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191.
Mary Marshall Zhaoguo Zhu Rachel Harris Prof. Dr. Kit H. Bowen Wei Wang Jie Wang Chu Gong Prof. Dr. Xinxing Zhang 《Chemphyschem》2021,22(1):5-8
Thorium and its compounds have been widely investigated as important nuclear materials. Previous research focused on the potential use of thorium hydrides, such as ThH2, ThH4, and Th4H15, as nuclear fuels. Here, we report studies of the anion, ThH5−, by anion photoelectron spectroscopy and computations. The resulting experimental and theoretical vertical detachment energies (VDE) for ThH5− are 4.09 eV and 4.11 eV, respectively. These values and the agreement between theory and experiment facilitated the characterization of the structure of the ThH5− anion and showed its neutral counterpart, ThH5 to be a superhalogen. ThH5−, which exhibits a C4v structure with five Th−H single bonds, possesses the largest known H/M ratio among the actinide elements, M. The adaptive natural density partitioning (AdNDP) method was used to further analyze the chemical bonding of ThH5− and to confirm the existence of five Th−H single bonds in the ThH5− molecular anion. 相似文献
192.
Chang Su Jin‐Song Gong Jin‐Peng Ye Ji‐Meng He Rui‐Yi Li Min Jiang Yan Geng Yan Zhang Jing‐Hua Chen Zheng‐Hong Xu Jin‐Song Shi 《Macromolecular bioscience》2020,20(9)
Keratin is widely recognized as a high‐quality renewable protein resource for biomedical applications. Despite their extensive existence, keratin resources such as feathers, wool, and hair exhibit high stability and mechanical properties because of their high disulfide bond content. Consequently, keratin extraction is challenging and its application is greatly hindered. In this work, a biological extraction strategy is proposed for the preparation of bioactive keratin and the fabrication of self‐assembled keratin hydrogels (KHs). Based on moderate and controlled hydrolysis by keratinase, keratin with a high molecular weight of approximately 45 and 28 kDa that retain its intrinsic bioactivities is obtained. The keratin products show excellent ability to promote cell growth and migration and are conferred with significant antioxidant ability because of their intrinsically high cysteine content. In addition, without the presence of any cross‐linking agent, the extracted keratin can self‐assemble into injectable hydrogels. The KHs exhibit a porous network structure and 3D culture ability, showing potential in promoting wound healing. This enzyme‐driven keratin extraction strategy opens up a new approach for the preparation of keratin that can self‐assemble into injectable hydrogels for biomedical engineering. 相似文献
193.
Dr. Honghong Gong Yu Gu Yucheng Zhao Qinzhi Quan Shantao Han Prof. Dr. Mao Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(2):929-937
Ultra-high-molecular-weight (UHMW) polymers display outstanding properties and hold potential for wide applications. However, their precise synthesis remains challenging. Herein, we developed a novel reversible-deactivation radical polymerization based on the strong and selective fluorine–fluorine interaction, allowing chain-transfer agents to spontaneously differentiate into two groups that take charge of the chain growth and reversible deactivation of the growing chains, respectively. This method enables dramatically improved livingness of propagation, providing UHMW polymers with a surprisingly narrow molecular weight distribution (Đ≈1.1) from a variety of fluorinated (meth)acrylates and acrylamide at quantitative conversions under visible-light irradiation. In situ chain-end extensions from UHMW polymers facilitated the synthesis of well-defined block copolymers, revealing the excellent chain-end fidelity achieved by this method. 相似文献
194.
Xingxing Ge Xicheng Liu Zhenzhen Tian Shujiao Chen Xinyu Liu Lihua Guo Peiwei Gong Baoping Ling Xiang‐Ai Yuan Zhe Liu 《应用有机金属化学》2019,33(11)
Four half‐sandwich rutheniumII (RuII) complexes with triphenylamine‐modifed dipyridine frameworks were synthesized and characterized. The cytotoxicity of target complexes toward A549 (lung cancer cells), HeLa (cervical cancer cells) and HepG2 (hepatoma cells) were obtained by the MTT assay, which were superior to cisplatin with the IC50 values changed from 2.4 ± 0.1 μM to 9.2 ± 2.7 μM. Meanwhile, complexes possess the ability of antimetastasis to cancer cells. RuII complexes could be transported by serum albumin, catalyze the conversion of NADH (the reduced state of nicotinamide‐adenine dinucleotide) to NAD+ and induce the accumulation of reactive oxygen species, which confirmed the antineoplastic mechanism of oxidation. RuII complexes could enter A549 cells followed by a non‐energy dependent cellular uptake mechanism, target lysosomes with the Pearson's colocalization coefficient of 0.75, lead to lysosomal damage, disturb the cell cycle (S phase), and eventually induce apoptosis. The results demonstrate that these RuII complexes are potential anticancer agents with dual functions, including metastasis inhibition and lysosomal damage. 相似文献
195.
Dr. Jinghui Zhang Lei Gong Xiaoshuang Zhang Dr. Mengliang Zhu Chaorui Su Qing Ma Dr. Dongdong Qi Prof. Yongzhong Bian Prof. Hongwu Du Prof. Jianzhuang Jiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(61):13842-13848
Two-photon excited fluorescent (TPEF) materials are highly desirable for bioimaging applications owing to their unique characteristics of deep-tissue penetration and high spatiotemporal resolution. Herein, by connecting one, two, or three electron-deficient zinc porphyrin units to an electron-rich triazatruxene core via ethynyl π-bridges, conjugated multipolar molecules TAT-(ZnP) n (n=1–3) were developed as TPEF materials for cell imaging. The three new dyes present high fluorescence quantum yields (0.40–0.47) and rationally improved two-photon absorption (TPA) properties. In particular, the peak TPA cross section of TAT-ZnP (436 GM) is significantly larger than that of the ZnP reference (59 GM). The δTPA values of TAT-(ZnP)2 and TAT-(ZnP)3 further increase to 1031 and up to 1496 GM, respectively, indicating the effect of incorporated ZnP units on the TPA properties. The substantial improvement of the TPEF properties is attributed to the formation of π-conjugated quadrapole/octupole molecules and the extension of D -π-A-D systems, which has been rationalized by density function theory (DFT) calculations. Moreover, all of the three new dyes display good biocompatibility and preferential targeting ability toward cytomembrane, thus can be superior candidates for TPEF imaging of living cells. Overall, this work demonstrated a promising strategy for the development of porphyrin-based TPEF materials by the construction and extension of D -π-A-D multipolar array. 相似文献
196.
Fangyuan Zhou Lesong Li Kao Lin Feng Zhang Prof. Dr. Guo-Jun Deng Dr. Hang Gong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(19):4246-4250
The radical–radical coupling reaction is an important synthetic strategy. In this study, the iron-catalyzed radical–radical cross-coupling reaction based on the decarboxylation of keto acids and decarbonylation of aliphatic aldehydes to obtain valuable aryl ketones is reported for the first time. Remarkably, when tertiary aldehydes were used as carbonyl sources, ketone esters were selectively obtained instead of ketones. The gram-scale preparation of aryl ketone through this strategy was easily achieved by using only 3 mol % of the iron catalyst. As a proof-of-concept, the bioactive molecule flurprimidol was synthesized in two steps by using this strategy. 相似文献
197.
198.
A novel fiber-optic sensor structure fabricated by cascading two optical microfiber knot resonators (MKRs) is proposed and demonstrated in this paper. A theoretical model for describing the principle of the sensing structure is given and its temperature responses are characterized experimentally. Experimental results show that high-precision and simultaneous multi-point temperature sensing in micro-scale can be achieved. Such a sensing structure also has the potential for achieving dual-parameter measurement to eliminate the cross-talk between two parameters in micro-scale. 相似文献
199.
This paper presents a new algorithm for the prediction of indoor suspension particle dispersion based on a v2-f model. In order to handle the near-wall turbulence anisotropy properly, which is significant in the dispersion of fine particles, the particle eddy diffusivity is calculated using different formulae among regions of the turbulent core and in the vicinity of walls. The new algorithm is validated by several cases performed in two ventilated rooms with various air distribution patterns. The simulation results reveal that v2-f nonlinear turbulence model combined with a particle convective equation gives satisfactory agreement with the experimental data. It is generally found that the dynamic equation combined with the v2-f model can properly handle low Reynolds number (LRN) flows which are usually encountered in indoor air flows and fine particle dispersion. 相似文献
200.