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[This corrects the article DOI: 10.1039/D2RA06050G.].
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The article presents the method of producing gold nanoparticles using a high voltage arc discharge of alternating current with a frequency of 50 Hz in distilled water. The equipment necessary to carry out the process is described, including the construction of the reactor and the power source of a very simple design necessary to generate a high-voltage arc discharge between the electrodes. Arc discharge processes were carried out two times for 2 and 5 minutes, respectively, in ambient conditions without thermostating the reactor, at medium temperature varying in the range of 25-70 °C. The obtained gold nanoparticles were examined by means of various analytical techniques such as UV-vis spectroscopy, zeta potential measurement, energy dispersive X-ray analysis (EDS), X-ray diffraction (XRD). The morphology, surface, and size of the obtained nanoparticles were carried out using transmission electron microscopy (HRTEM) and dynamic light scattering (DLS). The concentration of the obtained colloids were determined using the mass spectrometry ICP-MS technique. The results show that high-voltage AC arc discharge is a simple and effective way to obtain stable gold nanoparticles under environmentally friendly conditions at relatively low production costs, and can be considered as an alternative to arc discharge nanoparticles synthesis by means of direct current (DC) methods.
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The circadian rhythm of the level of histamine (HI) and histidine decarboxylase (HD) and histamine-methyltransferase (HMT) activity in 6 brain and 5 ocular structures of the rabbit was studied. Clear circadian variations of the histaminergic parameters in two brain (hypothalamus and lateral geniculate body) and two ocular (retina and iris-ciliary body) tissues were found. It is suggested that HI in some brain and ocular structures may be functionally involved in activity that depends on circadian rhythm.
