Microwave performance of high-density bulk MgB2

We have performed microwave measurements on superconducting hot-isostatically- pressed (HIPed) bulk MgB2 using a parallel-plate resonator technique. The high density and strength of the HIPed material allowed preparation of samples with mirror-like surfaces for microwave measurements. The microwave surface resistance decreased by about 40% at 20 K when the root-mean-square surface roughness was reduced from 220 nm to 110 nm through surface-polishing and ion-milling. The surface resistance was independent of surface microwave magnetic field at least up to 4 Oe and below 30 K. We attribute this behavior, and the overall low surface resistance (~0.8 mOhms at 10 GHz and 20 K), to the high density of our samples and the absence of weak links between grains

Limitation of motion and shoulder disabilities in patients with cardiac implantable electronic devices.

The aim of this study is to investigate the presence of limitations in the shoulder range of motion (ROM) or the loss of upper extremity function on the affected side in patients with cardiac implantable electronic devices (CIEDs) with respect to the implantation time. Forty-nine patients (30 men and 19 women), mean age 64.84±11.18 years, who had been living with a CIED for less than 3 months were included in the short-term recipient (STR) group and 127 patients (85 men and 42 women), mean age 64.91±14.70 years, and with the device for longer than 3 months were included in the long-term recipients group. Shoulder ROMs were measured using a digital goniometer. The other arm was used as the control. The Constant-Murler Score, Shoulder Pain Disability Index, and Shoulder Disability Questionnaire were used to assess the functional status. Limitations of ROM for flexion, abduction, and internal rotation were found to be significantly lower in the arm on the side of CIED compared with the control arm. Significant differences in shoulder flexion, abduction, and external rotation in STRs were found compared with long-term recipient (P<0.05). However, the functional comparison of groups by the Constant-Murler Score was not significant. A low to moderate amount of shoulder disability measured by Shoulder Pain Disability Index and Shoulder Disability Questionnaire was found in patients with CIEDs, which was more prominent in STRs (P<0.05). Pain, association of CIED with pectoral muscles, a possible subtle ongoing capsular pathology, and avoidance behaviors of patients to minimize the risk of lead dislodgement might be related to restriction of motion and function in the shoulder joint in patients with CIEDs