Pyrolysis of phenyl acetate: a concerted reaction

A kinetic study reveals that the unimolecular decomposition of phenyl acetate into phenol and ketone occurs concertedly, probably via a four-cyclic transition state

Hyaluronic Acid (HA) Receptors and the Motility of Schwann Cell(-Like) Phenotypes

The cluster of differentiation 44 (CD44) and the hyaluronan-mediated motility receptor (RHAMM), also known as CD168, are perhaps the most studied receptors for hyaluronic acid (HA); among their various functions, both are known to play a role in the motility of a number of cell types. In peripheral nerve regeneration, the stimulation of glial cell motility has potential to lead to better therapeutic outcomes, thus this study aimed to ascertain the presence of these receptors in Schwann cells (rat adult aSCs and neonatal nSCs) and to confirm their influence on motility. We included also a Schwann-like phenotype (dAD-MSCs) derived from adipose-derived mesenchymal stem cells (uAD-MSCs), as a possible basis for an autologous cell therapy. CD44 was expressed similarly in all cell types. Interestingly, uAD-MSCs were RHAMM(low), whereas both Schwann cells and dASCs turned out to be similarly RHAMM(high), and indeed antibody blockage of RHAMM effectively immobilized (in vitro scratch wound assay) all the RHAMM(high) Schwann(-like) types, but not the RHAMM(low) uAD-MSCs. Blocking CD44, on the other hand, affected considerably more uAD-MSCs than the Schwann(-like) cells, while the combined blockage of the two receptors immobilized all cells. The results therefore indicate that Schwann-like cells have a specifically RHAMM-sensitive motility, where the motility of precursor cells such as uAD-MSCs is CD44- but not RHAMM-sensitive; our data also suggest that CD44 and RHAMM may be using complementary motility-controlling circuits

Psychopathology of addiction: May a SCL-90-based five dimensions structure be applied irrespectively of the involved drug?

BACKGROUND: We previously found a five cluster of psychological symptoms in heroin use disorder (HUD) patients: ‘worthlessness-being trapped’, ‘somatic-symptoms’, ‘sensitivity-psychoticism’, ‘panic-anxiety’, and ‘violence-suicide’. We demonstrated that this aggregation is independent of the chosen treatment, of intoxication status and of the presence of psychiatric problems. METHODS: 2314 Subjects, with alcohol, heroin or cocaine dependence were assigned to one of the five clusters. Differences between patients dependent on alcohol, heroin and cocaine in the frequency of the five clusters and in their severity were analysed. The association between the secondary abuse of alcohol and cocaine and the five clusters was also considered in the subsample of HUD patients. RESULTS: We confirmed a positive association of the ‘somatic symptoms’ dimension with the condition of heroin versus cocaine dependence and of the ‘sensitivity-psychoticism’ dimension with the condition of alcohol versus heroin dependence. ‘Somatic symptoms’ and ‘panic anxiety’ successfully discriminated between patients as being alcohol, heroin or cocaine dependents. Looking at the subsample of heroin dependents, no significant differences were observed. CONCLUSIONS: The available evidence coming from our results, taken as a whole, seems to support the extension of the psychopathological structure previously observed in opioid addicts to the population of alcohol and cocaine dependents

Psychopathological symptoms of patients with heroin addiction entering opioid agonist or therapeutic community treatment.

The relationship between substance use disorders and psychiatric pathology is still an open question. The main aim of the present study was to verify whether the five psychopathological dimensions identified through the SCL-90 tool in a previous study carried out on patients with heroin addiction entering an outpatient opioid agonist treatment (OAT) were also observable in those entering a residential treatment community (TC). Further aims were to look at differences in the psychopathological profiles of patients entering a TC versus an OAT treatment and at the correlation between gender and the observed psychopathology.A confirmatory factor analysis was performed on the results of SCL-90 filled by 1,195 patients with heroin dependence entering TC treatment. It replicates the extraction method previously used on 1,055 OAT patients with heroin addiction by using a principal component factor analysis (PCA). The association between the kind of treatment received (TC or OAT), gender, and the psychopathological dimensions was assessed through logistic regression and general linear model (GLM) analysis.The PCA carried out on the SCL-90 results of patients entering a TC yielded a five-factor solution, confirming the same dimensions observed in patients entering an OAT: 'worthlessness and being trapped', 'somatization', 'sensitivity-psychoticism', 'panic anxiety', and 'violence-suicide'. The logistic regression analysis showed a statistically significant association between 'somatization' and 'violence-suicide' severity score and OAT. GLM analysis showed that psychopathological factorial scores for 'worthlessness-being trapped', 'somatic symptoms', and 'panic anxiety' dimensions were more severe in OAT vs TC male patients and in TC vs OAT female ones. 'Violence suicide' followed the same severity pattern for males, but did not differ in TC vs OAT females, while 'sensitivity-psychoticism' did not differ in OAT vs TC patients. The five dimensions did not differ in OAT males vs females.Our research appears to confirm the existence of a specific aggregation of psychological/psychiatric features within the category of individuals with heroin addiction. It also shows a correlation between the dominant psychopathological subgroup and the assignment to TC versus OAT. Further research is needed to clarify the differences between the five psychopathological subgroups and their determinants

The ATLAS Level-1 muon topological trigger information for run 2 of the LHC

For run 2 of the LHC, the ATLAS Level-1 trigger system will include topological information on trigger objects in order to cope with the increased trigger rates. The existing Muon-to-Central-Trigger- Processor interface (MUCTPI) has been modified in order to provide coarse-grained topological information on muon candidates. A MUCTPI- to-Level-1-Topological-Processor interface (MuCTPiToTopo) has been developed to receive the electrical information and to send it optically to the Level-1 Topological Processor (L1TOPO). This poster will describe the different modules mentioned above and present results of functionality and connection tests performed

Very low pressure pyrolysis of phenyl acetate

The kinetics of the unimolecular decomposition of phenyl acetate into phenol and ketene, reaction (1): PhOCOCH_3 → PhOH + CH_2=C=O has been studied under very low-pressure conditions between 950 and 1120 K. In this range alternative processes such as the Fries rearrangement to o-hydroxyacetophenone or bond fission into phenoxyl and acetyl radicals are not observed. Based on present and previous evidence a novel four-center transition state is proposed for reaction (1) which corresponds to the high-pressure Arrhenius expression log (k_1, s^(−1)) = 12.8 – 56.2/θ, θ = 4.575 × 10^(−3)T kcal/mol

Temperature dependence of cage processes in the photofragmentation of phenyl acetate

It was found that the ratio of initial yields of o-hydroxyacetophenone and phenol in the photodecomposition of phenyl acetate in hexane is a linear function of ηT^(1/2) between 224 and 330 K. The observed temperature dependence is ascribed to the competition between combination and disproportionation of acetyl and phenoxy radicals rather than to geminate combination and escape from the solvent cage

Kinetics and thermochemistry of the equilibrium 2 acetylene ⇌ C_4H_4: direct evidence against a chain mechanism

It is shown that recent real-time measurements of the initial rates of decomposition of vinylacetylene behind incident shock waves together with earlier kinetic data for acetylene dimerization closely satisfy detailed balance, i.e., k_1/2k_(-1) = K_1 (Hidaka, Y.; Tanaka, K.; Suga, M. Chem. Phys. Lett. 1986, 130, 195; Skinner, G. B.; Sokoloski, E. M. J. Phys. Chem. 1960,64, 1952). The short times involved (t < 20 µs) allow molecular species, or their isomers, to take part in reactions 1 and -1 but specifically exclude free monoradical chain mechanisms. Since a one-step concerted dimerization is otherwise untenable on kinetic grounds, the intermediacy of vinylidene (H_2C=C:) in reaction 1 is proposed on the basis of ab initio calculations