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Catalytic performance enhancement by alloying Pd with Pt on ordered mesoporous manganese oxide for methane combustion 被引量:7
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作者 Peng Xu Zhixing Wu +4 位作者 Jiguang Deng Yuxi Liu Shaohua Xie guangsheng guo Hongxing Dai 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期92-105,共14页
Ordered mesoporous Mn2O3 (meso‐Mn2O3) and meso‐Mn2O3‐supported Pd, Pt, and Pd‐Pt alloy x(PdyPt)/meso‐Mn2O3; x = (0.10?1.50) wt%; Pd/Pt molar ratio (y) = 4.9?5.1 nanocatalysts were prepared using KIT‐6‐templated... Ordered mesoporous Mn2O3 (meso‐Mn2O3) and meso‐Mn2O3‐supported Pd, Pt, and Pd‐Pt alloy x(PdyPt)/meso‐Mn2O3; x = (0.10?1.50) wt%; Pd/Pt molar ratio (y) = 4.9?5.1 nanocatalysts were prepared using KIT‐6‐templated and poly(vinyl alcohol)‐protected reduction methods, respectively.The meso‐Mn2O3 had a high surface area, i.e., 106 m2/g, and a cubic crystal structure. Noble‐metalnanoparticles (NPs) of size 2.1?2.8 nm were uniformly dispersed on the meso‐Mn2O3 surfaces. AlloyingPd with Pt enhanced the catalytic activity in methane combustion; 1.41(Pd5.1Pt)/meso‐Mn2O3gave the best performance; T10%, T50%, and T90% (the temperatures required for achieving methaneconversions of 10%, 50%, and 90%) were 265, 345, and 425 °C, respectively, at a space velocity of20000 mL/(g?h). The effects of SO2, CO2, H2O, and NO on methane combustion over1.41(Pd5.1Pt)/meso‐Mn2O3 were also examined. We conclude that the good catalytic performance of1.41(Pd5.1Pt)/meso‐Mn2O3 is associated with its high‐quality porous structure, high adsorbed oxygen species concentration, good low‐temperature reducibility, and strong interactions between Pd‐Pt alloy NPs and the meso‐Mn2O3 support. 展开更多
关键词 Ordered mesoporous manganese oxide Pd‐Pt alloy nanoparticle Supported noble metal catalyst Strong metal‐support interaction Methane combustion
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基于微流控芯片的体外血管网络模型的研究进展
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作者 王芳田 赵亮 +1 位作者 郭广生 汪夏燕 《化学进展》 SCIE CAS CSCD 北大核心 2024年第6期840-850,共11页
血管是人体维持器官特定功能和调节体内稳态的重要生理系统。随着组织工程技术和微流控技术的不断发展,基于微流控芯片技术的体外微血管系统已经成为生物医学工程领域重要的在体外重构血管模型的手段,为基础研究和转化医学研究提供了新... 血管是人体维持器官特定功能和调节体内稳态的重要生理系统。随着组织工程技术和微流控技术的不断发展,基于微流控芯片技术的体外微血管系统已经成为生物医学工程领域重要的在体外重构血管模型的手段,为基础研究和转化医学研究提供了新的工具。微流控技术弥补了传统体外血管模型存在的缺陷,具有巨大的应用潜力。本综述中,我们总结和讨论了微流控体外血管模型的主要构建方法以及各种方法的异同点,为建立更加可靠的体外血管系统模型提供参考。我们也探讨了在这些体外微血管模型的构建过程中,微流控技术所起到的决定性作用和其独特的优势。 展开更多
关键词 血管内皮细胞 微生理系统 微流控技术 血管网络
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Single-cell mass spectrometry studies of drug metabolism heterogeneity and primary resistance to gefitinib in non-small cell lung cancer cells
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作者 Guizhen Zhu Yaoyao Zhao +5 位作者 Wenmei Zhang Yuanyuan Wu Yuanxing Liu guangsheng guo Xiayan Wang Zhihong Liu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第2期436-440,共5页
Patients with epidermal growth factor receptor(EGFR)wild-type non-small cell lung cancer(NSCLC)often show primary resistance to gefitinib therapy.It is thus necessary to study the metabolism of gefitinib in NSCLC cell... Patients with epidermal growth factor receptor(EGFR)wild-type non-small cell lung cancer(NSCLC)often show primary resistance to gefitinib therapy.It is thus necessary to study the metabolism of gefitinib in NSCLC cells to comprehensively reveal the reasons for the primary resistance of tumors.Herein,we develop a platform for studying drug metabolism heterogeneity based on single-cell mass spectrometry(sDMH-scMS)by integrating living-cell electrolaunching ionization MS(ILCEI-MS)and high-performance liquid chromatography-MS(HPLC-MS)analysis,and the primary resistance of NSCLC cells to gefitinib was studied using this platform.The ILCEI-MS analysis showed that approximately 11.9%of NSCLC single cells contained the gefitinib metabolite M11;HPLC-MS detection diluted the intensity of M11 in subpopulations and concealed the heterogeneity of drug metabolism in tumor single cells.The intensity of gefitinib in EGFR wild-type A549 cells was markedly lower than in mutant PC9 cells,and the intensity of gefitinib metabolites was significantly higher than in PC9 cells,suggesting that the primary resistance of NSCLC cells is related to gefitinib metabolism.Moreover,the combination of gefitinib and the drug-metabolizing enzyme inhibitorα-naphthoflavone was shown to overcome the primary resistance of the NSCLC cells.Overall,the results of this study are expected to be applicable for clinical drug resistance diagnosis and treatment at the single-cell level. 展开更多
关键词 Single-cell mass spectrometry Drug metabolism Non-small cell lung cancer GEFITINIB Primary resistance
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Abrasion Resistance Enhancement of Ultrafine-structured WC-Co Coating Fabricated by using in situ Synthesized Composite Powder 被引量:7
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作者 Haibin Wang Xiaoyan Song +2 位作者 Chongbin Wei Yang Gao guangsheng guo 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2013年第11期1067-1073,共7页
The ultrafine WC-Co composite powder was synthesized by a newly developed rapid route based on in situ reactions. By using the as-synthesized composite powder, the granulation processing was then carried out to prepar... The ultrafine WC-Co composite powder was synthesized by a newly developed rapid route based on in situ reactions. By using the as-synthesized composite powder, the granulation processing was then carried out to prepare the ultrafine-structured thermal spraying feedstock. The influences of the heat-treatment process on density of the feedstock powder, phase constitution and wear resistance of the resultant WC-Co coatings fabricated by high velocity oxy-fuel (HVOF) were investigated. The results showed that increasing the heating temperature and extending the holding time leaded to remarkable increase in the density and flowability of the feedstock powder. As a result, the decarburization of the in-flight particles could be decreased and the wear resistance of coating was significantly enhanced. The present study demonstrated that the developed techniques for the ultrafine powder and its thermal-sprayed coatings had very promising applications in scaling up to produce ultrafine-structured cermet coatings with excellent performance. 展开更多
关键词 WC-Co composite powder DECARBURIZATION Density Ultrafine-structured coating Abrasion resistance
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Anomalous enhancement of fluorescence of carbon dots through lanthanum doping and potential application in intracellular imaging of ferric ion 被引量:4
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作者 Shenghong Yang Xiaohan Sun +3 位作者 Zhaoyan Wang Xiayan Wang guangsheng guo Qiaosheng Pu 《Nano Research》 SCIE EI CAS CSCD 2018年第3期1369-1378,共10页
An anomalous enhancement of fluorescence of carbon dots (CDs) was observed via lanthanum (La) doping. La-doped CDs (La-CDs) were prepared through microwave pyrolysis within 4 min. With La^3+ doping, the emissio... An anomalous enhancement of fluorescence of carbon dots (CDs) was observed via lanthanum (La) doping. La-doped CDs (La-CDs) were prepared through microwave pyrolysis within 4 min. With La^3+ doping, the emission band shifted from blue to green although LaB+ is non-fluorescent. The quantum yield and fluorescence lifetime improved by about 20% and 35%, respectively. All experiment results indicate that La^3+ doping is an effective way to tune fluorescence and improve the performance of CDs. Another unique attribute of La-CDs is high sensitivity to Fe^3+. The La-CD-based fluorescence probe was established and used for sensitive and selective detection of Fe^3+ with a limit of detection of 91 nmol/L. The proposed fluorescence probe also was successfully employed to visualize intracellular Fe^3+ in live HeLa cells through cell imaging. It was also shown that yttrium exhibited the same fluorescence enhancement effect as La. The results may provide a new route for preparing CDs with special properties. 展开更多
关键词 rear earth doping carbon dots fluorescence tuning ferric ion cell imaging
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Synthesis and characterization of a novel binuclear iron phthalocyanine/reduced graphene oxide nanocomposite for non-precious electrocatalyst for oxygen reduction 被引量:3
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作者 Ruonan Li Dongtang Zhang +2 位作者 Yingyan Zhou Xiayan Wang guangsheng guo 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第6期746-751,共6页
Binuclear iron phthalocyanine/reduced graphene oxide(bi-Fe Pc/RGO) nanocomposite with good electrocatalytic activity for ORR in alkaline medium was prepared in one step. High angle annular dark field image scanning tr... Binuclear iron phthalocyanine/reduced graphene oxide(bi-Fe Pc/RGO) nanocomposite with good electrocatalytic activity for ORR in alkaline medium was prepared in one step. High angle annular dark field image scanning transmission electron microscopy(HAADF-STEM) and energy dispersive X-ray spectroscopy element mapping results show bi-Fe Pc was uniformly distributed on RGO. An obvious cathodic peak located at about-0.23 V(vs. SCE) in CV and an onset potential of-0.004 V(vs. SCE) in LSV indicate the as-prepared bi-Fe Pc/RGO nanocomposite possesses high activity which is closed to Pt/C for ORR. The ORR on bi-Fe Pc/RGO nanocomposite follows four-electron transfer pathway in alkaline medium. Compared with Pt/C, there is only a slight decrease(about 0.02 V vs. SCE) for bi-Fe Pc/RGO nanocomposite when the methanol exists. The excellent activity and methanol tolerance in alkaline solutions proves that bi-Fe Pc/RGO nanocomposite could be considered as a promising cathode catalyst for alkaline fuel cells. 展开更多
关键词 binuclear iron phthalocyanine reduced graphene oxide in situ synthesis crossover effect non-precious metal catalysts
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A pico-HPLC-LIF system for the amplification-free determination of multiple miRNAs in cells 被引量:2
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作者 Wenmei Zhang Zunsheng Han +4 位作者 Yingqi Liang Qi Zhang Xiangnan Dou guangsheng guo Xiayan Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第7期2183-2186,共4页
MicroRNAs are a class of important biomarkers,and the simultaneous detection of multiple miRNAs can provide valuable information about many diseases and biological processes.Amplification-free determination has been d... MicroRNAs are a class of important biomarkers,and the simultaneous detection of multiple miRNAs can provide valuable information about many diseases and biological processes.Amplification-free determination has been developed for the analysis of multiple miRNAs because of its characteristic low cost and high fidelity.Herein,a method for the amplification-free analysis and simultaneous detection of multiple miRNAs based on a so-called pico-HPLC-LIF system is described.In this process,a bare open capilla ry with an inner diameter of 680 nm is used as a sepa ration column for a sample volume of several hundreds of femtoliters(300 fL),followed by separation and detection.The technique has a zeptomolar limit of detection.The method was applied to detect cellular miRNA from adenocarcinomic human alveolar basal epithelial(A549)cell extracts,and the simultaneous detection of the mir-182,miR-155,and let-7 a was achieved.The results showed that the expression of mir-182 and miR-155 was up-regulated and that of let-7 a was down-regulated in A549 cells.This method for multiple miRNAs detection is expected to have broad applications in miRNA-based disease diagnosis,prognosis,treatment,and monitoring. 展开更多
关键词 Multiple miRNAs Amplification-free Pico-HPLC NANOCAPILLARY Laser-induced fluorescence
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Influence of elution conditions on DNA transport behavior in free solution by hydrodynamic chromatography 被引量:1
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作者 Lei Liu Vijaykumar Veerappan +2 位作者 Yuzhi Bian guangsheng guo Xiayan Wang 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第10期1605-1611,共7页
We have previously developed bare narrow-bore capillary chromatography. In this work, high-performance DNA separation was realized for a size range of 10–800 base pairs(bp) utilizing bare narrow-bore capillary chroma... We have previously developed bare narrow-bore capillary chromatography. In this work, high-performance DNA separation was realized for a size range of 10–800 base pairs(bp) utilizing bare narrow-bore capillary chromatography with 750 nm- radius capillaries. Separation behavior of double-stranded DNA(ds DNA) fragments was investigated over a range of eluent concentrations and elution pressures. DNA molecules were hydrodynamically separated in a size-dependent manner in free solution without any sieving matrices, with the longer fragments being eluted out from the capillary earlier. It was found that the eluent concentration variously influenced the transport behavior for different-sized DNA fragments depending upon the configuration of DNA molecules and the association of counterions. Ionic strength of the solutions strongly impacted DNA persistence length. Enhanced elution pressure could shorten analysis time with a slight loss in resolution. Excellent efficiency of two million theoretical plates per meter was achieved, which indicates the enormous potential of bare narrow-bore capillary chromatography for the analysis of DNA fragments. These findings would be useful in understanding the transport behavior of DNA fragments in confined dimensions for chromatography in free solution. 展开更多
关键词 DNA separation transport behavior CHROMATOGRAPHY
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Ultra-thin temperature controllable microwell array chip for continuous real-time high-resolution imaging of living single cells
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作者 Yuanyuan Wu Lei Zhao +3 位作者 Yaran Chang Liang Zhao guangsheng guo Xiayan Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第11期3446-3449,共4页
Single-cell imaging,a powerful analytical method to study single-cell behavior,such as gene expression and protein profiling,provides an essential basis for modern medical diagnosis.The coding and localization functio... Single-cell imaging,a powerful analytical method to study single-cell behavior,such as gene expression and protein profiling,provides an essential basis for modern medical diagnosis.The coding and localization function of microfluidic chips has been developed and applied in living single-cell imaging in recent years.Simultaneously,chip-based living single-cell imaging is also limited by complicated trapping steps,low cell utilization,and difficult high-resolution imaging.To solve these problems,an ultra-thin temperature-controllable microwell array chip(UTCMA chip)was designed to develop a living single-cell workstation in this study for continuous on-chip culture and real-time high-resolution imaging of living single cells.The chip-based on ultra-thin ITO glass is highly matched with an inverted microscope(or confocal microscope)with a high magnification objective(100×oil lens),and the temperature of the chip can be controlled by combining it with a home-made temperature control device.High-throughput single-cell patterning is realized in one step when the microwell array on the chip uses hydrophilic glass as the substrate and hydrophobic SU-8 photoresist as the wall.The cell utilization rate,single-cell capture rate,and microwell occupancy rate are all close to 100%in the microwell array.This method will be useful in rare single-cell research,extending its application in the biological and medical-related fields,such as early diagnosis of disease,personalized therapy,and research-based on single-cell analysis. 展开更多
关键词 Ultra-thin microchip Temperature controllable Living single cells One-step patterning Continuous culture High-resolution imaging
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Development of Ultranarrow-Bore Open Tubular High Efficiency Liquid Chromatography
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作者 Yingyan Zhou guangsheng guo Xiayan Wang 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2022年第1期137-152,共16页
Chromatography theory shows that when the inner diameter of the chromatography column is very narrow(e.g.,1—2μm),the maximum efficiency will be produced in liquid chromatography.In addition,the increasing demand for... Chromatography theory shows that when the inner diameter of the chromatography column is very narrow(e.g.,1—2μm),the maximum efficiency will be produced in liquid chromatography.In addition,the increasing demand for ultrasmall volume sample analysis has produced the trend of narrowing the diameter of the liquid chromatography column.Experiments have verified that ultranarrow-bore open tubular liquid chromatography(i.d.≤2μm)has the advantages of small sample requirement and high separation efficiency.However,there also exist huge challenges along with such obvious advantages.This review summarizes the efforts made by our research group and other research groups to develop this field.We hope that in the near future,ultranarrow bore open-tube liquid chromatography can be successfully and maturely applied to the application of analytes with ultrasmall size and volume such as single-cell and even subcellular organelles omics research. 展开更多
关键词 Ultra narrow-bore Liquid chromatography Ultrahigh separation efficiency Pico-PLOT column Analytical methods
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