ISSN:0022-1945    

DOI:10.1080/09291017909359656

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Ninety‐eight recordings of serial temperatures each taken at 30 sec intervals from both the dorsum of the hand and the axilla were made. A total of 23 fully clothed healthy persons at rest was monitored using an electronic thermometer with instant readout and multiple themocouple probes. Raw data were processed by a computerized program of autocorrelation for a time series analysis. The autocorrelograms indicated significant spontaneous ultradian periodicities for both hand and axillary temperatures. The cycle lengths were independent of gender, but sensitive to age. Observations of the tympanic membrane temperature and that of the nailfold on a further two subjects suggested that hypothalamic temperature oscillations of similar periodicity may be the source of the temperature rhythms of the hand and the axilla.

ISSN:0022-1945    

DOI:10.1080/09291017909359658

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The activity of nuclear protein kinases in rat liver changes during 24 h: with casein as a substrate two maxima of [y‐32P]ATP labelling at 9.00 h and 1.00 h were observed, whereas with histones as substrates only one maximum is registered. 5 x 10‐5M c AMP did no t alter the level or phasing of the kinase activity in the first series of experiments, it increased the level of activity in the second series.

ISSN:0022-1945    

DOI:10.1080/09291017909359659

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Different fractions of ribosomal RNA (28 S, 18 S, 5 S) and transfer RNA (4 S) of rat liver were separated using phenol extraction and gel electrophoretic methods. The concentrations of all fractions except 5 S show a daily rhythmicity with a maximum between 11.00 h and 19.00 h and a minimum at 7.00 h.3H‐uridine incorporation also varies within 24 h; in the 4 S fraction two maxima at 11.00 h and 23.00 h and two minima at 19.00 h and 7.00 hcan be distinguished, whereas in the 28 Sand 18 S one maximum about 7.00–11.00 h and one minimum at 23.00 h is observed. Injection of cycloheximide 2.5 h before the RNA measurements reduces the amount and3H‐labelling of the 28 S and 18 S fractions considerably.

ISSN:0022-1945    

DOI:10.1080/09291017909359660

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The diurnal rhythm of rat liver tyrosine aminotransferase was investigated under conditions allowing enzyme activation. The amount of activated enzyme represented only a small proportion of total enzyme. Therefore, the activation mechanism cannot be responsible for the diurnal variations in overall activity. Instead, the results are compatible with the earlier assumption of a generation of the rhythm by periodicde novosynthesis of enzyme protein. Although not of causal importance for the overall rhythm, activation of tyrosine aminotransferase behaved rhythmically: during the phases of the normal diurnal increase in enzyme activity, a certain proportion of enzyme was activated, whereas during the phases of the diurnal decline no activation was observed under the same experimental conditions. Though appearingly correlated with the diurnal stimulation of enzyme production, activation is not a characteristic forde novosynthesized tyrosine aminotransferase, as demonstrated by experiments with hydrocortisone inductions.

ISSN:0022-1945    

DOI:10.1080/09291017909359661

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The results of kinetic studies of AIB uptake into rat liver slices suggested that AIB is transported into this tissue by at least two distinct transport systems which may differ in respect of their Na dependence and their kinetic characteristics. Only the Na+‐requiring low‐Kt mode of uptake seems to show diurnal rhythm changes. Uptake velocities at low AIB concentrations in the incubation medium were analysed by Lineweaver‐Burk plots. The data revealed that the daily maximum of AIB transport is primarily due to a reduction of the apparent Ki for AIB uptake.

ISSN:0022-1945    

DOI:10.1080/09291017909359662

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

In male rats, hepatic serine: pyruvate aminotransferase shows a diurnal rhythm of activity. The periodicity differs from those of other rate‐limiting enzymes in the amino acid catabolism by a biphasic pattern. Fasting did not prevent the diurnal increase in enzyme activity.

ISSN:0022-1945    

DOI:10.1080/09291017909359663

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Acetylcholinesterase (AChE) activity in the brain ofCatolesandMusexhibited cyclical variations during the 24 h period of the solar day. Crest values for AChE activity at 08.00 h inCaloleswas 180° out of phase with those ofMus. Rhythm characteristics viz., M, A,ϕ(computed acrophase) and D (periodicity index) differed for the animals. Also, in both cases Ho (Null Hypothesis) was rejected (A ? o). Hence a significant and phase‐synchronized rhythm with angular frequencyω(held constant at one cycle per 24 h) was observed. These observations were correlated to motoric patterns of the animals.

ISSN:0022-1945    

DOI:10.1080/09291017909359664

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The use of a Maximum Entropy method for the analysis of short‐time biomredical rhythms is described using examples taken from gastro‐intestinal electrical slow‐waves, human digit blood flow, rat locomotor activity and psychological mood data. The method is similar to auto‐regressive modelling in that it estimates coefficients in a difference equation model which are related to spectral components. Fine spectral resolution of short time‐series is obtained in the Maximum Entropy method by predictive extrapolation of the time‐series, unlike the methods of Fast Fourier Transforms and Periodogram via Autocorrelation Functions. It is shown that Maximum Entropy is superior to normal auto‐regressive analysis for signals having a higher noise content and that problems caused by initial phase‐shift are no more severe than for the zero‐extended FFT analysis and normal auto‐regressive techniques.

ISSN:0022-1945    

DOI:10.1080/09291017909359665

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0022-1945    

DOI:10.1080/09291017909359655

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor