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Maintaining constant gate control is important for ensuring accurate MOSFET adjustment of drive strength by changing its size. In the negative capacitance field-effect transistor (NCFET), the nonuniform distribution of ferroelectric polarization and capacitance match are sensitive to the size and tend to increase the fluctuation of gate control. In the current work, a detailed simulation of an NC-FinFET was carried out to clarify the effect of structural factors on its gate control. These factors include the fin structure (length, width, and height), the doping concentration in the GaAs channel, and the ferroelectric film thickness. Simulation results indicate that the subthreshold swing (SS) of an NC-FinFET with a complex oxide 0.85BiTi0.1Fe0.8Mg0.1O3-0.15CaTiO3 (BTFM-CTO) film is less sensitive to the variation in structural factors than that with HfO2 or PZT film. Thus, the fluctuation in gate control can be significantly ameliorated with a suitable set of structural factors and ferroelectric parameters. The current work generates new insights into the fluctuation of gate control with varying structural factors and adjustment of NC-FinFET drive strength, which are essential for the application of the NC-FinFET in analog circuits. This manuscript was edited for English language/grammar. Some of the text was difficult to interpret. [ABSTRACT FROM AUTHOR]

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been a major approach for glycan analysis. However, the preferential cleavage of the sialic acid moiety by in- and post-source decay influences the determination of sialylated glycans by MALDI-MS. Many chemical derivatization methods were introduced to stabilize the sialylated glycan during MALDI-MS. Among current derivatization methods, methylamidation is a promising means for simultaneous analysis of natural sialylated glycans regardless of their sialic acid linkage types. Here, a novel derivatization method was developed, in which proteins were conjugated on the solid-phase support in order to stabilize the sialic acids by methylamidation and to reduce sample loss and contamination during the derivatization process. This derivatization strategy was used to investigate N-glycans from fetuin, a glycoprotein containing different types of complex N-glycans. The developed method was also applied to the N-glycan profiling of human serum from patients and healthy volunteers. Results were consistent with N-glycan profiling by HPLC-fluorescence detection. This new method provided a sensitive, simple, and robust approach for profiling glycan structures of complex samples. [ABSTRACT FROM AUTHOR]

O-Acetylation of sialic acid in protein N-glycans is an important modification and can occur at either 4-, 7-, 8- or 9-position in various combinations. This modification is usually labile under alkaline reaction conditions. Consequently, a permethylation-based analytical method, which has been widely used in glycomics studies, is not suitable for profiling O-acetylation of sialic acids due to the harsh reaction conditions. Alternatively, methylamidation can be used for N-glycan analysis without affecting the base-labile modification of sialic acid. In this report, we applied both permethylation and methylamidation approaches to the analysis of O-acetylation in sialic acids. It has been demonstrated that methylamidation not only stabilizes sialic acids during MALDI processing but also allow for characterization of their O-acetylation pattern. In addition, LC-MS/MS experiments were carried out to distinguish between the O-acetylated glycans with potential isomeric structures. The repeatability of methylamidation was examined to evaluate the applicability of the approach to profiling of O-acetylation in sialic acids. In conclusion, the combination of methylamidation and permethylation methodology is a powerful MALDI-TOF MS-based tool for profiling O-acetylation in sialic acids applicable to screening of N-glycans. [ABSTRACT FROM AUTHOR]