intensifies the impact of Ca(OH) + on the collector, thereby diminishing its adsorption strength. The introduction of −C−O−C− does not modify the sensitivity of the −O 2 PS 2 − -type collector to Ca(OH) + . Furthermore, the adsorption of alkane −C 2 PS 2 − -type collectors on mineral surfaces remains unaffected by the attenuating effect of Ca(OH) + . The results of the flotation tests, Zeta potential, and adsorption capacity assessments further validated the conclusions derived from computational chemistry analyses. The results provide valuable insights for the future design and advancement of innovative collectors customized for silver ore applications.
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Nature Communications
·
2025
·Vol. 16
·期 1
·1-19
·
IF 15.7
Zhang Yu,Zhang Tingting,Xiao Xue,Wang Yejun,Kawalek Adam,Ou Jinzhao,Ren Anmin,Sun Wenhao,de Bakker Vincent,Liu Yujie,Li Yuelong,Yang Liang,Ye Liang,Jia Ning,Veening Jan-Willem,Liu Xue
With the rise of antibiotic-resistant bacteria, non-antibiotic therapies like gallium gain increasing attention. Intravenous gallium nitrate is under Phase II clinical trials to treat chronic Pseudomonas aeruginosa infections in cystic fibrosis patients. However, its clinical efficacy is constrained by the achievable peak concentration in human tissue. To address this limitation, we apply a genome-wide CRISPR interference approach (CRISPRi-seq) to identify potential synergistic targets with gallium. We classify the essential genes by response time and growth reduction, pinpointing the most vulnerable therapeutic targets in this species. In addition, we identify a highly conserved gene, fprB , encoding a ferredoxin-NADP⁺ reductase, whose deletion sensitizes P. aeruginosa to gallium, lowering its MIC by 32-fold and shifting mode of action from bacteriostatic to bactericidal. Further investigation reveals that FprB plays a critical role in modulating oxidative stress induced by gallium, via control of iron homeostasis and reactive oxygen species accumulation. Deleting fprB enhances gallium’s efficacy against biofilm formation and improves outcomes in a murine lung infection model of P. aeruginosa , suggesting FprB is a promising drug target in combination with gallium. Overall, our data show CRISPRi-seq as a powerful tool for systematic genetic analysis of P. aeruginosa , advancing the identification of novel therapeutic targets.
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Nature Communications
·
2025
·Vol. 16
·期 1
·1-20
·
IF 15.7
Zhang Zehong,Wan Qianyi,Zhu Yuedan,Ye Jinbao,Fu Fang,Fan Xinxin,Chen Haiou,Ren Gang,Jiang Wei,Guo Xiaoxin,Zhou Juanyu,Yan La,Yan Jinhua,Liu Xingzhu,Yuan Yu,Chen Yi,Chen Haiyang
Intestinal stem cell (ISC) aging diminishes the regenerative capacity of the intestinal epithelia, but effective therapeutic strategies to counteract human ISC aging remain elusive. Here, we find that the synthesis of α-lipoic acid (ALA) is reduced in old human small intestine. Notably, ALA supplementation inhibits ISC aging and decreases the number of atypical Paneth cells in old human intestinal organoids and in old mouse small intestines. Importantly, we discern that the effect of ALA on mitigating ISC aging is contingent upon the presence of Paneth cells. Inhibiting the mTOR pathway in Paneth cells with ALA or rapamycin significantly increases cyclic ADP ribose (cADPR) secretion and decreases Notum secretion, which, in turn, enhances ISC functions. In this work, our findings substantiate the role of ALA in inhibiting human ISC aging and present a potential therapeutic approach for managing age-related human intestinal diseases.
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MICROCHIMICA ACTA
·
2025
·Vol. 192
·期 6
·1-11
·
IF 5.3
Zhang Hui,Ji Yahui,You Nana,Hu Xiaoping,Chen Feifei,Wang Fei,Liu Gen
Ratiometric electrochemiluminescence (ECL) assays have attracted widespread attention in biosensing owing to their precise measurements by eliminating environmental interferences. In this work, g-C 3 N 4 , gold nanoparticles, CuO and luminol were integrated onto hollow carbon spheres (HCS) in sequence to fabricate potential-resolved ECL nanoprobes. The system consists of g-C 3 N 4 as cathode ECL emitters and luminol as anode ECL emitters. The ECL of g-C 3 N 4 is quenched by CuO due to the resonance energy transfer (RET). However, after adding dopamine (DA), the ECL signal is restored due to the redox reaction between CuO and DA. Meanwhile, there is a quenching effect between DA and luminol because DA interferes with the radical reaction process of luminol. Therefore, DA causes the reciprocal changes in cathodic ECL and anodic ECL. This phenomenon can be leveraged to create a ratiometric ECL signal, enabling the quantitative detection of DA. The developed ECL sensor exhibited a sensitive detection toward DA, performing a wide linearity in the range 5.0 × 10 –4 ~ 1.0 × 10 –9 M with a low detection limit of 2.3 × 10 –11 M (S/N = 3). Furthermore, this strategy exhibited a good practicality to detect DA in human urine, providing a promising strategy in ECL bioanalysis. Graphical abstract
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MICROCHIMICA ACTA
·
2025
·Vol. 192
·期 10
·1-15
·
IF 5.3
Xiao Aijin,Li Meng,Hu Yiluo,Zhang Wei,Bai Huiping,Pan Xuejun,Jiang Fengzhi
A CuFeO 2 /NiCo-LDH heterojunction electrochemical sensor (LDH: layered double hydroxide) was developed for the sensitive detection of tetracycline (TC). The sensor was constructed by integrating ZIF-67-derived nanocage NiCo-LDH on nickel foam with CuFeO 2 , forming a p-n heterojunction that enhanced electron transfer and TC adsorption. The sensor exhibited bilinear detection ranges (0.00594 ~ 1 and 1 ~ 25 μM) and a low detection limit of 1.98 nM. Recoveries in real water samples ranged from 92.0 to 109.0%, with relative standard deviations not exceeding 4.5%. In situ Raman spectroscopy and density functional theory calculations confirmed the involvement of multiple redox pairs (Ni 3+ /Ni 2+ , Co 3+ /Co 2+ , Fe 3+ /Fe 2+ and Cu 2+ /Cu + ) and strong interfacial adsorption energy. This sensor presents a practical and efficient approach for onsite TC monitoring. Graphical
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JOURNAL OF FUSION ENERGY
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2025
·Vol. 44
·期 1
·1-14
·
IF 2.1
Hu Xin,Tan Guangfan,Cai Liang,Yi Biao,Xu Dajun,Gao Zeyu,Dong Xiaoxu,Li Yusha,Zhang Yingchun
In order to meet the huge demand for millimetre-sized Li 2 TiO 3 ceramic pebbles for future fusion reactors, the aim of this work was to develop a combination of microfluidic and UV curing techniques to greatly improve the preparation efficiency. By employing a cross-junction microfluidic device, large-sized droplets were controllably generated and subsequently subjected to in-situ UV curing, enabling rapid solidification of resin-based ceramic slurries. Systematic investigations revealed critical processing parameters: (1) The rheological behavior of ceramic slurries was governed by solid content and dispersant concentration, directly influencing droplet stability during microfluidic manipulation. (2) UV curing efficacy depended on exposure time(10 ~ 40 s), aging time (30 ~ 120 s) and solid content, and the optimised conditions allow complete cross-linking of 2 mm green pebbles. (3) Post-sintering at an ultra-low heating rate (0.5 °C/min) produced Li 2 TiO 3 ceramic pebbles with a relatively dense microstructure and high crush load(42 N).This microfluidic and UV curing strategy demonstrates potential process controllability and scalability.
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