Predictive value of vascular endothelial growth factor (VEGF) in metastasis and prognosis of human colorectal cancer

Vascular endothelial growth factor (VEGF) may affect the phenotype of cancer cells, such as growth velocity and metastatic potential, due to its probable multifunctional property including a mitogenic activity for vascular endothelial cells. The present study was designed to investigate the association of VEGF mRNA expression with progression and metastasis of human colorectal cancer. The level of VEGF mRNA expression was quantified by Northern blot hybridization in tumorous and non-tumorous tissues obtained from 60 primary colorectal cancer patients. The ratio of the former to the latter was defined as the VEGF T/N ratio, and the prognostic significance of this ratio, following surgery, in addition to the relationship to progression and metastatic potential, was evaluated. The value of the VEGF T/N ratio was significantly correlated with the depth of tumour infiltration (P=0.046), the incidence of liver metastasis (P < 0.0001) and lymph node metastasis (P=0.036). Patient prognosis was estimated by the Kaplan-Meier method and the log-rank test. When the VEGF T/N ratio was higher than 4.8 for which the chi2 value of the log-rank test was maximal, the tumour was defined as showing overexpression of VEGF mRNA. Patients with overexpression of VEGF mRNA demonstrated poorer survival than patients without overexpression of VEGF mRNA (P < 0.001). The overall estimated hazard ratio for death in patients with overexpression of VEGF mRNA was 1.94 according to a multivariate analysis (P=0.005). Thus, VEGF is associated with the progression, invasion and metastasis of colorectal cancer, and overexpression of VEGF mRNA in the primary tumour is assumed to be closely correlated with poor prognosis in colorectal cancer patients. Moreover, the VEGF T/N ratio may be used as an independent prognostic marker in colorectal cancer patients.     

An automatic temperature compensation of internal sense ground forsubquarter micron DRAM's

This paper describes DRAM array driving techniques and the parameter scaling techniques for low voltage operation using the boosted sense ground (BSG) scheme and further improved methods. Temperature compensation and adjustable internal voltage levels maintain a small subthreshold leakage current for a memory cell transistor (MC-Tr), and a distributed BSG (DBSG) scheme and a column decoded sensing (CDS) scheme achieve the effective scaling. These schemes can set the DRAM array free from the leakage current problem and the influence of temperature variations. Therefore, parameters for the MC-Tr, threshold voltage (V _th), and the boosted voltage for the gate bias can be scaled down, and it is possible to determine the V_th of the MC-Tr simply (0.45 V at K=0.4) for the satisfaction of the small leakage current, for high speed and stable operation, and for high reliability (V_PP is below 2 V_CC). They are applicable to subquarter micron DRAM's of 256 Mb and more     

T6固溶处理对圆柱形铝合金铸件尺寸效应的影响

作者用不同壁厚和重量的圆柱形铝合金铸造试块进行了固溶时效处理对其组织（DendriteArmSpacing，即树枝晶干间距，简称D．A．S）和机械强度影响的试验。结果表明，AC4B铝合金铸件的D．A．S和机械强度的尺寸效应表现为铸件模量（体积与表面积的比值，即V／S）的函数；对经过T6热处理的试块，所测出的尺寸效应也保持为铸件模量的函数关系。     

Uncertainty of calibration of 2D planar Coordinate Measuring Machine

When the kinematic parameters of 2D planar Coordinate Measuring Machine are calibrated in self-calibration method, it is shown how to estimate the uncertainty of calibration and how to estimate the uncertainty of measurement. In this paper, the uncertainty of probing and the uncertainty of sensors are considered as the contributors of uncertainty. Two different types of CMMs are applied to two different artefacts for calibration and those measures in some different orientations for estimation of uncertainty. The effectiveness of the difference of CMMs, the artefacts and the measurement orientations are compared. As a result, it is proved that the uncertainty distribution is different in the orientation of measurement and the uncertainty could be smaller by selecting measurement orientation.     

A model-predictive hypnosis control system under total intravenous anesthesia

In ambulatory surgery, anesthetic drugs must be administered at a suitable rate to prevent adverse reactions after discharge from the hospital. To realize more appropriate anesthesia, we have developed a hypnosis control system, which administers propofol as an anesthetic drug to regulate the bispectral index (BIS), an electroencephalography (EEG)-derived index reflecting the hypnosis of a patient. This system consists of three functions: 1) a feedback controller using a model-predictive control method, which can adequately accommodate the effects of time delays; 2) a parameter estimation function of individual differences; and 3) a risk control function for preventing undesirable states such as drug overinfusion or intraoperative arousal. With the approval of the ethics committee of our institute, 79 clinical trials took place since July 2002. The results show that our system can reduce the total amount of propofol infusion and maintain the BIS more accurately than anesthesiologist's manual adjustment.     

Robust stability of state-predictive and Smith control systems for plants with a pure delay

Robust stability of the state-predictive and the Smith control systems for plants with a pure delay is studied. First, the Nyquist-type stability condition is derived for robust stability. Then, the condition is transformed and a robust stability criterion is given in terms of the Nyquist plots of the complementary sensitivity function and the error function. Based on this criterion, we present a method to obtain graphically stability margins in the delay-time and the gain. © 1998 John Wiley & Sons, Ltd.     

Asymmetric mutation model in genetic algorithm

Genetic algorithms (GAs) are stochastic optimization techniques, and the theoretical study of the process of GA evolution is very important in the application of GA. Mutation is one of most important operators in GA, and Markov chain theory has attracted researchers’ attention for the study of mutation. By applying Markov chain to study symmetric mutation model in GA, we have obtained the relation between the mutation rate and the evolution of the first order schema. This paper theoretically analyzes the effects of mutation rates on GA with asymmetric mutation, and studies the evolution and stationary distribution of the first order schema. This study focuses on effects of asymmetry to the linkage of loci, and shows the degree of asymmetry in mutation has a large effect on the evolution of the first order schema.     

A speed-enhanced DRAM array architecture with embedded ECC

An array architecture with countermeasures for the smaller signal charge caused by scaling down is proposed. Based on a new access model, the combination of a hierarchical data bus configuration and multipurpose register (MPR) provides high-speed array access. The MPR also includes practical array-embedded error checking and correcting (ECC) with little area penalty and no access overhead in the page mode. The array architecture is applied to a scaled-down 16-Mb DRAM and has achieved high performance