Nickel dioxide polymorphs as lithium insertion electrodes

Five kinds of nickel dioxide polymorphs, Li_xNiO₂ with x≈0, were prepared by treating LiNiO₂ with sulfuric acid solutions, occasionally followed by low-temperature heating. Here we report their structure and properties as lithium insertion electrodes. Acid-treated Li_0.10NiO₂ with two layered phases turned into a single-layered compound at 160 °C and then to a spinel-related compound at 170 °C. Acid-treated Li_0.04NiO₂ contained a phase with a cadmium iodide structure, which was not observed with Li_0.10NiO₂. Heating this Li_0.04NiO₂ yielded a spinel-related compound on heating. The NiO distances in these compounds suggested that the nickel oxidation state was kept approximately +4. These ‘nickel dioxide’ polymorphs exhibited varied characteristics as lithium insertion electrodes. We discuss the electrode behavior together with the structural changes that occur during lithium insertion. We also examined the effect of the electrode drying condition on the cycling performance.     

A new bumping process using lead-free solder paste

In this paper, we report development of a new process for lead-free solder bumping with no flux residues, using stencil printing and hydrogen radicals, which can lessen both the environmental load and the manufacturing cost of solder bumping. In this process the reduction of the hydrogen radicals, instead of the flux, will eliminate the surface oxides of the stencil printed lead-free solder paste. Sn-3.0Ag-0.5Cu lead-free solder paste, which contains no residue flux was printed on an 8-in wafer. Hydrogen plasma was radiated for a minute during the reflow process, and the printed paste formed a bump. Reflow experiments without hydrogen radicals treatment were also carried out for comparison, where no successful reflow could be observed.     

Sources of the neurotoxin quinolinic acid in the brain of HIV-1-infected patients and retrovirus-infected macaques

This study investigated the sources of quinolinic acid, a neurotoxic tryptophan-kynurenine pathway metabolite, in the brain and blood of HIV-infected patients and retrovirus-infected macaques. In brain, quinolinic acid concentrations in HIV-infected patients were elevated by > 300-fold to concentrations that exceeded cerebrospinal fluid (CSF) by 8.9-fold. There were no significant correlations between elevated serum quinolinic acid levels with those in CSF and brain parenchyma. Because nonretrovirus-induced encephalitis confounds the interpretation of human postmortem data, rhesus macaques infected with retrovirus were used to examine the mechanisms of increased quinolinic acid accumulations and determine the relationships of quinolinic acid to encephalitits and systemic responses. The largest kynurenine pathway responses in brain were associated with encephalitis and were independent of systemic responses. CSF quinolinic acid levels were also elevated in all infected macaques, but particularly those with retrovirus-induced encephalitis. In contrast to the brain changes, there was no difference in any systemic measure between macaques with encephalitis vs. those without. Direct measures of the amount of quinolinic acid in brain derived from blood in a macaque with encephalitis showed that almost all quinolinic acid (>98%) was synthesized locally within the brain. These results demonstrate a role for induction of indoleamine-2,3dioxygenase in accelerating the local formation of quinolinic acid within the brain tissue, particularly in areas of encephalitis, rather than entry of quinolinic acid into the brain from the meninges or blood. Strategies to reduce QUIN production, targeted at intracerebral sites, are potential approaches to therapy.     

Characteristics of laminated alloy films heads for high frequencyrecording

Excellent performance of laminated Fe-Si-Al alloy film heads is demonstrated in applications to high-definition VCR and to digital recording. It is emphasized that these results are derived not only from the ring-shaped core geometry but also from the isotropic behavior in the magnetic properties of the sputtered Fe-Si-Al alloy films. The experimental results on the isotropic magnetic behavior are summarized. A mass-production process for the laminated alloy film heads is introduced, emphasizing the importance of stacked bar fabrication steps     

Natural history of scoliosis in spastic cerebral palsy

BACKGROUND: Although the frequent occurrence of scoliosis in patients who have spastic cerebral palsy is well known and surgical treatment has often been recommended for these patients, little is known about the natural history of scoliosis in this population. We aimed to clarify the natural history of scoliosis from childhood through to adulthood and provide objective data on proper surgical indications for such patients. METHODS: The participants were 37 institutionalised patients with severe spastic cerebral palsy and scoliosis. All the participants had a series of radiographs taken, starting at a mean age of 7.8 years; they were followed up for an average of 17.3 years. We retrospectively reviewed radiographs and assessed the effect of five factors on progression of scoliosis: sex, degree of spasticity, initial physical capability, pattern of spinal curve, and location of curve. FINDINGS: Scoliosis usually started before the age of 10 years and progressed rapidly during the growth period. In many cases, even after growth had ended, continuous progression was seen. The mean magnitude of the curves at final examination was 55 degrees (Cobb angle). In 11 (85%) of 13 patients who had a spinal curve of more than 40 degrees before age 15 years, the scoliosis progressed to more than 60 degrees by the time of the final examination. Meanwhile, in only three (13%) of 24 patients who had a curve of less than 40 degrees at age 15 years, did the scoliosis progress to more than 60 degrees. Severe scoliosis (> or = 60 degrees) developed predominantly in those who had total body involvement (67%), were bedridden (100%), or had throacolumbar curves (57%). INTERPRETATION: The risk factors for progression of scoliosis in spastic cerebral palsy are: having a spinal curve of 40 degrees before age 15 years; having total body involvement; being bedridden; and having a thoracolumbar curve. Patients with these risk factors might benefit from early surgical intervention to prevent progression to severe scoliosis.