Search results for "Reactivity"
showing 10 items of 880 documents
Can the absence of solvation of neutral reagents by ionic liquids be responsible for the high reactivity in base-assisted intramolecular nucleophilic…
2005
[reaction: see text] The kinetics of the rearrangement of the Z-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole (1a) into the relevant 4-benzoylamino-2,5-diphenyl-1,2,3-triazole (2a) induced by amines have been studied in two room-temperature ionic liquids (IL-1, [BMIM][BF4] and IL-2, [BMIM][PF6]). The data collected show that the reaction occurs faster in ionic liquids than in other conventional solvents previously studied (both polar or apolar, protic or aprotic). Presumably, this could depend on their peculiar ability to minimize the strong substrate-solvent, amine-solvent and amine-amine interactions occurring in conventional solvents.
Effects of Briquetting and High Pyrolysis Temperature on Hydrolysis Lignin Char Properties and Reactivity in CO-CO2-N2 Conditions
2021
Carbonaceous reductants for pyrometallurgical applications are usually obtained from fossil-based sources. The most important properties of the reductants greatly depend on the application and the feeding of the reductant into the process. However, the mechanical strength, calorific value, fixed carbon content, and reactivity of the reductant are the properties that usually define the applicability of the reductant for different processes. The reactivity of the biochars is usually high in comparison to metallurgical coke, which may restrict the applicability of the biochar in reduction processes. One cause of the higher reactivity is the higher surface area of the biochars, which can be sup…
Biogenic Fenton process - A possible mechanism for the mineralization of organic carbon in fresh waters.
2020
To explore the mechanisms that mineralize poorly bioavailable natural organic carbon (OC), we measured the mineralization of OC in two lake waters over long-term experiments (up to 623 days) at different pH and iron (Fe) levels. Both the microbial and photochemical mineralization of OC was higher at pH acidified to 4 than at the ambient pH 5 or an elevated pH 6. During 244 days, microbes mineralized up to 60% of OC in the 10-mu m filtrates of lake water and more than 27% in the 1-mu m filtrates indicating that large-sized microbes/grazers enhance the mineralization of OC. A reactivity continuum model indicated that the acidification stimulated the microbial mineralization of OC especially i…
Effects of physical provocations on heart rate reactivity and reactive aggression in children
2006
This article presents complementary data on the relationship between the intensity of offensive and defensive aggression that was investigated by means of the computerised Pulkkinen Aggression Machine (PAM) paradigm [Juujarvi et al., 2001; Aggr Behav 27:430-445]. The recording of the electrocardiogram was conducted in a sample of 109 children (61 boys and 48 girls) while they completed the PAM. Across the conditions of controlled aggression, the simulated attack and defence evoked a mean increase of HR by 2.7 beats per minute (bpm), but the variation between children was substantial (-10.9 to +11.4 bpm). Children who showed a strong HR increase, moderate HR increase, or HR decrease were com…
The spectrum of allergic (cross-)sensitivity in clinical patch testing with 'para amino' compounds
2002
Background: Allergic contact sensitization to ‘para amino’ compounds is frequent and the spectrum of cross-reactivity between members of this chemical group is variable. Methods: A retrospective analysis of clinical patch test data obtained with a special test series in the centres of the Information Network of Departments of Dermatology (IVDK) between 1995 and 1999. Results: In the 638 patients tested with the above test panel positive reactions were observed most often to p-aminoazobenzene (16.2%), p-phenylenediamine (14.1%), p-toluylenediamine (10.0%), followed by 4,4′-diaminodiphenylmethane (8.5%), Disperse Orange 3 (8.4%) and p-aminophenol (3.1%). Among the 544 patients tested with p-p…
Pharmacological manipulation of serotonin receptors during brain embryogenesis favours stress resiliency in female rats
2018
Manipulations of the serotonin transmission during early development induce long-lasting changes in the serotonergic circuitry throughout the brain. However, little is known on the developmental consequences in the female progeny. Therefore, this study aimed at exploring the behavioural effects of pre- and postnatal stimulation of the serotonergic system by 5-methoxytryptamine in adolescent female rats on behavioural reactivity and anxiety- like phenotype. Our results show that perinatal 5- methoxythyptamine decreased total distance travelled and rearing frequency in the novel enviroment, and increased the preference for the centre of the arena in the open field test. Moreover, perinatal 5-…
Dissociation of airway responsiveness and bronchoalveolar lavage (BAL) cell composition in sensitized guinea-pigs after daily inhalation of ovalbumin
1994
Summary. The association between inflammatory cell influx, cell activation status and change of airway responsiveness to acelylcholine (ACh) after daily inhalation of ovalbumin (OA) in sensitized guinea–pigs was investigated. Starting 3 weeks after sensitization (OA at 50mg/kg s.c. + i.p.) guinea–pigs were exposed daily to 2% OA (10min: undercover of 0.5Smg/kg mepyramine i.p. 15min before OA) for 2 weeks. Concentration–response curves (CRCs) for inhaled ACh were performed 24 h after the last OA–challenge and 24 h after another single OA–inhalation 1 week later. CRCs for inhaled ACh were neither affected 24 h after the last OA challenge (daily for two weeks) nor 24 h after another OA–inhalat…
Ambulatory assessment as a means of longitudinal phenotypes characterization in psychiatric disorders
2014
Abstract Ambulatory Assessment (AA) comprises the use of in-field methods to assess individuals’ behavior, physiology, and the experience as they unfold in naturalistic settings. We propose that AA is favorable for the investigation of gene–environment interactions and for the search for endophenotypes, being able to assess the experienced environment and to track basic regulatory processes, such as stress reactivity, affective instability, and reward experience, which are potential common factors that underlie psychiatric disorders. In this article, we (a) first describe briefly the rationale of AA and summarize the key advantages of the approach, (b) highlight within-subject regulatory pr…
Diferencias entre hombres y mujeres en los trastornos de ansiedad: una aproximación psicobiológica
2009
Los trastornos de ansiedad son, en la actualidad, enfermedades psiquiátricas muy frecuentes e incapacitantes. Las mujeres en edad reproductiva son más vulnerables a desarrollar trastornos de ansiedad, aproximadamente entre 2 a 3 veces más que los hombres. Ser hombre o mujer no sólo puede influir en la prevalencia de los trastornos mentales, sino también en la manifestación y expresión de los síntomas, la voluntad para solicitar asistencia médica o psicológica, el curso de la enfermedad, incluso en la respuesta al tratamiento. Cada vez hay pruebas más sólidas de que existen diferencias entre ambos sexos respecto a la anatomía cerebral, la neuroquímica y los patrones de activación y respuesta…
Bronchodilator and anti-inflammatory activities of SCA40: studies in human isolated bronchus, human eosinophils, and in the guinea-pig in vivo.
1998
There is currently interest in the use of inhibitors of cyclic nucleotide phosphodiesterases (PDE) as potential anti-asthma agents. In this study we examined the effects of SCA40 (6-bromo-8-methylaminoimidazol-[1,2-a] pyrazine-2-carbonitrile), a preferential inhibitor of PDE 3 also endowed with PDE 4 and 5 inhibitory activities, on isolated bronchus and eosinophil functions and in an animal model of asthma. SCA40 (1 nM-0.1 mM) produced concentration-dependent inhibition of spontaneous and stimulated tone of human isolated bronchus and reached a maximal relaxation similar to that of theophylline (3 mM). The potency (-log EC50 values) of SCA40 against spontaneous tone (6.52 +/- 0.10) was grea…