29 research outputs found

    Formalization model of expert knowledge about a technical index level of engineering products

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    The authors set a timely problem that concerns development of decision making models, which allow formalizing expert subjective ideas about technical index level of engineering products. The authors proposed a formalization model of expert knowledge about technical index level of engineering products on the basis of fuzzy sets. The model has a method of membership-function construction for linguistic variable terms on the basis of exponential functions

    Validation, reproducibility and safety of trans dermal electrical stimulation in chronic pain patients and healthy volunteers

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    <p>Abstract</p> <p>Background</p> <p>Surrogate pain models have been extensively tested in Normal Human Volunteers (NHV). There are few studies that examined pain models in chronic pain patients. Patients are likely to have altered pain mechanisms. It is of interest to test patient pain responses to selective pain stimuli under controlled laboratory conditions.</p> <p>Methods</p> <p>The Institutional Ethic Committee approved the study. 16 patients with chronic neuropathic radiculopathy and 16 healthy volunteers were enrolled to the study after obtaining informed consent. During electrical stimulation (150 minutes for volunteers and 75 minutes for patients) the following parameters were measured every 10 minutes:</p> <p>Ongoing pain: Visual Analogue Scale (VAS) and Numeric Rate Scale (NRS)</p> <p>Allodynia (soft foam brush)</p> <p>Hyperalgesia (von Frey monofilament 20 g)</p> <p>Flare</p> <p>For each endpoint, the area under the curve (AUC) was estimated from the start of stimulation to the end of stimulation by the trapezoidal rule. The individual AUC values for both periods were plotted to show the inter- and intra-subject variability. For each endpoint a mixed effect model was fitted with random effect subject and fixed effect visit. The estimate of intra-subject variance and the mean value were then used to estimate the sample size of a crossover study required to have a probability of 0.80 to detect a 25% change in the mean value. Analysis was done using GenStat 8<sup>th </sup>edition.</p> <p>Results</p> <p>Each endpoint achieved very good reproducibility for patients and NHV. Comparison between groups revealed trends towards:</p> <p>Faster habituation to painful stimuli in patients</p> <p>Bigger areas of hyperalgesia in patients</p> <p>Similar area of allodynia and flare (no statistical significance)</p> <p>Conclusion</p> <p>The differences demonstrated between patients and NHVs suggest that the electrical stimulation device used here may stimulate pathways that are affected in the pathological state.</p

    Highly Efficient CO<sub>2</sub> Sorbents: Development of Synthetic, Calcium-Rich Dolomites

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    The reaction of CaO with CO<sub>2</sub> is a promising approach for separating CO<sub>2</sub> from hot flue gases. The main issue associated with the use of naturally occurring CaCO<sub>3</sub>, that is, limestone, is the rapid decay of its CO<sub>2</sub> capture capacity over repeated cycles of carbonation and calcination. Interestingly, dolomite, a naturally occurring equimolar mixture of CaCO<sub>3</sub> and MgCO<sub>3</sub>, possesses a CO<sub>2</sub> uptake that remains almost constant with cycle number. However, owing to the large quantity of MgCO<sub>3</sub> in dolomite, the total CO<sub>2</sub> uptake is comparatively small. Here, we report the development of a synthetic Ca-rich dolomite using a coprecipitation technique, which shows both a very high and a stable CO<sub>2</sub> uptake over repeated cycles of calcination and carbonation. To obtain such an excellent CO<sub>2</sub> uptake characteristic it was found to be crucial to mix the Ca<sup>2+</sup> and Mg<sup>2+</sup> on a molecular level, that is, within the crystalline lattice. For sorbents which were composed of mixtures of microscopic crystals of CaCO<sub>3</sub> and MgCO<sub>3</sub>, a decay behavior similar to natural limestone was observed. After 15 cycles, the CO<sub>2</sub> uptake of the best sorbent was 0.51 g CO<sub>2</sub>/g sorbent exceeding the CO<sub>2</sub> uptake of limestone by almost 100%

    Current knowledge of buprenorphine and its unique pharmacological profile

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    Despite the increasing clinical use of transdermal buprenorphine, questions have persisted about the possibility of a ceiling effect for analgesia, its combination with other \u3bc-opioid agonists, and the reversibility of side effects. In October 2008, a consensus group of experts met to review recent research into the pharmacology and clinical use of buprenorphine. The objective was to achieve consensus on the conclusions to be drawn from this work. It was agreed that buprenorphine clearly behaves as a full \u3bc-opioid agonist for analgesia in clinical practice, with no ceiling effect, but that there is a ceiling effect for respiratory depression, reducing the likelihood of this potentially fatal adverse event. This is entirely consistent with receptor theory. In addition, the effects of buprenorphine can be completely reversed by naloxone. No problems are encountered when switching to and from buprenorphine and other opioids, or in combining them. Buprenorphine exhibits a pronounced antihyperalgesic effect that might indicate potential advantages in the treatment of neuropathic pain. Other beneficial properties are the compound's favorable safety profile, particularly in elderly patients and those with renal impairment, and its lack of effect on sex hormones and the immune system. The expert group agreed that these properties, as well as proven efficacy in severe pain and favorable tolerability, mean that buprenorphine can be considered a safe and effective option for treating chronic cancer and noncancer pain

    NMIO Technical Bulletin

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    The technical bulletin looks to leverage advances in science and technology to solve emerging problems and safeguard the maritime environmen

    Spinal endocannabinoids and CB1 receptors mediate C-fiber-induced heterosynaptic pain sensitization

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    Diminished synaptic inhibition in the spinal dorsal horn is a major contributor to chronic pain. Pathways that reduce synaptic inhibition in inflammatory and neuropathic pain states have been identified, but central hyperalgesia and diminished dorsal horn synaptic inhibition also occur in the absence of inflammation or neuropathy, solely triggered by intense nociceptive (C-fiber) input to the spinal dorsal horn. We found that endocannabinoids, produced upon strong nociceptive stimulation, activated type 1 cannabinoid (CB1) receptors on inhibitory dorsal horn neurons to reduce the synaptic release of gamma-aminobutyric acid and glycine and thus rendered nociceptive neurons excitable by nonpainful stimuli. Our results suggest that spinal endocannabinoids and CB1 receptors on inhibitory dorsal horn interneurons act as mediators of heterosynaptic pain sensitization and play an unexpected role in dorsal horn pain-controlling circuits
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