1-µm bubble ion-implanted devices with two-level ion-implanted layers between propagation tracks

A new kind of 1-μm bubble device with two ion-implanted layers between propagation tracks has been studied. The ion-implanted layer in the center between two adjacent propagation tracks is thinner than that in the vicinity of the propagation track edge, where bubbles adhere. The unimplanted area is produced by the use of both photoresist and Mo masks to stop the ions, whereas the thinner implanted layer is produced by the use of the thin Mo mask alone. The ion-implantation mask-making for fabricating two ion-implanted layers is achieved with a gas plasma etch procedure. This structure makes it possible to scale down a loop period and create a circuit of high density. Reliable propagation margins for minor loops with 4 × 3 μm cell sizes can be obtained.     

Source of ATP for hexokinase-catalyzed glucose phosphorylation in tumor cells: dependence on the rate of oxidative phosphorylation relative to that of extramitochondrial ATP generation

We isolated highly intact and tightly coupled mitochondria from the rat ascites hepatoma cell line AH130 by disruption of the cell membrane by nitrogen cavitation. These isolated mitochondria were found to have essentially the same functional properties as rat liver mitochondria, but unlike the latter, hexokinase (HK) was bound to their membrane. Using the tumor mitochondrial preparation, we examined the source of ATP for phosphorylation of glucose by HK under conditions in which intra- and extramitochondrial ATP-generation systems operated separately or together. Results showed that the membrane-bound HK utilized ATP derived from the most efficiently operating ATP generation system, i.e., oxidative phosphorylation. However, when the rate of extramitochondrial ATP generation was much greater than that of oxidative phosphorylation, HK used ATP from the extramitochondrial ATP-generation system.     

The composition of particulate phosphorus: A case study of the Grand River,Canada

We examined the fractions of particulate phosphorus (PP) in the lower reaches of the Grand River, Canada, to test the hypothesis that the river is a source of both particulate-bound orthophosphate and labile species of PP. At the mouth of the Grand River, the proportion of particulate organic P (POP) was, on average, 57.7% of total PP, which was significantly higher than the proportion of particulate inorganic P (PIP) in PP. Analysis with ³¹P nuclear magnetic resonance (NMR) spectroscopy showed that the proportion of P species other than orthophosphate in the NaOH- EDTA extract was 1.75 times greater than that of orthophosphate. Labile P species (e.g. nucleotides and pyrophosphate) were present in the NMR spectrum; whereas, refractory organic P (myo-inositol hexakisphosphate) was absent. These results suggest that during winter and spring, the Grand River supplies primarily bioavailable phosphorus species in organic forms to Lake Erie, rather than inorganic orthophosphate. These results suggest that labile organic P is contained in PP rather than alkaline extractable inorganic P. Future studies should examine POP species in other rivers of the Lake Erie watershed.     

Growth of large-diameter (∼4 nm) single-wall carbon nanotubes in the nanospace of mesoporous material SBA-15

Single-wall carbon nanotubes (SWCNTs) have been synthesized by supported-catalyst chemical vapor deposition (CCVD) using one-dimensional (1D) channels of mesoporous silica (SBA-15; mean channel diameter, 6.0 nm) functionalized with carboxyl groups where Co and Fe complexes are encapsulated. The synthesized SWCNTs have much larger diameters than the SWCNTs synthesized by conventional CCVD. Transmission electron microscope observations reveal that large-diameter SWCNTs (<4.2 nm) are grown in 1D channels of SBA-15. Large metal particles formed in the channels should play an important role in the growth of the SWCNTs with larger diameters.     

Development of a food frequency questionnaire to estimate habitual dietary intake in Japanese children

Background  

Food frequency questionnaires (FFQ) are used for epidemiological studies. Because of the wide variations in dietary habits within different populations, a FFQ must be developed to suit the specific group. To date, no FFQ has been developed for Japanese children. In this study, we developed a FFQ to assess the regular dietary intake of Japanese children. The FFQ included questions regarding both individual food items and mixed dishes.     

Morphological Changes in Process-Related Large Pores of Granular Compacted and Sintered Alumina

Large pore defects clearly develop in Al₂O₃ ceramics during sintering. These large pores originate from voids caused by the incomplete deformation and adhesion of powder particles in collapsed dimples at the centers and boundaries of granules in the green compacts. The coalescence of pores, with limited shrinkage, during densification and grain growth in the late intermediate to final stages of sintering, is considered responsible for the development of the large pores. The mechanism of pore coalescence is explained by thermodynamic arguments, which demonstrate that the largest pores result in a stable system.     

Determination of lamellar twisting manner in a banded spherulite with scanning microbeam X-ray scattering

We investigated lamellar twisting manner in a banded spherulite, the blend of poly-(?-caprolactone) and poly-(vinyl butyral), with scanning microbeam X-ray diffraction. We obtained the diffraction contour intensity map with a scanning pitch of 1 μm by employing a rotation of a spherulite around its radial direction along which the microbeam scans. The results confirm that the twisting manner depends on the crystallization temperature and that it changes from continuous twisting to step-wise twisting with the increase of crystallization temperature. Moreover, we observed that the phase of long-period lamellar twisting advanced by about 15° compared to that of short-period lamella. In addition, it was confirmed that c-axis of packing structure was normal to lamella, which was represented by dominant short-period lamella.