13,525 research outputs found
Consistent Hamiltonian models for space-momentum diffusion
No full textWe develop a unified Hamiltonian approach to the diffusion of a particle
coupled to a dissipative environment, an archetypal model widely invoked
to interpret condensed phase phenomena, such as polymerization and
cold-atom diffusion in optical lattices. By appropriate choices of the
coupling functions, we reformulate phenomenological diffusion models by
adding otherwise ignored space-momentum terms. We thus numerically
predict a variety of diffusion regimes, from diffusion saturation to
superballistic diffusion. With reference to ultracold atoms in optical
lattices, we also show that time correlated external noises prevent
superdiffusion from exceeding Richardson???s law. Some of these results
are unexpected and call for experimental validation
Cell viability treated by JD and Oridonin.
No full text<p>A. EC109 cells were treated for 24 h, 48 h and 72 h with 5-FU as a positive control. B-F. JD treatment of 24h, 48h and 72h to human esophageal cell lines EC109, EC9706, KYSE450, KYSE750 and TE-1, respectively. G-K. Oridonin treatment of 24h, 48h and 72h to human esophageal cell lines EC109, EC9706, KYSE450, KYSE750 and TE-1, respectively. L. JD treatment of 24h, 48h and 72h on normal cell line GES-1. M. JD treatment of 24h, 48h and 72h on normal cell line HL7702. Cell viability was determined by MTT assay and results are shown as the Mean ± SD of 3 independent experiments.</p
Occupational risk and the development of premalignant skin lesions among paraquat manufacturers
No full textDopamine receptors in the stellate ganglion of the dog
No full textEffects of fenoldopam, a selective DA1 dopamine receptor agonist, and dipropyl dopamine and propylphenethyl dopamine, preferential DA2 dopamine receptor agonists, on ganglion transmission were studied in pentobarbital-anesthetized, open-chest dogs. Tachycardia induced by electrical stimulation (supramaximal voltage, 0.5 ms duration, 1-2 Hz) of the preganglionic cardio-accelerator nerves was monitored as a measure of ganglionic transmission. Drugs were injected into the costocervical artery (i.a.) close to the arterial supply of the ganglion. Doses required to produce 30-40% inhibition of ganglionic transmission by the i.a. route were 2-8 micrograms for dipropyl dopamine, 4-16 micrograms for propylphenethyl dopamine, and 100 micrograms for fenoldopam. At these doses none of the agonists affected tachycardia induced by electrical stimulation of the postganglionic nerve. Domperidone (5 micrograms/kg i.v.), a selective DA2 dopamine receptor antagonist, markedly antagonized the effects of dipropyl dopamine and propylphenethyl dopamine, but had only minor (and statistically insignificant) effects on the inhibitory effect of fenoldopam. SCH 23390 (5 micrograms/kg i.v.), a selective and potent DA1 antagonist, failed to modify the effects of any of the agonists. In a separate series, infusion of fenoldopam, 20 micrograms/kg per min i.v. for 5-7 min, facilitated postganglionic nerve stimulation and blocked the inhibitory effect of UK 14,304, an alpha 2-adrenoceptor agonist, on the postganglionic nerve. These results confirm and support the presence of DA2 but do not support the presence of the prototypal DA1 dopamine receptor in the mammalian ganglia. Furthermore, the alpha 2-adrenoceptor blocking property of fenoldopam points to the complication of using i.v. administration for studying its ganglionic actions while monitoring the target tissue effects in response to preganglionic nerve stimulation
Dopamine receptors in the stellate ganglion of the dog
No full textEffects of fenoldopam, a selective DA1 dopamine receptor agonist, and dipropyl dopamine and propylphenethyl dopamine, preferential DA2 dopamine receptor agonists, on ganglion transmission were studied in pentobarbital-anesthetized, open-chest dogs. Tachycardia induced by electrical stimulation (supramaximal voltage, 0.5 ms duration, 1-2 Hz) of the preganglionic cardio-accelerator nerves was monitored as a measure of ganglionic transmission. Drugs were injected into the costocervical artery (i.a.) close to the arterial supply of the ganglion. Doses required to produce 30-40% inhibition of ganglionic transmission by the i.a. route were 2-8 micrograms for dipropyl dopamine, 4-16 micrograms for propylphenethyl dopamine, and 100 micrograms for fenoldopam. At these doses none of the agonists affected tachycardia induced by electrical stimulation of the postganglionic nerve. Domperidone (5 micrograms/kg i.v.), a selective DA2 dopamine receptor antagonist, markedly antagonized the effects of dipropyl dopamine and propylphenethyl dopamine, but had only minor (and statistically insignificant) effects on the inhibitory effect of fenoldopam. SCH 23390 (5 micrograms/kg i.v.), a selective and potent DA1 antagonist, failed to modify the effects of any of the agonists. In a separate series, infusion of fenoldopam, 20 micrograms/kg per min i.v. for 5-7 min, facilitated postganglionic nerve stimulation and blocked the inhibitory effect of UK 14,304, an alpha 2-adrenoceptor agonist, on the postganglionic nerve. These results confirm and support the presence of DA2 but do not support the presence of the prototypal DA1 dopamine receptor in the mammalian ganglia. Furthermore, the alpha 2-adrenoceptor blocking property of fenoldopam points to the complication of using i.v. administration for studying its ganglionic actions while monitoring the target tissue effects in response to preganglionic nerve stimulation
Consideration of Interference Correlation Properties in a JD-CDMA Mobile Radio System with Coherent Receiver Antenna Diversity
No full textIn code division multiple access (CDMA) mobile radio systems, both intersymbol interference and multiple access interference arise which can be combatted by using Joint Detection (JD) techniques, to reduce the degradation in performance resulting from time variance, coherent receiver antenna diversity (CRAD) can be used. The application of JD techniques offers the possibility to exploit the knowledge of noise covariances at the receiver. If only intercell (cochannel) interference is considered, the noise covariances in the uplink receiver of a multiple receiver antenna CDMA mobile radio system depend mainly on the directions of arrival (DOAs) of the interfering signals and the receiver antenna placement. Therefore, if the interferer DOAs are known at the base station, these covariances could be estimated. In this thesis, a realistic model of the uplink of a JD CDMA mobile radio system with CRAD is described in which the above mentioned interference cancelling method is used. Simulation results according to this model are given and evaluated.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Identification of the Li sites in the Li ion conductor, Li6SrLa2Nb2O12, through neutron powder diffraction studies
No full textIn this paper a neutron powder diffraction structural study of the Li ion conducting garnet-related system, Li6SrLa2Nb2O12, is reported. The results show that this phase is cubic, space group Ia-3d, and contains Li in two partially occupied crystallographic sites. The first site, Li1, corresponds to the ideal tetrahedral site in the garnet framework and possesses an occupancy of 0.59(1). The second site, Li2, is significantly more distorted and possesses an occupancy of 0.352(3). Compared to the related Li5La3Nb2O12 System, the Li2 site occupancy is greatly increased, while the Li1 site occupancy is reduced. Despite these large differences in site occupancies, the reported conductivities for Li5La3Nb2O12 and Li6SrLa2Nb2O12 are similar, showing the complexities of these new garnet Li ion conductor
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