Catalysis Science & Technology
·
2019
·Vol. 9
·期 23
·6659-6668
·
IF 5.726
Jie Yang,Haochen Yu,Yanbing Wang,Fuyuan Qi,Haodong Liu,Lan-Lan Lou,Kai Yu,Wuzong Zhou,Shuangxi Liu
Four types of Ca–Mn oxides, CaMnO3, CaMn2O4, CaMn3O6 and Ca2Mn3O8, have been prepared and used as supports for Pd nanoparticles. The oxygen activation capacity of these oxides and the catalytic activity of the oxide supported Pd nanocatalysts have been investigated using the aerobic oxidation of 5-hydroxymethyl-2-furfural as a model reaction. It is found that the local coordination environment of lattice oxygen sites plays a crucial role on their redox properties and charge transfer ability from Pd nanoparticles to the support. In particular, the Ca–Mn oxide with lower oxygen coordination number, weaker metal–oxygen bonds and tunnel crystal structure, e.g. CaMn2O4, exhibits promoted oxygen activation capacity, and stronger electron transfer ability. Consequently, Pd/CaMn2O4 exhibits the highest catalytic activity among these catalysts, providing a promising yield of 2,5-furandicarboxylic acid. This work may shed light on future investigations on the design of local structure of active oxygen sites in oxides or oxide supported catalysts for redox reactions.
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Gland Surgery
·
2022
·
IF 2.16
Meili Zhang,Jialei Gu,Wendong Wang,Kejing Wang,Linfeng Zheng,Jianguo Feng,Jinbiao Shang
Background Identifying the high recurrence group of patients with early-stage papillary thyroid cancer (PTC) is the greatest challenge in the management of this disease. It has been noted that B-type Rafkinase (BRAF) V600E mutation and programmed death ligand 1 (PD-L1) are associated in PTC and highly expressed in PTC, correlating in PTC as potential prognostic biomarkers. However, whether they can be used to predict the aggressiveness and recurrence of early PTC remains unclear. Methods Clinicopathological data of 137 patients with early PTC [tumor-node-metastasis (TNM) stage I–II] who underwent surgery in Zhejiang Cancer Hospital between 2008 and 2010 were retrospectively analyzed. BRAF V600E mutation and PD-L1 was detected by immunohistochemistry. The median follow-up time was 136 months (interquartile range 5.8). The presence of tumor confirmed by imaging or pathology or lymph node metastasis was considered as tumor recurrence. The association of both alone and in combination with clinicopathological features and recurrence was statistically analyzed respectively. The risk of recurrence was assessed using Cox regression models. Results Most of the 137 early PTC were female (78.1%). The mean age was 43.2±12.1 years. The median tumor size was 1.4 cm; 14 patients developed recurrence during follow-up period; 56 patients (40.9%) were detected positive for BRAF V600E mutation; 76 patients (55.5%) were detected positive for PD-L1. Patients with both BRAF V600E mutation and PD-L1 expression had larger tumors (P=0.038), were more likely to have extrathyroidal invasion (P=0.045), and had a lower rate of cervical lymph node metastasis (P=0.046). The recurrence rate was 17.5% (7/40) in patients with BRAF V600E mutation and PD-L1 double expression compared to 8.9% (4/45) in patients with BRAF V600E mutation and PD-L1 double negative [hazard ratio (HR) =1.267; 95% CI: 0.841–1.909; P=0.257]. Survival curves showed flatter recurrence-free survival (RFS) curves in positive BRAF V600E mutation only and PD-L1 expression only, whereas decreased sharply in positive expression of both BRAF V600E mutation and PD-L1; however, the differences were not significant (P>0.05). Conclusions The combination of BRAF V600E mutation and PD-L1 to identify group at higher risk of recurrence in early PTC has insufficient clinical evidence and should be used with caution in the clinical management of PTC.
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PubMed
高影响因子
Journal of Environmental Sciences
·
2023
·
IF 6.9
Anqi Lu,Xiaokang Xiang,Ming Lei,Shuangshuang Huang,Bingbing Liang,Siyu Zhao,Lihua Zhu,Heqing Tang
The reduction of nitrobenzene to aniline is very important for both pollution control and chemical synthesis. Nevertheless, difficulties still remain in developing a catalytic system having high efficiency and selectivity for the production of aniline. Herein, it was found that PdO nanoparticles highly dispersed on TiO 2 support (PdO/TiO 2 ) functioned as a highly efficient catalyst for the reduction of nitrobenzene in the presence of NaBH 4 . Under favorable conditions, 95% of the added nitrobenzene (1 mmol/L) was reduced within 1 min with an ultra-low apparent activation energy of 10.8 kJ/mol by using 0.5%PdO/TiO 2 as catalysts and 2 mmol/L of NaBH 4 as reductants, and the selectivity to aniline even reached up to 98%. The active hydrogen species were perceived as dominant species during the hydrogenation of nitrobenzene by the results of isotope labeling experiments and ESR spectroscopic. A mechanism was proposed as follows: PdO activates the nitro groups and leads to in-situ generation of Pd, and the generated Pd acts as the reduction sites to produce active hydrogen species. In this catalytic system, nitrobenzene prefers to be adsorbed on the PdO nanoparticles of the PdO/TiO 2 composite. Subsequently, the addition of NaBH 4 results in-situ generation of a Pd/PdO/TiO 2 composite from the PdO/TiO 2 composite, and the Pd nanoclusters would activate NaBH 4 to generate active hydrogen species to attack the adsorbed nitro groups. This work will open up a new approach for the catalytic transfer hydrogenation of nitrobenzene to aniline in green chemistry.
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International Journal of Nanomedicine
·
2023
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IF 8
Yan Zhou,Zekun Zhou,Xiaojuan Wu,Zefeng Wang,Wangdan Qi,Jing Yang,Liming Qing,Juyu Tang,Le Deng
Purpose We aimed to develop an oxidative-stress-activated palladium-copper nanozyme to reduce bacterial’s heat sensitivity by down-regulating heat shock proteins to overcome the shortcomings of conventional photothermal antimicrobial therapy and achieve mild photothermal bactericidal efficacy.Methods We first synthesized palladium-copper nanozymes (PC-NPs) by hydration and used transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy to demonstrate their successful preparation. Their photothermal therapy (PTT) and chemo-dynamic therapy (CDT) activities were then determined by a series of photothermal performance tests and peroxidase-like performance tests, and the destruction of heat shock proteins by reactive oxygen species (ROS) was verified at the protein level by Western Blotting tests, providing a basis for the effective bacteria-killing by the mild-temperature photothermal treatment subsequently applied. We also validated this promising programmed and controlled antimicrobial treatment with palladium-copper nanozymes by in vivo/in vitro antimicrobial assays. A hemolysis assay, MTT cytotoxicity test and histopathological analysis were also performed to assess the in vivo safety of PC-NPs.Results In the micro-acidic environment of bacterial infection, PC-NPs showed peroxidase-like activity that broke down the H2O2 at the wound into hydroxyl radicals and down-regulated bacterial heat shock proteins. The application of PC-NPs increased bacteria’s sensitivity to subsequent photothermal treatment, enabling the elimination of bacteria via mild photothermal treatment.Conclusion The programmed synergistic catalytic enhancement of CDT and mild photothermal therapy achieves the most efficient killing of bacteria and their biofilms, which brings future thinking in the relationship between heat shock proteins and oxidative stress damage in bacteria.
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高影响因子
Analytical Methods
·
2023
·Vol. 15
·期 30
·3642-3649
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IF 3.1
Kai Zhang,Xiaoyuan Zhang,Yanqin Rong,Qingfang Niu,Pengyue Jin,Xuewen Ma,Cheng Yang,Wenting Liang
Ractopamine (RAC) is universally known for improving lean meat percentage in livestock and thus is widely introduced as a feed additive. However, it is difficult to eliminate the RAC residue in animal tissues from the biological system and will inevitably harm human health. Hence, detecting RAC molecules in biological samples is extremely significant. Herein, a novel strategy of supramolecular recognition-enhanced electrochemical sensing is presented. This platform was constructed by coupling β-cyclodextrin (β-CD) with palladium nanoparticles (Pd NPs)-functionalized three-dimensional reduced graphene oxide (3D-rGO) to form a nanocomposite (3D-rGO/Pd/β-CD), which was further used to modify a glassy carbon electrode (GCE) for RAC detection. Benefiting from the attractive electrical conductivity and catalytic activity of 3D-rGO/Pd, as well as the unique small-molecule-recognition ability of β-CD demonstrated by 1H NMR spectrum, which revealed the 1 : 2 binding mode of RAC with β-CD, increased peak current signals of RAC were observed in the cyclic voltammetry (CV) test. Under optimized conditions, the wide linear concentration range spanned 1–95 μM, along with a relatively low detection limit of 0.12 μM (S/N = 3), as evidenced by the differential pulse voltammetry (DPV) approach. The platform also exhibited satisfactory stability and fine reproducibility, as well as high selectivity and good anti-interference capability. Moreover, this as-obtained sensor was efficiently applied in pork samples with a high recovery rate (96.44–103.99%), which provides a promising view of its electrochemical biosensing ability in practical applications.
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Arabian Journal of Chemistry
·
2023
·
IF 6
Yongyong Shi,Donghai Jiang,Liming Zhou,Jingyun Zhao,Jun Ma,Qian Lin,Hongyan Pan
Directly synthesizing H 2 O 2 from H 2 and O 2 at atmospheric pressure requires a highly efficient Pd catalyst, which poses a challenge for reasonable design and simple synthesis of Pd catalyst. In this study, a series of Pd/NPCS catalysts were synthesized by various methods with mono-disperse, uniform-size and N-doped porous carbon sphere named NPCS as the support and PdCl 2 as the palladium precursor. The results indicated that the ultrasonic-assisted-microwave quick synthesis method significantly reduced the synthesis time of Pd catalyst. The Pd nanoparticles obtained via this method were well-distributed on the NPCS support, with a smaller particle size, a narrower particle size distribution range, and more exposed Pd active sites, which leading to improved H 2 O 2 generation rate compared to traditional preparation methods. Additionally, N-doped, high specific surface area, and abundant mixed micro-mesoporous pore structure of NPCS support improved the transfer and diffusion performance of Pd/NPCS catalysts, facilitating the adsorption of reactants and desorption of H 2 O 2 from Pd active sites, and effectively inhibited hydrogenation and decomposition side reactions caused by the breaking of the O-O bond. The ultrasonic-assisted-microwave quick synthesis method and excellent NPCS support synergistically improved the catalytic activity and stability of Pd/NPCS catalyst. These findings provide insight into the design and preparation of efficient Pd catalysts for directly synthesizing H 2 O 2 at atmospheric pressure.
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RSC Advances
·
2015
·Vol. 5
·期 50
·40227-40235
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IF 3.84
Fangyuan Yi,Fugui Xu,Yong Gao,Huaming Li,Daoyong Chen
In this study, the preparation of styrene/divinylbenzene-based macrocellular polymers of high internal phase emulsions (polyHIPEs) with interconnected open-cell structure as well as their application as support for Pd nanoparticles are presented. Firstly, water in oil high internal phase emulsions (HIPEs) were generated by adding the water stepwise to the oil phase (styrene and divinylbenzene) containing Janus polymer nanoparticles that consist of a linear poly(methyl methacrylate) “tail” and a cross-linked poly(4-vinylpyridine) “head”. The generated water in oil HIPEs stabilized solely by Janus polymer nanoparticles were then converted to polyHIPEs foams by polymerizing the external continuous oil phase, followed by the extraction with methanol and the drying under the reduced press. Scanning electron microscopy observation revealed that the as-produced macrocellular polyHIPEs were foam structure with closed and/or partially open-cells. Partial cells covered by a thin polymer film were peeled off during the post-treatment. Some key factors influencing the polyHIPEs morphologies, including emulsifier particles content, the mole ratio of styrene to divinylbenzene and the internal phase volume fraction were investigated, and macrocellular polyHIPEs with interconnected open-cell morphologies could be achieved under optimal conditions. Benefited from the strong interaction between the emulsifier particles embedded in the polyHIPEs and H2PdCl4 precursor, Pd nanoparticles were facilely supported in situ within the macrocellular polyHIPEs without any functional monomers or post-functionalization requirement. The obtained Pd@macrocellular polymer hybrid foams were then applied for the heterogeneous Suzuki–Miyaura carbon–carbon coupling reactions between iodobenzene and benzeneboronic acid, and a high catalytic activity with a good recyclability were demonstrated.
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CATALYSIS LETTERS
·
2024
·Vol. 155
·期 1
·1-15
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IF 2.3
Gao Qing,Yu Yingxue,Wang Chengyun,Xiang Rui,Lu Hao
Designing an efficient Pd-based catalyst with high atom utilization efficiency is a pressing priority, presenting a significant challenge for the practical deployment of electrocatalytic hydrodechlorination (EHDC), a promising method for degrading hazardous chlorophenols (CPs). Herein, a hybrid Pd/Co(OH) 2 /NF electrode for the dechlorination of 2,4- dichlorophenol (2,4-DCP) is fabricated by a newly developed etching-deposition approach. Physical characterizations demonstrate that ultra-fine Pd nanoparticles (1.57 ± 0.29 nm) accompany with Pd 2+ hydroxides are uniformly deposited on the surface of Co(OH) 2 nanowire arrays. EHDC tests on Pd/Co(OH) 2 /NF show an impressive catalytic performance with a 94.5% removal efficiency within 2 h, fast reaction kinetics (0.024 min − 1 ) and remarkable current efficiency (55.4%), highly competitive with literature reports. Mechanism investigations indicate that the even distribution of Pd nanoparticles and coexistence of Pd 2+ sites facilitate the production of active H * and activation of C-Cl, contributing to the improvement of activity.
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Food Bioscience
·
2025
·
IF 5.9
Yixuan Wang,Songyu Yang,Shengbin Chen,Yingbing Zuo,Xiaoyu Mu,Hongmei Zhou,Yufei Yao,Xiaoping Peng,Wenjuan Li
This study aimed to explore the anti-tumor activity and mechanisms of the ethanol-soluble acidic components (ESAC) of Camellia oleifera cake through a combination of network pharmacology, in vitro and in vivo studies, and metabolomics based on UPLC-Q-TOF/MS. Additionally, the potential application of ESAC in combination with PD-1 inhibitors was explored. In this work, our results demonstrated that ESAC exhibited anti-tumor activities mediated by regulated cell death (RCD), which were associated with apoptosis, pyroptosis, and ferroptosis. UPLC-Q-TOF/MS-based serum metabolomics revealed that metabolic disorders were occurred in tumor group when compared to control group. In contrast, ESAC significantly inhibited abnormal energy metabolism including glycolysis, tricarboxylic acid cycle, and amino acid metabolism. Consequently, hexokinase and malate dehydrogenase, key enzymes of energy metabolism, were determined, and data showed that treatment of tumor mice with ESAC significantly suppressed activities of these metabolic enzymes when compared to tumor group, confirming that mitigating metabolic disorders contributed to the anti-tumor activities of ESAC. Moreover, ESAC could also reduced PD-L1 expression in tumor tissue, which was similar to the effect of PD-1 inhibitor. Furthermore, combination treatment with ESAC and PD-1 inhibitor was superior to either treatment alone, and it enhanced pyroptosis through the NLRP3/Caspase-1/GSDMD pathway. Together, we concluded that metabolic correction and PD-L1 inhibition were the critical mechanisms to exert anti-tumor activities of ESAC.
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CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Siqi Wu,Jianshan Chen,Rong Guo,Haoyi Tong,Shanshan Zong,Zhifang Diao,Yeyan Qin,Yuangen Yao
Efficient production of dimethyl carbonate (DMC) from methyl nitrite (MN) carbonylation based on PdCu/NaY zeolite catalysts is highly desired for industrial applications. The introduction of boron species into the initial gels of NaY synthesis is a cost-effective modification strategy for boosting the catalytic performance. It not only introduces trace amounts of framework boron but also regulates the distribution of framework aluminum (Al F ) species. Most importantly, the synergistic effect of framework boron and Al-rich region significantly enhanced the metal − support interaction, thus promoting more electrons to be transferred from metal to support. This strategy allows the palladium active species to remain in an electron-deficient state more easily. The carbon monoxide (CO) adsorption and the critical intermediate species *CH 3 COO are more easily formatted on PdCu/NaBY catalyst, which leads to superior weight-time yields (WTY DMC up to 1507·g·kg cat − 1 ·h − 1 ), and CO conversion to DMC (C CO up to 83 %). Our design is of great importance for developing metal-zeolites catalysts, which motivates the industrial application of Pd-based catalysts in the MN carbonation of DMC field.
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Nanoscale
·
2015
·Vol. 7
·期 17
·7615-7623
·
IF 7.394
Lu Lin,Tong Zhang,Haiou Liu,Jieshan Qiu,Xiongfu Zhang
Controllable encapsulation of nanoparticles with metal organic frameworks (MOFs) has been an efficient way to impart the unique chemical and physical properties of the nanoparticles to metal organic frameworks and create new types of multifunctional MOF core–shell materials with enhanced properties. Here, a novel ZnO support-induced encapsulation strategy is reported to efficiently fabricate a Pd/ZnO@ZIF-8 core–shell catalyst, with Pd/ZnO as the core and ZIF-8 as the shell. The novel synthesis procedure involves first loading Pd nanoparticles onto the surface of the ZnO microsphere to form a Pd/ZnO core and then coating the core with a layer of defect-free ZIF-8 shell via ZnO-induced in situ ZIF-8 growth to obtain the Pd/ZnO@ZIF-8 core–shell catalyst. It was crucial that the ZIF-8 was in situ formed from the ZnO core in an ethanol solution only containing 2-methylimidazole under mild conditions. This strategy allowed for the growth of ZIF-8 right on the surface of Pd/ZnO via the reaction between ZnO and the 2-methylimidazole ligands, and thus avoided the random deposition of ZIF-8 crystals on the Pd/ZnO core as in the case of the conventional ZIF-8 synthesis solution. Furthermore, use of ethanol as the solvent also favored achievement of the well-defined Pd/ZnO@ZIF-8 structure, since the ethanol solution of 2-methylimidazole was able to keep the balance between ZnO dissolution and ZIF-8 formation. The as-prepared Pd/ZnO@ZIF-8 core–shell microsphere as an efficient catalyst displayed excellent performance in terms of size-selectivity, stability and anti-poisoning in the liquid hydrogenations of alkenes.
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高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Fei Wang,Jiangge Teng,Zixu Li,Chao Fang,Kai Ma,Yanxiong Ke,Qiang Jia,Changhu Chu
A facile and readily available Fe-ppm-Pd/C catalyst has been developed for catalyzing Suzuki-Miyaura cross-coupling reactions. When combined with dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl) phosphine (SPhos), this catalyst, with low levels of palladium (as low as 180 ppm), efficiently facilitates cross-coupling reactions between aryl boronic acids (or aryl neopentyl-1,3-diol boronic ester) and a wide range of aryl halides, including inactivated aryl chlorides. Additionally, the recovered Fe-ppm-Pd/C catalyst has demonstrated sustained catalytic activity over four runs, indicating minimal decline in performance. This suggests the catalyst's potential for long-term use and its practicality in industrial applications.
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