On improving physical selectivity in the treatment of cancer: A systems modelling and optimisation approach

This paper presents the results arising from a practical implementation of a novel hybrid optimisation scheme, used to solve the inverse problem in radiotherapy treatment planning (RTP). A matrix-based beam model which has been developed making use of a control systems modelling approach is used, together with a hybrid optimisation scheme. Patient-specific compensator profiles are deduced from the intensity modulated beam profiles obtained from the hybrid scheme, with use being made of an exponential attenuation factor coupled with a point spread convolution function to account for the scatter in the compensator. A good agreement between the predicted and actual conformational distributions is achieved.     

The effectiveness of topical diclofenac for lateral epicondylitis

Clinical evidence for a dominant mode of inheritance and anticipation in periodic catatonia, a distinct subtype of schizophrenia, suggests that trinucleotide repeat expansions may be involved in the aetiology of this disorder. Since genes with triplet repeats are putative canditates for causing schizophrenia, we have analysed the polymorphic B33 CTG repeat locus on chromosome 3 in 45 patients with periodic catatonia and 43 control subjects. The B33 CTG repeat locus was highly polymorphic, but all alleles in both the patient and control groups had repeat lengths within the normal range. We conclude that susceptibility to periodic catatonia is not influenced by variation at the B33 CTG repeat locus. Nevertheless, that periodic catatonia displays dominant inheritance and anticipation, characteristic of genetic disorders involving trinucleotide repeats, justifies further screening for triplet repeat expansions in this illness.     

An improved MOSFET model for circuit simulation

Problems that have continued to remain in some of the recently published MOSFET compact models are demonstrated in this paper. Of particular interest are discontinuities observed in these models at the boundary between forward and reverse mode operation. A new MOSFET model is presented that overcomes the errors present in state-of-the-art models. Comparison with measured data is also presented to validate the new model     

The combined effects of deuterium anneals and deuteratedbarrier-nitride processing on hot-electron degradation in MOSFET's

This paper describes the combined effects of deuterium anneals and deuterated barrier-nitride processing on hot-electron degradation in MOSFETs. Devices subjected to a 60-min, 400°C, 10% deuterium/90% nitrogen anneal after silicidization show a 32× improvement in hot-electron lifetime. These same devices are then passivated with a deuterated barrier-nitride layer formed using deuterated ammonia (ND₃) and conventional silane (SiH₄). Further deuterium anneals along with conventional contact and metal-level processes are used to integrate the devices. Hot-electron stressing and SIMS analysis performed at various points in the processing give insight to methods of retaining the beneficial effects of deuterium during subsequent thermal processing     

Brain cytochrome oxidase activity after kindled seizures: a quantitative histochemical mapping study

A Japanese male patient with myelodysplastic syndrome (MDS) was shown to have associated Tn syndrome; the first report of Tn syndrome with MDS. The Tn expression was demonstrated on erythrocytes, granulocytes, monocytes, platelets, and lymphocytes by flow cytometric analysis using a lectin and an antibody. Electrophoresis of erythrocyte membrane proteins revealed slower mobility of glycophorin B from the patient than that from normal individuals, suggesting a glycophorin B molecular abnormality.     

A fuzzy-logic approach to industrial control problems

Increasing demands for improved profitability and product quality, together with a growing awareness of the effects of industrial wastage on the environment, is forcing manufacturers to closely examine their process operations. As a consequence there is currently significant research and development activity aimed at improving control system strategies in a variety of industrial sectors. Recent years have witnessed renewed interest in fuzzy logic and rule-based control strategies and, by considering two illustrative industrial case studies, this paper highlights some of the potential advantages. This work was presented, in part, at the International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20, 1996     

Evaluating microbial safety of slow partial-cooking processes for bacon: use of a predictive tool based on small-scale isothermal meat inoculation studies

The objective of this study was to develop a predictive tool for evaluating the safety of slow cooking of pork products and identifying associated critical limits. Small-scale (25 g) ground pork isothermal inoculation studies were done to determine Salmonella serovars, Escherichia coli O157:H7, and Staphylococcus aureus estimated critical times (time until growth reached a predefined increase of concern). Estimated critical time values ranged from 720 min at 21 degrees C (S. aureus) to 120 min at 40.6 degrees C (E. coli O157:H7) and were used to develop a multiple-temperature-interval predictive tool for non-isothermal processes. To test predictions, cured-pumped pork bellies were inoculated with Salmonella serovars, E. coli O157:H7, and S. aureus, subjected to slow partial cooking, and quantitatively analyzed for pathogens. Processes lasted 6 to 18 h, with the product interior temperature within the 21 to 46 degrees C range for 263 to 1080 min (high-humidity processes) and 217 to 921 min (low-humidity processes). Growth of Salmonella serovars (>0.3 log), E. coli O157:H7 (>0.3 log), and S. aureus (>1.3 log) in the pork belly interior was predicted for 10, 14, and 5 of 18 trials, respectively. The tool was fail-safe, because pathogen growth, relative to time zero, did not occur anytime regardless of whether it was predicted. For the pork belly surface, the tool performed similarly. Estimated critical time values obtained by fitting the Baranyi equation to isothermal experiment data were also determined and, if used in the predictive tool, would result in even more conservative predictions. Our study substantiates the safety of the tested bacon slow partial-cooking processes and the potential usefulness of our isothermal-based tool in process safety evaluation.     

On stabilization of bilinear uncertain time-delay stochasticsystems with Markovian jumping parameters

In this paper, we investigate the stochastic stabilization problem for a class of bilinear continuous time-delay uncertain systems with Markovian jumping parameters. Specifically, the stochastic bilinear jump system under study involves unknown state time-delay, parameter uncertainties, and unknown nonlinear deterministic disturbances. The jumping parameters considered here form a continuous-time discrete-state homogeneous Markov process. The whole system may be regarded as a stochastic bilinear hybrid system that includes both time-evolving and event-driven mechanisms. Our attention is focused on the design of a robust state-feedback controller such that, for all admissible uncertainties as well as nonlinear disturbances, the closed-loop system is stochastically exponentially stable in the mean square, independent of the time delay. Sufficient conditions are established to guarantee the existence of desired robust controllers, which are given in terms of the solutions to a set of either linear matrix inequalities (LMIs), or coupled quadratic matrix inequalities. The developed theory is illustrated by numerical simulation