Laboratories In Japan Research Articles

Interlaboratory comparison of olfactometry in Japan

In 2000, 2001, and 2002, interlaboratory comparison of olfactometry was carried out in order to collect basic data for the establishment of a quality control procedure and the determination of quality criteria for the triangular odour bag method. In 2000, interlaboratory comparison was conducted by using a measurement method for samples taken at smoke stacks. On the other hand, the measurement method for samples taken at boundary lines was used for interlaboratory comparison in 2001. A total of seven olfactometry laboratories in Japan participated in each test, and mean values, repeatability standard deviations, reproducibility standard deviations, and standard deviations under intermediate conditions of detection threshold of ethyl acetate were calculated from the results. These values can be used in a quality control process of olfactometry. In 2002, interlaboratory comparison was carried out by using a measurement method for samples taken at smoke stacks. A total of 137 olfactometry laboratories in Japan participated in the test, and 69% of them lay within the permissible range of the odour index.

Pseudohyperkalaemia at commercial laboratories in Japan: a questionnaire survey.

Pseudohyperkalaemia caused by recentrifugation after storage or delay in separation of serum from blood cells is not uncommon. The purpose of this study was to audit pseudohyperkalaemia at commercial laboratories in Japan. A questionnaire asking about how samples are handled for potassium measurement and information on pseudohyperkalaemia was sent to 431 commercial laboratories. A total of 263 (response rate 61%) questionnaires were returned and suitable for analysis. Pseudohyperkalaemia caused by recentrifugation was seen at 145 (70%) laboratories. Pseudohyperkalaemia caused by delay in separation of serum was also seen in many laboratories. Blood samples were centrifuged on site in only 46% of hospitals and in 17% of clinics served by these laboratories. The longest average time from venesection to centrifugation was 18 h. Although half the laboratories had asked their client facilities to centrifuge blood samples on site, very few complied. Pseudohyperkalaemia is not uncommon at commercial laboratories in Japan. Further efforts are necessary to avoid inappropriate handling at blood collection sites and in laboratories.

Scientific Reviews: GEM: The General Materials Diffractometer at ISIS-Multibank Capabilities for Studying Crystalline and Disordered Materials

The aim of the GEM project at the ISIS pulsed neutron source was to develop a world-leading general materials diffractometer [1-5]. In mid-1995, a proposal from a Collaborative Research Group (CRG) headed by P. Day (The Royal Institution) and J. Enderby (University of Bristol) (Figure 1) was awarded funding by the U.K. Engineering and Physical Sciences Research Council (EPSRC) for the construction of GEM. This came into operation during 1999 with continued work on enhancing the detector array resulting from funding obtained in collaboration with the RIKEN laboratory in Japan. Additional funding was subsequently obtained from EPSRC by the ISIS Facility in order to continue work on completion of the detector array.

Modeling flow and transport in saturated fractured rock to evaluate site characterization needs

Using regional geographic, geologic, surface and subsurface hydrologie, and geophysical data for the Tono area in Gifu, Japan, we develop a numerical model to simulate subsurface flow and transport in a 4 km x 6 km x 3 km thick fractured granite rock mass overlain by sedimentary layers. Individual fractures are not modeled explicitly. Rather, large-scale features such as lithologic layering and major fault zones are assigned deterministically, and continuum permeability and porosity distributions are assigned stochastically, based on well-test data and fracture density measurements. The model simulates the steady-state groundwater flow through the site, and then stream trace analysis is used to calculate travel times to the model boundary from specified points. The study is being conducted as a part of the site characterization effort for the Mizunami Underground Research Laboratory in Japan. Predicted travel times range from 1 to 25 years. Several other research groups also developed models based on the same data set, and comparison between different models' results highlight which aspects of site characterization need to be improved in order to increase confidence in model predictions. A wide range in travel times obtained by the different research groups (1-10,000,000 years) can be largely attributed to orders of magnitude differences in the effective porosity used for the fracture network. This underscores the importance of improved porosity estimates as a key component of future site characterization.

Working with living krill – the people and the places

The fascination of Antarctic scientists with Antarctic krill and their capabilities has a long and varied history, and prompted many scientists to maintain and manipulate krill under laboratory conditions. Starting in the Discovery era with Mackintosh at the King Edward Point labs on South Georgia, 1930, scientists have collected krill from sailing vessels, small boats, inflatable zodiacs and large ice-breaking vessels. Krill have been maintained in small and large jars, deep rectangular tanks, large round tanks and in flow-through and recycling systems. They have been maintained both on board research vessels and in laboratories, in flowing seawater systems at ambient conditions and in temperature-controlled environmental rooms. A few researchers have transported living krill back to their home laboratories, for example tropical laboratories in Japan (Murano) and Australia (Ikeda), temperate laboratories (Nicol) in Australia, a northern European laboratory in Germany (Marschall) and a sunny maritime laboratory in California (Ross and Quetin). The goals have been varied: short-term experiments to understand in situ physiological rates, long-term experiments to test the effects of manipulations or controlled changes in environmental conditions, and behavioral responses. We take you on a brief historical tour as we trace the lineage of modern day research on living Antarctic krill.

Emerging rickettsial infections in Sri Lanka: the pattern in the hilly Central Province.

To identify different rickettsial infections using a specific immunofluorescent technique in patients clinically diagnosed as 'typhus fever' in the Central Province of Sri Lanka, and to define the clinical picture, assess the severity of infection and to determine the pattern of geographical distribution of the infections of the hospital-based patients. A specific indirect immunofluorescent antibody technique was used on the sera of two groups of patients in laboratories in Japan and Thailand. We serodiagnosed infections with Orientia tsutsugamushi, Rickettsia typhi and spotted fever group in 56 of 118 clinically investigated patients. There were eight infections with O. tsutsugamushi, two with R. typhi and 10 spotted fever group patients with IgM antibodies suggestive of acute infection. Nineteen patients had antibodies against these three rickettsial species, suggestive of past exposure, co-infection or cross-reactivity of antigens. Discrete, erythematous maculopapular rash was common to all three types of infection except for five patients who had no rash. Five patients positive for spotted fever antibodies developed fern-leaf type skin necrosis with severe illness. Duration of the febrile period ranged from 4 to 23 days with defervescence occurring after specific antibiotic treatment. The study has shown the presence of different types of rickettsial infections in the Central Province of Sri Lanka. The characterization of the clinical picture and the severity of infection provide useful information for the proper management of the patients in the future.

Prevalence of inherited myeloperoxidase deficiency in Japan.

The microbicidal activity of the myeloperoxidase (MPO)-hydrogen peroxide-halide system has been implicated as the most efficient, oxygen-dependent antimicrobial component of neutrophil host defense. Unexpectedly, individuals with MPO deficiency suffer few clinical consequences. In order to understand better the clinical impact of MPO deficiency, we surveyed several clinical hematology laboratories in Japan to assess the prevalence of MPO deficiency in the general population. MPO activity was determined by flow cytometry using the Technicon H series of automated systems. We identified 26 cases of complete MPO deficiency, prevalence 1 in 57,135, and 129 cases of partial deficiency, prevalence 1 in 17,501. The distribution of complete and partial deficiencies differed among the laboratories studied.

Agonist contractions against electrically stimulated antagonists

Yanagi T, Shiba N, Maeda T, Iwasa K, Umezu Y, Tagawa Y, Matsuo S, Nagata K, Yamamoto T, Basford JR. Agonist contractions against electrically stimulated antagonists. Objective: To assess an exercise program that uses electrically stimulated antagonists to resist agonist muscle contractions. Design: In 1 limb, electrically stimulated antagonists resisted elbow flexion and extension. In the other, stimulation occurred without volitional muscle contraction. Setting: A biomechanics laboratory in Japan. Participants: Twelve men between the ages of 19 and 24 years. Subjects served as their own controls. Intervention: Subjects trained 3 times a week for 12 weeks. Each session consisted of 10 sets of 10 elbow flexor and extensor contractions. Main Outcome Measures: Isokinetic elbow extension and flexion torques. Biceps and triceps brachii cross-sectional areas. Results: Elbow extension torques increased (32.85% at 30°/s, 27.20% at 60°/s, 26.16% at 90°/s; all P≤.02) over the training period in limbs that trained against electrically stimulated antagonists. Control limb extension torque increases were smaller (8.52% –14.91%) and did not reach statistical significance. Elbow flexion torques improved in both groups, but the changes did not reach statistical significance. Cross-sectional areas increased in all muscles but were most marked in the antagonist stimulated limbs: triceps 16.20% versus 4.25% ( P=.01) and biceps 16.65% versus 7.00% ( P=.005). Conclusions: Exercises that use electrically stimulated antagonist muscles may be effective in increasing muscle strength and mass.

Measurements of physical properties of gas hydrates and in situ observations of formation and decomposition processes via Raman spectroscopy and X-ray diffraction

Gas hydrate properties and phase transition kinetics were studied using Raman spectroscopic and X-ray diffraction methods. These techniques have the advantage of measuring physical properties such as crystal structure, gas composition, and cage occupancy of gas molecules without decomposing the sample. In situ observations using these techniques are indicative of formation and decomposition processes in gas hydrates. Raman spectroscopy is used for the analysis of gas concentrations and gas compositions of gas hydrates. The ν1 symmetrical C–H stretching vibration mode of methane molecules in the hydrate phase shows a doublet, and the relative intensity of the peaks determines the cage-occupancy ratio. However, as the Raman method is not standard for this application, we evaluated the method by analyzing the same methane hydrate sample using NMR and Raman scattering in a laboratory in Canada and also comparing the data with the Raman measurements made on the same sample in a laboratory in Japan. The data were consistent with all three measurements. In addition, in situ measurements of hydrate formation and decomposition were done by X-ray diffraction. The transformation of ice into CO2 hydrates occurred in two steps: at first a CO2 hydrate layer rapidly formed a coating on the ice surface and then the CO2 hydrate slowly grew according to the diffusion rates of CO2 and H2O molecules through the hydrate layer to the reaction sites. The same methods were used to observe the self-preservation effect of methane hydrates. PACS Nos.: 82.80Ch, 61.10Nz

Nasal continuous positive airway pressure improves quality of life in obesity hypoventilation syndrome.

We studied the quality of life of obesity hypoventilation syndrome (OHS) by comparing it with age- and body mass index-matched patients without hypoventilation and age-matched obstructive sleep apnea (OSA) patients with body mass index (BMI) under 30, and the efficacy of nasal continuous positive airway pressure (CPAP) therapy for 3 to 6 months on the quality of life in these patients. Prospectively recruited patients from six sleep laboratories in Japan were administered assessments of the general health status by the Short-Form 36 Health Survey (SF-36) and subjective sleepiness by the Epworth Sleepiness Scale (ESS). Compared with matched healthy subjects, OHS and OSA patients not yet treated had worse results on the ESS scores and the SF-36 subscales for physical functioning, role limitations due to physical problems, general health perception, energy/vitality, role limitations due to emotional problems, and social functioning. The ESS scores of OHS patients were worse than those of the OSA groups including the age- and BMI-matched OSA patients. In the SF-36 subscales of OHS patients, only the subscale of social functioning showed worse results compared with that of BMI-matched OSA patients. After 3 to 6 months of treatment, ESS scores and these SF-36 subscales in all three patient groups improved to the normal level. These results suggested that the quality of life of OHS before nasal CPAP was significantly impaired and that nasal CPAP for OHS improved the quality of life associated with the improvement of daytime sleepiness to the level of the other OSA patients.

Oxygen Storage Materials for Automotive Catalysts: Ceria-Zirconia Solid Solutions

This paper reviews progress in the development of oxygen storage materials for automotive exhaust catalysts. The research was mainly conducted as a study and development exercise in the author's laboratory in Japan. Ceria-lanthana solid solutions (CL) and the first generation of ceriazirconia solid solutions (CZ) were developed as excellent oxygen storage materials for automotive catalysts in the 1980s. These materials consist of ceria doped with less than 20 mol% of La4+ or Zr4+. An increase in oxygen defects in CL and CZ under reductive conditions is responsible for an enhanced oxygen storage capability on the cerium atoms. An accurate measure of the oxygen storage capacity (OSC) per cerium is very important for theoretical and practical treatments of the catalyst. The term “partial OSC” was introduced to describe this capacity and to differentiate it from the usual definition of the OSC, known also as the “total OSC”. After the development of CL and CZ, a new technology was developed to dissolve more than 20 mol% of zirconia in the ceria, allowing second generation CZ and third generation CZ (known as ACZ, which is doped with alumina) to be successfully developed in the 1990s. The partial OSC of these materials increases with increasing amounts of zirconia dissolved in the ceria, and also with decreasing material particle size after an engine durability test. In the case of ACZ, alumina was added to CZ based on the “diffusion barrier concept”, in which a diffusion barrier layer inhibits the coagulation of CZ and A when the material is required for duty at high temperature in air. Furthermore, the relationship between the total or partial OSC and the structure of the ceriazirconia solid solutions is explained in this paper. For ceriazirconia solid solutions composed of equimolar CeO2 and ZrO2(Ce/Zr=1), the total or partial OSC of the κ-phase CeZrO4, in which the cerium and zirconium ions are regularly distributed, was about twice as large as that of a ceriazirconia solid solution with a relatively irregular distribution of cerium and zirconium ions, and about five times larger than that of a mixture of ceria powder and zirconia containing only a small amount of ceriazirconia solid solution. It corresponds to about 89% of the theoretical maximum value. For a ceriazirconia solid solution composed of non-equimolar CeO2 and ZrO2(Ce/Zr ≠ 1), the partial OSC of a ceria-κ-phase solid solution with a zirconia content of between 30 and 50mol% is much higher than that of a ceriazirconia solid solution of the same zirconia content. The partial OSC of a κ-phase and zirconia mixed oxide, which is formed by reducing the material at 1200 °C, reaches a value above 0.20 mol-O2/mol-Ce (about 80% of the theoretical maximum value of the partial OSC), when the zirconia content is between 50 and 80 mol%. The Toyota Motor Corp. has put automotive three-way catalysts containing the first, second and third generations of CZ into practical use on a global basis.

The physics of hypernuclei

Aldo Zenoni, Universitii di Brescia and INFN Sezione di Pavia, Brescia, Italy Paola Gianotti, INFN Laboratori Nazionali di Frascati, Frascati, Italy The physics of hypernuclei nuclei (with new quantum numbers), in direction of other exotic nuclear systems (charmed nuclei and so on). A hypernucleus is generally indicated with the symbol of the parent nucleus with the suffix A, indicating that a A particle has replaced a neutron. ~ C means a nuclear system composed of 6 protons, 5 neutrons and one A particle. Three events of double hypernuclei were observed, in which 2 nucleons are substitutedby 2 A particles. One example is ,J. He, a system composed of2 protons, 2 neutrons and 2 A particles. The concept of hypernuclei can be extended to nuclei where a nucleon is replaced by hyperons other than the A one. Experimental evidence was claimed ofthe existence ofE-hypernuclei, in which a nucleon is replaced by a L hyperon. This is rather surprising since, in nuclear matter, the L can decay through a strong interaction process (L + N~A + N) giving very largewidths for the hypernuclear states, unless a strong suppression mechanism is at work. However, the experimental evidence of the existence of narrow L-hypernuclei is rather controversial and only the case of tHe is considered unambiguous. After the very first evidence of hyperfragments in cosmic ray interactions with nuclei, starting from the end of the Sixties, the installation ofbeams ofKmesons at particle accelerators made it possible to study the formation of hypernuclei in the laboratory. Hypernuclei were produced copiouslywith little background, the required negative for A hyperon production being present in the beam. The typical utilized was the strangeness where a neutron hit by a Kis changed into a A hyperon emitting a 1t(K+ n~ A + rr-). The experimental techniques used in these experiments were photographic emulsions and bubble chambers (filled with He or heavy liquids) exposed to Kbeams. These experiments mainly measured the hyperon binding energies, by means of the kinematical analysis of the disintegration star, and observed the principal decay modes of the hypernuclei. Starting from the Seventies, the study ofhypernuclei was continued with Kbeams by means of counter techniques with magnetic spectrometers and the introduction of new particle detectors (multiwire proportional chambers and drift chambers). The identification ofwell defined excited hypernuclear levels, by means of the kinematical analysis of the production reaction, was one of the most important results of a first series of experiments started at CERN and continued at Brookhaven (USA). The physical interpretation ofthese spectra was possible in terms of microscopic descriptions of the A-nucleus and A-nucleon potentials. In the Eighties, a new technique for hypernucleus production was introduced at the Brookhaven laboratory,bymeans ofintense beams ofhigh energy 1t+. With this technique the A hyperon is produced inside the nucleus by an associated production reaction (1t+ + n ~ A + K+). This has a reduced cross section, compared to the strangeness exchange reaction, however this drawback is over compensated by the greater intensities of the 1t+ beams. The technique was fully exploited at the KEK laboratory in Japan where, for more than ten years, a great wealth of excellent hypernuclear data were produced, concerning both spectroscopyand decay ofhypernuclei. The interest in these new data has triggered the attention ofthe nuclear physics community and, in the last few years, different laboratories around the world have started a hypernuclear physics program: COSY at Jiilich in Germany, TJNAF at Newport News in USA, Nuclotron in Dubna (Russia). Inparticular, it isworth mentioning the Italian hypernudear project, the FINUDA experiment (acronim of Flsica NUcleare a DAne) at the Laboratori Nazion'. ,.

Research Activities on Neutrorics under ASTE Collaboration at AGS/BNL

A series of experiments on a mercury spallation target using high-peak-power GeV proton-beam from the Alternating Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL) has been performed under an international collaboration among the laboratories in Japan, U.S. and Europe, namely the ASTE (AGS Spallation Target Experiment) collaboration. This paper reviews the current status of the experiments on neutronic performance of the mercury target.

The 3He/4He ratio of the new internal He Standard of Japan (HESJ).

We have prepared an artificial mixture of 3He and 4He to be used as an internal standard for precise 3He/4He measurements of terrestrial mantle-derived samples. The mixture is named HESJ (He Standard of Japan). The 3He/4He ratio of HESJ was determined by obtaining the weighted average of repeated analyses from five machines in four laboratories in Japan. The recommended value of the 3He/4He ratio of HESJ relative to the air value (R/Ra) is 20.63 ± 0.10. HESJ is available to all researchers.

Quantitative visualization of the leading-edge vortices on a delta wing by using pressure-sensitive paint

Leading-edge vortices on a simple delta wing were visualized by using pressure-sensitive paint (PSP). PSP is an optical pressure measurement technique based on oxygen quenching of luminescent molecules. In the present study, we used PSP composed of platinum octaethylporphyrine (PtOEP) and fluoropolymer (poly-IBM-co-TFEM [Poly (isobutylmethacrtlate-co-trifluoroethylate)]). This new paint has higher sensitivity to pressure and lower sensitivity to temperature than previous ones, reducing an error due to temperature variation during a wind tunnel test. A thin coating of PSP was applied to a delta wing model with 70-degree leading-edge sweep. The coating was excited by Xenon light and emission from the coating was detected by a high-resolution CCD camera. Tests were done at subsonic speeds in the 0.2-m Supersonic Wind Tunnel at the National Aerospace Laboratory in Japan. Complicated flow structures on the delta wing including primary and secondary vortices were clearly visualized using pressure-sensitive paint. An a priori calibration technique was used to convert measured luminescent intensity into pressure. The obtained pressure distributions were in good agreement with pressure tap data. Pressure maps were obtained for various Mach numbers, Reynolds numbers and angles of attack. It was found that an increase in Mach number delayed vortex breakdown while Reynolds number had little effect on the vortex formation.

Development of high temperature superconducting current feeders for a large-scale superconducting experimental fusion system

The National Institute for Fusion Science (NIFS), in collaboration with universities and laboratories in Japan, the Forschungszentrum Karlsruhe (FZK) and the Max-Planck Institut fur Plasma Physik (IPP) in Germany, is planning to develop high temperature superconducting (HTS) current feeders for large-scale superconducting coils. Two programs are being progressed: one is a current feedthrough for superfluid helium (He II) cooled superconducting coils; the other is current leads for experimental fusion system. The paper describes the present status of the two programs, including joint experiments of a 20 kA Bi-2223 current lead developed by FZK and development of a prototype YBCO bulk current feedthrough for He II cooled superconducting coils. In addition, the test results of Bi-2212 tubes fabricated by diffusion process, applicable to HTS current leads, are described Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/.

Selection of more appropriate PCR primer pairs for improved efficiency in detecting Norwalk-like virus (NLV) RNA.

A pair of primers, NV35 and NV36, and another pair of primers, NV81 and NV82/SM82, are commonly used for polymerase chain reaction (PCR) detection of Norwalk-like virus (NLV) genome RNA sequences in authorized test laboratories in Japan. However, the efficiency of NLV genome RNA detection with these primer pairs has been less than satisfactory. In the present study, we attempted to establish more appropriately matched primer pairs for improved detection of NLV genome RNA sequences using a combination of primers including NV35, NV36, NV81, NV82/SM82, SR33, and SRs (a mixture of 4 primers SR46, SR48, SR50, and SR52). We also evaluated appropriate primers for improved reverse transcription of NLV genome RNA. Stool samples used for detection of NLV included 18 samples collected from NLV-infected patients who ingested oysters (group 1) and 13 samples collected from those who did not ingest oysters (group 2). Reverse transcription of RNA genome with primer NV35 was less efficient compared with that with primer SR33 or NV81. When PCR products obtained with NV35 and NV36 as a pair of primers were subjected to gel electrophoresis, a strong extra band was detected compared with those obtained with other primer pairs. Since this extra band may represent heterodimeric or homodimeric hybrids, or intramolecular hybrids derived from these primers, this template-independent hybridization could lower the efficiency of primer-dependent polymerase reaction. Of 18 primer pairs, a pair of NV81 and SRs provided the best detection of PCR products following reverse transcription of NLV RNA with SR33 or NV81. The detection rate was 61% for both reverse transcription with SR33 and that with NV81. After reverse transcription using SR33 as a primer, nested PCR using a pair of NV81 and SRs following primary PCR using a pair of NV81 and NV82/SM82 increased the detection rate to 89% in group 1 and 100% in group 2.

The State and Prospect of Nortable Venture Business Laboratories in Japan

The State and Prospect of Nortable Venture Business Laboratories in Japan

Bioassay for endocrine disruptors by using yeast two-hybrid system

One of the urgent tasks in understanding endocrine disruptors (EDs) is to compile a list of suspected substances among the huge number of chemicals by using the screening test method. An in vitro screening test is a more useful tool for primary selection of suspected EDs. We have developed an assay for EDs using the yeast two-hybrid system. The assay is based on the ligand-dependent interaction of two proteins, a hormone receptor and a coactivator, and the hormonal activity is detected by beta-galactosidase activity. This assay is a very simple and inexpensive test method with high repeatability to detect the agonist, and it is applicable for the detection of antagonist and active compounds after metabolism. Accordingly, it has been used in more than 40 laboratories in Japan. To date, we have tested the estrogenic activity of more than 500 chemicals including natural substances, medicines, pesticides and industrial chemicals. Sixty-four compounds were evaluated as positive and most of these possessed a common structure: phenol with a hydrophobic moiety at the para-position without bulky groups at the ortho-position. These results are expected to facilitate further risk assessment of chemicals, especially EDs.

JNdi-1: a neodymium isotopic reference in consistency with LaJolla neodymium

A neodymium oxide with relative 143Nd/ 144Nd ratio 1.000503±1(1 σ m) to LaJolla Nd was prepared as a new isotopic reference. The neodymium reagent was selected from two points of view as follows. The first is low abundance of neighboring elements Ce and Sm, which affects isobaric interference. The second is high 143Nd/ 144Nd ratio, which is closer to those of chondritic and mantle-derived materials. The 143Nd/ 144Nd ratio of the reagent was measured alternately with LaJolla Nd to get a coherency with LaJolla Nd using 12 mass spectrometers in 11 laboratories in Japan. Aliquots of this neodymium oxide reagent named JNdi-1 are available upon request from the Geological Survey of Japan and may be useful for precise interlaboratory calibration of Nd isotopes.