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161.
Interaction between phenolic substances and microbial polysaccharides in soil aggregation 总被引:1,自引:0,他引:1
Summary The stability of synthetic soil aggregates containing the extracellular polysaccharide fromLipomyces starkeyi is increased and is more persistant when aggregates are infiltrated with either tannic acid or the products from decomposing
herbage. Mixing tannic acid with polysaccharide during the preparation of aggregates had no effect.
In a field experiment, addition of glucose produced a rapid improvement in soil aggregation which was considered to be due
to the formation of microbial polysaccharides. The effect, however, had virtually disappeared after six months. By contrast
glucose-treated plots receiving tannic acid 28 and 42 days after the glucose had been applied showed no sign of diminished
aggregation at the end of the experiment. 相似文献
162.
163.
The relationship of plasma calcium levels to changes in plasma specific gravity, total protein, and albumin induced by venous stasis was investigated. Factors were derived for adjusting calcium results to offset the effects of variation in protein concentration and thus to make them of increased discriminatory value to the clinician. The validity of an existing specific gravity correction has been substantiated, but a more exact adjustment of 0·23 mg/100 ml of calcium for every 0·001 change in specific gravity is proposed. We recommend for automated laboratories that the factor based on albumin be used: 0·09 mg/100 ml of calcium should be subtracted from the total calcium value for every increase of 0·1 g in albumin above 4·6 g/100 ml, and a corresponding addition should be made for values of albumin below 4·6 g/100 ml.Using a calcium specific electrode, it has been shown that the ionized calcium concentration does not alter with prolonged venous stasis. 相似文献
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165.
On the existence of a G 0 -phase in the cell cycle 总被引:4,自引:0,他引:4
166.
Summary It has been found that sections of paraffin-embedded tissue attached to glass slides with a nitrocellulose-based adhesive instead of albumen retain their original morphology and integrity when deaminated with solutions of sodium hypochlorite. 相似文献
167.
Structure and physiology of the locust femoral chordotonal organ 总被引:1,自引:0,他引:1
M D Burns 《Journal of insect physiology》1974,20(7):1319-1339
The connective chordotonal organs (COs) in the femora of the prothoracic and mesothoracic legs of the locust Schistocerca gregaria are divided into two parts, the proximal and the distal scoloparia. The proximal scoloparium contains about 150 small neurons and is anchored to the femoral cuticle. The distal scoloparium contains about 50 larger neurons and is connected at its proximal end to both the cuticle and the flexor tibiae muscle.Records were made from the distal scoloparium, classifying units by spike size. The tibial position/total activity response curve is ∪-shaped but when a small number of units is selected the responses occur only when the tibia is on one side of its centre position. The tonic responses display considerable hysteresis and a degree of adaptation which varies with the tibial angle. Units with phasic and phasic-tonic responses are common and their responsiveness depends on the range of angles the tibia is moved through. The same units respond strongly to flexor tibiae contraction with the tibia either fixed or free, and so may serve as receptors for tension in that muscle.The CO mediates phasic resistance reflexes in all three extensor tibiae motoneurons and tonic reflexes in the extensor ‘slow’ neuron. It is suggested that the very detailed information furnished by the CO is used in a complex way in the control of the femoral muscles. 相似文献
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