APPLIED CATALYSIS A-GENERAL
·
2015
·
IF 3.942
Jun Chen,Shuanghong Tian,Jiang Lu,Ya Xiong
This study aims to provide a direction to tailor catalytic activity of catalyst by selectively exposing a crystal facet. Herein three sheet-like MgO materials with the primarily exposed crystal facet of (1 1 1), (1 1 0), (2 0 0) were prepared, respectively. Results show that the catalytic ozonation on each MgO substantially enhanced the removal of 4-chlorophenol and total organic carbon when compared with ozonation alone or that on traditional MgO. The pseudo first-order reaction constant of 4-chlorophenol removal in ozonation catalyzed by MgO(1 1 1), MgO(1 1 0), MgO(2 0 0) is 4.8, 2.5, 3.1 times higher than that in the single ozonation, respectively. When different dosage but the same surface area of MgO was applied, their catalytic activities changed as MgO(1 1 1) > MgO(1 1 0) > MgO(2 0 0). It indicates that the catalytic activity significantly depends on the crystal facet besides the surface area. That is because the drawbacks, such as edges, steps, and kinks, on each facet decreased in the order of (1 1 1) > (1 1 0) > (2 0 0). CO 2 -TPD and zeta potential measurement show that the drawbacks caused more and stronger surface basic groups in the form of hydroxyl and isolated oxygen due to the availability of more unsaturated coordination sites. These active basic centers make the easy formation of basic microenvironment near MgO particles and thus favor the ozonation. Finally, the catalytic mechanism was explored and compared by evaluating the ozone decomposition, qualitatively and quantitatively identifying hydroxyl radicals, and determining the ozone utilization efficiency. It reveals that MgO with more surface basic groups can enhance the transformation rate of ozone to hydroxyl radicals more efficiently. All these results show that MgO is a very potential ozonation catalyst and the catalytic activity can be tailored by exposing crystal facet with more drawbacks.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
IMMUNITY
·
2024
·
IF 25.5
Rui Ding,Xiaoyan Yu,Zhilin Hu,Yu Dong,Haiyan Huang,Yuerong Zhang,Qiaoqiao Han,Zhi-Yu Ni,Ren Zhao,Youqiong Ye,Qiang Zou
RNA splicing is involved in cancer initiation and progression, but how it influences host antitumor immunity in the metabolically abnormal tumor microenvironment (TME) remains unclear. Here, we demonstrate that lactate modulates Foxp3-dependent RNA splicing to maintain the phenotypic and functional status of tumor-infiltrating regulatory T (Treg) cells via CTLA-4. RNA splicing in Treg cells was correlated with the Treg cell signatures in the TME. Ubiquitin-specific peptidase 39 (USP39), a component of the RNA splicing machinery, maintained RNA-splicing-mediated CTLA-4 expression to control Treg cell function. Mechanistically, lactate promoted USP39-mediated RNA splicing to facilitate CTLA-4 expression in a Foxp3-dependent manner. Moreover, the efficiency of CTLA-4 RNA splicing was increased in tumor-infiltrating Treg cells from patients with colorectal cancer. These findings highlight the immunological relevance of RNA splicing in Treg cells and provide important insights into the environmental mechanism governing CTLA-4 expression in Treg cells.
研究领域:
免疫学
·
肿瘤学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Zhenjun Zhao,Jingyi Chi,Zhang FangFang,Yinglin Song,Wenda Xv,Yan Li,Hui Shi
4-Octylphenol, a major environmental degradation product of alkylphenols (Aps) used in industry, is an endocrine-disrupting chemical with significant estrogenic activity. It is one of the most toxic Aps, poorly biodegradable in the environment, and can accumulate in organisms through the food chain, thereby affecting the male reproductive system. In this study, the effect of 4-octylphenol on male reproductive health was analyzed. Male pubertal mice were exposed to 4-octylphenol at doses of 0, 1, 10, and 100 mg/kg once daily for 28 days. Our findings indicated that pubertal exposure to 4-octylphenol has significant negative effects on the male reproductive system. Pubertal mice exposed to 4-octylphenol exhibited dose-dependent reproductive toxicity. In the medium- and high-dose groups, a significant reduction in testicular mass, structural damage to the seminiferous tubules, increased oxidative stress and apoptosis within the testicular tissue, and a decline in sperm quality were observed. Additionally, autophagy processes in the testicular tissue, germ cell proliferation, and meiotic processes are inhibited. Serum testosterone and estradiol levels decreased, whereas oxidative stress levels in the testes and spermatozoa increased. In contrast, the low-dose group showed only a reduction in body weight, a decrease in motile sperm count, and mild oxidative stress in the testes without significant pathological changes in Western blot experiments. These results indicate that 4-octylphenol exposure during puberty caused reproductive toxicity in male mice.
研究领域:
毒理学
·
内分泌学
·
生殖健康
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2024
·
IF 3.3
Yan-Ling Liu,Xian-Chen He,Jie Gao,Ke-Rong Li,Kai Chen,Hao-Yue Xiang,Hua Yang
Herein, visible light-induced, nickel-catalyzed direct functionalization of the Hantzsch esters (HEs) with readily accessible alkyl bromides has been successfully achieved by taking advantage of HE as the reductant and substrate through an aromatization-dearomatization process. In this strategy, the single electron reduction of alkyl bromides by reactive Ni(I) species is essential for the success of this late-stage transformation. A wide range of 4-alkyl-1,4-dihydropyridines were rapidly assembled in moderate to good yields under mild conditions, rendering this photoinduced approach attractive for synthetic and medicinal chemistry.
研究领域:
有机化学
·
光化学
·
催化
·
合成方法学
·
药物化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2019
·
IF 5.714
Zhao Yang,Xu Zhang,Siji Pu,Renxiang Ni,Ying Lin,Yong Liu
A novel heterogeneous Fenton-like system (Mg/Fe-O 2 ) which could directly convert oxygen (O 2 ) to hydrogen peroxide/hydroxyl radicals (H 2 O 2 / • OH) was developed and used to degrade 4-chlorophenol. The Mg/Fe bimetallic particles were prepared by chemical displacement process and characterized by XRD, SEM and TEM. The in situ continuous production of H 2 O 2 / • OH and the effect of the mole ratio of Mg to Fe in the Mg/Fe bimetallic particles and the operating parameters on the degradation 4-chlorophenol in Mg/Fe-O 2 system were investigated in detail. It was found that the Mg/Fe bimetallic particles with the mole ratio of Mg to Fe of 32:1 had the best performance for the 4-chlorophenol degradation and the maximum cumulative concentration of H 2 O 2 , the degradation efficiency of 4-chlorophenol and the removal efficiency of TOC in Mg/Fe-O 2 system were 34.5 mg/L, 100% and 91.8%, respectively, at pH 3, O 2 flow rate 400 mL/min, dosage of Mg/Fe bimetallic particles 2 g/L, 4-chlorophenol initial concentration 50 mg/L and reaction time 60 min. It was revealed by radical scavenging experiments that • OH, particularly the surface-bound • OH, were the predominant reactive oxygen species in Mg/Fe-O 2 system for the degradation of 4-chlorophenol. The main intermediates of 4-chlorophenol degradation were detected by high-resolution liquid chromatography equipped with time-of-flight mass spectrometry (HRLC–ToF-MS) and ion chromatography (IC). Based the results of control experiments and the electrochemical tests, the possible pathway and mechanism of 4-chlorophenol degradation in Mg/Fe-O 2 system were tentatively proposed.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Taotao Zhao,Yuchi Liu,Chenyang Shen,Gui Liu,Jun Yao,Xiaofeng Qian,Qiang He,Feifei Mei,Deming Meng,Xuefeng Guo,Luming Peng,Nianhua Xue,Yan Zhu,Yuming Zhou,Weiping Ding
Here, we report a high-performance catalyst MoS x @HSSZ-39 for conversion of CO x to C 2–4 hydrocarbons, in which MoS x clusters for CO x hydrogenation at the first to intermediate methanol and then the zeolitic acid sites surrounding for further conversion of methanol to hydrocarbons. For CO 2 hydrogenation, C 2–4 hydrocarbons of ∼90% selectivity in organic products at 32.7% of CO 2 conversion and excellent stability of 1000 h on stream are obtained. For CO hydrogenation, 95% of C 2–4 hydrocarbons, 83% of LPG or 74% of propane selectivities at > 22% CO conversion and stable more than 200 h on stream are obtained. The cooperation among the MoS x clusters and the zeolitic acid sites constitutes the catalyst of intimate bifunction, which is the key to the high catalytic performance for CO x hydrogenation.
研究领域:
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Jie Yang,Huimin Du,Yue Deng,Meifang Liu,Xingzuo Liu,Jun Yang,Shanshan Hu
Quantitative detection of permanganate ( MnO 4 ‐ ) and 4-nitrophenol (4-NP) is essential for environmental safety. Fluorescence detection technology is one of the most widely used detection technologies, which can be used for the detection of various anions and organic pollutants. In this paper, Ba 4 Lu 3 F 17 :Tb 3+ phosphors were successfully obtained by hydrothermal method. The morphology transition of Ba 4 Lu 3 F 17 crystal from nanoparticles through octahedron to hexagonal prism was realized in the pH range of 3–11. The best luminescent samples were obtained by changing the type of additives and the doping concentration of Tb 3+ ions. The obtained Ba 4 Lu 3 F 17 :Tb 3+ has high selectivity and anti-interference for MnO 4 ‐ and 4-NP detection, with the detection limits being 0.79 μM and 1.28 μM, respectively.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Zhenlong Song,Yuzhen Hu,Song Li,Jianguo Liu,Xinghua Zhang,Longlong Ma,Lungang Chen,Qi Zhang
Valorizing lignin into valuable chemicals requires the selective breaking of a large number of C–O bonds found in the β–O–4 structure. In this study, we present a one-pot strategy that utilizes two NiO/TiO2 catalysts for the photocatalytic depolymerization of β–O–4 alcohols. The S-1.6%NiO/TiO2 catalyst is used for the dehydrogenation of β–O–4 alcohols at 450 nm. Then, the L-0.8%NiO/TiO2 catalyst is employed for the hydrogenolysis of β–O–4 ketones at 365 nm. Remarkably, the dehydrogenation–hydrogenolysis tandem reaction can be conducted in one pot, which affords high yields of ketones and phenols (up to 89%) from β–O–4 alcohols. Additionally, the L-0.8%NiO/TiO2 catalyst prepared in this article is the smallest NiO/TiO2 photocatalyst reported to date, and the size of NiO in the S-1.6%NiO/TiO2 catalyst is even small enough to enter the lattice of TiO2. We successfully regulated the reaction selectivity by controlling the loading method and the amount of NiO. Our work offers a promising solution for efficiently cleaving target bonds in lignin and provides insights into the design of efficient photocatalysts.
研究领域:
化学工程
·
材料科学
·
可再生资源转化
✓ 已验证
DOI
高影响因子
Polymers
·
2025
·Vol. 17
·期 3
·318
·
IF 4.9
Linyi Shui,Xianxin Guo,Jinrong Li,Zimeng Li,Qinghua Zhao,Guohua Chen,Xiaomin Zhao
Long-chain hyperbranched polyesters (LHBPx, x = 1, 2, 3) with varying lengths of branched chains were synthesized through a thiol-ene click reaction. Subsequently, LHBPx was incorporated into PA4 via the solution method to prepare a LHBPx/PA4 polymer blend, aiming to address the limitations of PA4, such as its narrow thermal processing window (△T = Td5−Tm) and high brittleness. The results demonstrated that the addition of LHBPx enhanced the △T of PA4 from 1.6 °C to 14.5 °C (LHBP3/PA4), increasing the rheological properties of LHBPx/PA4 polymer blends, thereby improving its thermal processability. Compared with PA4, the elongation at the break of the LHBP3/PA4 polymer blend was increased by 20.4%, and the brittle fracture was changed into a ductile fracture. The crystallinity of PA4 was greatly decreased, from 54.41% to 37.42%, owing to the incorporation of LHBPx, whereas Tmof PA4 had almost no change. It was explained that LHBPx hindered the crystal growth stage, whereas it promoted the nucleation stage of PA4, resulting in no significant change in crystal type. Moreover, the longer the branched chain of LHBPx was, the more pronounced the improvement in the thermal processability and toughness of PA4 became. Above all, this work was meaningful for the potential application of PA4 in industrial plastics.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Current Protocols
·
2021
·Vol. 1
·期 10
·e274
·
IF 0
Jingyi Wang,Jiachen Shang,Yu Xiang,Aijun Tong
Functionalized oligonucleotides (ONs) are widely applied as target recognition molecules for biosensing and gene regulation. Herein, we describe a general method for post-synthetic modification of ONs based on the oxidative amination of 4-thio-2′-deoxyuridine (4SdU) with sodium periodate and several amines. Alkyne-/azide-, biotin-, and fluorophore-modified ONs were prepared by modifying 4SdU-containing ONs with the corresponding amines and characterized for their bioorthogonal reactivity, streptavidin-binding affinity, and fluorescence properties, respectively. We synthesized three fluorophore-modified ONs with and without the aromatic fluorophores conjugated to modified nucleobases and investigated their emission properties. © 2021 Wiley Periodicals LLC. Basic Protocol 1 : Post-synthetic modification of ONs Supporting Protocol : Preparation of dansyl ethylenediamine Basic Protocol 2 : Quantification of ON reaction yields Basic Protocol 3 : Characterization of modified ONs
研究领域:
生物化学
·
分子生物学
·
化学生物学
✓ 已验证
DOI
Drug Design Development and Therapy
·
2017
·
IF 2.822
Jingrun Chen,Junjie Liu,Dongxiao Cui,Chaoqun Yan,Liqiang Meng,Liqian Sun,Shurong Ban,Rui Ge,Taigang Liang,Qingshan Li
This study deals with the design and synthesis of a series of novel 4-methoxy-substituted and 5-methyl-substituted (3′S,4′S)-(−)-cis-khellactones. The newly synthesized compounds were characterized by 1H nuclear magnetic resonance (NMR), 13C-NMR, mass spectrometry, and elemental analysis. All the derivatives were subjected to in vitro cytotoxicity screening against HEPG-2 (human liver carcinoma), SGC-7901 (human gastric carcinoma), and LS174T (human colon carcinoma), by using the MTT assay. The results revealed that several of the 4-methoxy-substituted compounds exhibited potent cytotoxicity. Among these, compound 12e showed the highest activity against cancer cells which 50% inhibitory concentration (IC50) values were in the range of 6.1–9.2 μM with low toxicity on normal human hepatocyte. Preliminary investigation of possible mechanisms of action of compound 12e against HEPG-2 cells indicated possible induction of apoptosis, as determined by morphological observations and Annexin V/propidium iodide (PI) double staining, in addition to apparent dissipation of mitochondrial membrane potential (MMP), as measured by 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide (JC-1) staining in combination with the activation of caspase-9 and caspase-3 by Western blot analysis. Overall, the data suggest that compound 12e may be a promising potential anti-cancer agent that could act primarily by inducing apoptosis through the mitochondria-mediated intrinsic pathway in human hepatoma cells.
研究领域:
药理学
·
肿瘤学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Zhuang Li,Zi-Chun Fan,Xiang Bai,Xian-Yong Wei,Yierxiati. Dilixiati,Qian-Qian Kong,Ji Zhao,Yong-Hui Feng,Jun-Long Wang,Xing Fan,Xiao-Yan He,Hai-Xu Zou,Zhi-Min Zong
MY zeolites with mesopores were prepared by hydrothermal method using functionalized SiO 2 (F-SiO 2 ) as a silica source, and hydrophobic bifunctional Ru/MY- O catalysts were obtained by deposition precipitation method and silylation treatment. This work aims at obtaining polycyclic alkane (PCA) based high-density hydrocarbon fuels (HDHFs). We focused on the catalytic hydroconversion (CHC) of 2-phenoxy-1-phenylethanol (PP-ol) and oxydibenzene (ODB), two typical lignin-related model compounds (LRMCs), over Ru/MY- O . The effects of different reaction conditions and catalysts on the product distribution in PP-ol and ODB were investigated. The partial hydrogenation of ODB was found to be a necessary step before achieving C-O ether bond cleavage and C-C bond coupling. The balance of metal/acidic sites is critical for maximizing PCA yields. Changes in the metal/acid ratio had a greater effect on PCA yield in PP-ol than in ODB. Poor stability of cycloalkyl cations and partial hydrogenation of ODB hinder the generation of C-C coupling products. The incorporation of mesopores and hydrophobic treatment were found to weaken the negative effects of C-C bond coupling products and water on the catalyst. The conversion of Ru 3 /MY- O was improved by nearly 10% compared to Ru 3 /Y in the fifth cycle reaction. This work provided a theoretical basis for the generation of HDHFs from lignin.
研究领域:
化学工程
·
催化
·
可再生能源
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）