BiCMOS adjustable linear current mirror

Two novel BiCMOS adjustable gain linear current mirrors are presented. Variable gain is achieved by introducing a DC voltage into the control loop. Simulation and experimental results indicate that the gain is linear over several decades of signal current. The circuits are designed for maximum voltage swing with cascoded output to provide high output resistance     

Mutant p53 expression: a marker of diminished survival in well-differentiated soft tissue sarcoma

The aim of this study was to assess the translational value of the quantitative assay of mutant p53 protein expression as both a prognostic indicator and a tool to determine appropriate therapy in a group of relatively innocuous and morphologically similar soft tissue sarcomas (STSs). Using a quantitative ELISA, we analyzed mutant p53 protein expression in 47 well-differentiated (grade I) STSs from patients treated in our Department of Surgical Oncology. Sixteen of 47 tumors expressed up to 42.6 ng mutant p53 protein/mg total protein. After a mean follow-up of 112 months, 63% of the patients with mutant p53+ tumors but only 16% of the patients with mutant p53- tumors had died (P < 0.01). Mutant p53 expression of >/=4.5 ng predicted even greater reduction in survival. These data show that mutant p53 expression identifies biologically aggressive grade I STSs. This molecular marker should have translational value as a tool to select those patients likely to benefit from aggressive multimodal therapy and intense surveillance.     

Monitoring the injured brain in intensive care: present and future

The methods of monitoring the injured brain in intensive care have relied mainly on intermittent measurement. There is now increasing clinical interest in newer continuous forms of bedside monitoring that can help direct therapy earlier and more precisely. This article reviews continuous methods of monitoring cerebral perfusion, oxygenation, brain chemistry and function.     

The effect of heat setting on the structure and mechanical properties of poly(ethylene terephthalate) fiber. II. The elastic modulus and its dependence on structure

The effects of temperature, time of heat setting, and rate of cooling on the elastic modulus of free-and taut-annealed poly(ethylene terephthalate) (PET) fibers were determined at different time scales using Instron, Rheovibron, and pulse propagation meter. The correlation of the elastic modulus with structure is critically examined in terms of the widely used simple one-phase and two-phase models for fiber modulus. It is concluded that these simple models are not universally applicable.     

Theoretical analysis of the Fresnel lens as a function of design parameters

The author has studied the theoretical performance of the Fresnel lens as a function of the design parameters—i.e. the radius to the centre of the steps, the focal distance from the back of the lens to the plane of the image with the object (i.e. the sun) at infinity, the thickness of the lens plate, the step width and the refractive index of the material (with respect to air)—used in its fabrication. Numerical calculations have also been carried out for a Fresnel lens of perspex sheet.     

Activation of the mas oncogene involves coupling to human alphoid sequences

We have shown previously that mouse NIH3T3 cells transfected with DNA from a human ovarian carcinoma were rendered tumourigenic by an activated mas oncogene in four independent transfection experiments. In all cases the 5'-noncoding region was rearranged in comparison to the original ovarian tumour DNA. We now report that in all four transfectants the newly acquired sequences consist of human centromeric alpha satellite repeat DNA. In at least three transfectants the alphoid DNA originates from the centromere of chromosome three. Analysis of the sequences of the recombination site in one transfectant revealed that a homologous sequence of five base pairs (CAGCA) is present in both parental strands, and might thus have contributed to the recombinational event. To establish a conclusive role for alphoid DNA in the activation of mas, we performed a co-transfection experiment in NIH3T3 cells with cloned alphoid DNA and the mas coding sequence. We show that the transfectants expressing a transformed phenotype contain amplified mas linked to alphoid DNA. NIH3T3 cells transfected with plasmids that contained alphoid sequences cloned directly upstream of the mas coding sequence, and injected into nude mice, gave rise to tumours with amplified mas sequences (7/7). In six of these tumours the alphoid sequences were amplified as well. Our data suggest a novel mechanism of oncogene activation: recombination with normal alphoid repeat DNA resulting in amplification of the oncogene.     

Solubility of calcium sulphate dihydrate in hydrochloric acid solutions

Solubilities of CaSO₄, 2H₂O in hydrochloric acid solutions of concentration up to normal have been studied for temperatures from 20° to 70°. Results are discussed in relation to the Debye-Huckel theory.     

Fault Anticipator for Substation Equipment

Following an inordinate number of in-service failures of 230-kV current transformers, a need was perceived for some sort of early failure warning device for equipment in substations. The development and evaluation of an inexpensive partial discharge detection system for continuous on-line monitoring of substation equipment is described in this paper. The source of partial discharge activity, which nearly always precedes failure in high voltage equipment for times from minutes to months, may be unequivocally identified in a noisy substation environment, with no false alarms. Possible personnel hazard and damage to other equipment caused by an explosive failure can be avoided with appropriate operator action upon an alarm.