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101.
A sensitive fluorescent probe, 2,2'-bisbenzimidazole (L), for CN has been developed. This structurally simple receptor displays great selectivity for the cyanide anion over other common inorganic anions in an aqueous environment. In addition, further study demonstrates the lower detection of the fluorescence response of the sensor to CN is in 10 9 mol/L range. Thus, the present probe should be applicable as a practical system for the monitoring of cyanide concentrations in aqueous samples. 相似文献
102.
Xiaojian Shi Yelian Miao Jie Yu Chen Jun Chen Wenli Li Xun He Jining Wang 《Applied biochemistry and biotechnology》2014,172(6):3042-3053
Freeze-tolerant baker’s yeasts are required for the processing of frozen doughs. The present study was carried out to investigate the cell survival rate after frozen storage and the change of fermentability in dough due to frozen storage, and to discuss quantitatively the relationship of freeze tolerance with intracellular trehalose, amino acids, and glycerol, using six types of baker’s yeasts as the test materials. The experimental results showed that the fermentability of yeast cells in frozen dough was strongly correlated with the cell survival rate. The baker’s yeast with a higher level of cell survival rate had a larger increase in the total intracellular compound content after frozen storage, and the cell survival rate increased linearly with increasing total intracellular compound content in frozen yeast cells. Trehalose was a primary compound affecting freeze tolerance, followed by glutamic acid, arginine, proline, asparagic acid, and glycerol. The basic information provided by the present study is useful for exploring the freeze-tolerance mechanisms of baker’s yeast cells, breeding better freeze-tolerant baker’s yeast strains, and developing more effective cryoprotectants. 相似文献
103.
Prof. Dr. Su-Yun Zhang Dr. Han Miao Dr. He-min Zhang Jun-Hao Zhou Prof. Dr. Qiang Zhuang Prof. Dr. Yu-Jia Zeng Prof. Dr. Zhiming Gao Prof. Dr. Jiayin Yuan Prof. Dr. Jian-Ke Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22293-22300
The capability to significantly shorten the synthetic period of a broad spectrum of open organic materials presents an enticing prospect for materials processing and applications. Herein we discovered 1,2,4-triazolium poly(ionic liquid)s (PILs) could serve as a universal additive to accelerate by at least one order of magnitude the growth rate of representative imine-linked crystalline open organics, including organic cages, covalent organic frameworks (COFs), and macrocycles. This phenomenon results from the active C5-protons in poly(1,2,4-triazolium)s that catalyze the formation of imine bonds, and the simultaneous salting-out effect (induced precipitation by decreasing solubility) that PILs exert on these crystallizing species. 相似文献
104.
Zhiwei Tie Prof. Zhiqiang Niu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(48):21477-21487
Organic electroactive compounds are attractive to serve as the cathode materials of aqueous zinc-ion batteries (ZIBs) because of their resource renewability, environmentally friendliness and structural diversity. Up to now, various organic electrode materials have been developed and different redox mechanisms are observed in aqueous Zn/organic battery systems. In this Minireview, we present the recent developments in the energy storage mechanisms and design of the organic electrode materials of aqueous ZIBs, including carbonyl compounds, imine compounds, conductive polymers, nitronyl nitroxides, organosulfur polymers and triphenylamine derivatives. Furthermore, we highlight the design strategies to improve their electrochemical performance in the aspects of specific capacity, output voltage, cycle life and rate capability. Finally, we discuss the challenges and future perspectives of aqueous Zn/organic batteries. 相似文献
105.
Dr. Ya-Nan Chen Dr. Miao Li Yunzhi Wang Jing Wang Dr. Ming Zhang Dr. Yuanyuan Zhou Dr. Jianming Yang Dr. Yahui Liu Prof. Feng Liu Prof. Zheng Tang Prof. Qinye Bao Prof. Zhishan Bo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(50):22903-22909
Fused-ring electron acceptors have made significant progress in recent years, while the development of fully non-fused ring acceptors has been unsatisfactory. Here, two fully non-fused ring acceptors, o-4TBC-2F and m-4TBC-2F, were designed and synthesized. By regulating the location of the hexyloxy chains, o-4TBC-2F formed planar backbones, while m-4TBC-2F displayed a twisted backbone. Additionally, the o-4TBC-2F film showed a markedly red-shifted absorption after thermal annealing, which indicated the formation of J-aggregates. For fabrication of organic solar cells (OSCs), PBDB-T was used as a donor and blended with the two acceptors. The o-4TBC-2F-based blend films displayed higher charge mobilities, lower energy loss and a higher power conversion efficiency (PCE). The optimized devices based on o-4TBC-2F gave a PCE of 10.26 %, which was much higher than those based on m-4TBC-2F at 2.63 %, and it is one of the highest reported PCE values for fully non-fused ring electron acceptors. 相似文献
106.
G-protein-coupled receptors (GPCRs) are the largest family of human membrane proteins and serve as primary targets of approximately one-third of currently marketed drugs. In particular, adenosine A1 receptor (A1AR) is an important therapeutic target for treating cardiac ischemia–reperfusion injuries, neuropathic pain, and renal diseases. As a prototypical GPCR, the A1AR is located within a phospholipid membrane bilayer and transmits cellular signals by changing between different conformational states. It is important to elucidate the lipid–protein interactions in order to understand the functional mechanism of GPCRs. Here, all-atom simulations using a robust Gaussian accelerated molecular dynamics (GaMD) method were performed on both the inactive (antagonist bound) and active (agonist and G-protein bound) A1AR, which was embedded in a 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) lipid bilayer. In the GaMD simulations, the membrane lipids played a key role in stabilizing different conformational states of the A1AR. Our simulations further identified important regions of the receptor that interacted distinctly with the lipids in highly correlated manner. Activation of the A1AR led to differential dynamics in the upper and lower leaflets of the lipid bilayer. In summary, GaMD enhanced simulations have revealed strongly coupled dynamics of the GPCR and lipids that depend on the receptor activation state. © 2019 Wiley Periodicals, Inc. 相似文献
107.
Anthony Jolly Dandan Miao Maxime Daigle Prof. Dr. Jean-François Morin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(12):4652-4661
The solution-phase synthesis is one of the most promising strategies for the preparation of well-defined graphene nanoribbons (GNRs) in large scale. To prepare high quality, defect-free GNRs, cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate the presence of various functional groups. In this Minireview, we present the latest synthetic approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd- and Ni-catalyzed reactions. 相似文献
108.
Dr. Qing Li Shenhua Li Dr. Shasha He Wan Chen Penghui Cheng Dr. Yan Zhang Prof. Qingqing Miao Prof. Kanyi Pu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7084-7089
Discriminative detection of invasive and noninvasive breast cancers is crucial for their effective treatment and prognosis. However, activatable probes able to do so in vivo are rare. Herein, we report an activatable polymeric reporter (P-Dex) that specifically turns on near-infrared (NIR) fluorescent and photoacoustic (PA) signals in response to the urokinase-type plasminogen activator (uPA) overexpressed in invasive breast cancer. P-Dex has a renal-clearable dextran backbone that is linked with a NIR dye caged with an uPA-cleavable peptide substrate. Such a molecular design allows P-Dex to passively target tumors, activate NIR fluorescence and PA signals to effectively distinguish invasive MDA-MB-231 breast cancer from noninvasive MCF-7 breast cancer, and ultimately undergo renal clearance to minimize the toxicity potential. Thus, this polymeric reporter holds great promise for the early detection of malignant breast cancer. 相似文献
109.
Borate is considered one of the most important additives for improving the fire-resistance of combustible polymers because of its smoke suppression, low toxicity, and good thermal stability. However, the size of prepared borate is usually in the micrometer range, which makes it difficult to disperse in a polymer matrix, thus hindering its use as fire-retardant material. The preparation and application of borate nanomaterial as flame retardant is considered an effective method. However, the preparation of barium borate nanomaterials as flame retardant has not been reported. In this paper, nanosheets and nanoribbons with different sizes for a new barium borate BaO·4B2O3·5H2O are prepared by hydrothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), thermogravimetric analysis-differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The flame-retardant properties of polypropylene (PP)/BaO·4B2O3·5H2O composites are investigated by thermogravimetric analysis (TG), differential scanning calorimetry (DSC) thermal analysis methods and limited oxygen index (LOI) method. Considering the near TG mass losses and the near LOI values for PP with 10% prepared BaO·4B2O3·5H2O nanosheet and nanoribbon, their flame-retardant properties need to be further evaluated by non-isothermal decomposition kinetic method. The apparent activation energy for this decomposition reaction was obtained from the slope by plotting ln(β/Tp2) against 1/Tp according to Kissinger's model. With the reduction of TG mass loss, increased heat absorption in DSC under N2 atmosphere, increased apparent activation energy Ea for the thermal decomposition of PP/BaO·4B2O3·5H2O composite as well as increased LOI value, the flame-retardant performance of prepared BaO·4B2O3·5H2O samples with PP gradually improved from bulk to nanoribbon to nanosheet. This can be attributed to the decrease in the size of BaO·4B2O3·5H2O samples because the smaller sample size leads to improved dispersion and increased contact area with the polymer. The flame-retardant mechanism is discussed by analyzing the after-flame chars of the PP/BaO·4B2O3·5H2O composite in SEM images, which show that the char layer is more compact and continuous for the PP/BaO·4B2O3·5H2O nanosheet composite. The influence of loading BaO·4B2O3·5H2O nanomaterials on the mechanical properties of PP is also tested using a universal material testing machine, in which the PP/BaO·4B2O3·5H2O nanosheet composite has higher tensile strength. The PP/BaO·4B2O3·5H2O nanosheet composite has the best flame-retardant and mechanical properties, which is promising to be developed for the application as flame-retardant material. 相似文献
110.
Anthony Jolly Dandan Miao Maxime Daigle Jean‐Franois Morin 《Angewandte Chemie (International ed. in English)》2020,59(12):4624-4633
The solution‐phase synthesis is one of the most promising strategies for the preparation of well‐defined graphene nanoribbons (GNRs) in large scale. To prepare high quality, defect‐free GNRs, cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate the presence of various functional groups. In this Minireview, we present the latest synthetic approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd‐ and Ni‐catalyzed reactions. 相似文献