Electromyography (EMG) is the superposition of motor unit action potential (MUAP) in many muscle fibers in time and space. In real measurement, EMG signals will contaminate Electromyography signals, therefore they bring great difficulties to the qualified analysis and interpretation of EEG signals, and it is a momentous step to remove EMG artifacts from EEG signals. In the recent years, new methods were developed for EEG artifacts removal such as Multivariate Empirical Mode Decomposition and Singular Spectrum Analysis. In particular, some researchers combined the two methods and used their respective advantages to remove artifacts more thoroughly without affecting the EEG signal, such as the combination of Independent Component Analysis and Wavelet Method. In this paper, new methods for muscular artifacts removal from EEG above are discussed. Moreover, traditional methods including signal transform, filtering methods and Blind source separation (BSS) are also reviewed.

Structural designs combining cycloparaphenylenes (CPPs) backbone with planar chiral [2.2]paracyclophane ([2.2]PCP) lead to optical‐active chiral macrocycles with intriguing properties. X‐ray crystal analysis revealed aesthetic necklace‐shaped structures and size‐dependent packages with long‐range channels. The macrocycles exhibit unique photophysical properties with high fluorescence quantum yield of up to 82 %, and the fluorescent color varies with ring size. In addition, size‐dependent chiroptical properties with moderately large CPL dissymmetry factor of 10−3 and CPL brightness in the range of 30–40 M−1 cm−1 were observed.

Latia neritoides is a small limpet-like snail that produces a bright green bioluminescence (BL) via a unique light-emitting system. The process, mechanism, and even light emitter of its light emission remain unknown, although this BL has been known for decades. Unlike the other BL systems, neither the luciferin (Luc) nor the oxyluciferin (OxyLuc) of Latia is fluorescent according to the previous experiments. To help to identify its bioluminophore, we studied the geometrical and electronic structures and absorption and fluorescence spectra of Latia Luc and its six analogs as well as its OxyLuc in the gas phase and in water. The calculated results provide clear evidence of the lack of fluorescence in the Luc and OxyLuc of Latia. For the analogs of Latia Luc, the electron-withdrawing or electron-donating ability of the substituted group affects the fluorescence. The results shed new light on the BL mechanism and will likely aid the understanding of Latia BL.

As the most common bioluminescence (BL), firefly BL, is of great significance in the fields of biotechnology, biomedicine and so on. The entire BL process involves a series of complicate in vivo chemical reactions. The BL is initiated by the enzymatic oxidation of luciferin. This is a spin-forbidden reaction of low efficiency, because that luciferin is in singlet state and O 2 is in triplet state. However, firefly is till-now the most efficient system of converting chemical energy to light energy. Why this spin-forbidden reaction occurs efficiently? A single electron transfer (SET) mechanism has been confirmed on this reaction by experiments. However, there is lack of a complete and detailed description of the mechanism and reaction process. Via a calculation of density functional theory (DFT), this article described the complete process of this reaction. The oxygenation of luciferin is initiated by a SET from singlet L 3to triplet O 2 to form RC 3 [L •2-…O 2 •-]. Then the reaction is carried out on the potential energy surface (PES) of triplet state (T 1), on which O 2 •performs a nucleophilic attack on C4 of L •2-. There is an intersystem crossing between the ground (S 0) and T 1 PESs nearby the first transition state (TS1). After the ISC (intersystem crossing), the reaction continuously undergoes on the S 0 PES to produce dioxetanone FDO via two TSs and two intermediates (Ints). The analysis on electron densities and natural orbitals indicates that there is a quick reaction of biradical annihilation around the ISC. About 11.9 kcal•mol-1 energy is needed to reach the ISC before the whole reaction occurs on the S 0 PES. The highest barrier of the reactions on the S 0 PES is only 4.2 kcal•mol-1. The biradical annihilation around the ISC and the very low energy barriers explain the reason of the spin-forbidden reaction with high efficiency. This study is helpful for understanding the initiation of firefly BL and the other oxygen-dependent BL. Keywords luciferin; oxygenation; mechanism; single electron transfer; density functional theory 1 引言 生物发光是一种有趣的现象, 给自然界增加了闪亮 的色彩 [1,2]. 大多数的发光生物(80%)生存于海洋之中 [3] , 而人们最熟知的发光生物是萤火虫(firefly) [4]. 萤火虫生 物发光的光量子产率达 0.41 [5] , 已在基因表达、体内成 像、药物筛选等生命科学和医学技术领域得到广泛的实 际应用. 萤火虫属于鞘翅目萤科(Lampyrinae) [6] , 目前发 现有超过 2000 种萤火虫广泛分布于世界各地. 经过多 年的实验 [7-9] 和理论研究 [10-13] , 人们认识到萤火虫生物 发光的过程包含荧光素(LH 2)催化氧化生成高能中间 体、高能中间体解离生成发光体、发光体发出可见光和 荧光素分子的再生四个阶段. 后三个阶段的机理得到了 详细的理论研究和机理阐释 [14-16] , 但第一阶段的反应机 理至今仍未有全面可靠的理论研究. 这一氧化反应是萤 火虫生物发光, 也是所有氧气依赖型的生物发光体系的

We report herein the regioselective synthesis of all-carbon lemniscular nanohoops bis-po-CC and bis-pm-TC by the rational control of ring closures at the different positions of planar chiral tetrasubstituted [2.2]paracyclophane. Topological...