ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2016
·
IF 2.922
Yiying Zhang,Dongxiang Zhang,Kai Dong,Penghao Lv,Siping Pang,Chenghui Sun
The kinetics of the nitration reaction of 2,6,8,12-tetraacetyl-4,10-dinitro-2,4,6,8,10,12-hexaazaisowurtzitane (TADN) in HNO3–H2SO4 nitrating agent has been studied. The reaction network of the nitration reaction is constructed according to analysis of the experimental results. A kinetics model is introduced and the kinetics parameters are estimated by data fitting. Statistical analysis verifies that the kinetics model is in good agreement with the experimental data. Therefore, the reaction kinetics model can be applied to process analysis and scale-up of nitration of TADN to 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW).
研究领域:
化学动力学
·
有机化学
✓ 已验证
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2020
·
IF 4.872
Yongfei Gao,Zhicheng Xie,Jingxue Zhu,Honglei Cao,Jianguo Tan,Jianfeng Feng,Lin Zhu
Organisms are increasingly tolerant to metal toxicity in the natural ecosystems, which did not match the results of the environmental risk assessment (ERA) of metals based on toxicity data from organisms in the laboratory. Studies have described the effects of pre-exposure to metals on metal toxicity tolerance in terms of the toxicokinetic (TK) process; however, the toxicodynamic (TD) process may be more susceptible to metal pre-exposure. Therefore, to determine whether pre-exposure to low concentrations of silver (Ag) or cadmium (Cd) affects the metal TK and TD processes of zebrafish ( Danio rerio ) larvae, we investigated four TK–TD model parameters that control tolerance and sensitivity to metal toxicity on the survival. Our results showed that the killing rate ( k s ) of larvae exposed to high Cd concentrations was significantly lower following pre-exposure to 10 μg/L Cd than that of larvaenot pre-exposed. However, the k s for high Ag concentrations was significantly higher in zebrafish larvae following pre-exposure to 2 μg/L Ag than in larvae not pre-exposed. In other words, a one-day pre-exposure to 2 µg/L Ag rendered the larvae more sensitive to Ag during a subsequent 4-day exposure to higher Ag concentrations, whereas a one-day pre-exposure to 10 µg/L Cd rendered the larvae more tolerance to Cd during a subsequent 4-day exposure to higher Cd concentrations. Our results further the current understanding of toxic metal tolerance mechanisms, both in TK and TD processes, and they will guide future laboratory studies to assess actual pre-exposure scenarios that occur in natural environments. Thus, our study can help reduce uncertainty in testing and improve ecological management concerning metal risk assessments.
研究领域:
生态毒理学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2024
·Vol. 160
·期 16
·
IF 3.1
Du Luchao,An Jie,Katayama Tetsuro,Duan Menghan,Shi XiaoPing,Wang Yunpeng,Furube Akihiro
In recent years, all-inorganic perovskite materials have become an ideal choice for new thin film solar cells due to their excellent photophysical properties and have become a research hotspot. Studying the ultrafast dynamics of photo-generated carriers is of great significance for further improving the performance of such devices. In this work, we focus on the transient dynamic process of CsPbBr 3 /TiO 2 composite systems with different Mn 2+ doping contents using femtosecond transient absorption spectroscopy technology. We used singular value decomposition and global fitting to analyze the transient absorption spectra and obtained three components, which are classified as hot carrier cooling, charge transfer, and charge recombination processes, respectively. We found that the doping concentration of Mn 2+ has an impact on all three processes. We think that the following two factors are responsible: one is the density of defect states and the other is the bandgap width of perovskite. As the concentration of doped Mn 2+ increases, the charge transfer time constant shows a trend of initially increasing, followed by a subsequent decrease, reaching a turning point. This indicates that an appropriate amount of Mn 2+ doping can effectively improve the photoelectric performance of solar cell systems. We proposed a possible charge transfer mechanism model and further elucidated the microscopic mechanism of the effect of Mn 2+ doping on the interface charge transfer process of the CsPbBr 3 /TiO 2 solar cell system.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2019
·
IF 5.714
Yan Zhang,Jianfeng Feng,Yongfei Gao,Xinyong Liu,Liang Qu,Lin Zhu
Accurately predicting the accumulation and toxicity of metals in organisms is a challenging work in ecotoxicology . Here, we developed and validated a physiologically based toxicokinetic and toxicodynamic (PBTK-TD) model for adult zebrafish exposed to Cd and Pb. The model included the gill, liver, intestine, gonad, carcass, and brain, which were linked by blood circulation in the PBTK process and by dynamic relationships between the target organ concentrations and mortality in the TD process. Results showed that the PBTK sub-model can accurately describe and predict the uptake, distribution and disposition kinetics of Cd and Pb in zebrafish. The exchange rates and the accumulation of the metals in the organs were significantly different. For Cd, the highest exchange rate was between blood and liver, and the greatest accumulation of Cd occurred in the liver. For Pb, the greatest accumulation occurred in the gill. The TD sub-model further indicated that metal concentrations in the gill may effectively act as more suitable indicator of Cd and Pb toxic effect than whole body or other organs. The proposed PBTK-TD model is helpful to understanding the fundamental processes by which zebrafish regulate the uptake and disposition of metal and to quantitatively predicting metal toxicity.
研究领域:
生态毒理学
·
环境科学
✓ 已验证
DOI
高影响因子
AQUA-Water Infrastructure Ecosystems and Society
·
2025
·Vol. 74
·期 2
·159-174
·
IF 2.3
Sun Yao,Duan Runbin,Li Yuzhen,Lu Xinyu,Gao Jiangqi,Zhu Bingzi
View large Download slide View large Download slide Close modal The adsorption and desorption kinetics of antibiotics on natural soils in various aqueous solutions are crucial for understanding their occurrence, transport, and bioavailability in the environment. This study investigated the adsorption and desorption kinetics of three fluoroquinolone carboxylic acids (FQCAs), namely ciprofloxacin, ofloxacin, and levofloxacin, on red clay soil using batch experiments conducted with pure water, treated wastewater effluent, lake water, river water, and stormwater runoff. The research identified pH, electrical conductivity (EC), and organic suspended solids (OSS) as primary water quality parameters that negatively impacted the adsorbed and desorbed masses of FQCAs at equilibrium. Higher pH, EC, and OSS significantly reduced the initial adsorption rates and adsorption efficiencies and promoted initial desorption and desorption efficiencies. FQCAs adsorption processes exhibited a rapid phase mainly governed by external mass transfer and a slower phase primarily limited by intra-particle diffusion, both influenced by boundary layer effects. The adsorption removal of FQCA's ranged from 65.82 to 98.33%, but desorption was only 1.35–3.09%. These findings highlight the potential of red clay soil as an effective and environmentally friendly adsorbent for mitigating FQCA pollution. Future research should focus on investigating FQCA degradation after adsorption in soil and their transport dynamics under diverse field conditions. Measured q e and average adsorption rate over the first 20 s showed strong negative correlations with pH (pH > 7), electrical conductivity, and organic suspended solids. The q e of ciprofloxacin, ofloxacin, and levofloxacin was higher in pure water (PW) and lower in treated wastewater and lake water. Both adsorption and desorption exhibited a fast phase and a slower phase. High adsorption capacities and low desorption were observed. Lower desorption was observed in PW.
研究领域:
环境科学
·
土壤学
·
污染控制
✓ 已验证
产品关联
DOI
高影响因子
MOLECULAR PHYSICS
·
2024
·
IF 1.6
Gang Wang,Lina Ding,Yang Liu,Yonggang Yang,Yufang Liu
2-(2'-Hydroxyphenyl) benzimidazole (HBI) and its derivatives are widely used in fluorescent probes, luminescent materials, and other sensing materials. In this study, the time-resolved fluorescence behaviour, and excited-state dynamics of HBI and 2-phenyl-1H-benzo[d]imidazole (BI) were studied using femtosecond transient absorption (fs-TA) spectroscopy. The stimulated emission (SE) and excited-state absorption signals of the BI molecule were located at 355 and 437 nm, respectively. For HBI, these signals were located at 475 and 384 nm, respectively. The SE signals of the BI and HBI molecules in their fs-TA spectra were consistent with the experimental short-wave fluorescence at 340 and 460 nm, respectively, in the steady-state spectra. The long-wave signal of HBI at 475 nm indicates its dual fluorescence, which may be caused by proton transfer or conformational torsion after photoexcitation. The large theoretical energy barrier of 40.97 kcal/mol in first excited (S1) state of HBI excludes the latter hypothesis. Additionally, the small energy barrier (1.88 kcal/mol) in the S1 state confirmed the excited-state intramolecular proton transfer (ESIPT). This indicates that ESIPT induces dual fluorescence behaviour of the HBI molecule, which was also demonstrated by the infrared spectra, theoretical fluorescence peaks, and molecular orbitals.
研究领域:
光化学
·
物理化学
·
理论化学
✓ 已验证
DOI
高影响因子
PHYSICS OF FLUIDS
·
2024
·Vol. 36
·期 7
·
IF 4.1
Li Mofan,Yang Donghai,Chen Conglei,Lv Shiyi,Miao Jiaxu,He Limin
Unconventional crude oil and offshore oilfield extraction often lead to the formation of stable oil–water emulsions with high mineralization, posing significant threats to environmental protection and pipeline transportation safety. Electric–magnetic coupling separation technology represents a novel approach to emulsion breaking, offering superior separation performance compared to the conventional electric coalescence methods. However, its underlying mechanism remains elusive. To address this gap, this study comparatively investigates the liquid bridge dynamic during droplet coalescence under a single electric field and electric–magnetic coupling field conditions. High-speed camera experiments reveal that synchronized coupled magnetic fields suppress the extension of liquid bridges, with this suppression effect being augmented by increasing ion concentration and electric field strength. Nevertheless, the enhancement of the inhibition effect is not pronounced at electric field strengths up to 224 kV m −1 and within the frequency range of 50–500 Hz. Molecular dynamics simulations demonstrate that the mutual repulsion effect between water molecules and the hydration effect between water molecules and ions are intensified under the coupling field. Finally, by integrating flow field and velocity analyses, a mechanism is proposed to elucidate the hysteresis in the evolution of liquid bridges, attributed to the mutual repulsion of water molecules hydrated by deflecting ions and convecting water molecules in the coupled field. This study offers valuable insights for the development of electric–magnetic coupling separation techniques, with implications for mitigating oil contamination and facilitating dewatering treatments.
研究领域:
石油工程
·
环境科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2017
·
IF 2.603
Ling-Li Wang,Dong-Sheng Zhao,Wei Shi,Zhuo-Qing Li,Zi-Tian Wu,Ping Li,Hui-Jun Li
It is vital to monitor the holistic toxicokinetics of toxic Chinese herbal medicines (CHMs) for safety. Although an integrated strategy based on the area under the curve (AUC) has been proposed to characterize the pharmacokinetic/toxicokinetic properties of CHMs, improvement is still needed. This study attempted to use 50% inhibitory concentration (IC 50 ) as weighting coefficient to investigate holistic toxicokinetics of the major diosbulbins i.e. diosbulbin A (DA), diosbulbin B (DB), and diosbulbin C (DC) after oral administration of Dioscorea bulbifera rhizome (DBR) extract. Firstly, the cytotoxicities of the three diosbulbins on human hepatic L02 cells were evaluated and the IC 50 values were calculated. Then, integrated toxicokinetics of multiple diosbulbins based on AUC and IC 50 were determined. Finally, correlations between integrated plasma concentrations and hepatic injury biomarkers including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bile acid (TBA) were analyzed. As a result, integrated plasma concentrations were correlated well with TBA and the correlation between TBA and IC 50 -weighting integrated plasma concentrations was better than that of AUC-weighting integrated plasma concentrations. In conclusion, the newly developed IC 50 -weighting method is expected to generate more reasonable integrated toxicokinetic parameters, which will help to guide the safe usage of DBR in clinical settings.
研究领域:
中药学
·
毒理学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Yan Liu,Chenggang Han,Tao Lu,Yi Liu,Hao Chen,Can Yang,Yanbei Tu,Yanfang Li
Xanthine oxidase (XO) plays a vital role in inducing hyperuricemia and increasing the level of superoxide free radicals in blood, and is proved as an important target for gout. Chrysoeriol (CHE) is a natural flavone with potent XO inhibitory activity (IC 50 = 2.487 ± 0.213 μM), however, the mechanism of interaction is still unclear. Therefore, a comprehensive analysis of the interaction between CHE and XO was accomplished by enzyme kinetics , isothermal titration calorimetry (ITC), multi-spectroscopic methods, molecular simulation and ADMET. The results showed that CHE acted as a rapid reversible and competitive-type XO inhibitor and its binding to XO was driven by hydrogen bonding and hydrophobic interaction. Moreover, CHE exhibited a strong fluorescence quenching effect through a static quenching procedure and induced conformational changes of XO. Its binding pattern with XO was revealed by docking study and the binding affinity to XO was enhanced by the interactions with key amino acid residues in the active pocket of XO. Further, CHE showed good stability and pharmacokinetic behavior properties in molecule dynamic simulation and ADMET prediction. Overall, this study shed some light on the mechanism of interaction between CHE and XO, also provided some valuable information concerning the future therapeutic application of CHE as natural XO inhibitor.
研究领域:
生物化学
·
药物化学
·
计算生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Qiang Ma,Lijun Jiang,Bowen Yang,Bowen Xu,Qingyuan Wang,Qihong Wu,Ping Ning,Yingjie Zhang,Jin Huang,Jiming Hao
Gaseous thallium (Tl) pollution events, primarily caused by non-ferrous mineral refineries and fossil fuel combustion, have increased over the past few decades. To prevent gaseous Tl distribution from flue gas, MnO2/CeO2@HKUST-1 (MCH) was synthesized and found to achieve a gaseous Tl(I) removal level of up to 90% at 423 K, a weight hourly space velocity (WHSV) of 2000 h–1/mL with an Mn dose of 10%, maintained over 10 h. The best Mn/Ce ratio was found to be 9:1. To further investigate surface kinetic behavior, four commonly used kinetic models were applied, including the Eley–Rideal (ER) model, Langmuir–Hinshelwood (LH) model, Mars–van Krevelen (MVK) model, and pseudo-first-order (PFO) model. While the ER and LH models had the slightest deviation, the MVK model was the most reliable. The CatMAP software was also used to match the simulation deviation. This work demonstrated the Tl removal mechanism and provided insights into the accuracy of kinetic models on minor-radius heavy metal. Thus, this research may help promote the design of reactors, heavy metal removal rates, and flue gas purification technology selection.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Laser & Photonics Reviews
·
2023
·Vol. 17
·期 12
·2300533
·
IF 11
Peipei Ma,Lihe Yan,Jinhai Si,Tianyu Huo,Zhenqiang Huang,Wenjiang Tan,Jin Xu,Xun Hou
Single-crystal halide perovskites are among the most promising semiconductor candidates for highly efficient optoelectronic devices due to their higher stability against moisture and light radiation and lower trap density than their polycrystalline counterparts. In this work, single-crystal MAPbBr 3 microcavities with controllable geometries and sizes are fabricated using a template-limited method combined with an anti-solvent diffusion growth method. The single-crystal microcavities emit lasers around 550 nm under femtosecond laser excitation, with a lasing threshold of ≈35 µJ cm −2 and a quality factor of 1135, as well as excellent long-term operation stability. The temporal-spatial evolution of the lasing process in an individual microcavity is achieved by the microscopic optical Kerr-gating technique. The temporal behaviors including pulse duration and build-up time, emission spectra shift, and lasing mode evolution as a function of pump fluence are unveiled, and the complex relationship between the light-induced carrier dynamics and lasing properties is clarified. Spatial heterogeneous lasing dynamics are also observed in an individual microdisk, which is attributed to the non-uniform optical losses and carrier densities driven by structural imperfections. This study can provide a fabrication strategy for perovskite on-chip optoelectronic devices, as well as a deeper understanding of the carrier-density-driven lasing dynamics in microcavities.
研究领域:
材料科学
·
光学
·
半导体物理
✓ 已验证
DOI
高影响因子
Nature Nanotechnology
·
2025
·
IF 34.9
Wang Dong,Ji Lei,Li You,Xu Meng,Wang Hao,Brovelli Sergio,Qiao Zeng-Ying,Zhang Jiatao,Li Yadong
Chemodynamic therapy and sonodynamic therapy are two promising tumour therapeutic strategies. However, lack of highly effective sonosensitizers and control over chemodynamic therapy limit their application. Here we synthesize silver-doped zinc selenide quantum dots with atomically dispersed superficial Fe and show that they act as efficient sonosensitizers, catalysers and immunoreagents. Surface modification with an in situ self-assembly peptide drives accumulation in tumours. Superficial Fe III remains stable and converts to Fe II only under ultrasonic processing, reverting to Fe III upon ultrasound cessation. Under ultrasound stimulation, superficial Fe undergoes valence change with concomitant amelioration of the hypoxic tumour microenvironment and production of sonodynamic therapy-beneficial hydroxyl radicals. Furthermore, silver doping suppressed nonradiative recombination of excitons, leading to improved production of singlet oxygen. Meanwhile, selenium promotes robust systemic immune responses for the inhibition of tumour metastases. This nano-platform allows control of valence switching of atomically dispersed catalysts, representing an effective tool for chemodynamic/sonodynamic/immunotherapy.
研究领域:
生物医学
·
纳米技术
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）