Crossed beam reaction of phenyl and D5-phenyl radicals with propene and deuterated counterparts--competing atomic hydrogen and methyl loss pathways.

We conducted the crossed molecular beams reactions of the phenyl and D5-phenyl radicals with propylene together with its partially deuterated reactants at collision energies of ~45 kJ mol(-1) under single collision conditions. The scattering dynamics were found to be indirect and were mainly dictated by an addition of the phenyl radical to the sterically accessible CH(2) unit of the propylene reactant. The resulting doublet radical isomerized to multiple C(9)H(11) intermediates, which were found to be long-lived, decomposing in competing methyl group loss and atomic hydrogen loss pathways with the methyl group loss leading to styrene (C(6)H(5)C(2)H(3)) and the atomic hydrogen loss forming C(9)H(10) isomers cis/trans 1-phenylpropene (CH(3)CHCHC(6)H(5)) and 3-phenylpropene (C(6)H(5)CH(2)C(2)H(3)). Fractions of the methyl versus hydrogen loss channels of 68 ± 16% : 32 ± 10% were derived experimentally, which agrees nicely with RRKM theory. As the collision energy rises to 200 kJmol(-1), the contribution of the methyl loss channel decreases sharply to typically 25%; the decreased importance of the methyl group loss channel was also demonstrated in previous crossed beam experiments conducted at elevated collision energies of 130-193 kJ mol(-1). The presented work highlights the interesting differences of the branching ratios with rising collision energies in the reaction dynamics of phenyl radicals with unsaturated hydrocarbons related to combustion processes. The facility of forming styrene, a common molecule found in combustion against the elusiveness of forming the cyclic indane molecule demonstrates the need to continue to explore the potential surfaces through the combinative single collision experiment and electronic structure calculations.

Reaction of phenyl radical with propylene as a possible source of indene and other polycyclic aromatic hydrocarbons: an ab initio/RRKM-ME study.

Ab initio G3(MP2,CC)//B3LYP/6-311G** calculations have been performed to investigate the potential energy surface (PES) and mechanism of the reaction of phenyl radical with propylene followed by kinetic RRKM-ME calculations of rate constants and product branching ratios at various temperatures and pressures. The reaction can proceed either by direct hydrogen abstraction producing benzene and three C(3)H(5) radicals [1-propenyl (CH(3)CHCH), 2-propenyl (CH(3)CCH(2)), and allyl (CH(2)CHCH(2))] or by addition of phenyl to the CH or CH(2) units of propylene followed by rearrangements on the C(9)H(11) PES producing nine different products after H or CH(3) losses. The H abstraction channels are found to be kinetically preferable at temperatures relevant to combustion and to contribute 55-75% to the total product yield in the 1000-2000 K temperature range, with the allyl radical being the major product (~45%). The relative contributions of phenyl addition channels are calculated to be ~35% at 1000 K, decreasing to ~15% at 2000 K, with styrene + CH(3) and 3-phenylpropene + H being the major products. Collisional stabilization of C(6)H(5) + C(3)H(6) addition complexes is computed to be significant only at temperatures up to 1000-1200 K, depending on the pressure, and maximizes at low temperatures of 300-700 K reaching up to 90% of the total product yield. At T > 1200 K collisional stabilization becomes negligible, whereas the dissociation products, styrene plus methyl and 3-phenylpropene + H, account for up to 45% of the total product yield. The production of bicyclic aromatic species including indane C(9)H(10) is found to be negligible at all studied conditions indicating that the phenyl addition to propylene cannot be a source of polycyclic aromatic hydrocarbons (PAH) on the C(9)H(11) PES. Alternatively, the formation of a PAH molecule, indene C(9)H(8), can be accomplished through secondary reactions after activation of a major product of the C(6)H(5) + C(3)H(6) addition reaction, 3-phenylpropene, by direct hydrogen abstraction by small radicals, such as H, OH, CH(3), etc. It is shown that at typical combustion temperatures 77-90% of C(9)H(9) radicals formed by H-abstraction from 3-phenylpropene undergo a closure of a cyclopentene ring via low barriers and then lose a hydrogen atom producing indene. This results in 7.0-14.5% yield of indene relative to the initial C(6)H(5) + C(3)H(6) reactants within the 1000-2000 K temperature range.

High-temperature oxidation chemistry of n-butanol--experiments in low-pressure premixed flames and detailed kinetic modeling.

An automated reaction mechanism generator is used to develop a predictive, comprehensive reaction mechanism for the high-temperature oxidation chemistry of n-butanol. This new kinetic model is an advancement of an earlier model, which had been extensively tested against earlier experimental data (Harper et al., Combust. Flame, 2011, 158, 16-41). In this study, the model's predictive capabilities are improved by targeting isomer-resolved quantitative mole fraction profiles of flame species in low-pressure flames. To this end, a total of three burner-stabilized premixed flames are isomer-selectively analyzed by flame-sampling molecular-beam time-of-flight mass spectrometry using photoionization by tunable vacuum-ultraviolet synchrotron radiation. For most species, the newly developed chemical kinetic model is capable of accurately reproducing the experimental trends in these flames. The results clearly indicate that n-butanol is mainly consumed by H-atom abstraction with H, O, and OH, forming predominantly the α-C(4)H(9)O radical (CH(3)CH(2)CH(2)˙CHOH). Fission of C-C bonds in n-butanol is only predicted to be significant in a similar, but hotter flame studied by Oßwald et al. (Combust. Flame, 2011, 158, 2-15). The water-elimination reaction to 1-butene is found to be of no importance under the premixed conditions studied here. The initially formed isomeric C(4)H(9)O radicals are predicted to further oxidize by reacting with H and O(2) or to decompose to smaller fragments via ß-scission. Enols are detected experimentally, with their importance being overpredicted by the model.

Cognitive effects of lithium carbonate and haloperidol in treatment-resistant aggressive children.

The effects of lithium carbonate and haloperidol on cognition were examined in a placebo-controlled, double-blind study of 61 treatment-resistant, hospitalized school-aged children. They all had a DSM-III diagnosis of conduct disorder-- undersocialized , aggressive, with a profile of highly explosive and aggressive behavior. Children were assessed at the end of a two-week placebo-baseline period and again after four weeks of treatment. Drug effects on cognition were mild. Haloperidol (mean dose, 2.95 mg/day) caused significant decreases in Porteus Maze test quotient scores and a slowing of reaction time (RT) on a simple RT task. Lithium carbonate (mean dose, 1,166 mg/day) adversely affected qualitative scores on the Porteus Maze test. No significant treatment effects were found for the Matching Familiar Figures Test, short-term recognition memory and concept attainment tasks, or the Stroop Test.

Behavioral efficacy of haloperidol and lithium carbonate. A comparison in hospitalized aggressive children with conduct disorder.

The efficacy and safety of haloperidol, lithium carbonate, and placebo were critically assessed in 61 treatment-resistant, hospitalized children aged 5.2 to 12.9 years with diagnoses of conduct disorder, aggressive type. In this double-blind and well-controlled study, the optimal dosages of haloperidol ranged from 1.0 to 6.0 mg/day and those of lithium carbonate from 500 to 2,000 mg/day. For the assessment of behavioral changes and untoward effects, various rating scales were used in different settings. Both haloperidol and lithium carbonate were found to be significantly superior to placebo in decreasing behavioral symptoms. Although both medications were clinically effective, haloperidol was associated more often with untoward effects than was lithium carbonate.

Haloperidol in the treatment of infantile autism: effects on learning and behavioral symptoms.

In this double-blind, placebo-controlled study the administration of haloperidol resulted in significant decreases in behavioral symptoms and in general clinical improvement in 40 autistic children ages 2.33 to 6.92 years. Haloperidol also produced greater facilitation and retention of discrimination learning in the laboratory. No adverse effects were observed at therapeutic doses, which ranged from 0.5 to 3.0 mg/day or 0.019 to 0.217 mg/kg per day.

Schizophrenia with childhood onset: a phenomenological study of 38 cases.

Thirty-eight hospitalized children, ages 5.7 to 11.11 years, diagnosed with schizophrenic disorder by DSM-III criteria, are characterized regarding age, sex, race, socioeconomic status, pre- and perinatal complications, electroencephalogram, intelligence quotient, and family history of major psychiatric disorder. Clinical course, including age at onset of general and psychotic psychiatric symptoms and initial diagnosis of schizophrenic disorder, presence of DSM-III symptoms, hospital course, and response to antipsychotics are reviewed.

The novel differentiation of human blood mononuclear cells into CD1a-negative dendritic cells is stimulated in the absence of exogenous cytokines by an extract prepared from pinecones.

The production of dendritic cells, both in-vivo and in-vitro, has become the intense focus of research activities. Common to many of these production protocols is the use of cytokines, typically granulocyte-monocyte colony stimulating factor and either interleukin 4 or tumor necrosis factor alpha or a combination of all three. Herein, we report our findings that a proprietary pinecone extract is capable of in a dose-dependent manner, and in the absence of exogenous cytokines, the rapid differentiation from peripheral blood mononuclear cells of mature CD1a-negative dendritic cells.

Plasma growth hormone response to insulin-induced hypoglycemia in infantile autism: a pilot study.

Plasma growth hormone responses to insulin-induced hypoglycemia were examined in eight preschool-age autistic children. Six of these children were examined on two separate occasions: during the period of baseline evaluation and after 4 weeks of daily haloperidol administration. On at least one occasion, half of this small sample exhibited persistent elevation of growth hormone levels, with a failure to return to baseline values over the course of a 135-minute period postinsulin infusion. These data are consistent with the occurrence of hypothalamic dysfunction in subgroups of autistic children. Short-term administration of haloperidol did not diminish the ability of the pituitary to secrete growth hormone in response to insulin-induced hypoglycemia.

Plasma growth hormone response to oral l-dopa in infantile autism.

In order to assess further the occurrence of hypothalamic dysfunction in infantile autism and its possible relationship to dopaminergic abnormalities, the l-dopa provocative test was performed in 22 patients fulfilling DSM-III criteria for this disorder. The results indicate a high incidence (at least 30%) of blunted plasma growth hormone (GH) responses following oral administration of l-dopa in this sample. These data suggest an alteration of hypothalamic dopamine receptor sensitivity in the patients with blunted responses. Thus, a subgroup of autistic patients within a descriptively homogeneous diagnostic category shows evidence of hypothalamic dysregulation and dopaminergic abnormalities.

The effects of haloperidol on learning and behavior in autistic children.

The effects of haloperidol on behavioral symptoms and learning were critically assessed in autistic children in an ongoing double-blind placebo-controlled clinical trial. Children were randomly assigned to haloperidol-placebo-haloperidol or placebo-haloperidol-placebo treatment sequences. Statistically, haloperidol was significantly superior to placebo in reducing behavioral symptoms. In discrimination learning paradigm, children receiving haloperidol learned the discrimination while those on placebo did not. Discrimination attained on haloperidol was retained when the children were switched to placebo.

Behavior-disordered and aggressive children: new advances in pharmacotherapy.

The status of children's psychopharmacology is reviewed in the context of differences from its adult counterpart. An overview is presented of recent psychopharmacological developments in the treatment of childhood behavioral disorders. The disorders are grouped according to the potential usefulness of medication. The focus is on clinical efficacy and safety of drug usage. The effect of psychoactive drugs on cognitive functions in the laboratory is referred to, as well as the value of determining drug levels in clinical practice. It is concluded that drug administration in isolation is not the treatment of choice. Drug therapy is a valuable adjunct, however, to psychosocial interventions.

XX male pseudohermaphroditism in a horse.

A pseudohermaphrodite horse with aggressive stallion-like behavior and ambiguous external genitalia was gonadectomized. The hypoplastic gonads removed from the abdomen were confirmed by histologic examination to be testes. Examination of blood and fibroblasts revealed a 64,XX karyotype.

Effects of lithium carbonate and haloperidol on cognition in aggressive hospitalized school-age children.

A comparison of the effects of lithium, haloperidol, and placebo on cognition is reported for a sample of hospitalized school-age children with a behavioral profile of aggressiveness and explosiveness. In this double-blind study, patients were randomly assigned to one of three treatment conditions. The cognitive battery was administered at the end of a 2-week placebo baseline period and again after 4 weeks of treatment. It included a simple reaction time (RT) task with preparatory intervals of 1, 4, and 8 seconds, the Porteus Mazes, and the Matching Familiar Figures Test. Drug effects on cognition, when found, were mild. Slower and more variable RTs were found on the RT task in the haloperidol group (mean dose, 3.1 mg/day), particularly at the 4- and 8-second preparatory intervals in comparison to placebo. This appeared to reflect decreased ability to hold a preparatory set. No other effects of haloperidol on cognitive performance were found. Lithium carbonate (mean dose, 1150 mg/day) caused a deterioration in qualitative performance on the Porteus Maze Test when compared with haloperidol but had no effect on test quotient scores or on the other cognitive measures. Results are discussed in terms of dose effects and the influences of task demands. This is part of a study critically assessing the effects of lithium and haloperidol on behavioral symptoms and other parameters.

Blood platelet monoamine oxidase activity in schizophrenic children and their families. A preliminary study.

In this study monoamine oxidase (MAO) activity was measured in blood platelets of 21 individuals (age 2 6/12-19 years) who were diagnosed at preschool age as schizophrenics; MAO activity was not significantly different from that found in normals. An insignificant correlation was found between MAO activity in patients and age; a similar correlation for normals was also insignificant. In a sample of 15 families, no significant correlation between MAO activity of patients and their parents was obtained.