BackgroundDrug-use in sexual settings among men who have sex with men (MSM) is increasing across Europe and is a key driver of sexually transmitted infections (STIs). Chemsex is evolving with increasing use of new psychoactive substances and diversification of context, shifting from private homes to diverse settings. Our aim was to assess changes in drug-use for sex among MSM who attended our STI/HIV reference center in two different periods over the last 8 years.MethodsWe compared two cross-sectional surveys conducted at the STI/HIV center of the San Gallicano Dermatological Institute (Rome, Italy) in 2018 (using paper-based, self-administered questionnaires) and 2024-2025 (using online self-administered questionnaires). The main outcome was the self-reported sexualized drug-use and chemsex (i.e., use of any of the three classic "chems": crystal methamphetamine, mephedrone, and GHB/GBL) in the previous year. Proportions were compared using Fisher's exact test or chi-square test, as appropriate.ResultsThe surveys included 354 MSM in 2018 and 331 MSM in 2024-2025. Overall, chemsex significantly increased from 5.1% in 2018 to 19.0% in 2024-2025 (p < 0.0001), both among MSM living with HIV (p < 0.0001) and MSM not living with HIV (p = 0.0005). A significant increase was observed in the use of crystal meth (2.3% vs 8.2%, p = 0.0005), mephedrone (4.0% vs 9.4%, p = 0.005), and GHB/GBL (3.4% vs 16.9%, p < 0.0001). Synthetic cathinones (from 0 to 2.7%, p = 0.001) and cannabinoids (from 0 to 0.9%, p = 0.112) emerged as new substances reported only in the most recent survey.ConclusionsIn our setting, drug-use for sex increased over time among MSM, with expansion of chemsex and diversification of substances. This behavioral change may increase STI/HIV transmission. Public health & STI/HIV services should update screening, counselling and harm reduction strategies to address these evolving patterns.

Two N-alkyl derivatives of 2-meth-oxy-5-nitro-aniline, namely, 2-meth-oxy-N-(4-methyl-benz-yl)-5-nitro-aniline (C15H16N2O3, orange crystals) and 2-meth-oxy-5-nitro-N-(tri-phenyl-meth-yl)aniline ethanol quatersolvate (C26H22N2O3·0.25C2H5OH, yellow crystals), have been prepared and analyzed by single-crystal X-ray diffraction to determine if these compounds display the same face-to-face π-stacking arrangement as observed in the un-alkyl-ated parent compound. The tri-phenyl-methyl derivative crystallizes with 0.25 ethanol mol-ecules, the contribution of which has been modeled with a solvent mask due to a high degree of disorder. The UV-Vis spectra show that the benzyl derivative displays concentration-dependent shifts in the visible portion of the spectrum, shifting to longer wavelengths with higher concentration, which is attributed to aggregation in solution. This behavior is similar to that observed for the parent compound. In contrast, the tri-phenyl-methyl derivative shows an attenuated concentration dependence on visible absorption, which does not display as great a red shift, and therefore represents a lesser tendency for aggregation in solution. The crystal packing for these compounds is distinguishing, with the benzyl derivative π-stacking in a face-to-face manner with dipole moments oriented anti-parallel, while the sterically demanding tri-phenyl-methyl group prevents direct π-stacking for this compound. The packing observed for these compounds supports the hypothesis that an inter-molecular charge-transfer process is responsible for the orange color of crystals of the benzyl derivative. It is concluded that sterically undemanding groups attached at the amino group could deliver materials which mimic the color center formation hypothesized for the parent compound. These types of structural changes may have useful applications in the field of organic semiconductors.

The title compound, C17H18N4O4, consists of almost planar isatin and triazole rings inclined by 78.47 (5)°, as well as a butyl acetate moiety bonded to the N atom of the triazole ring. In the crystal, mol-ecules link into a semicolon shape along the b-axis direction through bifurcated C-H⋯O hydrogen bonds. Aromatic π-π and C-H⋯π(ring) inter-actions also help to consolidate the crystal packing. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (40.6%), H⋯O/O⋯H (26.6%), H⋯N/N⋯H (13.8%) and H⋯C/C⋯H (8.9%) inter-actions. The volume of the crystal voids and the percentage of free space in the unit cell were calculated to be 82.1 Å3 and 10.0%, respectively, showing that there is no large cavity in the crystal packing. Computational methods revealed C-H⋯O hydrogen-bonding energy of -11.6 kJ mol-1. The evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated via the dispersion energy contributions in the crystal structure.

Terahertz (THz) radiation is rapidly gaining attention for applications in biomedical diagnostics, security, and wireless communication. Polymers play a central role in advancing THz technologies, as they are ideal for lenses, filters, waveguides, and metasurfaces. However, material selection is driven by commercial availability rather than by the rational design of their composition, and progress is hindered by the limited availability of polymers that combine low THz losses with high printability. To address this problem, the relationship between polymer composition and THz transparency in photocurable resins is here investigated, establishing practical guidelines for tailoring THz response through resin composition. A comprehensive framework is developed to predict THz properties based on key structural features, including heteroatoms, cyclic structures, secondary forces, and the carbon-to-oxygen (C/O) ratio. In particular, (meth)-acrylic resins with aliphatic backbones exhibit predictable behavior, enabling the estimation of their THz response directly from the C/O atomic ratio. Using the best-performing formulations, photonic crystals for THz modulation were fabricated via digital light processing (DLP) 3D printing. These devices are used to demonstrate how geometric parameters, fabrication precision, and material properties influence the THz devices' response. Comparisons between THz-optimized formulations and commercial resins highlight the importance of combining high printability and THz transparency in the fabrication of functional devices, demonstrating that proper resin design enables the decrease of the absorption coefficient up to 5 cm-1 at 1THz (vs 19-30 cm-1 of commercial resins usually employed for 3D-printed THz devices), maintaining a sufficient printability, resulting in an extension of the range of controllable response of the photonic crystals up to 2 THz, well beyond the sub-0.5 THz limit typically reported in the literature for similar structures. This material-driven approach establishes a rational pathway for designing polymers tailored for THz applications while enabling the fabrication of technologically relevant devices with accessible and low-cost 3D printing.

Because there is no published experience with methamphetamine as a therapeutic agent during breastfeeding, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. One expert recommends that amphetamines not be used therapeutically in nursing mothers.[1] Methamphetamine should not be used as a recreational drug by nursing mothers because it may impair their judgment and childcare abilities. Methamphetamine and its metabolite, amphetamine, are detectable in breastmilk and infant's serum after abuse of methamphetamine by nursing mothers. However, these data are from random collections rather than controlled studies because of ethical considerations in administering recreational methamphetamine to nursing mothers. Other factors to consider are the possibility of positive urine tests in breastfed infants which might have legal implications, and the possibility of other harmful contaminants in street drugs. Breastfeeding is generally discouraged in mothers who are actively abusing amphetamines.[2-5] In mothers who abuse methamphetamine while nursing, withholding breastfeeding for 48 to 100 hours after the maternal use been recommended, although in many mothers methamphetamine is undetectable in breastmilk after an average of 72 hours from the last use.[6,7] It has been suggested that breastfeeding can be reinstated 24 hours after a negative maternal urine screen for amphetamines.[7]

The crystal of ethyl 3-hy-droxy-benzoate, C9H10O3, comprises two independent mol-ecules in the asymmetric unit. Each mol-ecule is approximately planar with the ethyl group directed away from the carbonyl-O atom. The planarity is reflected in the phenyl-C-C-O-C(methyl-ene) torsion angles of -179.40 (10) and 177.88 (11)°, respectively. The greatest difference between the mol-ecules is found in the relative orientations of the methyl groups as seen in the carboxyl-ate-C-O-C-C(meth-yl) torsion angles of -178.76 (11) and -171.12 (13)°, respectively. In the crystal, hydroxyl-O-H⋯O(carbon-yl) hydrogen-bonding occurs within almost planar chains along [100].

The title imidazolium picrate salt, C24H23N2O+·C6H2N3O7 -, crystallizes in the triclinic space group P1. The asymmetric unit consists of one imidazolium cation and one picrate anion. The mol-ecular structure is consolidated by an intra-molecular N-H⋯O hydrogen bond within the imidazolium cation and by an inter-molecular N-H⋯O hydrogen bond between the imidazolium cation and the picrate anion. In the crystal, the ions are further associated through π-π stacking inter-actions, contributing to the supra-molecular packing arrangement. Two nitro groups of the picrate anion were modelled as disordered over two positions.

The title complex, bis-{μ4-(E)-2-[(5-meth-oxy-2-oxido-benzyl-idene)amino]-benzoato}bis-{μ2-(E)-2-[(5-meth-oxy-2-oxido-benzyl-idene)amino]-benzoato}tetra-copper(II), [Cu4(C15H11NO4)4] or Cu4(L)4, was synthesized by the solvothermal reaction of (E)-2-[(2-hy-droxy-5-meth-oxy-benzyl-idene)amino]-benzoic acid (H2 L) with copper(II) chloride. It crystallizes in the triclinic system with space group Pī. The tetra-nuclear structure consists of two fully symmetric dinuclear copper moieties. In the dinuclear copper structural unit, both copper(II) metal centers exhibit a five-coordinate NO4 environment. Of the four coordinating oxygen atoms, two are phenolate oxygen atoms acting as bridges from two different ligands, while the other two oxygen atoms are derived from the carboxyl groups of two distinct ligands, respectively. SHAPE analysis indicates that both copper(II) centers adopt a distorted trigonal-bipyramidal (D 3h ) geometry. C-H⋯O hydrogen bonds and C-H⋯π inter-actions contribute to the cohesion of the crystal packing.

The crystal structure of the (1R,2S,5R) diastereomer of acoltremon [systematic name: (1R,2S,5R)-2-isopropyl-N-(4-meth-oxy-phen-yl)-5-methyl-cyclo-hexane-1-carboxamide], C18H27NO2, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Acoltremon crystallizes in space group P212121 and the crystal structure consists of corrugated layers lying parallel to the bc plane. N-H⋯O hydrogen bonds link the mol-ecules into chains propagating along the a-axis direction, with graph-set descriptor C 1 1(4).

catena-Poly[aluminium(III)-μ-hydroxido-κ2 O:O-di-μ-methane-sulfonato-κ4 O:O'], [Al(OH)(CH3SO3)2] n , was prepared by mild hydro-thermal synthesis at 523 K and crystallizes as millimetre-sized clear and colourless needles. The asymmetric unit contains half of the repeating structure, one-dimensional (AlO6)∞ chains corner sharing through the axial hydroxyl group with a bend of ∼137ο. The extended structure shows the chains are connected through weak meth-yl-hydrogen bonding in the [001] direction and strong hydrox-yl-hydrogen bonding in the [100] direction. This is the second aluminium-based methane-sulfonate salt reported to date.

In the presence of tri-methyl-amine, new compounds were obtained by aryl-sulfonyl-ation of 3-(piperidin-2-yl)pyridine (the alkaloid anabasine), namely: (S)-3-{1-[(4-chloro-phen-yl)sulfon-yl]piperidin-2-yl}pyridine, C16H17ClN2O2S (1); (S)-3-[1-(4-methyl-phen-yl)piperidin-2-yl]pyridine, C17H20N2O2S (2); (S)-3-{1-[(4-meth-oxy-phen-yl)sulfon-yl]piperidin-2-yl}pyridine, C17H20N2O3S (3); and (S)-3-{1-[(3,4-di-methyl-phen-yl)sulfon-yl]piperidin-2-yl}pyridine, C18H22N2O2S (4). In the crystal structures, the spatial arrangement of the pyridine and piperidine rings around the Csp 2-C* bond, as well as the orientation of the benzene ring of the aryl-sulfonyl group relative to the anabasine moiety, are analyzed.

The title com-pound, C14H14N4OS, was crystallized at -20 °C by ether diffusion into an ethanol solution. The dihedral angle between the planes of the aromatic rings is 38.19 (19)° and the mol-ecular conformation is supported by two intra-molecular N-H⋯N hy-dro-gen bonds. In the extended structure, N-H⋯O hy-dro-gen bonds link the mol-ecules into [011] chains. Hirshfeld surface analysis shows that H⋯H (44%), C⋯H/H⋯C (25%) and S⋯H/H⋯S (11.4%) contacts contibute the largest amounts.

The crystal structure of avutometinib (systematic name: 3-{[3-fluoro-2-(methyl-sulfamoyl-amino)-pyridin-4-yl]meth-yl}-4-methyl-7-(pyrimidin-2-yloxy)-chro-men-2-one), C21H18FN5O5S, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Avutometinib crystallizes in space group P1 (#2). The crystal structure is composed of layers parallel to the ab plane. N-H⋯O hydrogen bonds link the layers along the a-axis direction. The mol-ecule is Z-shaped.