SENJU: a new time-of-flight single-crystal neutron diffractometer at J-PARC.

SENJU is a new single-crystal time-of-flight neutron diffractometer installed at BL18 at the Materials and Life Science Experimental Facility of the Japan Accelerator Research Complex (J-PARC). The diffractometer was designed for precise crystal and magnetic structure analyses under multiple extreme sample environments such as low temperature, high pressure and high magnetic field, and for diffraction measurements of small single crystals down to 0.1 mm3 in volume. SENJU comprises three choppers, an elliptical shape straight supermirror guide, a vacuum sample chamber and 37 scintillator area detectors. The moderator-to-sample distance is 34.8 m, and the sample-to-detector distance is 800 mm. The wavelength of incident neutrons is 0.4-4.4 Š(first frame). Because short-wavelength neutrons are available and the large solid angle around the sample position is covered by the area detectors, a large reciprocal space can be simultaneously measured. Furthermore, the vacuum sample chamber and collimator have been designed to produce a very low background level. Thus, the measurement of a small single crystal is possible. As sample environment devices, a newly developed cryostat with a two-axis (ω and φ axes) goniometer and some extreme environment devices, e.g. a vertical-field magnet, high-temperature furnace and high-pressure cell, are available. The structure analysis of a sub-millimetre size (0.1 mm3) single organic crystal, taurine, and a magnetic structure analysis of the antiferromagnetic phase of MnF2 have been performed. These results demonstrate that SENJU can be a powerful tool to promote materials science research.

Fibrinogen measurements in plasma and whole blood: a performance evaluation study of the dry-hematology system.

BACKGROUND: An accurate and rapid determination of fibrinogen level is important during hemorrhage to establish a timely hemostatic intervention. The accuracy of fibrinogen measurements may be affected by the specific methodology for its determination, fluid therapies, and anticoagulant agents. The dry-hematology method (DRIHEMATO®) is a novel approach to determine fibrinogen levels in plasma and whole blood based on thrombin-activated coagulation time. We hypothesized that plasma or whole blood fibrinogen level using the dry-hematology method would be similar to those measured with conventional plasma fibrinogen assays. METHODS: Acquired hypofibrinogenemia was modeled by serial dilutions of blood samples obtained from 12 healthy volunteers. Citrated whole blood samples were diluted with either normal saline, 5% human albumin, or 6% hydroxyethyl starch to achieve 25%, 50%, and 75% volume replacement. The dry-hematology method, the Clauss method, the prothrombin time (PT)-derived method, determination of antigen levels, and thromboelastometric fibrin formation were compared in plasma or whole blood samples. The effect of heparin on each assay was examined (0 to 6 IU/mL). Comparisons of dry-hematology and other methods were also conducted using ex vivo samples obtained from cardiac surgical patients (n = 60). RESULTS: In plasma samples, there were no significant differences between dry-hematology and the Clauss method, while dry-hematology showed lower fibrinogen levels compared with PT-derived and antigen level methods. The dry-hematology method yielded acceptable concordance correlation coefficients (Pc) with the Clauss method, the PT-derived method, and fibrinogen antigen levels (Pc = 0.91-0.99). The type of diluents and heparin affected the results of the PT-derived method and thromboelastometric assay, but not the dry-hematology method. In cardiac surgical patients, the overall correlation in fibrinogen levels between dry-hematology and the other methods was comparable to the results from in vitro dilution experiments. The dry-hematology reported higher fibrinogen values in whole blood compared with those measured in plasma samples, but hematocrit adjustment decreased the bias between whole blood and plasma samples from 73 mg/dL (95% prediction interval: 40, 106) to -13 mg/dL (95% prediction interval: -35, 8.5). CONCLUSIONS: This study demonstrated that fibrinogen levels can be accurately assessed by the dry-hematology method in plasma and the results are not affected by heparin or colloids. For whole blood fibrinogen measurements by dry-hematology, hematocrit adjustment is necessary to compensate for dynamic changes in hematocrit in perioperative bleeding settings.

Mode-distribution analysis of quasielastic neutron scattering and application to liquid water.

A quasielastic neutron scattering (QENS) experiment is a particular technique that endeavors to define a relationship between time and space for the diffusion dynamics of atoms and molecules. However, in most cases, analyses of QENS data are model dependent, which may distort attempts to elucidate the actual diffusion dynamics. We have developed a method for processing QENS data without a specific model, wherein all modes can be described as combinations of the relaxations based on the exponential law. By this method, we can obtain a distribution function B(Q,Γ), which we call the mode-distribution function (MDF), to represent the number of relaxation modes and distributions of the relaxation times in the modes. The deduction of MDF is based on the maximum entropy method and is very versatile in QENS data analysis. To verify this method, reproducibility was checked against several analytical models, such as that with a mode of distributed relaxation time, that with two modes closely located, and that represented by the Kohlrausch-Williams-Watts function. We report the first application to experimental data of liquid water. In addition to the two known modes, the existence of a relaxation mode of water molecules with an intermediate time scale has been discovered. We propose that the fast mode might be assigned to an intermolecular motion and the intermediate motion might be assigned to a rotational motion of the water molecules instead of to the fast mode.

Ultra-high-speed image signal accumulation sensor.

Averaging of accumulated data is a standard technique applied to processing data with low signal-to-noise ratios (SNR), such as image signals captured in ultra-high-speed imaging. The authors propose an architecture layout of an ultra-high-speed image sensor capable of on-chip signal accumulation. The very high frame rate is enabled by employing an image sensor structure with a multi-folded CCD in each pixel, which serves as an in situ image signal storage. The signal accumulation function is achieved by direct connection of the first and the last storage elements of the in situ storage CCD. It has been thought that the multi-folding is achievable only by driving electrodes with complicated and impractical layouts. Simple configurations of the driving electrodes to overcome the difficulty are presented for two-phase and four-phase transfer CCD systems. The in situ storage image sensor with the signal accumulation function is named Image Signal Accumulation Sensor (ISAS).

Studies on novel bacterial translocase I inhibitors, A-500359s. V. Enhanced production of capuramycin and A-500359 A in Streptomyces griseus SANK 60196.

Streptomyces griseus SANK 60196 produces the novel nucleoside antibiotics A-500359 A, C, D and capuramycin. Enhanced production of capuramycin and A-500359 A was achieved through a number of medium modifications and a series of single colony isolations. The addition of maltose instead of glucose as the carbon source in a primary medium resulted in a 20-fold increase in the productivity of capuramycin. Furthermore, the addition of cobalt chloride (CoCl2) and yeast extract to the medium containing maltose drastically altered the production ratio of A-500359 A to capuramycin. Thus, the yield of A-500359 A increased up to 600 microg/ml in an optimal medium, while the yield in the primary medium was 1 microg/ml.

Studies on novel bacterial translocase I inhibitors, A-500359s. I. Taxonomy, fermentation, isolation, physico-chemical properties and structure elucidation of A-500359 A, C, D and G.

In the course of our screening for bacterial phospho-N-acetylmuramyl-pentapeptide-translocase (translocase I: EC 2.7.8.13) inhibitors, we found inhibitory activity in the cultured broth of the strain identified as Streptomyces griseus SANK 60196. The strain produced capuramycin and four novel capuramycin derivatives designated as A-500359 A, C, D and G. Purification and structural analysis were performed, and the structures of A-500359 A, C, D and G were elucidated as 6'''-methylcapuramycin, 3'-demethyl-6'''-methylcapuramycin, 2''-deoxy-6'''-methylcapuramycin and 3'-demethylcapuramycin, respectively.

Studies on novel bacterial translocase I inhibitors, A-500359s. III. Deaminocaprolactam derivatives of capuramycin: A-500359 E, F, H; M-1 and M-2.

Novel derivatives of capuramycin were obtained when 10 mM of 2-aminoethyl-L-cysteine (AEC), an inhibitor of aspartokinase, was added to the culture of Streptomyces griseus SANK 60196, the producer of A-500359. They were purified from the culture filtrate and their chemical structures were elucidated as a deaminocaprolactam derivative of capuramycin designated as A-500359 F, A-500359 E, a methyl ester of A-500359 F, and A-500359 H, a 3'-demethyl derivative of A-500359 F. Two other compounds, A-500359 M-1 and A-500359 M-2, were purified from the same medium and their structures were elucidated. A-500359 E, F, H, M-1 and M-2 inhibited bacterial translocase I with an IC50 of 0.027 microM, 1.1 microM, 0.008 microM, 0.058 microM and 0.010 microM, respectively. A-500359 E, M-1 and M-2 inhibited the growth of mycobacteria as well.