质谱仪技术进展、自主创新研发和开放共享使用现状

简要梳理了质谱技术发展历史,在此基础上,重点总结了中国自主创新质谱仪技术取得的突破,特别是2011年以来,研发人员自主研发了几款成熟的高分辨质谱仪,有力地推动了中国自主创新仪器研制的进展.在大型仪器设备开放共享评价考核数据分析的基础上,分析了高校和科研院所质谱仪的开放共享使用情况.     

量子化学的研究现状、发展趋势与展望*

"本文通过对最近三届量子化学Sanibel国际研讨会和全国量子化学第5届学术讨论会会议内容的对比,评述了当前国际、国内约量子化学研究现状与发展趋势,并粗浅地探讨了我国量子化学的发展战略。     

Micro- and Nanoscale Heterogeneities in Zeolite Beta as Measured by Atom Probe Tomography and Confocal Fluorescence Microscopy

Micro- and nanoscale information on the activating and deactivating coking behaviour of zeolite catalyst materials increases our current understanding of many industrially applied processes, such as the methanol-to-hydrocarbon (MTH) reaction. Atom probe tomography (APT) was used to reveal the link between framework and coke elemental distributions in 3D with sub-nanometre resolution. APT revealed 10–20 nanometre-sized Al-rich regions and short-range ordering (within nanometres) between Al atoms. With confocal fluorescence microscopy, it was found that the morphology of the zeolite crystal as well as the secondary mesoporous structures have a great effect on the microscale coke distribution throughout individual zeolite crystals over time. Additionally, a nanoscale heterogeneous distribution of carbon as residue from the MTH reaction was determined with carbon-rich areas of tens of nanometres within the zeolite crystals. Lastly, a short length-scale affinity between C and Al atoms, as revealed by APT, indicates the formation of carbon-containing molecules next to the acidic sites in the zeolite.     

Fluorescence Dynamics in the Endoplasmic Reticulum of a Live Cell: Time‐Resolved Confocal Microscopy

Fluorescence dynamics in the endoplasmic reticulum (ER) of a live non‐cancer lung cell (WI38) and a lung cancer cell (A549) are studied by using time‐resolved confocal microscopy. To selectively study the organelle, ER, we have used an ER‐Tracker dye. From the emission maximum of the ER‐Tracker dye, polarity (i.e. dielectric constant, ?) in the ER region of the cells (≈500 nm in WI38 and ≈510 nm in A549) is estimated to be similar to that of chloroform ( =506 nm, ?≈5). The red shift by 10 nm in in the cancer cell (A549) suggests a slightly higher polarity compared to the non‐cancer cell (WI38). The fluorescence intensity of the ER‐Tracker dye exhibits prolonged intermittent oscillations on a timescale of 2–6 seconds for the cancer cell (A549). For the non‐cancer cell (WI38), such fluorescence oscillations are much less prominent. The marked fluorescence intensity oscillations in the cancer cell are attributed to enhanced calcium oscillations. The average solvent relaxation time (<τ_s>) of the ER region in the lung cancer cell (A549, 250±50 ps) is about four times faster than that in the non‐cancer cell (WI38, 1000±50 ps).     

全内反射荧光成像技术及其在单分子检测中的研究进展

全内反射荧光显微镜技术是当今最灵敏的生物成像和检测方法之一,可以直接探测单个荧光分子。这种方法已成功地用于生命科学、化学、物理学等研究领域,获得了常规方法无法得到的重要信息。本文介绍了全内反射荧光显微镜的工作原理和实验技术,总结了近年来这种单分子检测方法在生命科学、化学等领域的重要应用,并对其发展前景进行了展望。     

Ruthenium(II) Complex Enantiomers as Cellular Probes for Diastereomeric Interactions in Confocal and Fluorescence Lifetime Imaging Microscopy

Ruthenium dipyridophenazine (dppz) complexes are sensitive luminescent probes for hydrophobic environments. Here, we apply multiple-frequency fluorescence lifetime imaging microscopy (FLIM) to Δ and Λ enantiomers of lipophilic ruthenium dppz complexes in live and fixed cells, and their different lifetime staining patterns are related to conventional intensity-based microscopy. Excited state lifetimes of the enantiomers determined from FLIM measurements correspond well with spectroscopically measured emission decay curves in pure microenvironments of DNA, phospholipid membrane or a model protein. We show that FLIM can be applied to monitor the long-lived excited states of ruthenium complex enantiomers and, combined with confocal microscopy, give new insight into their biomolecular binding and reveal differences in the microenvironment probed by the complexes.     

化学新创实验的现状与发展对策

近年来,化学实验教学改革取得很大成就。本文对当前国内高校的化学新创实验设计的现状进行了分析,探讨了未来新创实验的选题方向、创制途径、教学实施和评价方法,希望对同行有参考价值。     

Efficient Photoconversion Distorts the Fluorescence Lifetime of GFP in Confocal Microscopy: A Model Kinetic Study on Mutant Thr203Val

Phototransformations of autofluorescent proteins are applied in high‐resolution microscopy and in studying cellular transport, but they are detrimental when accidentally occurring in blinking or photobleaching (BL). Here, we investigate the kinetics of phototransformations of a photoactivatable green fluorescent protein (GFP) in confocal microscopy. Photoconversion (PC) is achieved by excitation of the barely present anionic chromophore state R_eq^? in the GFP mutant Thr203Val. Besides the shift of the equilibrium between the neutral chromophore state RH and R_eq^?, the photoconverted anionic chromophore R_PC^? exhibits a reduced fluorescence lifetime τ_fl=2.2 ns. In fluorescence lifetime imaging microscopy, τ_fl is found to depend, however, on the excitation conditions and history. The underlying photochemistry is described by the kinetic scheme of consecutive reactions, R_eq^?→R_PC^?→P_dark, in which the anionic chromophore species and the dark protein P_dark are coupled by PC and BL. Time‐correlated single‐photon‐counting detection in a confocal geometry of freely diffusing species is used to compute the quantum yields for PC and BL, Φ_PC and Φ_BL. The assessed values are Φ_PC=5.5×10^?4 and Φ_BL>1×10^?5. Based on these values, PC provokes misinterpretation in fluorescence resonance energy transfer experiments and is responsible for spectroscopic peculiarities in single‐molecule detection.     

双光子激光共焦扫描显微技术在环境化学中的应用及展望

介绍了双光子激光共焦扫描显微技术的基本原理,评述了该技术与传统荧光显微技术和单光子激光共焦扫描显微技术的异同,并且结合双光子激光共焦扫描显微技术在实际工作中的应用,评述了其在环境化学中的应用潜力及发展前景.     

含砷工业废水处理现状与进展

介绍了用沉淀法、离子交换法、吸附法、萃取法、电凝聚法、膜分离技术、浮选法、生物技术、光催化氧化法处理含砷废水的原理、优缺点以及适用范围,并提出了开发新型吸附材料、新型除砷技术、稳定沉淀技术和多种除砷技术联用的展望.