The occurrence of aromaticity in organic molecules is widely accepted, but its occurrence in purely metallic systems is less widespread. Molecules comprising only metal atoms (M) are known to be able to exhibit aromatic behaviour, sustaining ring currents inside an external magnetic field along M–M connection axes (σ-aromaticity) or above and below the plane (π-aromaticity) for cyclic or cage-type compounds. However, all-metal compounds provide an extension of the electrons’ mobility also in other directions. Here, we show that regular {Bi6} prisms exhibit a non-localizable molecular orbital of f-type symmetry and generate a strong ring current that leads to a behaviour referred to as φ-aromaticity. The experimentally observed heterometallic cluster [{CpRu}3Bi6]–, based on a regular prismatic {Bi6} unit, displays aromatic behaviour; according to quantum chemical calculations, the corresponding hypothetical Bi62− prism shows a similar behaviour. By contrast, [{(cod)Ir}3Bi6] features a distorted Bi6 moiety that inhibits φ-aromaticity.

In this report, we present intricate pathways for the synthesis of linear nickel­(I) silylamide K­{m}­[Ni­(NR2)2] (NR2 = −N­(SiMe3)2). This is achieved first via the reduction of nickel­(II) trisamide Li­(donor)4[Ni­(NR2)3] (Li­(thf) x [1]) with KC8 in the presence of 18-crown-6 or crypt.222. In due course, the behavior of Li­(donor)4[Ni­(NR2)3] as a source of masked two-coordinate nickel­(II) hexamethyldisilazanide is explored, leading to the formation of nickel­(I) and nickel­(II) N-donor adducts, as well as metal–metal-bonded dinickel­(I) trisamide K­(toluene)­[Ni2(NR2)3] (K­(toluene)­[5]). Finally, a convenient and reliable synthesis of K­{m}­[Ni­(NR2)2] by ligand exchange of phosphines in [Ni­(NR2)­(PPh3)2] with K­{m}­(NR2) is presented. This allows for the comprehensive analysis of its electronic properties which reveals a fluxional behavior in solution with tight anion/cation interactions.

Objectives Chemsex refers to the use of sex‐enhancing drugs among men who have sex with men (MSM) in combination with specific sexual and social behaviours. Longitudinal data on this development and the associated health risks are scarce. Methods Data on all recreational drugs reported in the Swiss HIV Cohort Study (SHCS) from 2007 to 2017 were collected. Drug use was analysed longitudinally for all drug classes. In addition, potential associations between patient characteristics and the consumption of methamphetamine, γ‐hydroxybutric acid/γ‐butyrolactone (GHB/GBL), 3,4‐methylenedioxymethamphetamine (MDMA/XTC), cocaine and amphetamine were analysed. Results We analysed 166 167 follow‐up entries for 12 527 SHCS participants, including 7101 free text field entries containing information about recreational drugs other than cannabis, cocaine and heroin. Overall, we observed a stable percentage (9.0%) of recreational drug use (excluding cannabis, amyl nitrite and prescription drugs). For MSM, however, there was an increase in overall drug use from 8.8% in 2007 to 13.8% in 2017, with particularly large increases for methamphetamine (from 0.2 to 2.4%; P < 0.001) and GHB/GBL (from 1.0 to 3.4%; P < 0.001). The use of each of the potentially sex‐enhancing drugs methamphetamine, GHB/GBL, cocaine, XTC/MDMA and amphetamine was significantly associated with condomless sex with nonsteady partners, and higher prevalences of depression, syphilis and hepatitis C. Conclusions The significant increase in the use of chemsex drugs among MSM in the SHCS and the strong association with coinfections and depression highlights the need for harm reduction programmes tailored to MSM. According to our results, improving knowledge about recreational drugs is important for all health care professionals working with people living with HIV.

The aim of the present study was to investigate the short- and long-term effects of glucocorticoids [corticosterone (CORT), dexamethasone (DEX), 6-methylprednisolone (6-MP)] and gonadal steroids [17beta-estradiol (E(2)), progesterone (PROG), testosterone (TEST)] on the levels of the antioxidant glutathione (GSH) in different cell systems of the CNS (neuronal hippocampal HT22 cells, primary hippocampal and neocortical brain cells, and C(6) glioma cells). In HT22 cells, steroids exerted mainly long-term effects. Significant increases of GSH levels were detectable after a 24 hr treatment with 10(-7) M of DEX (122% +/- 5%), 6-MP (208% +/- 32%), E(2) (134% +/- 10%), and TEST (155% +/- 17%). A significant decrease occurred after incubation with PROG for 24 hr (79% +/- 9%). In primary hippocampal cultures, a 24 hr treatment with DEX (140% +/- 8%), E(2) (123% +/- 6%), and PROG (118% +/- 5%) led to significant increases of the GSH levels, whereas, in neocortical primary cultures, only an incubation with E(2) increased GSH (149% +/- 8%). In C(6) cells, hormone treatment led to both significant short-term (1 hr: CORT 114% +/- 5%, DEX 90% +/- 3%, E(2) 88% +/- 3%; 3 hr: DEX 115% +/- 5%, E(2) 122% +/- 6%, TEST 78% +/- 4%) and significant long-term (24 hr: CORT 74% +/- 4%, 6-MP 84% +/- 5%, E(2) 115% +/- 6%, PROG 91% +/- 4%, TEST 116% +/- 5%) effects. In summary, we were able to demonstrate differential effects of steroids on GSH levels in different cellular CNS models, showing an important influence of steroids and especially E(2) on antioxidative cellular functions in neuronal and glial cells.