The anodic conversion of 2,4,6-tri-tert-butylphenol in methanol, leading to 2,4,6-tris( l,l-dimethylethyl)-4-methoxy-2,5-cyclohexadien-l-one, has been followed by two types of 13C NMR experiments: (a) a static procedure, inserting the electrodes directly into a rotating NMR tube and (b) a continuous flow procedure, combining electrochemical and NMR flow cells. During electrolysis the resolution of the 13C NMR spectra decreased in the static procedure owing to magnetic field gradients. In the flow procedure the resolution was comparable with that of routine spectra.
THE researches of Sch layer (), his co-workers and others have made it desirable that some further investigation of the metabolism of the kidney during diuresis, should be made. Schlayer recognises two kinds of diuresis, the mechanism of the one is vascular and the other tubular. The action of the vascular diuretics is maintained after the cells of the tubules have been poisoned with salts of the heavy metals. The original intention of our research was to investigate the vascular diuretics for the purpose of finding out whether, or no, their action was associated with increased metabolism of the kidney, and if so whether such had its seat in the glomerular epithelium.Heretofore the onlv diuretics whose action on the mammalian kidney (2) has been studied in this way are urea, sodium sulphate and phloridzin. There is a considerable amount of evidence culled from various organs in the body-striped (8), and cardiac muscle(4, submaxillary (5) and parotid glands (6), pancreas (7), kidney with certain diuretics (8), intestine (9) which leads us to suppose that activity of the organ is associated with an immediate increase in the oxygen taken up by it, assurming that the oxygen is available, and we have regarded it as a fair assumption that if urine appears without increased oxidation in the kidney itself, the mechanism which accounts for its appearance is a purely physical one, whereas if there is a well marked increase in the metabolism of the kidney a secretory process is called into play.General method of experiment. Our experiments have been performed on cats and rabbits; dogs proved unsuitable, because the large doses of diuretic necessary were retained in the tissues to such an extent that it was found impossible to free the animal from them. The dissections do not differ materially from those described by PH. XLI. 10
EXPERIMENTS on the volume of the heart lhave been carried out by several investigators, e.g. Johansson and Tigerstedt', Stefani2, and Fran9ois-Franck . In 1906 Henderson4 published a paper on the subject in wbicb he gives a critical account of previous experiments as well as a description of his own investigations. His statements may be briefly summarised as follows.During the period of discharge the volume curve of the ventricles shows a sudden and steep descent, beginning with the moment of the opening of the semilunar valves and accounting for 90 per cent. of the total output from the ventricle. At the bottom the volume curve is rounded and comes to a blunt point, at the apex of which the semilunar valves close. For a brief period immediately following the completion of systole all the heart valves are probably closed. Yet during this period, according to Henderson, the volume curve rises sharply, a slight notch in the curve sometimes marking the end of this brief period. He attributes this initial increase in the bulk of the ventricles to the rush of blood from the aorta into the coronary vessels. During the, period of filling of the ventricles the moment of opening of the auriculo-ventricular valves is marked by a rapid movement upwards of the volume curve. The line traced by the lever rises steeply and often nearly straight almost to its summit, then curves quickly and runs for some time parallel to the abscissa. Thus the filling of the ventricles occupies only the early part of diastole and is as rapid a process as the emptying in systole. According to this author, the volume curve during the latter part of diastole runs parallel to the abscissa, indicating that during this period no movement of blood occurs into the ventricles. Henderson suggests the name " diastasis " for this period, and states that differences in the rate of the heart beat depend almost entirely on lengthening or shortening of this period. In a very rapidly beating heart the period of diastasis entirely disappears, the volume curve becoming simply a series of sharp up and down strokes. He suggests that the contraction of the auricles increases the ventricular volume at the most to the extent of a few drops.
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