CELLULOSE
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2025
·
IF 4.8
Zhao Yao,Wang Xueping,Li Bowen,Si Tian,Gao Xin,Peng Lincai,Zhang Heng
The cellulose catalytic oxidation system mainly comprises inorganic ion-based oxidants. Hence, the selective oxidation of C 6- primary hydroxy groups (C 6 -OH) of cellulose, catalyzed by piperidine free radicals, was limited to the homogeneous cellulosic system containing protic solvents or heterogeneous system. In this work, the use of the catalytic system containing 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl (4-AcNH-TEMPO) was extended to the cellulosic solution in N, N-dimethylacetamide (DMAc) and combined with chlorine dioxide. Results showed that the carboxyl content was 0.832 mmol/g. Meanwhile, the degree of polymerization decreased from 900 to 489. This study provides an effective route for the homogeneous selective oxidation of primary hydroxy groups in cellulose and explored its oxidation mechanism in DMAc solvent. Furthermore, studies showed that the reactive chlorine species- ClO·, Cl·, and ClO 2 played a crucial role in the oxidation process. The methodology developed here displayed great potential to be utilized to various biomolecules in aprotic solvents homogeneous system based on 4-AcNH-TEMPO as oxidation catalysts.
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MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 5
·1-10
·
IF 5.3
Chen Chen,Liang Zhigang,Li Xinyang,Xu Feifei,Xu Guanhong,Wei Fangdi,Yang Jing,Hu Qin,Cen Yao
A green and sensitive ratio fluorescence strategy was proposed for the detection of formaldehyde (FA) in food based on a kind of metal–organic frameworks (MOFs), MIL-53(Fe)-NO 2 , and nitrogen-doped Ti 3 C 2 MXene quantum dots (N-Ti 3 C 2 MQDs) with a blue fluorescence at 450 nm. As a type of MOFs with oxidase-like activity, MIL-53(Fe)-NO 2 can catalyze o -phenylenediamine (OPD) into yellow fluorescent product 2,3-diaminophenazine (DAP) with a fluorescent emission at 560 nm. DAP has the ability to suppress the blue light of N-Ti 3 C 2 MQDs due to inner filter effect (IFE). Nevertheless, Schiff base reaction can occur between FA and OPD, inhibiting DAP production. This results in a weakening of the IFE which reverses the original fluorescence color and intensity of DAP and N-Ti 3 C 2 MQDs. So, the ratio of fluorescence intensity detected at respective 450 nm and 560 nm was designed as the readout signal to detect FA in food. The linear range of FA detection was 1–200 µM, with a limit of detection of 0.49 µM. The method developed was successfully used to detect FA in food with satisfactory results. It indicates that MIL-53(Fe)-NO 2 , OPD, and N-Ti 3 C 2 MQDs (MON) system constructed by integrating the mimics enzyme, enzyme substrate, and fluorescent quantum dots has potential application for FA detection in practical samples. Graphical Abstract
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RESPIRATORY RESEARCH
·
2025
·Vol. 26
·期 1
·1-17
·
IF 5
Ren Shencheng,Zhu Junkan,Shan Guangyao,Liang Jiaqi,Bian Yunyi,Lin Han,Shi Haochun,Pan Binyang,Zhao Guangyin,Yang Huiqin,Huang Xiaolong,Zhan Cheng,Ge Di,Bi Guoshu
Background Lung cancer remains the leading cause of cancer-related mortality globally, with lung adenocarcinoma (LUAD) being the most prevalent subtype. Despite extensive research efforts, the role of transcription factors in LUAD progression remains largely uncharacterized. In this study, we focused on ZNF266, a transcription factor whose impacts on LUAD have not been investigated. Methods Using high-throughput sequencing data, we observed a significant downregulation of ZNF266 expression in LUAD tissues. To validate this finding, we conducted a retrospective analysis of nearly three thousand LUAD patients’ data from public databases and our institution. Functional studies were performed using cell lines, organoids, and xenograft models to assess the role of ZNF266 in LUAD progression. RNA sequencing, chromatin immunoprecipitation, DNA pull-down assays, and dual-luciferase reporter assays were employed to elucidate the underlying mechanism. Additionally, adeno-associated virus (AAV)-mediated overexpression of ZNF266 was used to evaluate its therapeutic potential. Results Patients with low ZNF266 expression had poorer prognosis compared to those with high expression. ZNF266 inhibits the malignant phenotypes of LUAD, including proliferation, migration, and invasion. Mechanistically, ZNF266 binds to the promoter region of CA9, suppressing its transcription. This leads to a reduction in intracellular pH and subsequent inhibition of the mTOR signaling pathway, which is crucial for cancer cell growth and survival. Furthermore, AAV-mediated overexpression of ZNF266 significantly inhibited tumor growth in patient-derived xenograft models. Conclusions Our study demonstrated that ZNF266 inhibits LUAD progression in a pH-dependent manner via modulating CA9 expression, uncovering its therapeutic significance for LUAD treatment.
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CANCER CHEMOTHERAPY AND PHARMACOLOGY
·
2024
·
IF 2.7
Ma Xuan,Sun Zhenou,Chen Hui,Cao Lixing,Zhao Shuang,Fan Lihong,Zhao Chong,Yin Shutao,Hu Hongbo
Purpose 18β-glycyrrhetinic acid (GA), the main metabolite of glycyrrhizic acid extracted from the root of licorice, has been reported to possess anti-cancer and immunomodulatory activity, but the mechanisms are not well understood. Recent studies have shown that ferroptosis of immune cells is involved in tumor-associated immune suppression. The purpose of this study was to investigate whether the enhanced immune response via inhibiting immune cell ferroptosis contributed to the anticancer effect of 18β-GA. Methods Lewis Lung carcinoma mouse model and Murine CD8 + T cell culture model were used to examine the changes of immune response and ferroptosis of immune cells. Results We found that 18β-GA was effective against lung cancer accompanied by enhanced activation of tumor-infiltrating CD8 + T cells in Lewis Lung carcinoma mouse model. Furthermore, we demonstrated that the boosted immune response by GA was attributed to its ability to inhibit arachidonic acid (AA)-mediated CD8 + T ferroptosis via suppressing CD36 expression. Conclusion The findings of the present study unraveled a novel mechanism underlying the anti-cancer and immunomodulatory activity of 18β-GA and support that 18β-GA holds potential to be used as an immune enhancer for lung cancer prevention or treatment.
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Nano Research
·
2024
·Vol. 17
·期 7
·6119-6126
·
IF 9.5
Li Ziwei,Yu Yue,Yang Dongyue,Wang Jin,Yan Junmin,Huang Gang,Liu Tong,Zhang Xinbo
Li-O 2 batteries with high energy density hold significant promise as next-generation energy storage systems. However, Li-O 2 batteries have poor cycling performance at high current densities and large capacities, primarily due to the high impedance caused by the instability of the lithium anode and the sluggish kinetics in the discharge products decomposition on the cathode. Herein, we investigated a bifunctional nitrile additive (2-methoxy benzonitrile (2-MBN)) with good chemical/electrochemical stability to improve the performances of Li-O 2 batteries. The 2-MBN could actively modify the anode by ensuring uniform Li + deposition and optimizing the composition of solid electrolyte interphase (SEI). Meanwhile, it could also facilitate the decomposition of discharge products by inducing the formation of sheet-like Li 2 O 2 , significantly reducing the battery charge overpotential. The bifunctional effects of 2-MBN for the anode and cathode enable Li-O 2 batteries to achieve a stable lifetime of 97 cycles at a current density of 600 mA·g −1 with a fixed capacity of 2000 mAh·g −1 , much better than that of Li-O 2 batteries without 2-MBN (28 cycles). The inclusion of 2-MBN provides an effective approach for attaining high-performance Li-O 2 batteries.
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PLANT FOODS FOR HUMAN NUTRITION
·
2009
·Vol. 64
·期 4
·293-296
·
IF 1.69
Chen Yulong,Duan Jun,Yang Shaoyu,Yang En,Jiang Yuming
Oolong tea is one of the most popular beverages due to the presence of significant amount of catechins. Experiments were conducted to investigate the effect of girdling treatment on levels of catechins in fresh tea leaf related to quality of the ‘Huang Zhi Xiang’ Oolong tea ( Camellia sinensis ). The variations in the levels of catechins in fresh tea leaf and the quality score (QS) of the ‘Huang Zhi Xiang’ Oolong tea were examined. The study demonstrated that girdling treatment increased significantly the levels of (−)-epicatechin, (−)-epigallocatechin, (−)-epigallocatechin gallate, (−)-epicatechin gallate, total catechins, simple catechin, and catechin gallate present in fresh leaf of tea trees. Furthermore, the girdling treatment improved significantly the quality of the ‘Huang Zhi Xiang’ Oolong tea. Thus, it was suggested that application of girdling treatment could be an effective agronomic practice to increase the quality of ‘Huang Zhi Xiang’ Oolong tea.
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WATER AIR AND SOIL POLLUTION
·
2011
·Vol. 223
·期 2
·679-686
·
IF 1.765
Wang Ting,Song Ye,Li Bin,Zhou Xiaoguang
Crosslinking carboxymethyl starch (CCMS) powder of degree of substitution (DS) 0.43–0.59 was prepared by the process of two steps of alkali addition synthesis. The technique of powder coupling with ultrafiltration was used to absorb Cu 2+ , Zn 2+ , Ni 2+ , Pb 2+ , and Cd 2+ from aqueous solutions. FTIR was used to demonstrate the successfully grafting of carboxymethyl groups, and the technique of microwave plasma torch atomic emission spectrometer was applied in rapid determination of the aforementioned heavy metals ions. The results revealed that the removal sequence of heavy metal ions followed the order of Pb 2+ >Cu 2+ >Cd 2+ >Zn 2+ >Ni 2+ . By assistant of diethylene triamine penlaacetic acid, the quaternary system of Pb 2+ /Ni 2+ /Cd 2+ /Cu 2+ mixture solution could have the ideal separation. Besides, the influence of pH, ζ potential, DS value, and membranes molecular weight cut-off on removal of 20 mg L −1 Pb 2+ or Ni 2+ was also investigated.
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MICROCHIMICA ACTA
·
2010
·Vol. 168
·期 1
·153-159
·
IF 2.648
Ma Jingjun,Zhang Jingwen,Du Xin,Lei Xia,Li Jingci
A simple and efficient liquid-phase microextraction technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction (USAE-SFODME) combined with flame atomic absorption spectrometry, for the extraction and determination of trace amounts of zinc in water samples. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. The main parameters affecting the performance of USAE-SFODME, such as type of extraction solvent as well as extraction volume, time, temperature, pH, the amount of the chelating agent, and salt effect were investigated and optimized. Under optimized experimental conditions a preconcentration factor of 76 was obtained using only 5.0 mL of water sample. The calibration graph was linear in the range from 20 to 450 μg L −1 with a detection limit of 0.79 μg L −1 . The relative standard deviation for ten replicate measurements of 20 and 300 μg L −1 of zinc were 4.0 and 2.8 %, respectively. The proposed method was applied to tap water, sea water, and river water, and its accuracy was assessed through the analysis of certified reference water and recovery experiments.
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MICROCHIMICA ACTA
·
2011
·Vol. 177
·期 1
·23-30
·
IF 2.578
Wu Qiuhua,Liu Min,Ma Xiaoxing,Wang Weina,Wang Chun,Zang Xiaohuan,Wang Zhi
We have developed a highly sensitive microextraction method for the preconcentration of some phthalate esters such as diethyl phthalate, di- n -propylphthalate, di- n -butyl-phthalate, dicyclohexyl-phthalate, and diethyl-hexyl phthalate prior to their determination by HPLC. It is based on a magnetic graphene nanocomposite as an effective adsorbent. The effects of the amount of the extractant composite employed, extraction time, pH values, salt concentration and desorption conditions were investigated. Under the optimum conditions, the enrichment factors range from 1574 to 2880. Response is linear in the concentration range from 0.1 to 50 ng mL −1 . The limits of detection (at S / N = 3) were between 0.01 and 0.04 ng mL −1 . The method was successfully applied to the determination of five phthalate esters in water and beverage samples.
A novel microextraction method was developed by using magnetic graphene nanocomposite as an effective adsorbent for the preconcentration of some trace phthalate esters in water and beverage samples followed by high performance liquid chromatography with ultraviolet detection. The enrichment factors of the method for the compouds were achieved ranging from 1574 to 2880.
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Science China-Chemistry
·
2011
·Vol. 55
·期 3
·352-358
·
IF 0
Liu Wei,Sun MingLiang,Wang Wei,Song LingXia,Ge HongLun,Sun Miao,Zhang QingJie
Polyfluorene (PF) film has been successfully electropolymerized at lower potential (0.91 V vs. Ag/AgCl) in the mixed electrolyte of boron trifluoride diethyl etherate and trifluoroacetic acid. The PF film is characterized to have about 10 repeat units and no presence of ketonic defect site. UV-vis and photoluminescent spectral studies indicate that the PF film is blue light emitting. From cyclic voltammetry and galvanostatic charge-discharge tests in 1 M lithium perchlorate/acetonitrile electrolyte, the polyfluorene/activated carbon electrode shows a specific capacitance of 227.1 F g −1 (per active layer mass) and reversible redox reaction at the potential of 1.4 V in a three electrode configuration. An asymmetric electrochemical capacitor based on this composite electrode and activated carbon electrode exhibits a specific energy of 14.7 Wh kg −1 (per active layer mass). These results indicate that electrochemically prepared polyfluorene could be used as energy storage component for electrochemical application.
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MICROCHIMICA ACTA
·
2024
·Vol. 192
·期 1
·1-15
·
IF 5.3
Zhang Ai-ping,Fan Yi-xuan,Wang Ning,Yu Hao
A nanocomposite consisting of gold nanoparticles (AuNPs), poly(diallyldimethylammonium chloride) (PDDA), and reduced graphene oxide (rGO) was fabricated by a two-step chemical reduction method. Firstly, a PDDA-rGO composite was prepared by using hydrazine hydrate as a reducing agent. Subsequently, the AuNP-PDDA-rGO composite was prepared in ethylene glycol with PDDA-rGO and HAuCl 4 as raw materials using sodium citrate as a reduction agent. The resulting composite was characterized using X-ray powder diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), and electrochemical methods. This composite was then modified on a glassy carbon electrode (GCE) by the dropping method. The electrochemical behavior of bromate on this modified electrode was investigated. The results showed that PDDA-rGO can be used as a good carrier to obtain AuNPs with small particle sizes and good dispersion. The AuNPs and PDDA-rGO in composite enhanced the electrochemical activity of the electrode. Under the synergistic action of each component, the resulting electrode exhibited high activity for the electrochemical reduction of bromate. Based on this, an amperometric bromate sensor was fabricated in N 2 -saturated 0.10 mol/L HCl with attractive features including a wide linear range of 1.0 × 10 −7 –1.7 × 10 −3 mol/L, a low detection limit (3 s b ) of 3.2 × 10 −8 mol/L, and a high sensitivity of 2317 µA/mM/cm 2 . The sensor was successively used for the determination of bromate in drinking water. Graphical
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Nature Communications
·
2024
·Vol. 15
·期 1
·1-14
·
IF 14.7
Liu Shikai,Li Yuheng,Wang Di,Xi Shibo,Xu Haoming,Wang Yulin,Li Xinzhe,Zang Wenjie,Liu Weidong,Su Mengyao,Yan Katherine,Nielander Adam C.,Wong Andrew B.,Lu Jiong,Jaramillo Thomas F.,Wang Lei,Canepa Pieremanuele,He Qian
The reconstruction of Cu catalysts during electrochemical reduction of CO 2 is a widely known but poorly understood phenomenon. Herein, we examine the structural evolution of Cu nanocubes under CO 2 reduction reaction and its relevant reaction conditions using identical location transmission electron microscopy, cyclic voltammetry, in situ X-ray absorption fine structure spectroscopy and ab initio molecular dynamics simulation. Our results suggest that Cu catalysts reconstruct via a hitherto unexplored yet critical pathway - alkali cation-induced cathodic corrosion, when the electrode potential is more negative than an onset value ( e.g ., −0.4 V RHE when using 0.1 M KHCO 3 ). Having alkali cations in the electrolyte is critical for such a process. Consequently, Cu catalysts will inevitably undergo surface reconstructions during a typical process of CO 2 reduction reaction, resulting in dynamic catalyst morphologies. While having these reconstructions does not necessarily preclude stable electrocatalytic reactions, they will indeed prohibit long-term selectivity and activity enhancement by controlling the morphology of Cu pre-catalysts. Alternatively, by operating Cu catalysts at less negative potentials in the CO electrochemical reduction, we show that Cu nanocubes can provide a much more stable selectivity advantage over spherical Cu nanoparticles.
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