Coupling ratio control of polymeric waveguide couplers by bending

Directional couplers are successfully fabricated on acrylic substrates using polymers synthesised from deuterated methacrylate and deuterated fluoromethacrylate monomers. The excess loss of a 50 mm long coupler is about 0.7 dB including waveguide and fibre coupling losses. A novel method is proposed for tuning the coupling ratio. By bending the coupler, high precision control of within 1% is attained without optical polarisation dependence.<>     

Acetaminophen-Induced Rat Hepatotoxicity Based on M1/M2-Macrophage Polarization,in Possible Relation to Damage-Associated Molecular Patterns and Autophagy

Overdose of acetaminophen (APAP), an antipyretic drug, is an important cause of liver injury. However, the mechanism in the rat model remains undetermined. We analyzed APAP-induced hepatotoxicity using rats based on M1/M2-macrophage functions in relation to damage-associated molecular patterns (DAMPs) and autophagy. Liver samples from six-week-old rats injected with APAP (1000 mg/kg BW, ip, once) after 15 h fasting were collected at hour 10, and on days 1, 2, 3, and 5. Liver lesions consisting of coagulation necrosis and inflammation were seen in the affected centrilobular area on days 1 and 2, and then, recovered with reparative fibrosis by day 5. Liver exudative enzymes increased transiently on day 1. CD68⁺ M1-macrophages increased significantly on days 1 and 2 with increased mRNAs of M1-related cytokines such as IFN-γ and TNF-α, whereas CD163⁺ M2-macrophages appeared later on days 2 and 3. Macrophages reacting to MHC class II and Iba1 showed M1-type polarization, and CD204⁺ macrophages tended to be polarized toward M2-type. At hour 10, interestingly, HMGB1 (representative DAMPs) and its related signals, TLR-9 and MyD88, as well as LC3B⁺ autophagosomes began to increase. Collectively, the pathogenesis of rat APAP hepatotoxicity, which is the first, detailed report for a rat model, might be influenced by macrophage functions of M1 type for tissue injury/inflammation and M2-type for anti-inflammatory/fibrosis; particularly, M1-type may function in relation to DAMPs and autophagy. Understanding the interplayed mechanisms would provide new insight into hepato-pathogenesis and contribute to the possible development of therapeutic strategies.     

Effects of fermentation conditions and soybean peptide supplementation on hyaluronic acid production by Streptococcus thermophilus strain YIT 2084 in milk

To increase the hyaluronic acid (HA) yield from Streptococcus thermophilus YIT 2084, fermentation conditions (pH, temperature, agitation, aeration) were optimized in milk-based medium, and the effects of supplemental soybean peptides, which have different molecular weight distributions, were determined. HA production was enhanced to approximately 100 mg/l at pH 6.8 and 33–40 °C. Agitation speed and aeration rate slightly affected HA production. Soybean peptides including those of high molecular weight (approximately 27 to 130 kDa) further increased HA production to 208 mg/l under the optimal condition (pH 6.8, 35 °C, 100 rpm), which was 20-fold greater than non-optimal condition. HA production was no longer related to the specific growth rate. The HA produced under the optimal condition included a large amount of high-molecular-weight fraction of 100 to 2000 kDa, compared with under the basal condition without optimization.     

Prophylactic effect of papaverine prolonged-release pellets on cerebral vasospasm in dogs

OBJECTIVE: A drug delivery system using copoly(lactic/glycolic acid) was developed for the intracranial administration of papaverine. A rod-shaped implant prepared by a heat compression method was tested to determine its efficacy in preventing cerebral vasospasm in dogs. METHODS: Sixteen dogs were randomly assigned to one of two groups, i.e., placebo or papaverine. Control angiography was performed, followed by right craniectomy and the induction of subarachnoid hemorrhage by the placement of a clot in the Sylvian fissure. Two pellets, containing either 25 mg of papaverine or no papaverine, were placed in the cistern. In in vitro studies, 56% of the actual papaverine loading was released in the first 4 days and 78% within 8 days. On Day 7, angiography was repeated and the animals were killed. A similar experiment using low-dose pellets containing 5 mg of papaverine, half of which was released within 7 days, was performed with 16 mongrel dogs. RESULTS: There were significant differences between the papaverine- and placebo-treated groups in the reductions of vessel diameters of the internal carotid, middle cerebral, and anterior cerebral arteries on the clot side. The mean concentration of papaverine in the clot was 4.5 x 10(-4) mol/L. The low-dose pellet failed to prevent cerebral vasospasm, although the mean concentration of papaverine in the clot was 2.3 x 10(-5) mol/L. CONCLUSION: A prolonged-release preparation of papaverine that could be implanted intracranially at the time of surgery prevented vasospasm significantly while maintaining an appropriate concentration of papaverine in the cistern.     

Optimal boiler control through real-time monitoring of unburned carbon in fly ash by laser-induced breakdown spectroscopy

A laser-induced breakdown spectroscopy (LIBS) technique has been applied for detection of unburned carbon in fly ash, and an automated LIBS unit has been developed and applied in a 1000-MW pulverized-coal-fired power plant for real-time measurement, specifically of unburned carbon in fly ash. Good agreement was found between measurement results from the LIBS method and those from the conventional method (Japanese Industrial Standard 8815), with a standard deviation of 0.27%. This result confirms that the measurement of unburned carbon in fly ash by use of LIBS is sufficiently accurate for boiler control. Measurements taken by this apparatus were also integrated into a boiler-control system with the objective of achieving optimal and stable combustion. By control of the rotating speed of a mill rotary separator relative to measured unburned-carbon content, it has been demonstrated that boiler control is possible in an optimized manner by use of the value of the unburned-carbon content of fly ash.     

Superconducting Gap Structure of YNi2B2C Determined by Thermal Conductivity

In order to determine the superconducting gap structure of the borocarbide superconductor YNi₂B₂C, we have measured the angular variation of the c-axis thermal conductivity _zz in magnetic field rotated within the ab-planes. A clear fourfold symmetry with narrow cusps was observed in the angular variation of _zz . These results provide a strong evidence that the gap function has point nodes which are located along the a- and b-axes of the crystal.     

Alkylation of pyrazoles with alcohols over zeolites

HY zeolite is a highly active catalyst for the vapor-phase N-alkylation of pyrazoles with alcohols. For example, the reactions of pyrazole and 4-methylpyrazole with methanol over HY afford N-methylpyrazole and 1,4-dimethylpyrazole, respectively, in a 100% yield at 573 K. This revised version was published online in July 2006 with corrections to the Cover Date.     

Aerobic Oxidative Coupling of o‐Xylene: Discovery of 2‐Fluoropyridine as a Ligand to Support Selective Pd‐Catalyzed C?H Functionalization

An improved method for the direct oxidative coupling of o‐xylene could provide streamlined access to an important monomer used in polyimide resins. The use of 2‐fluoropyridine as a ligand has been found to enable unprecedented levels of chemo‐ and regioselectivity in this palladium‐catalyzed aerobic oxidative coupling reaction. Preliminary insights have been obtained into the origin of the effectiveness of 2‐fluoropyridine as a ligand.