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The high pressure technique developed in physics may give a new possibility if it is applied to a biological study. We have been studying the tolerance of small living samples such as planktons and mosses, and found that all of them were alive after exposed to extremely high hydrostatic pressure of 7.5 GPa. This technique has been extended to a higher plant Trifolium lepens L. (white clover). A few seeds of white clover were exposed to 7.5 GPa for up to 6 days. After the pressure was released, they were seeded on agar, or directly on sowing soil. Seventeen out of the total 22 seeds exposed to the high pressure were found to be alive. Those exposed for up to 1 day and seeded on agar germinated roots. Those exposed for up to 1 h and seeded on soil germinated stems and leaves. The present technique has the possibility of being applied to improve breed of plants and to discover a very strong species that stands against very severe environmental conditions. [ABSTRACT FROM AUTHOR]

Lotus-type porous metal with many straight pores is attractive as a heat sink, because larger heat transfer capacity is obtained, owing to the small diameter of the pores. In order to use lotus-type porous metal effectively as a heat sink, it is important to clarify the effective conductivity and to consider the pore effect on heat conduction in the lotus-type porous metal. Because lotus-type porous metal is an anisotropic material, a steady state comparative-longitudinal heat flow (SCHF) method for thermal conductivity, referring to the ASTM standard, is thought to be better than a nonsteady method such as a laser flash method. This paper investigated the variable of the steady state comparative-longitudinal heat flow method by using specimens of different thicknesses (SCHF-DT) method for measuring the effective thermal conductivity. As a result, the uncertainty of effective thermal conductivity of a specimen was found to be smaller, as the diameter of a rod became larger and the length of a rod became shorter. In addition, it was found by error analysis that a dominant factor in the uncertainty of this method was the contact thermal difference between the rod and specimen. [ABSTRACT FROM AUTHOR]

Direct measurements of pressure dependence of the magnetization were made in Mn2-xCrxSb intermetallic compounds in a temperature range between 4.2 K and 200 K under various hydrostatic pressures up to 1 GPa. The magnetization in the low temperature antiferromagnetic state increased and a new magnetic phase which has an intermediate magnetization was attained at 0.5 GPa. The magnetization in the high temperature ferrimagnetic state decreased monotonically with pressure. The ferrimagnetic to antiferromagnetic phase transition temperature decreased with pressure.

Protease-resistant, misfolded isoforms (PrP Sc ) of a normal cellular prion protein (PrP C ) in the bodily fluids, including blood, urine, and saliva, are expected to be useful diagnostic markers of prion diseases, and nonhuman primate models are suited for performing valid diagnostic tests for human Creutzfeldt-Jakob disease (CJD). We developed an effective amplification method for PrP Sc derived from macaques infected with the atypical L-type bovine spongiform encephalopathy ( l -BSE) prion by using mouse brain homogenate as a substrate in the presence of polyanions and l -arginine ethylester. This method was highly sensitive and detected PrP Sc in infected brain homogenate diluted up to 10 10 by sequential amplification. This method in combination with PrP Sc precipitation by sodium phosphotungstic acid is capable of amplifying very small amounts of PrP Sc contained in the cerebrospinal fluid (CSF), saliva, urine, and plasma of macaques that have been intracerebrally inoculated with the l -BSE prion. Furthermore, PrP Sc was detectable in the saliva or urine samples as well as CSF samples obtained at the preclinical phases of the disease. Thus, our novel method may be useful for furthering the understanding of bodily fluid leakage of PrP Sc in nonhuman primate models. [ABSTRACT FROM AUTHOR]

Research has shown the presence of high levels of arsenic (up to 2666 mg As kg) in tailings from a gold mining area of Brazil. This is an important point of attention, generating concerns about impacts on human health. Yet, a recent study showed that As bioaccessibility in the same area was very low (<4.4 %). Thus, determination of the direct solid-phase speciation of As in the mine tailings and windblown dust is needed to explain this low bioaccessibility. Mine samples were collected from four subareas and windblown dust from eight sites. Synchrotron-based bulk-X-ray absorption near-edge structure (bulk-XANES) spectroscopy, micro-X-ray absorption near-edge structure (μ-XANES), and μ-X-ray fluorescence (μ-SXRF) spectroscopy were applied to determine As speciation. Bulk-XANES spectra indicated that As occurs as the As(V) oxidation state. Micro-XANES and μ-SXRF analyses revealed that As was also present as arsenopyrite (FeAsS) and its weathering products, but mostly it was As(V) as poorly crystalline ferric arsenate. This supports the findings of low bioaccessible As and highlights the importance of Fe oxides in immobilizing As in the terrestrial environment. All air particulate samples exhibited As-rich particles (up to 313 mg As kg). The air particulates exhibited solid-phase As species very similar to those found in the mine samples, which indicates that As in the windblown dust is not easily available. [ABSTRACT FROM AUTHOR]