Rapid identification of glycerophospholipids from RAW264.7 cells by UPLC/ESI ‐QTOF‐MS

The study aims to develop a rapid, sensitive ultra‐performance liquid chromatography coupled with an electrospray ionization quadruple time‐of‐flight tandem mass spectrometry (UPLC/Q‐TOF‐MS) analytical method for identifying glycerophospholipids (GPLs) from RAW264.7 cells. A total of 78 GPLs including 22 phosphatidylethanolamines (PEs), 49 phosphatidylcholines (PCs), four phosphatidylglycerols, one phosphatidylinositol and two unknown GPLs were identified. PC (14:0/16:1), PC (14:0/16:0), PE (0:0/20:3), PE (22:5/0:0) and PE (22:3/0:0) were identified for the first time. The UPLC/Q‐TOF‐MS method is suitable for targeting analysis of GPLs from RAW264.7 cells, which allows us to find out new GPLs compositions related to inflammatory diseases and to explain their pharmacological roles in inflammatory process. Copyright © 2014 John Wiley & Sons, Ltd.     

Study on the relationship between chromatographic retention behaviour and molecular structure

Summary With the molecular hydrophobic feature represented by Van der Waals molecular volume, the-hydrophilic parameter of substituting groups in mono-substituted benzenes was determined, in order to predict the retention of substituted benzenes in RP-HPLC. Thus it is possible to predict the retention of multi-functional substituted benzenes. The agreement between the calculated and the measured retention values shows that the proposed model to deal with retention of solutes is reasonable.     

韧性金属大变形拟流动角点理论及应用

本文提出韧性金属弹塑性大变形拟流动角点理论（ｑｕａｓｉ－ｆｌｏｗｃｏｒｎｅｒｔｈｅｏｒｙ）．该理论从塑性变形正交法则出发，将”模量衰减函数”及屈服面的尖点效应引入本构模型，从而实现了由正交法则本构模型向非正交法则本构模型以及从塑性加载向物理弹性却载的光滑过渡，使一般无角点各向异性硬化屈服函数与有角点硬化情形相结合成为可能．用于数值模拟各向异性金属薄板单向拉伸失稳与剪切带分析并与实验结果作比较，表明本文理论的有效性．     

Coloring ultrasensitive MRI with tunable metal–organic frameworks

As one of the most important imaging modalities, magnetic resonance imaging (MRI) still faces relatively low sensitivity to monitor low-abundance molecules. A newly developed technology, hyperpolarized ¹²⁹Xe magnetic resonance imaging (MRI), can boost the signal sensitivity to over 10 000-fold compared with that under conventional MRI conditions, and this technique is referred to as ultrasensitive MRI. However, there are few methods to visualize complex mixtures in this field due to the difficulty in achieving favorable “cages” to capture the signal source, namely, ¹²⁹Xe atoms. Here, we proposed metal–organic frameworks (MOFs) as tunable nanoporous hosts to provide suitable cavities for xenon. Due to the widely dispersed spectroscopic signals, ¹²⁹Xe in different MOFs was easily visualized by assigning each chemical shift to a specific color. The results illustrated that the pore size determined the exchange rate, and the geometric structure and elemental composition influenced the local charge experienced by xenon. We confirmed that a complex mixture was first differentiated by specific colors in ultrasensitive MRI. The introduction of MOFs helps to overcome long-standing obstacles in ultrasensitive, multiplexed MRI.

Metal organic frameworks with tunable pore structures are able to provide varied chemical environments for hyperpolarized ¹²⁹Xe atom hosting, which results in distinguishing magnetic resonance signals, and stains ultra-sensitive magnetic resonance imaging (MRI) with diverse colors.     

Study on the contents of trace rare earth elements and their distribution in wheat and rice samples by RNAA

The concentrations of 8 REE (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in wheat and rice samples have been determined by RNAA. The contents and distributions of REE in each part of the plants (i.e. root, leaf, stem, husk and seed) and their host soils were studied, which included samples applied with rare earch elements in farming and control samples. The effects of applying rare earths on the uptake of REE by the plants and the REE accumulation in the grains on human health were also discussed in this paper.     

Pafuranones A and B,two dimeric polyketides from a rare marine algae-derived fungus Paraconiothyrium sp.

A pair of dimeric polyketide epimers formed through conjugate addition and intramolecular lactonization were identified from the culture of a rare marine algae-derived fungus, Paraconiothyrium sp. OUCMDZ-3316.     

Multi-stimulus Room Temperature Phosphorescent Polymers Sensitive to Light and Acid cyclically with Energy Transfer

The stimulus-responsive room temperature phosphorescent (RTP) materials have endowed wide potential applications. In this work, by introducing naphthalene and spiropyran (SP) into polyacrylamide as the energy donor and acceptor respectively, a new kind of brilliant dynamic color-tunable amorphous copolymers were prepared with good stability and processibility, and afterglow emissions from green to orange in response to the stimulus of photo or acid, thanks to multi-responsibility of SP and the energy transfer between naphthalene and SP. In addition to the deeply exploring of the inherent mechanism, these copolymers have been successfully applied in dynamically controllable applications in information protection and delivery.     

A Dual-Responsive Liquid Crystal Elastomer for Multi-Level Encryption and Transient Information Display

Information security has gained increasing attention in the past decade, leading to the development of advanced materials for anti-counterfeiting, encryption and instantaneous information display. However, it remains challenging to achieve high information security with simple encryption procedures and low-energy stimuli. Herein, a series of strain/temperature-responsive liquid crystal elastomers (LCEs) are developed to achieve dual-modal, multi-level information encryption and real-time, rewritable transient information display. The as-prepared polydomain LCEs can change from an opaque state to a transparent state under strain or temperature stimuli, with the transition strains or temperatures highly dependent on the concentration of long-chain flexible spacers. Information encrypted by different LCE inks can be decrypted under specific strains or temperatures, leading to multi-level protection of information security. Furthermore, with the combination of the phase transition of polydomain LCEs and the photothermal effect of multi-walled carbon nanotubes (MWCNTs), we achieved a repeatable transient information display by using near-infrared (NIR) light as a pen for writing. This study provides new insight into the development of advanced encryption materials with versatility and high security for broad applications.     

Aptamer-LYTACs for Targeted Degradation of Extracellular and Membrane Proteins

Recently, lysosome targeting chimeras (LYTACs) have emerged as a promising technology that expands the scope of targeted protein degradation to extracellular targets. However, the preparation of chimeras by conjugation of the antibody and trivalent N-acetylgalactosamine (tri-GalNAc) is a complex and time-consuming process. The large uncertainty in number and position and the large molecular weights of the chimeras result in low internalization efficiency. To circumvent these problems, we developed the first aptamer-based LYTAC (Apt-LYTAC) to realize liver-cell-specific degradation of extracellular and membrane proteins by conjugating aptamers to tri-GalNAc. Taking advantage of the facile synthesis and low molecular weight of the aptamer, the Apt-LYTACs can efficiently and quickly degrade the extracellular protein PDGF and the membrane protein PTK7 through a lysosomal degradation pathway. We anticipate that the novel Apt-LYTACs will expand the usage of aptamers and provide a new dimension for targeted protein degradation.     

One Novel 3D Supramolecular Network Based on Dicobalt-Carboxylate Secondary Building Units with Polycarboxylate Ligands 1, 2, 3, 4-Butanetetracarboxylic Acid

A novel cobalt–carboxylate framework constructed from secondary building units (SBUs), {[Co₁₆(btca)₈(H₂O)₄₀]·16H₂O}_n (1) (H₄btca = 1,2,3,4-butanetetracarboxylic acid) has been hydrothermally synthesized and characterized by techniques of single-crystal X-ray diffraction analyses, elemental analyses, infrared spectra, powder X-ray diffraction and thermogravimetric analyses. The complex exhibits 2D 4-connected sql net with (4⁴ × 6²) topology symbol built from [Co₂(COO)₄(H₂O)₅] SBUs and is further extended into a 3D supramolecular architecture via strong O–H···O hydrogen bonds. Moreover, the magnetic measurements indicate complex 1 exhibit antiferromagnetic behavior.