Advanced cantilevers for magnetic force microscopy and high frequency magnetic force microscopy.

In order to improve the spatial resolution achieved by magnetic force microscopy (MFM) technique and its derivatives, we employ here advanced MFM tips fabricated by means of focused ion beam (FIB) milling. The magnetic coating applied on these tips is a CoCr film of 10 nm thickness. The MFM measurements on hard disk test samples reveal the achieved high resolution, and the measurement on a garnet film demonstrates the low invasiveness. High-frequency MFM (HF-MFM) is a development of the MFM technique to observe the HF stray fields emerging from magnetic recording writer poles at their operating conditions. By means of HF-MFM, magnetic recording writer poles are characterized in the frequency range 100-1,000 MHz. Up to now, all HF-MFM experiments conducted were using standard MFM cantilevers. From the HF-MFM images obtained using the advanced MFM cantilevers, it is clearly seen that the spatial resolution is considerably improved over the images obtained using standard MFM tips. However, the 10 nm thick magnetic coating of the cantilevers is found to work properly only at frequencies of up to about 500 MHz.

Injury of the dorsal sensory branch of the ulnar nerve as a complication of arthroscopic repair of the triangular fibrocartilage.

This report presents a case of direct injury to the dorsal sensory branch of the ulnar nerve caused by arthroscopic repair of the triangular fibrocartilage complex. The dorsal sensory branch of the ulnar nerve was strangulated by one of the three pull-out sutures of the joint capsule, just ulnar to the extensor carpi ulnaris tendon. Pain and dysaesthesia of the ulnar side of the wrist was completely relieved after excision of the injured nerve segment. This complication can be avoided by careful exploration of the dorsal sensory branch of the ulnar nerve prior to suturing or passage of instruments during arthroscopy.

Simple bone cyst in cervical vertebral spinous process and laminae: report of a case.

Simple (unicameral or solitary) bone cysts are the only true cysts of primary intraosseous origin. These cysts involve the metaphysis of long tubular bones such as the proximal humerus and proximal femur and, occasionally, the proximal tibia, distal femur, patella, ilium, rib, and calcaneus. They are very rarely found in vertebrae, especially in the cervical vertebral spinous process and laminae. We report a 14-year-old boy with an expansile, bubbly cystic lesion in the spinous process and laminae of the seventh cervical vertebra. Histopathologic examination showed a cyst surrounded by thin fibrous or fibro-osseous wall without any lining epithelial cells, compatible with a simple bone cyst. As far as we know, this is the first case of simple bone cyst involving the spinous process and laminae of a cervical vertebra reported in Taiwan.

Constructing hysteretic memory in neural networks.

Hysteresis is a unique type of dynamic, which contains an important property, rate-independent memory. In addition to other memory-related studies such as time delay neural networks, recurrent networks, and reinforcement learning, rate-independent memory deserves further attention owing to its potential applications. In this paper, we attempt to define hysteretic memory (rate independent memory) and examine whether or not it could be modeled in neural networks. Our analysis results demonstrate that other memory-related mechanisms are not hysteresis systems. A novel neural cell, referred to herein as the propulsive neural unit, is then proposed. The proposed cell is based on a notion related the submemory pool, which accumulates the stimulus and ultimately assists neural networks to achieve model hysteresis. In addition to training by backpropagation, a combination of such cells can simulate given hysteresis trajectories.