Search

We developed a CANDLES-III system to study the neutrino-less double beta (0$\nu\beta\beta$) decay of $^{48}$Ca. The proposed system employs 96 CaF$_{2}$ scintillation crystals (305 kg) with natural Ca ($^{\rm nat.}$Ca) isotope which corresponds 350\,g of $^{48}$Ca. External backgrounds were rejected using a 4$\pi$ active shield of a liquid scintillator surrounding the CaF$_2$ crystals. The internal backgrounds caused by the radioactive impurities within the CaF$_2$ crystals can be reduced effectively through analysis of the signal pulse shape. We analyzed the data obtained in the Kamioka underground for a live-time of 130.4\,days to evaluate the feasibility of the low background measurement with the CANDLES-III detector. Using Monte Carlo simulations, we estimated the background rate from the radioactive impurities in the CaF$_{2}$ crystals and the rate of high energy $\gamma$-rays caused by the (n, $\gamma$) reactions induced by environmental neutrons. The expected background rate was in a good agreement with the measured rate, i.e., approximately 10$^{-3}$ events/keV/yr/(kg of $^{\rm nat.}$Ca), in the 0$\nu\beta\beta$ window. In conclusion, the background candidates were estimated properly by comparing the measured energy spectrum with the background simulations. With this measurement method, we performed the first search for 0$\nu\beta\beta$ decay in a low background condition using a detector with a Ca isotope, in which the Ca present was not enriched, in a scale of hundreds of kg. The $^{48}$Ca isotope has a high potential for use in 0$\nu\beta\beta$ decay search, and is expected to be useful for the development of a next-generation detector for highly sensitive measurements.

In the CANDLES experiment aiming to search for the very rare neutrino-less double beta decays (0νββ) using 48Ca, we introduced a new shielding system for high energy γ-rays from neutron captures in massive materials near the detector, in addition to the background reduction for 232Th decays in the 0νββ target of CaF2 crystals. The method of background reduction and the performance of newly installed shielding system are described.

CAlcium fluoride for the study of Neutrinos and Dark matters by Low-energy Spectrometer (CANDLES) searches for neutrino-less double beta decay of $^{48}$Ca using a CaF$_2$ scintillator array. A high Q-value of $^{48}$Ca at 4,272 keV enabled us to achieve very low background condition, however, at the same it causes difficulties in calibrating the detector's Q-value region because of the absence of a standard high-energy $\gamma$-ray source. Therefore, we have developed a novel calibration system based on $\gamma$-ray emission by neutron capture on $^{28}$Si, $^{56}$Fe and $^{58}$Ni nuclei. In the paper, we report the development of the new calibration system as well as the results of energy calibration in CANDLES up to 9 MeV., Comment: 6 pages, 7 figures

High energy γ rays with several MeV produced by (n,γ) reactions can be a trouble for low background measurements in the underground laboratories such as double beta decay experiments. In the CANDLES project, which aimed to observe the neutrino-less double beta decay from 48Ca, γ rays caused by (n,γ) reactions were found to be the most significant background. The profile of the background was studied by measurements with a neutron source and a simulation with a validity check of neutron processes in Geant4. The observed spectrum of γ rays from (n,γ) reactions was well reproduced by the simulated spectra, which were originated from the surrounding rock and a detector tank made of stainless steel. The environmental neutron flux was derived by the observed event rate of γ rays from (n,γ) reactions using the simulation. The thermal and non-thermal neutron flux were found to be ( 1.3 ± 0.6 ) × 10 − 6 cm − 2 s − 1 and ( 1.1 ± 0.5 ) × 10 − 5 cm − 2 s − 1 , respectively. It is necessary to install an additional shield to reduce the background from (n,γ) reaction to the required level.

Single crystal growth of undope CaCl 2 , CaBr 2 and CaI 2 was performed by Bridgman–Stockbarger (BS) method. Investigations of their crystal phases, luminescence and scintillation properties such light yield, energy resolution decay time were performed. In addition, linearity of gamma-ray response in 32–1275 keV range were also evaluated. The light output of 106,000 photon/MeV, energy resolution of 3.2%@662 keV, and scintillation decay time of 834 ns (84%) 1460 ns (16%) were observed. Luminescence properties of CaBr 2 also firstly reported.

Finite element method based numerical simulation (CAE) came to be utilized in the strength design by the development of the design technology. In particular, it is very important to use CAE when evaluating the safety of products subjected to impact loads. This is because the Product testing with impact load is difficult and expensive to perform. However, there are two major problems with this CAE. The first problem is the high cost of installing and maintaining CAE software. The second problem is that only some of the materials implemented with CAE have material properties that take into account the strain rate dependence needed to assess material fracture. Ductile fracture prediction formulas for evaluating material failure are implemented in many CAE software. However, in order to use the ductile fracture prediction formula, material properties that take strain rate dependence into consideration are required. In this study, we examined a design method based on an energy of fracture of materials and input energy of impact phenomenon by using experiments and numerical simulations without using material properties considering strain rate dependence. In this research, static three-point bending test, Charpy impact test and elasto-plastic analysis were performed to confirm the validity of the proposed design method. Firstly, In the three-point bending test, the amount of energy input to the test pieces was examined. Secondly, in the Charpy impact test, the same energy as the static three-point bending test was input to the test pieces. Thirdly, the elasto-plastic analysis used material properties that did not take into account the strain rate dependence obtained from static tensile tests. Finally, these results were compared. As results of comparison, it is clear to the efficacy of the proposed impact strength design method.

In a neutrinoless double-beta decay ($0\nu\beta\beta$) experiment, energy resolution is important to distinguish between $0\nu\beta\beta$ and background events. CAlcium fluoride for studies of Neutrino and Dark matters by Low Energy Spectrometer (CANDLES) discerns the $0\nu\beta\beta$ of $^{48}$Ca using a CaF$_2$ scintillator as the detector and source. Photomultiplier tubes (PMTs) collect scintillation photons. At the Q-value of $^{48}$Ca, the current energy resolution (2.6%) exceeds the ideal statistical fluctuation of the number of photoelectrons (1.6%). Because of CaF$_2$'s long decay constant of 1000 ns, a signal integration within 4000 ns is used to calculate the energy. The baseline fluctuation ($\sigma_{baseline}$) is accumulated in the signal integration, thus degrading the energy resolution. This paper studies $\sigma_{baseline}$ in the CANDLES detector, which severely degrades the resolution by 1% at the Q-value of $^{48}$Ca. To avoid $\sigma_{\rm baseline}$, photon counting can be used to obtain the number of photoelectrons in each PMT; however, a significant photoelectron signal overlapping probability in each PMT causes missing photoelectrons in counting and reduces the energy resolution. "Partial photon counting" reduces $\sigma_{baseline}$ and minimizes photoelectron loss. We obtain improved energy resolutions of 4.5-4.0% at 1460.8 keV ($\gamma$-ray of $^{40}$K), and 3.3-2.9% at 2614.5 keV ($\gamma$-ray of $^{208}$Tl). The energy resolution at the Q-value is estimated to be improved from 2.6% to 2.2%, and the detector sensitivity for the $0\nu\beta\beta$ half-life of $^{48}$Ca can be improved by 1.09 times., Comment: This manuscript is prepared for submission to IEEE Transaction on Nuclear Science. It contains 11 pages, 19 figures, and 1 table

The neutrino-less double beta decay (0νββ) is a powerful tool to probe the neutrino mass. The 0νββ is forbidden in Standard Model (SM) due to the violation of lepton number conservation. In experiments searching for 0νββ, the two-neutrino double beta decay (2νββ), which is an allowed process in SM, behaves as an irreducible background within the energy of interest. To discriminate the 0νββ from 2νββ, the energy resolution must be improved. The CANDLES experiment is searching for the 0νββ of 48Ca using CaF 2 (pure) scintillator as the detector and the source. Scintillation photons are collected by Photo Multiplier Tubes (PMTs) surrounding the crystals. A Flash Analog-to-Digital Converter records the waveform of each PMT. Because of the long decay time of CaF 2 (1 µsec), we make a signal integral of 4 µsec to calculate the obtained energy. Thus, the other fluctuation in the baseline is accumulated in the signal integration, and it makes the energy resolution worse. To reduce this fluctuation, we can count the number of photoelectrons in every PMT. Still, we have a significant overlapping probability of single photoelectron signals. This overlapping probability implies the photoelectrons lost, which causes terrible energy resolution. To improve the energy resolution, we introduce an alternative method named "partial photon counting" by dividing the waveform into two parts, then, perform signal integral in the prompt part and photon counting the second part. As a result, the energy resolution is reduced 4.0-3.5 % at 1460 keV (γ-ray of 40K) and 3-2.7 % at 2615 keV (γ-ray of 208Tl).

A new data acquisition (DAQ) system for the CANDLES experiment was developed using the SpaceWire protocol and the DAQ-Middleware framework. The CANDLES experiment uses a trigger board and Flash Analog-to-Digital Converters (FADCs). The SpaceWire helps us construct the DAQ system with a flexible and multi-path access to FADCs and the trigger board. FADCs have a ring buffer with three buffers to detect sequential decays from backgrounds. We developed the DAQ system with parallel read-out to reduce the dead time at high trigger rates using three read-out personal computers (PCs) that are connected to the three buffers in FADCs one by one. Each PC connects all FADCs and the trigger board and gathers a complete data set of one event without any event builder. The maximum DAQ speed of parallel read-out by three PCs was 2.4 times higher than that of single read-out. In order to collect event data sets from PCs, we built the network distributed DAQ system through Ethernet, which is naturally introduced with the DAQ-Middleware. To realize remote monitoring and histogram modification while the DAQ running, we also developed a dynamic online monitor system independent with the DAQ-Middleware.

CANDLES studies the double beta decay of 48Ca through CaF2 scintillation crystals. The CANDLES III detector, located in Kamioka underground laboratory, is currently running. Here we describe recent status of data analysis which includes detector performance, detector stability, and background estimation. Current sensitivity for 0 ν β β half-life is also discussed in this paper.

CANDLES aims to measure the very rare neutrino-less double beta decays using 48Ca which has the highest value among all isotope candidates. Low background techniques are the key to observe such rare phenomena. The largest background was found to be the high energy gamma rays from neutron captures on abundant material near the detector. The shielding system consisted of lead and B-contained rubber sheet was constructed to reduce the background. Performance of the constructed shielding system were described in this paper.

CANDLES is the project to search for neutrino-less double beta decay ( 0νββ ) of 48 Ca. The observation of 0νββ will prove existence of a massive Majorana neutrino. For the 0νββ measurement, we need a low background condition because of a low decay rate of 0νββ . Now we installed the CANDLES III system at the Kamioka underground laboratory. The CANDLES III system realizes the low background condition by a characteristic structure and data analyses for background rejection. Here we report performances of the CANDLES III system.

The neutrino-less double beta decay is acquiring great interest after the confirmation of neutrino oscillation which demonstrated nonzero neutrino mass. In order to search for neutrino-less double beta decay of $^{48}$Ca, we proposed the CANDLES project by using CaF$_{2}$(pure) scintillators. Now we installed the CANDLES III system at the Kamioka underground laboratory. The CANDLES III system realizes the low background condition by a characteristic structure and data analyses for background rejection. Furthermore we installed new shielding system in order to reduce $\gamma$-ray backgrounds from neutron capture reaction. Here we report performances of the CANDLES III system.

We have studied the neutrino-less double beta decay(0νββ) of 48Ca by using CaF2(pure) scintillators. Analysis for rejection of backgrounds(212Bi→ 212Po events and 208Tl events) was effective to reduce backgrounds in Qββ-value region. No events are observed in the Qββ-value region for the data of 131 days × 86 kg. It gives a lower limit (90% confidence level) of (math) > 6.2 × 1022 year (preliminary) for the half-life of 0νββ of 48Ca.

In order to shed light on the effect of fluid flow on biofilm formation observed in micro channel devices, a fluid flow in a millimeter-size channel with varying cross-section was numerically simulated. Simulation results show that the rate of film formation in the narrower section is higher, compared with that in the larger section, due to enhanced mass transport by the faster flow in this section. It appears that faster flow gives rise to the transport of more nutrients to the seed leading to more growth. It was also found that the inlet nutrient concentration strongly affects the grown biofilm structure in terms of size and density.

As one of the countries that have invested greatly in the field of bioscience, Japan is facing difficulties introducing human genetic research to the market. A key issue is how to regulate the quality of genetic testing. Since genetic testing is a part of clinical laboratory tests, the regulatory framework for these tests should cover the regulation of genetic testing. Nevertheless, the quality of clinical laboratory tests has been regulated largely by the authority of medical professionals. The fact that genetic testing can be provided without supervision of medical professionals reveals the necessity for the regulation of quality of genetic testing. While medical geneticists have publicly criticized direct-to-consumer (DTC) genetic testing, a group of industries related to DTC genetic testing have established self-regulatory guidelines on the quality control of genetic analysis, based on the OECD guidelines. This article describes the regulatory framework for clinical laboratory tests including genetic tests, and the gaps in regulation, which are particularly highlighted by the appearance of DTC genetic testing. Furthermore the current initiatives taken by different organizations, especially the self-regulatory initiatives by related industries, will be discussed. To conclude the article, recommendations to improve the situation will be made.

Using atom probe field ion microscopy (APFIM), the structure of the apex of single-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube (MWCNT) has been studied. By analyzing the FIM image, it became possible to identify the chirality and conductivity of SWCNT. However, a clear FIM image was not successfully obtained for MWCNT due possibly to the difference in heights of each graphene wall. AP of FIM images showed that ions of carbon clusters, such as C 14 +, C 15 +, C 18 + and C 20 +, were field evaporated from SWCNT and MWCNT. Since all of these carbon clusters may include a pentagonal plane, it is considered that, under high electric field, a hexagonal plane of graphene reconstructed into pentagonal plane and consequently these clusters field evaporated by the local concentration of electric field at the protruded pentagonal plane.

With 1 MeV/u H + , He 2+ and Li 3+ beams incident on a carbon foil of 2.2 μg/cm 2 in thickness, the statistical distributions of the number of simultaneously emitted secondary electrons (SE’s) have been measured as a function of the emergent angle of foil-transmitted ions in the range from 0.0 mrad to 4.0 mrad for every 0.5 mrad step. The measurement of SE’s was carried out in the forward and backward directions of the incident beam independently. The SE yields, that is, the mean number of emitted electrons per incident ion, increase with increasing the emergent angle and saturate at larger angles. This trend is common to the projectiles used and also to the forward and backward directions. As a result of a Monte Carlo simulation taking account of the impact parameter dependent energy loss in a single collision of a proton with a carbon atom, it is found that the calculated energy losses exhibit an emergent angular dependence quite similar to that of the measured SE yields. However the measured SE yields divided by the square of the projectile atomic number, Z P , becomes smaller with increasing Z P , especially for the backward emission. A similar observation has been reported by other authors and this trend seems to originate from the preferencial fast internal SE production by heavier projectiles followed by their escape from a thin target foil.

A low background HPGe detector system was developed at CANDLES Experimental Hall for multipurpose use. Various low background techniques were employed, including hermatic shield design, radon gas suppression, and background reduction analysis. A new pulse shape discrimination (PSD) method was specially created for coaxial Ge detector. Using this PSD method, microphonics noise and background event at low energy region less than 200 keV can be rejected effectively. Monte Carlo simulation by GEANT4 was performed to acquire the detection efficiency and study the interaction of gamma-rays with detector system. For rare decay measurement, the detector was utilized to detect the nature’s most stable isomer tantalum-180m (180Tam) decay. Two phases of tantalum physics run were completed with total livetime of 358.2 days, which Phase II has upgraded shield configuration. The world most stringent half-life limit of 180Tam has been successfully achieved.

CANDLES is a double beta decay experiment using 48Ca in CaF2 crystals. The measurement is being performed with prototype detector (CANDLES III) for high sensitive measurement in the future. Recent status of detector improvements and background reduction techniques are described in this paper.

The CANDLES experiment is a study of the double beta decay of $^{48}{\rm Ca}$ nuclei. The detector consists of two scintillators. One is the ${\rm CaF}_{2}$ crystal that acts as a source of double beta decay and a scintillator. The other is a liquid scintillator, which is used for gamma-veto. The total light collected from the liquid scintillator is on the same order of magnitude as that of the ${\rm CaF}_{2}$ scintillator, but the decay constant of the liquid scintillator is one or more orders of magnitude shorter than that of the ${\rm CaF}_{2}$ scintillator. Therefore, if we trigger the signal by pulse height, the energy threshold of the liquid scintillator light will be one or more orders of magnitude lower than that of the ${\rm CaF}_{2}$ scintillator. A high counting rate in the liquid scintillator causes deadtime; in order to avoid this problem, we have developed a new trigger system. In this paper, we describe the use of this trigger system in the CANDLES experiment and its performance after installation in 2013.

We have experimentally evaluated the background noise in a Cauchois-type high-resolution Compton scattering spectrometer at SPring-8. The signal-to-noise ratio (S/N) in the energy profile of Compton scattered X-rays from 3 mm thick Cu was found to be 78 at the Compton peak for the incident X-ray energy of 115 keV. The experimental S/N is in good agreement with the value of 80 estimated from simple considerations. The achieved S/N in the spectrometer is high enough for most Compton scattering experiments.

A new X-ray spectrometer has been installed in the BL08W beamline at SPring-8 for high-resolution Compton scattering measurements using 90–120 keV X-rays. The spectrometer consists of a Cauchois-type triple-crystal analyzer and a quasi position sensitive detector with four slits. The detector works not only as a position-sensitive detector but also as an energy sensitive detector, which allows for low background noise measurements. An overall resolution of 0.10 atomic units in momentum space has been achieved at the incident X-ray energy of 115 keV. Compton profiles of niobium have been measured along the [1 0 0] and [1 1 0] directions in order to demonstrate the performance of the spectrometer.

We report high-resolution Compton profiles of two single crystals of Be with surface normals oriented along the [0001] and [1120] directions. The results are compared and contrasted with corresponding, highly accurate all-electron computations based on the band theory framework within the local-density approximation (LDA). A reasonable overall level of agreement is seen between theory and experiment with respect to the shapes of the Compton profiles, as well as the Fermi-surface-induced finer structure in the first and second spectral derivatives. However, the measured profiles are lower than theory at low momenta, clearly displaying broadened Fermi surface features compared with the theoretical predictions, and point to the importance of electron correlation effects beyond the LDA for a proper description of the momentum density. The aforementioned similarities and differences between theory and experiment in Be are rather like the situation that has been observed in recent high-resolution Compton studies of other materials.

The observation of neutrino-less double beta decay (0νββ) would be the most practical way to prove the Majorana nature of the neutrino and lepton number violation. CANDLES studies 48Ca double beta decay using CaF2 scintillator. The main advantage of 48Ca is that it has the highest Q-value (4.27 MeV) among all the isotope candidates for 0νββ. The CANDLES III detector is currently operating with 300kg CaF2 crystals in the Kamioka underground observatory, Japan. In 2014, a detector cooling system and a magnetic cancellation coil was installed with the aim to increase light emission of CaF2 scintillator and photo-electron collection efficiency of the photo-multipliers. After this upgrade, light yield was increased to 1000 p.e./MeV which is 1.6 times larger than before. According to data analysis and simulation, main background source in CANDLES is turned out to be high energy external gamma-ray originating neutron capture on the surrounding materials, so called (n,γ). Upgrading the detector by installing neutron and gamma-ray shield can reduce the remaining main backgrounds by two order magnitude. In this report, we discuss the detail of (n,γ) and background reduction by additional shielding.

This study not only examined the spatiotemporal variations of permafrost active layer thickness (ALT) during 1948–2006 over the terrestrial Arctic regions experiencing climate changes, but also identified the associated drivers based on observational data and a simulation conducted by a land surface model (CHANGE). The focus on the ALT extends previous studies that have emphasized ground temperatures in permafrost regions. The Ob, Yenisey, Lena, Yukon, and Mackenzie watersheds are foci of the study. Time series of ALT in Eurasian watersheds showed generally increasing trends, while ALT in North American watersheds showed decreases. An opposition of ALT variations implicated with climate and hydrological variables was most significant when the Arctic air temperature entered into a warming phase. The warming temperatures were not simply expressed to increases in ALT. Since 1990 when the warming increased, the forcing of the ALT by the higher Annual Thawing Index in the Mackenzie and Yukon Basins was offset by the combined effects of less insulation caused by thinner snow depth and drier soil during summer. In contrast, the increasing Annual Thawing Index together with thicker snow depth and higher summer soil moisture in the Lena contributed to the increase in ALT. The results imply that the soil thermal and moisture regimes formed in the pre-thaw season(s) provide memory that manifests itself during the summer. While it is widely believed that ALT will increase with global warming, this hypothesis may need modification because the ALT also shows responses to variations in snow depth and soil moisture that can over-ride the effect of air temperature. The dependence of the hydrological variables driven by the atmosphere further increases the uncertainty in future changes of the permafrost active layer.

A total and a magnetic Compton profile of an Fe-5.8 at.% Si single crystal are measured with a momentum resolution of 0.12 atomic units, a much higher resolution than that of any previous works. From these the majority- and minority-spin electron momentum distributions are deduced. The results are compared with those obtained by FLAPW calculations for pure Fe.

Time-differential perturbed-angular-correlation spectra of the amorphous Cu-Hf alloys prepared by mechanical alloying and melt spinning were measured. The short-range structures in mechanically alloyed and melt-spun amorphous Cu-Hf alloys are compared from a microscopic point of view. It is seen that in the melt-spun amorphous alloy, Hf can occupy a disordered-Hf site or a site as in intermetallic-like Cu 3 Hf 2

Tsunami is generated by a sudden deformation of the seafloor, such as uplift and subsidence, caused by fault motion of an earthquake below the seafloor. Numerical simulation of tsunami propagation is frequently used to predict the arrival time and the order of magnitude of the inundation for disaster mitigation purposes. In the propagation process, reflected waves are generated by the change in water depths and influence the tsunami height estimation, in particular in the later phases. In this study, we try to simulate tsunami propagation to accommodate the 2-D varying seafloor topography. In our simulation code, we assume water as a non-viscous fluid. A finite difference method (FDM) is employed using three equations; the equations of continuity, motion, and barotropy. In this study, we simulate the tsunami generation by a sudden change in the water depth and the propagation, using the Pearson approximation to accommodate the spatially varying water depth. We impose the seafloor topography on the basis of the 500m-mesh bathymetry data that JODC (Japan Oceanographic Data Center) provides. We assume a domain included in the data region and simulate tsunami. By using this method, we are able to calculate not only the propagation velocity due to the change in the water depth, but also reflected waves at the same time.

On confirme que cet alliage amorphe possede un ordre a courte distance de type quasicristallin. Cet ordre contient des defauts relativement nombreux tels que des lacunes, desinclinaisons et ordre a courte distance de type cristallin. Cette structure est coherente avec le modele Kleman-Sadoc-Nelson

A 78-year-old man was referred to our hospital with syncope and palpitation. A Holter electrocardiography (ECG) revealed sick sinus syndrome (SSS), and an enhanced chest computed tomography (CT) scan showed persistent left superior vena cava (PLSVC) and absent right superior vena cava. Myocardial leads and a pacemaker implantation were peformed through left anterior thoracotomy approach. There were only 10 reports of pacemaker implantation in a patient with SSS complicated with PLSVC and absent right superior vena cava in Japan. Open thoracotomy approach was thought to be usuful for these patients.

The statistical distributions of the number of secondary electrons (SEs) emitted per projectile from a thin carbon foil under irradiation with the frozen-charged ${\mathrm{H}}^{0}$ and ${\mathrm{H}}^{+}$ projectiles of $2.5--3.5\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ have been measured as a function of the emergent angle of projectiles in the range from $0.0\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}2.0\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}$ in every $0.5\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}$ step. The measurement of SEs was carried out in the forward and the backward directions of the incident beam independently. From $0.0\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}$ to $\ensuremath{\sim}1.0\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}$, the SE yields, that is, the mean number of emitted electrons per incident ion, increase with increasing emergent angle and tend to be saturated at larger angles. This is a common trend, regardless of incident energies and charge states of a projectile and also of emitted directions of SEs. Quantitatively, the saturated SE yields at larger angles for the ${\mathrm{H}}^{+}$ penetration are about 40--50 % larger than those at $0.0\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}$. On the other hand, the corresponding relative increase for the ${\mathrm{H}}^{0}$ penetration reaches as high as $\ensuremath{\sim}100%$ or more. The observed proton-hydrogen difference is well reproduced in the calculated energy losses by a Monte Carlo simulation including the impact parameter dependent stopping cross sections in a single collision of a hydrogen or a proton with a carbon atom.

An X-ray spectrometer for high-resolution Compton profile measurements using 90–120 keV X-rays has been designed and constructed at SPring-8. A Cauchois-type triply layered bent-crystal analyzer was employed for the energy analysis. A novel use of a solid-state detector with a large active area was devised as a position-sensitive detector. A resolution of 0.10 atomic units in electron momentum has been achieved at an incident X-ray energy of 115 keV. A Compton profile of a single crystal of Nb was measured with a counting rate of 30 counts s−1 at the Compton peak, which demonstrates that the spectrometer is capable of measuring Compton profiles of heavy-element materials.

Lysinuric protein intolerance (LPI) is a rare inherited disease caused by defective transport of the dibasic amino acids at the basolateral membranes of epithelial cells in the renal tubules and small intestine. The metabolic defect leads to brain dysfunction caused by hyperammonemia with a functional impairment of the urea cycle. Recently, mutations in the human SLC7A7 cDNA coding for y(+)LAT-1, which express dibasic amino acid transport activity, were reported to be responsible for LPI. In the present study, we examined the genomic structure of SLC7A7 by DNA sequencing of PCR products, and determined that the gene had 11 exons and 10 introns spanning about 18 kb of genomic DNA. We also identified an alternative RNA splicing at the 5' untranslated region of the SLC7A7 mRNA in human peripheral blood leukocytes, cultured lymphoblasts, and fibroblasts. As a result of mutational analysis of SLC7A7 in three Japanese LPI families, we found a nonsense mutation (R410X), a splicing mutation(911+1GA) in intron 4, and four silent polymorphisms (201C/T, 445A/G, 784C/T, 946T/C). Identification of the genomic structure of SLC7A7 may provide a molecular basis for a genetic survey for LPI.

We report high-resolution Compton profiles (CP's) of Al along the three principal symmetry directions at a photon energy of 59.38 keV, together with corresponding highly accurate theoretical profiles obtained within the local-density approximation (LDA) based band-theory framework. A good accord between theory and experiment is found with respect to the overall shapes of the CP's, their first and second derivatives, as well as the anisotropies in the CP's defined as differences between pairs of various CP's. There are however discrepancies in that, in comparison to the LDA predictions, the measured profiles are lower at low momenta, show a Fermi cutoff which is broader, and display a tail which is higher at momenta above the Fermi momentum. A number of simple model calculations are carried out in order to gain insight into the nature of the underlying 3D momentum density in Al, and the role of the Fermi surface in inducing fine structure in the CP's. The present results when compared with those on Li show clearly that the size of discrepancies between theoretical and experimental CP's is markedly smaller in Al than in Li. This indicates that, with increasing electron density, the conventional picture of the electron gas becomes more representative of the momentum density and that shortcomings of the LDA framework in describing the electron correlation effects become less important., Comment: 7 pages, 6 figures, regular article

Recently, the research on hybrid artificial organs such as heart, liver, and kidney has been reported to yield new possibilities for clinical use. However, there have been few reports on the practical use of a hybrid artificial lung, primarily due to difficulties in the concept for its application and techniques for cell attachment. In this study, we investigated the possibility for developing a novel strategy: a hybrid artificial lung with constitutive nitric oxide synthase (NOS) and interleukin (IL)-10 gene-transfected endothelial cells to attenuate inflammatory reactions induced by cardiopulmonary bypass.First, we performed an in vitro study to confirm the efficacy of our gene transfection into endothelial cells. Constitutive nitric oxide synthase and IL-10 cDNA were transfected into endothelial cells according to the hemagglutinating virus of Japan-liposome method. Levels of nitric oxide released from the endothelial constitutive NOS (ecNOS)-transfected endothelial cells were significantly higher than those of control cells (24 hours after the stimulation by lipopolysaccharide: 284.5 +/- 54.0 versus 95.7 +/- 27.9 mumol/L, P = 0.0001). On the other hand, IL-8 levels in the transfected endothelial cells were significantly lower than those in the control group (48 hours after stimulation by tumor necrosis factor-alpha: 3.1 +/- 2.4 versus 62.1 +/- 1.3 ng/mL, P = 0.0002), and IL-10 was detected in the transfected group but not in the control group. Next, we performed an in vivo study to evaluate the possibility of developing a hybrid artificial lung. One-hour partial cardiopulmonary bypass with this lung was established in rats undergoing femorofemoral bypass. Artificial lungs with no cells (group C; n = 5), that were coated with untreated endothelial cells (group E; n = 5), or that were coated with ecNOS and IL-10 gene-transfected endothelial cells (group T; n = 3) were used. At 45 minutes after the initiation of cardiopulmonary bypass, group T showed higher nitric oxide levels than groups C and E (T versus C versus E: 75.2 +/- 6.8 versus 67.2 +/- 4.3 versus 68.6 +/- 5.2 mumol/L, P = NS). The serum IL-8 levels just after cardiopulmonary bypass in group T were significantly lower than those in group C (1728 +/- 282 versus 4275 +/- 145 pg/mL, P = 0.0151). The Pao2 levels in group T just after weaning from cardiopulmonary bypass were significantly higher than those in group C (271.3 +/- 41.7 versus 136.6 +/- 12.3 mm Hg, P = 0.0362).These results demonstrate that a hybrid artificial lung with IL-10 and ecNOS gene-transfected endothelial cells inhibited IL-8 release and increased nitric oxide production. This suggests the possibility of developing a hybrid artificial lung capable of preserving native lung function by attenuating cardiopulmonary bypass-induced inflammatory reactions via inhibition of IL-8 release and enhanced nitric oxide production.

The key to the successful implantation of a left ventricular assist system (LVAS) for patients with end stage cardiac disease is whether the functions of other vital organs are irreversibly damaged or not. The portable cardiopulmonary support system (PCPS) is not only as convenient as, but is more powerful than, the intra-aortic balloon pump (IABP) in resuscitating impaired end organ function. To investigate the efficacy of PCPS in end stage cardiac disease, end organ function before and after the application of PCPS was retrospectively analyzed for end stage cardiac disease. From 1992 to 1996, five cardiomyopathy patients with deterioration in end organ function, despite application of IABP, underwent PCPS support before implantation of LVAS. Urine volume and levels of liver enzymes (sAST and sALT) and serum creatinine were determined before and after institution of PCPS. After the start of PCPS, the urine output increased significantly (1,840 +/- 450-4,340 +/- 470 ml/day, p0.01), and levels of sAST, sALT, and serum creatinine decreased significantly (630 +/- 220-150 +/- 50 IU/L, 630 +/- 260-260 +/- 130 IU/L, and 2.9 +/- 0.5-1.2 +/- 0.1 mg/dl, respectively; p0.05). All five patients were successfully bridged to LVAS implantation, and none died of multiple organ failure caused by pre-existing cardiac failure. These results indicate that PCPS before LVAS implantation is useful in resuscitating impaired end organ function and improving the survival rate with LVAS implantation for end stage cardiac disease.

Although nitric oxide (NO) is an important biological mediator, its excessive production in inflammation is thought to be a causative factor for cellular injury and, over the long term, cancer. In the present study, the effects of several fatty acids on NO production in murine macrophage cell line RAW264 cells stimulated with lipopolysaccharide were examined. Suppression of NO production was observed with the omega 3 polyunsaturated fatty acids (PUFAs), docosahexaenoic acid, eicosapentaenoic acid and alpha-linolenic acid, in a dose-dependent fashion. In contrast, no inhibition was observed with omega 6 PUFA (linoleic acid), omega 9 PUFA (oleic acid) or a saturated fatty acid (stearic acid). Western and northern blot analyses suggested that suppression of the induction of inducible NO synthase gene expression is responsible for the inhibition of NO production by omega 3 PUFAs. The inhibitory effect of omega 3 PUFA on NO production in activated macrophages could contribute to their cancer chemopreventive influence.

Human heart fatty acid-binding protein (HH-FABP), which is a low molecular weight protein and abundant in the cytoplasm of myocardial cells, is reported to be released into the circulation shortly after the onset of acute myocardial damage. However, the changes in serum HH-FABP levels in open heart surgery have not been elucidated. To determine whether HH-FABP enables the earlier detection of myocardial damage caused by ischemia-reperfusion in open heart surgery, we measured the serial levels of serum HH-FABP, CK-MB and Troponin T (TnT) at every 15 min for 48 hours after reperfusion in 10 adult patients with coronary artery bypass graft. The serum HH-FABP levels reached the peak within 60 min after reperfusion (mean +/- SD; 49 +/- 7 min), and this was significantly (p0.001) earlier than CK-MB (212 +/- 108 min) and TnT (244 +/- 150 min). The peak value of serum HH-FABP had a significant correlation to the peak value of serum CK-MB or TnT (r = 0.815, p = 0.02; r = 0.925, p = 0.0001, respectively). These results indicate that serum HH-FABP enables the earlier detection of myocardial damage than the other markers in the patients with open heart surgery.

A 22-year-old female who had been suffering from Graves' disease developed p-ANCA positive necrotizing vasculitis. Her Graves' disease has been treated with propylthiouracil (PTI) for 6 years, which failed to improve serum TSH. She developed transient and recurrent polyarthralgia 4 years before. Because of microscopic hematuria and polyarthralgia, She visited our hospital last year. She had hypergammaglobulinemia and microhematuria at that time. But no autoantibody was noted except anti-microsomal antibody at that time. Skin biopsy from her finger subdermal nodule revealed necrotizing vasculitis of small vessels. Serum p-ANCA was positive. She was admitted under the diagnosis of p-ANCA positive necrotizing vasculitis. Renal biopsy revealed mesangium proliferative glomerulonephritis. Since she developed telescoped sediments after admission, predonisolone (PSL) 50 mg daily was started. Clinical and laboratory findings improved quite well. PSL was gradually tapered after 6 weeks. She is being maintained in good condition on tapering doses of both PSL and PTI. The coincidence of Graves' disease and vasculitis is rare. This case may provide some important immunological insights into the study of pathogenesis of necrotizing vasculitis and Graves' disease.

Concomitant planned therapy consisting of a coronary artery bypass operation and percutaneous transluminal coronary angioplasty (PTCA) was attempted to shorten the period of cardiac arrest and make operations safer in patients undergoing emergency coronary artery bypass operations or coronary artery bypass operations in cases of significantly reduced left ventricle function or small perfusion lesions. The bypass operation was performed to treat only the main lesion and PTCA was undertaken 1-2 months later for coronary revascularization to treat secondary lesions. Finally, complete coronary revascularization was achieved. This concomitant method was performed on three cases. In all of these cases, two grafts were made and 1-2 lesions were dilated by PTCA. It was suggested that planned concomitant coronary artery bypass operations and PTCA provide a safer method of treatment in certain selected cases.