The relationship between chromosome damage and cell killing in UV-irradiated normal and xeroderma pigmentosum cells

It is shown that the distribution of identical amino acid residues in the primary structure of 83 non-homologous proteins containing about 14 000 amino acids is near to a casual one, i.e. it is determined by the amino acid composition. A characteristic feature of such distribution is an increased probability of a common grouping of amino acid residues.     

Interaction of Recombining Atomic Nitrogen with Gaseous Plasmas

Experiments are reviewed which measure the three-body volume recombination coefficient of neutral nitrogen atoms in nitrogen gas making use of an electron spin resonance (ESR) technique to determine the atomic concentration. The nitrogen atoms were created in an electrodeless discharge and were carried to the ESR detector by a stream of flowing gas. The temperature dependence of the atomic recombination coefficient near 300°K and the number of photons emitted in the Rayleigh afterglow bands per recombination have been determined. It has been found that the loss rate of nitrogen atoms is considerably enhanced when the atomic stream is exposed to a feeble DC discharge. The removal mechanism appears to be one of ionization of nitrogen atoms by electronic bombardment followed by a comparatively rapid ambipolar diffusion. If, however, the stream of atoms passes through a region containing a decaying afterglow plasma in nitrogen where the electronic temperature is low, it is observed that the electronic ambipolar diffusion coefficient is enhanced in the presence of atoms. The above implies an energy transfer mechanism between the recombining atoms and the cool electrons. This effect is presently being explored by observing the change in light emitted by the nitrogen electronic afterglow and the change in electronic concentration and electron-neutral collision frequency with microwaves upon intoducing atoms into the afterglow plasma.     

A comparison of ketamine and the combination ketamine-xylazine for effective surgical anesthesia in the rabbit

Ketamine alone and the combination ketamine-xylazine were evaluated as surgical anesthetics in rabbits. It was found that ketamine alone provided inadequate analgesia for ventral abdominal incisions or exposure of the femur. The combination of xylazine with ketamine did provide adequate enalgesia for both surgical procedures.     

The 10 KM/S, 10 KG railgun

The system design for a railgun powered by capacitor-based energy stores distributed along its length is presented. It is assumed that it is required to accelerate a mass of 10 kg to a velocity of 10 km/s. Parameters for the railgun and its energy stores are derived, and the performance of the system is computed with particular attention being paid to the efficiency with which store energy is converted to launch-package kinetic energy. It is shown that efficiencies of 90% can be expected from a properly designed system     

Reduction of stomach ulceration by hypothalamic stimulation in the unrestrained rat

A rechargeable demand pulse generator for permanent transvenous cardiac pacing was evaluated in 66 patients. During a cumulative follow-up period of 895 patient months there was no instance of failure of either the pulse generator or of the recharging circuit. Acceptance of the recharging concept was high, there being only one patient in whom it was necessary to replace the rechargeable generator because of inability to master the recharging technique. The early findings indicate that with proper patient selection the rechargeable pulse generator promises to be an important contribution to pacemaker therapy.     

A renal cause for massive retroperitoneal hemorrhage--renal angiomyolipoma

In any case of intra-abdominal trauma or hemorrhage a preoperative IVP is essential to determine the renal status. Preoperative catheter occlusion of the renal artery in these vascular tumors may be attempted to decrease blood loss. Stigmas of tuberous sclerosis should be sought in patients with vascular renal tumors, especially if they are bilateral. Conservation of renal tissue in tuberous sclerotic patients harboring renal angiomyolipomas is important.