Search results for "pine"
showing 10 items of 2022 documents
Raman and infrared spectromicroscopy of manganese oxides
2009
Abstract Confocal micro-Raman and micro-FT-IR spectroscopies have been used to probe the phase composition of nominally pure single-crystal MnO and mixed MnO–Mn 3 O 4 samples, grown by the method of chemical transport reactions on MgO(1 0 0) substrate. The presence of spinel Mn 3 O 4 phase has been clearly detected in both samples by Raman and FT-IR spectroscopies. The size of the spinel Mn 3 O 4 phase regions has been estimated to be below 20 μm.
Electrophysiologic and inotropic effects of alpha-adrenoceptor stimulation in human isolated atrial heart muscle.
1992
The effects of α-adrenoceptor stimulation on force of contraction were investigated in human atrial heart muscle and compared with those of β-adrenoceptor stimulation. The maximal positive inotropic effect produced by stimulation of α-adrenoceptors with phenylephrine (in the presence of atenolol 10 μmol/l) was significantly smaller than that seen in response to β-adrenoceptor stimulation with isoprenaline. The maximal effect of phenylephrine (25% of the maximal effect of isoprenaline) required far higher concentrations (1 mmol/l) than isoprenaline (100 nmol/l); the EC50 values amounted to 33.1 μmol/l and 3.3 nmol/l, respectively. In the presence of the α-adrenoceptor blocking agent phentola…
Adrenoceptor-mediated changes of action potential and force of contraction in human isolated ventricular heart muscle.
1988
Abstract 1. The effects of alpha-adrenoceptor stimulation on the action potential and force of contraction were investigated in human isolated ventricular heart muscle and compared with those of beta-adrenoceptor stimulation. 2. The maximal stimulation by isoprenaline of beta-adrenoceptors produced large changes in the force of contraction, which were accompanied by moderate increases in the height of the action potential. The maximal inotropic effect produced by stimulation of alpha-adrenoceptors with phenylephrine, in the presence of propranolol (1 mumol 1(-1)) was much smaller (about 10% of that seen in response to beta-adrenoceptor stimulation), and no significant changes of the action …
Electrical and mechanical activity of mammalian heart muscle fibres treated with papaverine
1977
The action of papaverine on electrical and mechanical activity was investigated in ventricular and atrial heart muscle fibres from guinea-pigs and cats. 1. Papaverine (10−5 M–5×10−5M) had positive, negative or no inotropic effects in ventricular preparations; positive inotropic effects were not observed after pretreatment of the animals with reserpine. In atrial preparations, papaverine (2×10−5M) had a positive inotropic effect that was independent of endogenously stored catecholamines. 2. The effects of isoprenaline and dibutyryl cyclic AMP were potentiated by papaverine (10−5 M–2×10−5M). 3. The action potential duration was always prolonged by papaverine in ventricular as well as in atria…
Adjunctive clotiapine for the management of delusions in two adolescents with anorexia nervosa
2021
Clotiapine is an atypical antipsychotic indicated for the management of a series of acute psychotic disorders. The current literature lacks evidence concerning the tolerability and clinical use of this drug in the management of individuals with anorexia nervosa (AN). In this study, we report two cases of adolescents with AN, treated with clotiapine. The reason for the administration of clotiapine was, for both patients, the manifestation of bizarre delusions concerning food and calories. Patient 1 presented a presyncope after the first dose of clotiapine, and treatment was rapidly discontinued. Patient 2 was treated with clotiapine for 9 months; doses were titrated from 20 mg/day to 70 mg/d…
Flow-Injection Spectrophotometric Determination of Phenolic Drugs and Carbamate Pesticides by Coupling with Diazotized 2,4,6-Trimethylaniline
1999
Abstract A flow-injection (FI) spectrophotometric system is proposed for the determination of phenols and carbamates. In the FI manifolds, the solutions of phenols or carbamates (the latter after hydrolysis with NaOH) were injected into a diazonium ion carrier stream at pH 9.5 (buffered with tetrahydroborate), which was formed by mixing 2,4,6-trimethylaniline (TMA) with nitrate in a sodium dodecyl sulfate aqueous micellar medium. Absorbance was measured at 550 nm. The system combines the advantages derived from the use of TMA for the coupling of phenols in basic micellar media, because of the inhibition of the self-coupling reaction of the reagent, with the precision and speed of the FI pro…
Early Social Isolation Stress and Perinatal NMDA Receptor Antagonist Treatment Induce Changes in the Structure and Neurochemistry of Inhibitory Neuro…
2017
AbstractThe exposure to aversive experiences during early life influences brain development and leads to altered behavior. Moreover, the combination of these experiences with subtle alterations in neurodevelopment may contribute to the emergence of psychiatric disorders, such as schizophrenia. Recent hypotheses suggest that imbalances between excitatory and inhibitory (E/I) neurotransmission, especially in the prefrontal cortex and the amygdala, may underlie their etiopathology. In order to understand better the neurobiological bases of these alterations, we studied the impact of altered neurodevelopment and chronic early-life stress on these two brain regions. Transgenic mice displaying fl…
Different and common intracellular calcium-stores mobilized by noradrenaline and caffeine in vascular smooth muscle.
1992
Noradrenaline (NA) 1 microM and caffeine (CAF) 10 mM induce a contractile response in isolated rat aorta maintained at 37 degrees C either in the presence or absence of extracellular calcium. In Ca-free media the contractile response was reduced and contractile activity of CAF only occurred at 25 degrees C. NA induced a biphasic response in Ca-free medium, with a fast phasic contraction followed by a smaller more sustained contraction. The response induced by CAF consisted of a fast transient contraction which returned to a level below the resting tone. After washing, further addition of NA or CAF evoked no increase in smooth muscle tension. The influence of Mg-depletion in the extracellula…
Inactivation and tachyphylaxis of heat-evoked inward currents in nociceptive primary sensory neurones of rats.
2000
In contrast to other sensory modalities, pain does not decrease when a noxious stimulus is applied at constant intensity (Greene & Hardy, 1962). From this lack of adaptation on the perceptive level it has traditionally been implied that primary nociceptive afferents also do not adapt upon constant stimulation. This is in contrast to the results of recordings from these afferents, which exhibit pronounced adaptation for physical as well as chemical stimuli (Meyer et al. 1994). Peripheral adaptation of nociceptive nerve endings is compensated by central summation (Mendell & Wall, 1965; Price et al. 1977); this slow summation process of small fibre input to the dorsal horn of the spinal cord i…
Effects of different agents on the contractile response elicited by extracellular calcium after depletion of internal calcium stores in rat isolated …
1993
Abstract Noradrenaline, 1 μm, induced a sustained contractile response in rat isolated aorta in the presence and in the absence of extracellular Ca2+. After depleting the noradrenaline-sensitive intracellular Ca2+ stores, an increase in the basal tone of the aorta was observed during the incubation period in the presence of Ca2+ and in the absence of the agonist. We have tested the possible pathways through which Ca2+ enters the cell to refill the previously depleted Ca2+ pools, a process that is accompanied by an increase in tension. The magnitude of this increase does not depend on the presence of Mg2+ in the extracellular medium nor on the temperature, suggesting that it is mediated by a…