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The article reports on the Ibaraki biological crystal diffractometer (IBIX) for protein crystallography, a next-generation neutron source that is installed at the Japan Proton Accelerator Research Complex in December 2008. The IBIX performed according to expectation when it is used to analyze a sampling of organic crystals at an accelerator power of 120 kilowatts. The facility plans to operate the IBIX at one megawatt to improve its efficiency.

We investigated the relationship between mammary gland volume (MGV) of the breast as measured with three-dimensional chest computed tomography (CT) and breast cancer risk. Univariate analysis was used to assess the relationship between MGV and known risk factors in 427 healthy women. A case control study (97 cases and 194 controls) was conducted to assess breast cancer risk. MGV was significantly smaller for postmenopausal women than for premenopausal women, and was significantly larger for women with a family history of breast cancer than for women without. MGV, body mass index (BMI), and rate of family history of breast cancer were significantly higher among breast cancer patients than among healthy women, and number of deliveries was significantly lower among breast cancer patients. In postmenopausal women, age at menarche was significantly younger for breast cancer patients. MGV correlated well with breast cancer risk factors. The highest odds ratio was 4.9 for premenopausal women with the largest MGV. Regardless of menopausal status, the greater the MGV, the higher the odds ratio. Our results constitute the first reliable data on the relationship between MGV and breast cancer obtained through exact volume analysis. [ABSTRACT FROM AUTHOR]

Abstract: A new photon-counting 2D detector and time-of-flight (TOF) data-acquisition (DAQ) electronics were developed as a system for iBIX diffractometer in J-PARC. The detector system is composed of two ceramic ZnS/10B2O3 scintillator sheets, 256×2 wavelength-shifting (WLS) fibers, eight 64 ch multi-anode photomultipliers (PMT), a high-speed 512-channel amplifier and discriminator, and a 512-channel encoder module with FPGA for time and position determination. The scintillator sheets have high detection efficiency, 30% and 45% at 1.8Å for 0.2 and 0.3mm in thickness, respectively. The WLS fibers (0.5-mm square type) are arranged along X and Y directions with gaps of 0.02mm; therefore the size of one pixel is 0.52mm. The PMT have 17% of quantum efficiency for the light from WLS fibers. The detective region (133×133mm2) has more than 66% in the front face of the detector. The amplifier and discriminator module has 300MHz of frequency band, fixed gain (60), and 20–300mV of discriminator level. The encoder module has many coincidence modes including various pattern-matching methods and a centroid-computation method. The pulse-pair resolution is 4–5μs. For the DAQ module, we can use both of histogram and event modes for measurement. The recording rate is 5×105 events/s for the event mode. Maximum number of the time-channel bins is 4096 for the histogram mode. [Copyright &y& Elsevier]

Abstract: We have developed new data processing software for a new time-of-flight (TOF) single crystal neutron diffractometer at the Materials and Life-science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC); IBARAKI Biomolecular Crystal Diffractometer (iBIX). This software, named “STARGazer”, makes a HKLF list from three-dimensional (x, y, TOF) raw data of the iBIX. The STARGazer has both a data processing part and a data visualization part. The former part is a main part to make a HKLF list. This part has fundamental data processing functions and additional functions, real-space indexing, refinement of detector positions simultaneously with an UB matrix, and finding overlapping Bragg reflections, to process diffraction data of bio-macromolecular crystal which has large unit cell volumes. The latter part displays the three-dimensional raw data with predicted positions of Bragg reflections to confirm how well an obtained UB matrix fits to the raw data. In the near future, a function to process overlapping Bragg reflections based on a profile fitting technique will be added to the STARGazer. [Copyright &y& Elsevier]

Abstract: Since 2004, Ibaraki Prefectural Government in Japan has started to construct a Time-of-Flight (TOF) neutron diffractometer for biological macromolecules for industrial use at J-PARC, near JRR-3 in JAEA. From 2008, Ibaraki University will operate this machine with the support of Ibaraki Prefecture in order for users to do experiments. The diffractometer is designed so that it can measure crystals the maximum cell dimension of which is up to around 160Å. It is expected to measure more than 100 samples per year if they have 2mm3 in crystal volume. As a result, the efficiency will be more than 100 times higher than that of the present high performance diffractometer, BIX-4 in JRR-3 reactor in JAEA. To realize this performance, a coupled moderator (intense neutrons, but broad pulse in time resolution) was selected. In addition, two important and key items should be developed: a new detector with high spatial resolution (less than 1mm) and a special program to de-convolute overlapped Bragg reflections on the raw data. The detector uses ZnS:Ag/6LiF scintillator with wavelength-shift-fiber (WLSF) system. The program has been designed using a complicated kind of profile-fitting method. The current status of these developments as well as the diffractometer constructions is reported. [Copyright &y& Elsevier]

Ibaraki Prefectural Government together with Ibaraki University and Japan Atomic Energy Agency (JAEA) has almost finished constructing a time-of-flight (TOF) neutron diffractometer for biological macromolecules for industrial use at J-PARC, IBARAKI Biological Crystal Diffractometer (iBIX). Since 2009, Ibaraki University has been asked to operate this machine in order for users to do experiments by Ibaraki Prefecture. The diffractometer is designed to cover sample crystals which have their cell edges up to around 150 A. It is expected to measure more than 100 samples per year if they have 2 mm(3) in crystal volume, and to measure even around 0.1 mm(3) in crystal volume of biological samples. The efficiency of iBIX is also expected about 100 times larger than those of the present high performance diffractometers at JRR-3 in JAEA when 1MW power realizes in J-PARC. Since December 2008, iBIX has been open to users and several proteins and organic compounds were tested under 20 kW proton power of J-PARC. It was found that one of their proteins was diffracted up to 1.4 A in d-spacing, which was nearly comparable resolution to that of BIX-3 in JRR-3 when used the same crystal as at iBIX for reasonable exposure time. In May 2009, 14 detector units were set up. By the end of fiscal year 2009, the basic part of data reduction software will be finished and an equipment blowing low temperature gas to the sample will be installed with the cooperation of JAEA.

Objective: The purpose of this study is to clarify whether type 2 diabetes (DM) is a risk factor for asymptomatic (silent) ischemic brain lesion, which is controversial at present., Subjects and Methods: The subjects (n=187), who showed normal results on both neurological and neuropsychological examinations, underwent a 75-g OGTT and were examined by brain MRI on T1-weighted, T2-weighted, and FLAIR (fluid-attenuated inversion recovery) images. Their brain MRIs were evaluated quantitatively with the ischemia rating scale defined here. The subjects were grouped based on their glucose tolerance: normal glucose tolerance (NGT) (n=48), impaired glucose tolerance (IGT) (n=62), and DM (n=65). The subjects with DM were further divided based on their duration of illness: 20 with short duration (short DM: 1.3+0.8 years) and 45 with long duration (long DM; 8.9+/-5.4 years). Ages were matched among the groups., Results: The percentages of individuals with asymptomatic ischemic brain lesion were 81% in NGT, 74% in IGT, 65% in short DM, and 78% in long DM. No significant difference was observed among the groups in terms of the percentage. Namely, even in individuals with a long history of DM without clinical stroke, the prevalence of asymptomatic ischemic brain lesion was not different from that of the other groups. Multiple regression and multiple logistic regression analyses showed that age and hypertension were significant independent risk factors for asymptomatic ischemic brain lesion, whereas hypercholesterolemia, smoking, and glucose intolerance, including IGT, short DM and long DM, were not., Conclusion: DM is not a risk factor for asymptomatic ischemic brain lesion.