Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Bis

  • chiral bis
  • novel bis

  • Terms modified by Bis

  • bis score
  • bis zu

  • Selected Abstracts

    Bispectral Electroencephalographic Analysis of Patients Undergoing Procedural Sedation in the Emergency Department

    James R. Miner MD
    Abstract Objective: To determine whether there is a correlation between the level of sedation achieved during procedural sedation (PS) in the emergency department as determined by bispectral electroencephalographic (EEG) analysis (BIS) and the rate of respiratory depression (RD), the patient's perception of pain, recall of the procedure, and satisfaction. Methods: This was a prospective observational study conducted in an urban county hospital of adult patients undergoing PS using propofol, methohexital, etomidate, and the combination of fentanyl and midazolam. Consenting patients were monitored by vital signs, pulse oximetry, nasal-sample end-tidal carbon dioxide (ETCO2), and BIS monitors during PS. Respiratory depression (RD) was defined as an oxygen saturation <90%, a change from baseline ETCO2 of >10 mm Hg, or an absent ETCO2 waveform at any time during the procedure. After the procedure, patients were asked to complete three 100-mm visual analog scales (VASs) concerning their perception of pain, recall of the procedure, and satisfaction with the procedure. Patients were divided into four groups based on the lowest BIS score recorded during the procedure, group 1, >85; group 2, 70,85; group 3, 60,69; group 4, <60. Rates of RD and VAS outcomes were compared between groups using chi-square statistics. Results: One hundred eight patients were enrolled in the study. No serious adverse events were noted. RD was seen in three of 14 (21.4%) of the patients in group 1, seven of 34 (20.6%) in group 2, 16 of 26 (61.5%) in group 3, and 18 of 34 (52.9%) in group 4. The rate of RD in patients in group 2 was not significantly different from that in group 1 (p = 0.46). The rate of RD in group 2 was significantly lower than that in groups 3 (p = 0.0003) and 4 (p = 0.006). For the VAS data, when group 1 was compared with the combined groups 2, 3, and 4, it had significantly higher rates of pain (p = 0.003) and recall (p = 0.001), and a dissatisfaction rate (p = 0.085) that approached significance. When groups 2, 3, and 4 were compared with chi-square test, there was not a significant difference in pain (p = 0.151), recall (p = 0.27), or satisfaction (p = 0.25). Conclusions: Patients with a lowest recorded BIS score between 70 and 85 had the same VAS outcomes as more deeply sedated patients and the same rate of RD as less deeply sedated patients. This range of scores represented the optimally sedated patients in this study. [source]

    Automatic and controlled processes in behavioural control: Implications for personality psychology

    Philip J. Corr
    Abstract This paper highlights a number of unresolved theoretical issues that, it is argued, continue to impede the construction of a viable model of behavioural control in personality psychology. It is contended that, in order to integrate motivation, emotion, cognition and conscious experience within a coherent framework, two major issues need to be recognised: (a) the relationship between automatic (reflexive) and controlled (reflective) processing and (b) the lateness of controlled processing (including the generation of conscious awareness),phenomenally, such processing seems to ,control' behaviour, but experimentally it can be shown to postdate the behaviour it represents. The implications of these two major issues are outlined, centred on the need to integrate theoretical perspectives within personality psychology, as well as the greater unification of personality psychology with general psychology. A model of behavioural control is sketched, formulated around the concept of the behavioural inhibition system (BIS), which accounts for: (a) why certain stimuli are extracted for controlled processing (i.e. those that are not ,going to plan', as detected by an error mechanism) and (b) the function of controlled processing (including conscious awareness) in terms of adjusting the cybernetic weights of automatic processes (which are always in control of immediate behaviour) which, then, influence future automatically controlled behaviour. The relevance of this model is illustrated in relation to a number of topics in personality psychology, as well related issues of free-will and difficult-to-control behaviours. Copyright 2010 John Wiley & Sons, Ltd. [source]

    Disinhibitory trait profile and its relation to Cluster B personality disorder features and substance use problems

    Jeanette Taylor
    Abstract Certain personality and motivational traits may present vulnerability towards disinhibitory psychopathology (e.g. antisocial personality disorder, substance abuse). Cluster analysis was used to separately group 306 women and 274 men on impulsivity, Constraint, Negative Emotionality, behavioural activation system (BAS), and behavioural inhibition system (BIS) scores. As expected, a ,disinhibited' group with low Constraint, high impulsivity, weak BIS, and strong BAS emerged that showed elevated drug use problems, and histrionic and antisocial personality disorder features across gender. A ,high affectivity' group with high Negative Emotionality and strong BIS also showed elevated drug use problems and personality disorder features. Results suggested that two different trait profiles are associated with disinhibitory psychopathology and both may present vulnerability toward the development of such disorders. Copyright 2006 John Wiley & Sons, Ltd. [source]

    The assessment of behavioural activation,the relationship between positive emotionality and the behavioural activation system

    Lena C. Quilty
    Much personality research suggests that the variance in personality can be accounted for by a few dimensions, often hypothesized to be connected to neurological circuits. Gray's (1982) behavioural activation system (BAS) and behavioural inhibition system (BIS) in particular propose to explain for a variety of behaviour. This investigation sought to determine whether Positive Emotionality is an appropriate measure of the BAS, and how Tellegen's (1985) constructs are related to BAS activity. Measures of BAS and Positive Emotionality were administered to undergraduates. Confirmatory factor analyses revealed that, while Positive Emotionality can be used as an indicator of BAS activity, it is better conceived of as a distinct, correlated construct. In addition, not all components of Positive Emotionality were related to BAS activity, and BAS was further related to components of Negative Emotionality and Constraint. Copyright 2004 John Wiley & Sons, Ltd. [source]

    Construct validity and generalizability of the Carver,White behavioural inhibition system/behavioural activation system scales

    Luigi Leone
    The factorial structure and invariance of the BIS/BAS scales of Carver and White were assessed across three samples from the USA, UK, and Italy. Previous validation studies of the BIS/BAS scales relied on individual samples drawn from English-speaking populations only and failed to formally assess generalizability. The current study shows that the four-factor structure proposed by Carver and White,i.e. one BIS and three BAS facets,achieved satisfactory psychometric properties in all three samples and that measurement invariance was obtained across countries. Latent mean differences due to gender and country were also investigated. Theoretical issues concerning the validity of the BIS/BAS scales are addressed. Copyright 2001 John Wiley & Sons, Ltd. [source]

    Boiling heat transfer coefficient of R22 and an HFC/HC refrigerant mixture in a fin-and-tube evaporator of a window air conditioner

    M. Herbert Raj
    Abstract The commonly used refrigerant in unitary type air conditioners is R22 and its phase out schedule in developing countries is to commence from 2015. Many alternatives to R22 are found in published literature in which R407C has similar characteristics to those of R22 except for its zeotropic nature. However, R407C which is an HFC is made compatible with the mineral oil lubricant in the system compressor by the addition of 20% of HC. This HFC/HC mixture called the M20 refrigerant mixture is reported to be a retrofit refrigerant for R22. Though its latent heat value is greater than that of R22, its refrigerating capacity is lower when it is used to retrofit R22 window air conditioners. Hence, a heat transfer analysis was conducted in the evaporator of a room air conditioner, for practically realized heat flux conditions during standard performance testing. The tests were conducted as per the BIS and ASHRAE standards. Kattan,Thome,Favrat maps are used to confirm the flow patterns, which prevail inside the fin-and-tube evaporator in the tested operating conditions. It is revealed that the heat transfer coefficient/heat fluxes are poorer for M20 because of the lower mass flow rate and higher vapor fraction at the entry of the evaporator than that of R22 in the prevailing operating conditions. The heat transfer coefficients of the M20 refrigerant mixture under various test conditions are lower in the range of 14% to 56% than those of R22. 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( DOI 10.1002/htj.20299 [source]

    A voxel-based morphometry study of frontal gray matter correlates of impulsivity,

    HUMAN BRAIN MAPPING, Issue 4 2009
    Koji Matsuo
    Abstract Impulsivity is a personality trait exhibited by healthy individuals, but excessive impulsivity is associated with some mental disorders. Lesion and functional neuroimaging studies indicate that the ventromedial prefrontal region (VMPFC), including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) and medial prefrontal cortex, and the amygdala may modulate impulsivity and aggression. However, no morphometric study has examined the association between VMPFC and impulsivity. We hypothesized that healthy subjects with high impulsivity would have smaller volumes in these brain regions compared with those with low impulsivity. Sixty-two healthy subjects were studied (age 35.4 12.1 years) using a 1.5-T MRI system. The Barratt impulsiveness scale (BIS) was used to assess impulsivity. Images were processed using an optimized voxel-based morphometry (VBM) protocol. We calculated the correlations between BIS scale scores and the gray matter (GM) and white matter (WM) volumes of VMPFC and amygdala. GM volumes of the left and right OFC were inversely correlated with the BIS total score (P = 0.04 and 0.02, respectively). Left ACC GM volumes had a tendency to be inversely correlated with the BIS total score (P = 0.05). Right OFC GM volumes were inversely correlated with BIS nonplanning impulsivity, and left OFC GM volumes were inversely correlated with motor impulsivity. There were no significant WM volume correlations with impulsivity. The results of this morphometry study indicate that small OFC volume relate to high impulsivity and extend the prior finding that the VMPFC is involved in the circuit modulating impulsivity. Hum Brain Mapp 2009. 2008 Wiley-Liss, Inc. [source]

    A clinical prospective comparison of anesthetics sensitivity and hemodynamic effect among patients with or without obstructive jaundice

    L.-Q. YANG
    Background: To compare isoflurane anesthesia in patients with or without hyperbilirubinemia undergoing hepatobiliary surgery. Methods: Forty-two patients with obstructive jaundice and 40 control patients with normal liver function scheduled for hepatobiliary surgery under isoflurane anesthesia were studied. Anesthesia was induced with propofol (1.5,2 mg/kg) and remifentanil (2 ,g/kg). After tracheal intubation, anesthesia was titrated using isoflurane in oxygen-enriched air, adjusted to maintain a bispectral index (BIS) value of 46,54. Ephedrine, atropine and remifentanil were used to maintain hemodynamic parameters within 30% of the baseline. The mean arterial blood pressure (MAP), heart rate (HR), drug doses and the time taken to recover from anesthesia were recorded. Results: Demographic data, duration and BIS values were similar in both groups. Anesthesia induction and maintenance were associated with more hemodynamic instability in the patients with jaundice and they received more ephedrine and atropine and less remifentanil and isoflurane (51.124.2 vs. 84.620.3 mg/min; P for all <0.05) than control patients. Despite less anesthetic use, the time to recovery and extubation was significantly longer than that in control. Conclusion: Patients with obstructive jaundice have an increased sensitivity to isoflurane, more hypotension and bradycardia during anesthesia induction and maintenance and a prolonged recovery time compared with controls. [source]

    Correlation and agreement between the bispectral index vs. state entropy during hypothermic cardio-pulmonary bypass

    Background: The bispectral index (BIS) and spectral entropy enable monitoring the depth of anaesthesia. Mild hypothermia has been shown to affect the ability of electroencephalography monitors to reflect the anaesthetic drug effect. The purpose of this study was to investigate the effect of hypothermia during a cardio-pulmonary bypass on the correlation and agreement between the BIS and entropy variables compared with normothermic conditions. Methods: This prospective clinical study included coronary artery bypass grafting patients (n=25) evaluating correlation and agreement (Bland,Altman analysis) between the BIS and both spectral and response entropy during a hypothermic cardio-pulmonary bypass (31,34 C) compared with nomothermic conditions (34,37.5 C). Anaesthesia was maintained with propofol and sufentanil and adjusted clinically, while the anaesthetist was blinded to the monitors. Results: The BIS and entropy values decreased during cooling (P<0.05), but the decrease was more pronounced for entropy variables compared with BIS (P<0.05). The correlation coefficients (biasSD; percentage error) between the BIS vs. spectral state entropy and response entropy were r2=0.56 (111; 42%) and r2=0.58 (,211; 43%) under normothermic conditions, and r2=0.17 (1012; 77%) and r2=0.18 (911; 68%) under hypothermic conditions, respectively. Bias was significantly increased under hypothermic conditions (P<0.001 vs. normothermia). Conclusion: Acceptable agreement was observed between the BIS and entropy variables under normothermic but not under hypothermic conditions. The BIS and entropy variables may therefore not be interchangeable during a hypothermic cardio-pulmonary bypass. [source]

    The effects of obstructive jaundice on the pharmacodynamics of propofol: does the sensitivity of intravenous anesthetics change among icteric patients?

    J. C. SONG
    Background Some studies suggest that certain clinical symptoms of cholestasis, such as fatigue and pruritus, result from altered neurotransmission. Patients with obstructive jaundice also have labile blood pressure and heart rate. In the present study, the authors investigated whether obstructive jaundice affects a patient's sensitivity to hypnotics and the haemodynamic profile of propofol. Methods Thirty-six ASA physical status I/II/III patients with serum total bilirubin (TBL) from 7.8 to 362.7 ,mol/l scheduled for bile duct surgery were recruited. A computer-controlled propofol infusion programmed for effect site target was used to rapidly attain and maintain sequential increase of the compartment concentration (from 1 to 3 ,g/ml). Each target-controlled concentration was maintained for about 12 min, and arterial blood samples were drawn for propofol concentration determination. The bispectral index (BIS) and mean arterial pressures (MAP) were used as indices of the propofol effect. The relation between the concentration and the effects was described by the Hill equation. The pharmacodynamic parameters were optimized using a nonlinear mixed-effect model. Results TBL was not a significant covariate of EC50 for the pharmacodynamic model. For BIS and MAP, the parameters of the pharmacodynamic model were Emax=75.77%, EC50=2.34 ,g/ml, and ,=1.82, and Emax=47.83%, EC50=1.49 ,g/ml, and ,=1.88, respectively. Conclusions We demonstrated that obstructive jaundice with serum TBL from 7.8 to 362.7 ,mol/l had no effect on propofol pharmacodynamics observed by BIS and MAP. [source]

    On-Pump Beating Heart Versus Hypothermic Arrested Heart Valve Replacement Surgery

    mit Karadeniz M.D.
    Methods: Fifty valvular surgery patients were randomly assigned into three groups. Sixteen patients underwent beating heart valve replacement with normothermic bypass without cross-clamping the aorta, 17 patients underwent the same procedure with cross-clamping the aorta and retrograde coronary sinus perfusion, and the remaining 17 patients had conventional surgery with hypothermic bypass and cardioplegic arrest. Results: Two-channel electroencephalography (EEG) was recorded to assess changes in cerebral cortical synaptic activity and 95% spectral edge frequency values were recorded continuously. Bispectral monitoring was used to measure the depth of anesthesia. Blood flow rates in middle cerebral artery (MCA) were measured by transcranial Doppler (TCD). Reduction in spectral edge frequency (>50%) or bispectral index (BIS) (<20) or transcranial Doppler flow velocity (>50%) was detected in four patients in Group 1, five patients in Group 2, and three patients in Group 3. BIS or EEG values never reached zero, which indicates isoelectric silence during surgery. Gross neurological examinations were normal in all patients postoperatively. Conclusion: There is no difference regarding neurological monitoring results between on-pump beating heart and hypothermic arrested heart valve replacement surgery. Also no significant difference was encountered among the groups regarding the clinical outcomes. [source]

    Prospective evaluation of the time to peak effect of propofol to target the effect site in children

    H. R. MUOZ
    Background: The plasma-effect site equilibration rate constant (ke0) of propofol has been determined in children with the use of the time to maximum effect (tpeak), however, it has not been validated. The objective was to measure the tpeak; of propofol with two depths of anesthesia monitors in children and to evaluate these measurements with a target-controlled infusion (TCI) system. Methods: Unpremedicated, ASA I children from 3 to 11 years were studied. In Part 1, children were monitored simultaneously with the bispectral index (BIS) and the A-Line ARX-index (AAI) from the Alaris A-Line auditory-evoked potential monitor/2. The tpeak after a bolus dose of propofol was measured. In Part 2, the tpeak measured was used to target the effect site with a TCI system. The median (MD) and the absolute median (MDA) difference between the predicted time of peak concentration at the effect site (Ce) and the measured time of peak effect in the index of depth of anesthesia (terror) was used to evaluate the performance of the system. Results: The BIS recordings were of a better quality than the AAI. The mean standard deviation tpeak was 65 14 s with the BIS (n=25) and 201 74 s with the AAI (n=10)(P<0.001). Validation was only performed with the BIS monitor in 40 children, yielding an MD terror of ,9.5 s and an MDA terror of 10.0 s. Conclusions: The small delay between the evolution of Ce of propofol and the observed effect suggests that this can be a useful model to target the effect site in children. [source]

    Influence of hypobaric hypoxia on bispectral index and spectral entropy in volunteers

    T. IKEDA
    Background: Hypoxia has been shown to change electroencephalogram parameters including frequency and amplitude, and may thus change bispectral index (BIS) and spectral entropy values. If hypoxia per se changes BIS and spectral entropy values, BIS and spectral entropy values may not correctly reflect the depth of anaesthesia during hypoxia. The aim of this study was to examine the changes in BIS and spectral entropy values during hypobaric hypoxia in volunteers. Methods: The study was conducted in a high-altitude chamber with 11 volunteers. After the subjects breathed 100% oxygen for 15 min at the ground level, the simulated altitude increased gradually to the 7620 m (25,000 ft) level while the subjects continued to breathe oxygen. Then, the subjects discontinued to breath oxygen and breathed room air at the 7620 m level for up to 5 min until they requested to stop hypoxic exposure. Oxygen saturation (SpO2), heart rate, 95% spectral edge frequency (SEF), BIS, response entropy (RE), and state entropy (SE) of spectral entropy were recorded throughout the study period. Results: Of the 11 subjects, seven subjects who underwent hypoxic exposure for 4 min were analysed. SpO2 decreased to 69% at the 7620 m level without oxygen. However, SEF, BIS, RE, and SE before and during hypoxic exposure were almost identical. Conclusion: These data suggest that hypoxia of oxygen saturation around 70% does not have a strong effect on BIS and spectral entropy. [source]

    Psychometric evaluation of the body investment scale for use with adolescents

    Augustine Osman
    Abstract We conducted two studies to examine the psychometric properties of the Body Investment Scale (BIS; Orbach & Mikulincer, 1998) in U.S. adolescent samples. The BIS was designed to assess bodily experiences that are associated with suicide-related behaviors. In Study 1, confirmatory factor analysis (CFA) with data from a combined sample of 204 high school adolescents (83 boys, 121 girls) and 197 psychiatric inpatient (101 boys, 96 girls) adolescents provided moderate support for the oblique four-factor solution: Body Feelings (,=.86, 95% CI=.83,.89), Body Touch (,=.71, 95% CI=.65,.76), Body Care (,=.78, 95% CI=.71,.81), and Body Protection (,=.78, 95% CI=.73,.82); robust comparative fit index=.88 and the robust Tucker Lewis Index=.83. The second-order factor model also provided moderate fit to the data. In Study 2, results of the CFA with data from adolescent psychiatric inpatients (N=205; 101 boys, 104 girls) provided additional support for the four-factor solution. In addition, results of the receiver operating characteristic and logistic regression analyses showed that scores on the Body Feelings and Body Protection scales were most useful in differentiating the responses of suicidal and nonsuicidal adolescents, all Cohen's d values >.30. The study also examined associations between scores on the BIS scales and the validation self-report measures of hopelessness, suicide-related behavior, and reasons for living. 2009 Wiley Periodicals, Inc. J Clin Psychol 66: 259,276, 2010. [source]

    Configurational assignments of the diastereomers of 3,3,-(1,2-ethanediyl)bis[2-(3-fluorophenyl)-5-methyl-4-thiazolidinone] derivative with four stereogenic centers

    Maria Gabriella Vigorita
    Diastereomers of antiinflammatory/analgesic and antihistaminic 3,3,[(1,2-ethanediyl)bis(2-aryl-4-thiazo-lidinone)] derivatives possessing two stereogenic centers (indicated as BIS 2*C) have been widely investigated in recent years. The 5,5,-dimethyl analogues (BIS 4*C), now reported, have been synthesized by reaction of () ,-mercaptopropionic acid and N,N' -di(3-fluorobenzyliden)ethylenediamine. Because the 2 and 2,carbons bear the same groups and similarly the 5 and 5, carbons, and the latter groups are different from the former, four enantiomeric pairs and two meso forms exist in this situation. These diastereomers were identified by the concerted use of nmr spectroscopy and hplc on chiral stationary phase. [source]

    Comparison of closed loop vs. manual administration of propofol using the Bispectral index in cardiac surgery

    Background: In recent years, electroencephalographic indices of anaesthetic depth have facilitated automated anaesthesia delivery systems. Such closed-loop control of anaesthesia has been described in various surgical settings in ASA I,II patients (1,4), but not in open heart surgery characterized by haemodynamic instability and higher risk of intra-operative awareness. Therefore, a newly developed closed-loop anaesthesia delivery system (CLADS) to regulate propofol infusion by the Bispectral index (BIS) was compared with manual control during open heart surgery. Methods: Forty-four adult ASA II,III patients undergoing elective cardiac surgery under cardiopulmonary bypass were enrolled. The study participants were randomized to two groups: the CLADS group received propofol delivered by the CLADS, while in the manual group, propofol delivery was adjusted manually. The depth of anaesthesia was titrated to a target BIS of 50 in both the groups. Results: During induction, the CLADS group required lower doses of propofol (P<0.001), resulting in lesser overshoots of BIS (P<0.001) and mean arterial blood pressure (P=0.004). Subsequently, BIS was maintained within 10 of the target for a significantly longer time in the CLADS group (P=0.01). The parameters of performance assessment, median absolute performance error (P=0.01), wobble (P=0.04) and divergence (P<0.001), were all significantly better in the CLADS group. Haemodynamic stability was better in the CLADS group and the requirement of phenylephrine in the pre-cardiopulmonary bypass period as well as the cumulative dose of phenylephrine used were significantly higher in the manual group. Conclusion: The automated delivery of propofol using CLADS was safe, efficient and performed better than manual administration in open heart surgery. [source]

    Different bispectral index values from both sides of the forehead in unilateral carotid artery stenosis

    E. H. LEE
    Bispectral index (BIS) values derived from the left and right forehead are usually the same. We report on two patients with unilateral carotid artery stenosis in whom we observed differences between the BIS values obtained from sensors placed on each side of the forehead. During surgery, the BIS values of the diseased side decreased more than those of the opposite side when the mean arterial pressure decreased below 70 mmHg. BIS monitors should be used with caution in patients with unilateral carotid artery and cerebrovascular disease. [source]

    Influence of Alcohol Use Experience and Motivational Drive on College Students' Alcohol-Related Cognition

    ALCOHOLISM, Issue 8 2009
    Roisin M. O'Connor
    Background:, Cognitive processes are thought to be pivotal to risk for heavy drinking. However, few studies have examined the alcohol cue-activated positive and negative semantic memory networks that may be pivotal to drinking behavior. Moreover, much is to be understood about the influences of cognitive processes, particularly in high-risk drinking samples such as college students. The current study examines the sequential process of alcohol cues activating valenced semantic memory networks, and the influences of prior drinking experience and individual differences in motivational drive on this automatic (implicit) cognitive process. Methods:, Participants (N = 138, 52% women) were college freshmen prescreened to represent the full range of drinking experience (i.e., current abstainers, light and heavy drinkers). Participants completed self-reports of past month alcohol use, and individual differences in behavioral inhibition system (BIS) and behavioral approach/activation system (BAS). Alcohol cue-elicited positive and negative semantic memory networks were assessed using a priming task. Results:, Results from the priming task revealed that for light drinkers alcohol cues were equally as likely to activate positive and negative semantic memory networks, suggesting relatively neutral cue-elicited alcohol attitudes. Conversely, for heavy drinkers, alcohol cues more readily activated positive relative to negative semantic memory networks, suggesting relatively positive cue-elicited alcohol attitudes. Furthermore, positive alcohol cue-elicited semantic memory networks (positive attitudes) were evident for individuals characterized by a strong BAS and weak BIS (as hypothesized) and those characterized by a weak BAS and weak BIS. Conclusions:, The findings suggest that alcohol-cue elicited positive semantic memory networks may be pivotal to risk for heavy drinking. Specifically, it is via the influence on this cognitive process that prior drinking experience and individual differences in motivational drive, respectively, may maintain and predispose individuals to risk for heavy alcohol use. [source]

    Seafloor glacial features reveal the extent and decay of the last British Ice Sheet, east of Scotland,

    Alastair G. C. Graham
    Abstract Three-dimensional (3D) seismic datasets, 2D seismic reflection profiles and shallow cores provide insights into the geometry and composition of glacial features on the continental shelf, offshore eastern Scotland (58 N, 1,2 W). The relic features are related to the activity of the last British Ice Sheet (BIS) in the Outer Moray Firth. A landsystem assemblage consisting of four types of subglacial and ice marginal morphology is mapped at the seafloor. The assemblage comprises: (i) large seabed banks (interpreted as end moraines), coeval with the Bosies Bank moraine; (ii) morainic ridges (hummocky, push and end moraine) formed beneath, and at the margins of the ice sheet; (iii) an incised valley (a subglacial meltwater channel), recording meltwater drainage beneath former ice sheets; and (iv) elongate ridges and grooves (subglacial bedforms) overprinted by transverse ridges (grounding line moraines). The bedforms suggest that fast-flowing grounded ice advanced eastward of the previously proposed terminus of the offshore Late Weichselian BIS, increasing the size and extent of the ice sheet beyond traditional limits. Complex moraine formation at the margins of less active ice characterised subsequent retreat, with periodic stillstands and readvances. Observations are consistent with interpretations of a dynamic and oscillating ice margin during BIS deglaciation, and with an extensive ice sheet in the North Sea basin at the Last Glacial Maximum. Final ice margin retreat was rapid, manifested in stagnant ice topography, which aided preservation of the landsystem record. Copyright 2008 John Wiley & Sons, Ltd. [source]

    Pre-oxygenation enhances induction with sevoflurane as assessed using bispectral index monitoring

    A. Fassoulaki
    Background:, Several methods may enhance the inhalational induction of anesthesia. In this randomized double-blind study, we evaluated the speed of induction of anesthesia with sevoflurane with or without pre-oxygenation. Methods:, Fifty-four patients scheduled for hysteroscopy received for 10 min air or 100% oxygen via a facemask followed by , 7% sevoflurane in 100% oxygen. During the first 300 s of sevoflurane administration, bispectral index (BIS) values were recorded every 30 s in all patients. In 14 patients, seven in each group, BIS, endtidal CO2, tidal volume, respiratory rate, SpO2, and heart rate were recorded every minute during the pre-induction period and every 30 s during the first 5 min of sevoflurane administration. Results:, The BIS, endtidal CO2, tidal volume and respiratory rate did not differ between the oxygen or air breathing groups (P = 0.696, P = 0.999, P = 0.388, and P = 0.875, respectively), though the oxygen group exhibited lower tidal volumes by 16,20%. The SpO2 and heart rates were higher in the oxygen breathing group (P < 0.001 and P = 0.042, respectively). During sevoflurane administration, BIS values were lower in the oxygen group vs. the group breathing air, in particular at 90, 120, 150, 180 and 210 s (P = 0.001, P = 0.001, P = 0.001, P = 0.001 and P = 0.030, respectively). The endtidal CO2 and the tidal volumes between the groups did not differ. The two groups differed in the SpO2 and the heart rates during induction (P = 0.004 and 0.003, respectively). Conclusions:, Before sevoflurane administration, breathing 100% oxygen for 10 min enhances induction of anesthesia with sevoflurane. [source]

    Bispectral Index values are higher during halothane vs. sevoflurane anesthesia in children, but not in infants

    J. J. Edwards
    Background:, Previously, we have shown in adult patients that bispectral index score (BIS) values are significantly higher during halothane anesthesia (53,61 units) as compared with those observed during equipotent concentrations of sevoflurane (39,43 units). Because halothane is frequently used in the pediatric setting, we tested the hypothesis that BIS values observed in children might also be higher during general anesthesia with halothane than with sevoflurane. Methods:, Forty-one healthy, unpremedicated pediatric patients scheduled for elective operations received either halothane or sevoflurane titrated as appropriate for surgical stimulation. Results:, During maintenance sevoflurane anesthesia (n = 20), the mean BIS values and percent end-tidal concentrations were 44 14 and 2.1 0.6, respectively, whereas for the halothane group (n = 21) the corresponding values were 61 7 and 1.1 0.4, respectively. Conclusion:, These findings suggest that BIS values are higher during halothane vs. sevoflurane anesthesia in children, but not in infants [source]

    Rigid Crosslinked Polyacrylamide Monoliths with Well-Defined Macropores Synthesized by Living Polymerization

    Joji Hasegawa
    Abstract Rigid crosslinked polyacrylamide monoliths with well-defined macropores have been successfully fabricated by organotellurium-mediated living radical polymerization (TERP) accompanied by spinodal decomposition. The TERP forms homogeneous networks derived from N,N -methylenebis(acrylamide) (BIS), in which spinodal decomposition is induced to form macropores. Macropore diameter can be controlled from submicrons to a few microns, and also the obtained networks contain mesopores in the macroporous skeletons, which are collapsed by evaporative drying. They are promising materials with hydrophilic polyacrylamide surfaces and have enough strength to preserve the macropores from the surface tension arising in the repetitive swelling and drying that may occur in many applications. [source]

    Effects of subanaesthetic and anaesthetic doses of sevoflurane on regional cerebral blood flow in healthy volunteers.

    A positron emission tomographic study
    Background:, We tested the hypothesis that escalating drug concentrations of sevoflurane are associated with a significant decline of cerebral blood flow in regions subserving conscious brain activity, including specifically the thalamus. Methods:, Nine healthy human volunteers received three escalating doses using 0.4%, 0.7% and 2.0% end-tidal sevoflurane inhalation. During baseline and each of the three levels of anaesthesia one PET scan was performed after injection of . Cardiovascular and respiratory parameters were monitored and electroencephalography and bispectral index (BIS) were registered. Results:, Sevoflurane decreased the BIS values dose-dependently. No significant change in global cerebral blood flow (CBF) was observed. Increased regional CBF (rCBF) in the anterior cingulate (17,21%) and decreased rCBF in the cerebellum (18,35%) were identified at all three levels of sedation compared to baseline. Comparison between adjacent levels sevoflurane initially (0 vs. 0.2 MAC) decreased rCBF significantly in the inferior temporal cortex and the lingual gyrus. At the next level (0.2 MAC vs. 0.4 MAC) rCBF was increased in the middle temporal cortex and in the lingual gyrus, and decreased in the thalamus. At the last level (0.4 MAC vs. 1 MAC) the rCBF was increased in the insula and decreased in the posterior cingulate, the lingual gyrus, precuneus and in the frontal cortex. Conclusion:, At sevoflurane concentrations at 0.7% and 2.0% a significant decrease in relative rCBF was detected in the thalamus. Interestingly, some of the most profound changes in rCBF were observed in structures related to pain processing (anterior cingulate and insula). [source]

    Dexmedetomidine and arousal affect subthalamic neurons,

    MOVEMENT DISORDERS, Issue 9 2008
    William Jeffrey Elias MD
    Abstract Stereotactic neurosurgeons hesitate to employ sedation in cases requiring microelectrode recording (MER). We report our experience with dexmedetomidine during MER of subthalamic nucleus (STN). Eleven Parkinsonian patients received dexmedetomidine during deep brain stimulation surgery. Seven received continuous IV infusions during MER in the STN. The bispectral index (BIS) was used to estimate the level of consciousness. The quality of MER was evaluated as a function of BIS, clinical arousal, and dexmedetomidine dose. MER during wakefulness (BIS > 80; 0.1 to 0.4 mcg/kg/hr dexmedetomidine) was similar to the unmedicated state. Subthalamic MER was reduced when the patient was asleep or unarousable (BIS < 80). Anxiolysis persisted for hours. Arousal affects STN neurons. Dexmedetomidine "cooperative sedation," from which the patient is easily aroused, provides interpretable STN MER and prolonged anxiolysis. We suggest dexmedetomidine infusions without a loading dose, a relatively low infusion rate, and discontinuation after completion of the bur holes. 2008 Movement Disorder Society [source]

    Bispectral index, predicted and measured drug levels of target-controlled infusions of remifentanil and propofol during laparoscopic cholecystectomy and emergence

    S. C. Hymork
    Background: Target-controlled infusions (TCI) have been launched as simple, accurate and reliable delivery systems of intravenous drugs. Bispectral index of EEG (BIS) seems promising in measuring hypnotic effect of anaesthetic drugs. The aims of this study were to evaluate the accuracy of TCI systems in patients undergoing laparoscopic cholecystectomy and to correlate measured drug levels to BIS values. Data were analysed for possible gender differences during emergence. Methods: After written informed consent, 20 patients were enrolled in an open study. Remifentanil was set at 7.5 ng/ml as target throughout the whole procedure, and propofol at 5 ,g/ml at induction and 3 ,g/ml after intubation. Values in blood samples of remifentanil and propofol were correlated to the estimated values and to systolic blood pressure and BIS. BIS values and measured drug levels during emergence and emergence time were compared for the two sexes. Results: Measured drug values varied considerably from the set target with a prediction error of ,22% for remifentanil and 49% for propofol. The anaesthesia level was regarded as quite deep with a mean BIS during stable surgery of 427, and at this level we found no correlation between measured values of either of the two drugs and BIS. The emergence time was significantly shorter for women (12.62.5 min) than for men (19.04.2 min) (P=0.001), with no significant differences in measured levels of propofol or remifentanil or BIS during the emergence period. Conclusion: Present systems for TCI of remifentanil and propofol result in large intra- and interindividual variations in measured drug levels, and measured levels differ from target. There may be possible interaction between the two anaesthetics at a pharmacokinetic level. Within the level of anaesthesia studied here, BIS was not an indicator of the actual drug levels. Women woke up significantly faster than men. [source]

    Effects of dexmedetomidine on intraoperative motor and somatosensory evoked potential monitoring during spinal surgery in adolescents

    Summary Background:, Dexmedetomidine may be a useful agent as an adjunct to an opioid,propofol total intravenous anesthesia (TIVA) technique during posterior spinal fusion (PSF) surgery. There are limited data regarding its effects on somatosensory (SSEPs) and motor evoked potentials (MEPs). Methods:, The data presented represent a retrospective review of prospectively collected quality assurance data. When the decision was made to incorporate dexmedetomidine into the anesthetic regimen for intraoperative care of patients undergoing PSF, a prospective evaluation of its effects on SSEPs and MEPs was undertaken. SSEPs and MEPs were measured before and after the administration of dexmedetomidine in a cohort of pediatric patients undergoing PSF. Dexmedetomidine (1 ,gkg,1 over 20 min followed by an infusion of 0.5 ,gkg,1h,1) was administered at the completion of the surgical procedure, but prior to wound closure as an adjunct to TIVA which included propofol and remifentanil, adjusted to maintain a constant depth of anesthesia as measured by a BIS of 45,60. Results:, The cohort for the study included nine patients, ranging in age from 12 to 17 years, anesthetized with remifentanil and propofol. In the first patient, dexmedetomidine was administered in conjunction with propofol at 110 ,gkg,1min,1 which resulted in a decrease in the bispectral index from 58 to 31. Although no significant effect was noted on the SSEPs (amplitude or latency) or the MEP duration, there was a decrease in the MEP amplitude. The protocol was modified so that the propofol infusion was incrementally decreased during the dexmedetomidine infusion to achieve the same depth of anesthesia. In the remaining eight patients, the bispectral index was 52 6 at the start of the dexmedetomidine loading dose and 49 4 at its completion (P = NS). There was no statistically significant difference in the MEPs and SSEPs obtained before and at completion of the dexmedetomidine loading dose. Conclusion:, Using the above-mentioned protocol, dexmedetomidine can be used as a component of TIVA during PSF without affecting neurophysiological monitoring. [source]

    Effect of oral midazolam premedication on the awakening concentration of sevoflurane, recovery times and bispectral index in children

    Keith K. Brosius MD
    Background: We sought to determine the influence of preoperative oral midazolam on: (i) measures of anaesthetic emergence; (ii) recovery times and (iii) intraoperative bispectral index (BIS) measurements during sevoflurane/N2O anaesthesia in paediatric patients. Methods: Fifty-two patients, aged 1,10 years, ASA I,II, were enrolled in a prospective double-blinded study. Patients were randomized to receive either midazolam 0.5 mgkg,1 (M) or midazolam vehicle (P) as premedication. After inhalation induction and intubation, expired sevoflurane was stabilized at 3% in 60% N2O and the corresponding BIS (BIS I) recorded. At the completion of surgery, sevoflurane was stabilized at 0.5% and the BIS (BIS E) again recorded. Awakening time, expired sevoflurane/N2O awakening concentrations and recovery times were recorded. Results: There were no significant differences between groups in awakening time, sevoflurane or N2O awakening concentrations, time to PACU discharge, time to hospital discharge or in BIS I and BIS E measurements. [source]

    Use of the Bispectral Index monitor to aid titration of propofol during a drug-assisted interview

    Greta M. Palmer MB
    We report two drug-assisted interviews with propofol in an 18-year-old with the diagnosis of Complex Regional Pain Syndrome type 1. We describe difficulty in titration of propofol in the first interview. Consequently, in the second interview, the Bispectral Index (BIS) monitor was applied to assist adjustment of the propofol infusion. This facilitated the achievement of a prolonged sedative-hypnotic state for a successful neuropsychological evaluation. Pertinent information was obtained from this patient. However, the role of drug-assisted interviews as a technique needs to be further elucidated. [source]

    The association between harmful alcohol use and Internet addiction among college students: Comparison of personality

    Ju-Yu Yen md
    Aims:, This study aimed to (i) evaluate the association between Internet addiction and harmful alcohol use, and (ii) evaluate the associated personality characteristics of Internet addiction as well as harmful alcohol use. Methods:, A total of 2453 college students were invited to complete the Chen Internet Addiction Scale, Behavior Inhibition System and Behavior Approach System Scale(BIS/BAS scale), and the Alcohol Use Disorders Identification Test from May 2005 to May 2006. Results:, The results demonstrated Internet addiction was associated with harmful alcohol use among college students. College students with Internet addiction had higher scores on the BIS and BAS fun-seeking subscales. However, college students with harmful alcohol use had higher scores on the BAS drive and fun-seeking subscales, and lower scores on the BIS subscale. Conclusions:, Internet addiction is associated with harmful alcohol use. Furthermore, fun seeking was the shared characteristic of these two problem behaviors and might contribute to the association. However, further studies are necessary to evaluate the underlying mechanisms accounting for the association between Internet addiction and harmful alcohol use. [source]

    The role of fear in persuasion

    PSYCHOLOGY & MARKETING, Issue 11 2004
    James Price Dillard
    Previous research on fear/threat appeals has correlated fear intensity with persuasion. However, fear might influence persuasion in at least four conceptually distinct ways: (a) the proclivity to experience fear, (b) the rise from baseline to peak, (c) peak intensity, and (d) the decline from peak to postmessage fear. A study was conducted in which 361 participants read a message that first described the dangers of influenza, then advocated obtaining a free vaccination. Significant positive correlations were observed between tonic, that is, traitlike, activation of the behavioral-inhibition system (BIS) and various indices of fear arousal. Nonsignificant correlations were observed between the behavioral-activation system (BAS) and the same indices. Both rise and peak measures of fear predicted persuasion, but decline in fear had no discernible impact on persuasion. 2004 Wiley Periodicals, Inc. [source]