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The aqueous corrosion behavior of low-alloy steel with aluminum contents was examined in a 10 wt% H2SO4 (pH 0.13) solution using electrochemical techniques and surface analyses. The corrosion resistance of the new alloy steel was evaluated in terms of electrochemical parameters, such as passive current density, film, and charge transfer resistances. The results showed that a high Al content in the steel imparted better passivation behavior resulting in a lower corrosion rate. It related to the enrichment of iron carbonate and hydrocarbon by the dissolution of the carbide phase. [ABSTRACT FROM AUTHOR]

To evaluate the effects of plasma total homocysteine (tHcyt) and the MTHFR 677C>T polymorphism on determining the intracranial- (IC) and extracranial (EC) locations of atherosclerosis. Brain MR angiography was performed on 463 patients with symptomatic ischaemic stroke to detect significant atherosclerosis (more than 50% stenosis of vessel diameter) in the IC- and EC arteries. Relationships between IC- or EC atherosclerosis and plasma tHcyt level and/or MTHFR 677C>T genotypes were analyzed after adjusting for vascular risk factors. The odd ratios (ORs) of plasma tHcyt were not significantly higher in patients with either IC- or EC atherosclerosis than in patients with no atherosclerosis. When the study subjects were stratified into three subgroups according to their plasma tHcyt levels, neither the crude ORs nor adjusted ORs of each IC- and EC atherosclerosis in highest and middle plasma tHcyt tertile were significantly different from those in lowest plasma tHcyt tertile. The ORs of the MTHFR 677TT genotype in IC- and EC atherosclerosis were not significantly different from those in no atherosclerosis. There was no dose-dependent effect of MTHFR 677T allele on either IC- or EC atherosclerosis. Plasma tHcyt level and the MTHFR 677C>T polymorphism do not contribute to the distribution of cervico-cerebral atherosclerosis in ischaemic stroke patients. [ABSTRACT FROM AUTHOR]

Sildenafil citrate (Viagra®) is one of the frequently prescribed drugs for men with erectile dysfunction. We describe a 52-year-old man with bilateral middle cerebral artery (MCA) territory infarction after sildenafil use. He ingested 100 mg of sildenafil and about 1 h later, he complained of chest discomfort, palpitation and dizziness followed by mental obtundation, global aphasia and left hemiparesis. Brain magnetic resonance imaging documented acute bilateral hemispheric infarction, and cerebral angiography showed occluded bilateral MCA. Despite significant bilateral MCA stenosis and cerebral infarction, systemic hypotension persisted for a day. We presume that cerebral infarction was caused by cardioembolism with sildenafil use. [ABSTRACT FROM AUTHOR]

A simple-but-efficient calibration-spur reduction technique is introduced that utilises the digital-and-analogue hybrid return-to-zero (HRZ) method in a current-steering DAC employing a roundrobin- fashioned background current-source calibration scheme. A simulation with a 12 b 500 MS/s current-steering DAC showed 9.9 and 7.8 dB improvements in the spur-free dynamic range and signalto-noise + distortion ratio, respectively, owing to the reduced calibration spur by the proposed HRZ technique. [ABSTRACT FROM AUTHOR]

A simple‐but‐efficient calibration‐spur reduction technique is introduced that utilises the digital‐and‐analogue hybrid return‐to‐zero (HRZ) method in a current‐steering DAC employing a round‐robin‐fashioned background current‐source calibration scheme. A simulation with a 12 b 500 MS/s current‐steering DAC showed 9.9 and 7.8 dB improvements in the spur‐free dynamic range and signal‐to‐noise + distortion ratio, respectively, owing to the reduced calibration spur by the proposed HRZ technique. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the case study of a woman with multiple myeloma treated through autologous blood stem cell transplantation.