Environmental Science-Nano
·
2023
·Vol. 11
·期 1
·309-323
·
IF 7.3
Xin Liu,Xiang He,Zhi-Cheng Ma,Xi Xi,Shuang-Xi Wang
Organic ammonium salts which are formed from heterogeneous reactions are one of the important components of nitrogen-containing organic compounds (NOCs) in the atmosphere. In order to investigate the formation process of organic ammonium salts, a gas-flow system with the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technique was applied to monitor the influence of a simulated illumination on the heterogeneous reactions of toluene/O3/NH3 on hematite nanoparticles. The results revealed that toluene was transformed into benzoic acid under the action of oxidants (O3 and OH radicals). The carboxylic acid was neutralized with NH3 to form ammonium benzoate. The effect of light intensities on the reaction kinetics of ammonium benzoate formation from the heterogeneous reactions was also analyzed. With an increase in the light intensity from dark to 36 mW cm−2, the reaction rates increased from (1.20 ± 0.02) × 1018 ions per g s−1 to (2.30 ± 0.09) × 1018 ions per g s−1. This induced the formation of abundant active radicals, which accelerated the conversion of toluene to ammonium benzoate on hematite nanoparticles. However, the reaction rates decreased to (1.80 ± 0.03) × 1018 ions per g s−1 as the light intensity continued to increase to 100 mW cm−2. The yield of organic ammonium salts might be reduced owing to the volatilization of ammonium benzoate at a high light intensity. Meanwhile, the initial uptake coefficient showed a similar change trend. The values of the uptake coefficient increased by 81.1% when the light intensity increased from 0 mW cm−2 to 36 mW cm−2 but decreased by 21.1% when the light intensity increased from 36 mW cm−2 to 100 mW cm−2. Our results not only propose the heterogeneous reaction kinetics of toluene/O3/NH3 on the nanoscale hematite surface under different light intensity conditions, but also provide a theoretical support for further understanding the conversion process of volatile organic compounds (VOCs) under combined atmospheric pollution.
研究领域:
大气化学
·
环境科学
✓ 已验证
DOI
高影响因子
BMC PLANT BIOLOGY
·
2023
·Vol. 23
·期 1
·1-14
·
IF 5.3
Li Guohui,Song Cheng,Manzoor Muhammad Aamir,Li Daoyuan,Cao Yunpeng,Cai Yongping
Background The enzyme phenylalanine ammonia lyase (PAL) controls the transition from primary to secondary metabolism by converting L-phenylalanine (L-Phe) to cinnamic acid. However, the function of PAL in pear plants ( Pyrus bretschneideri ) has not yet been fully elucidated. Results We identified three PAL genes ( PbPAL1 , PbPAL2 and PbPAL3 ) from the pear genome by exploring pear genome databases. The evolutionary tree revealed that three PbPAL s were classified into one group. We expressed PbPAL1 and PbPAL2 recombinant proteins, and the purified PbPAL1 and PbPAL2 proteins showed strict substrate specificity for L-Phe, no activity toward L-Tyr in vitro, and modest changes in kinetics and enzyme characteristics. Furthermore, overexpression of PbAL1 and PbPAL1 -RNAi, respectively, and resulted in significant changes in stone cell and lignin contents in pear fruits. The results of yeast one-hybrid (Y1H) assays that PbWLIM1 could bind to the conserved PAL box in the PbPAL promoter and regulate the transcription level of PbPAL2. Conclusions Our findings not only showed PbPAL’s potential role in lignin biosynthesis but also laid the foundation for future studies on the regulation of lignin synthesis and stone cell development in pear fruit utilizing molecular biology approaches.
研究领域:
植物学
·
分子生物学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Angxin Tong,Xiaojun Tang,Feng Zhang,Bin Wang
In this study, we mainly focused on predictable regularities of the red shift of ultraviolet spectra for β-phenylethylamine (PEA), NaCl and NaOH in aqueous solution. The absorption peaks of the UV spectra near 191 nm of NaCl, NaOH and PEA in aqueous solution moved in the direction of a red shift while the molar absorption coefficient at the peak increased regularly with the increasing solution concentration. These shifts were obtained for solutions with concentrations ranging from 3.68 to 1000 mmol/L for NaCl, from 0.762 to 2000 mmol/L for NaOH, and from 0.0515 to 8.91 mmol/L for PEA. The plots of the logarithm of the solution concentration for NaCl and PEA versus the absorbance at 191 nm and at the peak were linear, and the plots of the logarithm of the solution concentration for NaCl and PEA versus the wavelength at the peak (shifted from 191 nm) were also linear. In addition, the plots of the logarithm of the solution concentration for NaOH that ranged from 0.762 to 1.96 mmol/L versus the absorbance at 191 nm and at the peak were linear as well as the plots of the logarithm of the solution concentration for NaOH that ranged from 1.96 to 2000 mmol/L versus the wavelength at the peak. The slopes of the absorbance at 191 nm of PEA, NaCl and NaOH were somewhat similar to the absorbance at the peak separately, whereas the slopes of the wavelengths at the peak were different from them. Finally, in order to obtain the predictable regularity of the red shift of the UV spectrum for the mixture, 22 ternary mixtures were prepared. The results indicate that the inhibiting effect of hydroxide ions (OH-) caused the wavelength near 206 nm to remain unchanged when the solution concentration of NaOH in the mixture was more than 0.762 mmol/L.
研究领域:
化学
·
光谱学
·
分析化学
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2014
·
IF 0.987
Ruihua Huang,Bo Wang,Bingchao Yang,Dongsheng Zheng,Zengqiang Zhang
An adsorbent was prepared from bentonite modified by hexadecyltrimethylammonium bromide (HDTMAB) and N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HTCC). This adsorbent was named as HDTMAB–HTCC bentonite. It would be used for the simultaneous adsorption of phenol and Cr(VI) from aqueous solution. By the method of single-factor experiment, the optimum preparation conditions of HDTMAB–HTCC bentonite were obtained. For bentonite (5 g), 1.0 g HDTMAB and 0.5 g HTCC were adopted as the modifying reagents. The reaction was carried out for 2 h at 80°C. The removals towards phenol and Cr(VI) enhanced with the increase in the amount of adsorbent dosage. The relatively high removals towards phenol and Cr(VI) occurred at a pH value of 1.5 or so. During the simultaneous adsorption process of phenol and Cr(VI), phenol was adsorbed by the partition from the organic phase formed by HDTMAB, while Cr(VI) was mostly adsorbed by the electrostatic interactions between HTCC and Cr(VI). No direct competition was observed due to different adsorption sites.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
LIQUID CRYSTALS
·
2020
·
IF 2.908
Tianwen Fan,Rongxin Shi,Huaying Tang,Hongyu Guo,Fafu Yang
This paper reported not only the first fluorescein liquid crystals but also revealed the influence of peripheral alkyl chains on mesomorphic properties and photophysical properties. Novel fluorescein-triphenylene dimers 4a–4f with different alkyl chains were designed and synthesised in yields of 76–83%. Samples 4a, 4b, 4c and 4d with CH3 and C4H9 exhibited the columnar mesophase but samples 4e and 4f with C8H17 showed no mesophase. The longer alkyl chains on fluorescein units resulted in the lower phase transition temperature. The too long alkyl chain destroyed the liquid crystalline behaviour. Their fluorescence quantum yields were as high as 0.78–0.87 in CH2Cl2 solution and 0.11–0.17 in solid states. The longer alkyl chains leaded to the higher emission efficiencies.
研究领域:
材料化学
·
物理化学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 2
·877
·
IF 4.6
Xuan Chen,Siyu Fang,Ping Xue,Jiming Huang,Mi Tang,Zhengbang Wang
The development of tunable molecule separation membranes requires materials with remote controllability and ultra-high separation capability. In this paper, a novel photoswitchable metal organic framework (MOF) thin film (Cu2(AzoBPDC)2) was prepared by liquid phase epitaxial layer-by-layer assembly to realize the reversible remote-controlled switching. The azobenzene side groups in the Cu2(AzoBPDC)2thin film showed excellent reversible photoswitching performance under UV (365 nm) and Vis (450 nm) irradiation, achieving the remote-controlled mode of the diffusion flux of polar gas molecules in the MOF thin film.Keywords:metal–organic frameworks;azobenzene;photoswitchable;gas separation
研究领域:
材料科学
·
化学工程
·
光化学
✓ 已验证
DOI
PubMed
高影响因子
TALANTA
·
2016
·
IF 4.035
Qiang Chen,Junfeng Zuo,Xue He,Xiujuan Mo,Ping Tong,Lan Zhang
In this paper, a simple, rapid and sensitive fluorescence method based on the formation of terbium (Tb 3+ ) complex has been developed for the rapid detection of Tb 3+ in water. The fluorescence sensor has been studied by using terbium complexed with thiabendazole (TBZ) while acetonitrile (MeCN) as solvent. The complex was made up of TBZ as small-molecule ligand and Tb 3+ as central ion. Fluorescence spectroscopy and UV spectroscopy together were used to study the behavior of the complexation of TBZ-Tb in this medium. Enhancement fluorescence was observed due to the efficient energy transfer process from TBZ to Tb 3+ . And the affecting factors of the enhancement fluorescence were also studied in detail. Under optimal conditions, a linear relationship was obtained between the enhanced fluorescence intensity and the concentration of Tb 3+ in a range of 5.0×10 −6 M–3.0×10 −5 M. The sensor was used for the detection of Tb 3+ in river water samples, and the result was satisfactory. In the meantime, a linear relationship was also obtained between the enhanced fluorescence intensity and the concentration of TBZ in a range of 8.0×10 −6 M–4.0×10 −5 M. Moreover, the method was successfully extended for the detection of TBZ in juice samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Kamile Arkin,Yuxin Zheng,Jiawei Hao,Siyi Zhang,Qingkun Shang
The use of nanomaterials such as carbon dots (CDs) as rapid detection fluorescent nanoprobes is a hot topic in the field of analytical chemistry. In this paper, blue, green, and red CDs with high fluorescence quantum yields (24, 54, and 38%, respectively) were obtained from m-phenylenediamine and urea by hydrothermal synthesis and chromatographic separation. After investigating the structures and properties of the obtained CDs, three distinct and sensitive fluorescent nanoprobes with different functions were successfully constructed. The first nanoprobe derived from blue CDs could be used to detect the pH of a strong acid solution (pH 3.0); a rapid detection kit was designed based on it. The second nanoprobe based on Green CDs with ellagic acid (EA) modification allowed the sensitive determination of Fe3+ ions in aqueous solutions. The final probe derived from Red CDs could be used to test for organic acids in liquor. The test results of the commercial liquor were consistent with the standard methods. The detection mechanism of the three fluorescent probes was proposed. Using CDs to construct multifunctional fluorescent nanoprobes is beneficial for the application of CDs to rapid and specific detection and recognition.
研究领域:
分析化学
·
纳米材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Qilin Yang,Yitao Bai,Shuangping Liu,Xiao Han,Tiantian Liu,Dongna Ma,Jian Mao
Elevated levels of biogenic amines (BAs) in fermented food can have negative effects on both the flavor and health. Mining enzymes that degrade BAs is an effective strategy for controlling their content. The study screened a strain of Lactobacillus hilgardii 1614 from fermented food system that can degrade BAs. The multiple copper oxidase genes LHMCO1614 were successfully mined after the whole genome protein sequences of homologous strains were clustered and followed by homology modeling. The enzyme molecules can interact with BAs to stabilize composite structures for catalytic degradation, as shown by molecular docking results. Ingeniously, the kinetic data showed that purified LHMCO1614 was less sensitive to the substrate inhibition of tyramine and phenylethylamine. The degradation rates of tyramine and phenylethylamine in huangjiu (18% vol) after adding LHMCO1614 were 41.35 and 40.21%, respectively. Furthermore, LHMCO1614 demonstrated universality in degrading tyramine and phenylethylamine present in other fermented foods as well. HS-SPME-GC-MS analysis revealed that, except for aldehydes, the addition of enzyme treatment did not significantly alter the levels of major flavor compounds in enzymatically treated fermented foods (p > 0.05). This study presents an enzymatic approach for regulating tyramine and phenylethylamine levels in fermented foods with potential applications both targeted and universal.
研究领域:
微生物学
·
食品安全
·
酶学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Tong Wei,Baoling Niu,Guohua Zhao
Exploring the adsorption and selective removal mechanism of target pollutants on the catalytic interface is an important research topic in the field of environmental sewage treatment. However, the molecular recognition based on the surface of single crystals is still unclear. Single crystal molecularly imprinted TiO2 (001-MI-TiO2) with a highly exposed {001} plane was prepared by a hydrothermal method to characteristically adsorb and degrade phenol. The kinetics of phenol oxidation on 001-MI-TiO2 was 12.93 times that of polycrystal nonimprinted TiO2. The phenol adsorption quantity of 001-MI-TiO2 was 1.68 times that of the polycrystal molecularly imprinted TiO2 (MI-TiO2). Compared with MI-TiO2, the significantly increased removal of phenol on 001-MI-TiO2 mainly attributed to the enhanced adsorption quantity and better photocatalytic performance. The recognition mechanism of phenol on the 001-MI-TiO2 during the adsorption process was studied using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), which indicated enhanced adsorption of phenol when compared with MI-TiO2. The recognition between the phenol molecule and the imprinted sites mainly relied on the hydrogen bond between the π bond of the benzene ring and the hydroxyl group on the surface of TiO2. Besides, the interferent ATR-FTIR results showed that the single crystal surface can significantly reduce noncharacteristic adsorption, indicating good selectivity for the targets. In addition, the degradation intermediates during the photocatalytic process were further analyzed by in situ infrared technology.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2022
·
IF 6.535
Xing Yuan,Chaohe Zheng,Zuwei Xu,Qinghua Yang,Tiantian Zhang,Xi Luo,Haibo Zhao
Photothermocatalytic oxidation is an environmentally-friendly, low-temperature, and high-efficient method to remove the air pollutant. Yet, the lack of active, inexpensive, and superior stability catalysts has greatly limited its extensive utilization. In this work, the effect of single-atom Pt loading on TiO 2 support has been theoretically and experimentally studied to improve photothermocatalytic performance for the toluene combustion through flame spray pyrolysis (FSP). Pt loading can play two crucial roles into TiO 2 optimization: (1) The low-valence Pt cation incorporated into TiO 2 lattice is dramatically responsible for the anatase-rutile transformation (ART) and formation of sufficient oxygen vacancies ; (2) Introducing the defect energy level and Pt-3d orbitals remarkably promote the charge separation efficiency of single-atom catalysts. Moreover, the existence of single-atom Pt nanoparticles can signally boost the activity of surface adsorbed and lattice oxygen, as well as substantially reduce the oxygen vacancy formation energy. Thus, the toluene removal under light irradiation reaches 90% conversion below 160 °C and is maximally 18 °C lower than that under only thermocatalytic oxidation. It is attributed to larger specific surface area (SSA), outstanding low-temperature reducibility, extremely dispersed hybrid PtO x , more surface active oxygen, and higher mobility of bulk oxygen. Interestingly, when the oxygen-fuel equivalent ratio φ distinctly increases by shifting precursor solvent from xylene to ethanol, the photothermocatalytic property of toluene can be remarkably enhanced on single-atom Pt catalysts. It is due to the higher Pt dispersion resulting from more intense burning and drastic turbulent mixing, as well as the superior ratio of the metallic Pt active sites originating from higher flame temperature. Eventually, the rate-determining step of C 7 H 8 combustion on Pt/TiO 2 and Cu/TiO 2 slab are all the C C bond fracture of maleic anhydride to form acetic anhydride species, with the energy barriers of 112.03 and 188.74 kJ/mol, respectively.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Linli Hou,Yonghai Song,Yingjie Xiao,Rong Wu,Li Wang
Fluorescent metal-organic frameworks (MOFs) have attracted wide attention in fluorescence detection. Herein, a novel sensing platform for highly selective and sensitive detection of Fe 3+ in aqueous solution was proposed based on 2,5-dihydroxyterephthalic acid (DOBDC)-Zn 2+ MOFs (ZnMOF-74). The as-prepared ZnMOF-74 exhibited uniform clavicorn nanostructures and high day-to-day stability in acidic aqueous solution (pH 4.0). Because of the special response of phenolic hydroxyl groups of DOBDC with Fe 3+ , the cation exchange between Fe 3+ and Zn 2+ occurred, which caused collapse of the skeleton and formed a blue weak-fluorescent iron(III)-phenol salt complex (Fe-DOBDC), which led to the effective fluorescence quenching of ZnMOF-74. ZnMOF-74 was used as a probe for detection of Fe 3+ under relatively acidic condition with a good linear range of 0.1–100 μM and a low detection limit of 40 nM. The fluorescence probe was also applied to determine Fe 3+ in real river water and human serum with good recovery and accuracy. This work provided a good Fe 3+ sensor based on ZnMOF-74 due to high affinity between phenolic hydroxyl group and Fe 3+ .
研究领域:
材料科学
·
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）