Native gold occurs as very small to microscopic particles embedded in rock, often together with quartz or sulfide minerals such as "fools gold", which is a pyrite. These are called lode deposits. The metal in a native state is also found in the form of free flakes, grains or larger nuggets that have been eroded from rocks and end up in alluvial deposits called placer deposits. Such free gold is always richer at the exposed surface of gold-bearing veins, owing to the oxidation of accompanying minerals followed by weathering; and by washing of the dust into streams and rivers, where it collects and can be welded by water action to form nuggets. Gold sometimes occurs combined with tellurium as the minerals calaverite, krennerite, nagyagite, petzite and sylvanite (see telluride minerals), and as the rare bismuthide maldonite (Au2Bi) and antimonide aurostibite (AuSb2). Gold also occurs in rare alloys with copper, lead, and mercury: the minerals auricupride (Cu3Au), novodneprite (AuPb3) and weishanite ((Au,Ag)3Hg2). Recent research suggests that microbes can sometimes play an important role in forming gold deposits, transporting and precipitating gold to form grains and nuggets that collect in alluvial deposits.Another recent study has claimed water in faults vaporizes during an earthquake, depositing gold. When an earthquake strikes, it moves along a fault. Water often lubricates faults, filling in fractures and jogs. About 10 kilometres (6.2 mi) below the surface, under very high temperatures and pressures, the water carries high concentrations of carbon dioxide, silica, and gold. During an earthquake, the fault jog suddenly opens wider.
Levoketoconazole, sold under the brand name Recorlev, is a steroidogenesis inhibitor that is used for the treatment of Cushings syndrome. Levoketoconazole was approved for medical use in the United States in December 2021.Levoketoconazole is the levorotatory or (2S,4R) enantiomer of ketoconazole, and it is an inhibitor of the enzymes CYP11B1 (11β-hydroxylase), CYP17A1 (17α-hydroxylase/17,20-lyase), and CYP21A2 (21-hydroxylase). It inhibits glucocorticoid biosynthesis and hence circulating levels of glucocorticoids, thereby treating Cushings syndrome. In addition to its increased potency, the drug is 12-fold less potent than racemic ketoconazole in inhibiting CYP7A1 (cholesterol 7α-hydroxylase), theoretically resulting in further reduced interference with bile acid production and metabolite elimination and therefore less risk of hepatotoxicity. Levoketoconazole has also been found to inhibit CYP11A1 (cholesterol side-chain cleavage enzyme) and CYP51A1 (lanosterol-14α-demethylase), similarly but more potently relative to ketoconazole. References
External links
"Levoketoconazole". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03277690 for "A Study to Assess the Safety and Efficacy of Levoketoconazole in the Treatment of Endogenous Cushings Syndrome" at ClinicalTrials.gov
Clinical trial number NCT01838551 for "Treatment for Endogenous Cushings Syndrome (SONICS)" at ClinicalTrials.gov