Structure-Stability Relationship in Aqueous Colloids of Latex Particles and Gemini Surfactants.

The influence of gemini surfactants (GSs) on the charging and aggregation features of anionic sulfate modified latex (SL) particles was investigated by light scattering techniques in aqueous dispersions. The GSs of short alkyl chains (2-4-2 and 4-4-4) resembled simple inert salts and aggregated the particles by charge screening. The adsorption of GSs of longer alkyl chains (8-4-8, 12-4-12, and 12-6-12) on SL led to charge neutralization and overcharging of the particles, giving rise to destabilization and restabilization of the dispersions, respectively. The comparison of the interfacial behavior of dimeric and the corresponding monomeric surfactants revealed that the former shows a more profound influence on the colloidal stability due to the presence of double positively charged head groups and hydrophobic tails, which is favorable to enhancing both electrostatic and hydrophobic particle-GS and GS-GS interactions at the interface. The different extent of the particle-GS interactions was responsible for the variation of the GS destabilization power, following the 2-4-2 < 4-4-4 < 8-4-8 < 12-4-12 order, while the length of the GS spacer did not affect the adsorption and aggregation processes. The valence of the background salts strongly influenced the stability of the SL-GS dispersions through altering the electrostatic interactions, which was more pronounced for multivalent counterions. These findings indicate that both electrostatic and hydrophobic effects play crucial roles in the adsorption of GSs on oppositely charged particles and in the corresponding aggregation mechanism. The major interparticle forces can be adjusted by changing the structure and concentration of the GSs and inorganic electrolytes present in the systems.

Changes in illicit, licit and stimulant designer drug use patterns in South-East Hungary between 2008 and 2015.

The aim of this work is to present the changes in classical illicit and licit drug, as well as stimulant designer drug (SDD) consumption of suspected drug users in South-East Hungary between 2008 and 2015. Urine and/or blood samples of 2976 subjects were analyzed for these groups of substances of which 1777 (59.7%) were tested positive. THC was the most frequent (32.2%) substance, followed by classical stimulants (amphetamine, metamphetamine, MDMA, cocain) (21.4%), SDDs (17.0%), benzodiazepines (15.5%), medical opiates (codeine without morphine, methadone, tramadol) (4.03%), and morphine with or without 6-acethyl-morphine (1.98%). The annual rate of cannabis consumption continuously decreased after 2010. The use of classical stimulants was constant, except for a significant increase in 2015. Benzodiazepine incidence increased and remained steady after 2011. Medical opiate and morphine frequency was variable. SDDs were found in the highest number in 2012-13, exceeding the frequency of classical stimulants. The most prevalent SDDs were as follows: 2010 - mephedrone, 2011 - 4-MEC, methylone, MDPV, 4-FMC, and 4-FA, and 2012-2015 - pentedrone. Beside pentedrone, 3-MMC, αPVP, αPHP, and 4-CMC were detected with a notable number in this period. Multi-drug use was found in 30-43% of suspects tested positive between 2008 and 2014, which elevated to 52% in 2015. The frequency of substances in the biological samples corresponded to their seizure rate. When SDDs were included on the NPS list, their frequency in biological samples and in seized materials slightly decreased or did not change. However, a marked decrease was observed following classification as illicit drugs.

Frequency and structure of stimulant designer drug consumption among suspected drug users in Budapest and South-East Hungary in 2012-2013.

Identification of abuse and frequency patterns of stimulant designer drugs (SDDs) provides important information for their risk assessment and legislative control. In the present study urine and/or blood samples of suspected drug users in criminal cases were analysed by GC-MS for 38 SDDs, and for the most frequent illicit and psychoactive licit drugs in Hungary. Between July 2012 and June 2013, 2744 suspected drug users were sampled in Budapest and during 2012 and 2013, 774 persons were sampled in South-East Hungary (Csongrád County - neighbour the Romanian and Serbian borders). In Budapest 71.4% of cases, and in South-East Hungary 61% of cases were positive for at least one substance. Pentedrone was the most frequent SDD in both regions; however, the frequency distribution of the remaining drugs was highly diverse. SDDs were frequently present in combination with other drugs - generally with amphetamine or other stimulants, cannabis and/or benzodiazepines. The quarterly distribution of positive samples indicated remarkable seasonal changes in the frequency and pattern of consumption. Substances placed on the list of illicit drugs (mephedrone, 4-fluoro-amphetamine, MDPV, methylone, 4-MEC) showed a subsequent drop in frequency and were replaced by other SDDs (pentedrone, 3-MMC, methiopropamine, etc.). Newly identified compounds from seized materials were added to the list of new psychoactive substances ("Schedule C"). While the risk assessment of substances listed in Schedule C has to be performed within 2 years after scheduling, continuous monitoring of their presence and frequency among drug users is essential. In summary, our results suggest which substances should be dropped from the list of SDDs measured in biological samples; while the appearance of new substances from seized materials indicate the need for developing adequate standard analytical methods.

The frequency of alcohol, illicit and licit drug consumption in the general driving population in South-East Hungary.

In the framework of the DRUID (Driving under the Influence of Drugs, Alcohol, and Medicines) EU-6 project, a roadside survey was performed in South-East Hungary to determine the incidence of alcohol and the most frequent illicit and licit drug consumption (amphetamines, THC, illicit and medical opiates, cocaine, ketamine, benzodiazepines, zopiclone and zolpidem) in the general driving population. All 3110 drivers stopped between 01 January 2008 and 31 December 2009 were checked for alcohol, and among them 2738 persons (87.7%) participated in the further examinations, on a voluntary basis. Licit and illicit drugs were determined from their oral fluid samples by GC-MS analysis. Illicit drugs were detected in 27 cases (0.99%), licit drugs in 85 cases (3.14%), and alcohol (cut off: 0.1g/l) was found in 4 (0.13%) cases. Illicit drug consumption was the highest among men of the ages 18-34, during the spring, and on the week-end nights. With respect to licit drugs, the highest incidence was found among women over the age of 50, during the summer, and on the week-days. All alcohol positive cases were men over the age of 35. In comparison to international European averages, the alcohol and illicit drug consumption was low, but the licit drug consumption was over the European average.