JOURNAL OF PHYSICAL CHEMISTRY A
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2024
·
IF 2.7
Alexander M. Mebel,Wang Li,Luna Pratali Maffei,Carlo Cavallotti,Alexander N. Morozov,Chang-Yang Wang,Jiu-Zhong Yang,Long Zhao,Ralf I. Kaiser
To understand the reactivity of resonantly stabilized radicals, often found in relevant concentrations in gaseous environments, it is important to determine their main reaction pathways. Here, it is investigated whether the fulvenallenyl radical (C7H5·) reacts preferentially with closed-shell molecules or radicals. Electronic structure calculations on the C10H9 potential energy surface accessed by the reactions of C7H5· with methylacetylene (CH3CCH) and allene (H2CCCH2) were combined with RRKM-ME calculations of temperature- and pressure-dependent rate constants using the automated EStokTP software suite and kinetic modeling to assess the reactivity of C7H5· with closed-shell unsaturated hydrocarbons. Experimentally, the reactions were attempted in a chemical microreactor heated to 998 ± 10 K by preparing fulvenallenyl radicals via pyrolysis of trichloromethylbenzene (C7H5Cl3) and seeding the radicals in methylacetylene or allene carrier gas, with product identification by means of photoionization mass spectrometry. The measured photoionization efficiency curve of m/z = 128 was assigned to a linear combination of the reference curves of two C10H8 isomers, azulene (minor) and naphthalene (major), presumably resulting from the C7H5· plus C3H4 reactions. However, the calculations demonstrated that these reactions are too slow, and kinetic modeling of processes in the reactor allowed us to conclude that the observation of naphthalene and azulene is due to the C7H5· plus C3H3· reaction, where propargyl is produced by direct hydrogen atom abstraction by chlorine (Cl) atoms from allene or methylacetylene and Cl stem from the pyrolysis of C7H5Cl3. Modeling results under the copyrolysis conditions of toluene and methylacetylene in high-temperature shock tube experiments confirmed the prevalence of the fulvenallenyl reaction with propargyl over its reactions with C3H4 even when the concentrations of allene and methylacetylene largely exceed that of propargyl. Overall, the reactions of fulvenallenyl with both allene and methylacetylene were found to be noncompetitive in the formation of naphthalene and azulene thus attesting the inefficiency of the fulvenallenyl radical reactions with the prototype closed-shell hydrocarbon species. In the meantime, the new reaction pathways revealed, including H-assisted isomerizations between C10H8 isomers and decomposition reactions of various C10H9 isomers, emerge as relevant and are recommended for inclusion in combustion kinetic models for naphthalene formation.
研究领域:
物理化学
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燃烧科学
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反应动力学
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理论化学
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质谱分析
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高影响因子
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY
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2021
·
IF 3.636
Feng-Ying Gao,Xin Zhou,Mai-Xin Lu,Miao Wang,Zhi-Gang Liu,Jian-Meng Cao,Xiao-Li Ke,Meng-Meng Yi,Deng-Gao Qiu
Toll-like receptors (TLRs) play a critical role in the innate immune response of fish. In this study, we isolated the cDNA sequence of Nile tilapia TLR1 ( On TLR1). The deduced OnTLR1 protein contains a signal peptide , 7 leucine-rich repeats (LRRs), a C-terminal LRR (LRR-CT), a transmembrane region and a highly conserved TIR domain. In healthy Nile tilapia, the On TLR1 transcript was broadly expressed in all examined tissues, with the highest expression levels in the spleen . After infection with Streptococcus agalactiae , the On TLR1 transcripts were upregulated in the gill and kidney. After stimulation with polyinosinic-polycytidylic acid (poly(I:C)), the expression levels of On TLR1 were significantly downregulated in the intestine , whereas On TLR1 transcripts were significantly upregulated in the kidney. After challenge with lipopolysaccharide (LPS), the expression levels of On TLR1 were significantly upregulated in the spleen and kidney. The subcellular localization showed that On TLR1 was expressed in the cytoplasm. TLR1 significantly increased MyD88-dependent NF-κB activity. However, the results of a pull-down assay showed that On TLR1 did not interact with MyD88 or TIRAP. Binding assays revealed the specificity of OnTLR1 for pathogen-associated molecular patterns (PAMPs) and bacteria that included S. agalactiae , Aeromonas hydrophila and poly(I:C) and LPS. Taken together, these findings suggest that OnTLR1, as a pattern recognition receptor (PRR), might play an important role in the immune response to pathogen invasion.
研究领域:
免疫学
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分子生物学
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鱼类生物学
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病原识别
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Lei Tian,Hualin Jiang,Pinghua Chen,Qi Wang,Pingping Niu,Yangming Shi,Minghui Zhou,Yuancheng Qing,Xvbiao Luo
Competing for adsorption active sites decrease the efficiency of simultaneous adsorption of co-existent adsorbates. On the other hand, different adsorbates being desorbed at the same eluting condition will cause they are mixed together after the desorption, and ruin the recovery. Aim at these problems, a novel adsorbent with two functional domains was designed in this study. This adsorbent is a nano hybrid with two functional domains. One is GO domain which is responsible for the adsorption of inorganic metal ions ; another is PNIPAm domain which is responsible for the adsorption of organic molecules. This two-function-domain structure can avoid organic and inorganic adsorbates to compete the same adsorption active sites. Pb 2+ and 4-NP were taken as the model inorganic and organic adsorbates in this study. The locations of adsorbed Pb 2+ and 4-NP were confirmed by the results of adsorption experiments, BET and XPS analysis. The structure of hybrid was studied by FTIR, Raman spectra and TGA analysis. The hybrid exhibits high adsorption capacity toward Pb 2+ and 4-NP with high anti-inference ability. Furthermore, Pb 2+ and 4-NP can be efficiently desorped one by one with acidic or alkalinous condition, respectively. So they will not be mixed together after the desorption, and can be sequentially recovered. Due to the high efficiency and easy operation, the hybrid is considered as a promising adsorbent to simultaneously adsorb and recover organic and inorganic resources, and the method reported here could provide a new thinking way to develop highly effective adsorbents.
研究领域:
环境科学
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材料科学
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
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IF 5.518
Xinchen Chen,Hongtao Xia,Jianqi Lv,Yuting Liu,Yang Li,Lejin Xu,Chuting Xie,Yun Wang
Reasonable surface modification and increasing structural porosity were two key factors to improve the adsorption performance of biochar in the adsorption field. In this study, three different proportions of bamboo-based magnetic biochar modified with Fe 3 O 4 (Fe 3 O 4 @MBC) were synthesized by “one-can” method. BET showed that this method could effectively increase the specific surface area (129.79 m 2 g −1 ) and VSM indicated Fe 3 O 4 @MBC had an excellent magnetic response (32.84 emu g −1 ), which was conducive to the separation after adsorption. The accurate matching of pseudo-second-order kinetic model, thermodynamic model and Langmuir isotherm showed that at 298 K, pH = 4.5, the adsorption process dominated by chemical complexation and monolayer adsorption was spontaneous, endothermic and disordered. Saturated adsorption capacity of Fe 3 O 4 @MBC with the more Fe 3 O 4 loading proportion could reach 70.45 mg g −1 within 12 h. The loading of Fe 3 O 4 by “one-can” method not only provided abundant Fe-O groups to assist adsorption, but also magnetized bamboo matrix. Results showed that adsorption mechanism of U(VI) by Fe 3 O 4 @MBC included electrostatic action and chemical complexation involving Fe-O, carbonyl group and ample oxygen-containing functional groups. Therefore, Fe 3 O 4 @MBC with easy separation, excellent regeneration, remarkable economic potential and green value provided a novel solution for the field of radioactive wastewater treatment.
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高影响因子
CATENA
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2022
·
IF 6.367
Yuhang Jiang,Xiaoqin Lin,Muhammad Umar Khan,Wenjia Jiang,Yina Xu,Zhong Li,Wenxiong Lin
Leaf and branch pruning is essential for improving the productivity of continuously cropped leaf-harvested crops, such as tea, which is conductive to stabilize the production, delay the aging, and subsequently improve economic benefits. Generally, farmers adopt crew-cut pruning to get more yield in tea orchard pruning management. However, the long-term effects of crew-cut pruning on ecosystem of tea orchard are unclear. The present study investigated the environmental differences of ecosystem between crew-cut tea (CT) pruning and umbrella-shaped tea (UT) pruning treatments in the Tieguanyin tea orchards of China. We analyzed the soil enzymes activities, the rhizosphere and phyllosphere's microbial communities, the secondary metabolites of fresh tea shoots, and the insect abundance and its diversity in the two types of tea orchards. The results showed that both saccharase and urease were improved at different soil layers by UT. Fresh tea shoots analysis revealed 22.91% and 16.59% higher epigallocatechin gallate and epicatechin gallate levels, respectively under UT regime than those in CT, but a 9.42% lower ratio of polyphenol to the amino acid in comparision with that in CT. The total volatiles, especially ( E )-geraniol and furanoid linalool oxides, in the fresh shoots of UT were also significantly higher than those in CT. Further analysis showed that UT had more beneficial insects than CT. In contrast, tea gardens in CT were at a higher risk of pest attack than that in UT. Prolonged umbrella pruning of tea plantations significantly improved the bacterial diversity and the beneficial fungi in the leaf surface. Moreover, the relative abundances of rhizobia and ammonia-oxidizing bacteria in the rhizosphere were higher in UT than that in CT. The findings suggest that tea pruning in umbrella-shaped can reduce rhizosphere soil degradation and improve the ecosystem functioning, suggesting that proper pruning pattern is needed to improve tea quality.
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WATER RESEARCH
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2022
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IF 13.4
Yang Guo,Jingfei Long,Jun Huang,Gang Yu,Yujue Wang
Reactive oxygen species (ROS) such as hydroxyl radicals (•OH), superoxide radicals (O 2 •− ), and singlet oxygen ( 1 O 2 ) have often been suggested to play a role in ozone-resistant pollutant abatement during catalytic ozonation. However, there are significant controversies regarding their relative importance in literature. Currently, the role of ROS in pollutant abatement is commonly evaluated by the quenching method based on the assumption that the added ROS quenchers (e.g., tert-butanol (TBA) and para-benzoquinone (pBQ)) quench only the target ROS, but do not considerably influence other reaction mechanisms of catalytic ozonation. However, we hypothesized that this assumption is possibly unrealistic and a main cause for the controversies reported in literature. To test this hypothesis, this study evaluated the effects of six commonly used ROS quenchers (TBA, pBQ, methanol (MeOH), 4-chloro-7-nitrobenzo-2-oxa-1,3-dizole (NBD-Cl), furfuryl alcohol (FFA), and sodium azide (NaN 3 )) on the mechanism of catalytic ozonation with manganese dioxide. The results show that rather than only quenching their target ROS, these quenchers can profoundly change the catalytic ozonation system through various mechanisms, e.g., interrupting the radical chain reaction of O 3 decomposition, blocking the active sites of catalysts, and consuming O 3 in the system. Due to the significant confounding effects of ROS quenchers on the reaction mechanism, the quenching method actually cannot reveal the role of ROS in pollutant abatement and often misinterpreted the catalytic ozonation mechanism. The results indicate that the commonly used quenching method is probably not an appropriate way to investigate the role of ROS in pollutant abatement during catalytic ozonation, and many previously reported mechanisms obtained with the quenching method may need a revisit.
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DOI
PubMed
高影响因子
Frontiers in Nutrition
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2023
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IF 5
Su Hongxia,Chen Zhanpeng,Zhao Yuan,An Jiejie,Huang Haohe,Liu Ren,Huang Chongxing
Introduction: Chlorine dioxide (ClO2) is a safe and efficient bactericide with unique advantages in reducing foodborne illnesses, inhibiting microbial growth, and maintaining the nutritional quality of food. However, gaseous ClO2 is sensitive to heat, vibration, and light, which limits its application.Methods: In this study, a ClO2 precursor-stabilized ClO2 aqueous solution was encapsulated by the double emulsion method, and a high-performance ClO2 self-releasing polyvinyl alcohol (PVA) film was prepared to investigate its performance and effect on blueberry quality during storage.Results: The self-releasing films had the best overall performance when the microcapsule content was 10% as the film's mechanical properties, thermal stability, and film barrier properties were significantly improved. The inhibition rates of Listeria monocytogenes and Escherichia coli were 93.69% and 95.55%, respectively, and the mycelial growth of Staphylococcus griseus was successfully inhibited. The resulting ClO2 self-releasing films were used for blueberry preservation, and an experimental study found that the ClO2 self-releasing antimicrobial film group delayed the quality decline of blueberries. During the 14-day storage period, no mold contamination was observed in the ClO2 self-releasing film group, and blueberries in the antibacterial film group had higher anthocyanin accumulation during the storage period.Discussion: Research analysis showed that films containing ClO2 microcapsules are promising materials for future fruit and vegetable packaging.
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PubMed
高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 40
·17508-17515
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IF 4.197
Shuhao Qin,Lei Dong,Zhuqi Chen,Sicheng Zhang,Guochuan Yin
In Wacker oxidation and inspired Pd(II)/Cu(II)-catalyzed C–H activations, copper(II) is believed to serve in re-oxidizing of Pd(0) in the catalytic cycle. Herein we report that non-redox metal ions like Sc(III) can promote Wacker-type oxidations even better than Cu(II); both Sc(III) and Cu(II) can greatly promote Pd(II)-catalyzed olefin isomerization in which the redox properties of Cu(II) are not essential, indicating that the Lewis acid properties of Cu(II) can play a significant role in Pd(II)-catalyzed C–H activations in addition to its redox properties. Characterization of catalysts using UV-Vis and NMR indicated that adding Sc(OTf)3 to the acetonitrile solution of Pd(OAc)2 generates a new Pd(II)/Sc(III) bimetallic complex having a diacetate bridge which serves as the key active species for Wacker-type oxidation and olefin isomerization. Linkage of trivalent Sc(III) to the Pd(II) species makes it more electron-deficient, thus facilitating the coordination of olefin to the Pd(II) cation. Due to the improved electron transfer from olefin to the Pd(II) cation, it benefits the nucleophilic attack of water on the olefinic double bond, leading to efficient olefin oxidation. The presence of excess Sc(III) prevents the palladium(0) black formation, which has been rationalized by the formation of the Sc(III)⋯H–Pd(II) intermediate. This intermediate inhibits the reductive elimination of the H–Pd(II) bond, and facilitates the oxygen insertion to form the HOO–Pd(II) intermediate, and thus avoids the formation of the inactive palladium(0) black. The Lewis acid promoted Wacker-type oxidation and olefin isomerization demonstrated here may open up a new opportunity in catalyst design for versatile C–H activations.
研究领域:
化学
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催化科学
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PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Binbin Shao,Jing Deng,Hongyu Dong,Shuchang Wang,Enchao Li,Xiaohong Guan
Recent research has primarily focused on the utilization of reductants as activators for Fe(VI) to generate high-valent iron species (Fe(IV)/Fe(V)) for the degradation of emerging organic contaminants (EOCs). However, a significant drawback of this approach arises from the reaction between reductants and ferrates, leading to a decrease in oxidation capacity. This study introduces a novel discovery that highlights the potential of the iron(III)-(1,10-phenanthroline) (Fe(III)-Phen) complex as an activator, effectively enhancing the degradation of EOCs by Fe(VI) and augmenting the overall oxidation capacity of Fe(VI). The degradation of EOCs in the Fe(VI)/Fe(III)-Phen system is facilitated through two mechanisms: a direct electron transfer (DET) process and electron shuttle action. The DET process involves the formation of a Phen-Fe(III)–Fe(VI)* complex, which exhibits a stronger oxidation ability than Fe(VI) alone and can accept electrons directly from EOCs. On the other hand, the electron shuttle process utilizes Fe(III)-Phen as a redox mediator to transfer electrons from EOCs to Fe(VI) through the Fe(IV)/Fe(III) or Fe(IV)/Fe(II)/Fe(III) cycle. Moreover, the Fe(III)-Phen complex can improve the utilization efficiency of Fe(V) by preventing its self-decay. This study’s findings may present a viable option for utilizing an effective catalyst to enhance the oxidation of EOCs by Fe(VI) and Fe(V).
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高影响因子
Soft Matter
·
2020
·Vol. 16
·期 18
·4407-4413
·
IF 3.14
Hao Xu,Fu-Kuan Shi,Xiao-Ying Liu,Ming Zhong,Xu-Ming Xie
Constructing a multi-bond network (MBN), which involves hierarchical dynamic bonds with different bond association energies, is an effective method for achieving super tough hydrogels. In this work, a small amount of poly(vinyl alcohol) (PVA) is introduced into a loosely chemically crosslinked poly(acrylic acid) (PAA) network. The hydrophilic PVA chains can physically interact and form hydrogen bonds with the PAA chains. After a freeze–thaw process, PVA could partially crystallize and the generated microcrystals could become new crosslinking points of the hydrogels. Meanwhile, the hydrogen bonds between PAA and PVA, which connect to the microcrystal “core” through PVA chains, could also become new crosslinking points of the hydrogels. The obtained ternary-crosslinked hydrogels (T-gel 10%) exhibit toughness as high as 8 times that in pure PAA hydrogels. When the PVA content exceeds 15 wt%, PVA chains will run through the whole PAA network. Thus the PVA chains will be crosslinked by microcrystals through freeze–thaw treatment, leading to a double network structure, resulting in a brittle hydrogel. The step-increased modulus of the hydrogels with different PVA contents clearly demonstrates the change in the network structure of the hydrogels. Successively, Fe3+ is introduced into the MBN hydrogels as a third cross-linking point. The obtained quaternary-crosslinked hydrogels (Q-gel 10%-Fe5) (50 wt% water content) exhibit significantly improved mechanical properties: tensile strength as high as 6.83 MPa with a fracture energy of 29.9 MJ m−3. This work provides clear insight into the relationship between network structure and mechanical properties in super tough MBN hydrogels.
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高影响因子
ACS Biomaterials Science & Engineering
·
2017
·
IF 3.234
Feng Li,Tianyu Li,Xuexiang Han,Hao Zhuang,Guangjun Nie,Huaping Xu
Selenium is a unique, essential trace element that plays an important role in the antioxidant defense and redox regulation of biological processes. We have reported that novel selenium-containing platinum-based anticancer molecules (EG-Se/Pt) had selective cytotoxicity toward cancer cells. Herein, we found the underlying mechanism of selective cytotoxicity to be closely related to the glutathione antioxidant defense system. Elevated reactive oxygen species (ROS) make cancer cells more vulnerable to further elevation of ROS. EG-Se/Pt can induce abnormal increases in ROS by depletion of glutathione. Consequently, the mitochondrial membrane potential collapses and cytochrome c is released, resulting in cell apoptosis. However, EG-Se/Pt analogues, such as EG-Se/Cu and EG-Se/Ni, did not exhibit glutathione depletion capacity or selective killing activity in our investigation, although they can effectively kill cancer cells. These results suggest that the glutathione antioxidant system is an effective target to enable therapeutic selectivity. The amphiphilic property of the selenium–platinum coordination molecules facilitates their assembly into nanoparticles and prolongs the circulation time of the drug in the bloodstream, which is important for in vivo drug delivery. Our in vivo anticancer study demonstrated that the tumor growth inhibition rate of EG-Se/Pt can reach 69% (p < 0.05). What is more encouraging is that EG-Se/Pt exhibited minimal side effects compared to cisplatin. This work also provides new opportunities for the development of therapeutic strategies against cancer.
研究领域:
肿瘤学
·
药理学
·
生物化学
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PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Bin Li,Ting Zhang,Zhaoguang Yang
Response surface methodology was employed to investigate the effects of nitrogen ( X 1 ), phosphorus ( X 2 ), and glucose ( X 3 ) on arsenic removal by fungal-algal pellets. X 1 , X 3 , and X 1 X 3 had significant effects. Arsenic accumulation and transformation were compared among Chlorella vulgaris , Aspergillus oryzae , and fungal-algal pellets under different arsenate and phosphorus concentrations. Fungal-algal pellets had the highest removal rate and was best able to accumulate arsenate in all treatments. The reduction of arsenate to arsenite was found in all tested organisms, while arsenic methylation was only identified in C . vulgaris . The biomass of fungal-algal pellets was not inhibited by arsenate. SEM micrographs showed that arsenic led to a change in mycelial structure from compact to loose pellets. FT-IR spectra showed that four functional groups might be involved in arsenate adsorption. Arsenic tolerance and accumulation in fungal-algal pellets opens the way to its potential application in the remediation of arsenic from contaminated water.
研究领域:
环境科学
·
微生物学
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DOI
高影响因子
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