If thioctic acid is an intermediate in photosynthesis closely related to the primary photochemical act as proposed by Calvin and Barltrop,I it should be possible to realize experimental conditions under which the concentration of thioctic acid limits the quantum efficiency of photosynthesis as well as the closely related Hill reaction. Conditions under which the amounts of thioctic acid and oxi...

1. ARNON, D. I. Copper enzymes in isolated chloroplasts. Polyphenol oxidase in Beta uulgaris. Plant Physiol. 24: 1-15. 1949. 2. ARNON, D. I., ALLEN, M. B., and WHATLEY. F. R. Photosynthesis by isolated chloroplasts. IV. General concept and comparison of three photochemical reactions. Biochim. Biophys. Acta 20: 449-461. 1956. 3. ARNON, D. I., WHATLEY, F. R. and ALLEN, M. B. Assimilatory power in...

Experiments in which chloroplasts were washed with tris and tricine buffers at different pH's indicated that the non-protonated (uncharged) form of tris was inhibitory to the Hill reaction while the protonated form of tris and the zwitterionic forms of tricine were non-inhibitory. Buffers analogous to tris and tricine gave similar results. Photoreduction of NADP could be restored to the inhibit...

The various permutations of the Maillard aminosugar "browning" reaction (Maillard, 1912) have attracted the attention of microbiologists only within recent years, although food technologists have long been concerned with this class of reactions (Kline, 1950). Although Lewis (1930) warned of the effects of such reactions in bacteriologic culture media, their potential significance in many types ...

Digestion of spinach chloroplasts with pancreatic lipase or trypsin effectively uncoupled electron transport. Continued digestion led to inhibition of saturated rates of Hill reaction activity and a decrease in quantum yield. Irradiation with ultraviolet light decreased the quantum yield and inhibited Hill activity, but did not uncouple. Ascorbate-dichlorophenol-indophenol-mediated reduction of...

Symbiotic associations of bean plants (Phaseolus vulgaris L. cv. Blue Lake) and Rhizobium phaseoli strain 127K17 were treated with the Hill reaction inhibitor bentazon (3-isopropyl-1 H-2,1,3-benzothiadiazin-4-(3H)-one-2,2-dioxide). Plants receiving foliar and root treatments of 1.8 kilograms per hectare bentazon were assayed at 6 hour intervals for N(2)-fixing capacity by measuring C(2)H(2)-dep...

1. ARNON, D. I. Copper enzymes in isolated chloroplasts. Polyphenol oxidase in Beta uulgaris. Plant Physiol. 24: 1-15. 1949. 2. ARNON, D. I., ALLEN, M. B., and WHATLEY. F. R. Photosynthesis by isolated chloroplasts. IV. General concept and comparison of three photochemical reactions. Biochim. Biophys. Acta 20: 449-461. 1956. 3. ARNON, D. I., WHATLEY, F. R. and ALLEN, M. B. Assimilatory power in...

Hill activity with ferricyanide and nicotinamide adenine dinucleotide phosphate and photoreduction of NADP and methyl red supported by ascorbate and 2,6-dichloroindophenol were studied as a function of the size of chloroplast fragments. Sonic treatment of chloroplasts resulted in a decrease in Hill activity with NADP and ferricyanide. The decrease was accompanied by a change in the dependency o...

The incidence of typhus in the surrounding hill tracts of Shillong in an endemic form is an occurrence more than one year old. It might have been present for a far longer period, but the presence of the disease was seldom suspected. In this series the first case that was positively diagnosed by a high titre Weil-Felix reaction occurred on 27th November, 1948. After that many more clinically typ...

1 Center for Nanotechnology in Drug Delivery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2 Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 3 UNC Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United S...