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  • Author: J. Tanaka x
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Abstract

Photosynthetic activities of submerged seaweeds before and after drying were measured in eighteen species collected from different vertical positions from a Pacific shore at Shimoda City in Japan. The seaweeds were desiccated until the cellular water levels equilibrated with the air in the chamber under various humidities at 10 °C. Relative water contents of all species drastically decreased as the cellular water potentials were reduced from 0 to −14MPa and gradually decreased in the range from −14 to −158MPa. Porphyra dentata, which is an upper intertidal species, recovered photosynthetic activity from the lowermost water potential of −158MPa, while the plants collected from the lower intertidal and subtidal zones reduced their photosynthetic activities after desiccation to comparatively higher water potentials from 0 to −14MPa. Other species collected from the middle intertidal zone reduced their photosynthetic activities following desiccation to water potentials in the range from −14 to −158MPa. It is concluded that the cellular abilities of desiccation tolerance in intertidal seaweeds varied between the species examined and correlated with their vertical position within the tidal zone.

Abstract

C12H15CuNO6, triclinic, P1̅ (No. 2), a = 7.363(2) Å, b = 8.985(2) Å, c = 10.349(2) Å, α = 97.438(4)°, β = 100.846(4)°, ϒ = 106.334(4)°, V = 633.1 Å3, Z = 2, R gt (F) = 0.029, wR obs (F 2 ) = 0.073, T = 298 K

Abstract

Although the renal artery blood flow velocity has been investigated recently using the ultrasound Doppler method, little is known about the longitudinal change of renal artery blood flow velocity and its relationship with urine volume in very low birth weight infants. Thus, we measured renal artery blood flow velocities by means of the pulse Doppler method in 28 very low birth weight infants. Maximum, minimum, and mean blood flow velocities were determined at postnatal days 0, 1, 2, 3, 4, 5, 6, 13, 20, and 27. The resistance index was also calculated. The maximum and mean blood flow velocities increased gradually after birth, and were significantly higher at 13, 20, and 27 days after birth. The minimum blood flow velocity and the resistance index were relatively constant during the study period. The mean blood flow velocities were also analyzed for any correlation with urine volume. There was a poor correlation between urine volume (ml/kg/day) and mean blood flow velocity (cm/s) (Y = 2.38X + 57.4, Y: urine volume, X: mean blood flow velocity, n=161, r=0.338, P < 0.01). However, if the mean renal artery blood flow velocity was less than 10 cm/s, oliguria was observed in most cases. The measurement of the renal artery blood flow velocities appears to be useful in understanding the background condition of renal function in very low birth weight infants.

The major constituent of the yellow frond exudate of the fern Notholaena sulphured was identified by spectroscopic methods as 3,5,2′-trihydroxy-7-methoxy-8-acetoxy flavone and its structure was confirmed by synthesis. This novel natural flavonoid was also detected in the frond exudate of five other Notholaena species. In the yellow form of N. sulphurea, the rare 5,2′- dihydroxy-7,8-dimethoxy flavone was also found, along with some trivial flavonoids. The white form of N. sulphurea produces three dihydrochalcones that are accompanied by some kaempferol methyl ethers and apigenin-7-methyl ether. The 3-acetoxy as well as the 3-butyroxy and the 4′- butyroxy derivatives of 7-methyl aromadendrin were also identified in this material. One of them was shown to belong to the extremely rare group of 3-cis-dihydroflavonols.