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Failure involving Diphtheria Toxin Product to Cause Parkinson-Like Habits within Mice.
Finally, water evaporation experiments were carried out using a 3D-printed carbonized resorcinol-formaldehyde aerogel (CA) to further exhibit the potential applications of this novel technology in solar steam generation. The evaporation rate (1.57 kg m-2 h-1) and efficiency (88.38%) of 3D-printed CA were higher than those of bulk CA (1.21 kg m-2 h-1 and 69.82%). This paper systematically studies the control of DIW parameters for aerogel-based sol-gel inks and shows a potential application in high-efficiency 3D-printed evaporators.In this work, ruthenium(II)-catalyzed C-C/C-N annulation of 2-arylquinazolinones with vinylene carbonate is reported to synthesize fused quinazolinones. This catalytic system tolerates a wide range of substrates with excellent functional-group compatibility. In this transformation, the vinylene carbonate acts as an ethynol surrogate without any external oxidant involved. Furthermore, preliminary mechanistic studies were conducted, and a plausible catalytic cycle was also proposed.An expedient synthesis of β-silyl α-amino acids is reported via the application of visible-light-mediated hydrosilylation. The reaction utilizes readily accessible and structurally diverse hydrosilanes to provide radicals for conjugate addition to dehydroalanine ester and analogues. Notably, the use of chiral methyleneoxazolidinone as the substrate and chiral inducer enabled the highly stereoselective synthesis. Furthermore, the reaction could also be performed in a continuous flow fashion and scaled up to the gram scale.Synthesis of complex di(selenophen-3-yl)diselenides and 3-methylene-3H-1,2-diselenoles directly from 1-bromobutadiynes is described. The transformation is performed under conditions used before for the synthesis of simple selenophenes from butadiynes. The reaction is operationally straightforward, and complex products were obtained in high yields. Structures of the final products were unambiguously confirmed by the means of 77Se NMR and single-crystal X-ray diffraction.Halogenation brings about dramatic variations to the performance of self-assembled organic species, such as luminescence and crystallinity, but it has seldom been utilized for chirality control. Here we show the halogenation effect of self-assembling organic building units on supramolecular chirality and chiroptical responses. N-terminal aromatic amino acids with different substituted halogen atoms at p-phenylalanine residues self-assembled into one-dimensional fibrous structures. Halogenation induced the emergence of macroscopic chirality regardless of halogen properties like electronegativity, generating exclusive homochiral helical structures. Solid-state X-ray structures and time-dependent density functional theory were utilized for calculated electronic circular dichroism spectra, which evidenced the diverse driving forces to enable chiral molecular arrangements, including H-bonds and halogen bonds. Red-shifted luminescence was observed in brominated building units, giving rise to active circularly polarized luminescence. This work elucidates the multiple roles of halogen in chiral self-assembly systems, which provides insight into the rational control over supramolecular chirality and their chiroptical applications.Diamino protic ionic liquids (DPILs) possess a wide application prospect in the field of acid gas absorption. In this work, two representative DPILs, that is, dimethylethylenediamine 4-fluorophenolate ([DMEDAH][4-F-PhO]) and dimethylethylenediamine acetate ([DMEDAH][OAc]), which had been proved to display favorable CO2 absorption performance in experiments, were selected. Based on the solvation model, the different mechanisms of CO2 absorption by [DMEDAH]+ cations combined with different anions were investigated using the dispersion-corrected density functional theory method. Above all, the possible active sites of the reaction between DPILs and CO2 were analyzed by electrostatic potential (ESP) and electronegativity, and the transition states in each path were searched and verified by frequency calculation and intrinsic reaction coordinate calculation. Furthermore, the Gibbs free energy and reaction heat of each path were calculated, and the free energy barrier and enthalpy barrier diagrams were shown. It was found that the absorption path by the anion of [DMEDAH][4-F-PhO] was favorable in kinetics, while the absorption path by the cation was thermodynamically beneficial. In addition, [DMEDAH][OAc] only showed the possibility of cation absorption, and the mechanism of the transfer of active protons to weak acid anions and the formation of acetic acid molecules was more favorable. Moreover, through the structural analysis, bond order and bond energy calculation, ESP analysis of the ion pair absorption configuration, and comparison with the products of CO2 absorbed by isolated ions, it was found that the interaction between anions/cations and CO2 could weaken or enhance the interaction between anions and cations in different reaction steps. Hopefully, this study is helpful to understand the absorption mechanism of CO2 by DPILs and provides a theoretical basis for the R&D of multi-active site functionalized ILs.An investigation of the properties and reactivity of fluoromethylsulfonium salts resulted in the redesign of the reagents for fluoromethylene transfer chemistry. The model reaction, fluorocyclopropanation of nitrostyrene, turned out to be a suitable platform for the discovery of more streamlined fluoromethylene transfer reagents. The incorporation of halides on one aryl ring increased the reactivity, and 2,4-dimethyl substitution on the other aryl ring provided a balance between the reactivity/crystallinity of the reagent as well as the atom economy. The utility of new reagents was demonstrated by the development of an efficient fluorocyclopropanation protocol to access a range of monofluorinated cyclopropane derivatives.Macrocage molecules with a bridged π-electron system could be assumed as crystalline molecular gyrotops because of the structural similarity and the rotatable π-electron system. In this study, 1,2-difluoro-3,6-phenylene-bridged macrocages were designed and synthesized as crystalline molecular gyrotops with a dipolar rotor. The thermal ring dynamics of the dipolar rotor in the crystal were investigated by solid-state NMR and dielectric spectroscopy. The gyrotop that was surrounded by three C14-alkyl chains exhibited an exchange between two stationary positions in the crystalline state. In contrast, the gyrotop cage consisting of C18 chains exhibited no dynamics in the crystalline state. Although the corresponding phenylene derivatives exhibit a facile rotational motion of the phenylene group in the crystalline state, the dynamics of each derivative was observed to be different. The reason for this difference is ascribed to the difference in the bulkiness between the fluorine and hydrogen atoms in the rotor.Snow serves as a vital scavenging mechanism to gas-phase and particle-phase organic nitrogen substances in the atmosphere, providing a significant link between land-atmosphere flux of nitrogen in the surface-earth system. Here, we used optical instruments (UV-vis and excitation-emission matrix fluorescence) and a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) to elucidate the molecular composition and potential precursors of snow samples collected simultaneously at four megacities in North China. The elemental O/N ratio (≥3), together with the preference in the negative ionization mode, indicates that the one and two nitrogen atom-containing organics (CHON1 and CHON2) in snow were largely in the oxidized form (as organic nitrates, -ONO2). This study assumed that scavenging of particle-phase and gas-phase organic nitrates might be significant sources of CHON in precipitation. learn more A gas-phase oxidation process and a particle-phase hydrolysis process, at a molecular level, were used to trace the potential precursors of CHON. Results show that more than half of the snow CHON molecules may be related to the oxidized and hydrolyzed processes of atmospheric organics. Potential formation processes of atmospheric organics on a molecular level provide a new concept to better understand the sources and scavenging mechanisms of organic nitrogen species in the atmosphere.Despite the recent advances in cancer therapeutics, highly aggressive cancer forms, such as glioblastoma (GBM), still have very low survival rates. The intracellular scaffold protein syntenin, comprising two postsynaptic density protein-95/discs-large/zona occludens-1 (PDZ) domains, has emerged as a novel therapeutic target in highly malignant phenotypes including GBM. Here, we report the development of a novel, highly potent, and metabolically stable peptide inhibitor of syntenin, KSL-128114, which binds the PDZ1 domain of syntenin with nanomolar affinity. KSL-128114 is resistant toward degradation in human plasma and mouse hepatic microsomes and displays a global PDZ domain selectivity for syntenin. An X-ray crystal structure reveals that KSL-128114 interacts with syntenin PDZ1 in an extended noncanonical binding mode. Treatment with KSL-128114 shows an inhibitory effect on primary GBM cell viability and significantly extends survival time in a patient-derived xenograft mouse model. Thus, KSL-128114 is a novel promising candidate with therapeutic potential for highly aggressive tumors, such as GBM.In this work, a tetradentate N,O-hybrid 2,9-bis(diphenylphosphine oxide)-1,10-phenanthroline (Ph2-BPPhen) ligand was studied for the coextraction of trivalent f-block elements from nitric acid media. The extraction as well as the complexation behaviors of Ph2-BPPhen with f-block elements were thoroughly investigated using 31P and 1H NMR spectrometry, UV-vis spectrophotometry, single crystal X-ray diffraction, and density functional theoretical (DFT) calculation. Ph2-BPPhen exhibits remarkably extraction ability for both Am(III) and Eu(III) and more than 99.5% of Am(III) and Eu(III) were extracted from 1.0 M HNO3 solution. Slope analysis suggests that both 21 and 11 ligand/metal complexes were probably formed during the extraction. The 11 and 21 Ln(III) complexes with Ph2-BPPhen were also identified in CH3OH solution by NMR spectrometry, and the stability constants were determined via UV-vis spectrophotometry. Structures of the 11 Eu(Ph2-BPPhen)(NO3)3 and Am(Ph2-BPPhen)(NO3)3 complexes were further elucidated by single X-ray crystallography and DFT calculations. The higher extractability of Ph2-BPPhen toward trivalent Am(III) and Eu(III) compared with the previously reported phenanthroline-derived amide and phosphonate ligands was attributed to the stronger affinity of the -P═O(R)2 group to metal ions. The results from this work indicate that the N,O-hybrid 1,10-phenanthroline derived phosphine oxide ligand can serve as a new and promising candidate for coextraction of trivalent f-block elements in the treatment of nuclear waste.We report a palladium-catalyzed, ligand promoted, C-H fluorine-containing olefination of anilides with 4-bromo-3,3,4,4-tetrafluorobutene as the fluorinated reagent, which has a potential transformation into other compounds due to its -CF2CF2Br functional group. -CF2CF2H was obtained by using the mild reducing agent sodium borohydride. Bioactive compounds such as aminoglutethimide derivative and propham were well-tolerated in this reaction, both of which highlight the synthetic importance of this method.
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