The idea of applying ultrasound (US) as a green activation method in chemical transformations, especially in catalytic alcohol oxidations, technically and ecologically appeals to chemists. In the present work, as an attempt to fulfill the idea of designing an eco-friendly system to oxidize alcoholic substrates into corresponding aldehydes, we developed multifunctional tungstate-decorated CQD base catalyst, A-CQDs/W, and examined its sonooxidation performance in presence of H2O2 as a green oxidant in aqua media. By comparing the catalyst performance in oxidize benzyl alcohol as a testing model to benzaldehyde (BeOH) prior and after US irradiation—trace vs 93%- the key role of ultrasonic irradiation in achieving high yield is completely appreciated. Exceptional thermal and compression condition that is created as a result of acoustic waves is in charge of unparalleled yield results in this type of activation method. The immense degree of reagent interaction in this method, ensures the maximum yield in notably low time, which in turn leads to decrease in the number of unreacted reagents and by-products. Meanwhile, the need for using toxic organic solvents and hazardous oxidants, auxiliaries and phase transfer catalyst (PTC) is completely obviated.
Aging is a biological process determined through time-related cellular and functional impairments, leading to a decreased standard of living for the organism. Recently, there has been an unprecedented advance in the aging investigation, especially the detection that the rate of senescence is at least somewhat regulated via evolutionarily preserved genetic pathways and biological processes. Hematopoietic stem cells (HSCs) maintain blood generation over the whole lifetime of an organism. The senescence process influences many of the natural features of HSC, leading to a decline in their capabilities, independently of their microenvironment. New studies show that HSCs are sensitive to age-dependent stress and gradually lose their self-renewal and regeneration potential with senescence. MicroRNAs (miRNAs) are short, non-coding RNAs that post-transcriptionally inhibit translation or stimulate target mRNA cleavage of target transcripts via the sequence-particular connection. MiRNAs control various biological pathways and processes, such as senescence. Several miRNAs are differentially expressed in senescence, producing concern about their use as moderators of the senescence process. MiRNAs play an important role in the control of HSCs and can also modulate processes associated with tissue senescence in specific cell types. In this review, we display the contribution of age-dependent alterations, including DNA damage, epigenetic landscape, metabolism, and extrinsic factors, which affect HSCs function during aging. In addition, we investigate the particular miRNAs regulating HSCs senescence and age-associated diseases.
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