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Readily Prepared and Tunable Ionic Organocatalysts for Ring-opening Polymerization of Lactones

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Chinese Journal of Polymer Science 2019年第12期37卷 1205-1214,I0005页

作者： Zhuo-Lun Jiang Jun-Peng zhao guang-zhao Zhang Faculty of Materials Science and Engineering South China University of Technology

Highly potent ionic organocatalyst is developed for room-temperature controlled ring-opening polymerization(ROP)of lactones,includingδ-valerolactone,ε-caprolactone,andδ-*** catalysts are prepared by simply mixing tetra-n-butyl ammonium hydroxide and a(thio)urea at elevated temperature under vacuum,and used in cooperation with an alcoholic *** performance of the catalyst is readily adjusted and optimized through variation of the(thio)urea precursor,catalyst composition,and reaction ***-derived catalysts are generally superior to thiourea-derived *** with proper N-substituents,the catalyst affords both high polymerization efficiency and high selectivity for monomer enchainment over macromolecular transesterification,even at high monomer conversion and/or substantially extended reaction *** addition to acidity,structural symmetry of the urea also proves decisive for the catalytic activity,which enables a catalyst-assisted proton transfer process for the ring-opening of lactone and thus provides a novel mechanistic insight for ROP catalyzed by hydrogen-bonding type bifunctional ionic organocatalysts.

关键词： Organocatalytic polymerization Ring-opening polymerization Polyester

Theoretical study on separation density of gravity beneficiation

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Journal of Coal Science & Engineering(China) 2010年第2期16卷 193-197页

作者： JIAO hong-guang zhao Xiao-nan zhao Yue-min School of Materials Science and Engineering Henan Polytechnic University Jiaozuo 454003 China School of Chemical Engineering and Technology China University of Mining ＆Technology Xuzhou 221008 China

Separation density is one of the most concerned operating parameters in gravity *** equal-errors cut point or distribution density is usually used as practical separation density in gravity beneficiation, the gravity separating process complexly affected by many kinds of factors is actually carried out at a fluctuant density; namely, the practical separation density is essentially a random *** studied results show that the equal-errors cut point is the mathematical expectation of this random variable, and the distribution density corresponds to the highest separation efficiency in the gravity separation *** shows that the distribution density is the best working point of the gravity separation equipment under a particular operating ***,in order to fully develop the function of the gravity separation equipment, the distribution density should be close to the theoretical separation density unlimitedly in the range of minimum fluctuation.

关键词： separation density gravity beneficiation equal-errors cut point distribution density random variable

Separation of salidroside from the fermentation broth of engineered Escherichia coli using macroporous adsorbent resins

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Chinese Journal of Chemical Engineering 2022年第4期35卷 260-267页

作者： Xiaocui Sun Xue Liu guang-Rong zhao Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Georgia Tech Shenzhen Institute Tianjin UniversityShenzhen 518071China

Salidroside(8-O-β-D-glucoside of tyrosol),a plant-derived natural product,is used for treatment of hypoxia,fatigue and aging *** availability of salidroside is restricted since it is extracted from3-5 years old Rhodiola roots,which grow very slowly in the cold region of northern hemisphere of *** laboratory has constructed an engineered Escherichia coli and established a fermentation process to produce salidroside from *** this article,nine macroporous resins from polarity to non-polarity,including NKA-9,S-8,AB-8,SP825,D101,LSA-8,LX-12,LX-18 and LX-68 resins,were tested to separate salidroside from fermentation *** static and dynamic experiments,the weakly polar SP825 resin had a better separation efficiency among nine *** adsorption kinetic and isotherm of salidroside on the SP825 resin were determined,and the pseudo-second-order kinetic model and Langmuir model could be fitted *** effects of the pH on adsorption and ethanol concentration on desorption were investigated,and an optimal separation process was *** adsorption for salidroside in the SP825 resin column was conducted with loading 150 ml at pH 7,and desorpted by washing 50 ml of80%ethanol *** the best process conditions,the purity and yield of salidroside in the final product were 91.6%and 74.0%,*** results showed that the macroporous SP825 resin would be feasible and effective to prepare salidroside and has promising application in the downstream process of microbial fermentation.

关键词： Adsorption Desorption Fermentation Macroporous resin Salidroside

A convergent mean shift algorithm to select targets for LAMOST

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Research in Astronomy and Astrophysics 2009年第7期9卷 803-811页

作者： guang-Wei Li Gang zhao National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

This paper firstly finds that the Mean Shift Algorithm used by the Observation Control System （OCS） Research Group of the University of Science and Technology of China in Survey Strategy System 2.10 （SSS2.10） to select targets for the Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） is not convergent in theory. By carefully studying the mathematical formulation of the Mean Shift Algorithm, we find that it tries to find a point where some objective function achieves its maximum value; the Mean Shift Vector can be regarded as the ascension direction for the objective function. If we regard the objective function as the numerical description for the imaging quality of all targets covered by the focal panel, then the Mean Shift Algorithm can find the place where the imaging quality is the best. So, the problem of selecting targets is equal to the problem of finding the place where the imaging quality is the best. In addition, we also give some effective heuristics to improve computational speed and propose an effective method to assign point sources to the respective fibers. As a result, our program runs fast, and it costs only several seconds to generate an observation.

关键词： methods: data analysis - methods: statistical

Two-electron oxygen reduction reaction by high-loading molybdenum single-atom catalysts

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Rare Metals 2020年第5期39卷 455-457页

作者： Xuan zhao Yan-guang Li Institute of Functional Nano and Soft Materials Jiangsu Key Laboratory for Carbon-Based Functional Materials and DevicesSoochow UniversitySuzhou 215123China

Hydrogen peroxide(H2O2)is an important environmentally friendly chemical and potential energy carrier and has been widely used for a range of applications,such as paper and pulp bleaching,chemical synthesis and wastewater treatment[1,2].Nowadays,about 95%H2O2is produced from the anthraquinone oxidation process,which unfortunately is energy intensive and far from economical[3].The direct synthesis of H2O2from H2and O2is a green method,but it has the potential hazard of explosion[4].

关键词： synthesis method Hydrogen

Synthesis,Crystal and Biological Activity of 3-(2,4-Difluorobenzyl)-5-(p-tolyl)-7-(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-2-amine

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Chinese Journal of Structural Chemistry 2020年第10期39卷 1912-1917,1746页

作者： JI Xiao-Hui zhao Juan LU Jiu-Fu GE hong-guang Shaanxi Key Laboratory of Catalysis College of Chemical&EnvironmentScienceShaanxi University of TechnologyHanzhong 723001China

The title compound 3-(2,4-difluorobenzyl)-5-(p-tolyl)-7-(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-2-amine(6)was synthesized by the condensation of 4,4,4-trifluoro-1-(p-tolyl)butane-1,3-dione(5)with 4-(2,4-difluorobenzyl)-1H-pyrazole-3,5-diamine(4).The latter was prepared from 2,4-difluorobenzaldehyde(1)and malononitrile through Knoevenagel condensation and NaBH3CN reduction and then cyclisation with hydrazine *** crystal structure of the title compound was determined and its crystal belongs to the triclinic system,space group P with a=5.4939(9),b=10.6480(17),c=16.508(3)Å,α=93.226(2)°,β=97.050(2)°andγ=98.325(2)°.In addition,the compound possesses distinct effective inhibition on the proliferation of MKN45,HT-29 and K562 cell lines with IC50 values of 5.57,7.72 and 0.83μM,respectively,displaying promising anticancer activity.

关键词： pyrazolo[1 5-a]pyrimidine synthesis X-ray diffraction antitumor activity

Effects of Rapamycin on the Differentiation and Function of Macrophages In Vitro

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Agricultural Sciences in China 2009年第5期8卷 620-627页

作者： SHEN hong WU Guo-juan LIU guang-wei MA Hai-xia LIAO An-yan zhao Yong Department of Animal Science and Technology Beijing University of Agriculture Beijing 102206 P.R.China State Key Laboratory of Biomembrane and Membrane Biotechnology/Institute of Zoology Chinese Academy of Sciences Beijing 100101 P.R. China The Third Hospital Affiliated to Beijing University of Chinese Medicine Beijing 100029 P.R.China

Macrophages have been generated from bone marrow progenitor cells （BMPCs） with macrophage colony-stimulating factor （M-CSF）. Rapamycin （rapa） is an immunosuppressive drug, which could prevent renal graft rejection and inhibit tumor growth to yield antiproliferative activity in a variety of malignancies. However, the direct effect of rapa on the development of macrophages is unknown. In this study, we explored the direct effect of rapa on the differentiation and function of macrophages differentiated from mouse BMPCs in vitro in the presence of M-CSF. The experimental data showed that rapa prevented the differentiation of macrophagcs by down-regulating CD80 and CD86 expression but upregulating F4/80 expression, as well as by reducing the capacity of differentiated macrophages to stimulate lymphocyte proliferation in the allogeneic mixed lymphocyte reaction. Furthermore, the phagocytic capacity of differentiated macrophages was significantly reduced by rapa. Therefore, rapa may directly inhibit macrophage differentiation and function, which may have been one of the major targets for rapa to mediate its immunosuppressive properties.

关键词： function macrophages rapamycin differentiation

Identification of pollution sources in river based on particle swarm optimization

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Journal of Hydrodynamics 2021年第6期33卷 1303-1315页

作者： guang-han Zhang Xiao-dong Liu Si Wu Zu-lin Hua Li zhao hong-qin Xue Peng Wang Key Laboratory ofIntegrated Regulation and Resource Development on Shallow Lake ofMinistry of Education College of EnvironmentHohai UniversityNanjing 210098China School of Civil Engineering Nanjing Forestry UniversityNanjing 210037China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210098China Jiangsu Environmental Industry CO. LTDNanjing 210037China

The pollution sources identification model is presented by the coupling of the river water quality model and particle swarm optimization(PSO)algorithm to estimate pollution sources from the measured/simulated contaminant concentration in the ***“twin experiment”is adopted to verify the feasibility of the identification model,and three cases are constructed to explore the results of the identification model in different *** experiment test demonstrated that the identification model is effective and efficient,while the model can accurately figure out the quantities of the pollutants and position of a single pollution source or multiple sources,with the relative error of the mean is less than 3%.Many factors are explored,including the level of random disturbance and the impact of particle population *** outcome showed that the disturbance level is less than 5%,thus the precision is preferable,and when the number of particles is three,the identification is the *** performing multiple sources,identification of multiple sets of monitoring sections respectively can obtain more accurate results with less *** this paper,the optimization method of the inverse problem is applied to the identification of river pollution sources,which can help us to identify pollution sources and provide us a scientific basis for subsequent water pollution control and prevention.

关键词： Identification model particle swarm optimization(PSO)optimization source identification surface water

Mitochondrial Modulation of Apoptosis Induced by Low-dose Radiation in Mouse Testicular Cells

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Biomedical and Environmental Sciences 2013年第10期26卷 820-830页

作者： FANG Fang GONG Ping Sheng zhao hong guang BI Yu Jing zhao Gang GONG Shou Liang WANG Zhi Cheng Key Laboratory of Radiobiology Ministry of HealthSchool of Public HealthJilin University Key Laboratory for Molecular Enzymology and Engineering Ministry of Education Nuclear Medicine First Hospital of Jilin University State Key Laboratory of Pathogen and Biosecurity Academy of Military Medical Sciences

Objective To investigate whether apoptosis induced by low-dose radiation （LDR） is regulated by mitochondrial pathways in testicular cells. Methods Male mice were exposed to whole-body LDR, and changes in mitochondrial function and in expression of apoptotic factors were analyzed in the testicular cells as follows. Total nitric-oxide synthase （T-NOS） and Na＋/K＋ ATPase activities were biochemically assayed. Reactive oxygen species （ROS） and mitochondrial membrane potential （Adjm） were determined by flow cytometry using fluorescent probes. Levels of mRNAs encoding cytochrome c （Cyt c） and apoptosis-inducing factor （AIF） were quantified by real-time reverse-transcription PCR （RT-PCR）. Expression of Cyt c, AIF, caspase-9, and caspase-3 at the protein level was assessed by western blotting and immunohistochemistry. Results LDR induced an increase in T-NOS activity and ROS levels, and a decrease in Na＋/K~ ATPase activity and mitochondrial A^m, in the testicular cells. The intensity of these effects increased with time after irradiation and with dose. The cells showed remarkable swelling and vacuolization of mitochondria, and displayed a time- and dose-dependent increase in the expression of Cyt c, AIF, procaspase-9, and procaspase-3. Activation of the two procaspases was confirmed by detection of the cleaved caspases. The changes in expression of the four apoptotic factors were mostly limited to spermatogonia and spermatocytes. Conclusion LDR can induce testicular cell apoptosis through mitochondrial signaling pathways

关键词： Mitochondria Low-dose radiation Testis Apoptosis Cytochrome c