24,377 research outputs found
The influence of Ό-opioid and noradrenaline reuptake inhibition in the modulation of pain responsive neurones in the central amygdala by tapentadol in rats with neuropathy
Treatments for neuropathic pain are either not fully effective or have problematic side effects. Combinations of drugs are often used. Tapentadol is a newer molecule that produces analgesia in various pain models through two inhibitory mechanisms, namely central Ό-opioid receptor (MOR) agonism and noradrenaline reuptake inhibition. These two components interact synergistically, resulting in levels of analgesia similar to opioid analgesics such as oxycodone and morphine, but with more tolerable side effects. The right central nucleus of the amygdala (CeA) is critical for the lateral spinal ascending pain pathway, regulates descending pain pathways and is key in the emotional-affective components of pain. Few studies have investigated the pharmacology of limbic brain areas in pain models. Here we determined the actions of systemic tapentadol on right CeA neurones of animals with neuropathy and which component of tapentadol contributes to its effect. Neuronal responses to multimodal peripheral stimulation of animals with spinal nerve ligation or sham surgery were recorded before and after two doses of tapentadol. After the higher dose of tapentadol either naloxone or yohimbine were administered. Systemic tapentadol resulted in dose-dependent decrease in right CeA neuronal activity only in neuropathy. Both naloxone and yohimbine reversed this effect to an extent that was modality selective. The interactions of the components of tapentadol are not limited to the synergy between the MOR and α2-adrenoceptors seen at spinal levels, but are seen at this supraspinal site where suppression of responses may relate to the ability of the drug to alter affective components of pain
Phase transition in site-diluted Josephson junction arrays: A numerical study
We numerically investigate the intriguing effects produced by random
percolative disorder in two-dimensional Josephson-junction arrays. By dynamic
scaling analysis, we evaluate critical temperatures and critical exponents with
high accuracy. It is observed that, with the introduction of site-diluted
disorder, the Kosterlitz-Thouless phase transition is eliminated and evolves
into a continuous transition with power-law divergent correlation length.
Moreover, genuine depinning transition and creep motion are studied, evidence
for distinct creep motion types is provided. Our results not only are in good
agreement with the recent experimental findings, but also shed some light on
the relevant phase transitions.Comment: 7 pages, 8 figures, Phys. Rev. B (in press
Polyoxometalate multi-electron-transfer catalytic systems for water splitting
The viable production of solar fuels requires a visible-light-absorbing unit, a H2O (or CO2) reduction catalyst (WRC), and a water oxidation catalyst (WOC) that work in tandem to split water or reduce CO2 with H2O rapidly, selectively, and for long periods of time. Most catalysts and photosensitizers developed to date for these triadic systems are oxidatively, thermally, and/or hydrolytically unstable. Polyoxometalates (POMs) constitute a huge class of complexes with extensively tunable properties that are oxidatively, thermally, and (over wide and adjustable pH ranges) hydrolytically stable. POMs are some of the fastest and most stable WOCs to date under optimal conditions. This Microreview updates the very active POM WOC field; it reports the application of POMs as WRCs and initial self-assembling metal oxide semiconductorâphotosensitizerâPOM catalyst triad photoanodes. The complexities of investigating these POM systems, including but not limited to the study of POM-hydrated metal-ionâmetal-oxide speciation processes, are outlined. The achievements and challenges in POM WOC, WRC, and triad research are outlined
Averaging approximation to singularly perturbed nonlinear stochastic wave equations
An averaging method is applied to derive effective approximation to the
following singularly perturbed nonlinear stochastic damped wave equation \nu
u_{tt}+u_t=\D u+f(u)+\nu^\alpha\dot{W} on an open bounded domain
\,, \,. Here is a small parameter
characterising the singular perturbation, and \,, \,, parametrises the strength of the noise. Some scaling transformations
and the martingale representation theorem yield the following effective
approximation for small , u_t=\D u+f(u)+\nu^\alpha\dot{W} to an error of
\ord{\nu^\alpha}\,.Comment: 16 pages. Submitte
Experimental evaluation of Chathusama Vati for its Anti-Diarrheal Activity
Background: Diarrhea is the condition of having three or more loose or liquid bowel movements per day. The loss of fluids through diarrhea can cause dehydration and electrolyte disturbances such as potassium deficiency or other salt imbalance. According to the World Health Organization, diarrhea affects 3-5 billion people per year worldwide and cause 5 million death per year. It is an important health problem in all age groups and is a major cause of death in socio-economical backward class of people. Aim and Objective: An experimental evaluation of Chathusama Vati for its anti-diarrheal activity. Methods: The experimental study was a three-group experimental study, conducted on 6 different rats on each group. Total 18 healthy albino rats weighing between 150 gm to 200gm will be taken and divided randomly into three groups; Rats were induced diarrhea with castor oil orally. Rats of group 1 will be administered with distilled water served as control group. Group 2 will be administered with Loperamide 5 mg/kg. Group 3 will be administered with Chathusama Vati (HumandoseĂ0.018). Results: In the experimental study the result was showed as the Chathusama Vati has significant action in Diarrhea. Conclusion: From the experimental study the result it was found that Chathusama Vati showed mild ant- diarrheal activity
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