Science China-Chemistry
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2017
·Vol. 61
·期 3
·276-280
·
IF 4.132
Qi Guangyu,Wang Kai,Xiao Guanjun,Zou Bo
Pressure, as a thermodynamic parameter, provides an appropriate method to detect weak intermolecular interactions. The C–H···H–B dihydrogen bond is so weak that the experimental evidence of this interaction is still limited. A combination of in situ high pressure Raman spectra and angle-dispersive X-ray diffraction (ADXRD) experiments was utilized to explore the dihydrogen bonds in dimethylamine borane (DMAB). Both Raman and ADXRD measurements suggested that the crystal structure of DMAB is stable in the pressure region from 1 atm (1 atm=1.01325×10 5 Pa) to 0.54 GPa. The red shift of CH stretching and CH 3 distortion modes gave strong evidence for the existence of C–H···H–B dihydrogen bonds. Further analysis of Raman spectra and Hirshfeld surface confirmed our proposal. This work provided a deeper understanding of dihydrogen bonds. And we wish that high pressure could be applied to identify other unconfirmed hydrogen or dihydrogen bond.
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MICROCHIMICA ACTA
·
2017
·Vol. 185
·期 1
·1-9
·
IF 4.58
Lu Simin,Zhang Xiao,Chen Ling,Yang Ping
A colorimetric method is described for the determination of ferrous ion (Fe 2+ ) with high sensitivity and selectivity. The method is based on catalytic etching of gold nanorod (NR). In an acid condition, Fe 2+ reacts with H 2 O 2 to produce superoxide radical (O 2
•− ) that etches gold NRs from the low energy surface along the longitudinal direction preferentially. As a result, the changes in the absorption spectrum and color of gold NR can be measured and also can be detected visually. Under the optimal conditions, the assay has very low detection limit (13.5 nM) and a linear response in a concentration range of 75 to 1 μM. The method was applied to the determination of Fe 2+ in spiked samples of fetal bovine serum and also transferred to a kind of test stripe for use in fast practical applications. A unique colorimetric sensing method is demonstrated for the colorimetric detection of Fe 2+ , again based on the oxidation of gold nanorods which leads to the blue-shift of the absorption.
A unique colorimetric sensing method was shown for the colorimetric detection of Fe 2+ . Fe 2+ reacts with H 2 O 2 to generate superoxide radical that oxidize gold nanorods. This leads to a color change from blue-green to pink.
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MICROCHIMICA ACTA
·
2017
·Vol. 185
·期 1
·1-7
·
IF 4.58
Wang Jun,Ma Kui,Yin Huanshun,Zhou Yunlei,Ai Shiyun
An aptamer based method is described for the electrochemical determination of ampicillin. It is based on the use of DNA aptamer, DNA functionalized gold nanoparticles (DNA-AuNPs), and single-stranded DNA binding protein (ssDNA-BP). When the aptamer hybridizes with the target DNA on the AuNPs, the ssDNA-BP is captured on the electrode surface via its specific interaction with ss-DNA. This results in a decreased electrochemical signal of the redox probe Fe(CN) 6
3− which is measured best at a voltage of 0.188 mV (vs. reference electrode). In the presence of ampicillin, the formation of aptamer-ampicillin conjugate blocks the further immobilization of DNA-AuNPs and ssDNA-BP, and this leads to an increased response. The method has a linear reposne that convers the 1 pM to 5 nM ampicillin concentration range, with a 0.38 pM detection limit (at an S/N ratio of 3). The assay is selective, stable and reproducible. It was applied to the determination of ampicillin in spiked milk samples where it gave recoveries ranging from 95.5 to 105.5%.
Schematic of a simple and sensitive electrochemical apta-biosensor for ampicillin detection. It is based on the use of gold nanoparticles (AuNPs), DNA aptamer, DNA functionalized AuNPs (DNA-AuNPs), and single-strand DNA binding protein (SSBP).
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CHROMATOGRAPHIA
·
2018
·Vol. 81
·期 4
·657-667
·
IF 1.401
Yu Guo-Wei,Cheng Qiang,Nie Jing,Wang Xia-Jun,Wang Peng,Li Zu-Guang,Lee Maw-Rong
Abstract Deep eutectic solvent has been gaining much attention in recent years due to its various novel properties. The present study develops a novel microwave-assisted hydrodistillation method based on pretreatment using deep eutectic solvent, for the extraction of essential oil (EO) from dry fruits of Amomum kravanh , Amomum tsaoko, and Amomum villosum , respectively. The process is optimized by single-factor experiments taking the improvement in the essential oil yield of A. kravanh as the target. The results indicate that using the reaction product of choline chloride and ethylene glycol as the deep eutectic solvent with 7:1 of mass ratio to fruit powder, the optimal conditions are (1) pretreatment stage: 500 W of microwave power, 50 °C of temperature, and 7 min of duration; (2) fast heating stage: 600 W of microwave power, 110 °C of temperature, and 5 min of duration; (3) hydrodistillation stage: 300 W of microwave power, 110 °C of temperature, and 30 min of duration. Under these conditions, the EO yields of A. kravanh , A. tsaoko, and A. villosum are 3.64, 2.16, and 1.62%, respectively. The EOs are analyzed by gas chromatography–mass spectrometry, with totally 63 compounds identified. In most cases, the new method brings about more identified compounds than the traditional methods. Moreover, the relative contents of hydrocarbons in most essential oils are improved by applying the new method. Thus, the approach based on deep eutectic solvent has been proved superior in the enhancement of essential oil production. Graphical abstract
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Parasites & Vectors
·
2018
·Vol. 11
·期 1
·1-9
·
IF 3.163
Yin Jianhai,Liu Congshan,Shen Yujuan,Zhang Haobing,Cao Jianping
Background Cystic echinococcosis is a global public health problem; however, the drugs (albendazole and mebendazole) currently recommended by WHO for its treatment, have limited efficacy. Therefore, novel drugs are required to provide more choices for the treatment of this disease. Methods The anthelmintic effects of ursolic acid (UA) were tested on Echinococcus granulosus protoscoleces, germinal cells and metacestodes in vitro. The in vivo efficacy of UA was investigated in mice following secondary infection with E. granulosus . Furthermore, the corresponding ultrastructural damage induced by UA was evaluated by electron microscopy. Results In vitro, 45.95 ± 5.30% of protoscoleces were killed by UA at 40 μg/ml, while the growth of more than 90% of germinal cells was inhibited by UA at 10 to 40 μg/ml. The same effect was observed in metacestodes 7 days after treatment with UA at 10, 20 and 40 μg/ml, and more than 50% of metacestodes showed loss of integrity at the end of the experiment. In vivo, metacestode weight was significantly reduced following oral administration of UA at 200 and 100 mg/kg (39.5 and 38.3%, respectively). Additionally, ultrastructural damage, such as alternations in germinal cell morphology and formation of vacuoles and lipid granules were observed in parasites treated with UA in vitro, while detachment of the germinal layer from the laminated layer was also seen in metacestodes in vivo. Conclusions UA was demonstrated to exert parasiticidal activity against E. granulosus in vitro and in vivo, thus implicating UA as a potential anti-echinococcosis agent.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2025
·
IF 3.8
Guo Mengyue,Ke Tongwei,Zhang Huiru,Zhang Jing,Qin Jia’an,Ruan Haonan,Tian Jiao,He Chunjiao,Luo Yawen,Qin Xuhua,Luo Jiaoyang,Yang Meihua
Thiamethoxam is one of the top three neonicotinoids found in the environment and in food. The widespread use of thiamethoxam in medicinal and edible herbs threatens their safe use. Therefore, it is particularly important to develop a rapid and simple approach to detect thiamethoxam residues in herbal medicines. In this study, colloidal carbon-based immunochromatographic strip (CNP-ICS) and colloidal gold-based immunochromatographic test strip (GNP-ICS) methods were respectively developed for the determination of thiamethoxam . The cutoff value of CNP-ICS was 0.1 ng mL −1 , which is six times more sensitive than that of the GNP-ICS method (0.6 ng mL −1 ). The CNP-ICS method was applied to detect thiamethoxam in medicinal and edible Lonicerae Japonicae Flos (LJF) for the first time, with a limit of detection of 10 ng g −1 . The detection results of thiamethoxam in 26 batches of LJF samples by the CNP-ICS were consistent with those of the LC–MS/MS method. High residue levels (10.16–530.40 ng g −1 ) and high detection rates (69.23%) of thiamethoxam in LJF were observed. The CNP-ICS prepared in this study has the merits of low cost, simple preparation, non-toxicity, and high sensitivity, which can be utilized for rapid field screening of thiamethoxam residues in complex matrices such as herbal medicines. Graphical
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Nature Communications
·
2024
·Vol. 15
·期 1
·1-19
·
IF 14.7
Yang Mei,Chen Tingting,Chen Xin,Pan Hongxian,Zhao Guoli,Chen Zhongxing,Zhao Nan,Ye Qianfang,Chen Ming,Zhang Shenrong,Gao Rongrong,Meek Keith M.,Hayes Sally,Ma Xiaowei,Li Xin,Wu Yue,Zhang Yiming,Kong Na,Tao Wei,Zhou Xingtao,Huang Jinhai
Keratoconus, a disorder characterized by corneal thinning and weakening, results in vision loss. Corneal crosslinking (CXL) can halt the progression of keratoconus. The development of accelerated corneal crosslinking (A-CXL) protocols to shorten the treatment time has been hampered by the rapid depletion of stromal oxygen when higher UVA intensities are used, resulting in a reduced cross-linking effect. It is therefore imperative to develop better methods to increase the oxygen concentration within the corneal stroma during the A-CXL process. Photocatalytic oxygen-generating nanomaterials are promising candidates to solve the hypoxia problem during A-CXL. Biocompatible graphitic carbon nitride (g-C 3 N 4 ) quantum dots (QDs)-based oxygen self-sufficient platforms including g-C 3 N 4 QDs and riboflavin/g-C 3 N 4 QDs composites (RF@g-C 3 N 4 QDs) have been developed in this study. Both display excellent photocatalytic oxygen generation ability, high reactive oxygen species (ROS) yield, and excellent biosafety. More importantly, the A-CXL effect of the g-C 3 N 4 QDs or RF@g-C 3 N 4 QDs composite on male New Zealand white rabbits is better than that of the riboflavin 5’-phosphate sodium (RF) A-CXL protocol under the same conditions, indicating excellent strengthening of the cornea after A-CXL treatments. These lead us to suggest the potential application of g-C 3 N 4 QDs in A-CXL for corneal ectasias and other corneal diseases.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 26
·1-13
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IF 2.8
Gao Qin,Zhao Nianshun,Wu Jiale,Yu Qi,Wang Li,Hu Juan,Lu Sha,Zheng Xiaofan
The solid-state reaction method was employed to synthesize (1− x )[0.90NaNbO 3 –0.10Bi(Mg 0.5 Ta 0.5 )O 3 ]– x (Bi 0.5 Na 0.5 ) 0.7 (Sr 0.7 La 0.2 ) 0.3 Ti 0.9 Zr 0.1 O 3 , denoted as (1− x )(NN–BMT)– x BNSLTZ ( x BNSLTZ). XRD analysis of x BNSLTZ confirmed that all samples possessed a pure perovskite structure. SEM micrographs demonstrated homogeneous grain distribution and minimal porosity. With an increasing concentration of BNSLTZ, there was a gradual reduction in average grain size. Impedance spectroscopy was utilized to investigate the electrical properties of x BNSLTZ across a frequency sweep of 10 Hz–1 MHz and over a temperature range of 420–560 °C. The complex impedance and modulus spectra reveal non-Debye-type dielectric relaxation, indicative of two contributing mechanisms: grain and grain boundary effects on conduction. Electric modulus analysis indicated that the low-frequency relaxation process was temperature independent. The dc conductivity variation with temperature follows the Arrhenius equation. The ac conductivity was found to adhere to Jonscher power law. The E a (the relaxation activation energy) and E c (conductance activation energy) confirmed the relaxation mechanism of 0.3BNSLTZ is dipolar conduction. The dielectric properties showed a significant dependence on both frequency and temperature. A dielectric anomaly pointed to the presence of a single relaxation behavior. It was observed that an increase in BNSLTZ concentration led to a decrease in the maximum dielectric constant. Optimum performance was obtained with the 0.3BNSLTZ ceramics, which has the smallest average grain size (1.54 μm), considerable resistance value ( R ~ 1000 K \({\Omega }cm\) ), and moderate dielectric constant ( ε r ~ 600), superior to the pure NN-BMT ceramic. These results demonstrate that the electrical property of the x BNSLTZ ceramics have some potential value in the application of electrical materials.
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Food Production Processing and Nutrition
·
2024
·Vol. 6
·期 1
·1-15
·
IF 4
Zhou Zheng,Jiang Haonan,Sun Haoyuan,Huang Xu-Hui,Cui Shuang,Zhou Dayong,Qin Lei
After thermal treatment, quail eggs pruduce an attractive flavor that is favored by consumers. In this study, the key aroma volatiles and their lipid precursors during thermal treatment were investigated by the electronic nose, GC-MS, GC-O-MS and UPLC-Q-Exactive HF-X. The results exhibited that the raw and fresh flavor of raw egg yolks came from 1-Octen-3-ol, 2-Ethyl-1-hexanol, 1-Decene, and 1-Undecene. 2-Methyl-3-octanone, Toluene, and some aromatic compounds worked synergistically to contribute to the aroma profile of boiled eggs. (+)-2-Bornanone, Octanal, 2-Methyl-butanal, Nonanal, (.+Dihydro-3-hydroxy-4,4-dimethyl-2(3 H)-furanone, 6,7-Dihydro-2,5-dimethyl-5 H-cyclopentapyrazine, (E)-2-methyl-6-(1-propenyl)-pyrazine, 2-Ethyl-3,5-dimethyl-pyrazine, 3,5-Diethyl-2-methyl-pyrazine, 2,5-Dimethyl-pyrazine were the key flavor compounds in the fried egg and gave it the popcorn and roasted flavors. The statistical analysis of the lipid profile revealed that brief, high-temperature heating (100 or 200 °C for 10 min) in typical boiled and fried quail eggs had minor effects on the lipid nutritional value. PE-related lipids, particularly those containing 18-carbon fatty acids, contributed to the aroma formation of fried quail eggs. Graphical Abstract
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Scientific Reports
·
2024
·Vol. 14
·期 1
·1-15
·
IF 3.8
Yue Jiayuan,Zheng Qi,Ding Shushu,Yin Yujian,Zhang Xiaodan,Wang Liyun,Gu Yipeng,Li Jiejia,Zhang Yuhan,Shi Yurou,Dong Yuetan,Zhu Qing,Duo Huixiao
In this study, the removal effect of a new MOF-on MOF adsorbent based on Cu–Co bimetallic organic frameworks on tetracycline antibiotics (TCs) in water system was studied. The adsorbent (Cu-MOF@Co-MOF) were synthesized by solvothermal and self-assembly method at different concentrations of Co 2+ /Cu 2+ . The characterization results of SEM, XRD, XPS, FTIR and BET indicated that the MOF-on MOF structure of Cu-MOF@Co-MOF exhibited the best recombination and physicochemical properties when the molar ratio of Co 2+ : Cu 2+ is 5:1. In addition, the Cu-MOF@Co-MOF have a high specific surface area and bimetallic clusters, which can achieve multi-target synergistic adsorption of TCs. Based on above advantages, Cu-MOF@Co-MOF provided a strong affinity and could efficiently adsorb more than 80% of pollutants in just 5 to 15 min using only 10 mg of the adsorbent. The adsorption capacity of tetracycline and doxycycline was 434.78 and 476.19 mg/g, respectively, showing satisfactory adsorption performance. The fitting results of the experimental data were more consistent with the Langmuir isotherm model and pseudo-second-order kinetic model, indicating that the adsorption process of TC and DOX occurred at the homogeneous adsorption site and was mainly controlled by chemisorption. Thermodynamic experiments showed that Cu-MOF@Co-MOF was thermodynamically advantageous for the removal of TCs, and the whole process was spontaneous. The excellent adsorption capacity and rapid adsorption kinetics indicate the prepared MOF-on MOF adsorbent can adsorb TCs economically and quickly, and have satisfactory application prospects for removing TCs in practical environments. The results of the study pave a new way for preparing novel MOFs-based water treatment materials with great potential for efficient removal.
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JOURNAL OF MOLECULAR HISTOLOGY
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2025
·Vol. 56
·期 2
·1-15
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IF 2.2
Hou Huailong,Qiu Zhengjun,Che Jingyi,Li Yanping,Sun Jingxuan,Zhang Weiwei,Ma Jinjie,Zhang Shuang,Li Mengdi,Niu Yumei,He Lina
Dental pulp stem cells (DPSCs), a subset of tooth-derived mesenchymal stem cells (MSCs), demonstrate significant promise in clinical stem cell therapy. However, prolonged in vitro expansion commonly results in compromised stemness, limiting therapeutic efficacy. Thus, maintaining the stemness of DPSCs during expansion and culture is a key challenge for regenerative medicine. In the current study, the impact of simulated microgravity (SMG) on DPSC stemness was investigated using the three-dimensional clinostat Cellspace-3D. After SMG treatment for 3 days, DPSCs demonstrated markedly enhanced replicative activity, proliferation efficiency, self-renewal capacity, and effective inhibition of the senescence process. Under specific differentiation induction conditions, DPSCs in the SMG group exhibited superior osteogenic, adipogenic, chondrogenic, and neural differentiation potentials. Additionally, DPSCs exhibited higher expression levels of the MSC surface markers Stro-1 and CD146 and stemness maintenance-related genes Oct4, Nanog, and Sox2 in the SMG group compared to those from the normal gravity (NG) group. To elucidate the potential molecular mechanisms by which SMG influences the stemness of DPSCs, transcriptome sequencing of total RNA was performed, and identified that differentially expressed genes (DEGs) are closely associated with the MAPK signaling pathway. Further verification experiments demonstrated that the MAPK/ERK signaling pathway was activated in the SMG group. In conclusion, SMG effectively maintains the stemness of DPSCs cultivated in vitro, and its mechanism of action may be associated with the activation of the MAPK/ERK signaling pathway.
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CATALYSIS LETTERS
·
2024
·
IF 2.3
Xu Pengfei,Ma Haiming,Shen Wenjuan,Quan Fengjiao,Li Jianfen,He Yun
Ammonia (NH 3 ) can be used as a fertilizer, a chemical or a new generation of fuel and has important agricultural and industrial value. Electrochemical NO 3 – -to-NH 3 (NITRR) can realize the conversion of waste into treasure and waste resources, which is a promising method for ammonia synthesis. However, the process of NITRR is very complicated, resulting in product diversification and poor selectivity. In this work, an iron modified cerium oxide in rod form (Fe/CeO 2 -rod) catalysts was designed and used for the NITRR. The Fe/CeO 2 -rod catalyst showed excellent activity, and achieves high Faradaic efficiency (FE 95%) and NH 3 yield rate (4.04 mg h –1 cm –2 ) in 0.1 M KOH electrolyte at – 0.52 V versus reversible hydrogen electrode. Furthermore, this catalyst exhibits a negligible activity decay during continuous electrolysis for 25 h. Further experiments provide the important role of Fe, which promote the formation of hydrogen radicals (H*). This study may provide new pathways to improve the activity of inexpensive catalysts for NITRR. Graphical Abstract
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