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A re-investigation of the synthesis of a Fe(III)-oxo-(4- t Bu-pyrazolido) complex revealed the presence of dinuclear species, which had confused an earlier investigation of this chemistry. The synthesis and characterization of the octanuclear all-ferric compounds [Fe 8 (μ 4 -O) 4 (μ -4-R-pz) 12 Cl 4 ], R = t Bu (1) and n Bu (2) by spectroscopic (1H NMR, UV–Vis, FTIR, 57Fe-Mössbauer) and electrochemical methods are reported along with the single crystal X-ray structure determination of complex 1. These studies were undertaken in order to correct some erroneous conclusions in a recent publication (Eur. J. Inorg. Chem., 2018 , 4925–4929; Eur. J. Inorg. Chem., 2018 , 4930–4931) regarding compound 1. [ABSTRACT FROM AUTHOR]

Ceterach officinarum Willd is a plant widespread throughout Europe and used in southern Italy as a diuretic. Beliefs in the benefits of C. officinarum aqueous extract in the treatment of calcium oxalate kidney stones are widely held. Little is known, however, about the actual mechanism of its antilithiatic action. Our results in this in vitro study corroborate C. officinarum aqueous extract as a good source of antioxidants with a high antioxidant effects. Our results also demonstrate a major impact of C. officinarum aqueous extract on in vitro induced calcium oxalate crystallization kinetics and crystal morphology, showing its critical role in kidney stone formation and/or elimination. We show that progressively increasing doses of C. officinarum aqueous extract cause a sequence of effects. A powerful inhibitory action on calcium oxalate monohydrate (COM) growth and aggregation is first observed. C. officinarum aqueous extract also appears highly effective in stimulating nucleation increasing the number and reducing the size of COM crystals, which become progressively thinner, rounded and concave in a dose-dependent manner. These shape-modified COM crystals are known to be less adherent to renal tubular cells and more easily excreted through the urinary tract preventing kidney stone formation. Further, C. officinarum aqueous extract promotes the formation of calcium oxalate dihydrate (COD) rather than the monohydrate so that, at the highest concentrations used, only COD crystals are observed, in significant greater numbers with a clear reduction in their size, in a dose-dependent manner. Furthermore, AFM analyses allowed us to reveal the presence of C. officinarum component(s) on the surfaces of COD and modified COM crystals. The crystal surface adsorbed component(s) are shown to be similarly active as the total aqueous extract, suggesting a trigger factor which may direct crystal modification towards COD forms. In urolithiasis pathogenesis COD crystals are less dangerous than the COM forms due to their lower affinity for renal tubular cells. Our results are important in understanding the mechanisms which guide the modification induced by C. officinarum on the crystallization process. Based on these data, together with no adverse toxic effect being observed on the in vitro model of human intestinal enterocytes, C. officinarum aqueous extract could represent an attractive natural therapy for the treatment of urolithiasis. [ABSTRACT FROM AUTHOR]

Long-dormant volcanoes (quiescence time is several 100's to 10.000's years between eruptions) pose a particular hazard, since the long repose time decreases the awareness and there is also a lack of monitoring. The dacitic Ciomadul Volcanic Complex in eastern-central Europe is an excellent example of such volcanoes. It is in a quiescent state for 30 kyr, yet combined geophysical, zircon geochronological, electrical conductivity experiment, petrologic and thermal modeling results suggest that there is still a magma reservoir with significant melt content beneath it. This crystal mush magma reservoir could have a lifetime for more than 300 kyr. Thus, Ciomadul has been categorized as a PAMS volcano, i.e., a volcano with Potentially Active Magma Storage.Understanding the reactivation timescale of such volcanoes is crucial, and therefore we conducted a detailed petrologic study of a 130 ka lava dome rock. This dacitic rock contains a wide range of mineral phases, including plagioclase, amphibole and biotite phenocrysts as well as accessory phases of apatite, titanite, zircon, quartz, K-feldspar, olivine, clinopyroxene and FeTi oxides. Felsic and mafic crystal clots are common and they represent a long-standing low temperature granodioritic shallow crustal crystal mush and an ascending hot mafic magma, respectively. Both the plagioclases and the amphiboles show complex zoning and have a bimodal compositional character even within single crystals. Geothermobarometry results imply 700-750 oC temperature for the felsic crystal mush and a strong reheating by >200 oC before the eruption. We conducted a detailed study of plagioclase phenocrysts involving high-resolution line measurements. In many cases, we found an abrupt strong increase of Fe and Sr at the outermost 10-20 micron wide crystal rim (FeO is 0.1-0.15 wt%, SrO is 0.2-0.3 wt% in most of the crystals, but they increase to 0.3-0.35 wt% and 0.45-0.7 wt%, respectively at the rim) suggesting a mafic magma influence and fast reactivation timescale. Following resorption, rim growth at plagioclases and diffusive re-equilibration could have happened within days of the mafic recharge event. Magma ascent rate was estimated based on the decompression reaction zones around amphiboles, and we got 6-10 days for the ascent from the shallow magma reservoir resided at 7-11 km depth. Thus, long dormancy or seemingly inactive state of PAMS volcanoes could change quickly what has to be considered in hazard assessments.This research was financed by the Hungarian National Research, Development and Innovation Fund (NKFIH) within No. K116528 and No. PD 121048 projects. [ABSTRACT FROM AUTHOR]