FORENSIC SCIENCE INTERNATIONAL
·
2014
·
IF 2.115
Ting Wang,Baohua Shen,Yan Shi,Ping Xiang,Zhiguo Yu
Methamphetamine (MA) and amphetamine (AM) are widely abused drugs. Differentiation of MA and/or AM abuse from therapeutic ingestion of MA and/or AM or one of their precursor drugs is therefore of relevance in clinical and forensic toxicology. The aim of the study was to develop a simple, rapid, and accurate method for the chiral separation and determination of R / S -MA and R / S -AM in urine using liquid chromatography electrospray ionization tandem mass spectrometry operating in the positive ion multiple-reaction monitoring (MRM) mode. 20 μL of urine was diluted 500 times and 20 μL was injected. The chromatographic system consisted of a Chirobiotic™ V2 column (2.1 mm × 250 mm, 5 μm), and the mobile phase was methanol containing 0.1% (v/v) glacial acetic acid and 0.02% (v/v) ammonium hydroxide. The method was fully validated through assessments of its linearity (0.05–50.00 mg/L, r 2 > 0.994 for all analytes), and LOQ (0.05 mg/L for all analytes). No matrix effect was observed. The method was successfully applied to 86 urine samples from suspected MA abusers. Only the S -isomers of MA and AM were detected in 72 samples. The concentrations of R -MA ranged from below the LOQ to 13.76 mg/L in 14 urine samples with both enantiomers of MA and/or AM. Pure S -MA is the most common found analyte in urine and principally used by abusers.
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高影响因子
HIGH PERFORMANCE POLYMERS
·
2014
·
IF 1.09
Jiangtao Liu,Guofei Chen,Xingzhong Fang
A series of isomeric poly(thioether ether imide)s (PTEIs) containing both thioether and ether linkages were prepared by aromatic nucleophilic substitution reaction of isomeric bis(chlorophthalimide)s (BCPIs) with bis(4-mercaptophenyl) ether (BMPE). The inherent viscosities of synthesized polymers were found in the range of 0.41–0.86 dL g−1 in N-methyl-2-pyrrolidone at 30°C. The glass transition temperature (Tg) of the isomeric PTEIs were 210–242°C and increased by increasing the content of 3-substituted phthalimide unit in the polymer backbone. The 5% weight loss temperature values reached up to 525–539°C under nitrogen and 523–534°C in air atmospheres, respectively, which indicated this kind of polyimide possessed excellent thermal stability. Flexible films could be cast from the polymer solution. The PTEI films exhibited moderate mechanical properties with tensile strengths of 106–127 MPa, elongations at break of 8.6–11.5%, and tensile moduli of 2.2–2.8 GPa, respectively. Dynamic mechanical thermal analysis results illustrated that the storage moduli (E′) of PTEI (a–e) almost completely maintained at about 2.3 GPa before reaching the corresponding Tg. It is noted that the minimum melt viscosity of isomeric PTEIs (a′–e′) decreased by increasing the content of unsymmetrical 3,4′-substituted phthalimide unit in the polymer main chain.
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JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2021
·Vol. 54
·期 40
·405101
·
IF 3.207
Wei-song Liu,Hui Yang,Lan Li
The heterostructure device based on polyvinylidene fluoride (PVDF)/MoS2 films was succesfully prepared and showed a good hysteresis feature with a unique resistive switching perpromance, where the logarithmic I–V curve looks like a butterfly. The on-off ratio for the resistive switching in the device based on PVDF/MoS2 films reaches 2.5 × 102 and the resistive switching happens at −0.9 V and −4.9 V for a half loop. The influence of the introduction of MoS2 and ferroelectric PVDF film was also studied and compared to a device based on a single film. The underlying physical mechanism for the unique resistive transition was attributed to the polarization field from the ferroelectric polymer PVDF and the S vacancies in MoS2.
研究领域:
材料科学
·
电子工程
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Chemical Biology & Drug Design
·
2017
·Vol. 90
·期 2
·167-174
·
IF 2.396
Wei Shi,Miaobo Pan,Hao Qiang,Qianqian Qiu,Wenlong Huang,Haiyan Lin,Hai Qian,Liang Ge
A novel mitochondria-targeting fluorescent probe compound S-N 3 for hydrogen sulfide (H 2 S) in living cells has been designed and synthesized in this study. This article contained the chemosynthesis and some studies on bioactivity of the target compound in living cells. Compound S-N 3 is easy to synthesize and can remain stable under the effect of pH, system and photostability. In addition, it shows low cytotoxicity in cell imaging. And it can react with H 2 S highly selective in PBS or FBS solution, which would cause the obvious increase in fluorescence intensity. Therefore, the low-cost detection method for H 2 S is allowed for monitoring the quantity of H 2 S existed in the mitochondria.
研究领域:
生物化学
·
分子生物学
·
细胞生物学
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高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2018
·Vol. 33
·期 5
·1176-1185
·
IF 0.524
Lu Guosen,Deng Min,Mo Liwu
C3S pastes containing 0%, 5%, 10%, and 15% nano-SiO2 mixed with de-ionized water and alkali solutions were prepared. When C3S was completely hydrated, the pastes were ground into powders with a particle size less than 80 μm. Adsorption and desorption characteristics of alkali ions adsorbed by C 3 S-nano SiO 2 pastes mixed with de-ionized water immersed in alkali solutions and those in C 3 S-nano SiO 2 pastes mixed with alkali solutions, were investigated. Meawhile, the adsorption mechanisms of alkali ions were discussed. Results showed that the contents of alkali ions adsorbed by C 3 S-nano SiO 2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO 2 and/or the initial alkali concentrations. In C 3 S-nano SiO 2 pastes mixed with de-ionized water, each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration. No obvious difference between the adsorption capacity of a given paste for K + and Na + was observed. Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste, and charge compensation of C-S-H gel, mainly by electrostatic interactions. In C 3 S-nano SiO 2 pastes mixed with alkali solutions, alkali ions may enter the structure of C-S-H gel to replace a part of Ca 2+ in the interlayer. This assumption is supported by the structural characterization of C-S-H gel using 29 Si MAS NMR.
研究领域:
材料科学
·
化学工程
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Chemical Engineering Journal Advances
·
2021
·
IF 0
Xiaomiao He,Saishuai Bai,Jizhou Jiang,Wee-Jun Ong,Jiahe Peng,Zhiguo Xiong,Guodong Liao,Jing Zou,Neng Li
Excitonic effects induced via Coulomb interactions and an appropriate interfacial contact of electrode modified materials play crucial roles in transfer/separation of interfacial charge carriers during the electrochemical sensing process. Herein, an oxygen vacancy (V o ) mediated step-scheme (S-scheme) heterojunction of WO 2.9 /g-C 3 N 4 was fabricated by electrostatic self-assembly of high-purity commercial WO 2.9 nanoparticles and ultrathin g-C 3 N 4 nanosheets, where g-C 3 N 4 nanosheets were prepared via polymerization followed ultrasonic-assisted exfoliation. The fabricated V o -S-scheme WO 2.9 /g-C 3 N 4 heterojunction-based sensor exhibited superior electrochemical performance for detecting environmental hormone 4-nitrophenol (4-NP). Due to the introduction of V o , an increased free-charge-carriers, a built-in electric field and a high adsorption energy are generated at the heterojunction interface, which all can significantly improve the sensitivity of this proposed sensor. It also showed good reproducibility, high accuracy, good recovery, and strong feasibility for 4-NP detection in real samples. This work not only conduces significantly to understanding the defective structures and S-scheme heterojunctions, but also provides new insights into designing and constructing novel efficient electrochemical sensors.
研究领域:
材料科学
·
环境科学
·
分析化学
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DOI
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Ping Su,Shikai Wang,Dong Zhang,Tengteng Liang,Huaihao Zhao,Nan Yang,Dafeng Zhang,Peiqing Cai,Xipeng Pu
Rational design of photocatalysts with photothermal effect to maximize light utilization is pivotal in achieving superior photocatalytic efficiency. In this work, by coating Cd 0.9 Zn 0.1 S (CZS) nanorods on hollow FeNi 2 S 4 (FNS) microspheres with photothermal effect, a novel FeNi 2 S 4 @Cd 0.9 Zn 0.1 S (FNS@CZS) Step-scheme (S-scheme) heterojunction photocatalyst was constructed for efficient photothermal-assisted hydrogen (H 2 ) evolution via simultaneously employing light and thermal energy. The hollow structure of FNS microsphere not only provides abundant reactive sites but also serves as a supportive substrate for CZS nanorods, effectively inhibiting their agglomeration. And the unique hollow structure of FNS allows for multiple reflections and refractions of visible light, enhancing the local temperature of the photocatalyst. This effectively minimizes thermal losses within the composite system, thereby enhancing the efficiency of light energy utilization. Furthermore, the formation of the S-scheme heterojunction facilitates the efficient separation of photogenerated charge carriers and enhances the activity of redox reactions, thereby boosting the overall photocatalytic activity. Experimental results reveal that the H 2 production rate of the FNS@CZS heterojunction reaches 12.9 mmol·g −1 ·h −1 , which is 25.1 times higher than that of pristine CZS. By controlling the experimental temperature, the impact of the photothermal effect on the photocatalytic H 2 production rate has been clarified. According to relevant evidence from infrared thermography and DFT calculations, comprehensive analyses and discussions were conducted on the photothermal effect and S-scheme charge transfer mechanisms. This study offers guidance on designing photothermal-enhanced photocatalysts to achieve satisfactory H 2 production activity.
研究领域:
材料科学
·
能源化学
·
环境科学
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高影响因子
ChemistryOpen
·
2019
·Vol. 8
·期 5
·643-649
·
IF 2.205
Boyu Du,Bingyang Liu,Xing Wang,Jinghui Zhou
Graphical Lignin explained : Phosphotungstic acid polyoxometalate catalyst showed high activity in the selective depolymerization of three types of lignin samples to phenolic monomers, and the impact of the structure differences on the distribution of phenolic monomers were well studied. Emphasis was placed on changing the types of lignin samples to control the secondary depolymerization of methoxy groups and greatly improving the selectivity of phenolic monomers. Herein we studied the chemical structure of different types of lignin samples and the potential to prepare phenolic monomers was illustrated by phosphotungstic acid catalysts. Different types of H/G/S lignin components had different structures. The lignin extracted from poplar had the highest molecular weight and β-O-4 aryl ether contents, followed by pine and straw lignin samples. After depolymerization by PTA catalyst, the yields of phenolic monomers detected was 8.06 wt % (poplar), 5.44 wt % (pine) and 4.52 wt % (straw), respectively. Further, the ratios of H/G/S in the phenol monomers were also different, indicating that the S, G and H types structural units were continuously transformed with each other during the reaction. In our study, the change in the types of lignin samples resulted into an improvement of the distribution of phenolic products, and also the selectivity of phenolic monomers significantly.
研究领域:
化学工程
·
可再生资源
·
催化科学
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高影响因子
TETRAHEDRON-ASYMMETRY
·
2014
·
IF 2.165
Rui-Jie Chen,Gao-Wei Zheng,Yan Ni,Bu-Bing Zeng,Jian-He Xu
A new NADH-dependent carbonyl reductase Rh CR capable of efficiently reducing the ε-ketoester ethyl 8-chloro-6-oxooctanoate (ECOO) to give ethyl ( S )-8-chloro-6-hydroxyoctanoate [( S )-ECHO], an important chiral precursor for the synthesis of ( R )-α-lipoic acid, was identified from Rhodococcus sp. ECU1014. Using recombinant Escherichia coli cells expressing Rh CR and glucose dehydrogenase used for the regeneration of cofactor, 440 g L −1 (2 M) of ECOO were stoichiometrically converted to ( S )-ECHO in a space–time yield of 1580 g L −1 d −1 without the external addition of any expensive cofactor.
研究领域:
生物催化
·
酶工程
·
合成化学
·
生物技术
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高影响因子
INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Zhi-Hui Shi,Mei Yang,Wen-Dong Yao,Wenlong Liu,Sheng-Ping Guo
Two chalcogenophosphates, SnPS2.86Se0.14 (1) and SnPSe3 (2), are isostructural and crystallize in the monoclinic noncentrosymmetric space group Pn. Their three-dimensional (3D) structures are constructed by [Sn(1)Q8] hendecahedra and [Sn(2)Q8] dodecahedra by sharing Q vertices and edges, leaving cavities for isolated [P2Q6] (Q = S/Se, Se) dimers. A second-harmonic-generation (SHG) measurement indicates that 1 is phase-matchable with a response of approximately 1.2 × AgGaS2 (AGS), which is verified by the theoretical calculation result. The powder sample of 1 exhibits a high laser-induced damage threshold of 3.9 × AGS. For comparison, the known SnPS3 (3) was also synthesized and evaluated using the same method. The chemical composition–NLO performance relationship of 1–3 is also discussed. Dipole moment calculation results suggest that [SnQ8] polyhedra make the main contribution to their excellent nonlinear optical (NLO) performance.
研究领域:
材料科学
·
非线性光学
·
晶体学
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高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Shasha Tang,Haidan Lin,Kai Dong,Jun Zhang,Chengji Zhao
The waste and desertion of petroleum-based epoxy resins have attracted increasing concerns on the damage and pollution to the environment because they are difficult to reprocess and reuse after curing. Once broken or injured, the recovery or degradation of composites is a tough challenge owing to their permanently cross-linked networks. In this paper, a novel guaiacol-based epoxy resin (BGF-EP) was prepared from renewable resources instead of conventional petroleum-based bisphenol A, curing with 4-aminophenyl disulfide (AFD). The epoxy vitrimer BGF-EP-AFD had appreciable thermal stability ( T g :143 °C, T d5% :295 °C), sufficient mechanical properties (tensile strength:55.54 MPa, elongation at break:12.23%) and stress relax from 300 min at 130 °C to 27.5 s at 200 °C. And the vitrimer could be reprocessed into a complete film. More excitingly, an efficient strategy was proposed to dissolve the cured resin and recycle its carbon fiber reinforced composites in a closed loop in an appropriate mixing solution (50%DMF/50%β-ME) at room temperature. The recovered carbon fibers are not altered and remain intact for the next utilization as confirmed by SEM. This work contributes the development of guaiacol-based renewable functional materials and provides a feasible and economical way to recycle and reprocess the carbon fiber reinforced epoxy composites.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Yuxin Liu,Tianye Wang,Ningning Song,Quanying Wang,Yuqing Wu,Ying Zhang,Hongwen Yu
An efficient, simple, and inexpensive N, S-co-doped hydrochar (SNHC) was synthesized from waste straw by a one-pot hydrothermal process without calcination for the removal of Cr(VI). SNHC demonstrated excellent adsorption performance for Cr(VI) and high stability, achieving a high capacity of 171.33 mg/g (293 K, pH 2) and a capacity retention of 82.73 % after five cycles. The adsorption behavior was determined as a multilayer adsorption process based on chemisorption according to the simulation the results of Freundlich adsorption isotherms and pseudo-second-order models. The characterization of SNHC revealed that graphite N and thiophene S formed by the material were the effective active sites, functioning as electron donors to contribute a significant amount of electrons to reduce Cr(VI) to Cr(III). Therefore, next to electrostatic adsorption and complexation, the synergistic reduction of Cr(VI) by graphite N and thiophene S was the main mechanism for Cr(VI) removal. Additionally, density functional theory calculations indicated a low adsorption energy of thiophene S, which increased the attractive interaction between SNHC and Cr(VI) and played the most important role in reducing Cr(VI). The mechanism of the effect of graphite N and thiophene S on Cr(VI) removal not only offered a comprehensive perspective on the role of N, S co-doped mediation in hydrochar but also provided the basic theory for its practical application.
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高影响因子
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