Recent years have witnessed a renaissance of radical cross‐coupling of cycloketone oximes which served as active cyanoalkyl radical via ring fragmentation in various transformations. It provided an ...efficient and practical strategy to introduce cyanoalkyl groups into organic compounds without using toxic cyanide sources. In this review, a comprehensive overview of recent advances in the field of redox‐active cycloketone oximes‐based cross‐couplings were covered. This review was categorized into two broad parts: non‐photocatalyzed and photocatalyzed cross‐couplings according to the reaction conditions. Moreover, the two broad parts were further divided into several sub‐sections depending on the nature of the bond formation. Some representative examples along with reaction mechanisms were also discussed.
Role of viral infection in sudden hearing loss Chen, Xin; Fu, Yao-yao; Zhang, Tian-yu
Journal of International Medical Research,
07/2019, Volume:
47, Issue:
7
Book Review, Journal Article
Peer reviewed
Open access
According to a recent epidemiological survey, the incidence of sudden sensorineural hearing loss (SSNHL) is increasing yearly. The cause of SSNHL is of great interest in research. To date, viral ...infection, vascular occlusion, abnormal cellular stress responses within the cochlea, and immune-mediated mechanisms are considered the most likely etiologies of this disease. Among these etiologies, the relationship between viral infection and sudden deafness has been unclear. In this review, we mainly discuss the viral hypothesis of SSNHL. There is little research proving or clearly indicating the pathogenesis of this disease. Further research is needed to elucidate the precise etiopathogenesis to better understand SSNHL and establish more suitable treatment to help restore hearing in affected patients.
The amino group is one of the most prevalent functional groups present in a wide range of organic molecules, which has been widely applied in various organic synthesis and pharmaceuticals. Alkyl ...amines could be converted in a single step into Katritzky salts which could serve as alkyl radical precursors to construct C−C bonds and C−X bonds via C(sp3)−N cleavage. This deaminative functionalization could be carried out under transition‐metal catalysis, photocatalysis, carbene catalysis or promoted by base. In this paper, recent developments in the deaminative functionalization of alkyl amines were covered. This review was categorized into four parts according to the nature of the bond formation. Some representative examples and corresponding reaction mechanisms were also summarized.
Alkyl amines could serve as alkyl radical precursors to construct C−C bonds and C−X bonds via C(sp3)−N cleavage. This review covered recent developments in the deaminative functionalization of alkyl amines.
The copper‐catalyzed stereoselective defluorinative borylation and silylation of gem‐difluoroalkenes was developed. The protocol led to the exclusive formation of Z type monofluoroalkenyl borons and ...silanes in generally good efficiency with broad substrate scope. The products formed could be readily transformed to other F‐containing molecules by taking advantage of the versatile reactivities of C−B and C−Si bonds. Experimental and theoretical mechanistic studies were conducted which support an olefin insertion/syn‐planar β‐F elimination pathway.
Peroxymonosulfate (PMS) is extensively used as an oxidant to develop the sulfate radical-based advanced oxidation processes in the decontamination of organic pollutants and various PMS activation ...methods have been explored. Visible-light-assisted PMS activation to construct a Fenton-like process has shown a great potential for pollution control. In our work, BiVO4 nanosheets were prepared using a hydrothermal process and used to activate PMS under visible light. A rapid degradation of ciprofloxacin (CIP) was achieved by dosing PMS (0.96 g/L), BiVO4 (0.32 g/L) under visible light with a reaction rate constant of 77.72-fold higher than that in the BiVO4/visible light process. The electron spin resonance and free radical quenching experiments indicate that reactive species of •O2−, h+, •OH and SO4•− all worked, where h+, •OH and SO4•− were found as the dominant contributors to the CIP degradation. The spectroscopic analyses further demonstrate that the photoinduced electrons were directly involved in the PMS activation process. The generated •O2− was partially utilized to activate PMS and more •OH was produced because of the chain reactions between SO4•− and H2O/OH−. In this process, PMS acted as an electron acceptor to transfer the photo-induced charges from the conduction band of BiVO4 and PMS was successfully activated to yield the high-powered oxidative species. From the degradation intermediates of CIP detected by a liquid-chromatography-mass spectrometer, the possible degradation pathways were proposed. The substantially decreased toxicity of CIP after the reaction was also observed. This work might provide new insights into the visible-light-assisted PMS activation mechanisms and is useful to construct environmentally-friendly catalytic processes for the efficient degradation of organic pollutants.
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•PMS was effectively activated by BiVO4 nanosheets for water purification under visible light.•Separation of electron/hole pairs and generation of oxidative species were enhanced.•Visible-light-assisted PMS activation Fenton-like mechanism was elucidated.•High mineralization and low biotoxicity validated the application potential of the system.
A long standing question in organic electronics concerns the effects of molecular orientation at donor/acceptor heterojunctions. Given a well-controlled donor/acceptor bilayer system, we uncover the ...genuine effects of molecular orientation on charge generation and recombination. These effects are studied through the point of view of photovoltaics-however, the results have important implications on the operation of all optoelectronic devices with donor/acceptor interfaces, such as light emitting diodes and photodetectors. Our findings can be summarized by two points. First, devices with donor molecules face-on to the acceptor interface have a higher charge transfer state energy and less non-radiative recombination, resulting in larger open-circuit voltages and higher radiative efficiencies. Second, devices with donor molecules edge-on to the acceptor interface are more efficient at charge generation, attributed to smaller electronic coupling between the charge transfer states and the ground state, and lower activation energy for charge generation.Molecular orientation profoundly affects the performance of donor-acceptor heterojunctions, whilst it has remained challenging to investigate the detail. Using a controllable interface, Ran et al. show that the edge-on geometries improve charge generation at the cost of non-radiative recombination loss.
Abstract A photoredox‐catalyzed three‐component sulfonaminoformyloxylation reaction between alkenes, N ‐aminopyridinium salts and DMF has been developed, which avoids the usage of erosive formic acid ...as the formyloxylation reagent. Besides DMF, alkyl and aryl carboxylic acids proved to be feasible nucleophiles to afford various β ‐amino esters. The robustness of this method was further demonstrated by its applicability in the late‐stage modification of biological molecules. Control experiments suggested that a sulfonamidyl radical was involved in this reaction.
Nonsense-mediated mRNA decay (NMD) is a quality-control mechanism that selectively degrades mRNAs harboring premature termination (nonsense) codons. If translated, these mRNAs can produce truncated ...proteins with dominant-negative or deleterious gain-of-function activities. In this review, we describe the molecular mechanism of NMD. We first cover conserved factors known to be involved in NMD in all eukaryotes. We then describe a unique protein complex that is deposited on mammalian mRNAs during splicing, which defines a stop codon as premature. Interaction between this exon-junction complex (EJC) and NMD factors assembled at the upstream stop codon triggers a series of steps that ultimately lead to mRNA decay. We discuss whether these proofreading events preferentially occur during a "pioneer" round of translation in higher and lower eukaryotes, their cellular location, and whether they can use alternative EJC factors or act independent of the EJC.
Recurrent spontaneous abortion (RSA), termed as two or more consecutive pregnancy loss is a great problem for some women of childbearing age. A large number of evidence confirm that there may be an ...immune background of RSA. As a member of the innate immune system, uterine natural killer (uNK) cells account for about 70% of total lymphocytes during pregnancy and play a critical role in the establishment and maintenance of pregnancy. This review mainly introduces the phenotype, origin, receptor, and function of uNK cells to illuminate its relationship with RSA.
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