JOURNAL OF BIOTECHNOLOGY
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2024
·
IF 4.1
Yufeng Zhou,Xiaolong Sun,Jiahuan Hu,Yingjie Miao,Xiangyu Zi,Xi Luo,Yongqian Fu
Serving as a vital medical intermediate and an environmentally-friendly preservative, D-PLA exhibits substantial potential across various industries. In this report, the urgent need for efficient production motivated us to achieve the rational design of lactate dehydrogenase and enhance catalytic efficiency . Surprisingly, the enzymatic properties revealed that a mutant enzyme , Lr LDH T247I/D249A/F306W/A214Y ( Lr LDH-M 1 ), had a viable catalytic advantage. It demonstrated a 3.3-fold increase in specific enzyme activity and approximately a 2.08-fold improvement of K cat . Correspondingly, molecular docking analysis provided a supporting explanation for the lower K m and higher K cat /K m of the mutant enzyme. Thermostability analysis exhibited increased half-lives and the deactivation rate constants decreased at different temperatures (1.47–2.26-fold). In addition, the mutant showed excellent resistance abilities in harsh environments, particularly under acidic conditions. Then, a two-bacterium ( E. coli /pET28a- lrldh -M 1 and E. coli /pET28a- ladd ) coupled catalytic system was developed and realized a significant conversion rate (77.7%) of D-phenyllactic acid, using 10 g/L L-phenylalanine as the substrate in a two-step cascade reaction.
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PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 13
·3975-3983
·
IF 6.1
Huiqin Yu,Fang Li,Jing Cao,Shifu Chen,Haili Lin
Developing highly active and stable bifunctional electrocatalysts for the oxidation of alcohols is critical for energy and chemical conversion. Herein, a NiCo2O4 nanowire on ultrathin porous carbon (NiCo2O4/C) was fabricated and exhibits superior electrocatalytic performance for both hydrogen evolution and benzyl alcohol (BA) oxidation in comparison with pristine NiCo2O4 free of carbon. It only needed 1.36 V vs. RHE to afford a current density of 50 mA cm−2 for BA oxidation. The overpotential for the HER (η10) is −93.0 mV vs. RHE. Furthermore, high yield (96.0%) and faradaic efficiency (98.6%) of benzoic acid were achieved in 10 consecutive stability tests. The outstanding electrocatalytic activity can be attributed to the following aspects: (1) the hierarchical architecture exposed more catalytic active sites and enhanced mass transport; (2) ultrathin porous carbon strengthened the affinity for the reaction medium; (3) strong electronic interactions optimized the energy band structure. DFT simulations proved that the Gibbs free energy of the rate-determining step was reduced when coupling with ultrathin porous carbon, thus lowering the energy barrier and accelerating the reaction process. Theoretical calculations further reveal that the moderate downshift in the Ed energy levels, which balance the adsorption and desorption of the intermediates, is the intrinsic reason for the promoted oxidation activity. This work could provide valuable insights into the design of highly efficient bifunctional electrocatalysts.
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2024
·
IF 3.3
Nawei Zhang,Yang Xu,Xiao Jia,Xiao Li,Jingnan Ren,Siyi Pan,Gang Fan,Jinchu Yang
BACKGROUND Citrus products often suffer from delayed bitterness, which is generated from the conversion of non-bitter precursors (limonoate A-ring lactone, LARL) to limonin under the catalysis of limonin D-ring lactone hydrolase (LDLH). In this study, LDLH was isolated and purified from sweet orange seeds, and a rapid and accurate high-performance liquid chromatography method to quantify LARL was developed and applied to analyze the activity and enzymatic properties of purified LDLH. RESULTS Purified LDLH (25.22 U mg −1 ) showed bands of 245 kDa and 17.5 kDa molecular weights in native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate PAGE analysis respectively. After a 24 h incubation under strongly acidic (pH 3) or strongly alkaline (pH 9) conditions, LDLH still retained approximately 100% activity. Moreover, LDLH activity was not impaired by thermal treatment at 50 °C for 120 min. Enzyme inhibition assays showed that LDLH was inactivated only after ethylenediaminetetraacetic acid treatment, and other enzyme inhibitors showed no significant effect on its activity. In addition, the LDLH activity of calcium ion (Ca 2+ ) intervention was 108% of that in the blank group, and that of zinc ion (Zn 2+ ) intervention was 71%. CONCLUSION LDLH purified in this study was a multimer containing 17.5 kDa monomer with a wide pH tolerance range (pH 3–9) and excellent thermal stability. Moreover, LDLH might be a metallopeptidase, and its activity was stimulated by Ca 2+ and significantly inhibited by Zn 2+ . These findings improve our understanding of LDLH and provide some important implications for reducing the bitterness in citrus products in the future. © 2024 Society of Chemical Industry.
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PubMed
高影响因子
Frontiers in Bioscience-Landmark
·
2024
·Vol. 29
·期 11
·389
·
IF 3.3
Jie Dai,Haiyan Huang,Liucheng Wu,Mei Ding,Xiangyang Zhu
Background: Vitamin D receptor (VDR) can prevent myocardial ischemia reperfusion injury (MIRI). Hence, we aimed to illuminate the effect of VDR on cerebral ischemia/reperfusion injury (CIRI). Methods: C57BL/6 mice and SK-N-SH cells were utilized to establish CIRI and cellular oxygen deprivation/reoxygenation (OGD/R) models. Mice were injected with 1 μg/kg Calcitriol or 1 μg/kg Paricalcitol (PC) and adenovirus-mediated VDR overexpression or knockdown plasmids. 2,3,5-triphenyl-tetrazolium chloride (TTC) and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed to measure the brain infarct volume and the apoptosis of cerebral cells. SK-N-SH cells were treated with 5 mM N-acetyl-L-cysteine (NAC) and transfected with VDR knockdown plasmid. Flow cytometry and Cell Counting Kit-8 (CCK-8) assays were employed to assess the apoptosis and cell viability. Enzyme-Linked Immunosorbent Assay (ELISA), quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) and Western blot were exploited to quantify the levels of reactive species oxygen (ROS), other oxidative stress-related factors, VDR and apoptosis-related factors. Results: The level of VDR in mouse cerebral tissue was elevated by CIRI (p < 0.001). CIRI-induced cerebral infarction (p < 0.001) and the apoptosis of cerebral cells (p < 0.001) in mice were mitigated by the activation of VDR. VDR overexpression abrogated while VDR silencing enhanced CIRI-induced infarction, oxidative stress and apoptosis of cerebral cells (p < 0.05). Furthermore, VDR silencing aggravated the oxidative stress and apoptosis in OGD/R-treated SK-N-SH cells (p < 0.05). NAC, a scavenger of oxidative stress, could reverse the effects of VDR silencing on apoptosis and oxidative stress in OGD/R-treated SK-N-SH cells (p < 0.01). Conclusion: VDR alleviates the oxidative stress to protect against CIRI.
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高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-10
·
IF 17.694
Yang Yang,Zhu Xiaojuan,Wang Lili,Lang Junyu,Yao Guohua,Qin Tian,Ren Zhouhong,Chen Liwei,Liu Xi,Li Wei,Wan Ying
Pd catalysts are widely used in alkynol semi-hydrogenation. However, due to the existence of scaling relationships of adsorption energies between the key adsorbed species, the increase in conversion is frequently accompanied by side reactions, thereby reducing the selectivity to alkenols. We report that the simultaneous increase in alkenol selectivity and alkynol conversion is achieved by manipulating interstitial atoms including B, P, C, S and N in Pd catalysts. A negative linear relationship is observed between the activation entropies of 2-methyl-3-butyn-2-ol and 2-methyl-3-buten-2-ol which is highly related to the filling of d -orbital of Pd catalysts by the modification of p -block elements. A catalyst co-modified by B and C atoms has the maximum d charge of Pd that achieves a 17-fold increase in the turn-over frequency values compared to the Lindlar catalysts in the semi-hydrogenation of 2-methyl-3-butyn-2-ol. When the conversion is close to 100%, the selectivity can be as high as 95%.
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RARE METALS
·
2025
·
IF 11
Huang De-Xuan,Zhao Jian-Wei,Hu Xue-Lei,Liu Tong
Transition metal oxides have garnered significant attention as electrocatalysts for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). However, their sluggish reaction kinetics and poor stability hinder commercial applications. Herein, we report the synthesis of a bimetallic cobalt manganese oxide, Co 0.99 Mn 2.01 O 4 (CMO), synthesized via a hydrothermal technique, which serves as a highly efficient bifunctional ORR/OER electrocatalyst owing to its impressive half-wave potential of 0.767 V and low overpotential of 1.677 V at 10 mA cm −2 . Theoretical calculations revealed that the d-band centers of Co 3d and Mn 3d in CMO, located at tetrahedral and octahedral sites, are positioned near the Fermi level, facilitating the adsorption of electrocatalytic intermediates. Furthermore, the distance between the Co 3d and O 2p band centers in CMO is smaller than that in Co 3 O 4 , and the distance between the Mn 3d and O 2p band centers in CMO is shorter than that in Mn 2 O 3 , indicating that the Co–O and Mn–O bonds in CMO exhibit greater covalency, significantly enhancing ORR/OER activity. Notably, CMO serves as an advanced air electrode material for rechargeable zinc-air batteries (ZABs), demonstrating improved charge–discharge performance with a low voltage gap of 0.87 V at 5 mA cm −2 , high peak power density of 124 mW cm −2 , and excellent cycle stability of over 540 h at 5 mA cm −2 . This superior ORR/OER activity, combined with the simple material combination, makes CMO a promising catalyst for rechargeable ZABs. Graphical
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TOXICOLOGY
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2019
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IF 3.547
Yuan Liao,Yuhao Luo,Nanjisha Ding,Juanmei Gao,Xingbao Wang,Wanhua Shen
Xylene and its derivatives are known to be neurotoxic to the central nervous system of animals. Our previous work has shown that para-xylene (PX) can cause an increase in apoptotic cells and abnormal avoidance behavior in Xenopus laevis . However, the mechanism underlying the impact of PX on neuronal structural and functional plasticity is less clear. Here, we examined the effects of PX on neuronal development and plasticity in the developing optic tectum. We found that HuC/D-positive neurons were more vulnerable than SOX2-positive progenitor cells or BLBP-positive radial glial cells after exposure to PX at 1 mM for 48 h. The further measurement of postsynaptic receptors and synaptic vesicle proteins showed that the expression levels of GluA1 and GluA2, but not Rab3a and SNAP25, were significantly decreased in the tectal brain. In vivo time-lapse images and electrophysiological recordings showed that PX exposure resulted in significant deficits in neuronal structure, particularly in the total dendritic branch length (TDBL), and visual stimulation-induced excitatory compound synaptic currents (eCSCs) without altering neurotransmitter release probability. Strikingly, coexposure to d -glucuronolactone (GA) and PX rescued the structural and functional deficits caused by PX exposure alone. Furthermore, we found that visual experience-induced structural, functional and behavioral plasticity was blocked by PX exposure, which was also rescued by the simultaneous administration of GA and PX . Thus, our findings indicate that PX is neurotoxic to brain development and plasticity and that GA may be considered a promising candidate to treat PX-induced defects in neural circuits.
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高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2025
·
IF 6.8
Lijun Ling,Wenyue Zhang,Rui Yue,Yijuan Jiang,Fanjin Kong,Rongxiu Mo,Lijun Feng,Yongpeng Zhou
Grapes are susceptible to fungal infections before, during transport, or after harvest, causing significant economic losses. Traditional methods have high equipment costs and are prone to the development of drug resistance. The antifungal potential of volatile organic compounds (VOCs) produced by endophytic bacteria is beginning to be understood. VOCs are ideal for post-harvest disease control in fruits and vegetables, as they can work without direct contact with the fruit. In this study, we isolated pathogenic fungi ( Penicillium crustosum G-4, Alternaria alternata G-5, Arthrinium phaeospermum G-8) from post-harvest rotting green grape and used G-8 as a test organism, screened the endophytic bacterium Bacillus toyonensis D-6 from Typhonium giganteum Engl. that could produce strong antagonistic active VOCs, analyzed the components of its VOCs and screened for the highly effective inhibitory compound 3-methylvaleric acid (3-MA). The inhibitory activities and mechanisms of action of the VOCs and antifungal compounds were investigated. The results showed that the VOCs and 3-MA produced by D-6 inhibited the growth and reproduction of the pathogenic fungi, which mainly exerted antagonistic effects by destroying the normal morphological structure of mycelium and spores and damaging the integrity of cell membranes. In addition, appropriate concentrations of VOCs and 3-MA inhibited the spread of pathogenic fungi on green grapes and effectively delayed the decline in fruit quality. This opens up new possibilities for post-harvest preservation of green grapes and provides a theoretical basis for related applications.
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高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 39
·15903-15914
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IF 5.7
Mengyuan Niu,Yuliang Yang,Yue Sun,Yu Hu,Kaiyue Song,Xiaoxia Sun
A novel chiral fluorescent probe, tetraphenylvinyltriazole-ribosyl ribose derivative (β,D)-RIB-TPE, was prepared by Click reaction. It can self-assemble into amphiphilic micron vesicles in methanol solution. (β,D)-RIB-TPE has good AIE properties with a large Stokes shift (redshift 61.8 nm), self-assembles into J-aggregates in a mixed solution with 98% water content, and exhibits a relative fluorescence intensity αAIE = 24, emitting bright blue fluorescence. In addition to the micron vesicles, (β,D)-RIB-TPE self-assembled into J-aggregates in different mixtures, showing different morphologies, such as a cross-linked network structure and an irregular bulk stacking structure. The fluorescent probe (β,D)-RIB-TPE could achieve high efficiency and rapid multi-channel detection of clopidogrel S-(+)-sulfate by fluorescence chromatography and CD spectroscopy. Infrared, nuclear magnetic titration, scanning electron microscopy and DFT calculations confirmed that the probe (β,D)-RIB-TPE recognized S-(+)-clopidogrel sulfate by an ICT mechanism. (β,D)-RIB-TPE and S-(+)-clopidogrel sulfate were co-assembled in methanol to form single-target drug-carrying micron vesicles with a smaller particle size than the self-assembled (β,D)-RIB-TPE vesicles and good drug embedding capacity.
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APPLIED ENERGY
·
2020
·
IF 8.848
Lijuan He,Songping Mo,Pengcheng Lin,Lisi Jia,Ying Chen,Zhengdong Cheng
Sugar alcohols have considerable potential for usage in medium-temperature thermal energy storage applications; however, they suffer from poor thermal reliability and low thermal conductivity . Nanoencapsulation is an effective approach to improve the thermal energy storage performance of the phase-change materials. Until now, nanoencapsulation of sugar alcohols with a high phase-change performance has been rarely reported. The objective of this study is to develop a method for the nanoencapsulation of sugar alcohols with an enhanced phase-change performance. D-mannitol nanocapsules with a silica–graphene oxide composite shell were synthesized and investigated to demonstrate the validity of this novel method. The morphology, size distribution, and core–shell microstructure of the nanocapsules were observed using a scanning electron microscope, particle size and zeta potential analyzer, and transmission electron microscope. In addition, the phase-change performance of the nanocapsules was studied using a differential scanning calorimeter, a thermogravimetric analyzer, and weight loss and appearance investigation. The results demonstrate that the melting and solidifying latent heat of the nanocapsules are 216.7 and 174.4 kJ/kg, respectively. The energy storage efficiency of the nanocapsules was 75.8% and its 96.1% was maintained after repeated thermal cycling. Compared with pure D-mannitol, the thermal conductivity of the nanocapsules was observed to increase by up to 128.6%. The novel nanocapsules exhibited good medium-temperature thermal energy storage prospects.
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RSC Advances
·
2015
·Vol. 5
·期 86
·70139-70146
·
IF 3.84
Xing-Long Li,Tao Pan,Jin Deng,Yao Fu,Hua-Jian Xu
Furfural is a biomass-based bulk chemical and its derivatives have potential applications as renewable fuels and chemicals. A water-tolerant and stable solid acid catalyst modified hydrated tantalum oxide (TA-p) was developed for catalytic conversion of D-xylose to furfural in water–organic solvent biphasic system. This process was performed both in a batch reactor and a continuous fixed-bed reactor. In the batch process, D-xylose conversion and furfural yield were significantly affected by the organic solvent, reaction temperature and reaction time. 1-Butanol, which could be obtained through the fermentation of biomass-based carbohydrates, was selected as organic phase and the highest furfural yield of 59% was achieved with D-xylose conversion of 96% at 180 °C in the continuous process. Moreover, the long-time stability test for 80 h under the optimal conditions showed the excellent stability of TA-p catalyst.
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高影响因子
ORGANOMETALLICS
·
2020
·
IF 3.804
Shuang Huang,Xi Hong,He-Zhen Cui,Bing Zhan,Zhi-Ming Li,Xiu-Feng Hou
Herein, an unprecedented bimetallic bis-NHC Cp*Ir complex 1 bearing 2-arylbenzo[d]oxazolyl and NHC ligands is reported. A significant increase in activity was observed for N-methylation of amines and reduction of aldehydes with MeOH catalyzed by 1 compared to the monometallic analogues (2–11). Under the optimal conditions, it showed to be highly effective in N-methylation of nitroarenes with MeOH as both C1 and H2 source. Substrates, including aromatic amines, ketones, and nitro compounds with various functional groups, can be well-tolerated. Mechanistic studies and DFT calculation highlight the significance of bimetallic centers cooperativity.
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