MELD score can predict early mortality in patients with rebleeding after band ligation for variceal bleeding

AIM:To investigate the outcomes,as well as risk factors for 6-wk mortality,in patients with early rebleeding after endoscopic variceal band ligation (EVL) for esophageal variceal hemorrhage (EVH).METHODS:Among 817 EVL procedures performed for EVH between January 2007 and December 2008,128 patients with early rebleeding,defined as rebleeding within 6 wk after EVL,were enrolled for analysis.RESULT:The rate of early rebleeding after EVL for acute EVH was 15.6% (128/817).The 5-d,6-wk,3-mo,and 6-mo mortality rates were 7.8%,38.3%,55.5%,and 58.6%,respectively,in these early rebleeding patients.The use of beta-blockers,occurrence of hypovolemic shock,and higher model for end-stage liver disease (MELD) score at the time of rebleeding were independent predictors for 6-wk mortality.A cut-off value of 21.5 for the MELD score was found with an area under ROC curve of 0.862 (P < 0.001).The sensitivity,specificity,positive predictive value,and negative predictive value were 77.6%,81%,71.7%,and 85.3%,respectively.As for the 6-mo survival rate,patients with a MELD score ≥ 21.5 had a significantly lower survival rate than patients with a MELD score < 21.5 (P < 0.001).CONCLUSION:This study demonstrated that the MELD score is an easy and powerful predictor for 6-wk mortality and outcomes of patients with early rebleeding after EVL for EVH.

Bits, Mass and Acceleration Issues in BSC

The goal of the present paper is to expand already published works in the frame of＂Banded speed cosmology＂ （BSC）. In particular this paper gives validated values for physical quantities not so far investigated in previous publications, i.e., the number of individual physical entity in the universe, as well as the maximum value for acceleration. Validates values mean identical quantities from a numerical point of view obtained with different theoretical procedures, additionally compared with data based on NASA observations with Planck probe.

Response Characteristics of Position Sensitive Detector under Oblique Incidence Condition

Based on Lucovsky equation,the response solution of 1-D position sensitive detector(PSD) is given under the condition of parallel light oblique incidence and Gaussian beam oblique incidence,and the response characteristics are analyzed by numerical calculation. The relation between oblique incident angle and output current is introduced and illustrated.

Prediction of Boiler Drum Pressure and Steam Flow Rate Using Artificial Neural Network

Numerical simulation of complex systems and components by computers is a fundamental phase of any modern engineering activity. The traditional methods of simulation typically entail long, iterative processes which lead to large simulation times, often exceeding transient real time. Artificial neural networks （ANNs） may be advantageous in this context, the main advantage being the speed of computation, the capability of generalizing from the few examples, robustness to noisy and partially incomplete data and the capability of performing empirical input-output mapping without complete knowledge of underlying physics. In this paper, the simulation of steam generator is considered as an example to show the potentialities of this tool. The data required for training and testing the ANN is taken from the steam generator at Abott Power Plant, Champaign （USA）. The total number of samples is 9600 which are taken at a sampling time of three seconds. The performance of boiler （drum pressure, steam flow rate） has been verified and tested using ANN, under the changes in fuel flow rate, air flow rate and load disturbance. Using ANN, input-output mapping is done and it is observed that ANN allows a good reproduction of non-linear behaviors of inputs and outputs.

A miniature pump with a fluid dynamic bearing

This paper describes the development of a miniature pump having an impeller with an exit diameter of 24 mm supported with the motor rotor by a fluid dynamic beating. Tests verify that the miniature pump is stable and quiet for rotational speeds larger than 4000 rain-1. The three-dimensional turbulent flow in the entire pump flow passage and the laminar flow in the fluid dynamic bearing were then simulated numerically. The average pump performance was well predicted by the simulations. Both the tests and the simulations show that there is no obvious Reynolds effect for the miniature pump within the tested range of rotational speeds. The numerical results also show that the beating capacity of the fluid dynamic bearing increases with the pump rotor rotational speed and the eccentricity ratio of the journal to the bushing. This pump is very compact, so it is a prom- ising device for surgical use.