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Glycosylation is one of the most important post-translational modifications (PTM), mediating physiological processes like cell adhesion, cell proliferation, cell signaling, and immune responses. The special functionality of glycosylation for cancer progression and metastasis were reported in recent researches. Analytical methods based on mass spectrometry (MS), especially liquid chromatography mass spectrometry (LC-MS), are the routine practices for protein glycosylation research. However, due to the high complexity and multiformity of glycan structures, as well as the existence of numerous isomers, in-depth analysis of glycosylation ends up as a major challenge for conventional LC-MS-based method. Ion mobility separation is a promising approach to fill the gap as it provides an additional separation dimension for mass spectrometry analysis based on structures and charges of the gas-phase ions. As a technology with an entirely different separation mechanism from that of liquid chromatography, ion mobility spectrometry (IM) has several properties superior to other separation facilities. First of all, unlike liquid chromatography or capillary electrophoresis which demand minutes of separation time, IM only requires a few milliseconds to finish the separation, and it is well compatible with fast mass spectrometry analysis. Besides, as a separation technique for gas phase ions, IM can be modularized and readily integrated into full-fledged LC-MS system. Most importantly, IM is proved to have great potential in glycan isomer discriminations. Given the aforementioned merits, ion mobility mass spectrometry (IM-MS) is gaining attention from glycomics community. This review summarized the basic principles of IM-MS and its applications in protein glycosylation research for the past five years. The means of enhancing isomeric separation performance of glycans were comprehensively discussed, including derivatization, forming metal and other noncovalent adducts, and utilizing high-resolution ion mobility spectrometry implementation. The various approaches of leveraging collision cross section (CCS) values to assist glycan identification and isomer discrimination were also summarized. Furthermore, as two monosaccharides with great biological and pathological significance, the IM-MS applications on fucoses and sialic acids were given special attention. As for glycopeptides, innovative spectra matching algorithms, novel ion activation techniques to facilitate glycan and peptide elucidations, and brand new quantification strategies for isomers were included, along with various glycoproteomic applications of IM-MS on biological samples. Finally, in terms of IM-MS applications in glycoprotein research, investigations of conformational properties, 3D structures, stabilities, and protein-protein interactions were covered. It was concluded that IM-MS is a promising method for protein glycosylation research with great potential.

In current work, myrrh residue, a special type of natural biomass, was used as the feedstock for carbon dots (CDs) preparation for the first time. The effect of synthesis conditions including ethylenediamine addition, reaction temperature, and reaction time on the CDs fluorescence intensity was investigated to construct a proper synthesis system. Under the suitable condition, CDs with an average particle size of 6.35 ± 1.07 nm and excitation wavelength dependence were prepared, and the CDs yield and the CDs quantum yield were 3.78% and 10.63%, respectively. The CDs obtained were used for the detection of various metal ions, and Fe3+ could be detected most sensitively due to its significant quenching effect. For low Fe3+ concentrations (0.2–1 mM), it had a good linear relationship with F0/F (the relative fluorescence intensity) that a standard curve (y = 0.3553x + 0.926) was built with R2 of 0.997 and the limit of detection (LOD) of 24.62 μM. While for high Fe3+ concentrations (1–15 mM), it also had a good linear relationship with F0/F that a standard curve (y = 0.3232x + 0.7636) was built with R2 of 0.991 and LOD of 27.06 μM. The CDs was used for the real samples detection with the recoveries ranged from 92.71 to 103.84%. The fluorescence quenching mechanism of CDs by Fe3+ was learned and the static quenching was the possible mechanism. In addition, based on the antioxidant properties of myrrh itself, the myrrh residue derived CDs also had antioxidant activities and thus had potential for antioxidant application. On the whole, this work can provide an attractive technology for chemical conversion from low-cost myrrh residue to functional CDs which can be applied for Fe3+ detection and antioxidation. [ABSTRACT FROM AUTHOR]

The article focuses on the rules formulated for the first selection committee of the Hong Kong Special Administrative Region (SAR) in China. It is stated that the Selection Committee would comprise of 400 permanent residents of Hong Kong. It is informed that these permanent residents would be from various sectors such as former politician, people from religious circles and financial sector, industrialists, and professional labors. The minimum qualifying age to become a member of the selection committee is above eighty years.