Direct cross-coupling between simple arenes and heterocyclic amines under mild conditions is undoubtedly important for C–N bonds construction. Selective C(sp2)-H amination is more valuable. Herein we show a selective C(sp2)-H amination of arenes (alkyl-substituted benzenes, biphenyl and anisole derivatives) accompanied by hydrogen evolution by using heterocyclic azoles as nitrogen sources. The reaction is selective for C(sp2)-H bonds, providing a mild route to N-arylazoles. The KIE (kinetic isotope effect) experiment reveals the cleavage of C–H bond is not involved in the rate-determining step. Kinetic studies indicate the first-order behaviour with respect to the arene component. It is interesting that this system works without the need for any sacrificial oxidant and is highly selective for C(sp2)-H activation, whereas C(sp3)-H bonds are unaffected. This study may have significant implications for the functionalization of methylarenes which are sensitive to oxidative conditions.
Fundamental understanding of constructing elevated catalysts to realize fast electron transfer and rapid mass transport in oxygen reduction reaction (ORR) chemistry by interface regulation and structure design is important but still ambiguous. Herein, a novel jellyfish-like Mott-Schottkytype electrocatalyst is developed to realize fast electron transfer and decipher the structure-mass transport connection during ORR process. Both spectroscopy techniques and density functional theory calculation demonstrate electrons spontaneously transfer from Fe to N-doped graphited carbon at the heterojunction interface, thus accelerating electron transfer from electrode to reactant. Dynamic analysis indicates unique structure can significantly improve mass transport of oxygen-species due to two factors: one is electrolyte streaming effect caused by tentacle-like carbon nanotubes; the other is effective collision probability in the semiclosed cavity. Therefore, this Mott-Schottky-type catalyst delievers superior ORR performance with high onset potential, positive half wave potential, and large current density. It also exhibits low overpotential when serving as an air cathode in Zn-air batteries. This work deepens understanding of the two key factors-electron transfer and mass transport-on determining the kinetic reaction of ORR process and offers a new avenue in constructing efficient Mott-Schottky electrocatalysts.
The advancement of miniaturized electronic devices requires the development of high-performance microsupercapacitors. The low areal energy density of microsupercapacitors with the interdigitated architecture is the major challenge hindering the application. Here, a simple method for the scalable fabrication of all-solid-state, flexible microsupercapacitors is demonstrated by direct graphene-carbon nanotube composite ink writing technology. The microsupercapacitors demonstrate good electrochemical performance with a high areal energy density of 1.36 µWh cm -2 and power density of 0.25 mW cm -2 , good cycling stability, and excellent mechanical flexibility. The method developed here sheds light on the simple method of preparing high-performance, all-solid-state, flexible microsupercapacitors in a straightforward and scalable process.
Considering the synthetic value of introducing active alcoholic hydroxyl group, developing C–H functionalization of alcohols is of significance. Herein, we present a photochemical method that under visible light irradiation, selectfluor can effectively promote the oxidative cross-coupling between alcohols and heteroarenes without the external photocatalysis, achieving the selective α sp3 C–H arylation of alcohol, even in the presence of ether. The N-F activation of selectfluor under blue LEDs irradiation is evidenced by electron paramagnetic resonance (EPR) study, which is the key process for the oxidative activation of α sp3 C–H alcohols. The observed reactivity may have significant implications for chemical transformations.
Background/Aims: Circular RNAs (circRNAs) play a significant role in the development and progression of various human cancers. However, the expression and function of circRNAs in cervical cancer (CC) have rarely been explored. The aim of this study was to investigate the biological function of circRNA8924 in CC and elucidate the possible molecular mechanism involved. Methods: Quantitative polymerase chain reaction was used to determine mRNA expression of circRNA8924, miR-518d-5p/519-5p and CBX8 in CC tissues and cells. CBX8 protein expression was measured by Western blotting. The CCK-8 assay was used to evaluate cell proliferation, and the transwell assay to determine cell migration and invasion. The luciferase reporter assay was used to determine the direct regulation of miR-518d-5p/519-5p and circRNA8924 or CBX8 Results: The study demonstrated that the expression level of circRNA8924 in CC was significantly higher than that in the adjacent normal tissues (P < 0.001), and that it was also associated with tumor size, FIGO staging and myometrial invasion. The knockdown of circRNA8924 significantly inhibited the proliferation, migration and invasion of CC cells SiHa and HeLa. The expression level of miR-518d-5p/519-5p was negatively correlated with circRNA8924, and circRNA8924 regulated CBX8 by competitively binding to miR-518d-5p/519-5p. Conclusions: CircRNA8924 is highly expressed in CC tissue and can be considered a competitive endogenous RNA of the miR-518d-5p/519-5p family to promote the malignant biological behavior of CC cells. It is suggested that it may serve as a new biomarker for CC diagnosis and disease progression and provide potential targets for targeted therapy.
Background: Kikuchi-Fujimoto disease, known as histiocytic necrotizing lymphadenitis, is a benign, self-limiting and systemic disorder involving lymph nodes with unknown aetiology. First reported in Japan, there has been an increase in its incidence globally. Because of its non-specific clinical features, the disease can be easily mistaken for other forms of lymphadenitis with a high rate of misdiagnosis and mistreatment, posing a considerable challenge. Case presentation: A case of young Chinese woman with fever and cervical lymphadenopathy is presented. Physical examinations and imaging techniques were used to rule out common forms of lymphadenitis (e.g. cat-scratch disease and tuberculous lymphadenitis). Laboratory tests were then conducted to exclude others such as systemic lupus erythematosus and non-Hodgkin lymphoma. After Kikuchi-Fujimoto disease was identified, the patient was managed with symptomatic treatments. Our case was compared with relevant cases in the literature. A diagnostic flow chart was proposed to facilitate the diagnosis and treatment. Conclusions: With its shared clinical features, Kikuchi-Fujimoto disease can be mistaken for other forms of lymphadenitis. A combined use of medical imaging and laboratory tests is the effective way to avoid misdiagnosis.
Copyright: Zhang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT Cerebrovascular disease such as stroke is one of the most common diseases in the aging population, and neural stem cells (NSCs) transplantation may provide an alternative therapy for cerebral ischemia. However, a hostile microenvironment in the ischemic brain offers is challenging for the survival of the transplanted cells. Considering the neuroprotective role of basic fibroblast growth factor (bFGF), the present study investigated whether bFGF gene-modified NSCs could improve the neurological function deficit after transient middle cerebral artery occlusion (MCAO) in adult male Sprague-Dawley rats. These rats were intravenously injected with modified NSCs (5×10 6 /200 μL) or vehicle 24 h after MCAO. Histological analysis was performed on days 7 and 28 after tMCAO. The survival, migration, proliferation, and differentiation of the transplanted modified C17.2 cells in the brain were improved. In addition, the intravenous infusion of NSCs and bFGF gene-modified C17.2 cells improved the functional recovery as compared to the control. Furthermore, bFGF promoted the C17.2 cell growth, survival, and differentiation into mature neurons within the infarct region. These data suggested that bFGF gene-modified NSCs have the potential to be a therapeutic agent in brain ischemia. www.impactjournals.com/oncotarget/
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