Frequency Stability of an Implantable Pressure Telemetry Capsule

An implantable pressure telemetry capsule was developed to permit monitoring cuff pressure in an artificial urethral sphincter during chronic conditions. Following implantation, the baseline frequency of the capsule was observed to increase by nearly 2 percent. A series of experiments was then conducted to determine whether this increase was caused by the temperature rise after implant, by fluid migration through the Silastic diaphragm, or by permeation of water vapor through the epoxy encapsulating the electronics. Elevated temperatures accounted for 84.5 percent of the frequency increase, migration through the diaphragm 11.85 percent of the total, and water permeation through the epoxy 3.65 percent.     

Ignition of aircraft fluids on high temperature engine surfaces

Temperatures created in aircraft jet engines have given rise to concern over hot surface ignition of flammable fluids. For some time, 500° F has been accepted as the maximum safe surface temperature. Under the specific conditions reported here, it appears that this figure can be increased significantly. Note: This paper was originally presented by the author at the National Air Transportation Meeting held in New York City, April 21–24, 1969, and was published by the Society of Automotive Engineers.     

Development of a dynamic shear angle model for wave-generating processes based on work-hardening slip-line field theory

A mathematical model has been developed for predicting the behavior of the shear plane oscillation during an orthogonal wave-generating process. The system governing equations of the model are derived theoretically from the fundamental theory of cutting mechanics by taking into account the changes of the stress conditions along the shear plane and the mean frictional coefficient on the tool-chip interface in response to the uncut chip thickness modulation. The model has been verified through simulation studies by reference to the work of a previous experimental investigation into cutting dynamics. The successful prediction of the shear angle variation not only proves the validity of the model but also confirms the soundness of the modelling approach proposed in this paper.     

Improving Homology-Directed Repair in Genome Editing Experiments by Influencing the Cell Cycle

Genome editing is currently widely used in biomedical research; however, the use of this method in the clinic is still limited because of its low efficiency and possible side effects. Moreover, the correction of mutations that cause diseases in humans seems to be extremely important and promising. Numerous attempts to improve the efficiency of homology-directed repair-mediated correction of mutations in mammalian cells have focused on influencing the cell cycle. Homology-directed repair is known to occur only in the late S and G2 phases of the cell cycle, so researchers are looking for safe ways to enrich the cell culture with cells in these phases of the cell cycle. This review surveys the main approaches to influencing the cell cycle in genome editing experiments (predominantly using Cas9), for example, the use of cell cycle synchronizers, mitogens, substances that affect cyclin-dependent kinases, hypothermia, inhibition of p53, etc. Despite the fact that all these approaches have a reversible effect on the cell cycle, it is necessary to use them with caution, since cells during the arrest of the cell cycle can accumulate mutations, which can potentially lead to their malignant transformation.