Prevalence of Polysubstance Abuse and Dual Diagnosis in Patients Admitted to Alcohol Rehabilitation Units for Alcohol-Related Problems in Italy: Changes in 15 Years.

AIMS: Alcohol abuse has long been known as a disease with social and economic burden to society. Given the complex nature of alcohol treatment, it is worthwhile to examine the change over time of patients admitted to residential alcohol abuse rehabilitation units. METHODS: The data were collected from two Italian projects on alcoholics performed in the mid-1990s (ASSALT) and in 2009 (CORRAL), respectively. Categorical variables were considered in terms of absolute and relative frequencies. Comparisons of relative frequencies between groups were assessed by means of Fisher's exact test. Mixed logistic regression models were fitted to CORRAL data to identify the predictors of the probability of being a polysubstance abuser or having a dual diagnosis. The association estimates were reported as adjusted odds ratios and relative 95% confidence intervals. RESULTS: Compared to the mid-1990s, in 2009 patients were older (P= 0.0003), with a higher level of education (P= 0.0204), with fewer comorbidities (liver disease except cirrhosis, P < 0.0001; polyneuropathy, P= 0.0001), more frequently polysubstance abusers (P < 0.0001), affected by dual diagnosis (P < 0.0001). In 2009, the probability of being a polysubstance abuser was higher in younger and in patients with dual psychiatric diagnosis. Female gender and polysubstance abuse were positively associated to the probability of being affected by dual psychiatric diagnosis. CONCLUSIONS: The increment of patients admitted to residential programs for alcohol dependence with polysubstance abuse and/or dual psychiatric diagnoses suggests the need to pay more attention to both psychological/psychiatric interventions and internal medicine/physical rehabilitation. SHORT SUMMARY: The results of this study suggest that further research is needed to identify the best treatment strategy that is safe and effective for the new population of alcoholics.

The autofocusing system of the IMAT neutron camera.

In this paper, we present the autofocusing system of the imaging instrument to be used on IMAT, a new neutron-imaging facility under construction at the ISIS (UK) target station 2. We have compared 16 different autofocus algorithms to select the one with the best performance. The algorithms have been evaluated by using both a qualitative analysis and a quantitative one. An overall score has been computed and the "contrast based" algorithm has been selected for the autofocusing system. The adopted setup together with the described autofocusing system makes the camera a user-friendly imaging device allowing the optimization of beam time use.

Enhancement of electrorheological effect by particle-fluid interaction.

The influence of interactions between particle surface and host fluids in electrorheological suspensions is explored. It is observed that dispersions of nanosized particles of titania in octanoid acid exhibit an anomalously large electrorheologic effect when compared with a similar dispersion of micrometric particles or with a more conventional colloidal suspension of silica in silicone oil. The effect is interpreted as originated by the formation of a thin layer of octanoid acid molecules with the surface of the titania solid particle. The experimental data are fitted with the outcomes of a modified version of conductive models existing in the literature. It is suggested that anomalous large electrorheological effect is mainly originated by the increasing of the effective radius of the nanometric particles, which results in an increasing of the effective volume fraction of the dispersed phase. It is also shown that the deformation of the soft shell around the solid particles, induced by Coulombic force, plays a not negligible role. Some hints for tailoring electrorheologic fluids suitable for different applications are proposed.

High-frequency propagating density fluctuations in deeply supercooled water: evidence of a single viscous relaxation.

We performed a Brillouin scattering experiment on deeply supercooled water and compared the results with similar literature data obtained both at the same and at higher values of the exchanged wave vector. The whole set of available experimental data can be well reproduced with the use of the generalized hydrodynamic model where all the involved thermodynamic parameters are fixed to their literature values. On the contrary, the model based on the memory function approach generates the wrong estimates for measurables when the same values of the thermodynamic parameters are used. This result confirms our recent criticisms against the utilization of models originating from linear response theory [Phys. Rev. E 84, 051202 (2011)]. The inconsistency between models explains apparent discrepancies between the different conclusions on water acoustic behavior which may be found in the literature. We demonstrate that the observed behavior can be explained by assuming only a single relaxation process that is typical of any viscoelastic system. With all thermodynamics quantities fixed, the hydrodynamic description needs only two parameters to model the experimental data, namely, the relaxation time and the high-frequency limit of the sound velocity. The whole body of the experimental data can be well reproduced when the relaxation time behaves in an Arrhenian manner and the difference between the relaxed and not relaxed sound velocities is a constant. The high-frequency sound velocity is never higher than 2200 m/s. We conclude that, at least from experiments performed within the hydrodynamic regime, there is no indication for a fast sound close to the hypersonic velocity observed in ice.

[Alcohol-addiction inpatient: characteristics of patients and rehabilitation program]. / La residenzialità alcologica ospedaliera: caratteristiche dei pazienti e dei percorsi terapeutici/riabilitativi.

AIM: The treatment of alcohol addiction in Italy has had a progressive evolution of therapeutic structures for in-and outpatients. During the last 20 years there had been a crescent presence of short residential treatment facilities (1-6 months) characterized by a high level of medical and psychotherapeutic intervention. About two years ago 12 of them jointed together in an association called CORRAL (COordinamento of Residenzialità Riabilitive Alcologiche). The aim of this study was to describe the socio-demographic medical and other characteristics of the patients coming for this type of treatment and to describe the characteristics of the residential treatment itself including referring and aftercare. METHODS: Two thousand sixty-one hospitalized patients of the 12 rehabilitative alcohol units were examined by using a questionnaire and collecting various sociodemographic variables and clinical diagnosis of the patients. Even it was asked who had referred the patients, the characteristics of the residential treatment and of the planned aftercare. RESULTS: The present residential facilities are mainly distributed in the North of Italy. The typical patient is male, with a high school instruction and with a comorbidity regarding psychiatric and liver disorders. The majority of the patients were referred by the public ambulatory services for addictions (SerT/SerD). The characteristics of the residential treatment were medical, pharmacological and psychotherapeutic interventions with a high intensity and the presence of a general-purpose staff. CONCLUSIONS: This study outlined a model of residential rehabilitation of alcohol disorders characterized by short duration and a complex, intense therapeutic intervention mainly addressed to patients with a severe clinical condition and a low level of social problems. Further research should be useful to understand better which sort of patient characteristics obtain a better clinical result and for that even economically a major effectiveness from this type of residential treatment.

Collective acoustic modes in liquids: a comparison between the generalized-hydrodynamics and memory-function approaches.

The most familiar approaches used to describe the dynamical structure factor from adiabatic density fluctuations in liquids are based on generalized hydrodynamics and on the memory function, respectively. We show that, contrary to the common belief, the two approaches are not fully equivalent. In particular, models based on the memory function of a normalized damped oscillator fail in reproducing the correct experimental spectral profiles of systems close to the relaxation process. The discrepancy is due to misleading interpretation of the theoretical memory-function expressions, producing an unavoidable mixing of spectral contribution at different wave vectors when the theory is forced beyond its limits of validity.

Communication: An extended model of liquid bridging.

Recent phenomenological studies have drawn attention to an appealing effect, observed for the first time in 1893, today known as water-bridge. The phenomenon has been ascribed to unknown properties of water. We report some experimental results showing that, contrary to a widely common belief, the phenomenon is not to be related with water neither with a property of hydrogen bonded networks. Using a very simple model, we show that the liquid bridge phenomenon is originated by electrostatic effects and can be reproduced in any dense fluid with no respect of its peculiar molecular properties. This basic approach is able to reproduce many of the experimentally observed features of the bridge formation. In perspective of future investigations, the possible phenomena responsible of the bridge stability, after its formation, are briefly discussed.

Some evidence of scaling behavior in the relaxation dynamics of aqueous polymer solutions.

The structural relaxation behavior of aqueous solution of poly(ethylene glycol) and methoxy-capped poly(ethylene glycol), both of mean molecular mass 400 g/mol, is investigated by Brillouin scattering experiments. In both cases non-Debye relaxation processes have been detected, proceeding on the picosecond time scale. The average values of the detected relaxation time distributions fail to follow the simple Arrhenius behavior. The temperature evolution of the relaxation time is adequately fitted using the phenomenological Vogel-Fulcher-Tamman (VFT) model. In spite of the different temperature and concentration dependences observed for the two kinds of systems, with the exception of the highest samples concentrations, a unique scaling behavior has been found for the real and imaginary parts of the loss modulus plotted as a function of the reduced inverse temperature, T(0)/T, T(0) being the VFT arrest temperature. The presence of a unique scaling law in aqueous solutions of polymers characterized by different end groups suggests the establishment of similar hydrogen-bonded local structures. Within this scenario, water acts as a stabilizer and plays the main role bridging neighboring polymer chains. The possible physical interpretation of the obtained fit parameters is discussed, and the results are compared with other literature findings.

Excess thermodynamic properties in mixtures of a representative room-temperature ionic liquid and acetonitrile.

The nature of the interactions between a representative room-temperature ionic liquid, namely 1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM][BF(4)]) and a common organic solvent, acetonitrile (CH(3)CN) has been investigated by means of Brillouin light scattering, over the whole concentration range and in the temperature range from -20 to 45 degrees C. Negative deviations from the ideal behavior of both molar volumes and adiabatic compressibility have been observed. This result has been interpreted within the framework of a well-established theoretical model, namely a nonadditive hard-sphere mixture. Despite that similar findings were rationalized in terms of enhanced interactions between molecules, a more detailed analysis of excess thermodynamic functions indicates that they are mainly due to excluded volume effects and that the differences in local intermolecular interactions act as higher order contributions: we have found that this can be a general feature of liquid mixtures. On this basis we present a reconsideration for excess thermodynamic data and for their role in providing direct information on intermolecular interactions.

Excess compressibility in binary liquid mixtures.

Brillouin scattering experiments have been carried out on some mixtures of molecular liquids. From the measurement of the hypersonic velocities we have evaluated the adiabatic compressibility as a function of the volume fraction. We show how the quadratic form of the excess compressibility dependence on the solute volume fraction can be derived by simple statistical effects and does not imply any interaction among the components of the system other than excluded volume effects. This idea is supported by the comparison of the experimental results with a well-established prototype model, consisting of a binary mixture of hard spheres with a nonadditive interaction potential. This naive model turns out to be able to produce a very wide spectrum of structural and thermodynamic features depending on values of its parameters. An attempt has made to understand what kind of structural information can be gained through the analysis of the volume fraction dependence of the compressibility.

Structuring effects and hydration phenomena in poly(ethylene glycol)/water mixtures investigated by brillouin scattering.

Aqueous solutions of poly(ethylene glycol) (PEG) of mean molecular mass of 600 g/mol (PEG600) are investigated by Brillouin scattering technique. At high PEG content, a relaxation phenomenon is observed, which is related to a local rearrangement of the polymer structure where the interaction, via hydrogen bonding, with the solvent molecules plays a role. The obtained values of the relaxation times match the literature data very well for a fast relaxation time revealed by dielectric relaxation measurements in very similar mixtures. The calculated concentration behaviors of the excess adiabatic compressibility turns out in good agreement with the previous findings from ultrasonic measurements at 3 MHz. The observed minimum in the adiabatic compressibility is interpreted as the result of the interaction between water and the EO units of the PEG chain, which results in a structure tighter then that typical of bulk water and of pure PEG600. Such a hypothesis is supported by the observation that volume fraction value of about 0.3 coincides with the concentration value at which full hydration of EO units takes place. The observation that at the same concentration, the polymer coils start to overlap each other further supports the idea that the adiabatic compressibility behavior is monitoring the structural evolution of the mixture. However, similar results are obtained for largely different binary mixture which suggests caution in taking this conclusion too literally. In particular, the hypothesis that the occurrence of an extreme in the excess adiabatic compressibility could be simply originated by statistical effects and that further work is required for disentangling entropic contribution from effects of hetero-association and self-aggregation of one or both the components.

Evidences of nonideal mixing in poly(ethylene glycol)/organic solvent mixtures by Brillouin scattering.

The concentration dependence of the hypersonic properties of solutions of poly(ethylene glycol) of mean molecular mass 600 g/mol (PEG600) in benzene and toluene has been investigated by Brillouin scattering. The two solvents are very similar in structure and chemical properties, but while benzene is nonpolar, toluene possess a modest dipole. In both solvents a high-frequency relaxation process has been observed at high concentrations which has been assigned to conformational rearrangements of the polymeric chains, triggered by reorientation of the side groups. In both cases, the concentration dependence of the adiabatic compressibility deviates significantly from linearity, indicating the existence of nonideal mixing phenomena driven by aggregation processes taking place in the systems. However, there is no temperature dependence for solutions of PEG600 in benzene; on the contrary, the results obtained for solutions of PEG600 in toluene are noticeably dependent on the temperature. The comparison of the experimental data with the results of previous experiments on similar systems allows a general picture for weakly interacting mixtures of hydrogen-bonded systems and organic solvents to be developed. In particular, in the presence of a nonpolar solvent molecule the local structure of the mixture is dominated by solute self-association processes and any resulting solute-solvent correlation is barely induced by excluded volume effects. At high enough dilution the self-aggregation of solute molecules produces a variety of new local topologies that cannot be observed in bulk solute, and as a consequence, the concentration evolution of the system is too rich to be described in terms of a linear combination of a few components over the whole concentration range. The situation seems to be simpler for the polar toluene solvent molecules, where a three-component model seems able to fit the experimental concentration dependence of the hypersonic velocity. This result is interpreted to imply that the interaction between the solvent dipoles and the active sites of the solute produces a relatively stable heterocoordination, while the relevance of self-association is partially reduced.

Structural relaxation processes in polyethylene glycol/CCl4 solutions by Brillouin scattering.

We present results of a Brillouin scattering experiment on solutions of poly(ethylene glycol) of mean molecular mass 600 g/mol (PEG600) in CCl4. The relaxation process detected has been assigned to conformational rearrangements of the polymeric chains, triggered by reorientation of the side groups. The concentration dependencies of the hypersound velocity and normalized absorption are compared against the indications from several models proposed in the literature. The concentration evolution of the system is described in terms of two distinct regimes. At high polymer content, the system is dominated by the structure of the dense polymer, where polymer-polymer interactions, together with excluded volume effects, induce the existence of a preferred local arrangement resulting in a narrow distribution of the relaxation times, with the average value of the relaxation time following a simple Arrhenius temperature dependence. As the concentration decreases, the original structure of the hydrogen bonded polymer network is destroyed, and a number of different local configuration coexist, giving rise to a wider distribution of relaxation times or to a multiple relaxation. At low concentrations, the experimental data are well fitted assuming a Vogel-Fulker-Tammon behavior for the average relaxation time. In addition, the observed deviation from the ideal behavior for the refractive index and the density suggests that CCl4 does not behave as an inert solvent, and due to polarization effects, it can develop local hetero-associated structures via electrostatic interaction with the O-H end groups of the polymeric chains. The hypothesis has been successfully tested by fitting the concentration behavior of the hypersonic velocity to a recent three-component model, suitable to describe the concentration dependence of sound velocity in moderately interacting fluids. The indication of the model furnishes a very high value for the association constant of the PEG600, confirming the literature indication that, in polymeric systems capable of developing long liner aggregates via hydrogen bonding interaction, the Brillouin probe is insensitive to the true length of the polymeric chains. The Brillouin scattering experiment just sees an effective hydrogen bonded aggregate that is huge relative to the length of the single polymeric chain and becomes sensitive only to the density fluctuations of the local segmental motions.

Single-particle dynamics of water molecules confined in a lecithin-based gel.

We present experimental measurements, obtained by a quasielastic neutron scattering experiment, of the self-diffusion coefficient of water confined in the dense structure of lecithin-based gels. The inelastic neutron scattering (INS) technique was also used to monitor the dynamic state of water molecules involved in the gel structure. It is shown that, at least in highly concentrated systems, the diffusional properties of water can be related with the growth process of worm-like aggregates. However, an interpretation of our data consistent with a number of experimental results in the literature and with INS indications requires the adoption of a model in which the gel structure is better described in terms of percolating aggregates rather than the usually described polymer-like entangled (not interconnected) network. In such a way, we are pointing out the existence of an interpretative controversy calling for further investigation to be disentangled. The source of the inconsistencies is found in the commonly accepted basic assumption of the existence of a simple scaling law, relating the average micellar length to the concentration.