Alcohol consumption in heroin users, methadone-substituted and codeine-substituted patients - Frequency and correlates of use

This retrospective study aims to determine whether there is a difference in the additional consumption of alcohol between addicts treated with methadone or dihydrocodeine (DHC) and untreated addicts injecting heroin. 1,685 patients admitted for opioid withdrawal between 1991 and 1997 were reviewed. Cross-reference tables and multiple logistic regression analyses were carried out. 28% of patients take more than 40 g of alcohol daily (on average 176 g). We found that patients who are treated with methadone or DHC drink alcohol significantly more often daily than the heroin-dependent patients (p<0.01). Using multiple regression analyses, the results were confirmed. Additionally, we found that co-abuse of alcohol was predicted by male gender, longer duration of drug use, additional daily consumption of tetrahydrocannabinol and daily consumption of benzodiazepines. Alcohol consumption by opioid-addicted patients treated with methadone or DHC presents a serious medical problem. Co-abuse of alcohol will receive more attention Copyright (C) 2003 S. Karger AG, Basel

A Parametric Approach for Determining Fishway Attraction Flow at Hydropower Dams

This article belongs to the Special Issue "Fish Passage at Hydropower Dams". Further information: https://www.mdpi.com/journal/water/special_issues/fish_passage_hydropower_da

Photoionization-induced pi <-> H site switching dynamics in phenol(+)-Rg (Rg = Ar, Kr) dimers probed by picosecond time-resolved infrared spectroscopy

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The ionization-induced pi H site switching reaction in phenol(+)-Rg (PhOH+-Rg) dimers with Rg = Ar and Kr is traced in real time by picosecond time-resolved infrared (ps-TRIR) spectroscopy. The ps-TRIR spectra show the prompt appearance of the non-vanishing free OH stretching band upon resonant photoionization of the pi-bound neutral clusters, and the delayed appearance of the hydrogen-bonded (H-bonded) OH stretching band. This result directly proves that the Rg ligand switches from the pi-bound site on the aromatic ring to the H-bonded site at the OH group by ionization. The subsequent H pi back reaction converges the dimer to a pi H equilibrium. This result is in sharp contrast to the single-step pi H forward reaction in the PhOH+-Ar-2 trimer with 100% yield. The reaction mechanism and yield strongly depend on intracluster vibrational energy redistribution. A classical rate equation analysis for the time evolutions of the band intensities of the two vibrations results in similar estimates for the time constants of the pi H forward reaction of tau(+) = 122 and 73 ps and the H pi back reaction of tau_ = 155 and 188 ps for PhOH+-Ar and PhOH+-Kr, respectively. The one order of magnitude slower time constant in comparison to the PhOH+-Ar-2 trimer (tau(+) = 7 ps) is attributed to the decrease in density of states due to the absence of the second Ar in the dimer. The similar time constants for both PhOH+-Rg dimers are well rationalized by a classical interpretation based on the comparable potential energy surfaces, reaction pathways, and density of states arising from their similar intermolecular vibrational frequencies

Microsolvation of the acetanilide cation (AA(+)) in a nonpolar solvent: IR spectra of AA(+)-L-n clusters (L = He, Ar, N-2; n <= 10)

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Infrared photodissociation (IRPD) spectra of mass-selected cluster ions of acetanilide (N-phenylacetamide), AA+–Ln, with the ligands L = He (n = 1–2), Ar (n = 1–7), and N2 (n = 1–10) are recorded in the hydride stretch (amide A, νNH, νCH) and fingerprint (amide I–III) ranges of AA+ in its 2A′′ ground electronic state. Cold AA+–Ln clusters are generated in an electron impact ion source, which predominantly produces the most stable isomer of a given cluster ion. Systematic vibrational frequency shifts of the N–H stretch fundamentals (νNH) provide detailed information about the sequential microsolvation process of AA+ in a nonpolar (L = He and Ar) and quadrupolar (L = N2) solvent. In the most stable AA+–Ln clusters, the first ligand forms a hydrogen bond (H-bond) with the N–H proton of trans-AA+ (t-AA+), whereas further ligands bind weakly to the aromatic ring (π-stacking). There is no experimental evidence for complexes with the less stable cis-AA+ isomer. Quantum chemical calculations at the M06-2X/aug-cc-pVTZ level confirm the cluster growth sequence derived from the IR spectra. The calculated binding energies of De(H) = 720 and 1227 cm−1 for H-bonded and De(π) = 585 and 715 cm−1 for π-bonded Ar and N2 ligands in t-AA+–L are consistent with the observed photofragmentation branching ratios of AA+–Ln. Comparison between charged and neutral AA(+)–L dimers indicates that ionization switches the preferred ion–ligand binding motif from π-stacking to H-bonding. Electron removal from the HOMO of AA+ delocalized over both the aromatic ring and the amide group significantly strengthens the C[double bond, length as m-dash]O bond and weakens the N–H bond of the amide group