Angiomyolipoma of the lung

Extrarenal angiomyolipomas are rare tumors that have been reported in several organs, including the liver, reproductive organs, skin, and retroperitoneum. In this report, we present the clinicopathologic findings of an angiomyolipoma of the lung in a 67-year-old man with no history of tuberous sclerosis or lymphangioleiomyomatosis. To our knowledge, this is the second reported case of pulmonary angiomyolipoma. The tumor was coincidentally found in the left lower lung in association with a hemothorax. Our case was histologically identical to angiomyolipoma occurring in the kidney, but immunohistologic staining for HMB-45 was negative, similar to the first reported case.     

Synthesis of [5'-11C]ribonucleoside and -2'-deoyribonucleoside derivatives from D-ribose

An approach to the synthesis of 2'-deoxy[5'-13C]ribonucleosides was achieved by the coupling reaction of a nucleic acid base derivative with D-[5-13C]ribose derivative (8). Compound 8 was derived from D-ribose (1) by way of methyl 2,3-di-O-benzyl(Bn)-D-ribofuranoside (2), 2,3-di-O-Bn-D-ribose diethyl dithioacetal (3), 2,3-di-O-Bn-D-ribose dibenzyl acetal (4), and 4-aldehydo-2,3-di-O-Bn-D-erythrose dibenzyl acetal (5), which was then successively subjected to Wittig reaction using Ph3P13CH3I-BuLi, highly stereoselective hydroxylation with OsO4 to give 2,3-di-O-Bn-D-ribose dibenzyl acetal (7), debenzylation with H2-Pd/C. The resulting 8 was subjected to coupling reaction with a nucleic acid base to give [5'-13C]ribonucleosides. The products were derived into the corresponding 2'-deoxy[5'-13C]ribonucleoside derivatives by the established manner.     

The corrosion behaviour of SS 41 steel in formic and acetic acids

The corrosion behaviour of SS 41 steel in formic acid and acetic acid was investigated by measuring the corrosion weight loss, the polarization curve and the impedance at the steel-solution interface. It was found that the corrosion rates of the steel in formic acid and acetic acid are markedly dependent on acid concentration and temperature. The corrosion rates in acetic acid are smaller than those in formic acid. The corrosion potential E_corr against pH of formic acid and acetic acid solutions shows a linear relationship.     

Robust porous SiOCH/Cu interconnects with ultrathin sidewall protection liners

Robust porous low-k/Cu interconnects have been developed for 65-nm-node ultralarge-scale integrations (ULSIs) with 180-nm/200-nm pitched lines and 100-nm diameter vias in a single damascene architecture. A porous plasma-enhanced chemical vapor deposition (PECVD)-SiOCH film (k=2.6) with subnanometer pores is introduced into the intermetal dielectrics on the interlayer dielectrics of a rigid PECVD-SiOCH film (k=2.9). This porous-on-rigid hybrid SiOCH structure achieves a 35% reduction in interline capacitance per grid in the 65-nm-node interconnect compared to that in a 90-nm-node interconnect with a fully rigid SiOCH. A via resistance of 9.7 /spl Omega/ was obtained in 100-nm diameter vias. Interconnect reliability, such as electromigration, and stress-induced voiding were retained with interface modification technologies. One of the key breakthroughs was a special liner technique to maintain dielectric reliability between the narrow-pitched lines. The porous surface on the trench-etched sidewall was covered with an ultrathin plasma-polymerized benzocyclobuten liner (k=2.7), thus enhancing interline time-dependent dielectric breakdown reliability. The introduction of a porous material and the control of the sidewall are essential for 65-nm-node and beyond scaled-down ULSIs to ensure high levels of reliability.     

FATIGUE STRENGTH OF NON-LOAD-CARRYING FILLET WELDED JOINTS: EFFECTS OF WELD RESIDUAL STRESSES AND STRESS CONCENTRATION

The fatigue strength of non-load-carrying fillet welded joints of KE36(TMCP) steel was studied. Both residual stress measurements and fatigue tests were carried out, with the plate thickness, the plate width and the heat input being varied. Specimens given a Post Weld Heat Treatment (PWHT) were also prepared. The plate width had no effect on the fatigue strength, because it hardly affected the transverse residual stresses at the weld toe. However, the heat input influenced the transverse residual stress distribution, and a significant difference in fatigue strength due to the heat input was observed, especially when N≥ 10⁶ cycles. It was also found that PWHT removed almost all the residual stresses at the weld toe, improving the fatigue strength drastically. In this study, the values of stress concentration factor K₂ were estimated by Machida's method and it was concluded that the thickness effect resulted from a combination of both stress concentration and residual stresses with the contribution of the latter being particularly significant for N≥ 10⁶ cycles.     

Superconducting current carrying capacities of the composite-processed Nb-Hf/Cu-Sn-Ga in high magnetic fields

The Nb₃Sn growth rate, H_c2, and J_c of composite processed Nb₃Sn are substantially increased by the addition of hafnium to the niobium core. Furthermore, simultaneous addition of hafnium to the core and gallium to the matrix significantly increases H_c2 and J_c in high magnetic fields. SEM observations indicate that the addition of hafnium to the core enhances the growth rate of the Nb₃Sn layer without increasing the grain size of Nb₃Sn while the addition of gallium to the matrix causes an increase in coarseness of Nb₃Sn grains. The XMA analysis indicates the presence of small amounts of gallium and hafnium in the Nb₃Sn layer, J_c of the Nb-Hf/Cu-Sn-Ga wire specimens exceeds 1 × 10⁵ A cm^?2 at 17 T, suggesting that multifilamentary Nb₃Sn composite wires capable of generating magnetic fields over 17 T may be feasible.