Analytical methods for locating modifications in nucleic acids

We reviewed and summarized the established methods and the breakthrough of the techniques for locating modifications in nucleic acids. In addition, we discussed the principles, applications, advantages and drawbacks of these methods.     

Molecular activation analysis for chemical species studies

Molecular activation analysis (MAA) refers to an activation analysis method that is able to provide information on the chemical species of elements in systems of interest, though its exact definition has yet to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because knowledge of bulk contents or concentrations is often insufficient to judge biological, environmental or geochemical effects of elements. The features, methodology and limitations of MAA are outlined, as well as the up-to-date MAA progress in our laboratory. Received: 14 August 1998 / Revised: 30 November 1998 / Accepted: 1 December 1998     

Integrative CAD/CAE/CAM for complicated panel metal stamping of oil pan used in the car engine

The oil pan used in car engine is one of the important structure parts in the car, which is, in general, deep drawn and difficult to form. The deep-drawing processes of the oil pan used in the engine for “Small Flag” Car of the First Automobile Manufactory is analyzed by using the integrative CAD/CAE/CAM technique of stamping die, including the CAD software CATIA and the sheet-metal stamping CAE software KMAS developed independently. Through an analysis of die structure and formability using the KMAS software, the primary twi-off deep-drawing has successfully been changed to the one-off deep-drawing, solving the key technical difficulties for the manufactory. Project supported by the National Natural Science Foundation of China (No. 19832020) and the Key Project of Ministry of Education of China.     

Control of femtosecond filamentation by field-free revivals of molecular alignment

We show that the filamentation dynamics of a femtosecond laser probe pulse can be readily controlled by properly matching it to the quantum revivals of pre-aligned molecules prepared through impulsive rotational Raman excitation with an advancing ultrashort pump pulse. Several features of the filamentation process including supercontinuum generation, the length of the plasma channel generated in the wake of the filament, the associated secondary radiations and the multiple filamentation pattern are all easily modified by tuning the cross phase modulation induced by the field-free revivals of molecular alignment, through the delay between the pump and the probe pulses. We show that molecular alignment can also be used to generate conical waves with extremely short intensity spike called shocked X-waves and to further tune the frequency of a few-cycle laser pulse in the wake of a self-guided intense filament.     

色谱法分离纯化富勒烯的研究进展

富勒烯是近年来研究较多的碳笼结构高分子化合物,基分离、纯化是影响该研究领域进展的关键因素。色谱法是目前分离富勒烯的重要手段,本文概述了该法在富勒烯分离、纯化中的应用,着重讨论了高效液相色谱固定相的发展。     

DNAzyme‐Loaded Metal–Organic Frameworks (MOFs) for Self‐Sufficient Gene Therapy

DNAzymes have been recognized as potent therapeutic agents for gene therapy, while their inefficient intracellular delivery and insufficient cofactor supply precludes their practical biological applications. Metal–organic frameworks (MOFs) have emerged as promising drug carriers without in‐depth consideration of their disassembled ingredients. Herein, we report a self‐sufficient MOF‐based chlorin e6‐modified DNAzyme (Ce6‐DNAzyme) therapeutic nanosystem for combined gene therapy and photodynamic therapy (PDT). The ZIF‐8 nanoparticles (NPs) could efficiently deliver the therapeutic DNAzyme without degradation into cancer cells. The pH‐responsive ZIF‐8 NPs disassemble with the concomitant release of the guest DNAzyme payloads and the host Zn²⁺ ions that serve, respectively, as messenger RNA‐targeting agent and required DNAzyme cofactors for activating gene therapy. The auxiliary photosensitizer Ce6 could produce reactive oxygen species (ROS) and provide a fluorescence signal for the imaging‐guided gene therapy/PDT.     

液相沉积法(LPD)在分析化学中的应用

液相沉积法(LPD)是湿化学法中发展起来的一种全新成膜方法,现已广泛应用于集成电路、金属-氧化物半导体、生物传感器、光催化及抗菌材料领域功能性薄膜的制备。本文简要介绍了液相沉积法的原理、特点及采用LPD法制备的多种金属氧化物薄膜,并详细综述了近年来液相沉积技术在分析化学领域中的应用,主要包括LPD在制备分离介质、化学传感器、复合电极等材料中的应用,并对LPD法在分析化学中的未来发展趋势进行了展望。     

腐殖酸键合硅胶固相萃取-液相色谱法测定辣椒粉及辣椒油中的苏丹红

以腐殖酸键合硅胶作为固相萃取介质,建立了固相萃取柱净化、高效液相色谱同时     

Φ125 mm光学级蓝宝石晶体生长

应用泡生法生长出φ125 mm×180 mm、质量为6 kg的蓝宝石晶体,晶体无色透明,绿光检测晶体内部无肉眼可见散射颗粒.晶体光学均匀性达到2.1×10~(-7),晶体沿a方向、c方向检测均无应力条纹.     

Improved synthetic route to n-B18H22

Simple iodine oxidation of the B(9)H(12)(-) anion in toluene at room temperature reliably gives excellent yields ( approximately 80%) of n-B(18)H(22) (anti-B(18)H(22)) and thus provides a convenient, large-scale, safe route to this important polyborane cluster.