ENERGY & FUELS
·
2024
·
IF 5.2
Qiqi Liang,Yan Fu,Shuaishuai Qiu,Jie Chang
The production of fuel and chemicals from renewable lignin supplies a sustainable chemical engineering process. In this study, Co–Pd bimetallic supported on porous polymer-derived nitrogen-doped carbon spheres (NDCS) was employed for the selective hydrogenolysis of organosolv lignin. Most of the products are phenolic monomers. At optimal conditions, 2.5 MPa H2, 280 °C for 5 h, 86.74% liquefaction of lignin and 36.38 wt % yield of phenolic monomers were obtained. Among these monomer products, 60.83% were identified as 4-hydroxy-3,5-dimethoxyphenylacetic acid (22.13 wt % yield), which is an important pharmaceutical intermediate. With the help of the characterization of catalysts and hydrogenolysis products, the reaction mechanism was proposed. The NDCS provided the prerequisites for metal anchoring and dispersion, and smaller metal particle sizes (2.56 nm) were obtained compared to those of undoped nitrogen carriers. Meanwhile, the synergistic interaction between Pd0 and Co0 promoted the conversion of active hydrogen. With active hydrogen, the C–C and C–O bonds in the lignin were cleaved, and then the active O was transferred to the Pd2+ and Co2+ sites and catalyzed the oxidation of 4-allyl-2,6-dimethoxyphenol to 4-hydroxy-3,5-dimethoxyphenylacetic acid. Lastly, cycling experiments demonstrated the remarkable stability of the catalyst.
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CELL RESEARCH
·
2023
·Vol. 33
·期 12
·923-939
·
IF 44.1
Liu Rui,Zeng Lin-Wen,Li Hui-Fang,Shi Jun-Ge,Zhong Bo,Shu Hong-Bing,Li Shu
Combination therapy with PD-1 blockade and IL-2 substantially improves anti-tumor efficacy comparing to monotherapy. The underlying mechanisms responsible for the synergistic effects of the combination therapy remain enigmatic. Here we show that PD-1 ligation results in BATF-dependent transcriptional induction of the membrane-associated E3 ubiquitin ligase MARCH5, which mediates K27-linked polyubiquitination and lysosomal degradation of the common cytokine receptor γ chain (γ c ). PD-1 ligation also activates SHP2, which dephosphorylates γ c Y357 , leading to impairment of γ c family cytokine-triggered signaling. Conversely, PD-1 blockade restores γ c level and activity, thereby sensitizing CD8 + T cells to IL-2. We also identified Pitavastatin Calcium as an inhibitor of MARCH5, which combined with PD-1 blockade and IL-2 significantly improves the efficacy of anti-tumor immunotherapy in mice. Our findings uncover the mechanisms by which PD-1 signaling antagonizes γ c family cytokine-triggered immune activation and demonstrate that the underlying mechanisms can be exploited for increased efficacy of combination immunotherapy of cancer.
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CHINESE JOURNAL OF CATALYSIS
·
2025
·
IF 17.7
Jun Wu,Liqian Liu,Xinyue Yan,Gang Pan,Jiahao Bai,Chengbing Wang,Fuwei Li,Yong Li
Development of efficient and stable metal catalysts for the selective aqueous phase hydrodeoxygenation (HDO) of biomass-derived oxygenates to value-added biofuels is highly desired. An innovative surface microenvironment modulation strategy was used to construct the nitrogen-doped hollow carbon sphere encapsulated with Pd (Pd@NHCS- X , X : 600–800) nanoreactors for catalytic HDO of biomass-derived vanillin in water. The specific surface microenvironments of Pd@NHCS catalysts including the electronic property of active Pd centers and the surface wettability and porous structure of NHCS supports could be well-controlled by the calcination temperature of catalysts. Intrinsic kinetic evaluations demonstrated that the Pd@NHCS-600 catalyst presented a high turnover frequency of 337.77 h –1 and a low apparent activation energy of 18.63 kJ/mol. The excellent catalytic HDO performance was attributed to the unique surface microenvironment of Pd@NHCS catalyst based on structure-performance relationship analysis and DFT calculations. It revealed that pyridinic N species dominated the electronic property regulation of Pd sites through electronic metal-support interaction (EMSI) and produced numerous electron-rich active Pd centers, which not only intensified the dissociation and activation of H 2 molecules, but also substantially improved the activation capability of vanillin via the enhanced adsorption of –C=O group. The fine hydrophilicity and abundant porous structure promoted the uniform dispersion of catalyst and ensured the effective access of reactants to catalytic active centers in water. Additionally, the Pd@NHCS-600 catalyst exhibited excellent catalytic stability and broad substrate applicability for the selective aqueous phase HDO of various biomass-derived carbonyl compounds. The proposed surface microenvironment modulation strategy will provide a new consideration for the rational design of high- performance nitrogen-doped carbon-supported metal catalysts for catalytic biomass transformation.
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Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yang Xiao,Chao Qu,Jingjing Zhang,Xi Chen,Wenjin Wang,Xuelong Zheng,Qing Ye
The dissociation of water is essential to water gas shift (WGS) reaction, and the presence of oxygen vacancies can facilitate this key step. Herein, a series of perovskite supported Pd single atoms catalysts were prepared via deposition precipitation method. The incorporation of Pd single atoms can effectively promote the formation of oxygen vacancy on the surface of the catalyst, improving the low temperature reducibility, the ratio of Mn 4 + /Mn 3+ and O ads /O lat compared with support. Among all samples, 0.82 Pd/La 0.5 Ca 0.5 MnO 3 /SBA-15 with the most oxygen vacancies presented 83.6 % CO conversion at 400 °C, specific reaction rate (0.54 mol CO g Pd −1 h −1 ), and TOF (3.77✕10 −2 s −1 ). DFT calculation proved that Pd doping can effectively decreased energy barrier of H 2 O dissociation, and promoted the formation of oxygen vacancies. This work provides experimental and theoretical insights into the rational design of highly active perovskite supported Pd single atom catalysts for WGS reaction.
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高影响因子
CATALYSIS LETTERS
·
2025
·Vol. 155
·期 10
·1-12
·
IF 2.4
Huang Qiuyun,Liu Shiyu,Shen Weihua,Fang Yunjin
Due to the modifiable properties and excellent stability, metal-organic frameworks (MOFs) are considered potential catalyst supports in heterogeneous reactions. UiO-66 with varying water contents were synthesized as supports of Pd for the carbonylation of methyl nitrite (MN) to dimethyl carbonate (DMC). In accordance with XRD, NH 3 -TPD, and SEM, the water contents showed a negative correlation on the amounts of acid sites and accelerated crystal aggregation. The Pd/UiO-66(x) demonstrated perfect selectivity of DMC (> 99%) and good CO conversion which were increased with the decrease of water contents. Moreover, the catalysts deactivated at the beginning of the reaction, and the catalytic deactivation was due to the damage of the C = O structure in UiO-66 frameworks. This work revealed the influence of water contents on the synthesis of UiO-66 and the deactivation process of MOF-based catalysts in MN carbonylation to DMC. Graphical
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高影响因子
Small
·
2022
·Vol. 18
·期 13
·2107809
·
IF 15.153
Qinyanqiu Xiang,Chao Yang,Yuanli Luo,Fan Liu,Jun Zheng,Weiwei Liu,Haitao Ran,Yang Sun,Jianli Ren,Zhigang Wang
The efficacy of immune checkpoint inhibition in inducing death of cancer cells is affected by the immunosuppressive “cold” tumor microenvironment, which results in a poor response by the patient's antitumor immune system. However, the immunomodulatory effects of immunogenic cell death in response to irritation by heat energy and reactive oxygen species (ROS) can switch the tumor microenvironment from “cold” to “hot.” This study has developed a nanoadjuvant for immune therapy using iron tungsten oxide (FeWOx)-based nanosheets with surface PEGylation (FeWOx-PEG). This FeWOx-PEG nanoadjuvant serves as a chemodynamic reagent via the Fenton reaction and acts as a photosensitizer for photodynamic and photothermal therapy under near-infrared II laser irradiation; however, it could also be used to augment tumor-infiltrating T-cells and provoke a systemic antitumor immune response by combining the immunogenic cell death triggered by ROS and photothermal therapy with the immune checkpoint blockade. This research demonstrates that application of the FeWOx-PEG nanoadjuvant under the guidance of magnetic resonance/computed tomography/photoacoustic imaging can eliminate the primary tumor and suppress the growth of distant tumors.
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ChemistryOpen
·
2019
·Vol. 8
·期 1
·87-96
·
IF 2.205
Chunshan Lu,Xuejie Zhang,Yani Qi,Haoke Ji,Qianwen Zhu,Hao Wang,Yebin Zhou,Zhenlong Feng,Xiaonian Li
Graphical On the surface : The surface-group-oriented nitrogen-doping strategy for activated carbon-supported Pd catalysts and the potential selective hydrogenation mechanism of p-chloronitrobenzene are presented. A nitrogen-carbon framework with the thickness of several molecules was fabricated through a straightforward nitrogen-doping strategy, in which specially designed surface-oxygen-containing groups (SOGs) first introduced onto the porous carbon support were used to guide the generation of a surface-nitrogen-containing structure through condensation reactions between SOGs and the amidogen group of organic amines under hydrothermal conditions. The results indicate that different kinds of SOGs generate different types and abundances of N species. The CO-releasing groups are apt to form a high proportion of amino groups, whereas the CO 2 -releasing groups, especially carboxyl and lactones, are mainly transformed into pyrrolic-type nitrogen. In the framework with dominant pyrrolic-type nitrogen, an electron-rich Pd activated site composed of Pd, pyrrolic-type N and C is built, in which electron transfer occurs from N to C and Pd atoms. This activated site contributes to the formation of electron-rich activated hydrogen and desorption of p-chloroaniline, which work together to achieve the superior selectivity about 99.90 % of p-chloroaniline and the excellent reusable performance. This strategy not only provides low-cost, nitrogen-doped carbon materials, but also develops a new method for the fabrication of different kinds of nitrogen species structures.
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ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Tianjiao Meng,Ningzhao Shang,Anaclet Nsabimana,Huimin Ye,Huan Wang,Chun Wang,Yufan Zhang
MicroRNA-21 (miR-21) has been widely investigated as important biomarkers for cancer diagnosis and treatment. Herein, a highly sensitive nonenzymatic electrochemical biosensor based on [email protected] frameworks ( [email protected] ) and target-catalytic hairpin assembly (CHA) with target recycling approach has been proposed for the detection of miR-21. The proposed biosensor integrates the efficient CHA strategy and excellent electrocatalytic performance of [email protected] nanocomposites. The concentration of miRNA-21 is related to the amount of the adsorbed electrocatalyst , leading to the different electrochemical signals for readout towards paracetamol (AP). This biosensor shows a low limit of detection of 0.713 fM with the dynamic range of 20 fM −600 pM under the optimal experimental conditions, providing a powerful platform for detecting miR-21. Furthermore, the designed biochemical self-assembly strategy of this electrochemical biosensor is promising candidate for potential applications in the analysis of other important genetic biomarkers for early diagnosis of cancers.
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高影响因子
Theranostics
·
2021
·
IF 11.556
Shi-Long Zhang,Yu-Qin Mao,Zheng-Yan Zhang,Zhan-Ming Li,Chao-Yue Kong,Hui-Ling Chen,Pei-Ran Cai,Bing Han,Tao Ye,Li-Shun Wang
Background: Anti-PD-1-based immunotherapy has emerged as a promising therapy for several cancers. However, it only benefits a small subset of colorectal cancer (CRC) patients. Mounting data supports the pivotal role of gut microbiota in shaping immune system. Pectin, a widely consumed soluble fiber, has been reported to ameliorate the imbalance of gut microbiota. Therefore, we aimed to explore the effect and the underlying mechanisms of pectin in improving anti-PD-1 mAb efficacy. Methods: The C57BL/6 mice were treated with a broad-spectrum antibiotic (ATB) cocktail to depleted endogenous gut microbiota and subsequently humanized with feces from healthy controls or newly diagnosed CRC patients. The antitumor efficacies of anti-PD-1 mAb combined with or without pectin were assessed using these mice. Flow cytometry and immunohistochemistry (IHC) were conducted to investigate the tumor immune microenvironment after treatment. The gut microbiota profiles and short-chain fatty acids (SCFAs) levels were determined by 16S ribosomal RNA (16S rRNA) gene sequencing and gas chromatography-mass spectrometry (GC-MS), respectively. The effect of gut microbiota on anti-PD-1 mAb efficacy after pectin supplement was further tested by fecal microbiota transplantation (FMT). Results: The anti-PD-1 mAb efficacy was largely impaired in the mice humanized with feces from newly diagnosed CRC patients compared to those from healthy controls. However, pectin significantly enhanced the anti-PD-1 mAb efficacy in the tumor-bearing mice humanized with CRC patient gut microbiota. Flow cytometry and IHC analysis revealed increased T cell infiltration and activation in the tumor microenvironment of mice treated with anti-PD-1 mAb plus pectin. In vivo depletion of CD8 + T cells diminished the anti-tumor effect of anti-PD-1 mAb combined with pectin. 16S rRNA gene sequencing showed that pectin significantly increased gut microbial diversity and beneficially regulated microbial composition. In addition, we identified unique bacterial modules that were significantly enriched in the anti-PD-1 mAb + pectin group, which composed of butyrate-producing bacteria indicative of good response to immunotherapy. Meanwhile, GC-MS showed that pectin altered the level of SCFA butyrate. Furthermore, butyrate, a main product of dietary fiber in gut microbial fermentation, was found to be sufficient to promote T cells infiltration and thus enhance the efficacy of anti-PD-1 mAb. In addition, FMT demonstrated the effects of pectin were dependent on gut microbiota. Importantly, the beneficial effects of pectin were confirmed in the mice humanized with gut microbiota from patient with resistance to anti-PD-1 mAb. Conclusion: Pectin facilitated the anti-PD-1 mAb efficacy in CRC via regulating the T cell infiltration in the tumor microenvironment, which was potentially mediated by the metabolite butyrate.
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高影响因子
ChemSusChem
·
2016
·Vol. 10
·期 5
·976-983
·
IF 7.116
Xin Li,Xiangheng Niu,Wenchi Zhang,Yanfang He,Jianming Pan,Yongsheng Yan,Fengxian Qiu
Graphical One pot for MORe : A one-pot dopamine self-polymerization mediated redox strategy is used to fabricate highly dispersed Pd nanoparticles anchored on a nitrogen-doped carbon support. The material is used to catalyze the methanol oxidation reaction (MOR) with higher mass activity and durability than commercial Pd/C. Exploration of advanced electrocatalysts to promote the sluggish methanol oxidation reaction (MOR) is of vital importance for developing high efficiency and low-cost direct methanol fuel cells. Highly dispersed palladium nanoparticles (Pd NPs) anchored on a nitrogen-doped carbon support were fabricated using a facile one-pot dopamine self-polymerization mediated redox strategy, in which dopamine not only acted as a moderate reductant to induce the formation of Pd NPs during self-polymerization but was also the precursor of the nitrogen-doped carbon support for Pd. The synthesized hybrid features the following characteristics: 1) High dispersity of Pd NPs, which exposed a high abundance of active surfaces and sites for heterogeneous electrocatalysis; 2) metal-support interactions, which may affect the surface chemistry and electron distribution of active Pd NPs; 3) the Pd NPs were partially imbedded or encapsulated into the support, thus reducing the possible agglomeration of Pd NPs during cyclic measurements. The electrocatalyst with such favorable features provided higher mass activity (2.2 times that of commercial Pd/C) and better durability (reduced loss of activity during simulated frequent startup–shutdown operations) for the MOR in alkaline media.
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ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Kai-Qiang Jing,Yu-Qing Fu,Zhe-Ning Chen,Teng Zhang,Jing Sun,Zhong-Ning Xu,Guo-Cong Guo
Strong metal–support interaction is crucial to the stability of catalysts in heterogeneous catalysis. However, reports on boosting interfacial electron transfer between metal and support via defect induction for enhanced metal–support interaction are limited. In this work, ultrathin reducible ZnTi-layered double hydroxide (LDH) nanosheets with rich oxygen defects were synthesized to stabilize Pd clusters, and the rich oxygen defects promoted Pd cluster bonding with Zn and Ti atoms in supports, thereby forming a metal–metal bond. Electron spin resonance (ESR), X-ray absorption fine spectra (XAFS), and density functional theory (DFT) calculations demonstrate remarkable interfacial electron transfer (0.62 e). The Pd/ZnTi-LDH catalyst shows superior catalytic stability for CO direct esterification to dimethyl oxalate. By contrast, the nonreducible Pd/ZnAl-LDH catalyst with a few oxygen defects shows minimal interfacial electron transfer (0.08 e), which leads to relatively poor catalytic stability. This work provides a deep insight into promoting the stability of catalysts by boosting interfacial electron transfer via defect induction.
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高影响因子
Nanoscale
·
2022
·Vol. 14
·期 20
·7596-7606
·
IF 8.307
Yiming Jiang,Jiawei Zhu,Li Li,Yahui Gao,Juncai Leng,Jiai Yan,Shuoming Liu,Feng Zhang,Han Liu,Chenlu Zhu,Lichun Guo,Haijiao Xie,Wei Zhao
Although the application of nanoscale artificial enzymes in various industries is an attractive way to circumvent the intrinsic drawbacks of natural enzymes, their catalytic constant (Kcat) as a critical reaction parameter is far from satisfactory. Presented here is the rational design and fabrication of a unique peroxidase mimic catalyst based upon Pd@PtxRu4−x (1 ≤ x ≤ 3) prepared by coating PtRu alloy as conformal, ultrathin shells on Pd nanocrystals. Benefiting from an optimal Pt/Ru ratio and well-defined {100} facets, together with confining the Pt–Ru alloy to a shell of averagely 3.3-atomic-layer thick (i.e. Pd@Pt–Ru3.3L), the nanocrystals exhibit the highest catalytic activity and kinetics (1.2 × 106 s−1), resulting in a significant increase of catalytic activity compared with the classical PtRu nanozyme (3.6 × 103 s−1) and horseradish peroxidase (4.0 × 103 s−1), respectively. The following density functional theory calculations demonstrate that the origin of the superior catalytic performance could be attributed to the modulation of the adsorption behavior of the key reaction intermediates on the surface. As a proof of concept, its peroxidase mimicking ability is adopted for sensing glucose and glutathione molecules in human serum, with a long linear range and high selectivity. This work opens new horizons for the future development of advanced catalysts based upon alloy nanocrystals for various applications.
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