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Background: This study sought to determine safe ranges of oblique angle, skin entry point and needle length by reviewing computed tomography (CT) scans and to evaluate the usefulness of a bent tip needle during celiac plexus block (CPB). Methods: CT scans of 60 CPB patients were reviewed. Image of the uppermost margin of L2 vertebral body was used to measure the minimal and maximal oblique angles and the distances from the midline to skin puncture point. The imaginary needle trajectory distance was calculated by three-dimensional measurement. When the procedure was performed by using a 10° bent tip needle under a 20° oblique X-ray fluoroscopic view, the distance (GF/G'F) from the midline to the actual puncture site was measured. Results: The imaginary safe oblique angle range was 26.4-34.2° and 27.7-36.0° on the right and left, respectively. The distance from the midline to skin puncture point was 6.1-7.6 cm on the right and 6.3-7.6 cm on the left. The needle trajectory distance at minimal angle was 9.6-11.6 cm on the right and 9.5-11.5 cm on the left. The distance of GF/G'F was 5.1-6.5 cm and 5.0-6.4 cm on the right and left, respectively. All imaginary parameters were correlated with BMI except for GF/G'F. All complications were mild and transient. Conclusions: We identified safe values of angles and distances using a straight needle. Furthermore, using a bent tip needle under a 20° oblique fluoroscopic view, we could safely perform CPB with smaller parameter values. [ABSTRACT FROM AUTHOR]

The Influence of the bending strain on the critical current (I[sub c]) in Ag alloy/Bi-2223 superconducting tapes was investigated at 77 K. The strain effect on I[sub c] degradation in the different bending modes is discussed in terms of sample geometry and n-value. The I[sub c] degradation behavior with bending occurring across the tape's width direction called 'hard bending' is discussed in particular, and compared with results under conventional bending tests known as 'easy bending'. It was found that I[sub c] degraded with increases in the bending strain. In the case of hard bending, greater degradation in I[sub c] occurred than under easy bending. This might be a result of the difference in the filaments cross-section of the tape and the generation of a new type of damage, such as local buckling, expected during hard bending. The n-value also decreased as the bending strain increased and its behavior was similar to the I[sub c]-bending strain relationship. [ABSTRACT FROM AUTHOR]

The deformation and fracture behaviors of a bulk amorphous metal, Zr-based one (Zr[sub 41.2]Ti[sub 13.8]CU[sub 12.5]Ni[sub 10]Be[sub 22.5]: Vitreloy), were investigated over a strain rate range (7 × 10[sup -4]~4 s[sup -1]). The uniaxial compression test and the indentation test using 3mm-diameter WC balls were carried out under the quasi-static loading condition. As a test result, at the uniaxial compression state, the fracture strength of the material was ~1,700MPa and the elastic strain limit was about 2%. The fracture strength showed a strain rate independent behavior up to 4 s[sup -1]. Using indentation tests, the plastic deformation behavior of the Zr-based BAM up to a large strain value of 15% could be achieved, even though it was the deformation under locally constrained condition. The Meyer hardness of the Zr-based BAM measured by static indentation tests was about 5 GPa and it revealed negligible strain hardening behavior. At indented sites, the plastic indentation occurred forming a crater and well-developed multiple shear bands were generated around it along the direction of 45° when the indentation load exceeded 7kN. With increasing indentation load, shear bands became dense. The fracture surface of the specimen after uniaxial compressive tests showed vein-like pattern, typical morphology of many BAMs. [ABSTRACT FROM AUTHOR]

Synthesis and device characteristics of highly scalable GeTe nanowire-based phase transition memory are reported. The authors have demonstrated reversible phase transition memory switching behavior in GeTe nanowires, and obtained critical device parameters, such as write and erase currents, threshold voltage, and programming curves. The diameter dependence of memory switching behavior in GeTe nanowires was studied and a systematic reduction of writing currents with decreasing diameter was observed, with currents as low as 0.42 mA for a 28 nm nanowire. Results show that nanowires are very promising for scalable memory applications and for studying size-dependent phase transition mechanisms at the nanoscale. [ABSTRACT FROM AUTHOR]