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Understanding the thermal stability of human serum proteins with the related near-infrared spectral variables selected by Monte Carlo-uninformative variable elimination

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Chinese Chemical Letters 2017年第7期28卷 1447-1452页

作者： xiu-Wei liu Xiao-Yu Cui Xiao-Ming Yu Wen-Sheng Cai Xue-Guang Shao Research Center for Analytical Sciences College of ChemistryNankai UniversityTianjin 300071Chino Laboratory of Clinic People's Hospital of Gaorni CityShandong 261000China Tianjin Key Laboratory of Biosensing and Molecular Recognition Tianjin 300071China State Key Laboratory of Medicinal Chemical Biology Tianjin 300071China Collaborative Innovation Center of Chernical Science and Engineering Tianjin 300071China

Understanding the thermal stability of the proteins in human serum is essential since human serum is the important source of pharmaceutical proteins. Near-infrared（NIR） spectroscopy was applied to the investigation of thermal changes in secondary structure and hydration of human serum ***, as a multicomponent system, the overlap of the broad NIR bands makes the structural analysis very difficult directly using the spectra of serum samples. Therefore, continuous wavelet transform（CWT） was used to improve the resolution of NIR spectra, and Monte Carlo-uninformative variable elimination（MC-UVE） method was applied to the selection of the variables associated with the proteins for the structural analysis. The variables（5956, 5867, 5815, 5747, 4525, 4401, 4359 and 4328 cm^-1） related to protein secondary structures and those（7074, 6951, 6827 and 6700 cm 1） connected with water species were selected. Then, the thermal stability was analyzed through the intensity variations of the selected variables with temperature from 30℃ to 80 ℃. It was found that the variation of the spectral variables related to both a-helix and b-sheet changes apparently around 60 ℃, indicating the beginning of the thermal denaturation and the transition from a-helix to b-sheet. Moreover, an obvious change was found around 60℃for the content of the water specie S3, i.e., the water cluster containing three hydrogen bonds. The result demonstrates that MC-UVE can identify the protein-related NIR spectral variables, and the water species may be a marker for investigation of the structural change of proteins in biochemical systems.

关键词： Near-infrared spectroscopy Temperature dependent spectroscopy Monte Carlo-uninformative variable elimination Protein Human serum

Electrocatalytic Determination of Dopamine in the Presence of Ascorbic Acid by Poly-L-proline and Ferricyanide Compound Film Modified Electrode

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Chemical Research in Chinese Universities 2009年第6期25卷 827-831页

作者： CAO Yan-xiu liu Xing-mei HUANG Hui ZHANG Xue-yu ZHANG Zhi-quan College of Chemistry Jilin University Changchun 130012 P. R. China

A novel biosensor was fabricated by the electrochemical polymerization of poly-L-proline（P-LP） and ferricyanide（FC） to form a compound film on a glassy carbon electrode（GCE）. The compound film modified electrode（P-LP/FC/GCE） shows electrocatalytic activity toward dopamine（DA） in a phosphate buffer solution（PBS, pH = 4.0） with a diminution of the overpotential and an increase in peak current. P-LP/FC/GCE was used to study the electrocatalytic oxidation of DA and ascorbic acid（AA） by means of cyclic voltammetry（CV）, differential pulse voltammetry（DPV） and amperometric i-t curve techniques. The overlapping anodic peaks of DA and AA were resolved into two well-defined voltammetric peaks in CV and DPV with the potential differences of about 200 and 225 mV, respectively. The peak current of DA is linearly change with the concentration of DA in a range of 1 × 10^-7 to 1.14 × 10^-4 mol/L with the correlation coefficient of 0.9997. The detection limit is 4.4~10-8 mol/L（S/N=3）. P-LP/FC/GCE exhibited an excellent selectivity, sensibility and stability for the determination of DA, and can be applied to the determination of dopamine injections with satisfied results.

关键词： L-Proline Ferricyanide Dopamine Modified electrode Electropolymerization

Cu(OAc)_(2)-Mediated Synthesis of Fullerodihydropyridine-3-ones via the Reaction of[60]Fullerene with β-Substituted Ethylamines in the Absence or Presence of Arylacetaldehydes

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Chinese Journal of Chemistry 2023年第13期41卷 1557-1565页

作者： xiu-Shan liu Hui-Juan Wang Fei-Lun Wu Jing-Wen Huo Xing-Yu Wang Fa-Bao Li Rui Sun Li liu Chao-Yang liu State Key Laboratory of Biocatalysis and Enzyme Engineering School of Life SciencesHubei UniversityWuhanHubei430062 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Center for Magnetic ResonanceWuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhanHubei430071 China Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional MoleculesCollege of Chemistry and Chemical EngineeringHubei UniversityWuhanHubei430062 China

A series of unreported fullerodihydropyridine-3-ones were synthesized as a new family of fullerene derivatives in moderate to good yields by a simple one-step reaction of[60]fullerene with cheap and readily available β-substituted ethylamines in the absence or presence of arylacetaldehydes under the assistance of Cu(OAc)_(2).The in situ generation of arylacetaldehydes by the C—N bond cleavage of arylethylamines avoided their complex synthesis in advance and realized the preparation of fullerodihydropyridine-3-ones with structural and functional diversities,which may have promising applications in perovskite solar cells to improve the performance of photovoltaic devices due to the existence of a largeπ-conjugated system on the dihydropyridine-3-one ring.

关键词： Fullerenes Copper β-Substituted ethylamines Arylacetaldehydes Fullerodihyd ropyridine-3-ones Radical reactions

Design of(GO/TiO2)N one-dimensional photonic crystal photocatalysts with improved photocatalytic activity for tetracycline degradation

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International Journal of Minerals,Metallurgy and Materials 2020年第6期27卷 830-839页

作者： Huan-huan Wang Wen-xiu liu Jing Ma Qian Liang Wen Qin Patrick Osei Lartey Xiao-jiang Feng Institute of New Carbon Materials Taiyuan University of TechnologyTaiyuan 030024China Zhongguancun Institute of Human Settlements Engineering and Materials Beijing 100083China

(GO/TiO2)N(GO represents graphene oxide,and N represents the period number of alternate superposition of two dielectrics)onedimensional photonic crystal with different lattice constants was prepared via the sol–gel technique,and its transmission characteristics for photocatalysis were *** results show that the lattice constant,filling ratio,number of periodic layers,and incident angle had effects on the band *** the lattice constant,filling ratio,number of periodic layers,and incident angle were set to 125 nm,0.45,21,and 0°,respectively,a gap width of 53 nm appeared at the central wavelength(322 nm).The absorption peak of the photocatalyst at 357 nm overlapped the blue edge of the photonic band gap.A slow photon effect region above 96%reflectivity *** degradation rate of tetracycline in(GO/TiO2)N photonic crystal was enhanced to 64%within 60 ***,the degradation efficiency of(GO/TiO2)N one-dimensional photonic crystal was effectively improved compared with those of the GO/TiO2 composite film and GO/TiO2 powder.

关键词： one-dimensional photonic crystal translight software transmission characteristics photocatalytic performance slow photon effect

Relationship between intestinal microbial dysbiosis and primary liver cancer

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Hepatobiliary & Pancreatic Diseases International 2019年第2期18卷 149-157页

作者： Lei Zhang Yong-Na Wu Tuo Chen Cheng-Hui Ren Xun Li Guang-xiu liu Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Key Laboratory of Extreme Environmental Microbial Resources and Engineering of Gansu Province University of Chinese Academy of Sciences The First Clinical Medical College Lanzhou University The First Hospital of Lanzhou University Lanzhou University Key Laboratory of Biotherapy and Regenerative Medicine of Gansu Province

Background: Intestinal microbial dysbiosis is involved in liver disease pathogenesis. However, its role in primary liver cancer(PLC), particularly in hepatocarcinogenesis remains unclear. The present study aimed to study the changes in intestinal flora at various stages of PLC and clarify the relationship between intestinal microbes and PLC. Methods: Twenty-four patients with PLC(PLC group), 24 patients with liver cirrhosis(LC group), and 23 healthy control individuals(HC group) were enrolled from October 2016 to October 2017. Stool specimens of the participants were collected and the genomic DNA of fecal bacteria was isolated. High-throughput pyrosequencing of 16 S r DNA was used to identify differences in gut bacterial diversity among HC, LC, and PLC groups. We also analyzed the relationship between clinical factors and intestinal microorganisms in LC and PLC groups. Results: Diversity of Firmicutes tended to decrease from the HC to LC and PLC groups at the phylum level. Among species, Enterobacter ludwigii displayed an increasing trend in the PLC group, wherein the relative abundance of Enterobacter ludwigii in the PLC group was 100 times greater than that in the HC and LC groups. The ratio of Firmicutes/Bacteroidetes was significantly decreased with the disease progression. In addition, the linear discriminant analysis effect size method indicated that Clostridia were predominant in the gut microbiota of the HC group, whereas Enterococcaceae, Lactobacillales, Bacilli and Gammaproteobacteria may be used as diagnostic markers of PLC. Redundancy analysis showed a correlation between intestinal microbial diversity and clinical factors AST, ALT, and AFP. Veillonella showed a significant positive correlation with AFP in the PLC group, whereas Subdoligranulum showed a negative correlation with AFP. Conclusions: This study indicates that dysbiosis of the gut microbiota might be involved in PLC development and progression.

关键词： Gut microbiota Microbial dysbiosis Hepatocarcinogenesis 16S rDNA

In situ introduction of dispersed metallic Ag nanoparticles into the channels of mesoporous carbon CMK-3

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Chinese Chemical Letters 2007年第8期18卷 1017-1020页

作者： Ai Bing Chen Wei Ping Zhang Yong liu xiu Wen Han Xin He Bao State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

An in situ reduction method has been developed to fabricate metallic Ag nanoparticles inside the channels of mesoporous carbon CMK-3. This approach combines function of the CMK-3 surface by oxidation using HNO3 with the subsequent absorption of Ag^＋ The resultant nanocomposite materials were characterized by nitrogen adsorption, X-ray diffraction, Auger electron spectroscopy and transmission electron microscopy. Compared with the conventional impregnation method, our approach shows that Ag nanonarticles of 2-4 nm can be uniformlv incorporated into CMK-3.

关键词： Ag nanoparticles Mesoporous carbon CMK-3 In situ synthesis

Resistivity-Temperature Behavior of CB-Filled HDPE Foaming Composites

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Chemical Research in Chinese Universities 2008年第2期24卷 215-219页

作者： LI Ji-xin ZHANG Guo LI Zhuo-shi WANG Xin-lei liu xiu-qi Key Laboratory of Automobile Materials Ministry of Education College of Materials Science and Engineering Jilin University Changchun 130012 P. R. China Petrochemical Engineering School Shenyang University of Technology Liaoyang Campus Liaoyang 111003 P R. China

High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black（ACEY） and super conductive carbon black（HG-1P） as conductive filler, low-density polyethylene（LDPE） as the second component, ethylene-vinyl acetate（EVA） and ethylene propylene rubber（EPR） as the third component, azobisformamide（AC） as foamer, and dicumyl peroxide（DCP） as cross-linker. The structure and resistivity-temperature behavior of high-density polyethylene（HDPE）/CB foaming conductive composites were investigated. Influences of carbon black, LDPE, EVA, EPR, AC, and DCP on the foaming performance and resistivity-temperature behavior of HDPE/CB foaming conductive composites were also studied. The results reveal that HDPE/CB foaming conductive composite exhibits better switching characteristic; ACET-filled HDPE foaming conductive composite displays better positive temperature coefficient（PYC） effect; whereas super conductive carbon black（HG-1P）-filled HDPE foaming conductive composite shows better negative temperature coefficient（NTC） effect.

关键词： Resistivity-temperature behavior Carbon black High-density polyethylene Foam Positive temperaturecoefficient(PYC) effect Negative temperature coefficient(NYC) effect

Mesozoic Thrust-Nappe and Extensional Structure Frameworks in the East Segment of Southeast Yangtze Block, Southeast China

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Journal of Earth Science 2020年第4期31卷 772-794页

作者： Xinqi Yu Ziwei Chen Jun Hu Yan Zeng xiu liu Yu He Zishen Wang Linghui Meng School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China Chongqing Institute of Geology&Mineral Resources Chongqing 400042China

Multi-stage Mesozoic thrust-nappe and extensional structures are distributed in the east segment of the Southeast Yangtze Block situated in the junction region of Zhejiang-Jiangxi-Anhui provinces. The features and genetic mechanism of the deformations were analyzed after a detailed field observation of their distribution, geometry, and kinematics. In addition, the time sequences of the thrust and extensional structures were determined by combining the results of the comparative analysis with the chronological evidence of strata and magmatic rocks cut by a fault or formed after a fault according to field facts. This study identified three stages of the nappe structures and at least two stages of the extensional structures during the Mesozoic. The geotectonic setting of the nappe and extensional structures was considered to be related to the different geodynamics in the study area including the Early Mesozoic geological event, i.e., N-S compression, forming Lantian fault, etc.;the Late Mesozoic flat-slab subduction, forming Xiaoxi thrust fault and tectonic window;and the roll-back of the paleoPacific Plate, forming extensional structures like basin marginal fault;the last compression, forming Wucheng-Shenxian fault. These findings provide additional evidence for remodeling the tectonic and geodynamic evolution of Southeast China.

关键词： Mesozoic nappe structure extensional structure time sequence east segment of the Southeast Yangtze Block

Quantitative multi-phase-field modeling of non-isothermal solidification in hexagonal multicomponent alloys

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China Foundry 2022年第3期19卷 263-274页

作者： Yong-biao Wang Ming-guang Wei Xin-tian liu Cong Chen Jian-xiu liu Yu-juan Wu Shuai Dong Li-ming Peng Henan Key Laboratory of Intelligent Manufacturing of Mechanical Equipment Zhengzhou University of Light IndustryZhengzhou 450002China National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite Shanghai Jiao Tong UniversityShanghai 200240China Luoyang Institute of Special Materials Research Luoyang 471600HenanChina

A quantitative multi-phase-field model for non-isothermal and polycrystalline solidification was developed and applied to dilute multicomponent alloys with hexagonal close-packed *** effects of Lewis coefficient and undercooling on dendrite growth were investigated *** show that large Lewis coefficients facilitate the release of the latent heat,which can accelerate the dendrite growth while suppress the dendrite tip *** greater the initial undercooling,the stronger the driving force for dendrite growth,the faster the growth rate of dendrites,the higher the solid fraction,and the more serious the solute *** simulated dendrite growth dynamics are consistent with predictions from the phenomenological theory but significantly deviate from the classical JMAK theory which neglects the soft collision effect and mutual blocking among ***,taking the Mg-6Gd-2Zn(wt.%)alloy as an example,the simulated dendrite morphology shows good agreement with experimental results.

关键词： multi-phase-field model non-isothermal solidification polycrystalline multicomponent alloys dendrite growth microstructure