INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Pin Gong,Xufeng Wang,Yewen Han,Hui Long,Wenjuan Yang,Fuxin Chen,Mengjiao Cui,Wenjun Zhai,Benzhong Zheng,Xuefeng Chen
This study devised optimal conditions to extract Eucommia ulmoides leaf (EUL) polysaccharides using a cellulase and pectinase composite enzyme system based on one-way experiments and response surface methodology. Crude EUL polysaccharides (EULPs) were extracted and purified using a DEAE chromatography column. The polysaccharides EUL-w, EUL1, EUL2, and EUL3 were obtained by elution with water, 0.1 mol/L NaCl, 0.2 mol/L NaCl, and 0.3 mol/L NaCl, respectively. The EUL-w fraction had the highest hypoglycemic activity based on its α-amylase and α-glucosidase activities. The preliminary structure of purified EUL-w1 was elucidated. In vitro hypoglycemic activity studies and metabolomics analyses suggested that EUL-w1 modulated glucose metabolism by mediating the AMPK/PI3K/Akt signaling pathway. Our findings provide novel insights and data support for the utilization of EULPs as an emerging food resource in functional foods.
研究领域:
药理学
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生物化学
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细胞生物学
·
代谢组学
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DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2014
·Vol. 215
·期 10
·1012-1021
·
IF 2.451
Wenchao Ma,Haochuan Chen,Yuhong Ma,Changwen Zhao,Wantai Yang
With fac -Ir(ppy) 3 as photoredox catalyst and ethyl 2-bromoisobutyrate (EBiB) as initiator, the homopolymerization of methyl methacrylate (MMA) in different solvents, such as N , N -dimethylformamide (DMF), acetonitrile, and anisole are run under irradiation of an LED lamp. The results show that anisole is a better solvent for the polymerization with regard to the polydispersity index (PDI). A well-controlled polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) is demonstrated and the clean block copolymer of PMMA- b -PPEGMA is prepared with PDI less than 1.3; however, the 2-(dimethylamino) ethyl methacrylate (DMAEMA) polymerization is poorly controlled. With the PMMA as macromolecular initiator, the block copolymer PMMA- b -PDMAEMA can be prepared with PDI around 2.0.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Lin Zhu,Chenglong Ma,Zhiqiang Wang,Xueqing Gong,Limei Cao,Ji Yang
Developing high-active, stable, and cost-efficient electrocatalysts for oxygen evolution reaction (OER) is urgent task in water splitting. Recently, iridium pyrochlores (A 2 Ir 2 O 7 ) have attracted broad attention as promising catalysts due to their unique electronic properties and the less iridium content relative to IrO 2 , while in iridium pyrochlores, the relatively high concentration of oxygen vacancies decreases the Ir-O hybridization, hindering the OER process. The electronic states of iridium-based pyrochlore M 2 Ir 2 O 7 (M = Lu, Pr) are rationally tuned through partial substitution in A-site of Zn 2+ for Lu 3+ or Pr 3+ , efficiently promoting its intrinsic activity. The optimal Pr 1.8 Zn 0.2 Ir 2 O 7 and Lu 1.8 Zn 0.2 Ir 2 O 7 electrocatalysts exhibit 114.6 and 135.32 A g Ir −1 high mass activity at 1.58 V vs. RHE. Combining X-ray absorption spectrum with DFT calculations , we demonstrate that the doping of Zn 2+ reduces the defective oxygen and regulates the electron distribution . The decrease of defective oxygen leads to the O-2p band center upshift, resulting in the Ir–O covalency promotion and the decrease of the binding energy between oxygen intermediates and Ir to accelerate the OER process. This work provides a fresh idea introducing small ionic radius Zn to solve the problem of high concentration of oxygen vacancies inevitably produced in the synthesis of pyrochlores.
研究领域:
材料科学
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电化学
·
催化
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DOI
高影响因子
Particuology
·
2022
·
IF 3.251
Hengyuan Liu,Xingjiang Wu,Jianhong Xu
Electrocatalytic nitrogen reduction reaction (NRR) is regarded as a potential routine to achieve environment-friendly ammonia production, because of its abundant nitrogen resources, clean energy utilization and flexible operation. However, it is hindered by low activity and selectivity, in which condition well-designed catalysts are urgently in need. In this work, a binary Mo/Ir nanodots/carbon (Mo/Ir/C) hetero-material is efficiently constructed via microfluidic strategy, of which the nanodots are homogeneously distributed on the carbon skeleton and the average size is approximately 1 nm. Excellent performance for NRR is obtained in 1 mol L −1 KOH, of which the optimized ammonia yield and faradic efficiency are 7.27 μg h −1 cm −2 and 2.31% respectively. Moreover, the optimized ammonia yield of 6.20 μg h −1 cm −2 and faradic efficiency of 10.59% are also obtained in 0.005 mol L −1 H 2 SO 4 . This work achieves the continuous-flow synthesis and controllable adjustment of hetero-materials for favorable morphologies, which provides an innovative pathway for catalyst design and further promotes the development of ammonia production field.
研究领域:
材料科学
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化学工程
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电化学
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催化
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DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2024
·Vol. 54
·期 10
·2269-2279
·
IF 2.4
Huang He,Chen Taipu,Fang Dahui,Cao Longsheng,Wang Guoxiang,Hao Jinkai,Shao Zhigang
The design of low-cost and high-performance anodic electrocatalyst is essential in proton exchange membrane water electrolysis (PEMWE) application. Herein, we design and synthesize a core–shell structure with Ir-rich shell and AuIr alloy core by using a simple liquid phase reduction method, which exposed a large number of active sites. The d-band center of Ir active sites, merely 2 nm in size, was shifted by the electronegativity difference between the Au and Ir atoms at the core–shell interface. The strong electronic effect can inhibit the dissolution and corrosion of Ir active sites under acidic and high potential conditions. As a result, Ir x @Au 0.25 Ir 0.75− x catalyst shows merely 235 mV overpotential at the current density of 10 mA cm −2 , 75 mV lower than the commercial Ir black catalyst, and 2.6-fold higher mass activity than the commercial Ir black catalyst. Furthermore, when Ir x @Au 0.25 Ir 0.75− x was used as the anionic catalyst, the electrolysis voltage at 1 A cm −2 is 1.7 V in PEMWE, and this activity was maintained for more than 100 h and had exhibited excellent stability, indicating its ideal prospects as an electrocatalyst. Graphical abstract AuIr alloy with Ir-rich core and AuIr alloy shell exposed numerous active sites and improved the utilization efficiency of electrocatalyst.
研究领域:
电化学
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材料科学
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催化
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纳米技术
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能量转换
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DOI
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.
研究领域:
无机化学
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催化
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有机金属化学
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DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Lihua Lu,Huijuan Su,Qingyun Liu,Feng Li
To improve the G-quadruplex specificity of Ir(III) complexes, a novel dinuclear Ir(III) complex (Din Ir(III)–1) was designed and synthesized through connecting two mononuclear Ir(III) complexes via a diphenyl bridge. Din Ir(III)–1 presents 3.4–4.1-fold enhancements for G-quadruplex relative to ssDNA and 4.3–5.3-fold enhancements relative to dsDNA in luminescence intensity, respectively, demonstrating an excellent G-quadruplex selectivity. Ascribed to its superior specificity to G-quadruplex, Din Ir(III)–1 was employed to construct a highly sensitive luminescent pesticides’ detection platform. The detection is based on acetylcholinesterase (AChE)-catalyzed hydrolysis product-induced DNA conformational transformation and subsequent terminal deoxynucleotidyl transferase (TdT) directed G-quadruplex formation. The assay exhibited a linear response between the emission intensity of Din Ir(III)–1 and the pesticide concentration in the range of 0.5–25 μg/L (R2 = 0.994), and the limit of detection for the pesticide was as low as 0.37 μg/L when using aldicarb as the model pesticide. Moreover, this strategy demonstrates good applicability for the pesticide detection in real samples. It is also versatile for the detection of other organophosphate or carbamate pesticides, which have the inhibition ability toward AChE. Therefore, the proposed approach is scalable for practical application in food safety and environmental monitoring fields and will provide promising solutions for the assay of pesticide residues.
研究领域:
分析化学
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材料科学
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环境科学
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食品科学
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DOI
PubMed
高影响因子
ANALYST
·
2019
·Vol. 145
·期 2
·530-536
·
IF 4.019
Mingying Zhao,Fagong Xu,Lun Wang,Hongqi Chen
Ferrous ion (Fe2+) is an important component of hemoglobin and plays a role in transporting O2 to human tissues. If iron deficiency is present, iron deficiency anemia may occur, so it is critical to develop sensitive and accurate methods to detect Fe2+. Herein, a novel luminescence energy transfer (ET) system has been designed for the sensitive detection of Fe2+ by a single-particle enumeration (SPE) method in the near-infrared (NIR) region through combining NIR-to-NIR β-NaGdF4:Yb,Tm@NaYF4 upconversion nanoparticles (UCNPs) and IR-808 dye. IR-808 dye can quench the luminescence of the UCNPs because of the efficient overlap between the absorption spectrum of IR-808 and the emission spectrum of the UCNPs. When Fe2+ and H2O2 are added to the system, the Fenton reaction produces hydroxyl radicals (˙OH). The generated ˙OH reacts with IR-808 and the structure of IR-808 is destroyed. As a result, the ET process is suppressed, causing recovery of the luminescence of the UCNPs, which is reflected as an increase in the number of luminescent particles. Accurate quantification of Fe2+ is achieved by statistically counting the target concentration-dependent luminescent particles. Under the optimal conditions, the linear detection range of Fe2+ is 5–10 000 nM, which is much wider than the ensemble luminescence spectra measurements in bulk solution. Moreover, this strategy can be applied to detection in serum samples with satisfactory results.
研究领域:
生物化学
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医学检测
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纳米技术
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DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Saijin Wang,Huiting Mao,Meng Wang,Ximing Cui,Ye Li,Yuxin Cao,Jiazheng Jin,Shi Zhou,Jinlian Li,Guogang Shan
Abnormal purine metabolism can result in oxidative stress and endothelial dysfunction, heightening the risks for conditions such as gout and cardiovascular disorders, which may subsequently trigger various physiological dysfunctions. Thus, the rapid and sensitive detection of metabolic abnormalities in purines is crucial for the early diagnosis and prevention of related diseases. Zebrafish has emerged as a popular model organism in metabolic, genetic, and toxicological studies due to its high genetic similarity to humans and the transparency of its embryos, facilitating observation. In this study, we developed a novel electrochemical sensor based on m OMe-Ir-PI/MWCNTs@PDA/GCE to detect purine molecules sensitively. Using this method, we analyzed the electrochemical behavior of zebrafish embryos, correlating the electrochemical signals with X/G and HX/A. Investigating purine metabolism in zebrafish embryos across different developmental stages, we found that from the cleavage stage to the somite formation stage, the activity of degrading enzymes increased, leading to enhanced purine oxidative degradation and the activation of metabolic pathways. This resulted in a decline in purine content, observed as decreasing electrochemical signals. Conversely, from the somite formation stage to hatching, cell differentiation, tissue formation, and organ development accelerated, leading to an increase in purines involved in energy metabolism and biosynthesis, which was reflected in rising electrochemical signals. This study represents the first application of electrochemical methods for detecting purine metabolism in zebrafish embryos throughout various developmental stages, thus providing insights into the role of purine metabolism in early life development.
研究领域:
生物化学
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分析化学
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发育生物学
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电化学
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分子生物学
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毒理学
·
遗传学
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DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-9
·
IF 14.7
Wei Jie,Tang Hua,Sheng Li,Wang Ruyang,Fan Minghui,Wan Jiale,Wu Yuheng,Zhang Zhirong,Zhou Shiming,Zeng Jie
The metal-support interactions (MSI) could greatly determine the electronic properties of single-atom catalysts, thus affecting the catalytic performance. However, the typical approach to regulating MSI usually suffers from interference of the variation of supports or sacrificing the stability of catalysts. Here, we effectively regulate the site-specific MSI of Ir single atoms anchored on Ni layered double hydroxide through an electrochemical deposition strategy. Cathodic deposition drives Ir atoms to locate at three-fold facial center cubic hollow sites with strong MSI, while anodic deposition drives Ir atoms to deposit onto oxygen vacancy sites with weak MSI. The mass activity and intrinsic activity of Ir single-atom catalysts with strong MSI towards oxygen evolution reaction are 19.5 and 5.2 times that with weak MSI, respectively. Mechanism study reveals that the strong MSI between Ir atoms and the support stimulates the activity of Ir sites by inducing the switch of active sites from Ni sites to Ir sites and optimizes the adsorption strength of intermediates, thereby enhancing the activity.
研究领域:
催化
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电化学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2021
·Vol. 28
·期 3
·e202103346
·
IF 5.236
Zhongxian Fan,Jiaen Xie,Tumpa Sadhukhan,Chao Liang,Can Huang,Wenqing Li,Tingxuan Li,Pingyu Zhang,Samya Banerjee,Krishnan Raghavachari,Huaiyi Huang
Graphical Four novel Ir(III) photo-catalysts ( Ir1 – Ir4 ) were synthesized and applied for photocatalytic cancer therapy. Upon blue and green light irradiation, these photocatalysts generated singlet oxygen and induced rapid photo-catalytic oxidation of the cellular coenzymes NAD(P)H. Ir2 triggered promising photo-induced anticancer activity via induction of intracellular redox imbalance and exhibited ideal in vivo photo-induced catalytic anticancer activity. Four photo-catalysts of the general formula [Ir(CO6/ppy) 2 (L)]Cl where CO6=coumarin 6 ( Ir1 – Ir3 ), ppy=2-phenylpyridine ( Ir4 ), L=4′-(3,5-di-tert-butylphenyl)-2,2′ : 6′,2′′-terpyridine ( Ir1 ), 4′-(3,5-bis(trifluoromethyl)phenyl)-2,2′ : 6′,2′′-terpyridine ( Ir2 and Ir4 ), and 4-([2,2′ : 6′,2′′-terpyridin]-4′-yl)-N,N-dimethylaniline ( Ir3 ) were synthesized and characterized. These photostable photo-catalysts ( Ir1 – Ir3 ) showed strong visible light absorption between 400–550 nm. Upon light irradiation (465 and 525 nm), Ir1 – Ir3 generated singlet oxygen and induced rapidly photo-catalytic oxidation of cellular coenzymes NAD(P)H. Ir1 – Ir3 showed time-dependent cellular uptake with excellent intracellular retention efficiency. Upon green light irradiation (525 nm), Ir2 provided a much higher photo-index (PI=793) than the clinically used photosensitizer, 5-aminolevulinicacid (5-ALA, PI>30) against HeLa cancer cells. The observed necro-apoptotic anticancer activity of Ir2 was due to the Ir2 triggered photo-induced intracellular redox imbalance (by NAD(P)H oxidation and ROS generation) and change in the mitochondrial membrane potential. Remarkably, Ir2 showed in vivo photo-induced catalytic anticancer activity in mouse models.
研究领域:
癌症研究
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光化学
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材料科学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2016
·Vol. 19
·期 4
·1109-1116
·
IF 8.506
Huan Liu,Dong-Liang Wang,Xia Chen,Yong Lu,Xiao-Li Zhao,Ye Liu
Mono-phosphines (L1 and L2) and diphosphines (L3 and L4) with typical π-acceptor character were prepared and applied in Ir(I)-catalyzed N-alkylation of amines with alcohols. It was found that the π-acceptor character of the applied phosphines is closely correlated to the catalytic efficiency of the [Ir(COD)Cl]2 complex for this green reaction. Compared to PPh3 as the typical σ-donor (i.e. with poor π-acceptor character), L1–L4 all resulted in the efficient N-alkylation of aniline to benzyl-aniline. While L1–L4 coordinated to the Ir(I)-catalyst, the consolidated Ir–P linkages due to π-backdonation could well protect the Ir-catalyst against deactivation, giving rise to the N-alkylation of aniline. On the other hand, the stabilized Ir-catalyst with the involvement of L2 could be recycled successfully for at least 4 runs in the ionic liquid of [MePh3P]Br without the detectable leaching of Ir and P elements in the organic products.
研究领域:
有机化学
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催化化学
·
绿色化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）