Home About us Contact
|
Home About us Contact | ||
|
|
||
Acceptable Agreement (acceptable + agreement)
Selected AbstractsCorrelation and agreement between the bispectral index vs. state entropy during hypothermic cardio-pulmonary bypassACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2010P. MEYBOHM 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 (bias±SD; percentage error) between the BIS vs. spectral state entropy and response entropy were r2=0.56 (1±11; 42%) and r2=0.58 (,2±11; 43%) under normothermic conditions, and r2=0.17 (10±12; 77%) and r2=0.18 (9±11; 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] Interobserver Agreement in Assessment of Clinical Variables in Children with Blunt Head TraumaACADEMIC EMERGENCY MEDICINE, Issue 9 2008Marc H. Gorelick MD Abstract Objectives:, To be useful in development of clinical decision rules, clinical variables must demonstrate acceptable agreement when assessed by different observers. The objective was to determine the interobserver agreement in the assessment of historical and physical examination findings of children undergoing emergency department (ED) evaluation for blunt head trauma. Methods:, This was a prospective cohort study of children younger than 18 years evaluated for blunt head trauma at one of 25 EDs in the Pediatric Emergency Care Applied Research Network (PECARN). Patients were excluded if injury occurred more than 24 hours prior to evaluation, if neuroimaging was obtained at another hospital prior to evaluation, or if the patient had a clinically trivial mechanism of injury. Two clinicians independently completed a standardized clinical assessment on a templated data form. Assessments were performed within 60 minutes of each other and prior to clinician review of any neuroimaging (if obtained). Agreement between the two observers beyond that expected by chance was calculated for each clinical variable, using the kappa (,) statistic for categorical variables and weighted kappa for ordinal variables. Variables with a lower 95% confidence limit (LCL) of , > 0.4 were considered to have acceptable agreement. Results:, Fifteen-hundred pairs of observations were obtained. Acceptable agreement was achieved in 27 of the 32 variables studied (84%). Mechanism of injury (low, medium, or high risk) had , = 0.83. For subjective symptoms, kappa ranged from 0.47 (dizziness) to 0.93 (frequency of vomiting); all had 95% LCL > 0.4. Of the physical examination findings, kappa ranged from 0.22 (agitated) to 0.89 (Glasgow Coma Scale [GCS] score). The 95% LCL for kappa was <0.4 for four individual signs of altered mental status and for quality (i.e., boggy or firm) of scalp hematoma if present. Conclusions:, Both subjective and objective clinical variables in children with blunt head trauma can be assessed by different observers with acceptable agreement, making these variables suitable candidates for clinical decision rules. [source] Direct and Rapid Detection of Diphtherotoxin via Potentiometric Immunosensor Based on Nanoparticles Mixture and Polyvinyl Butyral as MatrixesELECTROANALYSIS, Issue 24 2005Dianping Tang Abstract In this paper a novel potentiometric immunosensor for direct and rapid detection of diphtherotoxin (D-Ag) has been developed by means of self-assembly of monoclonal diphtheria antibody (D-Ab) onto a platinum electrode based on nanoparticles mixture (containing gold nanoparticles and silica nanoparticles) and polyvinyl butyral (PVB) as matrixes. At first, D-Ab was absorbed onto the surface of nanoparticles mixture, and then they were entrapped into polyvinyl butyral sol-gel network on a platinum electrode. The detection is based on the change in the potentiometric response before and after the antigen-antibody reaction in a phosphate buffer solution (pH,7.0). The immobilized D-Ab exhibited direct potentiometric response toward D-Ag. In comparison to the conventional applied methods, this strategy could allow antibodies immobilized with higher loading amount and better retained immunoactivity, as demonstrated by potentiometric response, cyclic voltammetry and electrochemical impedance spectroscopy of the immunosensor. The immunosensor with nanoparticles mixture exhibited much higher sensitivity, better reproducibility, and long-term stability than that with gold nanoparticles or silica nanoparticles alone. The linear range was from 5.0×10,3 to 1.2,,g,mL,1 with a detection limit of 1.1×10,3,,g,mL,1. Up to 16 successive assay cycles with retentive sensitivity were achieved for the probes regenerated with in 0.2,mol,L,1 glycine-hydrochloric acid (Gly-HCl) buffer solution and 0.25,mol,L,1 NaCl. Moreover, the immunosensor with nanoparticles mixture was applied to evaluate a number of practical specimens with potentiometric results in acceptable agreement with those given by the ELISA method, implying a promising alternative approach for detecting diphtherotoxin in the clinical diagnosis. [source] Heteroatoms and substituent effects: The importance of heteroatom hyperconjugationHETEROATOM CHEMISTRY, Issue 5 2002James F. King We have found that the specific rate of ,-sulfonyl carbanion formation in a ,-substituted sulfone shows a sizable dependence on the HC,C,X torsion angle. Defining kN = (kexch)X/(kexch)model (where the model has X = H or an alkyl group) we observed for a collection of ,-alkoxy sulfones (X = OR) acceptable agreement with the expression log kN = a + b cos2 , (where a = 1.70 and b = 2.62). Extension to other ,-substituents (X = RS, R2N, and R3N+) yields the same pattern, with the last showing very large dependence of kN on the torsion angle (b = 6.3). These observations are ascribed to the presence (in addition to the inductive and field effects) of negative hyperconjugation responsible for accelerations of 1000-fold and more, deriving from donation of the incipient negative charge on carbon into the ,*CX orbital in the transition state. These observations reflect, and at the same time underline, the importance of the low-lying antibonding orbitals present in heteroatomic molecules. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:397,405, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10067 [source] Modelling of air drying of Hac,haliloglu-type apricotsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2006Hakan Okyay Menges Abstract In this study a laboratory dryer was used for the thin layer drying of sulfured and non-sulfured apricots. The moisture ratio values throughout the drying process were calculated by 14 different mathematical models, namely Newton, Page, modified Page, modified Page-II, Henderson and Pabis, logarithmic, two-term, two-term exponential, Wang and Singh, Thompson, diffusion approximation, modified Henderson and Papis, Verma et al. and Midilli et al. models. Root mean square error, reduced chi-square, mean bias error, adjusted R -square and modelling efficiency were used as statistical parameters to determine the most suitable model among them. According to the results, the Page model was chosen to explain the thin layer drying behaviour of sulfured and non-sulfured apricots. The effects of drying air temperature (T) and velocity (V) on the constants and coefficients of the best moisture ratio model were determined by multiple regression analysis. The moisture ratio (MR) could be predicted by the Page model equation MR = exp(,ktn) with constants and coefficients k = 0.470893 + 0.078775V and n = 0.017786 exp(0.051935T) for sulfured apricots and k = 4.578252 + 1.144643T and n = 0.888040 + 0.145559V for non-sulfured apricots. It is possible to predict the moisture content of the product with the generalised Page model incorporating the effects of drying air temperature and velocity on the model constants and coefficients in the ranges T = 70,80 °C and V = 1,3 m s,1. This developed model showed acceptable agreement with the experimental results, explained the drying behaviour of the product and could also be used for engineering applications. Copyright © 2005 Society of Chemical Industry [source] An innovative method of die design and evaluation of flow balance for thermoplastics extrusion profilesPOLYMER ENGINEERING & SCIENCE, Issue 9 2009Abbas Zolfaghari In this article, a computational and experimental method for flow balancing of a U-shaped die profile with nonuniform thicknesses is presented. The approach was to implement a flow restricting mechanism along the melt flow path. A parametric study based on the restrictor dimensions was carried out to attain a preliminary optimal design. Simulations were performed using Fluent software to analyze the flow velocity at the die exit. Experimental study was then carried out at various restrictor positions for the purpose of attaining a desirable flow balance. The velocity at various segments of the die exit was measured utilizing an innovative procedure by implementing the "separating blades." Experimental findings were compared with those of simulations which showed an acceptable agreement. The results suggest that a flexible die can be designed to achieve a flow balance under various processing conditions. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] Interobserver Agreement in Assessment of Clinical Variables in Children with Blunt Head TraumaACADEMIC EMERGENCY MEDICINE, Issue 9 2008Marc H. Gorelick MD Abstract Objectives:, To be useful in development of clinical decision rules, clinical variables must demonstrate acceptable agreement when assessed by different observers. The objective was to determine the interobserver agreement in the assessment of historical and physical examination findings of children undergoing emergency department (ED) evaluation for blunt head trauma. Methods:, This was a prospective cohort study of children younger than 18 years evaluated for blunt head trauma at one of 25 EDs in the Pediatric Emergency Care Applied Research Network (PECARN). Patients were excluded if injury occurred more than 24 hours prior to evaluation, if neuroimaging was obtained at another hospital prior to evaluation, or if the patient had a clinically trivial mechanism of injury. Two clinicians independently completed a standardized clinical assessment on a templated data form. Assessments were performed within 60 minutes of each other and prior to clinician review of any neuroimaging (if obtained). Agreement between the two observers beyond that expected by chance was calculated for each clinical variable, using the kappa (,) statistic for categorical variables and weighted kappa for ordinal variables. Variables with a lower 95% confidence limit (LCL) of , > 0.4 were considered to have acceptable agreement. Results:, Fifteen-hundred pairs of observations were obtained. Acceptable agreement was achieved in 27 of the 32 variables studied (84%). Mechanism of injury (low, medium, or high risk) had , = 0.83. For subjective symptoms, kappa ranged from 0.47 (dizziness) to 0.93 (frequency of vomiting); all had 95% LCL > 0.4. Of the physical examination findings, kappa ranged from 0.22 (agitated) to 0.89 (Glasgow Coma Scale [GCS] score). The 95% LCL for kappa was <0.4 for four individual signs of altered mental status and for quality (i.e., boggy or firm) of scalp hematoma if present. Conclusions:, Both subjective and objective clinical variables in children with blunt head trauma can be assessed by different observers with acceptable agreement, making these variables suitable candidates for clinical decision rules. [source] CFD Simulation of Inlet Design Effect on Deoiling Hydrocyclone Separation EfficiencyCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 12 2009S. Noroozi Abstract An Eulerian-Eulerian three-dimensional CFD model was developed to study the effect of different inlet designs on deoiling hydrocyclone separation efficiency. Reynolds averaged Navier Stokes and continuity equations were applied to solve steady turbulent flow through the cyclone with the Reynolds stress model. In addition, the modified drag correlation for liquid-liquid emulsion with respect to the Reynolds number range and viscosity ratio of two phases was used and the simulation results were compared with those predicted by the Schiller-Naumann correlation. Pressure profile, tangential and axial velocities and separation efficiency of the deoiling hydrocyclone were calculated for four different inlet designs and compared with the standard design. The simulation results for the standard design demonstrate an acceptable agreement with reported experimental data. The results show that all new four inlet designs offer higher efficiencies compared to the standard design. The difference between the efficiency of the LLHC, of the new inlets and the standard design can be improved by increasing the inlet velocity. Furthermore, the simulations show that the separation efficiency can be improved by about 10 % when using a helical form of inlet. [source] Flow Structures of a Liquid Film Falling on Horizontal TubesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 6 2005J. Mitrovic Abstract Patterns of a liquid film falling across a vertical array of horizontal tubes change from droplet mode at low flow rates to liquid sheet at high flow rates. Between these limits, liquid columns form as a further stable flow pattern. The transition from one flow mode to another occurs via unstable structures consisting simultaneously of droplets and columns or of merging columns. The boundaries of the flow modes can be obtained from relationships expressing the flow rate as a function of physical properties, that is, the Reynolds number as a function of the Kapitza number. Correlations for the pattern boundaries recommended in the literature are compared with each other and found to be in acceptable agreement for practical purposes. [source] Determination of both the time constant of v,O2 and ,v,O2/,W from a single incremental exercise test: validation and repeatabilityCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2004Anita G. M. Wisén Summary A single incremental cycle exercise test including a steady-state load, combined with respiratory gas exchange, was performed with the objective of determining the time constant (o2) and the amount of oxygen required at each load (o2/,W) by using a novel equation. The protocol was validated using four exercise tests at different constant loads and conventionally fitted mono-exponential functions to determine o2, and interpolation of o2 versus load to determine o2/,W. No significant differences were seen between the means of either o2 or o2/,W determined with the two protocols. The correlation coefficient was 0·62 for o2 and 0·48 for o2/,W. The absolute differences (2 SD) were 11·6 s for o2 and 1·1 ml min,1 W,1 for o2/,W. The equations were compared in the same steady-state test and good agreement of o2 was obtained (R = 0·99). The 5,6-week repeatability (incremental test) was evaluated. No statistical differences were seen between the mean of the repeated tests. The difference between the tests (2 SD) were 20 s for o2 and 1·2 ml min,1 W,1 for o2/,W. In conclusion, o2 and o2/,W can be determined from a single incremental test. The validation showed an acceptable agreement, although the variations in absolute values were not negligible. This could partly be explained by the natural day-to-day variation and fluctuations in incoming raw data. The test,retest variation in absolute values was considerable, which must be taken into account when using o2 and o2/,W for evaluation of aerobic function. [source] | |||||||||||||