Effect of pressure on the solubilities ofo-,m- andp-xylene in water

The solubilities of o-, m- and p-xylene in water were measured at 25.0°C up to 250, 385, and 50 MPa, respectively. The solubility increased with increasing pressure up to 120 MPa (50 MPa for p-xylene) and then decreased. The reaction volumes, V^o accompanying the dissolution at 0.1 MPa were estimated as –3.6±0.5, –3.4±0.5, and –4.1±0.5 cm³-mol^–1 for o-, m-, and p-xylene, respectively, from the pressure dependences of the solubilities. The limiting partial molar volumes, of p- and o-xylene in water under high pressure were estimated from V^o and the molar volume of the xylene. The partial molar volumes decreased with increasing pressure. The reaction volume for the formation of intra-molecular pairwise hydrophobic interaction between the methyl groups, as proposed by Ben-Naim, is discussed for the V^o of p- and o-xylene at 0.1 MPa.     

Inhibitory effects of non-steroidal anti-inflammatory drugs on superoxide generation.

Effects of non-steroidal anti-inflammatory drugs (NSAID: amfenac sodium, diclofenac sodium, indomethacin and ketoprofen) on the generation of superoxide anion (O2-) by isolated rat polymorphonuclear leukocytes (PMN) were studied spectrophotometrically using cytochrome c. The effects of these drugs were also studied on O2- production by the xanthine-xanthine oxidase and reduced nicotinamide adenine dinucleotide phosphate (NADPH)-NADPH oxidase systems. Amfenac sodium, at 0.1 mM, inhibited significantly O2- generation in rat PMN induced by opsonized zymosan. At 0.5 mM, diclofenac sodium and indomethacin inhibited the O2- generation in rat PMN. All of the above drugs slightly inhibited O2- production by the xanthine-xanthine oxidase system. On the other hand, O2- production by the NADPH-NADPH oxidase system was significantly inhibited by the addition of amfenac sodium, ketoprofen or indomethacin. These results suggest that non-steroidal anti-inflammatory drugs do not work as an O2- scavenger and block O2- production by the NADPH-NADPH oxidase system of rat PMN. It is concluded that amfenac sodium and the other drugs are able to inhibit granulocyte O2- production by blocking the activation of NADPH-oxidase.     

A facile synthesis of (−)-prostaglandin E1 via a three-component coupling process

A very short synthesis of chiral prostaglandin E₁ methyl ester is described.     

Tumor cell detection method using complement-mediated cytolytic reaction and imaging sensor system

A novel tumor-detection system consisting of complementmediated cytolytic reaction and an image processing system was developed for the simple and rapid determination of tumor cells. The present system consists of a CCD image sensor, image memory board, personal computer, and microscope. When monoclonal antibody 3C4, which is specific to the guinea pig hepatoma L-10, was added to cell suspension, only L-10 cytolysis occurred. Cytolysis caused a decrease in brightness of the cells observed by phase-contrast microscopy. The phase contrast image of the cells before cytolysis was converted to a digitalized signal and stored in computer memory. After cytolysis, a brightness threshold above that of lysed cells was subtracted from the digitalized signal and compared to the signal stored before reaction. L-10 cells in mixed cell suspension were determined specifically by the system. Measurement time was only 2 sec and overall time, including reaction time, was approximately 30 min. Since this method does not require a cell washing process, automation of the whole system is possible.     

Thermolysis of reactive oligo(p-phenylene sulfide) containing disulfide bond

Oligo(phenylene sulfide) (OPS) containing one disulfide bond at the end of the chain, which was obtained by the oxidative polymerization of diphenyl disulfide, had a relatively low Td_10%(temperature for 10% weight loss) of 412 °C because of degradation of the disulfide bond. But this thermal cleavage of the disulfide bond promoted the curing reaction through thiophenoxy radical formation. OPS was allowed to react with diiodobenzene at 220 °C. The thermal stability of OPS was improved through the consumption of the disulfide bond and the coupling of the chain.