Bleeding infectious enteritis

A recent trend on bleeding intestinal infections in Japan was described. Salmonella Enteritidis infection occupied over 42% of food-borne diseases in 1996. Salmonella Enteritidis is the most popular infectious agent for food-borne outbreak in Japan. Salmonella Typhimurium DT104 which is widely spread in Europe and in U.S.A. is not common in Japan. We experienced large outbreak of foodbore EHEC/VTEC O157: H7 infections in 1996. Since then, diagnostic and therapeutic studies on EHEC/VTEC infection and haemolytic uremic syndrome are promoted by the Government. HACCP may take an important roll for the prevention of large outbreaks of foodbore EHEC/VTEC infections.     

Kinetics of the CaO  quartz  H2O reaction at 120° to 180°C in suspensions

Kinetics of hydrothermal reactions have been studied for mixtures of CaO and quartz (<10 μm 10–20 μm) with Ca/Si = 0.8 and 1.0 in stirred suspensions at 120 – 180°C. Reaction proceeds through the sequence: Ca(OH)₂ + SiO₂ → Ca-rich C-S-H + SiO₂ (at 120°C) → poorly crystalline tobermorite (at 140°C)→ highly crystalline tobermorite (at 180°C) → xonotlite at 180°C and Ca/Si = 1.0 and 180°C and Ca/Si = 0.8 if 10–20 μm quartz is used. Reaction is controlled by dissolution of the quartz. For both Ca/Si ratios the radius of the 10–20 μm quartz decreases at a constant rate, viz 0.85 μm/h at 180°C, 0.13 μm/h at 140°C, 0.04 μm/h at 120°C.     

High adhesion of diamond-like carbon thin film to an aluminum alloy achieved by substrate sputtering and redeposition method

A novel technique to improve the adhesion of a diamond-like carbon (DLC) film to an Al alloy was demonstrated in this study. DLC films were deposited by diode rf bias sputtering. The Al component in the substrate was initially deposited on a graphite target during the sputter-cleaning of the substrate. Then the graphite target and the deposited Al were simultaneously sputtered to form an interface layer between the DLC film and the substrate in the early stage of deposition. We call this method substrate sputtering and redeposition (SSRD), which enhanced the antiwear lifetime of DLC/Al alloy samples. X-ray photoelectron spectroscopy clarified that a thicker mixed layer of Al and C was formed around the interface in the case of a longer substrate sputtering duration in the SSRD method. This interface structure could account for the strong adhesion of the DLC film to the substrate and the reduced delamination of the film obtained using the SSRD method.     

Leukemia developing after 131I treatment for thyroid cancer in a patient with Werner's syndrome: molecular and cytogenetic studies

A 40-year-old female patient with Werner's syndrome (WS) suffering from thyroid cancer and myelodysplastic syndrome (MDS) is reported. She had been diagnosed as having WS complicated with thyroid cancer seven years previously. Total thyroidectomy and radioactive iodine (131I, 100 mCi/year) therapy for seven years had slowed the progression of thyroid cancer. She suffered a sudden onset of MDS at the age of 40 years. After six months she died from overt leukemia. We found an additional chromosome aberration of chromosome 10 in the progression of leukemia from MDS.     

High-Magnetic-Field XMCD as a Novel Tool for the Study of Valence Fluctuation Phenomena—Application to Eu-based Intermetallic Compounds

X-ray magnetic circular dichroism (XMCD) in Eu-based valence fluctuating compounds, EuNi₂(Si_1?x Ge _x )₂ (x=0.82, 0.85) and EuNi₂P₂ are investigated at high magnetic fields up to 40 T. Distinct two XMCD peaks corresponding to different valence states, i.e., Eu²⁺ and Eu³⁺ states are observed in EuNi₂(Si_1?x Ge _x )₂ (x=0.82) and EuNi₂P₂ at the L absorption edges (2p→5d). This suggests that the Eu 5d electrons are magnetically polarized in the both valence states. Since Eu³⁺ state has nonmagnetic ground state J=0, where J is total angular momentum, finite XMCD of Eu³⁺ state can be closely related to the magnetic polarization of the conduction electrons that is induced by the local magnetic moments of Eu²⁺ (J=7/2) state through the strong hybridization.     

Characterization of C-S-H from Highly Reactive β-Dicalcium Silicate Prepared from Hillebrandite

β-dicalcium silicate synthesized by thermal dissociation of hydrothermally prepared hillebrandite (Ca₂(SiO₃)(OH)₂) exhibits extremely high hydration activity. Characterization of the hydrates obtained and investigation of the hydration mechanism was carried out with the aid of trimethylsilylation analysis, ²⁹Si magic angle spinning nuclear magnetic resonance, transmission electron microscopy selected area electron diffraction, and XRD. The silicate anion structure of C-S-H consisted mainly of a dimer and a single-chain polymer. Polymerization advances with increasing curing temperature and curing time. The C-S-H has an oriented fibrous structure and exhibits a 0.73-nm dreierketten in the longitudinal direction. On heating, the C-S-H dissociates to form β-C₂S. The temperature at which βC₂S begins to form decreases with increasing chain length of the C-S-H or as the Ca/Si ratio becomes higher. The high activity of β-C₂S is due to its large specific surface area and the fact that the hydration is chemical-reaction-rate-controlled until its completion. As a result, the hydration progresses in situ and C-S-H with a high Ca/Si ratio is formed.     

Formation Processes of β-C2S by the Decomposition of Hydrothermally Prepared C-S-H with Ca(OH)2

A mixture of CaO and silicic acid prepared with a Ca/Si ratio of 2.0 was hydrothermally synthesized at 80° to 200°C, and the thermal decomposition behavior of the products (C-S-H with Ca(OH)₂) was analyzed using XRD, ²⁹Si MAS NMR, and the trimethylsililation method (TMS). It was found that the main silicate anion structure of C-S-H was a mixture of a dimer and a single-chain polymer (larger than Si₅O₁₆) and that polymerization advanced with an increase of the synthesizing temperature. On heating, the products decomposed to form β-C₂S. It was found that the decomposition was gradual and that the-higher the temperature of hydrothermal synthesis, the lower was the temperature of the decomposition into β-C₂S. Although the decomposition proceeded to form a monomer (β-C₂S) from the polymer and dimer, this dimer was resistant to heat and did not decompose unless heated to above 400°C.