Robustness Assessment of Life-Cycle-Management of CV Cables based on Degradation Diagnosis

Life-cycle management based on the degradation diagnosis is useful for preventing an unexpected failure and extending service life of electric power apparatuses, minimizing life-cycle cost. In our previous study, we formulated a numerical model of life-cycle management based on time-based maintenance and condition-based maintenance. Then, we applied the model for evaluating the economic effect of degradation diagnosis of power cables, assuming that the maximum length of water tree as a replacement criterion can be measured nondestructively. To carry out reliable life cycle management, however, accurate data on the relation between extent of degradation and failure probability or remaining life are necessary. In this study, we examine the influence of accuracy of the data used to determine the optimum diagnostic parameters and evaluate how the life-cycle cost is affected by the employment of inaccurate data. The results show that the condition-based maintenance with degradation diagnosis can be less subject to the accuracy of the back data and is possible to realize the reliable life-cycle management.journal articl

Impact of caveolin-1 expression on prognosis of pancreatic ductal adenocarcinoma

Caveolin-1 is a major component of caveolae and plays a regulatory role in several signalling pathways. Caveolin-1 was recently identified as a metastasis-related gene in prostate cancer. The clinical effects of caveolin-1 expression in pancreatic carcinoma, however, remain unknown. In this study, we have investigated the relationship between caveolin-1 expression and the clinicopathologic variables and clinical outcome in 79 patients with pancreatic adenocarcinoma undergoing surgical resection. Caveolin-1 expression was determined by immunohistochemistry, using a polyclonal anti-caveolin-1 antibody. Patients were divided into two groups based on the extent of caveolin-1 expression: a negative expression group (immunoreactivity in less than 50% of cells) and a positive expression group. Positive caveolin-1 immunostaining was detected in 32 cases (40.5% of total), while non-neoplastic ductal epithelium showed little or no staining. Positive caveolin-1 expression was correlated with tumour diameter (P=0.0079), histopathologic grade (P=0.0272) and poor prognosis (P=0.0008). Upon multivariate analysis with Cox's proportional hazards model, positive caveolin-1 expression was shown to be an independent negative predictor for survival (P=0.0358). These results suggest that caveolin-1 overexpression is associated with tumour progression, thereby indicating a poor prognosis for certain patients undergoing surgical resection for pancreatic carcinoma

RCAS1 as a tumour progression marker: an independent negative prognostic factor in gallbladder cancer

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) induces apoptosis in immune cells bearing the RCAS1 receptor. We sought to determine RCAS1 involvement in the origin and progression of gallbladder cancer, and also implications of RCAS1 for patient survival. RCAS1 expression was examined immunohistochemically in 110 surgically resected gallbladder specimens. The gallbladders represented 20 cases of cholecystitis with no associated pancreaticobiliary maljunction; 23 cases of cholecystitis with pancreaticobiliary maljunction; 14 cases of adenomyomatosis; 7 adenomas; and 46 cancers. High expression of RCAS1 (immunoreactivity in over 25% of cells) was observed in 32 of the 46 cancers (70%), but not in other diseases, including pre-cancerous conditions. RCAS1 immunoreactivity was associated with depth of tumour invasion (P = 0.0180), lymph node metastasis (P = 0.0033), lymphatic involvement (P = 0.0104), venous involvement (P = 0.0224), perineural involvement (P = 0.0351) and stage by the tumour, nodes and metastases (TNM) classification (P = 0.0026). Thus, RCAS1 expression may be a relatively late event in gallbladder carcinogenesis possibly promoting tumour progression. Cox regression multivariate analysis demonstrated RCAS1 positivity to be an independent negative predictor for survival (P = 0.0337; risk ratio, 12.690; 95% confidence interval, 1.216–132.423). High expression of RCAS1 significantly correlated with tumour progression and predicted poor outcome in gallbladder cancer. © 2001 Cancer Research Campaign http://www.bjcancer.co

An exactly solvable, spatial model of mutation accumulation in cancer

One of the hallmarks of cancer is the accumulation of driver mutations which increase the net reproductive rate of cancer cells and allow them to spread. This process has been studied in mathematical models of well mixed populations, and in computer simulations of three-dimensional spatial models. But the computational complexity of these more realistic, spatial models makes it difficult to simulate realistically large and clinically detectable solid tumours. Here we describe an exactly solvable mathematical model of a tumour featuring replication, mutation and local migration of cancer cells. The model predicts a quasi-exponential growth of large tumours, even if different fragments of the tumour grow sub-exponentially due to nutrient and space limitations. The model reproduces clinically observed tumour growth times using biologically plausible rates for cell birth, death, and migration rates. We also show that the expected number of accumulated driver mutations increases exponentially in time if the average fitness gain per driver is constant, and that it reaches a plateau if the gains decrease over time. We discuss the realism of the underlying assumptions and possible extensions of the model

Meteoric fluid‐rock interaction in Variscan shear zones

AbstractVariscan shear zones in the Armorican Massif represent sites of strong fluid‐rock interaction. The hydrogen isotope composition of muscovite (δDMs) from syntectonic leucogranite allows to determine the source of fluids that infiltrated the footwall of three detachment zones and the South Armorican Shear Zone. Using temperatures of hydrogen isotope exchange estimated from microstructural data, we calculate the hydrogen isotope ratios of water (δDwater) present within the shear zones during high‐temperature deformation. A ~40‰ difference in δDwater values from deep to shallow crustal level reveals a mixing relationship between deep crustal fluids with higher δD values that range from −34 to −33‰, and meteoric fluids with δD values as low as −74‰ in the upper part of detachment footwalls.</jats:p