Peroxidase-catalyzed oxidation of 3,5-dimethyl acetaminophen causes cell death by selective protein thiol modification in isolated rat hepatocytes

In this study we used a peroxidase model system (glucose/glucose oxidase and horseradish peroxidase) to investigate the effect of extracellularly generated reactive metabolites of 3,5-Me2-acetaminophen on cell viability and on cellular thiol levels. Incubation of hepatocytes with 3,5-Me2-acetaminophen in the presence of glucose/glucose oxidase and horseradish peroxidase caused a concentration-dependent loss of cell viability. Loss of viability was associated with decreased protein thiol levels. Addition of the reducing agent DTT, but not catalase, during the incubation restored cellular protein thiol levels and arrested the cell killing. Protein thiol depletion occurred selectively to the mitochondrial and microsomal fractions and was specific for a very limited number of protein bands. The data suggest that the oxidative modification of individual protein cysteine residues within the latter two organelle fractions is critically involved in the mechanism of toxicity.     

Complementary tunneling transistor for low power application

The metal oxide semiconductor field effect transistor (MOSFET) is scaling to a “tunneling epoch”, in which multiple leakage current induced by different tunneling effects exist. The complementary Si-based tunneling transistors are presented in this paper. The working principle of this device is investigated in detail. It is found that the band-to-band tunneling current is be controlled by the gate-to-source voltage. Due to the reverse biased p-i-n diode structure, an ultra-low leakage current is achieved. The sub-threshold swing of TFET is not limited by kt/q, which is the physical limit of the MOSFET. Using the CMOS compatible processes, the complementary TFETs (CTFET) are fabricated on one wafer. From a circuit point of view, the compatibility between TFET and MOSFET enables the transfer of CMOS circuits to CTFET circuits.     

Model metamorphosis

Model driven architectures (MDA) will become practical only if transformations from platform-independent to platform-specific models can be largely automated. Kafka, an extensible rule-based transformation language, and the Kase modeling tool enable automated, customized transformations that support round-trip engineering. With Kafka and Kase, developers can construct transformations without detailed knowledge of metamodels.     

Stereological estimation of mean nuclear volume in prostatic cancer,the reproducibility and the possible value of estimations on repeated biopsies in the course of disease

The reproducibility of stereological estimates of mean nuclear volume by using the principle of volume estimation of particles of arbitrary shape is investigated together with the possible prognostic value of the estimates in the course of advanced prostatic cancer. Repeated transurethral resection of the prostate was performed 14–93 months after the first resection in 14 of 85 consecutive patients in whom prostatic cancer was newly diagnosed in the period 1979–1983. Twelve of these fourteen patients needed endocrine treatment because of progression of the metastatic disease. The reproducibility of the estimations was excellent as the variation of the method was less than 1 % when the estimation of the mean nuclear volume was repeated at random on the same specimens after a time-interval of 2 months. The progression of the disease was evidenced by a significant histological upgrading and by a highly significant increase of the mean nuclear volume from the first to the second transurethral resection of the prostate.     

A computer simulation for teaching critical thinking skills

Telephone-based health services is a fast growing subspecialty of nursing practice. It is used in demand management and managed care organizations in a highly unregulated environment. The article presents background information and identifies the need for systematic studies of ethical implications inherent in telephone-based practice. Conclusions suggest that nurses need to become actively involved in ethical decision making related to this area of practice.     

Damage detection in a fibre reinforced composite beam using random decrement signatures

The potential application of the random decrement technique for the detection of damage in composite beam type structures is investigated in this paper. Analytical models of composite beams with various levels of delamination were developed, based on the assumed mode method, to obtain the system's response to a random input. An experimental study was conducted to validate the numerical results. Both the theoretical modelling and the experimental study showed that delamination had dissimilar effects on the random decrement signature at different sensing locations, indicating that a large database of random decrement signatures can be used, together with pattern recognition algorithms for the diagnosis of unknown damage. Differences between numerical and experimental results were attributed to the influence of the exciter and non-ideal boundary conditions in the experiments, and the simplistic treatment of structural damping in the models.