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Sample records for volatile general anesthetics

  1. Sodium channels as targets for volatile anesthetics

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    Karl F. Herold

    2012-03-01

    Full Text Available The molecular mechanisms of modern inhaled anesthetics although widely used in clinical settings are still poorly understood. Considerable evidence supports effects on membrane proteins such as ligand- and voltage-gated ion channels of excitable cells. Na+ channels are crucial to action potential initiation and propagation, and represent potential targets for volatile anesthetics. Inhibition of presynaptic Na+ channels leads to reduced neurotransmitter release at the synapse and could therefore contribute to the mechanisms by which volatile anesthetics produce their characteristic effects: amnesia, unconsciousness, and immobility. Early studies on crayfish and squid giant axon showed inhibition of Na+ currents by volatile anesthetics. Subsequent studies using native neuronal preparations and heterologous expression systems with various mammalian Na+ channel isoforms implicated inhibition of presynaptic Na+ channels in anesthetic actions. Volatile anesthetics reduce peak Na+ current and shift the voltage of half-maximal steady-state inactivation towards more negative potentials, thus stabilizing the fast-inactivated state. Furthermore recovery from fast-inactivation is slowed together with an enhanced use-dependent block during pulse train protocols. These effects can reduce neurotransmitter release by depressing presynaptic excitability, depolarization and Ca entry, and ultimately transmitter release. This reduction in transmitter release is more portent for glutamatergic vs. GABAergic terminals. Involvement of Na+ channel inhibition in mediating the immobility caused by volatile anesthetics has been demonstrated in animal studies, in which intrathecal infusion of the Na+ channel blocker tetrodotoxin increases volatile anesthetic potency, whereas infusion of the Na+ channels agonist veratridine reduces anesthetic potency. These studies indicate that inhibition of presynaptic Na+ channels by volatile anesthetics is involved in mediating some of

  2. Drug interactions: volatile anesthetics and opioids.

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    Glass, P S; Gan, T J; Howell, S; Ginsberg, B

    1997-09-01

    Multiple drugs are used to provide anesthesia. Volatile anesthetics are commonly combined with opioids. Several studies have demonstrated that small doses of opioid (i.e., within the analgesic range) result in a marked reduction in minimum alveolar concentration (MAC) of the volatile anesthetic that will prevent purposeful movement in 50% of patients at skin incision). Further increases in opioid dose provide only a further small reduction in MAC. Thus, a ceiling effect of the opioid is observed at a MAC value of the volatile anesthetic equal to its MAC awake. Recovery from anesthesia when an opioid is combined with a volatile anesthetic is dependent on the rate of decrease of both drugs to their respective concentrations that are associated with adequate spontaneous ventilation and awakening. Through an understanding of the pharmacodynamic interaction of volatile anesthetics with opioids and the pharmacokinetic processes responsible for the recovery from drug effect, optimal dosing schemes can thus be developed. A review of these pharmacodynamic and pharmacokinetic principles that will allow clinicians to administer drugs to provide a more optimal anesthetic is provided.

  3. Anesthetic action of volatile anesthetics by using Paramecium as a model.

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    Zhou, Miaomiao; Xia, Huimin; Xu, Younian; Xin, Naixing; Liu, Jiao; Zhang, Shihai

    2012-06-01

    Although empirically well understood in their clinical administration, volatile anesthetics are not yet well comprehended in their mechanism studies. A major conundrum emerging from these studies is that there is no validated model to assess the presumed candidate sites of the anesthetics. We undertook this study to test the hypothesis that the single-celled Paramecium could be anesthetized and served as a model organism in the study of anesthetics. We assessed the motion of Paramecium cells with Expert Vision system and the chemoresponse of Paramecium cells with T-maze assays in the presence of four different volatile anesthetics, including isoflurane, sevoflurane, enflurane and ether. Each of those volatiles was dissolved in buffers to give drug concentrations equal to 0.8, 1.0, and 1.2 EC50, respectively, in clinical practice. We could see that after application of volatile anesthetics, the swimming of the Paramecium cells was accelerated and then suppressed, or even stopped eventually, and the index of the chemoresponse of the Paramecium cells (denoted as I ( che )) was decreased. All of the above impacts were found in a concentration-dependent fashion. The biphasic effects of the clinical concentrations of volatile anesthetics on Paramecium simulated the situation of high species in anesthesia, and the inhibition of the chemoresponse also indicated anesthetized. In conclusion, the findings in our studies suggested that the single-celled Paramecium could be anesthetized with clinical concentrations of volatile anesthetics and therefore be utilized as a model organism to study the mechanisms of volatile anesthetics.

  4. Detection of volatile and soluble general anesthetics using a fluorescence-based fiber optic sensor: recent progress in chemical sensitivity and noise sources

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    Yager, Paul; Abrams, Susan B.

    1992-04-01

    A fiber optic sensor for general anesthetics based on the phase transition of immobilized phospholipid vesicles is under development. Current work centers on evaluating the sensor response to different anesthetics and instrumentation design. The fluorescence of laurdan- doped liposomes is found to respond linearly to the infusible anesthetics thiopental sodium and Propofol. Preliminary experiments have been performed to determine sources of noise in the optical and electronic components of the sensor as it is now configured. One potential noise source is the liposome sample at the fiber tip; photobleaching and thermal fluctuations due to heating by the illuminating 360 nm radiation can affect measurement of the anesthetic level. Heating of the sample is a factor at high illumination levels, but photobleaching, which reduces the signal intensity, does not alter the intensity ratio upon which the anesthetic concentration measurement is based. Optical microscopy of fiber tips embedded in liposomes allows direct observation of the light intensity near the tip of the fiber despite the extreme turbidity of the suspension. Light intensity drops to less than 10% of its maximum intensity at the fiber tip within 300 micrometers . Further use of this technique should allow monitoring the effects of photobleaching on the spatial distribution of the liposomes responsible for the measured optical signal.

  5. General anesthetics in children: neurotoxic or neuroprotective?

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    Jéssica Farias Rebouças

    2017-02-01

    Full Text Available Introduction: general anesthetics are involved in neuroprotection in adults after ischemic events and cognitive impairment, thus, they also may be associated with learning disorders in children exposed to them before three years of age. Objective: Describe about the neurotoxic effects of general anesthetics in experimental animals and children. Method: This is a systematic review, performed from search in databases and on PubMed using the keywords "neurotoxicity" and "general anesthetics," and "general anesthetics," "neurotoxicity", "children", "young child "and" pediatric ". Results: The search resulted in 185 articles. Out of these, 78 met our inclusion criteria. We found that there was a significant evidence of neurotoxicity induced by general anesthetics in experimental animals that were just born, resulting in late and permanent cognitive deficits. This effect was associated with multiple exposures, exposure length of time and combination of drugs. However, some studies found cognitive impairment after a single exposure to anesthetic. Conclusion: There is insufficient evidence to state that general anesthetics are neurotoxic and have the potential to trigger learning and behavior disabilities in children. However, we suggest caution in indicating surgery in children under three years old, analyzing risk-benefit and inserting the family in the decision process.   Keywords: Neurotoxicity; Neuroprotection; Cognitive Impairment; Children; General Anesthesics

  6. Relationship between potency and boiling point of general anesthetics: a thermodynamic consideration.

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    Dastmalchi, S; Barzegar-Jalali, M

    2000-07-20

    The most important group of nonspecific drugs is that of the general anesthetics. These nonspecific compounds vary greatly in structure, from noble gases such as Ar or Xe to complex steroids. Since the development of clinical anesthesia over a century ago, there has been a vast amount of research and speculation concerning the mechanism of action of general anesthetics. Despite these efforts, the exact mechanism remains unknown. Many theories of narcosis do not explain how unconsciousness is produced at a molecular level, but instead relate some physicochemical property of anesthetic agents to their anesthetic potencies. In this paper, we address some of those physicochemical properties, with more emphasis on correlating the anesthetic potency of volatile anesthetics to their boiling points based on thermodynamic principles.

  7. Sedation with volatile anesthetics in cardiothoracic intensive care unit patients

    OpenAIRE

    Hellström, Jan

    2014-01-01

    Volatile anaesthetics have been reported to provide protection against myocardial ischemia and reperfusion injury. This effect has been demonstrated in experimental studies when the volatile anaesthetics were provided either before (preconditioning) or after the ischemic period (postconditioning). Clinical trials of volatile anaesthetics versus intravenous anaesthesia for coronary artery bypass grafting (CABG) have reported reduced postoperative release of troponin, a biomarker...

  8. Blood flow and tissue oxygen pressures of liver and pancreas in rats: effects of volatile anesthetics and of hemorrhage.

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    Vollmar, B; Conzen, P F; Kerner, T; Habazettl, H; Vierl, M; Waldner, H; Peter, K

    1992-09-01

    The object of this investigation was to compare the effects of volatile anesthetics and of hemorrhage at comparable arterial blood pressures on splanchnic blood flow (radioactive microspheres) and tissue oxygenation of the liver and pancreas (surface PO2 [PSO2] electrodes). In contrast to earlier studies, we did not use identical minimum alveolar anesthetic concentration multiples as a reference to compare volatile anesthetics; rather, we used the splanchnic perfusion pressure. Under general anesthesia (intravenous chloralose) and controlled ventilation, 12 Sprague-Dawley rats underwent laparotomy to allow access to abdominal organs. Mean arterial pressure was decreased from 84 +/- 3 mm Hg (mean +/- SEM) at control to 50 mm Hg by 1.0 +/- 0.1 vol% halothane, 2.2 +/- 0.2 vol% enflurane, and 2.3 +/- 0.1 vol% isoflurane in a randomized sequence. For hemorrhagic hypotension, blood was withdrawn gradually until a mean arterial pressure of 50 mm Hg was attained. Volatile anesthetics and hemorrhage reduced cardiac output, and hepatic arterial, portal venous, and total hepatic blood flows by comparable degrees. Mean hepatic PSO2 decreased significantly from 30.7 +/- 2.6 mm Hg at control to 17.4 +/- 2 and 17.5 +/- 2 mm Hg during enflurane and isoflurane (each P less than 0.05) anesthesia, respectively. The decrease to 11.5 +/- 2.5 mm Hg was more pronounced during halothane anesthesia. Hemorrhagic hypotension was associated with the lowest hepatic PSO2 (3.4 +/- 1.3 mm Hg) and the highest number of hypoxic (0-5 mm Hg 86%) and anoxic PSO2 values (0 mm Hg 46%). Pancreatic blood flow and oxygenation remained unchanged from control during halothane and enflurane administration, whereas isoflurane increased both variables. Hemorrhagic hypotension slightly reduced pancreatic flow (-8%) but significantly decreased PSO2 from 58 +/- 5 mm Hg at control to 36 +/- 3 mm Hg, with 7% of all measured values in the hypoxic range. Thus, volatile anesthetics preserved pancreatic but not hepatic

  9. An innovative technique to improve safety of volatile anesthetics suction from the cardiopulmonary bypass circuit

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    Francesco De Simone

    2017-01-01

    Full Text Available Context: Myocardial injury during cardiac surgery on cardiopulmonary bypass (CPB is a major determinant of morbidity and mortality. Preclinical and clinical evidence of dose- and time-related cardioprotective effects of volatile anesthetic drugs exist and their use during the whole surgery duration could improve perioperative cardiac protection. Even if administering volatile agents during CPB are relatively easy, technical problems, such as waste gas scavenging, may prevent safe and manageable administration of halogenated vapors during CPB. Aims: The aim of this study is to improve the safe administration of volatile anesthesia during CPB. Settings and Design: Tertiary teaching hospital. Subjects and Methods: We describe an original device that collects and disposes of any volatile anesthetic vapors present in the exit stream of the oxygenator, hence preventing its dispersal into the operating theatre environment and adaptively regulates pressure of oxygenator chamber in the CPB circuit. Results: We have so far applied a prototype of this device in more than 1300 adult cardiac surgery patients who received volatile anesthetics during the CPB phase. Conclusions: Widespread implementation of scavenging system like the one we designed may facilitate the perfusionist and the anesthesiologist in delivering these cardioprotective drugs with beneficial impact on patients' outcome without compromising on safety.

  10. Does chronic occupational exposure to volatile anesthetic agents influence the rate of neutrophil apoptosis?

    LENUS (Irish Health Repository)

    Goto, Y

    2012-02-03

    PURPOSE: The purpose of this preliminary investigation was to determine whether the rate of neutrophil apoptosis in health care workers is influenced by exposure to volatile anesthetic agents. METHODS: Percentage neutrophil apoptosis (Annexin-V FITC assay) was measured in health care workers (n = 20) and unexposed volunteers (n = 10). For the health care workers, time weighted personal exposure monitoring to N2O, sevoflurane and isoflurane was carried out. RESULTS: The sevoflurane and isoflurane concentrations to which health care workers were exposed were less than recommended levels in all 20 cases. Percent apoptosis was less at 24 (but not at one and 12) hr culture in health care workers [50.5 (9.7)%; P = 0.008] than in unexposed volunteers [57.3 (5.1)%]. CONCLUSION: Inhibition of neutrophil apoptosis at 24 hr culture was demonstrated in health care workers chronically exposed to volatile anesthetic agents. Exposure was well below recommended levels in the both scavenged and unscavenged work areas in which the study was carried out. Further study is required to assess the effect of greater degrees of chronic exposure to volatile anesthetic agents on neutrophil apoptosis.

  11. Volatile anesthetics influence blood-brain barrier integrity by modulation of tight junction protein expression in traumatic brain injury.

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    Serge C Thal

    Full Text Available Disruption of the blood-brain barrier (BBB results in cerebral edema formation, which is a major cause for high mortality after traumatic brain injury (TBI. As anesthetic care is mandatory in patients suffering from severe TBI it may be important to elucidate the effect of different anesthetics on cerebral edema formation. Tight junction proteins (TJ such as zonula occludens-1 (ZO-1 and claudin-5 (cl5 play a central role for BBB stability. First, the influence of the volatile anesthetics sevoflurane and isoflurane on in-vitro BBB integrity was investigated by quantification of the electrical resistance (TEER in murine brain endothelial monolayers and neurovascular co-cultures of the BBB. Secondly brain edema and TJ expression of ZO-1 and cl5 were measured in-vivo after exposure towards volatile anesthetics in native mice and after controlled cortical impact (CCI. In in-vitro endothelial monocultures, both anesthetics significantly reduced TEER within 24 hours after exposure. In BBB co-cultures mimicking the neurovascular unit (NVU volatile anesthetics had no impact on TEER. In healthy mice, anesthesia did not influence brain water content and TJ expression, while 24 hours after CCI brain water content increased significantly stronger with isoflurane compared to sevoflurane. In line with the brain edema data, ZO-1 expression was significantly higher in sevoflurane compared to isoflurane exposed CCI animals. Immunohistochemical analyses revealed disruption of ZO-1 at the cerebrovascular level, while cl5 was less affected in the pericontusional area. The study demonstrates that anesthetics influence brain edema formation after experimental TBI. This effect may be attributed to modulation of BBB permeability by differential TJ protein expression. Therefore, selection of anesthetics may influence the barrier function and introduce a strong bias in experimental research on pathophysiology of BBB dysfunction. Future research is required to investigate

  12. The scavenging of volatile anesthetic agents in the cardiovascular intensive care unit environment: a technical report.

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    Pickworth, Thomas; Jerath, Angela; DeVine, Rita; Kherani, Nazmin; Wąsowicz, Marcin

    2013-01-01

    The use of volatile-based sedation within critical care environments has been limited by difficulties of drug administration and safety concerns over environment pollution and staff exposure in an intensive care unit (ICU) with no scavenging. The aim of this study was to develop a simple scavenging system to be used with the Anesthesia Conserving Device (AnaConDa(®)) and to determine whether or not ambient concentrations of residual anesthetic are within current acceptable limits. The scavenging system consists of two Deltasorb(®) canisters attached to the ICU ventilator in series. AnaConDa is a miniature vaporizer designed to provide volatile-based sedation within an ICU. The first ten patients recruited into a larger randomized trial assessing outcomes after elective coronary graft bypass surgery were sedated within the cardiac ICU using either isoflurane or sevoflurane. Sedation was guided by the Sedation Agitation Scale, resulting in an end-tidal minimum anesthetic concentration of volatile agent ranging from 0.1-0.3. At one hour post ICU admission, infrared photometric analysis was used to assess environmental contamination at four points along the ventilator circuit and scavenging system and around the patient's head. All measurements taken within the patient's room were below 1 part per million, which satisfies criteria for occupational exposure. This study shows that volatile agents can be administered safely within critical care settings using a simple scavenging system. Our scavenging system used in conjunction with the AnaConDa device reduced the concentration of environmental contamination to a level that is acceptable to Canadian standards and standards in most Western countries and thus conforms to international safety standards. The related clinical trial was registered at www.clinicaltrials.gov (NCT01151254).

  13. Volatile anesthetics for status asthmaticus in pediatric patients: a comprehensive review and case series.

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    Carrié, Sabrina; Anderson, Thomas Anthony

    2015-05-01

    Status asthmaticus is an acute, intractable asthma attack refractory to standard interventions that can lead to progressive respiratory failure. Successful management requires a fundamental understanding of the disease process, its clinical presentation, and proper evaluation. Treatment must be instituted early and is aimed at reversing the airway inflammation, bronchoconstriction, and hyper-reactivity that often lead to lower airway obstruction, impaired ventilation, and oxygenation. Most patients are effectively treated with standard therapy including beta2-adrenergic agonists and corticosteroids. Others necessitate adjunctive therapies and escalation to noninvasive ventilation or intubation. We will review the pathophysiology, evaluation, and treatment options for pediatric patients presenting with status asthmaticus with a particular focus on refractory status asthmaticus treated with volatile anesthetics. In addition, we include a proven approach to the management of these patients in the critical care setting, which requires close coordination between critical care and anesthesia providers. We present a case series of three patients, two of which have the longest reported cases of continuous isoflurane use in status asthmaticus. This series was obtained from a retrospective chart review and highlights the efficacy of the volatile anesthetic, isoflurane, in three pediatric patients with refractory life-threatening status asthmaticus. © 2015 John Wiley & Sons Ltd.

  14. The influence of volatile anesthetics on alveolar epithelial permeability measured by noninvasive radionuclide lung scan

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    Hung, Chih-Jen; Wu, Rick Sai-Chuen; Lin, Cheng-Chieh; Kao, Albert; Tsai, Jeffrey J.P.

    2003-01-01

    Many volatile anesthetics have long been thought to affect pulmonary functions including lung ventilation (LV) and alveolar epithelial permeability (AEP). The purpose of this study is to examine the influence of volatile anesthetics on LV and AEP by noninvasive radionuclide lung imaging of technetium-99m labeled diethylene triamine pentaacetic acid radioaerosol inhalation lung scan (DTPA lung scan). Twenty patients undergoing surgery and receiving volatile anesthesia with 1% halothane were enrolled as the study group 1. The other 20 patients undergoing surgery and receiving volatile anesthesia with 1.5% isoflurane were enrolled as the study group 2. At the same time, 20 patients undergoing surgery with intravenous anesthesia drugs were included as a control group. Before surgery, 1 hour after surgery, and 1 week after surgery, we investigated the 3 groups of patients with DTPA lung scan to evaluate LV and AEP by 99m Tc DTPA clearance halftime (T1/2). No significant change or abnormality of LV before surgery, 1 hour after surgery, or 1 week after surgery was found among the 3 groups of patients. In the control group, the 99m Tc DTPA clearance T1/2 was 63.5±16.4, 63.1±18.4, and 62.8±17.0 minutes, before surgery, 1 hour after surgery, and 1 week after surgery, respectively. In group 1, it was 65.9±9.3, 62.5±9.1, and 65.8±10.3 minutes, respectively. No significant change in AEP before surgery, 1 hour after surgery, or 1 week after surgery was found. However, in group 2, the 99m Tc DTPA clearance T1/2 was 65.5±13.2, 44.9±10.5, and 66.1±14.0 minutes, respectively. A significant transient change in AEP was found 1 hour after surgery, but it recovered 1 week after surgery. We conclude that volatile anesthesia is safe for LV and AEP, and only isoflurane can induce transient change of AEP. (author)

  15. Neurotoxicity of general anesthetics: A modern view of the problem

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    A. M. Ovezov

    2015-01-01

    Full Text Available All general anesthetics routinely used in clinical practice are noted to have a neurotoxic effect on the brain in different animal species including primates. The negative effects observed both in young and sexually mature animals include apoptotic neuronal cell death, suppression of neurogenesis and gliogenesis, neuroinflammation, as well as learning and memory impairments. A number of epidemiologic surveys have established an association between anesthesia in patients younger than 3 to 4 years and subsequent learning disabilities and language disorders whereas others have not found this link. In middle-aged and elderly patients, anesthesia is frequently associated with the development of postoperative cognitive dysfunction. The key component of its pathogenesis (general anesthesia itself or other factors, such as operative injury, an inflammatory response, pain syndrome, intraoperative complications, underlying disease in a patient remains unelucidated. It is concluded that there is a need for additional experimental and clinical studies of the pathogenesis of these undesirable phenomena to be prevented and corrected.

  16. Paired assessment of volatile anesthetic concentrations with synaptic actions recorded in vitro.

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    Stuart J McDougall

    Full Text Available The volatile anesthetic isoflurane poses a number of experimental challenges in the laboratory. Due to its rapid evaporation, the open conditions of most in vitro electrophysiological recording systems make the determination of actual isoflurane concentrations a challenge. Since the absolute anesthetic concentration in solution is directly related to efficacy, concentration measurements are important to allow comparisons between laboratory and clinical studies. In this study we quantify the sources of isoflurane loss during experimentation and describe a method for the measurement of isoflurane concentrations using gas chromatography and mass spectrometry simultaneous to in vitro electrophysiological measurements. Serial samples of perfused bath solution allowed correlation of isoflurane concentrations with ongoing biological effects. Saturated physiological solutions contained 13.4 +/- 0.2 mM isoflurane and were diluted to desired "nominal" concentrations for experiments. The perfusion system established stable isoflurane concentrations within the bath by 2 minutes. However, bath isoflurane concentrations varied substantially and unpredictably between experiments. The magnitudes of such discrepancies in isoflurane concentrations spanned clinically important levels. Our studies suggest that, despite countermeasures, solution handling significantly impacted the isoflurane content in the tissue bath. The magnitude of these discrepancies appears to necessitate systematic direct measurement of bath isoflurane concentrations during most in vitro conditions.

  17. Changes in Alpha Frequency and Power of the Electroencephalogram during Volatile-Based General Anesthesia

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    Darren Hight

    2017-05-01

    Full Text Available Oscillations in the electroencephalogram (EEG at the alpha frequency (8–12 Hz are thought to be ubiquitous during surgical anesthesia, but the details of how this oscillation responds to ongoing changes in volatile anesthetic concentration have not been well characterized. It is not known how often alpha oscillations are absent in the clinical context, how sensitively alpha frequency and power respond to changes in anesthetic concentration, and what effect increased age has on alpha frequency. Bipolar EEG was recorded frontally from 305 patients undergoing surgery with sevoflurane or desflurane providing general anesthesia. A new method of detecting the presence of alpha oscillations based on the stability of the rate of change of the peak frequency in the alpha range was developed. Linear concentration-response curves were fitted to assess the sensitivity of alpha power and frequency measures to changing levels of anesthesia. Alpha oscillations were seen to be inexplicably absent in around 4% of patients. Maximal alpha power increased with increasing volatile anesthetic concentrations in half of the patients, and decreased in the remaining patients. Alpha frequency decreased with increasing anesthetic concentrations in near to 90% of patients. Increasing age was associated with decreased sensitivity to volatile anesthesia concentrations, and with decreased alpha frequency, which sometimes transitioned into the theta range (5–7 Hz. While peak alpha frequency shows a consistent slowing to increasing volatile concentrations, the peak power of the oscillation does not, suggesting that frequency might be more informative of depth of anesthesia than traditional power based measures during volatile-based anesthesia. The alpha oscillation becomes slower with increasing age, even when the decreased anesthetic needs of older patients were taken into account.

  18. Assessing the impact on global climate from general anesthetic gases

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    Andersen, Mads P. Sulbæk; Nielsen, Ole John; Wallington, Timothy J.

    2012-01-01

    anthropogenic radiative forcing of climate, as measured relative to the start of the industrial era (approximately 1750). The family of anesthetic gases includes several halogenated organic compounds that are strong greenhouse gases. In this short report, we provide an overview of the state of knowledge...

  19. The Volatile Anesthetic Isoflurane Increases Endothelial Adenosine Generation via Microparticle Ecto-5′-Nucleotidase (CD73) Release

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    Kim, Mihwa; Ham, Ahrom; Kim, Katelyn Yu-Mi; Brown, Kevin M.; Lee, H. Thomas

    2014-01-01

    Endothelial dysfunction is common in acute and chronic organ injury. Isoflurane is a widely used halogenated volatile anesthetic during the perioperative period and protects against endothelial cell death and inflammation. In this study, we tested whether isoflurane induces endothelial ecto-5′-nucleotidase (CD73) and cytoprotective adenosine generation to protect against endothelial cell injury. Clinically relevant concentrations of isoflurane induced CD73 activity and increased adenosine generation in cultured human umbilical vein or mouse glomerular endothelial cells. Surprisingly, isoflurane-mediated induction of endothelial CD73 activity occurred within 1 hr and without synthesizing new CD73. We determined that isoflurane rapidly increased CD73 containing endothelial microparticles into the cell culture media. Indeed, microparticles isolated from isoflurane-treated endothelial cells had significantly higher CD73 activity as well as increased CD73 protein. In vivo, plasma from mice anesthetized with isoflurane had significantly higher endothelial cell-derived CD144+ CD73+ microparticles and had increased microparticle CD73 activity compared to plasma from pentobarbital-anesthetized mice. Supporting a critical role of CD73 in isoflurane-mediated endothelial protection, a selective CD73 inhibitor (APCP) prevented isoflurane-induced protection against human endothelial cell inflammation and apoptosis. In addition, isoflurane activated endothelial cells Rho kinase evidenced by myosin phosphatase target subunit-1 and myosin light chain phosphorylation. Furthermore, isoflurane-induced release of CD73 containing microparticles was significantly attenuated by a selective Rho kinase inhibitor (Y27632). Taken together, we conclude that the volatile anesthetic isoflurane causes Rho kinase-mediated release of endothelial microparticles containing preformed CD73 and increase adenosine generation to protect against endothelial apoptosis and inflammation. PMID:24945528

  20. Discriminative stimulus effects of inhaled 1,1,1-trichloroethane in mice: comparison to other hydrocarbon vapors and volatile anesthetics.

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    Shelton, Keith L

    2009-04-01

    Because the toxicity of many inhalants precludes evaluation in humans, drug discrimination, an animal model of subjective effects, can be used to gain insights on their poorly understood abuse-related effects. The purpose of the present study was to train a prototypic inhalant that has known abuse liability, 1,1,1-trichloroethane (TCE), as a discriminative stimulus in mice, and compare it to other classes of inhalants. Eight B6SJLF1/J mice were trained to discriminate 10 min of exposure to 12,000 ppm inhaled TCE vapor from air and seven mice were trained to discriminate 4,000 ppm TCE from air. Tests were then conducted to characterize the discriminative stimulus of TCE and to compare it to representative aromatic and chlorinated hydrocarbon vapors, volatile halogenated anesthetics as well as an odorant compound. Only the 12,000 ppm TCE versus the air discrimination group exhibited sufficient discrimination accuracy for substitution testing. TCE vapor concentration- and exposure time-dependently substituted for the 12,000 ppm TCE vapor training stimulus. Full substitution was produced by trichloroethylene, toluene, enflurane, and sevoflurane. Varying degrees of partial substitution were produced by the other volatile test compounds. The odorant, 2-butanol, did not produce any substitution for TCE. The discriminative stimulus effects of TCE are shared fully or partially by chlorinated and aromatic hydrocarbons as well as by halogenated volatile anesthetics. However, these compounds can be differentiated from TCE both quantitatively and qualitatively. It appears that the degree of similarity is not solely a function of chemical classification but may also be dependent upon the neurochemical effects of the individual compounds.

  1. Early exposure to volatile anesthetics impairs long-term associative learning and recognition memory.

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    Bradley H Lee

    Full Text Available Anesthetic exposure early in life affects neural development and long-term cognitive function, but our understanding of the types of memory that are altered is incomplete. Specific cognitive tests in rodents that isolate different memory processes provide a useful approach for gaining insight into this issue.Postnatal day 7 (P7 rats were exposed to either desflurane or isoflurane at 1 Minimum Alveolar Concentration for 4 h. Acute neuronal death was assessed 12 h later in the thalamus, CA1-3 regions of hippocampus, and dentate gyrus. In separate behavioral experiments, beginning at P48, subjects were evaluated in a series of object recognition tests relying on associative learning, as well as social recognition.Exposure to either anesthetic led to a significant increase in neuroapoptosis in each brain region. The extent of neuronal death did not differ between groups. Subjects were unaffected in simple tasks of novel object and object-location recognition. However, anesthetized animals from both groups were impaired in allocentric object-location memory and a more complex task requiring subjects to associate an object with its location and contextual setting. Isoflurane exposure led to additional impairment in object-context association and social memory.Isoflurane and desflurane exposure during development result in deficits in tasks relying on associative learning and recognition memory. Isoflurane may potentially cause worse impairment than desflurane.

  2. Allyl m-Trifluoromethyldiazirine Mephobarbital: An Unusually Potent Enantioselective and Photoreactive Barbiturate General Anesthetic

    Energy Technology Data Exchange (ETDEWEB)

    Savechenkov, Pavel Y.; Zhang, Xi; Chiara, David C.; Stewart, Deirdre S.; Ge, Rile; Zhou, Xiaojuan; Raines, Douglas E.; Cohen, Jonathan B.; Forman, Stuart A.; Miller, Keith W.; Bruzik, Karol S. (Harvard-Med); (Mass. Gen. Hosp.); (UIC)

    2012-12-10

    We synthesized 5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid (14), a trifluoromethyldiazirine-containing derivative of general anesthetic mephobarbital, separated the racemic mixture into enantiomers by chiral chromatography, and determined the configuration of the (+)-enantiomer as S by X-ray crystallography. Additionally, we obtained the {sup 3}H-labeled ligand with high specific radioactivity. R-(-)-14 is an order of magnitude more potent than the most potent clinically used barbiturate, thiopental, and its general anesthetic EC{sub 50} approaches those for propofol and etomidate, whereas S-(+)-14 is 10-fold less potent. Furthermore, at concentrations close to its anesthetic potency, R-(-)-14 both potentiated GABA-induced currents and increased the affinity for the agonist muscimol in human {alpha}1{beta}2/3{gamma}2L GABA{sub A} receptors. Finally, R-(-)-14 was found to be an exceptionally efficient photolabeling reagent, incorporating into both {alpha}1 and {beta}3 subunits of human {alpha}1{beta}3 GABAA receptors. These results indicate R-(-)-14 is a functional general anesthetic that is well-suited for identifying barbiturate binding sites on Cys-loop receptors.

  3. CT chest under general anesthesia: pulmonary, anesthetic and radiologic dilemmas

    International Nuclear Information System (INIS)

    Mahmoud, Mohamed; Towe, Christopher; Fleck, Robert J.

    2015-01-01

    Today's practice of medicine involves ever more complex patients whose care is coordinated with multidisciplinary teams. Caring for these patients can challenge all members of the health care team. Sedation/anesthesia in infants/toddlers as well as uncooperative or intellectually or emotionally impaired children who require imaging studies of the chest are ongoing challenges. High-quality computed tomography (CT) chest imaging studies in children under general anesthesia are extremely important for accurate interpretation and subsequent medical decision-making. Anesthesia-induced atelectasis may obscure or mimic true pathology creating a significant quality issue. Obtaining a high-quality, motion-free chest imaging study in infants and children under general anesthesia remains a difficult task in many institutions. Meticulous attention to anesthesia and imaging techniques and specialized knowledge are required to properly perform and interpret chest imaging studies. In this commentary, we discuss the continuous struggle to obtain high-quality CT chest imaging under general anesthesia. We will also discuss the major concerns of the anesthesiologist, radiologist and pulmonologist and why cooperation and coordination among these providers are critical for an optimal quality study.

  4. CT chest under general anesthesia: pulmonary, anesthetic and radiologic dilemmas

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, Mohamed [Cincinnati Children' s Hospital Medical Center, Department of Anesthesiology, Cincinnati, OH (United States); Towe, Christopher [Cincinnati Children' s Hospital Medical Center, Department of Pulmonary Medicine, Cincinnati, OH (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2015-07-15

    Today's practice of medicine involves ever more complex patients whose care is coordinated with multidisciplinary teams. Caring for these patients can challenge all members of the health care team. Sedation/anesthesia in infants/toddlers as well as uncooperative or intellectually or emotionally impaired children who require imaging studies of the chest are ongoing challenges. High-quality computed tomography (CT) chest imaging studies in children under general anesthesia are extremely important for accurate interpretation and subsequent medical decision-making. Anesthesia-induced atelectasis may obscure or mimic true pathology creating a significant quality issue. Obtaining a high-quality, motion-free chest imaging study in infants and children under general anesthesia remains a difficult task in many institutions. Meticulous attention to anesthesia and imaging techniques and specialized knowledge are required to properly perform and interpret chest imaging studies. In this commentary, we discuss the continuous struggle to obtain high-quality CT chest imaging under general anesthesia. We will also discuss the major concerns of the anesthesiologist, radiologist and pulmonologist and why cooperation and coordination among these providers are critical for an optimal quality study.

  5. Anesthetic management of comprehensive dental restoration in a child with glutaric aciduria type 1 using volatile sevoflurane

    Directory of Open Access Journals (Sweden)

    Wei-Nung Teng

    2014-10-01

    Full Text Available Glutaric aciduria type 1 (GA1 is a rare, inherited mitochondrial disorder that results from deficiency of mitochondrial glutaryl-CoA dehydrogenase. Most patients develop neurological dysfunction early in life, which leads to severe disabilities. We present a 37-month-old girl with GA1 manifested as macrocephaly and hypotonia who received comprehensive dental restoration surgery under general anesthesia with sevoflurane. She was placed on specialized fluid management during a preoperative fasting period and anesthesia was administered without complications. All the physiological parameters, including glucose and lactate blood levels and arterial blood gas were carefully monitored and maintained within normal range perioperatively. Strategies for anesthetic management should include prevention of pulmonary aspiration, dehydration, hyperthermia and catabolic state, adequate analgesia to minimize surgical stress, and avoidance of prolonged neuromuscular blockade. We administered general anesthesia with sevoflurane uneventfully, which was well tolerated by our patient with GA1. Additionally, communication with a pediatric geneticist and surgeons should be undertaken to formulate a comprehensive anesthetic strategy in these patients.

  6. General anesthetics inhibit erythropoietin induction under hypoxic conditions in the mouse brain.

    Directory of Open Access Journals (Sweden)

    Tomoharu Tanaka

    Full Text Available Erythropoietin (EPO, originally identified as a hematopoietic growth factor produced in the kidney and fetal liver, is also endogenously expressed in the central nervous system (CNS. EPO in the CNS, mainly produced in astrocytes, is induced under hypoxic conditions in a hypoxia-inducible factor (HIF-dependent manner and plays a dominant role in neuroprotection and neurogenesis. We investigated the effect of general anesthetics on EPO expression in the mouse brain and primary cultured astrocytes.BALB/c mice were exposed to 10% oxygen with isoflurane at various concentrations (0.10-1.0%. Expression of EPO mRNA in the brain was studied, and the effects of sevoflurane, halothane, nitrous oxide, pentobarbital, ketamine, and propofol were investigated. In addition, expression of HIF-2α protein was studied by immunoblotting. Hypoxia-induced EPO mRNA expression in the brain was significantly suppressed by isoflurane in a concentration-dependent manner. A similar effect was confirmed for all other general anesthetics. Hypoxia-inducible expression of HIF-2α protein was also significantly suppressed with isoflurane. In the experiments using primary cultured astrocytes, isoflurane, pentobarbital, and ketamine suppressed hypoxia-inducible expression of HIF-2α protein and EPO mRNA.Taken together, our results indicate that general anesthetics suppress activation of HIF-2 and inhibit hypoxia-induced EPO upregulation in the mouse brain through a direct effect on astrocytes.

  7. Volatile anesthetic rescue therapy in children with acute asthma: innovative but costly or just costly?.

    Science.gov (United States)

    Char, Danton S; Ibsen, Laura M; Ramamoorthy, Chandra; Bratton, Susan L

    2013-05-01

    To describe volatile anesthesia (VA) use for pediatric asthma, including complications and outcomes. Retrospective cohort study. Children's hospitals contributing to the Pediatric Health Information System between 2004-2008. Children 2-18 years old with a primary diagnosis code for asthma supported with mechanical ventilation. Those treated with VA were compared to those not treated with VA or extracorporeal membrane oxygenation. Hospital VA use was grouped as none, 10% among intubated children. One thousand five hundred and fifty-eight patients received mechanical ventilation at 40 hospitals for asthma: 47 (3%) received VA treatment at 11 (28%) hospitals. Those receiving a VA were significantly less likely to receive inhaled b-agonists, ipratropium bromide, and heliox, but more likely to receive neuromuscular blocking agents than patients treated without VA. Length of mechanical ventilation, hospital stay (length of stay [LOS]) and charges were significantly greater for those treated with VA. Aspiration was more common but death and air leak did not differ. Patients at hospitals with VA use >10% were significantly less likely to receive inhaled b agonist, ipratropium bromide, methylxanthines, and heliox, but more likely to receive systemic b agonist, neuromuscular blocking agents compared to those treated at hospitals not using VA. LOS, duration of ventilation, and hospital charges were significantly greater for patients treated at centers with high VA use. Mortality does not differ between centers that use VA or not. Patients treated at centers with high VA use had significantly increased hospital charges and increased LOS.

  8. Allergy to local and general anesthetics and to other drugs during surgical procedures

    OpenAIRE

    Ortega, María Claudia; Hospital Universitario San Ignacio; López, Santiago; Hospital Infantil Los Ángeles; Morato, Fabio F.; Hospital de Clínicas, São Paulo, Brasil; Kase Tanno, Luciana; Hospital de Clínicas, São Paulo, Brasil; Ensina, Luis Felipe C.; Hospital de Clínicas, São Paulo, Brasil

    2010-01-01

    Shock and hypersensitivity reactions to local and general anesthetics and to other drugs used during surgical procedures continue being a challenge in clinical practice. Allergic hypersensitivity can vary in presentation and intensity and might manifest itself from mild cutaneous symptoms to death. Las reacciones de choque e hipersensibilidad a los anestésicos locales y generales y a otros medicamentos utilizados durante los procedimientos quirúrgicos, continúan siendo un reto en la prácti...

  9. Trapping of Syntaxin1a in Presynaptic Nanoclusters by a Clinically Relevant General Anesthetic

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    Adekunle T. Bademosi

    2018-01-01

    Full Text Available Summary: Propofol is the most commonly used general anesthetic in humans. Our understanding of its mechanism of action has focused on its capacity to potentiate inhibitory systems in the brain. However, it is unknown whether other neural mechanisms are involved in general anesthesia. Here, we demonstrate that the synaptic release machinery is also a target. Using single-particle tracking photoactivation localization microscopy, we show that clinically relevant concentrations of propofol and etomidate restrict syntaxin1A mobility on the plasma membrane, whereas non-anesthetic analogs produce the opposite effect and increase syntaxin1A mobility. Removing the interaction with the t-SNARE partner SNAP-25 abolishes propofol-induced syntaxin1A confinement, indicating that syntaxin1A and SNAP-25 together form an emergent drug target. Impaired syntaxin1A mobility and exocytosis under propofol are both rescued by co-expressing a truncated syntaxin1A construct that interacts with SNAP-25. Our results suggest that propofol interferes with a step in SNARE complex formation, resulting in non-functional syntaxin1A nanoclusters. : Bademosi et al. use single-molecule imaging microscopy to understand how general anesthetics might affect presynaptic release mechanisms. They find that a clinically relevant concentration of propofol targets the presynaptic release machinery by specifically restricting syntaxin1A mobility on the plasma membrane. This suggests an alternate target process for these drugs. Keywords: super-resolution microscopy, sptPALM, propofol, etomidate, SNARE, Drosophila melanogaster, PC12, syntaxin1A, SNAP-25, neurotransmission

  10. General anesthetic and the risk of dementia in elderly patients: current insights

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    Hussain M

    2014-09-01

    Full Text Available Maria Hussain,1 Miles Berger,2 Roderic G Eckenhoff,3 Dallas P Seitz1 1Division of Geriatric Psychiatry, Department of Psychiatry, Queen’s University; 2Anesthesiology Department, Duke University Medical Center, Durham, NC, USA; 3Department of Anesthesiology and Critical Care, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA Abstract: In this review, we aim to provide clinical insights into the relationship between surgery, general anesthesia (GA, and dementia, particularly Alzheimer’s disease (AD. The pathogenesis of AD is complex, involving specific disease-linked proteins (amyloid-beta [Aß] and tau, inflammation, and neurotransmitter dysregulation. Many points in this complex pathogenesis can potentially be influenced by both surgery and anesthetics. It has been demonstrated in some in vitro, animal, and human studies that some anesthetics are associated with increased aggregation and oligomerization of Aß peptide and enhanced accumulation and hyperphosphorylation of tau protein. Two neurocognitive syndromes that have been studied in relation to surgery and anesthesia are postoperative delirium and postoperative cognitive dysfunction, both of which occur more commonly in older adults after surgery and anesthesia. Neither the route of anesthesia nor the type of anesthetic appears to be significantly associated with the development of postoperative delirium or postoperative cognitive dysfunction. A meta-analysis of case-control studies found no association between prior exposure to surgery utilizing GA and incident AD (pooled odds ratio =1.05, P=0.43. The few cohort studies on this topic have shown varying associations between surgery, GA, and AD, with one showing an increased risk, and another demonstrating a decreased risk. A recent randomized trial has shown that patients who received sevoflurane during spinal surgery were more likely to have progression of preexisting mild cognitive impairment compared to

  11. Seeking Structural Specificity: Direct Modulation of Pentameric Ligand-Gated Ion Channels by Alcohols and General Anesthetics

    Science.gov (United States)

    Trudell, James R.; Harris, R. Adron

    2014-01-01

    Alcohols and other anesthetic agents dramatically alter neurologic function in a wide range of organisms, yet their molecular sites of action remain poorly characterized. Pentameric ligand-gated ion channels, long implicated in important direct effects of alcohol and anesthetic binding, have recently been illuminated in renewed detail thanks to the determination of atomic-resolution structures of several family members from lower organisms. These structures provide valuable models for understanding and developing anesthetic agents and for allosteric modulation in general. This review surveys progress in this field from function to structure and back again, outlining early evidence for relevant modulation of pentameric ligand-gated ion channels and the development of early structural models for ion channel function and modulation. We highlight insights and challenges provided by recent crystal structures and resulting simulations, as well as opportunities for translation of these newly detailed models back to behavior and therapy. PMID:24515646

  12. Effectiveness of flumazenil on return of cognitive functions after a general anesthetic.

    Science.gov (United States)

    Pregler, J L; Mok, M S; Steen, S N

    1994-09-01

    Benzodiazepines used intra-operatively can occasionally cause prolonged sedation. Flumazenil (Romazicon) is an imidazobenzodiazepine that functions as a benzodiazepine receptor antagonist. This clinical investigation was designed to evaluate the efficacy and of intravenous flumazenil in reversing the central effects of midazolam after a general anesthetic using midazolam for maintenance. 30 ASA I-III inpatients entered and completed this study. All were interviewed preoperatively and baseline performance on a battery of psychomotor tests was obtained. Parameters measured included an assessment of sleep status, vital signs, responsiveness to verbal stimuli, quality of speech, facial expression, eye coordination, recognition of a picture card, finger-finger-to-nose (FFN) coordination and overall discharge readiness. General anesthesia was induced with midazolam. Midazolam and fentanyl were the primary maintenance agents combined with N2O and O2 (70:30) and a limited concentration of isoflurane. In the recovery room the test drug was administered in a double-blinded, randomized manner. 20 patients received flumazenil (F), the rest placebo (P). Testing was done at times 0, 5, 15, 30, 60, 120, and 180 min in the PACU. Memory testing consisted of recall of study pictures at 180 min and recognition on the first postoperative day. Demographic data were similar for both groups with the exception of age. The F group had a higher mean composite score (comprising responsiveness to verbal stimuli, speech, facial expression and eye coordination) and better FFN scores at 5, 15, and 30 min (p pictures better at 5 and 15 min (p WORDS)

  13. Estimating and Forecasting Generalized Fractional Long Memory Stochastic Volatility Models

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    Shelton Peiris

    2017-12-01

    Full Text Available This paper considers a flexible class of time series models generated by Gegenbauer polynomials incorporating the long memory in stochastic volatility (SV components in order to develop the General Long Memory SV (GLMSV model. We examine the corresponding statistical properties of this model, discuss the spectral likelihood estimation and investigate the finite sample properties via Monte Carlo experiments. We provide empirical evidence by applying the GLMSV model to three exchange rate return series and conjecture that the results of out-of-sample forecasts adequately confirm the use of GLMSV model in certain financial applications.

  14. The use of a volatile anesthetic regimen protects against acute normovolemic hemodilution induced myocardial depression in patients with coronary artery disease

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    Lorsomradee Sratwadee

    2009-01-01

    Full Text Available Background: Previous studies indicated that acute normovolemic hemodilution (ANH was associated with a depression of myocardial function in coronary surgery patients with baseline heart rate faster than 90 bpm. It was suggested that this phenomenon could be explained by the occurrence of myocardial ischemia. In the present study, we hypothesized that the cardioprotective properties of a volatile anesthetic regimen might protect against the ANH related myocardial functional impairment. Materials and Methods: Forty elective coronary surgery patients with baseline heart rate faster than 90 bpm were randomly allocated to receive different anesthetic regimens. Group A (n = 20 received midazolam-based anesthesia. Group B (n = 20 received a sevoflurane-based anesthesia. Five-lead electrocardiogram, pulse oximetry, capnography, radial arterial pressure, and Swan Ganz continuous thermodilution cardiac output via right internal jugular vein were monitored. Measurements were obtained before and after ANH. Data were compared using paired t test. All data were expressed as mean ± SD. Data were considered significant if P < 0.05. Results: After ANH, systemic vascular resistance was slightly decreased in group A while there was a significant decrease in group B. In group A, cardiac output was slightly decreased from 5.07±1.17 l/min to 5.02±1.28 l/min after ANH, whereas in group B, cardiac output was significantly increased from 4.84±1.21 l/min to 6.02±1.28 l/min after ANH. Conclusion: In coronary surgery patients, with baseline heart rate faster than 90 bpm, anesthesia with sevoflurane during ANH was associated with an improvement in myocardial function after ANH, which was not present in patients anesthetized with midazolam.

  15. On the Action of General Anesthetics on Cellular Function: Barbiturate Alters the Exocytosis of Catecholamines in a Model Cell System.

    Science.gov (United States)

    Ye, Daixin; Ewing, Andrew

    2018-01-22

    General anesthetics are essential in many areas, however, the cellular mechanisms of anesthetic-induced amnesia and unconsciousness are incompletely understood. Exocytosis is the main mechanism of signal transduction and neuronal communication through the release of chemical transmitters from vesicles to the extracellular environment. Here, we use disk electrodes placed on top of PC12 cells to show that treatment with barbiturate induces fewer molecules released during exocytosis and changes the event dynamics perhaps by inducing a less stable fusion pore that is prone to close faster during partial exocytosis. Larger events are essentially abolished. However, use of intracellular vesicle impact electrochemical cytometry using a nano-tip electrode inserted into a cell shows that the distribution of vesicle transmitter content does not change after barbiturate treatment. This indicates that barbiturate selectively alters the pore size of larger events or perhaps differentially between types of vesicles. Alteration of exocytosis in this manner could be linked to the effects of general anesthetics on memory loss. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Day-surgery patients anesthetized with propofol have less postoperative pain than those anesthetized with sevoflurane.

    LENUS (Irish Health Repository)

    Tan, Terry

    2012-02-01

    BACKGROUND: There have been recent studies suggesting that patients anesthetized with propofol have less postoperative pain compared with patients anesthetized with volatile anesthetics. METHODS: In this randomized, double-blind study, 80 patients undergoing day-case diagnostic laparoscopic gynecological surgery were either anesthetized with IV propofol or sevoflurane. The primary outcome measured was pain on a visual analog scale. RESULTS: Patients anesthetized with propofol had less pain compared with patients anesthetized with sevoflurane (P = 0.01). There was no difference in any of the other measured clinical outcomes. CONCLUSIONS: The patients anesthetized with propofol appeared to have less pain than patients anesthetized with sevoflurane.

  17. Nitrous Oxide and Nitrous Oxide-Free Low-Flow Anesthesia Using Bispectral Index Monitoring: Effects on Hemodynamics, Recovery Times, Volatile Anesthetic Consumption and Costs

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    Bengü Gülhan Köksal

    2010-12-01

    Full Text Available Aim: In this study, we aimed to compare the effects of desfluraneN2O and desflurane-fentanyl combinations on hemodynamics, recovery times, volatile anesthetic consumption and costs in low-flow desflurane anesthesia by bispectral index (BIS monitoring of depth of anesthesia. Methods: After approval of ethics committee and obtaining patient consents, 60 patients were divided into two equal groups randomly. Non-invasive blood pressure measurement, ECG, SpO2 and BIS were monitored. All patients received 10 L .min-1 100% oxygen with mask for 5 minute before intubation. 2 mg.kg-1 propofol, 2 μg.kg-1 fentanyl and 0.6 mg.kg-1 rocuronium bromide were administered at induction in both groups. Desfluran 6% was chosen for anesthesia maintenance. Group 1 received 50% O2-N2O mixture in 6 L.min-1 and Group 2 received 50% O2-air mixture in 6 L.min-1 as carrier gas. Low-flow anesthesia (1 L.min-1 was started after a 10-min period of initial high flow (6 L.min-1. In Group 2, infusion of fentanyl was begun in 1 μg.kg.hour-1 rate. Desflurane level was adjusted at a main BIS value of 40-60. Blood pressure, heart rate, FiO2, etO2, FiN22, EtN2O, FiCO2, EtCO2, Fidesfluran and Etdesflurane were recorded. Results: There were no significant differences between the two groups in terms of heart rate, arterial blood pressure, settings of desfluran and recovery time. BIS values (p<0.001 and anesthetic agent costs (p<0.001 were higher in Group 2. Conclusion: Using fentanyl infusion instead of nitrous oxide in low flow-anesthesia with desflurane did not alter the hemodynamic parameters. Fentanyl infusion with medical air-oxygen as carrier gas is an alternative technique, but increases BIS values and anesthetic agent costs. (The Medical Bulletin of Haseki 2010; 48: 132-8

  18. [Clinical observation on controlling antihypertension with the general anesthesia of TEAS and anesthetics in endoscopic endonasal surgery].

    Science.gov (United States)

    Zhao, Wensheng; Zhao Xian; Li, Jinjin; Fang, Jianqiao

    2015-12-01

    To study whether the dose of controlling antihypertensive drug is reduced by transcutaneous electrical acupoint stimulation (TEAS) and the anesthetics, as well as the control of blood pressure (BP) and heart rate (HR) in endoscopic endonasal surgery with general anesthesia. Sixty patients for selective endoscopic endonasal surgery with general anesthetics and controlling antihypertension involved were selected and randomized into a TEAS group, a sham-TEAS group, 30 cases in each one. The electric pads were attached to bilateral Hegu (LI 4), Zusanli (ST 36), Sanyinjiao (SP 6) and Quchi (LI 11), stimulated with Hans-200 apparatus, 3 to 5 mA, 2 Hz/100 Hz in the TEAS group based on the patients' response to comfort. No electric stimulation was applied to the sham-TEAS group. The general anesthesia started after 30 min intervention and lasted till the end of surgery. The BP and HR were observed and recorded at the end of monitoring in operation room, 10 min after tranquilization (T0), 30 min after intervention (Tj, after induction~of general anestiesa (T2), 30 min after surgery start (T3), 60 min after surgery start (T4) and 30 min after extubation (T5). The doses of vecuronium bromide, propofol and nitroglycerin were recorded statistically in surgery, as well as the operative bleeding volume, the operative time, the resuscitation time and the visual analogue scale (VAS) score after resuscitation. Compared with that at T0, the mean arterial pressure (MAP) at T2, T3, T4 and T5 in the TEAS group and at T3 and T4 in the sham-TEAS group was all reduced, indicating the significant difference (all P 0.05). HR was different at T2 to Ts in the sham-TEAS group statistically (all P 0.05). The general anesthesia with TEAS and anesthetics involved for controlling antihypertension contributes to the control of BP and HR in the patients in endoscopic endonasal surgery. The impacts are not obvious on the doses of antihypertensive drug, the general anesthetics, the operative bleeding

  19. General anesthetic octanol and related compounds activate wild-type and delF508 cystic fibrosis chloride channels

    OpenAIRE

    Marcet, Brice; Becq, Frédéric; Norez, Caroline; Delmas, Patrick; Verrier, Bernard

    2004-01-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel is defective during cystic fibrosis (CF). Activators of the CFTR Cl− channel may be useful for therapy of CF. Here, we demonstrate that a range of general anesthetics like normal-alkanols (n-alkanols) and related compounds can stimulate the Cl− channel activity of wild-type CFTR and delF508-CFTR mutant.The effects of n-alkanols like octanol on CFTR activity were measured by iodide (125I) efflux and patch-clamp techniques o...

  20. The effects of general anesthetics on ESR spectra of spin labels in phosphatidylcholine vesicles containing purified Na,K-ATPase or microsomal protein

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Makiko, E-mail: shibu@den.hokudai.ac.jp [Department of Dental Anesthesiology, Graduate School of Dental Medicine, Hokkaido University (Japan); Hiraoki, Toshifumi [Division of Applied Physics, Graduate School of Engineering, Hokkaido University (Japan); Kimura, Kunie; Fukushima, Kazuaki [Department of Dental Anesthesiology, Graduate School of Dental Medicine, Hokkaido University (Japan); Suzuki, Kuniaki [Department of Molecular Cell Pharmacology, Graduate School of Dental Medicine, Hokkaido University (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer We studied the effects of general anesthetics on liposome using ESR spectra. Black-Right-Pointing-Pointer Two spin labels, 5-DSA and 16-DSA, were located in different position in liposome. Black-Right-Pointing-Pointer Anesthetics did not change the environment around the spin labels in the liposome. Black-Right-Pointing-Pointer Anesthetics remained on the surface of the lipid bilayer of liposome. Black-Right-Pointing-Pointer Proteins in the liposome did not change the effects of anesthetics on liposome. - Abstract: We investigated the effects of general anesthetics on liposome containing spin labels, 5-doxyl stearic acid (5-DSA) and 16-doxyl stearic acid (16-DSA), and purified Na,K-ATPase or membrane protein of microsome using an electron spin resonance (ESR) spectroscopy. The spectra of 16-DSA in liposomes with both proteins showed three sharp signals compared with 5-DSA. The difference in the order parameter S value of 5-DSA and 16-DSA suggested that the nitroxide radical location of 5-DSA and 16-DSA were different in the membrane bilayer. The results were almost the same as those obtained in liposomes without proteins. The addition of sevoflurane, isoflurane, halothane, ether, ethanol and propofol increased the intensity of the signals, but the clinical concentrations of anesthetics did not significantly alter the S and {tau} values, which are indices of the fluidity of the membrane. These results suggest that anesthetics remain on the surface of the lipid bilayer and do not act on both the inside hydrophobic area and the relatively hydrophilic area near the surface. These results and others also suggest that the existence of Na,K-ATPase and microsomal proteins did not affect the environment around the spin labels in the liposome and the effects of anesthetics on liposome as a model membrane.

  1. Estimating and Forecasting Generalized Fractional Long Memory Stochastic Volatility Models

    NARCIS (Netherlands)

    S. Peiris (Shelton); M. Asai (Manabu); M.J. McAleer (Michael)

    2016-01-01

    textabstractIn recent years fractionally differenced processes have received a great deal of attention due to its flexibility in financial applications with long memory. This paper considers a class of models generated by Gegenbauer polynomials, incorporating the long memory in stochastic volatility

  2. Volatility

    Directory of Open Access Journals (Sweden)

    María Sánchez

    2016-11-01

    Full Text Available The action consists of moving with small kicks a tin of cola refresh -without Brand-from a point of the city up to other one. During the path I avoid bollards, the slope differences between sidewalks, pedestrians, parked motorcycles, etc. Volatility wants to say exactly that the money is getting lost. That the money is losing by gentlemen and by ladies who are neither financial sharks, nor big businessmen… or similarly, but ingenuous people, as you or as me, who walk down the street.

  3. Severe Bradycardia Possibly due to a Local Anesthetic Oral Mucosal Injection during General Anesthesia

    OpenAIRE

    Satoh, Kenichi; Ohashi, Ayako; Kumagai, Miho; Hoshi, Hideki; Otaka, Kousei; Joh, Shigeharu

    2015-01-01

    Local anesthesia may induce systemic complications leading to parasympathetic activity leading to bradycardia and hypotension. We report a case of a 50-year-old man undergoing dental surgery under general anesthesia who experienced severe bradycardia and hypotension after local anesthesia infiltration. Concerns regarding the utilization of a relatively large lumen injection needle for local anesthesia during general anesthesia are discussed.

  4. Carbon monoxide production from five volatile anesthetics in dry sodalime in a patient model: halothane and sevoflurane do produce carbon monoxide; temperature is a poor predictor of carbon monoxide production

    Directory of Open Access Journals (Sweden)

    Perez Roberto SGM

    2005-06-01

    Full Text Available Abstract Background Desflurane and enflurane have been reported to produce substantial amounts of carbon monoxide (CO in desiccated sodalime. Isoflurane is said to produce less CO and sevoflurane and halothane should produce no CO at all. The purpose of this study is to measure the maximum amounts of CO production for all modern volatile anesthetics, with completely dry sodalime. We also tried to establish a relationship between CO production and temperature increase inside the sodalime. Methods A patient model was simulated using a circle anesthesia system connected to an artificial lung. Completely desiccated sodalime (950 grams was used in this system. A low flow anesthesia (500 ml/min was maintained using nitrous oxide with desflurane, enflurane, isoflurane, halothane or sevoflurane. For immediate quantification of CO production a portable gas chromatograph was used. Temperature was measured within the sodalime container. Results Peak concentrations of CO were very high with desflurane and enflurane (14262 and 10654 ppm respectively. It was lower with isoflurane (2512 ppm. We also measured small concentrations of CO for sevoflurane and halothane. No significant temperature increases were detected with high CO productions. Conclusion All modern volatile anesthetics produce CO in desiccated sodalime. Sodalime temperature increase is a poor predictor of CO production.

  5. Can the dopaminergic-related effects of general anesthetics be linked to mechanisms involved in drug abuse and addiction?

    Science.gov (United States)

    Melo, A; Tavares, I; Sousa, N; Pêgo, J M

    2015-08-01

    General anesthetics (GA) are well known for the ability to induce a state of reversible loss of consciousness and unresponsiveness to painful stimuli. However, evidence from animal models and clinical studies show that GA exposure may induce behavioral changes beyond acute effects. Most research and concerns are focused on changes in cognition and memory. We will look at effects of GA on behavior that is mediated by the dopaminergic system. Pharmacological resemblance of GA with drugs of abuse, and the complexity and importance of dopaminergic systems in both reward seeking and addictive illnesses make us believe that it deserves an overview about what is already known and what matters to us as healthcare workers and specifically as anesthesiologists. A review of available evidence strongly suggests that there may be a link between the effects of GA on the brain and substance abuse, partly explained by their influence on the dopaminergic system. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  6. The effects of general anesthetics on ESR spectra of spin labels in phosphatidylcholine vesicles containing purified Na,K-ATPase or microsomal protein

    Science.gov (United States)

    Shibuya, Makiko; Hiraoki, Toshifumi; Kimura, Kunie; Fukushima, Kazuaki; Suzuki, Kuniaki

    2012-12-01

    We investigated the effects of general anesthetics on liposome containing spin labels, 5-doxyl stearic acid (5-DSA) and 16-doxyl stearic acid (16-DSA), and purified Na,K-ATPase or membrane protein of microsome using an electron spin resonance (ESR) spectroscopy. The spectra of 16-DSA in liposomes with both proteins showed three sharp signals compared with 5-DSA. The difference in the order parameter S value of 5-DSA and 16-DSA suggested that the nitroxide radical location of 5-DSA and 16-DSA were different in the membrane bilayer. The results were almost the same as those obtained in liposomes without proteins. The addition of sevoflurane, isoflurane, halothane, ether, ethanol and propofol increased the intensity of the signals, but the clinical concentrations of anesthetics did not significantly alter the S and τ values, which are indices of the fluidity of the membrane. These results suggest that anesthetics remain on the surface of the lipid bilayer and do not act on both the inside hydrophobic area and the relatively hydrophilic area near the surface. These results and others also suggest that the existence of Na,K-ATPase and microsomal proteins did not affect the environment around the spin labels in the liposome and the effects of anesthetics on liposome as a model membrane.

  7. ALGORITHM FOR GENERALIZED GARMAN EQUATION IN OPTION PRICING OF A FINANCIAL DERIVATIVES WITH STOCHASTIC VOLATILITY MODELS

    Directory of Open Access Journals (Sweden)

    Maxim Ioan

    2009-05-01

    Full Text Available In our paper we build a reccurence from generalized Garman equation and discretization of 3-dimensional domain. From reccurence we build an algorithm for computing values of an option based on time, momentan volatility of support and value of support on a

  8. General anesthetic octanol and related compounds activate wild-type and delF508 cystic fibrosis chloride channels.

    Science.gov (United States)

    Marcet, Brice; Becq, Frédéric; Norez, Caroline; Delmas, Patrick; Verrier, Bernard

    2004-03-01

    1. Cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel is defective during cystic fibrosis (CF). Activators of the CFTR Cl(-) channel may be useful for therapy of CF. Here, we demonstrate that a range of general anesthetics like normal-alkanols (n-alkanols) and related compounds can stimulate the Cl(-) channel activity of wild-type CFTR and delF508-CFTR mutant. 2. The effects of n-alkanols like octanol on CFTR activity were measured by iodide ((125)I) efflux and patch-clamp techniques on three distinct cellular models: (1). CFTR-expressing Chinese hamster ovary cells, (2). human airway Calu-3 epithelial cells and (3). human airway JME/CF15 epithelial cells which express the delF508-CFTR mutant. 3. Our data show for the first time that n-alkanols activate both wild-type CFTR and delF508-CFTR mutant. Octanol stimulated (125)I efflux in a dose-dependent manner in CFTR-expressing cells (wild-type and delF508) but not in cell lines lacking CFTR. (125)I efflux and Cl(-) currents induced by octanol were blocked by glibenclamide but insensitive to 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, as expected for a CFTR Cl(-) current. 4. CFTR activation by octanol was neither due to cell-to-cell uncoupling properties of octanol nor to an intracellular cAMP increase. CFTR activation by octanol requires phosphorylation by protein kinase-A (PKA) since it was prevented by H-89, a PKA inhibitor. 5. n-Alkanols chain length was an important determinant for channel activation, with rank order of potencies: 1-heptanoloctanoloctanol<1-decanol. Our findings may be of valuable interest for developing novel therapeutic strategies for CF.

  9. The location and nature of general anesthetic binding sites on the active conformation of firefly luciferase; a time resolved photolabeling study.

    Directory of Open Access Journals (Sweden)

    Sivananthaperumal Shanmugasundararaj

    Full Text Available Firefly luciferase is one of the few soluble proteins that is acted upon by a wide variety of general anesthetics and alcohols; they inhibit the ATP-driven production of light. We have used time-resolved photolabeling to locate the binding sites of alcohols during the initial light output, some 200 ms after adding ATP. The photolabel 3-azioctanol inhibited the initial light output with an IC50 of 200 µM, close to its general anesthetic potency. Photoincorporation of [(3H]3-azioctanol into luciferase was saturable but weak. It was enhanced 200 ms after adding ATP but was negligible minutes later. Sequencing of tryptic digests by HPLC-MSMS revealed a similar conformation-dependence for photoincorporation of 3-azioctanol into Glu-313, a residue that lines the bottom of a deep cleft (vestibule whose outer end binds luciferin. An aromatic diazirine analog of benzyl alcohol with broader side chain reactivity reported two sites. First, it photolabeled two residues in the vestibule, Ser-286 and Ile-288, both of which are implicated with Glu-313 in the conformation change accompanying activation. Second, it photolabeled two residues that contact luciferin, Ser-316 and Ser-349. Thus, time resolved photolabeling supports two mechanisms of action. First, an allosteric one, in which anesthetics bind in the vestibule displacing water molecules that are thought to be involved in light output. Second, a competitive one, in which anesthetics bind isosterically with luciferin. This work provides structural evidence that supports the competitive and allosteric actions previously characterized by kinetic studies.

  10. Anesthesia and Duchenne or Becker muscular dystrophy: review of 117 anesthetic exposures.

    Science.gov (United States)

    Segura, Leal G; Lorenz, Jessica D; Weingarten, Toby N; Scavonetto, Federica; Bojanić, Katarina; Selcen, Duygu; Sprung, Juraj

    2013-09-01

    Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are associated with life-threatening perioperative complications, including rhabdomyolysis, hyperkalemia, and hyperthermia. Current recommendations contraindicate use of succinylcholine and volatile anesthetics; however, the latter recommendation remains controversial. To review the perioperative outcomes of patients with DMD and BMD. We reviewed records of patients with DMD or BMD who underwent anesthetic management at our institution from January 1990 through December 2011. We identified 47 patients (DMD, 37; BMD, 10) who underwent 117 anesthetic exposures (DMD, 101; BMD, 16). Volatile anesthetic agents were used 66 times (DMD, 59; BMD, 7). One patient with undiagnosed BMD received succinylcholine and developed acute rhabdomyolysis and hyperkalemic cardiac arrest. All other major complications were attributed to the procedure (i.e., large bleeding), to preexisting comorbidities (i.e., respiratory failure, cardiac disease), or to both. Use of succinylcholine in children with dystrophinopathy is contraindicated. These patients have significant comorbidities and are frequently undergoing extensive operations; complications related to these factors can develop, as evidenced by our series. These complications may occur with use of volatile and nonvolatile anesthetics. However, because most of our patients were older than 8 years at the time of surgery, our observation cannot be generalized to younger dystrophin-deficient children. © 2013 John Wiley & Sons Ltd.

  11. Efficient "Myopic" Asset Pricing in General Equilibrium: A Potential Pitfall in Excess Volatility Tests

    OpenAIRE

    Willem H. Buiter

    1987-01-01

    Excess volatility tests for financial market efficiency maintain the hypothesis of risk-neutrality. This permits the specification of the benchmark efficient market price as the present discounted value of expected future dividends. By departing from the risk-neutrality assumption in a stripped-down version of Lucas's general equilibrium asset pricing model, I show that asset prices determined in a competitive asset market and efficient by construction can nevertheless violate the variance bo...

  12. Titration calorimetry of anesthetic-protein interaction: negative enthalpy of binding and anesthetic potency.

    Science.gov (United States)

    Ueda, I; Yamanaka, M

    1997-04-01

    Anesthetic potency increases at lower temperatures. In contrast, the transfer enthalpy of volatile anesthetics from water to macromolecules is usually positive. The transfer decreases at lower temperature. It was proposed that a few selective proteins bind volatile anesthetics with negative delta H, and these proteins are involved in signal transduction. There has been no report on direct estimation of binding delta H of anesthetics to proteins. This study used isothermal titration calorimetry to analyze chloroform binding to bovine serum albumin. The calorimetrically measured delta H cal was -10.37 kJ.mol-1. Thus the negative delta H of anesthetic binding is not limited to signal transduction proteins. The binding was saturable following Fermi-Dirac statistics and is characterized by the Langmuir adsorption isotherms, which is interfacial. The high-affinity association constant, K, was 2150 +/- 132 M-1 (KD = 0.47 mM) with the maximum binding number, Bmax = 3.7 +/- 0.2. The low-affinity K was 189 +/- 3.8 M-1 (KD = 5.29 mM), with a Bmax of 13.2 +/- 0.3. Anesthetic potency is a function of the activity of anesthetic molecules, not the concentration. Because the sign of delta H determines the temperature dependence of distribution of anesthetic molecules, it is irrelevant to the temperature dependence of anesthetic potency.

  13. The effect of preoperative suggestions on perioperative dreams and dream recalls after administration of different general anesthetic combinations: a randomized trial in maxillofacial surgery.

    Science.gov (United States)

    Gyulaházi, Judit; Varga, Katalin; Iglói, Endre; Redl, Pál; Kormos, János; Fülesdi, Béla

    2015-01-01

    Images evoked immediately before the induction of anesthesia with the help of suggestions may influence dreaming during anesthesia.The aim of the study was to assess the incidence of evoked dreams and dream recalls by employing suggestions before induction of anesthesia while administering different general anesthetic combinations. This is a single center, prospective randomized including 270 adult patients scheduled for maxillofacial surgical interventions. Patients were assigned to control, suggestion and dreamfilm groups according to the psychological method used. According to the anesthetic protocol there were also three subgroups: etomidate & sevoflurane, propofol & sevoflurane, propofol & propofol groups. Primary outcome measure was the incidence of postoperative dreams in the non-intervention group and in the three groups receiving different psychological interventions. Secondary endpoint was to test the effect of perioperative suggestions and dreamfilm-formation training on the occurrance of dreams and recallable dreams in different general anesthesiological techniques. Dream incidence rates measured in the control group did not differ significantly (etomidate & sevoflurane: 40%, propofol & sevoflurane: 26%, propofol & propofol: 39%). A significant increase could be observed in the incidence rate of dreams between the control and suggestion groups in the propofol & sevoflurane (26%-52%) group (p = 0.023). There was a significant difference in the incidence of dreams between the control and dreamfilm subgroup in the propofol & sevoflurane (26% vs. 57%), and in the propofol & propofol group (39% vs.70%) (p = 0.010, and p = 0.009, respectively). Similar to this, there was a significant difference in dream incidence between the dreamfilm and the suggestion subgroups (44% vs. 70%) in the propofol & propofol group (p = 0.019). Propofol as an induction agent contributed most to dream formation and recalls (χ2-test p value: 0.005). The content of images and dreams

  14. Chemical intermediate detection following corona discharge on volatile organic compounds: general method using molecular beam techniques

    International Nuclear Information System (INIS)

    He Luning; Sulkes, Mark

    2011-01-01

    Nonthermal plasma (NTP)-based treatments of volatile organic compounds (VOCs) have potential for effective environmental remediation. Theory and experiment that consider the basic science pertaining to discharge events have helped improve NTP remediation outcomes. If direct information on early post-discharge chemical intermediates were also available, it would likely lead to additional improvement in NTP remediation outcomes. To this point, however, experiments yielding direct information on post-NTP VOC intermediates have been limited. An approach using supersonic expansion molecular beam methods offers general promise for detection of post-discharge VOC intermediates. To illustrate the potential utility of these methods, we present mass spectra showing the growth of early products formed when pulsed corona discharges were carried out on toluene in He and then in He with added O 2 . Good general detection of neutral post-discharge species was obtained using 800 nm 150 fs photoionization pulses.

  15. Generalized Fractional Processes with Long Memory and Time Dependent Volatility Revisited

    Directory of Open Access Journals (Sweden)

    M. Shelton Peiris

    2016-09-01

    Full Text Available In recent years, fractionally-differenced processes have received a great deal of attention due to their flexibility in financial applications with long-memory. This paper revisits the class of generalized fractionally-differenced processes generated by Gegenbauer polynomials and the ARMA structure (GARMA with both the long-memory and time-dependent innovation variance. We establish the existence and uniqueness of second-order solutions. We also extend this family with innovations to follow GARCH and stochastic volatility (SV. Under certain regularity conditions, we give asymptotic results for the approximate maximum likelihood estimator for the GARMA-GARCH model. We discuss a Monte Carlo likelihood method for the GARMA-SV model and investigate finite sample properties via Monte Carlo experiments. Finally, we illustrate the usefulness of this approach using monthly inflation rates for France, Japan and the United States.

  16. A Hull and White Formula for a General Stochastic Volatility Jump-Diffusion Model with Applications to the Study of the Short-Time Behavior of the Implied Volatility

    Directory of Open Access Journals (Sweden)

    Elisa Alòs

    2008-01-01

    Full Text Available We obtain a Hull and White type formula for a general jump-diffusion stochastic volatility model, where the involved stochastic volatility process is correlated not only with the Brownian motion driving the asset price but also with the asset price jumps. Towards this end, we establish an anticipative Itô's formula, using Malliavin calculus techniques for Lévy processes on the canonical space. As an application, we show that the dependence of the volatility process on the asset price jumps has no effect on the short-time behavior of the at-the-money implied volatility skew.

  17. Estimating Price Volatility Structure in Iran’s Meat Market: Application of General GARCH Models

    Directory of Open Access Journals (Sweden)

    Z. Rasouli Birami

    2016-10-01

    Full Text Available Introduction: Over the past few years, the price volatility of agricultural products and food markets has attracted attention of many researchers and policy makers. This growing attention was started from the food price crisis in 2007 and 2008 when major agricultural products faced accelerated price increases and then rapidly decreased. This paper focused on the price volatility of major commodities related to three market levels of Iran’s meat market, including hay (the input level, calf and sheep (the wholesale level and beef and mutton (the retail level. In particular, efforts will made to find more appropriate models for explaining the behavior of volatility of the return series and to identify which return series are more volatile. The effects of good and bad news on the volatility of prices in each return series will also be studied. Materials and Methods: Different GARCH type models have been considered the best for modeling volatility of return series. Nonlinear GARCH models were introduced to capture the effect of good and bad news separately. The paper uses some GARCH type models including GARCH, Exponential GARCH (EGARCH, GJR-GARCH, Threshold GARCH (TGARCH, Simple Asymmetric GARCH (SAGARCH, Power GARCH (PGARCH, Non-linear GARCH (NGARCH, Asymmetric Power GARCH (APGARCH and Non-linear Power GARCH (NPGARCH to model the volatility of hay, calf, sheep, beef and mutton return series. The data on hay, calf, sheep, and beef and mutton monthly prices are published by Iran’s livestock support firm. The paper uses monthly data over the sample period of the May 1992 to the March 2014. Results and Discussion: Descriptive statistics of the studied return series show evidence of skewness and kurtosis. The results here show that all the series has fat tails. The significant p-values for the Ljung-Box Q-statistics mean that the auto-correlation exists in the squared residuals. The presence of unit roots in the return series is confirmed by the

  18. On the Modelling and Forecasting of Multivariate Realized Volatility: Generalized Heterogeneous Autoregressive (GHAR) Model

    Czech Academy of Sciences Publication Activity Database

    Čech, František; Baruník, Jozef

    2017-01-01

    Roč. 36, č. 1 (2017), s. 181-206 ISSN 0277-6693 R&D Projects: GA ČR GA13-32263S Institutional support: RVO:67985556 Keywords : Multivariate volatility * realized covariance * portfolio optimisation Subject RIV: AH - Economic s OBOR OECD: Economic Theory Impact factor: 0.747, year: 2016 http://library.utia.cas.cz/separaty/2017/E/barunik-0478479.pdf

  19. Choice of primary anesthetic regimen can influence intensive care unit length of stay after coronary surgery with cardiopulmonary bypass

    NARCIS (Netherlands)

    de Hert, Stefan G.; van der Linden, Philippe J.; Cromheecke, Stefanie; Meeus, Roel; ten Broecke, Pieter W.; de Blier, Ivo G.; Stockman, Bernard A.; Rodrigus, Inez E.

    2004-01-01

    BACKGROUND: Volatile anesthetics protect the myocardium during coronary surgery. This study hypothesized that the use of a volatile agent in the anesthetic regimen would be associated with a shorter intensive care unit (ICU) and hospital length of stay (LOS), compared with a total intravenous

  20. LOCAL ANESTHETICS IN PATIENTS WITH CARDIOVASCULAR DISEASES.

    Directory of Open Access Journals (Sweden)

    risto Daskalov

    2015-03-01

    Full Text Available A significant problem in the dental medicine is pain alleviation. Many studies in the dental anesthesiology result in the production of new agents for locoregional anesthesia. Objective: This article aim to present the results of the last studies on the effect of the local anesthetics used in the oral surgery on patients with cardiovascular diseases. Material: A general review of the existing literature on the effect of the adrenaline, included as vasoconstrictor in the local anesthetics, used in patients with cardiovascular diseases is made. The benefits of vasoconstrictors for the quality of the anesthetic effect are proven. Conclusion: A small amount of adrenaline in the anesthetic solution does not result in complications development in patients with controlled cardiovascular diseases. Articaine is recommended agent of first choice for local anesthesia in the oral surgery.

  1. Anesthetizing the obese child

    DEFF Research Database (Denmark)

    Mortensen, Anette; Lenz, Katja; Abildstrøm, Hanne

    2011-01-01

    drugs. This has important implications on how to estimate the optimal drug dose. This article offers a review of the literature on definition, prevalence and the pathophysiology of childhood obesity and provides suggestions on preanesthetic evaluation, airway management and dosage of the anesthetic...... drugs in these patients. The authors highlight the need of supplemental studies on various areas of the subject....

  2. Medical imaging technology shock and volatility of macro economics: Analysis using a three-sector dynamical stochastic general equilibrium REC model.

    Science.gov (United States)

    Han, Shurong; Huang, Yeqing

    2017-07-07

    The study analysed the medical imaging technology business cycle from 1981 to 2009 and found that the volatility of consumption in Chinese medical imaging business was higher than that of the developed countries. The volatility of gross domestic product (GDP) and the correlation between consumption and GDP is also higher than that of the developed countries. Prior to the early 1990s the volatility of consumption is even higher than GDP. This fact makes it difficult to explain the volatile market using the standard one sector real economic cycle (REC) model. Contrary to the other domestic studies, this study considers a three-sector dynamical stochastic general equilibrium REC model. In this model there are two consumption sectors, whereby one is labour intensive and another is capital intensive. The more capital intensive investment sector only introduces technology shocks in the medical imaging market. Our response functions and Monte-Carlo simulation results show that the model can explain 90% of the volatility of consummation relative to GDP, and explain the correlation between consumption and GDP. The results demonstrated the significant correlation between the technological reform in medical imaging and volatility in the labour market on Chinese macro economy development.

  3. Exploring microsolvation of the anesthetic propofol

    NARCIS (Netherlands)

    Leon, I.; Cocinero, E. J.; Millan, J.; Jaeqx, S.; Rijs, A. M.; Lesarri, A.; Castano, F.; Fernandez, J. A.

    2012-01-01

    Propofol (2,6-diisopropylphenol) is a broadly used general anesthetic. By combining spectroscopic techniques such as 1- and 2-color REMPI, UV/UV hole burning, infrared ion-dip spectroscopy (IRIDS) obtained under cooled and isolated conditions with high-level ab initio calculations, detailed

  4. Photoacoustic microscopy of cerebral hemodynamic and oxygen-metabolic responses to anesthetics

    Science.gov (United States)

    Cao, Rui; Li, Jun; Ning, Bo; Sun, Naidi; Wang, Tianxiong; Zuo, Zhiyi; Hu, Song

    2017-02-01

    General anesthetics are known to have profound effects on cerebral hemodynamics and neuronal activities. However, it remains a challenge to directly assess anesthetics-induced hemodynamic and oxygen-metabolic changes from the true baseline under wakefulness at the microscopic level, due to the lack of an enabling technology for high-resolution functional imaging of the awake mouse brain. To address this challenge, we have developed head-restrained photoacoustic microscopy (PAM), which enables simultaneous imaging of the cerebrovascular anatomy, total concentration and oxygen saturation of hemoglobin (CHb and sO2), and blood flow in awake mice. From these hemodynamic measurements, two important metabolic parameters, oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO2), can be derived. Side-by-side comparison of the mouse brain under wakefulness and anesthesia revealed multifaceted cerebral responses to isoflurane, a volatile anesthetic widely used in preclinical research and clinical practice. Key observations include elevated cerebral blood flow (CBF) and reduced oxygen extraction and metabolism.

  5. Anesthetic Care in Mozambique.

    Science.gov (United States)

    Lyon, Camila B; Merchant, Amina I; Schwalbach, Teresa; Pinto, Emilia F V; Jeque, Emilia C; McQueen, K A Kelly

    2016-05-01

    The World Bank and Lancet Commission in 2015 have prioritized surgery in Low-Income Countries (LIC) and Lower-Middle Income Countries (LMICs). This is consistent with the shift in the global burden of disease from communicable to noncommunicable diseases over the past 20 years. Essential surgery must be performed safely, with adequate anesthesia monitoring and intervention. Unfortunately, a huge barrier to providing safe surgery includes the paucity of an anesthesia workforce. In this study, we qualitatively evaluated the anesthesia capacity of Mozambique, a LIC in Africa with limited access to anesthesia and safe surgical care. Country-based solutions are suggested that can expand to other LIC and LMICs. A comprehensive review of the Mozambique anesthesia system was conducted through interviews with personnel in the Ministry of Health (MOH), a school of medicine, a public central referral hospital, a general first referral hospital, a private care hospital, and leaders in the physician anesthesia community. Personnel databases were acquired from the MOH and Maputo Central Hospital. Quantitative results reveal minimal anesthesia capacity (290 anesthesia providers for a population of >25 million or 0.01:10,000). The majority of physician anesthesiologists practice in urban settings, and many work in the private sector. There is minimal capacity for growth given only 1 Mozambique anesthesia residency with inadequate resources. The most commonly perceived barriers to safe anesthesia in this critical shortage are lack of teachers, lack of medical student interest in and exposure to anesthesia, need for more schools, low allocation to anesthesia from the list of available specialist prospects by MOH, and low public payments to anesthesiologists. Qualitative results show assets of a good health system design, a supportive environment for learning in the residency, improvement in anesthetic care in past decades, and a desire for more educational opportunities and teachers

  6. Anesthetic agents in patients with very long-chain acyl-coenzyme A dehydrogenase deficiency: a literature review.

    Science.gov (United States)

    Redshaw, Charlotte; Stewart, Catherine

    2014-11-01

    Very long-chain acyl-coenzyme A dehydrongenase deficiency (VLCADD) is a rare disorder of fatty acid metabolism that renders sufferers susceptible to hypoglycemia, liver failure, cardiomyopathy, and rhabdomyolysis. The literature about the management of these patients is hugely conflicting, suggesting that both propofol and volatile anesthesia should be avoided. We have reviewed the literature and have concluded that the source papers do not support the statements that volatile anesthetic agents are unsafe. The reports on rhabdomyolysis secondary to anesthesia appear to be due to inadequate supply of carbohydrate not volatile agents. Catabolism must be avoided with minimal fasting, glucose infusions based on age and weight, and attenuation of emotional and physical stress. General anesthesia appears to be protective of stress-induced catabolism and may offer benefits in children and anxious patients over regional anesthesia. Propofol has not been demonstrated to be harmful in VLCADD but is presented in an emulsion containing very long-chain fatty acids which can cause organ lipidosis and itself can inhibit mitochondrial fatty acid metabolism. It is therefore not recommended. Suxamethonium-induced myalgia may mimic symptoms of rhabdomyolysis and cause raised CK therefore should be avoided. Opioids, NSAIDS, regional anesthesia, and local anesthetic techniques have all been used without complication. © 2014 John Wiley & Sons Ltd.

  7. Local Anesthetic-Induced Neurotoxicity

    NARCIS (Netherlands)

    Verlinde, Mark; Hollmann, Markus W.; Stevens, Markus F.; Hermanns, Henning; Werdehausen, Robert; Lirk, Philipp

    2016-01-01

    This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk

  8. Dexmedetomidine as the primary anesthetic agent during cardiac surgery in an infant with a family history of malignant hyperthermia

    Directory of Open Access Journals (Sweden)

    Aymen Naguib

    2011-01-01

    Full Text Available Malignant hyperthermia (MH is an acute hypermetabolic crisis triggered in susceptible patients by the administration of succinylcholine or a volatile anesthetic agent. When providing anesthetic care for MH-susceptible agents, a total intravenous anesthetic (TIVA technique is frequently chosen. When choosing the components for TIVA, several options exist including the combination of propofol or dexmedetomidine with an opioid. We present our experience with the use of dexmedetomidine as a key component of the anesthetic regimen in a 5-month-old infant with a family history of MH. Previous reports of the use of dexmedetomidine in MH-susceptible patients are reviewed and its benefits in such patients discussed.

  9. $1.8 Million and counting: how volatile agent education has decreased our spending $1000 per day.

    Science.gov (United States)

    Miller, Scott A; Aschenbrenner, Carol A; Traunero, Justin R; Bauman, Loren A; Lobell, Samuel S; Kelly, Jeffrey S; Reynolds, John E

    2016-12-01

    Volatile anesthetic agents comprise a substantial portion of every hospital's pharmacy budget. Challenged with an initiative to lower anesthetic drug expenditures, we developed an education-based intervention focused on reducing volatile anesthetic costs while preserving access to all available volatile anesthetics. When postintervention evaluation demonstrated a dramatic year-over-year reduction in volatile agent acquisition costs, we undertook a retrospective analysis of volatile anesthetic purchasing data using time series analysis to determine the impact of our educational initiative. We obtained detailed volatile anesthetic purchasing data from the Central Supply of Wake Forest Baptist Health from 2007 to 2014 and integrated these data with the time course of our educational intervention. Aggregate volatile anesthetic purchasing data were analyzed for 7 consecutive fiscal years. The educational initiative emphasized tissue partition coefficients of volatile anesthetics in adipose tissue and muscle and their impact on case management. We used an interrupted time series analysis of monthly cost per unit data using autoregressive integrated moving average modeling, with the monthly cost per unit being the amount spent per bottle of anesthetic agent per month. The cost per unit decreased significantly after the intervention (t=-6.73, Pper unit decreased $48 after the intervention, with 95% confidence interval of $34 to $62. As evident from the data, the purchasing of desflurane and sevoflurane decreased, whereas that of isoflurane increased. An educational initiative focused solely on the selection of volatile anesthetic agent per case significantly reduced volatile anesthetic expense at a tertiary medical center. This approach appears promising for application in other hospitals in the rapidly evolving, value-added health care environment. We were able to accomplish this with instruction on tissue partition coefficients and each agent's individual cost per MAC

  10. Anesthetic services in Serbia

    Directory of Open Access Journals (Sweden)

    Majstorović Branislava M.

    2016-01-01

    Full Text Available Explanation the topic: Due to the development of knowledge and technology our world is becoming a global city where rapidly occur changes in political and economic milieu, such as the introduction of corporate capitalism in the economic crisis, contemporary migrations etc. Health care as a public good on one hand and as the highest individual value of each individual on the other hand, changes and suffers changes. Health care system policy insists on partnership relation of the individual with medical service providers. This refers to the a secure and accessible modern treatment of each individual and to the state as to rationalize and reduce medical costs with effective methods of treatment. Topic position in scientific/professional public: Anesthesiology is evolving along with the surgical disciplines. Highly sophisticated with organized service, anesthesiology is equally important because of the multiplicity of anesthetic services in the surgical treatment of the disease in terms of teamwork and multidisciplinary treatment of the disease. The intention is to provide a description of work, education and our results in the economic, geopolitical and cultural context of the Serbian health system policy as well as to improve safe performance, availability and cost rationalization in anesthesia. The health care system is territorially organized in Serbia. In hospitals, Serbia employs 940 anesthesiologists (1:7,575 inhabitants. According to data from the Regional Medical Chamber of Belgrade,382 anesthesiologists were registered in Belgrade out of total. Anesthesia department network is well organized in all surgical hospitals. Anesthesia services are available depending on the place of residence, type of surgical illness or injury, and the distance to the nearest clinic. Sub-specializations in the field of anesthesiology have not been introduced although pediatric, neurosurgery and cardiosurgical anesthesia have spontaniously singled, as well as

  11. Pattern recognition analysis of proton nuclear magnetic resonance spectra of brain tissue extracts from rats anesthetized with propofol or isoflurane.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawaguchi

    Full Text Available BACKGROUND: General anesthesia is routinely used as a surgical procedure and its safety has been endorsed by clinical outcomes; however, its effects at the molecular level have not been elucidated. General anesthetics influence glucose metabolism in the brain. However, the effects of anesthetics on brain metabolites other than those related to glucose have not been well characterized. We used a pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize the changes in holistic brain metabolic phenotypes in response to the widely used intravenous anesthetic propofol and the volatile anesthetic isoflurane. METHODOLOGY/PRINCIPAL FINDINGS: Rats were randomized into five groups (n = 7 each group. Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups. CONCLUSIONS/SIGNIFICANCE: The results of the present study showed that propofol and isoflurane exerted differential effects on holistic brain metabolism under anesthesia.

  12. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity......). Finally, we compute volatility discovery for 30 actively traded stocks in the U.S. and report that Nyse and Arca dominate Nasdaq....

  13. Detecting The Expected Rate of Return Volatility of Financing Instruments of Indonesian Islamic Banking through GARCH Modeling (Generalized Autoregressive Conditional Heteroscedasticity

    Directory of Open Access Journals (Sweden)

    Nurul Huda

    2015-04-01

    Full Text Available Objective - Islamic banks are banks which its activities, both fund raising and funds distribution are on the basis of Islamic principles, namely buying and selling and profit sharing. Islamic banking is aimed at supporting the implementation of national development in order to improve justice, togetherness, and equitable distribution of welfare. In pursuit of supporting the implementation of national development, Islamic banking often faced stability problems of financing instruments being operated. In this case, it is measured by the gap between the actual rate of return and the expected rate of return. The individual actual RoR of this instrument will generate an expected rate of return. This raises the gap or difference between the actual rate of return and the expected rate of return of individual instruments, which in this case is called the abnormal rate of return. The stability of abnormal rate of return of individual instruments is certainly influenced by the stability of the expected rate of return. Expected rate of return has a volatility or fluctuation levels for each financing instrument. It is also a key element or material basis for the establishment of a variance of individual instruments. Variance in this case indicates the level of uncertainty of the rate of return. Individual variance is the origin of the instrument base for variance in the portfolio finance that further a portfolio analysis. So, this paper is going to analyze the level of expected RoR volatility as an initial step to see and predict the stability of the fluctuations in the rate of return of Indonesian Islamic financing instruments.Methods – Probability of Occurence, Expected Rate of Return (RoR and GARCH (Generalized Autoregressive Conditional Heteroscedasticity.Results - The expected RoR volatility of the murabaha and istishna financing instruments tend to be more volatile than expected RoR volatility of musharaka and qardh financing instruments

  14. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  15. Iodine volatility

    International Nuclear Information System (INIS)

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany

  16. Monitoring Anesthetic Depth Modification, Evaluation and Application of the Correlation Dimension

    NARCIS (Netherlands)

    Broek, P.L.C. van den

    2003-01-01

    Anesthesia is administered to patients to facilitate surgical and diagnostic procedures. The anesthesiologist generally determines the amount of anesthetics needed on the basis of body weight. However, the inter-individual variation in sensitivity to anesthetics is wide and the needed level of

  17. Scientometrics of anesthetic drugs and their techniques of administration, 1984–2013

    Directory of Open Access Journals (Sweden)

    Vlassakov KV

    2014-12-01

    Full Text Available Kamen V Vlassakov, Igor Kissin Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Abstract: The aim of this study was to assess progress in the field of anesthetic drugs over the past 30 years using scientometric indices: popularity indices (general and specific, representing the proportion of articles on a drug relative to all articles in the field of anesthetics (general index or the subfield of a specific class of anesthetics (specific index; index of change, representing the degree of growth in publications on a topic from one period to the next; index of expectations, representing the ratio of the number of articles on a topic in the top 20 journals relative to the number of articles in all (>5,000 biomedical journals covered by PubMed; and index of ultimate success, representing a publication outcome when a new drug takes the place of a common drug previously used for the same purpose. Publications on 58 topics were assessed during six 5-year periods from 1984 to 2013. Our analysis showed that during 2009–2013, out of seven anesthetics with a high general popularity index (≥2.0, only two were introduced after 1980, ie, the inhaled anesthetic sevoflurane and the local anesthetic ropivacaine; however, only sevoflurane had a high index of expectations (12.1. Among anesthetic adjuncts, in 2009–2013, only one agent, sugammadex, had both an extremely high index of change (>100 and a high index of expectations (25.0, reflecting the novelty of its mechanism of action. The index of ultimate success was positive with three anesthetics, ie, lidocaine, isoflurane, and propofol, all of which were introduced much longer than 30 years ago. For the past 30 years, there were no new anesthetics that have produced changes in scientometric indices indicating real progress. Keywords: anesthetics, anesthetic adjuvants, mortality, safety margins, therapeutic indices

  18. The Thermodynamics of General and Local Anesthesia

    Science.gov (United States)

    Græsbøll, Kaare; Sasse-Middelhoff, Henrike; Heimburg, Thomas

    2014-05-01

    General anesthetics are known to cause depression of the freezing point of transitions in biomembranes. This is a consequence of ideal mixing of the anesthetic drugs in the membrane fluid phase and exclusion from the solid phase. Such a generic law provides physical justification of the famous Meyer-Overton rule. We show here that general anesthetics, barbiturates and local anesthetics all display the same effect on melting transitions. Their effect is reversed by hydrostatic pressure. Thus, the thermodynamic behavior of local anesthetics is very similar to that of general anesthetics. We present a detailed thermodynamic analysis of heat capacity profiles of membranes in the presence of anesthetics. This analysis is able to describe experimentally observed calorimetric profiles and permits prediction of the anesthetic features of arbitrary molecules. In addition, we discuss the thermodynamic origin of the cutoff-effect of long-chain alcohols and the additivity of the effect of general and local anesthetics.

  19. Local anesthetics for brain tumor resection: Current perspectives

    NARCIS (Netherlands)

    J.W. Potters (Jan Willem); M. Klimek (Markus)

    2018-01-01

    textabstractThis review summarizes the added value of local anesthetics in patients undergoing craniotomy for brain tumor resection, which is a procedure that is carried out frequently in neurosurgical practice. The procedure can be carried out under general anesthesia, sedation with local

  20. Anesthetic management of a horse with traumatic pneumothorax

    OpenAIRE

    Chesnel, Maud-Aline; Aprea, Francesco; Clutton, R. Eddie

    2012-01-01

    A traumatic pneumothorax and severe hemorrhage were present in a mare with a large thoracic wall defect, lung perforation, and multiple rib fractures. General anesthesia was induced to allow surgical exploration. We describe the anesthetic technique, and discuss the management of the ventilatory, hemodynamic, and metabolic disturbances encountered.

  1. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common...... in Finance. Nonparametric estimators are well suited for these events due to the flexibility of their functional form and their good asymptotic properties. However, the local polynomial kernel estimators are not consistent at points where the volatility function has a break. The estimator presented...

  2. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi......The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification...... estimate alternative specifications of the model using a set of daily bipower measures for 7 stock indexes and 16 individual NYSE stocks. The estimates of the jump component confirm that the probability of jumps dramatically increases during the financial crisis. Compared to other realized volatility...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  3. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    The persistent nature of equity volatility is investigated by means of a multi-factor stochastic volatility model with time varying parameters. The parameters are estimated by means of a sequential matching procedure which adopts as auxiliary model a time-varying generalization of the HAR model f...

  4. Volatility in energy prices

    International Nuclear Information System (INIS)

    Duffie, D.

    1999-01-01

    This chapter with 58 references reviews the modelling and empirical behaviour of volatility in energy prices. Constant volatility and stochastic volatility are discussed. Markovian models of stochastic volatility are described and the different classes of Markovian stochastic volatility model are examined including auto-regressive volatility, option implied and forecasted volatility, Garch volatility, Egarch volatility, multivariate Garch volatility, and stochastic volatility and dynamic hedging policies. Other volatility models and option hedging are considered. The performance of several stochastic volatility models as applied to heating oil, light oil, natural gas, electricity and light crude oil are compared

  5. Availability of anesthetic effect monitoring: utilization, intraoperative management and time to extubation in liver transplantation.

    Science.gov (United States)

    Schumann, R; Hudcova, J; Bonney, I; Cepeda, M S

    2010-12-01

    Titration of volatile anesthetics to anesthetic effect monitoring using the bispectral index (BIS) has been shown to decrease anesthetic requirements and facilitate recovery from anesthesia unrelated to liver transplantation (OLT). To determine whether availability of such monitoring influences its utilization pattern and affect anesthetic care and outcomes in OLT, we conducted a retrospective analysis in recipients with and without such monitoring. We evaluated annual BIS utilization over a period of 7 years, and compared 41 BIS-monitored patients to 42 controls. All received an isoflurane/air/oxygen and opioid-based anesthetic with planned postoperative ventilation. Data collection included age, body mass index (BMI), gender, Model for End-stage Liver Disease (MELD) score, and time to extubation (TtE). Mean preanhepatic, anhepatic, and postanhepatic end-tidal isoflurane concentrations were compared, as well as BIS values for each phase of OLT using the Kruskal-Wallis and Wilcoxon signed-rank tests, respectively. The use of anesthetic effect monitoring when available increased steadily from 15% of cases in the first year to almost 93% by year 7. There was no significant difference in age, gender, BMI, MELD, or TtE between groups. The BIS group received less inhalational anesthetic during each phase of OLT compared to the control group. However, this difference was statistically significant only during the anhepatic phase (P = .026), and was clinically not impressive. Within the BIS group, the mean BIS value was 38.74 ± 5.25 (mean ± standard deviation), and there was no difference for the BIS value between different transplant phases. Availability of anesthetic effect monitoring as an optional monitoring tool during OLT results in its increasing utilization by anesthesia care teams over time. However, unless integrated into an intraoperative algorithm and an early extubation protocol for fast tracking of OLT recipients, this utilization does not appear to provide

  6. Anesthetic gases and global warming: Potentials, prevention and future of anesthesia.

    Science.gov (United States)

    Gadani, Hina; Vyas, Arun

    2011-01-01

    Global warming refers to an average increase in the earth's temperature, which in turn causes changes in climate. A warmer earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans. Greenhouse gases make the earth warmer by trapping energy inside the atmosphere. Greenhouse gases are any gas that absorbs infrared radiation in the atmosphere and include: water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halogenated fluorocarbons (HCFCs), ozone (O3), perfluorinated carbons (PFCs), and hydrofluorocarbons (HFCs). Hazardous chemicals enter the air we breathe as a result of dozens of activities carried out during a typical day at a healthcare facility like processing lab samples, burning fossil fuels etc. We sometimes forget that anesthetic agents are also greenhouse gases (GHGs). Anesthetic agents used today are volatile halogenated ethers and the common carrier gas nitrous oxide known to be aggressive GHGs. With less than 5% of the total delivered halogenated anesthetic being metabolized by the patient, the vast majority of the anesthetic is routinely vented to the atmosphere through the operating room scavenging system. The global warming potential (GWP) of a halogenated anesthetic is up to 2,000 times greater than CO2. Global warming potentials are used to compare the strength of different GHGs to trap heat in the atmosphere relative to that of CO2. Here we discuss about the GWP of anesthetic gases, preventive measures to decrease the global warming effects of anesthetic gases and Xenon, a newer anesthetic gas for the future of anesthesia.

  7. Stochastic volatility of volatility in continuous time

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Veraart, Almut

    This paper introduces the concept of stochastic volatility of volatility in continuous time and, hence, extends standard stochastic volatility (SV) models to allow for an additional source of randomness associated with greater variability in the data. We discuss how stochastic volatility...... of volatility can be defined both non-parametrically, where we link it to the quadratic variation of the stochastic variance process, and parametrically, where we propose two new SV models which allow for stochastic volatility of volatility. In addition, we show that volatility of volatility can be estimated...

  8. Effects of nitrous oxide on the rat heart in vivo: another inhalational anesthetic that preconditions the heart?

    NARCIS (Netherlands)

    Weber, Nina C.; Toma, Octavian; Awan, Saqib; Frässdorf, Jan; Preckel, Benedikt; Schlack, Wolfgang

    2005-01-01

    BACKGROUND: For nitrous oxide, a preconditioning effect on the heart has yet not been investigated. This is important because nitrous oxide is commonly used in combination with volatile anesthetics, which are known to precondition the heart. The authors aimed to clarify (1) whether nitrous oxide

  9. Anesthetic Management and Complications of Percutaneous Aortic Valve Implantation

    Directory of Open Access Journals (Sweden)

    Tailur Alberto Grando

    2013-05-01

    Full Text Available Background and objective: Aortic stenosis is a highly prevalent and life-threatening disease. In elderly patients with comorbidities, percutaneous valve implantation is an option. The aim of the study was to describe the anesthetic management and complications of general anesthesia Method: Case series with 30-day and 24-month follow-ups after implantation of the CoreValve device performed at the Institute of Cardiology/University Foundation of Cardiology between December 2008 and January 2012. The patients underwent general anesthesia monitored with mean arterial pressure (PAM, electrocardiogram (ECG, pulse oximetry, capnography, transesophageal echocardiography, thermometry, and transvenous pacemaker. Results: Twenty-eight patients, mean age 82.46 years, 20.98% mean EuroSCORE, functional class III/IV, successfully underwent valve implantation. Nine patients required permanent pacemaker implantation. During follow-up, two patients died: one during surgery due to LV perforation and the other on the third day of unknown causes. At 24 months, one patient diagnosed with multiple myeloma died. This anesthetic technique proved to be safe. Conclusion: The initial experience with percutaneous aortic valve implantation under general anesthesia has proven to be safe and effective, with no significant anesthetic complications during this procedure. Keywords: Aesthesia, General, Cardiac Surgical Procedures, Aortic Valve Stenosis, Aged.

  10. The effects of composting approaches on the emissions of anthropogenic volatile organic compounds: A comparison between vermicomposting and general aerobic composting

    International Nuclear Information System (INIS)

    Bhattacharya, S.S.; Kim, Ki-Hyun; Ullah, Md. Ahsan; Goswami, L.; Sahariah, B.; Bhattacharyya, P.; Cho, Sung-Back; Hwang, Ok-Hwa

    2016-01-01

    Emission patterns of 13 VOCs were investigated in three types of vermicomposting systems (Eisenia fetida, Metaphire posthuma, and Lampito mauritii) in reference to a traditional aerobic composting system by feeding the systems with mixtures of three materials (coal ash (CA), municipal solid waste (MSW), and cow dung (CD)). On an average, the emission rates of aromatic VOCs (benzene, toluene, xylenes, and styrene) were two to three times higher than all other groups (aldehyde, ketones, esters, and alcohols) from all three types of feeding mixtures. However, the emission rates of aromatic VOCs were generally reduced over time in both aerobic composting and vermicomposting systems. Such reduction in the emission rates was most prominent from Eisenia-treated CD + MSW (1:1), Lampito-treated CD + CA (1:1), and Metaphire-treated CD. The results clearly indicated that the increase in humified organic C fractions (humic acid and fulvic acid) and the microbial biomass present during the biocomposting processes greatly reduced the emissions of VOCs. Hence, the study recommends that vermicomposting of coal ash and municipal solid waste in combination with cow dung in 1:1 ratio is an environmentally gainful proposition. - Highlights: • Emissions of volatile odorant gases from different composting treatments were investigated. • Emissions of 13 VOCs were quantified in three types of vermicomposting systems. • Systems are fed with mixtures of three materials: coal ash, cow dung, municipal wastes. • The optimum composition of three types of wastes is suggested for vermicomposting. - The emissions of VOCs from vermicomposting were controlled sensitively by humidified organic C fractions and microbial biomass during composting processes.

  11. Influence of Ventilation Strategies and Anesthetic Techniques on Regional Cerebral Oximetry in the Beach Chair Position: A Prospective Interventional Study with a Randomized Comparison of Two Anesthetics.

    Science.gov (United States)

    Picton, Paul; Dering, Andrew; Alexander, Amir; Neff, Mary; Miller, Bruce S; Shanks, Amy; Housey, Michelle; Mashour, George A

    2015-10-01

    Beach chair positioning during general anesthesia is associated with cerebral oxygen desaturation. Changes in cerebral oxygenation resulting from the interaction of inspired oxygen fraction (FIO2), end-tidal carbon dioxide (PETCO2), and anesthetic choice have not been fully evaluated in anesthetized patients in the beach chair position. This is a prospective interventional within-group study of patients undergoing shoulder surgery in the beach chair position that incorporated a randomized comparison between two anesthetics. Fifty-six patients were randomized to receive desflurane or total intravenous anesthesia with propofol. Following induction of anesthesia and positioning, FIO2 and minute ventilation were sequentially adjusted for all patients. Regional cerebral oxygenation (rSO2) was the primary outcome and was recorded at each of five set points. While maintaining FIO2 at 0.3 and PETCO2 at 30 mmHg, there was a decrease in rSO2 from 68% (SD, 12) to 61% (SD, 12) (P positioning. The combined interventions of increasing FIO2 to 1.0 and increasing PETCO2 to 45 mmHg resulted in a 14% point improvement in rSO2 to 75% (SD, 12) (P position. There was no significant interaction effect of the anesthetic at the study intervention points. Increasing FIO2 and PETCO2 resulted in a significant increase in rSO2 that overcomes desaturation in patients anesthetized in the beach chair position and that appears independent of anesthetic choice.

  12. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...... variance in out-of-sample evaluations rather than the squared return. We derive the theoretical results in a general framework that is not specific to the comparison of volatility models. Similar problems can arise in comparisons of forecasting models whenever the predicted variable is a latent variable....

  13. ACCURACY OF NONINVASIVE ANESTHETIC MONITORING IN THE ANESTHETIZED GIRAFFE (GIRAFFA CAMELOPARDALIS)

    DEFF Research Database (Denmark)

    Bertelsen, Mads F; Grøndahl, Carsten; Stegmann, George F

    2017-01-01

    This study evaluated the accuracy of pulse oximetry, capnography, and oscillometric blood pressure during general anesthesia in giraffes (Giraffa camelopardalis). Thirty-two giraffes anesthetized for physiologic experiments were instrumented with a pulse oximeter transmittance probe positioned...... on the tongue and a capnograph sampling line placed at the oral end of the endotracheal tube. A human size 10 blood pressure cuff was placed around the base of the tail, and an indwelling arterial catheter in the auricular artery continuously measured blood pressure. Giraffes were intermittently ventilated...... using a Hudson demand valve throughout the procedures. Arterial blood for blood gas analysis was collected at multiple time points. Relationships between oxygen saturation as determined by pulse oximetry and arterial oxygen saturation, between arterial carbon dioxide partial pressure and end...

  14. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  15. Management of exposure to waste anesthetic gases.

    Science.gov (United States)

    Smith, Francis Duval

    2010-04-01

    Anesthetic agents were developed in the 1700s, and nitrous oxide was first used in 1884. Research on the effects of waste anesthetic gas exposure started appearing in the literature in 1967. Short-term exposure causes lethargy and fatigue, and long-term exposure may be linked to spontaneous abortion, congenital abnormalities, infertility, premature births, cancer, and renal and hepatic disease. Today, perioperative staff members are exposed to trace amounts of waste anesthetic gas, and although this exposure cannot be eliminated, it can be controlled. Health care facilities are required to develop, implement, measure, and control practices to reduce anesthetic gas exposure to the lowest practical level. Exposure levels must be measured every six months and maintained at less than 25 parts per million for nitrous oxide and 2 parts per million for halogenated agents to be compliant with Occupational Safety and Health Administration standards. Copyright 2010 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  16. Local Anesthetics: Review of Pharmacological Considerations

    Science.gov (United States)

    Becker, Daniel E; Reed, Kenneth L

    2012-01-01

    Local anesthetics have an impressive history of efficacy and safety in medical and dental practice. Their use is so routine, and adverse effects are so infrequent, that providers may understandably overlook many of their pharmacotherapeutic principles. The purpose of this continuing education article is to provide a review and update of essential pharmacology for the various local anesthetic formulations in current use. Technical considerations will be addressed in a subsequent article. PMID:22822998

  17. Anesthetic considerations for awake craniotomy: case report

    Directory of Open Access Journals (Sweden)

    Cassiano Hamacek de Freitas

    Full Text Available Abstract Background and objectives: The conscious patient cooperation during neurological procedures has become necessary for the delimitation of areas to be managed by a neurosurgeon, with better results in the treatment of tumor lesions, vascular or epileptic foci, and lesser sequelae. The need for perioperative awareness (responsiveness to commands challenges anesthesiologists to further ensure patient safety during the procedure. Several techniques have been described for this purpose. Case report: In this case, interaction with the patient during brain tumor resection enabled a broad approach of the tumor lesion, limited by deficits in speech and naming observed during surgical manipulation, avoiding major consequences. The chosen technique was deepening of general anesthesia during surgical times of most painful stimulus with intraoperative awakening of the patient. Conclusions: Patient selection, an exhaustive explanation of the procedure to him, and the selection of drugs are crucial for a successful procedure. Laryngeal mask is useful in times requiring greater depth and anesthetic ventilation control, primarily in situations where endotracheal intubation may be hindered by the position. The continuous infusion of remifentanil and adjuncts in the awake period associated adequate analgesia and full consciousness.

  18. Identification of Host-Plant Volatiles and Characterization of Two Novel General Odorant-Binding Proteins from the Legume Pod Borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae.

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    Full Text Available Chemoreception is a key feature in selection of host plant by phytophagous insects, and odorant-binding proteins (OBPs are involved in chemical communication of both insects and vertebrates. The legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae is one of the key pest species of cowpea and widely distributed throughout tropical and subtropical regions, causing up to 80% of yield loss. In this study, we investigated the electrophysiological responses of female M. vitrata to floral volatiles from V. unguiculata. Seventeen electroantennogram-active compounds were identified from floral volatiles of V. unguiculata by coupled gas chromatography-electroantennography (GC-EAD and gas chromatography-mass spectrometry (GC-MS. Then, we cloned two novel full-length GOBP genes (MvitGOBP1 and MvitGOBP2 from the antennae of M. vitrata using reverse transcription PCR. Protein sequence analysis indicated that they shared high sequence similarity with other Pyralididae insect GOBPs and had the typical six-cysteine signature. Real-time PCR analysis indicated that MvitGOBP1-2 mRNA was highly expressed in the antennae of female adult with several thousands-fold difference compare to other tissue. Next, the recombinant MvitGOBP1-2 was expressed in Escherichia coli and purified using Ni ion affinity chromatography. Fluorescence binding assays demonstrated that MvitGOBP1-2 had different binding affinities with 17 volatile odorant molecules including butanoic acid butyl ester, limonene, 4-ethylpropiophenone, 1H-indol-4-ol, butanoic acid octyl ester and 2-methyl-3-phenylpropanal. In the field trapping experiment, these six floral volatiles could effectively attract female moths and showed significant difference compared with the blank lure. These results suggested that MvitGOBPs and the seventeen floral volatiles are likely to function in the olfactory behavior response of female moths, which may have played crucial roles in the selection of oviposition

  19. Anesthetic-Induced Oxidative Stress and Potential Protection

    Directory of Open Access Journals (Sweden)

    Cheng Wang

    2010-01-01

    Full Text Available Prolonged exposure of developing mammals to general anesthetics affects the N-methyl-D-aspartate (NMDA–type glutamate or γ-aminobutyric acid (GABA receptor systems and enhances neuronal toxicity. Stimulation of immature neurons by NMDA antagonists or GABA agonists is thought to increase overall nervous system excitability and may contribute to abnormal neuronal cell death during development. Although the precise mechanisms by which NMDA antagonists or GABA agonists cause neuronal cell death are still not completely understood, up-regulation of the NMDA receptor subunit NR1 may be an initiative factor in neuronal cell death. It is increasingly apparent that mitochondria lie at the center of the cell death regulation process. Evidence for the role of oxidative stress in anesthetic-induced neurotoxicity has been generated in studies that apply oxidative stress blockers. Prevention of neuronal death by catalase and superoxide dismutase in vitro, or by M40403 (superoxide dismutase mimetic in vivo, supports the contention that the involvement of reactive oxygen species (ROS and the nature of neuronal cell death in rodents is mainly apoptotic. However, more evidence is necessary to in order verify the role of the NMDA receptor subunit NR1 and ROS in anesthetic-induced neurodegeneration.

  20. Assessment of patient satisfaction with the preoperative anesthetic evaluation

    Directory of Open Access Journals (Sweden)

    Gebremedhn EG

    2014-09-01

    Full Text Available Endale Gebreegziabher Gebremedhn, Vidhya Nagaratnam Department of Anesthesia, School of Medicine, Gondar College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia Background: The evaluation of patient satisfaction is a core aspect of the continuous quality improvement in anesthesia service that can be affected by the preoperative anesthetist visit. This visit enables the anesthetist to know about the patient's general health status and the nature of surgery, to choose the type of anesthesia, and to discuss perioperative complications and their management with the patient. Patients have sometimes complained about the information given during the preoperative anesthetic evaluation in the University of Gondar teaching and referral hospital. The aim of this study was to determine the level of patient satisfaction with the preoperative anesthetist visit. Methods: A cross-sectional study was conducted from February 15 to April 15, 2013. All consecutive elective patients who were operated upon under anesthesia during the study period were interviewed 24 hours after operation. A pretested questionnaire and checklists, which were developed based on the hospital's anesthetic evaluation sheet, were used for data collection. Results: A total of 116 elective patients were operated upon under anesthesia during the study period. Of these, 102 patients were included in our study, with a response rate of 87.9%. Anesthetists introduced themselves to ~24% patients; provided information about anesthesia to ~32%, postoperative complications to ~21%, postoperative analgesia to ~18, and postoperative nausea and vomiting to ~21%; and spent adequate time with ~74%. Patients' questions were answered by the anesthetist in ~65% of cases, and ~65% of patients had reduced anxiety after the anesthetist visit. The patients' overall satisfaction with the preoperative anesthetist visit was ~65%. Conclusion and recommendation: Patient satisfaction with the

  1. Evaluation of satisfaction of individuals rehabilitated with zygomatic implants as regards anesthetic and sedative procedure: A prospective cohort study

    Directory of Open Access Journals (Sweden)

    Paulo H.T. Almeida

    2017-10-01

    Conclusion: There was no difference between the two groups as regards the anesthetic procedure. General satisfaction was high; there was emotional improvement after conclusion of the treatment, thus improving the quality of life.

  2. Role of Network Science in the Study of Anesthetic State Transitions.

    Science.gov (United States)

    Lee, UnCheol; Mashour, George A

    2018-04-23

    The heterogeneity of molecular mechanisms, target neural circuits, and neurophysiologic effects of general anesthetics makes it difficult to develop a reliable and drug-invariant index of general anesthesia. No single brain region or mechanism has been identified as the neural correlate of consciousness, suggesting that consciousness might emerge through complex interactions of spatially and temporally distributed brain functions. The goal of this review article is to introduce the basic concepts of networks and explain why the application of network science to general anesthesia could be a pathway to discover a fundamental mechanism of anesthetic-induced unconsciousness. This article reviews data suggesting that reduced network efficiency, constrained network repertoires, and changes in cortical dynamics create inhospitable conditions for information processing and transfer, which lead to unconsciousness. This review proposes that network science is not just a useful tool but a necessary theoretical framework and method to uncover common principles of anesthetic-induced unconsciousness.

  3. Recognition of anesthetic barbiturates by a protein binding site: a high resolution structural analysis.

    Directory of Open Access Journals (Sweden)

    Simon Oakley

    Full Text Available Barbiturates potentiate GABA actions at the GABA(A receptor and act as central nervous system depressants that can induce effects ranging from sedation to general anesthesia. No structural information has been available about how barbiturates are recognized by their protein targets. For this reason, we tested whether these drugs were able to bind specifically to horse spleen apoferritin, a model protein that has previously been shown to bind many anesthetic agents with affinities that are closely correlated with anesthetic potency. Thiopental, pentobarbital, and phenobarbital were all found to bind to apoferritin with affinities ranging from 10-500 µM, approximately matching the concentrations required to produce anesthetic and GABAergic responses. X-ray crystal structures were determined for the complexes of apoferritin with thiopental and pentobarbital at resolutions of 1.9 and 2.0 Å, respectively. These structures reveal that the barbiturates bind to a cavity in the apoferritin shell that also binds haloalkanes, halogenated ethers, and propofol. Unlike these other general anesthetics, however, which rely entirely upon van der Waals interactions and the hydrophobic effect for recognition, the barbiturates are recognized in the apoferritin site using a mixture of both polar and nonpolar interactions. These results suggest that any protein binding site that is able to recognize and respond to the chemically and structurally diverse set of compounds used as general anesthetics is likely to include a versatile mixture of both polar and hydrophobic elements.

  4. Forecasting volatility in the presence of Leverage Effect

    OpenAIRE

    Jean-Christophe Domenge; Rémi Rhodes; Vincent Vargas

    2010-01-01

    We define a simple and tractable method for adding the Leverage effect in general volatility predictions. As an application, we compare volatility predictions with and without Leverage on the SP500 Index during the period 2002-2010.

  5. Anesthetic management of schwannoma of the base of the tongue

    Directory of Open Access Journals (Sweden)

    Upma B Batra

    2011-01-01

    Full Text Available Schwannoma arising from the base of the tongue are very rare and only a few cases have been reported so far. Definitive diagnosis is always made after a histological examination. Apart from an anticipated difficult airway with a risk of airway obstruction upon induction of general anesthesia, anesthetic concerns also include possibility of trauma to the growth and bleeding with attendant risks. We discuss the awake fiberoptic technique used for endotracheal intubation in such a case. This case report highlights the importance of detailed history taking and clinical examination, with emphasis on airway assessment and preoperative planning.

  6. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Boyce, J. W.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Magna, T.; Ni, P.; Tartese, R.; hide

    2017-01-01

    The chapter will begin with an introduction that defines magmatic volatiles (e.g., H, F, Cl, S) versus geochemical volatiles (e.g., K, Rb, Zn). We will discuss our approach of understanding both types of volatiles in lunar samples and lay the ground work for how we will determine the overall volatile budget of the Moon. We will then discuss the importance of endogenous volatiles in shaping the "Newer Views of the Moon", specifically how endogenous volatiles feed forward into processes such as the origin of the Moon, magmatic differentiation, volcanism, and secondary processes during surface and crustal interactions. After the introduction, we will include a re-view/synthesis on the current state of 1) apatite compositions (volatile abundances and isotopic compositions); 2) nominally anhydrous mineral phases (moderately to highly volatile); 3) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar pyroclastic glass beads; 4) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar basalts; 5) volatile (moderately to highly volatile) abundances in and isotopic compositions of melt inclusions; and finally 6) experimental constraints on mineral-melt partitioning of moderately to highly volatile elements under lunar conditions. We anticipate that each section will summarize results since 2007 and focus on new results published since the 2015 Am Min review paper on lunar volatiles [9]. The next section will discuss how to use sample abundances of volatiles to understand the source region and potential caveats in estimating source abundances of volatiles. The following section will include our best estimates of volatile abundances and isotopic compositions (where permitted by available data) for each volatile element of interest in a number of important lunar reservoirs, including the crust, mantle, KREEP, and bulk Moon. The final section of the chapter will focus upon future work, outstanding questions

  7. The modifying effect of anesthetic technique on the metabolic and endocrine responses to anesthesia and surgery

    DEFF Research Database (Denmark)

    Kehlet, H

    1988-01-01

    and the widespread use of the term "stress free anesthesia" in surgery is therefore not valid. However, continuous administration of local anesthetic agents in the epidural space is the most effective technique in so far as reduction of the stress response is concerned. The clinical implication of a variable...... reduction in the stress response to surgery by different anesthetic techniques remains largely unsettled, since only few controlled studies have been published on the clinical effects of pain relief and general anesthesia. However, a vast amount of data exist from controlled studies comparing regional...... anesthesia with local anesthetics and general anesthesia. The cumulative experience from these studies have demonstrated an advantageous effect on postoperative morbidity parameters such as blood loss, postoperative thromboembolic complications, pulmonary infective complications, gastrointestinal motility...

  8. Local anesthetics for brain tumor resection: current perspectives

    Directory of Open Access Journals (Sweden)

    Potters JW

    2018-02-01

    Full Text Available Jan-Willem Potters, Markus Klimek Department of Anesthesiology, Erasmus MC, Rotterdam, The Netherlands Abstract: This review summarizes the added value of local anesthetics in patients undergoing craniotomy for brain tumor resection, which is a procedure that is carried out frequently in neurosurgical practice. The procedure can be carried out under general anesthesia, sedation with local anesthesia or under local anesthesia only. Literature shows a large variation in the postoperative pain intensity ranging from no postoperative analgesia requirement in two-thirds of the patients up to a rate of 96% of the patients suffering from severe postoperative pain. The only identified causative factor predicting higher postoperative pain scores is infratentorial surgery. Postoperative analgesia can be achieved with multimodal pain management where local anesthesia is associated with lower postoperative pain intensity, reduction in opioid requirement and prevention of development of chronic pain. In awake craniotomy patients, sufficient local anesthesia is a cornerstone of the procedure. An awake craniotomy and brain tumor resection can be carried out completely under local anesthesia only. However, the use of sedative drugs is common to improve patient comfort during craniotomy and closure. Local anesthesia for craniotomy can be performed by directly blocking the six different nerves that provide the sensory innervation of the scalp, or by local infiltration of the surgical site and the placement of the pins of the Mayfield clamp. Direct nerve block has potential complications and pitfalls and is technically more challenging, but mostly requires lower total doses of the local anesthetics than the doses required in surgical-site infiltration. Due to a lack of comparative studies, there is no evidence showing superiority of one technique versus the other. Besides the use of other local anesthetics for analgesia, intravenous lidocaine administration has

  9. Administration and monitoring of intravenous anesthetics

    NARCIS (Netherlands)

    Sahinovic, Marko M.; Absalom, Anthony R.; Struys, Michel M. R. F.

    2010-01-01

    Purpose of review The importance of accuracy in controlling the dose-response relation for intravenous anesthetics is directly related to the importance of optimizing the efficacy and quality of anesthesia while minimizing adverse drug effects. Therefore, it is important to measure and control all

  10. Asymmetric Realized Volatility Risk

    Directory of Open Access Journals (Sweden)

    David E. Allen

    2014-06-01

    Full Text Available In this paper, we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive. Even though returns standardized by ex post quadratic variation measures are nearly Gaussian, this unpredictability brings considerably more uncertainty to the empirically relevant ex ante distribution of returns. Explicitly modeling this volatility risk is fundamental. We propose a dually asymmetric realized volatility model, which incorporates the fact that realized volatility series are systematically more volatile in high volatility periods. Returns in this framework display time varying volatility, skewness and kurtosis. We provide a detailed account of the empirical advantages of the model using data on the S&P 500 index and eight other indexes and stocks.

  11. Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

    International Nuclear Information System (INIS)

    Souza, Kátina M.; Braz, Leandro G.; Nogueira, Flávia R.; Souza, Marajane B.; Bincoleto, Lahis F.; Aun, Aline G.; Corrente, José E.; Carvalho, Lídia R.; Braz, José Reinaldo C.; Braz, Mariana G.

    2016-01-01

    Highlights: • Anesthesiologists exposed to the most commonly used anesthetic gases were evaluated. • No alterations were detected for lymphocyte DNA damage detected by the comet assay. • Decreased frequencies of basal cells were detected in exfoliated buccal cells (BMCyt). • Increased frequencies of micronucleus and cytotoxicity were observed in BMCyt assay. • Anesthesiologists have genomic instability due to occupational exposure. - Abstract: Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide − N 2 O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N 2 O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170 ppm for N 2 O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and pyknosis, and

  12. Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Kátina M.; Braz, Leandro G.; Nogueira, Flávia R.; Souza, Marajane B.; Bincoleto, Lahis F.; Aun, Aline G. [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil); Corrente, José E.; Carvalho, Lídia R. [Instituto de Biociências de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Bioestatística, Botucatu (Brazil); Braz, José Reinaldo C. [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil); Braz, Mariana G., E-mail: mgbraz@hotmail.com [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil)

    2016-09-15

    Highlights: • Anesthesiologists exposed to the most commonly used anesthetic gases were evaluated. • No alterations were detected for lymphocyte DNA damage detected by the comet assay. • Decreased frequencies of basal cells were detected in exfoliated buccal cells (BMCyt). • Increased frequencies of micronucleus and cytotoxicity were observed in BMCyt assay. • Anesthesiologists have genomic instability due to occupational exposure. - Abstract: Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide − N{sub 2}O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N{sub 2}O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170 ppm for N{sub 2}O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and

  13. Cell shape changes induced by cationic anesthetics

    Science.gov (United States)

    1976-01-01

    The effects of local anesthetics on cultivated macrophages were studied in living preparations and recorded in still pictures and time-lapse cine-micrographs. Exposure to 12mM lidocaine or 1.5 mM tetracaine resulted in rounding in 10-15 min. Rounding was characterized by cell contraction, marked increase in retraction fibrils, withdrawal of cell processes, and, in late stages, pulsation-like activity and zeiosis. Cells showed appreciable membrane activity as they rounded. Respreading was complete within 15 min of perfusion in drug-free medium and entailed a marked increase in surface motility over control periods. As many as eight successive cycles of rounding and spreading were obtained with lidocaine without evidence of cell damage. The effects of anesthetics were similar to those observed with EDTA, but ethylene- glycol-bis(beta-aminoethylether)-N, N'-tetraacetic acid-Mg was ineffective. Rounding was also induced by benzocaine, an anesthetic nearly uncharged at pH 7.0. Quaternary (nondischargeable) compounds were of low activity, presumably because they are slow permeants. Lidocaine induced rounding at 10 degrees C and above but was less effective at 5 degrees C and ineffective at 0 degrees C. Rounding by the anesthetic was also obtained in media depleted or Na or enriched with 10 mM Ca or Mg. The latter finding, together with the failure of tetrodotoxin to induce rounding, suggests that the anesthetic effect is unrelated to inhibition of sodium conductance. It is possible that the drugs influence divalent ion fluxes or some component of the contractile cells' machinery, but a metabolic target of action cannot yet be excluded. PMID:814194

  14. Anesthetic equipment, facilities and services available for pediatric ...

    African Journals Online (AJOL)

    2011-04-09

    Apr 9, 2011 ... standards and increased use of disposable anesthetic equipment. An audit of equipment and facilities for anesthetic care in pediatric patients is important and should be carried out periodically to appraise the situation for upgrading of essential anesthetic facilities and equipment. Appendix A. 18th March, ...

  15. 21 CFR 868.5550 - Anesthetic gas mask.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic gas mask. 868.5550 Section 868.5550...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5550 Anesthetic gas mask. (a) Identification. An anesthetic gas mask is a device, usually made of conductive rubber, that is positioned over a...

  16. The Molecular Mechanisms of Anesthetic Action: Updates and Cutting Edge Developments from the Field of Molecular Modeling

    Directory of Open Access Journals (Sweden)

    Edward J. Bertaccini

    2010-07-01

    Full Text Available For over 160 years, general anesthetics have been given for the relief of pain and suffering. While many theories of anesthetic action have been purported, it has become increasingly apparent that a significant molecular focus of anesthetic action lies within the family of ligand-gated ion channels (LGIC’s. These protein channels have a transmembrane region that is composed of a pentamer of four helix bundles, symmetrically arranged around a central pore for ion passage. While initial and some current models suggest a possible cavity for binding within this four helix bundle, newer calculations postulate that the actual cavity for anesthetic binding may exist between four helix bundles. In either scenario, these cavities have a transmembrane mode of access and may be partially bordered by lipid moieties. Their physicochemical nature is amphiphilic. Anesthetic binding may alter the overall motion of a ligand-gated ion channel by a “foot-in-door” motif, resulting in the higher likelihood of and greater time spent in a specific channel state. The overall gating motion of these channels is consistent with that shown in normal mode analyses carried out both in vacuo as well as in explicitly hydrated lipid bilayer models. Molecular docking and large scale molecular dynamics calculations may now begin to show a more exact mode by which anesthetic molecules actually localize themselves and bind to specific protein sites within LGIC’s, making the design of future improvements to anesthetic ligands a more realizable possibility.

  17. Anesthetic and Perioperative Management of Patients With Brugada Syndrome.

    Science.gov (United States)

    Dendramis, Gregory; Paleologo, Claudia; Sgarito, Giuseppe; Giordano, Umberto; Verlato, Roberto; Baranchuk, Adrian; Brugada, Pedro

    2017-09-15

    Brugada syndrome (BrS) is an arrhythmogenic disease reported to be one among the leading causes of cardiac death in subjects under the age of 40 years. In these patients, episodes of lethal arrhythmias may be induced by several factors or situations, and for this reason, management during anesthesia and surgery must provide some precautions and drugs restrictions. To date, it is difficult to formulate guidelines for anesthetic management of patients with BrS because of the absence of prospective studies, and there is not a definite recommendation for neither general nor regional anesthesia, and there are no large studies in merit. For this reason, in the anesthesia management of patients with BrS, the decision of using each drug must be made after careful consideration and always in controlled conditions, avoiding other factors that are known to have the potential to induce arrhythmias and with a close cooperation between anesthetists and cardiologists, which is essential before and after surgery. In conclusion, given the absence of large studies in literature, we want to focus on some general rules, which resulted from case series and clinical practice, to be followed during the perioperative and anesthetic management of patients with BrS. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Anesthetic considerations and difficult airway management in a case of Noonan syndrome

    Directory of Open Access Journals (Sweden)

    Sukhminder Jit Singh Bajwa

    2011-01-01

    Full Text Available Noonan syndrome is a genetically transmitted autosomal dominant disorder characterized by various anatomic anomalies and pathophysiologic derangements. Anesthetic management in such cases poses a multitude of challenges, especially related to the airway management and maintenance of cardiovascular stability. We report a case of a 9-year-old male child weighing 24 kg, who was diagnosed as a case of Noonan syndrome and had undergone ligation of patent ductus arteriosus during early childhood. The child was operated on for release of bilateral neck bands under general anesthesia. The case report pertains to the successful airway and anesthetic management in the background of difficult airway and existence of various cardiac lesions.

  19. Volatility in GARCH Models of Business Tendency Index

    Science.gov (United States)

    Wahyuni, Dwi A. S.; Wage, Sutarman; Hartono, Ateng

    2018-01-01

    This paper aims to obtain a model of business tendency index by considering volatility factor. Volatility factor detected by ARCH (Autoregressive Conditional Heteroscedasticity). The ARCH checking was performed using the Lagrange multiplier test. The modeling is Generalized Autoregressive Conditional Heteroscedasticity (GARCH) are able to overcome volatility problems by incorporating past residual elements and residual variants.

  20. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    Directory of Open Access Journals (Sweden)

    Armstead Valerie

    2006-11-01

    Full Text Available Abstract Candida albicans is a dimorphic fungus that can grow in yeast morphology or hyphal form depending on the surrounding environment. This ubiquitous fungus is present in skin and mucus membranes as a potential pathogen that under opportunistic conditions causes a series of systemic and superficial infections known as candidiasis, moniliasis or simply candidiasis. There has been a steady increase in the prevalence of candidiasis that is expressed in more virulent forms of infection. Although candidiasis is commonly manifested as mucocutaneous disease, life-threatening systemic invasion by this fungus can occur in every part of the body. The severity of candidal infections is associated with its morphological shift such that the hyphal morphology of the fungus is most invasive. Of importance, aberrant multiplication of Candida yeast is also associated with the pathogenesis of certain mucosal diseases. In this study, we assessed the anti-candidal activity of the volatile anesthetic isoflurane in liquid form in comparison with the anti-fungal agent amphotericin B in an in vitro culture system. Exposure of C. albicans to isoflurane (0.3% volume/volume and above inhibited multiplication of yeast as well as formation of hyphae. These data suggest development of potential topical application of isoflurane for controlling a series of cutaneous and genital infections associated with this fungus. Elucidiation of the mechanism by which isoflurane effects fungal growth could offer therapeutic potential for certain systemic fungal infections.

  1. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Anand, M.; Boyce, J. W.; Burney, D.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Klima, R. L.; Magna, T.; Ni, P.; Steenstra, E.; Tartèse, R.; Vander Kaaden, K. E.

    2018-04-01

    This abstract discusses numerous outstanding questions on the topic of endogenous lunar volatiles that will need to be addressed in the coming years. Although substantial insights into endogenous lunar volatiles have been gained, more work remains.

  2. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  3. Normalization for Implied Volatility

    OpenAIRE

    Fukasawa, Masaaki

    2010-01-01

    We study specific nonlinear transformations of the Black-Scholes implied volatility to show remarkable properties of the volatility surface. Model-free bounds on the implied volatility skew are given. Pricing formulas for the European options which are written in terms of the implied volatility are given. In particular, we prove elegant formulas for the fair strikes of the variance swap and the gamma swap.

  4. Permanent and transitory oil volatility and aggregate investment in Malaysia

    International Nuclear Information System (INIS)

    Ibrahim, Mansor H.; Ahmed, Huson Joher Ali

    2014-01-01

    This paper investigates the relation between aggregate investment and oil volatility and its permanent and transitory components for a developing country, Malaysia. In the paper, the components generalized autoregressive conditional heteroskedasticity (CGARCH) model is utilized to decompose conditional oil volatility into permanent oil volatility and transitory oil volatility. Respectively reflecting fundamental-driven and random shifts in oil volatility, they are expected to exert differential effects on aggregate investment. Adopting a vector autoregression (VAR) framework to allow feedback effects between aggregate investment and its determinants, the paper documents evidence supporting the adverse effects of conditional oil volatility, permanent oil volatility and transitory oil volatility on aggregate investment and real output. Interestingly, contrary to the findings for the developed markets (US and OECD), the real effects of permanent oil volatility tend to be stronger. These findings are reasonably robust to variable specification and measurements in the VAR system. Hence, there is an indication that heightened oil volatility accounts for the slumps in Malaysia's aggregate investment after the Asian financial crisis. - Highlights: • Examines the role of oil volatility in Malaysia's aggregate investment. • Makes distinction between permanent and temporary volatility using CGARCH. • Both volatility components depress investment. • Permanent volatility has larger adverse effects. • Results are robust to alternative model specifications

  5. Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2013-01-01

    textabstractIn this paper we document that realized variation measures constructed from highfrequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive.

  6. Amyotrophic lateral sclerosis-A case report and mechanistic review of the association with toluene and other volatile organic compounds.

    Science.gov (United States)

    Ratner, Marcia H; Jabre, Joe F; Ewing, William M; Abou-Donia, Mohamed; Oliver, L Christine

    2018-03-01

    Unmasking of latent neurodegenerative disease has been reported following exposure to chemicals that share one or more mechanisms of action in common with those implicated in the specific disease. For example, unmasking of latent Parkinson's disease (PD) has been associated with exposure to anti-dopaminergic agents, while the progression of pre-existing mild cognitive impairment and unmasking of latent Alzheimer's disease has been associated with exposure to general anesthetic agents which promote Aβ protein aggregation. This literature review and clinical case report about a 45-year-old man with no family history of motor neuron disease who developed overt symptoms of a neuromuscular disorder in close temporal association with his unwitting occupational exposure to volatile organic compounds (VOCs) puts forth the hypothesis that exposure to VOCs such as toluene, which disrupt motor function and increase oxidative stress, can unmask latent ALS type neuromuscular disorder in susceptible individuals. © 2017 Wiley Periodicals, Inc.

  7. Clinical application of thoracic paravertebral anesthetic block in breast surgeries

    Directory of Open Access Journals (Sweden)

    Sara Socorro Faria

    2015-04-01

    Full Text Available INTRODUCTION: Optimum treatment for postoperative pain has been of fundamental importance in surgical patient care. Among the analgesic techniques aimed at this group of patients, thoracic paravertebral block combined with general anesthesia stands out for the good results and favorable risk-benefit ratio. Many local anesthetics and other adjuvant drugs are being investigated for use in this technique, in order to improve the quality of analgesia and reduce adverse effects. OBJECTIVE: Evaluate the effectiveness and safety of paravertebral block compared to other analgesic and anesthetic regimens in women undergoing breast cancer surgeries. METHODS: Integrative literature review from 1966 to 2012, using specific terms in computerized databases of articles investigating the clinical characteristics, adverse effects, and beneficial effects of thoracic paravertebral block. RESULTS: On the selected date, 16 randomized studies that met the selection criteria established for this literature review were identified. Thoracic paravertebral block showed a significant reduction of postoperative pain, as well as decreased pain during arm movement after surgery. CONCLUSION: Thoracic paravertebral block reduced postoperative analgesic requirement compared to placebo group, markedly within the first 24 h. The use of this technique could ensure postoperative analgesia of clinical relevance. Further studies with larger populations are necessary, as paravertebral block seems to be promising for preemptive analgesia in breast cancer surgery.

  8. Anesthetic management of external cephalic version.

    Science.gov (United States)

    Chalifoux, Laurie A; Sullivan, John T

    2013-09-01

    Breech presentation is common at term and its reduction through external cephalic version represents a noninvasive opportunity to avoid cesarean delivery and the associated maternal morbidity. In addition to uterine relaxants, neuraxial anesthesia is associated with increased success of version procedures when surgical anesthetic dosing is used. The intervention is likely cost effective given the effect size and the avoided high costs of cesarean delivery. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Increasing topical anesthetic efficacy with microneedle application.

    Science.gov (United States)

    Buhsem, Ömer; Aksoy, Alper; Kececi, Yavuz; Sir, Emin; Güngör, Melike

    2016-10-01

    Since topical anesthetics alone seldom provide adequate analgesia for laser resurfacing procedures, injectable forms of anesthesia are often required. However, their application is uncomfortable for the patient. In this study, it is investigated whether microneedle application would enhance the efficacy of topical anesthetics. Forty-seven patients participated in the study. Topical anesthetic agent EMLA was applied to the whole face of the patients. Microneedle treatment was applied to one side of the face with a roller-type device. Whole-face carbon dioxide laser resurfacing therapy was carried out then. The pain that patients experienced was assessed by using visual analog scale (VAS) method. VAS scores of two sides of the face were compared by using Wilcoxon signed-rank test. The mean of VAS score of the microneedle treated side was 2.1 ± 1.1 while that of the untreated side was 5.9 ± 0.9 and this difference was statistically significant (Wilcoxon signed-rank test, the Z-value is - 5.9683 and the p-value is < 0.001). This study revealed that microneedle application, with a roller-type device, is a safe and easy procedure in providing sufficient anesthesia for facial laser resurfacing without the need for supplementary nerve blocks or injections.

  10. Pacemakers and implantable cardioverter defibrillators - general and anesthetic considerations

    Directory of Open Access Journals (Sweden)

    Amy G. Rapsang

    2014-06-01

    Full Text Available A pacemaking system consists of an impulse generator and lead or leads to carry the electrical impulse to the patient's heart. Pacemaker and implantable cardioverter defibrillator codes were made to describe the type of pacemaker or implantable cardioverter defibrillator implanted. Indications for pacing and implantable cardioverter defibrillator implantation were given by the American College of Cardiologists. Certain pacemakers have magnet-operated reed switches incorporated; however, magnet application can have serious adverse effects; hence, devices should be considered programmable unless known otherwise. When a device patient undergoes any procedure (with or without anesthesia, special precautions have to be observed including a focused history/physical examination, interrogation of pacemaker before and after the procedure, emergency drugs/temporary pacing and defibrillation, reprogramming of pacemaker and disabling certain pacemaker functions if required, monitoring of electrolyte and metabolic disturbance and avoiding certain drugs and equipments that can interfere with pacemaker function. If unanticipated device interactions are found, consider discontinuation of the procedure until the source of interference can be eliminated or managed and all corrective measures should be taken to ensure proper pacemaker function should be done. Post procedure, the cardiac rate and rhythm should be monitored continuously and emergency drugs and equipments should be kept ready and consultation with a cardiologist or a pacemaker-implantable cardioverter defibrillator service may be necessary.

  11. Jakartans, Institutionally Volatile

    Directory of Open Access Journals (Sweden)

    Masaaki OKAMOTO

    2014-01-01

    Full Text Available Jakarta recently has gained even more central political attention in Indonesia since Joko Widodo (Jokowi and Basuki Purnama (Ahok became, respectively, the province’s governor and vice-governor in 2012. They started a series of eye-catching and populist programmes, drawing popular support from not only the people of Jakarta, but also among Indonesians in general. Jokowi is now even the most popular candidate for the presidential election in 2014. Their rise is phenomenal in this sense, but it is understandable if we look at Jakartan voters’ behaviour and the institutional arrangement that leads to it. Jakarta, as the national capital, has a unique arrangement in that the province has no autonomous regency or city. This paper argues that this arrangement causes Jakartans to be more politically volatile and describes how this institutional arrangement was created by analysing the minutes of the meeting to discuss the laws concerning Jakarta Province.

  12. Level Shifts in Volatility and the Implied-Realized Volatility Relation

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; de Magistris, Paolo Santucci

    We propose a simple model in which realized stock market return volatility and implied volatility backed out of option prices are subject to common level shifts corresponding to movements between bull and bear markets. The model is estimated using the Kalman filter in a generalization to the mult......We propose a simple model in which realized stock market return volatility and implied volatility backed out of option prices are subject to common level shifts corresponding to movements between bull and bear markets. The model is estimated using the Kalman filter in a generalization...... to the multivariate case of the univariate level shift technique by Lu and Perron (2008). An application to the S&P500 index and a simulation experiment show that the recently documented empirical properties of strong persistence in volatility and forecastability of future realized volatility from current implied...... volatility, which have been interpreted as long memory (or fractional integration) in volatility and fractional cointegration between implied and realized volatility, are accounted for by occasional common level shifts....

  13. Pharmacokinetics of inhaled anesthetics in green iguanas (Iguana iguana).

    Science.gov (United States)

    Brosnan, Robert J; Pypendop, Bruno H; Barter, Linda S; Hawkins, Michelle G

    2006-10-01

    To test the hypothesis that differences in anesthetic uptake and elimination in iguanas would counter the pharmacokinetic effects of blood:gas solubility and thus serve to minimize kinetic differences among inhaled agents. 6 green iguanas (Iguana iguana). Iguanas were anesthetized with isoflurane, sevoflurane, or desflurane in a Latin-square design. Intervals from initial administration of an anesthetic agent to specific induction events and from cessation of administration of an anesthetic agent to specific recovery events were recorded. End-expired gas concentrations were measured during anesthetic washout. Significant differences were not detected for any induction or recovery events for any inhalation agent in iguanas. Washout curves best fit a 2-compartment model, but slopes for both compartments did not differ significantly among the 3 anesthetics. Differences in blood:gas solubility for isoflurane, sevoflurane, and desflurane did not significantly influence differences in pharmacokinetics for the inhalation agents in iguanas.

  14. Epidermolysis bullosa, dental and anesthetic management: a case report.

    Science.gov (United States)

    Esfahanizade, Katayoun; Mahdavi, Ali Reza; Ansari, Ghassem; Fallahinejad Ghajari, Masoud; Esfahanizadeh, Abdolreza

    2014-09-01

    Epidermolysis bullosa (EB) is a group of rare inherited skin and mucous membrane disorders in which blister formation may arise spontaneously or following a minor friction. Various patterns of inheritance are explicated for the disease. The disease has a profound effect on oral mucosa and may result in high prevalence of dental caries. General anesthesia is sometimes the only choice for dental treatments in patients with EB. The following case report describes the dental and anesthetic management of an 12.5 -year-old girl with dystrophic type of EB. The patient was followed up every 6 months. New carious lesions were detected one year after the treatment, on the last visit. Presenting a perfect dental care to children with this disorder can be challenging for the in charge specialist, both pediatric dentist and anesthesiologist.

  15. Anesthetic considerations for awake craniotomy: case report

    Directory of Open Access Journals (Sweden)

    Cassiano Hamacek de Freitas

    2018-05-01

    Full Text Available Background and objectives: The conscious patient cooperation during neurological procedures has become necessary for the delimitation of areas to be managed by a neurosurgeon, with better results in the treatment of tumor lesions, vascular or epileptic foci, and lesser sequelae. The need for perioperative awareness (responsiveness to commands challenges anesthesiologists to further ensure patient safety during the procedure. Several techniques have been described for this purpose. Case report: In this case, interaction with the patient during brain tumor resection enabled a broad approach of the tumor lesion, limited by deficits in speech and naming observed during surgical manipulation, avoiding major consequences. The chosen technique was deepening of general anesthesia during surgical times of most painful stimulus with intraoperative awakening of the patient. Conclusions: Patient selection, an exhaustive explanation of the procedure to him, and the selection of drugs are crucial for a successful procedure. Laryngeal mask is useful in times requiring greater depth and anesthetic ventilation control, primarily in situations where endotracheal intubation may be hindered by the position. The continuous infusion of remifentanil and adjuncts in the awake period associated adequate analgesia and full consciousness. Resumo: Justificativa e objetivos: A colaboração consciente do paciente durante procedimentos neurológicos tem se tornado necessária para delimitar áreas a serem abordadas pelo neurocirurgião, com melhores resultados no tratamento de lesões tumorais, vasculares ou focos epiléticos e minimização de sequelas. A necessidade de consciência perioperatória e responsividade a comandos desafia o anestesiologista a garantir ainda a segurança do paciente durante o procedimento. Várias técnicas têm sido descritas para esse fim. Relato de caso: No presente caso, a interação com paciente durante ressecção de tumor cerebral

  16. Modelling of volatility in monetary transmission mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel [Department of Statistics and Operation Analysis, Faculty of Business and Economics, Mendel University in Brno, Zemědělská 1, 61300, Brno (Czech Republic); Bednářová, Petra [Institute of Technology and Business, Okružní 517/10, 370 01, České Budějovice (Czech Republic)

    2015-03-10

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches.

  17. Modelling of volatility in monetary transmission mechanism

    International Nuclear Information System (INIS)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel; Bednářová, Petra

    2015-01-01

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches

  18. Anesthetic salts used in dentistry: a literature review

    Directory of Open Access Journals (Sweden)

    Guilherme Klein Parise

    2017-08-01

    Full Text Available Local anesthetics allow a better and suitable control of pain in patients that submit to dental treatments. The pharmacology of local anesthetics is too complex, therefore it is important to know how to select the correct drug to each procedure to be accomplished. Thus, it is concluded that the production of a literary review material is of great relevance in order to gather current and important information about the local anesthetics most used in dentistry.

  19. Gestational trophoblastic disease with hyperthyroidism: Anesthetic management

    Directory of Open Access Journals (Sweden)

    Puneet Khanna

    2012-01-01

    Full Text Available The coexistence of hyperthyroidism with gestational trophoblastic disease is a known albeit rare clinical condition. We herein report the successful anesthetic management of such a case in our institute. There are only few case reports in literature of this association. Often, the diagnosis of hyperthyroid state is retrospective one, as it can be missed in the emergency scenario of patient requiring molar evacuation. This case report highlights the perioperative management and optimization of hyperthyroid state prior to surgical evacuation of the invasive hydatidiform mole.

  20. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast i......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  1. Pharmacoeconomics of inhaled anesthetic agents: considerations for the pharmacist.

    Science.gov (United States)

    Chernin, Eric L

    2004-10-15

    Types of economic analyses used for inhaled anesthetic agents, factors to consider in calculating the cost of inhaled anesthetics, limitations of pharmacoeconomic studies of these agents, and strategies for controlling inhaled anesthetic costs are discussed. Inhaled anesthetic agents comprise a substantial component of drug budgets. Calculation of the cost of administering an inhaled anesthetic should take into consideration the cost per mL, potency, waste, concentration and duration of gas delivery, fresh gas flow rate, molecular weight, and density. The use of newer inhaled anesthetic agents with low solubility in blood and tissue provides a more rapid recovery from anesthesia than older, more soluble agents, and also provides the same level of control of depth of anesthesia at a lower fresh gas flow rate and possibly a lower cost than older agents at a higher fresh gas flow rate. A more rapid recovery may facilitate fast-track recovery and yield cost savings if it allows the completion of additional surgical cases or allows a reduction in personnel overtime expenses. Interpretation of pharmacoeconomic studies of inhaled anesthetics requires an appreciation of the limitations in methodology and ability to extrapolate results from one setting to another. Pharmacists' efforts to reduce anesthetic waste and collaborate with anesthesiologists to improve the use of these agents can help contain costs, but improving scheduling and efficiency in the operating room has a greater potential to reduce operating room costs. Much can be done to control costs of anesthetic agents without compromising availability of these agents and patient care.

  2. Asymmetry Effects of shocks in Chinese Stock Markets Volatility

    DEFF Research Database (Denmark)

    Hou, Ai Jun

    2013-01-01

    The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modelling return volatility with the parametric GARCH family models. This paper therefore applies...... a generalized additive nonparametric smoothing technique to examine the volatility of the Chinese stock markets. The empirical results indicate that an asymmetric effect of negative news exists in the Chinese stock markets. Furthermore, compared with other parametric models, the generalized additive...

  3. Anesthetic Management of Narcolepsy Patients During Surgery: A Systematic Review.

    Science.gov (United States)

    Hu, Sally; Singh, Mandeep; Wong, Jean; Auckley, Dennis; Hershner, Shelley; Kakkar, Rahul; Thorpy, Michael J; Chung, Frances

    2018-01-01

    Narcolepsy is a rare sleep disorder characterized by excessive daytime sleepiness, sleep paralysis, and/or hypnagogic/hypnopompic hallucinations, and in some cases cataplexy. The response to anesthetic medications and possible interactions in narcolepsy patients is unclear in the perioperative period. In this systematic review, we aim to evaluate the current evidence on the perioperative outcomes and anesthetic considerations in narcolepsy patients. Electronic literature search of Medline, Medline in-process, Embase, Cochrane Database of Systematic Reviews databases, international conference proceedings, and abstracts was conducted in November 2015 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols guideline. A total of 3757 articles were screened using a 2-stage strategy (title-abstract followed by full text). We included case studies/series, cohort studies, and randomized controlled trials of narcolepsy patients undergoing surgical procedures under anesthesia or sedation. Preoperative narcolepsy symptoms and sleep study data, anesthetic technique, and perioperative complications were extracted. Screening of articles, data extraction, and compilation were conducted by 2 independent reviewers and any conflict was resolved by the senior author. A total of 19 studies including 16 case reports and 3 case series were included and evaluated. The majority of these patients received general anesthesia, whereas a small percentage of patients received regional anesthesia. Reported complications of narcolepsy patients undergoing surgeries were mainly related to autonomic dysregulation, or worsening of narcolepsy symptoms intra/postoperatively. Narcolepsy symptoms worsened only in those patient populations where the preoperative medications were either discontinued or reduced (mainly in obstetric patients). In narcolepsy patients, use of depth of anesthesia monitoring and total intravenous technique may have some advantage in terms

  4. Methods to produce calibration mixtures for anesthetic gas monitors and how to perform volumetric calculations on anesthetic gases.

    Science.gov (United States)

    Christensen, P L; Nielsen, J; Kann, T

    1992-10-01

    A simple procedure for making calibration mixtures of oxygen and the anesthetic gases isoflurane, enflurane, and halothane is described. One to ten grams of the anesthetic substance is evaporated in a closed, 11,361-cc glass bottle filled with oxygen gas at atmospheric pressure. The carefully mixed gas is used to calibrate anesthetic gas monitors. By comparison of calculated and measured volumetric results it is shown that at atmospheric conditions the volumetric behavior of anesthetic gas mixtures can be described with reasonable accuracy using the ideal gas law. A procedure is described for calculating the deviation from ideal gas behavior in cases in which this is needed.

  5. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over

  6. Improving Garch Volatility Forecasts

    NARCIS (Netherlands)

    Klaassen, F.J.G.M.

    1998-01-01

    Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH effects are allowed within each regime, so that our model

  7. Asymmetric Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2014-01-01

    markdownabstract__Abstract__ In this paper we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized

  8. The volatility of HOL

    International Nuclear Information System (INIS)

    Wren, D.J.; Sanipelli, G.

    1985-01-01

    The volatility of HOI has been measured using a mass spectrometer to analyze the gas phase above an aqueous solution. The HOI in solution was generated continuously in a flow reactor that combined I/sup -/ and OCl/sup -/ solutions. The analysis has resulted in a lower limit of 6X10/sup 3/ mol . dm/sup -3/ . atm/sup -1/ for the equilibrium constant for the reaction HOI(g)/equilibrium/HOI(aq). This value is a factor 30 greater than the best previous estimate. This new limit for HOI volatility results in higher total iodine partition coefficients, particularly for solutions with pH>8. The upper limit for the equilibrium constant is consistent with essentially zero volatility for HOI. The effect of HOI volatility on total iodine volatility is briefly discussed as a function of solution chemistry and kinetics

  9. MAC-sparing effect of nitrous oxide in sevoflurane anesthetized sheep and its reversal with systemic atipamezole administration

    Science.gov (United States)

    Scanu, Antonio; Melosu, Valentino; Careddu, Giovanni Mario; Sotgiu, Giovanni

    2018-01-01

    Introduction Nitrous oxide (N2O) is an anesthetic gas with antinociceptive properties and reduces the minimum alveolar concentration (MAC) for volatile anesthetic agents, potentially through mechanisms involving central alpha2-adrenoceptors. We hypothesized that 70% N2O in the inspired gas will significantly reduce the MAC of sevoflurane (MACSEVO) in sheep, and that this effect can be reversed by systemic atipamezole. Materials and methods Animals were initially anesthetized with SEVO in oxygen (O2) and exposed to an electrical current as supramaximal noxious stimulus in order to determine MACSEVO (in duplicates). Thereafter, 70% N2O was added to the inspired gas and the MAC re-determined in the presence of N2O (MACSN). A subgroup of sheep were anesthetized a second time with SEVO/N2O for re-determination of MACSN, after which atipamezole (0.2 mg kg-1, IV) was administered for MACSNA determinations. Sheep were anesthetized a third time, initially with only SEVO/O2 to re-determine MACSEVO, after which atipamezole (0.2 mg kg-1, IV) was administered for determination of MACSA. Results MACSEVO was 2.7 (0.3)% [mean (standard deviation)]. Addition of N2O resulted in a 37% reduction of MACSEVO to MACSN of 1.7 (0.2)% (p <0.0001). Atipamezole reversed this effect, producing a MACSNA of 3.1 (0.7)%, which did not differ from MACSEVO (p = 0.12). MACSEVO did not differ from MACSA (p = 0.69). Cardiorespiratory variables were not different among experimental groups except a lower ETCO2 in animals exposed to SEVO/N2O. Conclusions N2O produces significant MACSEVO-reduction in sheep; this effect is completely reversed by IV atipamezole confirming the involvement of alpha2-adrenoreceptors in the MAC-sparing action of N2O. PMID:29315308

  10. Evaluation of local anesthetic and antipyretic activities of Cinchona ...

    African Journals Online (AJOL)

    Purpose: To evaluate the local anesthetic and antipyretic activities of an aqueous extract of Cinchona officinalis (C. officinalis) in experimental animal models. Methods: Various doses of the aqueous extract was tested for its local anesthetic activity in guinea pigs and frogs using intracutaneous and plexus anesthesia, ...

  11. Anesthetic equipment, facilities and services available for pediatric ...

    African Journals Online (AJOL)

    Background: Facilities and equipment are known to contribute to improved patient care and outcome. Hospitals for sub‑specialized pediatric anesthetic service are routinely available worldwide. In Nigeria, such hospitals now exist. It is therefore relevant to study the facilities and equipment available for pediatric anesthetic ...

  12. [Anesthetic management of four patients with Fournier syndrome].

    Science.gov (United States)

    Sato, Rui; Tomioka, Toshiya; Orii, Ryo; Yamada, Yoshitsugu

    2008-03-01

    We experienced anesthetic managements of four patients with Fournier syndrome. In the anesthetic management of the patients with Fournier syndrome the following three points should be kept in mind; (a) the necessity of careful preoperative examination, (b) the better anesthesia, and (c) the careful postoperative care.

  13. THE EFFECT OF LOCAL ANESTHETICS ON TEAR PRODUCTION

    African Journals Online (AJOL)

    that local anesthetics measure only basic secretion thus reducing normal tear production/secretion, which is both reflex and basic. This could be attributed to the fact that local anesthetics have an adrenergic potentiating effects and because lacrimal fluid receive a preganglionic parasympathetic supply from lacrimal muscles ...

  14. Tolerance to acute isovolemic hemodilution. Effect of anesthetic depth

    NARCIS (Netherlands)

    van der Linden, Philippe; de Hert, Stefan; Mathieu, Nathalie; Degroote, Françoise; Schmartz, Denis; Zhang, Haibo; Vincent, Jean-Louis

    2003-01-01

    BACKGROUND: Acceptance of a lower transfusion trigger in the perioperative period requires study of the effects of anesthetic depth on the tolerance to acute isovolemic anemia. Anesthetic agents with negative effects on the cardiovascular system may exert proportionately greater depressant effects

  15. Anesthetic management for cesarean delivery of a parturient with impetigo herpetiformis.

    Science.gov (United States)

    Duffield, Adrienne T; Smith, Kathleen A

    2013-10-01

    Impetigo herpetiformis (IH), or generalized pustular psoriasis of pregnancy, is an exceedingly rare, generalized pustular skin eruption occurring during pregnancy associated with hypovolemia, sepsis, hypocalcemia, and airway edema. Fetal outcomes are generally poor, and parturients with IH may present with emergent indications for cesarean delivery due to placental insufficiency. We present a case of IH in a 19-year-old G1P0 who underwent successful general anesthesia for cesarean delivery. Her case highlights the anesthetic implications for patients afflicted with this rare disease, including perioperative pain management, airway concerns, considerations for neuraxial anesthesia, and monitoring challenges.

  16. Addition of lacal anesthetics to contrast media. Pt. 2

    International Nuclear Information System (INIS)

    Nilsson, P.; Almen, T.; Golman, K.; Jonsson, K.; Nyman, U.; Malmoe Allmaenna Sjukhus

    1988-01-01

    The acute intravenous toxicity (i.v. LD 50 ) of solutions of the ratio 1.5 contrast media metrizoate or diatrizoate and the ratio 3.0 contrast medium metrizamide was determined in mice with and without the addition of local anesthetics to the solutions. The two local anesthetics mepivacaine or lidocaine were added to final concentrations up to 2.0 mg/ml of the contrast medium solutions. This corresponds to clinically used concentrations. All additions of local anesthetics to the solutions increased the mortalities caused by the contrast medium solutions. Addition of local anesthetics to a final concentration of 2 mg/ml approximately doubled the acute intravenous toxicity of the contrast media. The ratio 3 contrast media produce less hypertonic solutions than the ratio 1.5 contrast media and should be preferred for angiography because they cause less pain and do not require the addition of local anesthetics which increase the acute toxicity of the solutions. (orig.)

  17. [Intra-anesthetic arterial hypotension in elderly patients during emergency surgery: what are the risk factors?

    Science.gov (United States)

    Boubacar Ba, El Hadji; Leye, Papa Alassane; Traoré, Mamadou Mour; Ndiaye, Pape Ibrahima; Gaye, Ibrahima; Bah, Mamadou Diawo; Fall, Mamadou Lamine; Diouf, Elisabeth

    2017-01-01

    Emergency anesthesia in elderly patients aged 65 years and older is complex. The occurrence of intraoperative incidents and arterial hypotension is conditioned by patients' initial health status and by the quality of intraoperative management. This study aimed to determine the incidence of intra-anesthetic arterial hypotension in elderly patients during emergency surgery and to assess the involvement of certain factors in its occurrence: age, sex, patient's history, ASA class, anesthetic technique. We conducted a retrospective descriptive and analytical study in the Emergency Surgery Department at the Aristide Le Dantec University Hospital from 1 March 2014 to 28 February 2015. We collected data from 210 patients out of 224 elderly patients aged 65 years and older undergoing emergency anesthesias (10.93%). Data of 101 men and 109 women were included in the analysis, of whom 64.3% had at least one defect. Patients' preoperative status was assessed using American Society of Anesthesiology (ASA) classification: 71% of patients were ASA class 1 and 2 and 29% were ASA class 3 and 4. Locoregional anesthesia was the most practiced anesthetic technique (56.7%). 28 patients (13.33%) had intra-anesthetic arterial hypotension, of whom 16 under general anesthesia and 12 under locoregional anesthesia. It was more frequent in patients with high ASA class and a little less frequent in patients with PAH and underlying heart disease. Arterial hypotension in elderly patients during emergency surgery exposes the subject to the risk of not negligible intraoperative hypotension, especially in patients with high ASA class. Prevention is based on adequate preoperative assessment and anesthetic management.

  18. Interior Volatile Reservoirs in Mercury

    Science.gov (United States)

    Anzures, B. A.; Parman, S. W.; Milliken, R. E.; Head, J. W.

    2018-05-01

    More measurements of 1) surface volatiles, and 2) pyroclastic deposits paired with experimental volatile analyses in silicate minerals can constrain conditions of melting and subsequent eruption on Mercury.

  19. Obstetric use of nitroglycerin: Anesthetic implications

    Directory of Open Access Journals (Sweden)

    Richa Saroa

    2013-01-01

    Full Text Available Nitroglycerin has been used in anesthetic practice for induced hypotension and managing perioperative hypertension and myocardial ischemia. Contrary to the continuous low dose infusions (5-20 mcg/min used for the same, intravenous bolus dosages are sometimes administered at the behest of obstetricians for removal of retained placenta. Use of nitroglycerine in managing retained placenta is undertaken as a last resort when other measures fail to relax the uterine smooth muscles. Intravenous nitroglycerine relaxes smooth muscle cells by releasing nitric oxide thus causing prompt cervico-uterine relaxation. However, administration of nitroglycerine in this manner is not without risks which should be kept in mind while using it for obstetric purposes. We hereby report a case of 22-year-old female scheduled for manual removal of placenta where unpredictable and unexpected hypoxemia was observed following nitroglycerine administration.

  20. Warmed local anesthetic reduces pain of infiltration.

    Science.gov (United States)

    Fialkov, J A; McDougall, E P

    1996-01-01

    The effect of warming local anesthetic on the amount of pain experienced during local infiltration was tested by comparing equal volumes of 40 degrees C- and 21 degrees C-infiltrates in each of 26 subjects. Six subjects were patients undergoing excision of two benign asymptomatic nevi in separate locations, and 20 subjects were healthy adult volunteers who were injected in bilateral antebrachial sites. The warmed and room temperature solutions were randomized to each side, so that each subject received both temperature injections in random order. All subjects and the injector were blinded. The rate of injection was time-controlled (0.05 ml/sec). Following both injections, subjects were asked to rate the pain experienced at each site. In addition, the subject was asked if there was no difference, a slight difference, or a substantial difference between the two sites. A two-tailed paired t-test was used to analyze the mean difference in pain scores for all subjects. Paired analysis of the pain scores for each subject eliminated intersubject variance of pain tolerance. The mean difference in pain score between the room temperature and warmed solutions was +1.5 (p < 0.0001). Of the 21 subjects (81%) who found the warmed solution less painful, 11 (52%) found the difference to be significant, while 10 (48%) found the difference to be slight. Two subjects (8%) found no difference between the two, while 3 subjects (11%) found the colder solution slightly less painful. We conclude that warming local anesthetic to 40 degrees C prior to subcutaneous injection is a simple, inexpensive means of reducing the pain of local infiltration.

  1. Differences in Motor Evoked Potentials Induced in Rats by Transcranial Magnetic Stimulation under Two Separate Anesthetics: Implications for Plasticity Studies.

    Science.gov (United States)

    Sykes, Matthew; Matheson, Natalie A; Brownjohn, Philip W; Tang, Alexander D; Rodger, Jennifer; Shemmell, Jonathan B H; Reynolds, John N J

    2016-01-01

    Repetitive transcranial magnetic stimulation (rTMS) is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs) are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however, results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS), a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when selecting an

  2. Chromosomal damage among medical staff occupationally exposed to volatile anesthetics, antineoplastic drugs, and formaldehyde

    Czech Academy of Sciences Publication Activity Database

    Mušák, L.; Šmerhovský, Z.; Halásová, E.; Osina, O.; Letková, L.; Vodičková, Ludmila; Poláková, Veronika; Buchancová, J.; Hemminki, K.; Vodička, Pavel

    2013-01-01

    Roč. 39, č. 6 (2013), s. 618-630 ISSN 0355-3140 Grant - others:MŠVV(SK) 26220220111; UK(SK) 1/0576/10 VEGA; MZd(SK) 2007/48-UK-13; GA MŠMT(CZ) Prvouk-P27/LF1/1 Institutional support: RVO:68378041 Keywords : anesthesiologist * antineoplastic drug * chromosomal aberration Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.095, year: 2013

  3. Pluto's Volatile Transport

    Science.gov (United States)

    Young, Leslie

    2012-10-01

    Pluto's varying subsolar latitude and heliocentric distance leads to large variations in the surface volatile distribution and surface pressure. I present results of new volatile transport models (Young 2012a, b). The models include insolation, thermal emission, subsurface conduction, heating of a volatile slab, internal heat flux, latent heat of sublimation, and strict global mass balance. Numeric advances include initial conditions that allow for rapid convergence, efficient computation with matrix arithmetic, and stable Crank-Nicholson timesteps for both bare and volatile-covered areas. Runs of the model show six distinct seasons on Pluto. (1) As Pluto approaches perihelion, the volatiles on the old winter pole (the Rotational North Pole, RNP) becomes more directly illuminated , and the pressure and albedo rise rapidly. (2) When a new ice cap forms on the Rotational South Pole, RSP, volatiles are exchanged between poles. The pressure and albedo change more slowly. (3) When all volatiles have sublimed from the RNP, the albedo and pressure drop rapidly. (4-6) A similar pattern is repeated near aphelion with a reversal of the roles and the poles. I will compare results with earlier Pluto models of Hansen and Paige (1996), show the dependence on parameters such as substrate inertia, and make predictions for the New Horizons flyby of Pluto in 2015. This work was supported, in part, by funding from NASA Planetary Atmospheres Grant NNG06GF32G and the Spitzer project (JPL research support Agreement 1368573). Hansen, C. J. and D. A. Paige 1996. Seasonal Nitrogen Cycles on Pluto. Icarus 120, 247-265. Young, L. A. 2012a. Volatile transport on inhomogeneous surfaces: I - Analytic expressions, with application to Pluto’s day. Icarus, in press Young, L. A. 2012b. Volatile transport on inhomogeneous surfaces: II. Numerical calculations, with application to Pluto's season. In preparation.

  4. Cleft lip and palate: recommendations for dental anesthetic procedure based on anatomic evidences

    Directory of Open Access Journals (Sweden)

    Ivy Kiemle Trindade-Suedam

    2012-02-01

    Full Text Available Patients with cleft lip and palate usually present dental anomalies of number, shape, structure and position in the cleft area and the general dentist is frequently asked to restore or extract those teeth. Considering that several anatomic variations are expected in teeth adjacent to cleft areas and that knowledge of these variations by general dentists is required for optimal treatment, the objectives of this paper are: 1 to describe changes in the innervation pattern of anterior teeth and soft tissue caused by the presence of a cleft, 2 to describe a local anesthetic procedure in unilateral and bilateral clefts, and 3 to provide recommendations to improve anesthetic procedures in patients with cleft lip and palate. The cases of 2 patients are presented: one with complete unilateral cleft lip and palate, and the other with complete bilateral cleft lip and palate. The patients underwent local anesthesia in the cleft area in order to extract teeth with poor bone support. The modified anesthetic procedure, respecting the altered course of nerves in the cleft maxilla and soft tissue alterations at the cleft site, was accomplished successfully and the tooth extraction was performed with no pain to the patients. General dentists should be aware of the anatomic variations in nerve courses in the cleft area to offer high quality treatment to patients with cleft lip and palate.

  5. The State of Anesthetic Services in Korea: A National Survey of the Status of Anesthesia Provider in the 2011-2013 Period

    Science.gov (United States)

    2016-01-01

    Active involvement of anesthesiologists in perioperative management is important to ensure the patients' safety. This study aimed to investigate the state of anesthetic services in Korea by identifying anesthetic service providers. From the insurance claims data of National Health Insurance for 3 yr, the Korean state of anesthetic services was analyzed. The claims for anesthesia from the medical institutions which hire their own anesthesiologist or with an anesthesiologist invitation fee are assumed to be the anesthesia performed by anesthesiologists. The annual anesthetic data were similar during the study period. In 2013, total counts of 2,129,871 were composed with general anesthesia (55%), regional anesthesia (36%) and procedural sedation with intravenous anesthetics (9%). About 80% of total cases of general anesthesia were performed in general hospitals, while more than 60% of the regional anesthesia and sedation were performed in the clinics and hospitals under 100 beds. Non-anesthesiologists performed 273,006 cases of anesthesia (13% of total) including 36,008 of general anesthesia, 143,134 of regional anesthesia, and 93,864 of sedation, mainly in the clinics and hospitals under 100 beds. All procedural sedations in the institutions without direct employed anesthesiologist were performed by non-anesthesiologists. Significant numbers of anesthesia are performed by non-anesthesiologist in Korea. To promote anesthetic services that prioritize the safety of patients, the standard to qualify anesthetic service is required. Surgeons and patients need to enhance their perception of anesthesia, and the payment system should be revised in a way that advocates anesthesiologist-performed anesthetic services. PMID:26770049

  6. Blood profiles in unanesthetized and anesthetized guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Williams, Wendy R; Johnston, Matthew S; Higgins, Sarah; Izzo, Angelo A; Kendall, Lon V

    2016-01-01

    The guinea pig is a common animal model that is used in biomedical research to study a variety of systems, including hormonal and immunological responses, pulmonary physiology, corticosteroid response and others. However, because guinea pigs are evolutionarily a prey species, they do not readily show behavioral signs of disease, which can make it difficult to detect illness in a laboratory setting. Minimally invasive blood tests, such as complete blood counts and plasma biochemistry assays, are useful in both human and veterinary medicine as an initial diagnostic technique to rule in or rule out systemic illness. In guinea pigs, phlebotomy for such tests often requires that the animals be anesthetized first. The authors evaluated hematological and plasma biochemical effects of two anesthetic agents that are commonly used with guinea pigs in a research setting: isoflurane and a combination of ketamine and xylazine. Hematological and plasma biochemical parameters were significantly different when guinea pigs were under either anesthetic, compared to when they were unanesthetized. Plasma proteins, liver enzymes, white blood cells and red blood cells appeared to be significantly altered by both anesthetics, and hematological and plasma biochemical differences were greater when guinea pigs were anesthetized with the combination of ketamine and xylazine than when they were anesthetized with isoflurane. Overall these results indicate that both anesthetics can significantly influence hematological and plasma biochemical parameters in guinea pigs.

  7. Can anesthetic treatment worsen outcome in status epilepticus?

    Science.gov (United States)

    Sutter, Raoul; Kaplan, Peter W

    2015-08-01

    Status epilepticus refractory to first-line and second-line antiepileptic treatments challenges neurologists and intensivists as mortality increases with treatment refractoriness and seizure duration. International guidelines advocate anesthetic drugs, such as continuously administered high-dose midazolam, propofol, and barbiturates, for the induction of therapeutic coma in patients with treatment-refractory status epilepticus. The seizure-suppressing effect of anesthetic drugs is believed to be so strong that some experts recommend using them after benzodiazepines have failed. Although the rationale for the use of anesthetic drugs in patients with treatment-refractory status epilepticus seems clear, the recommendation of their use in treating status epilepticus is based on expert opinions rather than on strong evidence. Randomized trials in this context are lacking, and recent studies provide disturbing results, as the administration of anesthetics was associated with poor outcome independent of possible confounders. This calls for caution in the straightforward use of anesthetics in treating status epilepticus. However, there are still more questions than answers, and current evidence for the adverse effects of anesthetic drugs in patients with status epilepticus remains too limited to advocate a change of treatment algorithms. In this overview, the rationale and the conflicting clinical implications of anesthetic drugs in patients with treatment-refractory status epilepticus are discussed, and remaining questions are elaborated. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  9. A placebo-controlled trial to evaluate an anesthetic gel when probing in patients with advanced periodontitis.

    LENUS (Irish Health Repository)

    Winning, Lewis

    2012-12-01

    The baseline periodontal examination is reported to be a painful dental procedure, but currently there are limited practical techniques to reduce this pain. The objective of this study is to evaluate the efficacy of an intrapocket anesthetic gel in the reduction of pain on periodontal probing in a group of untreated patients with generalized chronic periodontitis (CP).

  10. American options under stochastic volatility

    NARCIS (Netherlands)

    Chockalingam, A.; Muthuraman, K.

    2011-01-01

    The problem of pricing an American option written on an underlying asset with constant price volatility has been studied extensively in literature. Real-world data, however, demonstrate that volatility is not constant, and stochastic volatility models are used to account for dynamic volatility

  11. Comparison of anesthetic agents in the sea otter

    Energy Technology Data Exchange (ETDEWEB)

    Williams, T.D.; Kocher, F.H.

    1978-01-01

    Five anesthetic agents (CI744, etorphine, fentanyl, ketamine hydrochloride, and halothane) were tested to establish the dosage of a safe, effective, short-acting anesthetic for use in the sea otter. Etorphine, at a dosage of 0.75 mg per adult otter and used in conjunction with diazepam, at a dosage of 1.25 mg per adult otter, met most of the requirements for use under field conditions. Halothane, administered through an anesthetic machine, proved to be effective for use in a veterinary hospital.

  12. Challenges Encountered Using Ophthalmic Anesthetics in Space Medicine

    Science.gov (United States)

    Bayuse, T.; Law, J.; Alexander, D.; Moynihan, S.; LeBlanc, C.; Langford, K.; Magalhaes, L.

    2015-01-01

    On orbit, ophthalmic anesthetics are used for tonometry and off-nominal corneal examinations. Proparacaine has been flown traditionally. However, the manufacturers recently changed its storage requirements from room temperature storage to refrigerated storage to preserve stability and prolong the shelf-life. Since refrigeration on orbit is not readily available and there were stability concerns about flying proparacaine unrefrigerated, tetracaine was selected as an alternative ophthalmic anesthetic in 2013. We will discuss the challenges encountered flying and using these anesthetics on the International Space Station.

  13. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Luisa Ciobanu

    Full Text Available During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T(2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine. We showed that the brain/vessels contrast in T(2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation.

  14. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI

    International Nuclear Information System (INIS)

    Ciobanu, Luisa; Reynaud, Olivier; Le Bihan, Denis; Uhrig, Lynn; Jarraya, Bechir

    2012-01-01

    During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T2'*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7 T and 17.2 T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine). We showed that the brain/vessels contrast in T2'*- weighted images at 17.2 T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7 T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation. (authors)

  15. Anesthetic and Airways Management of a Dog with Severe Tracheal Collapse during Intraluminal Stent Placement

    Directory of Open Access Journals (Sweden)

    M. Argano

    2013-01-01

    Full Text Available This case report describes the anesthetic and airways management of a dog affected by 4th degree tracheal collapse and undergoing endoscope-guided intraluminal stent placement. After premedication with acepromazine and butorphanol, general anesthesia was induced with propofol and maintained with intravenous propofol and butorphanol in constant rate infusion. During intraluminal stent placement, oxygen was supplemented by means of a simple and inexpensive handmade device, namely, a ureteral catheter inserted into the trachea and connected to an oxygen source, which allowed for the maintenance of airways’ patency and adequate patient’s oxygenation, without decreasing visibility in the surgical field or interfering with the procedure. The use of the technique described in the present paper was the main determinant of the successful anesthetic management and may be proposed for similar critical cases in which surgical manipulation of the tracheal lumen, which may potentially result in hypoxia by compromising airways patency, is required.

  16. Interaction of Local Anesthetics with Biomembranes Consisting of Phospholipids and Cholesterol: Mechanistic and Clinical Implications for Anesthetic and Cardiotoxic Effects

    Directory of Open Access Journals (Sweden)

    Hironori Tsuchiya

    2013-01-01

    Full Text Available Despite a long history in medical and dental application, the molecular mechanism and precise site of action are still arguable for local anesthetics. Their effects are considered to be induced by acting on functional proteins, on membrane lipids, or on both. Local anesthetics primarily interact with sodium channels embedded in cell membranes to reduce the excitability of nerve cells and cardiomyocytes or produce a malfunction of the cardiovascular system. However, the membrane protein-interacting theory cannot explain all of the pharmacological and toxicological features of local anesthetics. The administered drug molecules must diffuse through the lipid barriers of nerve sheaths and penetrate into or across the lipid bilayers of cell membranes to reach the acting site on transmembrane proteins. Amphiphilic local anesthetics interact hydrophobically and electrostatically with lipid bilayers and modify their physicochemical property, with the direct inhibition of membrane functions, and with the resultant alteration of the membrane lipid environments surrounding transmembrane proteins and the subsequent protein conformational change, leading to the inhibition of channel functions. We review recent studies on the interaction of local anesthetics with biomembranes consisting of phospholipids and cholesterol. Understanding the membrane interactivity of local anesthetics would provide novel insights into their anesthetic and cardiotoxic effects.

  17. Induction of burst suppression or coma using intravenous anesthetics in refractory status epilepticus.

    Science.gov (United States)

    Kang, Bong Su; Jung, Keun-Hwa; Shin, Jeong-Won; Moon, Jang Sup; Byun, Jung-Ick; Lim, Jung-Ah; Moon, Hye Jin; Kim, Young-Soo; Lee, Soon-Tae; Chu, Kon; Lee, Sang Kun

    2015-05-01

    General anesthetic-induced coma therapy has been recommended for the treatment of refractory status epilepticus (RSE). However, the influence of electroencephalographic (EEG) burst suppression (BS) on outcomes still remains unclear. This study investigated the impact of intravenous anesthetic-induced BS on the prognosis of RSE using a retrospective analysis of all consecutive adult patients who received intravenous anesthetic treatment for RSE at the Seoul National University Hospital between January 2006 and June 2011. Twenty-two of the 111 episodes of RSE were enrolled in this study. Of the 22 RSE patients, 12 (54.5%) were women and 18 (81.4%) exhibited generalized convulsive status epilepticus. Sixteen patients (72.7%) were classified as having acute symptomatic etiology, including three patients with anoxic encephalopathy, and others with remote symptomatic etiology. Only two patients (9.1%) had a favorable Status Epilepticus Severity Score (0-2) at admission. All patients received midazolam (MDZ) as a primary intravenous anesthetic drug for RSE treatment; three (13.6%) received MDZ and propofol, and one (4.5%) received MDZ and pentobarbital. The rates of mortality and poor outcome at discharge were 13.6% (n=3) and 54.5% (n=12), respectively. While BS was achieved in six (27.5%) patients, it was not associated with mortality or poor outcome. Induced BS was associated with prolonged hospital stay in subgroup analysis when excluding anoxic encephalopathy. Our results suggest that induction of BS for treating RSE did not affect mortality or outcome at discharge and may lead to an increased length of hospital stay. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Anesthetic drug wastage in the operation room: A cause for concern

    Directory of Open Access Journals (Sweden)

    Kapil Chaudhary

    2012-01-01

    Full Text Available Context: The cost of anesthetic technique has three main components, i.e., disposable supplies, equipments, and anesthetic drugs. Drug budgets are an easily identifiable area for short-term savings. Aim: To assess and estimate the amount of anesthetic drug wastage in the general surgical operation room. Also, to analyze the financial implications to the hospital due to drug wastage and suggest appropriate steps to prevent or minimize this wastage. Settings and Design: A prospective observational study conducted in the general surgical operation room of a tertiary care hospital. Materials and Methods: Drug wastage was considered as the amount of drug left unutilized in the syringes/vials after completion of a case and any ampoule or vial broken while loading. An estimation of the cost of wasted drug was made. Results: Maximal wastage was associated with adrenaline and lignocaine (100% and 93.63%, respectively. The drugs which accounted for maximum wastage due to not being used after loading into a syringe were adrenaline (95.24%, succinylcholine (92.63%, lignocaine (92.51%, mephentermine (83.80%, and atropine (81.82%. The cost of wasted drugs for the study duration was 46.57% (Rs. 16,044.01 of the total cost of drugs issued/loaded (Rs. 34,449.44. Of this, the cost of wastage of propofol was maximum being 56.27% (Rs. 9028.16 of the total wastage cost, followed by rocuronium 17.80% (Rs. 2856, vecuronium 5.23% (Rs. 840, and neostigmine 4.12% (Rs. 661.50. Conclusions: Drug wastage and the ensuing financial loss can be significant during the anesthetic management of surgical cases. Propofol, rocuronium, vecuronium, and neostigmine are the drugs which contribute maximally to the total wastage cost. Judicious use of these and other drugs and appropriate prudent measures as suggested can effectively decrease this cost.

  19. Option Valuation with Observable Volatility and Jump Dynamics

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunoua, Bruno; Jeon, Yoontae

    Under very general conditions, the total quadratic variation of a jump-diffusion process can be decomposed into diffusive volatility and squared jump variation. We use this result to develop a new option valuation model in which the underlying asset price exhibits volatility and jump intensity...... dynamics. The volatility and jump intensity dynamics in the model are directly driven by model-free empirical measures of diffusive volatility and jump variation. Because the empirical measures are observed in discrete intervals, our option valuation model is cast in discrete time, allowing...

  20. Option Valuation with Observable Volatility and Jump Dynamics

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunoua, Bruno; Jeon, Yoontae

    2015-01-01

    Under very general conditions, the total quadratic variation of a jump-diffusion process can be decomposed into diffusive volatility and squared jump variation. We use this result to develop a new option valuation model in which the underlying asset price exhibits volatility and jump intensity...... dynamics. The volatility and jump intensity dynamics in the model are directly driven by model-free empirical measures of diffusive volatility and jump variation. Because the empirical measures are observed in discrete intervals, our option valuation model is cast in discrete time, allowing...

  1. Marfan Syndrome: Clinical, Surgical, and Anesthetic Considerations.

    Science.gov (United States)

    Castellano, José M; Silvay, George; Castillo, Javier G

    2014-09-01

    Marfan syndrome is a multisystem connective tissue disorder, with primary involvement of the cardiovascular, ocular, and skeletal systems. This autosomal heritable disease is mainly attributable to a defect in the FBN1 gene. Clinical diagnosis of Marfan syndrome has been based on the Ghent criteria since 1996. In 2010, these criteria were updated, and the revised guidelines place more emphasis on aortic root dilation, ectopia lentis, and FBN1 mutation testing in the diagnostic assessment of Marfan syndrome. Among its many different clinical manifestations, cardiovascular involvement deserves special consideration, owing to its impact on prognosis. Recent molecular, surgical, and clinical research has yielded profound new insights into the pathological mechanisms that ultimately lead to tissue degradation and weakening of the aortic wall, which has led to exciting new treatment strategies. Furthermore, with the increasing life expectancy of patients with Marfan syndrome, there has been a subtle shift in the spectrum of medical problems. Consequently, this article focuses on recent advances to highlight their potential impact on future concepts of patient care from a clinical, surgical, and anesthetic perspective. © The Author(s) 2013.

  2. Anesthetic considerations for pediatric electroconvulsive therapy.

    Science.gov (United States)

    Franklin, Andrew D; Sobey, Jenna H; Stickles, Eric T

    2017-05-01

    Electroconvulsive therapy is being used more frequently in the treatment of many chronic and acute psychiatric illnesses in children. The most common psychiatric indications for pediatric electroconvulsive therapy are refractory depression, bipolar disorder, schizophrenia, catatonia, and autism. In addition, a relatively new indication is the treatment of pediatric refractory status epilepticus. The anesthesiologist may be called upon to assist in the care of this challenging and vulnerable patient population. Unique factors for pediatric electroconvulsive therapy include the potential need for preoperative anxiolytic and inhalational induction of anesthesia, which must be weighed against the detrimental effects of anesthetic agents on the evoked seizure quality required for a successful treatment. Dexmedetomidine is likely the most appropriate preoperative anxiolytic as oral benzodiazepines are relatively contraindicated. Methohexital, though becoming less available at many institutions, remains the gold standard for induction of anesthesia for pediatric electroconvulsive therapy though ketamine, propofol, and sevoflurane are becoming increasingly viable options. Proper planning and communication between the multidisciplinary teams involved in the care of children presenting for electroconvulsive therapy treatments is vital to mitigating risks and achieving the greatest therapeutic benefit. © 2017 John Wiley & Sons Ltd.

  3. Oil and stock market volatility: A multivariate stochastic volatility perspective

    International Nuclear Information System (INIS)

    Vo, Minh

    2011-01-01

    This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility structure in an attempt to extract information intertwined in both markets for risk prediction. It offers four major findings. First, the stock and oil futures prices are inter-related. Their correlation follows a time-varying dynamic process and tends to increase when the markets are more volatile. Second, conditioned on the past information, the volatility in each market is very persistent, i.e., it varies in a predictable manner. Third, there is inter-market dependence in volatility. Innovations that hit either market can affect the volatility in the other market. In other words, conditioned on the persistence and the past volatility in their respective markets, the past volatility of the stock (oil futures) market also has predictive power over the future volatility of the oil futures (stock) market. Finally, the model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry. - Research Highlights: → This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility model. → The correlation between the two markets follows a time-varying dynamic process which tends to increase when the markets are more volatile. → The volatility in each market is very persistent. → Innovations that hit either market can affect the volatility in the other market. → The model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry.

  4. Toxic keratopathy due to abuse of topical anesthetic drugs.

    Science.gov (United States)

    Yeniad, Baris; Canturk, Serife; Esin Ozdemir, Fatma; Alparslan, Nilufer; Akarcay, Koray

    2010-06-01

    To describe 8 cases of toxic keratopathy due to abuse of topical anesthetic drugs. Clinical findings from patients with toxic keratopathy were investigated retrospectively. Two patients had toxic keratopathy bilaterally. Five of 8 patients had an ocular history of a corneal foreign body, 1 had basal membrane dystrophy, 1 had ultraviolet radiation, and 1 had chemical burn. All patients had undergone psychiatric consultation. Four patients had anxiety disorder and 1 had bipolar disease. Clinical signs were improved in all patients with discontinuation of topical anesthetic drug use along with adjunctive psychiatric treatment. Penetrating keratoplasty was performed in 2 patients. Toxic keratopathy due to topical anesthetic abuse is a curable disease. Early diagnosis and prevention of topical anesthetic drug use are the most important steps in the treatment of this condition. As these patients commonly exhibit psychiatric disorders, adjunctive psychiatric treatment may help to break the chemical addiction.

  5. ANESTHETIC MANAGEMENT FOR A PATIENT WITH ACUTE INTERMITTENT PORPHYRIA

    Directory of Open Access Journals (Sweden)

    Nenad Savić

    2010-09-01

    Full Text Available Acute intermittent porphyria is a rare metabolic disorder resulting from a partial deficiency of porphobilinogen deaminase, enzyme in the heme biosynthetic pathway. Its inheritance is autosomal dominant. A deficiency of porphobilinogen deaminase is not sufficient by its self to produce acute intermittent porphyria, and other activating factors must also be present. These include some drugs, hormones, infection, injury and alcohol. Besides others, anesthetics have been implicated in the triggering of a number of severe porphyric reactions. Although there is no clinical evidence, the fear of hypothesized porphyrinogenicity of repetitive anesthetics exposures still remains. Despite these doubts, we report here the case of uneventful repeated exposure to anesthetics in a patient suffering from acute intermittent porphyria, within a fifteen- month period. On both occasions, the patient was safely exposed to certain anesthetics included: propofol, sevoflurane, rocuronium, midazolam and fentanyl.

  6. Nocebo-induced hyperalgesia during local anesthetic injection.

    Science.gov (United States)

    Varelmann, Dirk; Pancaro, Carlo; Cappiello, Eric C; Camann, William R

    2010-03-01

    Common practice during local anesthetic injection is to warn the patient using words such as: "You will feel a big bee sting; this is the worst part." Our hypothesis was that using gentler words for administration of the local anesthetic improves pain perception and patient comfort. One hundred forty healthy women at term gestation requesting neuraxial analgesia were randomized to either a "placebo" ("We are going to give you a local anesthetic that will numb the area and you will be comfortable during the procedure") or "nocebo" ("You are going to feel a big bee sting; this is the worst part of the procedure") group. Pain was assessed immediately after the local anesthetic skin injection using verbal analog scale scores of 0 to 10. Median verbal analog scale pain scores were lower when reassuring words were used compared with the harsher nocebo words (3 [2-4] vs 5 [3-6]; P words improves the subjective experience during invasive procedures.

  7. Adherence of volatile propofol to various types of plastic tubing.

    Science.gov (United States)

    Maurer, F; Lorenz, D J; Pielsticker, G; Volk, T; Sessler, D I; Baumbach, J I; Kreuer, S

    2017-01-23

    Propofol is an intravenous anesthetic. Currently, it is not possible to routinely measure blood concentration of the drug in real time. However, multi-capillary column ion-mobility spectrometry of exhaled gas can estimate blood propofol concentration. Unfortunately, adhesion of volatile propofol on plastic materials complicates measurements. Therefore, it is necessary to consider the extent to which volatile propofol adheres to various plastics used in sampling tubing. Perfluoralkoxy (PFA), polytetrafluorethylene (PTFE), polyurethane (PUR), silicone, and Tygon tubing were investigated in an experimental setting using a calibration gas generator (HovaCAL). Propofol gas was measured for one hour at 26 °C, 50 °C, and 90 °C tubing temperature. Test tubing segments were then flushed with N 2 to quantify desorption. PUR and Tygon sample tubing absorbed all volatile propofol. The silicone tubing reached the maximum propofol concentration after 119 min which was 29 min after propofol gas exposure stopped. The use of PFA or PTFE tubing produced comparable and reasonably accurate propofol measurements. The desaturation time for the PFA was 10 min shorter at 26 °C than for PTFE. PFA tubing thus seems most suitable for measurement of volatile propofol, with PTFE as an alternative.

  8. Anesthetic Approach to a Child with Noonan's Syndrome

    Directory of Open Access Journals (Sweden)

    Zehra Hatipoglu

    2015-03-01

    Full Text Available Noonan syndrome is characterized by fascial and physical features along with congenital heart disease. In these patients, fascial features include short webbed neck, micrognathia, limited mouth opening and high arched palate. Pulmonary stenosis and hypertrophic obstructive cardiomyopathy are highly prevalent in Noonan's syndrome. The anesthetic management is important because of difficult airway and severe cardiac abnormalities. We reported that anesthetic management of a child with Noonan's syndrome. [Cukurova Med J 2015; 40(Suppl 1: 47-50

  9. Postoperative environmental anesthetic vapour concentrations following removal of the airway device in the operating room versus the postanesthesia care unit.

    Science.gov (United States)

    Cheung, Sara K; Özelsel, Timur; Rashiq, Saifee; Tsui, Ban C

    2016-09-01

    This study was designed to compare waste anesthetic gas (WAG) concentrations within patients' breathing zones after removal of the patient's airway device in the postanesthesia care unit (PACU) vs in the operating room (OR). Following Research Ethics Board approval and patient consent, we recruited patients undergoing surgery who received volatile anesthesia via an endotracheal tube or supraglottic airway. Patients had their airway device removed in the OR or in the PACU depending on the attending anesthesiologist's preference. Upon the patient's arrival in the PACU, concentrations of exhaled sevoflurane and desflurane were measured at their breathing zone (i.e., 15 cm from the patient's mouth and nose) using a single-beam infrared spectrophotometer. Seventy patients were recruited during the five-month study period. The median [interquartile range] WAG levels in the patients' breathing zones were higher when their airway devices were removed in the PACU vs in the OR. The WAG levels for sevoflurane were 0.7 [0.4-1.1] parts per million (ppm) vs 0.5 [0.4-0.7] ppm, respectively; median difference, 0.3; 95% confidence interval (CI), 0.1 to 0.6; P = 0.04. The WAG levels for desflurane were 2.4 [1.2-3.4] ppm vs 4.1 [2.5-5.2] ppm, respectively; median difference, 1.5; 95% CI, 0.3 to 2.7; P = 0.04. After a volatile-based anesthetic, our results suggest that removal of the airway device in the PACU vs in the OR increases the amount of waste anesthetic gas in a patient's breathing zone and thus potentially in the PACU nurse's working zone.

  10. The use of compound topical anesthetics: a review.

    Science.gov (United States)

    Kravitz, Neal D

    2007-10-01

    The author reviewed the history of, federal regulations regarding, risks of and adverse drug reactions of five compound topical anesthetics: tetracaine, adrenaline/epinephrine and cocaine (TAC); lidocaine, adrenaline/epinephrine and tetracaine (LET); lidocaine, tetracaine and phenylephrine (TAC 20 percent Alternate); lidocaine, prilocaine and tetracaine (Profound); and lidocaine, prilocaine, tetracaine and phenylephrine with thickeners (Profound PET). The author reviewed clinical trials, case reports, descriptive articles, and U.S. Food and Drug Administration (FDA) regulations and recent public advisory warnings regarding the federal approval of and risks associated with the use of compound topical anesthetics. Compound topical anesthetics are neither FDA-regulated nor -unregulated. Some compounding pharmacies bypass the new FDA drug approval process, which is based on reliable scientific data and ensures that a marketed drug is safe, effective, properly manufactured and accurately labeled. Two deaths have been attributed to the lay use of compound topical anesthetics. In response, the FDA has announced the strengthening of its efforts against unapproved drug products. Compound topical anesthetics may be an effective alternative to local infiltration for some minimally invasive dental procedures; however, legitimate concerns exist in regard to their safety. Until they become federally regulated, compound topical anesthetics remain unapproved drug products whose benefits may not outweigh their risks for dental patients.

  11. Anesthetic management of a patient with multiple sclerosis - case report

    Directory of Open Access Journals (Sweden)

    Eduardo Barbin Zuccolotto

    Full Text Available Abstract Background and objectives: Multiple sclerosis is a demyelinating disease of the brain and spinal cord, characterized by muscle weakness, cognitive dysfunction, memory loss, and personality disorders. Factors that promote disease exacerbation are stress, physical trauma, infection, surgery, and hyperthermia. The objective is to describe the anesthetic management of a case referred to urological surgery. Case report: A female patient, 44 years of age, with multiple sclerosis, diagnosed with nephrolithiasis, referred for endoscopic ureterolythotripsy. Balanced general anesthesia was chosen, with midazolam, propofol and remifentanil target-controlled infusion; sevoflurane via laryngeal mask airway; and spontaneous ventilation. Because the patient had respiratory difficulty presenting with chest wall rigidity, it was decided to discontinue the infusion of remifentanil. There was no other complication or exacerbation of disease postoperatively. Conclusion: The use of neuromuscular blockers (depolarizing and non-depolarizing is a problem in these patients. As there was no need for muscle relaxation in this case, muscle relaxants were omitted. We conclude that the combination of propofol and sevoflurane was satisfactory, not resulting in hemodynamic instability or disease exacerbation.

  12. Volatile liquid storage system

    International Nuclear Information System (INIS)

    Laverman, R.J.; Winters, P.J.; Rinehart, J.K.

    1992-01-01

    This patent describes a method of collecting and abating emission from a volatile liquid in an above ground storage tank. It comprises the liquid storage tank having a bottom, a vertical cylindrical circular wall having a lower edge portion joined to the bottom, and an external fixed roof, the tank having an internal floating roof floating on a volatile liquid stored in the tank, and air vent means in the tank in communication with a vapor space in the tank constituting at least the space above the floating roof when the floating roof floats on a predetermined maximum volume of volatile liquid in the tank; permitting ambient air; pumping emission laden air from the tank vapor space above the floating roof; and by means of the emissions abatement apparatus eliminating most of the emission from the emissions laden air with formation of a gaseous effluent and then discharging the resulting gaseous effluent to the atmosphere

  13. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  14. Pregnancy outcome after in utero exposure to local anesthetics as part of dental treatment: A prospective comparative cohort study.

    Science.gov (United States)

    Hagai, Aharon; Diav-Citrin, Orna; Shechtman, Svetlana; Ornoy, Asher

    2015-08-01

    Dental treatment and use of local anesthetics during pregnancy generally are considered harmless because of lack of evidence of adverse pregnancy effects. Data on the safety of dental treatment and local anesthetics during pregnancy are scant. Dental care is often a reason for concern both among women and their health care providers. The primary objective of this study was to evaluate the rate of major anomalies after exposure to local anesthetics as part of dental care during pregnancy. The authors performed a prospective, comparative observational study at the Israeli Teratology Information Services between 1999 and 2005. The authors followed 210 pregnancies exposed to dental local anesthetics (112 [53%] in the first trimester) and compared them with 794 pregnancies not exposed to teratogens. The rate of major anomalies was not significantly different between the groups (4.8% versus 3.3%, P = .300). There was no difference in the rate of miscarriages, gestational age at delivery, or birth weight. The most common types of dental treatment were endodontic treatment (43%), tooth extraction (31%), and tooth restoration (21%). Most women (63%) were not exposed to additional medications. Approximately one-half (51%) of the women were not exposed to dental radiography, and 44% were exposed to radiation, mostly bite-wing radiography. This study's results suggest that use of dental local anesthetics, as well as dental treatment during pregnancy, do not represent a major teratogenic risk. There seems to be no reason to prevent pregnant women from receiving dental treatment and local anesthetics during pregnancy. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

  15. Differences in motor evoked potentials induced in rats by transcranial magnetic stimulation under two separate anesthetics: implications for plasticity studies

    Directory of Open Access Journals (Sweden)

    Matthew Sykes

    2016-10-01

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS, a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when

  16. Fiberoptic laryngoscopy under general anesthesia in neonates

    NARCIS (Netherlands)

    L.J. Hoeve (Hans); R.H.M. van Poppelen

    1990-01-01

    textabstractAbstract In the Sophia Children's Hospital we perform fiberoptic laryngoscopy in neonates under general anesthesia without the use of muscle relaxants in the diagnostics of functional laryngeal disorders. The necessary diagnostic and anesthetic equipment is described. Special attention

  17. Ethyl-p-aminobenzoate (Benzocaine): efficacy as an anesthetic for five species of freshwater fish

    Science.gov (United States)

    Dawson, V.K.; Gilderhus, P.A.

    1979-01-01

    Ethyl-p-aminobenzoate (benzocaine) was tested for its efficacy as an anesthetic for rainbow trout (Salmo gairdnerii, brown trout (Salmo truttas, northern pike (Esox lucius). carp (Cyprinus carpio), and largemouth bass (Mieropterus salmoidesi. Since benzocaine is not water soluble, it was applied with acetone as a carrier. Concentrations of 100 to 200 mg!l were required for large adult northern pike, compared with 50 to 100 mg/l for small fish. Rates of sedation and recovery were slower in cold water than in warm water. Water hardness had little influence on the activity of benzocaine. Fish were anesthetized faster and recovered more slowly in acid than in alkaline water. Benzocaine produced deep anesthesia, but concentrations that rendered the fish handleable within 5 min were generally not safe for exposures longer than 15 min. Concentrations of benzocaine efficacious for fish were not acutely toxic to eggs of coho salmon (Oncorhynchus kisutch), chinook salmon (Oncorhynchus tshauiytschas, rainbow trout, brown trout, or lake trout (Salvelinus namaycush). Benzocaine is not registered for fishery use and is neither more effective nor safer than the registered anesthetic, tricaine methanesulfonate (MS-222l.

  18. Anesthetics rapidly promote synaptogenesis during a critical period of brain development.

    Directory of Open Access Journals (Sweden)

    Mathias De Roo

    Full Text Available Experience-driven activity plays an essential role in the development of brain circuitry during critical periods of early postnatal life, a process that depends upon a dynamic balance between excitatory and inhibitory signals. Since general anesthetics are powerful pharmacological modulators of neuronal activity, an important question is whether and how these drugs can affect the development of synaptic networks. To address this issue, we examined here the impact of anesthetics on synapse growth and dynamics. We show that exposure of young rodents to anesthetics that either enhance GABAergic inhibition or block NMDA receptors rapidly induce a significant increase in dendritic spine density in the somatosensory cortex and hippocampus. This effect is developmentally regulated; it is transient but lasts for several days and is also reproduced by selective antagonists of excitatory receptors. Analyses of spine dynamics in hippocampal slice cultures reveals that this effect is mediated through an increased rate of protrusions formation, a better stabilization of newly formed spines, and leads to the formation of functional synapses. Altogether, these findings point to anesthesia as an important modulator of spine dynamics in the developing brain and suggest the existence of a homeostatic process regulating spine formation as a function of neural activity. Importantly, they also raise concern about the potential impact of these drugs on human practice, when applied during critical periods of development in infants.

  19. The effects of anesthetic technique and ambient temperature on thermoregulation in lower extremity surgery.

    Science.gov (United States)

    Ozer, Ayse B; Tosun, Fadime; Demirel, Ismail; Unlu, Serap; Bayar, Mustafa K; Erhan, Omer L

    2013-08-01

    The purpose of our study was to determine the effects of anesthetic technique and ambient temperature on thermoregulation for patients undergoing lower extremity surgery. Our study included 90 male patients aged 18-60 years in American Society of Anesthesiologists Physical Status groups I or II who were scheduled for lower extremity surgery. Patients were randomly divided into three groups according to anesthetic technique: general anesthesia (GA), epidural anesthesia (EA), and femoral-sciatic block (FS). These groups were divided into subgroups according to room temperature: the temperature for group I was 20-22 °C and that for group II was 23-25 °C. Therefore, we labeled the groups as follows: GA I, GA II, EA I, EA II, FS I, and FS II. Probes for measuring tympanic membrane and peripheral temperature were placed in and on the patients, and mean skin temperature (MST) and mean body temperature (MBT) were assessed. Postoperative shivering scores were recorded. During anesthesia, tympanic temperature and MBT decreased whereas MST increased for all patients. There was no significant difference between tympanic temperatures in either the room temperature or anesthetic method groups. MST was lower in group GA I than in group GA II after 5, 10, 15, 20, 60 and 90 min whereas MBT was significantly lower at the basal level (p temperature affected thermoregulation in Group GA.

  20. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    2009-01-01

    This paper introduces a two-component volatility model based on first moments of both components to describe the dynamics of speculative return volatility. The two components capture the volatile and the persistent part of volatility, respectively. The model is applied to 10 Asia-Pacific stock ma...... markets. A positive or risk-premium effect exists between the return and the volatile component, yet the persistent component is not significantly priced for the return dynamic process....... markets. Their in-mean effects on returns are tested. The empirical results show that the persistent component is much more important for the volatility dynamic process than is the volatile component. However, the volatile component is found to be a significant pricing factor of asset returns for most...

  1. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock m......, a positive or risk-premium effect exists between return and the volatile component, yet the persistent component is not significantly priced for return dynamic process....... markets. Their in-mean effects on return are also tested. The empirical results show that the persistent component accounts much more for volatility dynamic process than the volatile component. However the volatile component is found to be a significant pricing factor of asset returns for most markets...

  2. Modeling returns volatility: Realized GARCH incorporating realized risk measure

    Science.gov (United States)

    Jiang, Wei; Ruan, Qingsong; Li, Jianfeng; Li, Ye

    2018-06-01

    This study applies realized GARCH models by introducing several risk measures of intraday returns into the measurement equation, to model the daily volatility of E-mini S&P 500 index futures returns. Besides using the conventional realized measures, realized volatility and realized kernel as our benchmarks, we also use generalized realized risk measures, realized absolute deviation, and two realized tail risk measures, realized value-at-risk and realized expected shortfall. The empirical results show that realized GARCH models using the generalized realized risk measures provide better volatility estimation for the in-sample and substantial improvement in volatility forecasting for the out-of-sample. In particular, the realized expected shortfall performs best for all of the alternative realized measures. Our empirical results reveal that future volatility may be more attributable to present losses (risk measures). The results are robust to different sample estimation windows.

  3. Testing for Co-integration in Vector Autoregressions with Non-Stationary Volatility

    DEFF Research Database (Denmark)

    Cavaliere, Guiseppe; Rahbæk, Anders; Taylor, A.M. Robert

    Many key macro-economic and financial variables are characterised by permanent changes in unconditional volatility. In this paper we analyse vector autoregressions with non-stationary (unconditional) volatility of a very general form, which includes single and multiple volatility breaks as special...

  4. Testing for Co-integration in Vector Autoregressions with Non-Stationary Volatility

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Rahbek, Anders Christian; Taylor, A. M. Robert

    Many key macro-economic and …nancial variables are characterised by permanent changes in unconditional volatility. In this paper we analyse vector autoregressions with non-stationary (unconditional) volatility of a very general form, which includes single and multiple volatility breaks as special...

  5. Quantifying requirements volatility effects

    NARCIS (Netherlands)

    Kulk, G.P.; Verhoef, C.

    2008-01-01

    In an organization operating in the bancassurance sector we identified a low-risk IT subportfolio of 84 IT projects comprising together 16,500 function points, each project varying in size and duration, for which we were able to quantify its requirements volatility. This representative portfolio

  6. Idiosyncratic Volatility Puzzle

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos

    from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong...

  7. Anesthetic management of renal transplant recipients during cesarean section

    Directory of Open Access Journals (Sweden)

    Pınar Zeyneloğlu

    2008-03-01

    Full Text Available BACKGROUND: The advances in surgical techniques and immunosuppression have improved results in organ transplantation which enabled pregnancies following the return of good health and normal endocrine function. Reports about the anesthetic management of renal transplant recipient (RTR during cesarean section (C/S were not found in the literature. The aim of this study is to present our experience in RTRs during C/S. MATERIALS-METHODS: Retrospect ive data regarding RTRs who underwent C/S among 1645 renal transplantations at Baskent Univer sity Hospital in Ankara between January 1977 and Decem ber 2007 have been collected from hospital records. RESULTS: Eleven live births occured from ten RTRs. Two of them from vaginal delivery and 9 from C/S. The mean maternal age was 28 ± 4.6 years. The time from transplantation to conception was 41.1 ± 30.4 months. The mean gestational age was 33.5 ± 3.6 weeks and all recipients were maintained on cyclosporine, azathioprine and corticosteroids before and during pregnancy for immunosuppression. Five C/Ss were performed under general anesthesia whereas spinal anesthesia was used in 4 patients. Renal function tests were stable in all of the patients and we did not observe any acute rejection. The mean birth weight was 1945 ± 689 gr. There were 7 premature and 7 low birth weight among 11 newborns. CONCLUSION: General and regional anesthesia can be safely used during cesarean delivery of the RTRs without increased risk of graft loses. Prematurity and low birth weight was mainly due to the cytotoxic drugs for immunosuppression. Perioperative management of RTRs should be handled by a team including anesthesiologists.

  8. Manure application and ammonia volatilization

    NARCIS (Netherlands)

    Huijsmans, J.F.M.

    2003-01-01

    Keywords: manure application, ammonia volatilization, environmental conditions, application technique, incorporation technique, draught force, work organization, costs Livestock manure applied on farmland is an important source of ammonia (NH3) volatilization, and NH3 is a major atmospheric

  9. The exploitation of volatile oil

    Institute of Scientific and Technical Information of China (English)

    MENG Teng; ZHANG Da; TENG Xiangjin; LINing; HAO Zaibin

    2007-01-01

    Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.

  10. Alternative Asymmetric Stochastic Volatility Models

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  11. A novel approach to scavenging anesthetic gases in rodent surgery.

    Science.gov (United States)

    Nesbitt, Jeffrey C; Krageschmidt, Dale A; Blanco, Michael C

    2013-01-01

    Laboratory animal procedures using gas anesthetics may amass elevated waste gas concentrations in operating rooms if controls are not implemented for capturing and removing the vapors. Area sampling using an infrared analyzer indicated isoflurane concentrations likely to exceed occupational exposure guidelines. Our study showed environmental concentrations of oxygen as high as 40% and isoflurane concentrations >100 ppm when no controls or merely passive controls were utilized. These extraneous isoflurane emissions were determined to be originating from the pre-procedural induction process as well as the gas delivery nose cone. A novel waste gas collection cylinder was designed to enclose the gas delivery nose cone and animal head during the administration of anesthetic gases. The vented cylinder utilized a house vacuum to remove the waste anesthetic gases from the surgical field. A commercially available induction chamber designed to be actively and externally exhausted was used to lower concentrations during the induction process. With implementation of local exhaust ventilation controls, waste anesthetic gas concentrations decreased to below recommended occupational exposure levels. In vitro (sham) testing compared favorably to in vivo measurements validating the reduction capability of active ventilation during rodent anesthetic administration. In vivo isoflurane reductions for the induction chamber emissions, the operating room, and the surgeon's breathing zone were 95%, 60%, and 53%, respectively. The same measurements for an in vitro procedure were 98%, 84%, and 87%, respectively.

  12. Economic considerations in the use of inhaled anesthetic agents.

    Science.gov (United States)

    Golembiewski, Julie

    2010-04-15

    To describe the components of and factors contributing to the costs of inhaled anesthesia, basis for quantifying and comparing these costs, and practical strategies for performing pharmacoeconomic analyses and reducing the costs of inhaled anesthetic agents. Inhaled anesthesia can be costly, and some of the variable costs, including fresh gas flow rates and vaporizer settings, are potential targets for cost savings. The use of a low fresh gas flow rate maximizes rebreathing of exhaled anesthetic gas and is less costly than a high flow rate, but it provides less control of the level of anesthesia. The minimum alveolar concentration (MAC) hour is a measure that can be used to compare the cost of inhaled anesthetic agents at various fresh gas flow rates. Anesthesia records provide a sense of patterns of inhaled anesthetic agent use, but the amount of detail can be limited. Cost savings have resulted from efforts to reduce the direct costs of inhaled anesthetic agents, but reductions in indirect costs through shortened times to patient recovery and discharge following the judicious use of these agents are more difficult to demonstrate. The patient case mix, fresh gas flow rates typically used during inhaled anesthesia, availability and location of vaporizers, and anesthesia care provider preferences and practices should be taken into consideration in pharmacoeconomic evaluations and recommendations for controlling the costs of inhaled anesthesia. Understanding factors that contribute to the costs of inhaled anesthesia and considering those factors in pharmacoeconomic analyses and recommendations for use of these agents can result in cost savings.

  13. Essays on nonparametric econometrics of stochastic volatility

    NARCIS (Netherlands)

    Zu, Y.

    2012-01-01

    Volatility is a concept that describes the variation of financial returns. Measuring and modelling volatility dynamics is an important aspect of financial econometrics. This thesis is concerned with nonparametric approaches to volatility measurement and volatility model validation.

  14. A comparison of anesthetic agents and their effects on the response properties of the peripheral auditory system.

    Science.gov (United States)

    Dodd, F; Capranica, R R

    1992-10-01

    Anesthetic agents were compared in order to identify the most appropriate agent for use during surgery and electrophysiological recordings in the auditory system of the tokay gecko (Gekko gecko). Each agent was first screened for anesthetic and analgesic properties and, if found satisfactory, it was subsequently tested in electrophysiological recordings in the auditory nerve. The following anesthetic agents fulfilled our criteria and were selected for further screening: sodium pentobarbital (60 mg/kg); sodium pentobarbital (30 mg/kg) and oxymorphone (1 mg/kg); 3.2% isoflurane; ketamine (440 mg/kg) and oxymorphone (1 mg/kg). These agents were subsequently compared on the basis of their effect on standard response properties of auditory nerve fibers. Our results verified that different anesthetic agents can have significant effects on most of the parameters commonly used in describing the basic response properties of the auditory system in vertebrates. We therefore conclude from this study that the selection of an appropriate experimental protocol is critical and must take into consideration the effects of anesthesia on auditory responsiveness. In the tokay gecko, we recommend 3.2% isoflurane for general surgical procedures; and for electrophysiological recordings in the eighth nerve we recommend barbiturate anesthesia of appropriate dosage in combination if possible with an opioid agent to provide additional analgesic action.

  15. Comparison of continuous interscalene block and subacromial infusion of local anesthetic for postoperative analgesia after open shoulder surgery.

    Science.gov (United States)

    Baskan, Semih; Cankaya, Deniz; Unal, Hidayet; Yoldas, Burak; Taspinar, Vildan; Deveci, Alper; Tabak, Yalcin; Baydar, Mustafa

    2017-01-01

    This study compared the efficacy of continuous interscalene block (CISB) and subacromial infusion of local anesthetic (CSIA) for postoperative analgesia after open shoulder surgery. This randomized, prospective, double-blinded, single-center study included 40 adult patients undergoing open shoulder surgery. All patients received a standardized general anesthetic. The patients were separated into group CISB and group CSIA. A loading dose of 40 mL 0.25% bupivacaine was administered and patient-controlled analgesia was applied by catheter with 0.1% bupivacaine 5 mL/h throughout 24 h basal infusion, 2 mL bolus dose, and 20 min knocked time in both groups postoperatively. Visual analog scale (VAS) scores, additional analgesia need, local anesthetic consumption, complications, and side effects were recorded during the first 24 h postoperatively. The range of motion (ROM) score was recorded preoperatively and in the first and third weeks postoperatively. A statistically significant difference was determined between the groups in respect of consumption of local anesthetic, VAS scores, additional analgesia consumption, complications, and side effects, with lower values recorded in the CISB group. There were no significant differences in ROM scoring in the preoperative and postoperative third week between the two groups but there were significant differences in ROM scoring in the postoperative first week, with higher ROM scoring values in the group CISB patients. The results of this study have shown that continuous interscalene infusion of bupivacaine is an effective and safe method of postoperative analgesia after open shoulder surgery.

  16. Intravenous sub-anesthetic ketamine for perioperative analgesia

    Directory of Open Access Journals (Sweden)

    Andrew W Gorlin

    2016-01-01

    Full Text Available Ketamine, an N-methyl-d-aspartate antagonist, blunts central pain sensitization at sub-anesthetic doses (0.3 mg/kg or less and has been studied extensively as an adjunct for perioperative analgesia. At sub-anesthetic doses, ketamine has a minimal physiologic impact though it is associated with a low incidence of mild psychomimetic symptoms as well as nystagmus and double vision. Contraindications to its use do exist and due to ketamine′s metabolism, caution should be exercised in patients with renal or hepatic dysfunction. Sub-anesthetic ketamine improves pain scores and reduces perioperative opioid consumption in a broad range of surgical procedures. In addition, there is evidence that ketamine may be useful in patients with opioid tolerance and for preventing chronic postsurgical pain.

  17. Anesthetic management in a pediatric patient with Noonan syndrome, hypopituitarism and hypothyroidism: A case report

    Directory of Open Access Journals (Sweden)

    Abdulkadir Yektaş

    2013-06-01

    Full Text Available Noonan syndrome is a genetically transmitted autosomaldominant disorder characterized by various anatomicanomalies and pathophysiologic derangements. Associatedanomalies include hyperthelorism, ptosis, micrognathia,downward sloping palpebral fissures, low-set ears,abnormal helix of ear, deeply grooved philtrum, short and/or webbed neck, low hairline and cervical vertebral anomalies.Patients with Noonan syndrome are known to presentwith challenging airways. Tracheal intubation can bedifficult because of airway and cervical vertebral anomaliesand bag mask ventilation may be difficult because ofasymmetrical face. We present a case of anesthetic managementfor Noonan syndrome. J Clin Exp Invest 2013;4 (2: 238-241Key words: Anesthesia, general, noonan syndrome, airwaymanagement

  18. Anesthetic management of minimally invasive intervention in children's oncohematology: preoperative patient management protocol

    Directory of Open Access Journals (Sweden)

    V. V. Shchukin

    2013-01-01

    Full Text Available Preoperative patient management protocol in the complex anesthetic support of minimally invasive interventions in pediatric oncology is described. Choice of general anesthesia method was determined by the specific clinical situation by analyzing all of the following factors: airway management, necessity and anticipated duration of unconsciousness, the need for analgesia, necessity and duration of immobilization, prevention of hypothermia, the presence and severity of disturbances in the hemostatic system, comfort for the child and his representatives (parents. Basic techniques of child preoperative examination, as well as the methodology for predicting the risk of perioperative adverse events are described.

  19. Anesthetic management of minimally invasive intervention in children's oncohematology: preoperative patient management protocol

    Directory of Open Access Journals (Sweden)

    V. V. Shchukin

    2014-07-01

    Full Text Available Preoperative patient management protocol in the complex anesthetic support of minimally invasive interventions in pediatric oncology is described. Choice of general anesthesia method was determined by the specific clinical situation by analyzing all of the following factors: airway management, necessity and anticipated duration of unconsciousness, the need for analgesia, necessity and duration of immobilization, prevention of hypothermia, the presence and severity of disturbances in the hemostatic system, comfort for the child and his representatives (parents. Basic techniques of child preoperative examination, as well as the methodology for predicting the risk of perioperative adverse events are described.

  20. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection...... and identified or characterized by gas chromatography-mass spectrometry. A total of 120 VOCs were characterized by retention index and mass spectra. Fifty-three compounds were characterized as terpenoid compounds, among which 18 could be identified. Among the VOCs were alkanes, alkenes, alcohols, esters, ketones....... The relationship between the excretion of geosmin and the production of spores was examined for one isolate. A good correlation between headspace geosmin and the number of spores was observed, suggesting that VOCs could be used to indicate the activity of these microorganisms in heterogeneous substrates....

  1. Topical anesthetic versus lidocaine infiltration in arteriovenous fistula cannulation

    Directory of Open Access Journals (Sweden)

    Anisha George

    2014-01-01

    Full Text Available Background: End stage renal disease (ESRD patients on maintenance hemodialysis undergo arterio-venous fistula (AVF cannulation prior to each hemodialysis session for blood access. Prior to cannulation lidocaine infiltration is done, which is often perceived as painful. Eutectic mixture of local anesthetic (EMLA has been found to significantly reduce pain associated with radial artery cannulation compared with lidocaine infiltration. Aims: To evaluate the efficacy of EMLA compared to infiltration of lidocaine in hemodialysis patients for AVF cannulation. Materials and Methods: A single-centre, crossover study of patients with an AVF on regular maintenance hemodialysis was performed in the dialysis unit of a tertiary care teaching hospital. The site of AVF, number of attempts for AVF cannulation and cannula insertion time were recorded. The patients were asked about the acceptability of application of the anesthetic, delay between anesthetic and cannulation and to score the pain on cannulation. Results: Fifty patients were included in the study. With the visual analog scale, pain score on infiltration was 4.8. Pain score on cannulation after topical application was 2.9 and after infiltration, 2.0. The number of attempts for cannulation and the cannula insertion time were similar. Anesthesia was more stressful in the injectable group rather than the topical group (P < 0.001. Delay between anesthetic and cannulation was unacceptable in the topical group (P < 0.001. Patient compliance was better during infiltration compared to topical (P < 0.005. Mean pain score during infiltration of anesthetic was significantly higher than cannulation pain after either anesthetic, although pain on cannulation was higher in the topical group (P < 0.001. Conclusions: EMLA offers a suitable alternative to lidocaine infiltration for patients using AVF for blood access.

  2. Detomidine reduces isoflurane anesthetic requirement (MAC) in horses.

    Science.gov (United States)

    Steffey, Eugene P; Pascoe, Peter J

    2002-10-01

    To quantitate the dose- and time-related magnitude of the anesthetic sparing effect of, and selected physiological responses to detomidine during isoflurane anesthesia in horses. Randomized cross-over study. Three, healthy, young adult horses weighing 485 ± 14 kg. Horses were anesthetized on two occasions to determine the minimum alveolar concentration (MAC) of isoflurane in O 2 and then to measure the anesthetic sparing effect (time-related MAC reduction) following IV detomidine (0.03 and 0.06 mg kg -1 ). Selected common measures of cardiopulmonary function, blood glucose and urinary output were also recorded. Isoflurane MAC was 1.44 ± 0.07% (mean ± SEM). This was reduced by 42.8 ± 5.4% and 44.8 ± 3.0% at 83 ± 23 and 125 ± 36 minutes, respectively, following 0.03 and 0.06 mg kg -1 , detomidine. The MAC reduction was detomidine dose- and time-dependent. There was a tendency for mild cardiovascular and respiratory depression, especially following the higher detomidine dose. Detomidine increased both blood glucose and urine flow; the magnitude of these changes was time- and dose-dependent CONCLUSIONS: Detomidine reduces anesthetic requirement for isoflurane and increases blood glucose concentration and urine flow in horses. These changes were dose- and time-related. The results imply potent anesthetic sparing actions by detomidine. The detomidine-related increased urine flow should be considered in designing anesthetic protocols for individual horses. Copyright © 2002 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

  3. Minimum Tracking Error Volatility

    OpenAIRE

    Luca RICCETTI

    2010-01-01

    Investors assign part of their funds to asset managers that are given the task of beating a benchmark. The risk management department usually imposes a maximum value of the tracking error volatility (TEV) in order to keep the risk of the portfolio near to that of the selected benchmark. However, risk management does not establish a rule on TEV which enables us to understand whether the asset manager is really active or not and, in practice, asset managers sometimes follow passively the corres...

  4. Recovering volatile liquids

    Energy Technology Data Exchange (ETDEWEB)

    Bregeat, J H

    1925-07-30

    The products of hydrogenation of alicyclic compounds, such as terpenes, for example, pinene or oil of turpentine, are used as washing liquids for absorbing vapours of volatile liquids from gases, such as natural gases from petroliferous regions, gases from the distillation of coal, lignite, schist, peat, etc. or from the cracking of heavy oils. Other liquids such as tar oils vaseline oils, cresols, etc. may be added.

  5. Understanding Interest Rate Volatility

    OpenAIRE

    Volker, Desi

    2016-01-01

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochast...

  6. MACROECONOMIC VARIABLES AND STOCK PRICE VOLATILITY IN NIGERIA

    Directory of Open Access Journals (Sweden)

    OSAZEE GODWIN OMOROKUNWA

    2014-10-01

    Full Text Available The purpose of this paper is to examine the relationship between stock price volatility and few macroeconomic variables such as inflation, exchange rate, GDP and interest rate. Annual time series data ranging from 1980 to 2011 was used for this study. The generalized autoregressive conditional heteroskedasticity (GARCH model was used in the empirical analysis. The findings of the study showed that stock prices in Nigeria are volatile. And that past information in the market have effect on stock price volatility in Nigeria. In addition, the study showed that interest rate and exchange have a weak effect on stock price volatility while inflation is the main determinant of stock price volatility in Nigeria. The authors recommend that inflation should be targeted as the main monetary policy aimed at directing the stock market.

  7. Life cycle greenhouse gas emissions of anesthetic drugs.

    Science.gov (United States)

    Sherman, Jodi; Le, Cathy; Lamers, Vanessa; Eckelman, Matthew

    2012-05-01

    Anesthesiologists must consider the entire life cycle of drugs in order to include environmental impacts into clinical decisions. In the present study we used life cycle assessment to examine the climate change impacts of 5 anesthetic drugs: sevoflurane, desflurane, isoflurane, nitrous oxide, and propofol. A full cradle-to-grave approach was used, encompassing resource extraction, drug manufacturing, transport to health care facilities, drug delivery to the patient, and disposal or emission to the environment. At each stage of the life cycle, energy, material inputs, and emissions were considered, as well as use-specific impacts of each drug. The 4 inhalation anesthetics are greenhouse gases (GHGs), and so life cycle GHG emissions include waste anesthetic gases vented to the atmosphere and emissions (largely carbon dioxide) that arise from other life cycle stages. Desflurane accounts for the largest life cycle GHG impact among the anesthetic drugs considered here: 15 times that of isoflurane and 20 times that of sevoflurane on a per MAC-hour basis when administered in an O(2)/air admixture. GHG emissions increase significantly for all drugs when administered in an N(2)O/O(2) admixture. For all of the inhalation anesthetics, GHG impacts are dominated by uncontrolled emissions of waste anesthetic gases. GHG impacts of propofol are comparatively quite small, nearly 4 orders of magnitude lower than those of desflurane or nitrous oxide. Unlike the inhaled drugs, the GHG impacts of propofol primarily stem from the electricity required for the syringe pump and not from drug production or direct release to the environment. Our results reiterate previous published data on the GHG effects of these inhaled drugs, while providing a life cycle context. There are several practical environmental impact mitigation strategies. Desflurane and nitrous oxide should be restricted to cases where they may reduce morbidity and mortality over alternative drugs. Clinicians should avoid

  8. The memory of volatility

    Directory of Open Access Journals (Sweden)

    Kai R. Wenger

    2018-03-01

    Full Text Available The focus of the volatility literature on forecasting and the predominance of theconceptually simpler HAR model over long memory stochastic volatility models has led to the factthat the actual degree of memory estimates has rarely been considered. Estimates in the literaturerange roughly between 0.4 and 0.6 - that is from the higher stationary to the lower non-stationaryregion. This difference, however, has important practical implications - such as the existence or nonexistenceof the fourth moment of the return distribution. Inference on the memory order is complicatedby the presence of measurement error in realized volatility and the potential of spurious long memory.In this paper we provide a comprehensive analysis of the memory in variances of international stockindices and exchange rates. On the one hand, we find that the variance of exchange rates is subject tospurious long memory and the true memory parameter is in the higher stationary range. Stock indexvariances, on the other hand, are free of low frequency contaminations and the memory is in the lowernon-stationary range. These results are obtained using state of the art local Whittle methods that allowconsistent estimation in presence of perturbations or low frequency contaminations.

  9. Validation of the bispectral index as an indicator of anesthetic depth in Thoroughbred horses anesthetized with sevoflurane.

    Science.gov (United States)

    Tokushige, Hirotaka; Kakizaki, Masashi; Ode, Hirotaka; Okano, Atsushi; Okada, Jun; Kuroda, Taisuke; Wakuno, Ai; Ohta, Minoru

    2016-01-01

    To evaluate the bispectral index (BIS) as an indicator of anesthetic depth in Thoroughbred horses, BIS values were measured at multiple stages of sevoflurane anesthesia in five horses anesthetized with guaifenesin and thiopental following premedication with xylazine. There was no significant difference between the BIS values recorded at end-tidal sevoflurane concentrations of 2.8% (median 60 ranging from 47 to 68) and 3.5% (median 71 ranging from 49 to 82) in anesthetized horses. These BIS values during anesthesia were significantly lower (Phorses (median 98 ranging from 98 to 98) or sedated horses (median 92 ranging from 80 to 93). During the recovery phase, the BIS values gradually increased over time but did not significantly increase until the horses showed movement. In conclusion, the BIS value could be useful as an indicator of awakening during the recovery period in horses, as previous reported.

  10. Anesthetic and Obstetric Management of Syringomyelia During Labor and Delivery: A Case Series and Systematic Review.

    Science.gov (United States)

    Garvey, Gráinne Patricia; Wasade, Vibhangini S; Murphy, Kellie E; Balki, Mrinalini

    2017-09-01

    Syringomyelia is a rare, slowly progressive neurological condition characterized by the presence of a syrinx within the spinal cord. Consensus regarding the safest mode of delivery and anesthetic management in patients with syringomyelia remains controversial and presents management dilemmas. This study reviews the cases of syringomyelia at our institution and provides a systematic review of the literature to guide decisions regarding labor and delivery management. A retrospective review of cases at our hospital from 2002 to 2014 and a systematic review of the literature from 1946 to 2014 were undertaken. Hospital records and electronic databases were interrogated using International Classification of Diseases, 10th Revision codes and the keywords "syringomyelia," "syringobulbia," and "pregnancy." Data regarding demographics, diagnosis, radiology reports, neurological symptoms, mode of delivery, anesthetic management, and maternal-fetal outcomes were collected. We collected and analyzed data on a total of 43 pregnancies in 39 patients. The most common location for syrinx was in the cervicothoracic region (41.9%). The large majority of patients (n = 34; 87%) demonstrated signs and symptoms associated with syringomyelia before delivery. Syringomyelia associated with Arnold Chiari malformation was documented in 49% (n = 21) cases. General anesthesia was the most commonly used (n = 21/30, 70%) anesthetic technique for cesarean delivery. The majority (n = 9/13, 69%) of patients had an epidural sited for labor analgesia. There were no maternal or neonatal complications associated with neuraxial anesthesia; however, 3 cases (14%) raised concerns regarding general anesthesia including difficult intubation, transient worsening of neurological symptoms postpartum, and prolonged muscle paralysis after atracurium. Despite concerns regarding aggravation of the syrinx with vaginal delivery, this mode of delivery has never caused any documented long-term worsening of neurological

  11. Can children undergoing ophthalmologic examinations under anesthesia be safely anesthetized without using an IV line?

    Directory of Open Access Journals (Sweden)

    Vigoda M

    2011-04-01

    Full Text Available Michael M Vigoda, Azeema Latiff, Timothy G Murray, Jacqueline L Tutiven, Audina M Berrocal, Steven GayerBascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USAPurpose: To document that with proper patient and procedure selection, children undergoing general inhalational anesthesia for ophthalmologic exams (with or without photos, ultrasound, laser treatment, peri-ocular injection of chemotherapy, suture removal, and/or replacement of ocular prosthesis can be safely anesthetized without the use of an intravenous (IV line. Children are rarely anesthetized without IV access placement. We performed a retrospective study to determine our incidence of IV access placement during examinations under anesthesia (EUA and the incidence of adverse events that required intraoperative IV access placement.Methods: Data collected from our operating room (OR information system includes but is not limited to diagnosis, anesthesiologist, surgeon, and location of IV catheter (if applicable, patient’s date of birth, actual procedure, and anesthesia/procedure times. We reviewed the OR and anesthetic records of children (>1 month and <10 years who underwent EUAs between January 1, 2003 and May 31, 2009. We determined the percentage of children who were anesthetized without IV access placement, as well as the incidence of any adverse events that required IV access placement, intraoperatively.Results: We analyzed data from 3196 procedures performed during a 77-month period. Patients’ ages ranged from 1 month to 9 years. Overall, 92% of procedures were performed without IV access placement. Procedure duration ranged from 1–39 minutes. Reasons for IV access placement included parental preference for antinausea medication and/or attending preference for IV access placement. No child who underwent anesthesia without an IV line had an intraoperative adverse event requiring insertion of an IV line.Conclusion: Our data suggest that for

  12. Effects of constant rate infusion of anesthetic or analgesic drugs on general anesthesia with isoflurane: A retrospective study in 200 dogs Efeitos da infusão intravenosa contínua de fármacos anestésicos ou analgésicos sobre a anestesia geral com isoflurano: Estudo retrospectivo em 200 cães

    Directory of Open Access Journals (Sweden)

    Sofia de Amorim Cerejo

    2013-09-01

    Full Text Available Constant rate infusion (CRI shows several advantages in balanced anesthesia, such as reduction of requirement for inhaled anesthetics and control of pain. The most commonly used drugs in these protocols are local anesthetics, dissociative, and opioids, which may be administered alone or in combinations. We evaluated the records of 200 dogs that underwent various surgical procedures with anesthetic or analgesic CRI in the perioperative period during 2011 and 2012 at the Veterinary Hospital of Franca University (Unifran, and identified possible complications during the transoperative period. Records evaluated included clinical state, laboratory tests, drugs used in premedication and induction, and CRI protocol. Acepromazine and morphine were the main drugs used in premedication. Propofol was used to induce anesthesia alone or in combination with other agents. We evaluated records of the 25 different CRI protocols. Fentanyl was the main drug employed in CRI, either alone or in combination. There were 128 episodes of anesthetic complications during CRI;the most common were hypotension, hypertension, and tachycardia, which occurred in 43 (32%, 35 (26.3%, and 19 (14.2% dogs, respectively. Cardiac arrhythmia was reported in only 4 dogs. Signs of respiratory depression were present in dogs treated with 6 different CRI protocols. The consumption of isoflurane (vol % reduced between 15.7% and 21.05% after 30minutes of the CRI in the fentanyl and fentanyl–lidocaine–ketamine CRI groups (pO uso de técnicas de infusão contínua (IC possui inúmeras vantagens na anestesia balanceada, como a redução do requerimento de anestésicos inalatórios e controle da dor. Os fármacos mais comumente utilizados nestes protocolos são os anestésicos locais, dissociativos e opioides, que podem ser administrados isoladamente ou em associações. Foram avaliados os prontuários de 200 cães que foram submetidos a diversos procedimentos cirúrgicos com IC de anest

  13. From micro- to nanostructured implantable device for local anesthetic delivery

    Directory of Open Access Journals (Sweden)

    Zorzetto L

    2016-06-01

    Full Text Available Laura Zorzetto,1 Paola Brambilla,1 Elena Marcello,1 Nora Bloise,2 Manuela De Gregori,3 Lorenzo Cobianchi,4,5 Andrea Peloso,4,5 Massimo Allegri,6 Livia Visai,2,7 Paola Petrini1 1Department of Chemistry, Materials and Chemical Engineering ‘G. Natta’, Politecnico di Milano, Milan, 2Department of Molecular Medicine, Centre for Health Technologies (CHT, INSTM UdR of Pavia, University of Pavia, 3Pain Therapy Service, IRCCS Foundation Policlinico San Matteo Pavia, Pavia, 4General Surgery Department, IRCCS Foundation Policlinico San Matteo, Pavia, 5Departments of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, 6Department of Surgical Sciences, University of Parma, Parma, 7Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Lab of Nanotechnology, Pavia, Italy Abstract: Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured

  14. Radiographic assessment of laryngeal reflexes in ketamine-anesthetized cats

    International Nuclear Information System (INIS)

    Robinson, E.P.; Johnston, G.R.

    1986-01-01

    The competence of the laryngeal closure reflexes of cats anesthetized with ketamine was assessed. Radiographic evaluations of the respiratory and digestive tracts were made after colloidal barium suspension was instilled into the pharynges of conscious and ketamine-anesthetized cats. There was a significant ketamine dose-related response of spread of contrast medium into the supraglottic laryngeal area and into the stomach 2 minutes after contrast medium was instilled into the pharynx (P less than 0.05). Cats did not aspirate contrast medium into the lower respiratory tract. Three ketamine-anesthetized cats aspirated contrast medium into the subglottic area of the larynx, and 2 of these cats also aspirated the material into the cranial part of the trachea. This material was coughed up and swallowed within 5 minutes. Transit time of contrast medium into the stomach seemed to be increased in 11 of the 15 cats given the larger dosages of ketamine (24, 36, 48 mg/kg of body weight), compared with that in conscious cats and those given ketamine at 12 mg/kg. Competent laryngeal protective reflexes in cats can be maintained with ketamine anesthesia. Contrast radiography could be used as a diagnostic aid in ketamine-anesthetized cats suspected of laryngeal reflex abnormalities

  15. Anesthetic management of cardiac patient for cataract surgery

    International Nuclear Information System (INIS)

    Farooq, F.B.; Sultan, S.T.

    2003-01-01

    We are reporting the successful anesthetic management of a 6 years old child, who had cyanotic congenital heart disease and underwent an operation for cataract extraction. Ketamine was used for the induction and maintenance of anesthesia. Ventilation was assisted manually by using laryngeal masks. (author)

  16. 21 CFR 346.10 - Local anesthetic active ingredients.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Local anesthetic active ingredients. 346.10 Section 346.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ingredient: (a) Benzocaine 5 to 20 percent. (b) Benzyl alcohol 1 to 4 percent. (c) Dibucaine 0.25 to 1...

  17. Trigeminal nerve injury associated with injection of local anesthetics

    DEFF Research Database (Denmark)

    Hillerup, Søren; Jensen, Rigmor H.; Ersbøll, Bjarne Kjær

    2011-01-01

    Background. The authors used comprehensive national registry and clinical data to conduct a study of adverse drug reactions (ADRs), in particular neurosensory disturbance (NSD), associated with local anesthetics used in dentistry. Methods. The study included data sets of annual sales of local...

  18. Anesthetic keratopathy presenting as bilateral Mooren-like ulcers

    Directory of Open Access Journals (Sweden)

    Khakshoor H

    2012-10-01

    Full Text Available Hamid Khakshoor,1 Majid Moshirfar,2 Rachel G Simpson,3 Hamid Gharaee,1 Amir H Vejdani,1 Steven M Christiansen,2 Jason N Edmonds,2 Nicholas L Behunin21Mashhad University of Medical Sciences, Department of Ophthalmology, Mashad, Iran; 2John A Moran Eye Center, University of Utah, Salt Lake City, UT, 3The University of Arizona College of Medicine, Phoenix, AZ, USAAbstract: This observational case report describes the development of bilateral Mooren-like ulcers in a patient with anesthetic keratopathy. A 42-year-old man with a recent history of minor eye trauma and pain self-treated with tetracaine eye drops presented with complaints of acutely worsening vision and severe pain bilaterally. His visual acuity at presentation was limited to hand motion. Slit-lamp examination revealed bilateral epithelial defects at the center of the cornea, and an area of stromal infiltration and thinning with an undermining leading edge resembling a Mooren's ulcer in both eyes. Corneal haze and hypopyon were visible. Anesthetic use was halted immediately and the patient was started on prednisolone and mycophenolate mofetil (Cellcept®, after which visual acuity gradually improved and pain decreased. Despite improvement of symptoms, residual epithelial defects remained, and the patient was ultimately treated with keratoplasty for recovery of vision. We suggest that anesthetic keratopathy should be included in the differential diagnosis for any patient presenting with ring-shaped stromal infiltrates or nonhealing epithelial defects.Keywords: anesthetic abuse, corneal damage, corneal ulceration

  19. A noninvasive monitoring device for anesthetics in fish

    DEFF Research Database (Denmark)

    Power, Deborah M.; Fuentes, Juan; Harrison, Adrian Paul

    2010-01-01

    A noninvasive device capable of recording both gill and lateral fin movements was assembled and used to analyze initial and post-treatment activity frequency (Hz) in fish exposed to anesthetics. Exposure of platy fish (Xiphosphorus maculatus) to saponins from quillaja bark (0.185 mM and 0.555 m...

  20. Local anesthetics: New insights into risks and benefits

    NARCIS (Netherlands)

    Lirk, P.

    2014-01-01

    Conventional local anesthetics in contemporary use block the voltage-gated sodium channel by binding to a specific site on the inner facet of the channel pore. Only little fractions of local anaesthetic are thought to participate in nerve blockade, the rest is absorbed into surrounding tissues or

  1. Hydrogen-1 NMR relaxation time studies in membrane: anesthetic systems

    International Nuclear Information System (INIS)

    Pinto, L.M.A.; Fraceto, L.; Paula, E. de; Franzoni, L.; Spisni, A.

    1997-01-01

    The study of local anesthetics'(LA) interaction with model phospholipid membranes is justified by the direct correlation between anesthetic's hydrophobicity and its potency/toxicity. By the same reason, uncharged LA species seems to play a crucial role in anesthesia. Most clinically used LA are small amphiphilics with a protonated amine group (pKa around 8). Although both charged (protonated) and uncharged forms can coexist at physiological pH, it has been shown (Lee, Biochim. Biophys. Acta 514:95, 1978; Screier et al. Biochim. Biophys. Acta 769:231, 1984) that the real anesthetic pka can be down-shifted, due to differential partition into membranes, increasing the ratio of uncharged species at pH 7.4. We have measured 1 H-NMR longitudinal relaxation times (T 1 ) for phospholipid and three local anesthetics (tetracaine, lidocaine, benzocaine), in sonicated vesicles at a 3:1 molar ratio. All the LA protons have shown smaller T 1 in this system than in isotropic phases, reflecting LA immobilization caused by insertion in the membrane. T 1 values for the lipid protons in the presence of LA were analyzed, in an attempt to identify specific LA:lipid contact regions. (author)

  2. The electoral volatility in Serbia: Comparison and explanation

    Directory of Open Access Journals (Sweden)

    Antonić Slobodan

    2005-01-01

    Full Text Available In the first part of this article the electoral volatility in Serbia is compared to those in other countries. The Pedersen’s Index for Serbia from 1990 to 2003 is 19.6, which means there is high electoral volatility. However, compared to other countries in transition, the volatility in Serbia turns out to be average. Therefore, I conclude that the causes of high volatility in Serbia could not be specific, but similar to the reasons in other post-communist countries. In the second part, I analyze the general reasons for the increased volatility. They are: the large number of parties participating in political life, and insufficient time, passed since the restoration of multiparty elections, for the voters to become more seriously tied to the parties, or for the parties to become socially anchored. In the third part, I analyze the particular causes of the increased volatility that are specific, first of all, for Serbia and other post-communist societies. They are: the fast change of social structure, which leads to a general feeling of social and personal insecurity, as well as the widespread dissatisfaction with the gap between the increase of social inequality and the number of social winners, which increases the frequency of protest voting. At the end, I conclude that, in time, some of these factors would probably lose their significance, so the volatility in Serbia would decrease. However, a noticeable decrease could hardly be expected during the next ten years at least.

  3. Monitoring volatile anaesthetic agents

    International Nuclear Information System (INIS)

    Russell, W.J.

    2000-01-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  4. Monitoring volatile anaesthetic agents

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W J [Royal Adelaide Hospital, SA (Australia). Department of Anaesthesia and Intensive Care

    2000-12-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  5. The Short-Time Behaviour of VIX Implied Volatilities in a Multifactor Stochastic Volatility Framework

    DEFF Research Database (Denmark)

    Barletta, Andrea; Nicolato, Elisa; Pagliarani, Stefano

    error bounds for VIX futures, options and implied volatilities. In particular, we derive exact asymptotic results for VIX implied volatilities, and their sensitivities, in the joint limit of short time-to-maturity and small log-moneyness. The obtained expansions are explicit, based on elementary...... approximations of equity (SPX) options. However, the generalizations needed to cover the case of VIX options are by no means straightforward as the dynamics of the underlying VIX futures are not explicitly known. To illustrate the accuracy of our technique, we provide numerical implementations for a selection...... functions and they neatly uncover how the VIX skew depends on the specific choice of the volatility and the vol-of-vol processes. Our results are based on perturbation techniques applied to the infinitesimal generator of the underlying process. This methodology has been previously adopted to derive...

  6. PERUBAHAN KOMPONEN VOLATIL SELAMA FERMENTASI KECAP [Change Volatile Components During Soy Sauce Fermentation

    Directory of Open Access Journals (Sweden)

    Anton Apriyantono1

    2004-08-01

    Full Text Available A study has been conducted to investigate changes of volatile components during soy sauce fermentation. During the fermentation, many volatile components produced may contribute to soy sauce flavor. THe volatile identified by GC-MS werw classified into hydrocarbon (15, alcohol (15, aldehyde (14, ester (14, ketone (9, benzene derivative (11, fatty acid (9, furan (5, terpenoid (18, pyrazine (3, thiazole (1, pyridine (1 and sulfur containing compound (2.Concentration of compounds found in almost all fermentation steps, such as hexanal and benzaldehyde did. These compounds may be derived from raw soybean, since they were all present in raw soybean and their concentration did not change during fermentation. Concentration of palmitic acid and benzeneacetaldehyde, in general, increased during all fermentation steps. They are probably derived from lipid degradation or microorganism activities. Concentrations of some fatty acids, esters and hydrocarbons, such as linoleic acid, methyl palmitate and heptadecane increased during salt fermentation only. Concentration of some other compounds, such as 2,4 decadienal decreased or undetected during fermentation.The absence of some volatile compounds, e.g. (E-nerolidol and (E,E-famesol in boiled soybean which were previously present in raw soybean may be due to evaporation of these compounds during boiling. Some volatile compounds such as, methyl heptadecanoate and few aromatic alcohols are likely derived from Aspergillus sojae, since these compounds were identified only in 0 day koji

  7. Ambient Volatility of Triethyl Phosphate

    Science.gov (United States)

    2017-08-01

    of materials is predictable using Raoult’s law. This report details the measurement of the effect of water vapor partial pressure on the volatility...empirical correlation taking into account nonideal behavior was developed to enable estimation of TEPO volatility at any combination of ambient...of the second component is expected to be one-half as much as in the absence of water vapor. Similarly, the measured volatility of the second

  8. On changes of measure in stochastic volatility models

    Directory of Open Access Journals (Sweden)

    Bernard Wong

    2006-01-01

    models. This had led many researchers to “assume the condition away,” even though the condition is not innocuous, and nonsensical results can occur if it is in fact not satisfied. We provide an applicable theorem to check the conditions for a general class of Markovian stochastic volatility models. As an example we will also provide a detailed analysis of the Stein and Stein and Heston stochastic volatility models.

  9. An Alternative Estimation of Market Volatility based on Fuzzy Transform

    OpenAIRE

    Troiano, Luigi; Villa, Elena Mejuto; Kriplani, Pravesh

    2017-01-01

    Realization of uncertainty of prices is captured by volatility, that is the tendency of prices to vary along a period of time. This is generally measured as standard deviation of daily returns. In this paper we propose and investigate the application of fuzzy transform and its inverse as an alternative measure of volatility. The measure obtained is compatible with the definition of risk measure given by Luce. A comparison with standard definition is performed by considering the NIFTY 50 stock...

  10. Disruption of the circadian period of body temperature by the anesthetic propofol.

    Science.gov (United States)

    Touitou, Yvan; Mauvieux, Benoit; Reinberg, Alain; Dispersyn, Garance

    2016-01-01

    The circadian time structure of an organism can be desynchronized in a large number of instances, including the intake of specific drugs. We have previously found that propofol, which is a general anesthetic, induces a desynchronization of the circadian time structure in rats, with a 60-80 min significant phase advance of body temperature circadian rhythm. We thus deemed it worthwhile to examine whether this phase shift of body temperature was related to a modification of the circadian period Tau. Propofol was administered at three different Zeitgeber Times (ZTs): ZT6 (middle of the rest period), ZT10 (2 h prior to the beginning of activity period), ZT16 (4 h after the beginning of the activity period), with ZT0 being the beginning of the rest period (light onset) and ZT12 being the beginning of the activity period (light offset). Control rats (n = 20) were injected at the same ZTs with 10% intralipid, which is a control lipidic solution. Whereas no modification of the circadian period of body temperature was observed in the control rats, propofol administration resulted in a significant shortening of the period by 96 and 180 min at ZT6 and ZT10, respectively. By contrast, the period was significantly lengthened by 90 min at ZT16. We also found differences in the time it took for the rats to readjust their body temperature to the original 24-h rhythm. At ZT16, the speed of readjustment was more rapid than at the two other ZTs that we investigated. This study hence shows (i) the disruptive effects of the anesthetic propofol on the body temperature circadian rhythm, and it points out that (ii) the period Tau for body temperature responds to this anesthetic drug according to a Tau-response curve. By sustaining postoperative sleep-wake disorders, the disruptive effects of propofol on circadian time structure might have important implications for the use of this drug in humans.

  11. Volatiles from solids

    Energy Technology Data Exchange (ETDEWEB)

    Loughrey, C T

    1939-08-24

    To remove volatiles from solids, such as oil shale, gases, and/or vapours are passed through a mass of the materials, the vapours and gases separated, and the vapours condensed. The volatile-containing solid materials are fed to a retort, and a shaft is driven to rotate an impeller so as to displace the liquid and create a vortex tube, which draws in gas from the atmosphere through an intake, twyer, interstices in the material in the retort, a conduit, chamber, tubes, another chamber and cylinder. This gas is carried outwardly and upwardly by the vortices in the liquid and is carried to discharge through three conduits. The vapours entrained by the gas are part condensed in the liquid and the remainder directed to a condenser. Steam may be delivered to the twyer through a nozzle of a pipe, with or without air, and combustible hydrocarbon fuel may be fed through the burner nozzle or solid fuel may be directed from feeder and combusted in the twyer.

  12. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  13. Volatility Mean Reversion and the Market Price of Volatility Risk

    NARCIS (Netherlands)

    Boswijk, H.P.

    2001-01-01

    This paper analyzes sources of derivative pricing errors in a stochastic volatility model estimated on stock return data. It is shown that such pricing errors may reflect the existence of a market price of volatility risk, but also may be caused by estimation errors due to a slow mean reversion in

  14. Application of unfolding transformation in the random matrix theory to analyze in vivo neuronal spike firing during awake and anesthetized conditions

    Directory of Open Access Journals (Sweden)

    Risako Kato

    2018-03-01

    Full Text Available General anesthetics decrease the frequency and density of spike firing. This effect makes it difficult to detect spike regularity. To overcome this problem, we developed a method utilizing the unfolding transformation which analyzes the energy level statistics in the random matrix theory. We regarded the energy axis as time axis of neuron spike and analyzed the time series of cortical neural firing in vivo. Unfolding transformation detected regularities of neural firing while changes in firing densities were associated with pentobarbital. We found that unfolding transformation enables us to compare firing regularity between awake and anesthetic conditions on a universal scale. Keywords: Unfolding transformation, Spike-timing, Regularity

  15. Propofol (2,6-diisopropylphenol) is an applicable immersion anesthetic in the axolotl with potential uses in hemodynamic and neurophysiological experiments

    DEFF Research Database (Denmark)

    Thygesen, Mathias; Rasmussen, Mikkel Mylius; Madsen, Jesper Guldsmed

    2017-01-01

    The Mexican axolotl (Ambystoma mexicanum) is an important model species in regenerative biology. Traditionally, axolotls are anesthetized using benzocaine or MS-222, both of which act to inhibit voltage gated sodium channels thereby preventing action potential propagation. In some...... neurophysiological experiments this is not desirable; therefore we tested propofol as an alternative anesthetic in the axolotl. We evaluated benzocaine, MS-222, and propofol's cardiovascular effects, effects on action potential propagation in the spinal cord, and gross limb regenerative effects. We found...... that propofol is applicable as a general anesthetic in the axolotl allowing for neurophysiological experiments and yielding a stable anesthesia with significantly less cardiovascular effect than both benzocaine and MS-222. Additionally, propofol did not affect gross limb regeneration. In conclusion we suggest...

  16. Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

    Science.gov (United States)

    Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

    2011-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

  17. Middle cerebral artery blood flow velocity during beach chair position for shoulder surgery under general anesthesia.

    Science.gov (United States)

    Hanouz, Jean-Luc; Fiant, Anne-Lise; Gérard, Jean-Louis

    2016-09-01

    The goal of the present study was to examine changes of middle cerebral artery (VMCA) blood flow velocity in patients scheduled for shoulder surgery in beach chair position. Prospective observational study. Operating room, shoulder surgery. Fifty-three consecutive patients scheduled for shoulder surgery in beach chair position. Transcranial Doppler performed after induction of general anesthesia (baseline), after beach chair positioning (BC1), during surgery 20minutes (BC2), and after back to supine position before stopping anesthesia (supine). Mean arterial pressure (MAP), end-tidal CO2, and volatile anesthetic concentration and VMCA were recorded at baseline, BC1, BC2, and supine. Postoperative neurologic complications were searched. Beach chair position induced decrease in MAP (baseline: 73±10mm Hg vs lower MAP recorded: 61±10mm Hg; P<.0001) requiring vasopressors and fluid challenge in 44 patients (83%). There was a significant decrease in VMCA after beach chair positioning (BC1: 33±10cm/s vs baseline: 39±14cm/s; P=.001). The VMCA at baseline (39±2cm/s), BC2 (35±14cm/s), and supine (39±14cm/s) were not different. The minimal alveolar concentration of volatile anesthetics, end-tidal CO2, SpO2, and MAP were not different at baseline, BC1, BC2, and supine. Beach chair position resulted in transient decrease in MAP requiring fluid challenge and vasopressors and a moderate decrease in VMCA. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A practical and convenient method for the synthesis of anesthetic drug thiopental: using thiourea and sodium ethoxide

    Directory of Open Access Journals (Sweden)

    Hojat Narimani

    2014-02-01

    Full Text Available A general, simple, practical and convenient method has been described for the synthesis of anesthetic drug thiopental using thiourea in the presence of sodium ethoxide. Anesthetic drug of thiopental was prepared in two stages; during the first stage, the alkylation of mthyl cyanoacetate was performed which was then to be followed by cyclization. Alkylation of methyl cyanoacetate which was performed by 2-iodopentane in the presence of sodium ethoxide reacts with thiourea and then the process was followed by thiopental prepration in excellent yield. Some important aspects of this methodology are the high reactivity of the substrates, avoidance of the use of hazardous solvents, simplicity of the product separation, low cost of the substrates and reagents and high yield of product. This is a applicable and efficient method for the preparation of thiopental anesthesia in high yield and in an appropriate time.

  19. Multifractal analysis of implied volatility in index options

    Science.gov (United States)

    Oh, GabJin

    2014-06-01

    In this paper, we analyze the statistical and the non-linear properties of the log-variations in implied volatility for the CAC40, DAX and S& P500 daily index options. The price of an index option is generally represented by its implied volatility surface, including its smile and skew properties. We utilize a Lévy process model as the underlying asset to deepen our understanding of the intrinsic property of the implied volatility in the index options and estimate the implied volatility surface. We find that the options pricing models with the exponential Lévy model can reproduce the smile or sneer features of the implied volatility that are observed in real options markets. We study the variation in the implied volatility for at-the-money index call and put options, and we find that the distribution function follows a power-law distribution with an exponent of 3.5 ≤ γ ≤ 4.5. Especially, the variation in the implied volatility exhibits multifractal spectral characteristics, and the global financial crisis has influenced the complexity of the option markets.

  20. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    We examine the effect of political 'institutions' on economic growth volatility, using data from more than 100 countries over the period 1960 to 2005, taking into account various control variables as suggested in previous studies. Our indicator of volatility is the relative standard deviation of the

  1. Fundamental volatility is regime specific

    NARCIS (Netherlands)

    Arnold, I.J.M.; MacDonald, R.; Vries, de C.G.

    2006-01-01

    A widely held notion holds that freely floating exchange rates are excessively volatile when judged against fundamentals and when moving from fixed to floating exchange rates. We re-examine the data and conclude that the disparity between the fundamentals and exchange rate volatility is more

  2. Spectral entropy in monitoring anesthetic depth.

    Science.gov (United States)

    Escontrela Rodríguez, B; Gago Martínez, A; Merino Julián, I; Martínez Ruiz, A

    2016-10-01

    Monitoring the brain response to hypnotics in general anesthesia, with the nociceptive and hemodynamic stimulus interaction, has been a subject of intense investigation for many years. Nowadays, monitors of depth of anesthesia are based in processed electroencephalogram by different algorithms, some of them unknown, to obtain a simplified numeric parameter approximate to brain activity state in each moment. In this review we evaluate if spectral entropy suitably reflects the brain electric behavior in response to hypnotics and the different intensity nociceptive stimulus effect during a surgical procedure. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Volatile organic compounds

    International Nuclear Information System (INIS)

    Silseth, May Liss

    1998-01-01

    The goal is: Not more emission of volatile organic compounds (VOCs) than necessary. The items discussed in this presentation are the VOCs, how to calculate emission of VOCs, how to reduce or avoid them, and different recovery processes. The largest source of Norwegian emissions of non methane VOCs (NMVOCs) is offshore loading of raw petroleum. Emissions of VOCs should be reduced mainly for two reasons: (1) on sunny days NMVOCs may react with NOx to form ozon and smog close to the surface, (2) ozone and smog close to the surface may be harmful to plants and animals, and they are hazardous to human health. As for the calculation of VOC emissions, the VOCON project will release the calculation program HCGASS in 1999. This project is a cooperative project headed by SINTEF/Marintek

  4. Governmentally amplified output volatility

    Science.gov (United States)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  5. Emerging non-volatile memories

    CERN Document Server

    Hong, Seungbum; Wouters, Dirk

    2014-01-01

    This book is an introduction to the fundamentals of emerging non-volatile memories and provides an overview of future trends in the field. Readers will find coverage of seven important memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), Multiferroic RAM (MFRAM), Phase-Change Memories (PCM), Oxide-based Resistive RAM (RRAM), Probe Storage, and Polymer Memories. Chapters are structured to reflect diffusions and clashes between different topics. Emerging Non-Volatile Memories is an ideal book for graduate students, faculty, and professionals working in the area of non-volatile memory. This book also: Covers key memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), and Multiferroic RAM (MFRAM), among others. Provides an overview of non-volatile memory fundamentals. Broadens readers' understanding of future trends in non-volatile memories.

  6. Recent developments in volatility modeling and applications

    Directory of Open Access Journals (Sweden)

    A. Thavaneswaran

    2006-01-01

    Full Text Available In financial modeling, it has been constantly pointed out that volatility clustering and conditional nonnormality induced leptokurtosis observed in high frequency data. Financial time series data are not adequately modeled by normal distribution, and empirical evidence on the non-normality assumption is well documented in the financial literature (details are illustrated by Engle (1982 and Bollerslev (1986. An ARMA representation has been used by Thavaneswaran et al., in 2005, to derive the kurtosis of the various class of GARCH models such as power GARCH, non-Gaussian GARCH, nonstationary and random coefficient GARCH. Several empirical studies have shown that mixture distributions are more likely to capture heteroskedasticity observed in high frequency data than normal distribution. In this paper, some results on moment properties are generalized to stationary ARMA process with GARCH errors. Application to volatility forecasts and option pricing are also discussed in some detail.

  7. Nonparametric methods for volatility density estimation

    NARCIS (Netherlands)

    Es, van Bert; Spreij, P.J.C.; Zanten, van J.H.

    2009-01-01

    Stochastic volatility modelling of financial processes has become increasingly popular. The proposed models usually contain a stationary volatility process. We will motivate and review several nonparametric methods for estimation of the density of the volatility process. Both models based on

  8. Anesthetic considerations in the patients of chronic obstructive pulmonary disease undergoing laparoscopic surgeries.

    Science.gov (United States)

    Khetarpal, Ranjana; Bali, Kusum; Chatrath, Veena; Bansal, Divya

    2016-01-01

    The aim of this study was to review the various anesthetic options which can be considered for laparoscopic surgeries in the patients with the chronic obstructive pulmonary disease. The literature search was performed in the Google, PubMed, and Medscape using key words "analgesia, anesthesia, general, laparoscopy, lung diseases, obstructive." More than thirty-five free full articles and books published from the year 1994 to 2014 were retrieved and studied. Retrospective data observed from various studies and case reports showed regional anesthesia (RA) to be valid and safer option in the patients who are not good candidates of general anesthesia like patients having obstructive pulmonary diseases. It showed better postoperative patient outcome with respect to safety, efficacy, postoperative pulmonary complications, and analgesia. So depending upon disease severity RA in various forms such as spinal anesthesia, paravertebral block, continuous epidural anesthesia, combined spinal epidural anesthesia (CSEA), and CSEA with bi-level positive airway pressure should be considered.

  9. Dissociative anesthetic combination reduces intraocular pressure (IOP in rabbits

    Directory of Open Access Journals (Sweden)

    Ewaldo de Mattos-Junior

    2014-02-01

    Full Text Available The aim of this study was evaluate the effects of three anesthetic combinations, ketamine-midazolam, ketamine-xylazine and tiletamine-zolazepam, on IOP in rabbits. In a experimental, blind, randomized, crossover study, six rabbits were anesthetized with each of 3 treatments in random order. Groups KM (ketamine, 30 mg/kg + midazolam, 1 mg/kg; KX (ketamine, 30 mg/kg + xylazine, 3 mg/kg; and TZ (tiletamine + zolazepam, 20 mg/kg. The drugs were mixed in the same syringe injected intramuscularly (IM into the quadriceps muscle. IOP was measured before drug administration (baseline and at 5-minute intervals for 30 minutes. The data were analyzed by a 2-way repeated measures ANOVA followed by Bonferroni test. All groups had significant decreases in IOP compared to baseline (p 0.05. Administration of either ketamine-midazolam, ketamine-xylazine, or tiletamine-zolazepam similarly decrease IOP in rabbits within 30 minutes of injection.

  10. Refractometry for quality control of anesthetic drug mixtures.

    Science.gov (United States)

    Stabenow, Jennifer M; Maske, Mindy L; Vogler, George A

    2006-07-01

    Injectable anesthetic drugs used in rodents are often mixed and further diluted to increase the convenience and accuracy of dosing. We evaluated clinical refractometry as a simple and rapid method of quality control and mixing error detection of rodent anesthetic or analgesic mixtures. Dilutions of ketamine, xylazine, acepromazine, and buprenorphine were prepared with reagent-grade water to produce at least 4 concentration levels. The refraction of each concentration then was measured with a clinical refractometer and plotted against the percentage of stock concentration. The resulting graphs were linear and could be used to determine the concentration of single-drug dilutions or to predict the refraction of drug mixtures. We conclude that refractometry can be used to assess the concentration of dilutions of single drugs and can verify the mixing accuracy of drug combinations when the components of the mixture are known and fall within the detection range of the instrument.

  11. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil.

    Science.gov (United States)

    Prontera, Andrea; Baroni, Stefano; Marudi, Andrea; Valzania, Franco; Feletti, Alberto; Benuzzi, Francesca; Bertellini, Elisabetta; Pavesi, Giacomo

    2017-01-01

    Awake craniotomy allows continuous monitoring of patients' neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic-sedative medication is increasing. Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management. The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure. In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used.

  12. Anesthetic Efficacy of Bupivacaine Solutions in Inferior Alveolar Nerve Block

    Science.gov (United States)

    Volpato, Maria Cristina; Ranali, José; Ramacciato, Juliana Cama; de Oliveira, Patrícia Cristine; Ambrosano, Glaúcia Maria Bovi; Groppo, Francisco Carlos

    2005-01-01

    The purpose of this study was to compare the anesthetic efficacy of 2 bupivacaine solutions. Twenty-two volunteers randomly received in a crossover, double-blinded manner 2 inferior alveolar nerve blocks with 1.8 mL of racemic bupivacaine and a mixture of 75% levobupivacaine and 25% dextrobupivacaine, both 0.5% and with 1 : 200,000 epinephrine. Before and after the injection, the first mandibular pre-molar was evaluated every 2 minutes until no response to the maximal output (80 reading) of the pulp tester and then again every 20 minutes. Data were analyzed using the Wilcoxon paired test and the paired t test. No differences were found between the solutions for onset and duration of pulpal anesthesia and duration of soft tissue anesthesia (P > .05). It was concluded that the solutions have similar anesthetic efficacy. PMID:16596912

  13. [Anesthetic management of a patient with Creutzfeldt-Jacob disease undergoing tracheal separation].

    Science.gov (United States)

    Kanzaki, Rieko; Hamada, Hiroshi; Fukuda, Hideki; Kawamoto, Masashi

    2012-10-01

    We gave anesthesia for tracheal separation in a patient with Creutzfeldt-Jakob disease. The patient, a 33-year-old woman, was bedridden and unable to communicate, and was going to undergo a tracheal separation procedure for repeated bouts of aspiration pneumonia. After a tracheostomy with local anesthesia and sedation with propofol, general anesthesia was induced and maintained with propofol (1.5-3.0 microg x ml(-1), target controlled infusion) and remifentanil (0.05-0.15 microg x kg(-1) x min(-1)). We did not use an anesthetic apparatus from the standpoint of infection control, and provided manual ventilation with a disposable Jackson-Rees circuit. During the operation, an entropy monitor indicated alternating extremely low (0-10) and high (90-100) values without circulatory change, probably due to a previously existing electroencephalographic abnormality. The surgery was uneventful, and spontaneous breathing and eyelid opening occurred about 10 minutes after discontinuation of remifentanil and propofol. In such infected patients, abnormal prion proteins can exist outside of the central nervous system throughout the period of anesthetic management. Therefore, careful infection control must be undertaken, even if the surgical site is not directly related to the central nervous system.

  14. Inconsistency between simultaneous blood pressure measurements in the arm, forearm, and leg in anesthetized children.

    Science.gov (United States)

    Keidan, Ilan; Sidi, Avner; Ben-Menachem, Erez; Tene, Yael; Berkenstadt, Haim

    2014-02-01

    To determine the accuracy and precision of simultaneous noninvasive blood pressure (NIBP) measurement in the arm, forearm, and ankle in anesthetized children. Prospective, randomized study. University medical center. 101 ASA physical status 1 and 2 children (aged 1-8 yrs) scheduled for elective surgery with general anesthesia. Simultaneous NIBP measurements were recorded at the arm, forearm, and ankle at 5-minute intervals. The systolic blood pressure difference between the arm-forearm or the arm-ankle was within the ± 10% range in 63% and 29% of measurements, and within the ± 20% range in 85% and 67% of measurements, respectively. The diastolic blood pressure difference between the arm-forearm or the arm-ankle was within the ± 10% range in 42% and 44% and within the ± 20% range in 67% and 74% of measurements, respectively. In patients in whom the initial three NIBP measurements were within the ± 20% range between the forearm and arm, 86% of the subsequent measurements were also within that limit. Forearm and ankle NIBP measurements are unreliable and inconsistent with NIBP measured in the arm of anesthetized children. These alternative BP measurement sites are not reliable in accuracy (comparison with reference "gold" standard) and precision (reproducibility). Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Cardiorespiratory and anesthetic effects of combined alfaxalone, butorphanol, and medetomidine in Thoroughbred horses.

    Science.gov (United States)

    Ohmura, Hajime; Okano, Atsushi; Mukai, Kazutaka; Fukuda, Kentaro; Takahashi, Toshiyuki

    2016-01-01

    This study evaluated induction of anesthesia and cardiorespiratory and anesthetic effects during maintained anesthesia with the combination of alfaxalone, medetomidine, and butorphanol. Alfaxalone (1.0 mg/kg) was administered to induce anesthesia after premedication with medetomidine (7.0 µg/kg), butorphanol (25 µg/kg), and midazolam (50 µg/kg) in six Thoroughbred horses. Intravenous general anesthesia was maintained with alfaxalone (2.0 mg/(kg∙hr)), medetomidine (5.0 µg/(kg∙hr)), and butorphanol (30 µg/(kg∙hr)) for 60 min. Electrical stimulation of the upper oral mucosa was used to assess anesthetic depth at 10 min intervals during anesthesia. Heart rate (HR), respiratory rate (RR), and mean arterial pressure (MAP) were measured. All horses became recumbent within 1 min after alfaxalone administration. Induction scores were 5 (best) in five horses and 4 in one horse. During the 60-min anesthesia, average HR, RR, and MAP were 35.8 ± 2.6 beat/min, 4.7 ± 0.6 breath/min, and 129 ± 3 mmHg, respectively. No horse moved with electrical stimulation; however, two horses experienced apnea (no respiration for 1 to 3 min). Recovery scores were 5 (best) in two horses and 3 in four horses. These results suggest that alfaxalone is effective for induction and maintenance of anesthesia and analgesia when combined with butorphanol and medetomidine for 60 min in Thoroughbreds. However, respiratory depression might require support.

  16. ANESTHETIC CONSIDERATION S IN CHRONIC OBSTRUCTIVE PULMON ARY DISEASE

    Directory of Open Access Journals (Sweden)

    Awati

    2015-03-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is a spectrum of diseases that includes emphysema, chronic bronchitis, and small airway disease. It i s characterized by progressive increased resistance to breathing. Patients with marked obstructive pulmonary disease are at increased risk for both intraoperative and Postoperative pulmonary complications. These patients require thorough preoperative prepa ration, meticulous intraoperative management & postoperative care. This article describes anesthetic considerations in a patient with COPD.

  17. Anesthetic Management in a Gravida with Type IV Osteogenesis Imperfecta

    Directory of Open Access Journals (Sweden)

    Elizabeth Vue

    2016-01-01

    Full Text Available Osteogenesis imperfecta (OI is an inherited disorder of the connective tissues caused by abnormalities in collagen formation. OI may present many challenges to the anesthesiologist. A literature review reveals a wide range of implications, from basic positioning to management of the difficult airway. We present the anesthetic management of a 25-year-old gravid woman with OI, fetal demise, and possible uterine rupture, admitted for an exploratory laparotomy.

  18. Volatility Exposure for Strategic Asset Allocation

    OpenAIRE

    Briere, Marie; Burgues, Alexandre; Signori, Ombretta

    2008-01-01

    This paper examines the advantages of incorporating strategic exposure to equity volatility into the investment-opportunity set of a long-term equity investor. We consider two standard volatility investments: implied volatility and volatility risk premium strategies. To calibrate and assess the risk/return profile of the portfolio, we present an analytical framework offering pragmatic solutions for long-term investors seeking exposure to volatility. The benefit of volatility exposure for a co...

  19. A Novel Anti-Pollution Filter for Volatile Agents During Cardiopulmonary Bypass: Preliminary Tests.

    Science.gov (United States)

    Nigro Neto, Caetano; Landoni, Giovanni; Tardelli, Maria Angela

    2017-08-01

    Concerns regarding pollution of the operating room by volatile anesthetics and effects on atmospheric ozone depletion exist. Volatile agents commonly are used during cardiopulmonary bypass to provide anesthesia independent of any supposed myocardial protective effects. The authors' aim was to create and to assess the performance of a prototype filter for volatile agents to be connected to the cardiopulmonary bypass circuit to avoid the emission of volatile agents to the operating room, and also to the environment without causing damage to the membrane oxygenator. Observational trial. University hospital. Prototype filter for volatile agents. The prototype filter was tested in a single ex vivo experiment. The main data measured during the test were pressure drop to detect interference with the performance of the oxygenator, back pressure to detect overpressure to the outlet gas jacket of the oxygenator, analysis of exhaled sevoflurane after the membrane oxygenator, and after the filter to detect any presence of sevoflurane. The prototype filter adsorbed the sevoflurane eliminated through the outlet portion of the oxygenator. During the entire test, the back pressure remained constant (4 mmHg) and pressure drop varied from 243 mmHg to 247 mmHg. The prototype filter was considered suitable to absorb the sevoflurane, and it did not cause an overpressure to the membrane oxygenator during the test. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Cardiac evaluation of anesthetized Grevy's zebras (Equus grevyi).

    Science.gov (United States)

    Adin, Darcy B; Maisenbacher, Herbert W; Ojeda, Nyurka; Fiorello, Christine V; Estrada, Amara H; Prosek, Robert; Citino, Scott B

    2007-02-01

    To determine ECG and echocardiographic measurements in healthy anesthetized Grevy's zebras (Equus grevyi). 20 healthy zebras. Auscultation, base-apex ECG, and echocardiography were performed on anesthetized zebras. Low-grade systolic murmurs were detected in the left basilar region in 4 of 20 zebras. Evaluation of ECGs from 19 zebras revealed sinus rhythm with a predominantly negative QRS complex and a mean +/- SD heart rate of 67 +/- 10 beats/min. Echocardiograms of sufficient image quality were obtained for 16 zebras. Interventricular septal thickness in diastole, left ventricular chamber in diastole and systole, left atrial diameter, and left ventricular mass were significantly and moderately correlated with estimated body weight (r values ranged from 0.650 to 0.884). Detectable swirling of blood in the right and sometimes the left ventricles was detected in 9 of 16 zebras, whereas physiologic regurgitation of blood was detected for the aortic valve in 3 zebras, pulmonary valve in 2 zebras, mitral valve in 2 zebras, and tricuspid valve in 1 zebra. Results of this study provide reference information for use in the cardiac evaluation of anesthetized Grevy's zebras.

  1. Anesthetic Efficacy in Irreversible Pulpitis: A Randomized Clinical Trial.

    Science.gov (United States)

    Allegretti, Carlos E; Sampaio, Roberta M; Horliana, Anna C R T; Armonia, Paschoal L; Rocha, Rodney G; Tortamano, Isabel Peixoto

    2016-01-01

    Inferior alveolar nerve block has a high failure rate in the treatment of mandibular posterior teeth with irreversible pulpitis. The aim of this study was to compare the anesthetic efficacy of 4% articaine, 2% lidocaine and 2% mepivacaine, all in combination with 1:100,000 epinephrine, in patients with irreversible pulpitis of permanent mandibular molars during a pulpectomy procedure. Sixty-six volunteers from the Emergency Center of the School of Dentistry, University of São Paulo, randomly received 3.6 mL of local anesthetic as a conventional inferior alveolar nerve block (IANB). The subjective signal of lip numbness, pulpal anesthesia and absence of pain during the pulpectomy procedure were evaluated respectively, by questioning the patient, stimulation using an electric pulp tester and a verbal analogue scale. All patients reported the subjective signal of lip numbness. Regarding pulpal anesthesia success as measured with the pulp tester, the success rate was respectively 68.2% for mepivacaine, 63.6% for articaine and 63.6% for lidocaine. Regarding patients who reported no pain or mild pain during the pulpectomy, the success rate was, respectively 72.7% for mepivacaine, 63.6% for articaine and 54.5% for lidocaine. These differences were not statistically significant. Neither of the solutions resulted in 100% anesthetic success in patients with irreversible pulpitis of mandibular molars.

  2. Physiological responses of cacharas Pseudoplatystoma reticulatum submitted to natural anesthetics

    Directory of Open Access Journals (Sweden)

    Milena Souza dos Santos Sanchez

    2014-02-01

    Full Text Available The present study the aimed to evaluate the induction time, recovery time and physiological responses of cacharas, Pseudoplatystoma reticulatum, submitted to eugenol and menthol. 42 cacharas were exposed to eugenol 100 mgL-1 (n=14 and menthol 150 mgL-1 (n=14 and the control group (n=14 which were not exposed to any anesthetics. At the time 0 and 24 hours after induction, the bloods of 7 fishes per treatment were collected to measure the hematologic parameters and plasma glucose evaluation. The recovery was conducted in aquariums free of anesthetic, and induction and recovery times were monitored. The results were submitted to analysis of variance (P0.05 for induction time, however the recovery time had a significant reduction (P<0.05 for the menthol 150 mgL-1. There was no treatment effects on hematologic parameters, except for mean corpuscular volume (VCM, which was observed an interaction effect between factors, once fish anesthetized with eugenol showed significant reduction (P<0.05 on VCM 24 hours after anesthesia. Plasma glucose values did not differ at 0 hour after induction. 24 hours after induction, both control group and fishes exposed to eugenol and menthol were significantly reduce in VCM. Eugenol at 100 mgL-1 and menthol at 150 mgL-1 may be safely induced in cachara during biometrics procedures.

  3. Methylparaben concentration in commercial Brazilian local anesthetics solutions

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Rodriguez da Silva

    2012-08-01

    Full Text Available OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo. Separation was performed using high performance liquid chromatography (HPLC with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v, pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v to 0.16% (m/v. One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

  4. Oral Topical Doxepin Rinse: Anesthetic Effect in Normal Subjects

    Directory of Open Access Journals (Sweden)

    Joel B Epstein

    2003-01-01

    Full Text Available Oral doxepin rinse has been reported to provide pain relief in patients with oral mucosal lesions due to cancer or cancer therapy. The purpose of this study was to assess the anesthetic effect of doxepin oral rinse in normal subjects to identify the duration of effect and to contrast the anesthetic effect with reported pain relief in patients with oral mucosal lesions. Normal volunteers were provided a solution of doxepin (5 mg/mL for oral rinsing. Oral numbness and adverse effects were recorded for a period of 4 h after rinsing. Doxepin rinse resulted in mucosal anesthesia in all subjects. Sedation/fatigue was reported in four of seven subjects. There were no taste complaints and no nausea reported. The limited duration of numbness/anesthesia in normal subjects compared with prior studies showing pain relief for more than 3 h in patients with mucosal lesions, suggests that the extended duration of pain relief in patients was due to analgesic effects rather than anesthetic effects. The majority of normal subjects reported sedation after use, but this was less common in patients with mucosal lesions.

  5. Development of lidocaine gels for enhanced local anesthetic action.

    Science.gov (United States)

    Shin, Sang-Chul; Cho, Cheong-Weon; Yang, Kyu-Ho

    2004-12-09

    In relieving local pains, lidocaine, one of ester type local anesthetics, has been used. To develop the lidocaine gels of enhanced local anesthetic effects, hydroxypropyl methylcellulose (HPMC) based bioadhesive polymer gel containing an enhancer was formulated. As the drug concentration in the gels increased up to 3%, the permeation rate of drug linearly increased, thereafter reaching a plateau. As the temperature of surrounding solutions increased, the permeation of drug increased. The activation energy of drug permeation was 3.29 kcal/mol for lidocaine. The permeation rate of drug through skin was studied using various enhancers, such as glycols, non-ionic surfactants, and bile salts. Among the enhancers studied, diethylene glycol showed the greatest enhancing effects on drug permeation through skin. The analgesic activity was examined using a tail-flick analgesimeter. In the area under the efficacy curve (AUEC) of the rat-tail flick tests, lidocaine gel containing diethylene glycol showed about 3.89-fold increase in analgesic activity compared with the control. The addition of vasoconstrictor in the gels prolonged the analgesic effects. The result of this study supports that the bioadhesive gel with efficient anesthetic effect could be developed using HPMC with combination of enhancer and vasoconstrictor.

  6. Latent Integrated Stochastic Volatility, Realized Volatility, and Implied Volatility: A State Space Approach

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  7. Option Valuation with Observable Volatility and Jump Dynamics

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jeon, Yoontae

    Under very general conditions, the total quadratic variation of a jump-diffusion process can be decomposed into diffusive volatility and squared jump variation. We use this result to develop a new option valuation model in which the underlying asset price exhibits volatility and jump intensity...... dynamics. The volatility and jump intensity dynamics in the model are directly driven by model-free empirical measures of diffusive volatility and jump variation. Because the empirical measures are observed in discrete intervals, our option valuation model is cast in discrete time, allowing...... for straightforward filtering and estimation of the model. Our model belongs to the affine class enabling us to derive the conditional characteristic function so that option values can be computed rapidly without simulation. When estimated on S&P500 index options and returns the new model performs well compared...

  8. A Note on the Equivalence between the Normal and the Lognormal Implied Volatility : A Model Free Approach

    OpenAIRE

    Grunspan, Cyril

    2011-01-01

    First, we show that implied normal volatility is intimately linked with the incomplete Gamma function. Then, we deduce an expansion on implied normal volatility in terms of the time-value of a European call option. Then, we formulate an equivalence between the implied normal volatility and the lognormal implied volatility with any strike and any model. This generalizes a known result for the SABR model. Finally, we adress the issue of the "breakeven move" of a delta-hedged portfolio.

  9. Anesthetic Preconditioning as Endogenous Neuroprotection in Glaucoma

    Directory of Open Access Journals (Sweden)

    Tsung-Han Chou

    2018-01-01

    Full Text Available Blindness in glaucoma is the result of death of Retinal Ganglion Cells (RGCs and their axons. RGC death is generally preceded by a stage of reversible dysfunction and structural remodeling. Current treatments aimed at reducing intraocular pressure (IOP are ineffective or incompletely effective in management of the disease. IOP-independent neuroprotection or neuroprotection as adjuvant to IOP lowering in glaucoma remains a challenge as effective agents without side effects have not been identified yet. We show in DBA/2J mice with spontaneous IOP elevation and glaucoma that the lifespan of functional RGCs can be extended by preconditioning RGCs with retrobulbar lidocaine in one eye at four months of age that temporary blocks RGC axonal transport. The contralateral, PBS-injected eye served as control. Lidocaine-induced impairment of axonal transport to superior colliculi was assessed by intravitreal injection of cholera toxin B. Long-term (nine months effect of lidocaine were assessed on RGC electrical responsiveness (PERG, IOP, expression of relevant protein (BDNF, TrkB, PSD95, GFAP, Synaptophysin, and GAPDH and RGC density. While lidocaine treatment did not alter the age-related increase of IOP, TrkB expression was elevated, GFAP expression was decreased, RGC survival was improved by 35%, and PERG function was preserved. Results suggest that the lifespan of functional RGCs in mouse glaucoma can be extended by preconditioning RGCs in early stages of the disease using a minimally invasive treatment with retrobulbar lidocaine, a common ophthalmologic procedure. Lidocaine is inexpensive, safe and is approved by Food and Drug Administration (FDA to be administered intravenously.

  10. Parallel Prediction of Stock Volatility

    Directory of Open Access Journals (Sweden)

    Priscilla Jenq

    2017-10-01

    Full Text Available Volatility is a measurement of the risk of financial products. A stock will hit new highs and lows over time and if these highs and lows fluctuate wildly, then it is considered a high volatile stock. Such a stock is considered riskier than a stock whose volatility is low. Although highly volatile stocks are riskier, the returns that they generate for investors can be quite high. Of course, with a riskier stock also comes the chance of losing money and yielding negative returns. In this project, we will use historic stock data to help us forecast volatility. Since the financial industry usually uses S&P 500 as the indicator of the market, we will use S&P 500 as a benchmark to compute the risk. We will also use artificial neural networks as a tool to predict volatilities for a specific time frame that will be set when we configure this neural network. There have been reports that neural networks with different numbers of layers and different numbers of hidden nodes may generate varying results. In fact, we may be able to find the best configuration of a neural network to compute volatilities. We will implement this system using the parallel approach. The system can be used as a tool for investors to allocating and hedging assets.

  11. HS-SPME-GC-MS ANALYSIS OF VOLATILE AND SEMI-VOLATILE COMPOUNDS FROM DRIED LEAVES OF Mikania glomerata Sprengel

    Directory of Open Access Journals (Sweden)

    Esmeraldo A. Cappelaro

    2015-03-01

    Full Text Available This paper reports on the identification of volatile and semi-volatile compounds and a comparison of the chromatographic profiles obtained by Headspace Solid-Phase Microextraction/Gas Chromatography with Mass Spectrometry detection (HS-SPME-GC-MS of dried leaves of Mikania glomerata Sprengel (Asteraceae, also known as 'guaco.' Three different types of commercial SPME fibers were tested: polydimethylsiloxane (PDMS, polydimethylsiloxane/divinylbenzene (PDMS/DVB and polyacrylate (PA. Fifty-nine compounds were fully identified by HS-SPME-HRGC-MS, including coumarin, a marker for the quality control of guaco-based phytomedicines; most of the other identified compounds were mono- and sesquiterpenes. PA fibers performed better in the analysis of coumarin, while PDMS-DVB proved to be the best choice for a general and non-selective analysis of volatile and semi-volatile guaco-based compounds. The SPME method is faster and requires a smaller sample than conventional hydrodistillation of essential oils, providing a general overview of the volatile and semi-volatile compounds of M. glomerata.

  12. Comparison of use of an infrared anesthetic gas monitor and refractometry for measurement of anesthetic agent concentrations.

    Science.gov (United States)

    Ambrisko, Tamas D; Klide, Alan M

    2011-10-01

    To assess agreement between anesthetic agent concentrations measured by use of an infrared anesthetic gas monitor (IAGM) and refractometry. SAMPLE-4 IAGMs of the same type and 1 refractometer. Mixtures of oxygen and isoflurane, sevoflurane, desflurane, or N(2)O were used. Agent volume percent was measured simultaneously with 4 IAGMs and a refractometer at the common gas outlet. Measurements obtained with each of the 4 IAGMs were compared with the corresponding refractometer measurements via the Bland-Altman method. Similarly, Bland-Altman plots were also created with either IAGM or refractometer measurements and desflurane vaporizer dial settings. Bias ± 2 SD for comparisons of IAGM and refractometer measurements was as follows: isoflurane, -0.03 ± 0.18 volume percent; sevoflurane, -0.19 ± 0.23 volume percent; desflurane, 0.43 ± 1.22 volume percent; and N(2)O, -0.21 ± 1.88 volume percent. Bland-Altman plots comparing IAGM and refractometer measurements revealed nonlinear relationships for sevoflurane, desflurane, and N(2)O. Desflurane measurements were notably affected; bias ± limits of agreement (2 SD) were small (0.1 ± 0.22 volume percent) at < 12 volume percent, but both bias and limits of agreement increased at higher concentrations. Because IAGM measurements did not but refractometer measurements did agree with the desflurane vaporizer dial settings, infrared measurement technology was a suspected cause of the nonlinear relationships. Given that the assumption of linearity is a cornerstone of anesthetic monitor calibration, this assumption should be confirmed before anesthetic monitors are used in experiments.

  13. Cardiovascular responses to microinjections of GABA or anesthetics into the rostral ventrolateral medulla of conscious and anesthetized rats

    Directory of Open Access Journals (Sweden)

    Lacerda J.E.C.

    2003-01-01

    Full Text Available The rostral ventrolateral medulla (RVLM contains neurons involved in tonic and reflex control of arterial pressure. We describe the effects of gamma-aminobutyric acid (GABA and anesthetics injected into the RVLM of conscious and urethane (1.2 g/kg, iv anesthetized Wistar rats (300-350 g. In conscious rats, bilateral microinjection of GABA (50 nmol/200 nl induced a small but significant decrease in blood pressure (from 130 ± 3.6 to 110 ± 5.6 mmHg, N = 7. A similar response was observed with sodium pentobarbital microinjection (24 nmol/200 nl. However, in the same animals, the fall in blood pressure induced by GABA (from 121 ± 8.9 to 76 ± 8.8 mmHg, N = 7 or pentobarbital (from 118 ± 4.5 to 57 ± 11.3 mmHg, N = 6 was significantly increased after urethane anesthesia. In contrast, there was no difference between conscious (from 117 ± 4.1 to 92 ± 5.9 mmHg, N = 7 and anesthetized rats (from 123 ± 6.9 to 87 ± 8.7 mmHg, N = 7 when lidocaine (34 nmol/200 nl was microinjected into the RVLM. The heart rate variations were not consistent and only eventually reached significance in conscious or anesthetized rats. The right position of pipettes was confirmed by histology and glutamate microinjection into the RVLM. These findings suggest that in conscious animals the RVLM, in association with the other sympathetic premotor neurons, is responsible for the maintenance of sympathetic vasomotor tone during bilateral RVLM inhibition. Activity of one or more of these premotor neurons outside the RVLM can compensate for the effects of RVLM inhibition. In addition, the effects of lidocaine suggest that fibers passing through the RVLM are involved in the maintenance of blood pressure in conscious animals during RVLM inhibition.

  14. Volatiles in the Martian regolith

    International Nuclear Information System (INIS)

    Clark, B.C.; Baird, A.K.

    1979-01-01

    An inventory of released volatiles on Mars has been derived based upon Viking measurements of atmospheric and surface chemical composition, and upon the inferred mineralogy of a ubiquitous regolith, assumed to average 200m in depth. This model is consistent with the relative abundances of volatiles (except for S) on the Earth's surface, but implies one-fifteenth of the volatile release of Earth if starting materials were comparable. All constituents are accommodated as chemical components of, or absorbed phases on, regolith materials--without the necessity of invoking unobservable deposits of carbonates, nitrates, or permafrost ice

  15. Anesthetic neuroprotection: antecedents and an appraisal of preclinical and clinical data quality.

    Science.gov (United States)

    Ishida, Kazuyoshi; Berger, Miles; Nadler, Jacob; Warner, David S

    2014-01-01

    Anesthetics have been studied for nearly fifty years as potential neuroprotective compounds in both perioperative and resuscitation medicine. Although anesthetics present pharmacologic properties consistent with preservation of brain viability in the context of an ischemic insult, no anesthetic has been proven efficacious for neuroprotection in humans. After such effort, it could be concluded that anesthetics are simply not neuroprotective in humans. Moreover, pharmacologic neuroprotection with non-anesthetic drugs has also repeatedly failed to be demonstrated in human acute brain injury. Recent focus has been on rectification of promising preclinical neuroprotection data and subsequent failed clinical trials. This has led to consensus guidelines for the process of transferring purported therapeutics from bench to bedside. In this review we first examined the history of anesthetic neuroprotection research. Then, a systematic review was performed to identify major clinical trials of anesthetic neuroprotection. Both the preclinical neuroprotection portfolio cited to justify a clinical trial and the design and conduct of that clinical trial were evaluated using modern standards that include the Stroke Therapy Academic Industry Roundtable (STAIR) and Consolidated Standards of Reporting Trials (CONSORT) guidelines. In publications intended to define anesthetic neuroprotection, we found overall poor quality of both preclinical efficacy analysis portfolios and clinical trial designs and conduct. Hence, using current translational research standards, it was not possible to conclude from existing data whether anesthetics ameliorate perioperative ischemic brain injury. Incorporation of advances in translational neuroprotection research conduct may provide a basis for more definitive and potentially successful clinical trials of anesthetics as neuroprotectants.

  16. Vasoconstriction Potency Induced by Aminoamide Local Anesthetics Correlates with Lipid Solubility

    Directory of Open Access Journals (Sweden)

    Hui-Jin Sung

    2012-01-01

    Full Text Available Aminoamide local anesthetics induce vasoconstriction in vivo and in vitro. The goals of this in vitro study were to investigate the potency of local anesthetic-induced vasoconstriction and to identify the physicochemical property (octanol/buffer partition coefficient, pKa, molecular weight, or potency of local anesthetics that determines their potency in inducing isolated rat aortic ring contraction. Cumulative concentration-response curves to local anesthetics (levobupivacaine, ropivacaine, lidocaine, and mepivacaine were obtained from isolated rat aorta. Regression analyses were performed to determine the relationship between the reported physicochemical properties of local anesthetics and the local anesthetic concentration that produced 50% (ED50 of the local anesthetic-induced maximum vasoconstriction. We determined the order of potency (ED50 of vasoconstriction among local anesthetics to be levobupivacaine > ropivacaine > lidocaine > mepivacaine. The relative importance of the independent variables that affect the vasoconstriction potency is octanol/buffer partition coefficient > potency > pKa > molecular weight. The ED50 in endothelium-denuded aorta negatively correlated with the octanol/buffer partition coefficient of local anesthetics (r2=0.9563; P<0.001. The potency of the vasoconstriction in the endothelium-denuded aorta induced by local anesthetics is determined primarily by lipid solubility and, in part, by other physicochemical properties including potency and pKa.

  17. The Third American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity: Executive Summary 2017.

    Science.gov (United States)

    Neal, Joseph M; Barrington, Michael J; Fettiplace, Michael R; Gitman, Marina; Memtsoudis, Stavros G; Mörwald, Eva E; Rubin, Daniel S; Weinberg, Guy

    2018-02-01

    The American Society of Regional Anesthesia and Pain Medicine's Third Practice Advisory on local anesthetic systemic toxicity is an interim update from its 2010 advisory. The advisory focuses on new information regarding the mechanisms of lipid resuscitation, updated frequency estimates, the preventative role of ultrasound guidance, changes to case presentation patterns, and limited information related to local infiltration anesthesia and liposomal bupivacaine. In addition to emerging information, the advisory updates recommendations pertaining to prevention, recognition, and treatment of local anesthetic systemic toxicity. WHAT'S NEW IN THIS UPDATE?: This interim update summarizes recent scientific findings that have enhanced our understanding of the mechanisms that lead to lipid emulsion reversal of LAST, including rapid partitioning, direct inotropy, and post-conditioning. Since the previous practice advisory, epidemiological data have emerged that suggest a lower frequency of LAST as reported by single institutions and some registries, nevertheless a considerable number of events still occur within the general community. Contemporary case reports suggest a trend toward delayed presentation, which may mirror the increased use of ultrasound guidance (fewer intravascular injections), local infiltration techniques (slower systemic uptake), and continuous local anesthetic infusions. Small patient size and sarcopenia are additional factors that increase potential risk for LAST. An increasing number of reported events occur outside of the traditional hospital setting and involve non-anesthesiologists.

  18. Pre-anesthetic Anxiety Level in Children with Congenital Heart Disease: Comparison between Maternal Presence during Anesthetic Induction and Midazolam Premedication

    Directory of Open Access Journals (Sweden)

    Ratna F Soenarto

    2016-09-01

    Full Text Available General anesthesia was needed by children with congenital heart disease (CHD who underwent cardiaccatheterization procedure and surgery. Pre-anesthetic anxiety in children with CHD can cause significantproblems during induction of anesthesia which leads to negative postoperative outcomes. This studycompared the role of maternal presence during anesthesia induction with midazolam premedication onpre-anesthetic anxiety level in children with CHD. Dr. Cipto Mangunkusumo National Hospital on April toSeptember 2014. Forty-five CHD patients aged 2-5 years old who underwent cardiac invasive procedurewere divided into P group (received midazolam premedication and M group (had maternal presence duringanesthesia induction. Modified Yale Pre-anxiety Scale (MYPAS was used for measuring anxiety level ineach patient during preoperative visit, on the time patient entered the procedure room and during induction ofanesthesia. There was no significant difference of MYPAS scores between the two groups in all measurementtimes. The MYPAS score results were non-anxious (median score 23.4 and the highest was at induction ofanesthesia. Inter-rater agreement test between 2 observers was good (k>0.5. In conclusion, there was nosignificant difference between the effect of maternal presence during induction of anesthesia and midazolampremedication on pre-anesthetic anxiety level in children with CHD. Keywords: pre-anesthetic anxiety, congenital heart disease, maternal presence, midazolam.   Peran Kehadiran Ibu selama Induksi Anestesia dengan PremedikasiMidazolam terhadap Tingkat Kecemasan Pra-anestesia Anak denganPenyakit Jantung Bawan Abstrak Pembiusan umum diperlukan oleh pasien dengan penyakit jantung bawaan (PJB pada saat kateterisasiatau pembedahan jantung. Kecemasan pra-anestesia dapat menimbulkan masalah saat induksi anestesiayang berdampak negatif pascapembedahan. Penelitian ini bertujuan untuk membandingkan efek premedikasimidazolam dan kehadiran ibu selama

  19. Extreme-Strike and Small-time Asymptotics for Gaussian Stochastic Volatility Models

    OpenAIRE

    Zhang, Xin

    2016-01-01

    Asymptotic behavior of implied volatility is of our interest in this dissertation. For extreme strike, we consider a stochastic volatility asset price model in which the volatility is the absolute value of a continuous Gaussian process with arbitrary prescribed mean and covariance. By exhibiting a Karhunen-Loève expansion for the integrated variance, and using sharp estimates of the density of a general second-chaos variable, we derive asymptotics for the asset price density for large or smal...

  20. Volatility of fragrance chemicals: patch testing implications.

    Science.gov (United States)

    Gilpin, Sarah J; Hui, Xiaoying; Maibach, Howard I

    2009-01-01

    Diagnostic and predictive patch testing to determine contact allergy due to fragrance materials requires applying a fixed dose of material to the skin. This dose can be affected by the volatile nature of fragrances; little data exist on how the loss of fragrance dose due to volatility affects patch testing. (1) To evaluate pH dependence and evaporation rates of two fragrance chemicals, geraniol, citronellol, and a common fragrance solvent, diethyl phthalate (DEP) and (2) Assess implications for predictive patch-testing methods for fragrances. pH analysis of each material at 1% for three values (4.0, 5.0, 7.0) was done over 40 hours. Volatility experiments for each material, nonradiolabeled and radiolabeled, were conducted over a 24-hour period, taking readings at six time points (5 minutes, 15 minutes, 40 minutes, 1 hour, 3 hours, and 24 hours). Evaporation rates were not sensitive to pH shifts from 4.0 to 7.0. Evaporation rates for nonradiolabeled materials were low: after 24 hours, geraniol lost 8.9%, citronellol 27.0% and DEP 14.5%. The volatility data for radiolabeled materials demonstrated that geraniol loses up to 39% of its dose, citronellol loses up to 26%, and DEP up to 14% within 40 minutes. The tendency of fragrance materials to evaporate can impact the dose being applied to the patch and therefore the result of the patch and ultimately the decision-making process regarding that fragrance material's safety. These data, developed with DEP, utilized in a predictive sensitization assay cannot be generalized.

  1. Fig volatile compounds--a first comparative study.

    Science.gov (United States)

    Grison-Pigé, Laure; Hossaert-McKey, Martine; Greeff, Jaco M; Bessière, Jean-Marie

    2002-09-01

    We analysed the compounds of volatile blends released by receptive figs of twenty Ficus species to attract their specific pollinating wasps. In all, 99 different compounds were identified. The compounds are mainly terpenoids, aliphatic compounds and products from the shikimic acid pathway. In each species blend, there are few major compounds, which are generally common among floral fragrances. Most species blends also include rare compounds, but generally their proportion in the blend is low. A possible basis for species-specificity of Ficus-wasp interactions is discussed in relation to the patterns of volatiles found in this interspecies comparison. Copyright 2002 Elsevier Science Ltd.

  2. Stochastic volatility and stochastic leverage

    DEFF Research Database (Denmark)

    Veraart, Almut; Veraart, Luitgard A. M.

    This paper proposes the new concept of stochastic leverage in stochastic volatility models. Stochastic leverage refers to a stochastic process which replaces the classical constant correlation parameter between the asset return and the stochastic volatility process. We provide a systematic...... treatment of stochastic leverage and propose to model the stochastic leverage effect explicitly, e.g. by means of a linear transformation of a Jacobi process. Such models are both analytically tractable and allow for a direct economic interpretation. In particular, we propose two new stochastic volatility...... models which allow for a stochastic leverage effect: the generalised Heston model and the generalised Barndorff-Nielsen & Shephard model. We investigate the impact of a stochastic leverage effect in the risk neutral world by focusing on implied volatilities generated by option prices derived from our new...

  3. Anesthetic management of hypertensive crisis in a three-year-old patient with undiagnosed severe renal artery stenosis: a case report.

    Science.gov (United States)

    Park, Sang-Hee; Lee, Yoon-Sook; Min, Too Jae; Kim, Woon Young; Kim, Jae Hwan; Park, Young Cheol

    2014-10-01

    Pediatric hypertensive crisis is a potentially life threatening medical emergency, usually secondary to an underlying disease. Hypertension commonly occurs during general anesthesia, and is usually promptly and appropriately treated by anesthesiologists. However in children with severe, unexplained, or refractory hypertension, it has the potential to cause morbidity and even mortality in susceptible patients. We report an anesthetic management of an unexpected hypertensive crisis that developed during general anesthesia in a three-year-old girl with undiagnosed severe left renal artery stenosis.

  4. Economic and Environmental Considerations During Low Fresh Gas Flow Volatile Agent Administration After Change to a Nonreactive Carbon Dioxide Absorbent.

    Science.gov (United States)

    Epstein, Richard H; Dexter, Franklin; Maguire, David P; Agarwalla, Niraj K; Gratch, David M

    2016-04-01

    Reducing fresh gas flow (FGF) during general anesthesia reduces costs by decreasing the consumption of volatile anesthetics and attenuates their contribution to greenhouse gas pollution of the environment. The sevoflurane FGF recommendations in the Food and Drug Administration package insert relate to concern over potential toxicity from accumulation in the breathing circuit of compound A, a by-product of the reaction of the volatile agent with legacy carbon dioxide absorbents containing strong alkali such as sodium or potassium hydroxide. Newer, nonreactive absorbents do not produce compound A, making such restrictions moot. We evaluated 4 hypotheses for sevoflurane comparing intervals before and after converting from a legacy absorbent (soda lime) to a nonreactive absorbent (Litholyme): (1) intraoperative FGF would be reduced; (2) sevoflurane consumption per minute of volatile agent administration would be reduced; (3) cost savings due to reduced sevoflurane consumption would (modestly) exceed the incremental cost of the premium absorbent; and (4) residual wastage in discarded sevoflurane bottles would be trash after filling vaporizers. The time from reaching a PICO2 = 3 mm Hg for 3 minutes until agent exhaustion (PICO2 = 5 mm Hg for 5 minutes) was evaluated. A total of N = 20,235 cases were analyzed (80.2% sevoflurane, 15.1% desflurane, and 4.7% isoflurane). Intraoperative FGF was reduced for cases in which sevoflurane was administered by 435 mL/min (95% confidence interval [CI], 391 to 479 mL/min; P administration decreased by 0.039 mL/min (95% CI, 0.029 to 0.049 mL/min; P 50%) canisters. We showed that an anesthesia department can transition to a premium, nonreactive carbon dioxide absorbent in a manner that is at least cost neutral by reducing FGF below the lower flow limits recommended in the sevoflurane package insert. This was achieved, in part, by electronically monitoring PICO2, automatically notifying the anesthesia technicians when to change the

  5. [Effect of different anesthetic methods on postoperative outcomes in elderly patients undergoing hip fracture surgery].

    Science.gov (United States)

    Wei, B; Zhang, H; Xu, M; Li, M; Wang, J; Zhang, L P; Guo, X Y; Zhao, Y M; Zhou, F

    2017-12-18

    To investigate the effect of general or regional anesthesia on postoperative cardiopulmonary complications and inpatient mortality after hip fracture surgery in elderly patients. A retrospective analysis was conducted according to the medical records of 572 elderly patients with hip fractures admitted to our hospital from January 1, 2005 to December 31, 2014. The age, gender, preoperative comorbidities, length of preoperative bedridden time, mechanism of injury, surgical types, anesthetic methods, major postoperative complications and inpatient mortality were recorded. Multivariate Logistic regression analysis was applied to analyze the impact of different anesthetic methods on inpatient mortality in these patients. Of the 572 patients, 392 (68.5%) received regional anesthesia. Inpatient death occurred in 8 (8/572, mortality: 1.4%), including 5 cases of RA group (5/392, mortality: 1.3%) and 3 cases of GA group (3/180, mortality: 1.7%). There was no statistically significant difference between the two groups in inpatient mortality (P>0.05). Multiple Logistic regression analysis showed that gender (odds ratio: 0.18, 95% CI: 0.03-1.05, P=0.057), age (odds ratio: 1.22, 95% CI: 1.07-1.38, P=0.002), preoperative pulmonary comorbidities (odds ratio: 12.09, 95% CI: 2.28-64.12, P=0.003) and surgical types (odds ratio: 9.36, 95% CI: 1.34-64.26, P=0.024) were risk factors for inpatient mortality. Postoperative cardiovascular complications occurred in 36 patients (36/572, morbidity: 6.3%), with 19 patients in RA group (19/392, morbidity: 4.8%),and 17 patients in GA group (17/180, morbidity: 9.4%). Multiple Logistic regression analysis showed that age (odds ratio: 1.13, 95% CI: 1.07-1.19, Pbedridden time (odds ratio: 1.11, 95% CI: 1.04-1.18, P=0.003) and anesthetic methods (odds ratio: 5.86, 95% CI: 2.98-11.53, Pelderly patients. Regional anesthesia is associated with a lower risk of pulmonary complications after surgical procedure compared with general anesthesia.

  6. Anesthetic management of a child with Down’s Syndrome having atlanto axial instability

    Directory of Open Access Journals (Sweden)

    Basant Bhattarai

    2009-01-01

    Full Text Available Down's syndrome is the most commonly encountered congenital anomaly in medical practice. These patients are of special concern to medical practice because of their associated problems with regard to respiratory, cardiovascular and other systemic problems. As these patients present for repeated surgeries like dental extraction, facial reconstruction and fixation of cervical spine, these patients pose challenges to the anesthesiologist because of their unique set of problems, namely atlantoaxial instability, small trachea, congenital heart disease and repeated chest infections due to lowered immunity. Their reactivity to inhalational anesthetics and atropine is variable. Here we present an interesting case report of a child with Down's syndrome who presented with atlantoaxial instability for MRI of cervical spine under general anesthesia. KeyWords:atlanto axial instability, down’s syndrome, trisomy 21

  7. Anesthetic management of a pediatric patient with hypohidrotic ectodermal dysplasia undergoing emergency surgery.

    Science.gov (United States)

    Ahiskalioglu, Elif Oral; Ahiskalioglu, Ali; Firinci, Binali; Dostbil, Aysenur; Aksoy, Mehmet

    2015-01-01

    Ectodermal dysplasias are rare conditions with a triad of hypotrichosis, anodontia and anhidrosis. In literature review there have been only a few reports of anesthetic management of patients with ectodermal dysplasias. Hyperthermia is a very serious risk which may occur due to the defect of sweat glands. The present case involves a 10-year-old child with ectodermal dysplasia who presented with an acute abdomen and was considered for an emergency surgery. Our aim was to demonstrate the successful management of this case using a combination of general and epidural anesthesia. It is important for anesthesiologist to have information about this syndrome in case of emergency operations, since it can prevent serious complications and even save lives. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  8. Ultrasound-guided greater auricular nerve block as sole anesthetic for ear surgery

    Directory of Open Access Journals (Sweden)

    Michael K. Ritchie

    2016-05-01

    Full Text Available A greater auricular nerve (GAN block was used as the sole anesthetic for facial surgery in an 80-year-old male patient with multiple comorbidities which would have made general anesthesia challenging. The GAN provides sensation to the ear, mastoid process, parotid gland, and angle of the mandible. In addition to anesthesia for operating room surgery, the GAN block can be used for outpatient or emergency department procedures without the need for a separate anesthesia team. Although this nerve block has been performed using landmark-based techniques, the ultrasoundguided version offers several potential advantages. These advantages include increased reliability of the nerve block, as well as prevention of inadvertent vascular puncture or blockade of the phrenic nerve, brachial plexus, or deep cervical plexus. The increasing access to ultrasound technology for medical care providers outside the operating room makes this ultrasound guided block an increasingly viable alternative.

  9. Anesthetic management of a pediatric patient with hypohidrotic ectodermal dysplasia undergoing emergency surgery

    Directory of Open Access Journals (Sweden)

    Elif Oral Ahiskalioglu

    2015-11-01

    Full Text Available Ectodermal dysplasias are rare conditions with a triad of hypotrichosis, anodontia and anhidrosis. In literature review there have been only a few reports of anesthetic management of patients with ectodermal dysplasias. Hyperthermia is a very serious risk which may occur due to the defect of sweat glands. The present case involves a 10-year-old child with ectodermal dysplasia who presented with an acute abdomen and was considered for an emergency surgery. Our aim was to demonstrate the successful management of this case using a combination of general and epidural anesthesia. It is important for anesthesiologist to have information about this syndrome in case of emergency operations, since it can prevent serious complications and even save lives.

  10. Anesthetic management of a pediatric patient with hypohidrotic ectodermal dysplasia undergoing emergency surgery

    Directory of Open Access Journals (Sweden)

    Elif Oral Ahiskalioglu

    2015-12-01

    Full Text Available ABSTRACT Ectodermal dysplasias are rare conditions with a triad of hypotrichosis, anodontia and anhidrosis. In literature review there have been only a few reports of anesthetic management of patients with ectodermal dysplasias. Hyperthermia is a very serious risk which may occur due to the defect of sweat glands. The present case involves a 10-year-old child with ectodermal dysplasia who presented with an acute abdomen and was considered for an emergency surgery. Our aim was to demonstrate the successful management of this case using a combination of general and epidural anesthesia. It is important for anesthesiologist to have information about this syndrome in case of emergency operations, since it can prevent serious complications and even save lives.

  11. [The effects of transversus abdominis plane block on analgesic and anesthetic consumption during total abdominal hysterectomy: a randomized controlled study].

    Science.gov (United States)

    Karaman, Tugba; Ozsoy, Asker Zeki; Karaman, Serkan; Dogru, Serkan; Tapar, Hakan; Sahin, Aynur; Dogru, Hatice; Suren, Mustafa

    A transversus abdominis plane block is a peripheral block method that has been used successfully for pain relief after total abdominal hysterectomy. However, the effects of the combination of the transversus abdominis plane block and general anesthesia on analgesic and anesthetic requirements remain unclear. This randomized placebo-controlled study is aimed to evaluate the effects of transversus abdominis plane block on analgesic and anesthetic consumption during total abdominal hysterectomy under general anesthesia. Sixty-six women undergoing total abdominal hysterectomy were randomized into two groups to receive general anesthesia alone (control group) or with transversus abdominis plane block using 20mL of 0.25% bupivacaine (transversus abdominis plane group). Intraoperative remifentanil and sevoflurane consumption were recorded. We also evaluated the postoperative pain, nausea, quality of recovery scores and rescue analgesic requirement during postoperative 24hours. The total remifentanil and sevoflurane consumption is significantly lower in transversus abdominis plane group; respectively mean (SD) 0.130 (0.25) vs. 0.094 (0.02) mcg.kg -1 .min -1 ; pplane group soon after surgery; median (range) 6 (2-10) vs. 3 (0-5); pplane group had significantly higher QoR-40 scores 190.5 (175-197) vs. 176.5 (141-187); pplane block with general anesthesia can provide reduced opioid and anesthetic consumption and can improve postoperative pain and quality of recovery scores in patients undergoing total abdominal hysterectomy. Copyright © 2018 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  12. On the Economic Evaluation of Volatility Forecasts

    DEFF Research Database (Denmark)

    Voev, Valeri

    We analyze the applicability of economic criteria for volatility forecast evaluation based on unconditional measures of portfolio performance. The main theoretical finding is that such unconditional measures generally fail to rank conditional forecasts correctly due to the presence of a bias term...... driven by the variability of the conditional mean and portfolio weights. Simulations and a small empirical study suggest that the bias can be empirically substantial and lead to distortions in forecast evaluation. An important implication is that forecasting superiority of models using high frequency...

  13. Anesthetic technique for inferior alveolar nerve block: a new approach

    Directory of Open Access Journals (Sweden)

    Dafna Geller Palti

    2011-02-01

    Full Text Available BACKGROUND: Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 13-29% of cases. OBJECTIVE: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. MATERIAL AND METHODS: A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side, and the second following the oclusal plane (left side, a line can be achieved whose projection coincides with the left mandibular foramen. RESULTS: The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar. CONCLUSION: This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry.

  14. Anesthetic technique for inferior alveolar nerve block: a new approach

    Science.gov (United States)

    PALTI, Dafna Geller; de ALMEIDA, Cristiane Machado; RODRIGUES, Antonio de Castro; ANDREO, Jesus Carlos; LIMA, José Eduardo Oliveira

    2011-01-01

    Background Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 1329% of cases. Objective Objective: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. Materials and Methods A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition) from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side), and the second following the oclusal plane (left side), a line can be achieved whose projection coincides with the left mandibular foramen. Results The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar. Conclusion This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry. PMID:21437463

  15. Central bronchial carcinoid: Management of a case and anesthetic perspectives

    Directory of Open Access Journals (Sweden)

    D Goswami

    2016-01-01

    Full Text Available Obstructing lesions of the central airways present with a variety of symptoms and are often associated with pneumonia or asthma-like states. Anesthesia to these patients often presents challenges right from the preoperative stabilization of underlying lung condition, mask ventilation in the supine position to maintaining oxygenation and ventilation in the intraoperative and postoperative period. We present here a case of a young woman with a central bronchial tumor with significant airway obstruction with potential for major bleeding and subsequent anesthetic management without lung sacrificing measures and cardiopulmonary bypass assistance.

  16. [Anesthetic considerations in sickle cell anemia: a case report].

    Science.gov (United States)

    Fernández-Meré, L A; Sopena-Zubiría, L A; Alvarez-Blanco, M

    2009-01-01

    Sickle cell anemia is the most common hemoglobinopathy. Advances in therapeutic techniques and anesthetic procedures have led to a considerable increase in the success of surgical procedures in these patients. We report the case of a 16-year-old black boy diagnosed with sickle cell anemia and beta-thalassemia who presented with chronic osteomyelitis of the tibia. He was scheduled for debridement of the lesion and musculocutaneous flap repair. We emphasize the importance of communication between anesthesiologists, surgeons, and hematologists in the perioperative period in order to determine the risk of complications and anticipate them.

  17. Cimetidine as pre-anesthetic agent for cesarean section

    DEFF Research Database (Denmark)

    Qvist, N; Storm, K; Holmskov, A

    1985-01-01

    In a prospective randomized study of 39 consecutive cesarean sections, 20 patients received cimetidine 400 mg intramuscularly as a pre-anesthetic, an 19 control patients were given NaCl. No perinatal effects on the infants were observed by cardiotocography before delivery, and K, Na, pH, PCO2, HC...... with uncomplicated pregnancies, cimetidine was found to cross the placenta at a maternal/cord blood ratio of 3:1. The drug could not be detected in any of the infants 2 hours after delivery....

  18. Anesthetic management in thyroid crisis triggered by molar pregnancy

    Directory of Open Access Journals (Sweden)

    Harun Aydoğan

    2012-09-01

    Full Text Available Clinical thyrotoxicosis is one of the rare complications of molar pregnancy. The cause of the symptoms associated with hyperthyroidism in mol hydatiform is the thyrotrophic effects of high levels of β-hCG. The hCG molecule consists of α and β subunits; the α subunit is identical to TSH and the β subunit has a similar structure to TSH. In this case report it was aimed to discuss the anesthetic management of a dilatation and curettage case in a patient with mol hydatiform and thyroid crisis. J Clin Exp Invest 2012; 3 (3: 433-434Key words: Hydatidiform mole, hyperthyroidism, anesthesia

  19. Multivariable analysis of anesthetic factors associated with time to extubation in dogs.

    Science.gov (United States)

    Kleine, Stephanie; Hofmeister, Erik; Egan, Katrina

    2014-12-01

    The purpose of this study was to identify factors that prolong the time to extubation in dogs. Anesthetic records of 900 dogs at a university teaching hospital were searched. Multiple linear regression was used to compare independent predictors (patient demographics, anesthetic and intraoperative variables) with the dependent variable (time to extubation). Induction with propofol (P temperature (P = 0.0000), and by 0.096 minutes for every 1 minute increase in anesthetic duration (P = 0.000). Anesthetic variables, which can be manipulated by the anesthetist, include choice of premedication and induction drugs, hypothermia, and duration of anesthesia. Published by Elsevier Ltd.

  20. Asymmetric News Effects on Volatility: Good vs. Bad News in Good vs. Bad Times

    OpenAIRE

    Laakkonen, Helinä; Lanne, Markku

    2008-01-01

    We study the impact of positive and negative macroeconomic US and European news announcements in different phases of the business cycle on the highfrequency volatility of the EUR/USD exchange rate. The results suggest that in general bad news increases volatility more than good news. The news effects also depend on the state of the economy: bad news increases volatility more in good times than in bad times, while there is no difference between the volatility effects of good news in bad and go...

  1. The relationship between trading volumes, number of transactions, and stock volatility in GARCH models

    Science.gov (United States)

    Takaishi, Tetsuya; Chen, Ting Ting

    2016-08-01

    We examine the relationship between trading volumes, number of transactions, and volatility using daily stock data of the Tokyo Stock Exchange. Following the mixture of distributions hypothesis, we use trading volumes and the number of transactions as proxy for the rate of information arrivals affecting stock volatility. The impact of trading volumes or number of transactions on volatility is measured using the generalized autoregressive conditional heteroscedasticity (GARCH) model. We find that the GARCH effects, that is, persistence of volatility, is not always removed by adding trading volumes or number of transactions, indicating that trading volumes and number of transactions do not adequately represent the rate of information arrivals.

  2. Volatility Properties of Polonium

    International Nuclear Information System (INIS)

    Eichler, B.

    2002-06-01

    Thermodynamical constants to describe evaporation processes of polonium are summarized and critically discussed. Additionally, systematic changes of the properties of the chalcogenes are analyzed, empirical correlations are proofed and cyclic processes are balanced. Accordingly, the existing values of entropies for polonium are acceptable. Questionable, however, are those values of enthalpies, which have been deduced from results of the experimental investigations of the vapor pressure temperature dependency, of the melting point, and of the boiling temperatures. Technical difficulties and possible error sources of the measurements resulting from the radioactive decay properties of 210 Po are discussed. Using extrapolative standard enthalpies and entropies as well as their temperature dependency, the equilibrium partial pressure of the monomeric and dimeric polonium above the pure condensed phase and the equilibrium constant of the dimerization reaction in the gas phase are calculated: log p/pa Po (g) = (11.797 ± 0.024) -(9883.4 ± 9.5)/T (for T = 298-600 K); = (10.661 ± 0.057) - (9328.4 ± 4.9)/T (for T = 500-1300 K); log p/pa Po 2 (g) = (13.698 ± 0.049) - (8592.3 ± 19.6)/T (for T = 298-600 K); = (11.424 ± 0.124) - (7584.1 ± 98.1)/T (for T = 500-1300 K); log K (dim) = (-4.895 ± 0.012) + (11071 ± 6)/T. According to these calculations and in contrast to other works, polonium evaporates in the entire temperature range between 298 and 1300 K in the dimeric state. Hence, 'latent heats' of the volatilization processes are clearly larger compared to literature data. Especially in the temperature range of the solid polonium the calculated vapor pressure curve shifts significantly to lower values, whereas the boiling point was almost reproduced by the calculation. The results of the extrapolation for the standard enthalpy of the gaseous monomeric polonium and the dimerization enthalpy ΔH 0 298 Po (g) = 188.9 kJ/mol and ΔH 0 298 (form) Po 2 (g) = 211.5 kJ/mol are

  3. Estimation of Dynamic Panel Data Models with Stochastic Volatility Using Particle Filters

    Directory of Open Access Journals (Sweden)

    Wen Xu

    2016-10-01

    Full Text Available Time-varying volatility is common in macroeconomic data and has been incorporated into macroeconomic models in recent work. Dynamic panel data models have become increasingly popular in macroeconomics to study common relationships across countries or regions. This paper estimates dynamic panel data models with stochastic volatility by maximizing an approximate likelihood obtained via Rao-Blackwellized particle filters. Monte Carlo studies reveal the good and stable performance of our particle filter-based estimator. When the volatility of volatility is high, or when regressors are absent but stochastic volatility exists, our approach can be better than the maximum likelihood estimator which neglects stochastic volatility and generalized method of moments (GMM estimators.

  4. Can we use volatility to diagnose financial bubbles? lessons from 40historical bubbles

    Directory of Open Access Journals (Sweden)

    Didier Sornette

    2018-03-01

    Full Text Available We inspect the price volatility before, during, and after financial asset bubbles in orderto uncover possible commonalities and check empirically whether volatility might be used as anindicator or an early warning signal of an unsustainable price increase and the associated crash. Someresearchers and finance practitioners believe that historical and/or implied volatility increase beforea crash, but we do not see this as a consistent behavior. We examine forty well-known bubbles and,using creative graphical representations to capture robustly the transient dynamics of the volatility, findthat the dynamics of the volatility would not have been a useful predictor of the subsequent crashes.In approximately two-third of the studied bubbles, the crash follows a period of lower volatility,reminiscent of the idiom of a “lull before the storm”. This paradoxical behavior, from the lensesof traditional asset pricing models, further questions the general relationship between risk and return.

  5. Fourier Spot Volatility Estimator: Asymptotic Normality and Efficiency with Liquid and Illiquid High-Frequency Data

    Science.gov (United States)

    2015-01-01

    The recent availability of high frequency data has permitted more efficient ways of computing volatility. However, estimation of volatility from asset price observations is challenging because observed high frequency data are generally affected by noise-microstructure effects. We address this issue by using the Fourier estimator of instantaneous volatility introduced in Malliavin and Mancino 2002. We prove a central limit theorem for this estimator with optimal rate and asymptotic variance. An extensive simulation study shows the accuracy of the spot volatility estimates obtained using the Fourier estimator and its robustness even in the presence of different microstructure noise specifications. An empirical analysis on high frequency data (U.S. S&P500 and FIB 30 indices) illustrates how the Fourier spot volatility estimates can be successfully used to study intraday variations of volatility and to predict intraday Value at Risk. PMID:26421617

  6. The cardiac anesthetic index of isoflurane in green iguanas.

    Science.gov (United States)

    Mosley, Craig A E; Dyson, Doris; Smith, Dale A

    2003-06-01

    To determine the cardiac anesthetic index (CAI) of isoflurane in green iguanas and whether butorphanol affected the CAI. Prospective randomized controlled trial. 7 healthy mature iguanas. In 5 iguanas, CAI was determined after induction of anesthesia with isoflurane alone, and in 5 iguanas, CAI was determined after induction of anesthesia with isoflurane and IM administration of butorphanol (1 mg/kg [0.45 mg/lb]). Three iguanas underwent both treatments. Animals were equilibrated for 20 minutes at 1.5 times the minimum alveolar concentration (MAC) of isoflurane and observed for evidence of cardiovascular arrest. If there was no evidence of cardiovascular arrest, end-tidal isoflurane concentration was increased by 20%, and animals were allowed to equilibrate for another 20 minutes. This process was repeated until cardiovascular arrest occurred or vaporizer output could no longer be consistently increased. The CAI was calculated by dividing the highest end-tidal isoflurane concentration by the MAC. None of the iguanas developed cardiovascular arrest and all survived. Mean +/- SD highest end-tidal isoflurane concentration during anesthesia with isoflurane alone (9.2 +/- 0.60%) was not significantly different from mean concentration during anesthesia with isoflurane and butorphanol (9.0 +/- 0.43%). The CAI was > 4.32. Results suggest that the CAI of isoflurane in green iguanas is > 4.32 and not affected by administration of butorphanol. Isoflurane appears to be a safe anesthetic in green iguanas.

  7. Effect of anesthetics on the radiosensitivity of a murine tumor

    Energy Technology Data Exchange (ETDEWEB)

    Sheldon, P.W.; Chu, A.M.

    1979-09-01

    The effect of four anesthetics on the single dose of x rays required to locally control 50% of implanted MT tumors was investigated. Compared with unanesthetized animals, no change in radiosensitivity was observed if mice were irradiated under either tribromoethanol or fentanyl-fluanisone-diazepam anesthesia. However, a small but significant degree of radioprotection was observed under chloral hydrate or pentobarbital anesthesia. Hypothermia or increased hypoxia are considered unlikely mechanisms for the protection, a direct chemical action being most probable. The preferred method for immobilizing the mice in order to locally irradiate the tumors was by simple physical restraint (with care taken to minimize physiological stress). However, if anesthesia was a necessity, the present work suggests that for the MT tumor at least the nonprotecting tribromoethanol and fentanyl-fluanisone-diazepam are preferable to the protecting chloral hydrate and pentobarbital. Tribromoethanol is preferable to fetanyl-fluanisone-diazepam in that it produces a smaller drop in temperature. However, it is only a short-acting anesthetic, and prolongation of the state of anesthesia by repeated doses simply prolongs the temperature decline so that there may be no real benefit over fentanyl-fluanisone-diazepam.

  8. The effect of different anesthetics on neurovascular coupling

    Science.gov (United States)

    Franceschini, Maria Angela; Radhakrishnan, Harsha; Thakur, Kiran; Wu, Weicheng; Ruvinskaya, Svetlana; Carp, Stefan; Boas, David A.

    2010-01-01

    To date, the majority of neurovascular coupling studies focused on the thalamic afferents' activity in layer IV and the corresponding large spiking activity as responsible for functional hyperemia. This paper highlights the role of the secondary and late cortico-cortical transmission in neurovascular coupling. Simultaneous scalp electroencephalography (EEG) and diffuse optical imaging (DOI) measurements were obtained during multiple conditions of event-related electrical forepaw stimulation in 33 male Sprague-Dawley rats divided into 6 groups depending on the maintaining anesthetic - alpha-chloralose, pentobarbital, ketamine-xylazine, fentanyl-droperidol, isoflurane, or propofol. The somatosensory evoked potentials (SEP) were decomposed into four components and the question of which best predicts the hemodynamic responses was investigated. Results of the linear regression analysis show that the hemodynamic response is best correlated with the secondary and late cortico-cortical transmissions and not with the initial thalamic input activity in layer IV. Baseline cerebral blood flow (CBF) interacts with neural activity and influences the evoked hemodynamic responses. Finally, neurovascular coupling appears to be the same across all anesthetics used. PMID:20350606

  9. The anesthetic management of button battery ingestion in children.

    Science.gov (United States)

    Ing, Richard J; Hoagland, Monica; Mayes, Lena; Twite, Mark

    2018-03-01

    Injuries related to button battery ingestion are common in children. This review provides an outline of the epidemiology, pathophysiology, management, and anesthetic implications in children who have ingested a button battery. A literature search was conducted in the United States National Library of Medicine PubMed database using the terms "button battery ingestion" and "children' and "removal" and "surgery" and "anesthesia". Ninety-six articles published in English were found from 1983-2017, and 62 of these articles were incorporated into this review. Additionally, the Internet was searched with the terms "button battery ingestion and children" to identify further entities, organizations, and resources affiliated with button battery ingestion in children. These additional sources were studied and included in this review. Button batteries are ubiquitous in homes and electronic devices. Since 2006, larger-diameter and higher-voltage batteries have become available. These are more likely to become impacted in the esophagus after ingestion and lead to an increase in severe morbidity and mortality due to caustic tissue injury. Children at the highest risk for complications are those under six years of age who have ingested batteries > 20 mm in diameter and sustain prolonged esophageal impaction at the level of the aortic arch with the negative pole oriented anteriorly. Anesthesiologists need to know about the epidemiology, pathophysiology, complications, and anesthetic management of children who have ingested button batteries.

  10. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil

    Directory of Open Access Journals (Sweden)

    Prontera A

    2017-03-01

    Full Text Available Andrea Prontera,1 Stefano Baroni,2 Andrea Marudi,2 Franco Valzania,3 Alberto Feletti,1 Francesca Benuzzi,4 Elisabetta Bertellini,2 Giacomo Pavesi1 1Department of Neurosurgery, Nuovo Ospedale Civile SAgostino-Estense, 2Department of Anesthesiology, Nuovo Ospedale Civile SAgostino-Estense, 3Department of Neurology, Nuovo Ospedale Civile S Agostino-Estense, 4Department of Neuroscience, University of Modena and Reggio Emilia, Modena, Italy Introduction: Awake craniotomy allows continuous monitoring of patients’ neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic–sedative medication is increasing.Methods: Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management.Results: The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure.Conclusion: In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used. Keywords: dexmedetomidine, awake surgery, anesthesia

  11. Effect of anesthetics on the radiosensitivity of a murine tumor

    International Nuclear Information System (INIS)

    Sheldon, P.W.; Chu, A.M.

    1979-01-01

    The effect of four anesthetics on the single dose of x rays required to locally control 50% of implanted MT tumors was investigated. Compared with unanesthetized animals, no change in radiosensitivity was observed if mice were irradiated under either tribromoethanol or fentanyl-fluanisone-diazepam anesthesia. However, a small but significant degree of radioprotection was observed under chloral hydrate or pentobarbital anesthesia. Hypothermia or increased hypoxia are considered unlikely mechanisms for the protection, a direct chemical action being most probable. The preferred method for immobilizing the mice in order to locally irradiate the tumors was by simple physical restraint (with care taken to minimize physiological stress). However, if anesthesia was a necessity, the present work suggests that for the MT tumor at least the nonprotecting tribromoethanol and fentanyl-fluanisone-diazepam are preferable to the protecting chloral hydrate and pentobarbital. Tribromoethanol is preferable to fetanyl-fluanisone-diazepam in that it produces a smaller drop in temperature. However, it is only a short-acting anesthetic, and prolongation of the state of anesthesia by repeated doses simply prolongs the temperature decline so that there may be no real benefit over fentanyl-fluanisone-diazepam

  12. Comparison between newer local anesthetics for myofascial pain syndrome management.

    Science.gov (United States)

    Zaralidou, A Th; Amaniti, E N; Maidatsi, P G; Gorgias, N K; Vasilakos, D F

    2007-06-01

    Myofascial pain syndromes are characterized by the presence of painful loci within muscles, tendons or ligaments, called trigger points. Infiltration of these points with local anesthetics is often used as a treatment modality. The aim of the study was to comparatively evaluate 0.25% levobupivacaine and 0.25% ropivacaine for trigger point injection regarding pain on injection, treatment efficacy and duration of symptoms remission. Sixty-eight patients, suffering from myofascial pain syndromes, were randomly assigned to two groups to receive either levobupivacaine or ropivacaine for trigger-point injection. After completion of the procedure, patients were asked to rate pain during injection and efficacy of the treatment, based on immediate relief. Two weeks later, they were asked about the duration of this relief. Statistical analysis did not reveal significant differences between groups with respect to pain during injection, efficacy of the treatment and duration of pain relief. The two local anesthetics seem to be equally effective for trigger point infiltration. (c) 2007 Prous Science. All rights reserved.

  13. Electroconvulsive therapy in the elderly: Anesthetic considerations and Psychotropic interactions

    Directory of Open Access Journals (Sweden)

    Harsh Garekar

    2017-01-01

    Full Text Available Electroconvulsive therapy (ECT has been found to be a rapid and effective treatment strategy for psychiatric and neurological conditions in the elderly, but the administration of ECT in the elderly can be challenging due to a high risk of adverse events. The increased risk can be attributed to a declined physiological reserve, the presence of physical comorbidities, and the use of multiple drugs, which interact with the electrical stimulus and the anesthetic medications used during the ECT procedure. The selection of appropriate induction agents and muscle relaxants should be guided by patient's clinical status and the psychotropic drugs being used. Modifications in the doses of psychotropic drugs also need to be carried out before ECT to reduce cardiovascular and neurological side effects. Modification in the conduct of anesthesia can also aid in augmenting seizures and in preventing common side effects of ECT. A vital step in preventing adverse events in the elderly is carrying out a thorough pre.ECT evaluation. Despite these challenges, ECT can be carried out safely in elderly patients with severe comorbidities, provided clinical ECT, and anesthetic parameters are adequately optimized.

  14. Modification of GABA-mediated inhibition by various injectable anesthetics.

    Science.gov (United States)

    Albertson, T E; Walby, W F; Joy, R M

    1992-09-01

    Increasing doses of the injectable anesthetics etomidate, Saffan, thiopental, ketamine, and xylazine and the vehicles saline and propylene glycol were administered to urethane-anesthetized rats. Their effects in vivo on perforant pathway-evoked field excitatory post-synaptic potentials and population spikes in the hippocampal dentate gyrus were determined. The primary purpose was to ascertain whether these compounds affect hippocampal excitability in a manner consistent with their proposed mechanisms of action. Compared with their respective vehicles, thiopental, etomidate, and xylazine reduced the amplitude of population spikes to single perforant pathway stimulation by 20-30% at the highest doses tested. Xylazine also increased the latency to onset of the population spike. No other effects were observed. Using paired pulse paradigms, it was determined that etomidate produced a dramatic, prolonged reduction in granule cell excitability at interpulse intervals of 10-100 ms. The magnitude of the effect was dose related and was reversible with the discontinuance of administration of the drug. Similar changes occurred with Saffan (althesin) and thiopental. Ketamine produced a small but significant depression in granule cell excitability during intervals of 10-200 ms. Xylazine had no effect. These data corroborate the importance of a prolongation of gamma-aminobutyric acid A-mediated inhibition to the mechanism of actions of etomidate, thiopental, and Saffan at relevant exposure concentrations in vivo.

  15. Tolerability of NGX-4010, a capsaicin 8% patch, in conjunction with three topical anesthetic formulations for the treatment of neuropathic pain

    Directory of Open Access Journals (Sweden)

    Webster LR

    2012-01-01

    Full Text Available Lynn R Webster1, John F Peppin2, Frederick T Murphy3,4, Jeffrey K Tobias5, Geertrui F Vanhove51Lifetree Clinical Research and Pain Clinic, Lifetree Medical Inc, Salt Lake City, UT, USA; 2Clinical Research Division, The Pain Treatment Center of the Bluegrass, Lexington, KY, USA; 3Altoona Center for Clinical Research, Duncansville, PA, USA; 4University of Pennsylvania, School of Medicine, Philadelphia, PA, USA; 5NeurogesX Inc, San Mateo, CA, USABackground: The objective of this study was to assess the safety, tolerability, and preliminary efficacy of NGX-4010, a capsaicin 8% patch, following pretreatment with three different topical anesthetics in patients with peripheral neuropathic pain.Methods: This open-label, multicenter study enrolled 117 patients with post-herpetic neuralgia, HIV-associated distal sensory polyneuropathy, or painful diabetic neuropathy. Patients received pretreatment with one of three lidocaine 4%-based topical anesthetics (L.M.X.4® [Ferndale Laboratories Inc, Ferndale, MI], Topicaine® Gel [Estela Basso, Jupiter, FL], or Betacaine Enhanced Gel 4 [Tiberius Inc, Tampa, FL] for 60 minutes followed by a single 60- or 90-minute NGX-4010 application, and were followed for 12 weeks. Tolerability and safety measures included “pain now” Numeric Pain Rating Scale (NPRS scores, dermal assessments, medication use for treatment-related pain, adverse events (AEs, clinical laboratory parameters, physical examinations, and vital signs. The primary efficacy variable was the percentage change in mean NPRS scores for “average pain for the past 24 hours” from baseline to weeks 2 through 12.Results: Treatment with NGX-4010 following pretreatment with any of the three topical anesthetics was generally safe and well tolerated. Nearly all patients completed ≥90% of the planned NGX-4010 application duration. The most common treatment-related AEs, application-site burning and application-site pain, were transient, mostly mild or moderate

  16. Hyperglycemia adversely modulates endothelial nitric oxide synthase during anesthetic preconditioning through tetrahydrobiopterin- and heat shock protein 90-mediated mechanisms.

    Science.gov (United States)

    Amour, Julien; Brzezinska, Anna K; Jager, Zachary; Sullivan, Corbin; Weihrauch, Dorothee; Du, Jianhai; Vladic, Nikolina; Shi, Yang; Warltier, David C; Pratt, Phillip F; Kersten, Judy R

    2010-03-01

    role in cardioprotection that is favorably modulated by volatile anesthetics and dysregulated by hyperglycemia. Enhancing the production of BH4 may represent a potential therapeutic strategy.

  17. Controversies in perioperative anesthetic management of the morbidly obese: I am a surgeon, why should I care?

    Science.gov (United States)

    Sinha, Ashish C; Singh, Preet Mohinder

    2015-05-01

    Over the last four decades, as the rates of obesity have increased, so have the challenges associated with its anesthetic management. In the present review, we discuss perioperative anesthesia management issues that are modifiable by the early involvement of the surgical team. We sum up available evidence or expert opinion on issues like patient positioning, postoperative analgesia, and the effect of continuous positive airway pressure (CPAP) ventilation on surgical anastomosis. We also address established predictors of higher perioperative risk and suggest possible management strategies and concerns of obese patients undergoing same day procedures. Finally, a generalized pharmacological model relevant to altered pharmacokinetics in these patients is presented.

  18. Macroeconomic dataset for generating macroeconomic volatility among selected countries in the Asia Pacific region

    Directory of Open Access Journals (Sweden)

    Yee Peng Chow

    2018-02-01

    Full Text Available This data article provides macroeconomic data that can be used to generate macroeconomic volatility. The data cover a sample of seven selected countries in the Asia Pacific region for the period 2004–2014, including both developing and developed countries. This dataset was generated to enhance our understanding of the sources of macroeconomic volatility affecting the countries in this region. Although the Asia Pacific region continues to remain as the most dynamic part of the world's economy, it is not spared from various sources of macroeconomic volatility through the decades. The reported data cover 15 types of macroeconomic data series, representing three broad categories of indicators that can be used to proxy macroeconomic volatility. They are indicators that account for macroeconomic volatility (i.e. volatility as a macroeconomic outcome, domestic sources of macroeconomic volatility and external sources of macroeconomic volatility. In particular, the selected countries are Malaysia, Thailand, Indonesia and Philippines, which are regarded as developing countries, while Singapore, Japan and Australia are developed countries. Despite the differences in level of economic development, these countries were affected by similar sources of macroeconomic volatility such as the Asian Financial Crisis and the Global Financial Crisis. These countries were also affected by other similar external turbulence arising from factors such as the global economic slowdown, geopolitical risks in the Middle East and volatile commodity prices. Nonetheless, there were also sources of macroeconomic volatility which were peculiar to certain countries only. These were generally domestic sources of volatility such as political instability (for Thailand, Indonesia and Philippines, natural disasters and anomalous weather conditions (for Thailand, Indonesia, Philippines, Japan and Australia and over-dependence on the electronic sector (for Singapore. Keywords

  19. Dual effect of local anesthetics on the function of excitable rod outer segment disk membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mashimo, T.; Abe, K.; Yoshiya, I.

    1986-04-01

    The effects of local anesthetics and a divalent cation, Ca2+, on the function of rhodopsin were estimated from the measurements of light-induced proton uptake. The light-induced proton uptake by rhodopsin in the rod outer segment disk membrane was enhanced at lower pH (4) but depressed at higher pHs (6 to 8) by the tertiary amine local anesthetics lidocaine, bupivacaine, tetracaine, and dibucaine. The order of local anesthetic-induced depression of the proton uptake followed that of their clinical anesthetic potencies. The depression of the proton uptake versus the concentration of the uncharged form of local anesthetic nearly describes the same curve for small and large dose of added anesthetic. Furthermore, a neutral local anesthetic, benzocaine, depressed the proton uptake at all pHs between 4 and 7. These results indicate that the depression of the proton uptake is due to the effect of only the uncharged form. It is hypothesized that the uncharged form of local anesthetics interacts hydrophobically with the rhodopsin in the disk membrane. The dual effect of local anesthetics on the proton uptake, on the other hand, suggests that the activation of the function of rhodopsin may be caused by the charged form. There was no significant change in the light-induced proton uptake by rhodopsin when 1 mM of Ca2+ was introduced into the disk membrane at varying pHs in the absence or presence of local anesthetics. This fact indicates that Ca2+ ion does not influence the diprotonating process of metarhodopsin; neither does it interfere with the local anesthetic-induced changes in the rhodopsin molecule.

  20. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    OpenAIRE

    Chen, Jinghui; Kobayashi, Masahito; McAleer, Michael

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The proposed test is a stochastic volatility version of the co-movement test proposed by Engle and Susmel (1993), who investigated whether international equity markets have volatility co-movement using t...

  1. The price of fixed income market volatility

    CERN Document Server

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  2. Volatility modeling of asset returns | Babayemi | International Journal ...

    African Journals Online (AJOL)

    This research was carried out using the daily close share price of Nestle Nigeria Plc to identify and model its volatility of returns in the Nigerian Stock Exchange Market. The result of the study showed that basic Generalized Conditionally Heteroskedastic Model (GARCH (1,1)) model (with Gaussian Error Assumptions) best ...

  3. Observability of market daily volatility

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2016-02-01

    We study the price dynamics of 65 stocks from the Dow Jones Composite Average from 1973 to 2014. We show that it is possible to define a Daily Market Volatility σ(t) which is directly observable from data. This quantity is usually indirectly defined by r(t) = σ(t) ω(t) where the r(t) are the daily returns of the market index and the ω(t) are i.i.d. random variables with vanishing average and unitary variance. The relation r(t) = σ(t) ω(t) alone is unable to give an operative definition of the index volatility, which remains unobservable. On the contrary, we show that using the whole information available in the market, the index volatility can be operatively defined and detected.

  4. Multiscaling and clustering of volatility

    Science.gov (United States)

    Pasquini, Michele; Serva, Maurizio

    1999-07-01

    The dynamics of prices in stock markets has been studied intensively both experimentally (data analysis) and theoretically (models). Nevertheless, while the distribution of returns of the most important indices is known to be a truncated Lévy, the behaviour of volatility correlations is still poorly understood. What is well known is that absolute returns have memory on a long time range, this phenomenon is known in financial literature as clustering of volatility. In this paper we show that volatility correlations are power laws with a non-unique scaling exponent. This kind of multiscale phenomenology is known to be relevant in fully developed turbulence and in disordered systems and it is pointed out here for the first time for a financial series. In our study we consider the New York Stock Exchange (NYSE) daily index, from January 1966 to June 1998, for a total of 8180 working days.

  5. Epidemiological profile of patients seen in the pre-anesthetic assessment clinic of a university hospital

    Directory of Open Access Journals (Sweden)

    Monica Loureiro Santos

    Full Text Available Abstract Objective Assess the demographic and clinical characteristics of surgical patients seen in the Pre-anesthetic Assessment Clinic of the Hospital Universitário Gaffrée e Guinle (APA/HUGG, in order to assist in the pursuit for quality, effectiveness, and resource rationalization of hospital management. Method Cross-sectional descriptive study with 491 patients undergoing elective surgery, treated at APA/HUGG Clinic from March to December 2014. The following variables were assessed: sex, age, BMI, smoking status, associated diseases, classification of MET's and ASA, presence of decompensated disease, medical associated appointments interconsultation, specialty and surgical risk, history of prior anesthetic-surgical procedure, and complications. Results There was a predominance of female (64.8% and overweight patients (55.9%, aged 18-59 years. The prevalence of associated diseases was high (71.3%, with hypertension pressure prevailing (50.1%. Most patients had clinically compensated morbidity (96.3% and long-term use of medication (77.4%. Regarding the surgical characteristics, the most frequent specialty was general and medium risk surgeries. The analysis of the characteristics by age showed that the elderly have more associated diseases and long-term use of medication, in addition to predominance of ASA II-III. Conclusion The epidemiological profile of surgical patients seen at the APA/HUGG was female, age 18-59 years, overweight, with associated diseases, long-term use of medication, without clinical decompensation, ASA II and MET's ≥4. Knowledge of the clinical characteristics of surgical patients is critical to schedule the perioperative care, allowing the improvement of quality and safety in anesthesia and surgery.

  6. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average...... return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  7. Exact probability distribution function for the volatility of cumulative production

    Science.gov (United States)

    Zadourian, Rubina; Klümper, Andreas

    2018-04-01

    In this paper we study the volatility and its probability distribution function for the cumulative production based on the experience curve hypothesis. This work presents a generalization of the study of volatility in Lafond et al. (2017), which addressed the effects of normally distributed noise in the production process. Due to its wide applicability in industrial and technological activities we present here the mathematical foundation for an arbitrary distribution function of the process, which we expect will pave the future research on forecasting of the production process.

  8. Local anesthetics disrupt energetic coupling between the voltage-sensing segments of a sodium channel.

    Science.gov (United States)

    Muroi, Yukiko; Chanda, Baron

    2009-01-01

    Local anesthetics block sodium channels in a state-dependent fashion, binding with higher affinity to open and/or inactivated states. Gating current measurements show that local anesthetics immobilize a fraction of the gating charge, suggesting that the movement of voltage sensors is modified when a local anesthetic binds to the pore of the sodium channel. Here, using voltage clamp fluorescence measurements, we provide a quantitative description of the effect of local anesthetics on the steady-state behavior of the voltage-sensing segments of a sodium channel. Lidocaine and QX-314 shifted the midpoints of the fluorescence-voltage (F-V) curves of S4 domain III in the hyperpolarizing direction by 57 and 65 mV, respectively. A single mutation in the S6 of domain IV (F1579A), a site critical for local anesthetic block, abolished the effect of QX-314 on the voltage sensor of domain III. Both local anesthetics modestly shifted the F-V relationships of S4 domain IV toward hyperpolarized potentials. In contrast, the F-V curve of the S4 domain I was shifted by 11 mV in the depolarizing direction upon QX-314 binding. These antagonistic effects of the local anesthetic indicate that the drug modifies the coupling between the voltage-sensing domains of the sodium channel. Our findings suggest a novel role of local anesthetics in modulating the gating apparatus of the sodium channel.

  9. Bupivacaine Lozenge Compared with Lidocaine Spray as Topical Pharyngeal Anesthetic before Unsedated Upper Gastrointestinal Endoscopy

    DEFF Research Database (Denmark)

    Salale, Nesrin; Treldal, Charlotte; Mogensen, Stine

    2014-01-01

    Unsedated upper gastrointestinal endoscopy (UGE) can induce patient discomfort, mainly due to a strong gag reflex. The aim was to assess the effect of a bupivacaine lozenge as topical pharyngeal anesthetic compared with standard treatment with a lidocaine spray before UGE. Ninety-nine adult...... with a lidocaine spray proved to be a superior option as topical pharyngeal anesthetic before an UGE....

  10. Anesthetic success of 1.8ml lidocaine 2% for mandibular tooth extraction. A pilot study

    Directory of Open Access Journals (Sweden)

    Pedro Aravena

    2013-04-01

    Full Text Available Aim: To determine the anesthetic effect of a 1.8ml cartridge of anesthetic lidocaine 2% with epinephrine 1:100,000 in inferior alveolar nerve block (NAI for the extraction in mandibular teeth. Material and methods: A pilot study with analitic design. Participating patients of Dental Emergency Service volunteers from Valdivia-Chile for mandibular teeth extractions attending between May and July of 2010. The anesthetic technique was performed by a dentist using only one cartridge of anesthetic to the NAI. After 15 minutes, the effect was considered effective when anesthetic not require reinforcement with additional anesthesia during extraction of teeth. We analyzed the relationship between success anesthetic effect with sex, age, diagnosis of tooth and type and level of pain observed (chi-square and logistic regression, p<0.05. Results: 62 patients were selected, of which only 47(75.8% was achieved anesthetic success. There was no statistical association with sex, age, type or dental diagnosis and perceived pain. Conclusion: Using a 1.8ml cartridge of anesthesia was effective in three of four patients treated by extraction of mandibular teeth. It suggests further research in relation to the clinical effectiveness of other anesthetics with the same dose in NAI.

  11. Binding of long-lasting local anesthetics to lipid emulsions.

    Science.gov (United States)

    Mazoit, Jean-Xavier; Le Guen, Régine; Beloeil, Hélène; Benhamou, Dan

    2009-02-01

    Rapid infusion of lipid emulsion has been proposed to treat local anesthetic toxicity. The authors wanted to test the buffering properties of two commercially available emulsions made of long- and of long- and medium-chain triglycerides. Using the shake-flask method, the authors measured the solubility and binding of racemic bupivacaine, levobupivacaine, and ropivacaine to diluted Intralipid (Fresenius Kabi, Paris, France) and Medialipide (B-Braun, Boulogne, France). The apparent distribution coefficient expressed as the ratio of mole fraction was 823 +/- 198 and 320 +/- 65 for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively, at 500 mg in the Medialipide/buffer emulsion; and 1,870 +/- 92 and 1,240 +/- 14 for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively, in the Intralipid/buffer emulsion. Decreasing the pH from 7.40 to 7.00 of the Medialipide/buffer emulsion led to a decrease in ratio of molar concentration from 121 +/- 3.8 to 46 +/- 2.8 for bupivacaine, and to a lesser extent from 51 +/- 4.0 to 31 +/- 1.6 for ropivacaine. The capacity of the 1% emulsions was 871 and 2,200 microM for the 1% Medialipide and Intralipid emulsions, respectively. The dissociation constant was 818 and 2,120 microM for racemic bupivacaine and levobupivacaine, and ropivacaine, respectively. Increasing the temperature from 20 to 37 degrees C led to a greater increase in affinity for ropivacaine (55%) than for bupivacaine (27%). When the pH of the buffer was decreased from 7.40 to 7.00, the affinity was decreased by a factor of 1.68, similar for both anesthetics. The solubility of long-acting local anesthetics in lipid emulsions and the high capacity of binding of these emulsions most probably explain their clinical efficacy in case of toxicity. The long-chain triglyceride emulsion Intralipid appears to be about 2.5 times more efficacious than the 50/50 medium-chain/long-chain Medialipide emulsion. Also, because of their higher hydrophobicity

  12. Anesthetic management with scalp nerve block and propofol/remifentanil infusion during awake craniotomy in an adolescent patient -A case report-

    Science.gov (United States)

    Sung, Bohyun; Park, Jin-Woo; Byon, Hyo-Jin; Kim, Jin-Tae; Kim, Chong Sung

    2010-01-01

    Despite of various neurophysiologic monitoring methods under general anesthesia, functional mapping at awake state during brain surgery is helpful for conservation of speech and motor function. But, awake craniotomy in children or adolescents is worrisome considering their emotional friabilities. We present our experience on anesthetic management for awake craniotomy in an adolescent patient. The patient was 16 years old male who would undergo awake craniotomy for removal of brain tumor. Scalp nerve block was done with local anesthetics and we infused propofol and remifentanil with target controlled infusion. The patient endured well and was cooperative before scalp suture, but when surgeon sutured scalp, he complained of pain and was suddenly agitated. We decided change to general anesthesia. Neurosurgeon did full neurologic examinations and there was no neurologic deficit except facial palsy of right side. Facial palsy had improved with time. PMID:21286435

  13. DOES ENERGY CONSUMPTION VOLATILITY AFFECT REAL GDP VOLATILITY? AN EMPIRICAL ANALYSIS FOR THE UK

    Directory of Open Access Journals (Sweden)

    Abdul Rashid

    2013-10-01

    Full Text Available This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the results suggest that the impacts of unpredictable variations in energy consumption on GDP volatility are asymmetric, depending on the intensity of volatility. In particular, we find that while there is no significant contemporaneous relationship between energy consumption volatility and GDP volatility in the first (low-volatility regime, GDP volatility is significantly positively related to the volatility of energy utilization in the second (high-volatility regime.

  14. Dose-Dependent Protective Effect of Inhalational Anesthetics Against Postoperative Respiratory Complications

    DEFF Research Database (Denmark)

    Grabitz, Stephanie D; Farhan, Hassan N; Ruscic, Katarina J

    2017-01-01

    OBJECTIVES: Inhalational anesthetics are bronchodilators with immunomodulatory effects. We sought to determine the effect of inhalational anesthetic dose on risk of severe postoperative respiratory complications. DESIGN: Prospective analysis of data on file in surgical cases between January 2007...... with endotracheal intubation. INTERVENTIONS: Median effective dose equivalent of inhalational anesthetics during surgery (derived from mean end-tidal inhalational anesthetic concentrations). MEASUREMENTS AND MAIN RESULTS: Postoperative respiratory complications occurred in 6,979 of 124,497 cases (5.61%). High...... inhalational anesthetic dose of 1.20 (1.13-1.30) (median [interquartile range])-fold median effective dose equivalent versus 0.57 (0.45-0.64)-fold median effective dose equivalent was associated with lower odds of postoperative respiratory complications (odds ratio, 0.59; 95% CI, 0.53-0.65; p

  15. Increased inspiratory pressure for reduction of atelectasis in children anesthetized for CT scan

    International Nuclear Information System (INIS)

    Sargent, Michael A.; Jamieson, Douglas H.; McEachern, Anita M.; Blackstock, Derek

    2002-01-01

    Background: Atelectasis is more frequent and more severe in children anesthetized for CT scan than it is in children sedated for CT scan.Objective: To determine the effect of increased inspiratory pressure on atelectasis during chest CT in anesthetized children. Materials and methods: Atelectasis on chest CT was assessed by two observers in three groups of patients. Group A comprised 13 children (26 lungs) anesthetized at inspiratory pressures up to and including 25 cm H 2 O. Group B included 11 children anesthetized at inspiratory pressures ≥30 cm H 2 O. Group C included 8 children under deep sedation. Results: Atelectasis was significantly more severe in group A than in groups B and C. There was no significant difference between groups B and C. Conclusion: An inspiratory pressure of 30 cm H 2 O is recommended for children anesthetized for CT scan of the chest. (orig.)

  16. Ultrasound-guided continuous interscalene block: the influence of local anesthetic background delivery method on postoperative analgesia after shoulder surgery: a randomized trial.

    Science.gov (United States)

    Hamdani, Mehdi; Chassot, Olivier; Fournier, Roxane

    2014-01-01

    Automated bolus delivery has recently been shown to reduce local anesthetic consumption and improve analgesia, compared with continuous infusion, in continuous sciatic and epidural block. However, there are few data on the influence of local anesthetic delivery method on local anesthetic consumption following interscalene blockade. This randomized, double-blind trial was designed to determine whether hourly automated perineural boluses (4 mL) of local anesthesia delivered with patient-controlled pro re nata (PRN, on demand) boluses would result in a reduction in total local anesthesia consumption during continuous interscalene blockade after shoulder surgery compared with continuous perineural infusion (4 mL/h) plus patient-controlled PRN boluses. One hundred one patients undergoing major shoulder surgery under general anesthesia with ultrasound-guided continuous interscalene block were randomly assigned to receive 0.2% ropivacaine via interscalene end-hole catheter either by continuous infusion 4 mL/h (n = 50) or as automated bolus 4 mL/h (n = 51). Both delivery methods were combined with 5 mL PRN boluses of 0.2% ropivacaine with a lockout time of 30 minutes. Postoperative number of PRN boluses, 24- and 48-hour local anesthetic consumption, pain scores, rescue analgesia (morphine), and adverse events were recorded. There were no significant differences in either the number of PRN ropivacaine boluses or total 48 hour local anesthetic consumption between the groups (18.5 [11-25.2] PRN boluses in the continuous infusion group vs 17 [8.5-29] PRN boluses in the automated bolus group). Postoperative pain was similar in both groups; on day 2, the median average pain score was 4 (2-6) in the continuous infusion group versus 3 (2-5) in the automated bolus group (P = 0.54). Nor were any statistically significant intergroup differences observed with respect to morphine rescue, incidence of adverse events, or patient satisfaction. In continuous interscalene blockade under

  17. The infrared spectral properties of frozen volatiles. [in cometary nuclei

    Science.gov (United States)

    Fink, U.; Sill, G. T.

    1982-01-01

    Since Whipple's dirty snowball model of comet nuclei, it has been generally accepted that volatile ices help to explain cometary phenomena. The infrared spectral properties of many substances that are potential candidates for frozen volatiles in the solar system are being pursued; indeed some of these frozen materials have been found in the solar system: H2O, CO2, and SO2. A review of laboratory spectra in the range 1 to 20 microns of H2O, CO2, SO2, CH4, NH3, H2S, CO, NH4HS and NH3.H2O is presented. Both reflection spectra of thick frosts and transmission spectra of thin films are shown, and their main characteristics are described. Hydrates, clathrates, and composite spectra are discussed. When it is possible to observe the nuclei of comets at close range, it may be possible to identify frozen volatiles by their infrared spectra.

  18. The effect of oil price volatility on strategic investment

    International Nuclear Information System (INIS)

    Henriques, Irene; Sadorsky, Perry

    2011-01-01

    In this paper, we investigate how oil price volatility affects the strategic investment decisions of a large panel of US firms. This paper uses key insights from the real options literature to develop a model of a company's strategic investment and shows how changes in oil price volatility can impact strategic investment decisions. The model is estimated using recently developed generalized method of moment estimation techniques for panel data sets. Empirical results are presented to show that there is a U shaped relationship between oil price volatility and firm investment. This is consistent with the predictions from the strategic growth options literature. The results should be useful to decision makers, investors, managers, policy makers and others who need to make strategic investment decisions in an uncertain world. (author)

  19. DONKEY MILK SHELF LIFE: MICROBIOLOGY AND VOLATILE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    F. Conte

    2010-03-01

    Full Text Available Organoleptics properties are important to evaluate the shelf life of food products. Sensory analysis is generally used for this purpose. In this study psychrotrophic, mesophilic bacteria, and pH values were correlated to volatile compounds. The quality of raw donkey milk stored for 3, 7, 10, 14 and 28 days at two different temperatures (3°C and 7°C was tested. Donkey milk volatiles for the first time in this study were identified. Different volatiles distribution were detected by Smart Nose and GCO during the trials and a correlation with bacteriological and pH data were shown. On the basis of the results the acceptability of 10 days storing at +3°C, and of 3-4 days at +7°C, for milk samples, was pointed out.

  20. Comparison of transcoelomic, contrast transcoelomic, and transesophageal echocardiography in anesthetized red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Beaufrère, Hugues; Pariaut, Romain; Rodriguez, Daniel; Nevarez, Javier G; Tully, Thomas N

    2012-10-01

    To assess the agreement and reliability of cardiac measurements obtained with 3 echocardiographic techniques in anesthetized red-tailed hawks (Buteo jamaicensis). 10 red-tailed hawks. Transcoelomic, contrast transcoelomic, and transesophageal echocardiographic evaluations of the hawks were performed, and cineloops of imaging planes were recorded. Three observers performed echocardiographic measurements of cardiac variables 3 times on 3 days. The order in which hawks were assessed and echocardiographic techniques were used was randomized. Results were analyzed with linear mixed modeling, agreement was assessed with intraclass correlation coefficients, and variation was estimated with coefficients of variation. Significant differences were evident among the 3 echocardiographic methods for most measurements, and the agreement among findings was generally low. Interobserver agreement was generally low to medium. Intraobserver agreement was generally medium to high. Overall, better agreement was achieved for the left ventricular measurements and for the transesophageal approach than for other measurements and techniques. Echocardiographic measurements in hawks were not reliable, except when the left ventricle was measured by the same observer. Furthermore, cardiac morphometric measurements may not be clinically important. When measurements are required, one needs to consider that follow-up measurements should be performed by the same echocardiographer and should show at least a 20% difference from initial measurements to be confident that any difference is genuine.

  1. Retrospective analysis of obstetric and anesthetic management of patients with placenta accreta spectrum disorders.

    Science.gov (United States)

    Riveros-Perez, Efrain; Wood, Cristina

    2018-03-01

    To assess the management and maternal outcomes of placenta accreta spectrum (PAS) disorders. A retrospective chart review was conducted of patients diagnosed with PAS disorders (placenta creta, increta, or percreta) who were treated at a US tertiary care center between February 1, 2011, and January 31, 2016. Obstetric management, anesthetic management, and maternal outcomes were analyzed. A total of 43 cases were identified; placenta previa was diagnosed among 33 (77%). Median age was 33 years (range 23-42). Median blood loss was 1500 mL (interquartile range 1000-2500); blood loss was greatest among the 10 patients with placenta percreta (3250 mL, interquartile range 2200-6000). Transfusion of blood products was necessary among 14 (33%) patients, with no difference in frequency according to the degree of placental invasion (P=0.107). Surgical complications occurred among 10 (23%) patients. Overall, 30 (70%) patients received combined spinal-epidural plus general anesthesia, 4 (9%) received only general anesthesia, and 9 (21%) underwent surgery with combined spinal-epidural anesthesia. One patient experienced difficult airway and another experienced accidental dural puncture. Placenta previa and accreta coexist in many patients, leading to substantial bleeding related to the degree of myometrial invasion. An interdisciplinary team approach plus the use of combined spinal-epidural anesthesia, transitioning to general anesthesia, were advisable and safe. © 2017 International Federation of Gynecology and Obstetrics.

  2. The effects of anesthetic agents on oxidative stress

    Science.gov (United States)

    Yakan, Selvinaz; Düzgüner, Vesile

    2016-04-01

    Oxidative stress can be defined as the instability between antioxidant defense of the body and the production of free radical that causes peroxydation on the lipid layer. Free radicals are reactive oxygen species that are produced in the course of normal metabolisms of aerobe organisms and they may cause disorders in cell structure and organelles by interacting macromolecules, like lipid, protein, nucleic acids. Therefore, they may cause cardiovascular, immune system, liver, kidney illnesses and many other illnesses like cancer, aging, cataract, diabetes. It is known that many drugs used for the purpose of anesthetizing may cause lipid peroxidation in organism. For these reasons, determining the Oxidative stress index of anaesthetic stress chosen in the ones that are exposed to long term anaesthetic agents and anaesthesia appliccations, is so substantial.

  3. Electrocardiographic evaluation of two anesthetic combinations in dogs

    Directory of Open Access Journals (Sweden)

    Tárraga K.M.

    2000-01-01

    Full Text Available This study aimed to investigate electrocardiographic changes in dogs aged 5 years or more submitted to two anesthetic combinations: atropine, levomeprazine, thiopental and halothane (ALTH, and atropine, tiletamine and zolazepam (ATZ. Forty dogs (24 males/16 females weighing 5-24kg, were used. Dogs had no cardiac problems and were submitted to tartarectomy. All animals were submitted to two electrocardiograms (ECG, one before anesthesia and other immediately before surgery. The dogs were divided into two groups: group 1 received ALTH and group 2 received ATZ. Alterations in the ST segment, T wave, cardiac rhythm and a significant reduction of vagal tonus index were observed in both groups, but in group 2 a significant reduction of the PR and QT intervals and an increase in heart rate were also observed. These data suggest that the ALTH combination caused fewer changes in the ECG than the ATZ combination.

  4. Carcinoid tumors: Challenges and considerations during anesthetic management

    Directory of Open Access Journals (Sweden)

    Sukhminder Jit Singh Bajwa

    2015-01-01

    Full Text Available Carcinoid tumors are rare, slow-growing neoplasms of neuroendocrine tissues from enterochromaffin or kulchitsky cells, which have the potential to metastasize. The mediators released from these tumors when bypass the hepatic metabolism, can lead to the possible development of carcinoid syndrome. This is a life-threatening complication, which can lead to profound hemodynamic instability, especially in a peri-operative period, when the patient is exposed to various types of noxious stimuli. Off late, use of octreotide, a synthetic analog of somatostatin, has significantly reduced the peri-operative morbidity and mortality. The current review discusses the various anesthetic challenges and considerations during peri-operative management of carcinoid tumors.

  5. Use of lipid emulsion therapy in local anesthetic overdose

    Directory of Open Access Journals (Sweden)

    Ozgur Karcioglu

    2017-10-01

    Full Text Available The use of intravenous lipid emulsion (ILE therapy as antidote in systemic toxicity of certain agents has gained widespread support. There are increasing data suggesting use of ILE in reversing from local anesthetic-induced systemic toxicity severe, life-threatening cardiotoxicity, although findings are contradictory. Efficiency of ILE was demonstrated in animal studies in the treatment of severe impairment of cardiac functions, via a mechanism for trapping lipophilic drugs in an expanded plasma lipid compartment (“lipid sink”. In patients with hemodynamic compromise and/or cardiovascular collapse due to lipid-soluble agents, ILE may be considered for resuscitation in the acute setting by emergency physicians. The most common adverse effects from standard ILE include hypertriglyceridemia, fat embolism, infection, vein irritation, pancreatitis, electrolyte disturbances and allergic reactions. The advantages of ILE include an apparent wide margin of safety, relatively low cost, long shelf-life, and ease of administration.

  6. GABAA Receptors, Anesthetics and Anticonvulsants in Brain Development

    Science.gov (United States)

    Henschel, Oliver; Gipson, Keith E.; Bordey, Angelique

    2008-01-01

    GABA, acting via GABAA receptors, is well-accepted as the main inhibitory neurotransmitter of the mature brain, where it dampens neuronal excitability. The receptor's properties have been studied extensively, yielding important information about its structure, pharmacology, and regulation that are summarized in this review. Several GABAergic drugs have been commonly used as anesthetics, sedatives, and anticonvulsants for decades. However, findings that GABA has critical functions in brain development, in particular during the late embryonic and neonatal period, raise worthwhile questions regarding the side effects of GABAergic drugs that may lead to long-term cognitive deficits. Here, we will review some of these drugs in parallel with the control of CNS development that GABA exerts via activation of GABAA receptors. This review aims to provide a basic science and clinical perspective on the function of GABA and related pharmaceuticals acting at GABAA receptors. PMID:18537647

  7. Anesthetic management of robot-assisted thoracoscopic thymectomy

    Directory of Open Access Journals (Sweden)

    Anil Karlekar

    2016-01-01

    Full Text Available Myasthenia gravis (MG is a rare disorder involving neuromuscular junction. In conjunction with medical therapy, thymectomy is a known modality of treatment of MG and has shown to increase the probability of remission and overall symptomatic improvement. For minimally invasive thymectomy, video-.assisted thoracoscopic surgery has been the preferred surgical approach till recently. The robotic surgical procedure must necessarily bring new challenges to the anesthesiologists to effectively meet the specific requirements of the technique. At present, there is a paucity of literature regarding the anesthetic concerns of robotic assisted thymectomy, patient in question specifically posed a challenge since different maneuvers and techniques had to be tried to obtain optimum surgical conditions with stable ventilatory and hemodynamic parameters. Concerns of patient positioning and hemodynamic monitoring have also been discussed.

  8. Eugenol as an anesthetic for juvenile common snook

    Directory of Open Access Journals (Sweden)

    Jurandir Joaquim Bernardes Júnior

    2013-08-01

    Full Text Available The objective of this work was to evaluate the efficacy of eugenol as an anesthetic for juvenile common snook, and to determine the minimum effective concentration for use in handling procedures. In the first trial, juvenile common snook were subjected to immersion baths at 25, 50, 75, 100, 125, and 150 mg L-1 eugenol concentrations, after which induction and recovery times were evaluated. In the second experiment, the lethal exposure time (LT50 at 75 mg L-1 was estimated. Minimum effective eugenol concentration was 50 mg L-1, andthe stage of deep anesthesia and recovery were, respectively, reached at 126.3 and 208.8 s. At 75 mg L-1, LT50 was 1,314 s, and induction time and recovery were also satisfactory; however, fish cannot tolerate over 229 s exposure.

  9. Buffered lidocaine and bupivacaine mixture - the ideal local anesthetic solution?

    Science.gov (United States)

    Best, Corliss A; Best, Alyssa A; Best, Timothy J; Hamilton, Danielle A

    2015-01-01

    The use of injectable local anesthetic solutions to facilitate pain-free surgery is an integral component of many procedures performed by the plastic surgeon. In many instances, a solution that has both rapid onset and prolonged duration of analgesia is optimal. A combination of lidocaine and bupivacaine, plain or with epinephrine, is readily available in most Canadian health care settings where such procedures are performed, and fulfills these criteria. However, commercially available solutions of both medications are acidic and cause a burning sensation on injection. Buffering to neutral pH with sodium bicarbonate is a practical method to mitigate the burning sensation, and has the added benefit of increasing the fraction of nonionized lipid soluble drug available. The authors report on the proportions of the three drugs to yield a neutral pH, and the results of an initial survey regarding the use of the combined solution with epinephrine in hand surgery.

  10. Volatility Spillovers Across Petroleum Markets

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kočenda, Evžen; Vácha, Lukáš

    2015-01-01

    Roč. 36, č. 3 (2015), s. 309-329 ISSN 0195-6574 R&D Projects: GA ČR GA14-24129S Keywords : Volatility spillovers * Asymmetry * Petroleum markets Subject RIV: AH - Economics Impact factor: 1.662, year: 2015 http://library.utia.cas.cz/separaty/2014/E/barunik-0438407.pdf

  11. Stochastic Volatility and DSGE Models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller

    This paper argues that a specification of stochastic volatility commonly used to analyze the Great Moderation in DSGE models may not be appropriate, because the level of a process with this specification does not have conditional or unconditional moments. This is unfortunate because agents may...

  12. Under Utilization of Local Anesthetics in Infant Lumbar Punctures

    Directory of Open Access Journals (Sweden)

    Gorchynski, Julie

    2008-01-01

    Full Text Available Background: Lumbar Puncture (LP is an invasive procedure frequently used to diagnose meningitis among the pediatric population. Neonates and infants have not routinely received local anesthesia prior to LP. Study Objective: To determine whether emergency medicine physicians and pediatricians use local analgesics on neonates and infants prior to performing an LP and to identify which local anesthetics, if any, were used. Methods: Prospective, cohort study of all infants, six months of age or less, that received an LP in the emergency department (ED or inpatient pediatric units for suspected meningitis during a period of year at a university tertiary care hospital. Results: A total sample population of 111 infants that received an LP within the study period. A control population of 42 adults received an LP. Only 40.4% (45/111 of the infants received local analgesia prior to LP: either 1% lidocaine, EMLA or a combination of the two. Infants were less likely to receive lidocaine or EMLA prior to LP compared to adult subjects (OR= 0.27; 95% CI0.12 to 0.62. No neonates that were less than one month of age received local procedural anesthesia by emergency medicine or pediatric physicians. ED physicians’ use of local anesthesia prior to LP increased with increasing age of the infant. The pediatricians in this study used local anesthesia prior to LP when the infant was at least five months of age. Discussion: The data objectively support recent literature regarding the under use or lack of use of analgesia prior to LP among neonates and infants. Local anesthetics should be used routinely without exception prior to performing an LP in the pediatric population.

  13. [Anesthetic Care of Patient With Heroin Addiction: A Case Report].

    Science.gov (United States)

    Lee, Wen-Yi; Kuo, Shu-Yu

    2018-04-01

    The use of illegal drugs in Taiwan is on the rise. Drug addicts often have complex physical, psychological, and social problems. In addition, they often avoid disclosing their illicit drug use by deceit, concealment, or under-reporting. Building and maintaining relationships of trust with drug-addict patients has become a critical issue in achieving better care quality. In this case report, we report on an anesthesia care process for a heroin addict who was admitted for open reduction and internal fixation surgery for the femur and patella fractures after a car accident. During the six-hour perioperative care period, starting from 11pm on November 30th to 5am on December 1st, 2015, the patient was not willing to disclose his illicit drug use before the surgery. However, the nurse anesthetist noticed signs and symptoms of drug use. The nurse empathized with the patient's worries, provided him with a safe communication environment, and gained trust from the patient in a timely manner, which then enabled the patient to fully disclose his illicit drug use with the nurse anesthetist. The anesthesia-care strategy was then modified according to client's condition. The nurse anesthetist played an important role of bridging communications between the patient and medical care staffs and of modifying the care strategies in a timely manner. During the care period, the blood-borne disease contamination was successfully prevented, the client received uneventful pain management, there was a lack of withdrawal symptoms, and the staffs and patient safety was maintained. The literature on the anesthetic care of heroin patients undergoing surgery is relatively limited in Taiwan. The findings in the current case report add information on providing anesthetic care to patients with drug addiction. Publishing additional case reports, research, and clinical recommendations is essential for improving care quality for this vulnerable population.

  14. From micro- to nanostructured implantable device for local anesthetic delivery

    Science.gov (United States)

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola

    2016-01-01

    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies

  15. Anesthetic drugs in status epilepticus: Risk or rescue?

    Science.gov (United States)

    Marsch, Stephan; Fuhr, Peter; Kaplan, Peter W.; Rüegg, Stephan

    2014-01-01

    Objective: To evaluate the risks of continuously administered IV anesthetic drugs (IVADs) on the outcome of adult patients with status epilepticus (SE). Methods: All intensive care unit patients with SE from 2005 to 2011 at a tertiary academic medical care center were included. Relative risks were calculated for the primary outcome measures of seizure control, Glasgow Outcome Scale score at discharge, and death. Poisson regression models were used to control for possible confounders and to assess effect modification. Results: Of 171 patients, 37% were treated with IVADs. Mortality was 18%. Patients with anesthetic drugs had more infections during SE (43% vs 11%; p < 0.0001) and a 2.9-fold relative risk for death (2.88; 95% confidence interval 1.45–5.73), independent of possible confounders (i.e., duration and severity of SE, nonanesthetic third-line antiepileptic drugs, and critical medical conditions) and without significant effect modification by different grades of SE severity and etiologies. As IVADs were used after first- and second-line drugs failed, there was a correlation between treatment-refractory SE and the use of IVADs, leading to insignificant results regarding the risk of IVADs and outcome after additional adjustment for refractory SE. Conclusion: Our findings heighten awareness regarding adverse effects of IVADs. Randomized controlled trials are needed to further clarify the association of IVADs with outcome in patients with SE. Classification of evidence: This study provides Class III evidence that patients with SE receiving IVADs have a higher proportion of infection and an increased risk of death as compared to patients not receiving IVADs. PMID:24319039

  16. Characterisation of selected volatile organic compounds in ...

    African Journals Online (AJOL)

    GCMS), was used to identify volatile compounds at three different temperatures. Fifty volatile compounds, inclusive of 14 acids, 14 alcohols, and 22 esters were identified and quantified in the two brands of indigenous banana beer samples. Only 12 ...

  17. Time-Varying Periodicity in Intraday Volatility

    DEFF Research Database (Denmark)

    Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor

    We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...

  18. A Fractionally Integrated Wishart Stochastic Volatility Model

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2013-01-01

    textabstractThere has recently been growing interest in modeling and estimating alternative continuous time multivariate stochastic volatility models. We propose a continuous time fractionally integrated Wishart stochastic volatility (FIWSV) process. We derive the conditional Laplace transform of

  19. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    We present and test a model relating a firm's idiosyncratic cost, its exporting status, and the volatilities of its domestic and export sales. In prior models of trade, supply costs for domestic and exports were linear and thus additively separable. We introduce a nonlinear cost function in order...... to link the domestic and export supply costs. This theoretical contribution has two new implications for the exporting firm. First, the demand volatility in the foreign market now directly affects the firm's domestic sales volatility. Second, firms hedge domestic demand volatility with exports. The model...... has several testable predictions. First, larger firms have lower total and domestic sales volatilities. Second, foreign market volatility increases domestic sales volatilities for exporters. Third, exporters allocate output across both markets in order to reduce total sales volatility. We find...

  20. Fluctuation behaviors of financial return volatility duration

    Science.gov (United States)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  1. Macroeconomic dataset for generating macroeconomic volatility among selected countries in the Asia Pacific region.

    Science.gov (United States)

    Chow, Yee Peng; Muhammad, Junaina; Amin Noordin, Bany Ariffin; Cheng, Fan Fah

    2018-02-01

    This data article provides macroeconomic data that can be used to generate macroeconomic volatility. The data cover a sample of seven selected countries in the Asia Pacific region for the period 2004-2014, including both developing and developed countries. This dataset was generated to enhance our understanding of the sources of macroeconomic volatility affecting the countries in this region. Although the Asia Pacific region continues to remain as the most dynamic part of the world's economy, it is not spared from various sources of macroeconomic volatility through the decades. The reported data cover 15 types of macroeconomic data series, representing three broad categories of indicators that can be used to proxy macroeconomic volatility. They are indicators that account for macroeconomic volatility (i.e. volatility as a macroeconomic outcome), domestic sources of macroeconomic volatility and external sources of macroeconomic volatility. In particular, the selected countries are Malaysia, Thailand, Indonesia and Philippines, which are regarded as developing countries, while Singapore, Japan and Australia are developed countries. Despite the differences in level of economic development, these countries were affected by similar sources of macroeconomic volatility such as the Asian Financial Crisis and the Global Financial Crisis. These countries were also affected by other similar external turbulence arising from factors such as the global economic slowdown, geopolitical risks in the Middle East and volatile commodity prices. Nonetheless, there were also sources of macroeconomic volatility which were peculiar to certain countries only. These were generally domestic sources of volatility such as political instability (for Thailand, Indonesia and Philippines), natural disasters and anomalous weather conditions (for Thailand, Indonesia, Philippines, Japan and Australia) and over-dependence on the electronic sector (for Singapore).

  2. Pyrolysis and volatilization of cocaine

    International Nuclear Information System (INIS)

    Martin, B.R.; Lue, L.P.; Boni, J.P.

    1989-01-01

    The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time

  3. A nonparametric approach to forecasting realized volatility

    OpenAIRE

    Adam Clements; Ralf Becker

    2009-01-01

    A well developed literature exists in relation to modeling and forecasting asset return volatility. Much of this relate to the development of time series models of volatility. This paper proposes an alternative method for forecasting volatility that does not involve such a model. Under this approach a forecast is a weighted average of historical volatility. The greatest weight is given to periods that exhibit the most similar market conditions to the time at which the forecast is being formed...

  4. Siderophile Volatile Element Partitioning during Core Formation.

    Science.gov (United States)

    Loroch, D. C.; Hackler, S.; Rohrbach, A.; Klemme, S.

    2017-12-01

    Since the nineteen sixties it is known, that the Earth's mantle is depleted relative to CI chondrite in numerous elements as a result of accretion and core-mantle differentiation. Additionally, if we take the chondritic composition as the initial solar nebular element abundances, the Earth lacks 85 % of K and up to 98 % of other volatiles. However one potentially very important group of elements has received considerably less attention in this context and these elements are the siderophile but volatile elements (SVEs). SVEs perhaps provide important information regarding the timing of volatile delivery to Earth. Especially for the SVEs the partitioning between metal melt and silicate melt (Dmetal/silicate) at core formation conditions is poorly constrained, never the less they are very important for most of the core formation models. This study is producing new metal-silicate partitioning data for a wide range of SVEs (S, Se, Te, Tl, Ag, As, Au, Cd, Bi, Pb, Sn, Cu, Ge, Zn, In and Ga) with a focus on the P, T and fO2dependencies. The initial hypothesis that we are aiming to test uses the accretion of major portions of volatile elements while the core formation was still active. The key points of this study are: - What are the effects of P, T and fO2 on SVE metal-silicate partioning? - What is the effect of compositional complexity on SVE metal-silicate partioning? - How can SVE's D-values fit into current models of core formation? The partitioning experiments will be performed using a Walker type multi anvil apparatus in a pressure range between 10 and 20 GPa and temperatures of 1700 up to 2100 °C. To determine the Dmetal/silicate values we are using a field emission high-resolution JEOL JXA-8530F EPMA for major elements and a Photon Machines Analyte G2 Excimer laser (193 nm) ablation system coupled to a Thermo Fisher Element 2 single-collector ICP-MS (LA-ICP-MS) for the trace elements. We recently finished the first sets of experiments and can provide the

  5. TMVOC, simulator for multiple volatile organic chemicals

    International Nuclear Information System (INIS)

    Pruess, Karsten; Battistelli, Alfredo

    2003-01-01

    TMVOC is a numerical simulator for three-phase non-isothermal flow of water, soil gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. It is an extension of the TOUGH2 general-purpose simulation program developed at the Lawrence Berkeley National Laboratory. TMVOC is designed for applications to contamination problems that involve hydrocarbon fuel or organic solvent spills in saturated and unsaturated zones. It can model contaminant behavior under ''natural'' environmental conditions, as well as for engineered systems, such as soil vapor extraction, groundwater pumping, or steam-assisted source remediation. TMVOC is upwards compatible with T2VOC (Falta et al., 1995) and can be initialized from T2VOC-style initial conditions. The main enhancements in TMVOC relative to T2VOC are as follows: a multicomponent mixture of volatile organic chemicals can be modeled; any and all combinations of the three phases water-oil-gas are treated; several non-condensible gases may be present; diffusion is treated in all phases in a manner that is fully coupled with phase partitioning. This paper gives a brief summary of the methodology used in TMVOC as well as highlighting some implementation issues. Simulation of a NAPL spill and subsequent remediation is discussed for a 2-D vertical section of a saturated-unsaturated flow problem

  6. Adhesion of volatile propofol to breathing circuit tubing.

    Science.gov (United States)

    Lorenz, Dominik; Maurer, Felix; Trautner, Katharina; Fink, Tobias; Hüppe, Tobias; Sessler, Daniel I; Baumbach, Jörg Ingo; Volk, Thomas; Kreuer, Sascha

    2017-08-21

    Propofol in exhaled breath can be measured and may provide a real-time estimate of plasma concentration. However, propofol is absorbed in plastic tubing, thus estimates may fail to reflect lung/blood concentration if expired gas is not extracted directly from the endotracheal tube. We evaluated exhaled propofol in five ventilated ICU patients who were sedated with propofol. Exhaled propofol was measured once per minute using ion mobility spectrometry. Exhaled air was sampled directly from the endotracheal tube and at the ventilator end of the expiratory side of the anesthetic circuit. The circuit was disconnected from the patient and propofol was washed out with a separate clean ventilator. Propofol molecules, which discharged from the expiratory portion of the breathing circuit, were measured for up to 60 h. We also determined whether propofol passes through the plastic of breathing circuits. A total of 984 data pairs (presented as median values, with 95% confidence interval), consisting of both concentrations were collected. The concentration of propofol sampled near the patient was always substantially higher, at 10.4 [10.25-10.55] versus 5.73 [5.66-5.88] ppb (p tubing was 4.58 [4.48-4.68] ppb, 3.46 [3.21-3.73] in the first hour, 4.05 [3.77-4.34] in the second hour, and 4.01 [3.36-4.40] in the third hour. Out-gassing propofol from the breathing circuit remained at 2.8 ppb after 60 h of washing out. Diffusion through the plastic was not observed. Volatile propofol binds or adsorbs to the plastic of a breathing circuit with saturation kinetics. The bond is reversible so propofol can be washed out from the plastic. Our data confirm earlier findings that accurate measurements of volatile propofol require exhaled air to be sampled as close as possible to the patient.

  7. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    NARCIS (Netherlands)

    J. Chen (Jinghui); M. Kobayashi (Masahito); M.J. McAleer (Michael)

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The

  8. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  9. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...

  10. How safe is deep sedation or general anesthesia while providing dental care?

    Science.gov (United States)

    Bennett, Jeffrey D; Kramer, Kyle J; Bosack, Robert C

    2015-09-01

    Deep sedation and general anesthesia are administered daily in dental offices, most commonly by oral and maxillofacial surgeons and dentist anesthesiologists. The goal of deep sedation or general anesthesia is to establish a safe environment in which the patient is comfortable and cooperative. This requires meticulous care in which the practitioner balances the patient's depth of sedation and level of responsiveness while maintaining airway integrity, ventilation, and cardiovascular hemodynamics. Using the available data and informational reports, the authors estimate that the incidence of death and brain injury associated with deep sedation or general anesthesia administered by all dentists most likely exceeds 1 per month. Airway compromise is a significant contributing factor to anesthetic complications. The American Society of Anesthesiology closed claim analysis also concluded that human error contributed highly to anesthetic mishaps. The establishment of a patient safety database for anesthetic management in dentistry would allow for a more complete assessment of morbidity and mortality that could direct efforts to further increase safe anesthetic care. Deep sedation and general anesthesia can be safely administered in the dental office. Optimization of patient care requires appropriate patient selection, selection of appropriate anesthetic agents, utilization of appropriate monitoring, and a highly trained anesthetic team. Achieving a highly trained anesthetic team requires emergency management preparation that can foster decision making, leadership, communication, and task management. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

  11. Comparison of the temperature and humidity in the anesthetic breathing circuit among different anesthetic workstations: Updated guidelines for reporting parallel group randomized trials.

    Science.gov (United States)

    Choi, Yoon Ji; Min, Sam Hong; Park, Jeong Jun; Cho, Jang Eun; Yoon, Seung Zhoo; Yoon, Suk Min

    2017-06-01

    For patients undergoing general anesthesia, adequate warming and humidification of the inspired gases is very important. The aim of this study was to evaluate the differences in the heat and moisture content of the inspired gases with low-flow anesthesia using 4 different anesthesia machines. The patients were divided into 11 groups according to the anesthesia machine used (Ohmeda, Excel; Avance; Dräger, Cato; and Primus) and the fresh gas flow (FGF) rate (0.5, 1, and 4 L/min). The temperature and absolute humidity of the inspired gas in the inspiratory limbs were measured at 5, 10, 15, 30, 45, 60, 75, 90, 105, and 120 minutes in 9 patients scheduled for total thyroidectomy or cervical spine operation in each group. The anesthesia machines of Excel, Avance, Cato, and Primus did not show statistically significant changes in the inspired gas temperatures over time within each group with various FGFs. They, however, showed statistically significant changes in the absolute humidity of the inspired gas over time within each group with low FGF anesthesia (P humidity of the inspired gas over time within each group with an FGF of 4 L/min (P humidities of the inspired gas for all anesthesia machines were lower than the recommended values. There were statistical differences in the provision of humidity among different anesthesia workstations. The Cato and Primus workstations were superior to Excel and Avance. However, even these were unsatisfactory in humans. Therefore, additional devices that provide inspired gases with adequate heat and humidity are needed for those undergoing general anesthetic procedures.

  12. Complete recovery from intractable complex regional pain syndrome, CRPS-type I, following anesthetic ketamine and midazolam.

    Science.gov (United States)

    Kiefer, Ralph-Thomas; Rohr, Peter; Ploppa, Annette; Altemeyer, Karl-Heinz; Schwartzman, Robert Jay

    2007-06-01

    To describe the treatment of an intractable complex regional pain syndrome I (CRPS-I) patient with anesthetic doses of ketamine supplemented with midazolam. A patient presented with a rapidly progressing contiguous spread of CRPS from a severe ligamentous wrist injury. Standard pharmacological and interventional therapy successively failed to halt the spread of CRPS from the wrist to the entire right arm. Her pain was unmanageable with all standard therapy. As a last treatment option, the patient was transferred to the intensive care unit and treated on a compassionate care basis with anesthetic doses of ketamine in gradually increasing (3-5 mg/kg/h) doses in conjunction with midazolam over a period of 5 days. On the second day of the ketamine and midazolam infusion, edema, and discoloration began to resolve and increased spontaneous movement was noted. On day 6, symptoms completely resolved and infusions were tapered. The patient emerged from anesthesia completely free of pain and associated CRPS signs and symptoms. The patient has maintained this complete remission from CRPS for 8 years now. In a patient with severe spreading and refractory CRPS, a complete and long-term remission from CRPS has been obtained utilizing ketamine and midazolam in anesthetic doses. This intensive care procedure has very serious risks but no severe complications occurred. The psychiatric side effects of ketamine were successfully managed with the concomitant use of midazolam and resolved within 1 month of treatment. This case report illustrates the effectiveness and safety of high-dose ketamine in a patient with generalized, refractory CRPS.

  13. Money growth volatility and the demand for money in Germany: Friedman's volatility hypothesis revisited

    OpenAIRE

    Brüggemann, Imke; Nautz, Dieter

    1997-01-01

    Recently, the Bundesbank claimed that monetary targeting has become considerably more diffcult by the increased volatility of short-term money growth. The present paper investigates the impact of German money growth volatility on income velocity and money demand in view of Friedman's money growth volatility hypothesis. Granger-causality tests provide some evidence for a velocity-volatility linkage. However the estimation of volatility-augmented money demand functions reveals that - in contras...

  14. Ambulatory anesthetic care in children undergoing myringotomy and tube placement: current perspectives.

    Science.gov (United States)

    Robinson, Hal; Engelhardt, Thomas

    2017-01-01

    Myringotomy and tube placement is one of the most frequently performed ear, nose and throat (ENT) surgeries in the pediatric population. Effective anesthetic management is vital to ensuring successful ambulatory care and ensuring child and parental satisfaction. This review summarizes recently published studies about the long-term effects of general anesthesia in young children, novel approaches to preoperative fasting and simplified approaches to the assessment and management of emergence delirium (ED) and emergence agitation (EA). New developments in perioperative ambulatory care, including management of comorbidities and day care unit logistics, are discussed. Long-term follow-up of children exposed to general anesthesia before the age of 4 years has limited impact on academic achievement or cognitive performance and should not delay the treatment of common ENT pathology, which can impair speech and language development. A more liberal approach to fasting, employing a 6-4-0 regime allowing children fluids up until theater, may become an accepted practice in future. ED and EA should be discriminated from pain in recovery and, where the child is at risk of harm, should be treated promptly. Postoperative pain at home remains problematic in ambulatory surgery and better parental education is needed. Effective ambulatory care ultimately requires a well-coordinated team approach from effective preassessment to postoperative follow-up.

  15. Modeling energy price dynamics: GARCH versus stochastic volatility

    International Nuclear Information System (INIS)

    Chan, Joshua C.C.; Grant, Angelia L.

    2016-01-01

    We compare a number of GARCH and stochastic volatility (SV) models using nine series of oil, petroleum product and natural gas prices in a formal Bayesian model comparison exercise. The competing models include the standard models of GARCH(1,1) and SV with an AR(1) log-volatility process, as well as more flexible models with jumps, volatility in mean, leverage effects, and t distributed and moving average innovations. We find that: (1) SV models generally compare favorably to their GARCH counterparts; (2) the jump component and t distributed innovations substantially improve the performance of the standard GARCH, but are unimportant for the SV model; (3) the volatility feedback channel seems to be superfluous; (4) the moving average component markedly improves the fit of both GARCH and SV models; and (5) the leverage effect is important for modeling crude oil prices—West Texas Intermediate and Brent—but not for other energy prices. Overall, the SV model with moving average innovations is the best model for all nine series. - Highlights: • We compare a variety of GARCH and SV models for fitting nine series of energy prices. • We find that SV models generally compare favorably to their GARCH counterparts. • The SV model with moving average innovations is the best model for all nine series.

  16. Impact of microorganism on polonium volatilization

    International Nuclear Information System (INIS)

    Momoshima, N.; Ishida, A.; Fukuda, A.; Yoshinaga, C.

    2007-01-01

    Volatilization of polonium by microorganisms, Chromobacterium violaceum, Escherichia coli and Bacillus subtilis was examined for pure cultures in LB medium at 30 deg C, showing relative Po emission intensity 100, 10 and 1, respectively. Chromobacterium violaceum pre-cultured in LB medium without Po and suspended in water with Po showed high Po volatilization in spite of poor nutriment condition. Antibiotics inhibit volatilization of Po and cultivation at low temperature greatly reduced volatilization. The results strongly support the biological effects on Po volatilization. (author)

  17. Quantitative estimates of the volatility of ambient organic aerosol

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2010-06-01

    high and variable ΔHvap assumptions. Our results also show that the amount of semivolatile gas-phase organics in equilibrium with the OA could range from ~20% to 400% of the OA mass, with smaller values generally corresponding to the higher ΔHvap assumptions. The volatility of various OA components determined from factor analysis of AMS spectra has also been assessed. In general, it is found that the fraction of non-volatile material follows the pattern: biomass burning OA < hydrocarbon-like OA < semivolatile oxygenated OA < low-volatility oxygenated OA. Correspondingly, the sensitivity to dilution and the estimated amount of semivolatile gas-phase material for the OA factors follows the reverse order. Primary OA has a substantial semivolatile fraction, in agreement with previous results, while the non-volatile fraction appears to be dominated by oxygenated OA produced by atmospheric aging. The overall OA volatility is thus controlled by the relative contribution of each aerosol type to the total OA burden. Finally, the model/measurement comparison appears to require OA having an evaporation coefficient (γe substantially greater than 10−2; at this point it is not possible to place firmer constraints on γe based on the observations.

  18. Quantitative estimates of the volatility of ambient organic aerosol

    Science.gov (United States)

    Cappa, C. D.; Jimenez, J. L.

    2010-06-01

    % to 400% of the OA mass, with smaller values generally corresponding to the higher ΔHvap assumptions. The volatility of various OA components determined from factor analysis of AMS spectra has also been assessed. In general, it is found that the fraction of non-volatile material follows the pattern: biomass burning OA hydrocarbon-like OA < semivolatile oxygenated OA < low-volatility oxygenated OA. Correspondingly, the sensitivity to dilution and the estimated amount of semivolatile gas-phase material for the OA factors follows the reverse order. Primary OA has a substantial semivolatile fraction, in agreement with previous results, while the non-volatile fraction appears to be dominated by oxygenated OA produced by atmospheric aging. The overall OA volatility is thus controlled by the relative contribution of each aerosol type to the total OA burden. Finally, the model/measurement comparison appears to require OA having an evaporation coefficient (γe) substantially greater than 10-2; at this point it is not possible to place firmer constraints on γe based on the observations.

  19. Anesthetic management of a parturient with Guillain-Barre syndrome posted for emergency caesarian section

    Directory of Open Access Journals (Sweden)

    Abhijit Paul

    2012-01-01

    Full Text Available We report the anesthetic management of a case of Guillain-Barre syndrome in the 34 th week of gestation coming for an emergency Cesarean section. The perioperative anesthetic challenges have been discussed with emphasis on the medical and anesthetic management which includes the use of plasma-pheresis, intravenous gamma-globulin, and the safety of preservative free 0.75% isobaric ropivacaine, which was administered intrathecally in this difficult medical condition with excellent hemodynamic, maternal, and fetal outcome. The sensory and motor blocks achieved were well suited to the clinical risks and conditions.

  20. An improved method for lifting and transporting anesthetized pigs within an animal facility

    DEFF Research Database (Denmark)

    Schumacher-Petersen, Camilla; Hammelev, Karsten Pharao; Flescher, Jens Erik

    2014-01-01

    Transporting anesthetized pigs in a laboratory setting often requires strenuous manual lifting, posing a hazard to the safety of animal care personnel and to the welfare of the pigs. The authors developed an improved approach to lifting and transporting anesthetized pigs weighing up to 350 kg using...... mechanical lifts. Different equipment was used to accommodate pigs of different sizes as well as the building designs of three animal facilities. Using the lifts, anesthetized pigs are carried on sheets to maintain their comfort while being transported. The approach refines previous methods for handling...

  1. Volatile constituents of Trichothecium roseum.

    Science.gov (United States)

    Vanhaelen, M; Vanhaelen-Fastre, R; Geeraerts, J

    1978-06-01

    In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.

  2. Chirospecific analysis of plant volatiles

    International Nuclear Information System (INIS)

    Tkachev, A V

    2007-01-01

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  3. Chirospecific analysis of plant volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Tkachev, A V [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-10-31

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  4. Forecasting volatility of crude oil markets

    International Nuclear Information System (INIS)

    Kang, Sang Hoon; Kang, Sang-Mok; Yoon, Seong-Min

    2009-01-01

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  5. Forecasting volatility of crude oil markets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sang Hoon [Department of Business Administration, Gyeongsang National University, Jinju, 660-701 (Korea); Kang, Sang-Mok; Yoon, Seong-Min [Department of Economics, Pusan National University, Busan, 609-735 (Korea)

    2009-01-15

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  6. Money, banks and endogenous volatility

    OpenAIRE

    Pere Gomis-Porqueras

    2000-01-01

    In this paper I consider a monetary growth model in which banks provide liquidity, and the government fixes a constant rate of money creation. There are two underlying assets in the economy, money and capital. Money is dominated in rate of return. In contrast to other papers with a larger set of government liabilities, I find a unique equilibrium when agents' risk aversion is moderate. However, indeterminacies and endogenous volatility can be observed when agents are relatively risk averse.

  7. Autoradiographic methods for studying marked volatile substances (1961)

    International Nuclear Information System (INIS)

    Cohen, Y.; Wepierre, J.

    1961-01-01

    The autoradiographic methods for animals used up to the present do not make it possible to localise exactly the distribution of marked volatile molecules. The Ullberg method (1954) which we have modified (Cohen, Delassue, 1959) involves cold desiccant. The method due to Pellerin (1957) avoids this desiccant but the histological comparison of the autoradiography with the biological document itself is difficult, if not impossible. Nevertheless, we have adopted certain points in the two methods and propose the following technique for the autoradiographic study of marked volatile molecules: 1- The surface of the frozen sample to be studied is prepared using a freezing microtome. 2- The last section, which is 20 μ thick and whose histological elements are parallel to those of the block, is dried by cooling and is used as the biological reference document for the autoradiography obtained, as is indicated in 3; 3- The radiography films are applied to the frozen block at -30 deg. C. The autoradiographs correspond to the radioactivity of the volatile molecule and of its non-volatile degradation products. 4- The radiographic film is also applied to the 20 μ section previously dried at -20 deg. C. This autoradiography corresponds to the radioactivity of the non-volatile degradation products of the molecule. 5- We confirmed the absence of diffusion of the volatile molecule and of pseudo-radiographic effects (photochemical and others). This method, which has enabled us to study the distribution of a carbide, para-cymene (C 14 ) 7, macroscopically in the case of a whole mouse and microscopically on the skin of a dog, can find general applications. (authors) [fr

  8. High-frequency volatility combine forecast evaluations: An empirical study for DAX

    Directory of Open Access Journals (Sweden)

    Wen Cheong Chin

    2017-01-01

    Full Text Available This study aims to examine the benefits of combining realized volatility, higher power variation volatility and nearest neighbour truncation volatility in the forecasts of financial stock market of DAX. A structural break heavy-tailed heterogeneous autoregressive model under the heterogeneous market hypothesis specification is employed to capture the stylized facts of high-frequency empirical data. Using selected averaging forecast methods, the forecast weights are assigned based on the simple average, simple median, least squares and mean square error. The empirical results indicated that the combination of forecasts in general shown superiority under four evaluation criteria regardless which proxy is set as the actual volatility. As a conclusion, we summarized that the forecast performance is influenced by three factors namely the types of volatility proxy, forecast methods (individual or averaging forecast and lastly the type of actual forecast value used in the evaluation criteria.

  9. Forecasting volatility for options valuation

    International Nuclear Information System (INIS)

    Belaifa, M.; Morimune, K.

    2006-01-01

    The petroleum sector plays a neuralgic role in the basement of world economies, and market actors (producers, intermediates, as well as consumers) are continuously subjected to the dynamics of unstable oil market. Huge amounts are being invested along the production chain to make one barrel of crude oil available to the end user. Adding to that are the effect of geopolitical dynamics as well as geological risks as expressed in terms of low chances of successful discoveries. In addition, fiscal regimes and regulations, technology and environmental concerns are also among some of the major factors that contribute to the substantial risk in the oil industry and render the market structure vulnerable to crises. The management of these vulnerabilities require modern tools to reduce risk to a certain level, which unfortunately is a non-zero value. The aim of this paper is, therefore, to provide a modern technique to capture the oil price stochastic volatility that can be implemented to value the exposure of an investor, a company, a corporate or a Government. The paper first analyses the regional dependence on oil prices, through a historical perspective and then looks at the evolution of pricing environment since the large price jumps of the 1970s. The main causes of oil prices volatility are treated in the third part of the paper. The rest of the article deals with volatility models and forecasts used in risk management, with an implication for pricing derivatives. (author)

  10. Human skin volatiles: a review.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

    2013-05-01

    Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

  11. Volatilization of gasoline from soil

    International Nuclear Information System (INIS)

    Arthus, P.

    1993-05-01

    Gasoline contaminated soil threatens water resources and air quality. The extent of the threat depends on gasoline behavior in soil, which is affected by various mechanisms such as volatilization. To quantify volatilization, gasoline spills were simulated in the laboratory using a synthetic gasoline and three dry soils. Total gasoline and individual gasoline compound concentrations in soil were monitored as a function of depth and time. The time to reduce overall gasoline concentration in coarse sand, sandy loam, and silt loam to 40% of initial concentration, averaged between surface and a 200-mm depth, ranged from 0.25 d to 10 d. A wicking phenomenon which contributed to gasoline flux toward the atmosphere was indicated by behavior of a low-volatility gasoline compound. Based on separate wicking experiments, this bulk immiscible movement was estimated at an upward velocity of 0.09 m/d for Delhi sandy loam and 0.05 m/d for Elora silt loam. 70 refs., 24 figs., 34 tabs

  12. Autoradiographic methods for studying marked volatile substances (1961); Methode.d'etude autoradiographique de substances marquees volatiles (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Y; Wepierre, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The autoradiographic methods for animals used up to the present do not make it possible to localise exactly the distribution of marked volatile molecules. The Ullberg method (1954) which we have modified (Cohen, Delassue, 1959) involves cold desiccant. The method due to Pellerin (1957) avoids this desiccant but the histological comparison of the autoradiography with the biological document itself is difficult, if not impossible. Nevertheless, we have adopted certain points in the two methods and propose the following technique for the autoradiographic study of marked volatile molecules: 1- The surface of the frozen sample to be studied is prepared using a freezing microtome. 2- The last section, which is 20 {mu} thick and whose histological elements are parallel to those of the block, is dried by cooling and is used as the biological reference document for the autoradiography obtained, as is indicated in 3; 3- The radiography films are applied to the frozen block at -30 deg. C. The autoradiographs correspond to the radioactivity of the volatile molecule and of its non-volatile degradation products. 4- The radiographic film is also applied to the 20 {mu} section previously dried at -20 deg. C. This autoradiography corresponds to the radioactivity of the non-volatile degradation products of the molecule. 5- We confirmed the absence of diffusion of the volatile molecule and of pseudo-radiographic effects (photochemical and others). This method, which has enabled us to study the distribution of a carbide, para-cymene (C{sup 14}) 7, macroscopically in the case of a whole mouse and microscopically on the skin of a dog, can find general applications. (authors) [French] Les methodes d'autoradiographies sur l'animal, proposees jusqu'a present, ne permettent pas de localiser de facon precise la distribution de molecules marquees volatiles. En effet, la methode de Ullberg (1954) que nous avons modifiee (Cohen, Delassue, 1959) necessite la dessiccation par le froid. La methode

  13. Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

    Science.gov (United States)

    Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

    2017-04-01

    Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Anesthetic and adjunctive drugs for fast-track surgery.

    Science.gov (United States)

    Baldini, G; Carli, F

    2009-08-01

    With the changes in health care dictated by economic pressure, there has been a realization that hospital stay could be shortened without compromising quality of care. Advances in surgical technology and anesthetic drugs have made an impact in the way perioperative care is delivered with some emphasis on multidisciplinary approach. From the expansion of ambulatory care, lessons were learnt how to apply same concepts to major surgery with the understanding that interventions to attenuate the surgical stress would facilitate the return to "baseline". Beside minimal invasive approach to surgery, anesthesia interventions are arranged with the intent to decrease the negative effects of surgical stress and pain, to minimize the side effects of drugs and at the same time to facilitate the recuperation which follows after surgery. Fast-track or accelerated care encompasses many aspects of anesthesia care, not only preoperative preparation and prehabilitation, but intraoperative attenuation of surgical stress and postoperative rehabilitation. The anesthesiologist is part of this team with the specific mission to use medications and techniques which have the least side effects on organ functions, provide analgesia which in turn facilitates the intake of food and mobilization out of bed. This chapter has been conceived with the intention to direct the clinician towards procedure-specific protocols where the choice of medications and techniques is based on published evidence. The success of implementing fast-track depends more on dynamic harmony amongst the various participants (surgeons, anesthesiologists, nurses, nutrtionists, physiotherapists) than on reaching an optimum level of excellence at each separate organization level.

  15. Infrared image monitoring of local anesthetic poisoning in rats

    Directory of Open Access Journals (Sweden)

    Angelo Manoel G. Carstens

    Full Text Available Abstract Background and objectives: To evaluate the thermographic predictive value of local anesthetic poisoning in rats that indicates the early recognition of thermal signs of intoxication and enable the immediate start of advanced life support. Methods: Wistar rats underwent intraperitoneal injection of saline and ropivacaine; they were allocated into pairs, and experiments performed at baseline and experimental times. For thermography, central and peripheral compartment were analyzed, checking the maximum and average differences of temperatures between groups. Thermographic and clinical observations were performed for each experiment, and the times in which the signs of intoxication occurred were recorded. In the thermal analysis, the thermograms corresponding to the times of interest were sought and relevant data sheets extracted for statistical analysis. Results: Basal and experimental: the display of the thermal images at times was possible. It was possible to calculate the heat transfer rate in all cases. At baseline it was possible to see the physiology of microcirculation, characterized by thermal distribution in the craniocaudal direction. It was possible to visualize the pathophysiological changes or thermal dysautonomias caused by intoxication before clinical signs occur, characterized by areas of hyper-radiation, translating autonomic nervous system pathophysiological disorders. In animals poisoned by ropivacaine, there was no statistically significant difference in heat transfer rate at the experimental time. Conclusions: The maximum temperature, medium temperature, and heat transfer rate were different from the statistical point of view between groups at the experimental time, thus confirming the systemic thermographic predictive value.

  16. Mechanics of anesthetic needle penetration into human sciatic nerve.

    Science.gov (United States)

    Pichamuthu, Joseph E; Maiti, Spandan; Gan, Maria G; Verdecchia, Nicole M; Orebaugh, Steven L; Vorp, David A

    2018-06-06

    Nerve blocks are frequently performed by anesthesiologists to control pain. For sciatic nerve blocks, the optimal placement of the needle tip between its paraneural sheath and epineurial covering is challenging, even under ultrasound guidance, and frequently results in nerve puncture. We performed needle penetration tests on cadaveric isolated paraneural sheath (IPS), isolated nerve (IN), and the nerve with overlying paraneural sheath (NPS), and quantified puncture force requirement and fracture toughness of these specimens to assess their role in determining the clinical risk of nerve puncture. We found that puncture force (123 ± 17 mN) and fracture toughness (45.48 ± 9.72 J m -2 ) of IPS was significantly lower than those for NPS (1440 ± 161 mN and 1317.46 ± 212.45 Jm -2 , respectively), suggesting that it is not possible to push the tip of the block needle through the paraneural sheath only, without pushing it into the nerve directly, when the sheath is lying directly over the nerve. Results of this study provide a physical basis for tangential placement of the needle as the ideal situation for local anesthetic deposition, as it allows for the penetration of the sheath along the edge of the nerve without entering the epineurium. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Differential regional metabolism of glucagon in anesthetized pigs

    DEFF Research Database (Denmark)

    Deacon, Carolyn F; Kelstrup, Mette; Trebbien, Ramona

    2003-01-01

    Glucagon metabolism under basal (endogenous) conditions and during intravenous glucagon infusion was studied in anesthetized pigs by use of midregion (M), COOH-terminal (C), and NH2-terminal (N)-RIAs. Arteriovenous concentration differences revealed a negative extraction of endogenous glucagon.......5 +/- 6.7%, M-, C-, N-RIA) and exogenous conditions (46.9 +/- 4.8, 46.4 +/- 6.0, 47.0 +/- 7.7%; M-, C-, N-RIA), indicating substantial elimination of the peptide. Hepatic glucagon extraction was undetectable under basal conditions and detected only by M-RIA (10.0 +/- 3.8%) during glucagon infusion......, indicating limited midregional cleavage of the molecule. The plasma half-life determined by C- and N-RIAs (2.7 +/- 0.2 and 2.3 +/- 0.2 min) were similar, but both were shorter than when determined by M-RIA (3.2 +/- 0.2 min, P Metabolic clearance rates were similar regardless of assay (14.4 +/- 1...

  18. A Comparison of Intramuscular Anesthetic Techniques in Chickens

    Directory of Open Access Journals (Sweden)

    Shahin Hajighahramani

    2017-02-01

    Full Text Available Background & Objective: Administration of anesthetic substances to chickens requires careful consideration for the safe delivery of the agent to the bird. The research objective was to evaluate several drug combinations for intramuscular anesthesia in chickens for physiologic, nutritional, pharmacological and other investigations. Meterial & Methods: Sixty healthy chickens were randomly assigned in six treatment groups and received Ketamine in combination with Xylazine, Midazolam or Acepromazine. Heart and respiratory rate, induction time, duration of surgical anesthesia and light anesthesia were measured. Results: Induction of anesthesia was significantly longer following Acepromazine- Ketamine and Midazolam- Ketamine compared to other groups (P<0.05. Duration of surgical anesthesia was longest with Xylazine- Midazolam- Ketamine and shortest with Midazolam-Ketamine and Acepromazine- Ketamine (P<0.05. Conclusion: In conclusion, the most effective drug combinations resulting in longer duration of surgical anesthesia, were Xylazine- Acepromazine- Ketamine and Xylazine- Midazolam- Ketamine. Other combinations did not produce appropriate surgical anesthesia, but they make slight changes in physiological data.

  19. The articulo-cardiac sympathetic reflex in spinalized, anesthetized rats.

    Science.gov (United States)

    Nakayama, Tomohiro; Suzuki, Atsuko; Ito, Ryuzo

    2006-04-01

    Somatic afferent regulation of heart rate by noxious knee joint stimulation has been proven in anesthetized cats to be a reflex response whose reflex center is in the brain and whose efferent arc is a cardiac sympathetic nerve. In the present study we examined whether articular stimulation could influence heart rate by this efferent sympathetic pathway in spinalized rats. In central nervous system (CNS)-intact rats, noxious articular movement of either the knee or elbow joint resulted in an increase in cardiac sympathetic nerve activity and heart rate. However, although in acutely spinalized rats a noxious movement of the elbow joint resulted in a significant increase in cardiac sympathetic nerve activity and heart rate, a noxious movement of the knee joint had no such effect and resulted in only a marginal increase in heart rate. Because this marginal increase was abolished by adrenalectomy suggests that it was due to the release of adrenal catecholamines. In conclusion, the spinal cord appears to be capable of mediating, by way of cardiac sympathetic nerves, the propriospinally induced reflex increase in heart rate that follows noxious stimulation of the elbow joint, but not the knee joint.

  20. Anesthetic Management of a Pediatric Patient with Arginase Deficiency

    Directory of Open Access Journals (Sweden)

    Abdulkadir Atım

    2011-09-01

    Full Text Available Arginase deficiency is an autosomal recessive disorder of the urea cycle in which a defect in conversion of arginine to urea and ornithine leads to hyperammonemia. Patients with urea cycle disorders may show increased protein catabolism due to inadequate intake of energy, protein and essential amino acids; infections, fever and surgery. A 12-year-old girl with arginase deficiency, ASA II who weighed 40 kg was scheduled for bilateral adductor, quadriceps and gastrocnemius tenotomies. She had mental retardation, spasticity and flexion posture of thelower limbs. Metabolic homeostasis was restored with appropriate diet. Successful anesthetic management allowed the patient to be discharged 48 hours after surgery. Increased levels of arginine and ammonia during or after surgery may lead to serious complications such as hypotension, cerebral edema, convulsions, hypothermia and spasticity. Thus special attention must be given to metabolic homeostasis and nutrition of the patients with arginase deficiency in the perioperative period. Primary goals should be to minimize stress levels by effective anxiolysis, provide an adequate amount of protein-free energy with proper fluid management and to obtain an effective preemptive and postoperative analgesia. In addition to a high level of knowledge, successful anesthesia requires professional communication among nursing staff, dietitians, pediatric metabolism specialist, surgeon and anesthesiologist.

  1. On fractality and chaos in Moroccan family business stock returns and volatility

    Science.gov (United States)

    Lahmiri, Salim

    2017-05-01

    The purpose of this study is to examine existence of fractality and chaos in returns and volatilities of family business companies listed on the Casablanca Stock Exchange (CSE) in Morocco, and also in returns and volatility of the CSE market index. Detrended fluctuation analysis based Hurst exponent and fractionally integrated generalized autoregressive conditional heteroskedasticity (FIGARCH) model are used to quantify fractality in returns and volatility time series respectively. Besides, the largest Lyapunov exponent is employed to quantify chaos in both time series. The empirical results from sixteen family business companies follow. For return series, fractality analysis show that most of family business returns listed on CSE exhibit anti-persistent dynamics, whilst market returns have persistent dynamics. Besides, chaos tests show that business family stock returns are not chaotic while market returns exhibit evidence of chaotic behaviour. For volatility series, fractality analysis shows that most of family business stocks and market index exhibit long memory in volatility. Furthermore, results from chaos tests show that volatility of family business returns is not chaotic, whilst volatility of market index is chaotic. These results may help understanding irregularities patterns in Moroccan family business stock returns and volatility, and how they are different from market dynamics.

  2. The effects of transversus abdominis plane block on analgesic and anesthetic consumption during total abdominal hysterectomy: a randomized controlled study

    Directory of Open Access Journals (Sweden)

    Tugba Karaman

    Full Text Available Abstract Background and objectives: A transversus abdominis plane block is a peripheral block method that has been used successfully for pain relief after total abdominal hysterectomy. However, the effects of the combination of the transversus abdominis plane block and general anesthesia on analgesic and anesthetic requirements remain unclear. This randomized placebo-controlled study is aimed to evaluate the effects of transversus abdominis plane block on analgesic and anesthetic consumption during total abdominal hysterectomy under general anesthesia. Methods: Sixty-six women undergoing total abdominal hysterectomy were randomized into two groups to receive general anesthesia alone (control group or with transversus abdominis plane block using 20 mL of 0.25% bupivacaine (transversus abdominis plane group. Intraoperative remifentanil and sevoflurane consumption were recorded. We also evaluated the postoperative pain, nausea, quality of recovery scores and rescue analgesic requirement during postoperative 24 hours. Results: The total remifentanil and sevoflurane consumption is significantly lower in transversus abdominis plane group; respectively mean (SD 0.130 (0.25 vs. 0.094 (0.02 mcg.kg-1.min-1; p < 0.01 and 0.295 (0.05 vs. 0.243 (0.06 mL.min-1; p < 0.01. In the postoperative period, pain scores were significantly reduced in transversus abdominis plane group soon after surgery; median (range 6 (2-10 vs. 3 (0-5; p < 0.001, at 2 h (5 [3-9] vs. 2.5 [0-6]; p < 0.001, at 6 h (4 [2-7] vs. 3[0-6], p < 0.001, at 12 h (3.5 [1-6] vs. 2 [1-5]; p = 0.003. The patients in the transversus abdominis plane group had significantly higher QoR-40 scores 190.5 (175-197 vs. 176.5 (141-187; p < 0.001. Conclusion: Combining transversus abdominis plane block with general anesthesia can provide reduced opioid and anesthetic consumption and can improve postoperative pain and quality of recovery scores in patients undergoing total abdominal hysterectomy.

  3. Local anesthetic-induced inhibition of human neutrophil priming: the influence of structure, lipophilicity, and charge

    NARCIS (Netherlands)

    Picardi, Susanne; Cartellieri, Sibylle; Groves, Danja; Hahnenekamp, Klaus; Gerner, Peter; Durieux, Marcel E.; Stevens, Markus F.; Lirk, Philipp; Hollmann, Markus W.

    2013-01-01

    Local anesthetics (LAs) are widely known for inhibition of voltage-gated sodium channels underlying their antiarrhythmic and antinociceptive effects. However, LAs have significant immunomodulatory properties and were shown to affect human neutrophil functions independent of sodium-channel blockade.

  4. Transient osteoporosis of pregnancy: A case report and review of anesthetic implications

    Directory of Open Access Journals (Sweden)

    Victor Eduardo Anillo Lombana

    2013-01-01

    We reviewed the anesthetic implications of this rare disease, particularly the use of a regional technique that removes the restrictive effect of the hip pain, and therefore increases the risk of a fracture.

  5. The origin of volatiles in the Earth's mantle

    Science.gov (United States)

    Hier-Majumder, Saswata; Hirschmann, Marc M.

    2017-08-01

    The Earth's deep interior contains significant reservoirs of volatiles such as H, C, and N. Due to the incompatible nature of these volatile species, it has been difficult to reconcile their storage in the residual mantle immediately following crystallization of the terrestrial magma ocean (MO). As the magma ocean freezes, it is commonly assumed that very small amounts of melt are retained in the residual mantle, limiting the trapped volatile concentration in the primordial mantle. In this article, we show that inefficient melt drainage out of the freezing front can retain large amounts of volatiles hosted in the trapped melt in the residual mantle while creating a thick early atmosphere. Using a two-phase flow model, we demonstrate that compaction within the moving freezing front is inefficient over time scales characteristic of magma ocean solidification. We employ a scaling relation between the trapped melt fraction, the rate of compaction, and the rate of freezing in our magma ocean evolution model. For cosmochemically plausible fractions of volatiles delivered during the later stages of accretion, our calculations suggest that up to 77% of total H2O and 12% of CO2 could have been trapped in the mantle during magma ocean crystallization. The assumption of a constant trapped melt fraction underestimates the mass of volatiles in the residual mantle by more than an order of magnitude.Plain Language SummaryThe Earth's deep interior contains substantial amounts of volatile elements like C, H, and N. How these elements got sequestered in the Earth's interior has long been a topic of debate. It is generally assumed that most of these elements escaped the interior of the Earth during the first few hundred thousand years to create a primitive atmosphere, leaving the mantle reservoir nearly empty. In this work, we show that the key to this paradox involves the very early stages of crystallization of the mantle from a global magma ocean. Using numerical models, we show

  6. Volatile element loss during planetary magma ocean phases

    Science.gov (United States)

    Dhaliwal, Jasmeet K.; Day, James M. D.; Moynier, Frédéric

    2018-01-01

    Moderately volatile elements (MVE) are key tracers of volatile depletion in planetary bodies. Zinc is an especially useful MVE because of its generally elevated abundances in planetary basalts, relative to other MVE, and limited evidence for mass-dependent isotopic fractionation under high-temperature igneous processes. Compared with terrestrial basalts, which have δ66Zn values (per mille deviation of the 66Zn/64Zn ratio from the JMC-Lyon standard) similar to some chondrite meteorites (∼+0.3‰), lunar mare basalts yield a mean δ66Zn value of +1.4 ± 0.5‰ (2 st. dev.). Furthermore, mare basalts have average Zn concentrations ∼50 times lower than in typical terrestrial basaltic rocks. Late-stage lunar magmatic products, including ferroan anorthosite, Mg- and Alkali-suite rocks have even higher δ66Zn values (+3 to +6‰). Differences in Zn abundance and isotopic compositions between lunar and terrestrial rocks have previously been interpreted to reflect evaporative loss of Zn, either during the Earth-Moon forming Giant Impact, or in a lunar magma ocean (LMO) phase. To explore the mechanisms and processes under which volatile element loss may have occurred during a LMO phase, we developed models of Zn isotopic fractionation that are generally applicable to planetary magma oceans. Our objective was to identify conditions that would yield a δ66Zn signature of ∼+1.4‰ within the lunar mantle. For the sake of simplicity, we neglect possible Zn isotopic fractionation during the Giant Impact, and assumed a starting composition equal to the composition of the present-day terrestrial mantle, assuming both the Earth and Moon had zinc 'consanguinity' following their formation. We developed two models: the first simulates evaporative fractionation of Zn only prior to LMO mixing and crystallization; the second simulates continued evaporative fractionation of Zn that persists until ∼75% LMO crystallization. The first model yields a relatively homogenous bulk solid

  7. Stochastic volatility models and Kelvin waves

    Energy Technology Data Exchange (ETDEWEB)

    Lipton, Alex [Merrill Lynch, Mlfc Main, 2 King Edward Street, London EC1A 1HQ (United Kingdom); Sepp, Artur [Merrill Lynch, 4 World Financial Center, New York, NY 10080 (United States)], E-mail: Alex_Lipton@ml.com, E-mail: Artur_Sepp@ml.com

    2008-08-29

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  8. Stochastic volatility models and Kelvin waves

    Science.gov (United States)

    Lipton, Alex; Sepp, Artur

    2008-08-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  9. Stochastic volatility models and Kelvin waves

    International Nuclear Information System (INIS)

    Lipton, Alex; Sepp, Artur

    2008-01-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics

  10. Uncertainty of Volatility Estimates from Heston Greeks

    Directory of Open Access Journals (Sweden)

    Oliver Pfante

    2018-01-01

    Full Text Available Volatility is a widely recognized measure of market risk. As volatility is not observed it has to be estimated from market prices, i.e., as the implied volatility from option prices. The volatility index VIX making volatility a tradeable asset in its own right is computed from near- and next-term put and call options on the S&P 500 with more than 23 days and less than 37 days to expiration and non-vanishing bid. In the present paper we quantify the information content of the constituents of the VIX about the volatility of the S&P 500 in terms of the Fisher information matrix. Assuming that observed option prices are centered on the theoretical price provided by Heston's model perturbed by additive Gaussian noise we relate their Fisher information matrix to the Greeks in the Heston model. We find that the prices of options contained in the VIX basket allow for reliable estimates of the volatility of the S&P 500 with negligible uncertainty as long as volatility is large enough. Interestingly, if volatility drops below a critical value of roughly 3%, inferences from option prices become imprecise because Vega, the derivative of a European option w.r.t. volatility, and thereby the Fisher information nearly vanishes.

  11. Wound infiltration with local anesthetics for post-operative pain relief in lumbar spine surgery

    DEFF Research Database (Denmark)

    Kjærgaard, M; Møiniche, S; Olsen, K S

    2012-01-01

    In this systematic review, we evaluated double-blind, randomized and controlled trials on the effect of wound infiltration with local anesthetics compared with the effect of placebo on post-operative pain after lumbar spine surgery.......In this systematic review, we evaluated double-blind, randomized and controlled trials on the effect of wound infiltration with local anesthetics compared with the effect of placebo on post-operative pain after lumbar spine surgery....

  12. Effect of a New Local Anesthetic Buffering Device on Pain Reduction During Nerve Block lnjections

    Science.gov (United States)

    2014-07-10

    the anticipation of pain associated with dental care is a significant deterrent in seeking treatment. With the advent of modern local anesthesia ...eliminate pain from dental injection to include: application of topical anesthesia , tissue pressure/vibration, cold application, and buffering of the local ...anesthetic solution. In dentistry , the effect of buffering local anesthetic solutions was first studied by Gros and Laewen in 1910 and then by

  13. Anesthetic considerations for a pediatric patient with Wolf-Hirschhorn syndrome: a case report

    OpenAIRE

    Tsukamoto, Masanori; Yamanaka, Hitoshi; Yokoyama, Takeshi

    2017-01-01

    Wolf-Hirschhorn syndrome is a rare hereditary disease that results from a 4p chromosome deletion. Patients with this syndrome are characterized by craniofacial dysgenesis, seizures, growth delay, intellectual disability, and congenital heart disease. Although several cases have been reported, very little information is available on anesthetic management for patients with Wolf-Hirschhorn syndrome. We encountered a case requiring anesthetic management for a 2-year-old girl with Wolf-Hirschhorn ...

  14. Anesthetic management of a child with autistic spectrum disorder and homocysteinemia

    Directory of Open Access Journals (Sweden)

    Deepak Choudhary

    2016-01-01

    Full Text Available Autistic spectrum disorder (ASD is a developmental disability of the central nervous system with rapid worsening. A subset of patients also has mitochondrial dysfunction leading to increased sensitivity to various anesthetic agents. Rarely, gene mutation in these patients results in homocysteinemia which causes higher incidences of thromboembolism, hypoglycemia, and seizures. Anesthetic management of ASD with homocysteinemia and refractory seizures has not been previously reported.

  15. Volume of Anesthetic in 0.5% Marcaine with 1:200,000 Epinephrine Dental Carpule

    Science.gov (United States)

    2016-04-01

    copyrighted material in the thesis manuscript entitled: "Volume of Anesthetic in 0.5% Marcaine with 1:200,000 Epinephrine Dental Carpule" Is...3. School/DepartmenUCenter: Army Postgraduate Dental School, AEGD-2 Program, Fort Hood, TX 4. Phone: (708) 227-2152 5. Type of clearance...X_Thesis _Article _Book _Poster _Presentation _Other 6. Title: "Volume of Anesthetic in 0.5% Marcaine with 1:200,000 Epinephrine Dental Carpule

  16. The anesthetics influence (ethilic-eter and urethane) on renal radiopharmaceuticals

    International Nuclear Information System (INIS)

    Muramoto, E.; Achando, S.S.; Araujo, E.B. de; Hamada, H.S.; Silva Valente Goncalves, R. da; Pereira, N.P.S. de; Silva, C.P.G. da.

    1990-01-01

    A comparative study was done using anesthetics like ether ethilic and urethane, in rats (Wistar). A significative variation was observed in the results obtained when renal radiopharmaceuticals were investigated. Using urethane, the renal uptake increase progressivelly due to the inhibition of the renal filtration and it starts to recuperate when the anesthetic effect was eliminated. Using ether ethilic the radiopharmaceuticals are quickly eliminated from the kidneys (tubular or glomerular filtration), showing that the renal function was protected. (author) [pt

  17. Anesthetic drugs accelerate the progression of postoperative metastases of mouse tumors.

    OpenAIRE

    Shapiro, J; Jersky, J; Katzav, S; Feldman, M; Segal, S

    1981-01-01

    Experiments were made to investigate the effect of four anesthetic drugs that are commonly used in surgical practice on the postoperative growth of mouse tumors in syngeneic recipients. These experiments revealed that some of the anesthetics when applied for surgical excision of the local tumor, strongly accelerated postoperative progression of spontaneous lung metastases produced by the 3LL Lewis lung carcinoma and by the B16 melanoma. Some of the drugs caused the appearance of metastases in...

  18. Intraosseous injection as an adjunct to conventional local anesthetic techniques: A clinical study

    OpenAIRE

    Mohamed Idris; Nasil Sakkir; Kishore Gopalakrishna Naik; Nandakishore Kunijal Jayaram

    2014-01-01

    Background: The achievement of successful local anesthesia is a continual challenge in dentistry. Adjunctive local anesthetic techniques and their armamentaria, such as intraosseous injection (the Stabident system and the X-tip system) have been proposed to be advantageous in cases where the conventional local anesthetic techniques have failed. Aim: A clinical study was undertaken using intraosseous injection system by name X-tip to evaluate its effectiveness in cases where inferior alve...

  19. Cimethidine pre-anesthetic. A prophylactic method against Mendelson's syndrome in cesarean section

    DEFF Research Database (Denmark)

    Qvist, N; Storm, K

    1983-01-01

    Twenty patients undergoing cesarean section received cimethidine 400 mg intramuscularly as pre-anesthetic approximately 70 minutes prior to gastric aspiration. The average pH was 5.05, as against 2.97 in the control group (p less than 0.01). No significant reduction in the aspirated volumes...... in the infants. Hence, cimethidine is a safe and useful pre-anesthetic for patients undergoing cesarean section, irrespective of indication and, consequently, much to be preferred to oral antacids....

  20. Immigration, borrowing constraints and housing market volatility in general equilibrium

    OpenAIRE

    Onshuus, Helene

    2016-01-01

    A loan-to-value borrowing constraint is a significant restriction on household behavior. All policy intervention seeks to steer agents' behavior away from what individual agents would consider optimal in the absence of restrictions. In the wake of the financial crisis in 2007-09 many regulators have turned to macroprudential tools to manage excessive risk-taking on an economy-wide level. In Norway a strict loan-to-value policy was imposed in June 2015, restricting the amount a household can b...

  1. Origin of Volatiles in Earth: Indigenous Versus Exogenous Sources Based on Highly Siderophile, Volatile Siderophile, and Light Volatile Elements

    Science.gov (United States)

    Righter, K.; Danielson, L.; Pando, K. M.; Marin, N.; Nickodem, K.

    2015-01-01

    Origin of Earth's volatiles has traditionally been ascribed to late accretion of material after major differentiation events - chondrites, comets, ice or other exogenous sources. A competing theory is that the Earth accreted its volatiles as it was built, thus water and other building blocks were present early and during differentiation and core formation (indigenous). Here we discuss geochemical evidence from three groups of elements that suggests Earth's volatiles were acquired during accretion and did not require additional sources after differentiation.

  2. Anesthetic management of adenoidectomy and tonsillectomy assisted by low-temperature plasma technology in children

    Directory of Open Access Journals (Sweden)

    Meng-meng LI

    2014-10-01

    Full Text Available Objective To explore the anesthetic management strategy in children undergoing adenoidectomy and tonsillectomy using low-temperature plasma technology. Methods Sixty ASA status I children scheduled for adenoidectomy and tonsillectomy with plasma technology in the First Affiliated Hospital of General Hospital of PLA from September to December of 2013 were enrolled in this study. After induction with propofol, sufentanil and cisatracurium, the children were randomly divided into combined inhalation and intravenous anesthesia group (CIIA group, n=30 and total intravenous anesthesia group (TIVA group, n=30. In CIIA group, anesthesia was maintained with continuous infusion of propofol and remifentanil combined with sevoflurane inhalation during the surgery. In TIVA group, anesthesia was maintained only with continuous infusion of propofol and remifentanil. The hemodynamic changes and time for extubation and leaving operating room were recorded, and the emergence agitation was assessed using Pediatric Anesthesia Emergence Delirium (PAED scale. Results There was no significant difference in hemodynamic changes between the two groups (P>0.05. The total dosages of propofol and remifentanil in TIVA group [10.5±3.4 mg/(kg.h and 16.1±5.3μg/(kg.h, respectively] were significantly higher than those of CIIA group [6.6±2.8 mg/(kg.h, 10.4±4.2 μg/(kg.h, P<0.05]. The times for extubation and leaving operating room were significantly shorter in TIVA group (8.8±3.7min, 6.2±2.9min than in CIIA group (19.8±4.3 min, 13.7±5.2 min, P<0.05, and the rate of emergence agitation during the recovery period in TIVA group (1/30 was significantly less than that in CIIA group (9/30, P<0.05. Conclusion  Total intravenous anesthesia with tracheal intubation could shorten the recovery time and lessen the emergence agitation during the recovery period, and it may be used as a safe, feasible and convenient anesthetic strategy for adenoidectomy and tonsillectomy with

  3. Ring Keratitis Associated With Topical Abuse of a Dilute Anesthetic After Refractive Surgery

    Directory of Open Access Journals (Sweden)

    Yu-Chih Hou

    2009-12-01

    Full Text Available Anesthetic toxic keratitis is rare and presents as a ring keratitis, which is often misdiagnosed as Acanthamoeba keratitis. Here, we report an unusual case of toxic keratitis caused by topical abuse of a dilute anesthetic. A 26-year-old woman presented with bilateral corneal edema, ring infiltrates, pigmented keratic precipitate, Descemet's membrane folding, and strong anterior chamber reactions 2 weeks after laser subepithelial keratomileusis surgery. Tracing back her medical history, topical dilute 0.1% proparacaine was prescribed and frequently used for 1 month. Toxic keratitis was suspected. After discontinuation of the topical anesthetic and initiation of treatment with topical 20% autologous serum, complete corneal epithelialization was achieved within 1 week. Corneal infiltrates and anterior chamber reaction gradually subsided. Vision improved from finger counting to 20/20 in the right eye and 20/25 in the left eye, but confocal microscopy showed decreased corneal endothelial cells. Topical abuse of a dilute topical anesthetic can cause severe toxic keratitis and endothelial cell loss. The physician must be aware of the signs of topical anesthetic abuse and should not prescribe even a dilute anesthetic for long-term use. Autologous serum can help in the recovery of toxic keratitis.

  4. Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke.

    Science.gov (United States)

    Wang, Hailian; Li, Peiying; Xu, Na; Zhu, Ling; Cai, Mengfei; Yu, Weifeng; Gao, Yanqin

    2016-01-01

    Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms.

  5. Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke

    Directory of Open Access Journals (Sweden)

    Hailian Wang

    2016-01-01

    Full Text Available Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms.

  6. Occurrence of paresthesia after dental local anesthetic administration in the United States.

    Science.gov (United States)

    Garisto, Gabriella A; Gaffen, Andrew S; Lawrence, Herenia P; Tenenbaum, Howard C; Haas, Daniel A

    2010-07-01

    Several studies have suggested that the likelihood of paresthesia may depend on the local anesthetic used. The purpose of this study was to determine if the type of local anesthetic administered had any effect on reports of paresthesia in dentistry in the United States. The authors obtained reports of paresthesia involving dental local anesthetics during the period from November 1997 through August 2008 from the U.S. Food and Drug Administration Adverse Event Reporting System. They used chi(2) analysis to compare expected frequencies, on the basis of U.S. local anesthetic sales data, with observed reports of oral paresthesia. During the study period, 248 cases of paresthesia occurring after dental procedures were reported. Most cases (94.5 percent) involved mandibular nerve block. The lingual nerve was affected in 89.0 percent of cases. Reports involving 4 percent prilocaine and 4 percent articaine were 7.3 and 3.6 times, respectively, greater than expected (chi(2), P paresthesia occurs more commonly after use of 4 percent local anesthetic formulations. These findings are consistent with those reported in a number of studies from other countries. Until further research indicates otherwise, dentists should consider these results when assessing the risks and benefits of using 4 percent local anesthetics for mandibular block anesthesia.

  7. Anesthetic management of peroral endoscopic myotomy for esophageal achalasia: a retrospective case series.

    Science.gov (United States)

    Tanaka, Eriko; Murata, Hiroaki; Minami, Hitomi; Sumikawa, Koji

    2014-06-01

    Peroral endoscopic myotomy (POEM) is a newly developed, less invasive treatment for esophageal achalasia that requires general anesthesia under positive pressure ventilation. In this retrospective case series, we describe the anesthetic management of 28 consecutive patients who underwent POEM for esophageal achalasia. Anesthesia was maintained with sevoflurane and remifentanil under positive pressure ventilation through a tracheal tube. Retained contents in the esophagus were evacuated just before anesthesia induction to prevent regurgitation into the trachea. The POEM procedure was performed using an orally inserted flexible fiberscope. Elevation of end-tidal carbon dioxide after initiating esophageal carbon dioxide insufflation was observed in all patients and was treated by minute adjustments to the ventilation volume. Scopolamine butylbromide-induced tachycardia in one patient was treated with landiolol hydrochloride, which is a short-acting beta 1-selective blocker. Minor subcutaneous emphysema around the neck was observed in one patient. POEM was successfully completed, and tracheas were extubated immediately after the procedure in all patients. Our findings suggest that prevention of aspiration pneumonia during anesthesia induction, preparation for carbon dioxide insufflation-related complications, and treatment of scopolamine butylbromide-induced tachycardia play important roles in safe anesthesia management of POEM for esophageal achalasia.

  8. [Anesthetic management for surgery of giant coronary aneurysms complicated with Churg-Strauss syndrome].

    Science.gov (United States)

    Kido, Koji; Tokuda, Rui; Suzuki, Tomofumi; Hanashiro, Ako; Kobashigawa, Teruyo; Mayama, Takashi; Kamikawa, Michie

    2014-04-01

    Few cases of Churg-Strauss syndrome (CSS) complicated by giant coronary aneurysms (CAs)have been reported thus far. We report a case of CSS in a 60-year-old man who underwent surgery for giant CAs, and was managed with anesthetics. The patient developed acute myocardial infarction, and was diagnosed with giant CAs in the right coronary artery (RCA, 11 cm) and circumflex artery (3 cm). The CA in RCA was communicating with the right ventricle. He had a history of pericardiectomy for pericarditis caused by the CSS and developed thrombocytopenia due to consumptive coagulopathy within the CAs. An operation, including ligation and excision of the CAs, and coronary artery bypass grafting was performed under general anesthesia and cardiopulmonary bypass. There was massive hemorrhage followed by hemodynamic instability while detaching the tight pericardial adhesion and fragile surface of the CAs. Massive transfusion was required along with inotropes administration and intraaortic balloon support. In this case, determination of the appropriate surgical timing was difficult because symptoms of the CSS became worse followed by rapid enlargement of the CAs, myocardial infarction, and thrombocytopenia. Steroids were administered for treating CSS, and the blood transfusion was sufficient. However, it was difficult to control the hemorrhage and maintain hemodynamic stability.

  9. A national survey into perioperative anesthetic management of patients with a fractured neck of femur

    Directory of Open Access Journals (Sweden)

    Soinikoski Mirka

    2012-07-01

    Full Text Available Abstract Background We made a survey among Finnish anesthesiologists concerning the current perioperative anesthetic practice of hip fracture patients for further development in patient care. Methods All members of the Finnish Society of Anesthesiologists with a known e-mail address (786 were invited to participate in an internet-based survey. Results The overall response rate was 55% (423 responses; 298 respondents participated in the care of hip fracture patients. Preoperative analgesia was mostly managed with oxycodone and paracetamol; every fifth respondent applied an epidural infusion. Most respondents (98% employed a spinal block with or without an epidural catheter for intraoperative anesthesia. Midazolam, propofol and/or fentanyl were used for additional sedation. General anesthesia was used rarely. Postoperatively, paracetamol and non-steroidal anti-inflammatory drugs and occasionally peroral oxycodone, were prescribed in addition to epidural analgesia. Conclusions The survey suggests that the impact of more individualised analgesia regimens, both preoperatively and postoperatively, should be investigated in further studies.

  10. Bayesian Option Pricing Framework with Stochastic Volatility for FX Data

    Directory of Open Access Journals (Sweden)

    Ying Wang

    2016-12-01

    Full Text Available The application of stochastic volatility (SV models in the option pricing literature usually assumes that the market has sufficient option data to calibrate the model’s risk-neutral parameters. When option data are insufficient or unavailable, market practitioners must estimate the model from the historical returns of the underlying asset and then transform the resulting model into its risk-neutral equivalent. However, the likelihood function of an SV model can only be expressed in a high-dimensional integration, which makes the estimation a highly challenging task. The Bayesian approach has been the classical way to estimate SV models under the data-generating (physical probability measure, but the transformation from the estimated physical dynamic into its risk-neutral counterpart has not been addressed. Inspired by the generalized autoregressive conditional heteroskedasticity (GARCH option pricing approach by Duan in 1995, we propose an SV model that enables us to simultaneously and conveniently perform Bayesian inference and transformation into risk-neutral dynamics. Our model relaxes the normality assumption on innovations of both return and volatility processes, and our empirical study shows that the estimated option prices generate realistic implied volatility smile shapes. In addition, the volatility premium is almost flat across strike prices, so adding a few option data to the historical time series of the underlying asset can greatly improve the estimation of option prices.

  11. Organic non-volatile memories from ferroelectric phase separated blends

    Science.gov (United States)

    Asadi, Kamal; de Leeuw, Dago; de Boer, Bert; Blom, Paul

    2009-03-01

    Ferroelectric polarisation is an attractive physical property for non-volatile binary switching. The functionality of the targeted memory should be based on resistive switching. Conductivity and ferroelectricity however cannot be tuned independently. The challenge is to develop a storage medium in which the favourable properties of ferroelectrics such as bistability and non-volatility can be combined with the beneficial properties provided by semiconductors such as conductivity and rectification. In this contribution we present an integrated solution by blending semiconducting and ferroelectric polymers into phase separated networks. The polarisation field of the ferroelectric modulates the injection barrier at the semiconductor--metal contact. This combination allows for solution-processed non-volatile memory arrays with a simple cross-bar architecture that can be read-out non-destructively. Based on this general concept a non-volatile, reversible switchable Schottky diode with relatively fast programming time of shorter than 100 microseconds, long information retention time of longer than 10^ days, and high programming cycle endurance with non-destructive read-out is demonstrated.

  12. Occupation of the cytochrome P450 substrate pocket by diverse compounds at general anesthesia concentrations.

    Science.gov (United States)

    LaBella, F S; Stein, D; Queen, G

    1998-10-02

    Each of a diverse array of compounds, at concentrations reported to effect general anesthesia, when added to liver microsomes, forms a complex with cytochromes P450 to generate, with reference to a cuvette containing microsomes only, a characteristic absorbance-difference spectrum. This spectrum results from a change in the electron-spin state of the heme iron atom induced upon entry by the anesthetic molecule into the enzyme catalytic pocket. The difference spectrum, representing the anesthetic-P450 complex, is characteristic of substances that are substrates for the enzyme. For the group of compounds as a whole, the magnitudes of the absorbance-difference spectra vary only about twofold, although the anesthetic potencies vary by several orders of magnitude. The dissociation constants (Ks), calculated from absorbance data and representing affinities of the anesthetics for P450, agree closely with the respective EC50 (concentration that effects anesthesia in 50% of individuals) values, and with the respective Ki (concentration that inhibits P450 catalytic activities half-maximally) values reported by us previously. The absorbance complex resulting from the occupation of the catalytic pocket by endogenous substrates, androstenedione and arachidonic acid, is inhibited, competitively, by anesthetics. Occupation of and perturbation of the heme catalytic pocket by anesthetic, as monitored by the absorbance-difference spectrum, is rapidly reversible. The presumed in vivo consequences of perturbation by general anesthetics of heme proteins is suppression of the generation of chemical signals that determine cell sensitivity and response.

  13. Inflation Volatility and the Inflation-Growth Tradeoff in India

    OpenAIRE

    Raghbendra Jha; Varsha S. Kulkarni

    2012-01-01

    This paper amends the New Keynesian Phillips curve model to include inflation volatility and tests the determinants of such volatility for India. It provides results on the determinants of inflation volatility and expected inflation volatility for OLS and ARDL (1,1) models and for change in inflation volatility and change in expected inflation volatility using ECM models. Output gap affects change in expected inflation volatility along (in the ECM model) and not in the other models. Major det...

  14. The Impact of Jump Distributions on the Implied Volatility of Variance

    DEFF Research Database (Denmark)

    Nicolato, Elisa; Pisani, Camilla; Pedersen, David Sloth

    2017-01-01

    We consider a tractable affine stochastic volatility model that generalizes the seminal Heston (1993) model by augmenting it with jumps in the instantaneous variance process. In this framework, we consider both realized variance options and VIX options, and we examine the impact of the distribution...... of jumps on the associated implied volatility smile. We provide sufficient conditions for the asymptotic behavior of the implied volatility of variance for small and large strikes. In particular, by selecting alternative jump distributions, we show that one can obtain fundamentally different shapes...

  15. Volatile accretion history of the Earth.

    Science.gov (United States)

    Wood, B J; Halliday, A N; Rehkämper, M

    2010-10-28

    It has long been thought that the Earth had a protracted and complex history of volatile accretion and loss. Albarède paints a different picture, proposing that the Earth first formed as a dry planet which, like the Moon, was devoid of volatile constituents. He suggests that the Earth's complement of volatile elements was only established later, by the addition of a small veneer of volatile-rich material at ∼100 Myr (here and elsewhere, ages are relative to the origin of the Solar System). Here we argue that the Earth's mass balance of moderately volatile elements is inconsistent with Albarède's hypothesis but is well explained by the standard model of accretion from partially volatile-depleted material, accompanied by core formation.

  16. Volatile communication in plant-aphid interactions.

    Science.gov (United States)

    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release. Copyright 2010 Elsevier Ltd. All rights reserved.

  17. Emergence from general anesthesia and the sleep-manifold

    Directory of Open Access Journals (Sweden)

    Darren Fletcher Hight

    2014-08-01

    Full Text Available The electroencephalogram (EEG during the re-establishment of consciousness after general anesthesia and surgery varies starkly between patients. Can the EEG during this emergence period provide a means of estimating the underlying biological processes underpinning the return of consciousness? Can we use a model to infer these biological processes from the EEG patterns? A frontal EEG was recorded from 84 patients. Ten patients were chosen for state-space analysis. Five showed archetypal emergences; which consisted of a progressive decrease in alpha power and increase peak alpha frequency before return of responsiveness. The five non-archetypal emergences showed almost no spectral EEG changes (even as the volatile general anesthetic decreased and then an abrupt return of responsiveness. We used Bayesian methods to estimate the likelihood of an EEG pattern corresponding to the position of the patient on a 2-dimensional manifold in a state space of excitatory connection strength vs change in intrinsic resting neuronal membrane conductivity. We could thus visualize the trajectory of each patient in the state-space during their emergence period. The patients who followed an archetypal emergence displayed a very consistent pattern; consisting of progressive increase in conductivity, and a temporary period of increased connection strength before return of responsiveness. The non-archetypal emergence trajectories remained fixed in a region of phase space characterized by a relatively high conductivity and low connection strength throughout emergence. This unexpected progressive increase in conductivity during archetypal emergence may be due to an abating of the surgical stimulus during this period. Periods of high connection strength could represent forays into dissociated consciousness, but the model suggests all patients reposition near the fold in the state space to take advantage of bi-stable cortical dynamics before transitioning to consciousness.

  18. Macroeconomic Volatility and Welfare in Developing Countries

    OpenAIRE

    Loayza, Norman V.; Rancière, Romain; Servén, Luis; Ventura, Jaume

    2007-01-01

    Macroeconomic Volatility and Welfare in Developing Countries: An Introduction Norman V. Loayza, Romain Ranciere, Luis Serven, ` and Jaume Ventura Macroeconomic volatility, both a source and a reflection of underdevelopment, is a fundamental concern for developing countries. This article provides a brief overview of the recent literature on macroeconomic volatility in developing countries, highlighting its causes, consequences, and possible remedies. to reduce domestic policy-induced macroecon...

  19. Identify and Manage the Software Requirements Volatility

    OpenAIRE

    Khloud Abd Elwahab; Mahmoud Abd EL Latif; Sherif Kholeif

    2016-01-01

    Management of software requirements volatility through development of life cycle is a very important stage. It helps the team to control significant impact all over the project (cost, time and effort), and also it keeps the project on track, to finally satisfy the user which is the main success criteria for the software project. In this research paper, we have analysed the root causes of requirements volatility through a proposed framework presenting the requirements volatility causes and how...

  20. Labour Demand and Exchange Rate Volatility

    OpenAIRE

    Udo Broll; Sabine Hansen

    2004-01-01

    The purpose of this paper is to assess under what conditions exchange rate volatility exerts a positive effect on a firm's labour demand. As the exchange rate volatility increases, so does the value of the export option provided the firm under study is flexible. Flexibility is important because it gives the firm option value. Higher volatility increases the potential gains from trade and may increase the demand for labour. This may explain part of the mixed empirical findings regarding the ef...

  1. Equity Volatility and Corporate Bond Yields

    OpenAIRE

    John Y. Campbell; Glen B. Taksler

    2002-01-01

    This paper explores the effect of equity volatility on corporate bond yields. Panel data for the late 1990s show that idiosyncratic firm-level volatility can explain as much cross-sectional variation in yields as can credit ratings. This finding, together with the upward trend in idiosyncratic equity volatility documented by Campbell, Lettau, Malkiel, and Xu (2001), helps to explain recent increases in corporate bond yields. The definitive version is available at www.blackwell-synergy.com.

  2. Mechanism of postarrhythmic renal vasoconstriction in the anesthetized dog.

    Science.gov (United States)

    Katholi, R E; Oparil, S; Urthaler, F; James, T N

    1979-07-01

    The mechanism of postarrhythmic renal vasoconstriction was studied in 28 dogs anesthetized with pentobarbital sodium (30 mg/kg i.v.). Rapid atrial or ventricular pacing or induction of atrial fibrilation were used to produce at least 20% prompt decrease in cardiac output and mean arterial blood pressure. Return to control cardiac output and blood pressure occurred within 3 minutes after cessation of the arrhythmia, but renal blood flow remained significantly decreased (26%) with gradual recovery by 17.7 +/- 6.6 min. Infusion of phentolamine (0.25 mg/min) into the renal artery, intravenous hexamethonium (l mg/kg), adrenal demedullation, or cooling the cervical vagi prevented postarrhythmic renal vasoconstriction. In contrast, renal denervation, intravenous bretylium (10 mg/kg), intravenous atropine (0.5 mg/kg) or intrarenal SQ 20881 (0.20 mg/min) has no effect on postarrhythmic renal vasoconstriction. Intravenous propranolol (0.5 mg/kg) intensified postarrhythmic renal vasoconstriction. These data suggested that the postarrhythmic renal vasoconstrictive response required intact vagi and was due to alpha adrenergic stimulation by adrenal catecholamines. However, femoral arterial catecholamine levels were not elevated above control during postarrhythmic renal vasoconstriction. We therefore sought local vascular pathways by which catecholamines might reach the kidneys. An adrenorenal vascular network was found in each dog. Collection of catecholamines from these vessels during postarrhythmic renal vasoconstriction in six dogs revealed catecholamine concentrations threefold higher than simultaneously collected femoral arterial catecholamines levels. Because ligation of these vessels abolished postarrhythmic renal vasoconstriction in each dog, we conclude that postarrhythmic renal vasconstriction is due to adrenal catecholamines reaching the kidneys through an adreno-renal vascular network and that the response requires intact vagi.

  3. Responses to negative pressure surrounding the neck in anesthetized animals.

    Science.gov (United States)

    Wolin, A D; Strohl, K P; Acree, B N; Fouke, J M

    1990-01-01

    Continuous positive pressure applied at the nose has been shown to cause a decrease in upper airway resistance. The present study was designed to determine whether a similar positive transmural pressure gradient, generated by applying a negative pressure at the body surface around the neck, altered upper airway patency. Studies were performed in nine spontaneously breathing anesthetized supine dogs. Airflow was measured with a pneumotachograph mounted on an airtight muzzle placed over the nose and mouth of each animal. Upper airway pressure was measured as the differential pressure between the extrathoracic trachea and the inside of the muzzle. Upper airway resistance was monitored as an index of airway patency. Negative pressure (-2 to -20 cmH2O) was applied around the neck by using a cuirass extending from the jaw to the thorax. In each animal, increasingly negative pressures were transmitted to the airway wall in a progressive, although not linear, fashion. Decreasing the pressure produced a progressive fall in upper airway resistance, without causing a significant change in respiratory drive or respiratory timing. At -5 cmH2O pressure, there occurred a significant fall in upper airway resistance, comparable with the response of a single, intravenous injection of sodium cyanide (0.5-3.0 mg), a respiratory stimulant that produces substantial increases in respiratory drive. We conclude that upper airway resistance is influenced by the transmural pressure across the airway wall and that such a gradient can be accomplished by making the extraluminal pressure more negative.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Pain and efficacy of local anesthetics for central venous access

    Directory of Open Access Journals (Sweden)

    William C Culp Jr

    2008-11-01

    Full Text Available William C Culp Jr1, Mohammed Yousaf2, Benjamin Lowry1, Timothy C McCowan3, William C Culp21Division of Cardiothoracic Anesthesiology, Scott and White Hospital, The Texas A&M University College of Medicine, Temple, TX, USA; 2Division of Interventional Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA; 3Department of Radiology, University of Mississippi Medical Center, Jackson, MS, USAPurpose: To compare pain during injection and efficacy of analgesia of local anesthetics during central venous line placement.Methods: Sixty-two patients were studied in a randomized, double-blinded prospective fashion. Patients received 1% lidocaine (L, buffered 1% lidocaine (LB, or 2% chloroprocaine (CP injected around the internal jugular vein for procedural analgesia for central venous access. Patients reported pain via a standard linear visual analog scale, with 0 representing no pain and 10 being the worst pain imaginable.Results: Overall patient perception of pain was better with CP and L than LB with mean scores of CP 2.4, L 2.6, LB 4.2. Pain with injection mean scores were CP 2.1, L 2.5, LB 3.2. Pain with catheter placement scores were CP 2.5, L 1.7, LB 3.4. Operator assessment of overall pain values were CP 1.9, L 2.2, LB 3.4. LB consistently scored the worst, though compared with CP, this only reached statistical significance in overall patient pain and pain at catheter insertion compared with L.Conclusion: Though chloroprocaine scored better than lidocaine in 3 of 4 parameters, this trend did not achieve statistical significance. Adding sodium bicarbonate to lidocaine isn’t justified in routine practice, nor is routine replacement of lidocaine with chloroprocaine.Keywords: local anesthesia, analgesia, central venous access, lidocaine, chloroprocaine

  5. Production Function of Outgassed Volatiles on Mercury: Implications for Polar Volatiles on Mercury and the Moon

    Science.gov (United States)

    Deutsch, A. N.; Head, J. W.

    2018-05-01

    We are interested in the flux of volatiles delivered to the polar regions of Mercury and the Moon through time. We integrate the production functions for volatile delivery from impacts, solar wind, and volcanism, which we focus on initially.

  6. [Solidification of volatile oil with graphene oxide].

    Science.gov (United States)

    Yan, Hong-Mei; Jia, Xiao-Bin; Zhang, Zhen-Hai; Sun, E; Xu, Yi-Hao

    2015-02-01

    To evaluate the properties of solidifying volatile oil with graphene oxide, clove oil and zedoary turmeric oil were solidified by graphene oxide. The amount of graphene oxide was optimized with the eugenol yield and curcumol yield as criteria. Curing powder was characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The effects of graphene oxide on dissolution in vitro and thermal stability of active components were studied. The optimum solidification ratio of graphene oxide to volatile oil was 1:1. Dissolution rate of active components had rare influence while their thermal stability improved after volatile oil was solidified. Solidifying herbal volatile oil with graphene oxide deserves further study.

  7. [Chemical components of Vetiveria zizanioides volatiles].

    Science.gov (United States)

    Huang, Jinghua; Li, Huashou; Yang, Jun; Chen, Yufen; Liu, Yinghu; Li, Ning; Nie, Chengrong

    2004-01-01

    The chemical components of the volatiles from Vetiveria zizanioides were analyzed by SPME and GC-MS. In the roots, the main component was valencene (30.36%), while in the shoots and leaves, they were 9-octadecenamide (33.50%), 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene (27.46%), and 1,2-benzendicarboxylic acid, diisooctyl ester(18.29%). The results showed that there were many terpenoids in the volatils. In shoot volatiles, there existed 3 monoterpenes, 2 sequiterpenes and 1 triterpene. Most of the volatiles in roots were sesquiterpenes.

  8. CAM Stochastic Volatility Model for Option Pricing

    Directory of Open Access Journals (Sweden)

    Wanwan Huang

    2016-01-01

    Full Text Available The coupled additive and multiplicative (CAM noises model is a stochastic volatility model for derivative pricing. Unlike the other stochastic volatility models in the literature, the CAM model uses two Brownian motions, one multiplicative and one additive, to model the volatility process. We provide empirical evidence that suggests a nontrivial relationship between the kurtosis and skewness of asset prices and that the CAM model is able to capture this relationship, whereas the traditional stochastic volatility models cannot. We introduce a control variate method and Monte Carlo estimators for some of the sensitivities (Greeks of the model. We also derive an approximation for the characteristic function of the model.

  9. The effect of volatility on percutaneous absorption.

    Science.gov (United States)

    Rouse, Nicole C; Maibach, Howard I

    2016-01-01

    Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy. A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption. A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs. Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.

  10. Option Price Decomposition in Spot-Dependent Volatility Models and Some Applications

    Directory of Open Access Journals (Sweden)

    Raúl Merino

    2017-01-01

    Full Text Available We obtain a Hull and White type option price decomposition for a general local volatility model. We apply the obtained formula to CEV model. As an application we give an approximated closed formula for the call option price under a CEV model and an approximated short term implied volatility surface. These approximated formulas are used to estimate model parameters. Numerical comparison is performed for our new method with exact and approximated formulas existing in the literature.

  11. What Can Rational Investors Do About Excessive Volatility and Sentiment Fluctuations?

    OpenAIRE

    Bernard Dumas; Alexander Kurshev; Raman Uppal

    2005-01-01

    Our objective is to understand the trading strategy that would allow an investor to take advantage of 'excessive' stock price volatility and 'sentiment' fluctuations. We construct a general equilibrium model of sentiment. In it, there are two classes of agents and stock prices are excessively volatile because one class is overconfident about a public signal. As a result, this class of irrational agents changes its expectations too often, sometimes being excessively optimistic, sometimes being...

  12. A novel local anesthetic system: transcriptional transactivator peptide-decorated nanocarriers for skin delivery of ropivacaine

    Directory of Open Access Journals (Sweden)

    Chen CY

    2017-06-01

    Full Text Available Chuanyu Chen, Peijun You Department of Anesthesiology, Shandong Jining No 1 People’s Hospital, Jining, Shandong, People’s Republic of China Purpose: Barrier properties of the skin and physicochemical properties of drugs are the main factors for the delivery of local anesthetic molecules. The present work evaluates the anesthetic efficacy of drug-loaded nanocarrier (NC systems for the delivery of local anesthetic drug, ropivacaine (RVC. Methods: In this study, transcriptional transactivator peptide (TAT-decorated RVC-loaded NCs (TAT-RVC/NCs were successfully fabricated. Physicochemical properties of NCs were determined in terms of particle size, zeta potential, drug encapsulation efficiency, drug-loading capacity, stability, and in vitro drug release. The skin permeation of NCs was examined using a Franz diffusion cell mounted with depilated mouse skin in vitro, and in vivo anesthetic effect was evaluated in mice. Results: The results showed that TAT-RVC/NCs have a mean diameter of 133.2 nm and high drug-loading capacity of 81.7%. From the in vitro skin permeation results, it was observed that transdermal flux of TAT-RVC/NCs was higher than that of RVC-loaded NCs (RVC/NCs and RVC injection. The evaluation of in vivo anesthetic effect illustrated that TAT-RVC/NCs can enhance the transdermal delivery of RVC by reducing the pain threshold in mice. Conclusion: These results indicate that TAT-decorated NCs systems are useful for overcoming the barrier function of the skin, decreasing the dosage of RVC and enhancing the anesthetic effect. Therefore, TAT-decorated NCs can be used as an effective transdermal delivery system for local anesthesia. Keywords: local anesthetic system, ropivacaine, transcriptional transactivator peptide, nanocarriers, skin delivery

  13. Assessment of the densities of local anesthetics and their combination with adjuvants: an experimental study.

    Science.gov (United States)

    Imbelloni, Luiz Eduardo; Moreira, Adriano Dias; Gaspar, Flávia Cunha; Gouveia, Marildo A; Cordeiro, José Antônio

    2009-01-01

    The relative density of a local anesthetic in relation to that of the cerebrospinal fluid (CSF) at 37 degrees C is one of the most important physical properties that affect the level of analgesia obtained after the subarachnoid administration of the drug. The objective of this study was to determine the density of local anesthetic solutions, with and without glucose, and the combination of the local anesthetic with adjuvants at 20 degrees C, 25 degrees C, and 37 degrees C. The density (g.mL(-1)) was determined by using a DMA 450 densimeter with a sensitivity of +/- 0.00001 g.mL(-1). The densities, and variations, according to the temperature were obtained for all local anesthetics and their combination with opioids at 20 degrees C, 25 degrees C, and 37 degrees C. The solution is hyperbaric if its density exceeds 1.00099, hypobaric when its density is lower than 1.00019, and isobaric when its density is greater than 1.00019 and lower than 1.00099. The densities of both local anesthetics and adjuvants decrease with the increase in temperature. At 37 degrees C, all glucose-containing solutions are hyperbaric. In the absence of glucose, all solutions are hypobaric. At 37 degrees C, morphine, fentanyl, sufentanil, and clonidine are hypobaric. The densities of local anesthetics and adjuvants decrease with the increase in temperature and increase when glucose is added. The knowledge of the relative density helps select the most adequate local anesthetic to be administered in the subarachnoid space.

  14. A Retrospective Observational Study of Anesthetic Induction Dosing Practices in Female Elderly Surgical Patients: Are We Overdosing Older Patients?

    Science.gov (United States)

    Akhtar, Shamsuddin; Heng, Joseph; Dai, Feng; Schonberger, Robert B; Burg, Mathew M

    2016-10-01

    Despite guidelines suggesting a 25-50 % reduction in induction doses of intravenous anesthetic agents in the elderly (≥65 years), we hypothesized that practitioners were not sufficiently correcting drug administration for age, contributing to an increased incidence of hypotension in older patients undergoing general anesthesia. We conducted a retrospective, observational study in a tertiary-care academic hospital. The study included 768 female patients undergoing gynecologic surgeries who received propofol-based induction of general anesthesia. Weight-adjusted anesthetic induction dosing, age-associated differences in dosing by ASA-PS (American Society of Anesthesiology-Physical Status), and hemodynamic outcomes between younger (18-64 years, n = 537) and older (≥65 years, n = 231) female patients were analyzed. Older patients received lower doses of propofol and midazolam than younger patients (propofol: 2.037 ± 0.783 vs 2.322 ± 0.834 mg/kg, p < 0.001; midazolam: 0.013 ± 0.014 vs 0.023 ± 0.042 mg/kg, p < 0.001). However, practitioners still consistently exceeded the FDA recommended dose (1-1.5 mg/kg) of propofol for elderly patients. There was no significant difference in the doses of fentanyl administered between the two age groups (1.343 ± 0.744 vs 1.363 ± 0.763 μg/kg, p = 0.744), and doses of fentanyl in older patients exceeded the recommended dose (0.5-1.0 μg/kg). Corresponding to observed overdosing of induction agents, older patients experienced larger decreases in post-induction blood pressure and were more likely to receive vasopressor therapy. Anesthetic induction doses of fentanyl and propofol were not sufficiently corrected in older patients in accordance with recommendations. Significantly greater frequency of post-induction hypotension occurred amongst older patients. Quality improvement efforts may lead to improved outcomes in this vulnerable population.

  15. Human Brain Networks: Spiking Neuron Models, Multistability, Synchronization, Thermodynamics, Maximum Entropy Production, and Anesthetic Cascade Mechanisms

    Directory of Open Access Journals (Sweden)

    Wassim M. Haddad

    2014-07-01

    Full Text Available Advances in neuroscience have been closely linked to mathematical modeling beginning with the integrate-and-fire model of Lapicque and proceeding through the modeling of the action potential by Hodgkin and Huxley to the current era. The fundamental building block of the central nervous system, the neuron, may be thought of as a dynamic element that is “excitable”, and can generate a pulse or spike whenever the electrochemical potential across the cell membrane of the neuron exceeds a threshold. A key application of nonlinear dynamical systems theory to the neurosciences is to study phenomena of the central nervous system that exhibit nearly discontinuous transitions between macroscopic states. A very challenging and clinically important problem exhibiting this phenomenon is the induction of general anesthesia. In any specific patient, the transition from consciousness to unconsciousness as the concentration of anesthetic drugs increases is very sharp, resembling a thermodynamic phase transition. This paper focuses on multistability theory for continuous and discontinuous dynamical systems having a set of multiple isolated equilibria and/or a continuum of equilibria. Multistability is the property whereby the solutions of a dynamical system can alternate between two or more mutually exclusive Lyapunov stable and convergent equilibrium states under asymptotically slowly changing inputs or system parameters. In this paper, we extend the theory of multistability to continuous, discontinuous, and stochastic nonlinear dynamical systems. In particular, Lyapunov-based tests for multistability and synchronization of dynamical systems with continuously differentiable and absolutely continuous flows are established. The results are then applied to excitatory and inhibitory biological neuronal networks to explain the underlying mechanism of action for anesthesia and consciousness from a multistable dynamical system perspective, thereby providing a

  16. Ambulatory anesthetic care in children undergoing myringotomy and tube placement: current perspectives

    Directory of Open Access Journals (Sweden)

    Robinson H

    2017-04-01

    Full Text Available Hal Robinson, Thomas Engelhardt Department of Anaesthesia, Royal Aberdeen Children’s Hospital, Aberdeen, UK Purpose: Myringotomy and tube placement is one of the most frequently performed ear, nose and throat (ENT surgeries in the pediatric population. Effective anesthetic management is vital to ensuring successful ambulatory care and ensuring child and parental satisfaction.Recent findings: This review summarizes recently published studies about the long-term effects of general anesthesia in young children, novel approaches to preoperative fasting and simplified approaches to the assessment and management of emergence delirium (ED and emergence agitation (EA. New developments in perioperative ambulatory care, including management of comorbidities and day care unit logistics, are discussed.Summary: Long-term follow-up of children exposed to general anesthesia before the age of 4 years has limited impact on academic achievement or cognitive performance and should not delay the treatment of common ENT pathology, which can impair speech and language development. A more liberal approach to fasting, employing a 6–4–0 regime allowing children fluids up until theater, may become an accepted practice in future. ED and EA should be discriminated from pain in recovery and, where the child is at risk of harm, should be treated promptly. Postoperative pain at home remains problematic in ambulatory surgery and better parental education is needed. Effective ambulatory care ultimately requires a well-coordinated team approach from effective preassessment to postoperative follow-up. Keywords: myringotomy, ventilation tubes, anesthesia, pediatrics, ambulatory, day case

  17. An estimation of the minimum effective anesthetic volume of 2% lidocaine in ultrasound-guided axillary brachial plexus block.

    LENUS (Irish Health Repository)

    O'Donnell, Brian D

    2009-07-01

    Ultrasound guidance facilitates precise needle and injectate placement, increasing axillary block success rates, reducing onset times, and permitting local anesthetic dose reduction. The minimum effective volume of local anesthetic in ultrasound-guided axillary brachial plexus block is unknown. The authors performed a study to estimate the minimum effective anesthetic volume of 2% lidocaine with 1:200,000 epinephrine (2% LidoEpi) in ultrasound-guided axillary brachial plexus block.

  18. Effectiveness of monetary and macroprudential shocks on consumer credit growth and volatility in Turkey

    Directory of Open Access Journals (Sweden)

    Meltem Gulenay Chadwick

    2018-06-01

    Full Text Available This paper proposes a panel VAR model to uncover the effect of monetary policy and macroprudential tightening probability on general purpose loans, housing loans, vehicle loans, credit cards and their respective volatilities in Turkey. To conduct our analysis, first, we compare a number of stochastic volatility models using our loan and credit card series in a formal Bayesian model comparison exercise, in order to determine the best volatility model for our series. Second we disclose the latent probability of macroprudential tightening from the binary information of policy episodes, using an instrumental variable probit model estimated by conditional maximum likelihood with heteroscedasticity robust standard errors. Lastly we estimate the dynamic impact of monetary policy and macroprudential measures using a panel VAR, incorporating the latent probability of tightening episodes, credit growth, industrial production growth, loan rates, inflation and credit growth volatilities into the endogenous system of equations. We conclude that macroprudential tightening is effective in dampening credit growth, credit growth volatility and reducing consumer price inflation. Besides, this effect is more prominent when macroprudential tools are administered in coordination with monetary policy. Keywords: Consumer loans, Monetary policy, Macroprudential policy, Stochastic volatility models, Credit growth volatility, IV probit model, Panel VAR model, JEL classification: C54, E44, E52

  19. Effect of oil price on Nigeria’s food price volatility

    Directory of Open Access Journals (Sweden)

    Ijeoma C. Nwoko

    2016-12-01

    Full Text Available This study examines the effect of oil price on the volatility of food price in Nigeria. It specifically considers the long-run, short-run, and causal relationship between these variables. Annual data on oil price and individual prices of maize, rice, sorghum, soya beans, and wheat spanning from 2000 to 2013 were used. The price volatility for each crop was obtained using Generalized Autoregressive Conditional Heteroskedascity (GARCH (1, 1 model. Our measure of oil price is the Refiner acquisition cost of imported crude oil. The Augmented Dickey–Fuller and Phillip–Perron unit root tests show that all the variables are integrated of order one, I (1. Therefore, we use the Johansen co-integration test to examine the long-run relationship. Our results show that there is no long-run relationship between oil price and any of the individual food price volatility. Thus, we implement a VAR instead of a VECM to investigate the short-run relationship. The VAR model result revealed a positive and significant short-run relationship between oil price and each of the selected food price volatility with exception of that of rice and wheat price volatility. These results were further confirmed by the impulse response functions. The Granger causality test result indicates a unidirectional causality from oil price to maize, soya bean, and sorghum price volatilities but does not show such relationship for rice and wheat price volatilities. We draw some policy implications of these findings.

  20. Flavour compounds in tomato fruits: identification of loci and potential pathways affecting volatile composition.

    Science.gov (United States)

    Mathieu, Sandrine; Cin, Valeriano Dal; Fei, Zhangjun; Li, Hua; Bliss, Peter; Taylor, Mark G; Klee, Harry J; Tieman, Denise M

    2009-01-01

    The unique flavour of a tomato fruit is the sum of a complex interaction among sugars, acids, and a large set of volatile compounds. While it is generally acknowledged that the flavour of commercially produced tomatoes is inferior, the biochemical and genetic complexity of the trait has made breeding for improved flavour extremely difficult. The volatiles, in particular, present a major challenge for flavour improvement, being generated from a diverse set of lipid, amino acid, and carotenoid precursors. Very few genes controlling their biosynthesis have been identified. New quantitative trait loci (QTLs) that affect the volatile emissions of red-ripe fruits are described here. A population of introgression lines derived from a cross between the cultivated tomato Solanum lycopersicum and its wild relative, S. habrochaites, was characterized over multiple seasons and locations. A total of 30 QTLs affecting the emission of one or more volatiles were mapped. The data from this mapping project, combined with previously collected data on an IL population derived from a cross between S. lycopersicum and S. pennellii populations, were used to construct a correlational database. A metabolite tree derived from these data provides new insights into the pathways for the synthesis of several of these volatiles. One QTL is a novel locus affecting fruit carotenoid content on chromosome 2. Volatile emissions from this and other lines indicate that the linear and cyclic apocarotenoid volatiles are probably derived from separate carotenoid pools.

  1. Fundamental uncertainty and stock market volatility

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2008-01-01

    We provide empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from participants in the Survey of Professional Forecasters over the period 1969 to 1996.

  2. Effects of Idiosyncratic Volatility in Asset Pricing

    Directory of Open Access Journals (Sweden)

    André Luís Leite

    2016-04-01

    Full Text Available This paper aims to evaluate the effects of the aggregate market volatility components - average volatility and average correlation - on the pricing of portfolios sorted by idiosyncratic volatility, using Brazilian data. The study investigates whether portfolios with high and low idiosyncratic volatility - in relation to the Fama and French model (1996 - have different exposures to innovations in average market volatility, and consequently, different expectations for return. The results are in line with those found for US data, although they portray the Brazilian reality. Decomposition of volatility allows the average volatility component, without the disturbance generated by the average correlation component, to better price the effects of a worsening or an improvement in the investment environment. This result is also identical to that found for US data. Average variance should thus command a risk premium. For US data, this premium is negative. According to Chen and Petkova (2012, the main reason for this negative sign is the high level of investment in research and development recorded by companies with high idiosyncratic volatility. As in Brazil this type of investment is significantly lower than in the US, it was expected that a result with the opposite sign would be found, which is in fact what occurred.

  3. Decomposing European bond and equity volatility

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditio...

  4. Current status of fluoride volatility method development

    Energy Technology Data Exchange (ETDEWEB)

    Uhlir, J.; Marecek, M.; Skarohlid, J. [UJV - Nuclear Research Institute, Research Centre Rez, CZ-250 68 Husinec - Rez 130 (Czech Republic)

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  5. Volatility transmission and patterns in Bund futures

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); R. van Ieperen; A.J. Menkveld (Bert); P. Kofman (Paul); M.P.E. Martens (Martin)

    1997-01-01

    textabstractWe analyze intraday volatility behavior for the Bund futures contract that is traded simultaneously at two competing exchanges. We investigate the transmission of volatility between the exchanges. We find that the lead/lag relations are restricted to a few minutes and do not reveal a

  6. Stock market volatility and macroeconomic uncertainty

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2006-01-01

    This paper provides empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from SPF survey participants over the period from 1969 to 1996. This link is much

  7. CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS ...

    African Journals Online (AJOL)

    CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS OF CLEOME VISCOSA FROM NIGERIA. Gabriel Olatunji, Peter Weyerstahl, Stephen Oguntoye. Abstract. The major volatile constituents of the oils from the integral parts of Cleome viscosa L. from Nigeria have been identified by GC, GC/MS and 1H NMR.

  8. The economic value of realized volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jacobs, Kris

    2014-01-01

    Many studies have documented that daily realized volatility estimates based on intraday returns provide volatility forecasts that are superior to forecasts constructed from daily returns only. We investigate whether these forecasting improvements translate into economic value added. To do so, we ...

  9. Firm-level volatility and exports

    NARCIS (Netherlands)

    Vannoorenberghe, G.C.L.

    2012-01-01

    This paper shows that the share of exports in the total sales of a firm has a positive and substantial impact on the volatility of its sales. Decomposing the volatility of sales of exporters between their domestic and export markets, I show using an identification strategy based on a firm-specific

  10. American option pricing with stochastic volatility processes

    Directory of Open Access Journals (Sweden)

    Ping LI

    2017-12-01

    Full Text Available In order to solve the problem of option pricing more perfectly, the option pricing problem with Heston stochastic volatility model is considered. The optimal implementation boundary of American option and the conditions for its early execution are analyzed and discussed. In view of the fact that there is no analytical American option pricing formula, through the space discretization parameters, the stochastic partial differential equation satisfied by American options with Heston stochastic volatility is transformed into the corresponding differential equations, and then using high order compact finite difference method, numerical solutions are obtained for the option price. The numerical experiments are carried out to verify the theoretical results and simulation. The two kinds of optimal exercise boundaries under the conditions of the constant volatility and the stochastic volatility are compared, and the results show that the optimal exercise boundary also has stochastic volatility. Under the setting of parameters, the behavior and the nature of volatility are analyzed, the volatility curve is simulated, the calculation results of high order compact difference method are compared, and the numerical option solution is obtained, so that the method is verified. The research result provides reference for solving the problems of option pricing under stochastic volatility such as multiple underlying asset option pricing and barrier option pricing.

  11. Mutual fund volatility timing and management fees

    NARCIS (Netherlands)

    Giambona, E.; Golec, J.

    2009-01-01

    This paper shows that compensation incentives partly drive fund managers’ market volatility timing strategies. Larger incentive management fees lead to less counter-cyclical or more pro-cyclical volatility timing. But fund styles or aggregate fund flows could also account for this relation;

  12. Some recent developments in stochastic volatility modelling

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Nicolato, Elisa; Shephard, N.

    2002-01-01

    This paper reviews and puts in context some of our recent work on stochastic volatility (SV) modelling for financial economics. Here our main focus is on: (i) the relationship between subordination and SV, (ii) OU based volatility models, (iii) exact option pricing, (iv) realized power variation...

  13. Volatility Determination in an Ambit Process Setting

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Graversen, Svend-Erik

    The probability limit behaviour of normalised quadratic variation is studied for a simple tempo-spatial ambit process, with particular regard to the question of volatility memorylessness.......The probability limit behaviour of normalised quadratic variation is studied for a simple tempo-spatial ambit process, with particular regard to the question of volatility memorylessness....

  14. Order flow and volatility: An empirical investigation

    NARCIS (Netherlands)

    Opschoor, A.; Taylor, N.; van der Wel, M.; van Dijk, D.

    2014-01-01

    We study the relationship between order flow and volatility. To this end we develop a comprehensive framework that simultaneously controls for the effects of macro announcements and order flow on prices and the effect of macro announcements on volatility. Using high-frequency 30-year U.S. Treasury

  15. Volatile organometallic and semiconductor materials

    International Nuclear Information System (INIS)

    Dickson, R.S.

    1991-01-01

    This article reports on a project concerned with the metal organic chemical vapour deposition (MOCVD) of mercury-cadmium telluride (MCT) undertaken by a research consortium based in the Clayton area involving Monash University Chemistry Department, Telecom Research Laboratories, and CSIRO Division of Material Sciences and Technology. An M.R. Semicon 226 MOCVD reactor, operating near atmospheric presure with hydrogen carrier gas has been used. Most applications of MCT are direct consequence of its responsiveness to radiation in infrared region spectrum. The main aims of the project were to prepare and assess a range of volatile organometallics that might find use as a dopant sources for MCT, to prepare and study the properties of a range of different lanthanide complexes for MOCVD applications and to fully characterize the semiconductor wafers after growth. 19 refs., 3 figs

  16. Volatility smile as relativistic effect

    Science.gov (United States)

    Kakushadze, Zura

    2017-06-01

    We give an explicit formula for the probability distribution based on a relativistic extension of Brownian motion. The distribution (1) is properly normalized and (2) obeys the tower law (semigroup property), so we can construct martingales and self-financing hedging strategies and price claims (options). This model is a 1-constant-parameter extension of the Black-Scholes-Merton model. The new parameter is the analog of the speed of light in Special Relativity. However, in the financial context there is no ;speed limit; and the new parameter has the meaning of a characteristic diffusion speed at which relativistic effects become important and lead to a much softer asymptotic behavior, i.e., fat tails, giving rise to volatility smiles. We argue that a nonlocal stochastic description of such (Lévy) processes is inadequate and discuss a local description from physics. The presentation is intended to be pedagogical.

  17. Estimating Stochastic Volatility Models using Prediction-based Estimating Functions

    DEFF Research Database (Denmark)

    Lunde, Asger; Brix, Anne Floor

    to the performance of the GMM estimator based on conditional moments of integrated volatility from Bollerslev and Zhou (2002). The case where the observed log-price process is contaminated by i.i.d. market microstructure (MMS) noise is also investigated. First, the impact of MMS noise on the parameter estimates from......In this paper prediction-based estimating functions (PBEFs), introduced in Sørensen (2000), are reviewed and PBEFs for the Heston (1993) stochastic volatility model are derived. The finite sample performance of the PBEF based estimator is investigated in a Monte Carlo study, and compared...... to correctly account for the noise are investigated. Our Monte Carlo study shows that the estimator based on PBEFs outperforms the GMM estimator, both in the setting with and without MMS noise. Finally, an empirical application investigates the possible challenges and general performance of applying the PBEF...

  18. Advanced Pre-clinical Research Approaches and Models to Studying Pediatric Anesthetic Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Cheng eWang

    2012-10-01

    Full Text Available Advances in pediatric and obstetric surgery have resulted in an increase in the duration and complexity of anesthetic procedures. A great deal of concern has recently arisen regarding the safety of anesthesia in infants and children. Because of obvious limitations, it is not possible to thoroughly explore the effects of anesthetic agents on neurons in vivo in human infants or children. However, the availability of some advanced pre-clinical research approaches and models, such as imaging technology both in vitro and in vivo, stem cell and nonhuman primate experimental models, have provided potentially invaluable tools for examining the developmental effects of anesthetic agents. This review discusses the potential application of some sophisticaled research approaches, e.g., calcium imaging, in stem cell-derived in vitro models, especially human embryonic neural stem cells, along with their capacity for proliferation and their potential for differentiation, to dissect relevant mechanisms underlying the etiology of the neurotoxicity associated with developmental exposures to anesthetic agents. Also, this review attempts to discuss several advantages for using the developing rhesus monkey models (in vivo, when combined with dynamic molecular imaging approaches, in addressing critical issues related to the topic of pediatric sedation/anesthesia. These include the relationships between anesthetic-induced neurotoxicity, dose response, time-course and developmental stage at time of exposure (in vivo studies, serving to provide the most expeditious platform toward decreasing the uncertainty in extrapolating pre-clinical data to the human condition.

  19. Hypnosis control based on the minimum concentration of anesthetic drug for maintaining appropriate hypnosis.

    Science.gov (United States)

    Furutani, Eiko; Nishigaki, Yuki; Kanda, Chiaki; Takeda, Toshihiro; Shirakami, Gotaro

    2013-01-01

    This paper proposes a novel hypnosis control method using Auditory Evoked Potential Index (aepEX) as a hypnosis index. In order to avoid side effects of an anesthetic drug, it is desirable to reduce the amount of an anesthetic drug during surgery. For this purpose many studies of hypnosis control systems have been done. Most of them use Bispectral Index (BIS), another hypnosis index, but it has problems of dependence on anesthetic drugs and nonsmooth change near some particular values. On the other hand, aepEX has an ability of clear distinction between patient consciousness and unconsciousness and independence of anesthetic drugs. The control method proposed in this paper consists of two elements: estimating the minimum effect-site concentration for maintaining appropriate hypnosis and adjusting infusion rate of an anesthetic drug, propofol, using model predictive control. The minimum effect-site concentration is estimated utilizing the property of aepEX pharmacodynamics. The infusion rate of propofol is adjusted so that effect-site concentration of propofol may be kept near and always above the minimum effect-site concentration. Simulation results of hypnosis control using the proposed method show that the minimum concentration can be estimated appropriately and that the proposed control method can maintain hypnosis adequately and reduce the total infusion amount of propofol.

  20. Anesthetic activity of plant essential oils on Cyprinus carpio (koi carp).

    Science.gov (United States)

    Khumpirapang, Nattakanwadee; Pikulkaew, Surachai; Anuchapreeda, Songyot; Okonogi, Siriporn

    2018-03-19

    The aims of this study were to investigate the anesthetic and cytotoxic effects of essential oils (EOs) of Ocimum basilicum (OBO), O. canum (OCO), and O. sanctum (OSO) on Cyprinus carpio (koi carp). For anesthetic effect, induction time to surgical anesthesia and recovery time were determined. For cytotoxicity effect, viability of fish peripheral blood nuclear cells (PBMCs) was investigated. Results indicated that increasing oil concentration caused significant (p OSO at 100, 200, and 300 mg/L gave the induction time of 169.5 ± 10.2, 62.8 ± 2.3, 45.3 ± 2.2 sec, respectively, significantly shorter than OCO, and OBO. The recovery time of anesthetized fish was dose dependent (p OSO and OBO, respectively. Within 10 min contact time of the EOs and fish PBMCs, the fish PBMC viability was higher than 80%. Increase contact time and EO concentration caused an increase in cytotoxicity to fish PBMC. OBO showed less toxic than OSO and OCO. Based on the desired induction and recovery times for anesthetizing koi carp, OBO, OCO, and OSO at 300, 200, and 100 mg/L, respectively were suggested to be the most suitable. It was concluded that OBO, OCO, and OSO can be used as natural anesthetics for fish.