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Novel Index (novel + index)
Selected AbstractsA simple noninvasive index can predict both significant fibrosis and cirrhosis in patients with chronic hepatitis CHEPATOLOGY, Issue 2 2003Chun-Tao Wai Information on the stage of liver fibrosis is essential in managing chronic hepatitis C (CHC) patients. However, most models for predicting liver fibrosis are complicated and separate formulas are needed to predict significant fibrosis and cirrhosis. The aim of our study was to construct one simple model consisting of routine laboratory data to predict both significant fibrosis and cirrhosis among patients with CHC. Consecutive treatment-naive CHC patients who underwent liver biopsy over a 25-month period were divided into 2 sequential cohorts: training set (n = 192) and validation set (n = 78). The best model for predicting both significant fibrosis (Ishak score , 3) and cirrhosis in the training set included platelets, aspartate aminotransferase (AST), and alkaline phosphatase with an area under ROC curves (AUC) of 0.82 and 0.92, respectively. A novel index, AST to platelet ratio index (APRI), was developed to amplify the opposing effects of liver fibrosis on AST and platelet count. The AUC of APRI for predicting significant fibrosis and cirrhosis were 0.80 and 0.89, respectively, in the training set. Using optimized cut-off values, significant fibrosis could be predicted accurately in 51% and cirrhosis in 81% of patients. The AUC of APRI for predicting significant fibrosis and cirrhosis in the validation set were 0.88 and 0.94, respectively. In conclusion, our study showed that a simple index using readily available laboratory results can identify CHC patients with significant fibrosis and cirrhosis with a high degree of accuracy. Application of this index may decrease the need for staging liver biopsy specimens among CHC patients. [source] Game theoretic approach to multiobjective designs: Focus on inherent safetyAICHE JOURNAL, Issue 1 2006Anjana Meel Abstract A method for designing processes that are inherently safer,with the primary focus on disturbances having the potential for unbounded hazardous responses,is introduced. In cases where safety is not threatened (as in isothermal fermentation reactors), but product quality can rapidly degrade, this method provides designs that ensure high product quality (as in pharmaceutical processes). Using game theory, the method accounts for the trade-offs in profitability, controllability, safety and/or product quality, and flexibility. For nonlinear processes that are hard to control; that is, have an unstable and/or nonminimum-phase steady state, over a wide range of operating conditions, extended bifurcation diagrams are introduced. When a steady state is nonminimum phase, the process may exhibit inverse response. The steady states of processes are classified on the basis of instability and nonminimum-phase behavior to segregate the operating regimes into distinct zones. Locally optimal designs, one corresponding to each zone, are obtained first. These are compared with other locally optimal designs at alternate operating conditions, and/or process reconfigurations, to obtain the globally optimal design using game theory. Four indices,profitability, controllability, safety and/or product quality, and flexibility,characterize the optimality of a design. A novel index for safe operation and/or product quality at a steady state is formulated as a function of the eigenvalues of the Jacobian of the process model and the Jacobian of the process zero dynamics, providing a quantitative measure of instability and nonminimum-phase behavior. The application of the proposed method to an isothermal, continuous stirred-tank reactor (CSTR) with van der Vusse reactions, an exothermic CSTR, and an anaerobic fermentor with substrate and product inhibition is presented. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] Model for end-stage liver disease score to serum sodium ratio index as a prognostic predictor and its correlation with portal pressure in patients with liver cirrhosisLIVER INTERNATIONAL, Issue 4 2007Teh-Ia Huo Abstract Background: The models for end-stage liver disease (MELD) and serum sodium (SNa) are important prognostic markers in cirrhosis. A novel index, MELD to SNa ratio (MESO), was developed to amplify the opposing effect of MELD and SNa on outcome prediction. Methods: A total of 213 cirrhotic patients undergoing hepatic venous pressure gradient (HVPG) measurement were retrospectively analyzed. Results: The MESO index correlated with HVPG (r=0.258, P<0.001) and Child,Pugh score (,=0.749, P<0.001). Using mortality as the end point, the area under receiver operating characteristic curve (AUC) was 0.860 for SNa, 0.795 for the MESO index and 0.789 for MELD (P values all >0.3) at 3 months. Among patients with Child,Pugh class A or B, the MESO index had a significantly higher AUC compared with MELD (0.80 vs. 0.766, P<0.001). A MESO index <1.6 identified 97% of patients who survived at 3 months and the predicted survival rate was 96.5%. In survival analysis, MESO index >1.6 independently predicted a higher mortality rate (relative risk: 3.32, P<0001) using the Cox model. Conclusions: The MESO index, which takes into account the predictive power of both MELD and SNa, is a useful prognostic predictor for both short- and long-term survival in cirrhotic patients. [source] A new synthetic index and a protocol for monitoring the status of Posidonia oceanica meadows: a case study at Sanremo (Ligurian Sea, NW Mediterranean)AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2006Monica Montefalcone Abstract 1.The status of a Posidonia oceanica meadow in front of the town of Sanremo, Italy, was studied through a combined use of benthic mapping and synthetic indices. 2.Mapping was accomplished by integrating side scan sonar imagery and data collected by scuba diving along transects placed perpendicularly to the coastline. A thematic map (scale 1:5000) was produced. Extent of the meadow, occurrence of dead matte areas, and morphology of the lower limit (with new definition) are all described. 3.Two synthetic environmental indices were applied to transect data in order to quantify the status of the meadow: the Conservation Index and the Substitution Index. The former is related to the proportion of dead matte; the latter is a novel index measuring the amount of replacement of the ,constructional' seagrass P. oceanica by the ,non-constructional' seagrass Cymodocea nodosa. The potential of a ,phase shift' in Ligurian Sea seagrass meadows is discussed. 4.The approach here proposed, based on detailed mapping plus synthetic indices, may provide immediate information to evaluate the state of Mediterranean Posidonia oceanica for monitoring and management. Copyright © 2006 John Wiley & Sons, Ltd. [source] Until what age should glaucoma be monitored and/or treated?ACTA OPHTHALMOLOGICA, Issue 2009A novel index that facilitates clinical decision making Purpose To calculate for which combinations of age and perimetric disease stage (mean deviation [MD]) treated and untreated glaucoma patients are unlikely to become blind during lifetime. Methods The probability of dying without blindness was calculated using the age and gender adjusted life expectancy values from the Statistics Netherlands and the progression rates of treated and untreated glaucoma patients from the Early Manifest Glaucoma Trial and the Groningen Longitudinal Glaucoma Study. Absence of blindness was defined as an MD better than -20 dB. Because it is difficult - or even impossible , to determine someone's individual life expectancy and rate of progression accurately, patients were assumed to reach the 90th percentile of the adjusted life expectancy and to progress with the 90th percentile of the rate of progression, leaving an a priori probability of becoming blind during lifetime of 2.5%. Results If MD+0.8*age, with MD in dB and age in years, is larger than 59, treated male patients were unlikely to become blind during lifetime. For untreated male patients the cut-off value was 66, and for treated and untreated female patients 61 and 68 respectively. Conclusion With this novel index, MD+0.8*age, the intensity of glaucoma monitoring and/or treatment can be reduced well-founded in the ageing patient. The index can be applied to either the worse or the better eye, depending on what is considered acceptable or possible given limited resources. [source] New capability indices for evaluating the performance of multivariate manufacturing processesQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 1 2010Jeh-Nan Pan Abstract Generally, an industrial product has more than one quality characteristic. In order to establish performance measures for evaluating the capability of a multivariate manufacturing process, several multivariate process capability indices have been developed in the past few years. Among them, Taam's MCp and MCpm indices have the drawback of overestimation and Hubele's three-component capability vector lacks simplicity in practice. In this article, taking the correlation among multiple quality characteristics into account, we develop two novel indices; NMCp and NMCpm. Using two numerical examples we demonstrate that the true performance of multivariate processes are accurately reflected in our NMCp and NMCpm indices and in their associated interval estimates. Finally, simulation results show that our indices outperform both those of Taam and Hubele. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||