APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Junjie Yang,Lei Liu
The friction influence of 2-D molybdenum disulfide (MoS 2 ) films deposited on different substrates (Si, SiO 2 and Al 2 O 3 ) by atomic layer deposition (ALD) has been investigated. All of the three substrates showed a trend of decreasing friction with increasing number of layers of MoS 2 , but the friction leveled off for more than 6 layers samples. Comparing these 2-D MoS 2 films with each other, MoS 2 on the Al 2 O 3 possesses the lowest friction, while MoS 2 on the Si possesses the highest one, owing to effect of substrate on the specific self-limiting reaction in ALD process. At the same time, the friction of the monolayer MoS 2 is strongest affected by sulfur deficient. As the number of layers increases, the influence of the substrate on the friction of MoS 2 can be approximately characterized by the work of adhesion. Greater work of adhesion corresponds to a higher friction force. When the thickness is more than 6 layers, the substrate effect disappears gradually. Moreover, the friction of 2-D MoS 2 could be controlled near linearly by changing plasma treatment time within the range from 1 to 20 s, which suggests a possible way for the friction control of 2-D MoS 2 on different substrate quasi-qualitatively or even qualitatively.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Subramanian Siva,Changzhu Li,Haiying Cui,Lin Lin
Isoeugenol is a natural dual antioxidant/prooxidant. In this research, the inclusion complex (IC) of isoeugenol with 2-hydroxypropyl- β -cyclodextrin (HP β CD) was prepared via the ultrasound (US) method. The US assisted isoeugenol/HP β CD-IC was investigated by various characterization techniques such as UV–Vis absorption, fluorescence, powder X-ray diffraction, Fourier transform infrared spectroscopy , thermal gravimetric analysis and differential scanning calorimetry . Absorption, fluorescence and infrared studies indicated that the alkyl chain of isoeugenol was deeply included in the HP β CD cavity. Through determinations of phase solubility and water solubility studies, significant enhancement of isoeugenol water solubility was confirmed after IC formation with the HP β CD. Thermal data proved that the IC formation significantly enhanced the thermal stability of isoeugenol. Antioxidant test results indicated that isoeugenol/HP β CD-IC exhibited better antioxidant activity than free isoeugenol due to its solubility enhancement. Furthermore, the isoeugenol/HP β CD-IC showed higher antibacterial activity of 96 ± 0.2% and 97 ± 0.5% against Staphylococcus aureus and Escherichia coli bacteria, respectively.
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INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Yaoguo Shen,Longjie Huang,Zhifeng Wang,Yingwu Zhou,XiaoLing Xue,Hong Lin,Renwen Yan,Sangen Zhao,Junhua Luo
SO4 tetrahedral groups have weak polarization anisotropy, which thus results in the small birefringence of sulfates. Here, we report new sulfate CsY(SO4)2·4H2O with unprecedented birefringence among deep-ultraviolet (deep-UV) sulfates. Its single crystal (10 mm × 3.5 mm × 1.5 mm) was simply grown by an aqueous solution evaporation technique, and it features a rare layered structure composed of YO9 polyhedra, SO4 tetrahedra, and H2O molecules. Interestingly, each SO4 group donates two oxygen atoms to edge-share with one adjacent YO9 polyhedron and thus causes severe distortion of these groups. The characteristic edge-sharing mode gives CsY(SO4)2·4H2O a large birefringence of ∼0.045@546 nm, which is the maximum among deep-UV sulfates and phosphates with similar non-π-conjugated anionic groups. The ultraviolet–visible-near-infrared diffuse reflection and transmission spectra, infrared spectrum, thermal stability, and theoretical calculations are also presented. The fascinating results will improve our understanding of sulfates and may provide useful insights into the exploration of deep-UV sulfates with large birefringence.
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iScience
·
2024
·
IF 4.6
WenYe Liu,Xi Liu,LingYa Li,ZhiPeng Tai,GuoLiang Li,Jing-Xia Liu
Summary Enhancers of polycomb 1 (EPC1) and 2 (EPC2) are involved in multiple biological processes as components of histone acetyltransferases/deacetylase complexes and transcriptional cofactors, and their dysfunction was associated with developmental defects and diseases. However, it remains unknown how their dysfunction induces hematopoietic stem and progenitor cell (HSPC) defects. Here, we show that depletion of EPC1 / 2 significantly reduced the number of hematopoietic stem and progenitor cells (HSPCs) in the aorta-gonad mesonephros and caudal hematopoietic tissue regions by impairing HSPC proliferation, and consistently downregulated the expression of HSPC genes in K562 cells. This study demonstrates the functions of EPC1 / 2 in regulating histone H3 acetylation, and in regulating DLST (dihydrolipoamide S-succinyltransferase) via H3 acetylation and cooperating with transcription factors serum response factor and FOXR2 together, and in the subsequent HSPC emergence and proliferation. Our results demonstrate the essential roles of EPC1 / 2 in regulating H3 acetylation, and DLST as a linkage between EPC1 and EPC2 with mitochondria metabolism, in HSPC emergence and proliferation.
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DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 32
·12352-12361
·
IF 4.569
Hongqiang Cui,Yongze Cao,Yuhang Zhang,Lei Li,Guojian Li,Sai Xu,Yichao Wang,Jinsu Zhang,Baojiu Chen
A series of Er3+/Yb3+ co-doped Cs3BiSr(P2O7)2 (CBSPO) phosphors with significant thermal enhancement were successfully prepared using the solid-state method and the thermal-enhancing effect was studied in detail. When the temperature increased from 303 to 723 K, the upconversion luminescence (UCL) emission intensities of 2H11/2 → 4I15/2 and 2H11/2 + 4S3/2 → 4I15/2 of Er3+ in CBSPO:0.1Er3+/0.2Yb3+ were enhanced 22.81 and 10.06 times under 980 nm laser excitation, respectively. Meanwhile, the UCL color of the sample obviously changed from orange to green with the increase in temperature. Furthermore, the UCL thermal enhancement mechanism was demonstrated, which originates from phonon-assisted transitions. In addition, the maximum absolute temperature sensitivity for CBSPO:0.1Er3+/0.2Yb3+ was calculated to be 0.01026 K−1 at 563 K via luminescence intensity ratio (LIR) technology. All the results show that the CBSPO:Er3+/Yb3+ phosphors can be used for safety warning and temperature measurement at high temperatures.
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Food Bioscience
·
2020
·
IF 3.067
Liang Gao,Xinyi Cheng,Xuwei Yu,Xiaosan Wang,Qingzhe Jin,Xingguo Wang
1-Oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) is a critical structured lipid in human milk fat and it plays an important role in infants' health. The development of an efficient method for such compound preparation is necessary. In this study, one- and two-step methods for OPL production by enzymatic acidolysis of fractionated palm stearin with mixed acids were compared in solvent-free and solvent systems. The results demonstrated that in the solvent system, the OPL contents by the one- and two-step methods were 45.8% and 56.7%, respectively. In the solvent-free system, the one- and two-step methods resulted in the formation of 43.7% and 54.8% OPL, respectively. Subsequently, acidolysis conditions of the two-step method were optimized. Under the optimum conditions, the content of OPL was 57.7%, and 83.2% of palmitic acid was at the sn-2 position . The prepared OPL has potential to be applied in infant formulas.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Imran Mahmood Khan,Sen Zhao,Sobia Niazi,Ali Mohsin,Muhammad Shoaib,Nuo Duan,Shijia Wu,Zhouping Wang
T-2 is a trichthecenes mycotoxin responsible for severe food poisoning and toxic influences in humans and animals. Therefore, a rapid and sensitive detection of T-2 is an urgent need to protect the public health mainly caused by the consumption of contaminated agricultural products. Herein, we have prepared one pot synthesis of aptamer functionalized silver nanoclusters (apt-AgNCs) for fluorescent detection of T-2 that relies on novel fluorescence resonance energy transfer (FRET). Apt-AgNCs, act as energy donor, were applied as fluorescent sensing probe whose fluorescence was quenched by MoS 2 employed as fluorescent acceptor. Introduction of target in proposed bioassay leads to desorption of Apt-AgNCs from MoS 2 , and recovery of fluorescence in a toxin concentration dependent-manner. A dynamic quantification range was 0.005–500 ng mL −1 while the LOD was 0.93 pg mL −1 . Spiking analysis reveals the efficiency and robustness of the developed assembly, with recovery percentages ranged from 89.46% to 102.08% and 90.41% to 107.75% in maize and wheat samples, respectively. The results were cross-verified using standard commercial T-2 EISA kit. In conclusion, developed bioassay may find good utility in testing for risk assessment of T-2 toxin.
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RSC Advances
·
2016
·Vol. 6
·期 54
·48737-48744
·
IF 3.289
Danfeng Hou,Jiayu Xin,Xingmei Lu,Xiaonan Guo,Huixian Dong,Baozeng Ren,Suojiang Zhang
1,4-Cyclohexanedimethanol (CHDM) is a highly valued and widely used monomer in the polymer industry. Bis(2-hydroxyethylene terephthalate) (BHET), the product of glycolysis of waste PET, is an excellent raw material for the preparation of CHDM. Herein, a series of monometallic, bimetallic and trimetallic supported catalysts were prepared for the one-pot conversion of BHET into CHDM by the impregnation method and good performance was found over trimetallic RuPtSn/Al2O3 catalysts containing various active sites to catalyze the hydrogenation of the phenyl and carbonyl groups. The influences of various reaction parameters including temperature, pressure and time on the hydrogenation reaction were studied, and 100% conversion and 87.1% yield of CHDM were obtained with the trimetallic supported catalyst with Ru/Sn 1.5. Moreover, through the comparison between various methods for the preparation of CHDM, the conversion of BHET into CHDM by the one-pot method is considered one of the most competitive methods.
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CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yongxing Wei,Chenxing Bai,Changqing Jin,Weitong Zhu,Lin Hu,Ruihua Nan,Zhonghua Dai
In this study, the temperature dependence of dielectric behaviours and the polarisation and electrostrain responses of 0.4Bi(Ni 1/2 Zr 1/2 )O 3 –0.6PbTiO 3 (0.4BNZ–0.6PT) were studied to better understand their electrical performance. A Rietveld refinement analysis of the XRD pattern, supported by bright-field TEM images, suggests the coexistence of tetragonal and pseudocubic phases. Above 398 K, the normalised piezoelectric coefficient ( d 33 ∗ ) increases due to heating, reaching 941 pm/V at 453 K. Most importantly, 0.4BNZ–0.6PT displays obvious frequency dispersion in the ferroelectric state. A low-temperature dielectric anomaly occurred at approximately 175 K that was related to the origin of the frequency dispersion. The planar electromechanical coupling constant ( k p ) also changed considerably after heating, increasing from 0.14 at 90 K to 0.43 at 300 K. This indicates an intrinsic relationship between the dielectric and piezoelectric behaviours. Our study demonstrates that there is a significant difference between typical ferroelectrics and the ferroelectric state of 0.4BNZ–0.6PT relaxor ferroelectrics.
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JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2020
·
IF 3.306
Yuhang Chen,Jie Zhang,Zhiyong Tang,Yuhan Sun
The 2-phenylethanol production by traditional chemical methods requires multi-step reactions, in which harsh conditions such as high temperature or strong acid/base are required and undesired by-products are easily produced. The visible light catalyzed anti-Markovnikov hydration of styrene is a single-step reaction using non-toxic catalyst under mild conditions. However, this reaction usually takes ten or even dozens of hours, facing the problem in scale up. The present work aims to intensify this reaction in continuous flow microreactor with comparison to traditional batch reactor. The effects of light source shape, reaction temperature, substrate concentration and catalyst concentration on the reaction were investigated. The continuous flow microreactor permitted to ensure more uniform light intensity and larger specific surface area, the reaction rate could thus be enhanced. The maximum productivity of 2-phenylethanol was 0.122 mol/(L.h), which was 2.5 times higher than that obtained in test tube under the same reaction conditions and 34 times higher than that reported in previous literature. The optimal photosensitizer concentration was 2 %. The increase of substrate concentration would lead to the addition reaction between styrene cationic intermediates with styrene, thereby decreasing the selectivity of 2-phenylethanol.
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RESEARCH ON CHEMICAL INTERMEDIATES
·
2013
·Vol. 40
·期 4
·1575-1581
·
IF 0.88
Liu Feng,Wang Meiyan,Teng Xinhuan,Zhang Peizhi,Jiang Lin
A series of 2-(5-methyl-3-(4-chloro/trifluoromethylphenyl)isoxazol-4-yl)-5-arylamino-1,3,4-oxadiazoles were synthesized from 4-chloro/trifluoromethyl benzaldehyde, ethyl acetoacetate, hydroxylamine hydrochloride, hydrazine hydrate, and aryl isocyanate by multi-step reactions. The structures of the target compounds were elucidated by IR, 1 H NMR, MS, and elemental analysis. All these compounds were tested for in vitro antifungal activities against Botrytis cinerea and Rhizoctonia cerealis by the mycelium growth rate method, and the results indicated that some compounds displayed high antifungal activity against Botrytis cinerea.
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JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Yuying Du,Yuanyuan Gao,Yanlong Gu,Li Lv,Ning Zhu,Limin Han,Xing Zeng
Owing to the diverse implication of carbazole scaffolds in medicinal chemistry, photoelectronic materials and chromophores, the molecules containing the carbazole motif have attracted significant attention over the years. In this work, the vibronic contributions to carbazole structures could facilely change the solvatochromic effect, absorption wavelength, emission wavelength, and Stokes shifts of six 2-carbonyl carbazole ketones fluorophores. Among them, the structure of 1-(1-methyl- 9H -carbazol-2-yl)ethanone (3a) were confirmed from single crystal XRD studies. The ratiometric detection of Fe(III) ion of 2-carbonyl carbazole ketone 3a were investigated. Furthermore, it was speculated that chemosensor 3a toward the recognition of Fe 3+ cation was dependent on its rigid structure and good coplanarity of the conjugated system, strong intramolecular charge-transfer of 3a .
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