Determination of 6s-trans conformation of retinal chromophore in sensory rhodopsin I and phoborhodopsin

8,16-Ethanoretinal 3 was synthesized from 2-methylcyclohexanone. From the binding experiments of 3 and 8,18-ethanoretinal 2 with apoproteins of sensory rhodopsin I and phoborhodopsin, it was found that retinal was incorporated as 6s-trans conformation in the both proteins.     

Therapeutic effects of prostacyclin analog on crescentic glomerulonephritis of rat

Prostacyclin (PGI2) is known to have a relaxative action on vascular smooth muscle, an inhibitory action against platelet activation and neutrophil function. Previous studies showed the preventive effects of PGI2 on lupus nephritis and Thy-1 nephritis, although the mechanism has not been clarified. Glomerular endothelial expression of intercellular adhesion molecule-1 (ICAM-1) is up-regulated in experimental and human glomerular diseases, and is known to facilitate leukocyte infiltration into the glomeruli, which ultimately induces the various glomerular injuries. In the present study, we evaluated the therapeutic effects of PGI2 on a rat model for crescentic glomerulonephritis and investigated its putative mechanism in relation to ICAM-1-mediated leukocyte recruitment. Wistar-Kyoto (WKY) rats were injected with nephrotoxic serum and received continuous intraperitoneal infusion of PGI2. PGI2 dramatically decreased proteinuria (123.0 +/- 18.8 vs. 31.6 +/- 4.5), crescent formation and deposition of fibrinogen in the glomeruli, while the deposition of rabbit IgG, rat IgG and rat C3 along the capillary walls was not changed. Furthermore, intraglomerular expression of ICAM-1 and infiltration of macrophages were significantly suppressed by administration with PGI2. In contrast, influx of CD4 or CD8 positive cells was not altered. The present results suggest that PGI2 shows the preventive effects on experimental crescentic glomerulonephritis by inhibiting intraglomerular coagulation and ICAM-1-mediated macrophage-glomerular endothelial cell adhesive pathway.     

Evolutionary history of free-swimming and sessile lifestyles in urochordates as deduced from 18S rDNA molecular phylogeny

Whether the ancestral chordates were free-swimming or sessile is a longstanding question that remains to be settled. Vertebrates and amphioxi are free-swimming, but the most basal chordate subphylum (the urochordates) includes both sessile and free-swimming species. Here, 1 report molecular phylogenetic analyses of 18S rDNA of urochordates to deduce which lifestyle is ancestral. This revealed a close relationship between salps and doliolids and paraphyly of the ascidians. An early divergence of larvaceans, which show a tadpole-like body plan throughout life, is also supported by the analyses. Based on this phylogeny, a free-swimming ancestor for chordates is more parsimonious than a sessile ancestor. The evolutionary history of various lifestyles of chordates from this ancestral form is proposed.     

An AlGaAs/GaAs short-cavity laser and its monolithic integration using microcleaved facets (MCF) process

This paper describes the microcleaved facets (MCF) process developed for AlGaAs/GaAs laser fabrication which can avoid the previous substrate cleavage and therefore be applicable to preparing both discrete short-cavity lasers and optoelectronic integrated circuits (OEIC's). An AlGaAs/GaAs double heterostructure ridge-waveguide laser with an extremely short cavity length, namely 20 μm, was first realized by this process. A threshold current as low as 20 mA and a single longitudinal mode lasing were achieved. The usefulness of this process for integrating a laser and a monitoring photodiode on a GaAs substrate is also demonstrated.     

Surface magnetism of type II superconductors

The magnetization of a type II superconductor in the mixed state is a sum of two contributions, one from an array of flux lines and the other from shielding currents flowing along the surface. The former can be evaluated with the help of results of neutron diffraction experiments, using an extrapolation procedure. The observed magnetization curve thus enables us to estimate the surface contribution. This process is applied to the data on niobium obtained by Schelten, Ullmaier, and Lippmann. It is found that at low temperatures (T/T _c =0.161 and 0.457), the surface contribution may not be reduced atH _c2 as much as theories predict. At higher temperatures (T/T _c =0.717 and 0.891), it is likely to be paramagnetic in a region rather close toH _c1 . Attractive interaction between flux lines is suggested to be a mechanism of this anomaly. However, more experimental and theoretical work is needed to establish these findings to help us understand the surface magnetism of type II superconductors.