scholarly journals Respiration of soybean plants in relation to their physiological conditions. IV. Time course changes in nitrogen metabolism in a leaf.

1989 ◽  
Vol 58 (4) ◽  
pp. 726-731
Author(s):  
Junko YAMAGISHI ◽  
Ryuichi ISHII ◽  
Atsuhiko KUMURA
Keyword(s):  
Nitrogen Metabolism ◽  
Time Course ◽  
Physiological Conditions ◽  
Course Changes ◽  
Soybean Plants

Influence of stable iodine on the uptake of the thyroid – model vs. experiment

2001 ◽  
Vol 40 (01) ◽  
pp. 31-37 ◽  
Author(s):  
U. Wellner ◽  
E. Voth ◽  
H. Schicha ◽  
K. Weber
Keyword(s):  
Time Course ◽  
Compartment Model ◽  
The Body ◽  
Iodine Uptake ◽  
Model Calculations ◽  
Physiological Conditions ◽  
Iodine Supply ◽  
Predicted Values ◽  
The Individual ◽  
Stable Iodine

Summary Aim: The influence of physiological and pharmacological amounts of iodine on the uptake of radioiodine in the thyroid was examined in a 4-compartment model. This model allows equations to be derived describing the distribution of tracer iodine as a function of time. The aim of the study was to compare the predictions of the model with experimental data. Methods: Five euthyroid persons received stable iodine (200 μg, 10 mg). 1-123-uptake into the thyroid was measured with the Nal (Tl)-detector of a body counter under physiological conditions and after application of each dose of additional iodine. Actual measurements and predicted values were compared, taking into account the individual iodine supply as estimated from the thyroid uptake under physiological conditions and data from the literature. Results: Thyroid iodine uptake decreased from 80% under physiological conditions to 50% in individuals with very low iodine supply (15 μg/d) (n = 2). The uptake calculated from the model was 36%. Iodine uptake into the thyroid did not decrease in individuals with typical iodine supply, i.e. for Cologne 65-85 μg/d (n = 3). After application of 10 mg of stable iodine, uptake into the thyroid decreased in all individuals to about 5%, in accordance with the model calculations. Conclusion: Comparison of theoretical predictions with the measured values demonstrated that the model tested is well suited for describing the time course of iodine distribution and uptake within the body. It can now be used to study aspects of iodine metabolism relevant to the pharmacological administration of iodine which cannot be investigated experimentally in humans for ethical and technical reasons.

Time course changes of vasopressin-induced enlargement of the rat intrastrial space and the effects of a vasopressin type 2 antagonist

2009 ◽  
Vol 129 (7) ◽  
pp. 709-715 ◽  
Author(s):  
Masahiko Nishimura ◽  
Akinobu Kakigi ◽  
Taizo Takeda ◽  
Teruhiko Okada ◽  
Katsumi Doi
Keyword(s):  
Time Course ◽  
Course Changes

Cerebral oxygenation changes in response to motor stimulation

1996 ◽  
Vol 81 (3) ◽  
pp. 1174-1183 ◽  
Author(s):  
H. Obrig ◽  
C. Hirth ◽  
J. G. Junge-Hulsing ◽  
C. Doge ◽  
T. Wolf ◽  
...  
Keyword(s):  
Time Course ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Motor Task ◽  
Hemoglobin Concentration ◽  
Hemodynamic Response ◽  
Blood Oxygenation ◽  
Initial Increase ◽  
Cerebral Hemodynamic ◽  
Course Changes

We studied cerebral hemodynamic response to a sequential motor task in 56 subjects to investigate the time course and distribution of blood oxygenation changes as monitored by near-infrared spectroscopy (NIRS). To address whether response is modulated by different performance velocities, a group of subjects (n = 12) was examined while performing the motor task at 1, 2, and 3 Hz. The results demonstrate that 1) the NIRS response reflects localized changes in cerebral hemodynamics, 2) the response, consisting of an increase in oxygenated hemoglobin concentration [oxy-Hb] and a decrease in deoxygenated hemoglobin concentration ([deoxy-Hb]), is lateralized and increases in amplitude with higher performance rates, and 3) changes in [oxy-Hb] and [deoxy-Hb] differ in time course. Changes in [oxy-Hb] are biphasic, with a fast initial increase and a pronounced poststimulus undershoot. The stimulus-associated decrease in [deoxy-Hb] is monophasic, and response latency is greater. We conclude that NIRS is able to detect even small changes in cerebral hemodynamic response to functional stimulation.

Time-course changes in clinical features of early-onset Japanese type 1 and type 2 diabetes: TWMU hospital-based study

2008 ◽  
Vol 82 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Yasuko Uchigata ◽  
Toshika Otani ◽  
Hiroko Takaike ◽  
Junnosuke Miura ◽  
Mari Osawa ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Clinical Features ◽  
Early Onset ◽  
Time Course ◽  
Course Changes

scholarly journals Patterns of Gene Expression Upon Infection of Soybean Plants by Phytophthora sojae

2004 ◽  
Vol 17 (10) ◽  
pp. 1051-1062 ◽  
Author(s):  
Pat Moy ◽  
Dinah Qutob ◽  
B. Patrick Chapman ◽  
Ian Atkinson ◽  
Mark Gijzen
Keyword(s):  
Gene Expression ◽  
Time Course ◽  
Phytophthora Sojae ◽  
Gene Microarray ◽  
Pathogenesis Related ◽  
Soybean Plants ◽  
Related Proteins ◽  
Phytoalexin Biosynthesis ◽  
Host Tissues ◽  
Mixed Samples

To investigate patterns of gene expression in soybean (Glycine max) and Phytophthora sojae during an infection time course, we constructed a 4,896-gene microarray of host and pathogen cDNA transcripts. Analysis of rRNA from soybean and P. sojae was used to estimate the ratio of host and pathogen RNA present in mixed samples. Large changes in this ratio occurred between 12 and 24 h after infection, reflecting the rapid growth and proliferation of the pathogen within host tissues. From the microarray analysis, soybean genes that were identified as strongly upregulated during infection included those encoding enzymes of phytoalexin biosynthesis and defense and pathogenesis-related proteins. Expression of these genes generally peaked at 24 h after infection. Selected lipoxygenases and peroxidases were among the most strongly downregulated soybean genes during the course of infection. The number of pathogen genes expressed during infection reached a maximum at 24 h. The results show that it is possible to use a single microarray to simultaneously probe gene expression in two interacting organisms. The patterns of gene expression we observed in soybean and P. sojae support the hypothesis that the pathogen transits from biotrophy to necrotrophy between 12 and 24 h after infection.

scholarly journals Foliar Application of Nitrogen Affects Metabolism and Productivity of Soybean

2021 ◽  
Vol 13 (10) ◽  
pp. 31
Author(s):  
Walquíria F. Teixeira ◽  
Evandro B. Fagan ◽  
Antônio P. M. Machado ◽  
Daniel Fortune ◽  
Fernando R. Moreira
Keyword(s):  
Nitrogen Metabolism ◽  
Photosynthetic Activity ◽  
Slow Release ◽  
Foliar Application ◽  
Reductase Activity ◽  
Urea Formaldehyde ◽  
Grain Filling ◽  
Control Treatment ◽  
Consequent Reduction ◽  
Soybean Plants

Soybean is one of the world’s most economically important crops and several factors can affect the productivity of this culture. Among these factors is the supply of needed nitrogen, especially in the reproductive stage, as it acts in photosynthetic activity and in grain filling. In view of this, the objective of our work was to evaluate the effect of foliar application of nitrogen in different reproductive stages in soybean culture. Two sources of nitrogen were used: conventional urea and urea-formaldehyde/triazone, both applied in reproductive stages R2, R3, R4, or R5, as well as a control treatment without foliar application of nitrogen. Plants submitted to foliar application of urea-formaldehyde/triazone showed an increase in nitrogen metabolism (percentage of nitrogen derived from the atmosphere [Ndfa] and nitrate reductase activity [NR]), an increase in peroxidase (POD), and the consequent reduction in hydrogen peroxide (H2O2) in all stages of application of this treatment. When urea-formaldehyde/triazone was applied in R4, it resulted in a 7% increase in yield. The application of conventional urea in reproductive stages R4 and R5 increased nitrogen metabolism and resulted in an increase in yield by 4%. However, conventional urea reduced yield when applied in stages R2 and R3. The use of low doses of foliar nitrogen in stages R4 and R5, increased nitrogen metabolism in soybean plants. The timing of the application has a direct impact on the results with the slow-release nitrogen (urea formaldehyde /triazone) showing better results when applied in stage R4 and better results for conventional urea in R5.

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