Biosynthesis of copolyesters by Hydrogenophaga pseudoflava from various lactones

1995 ◽  
Vol 41 (13) ◽  
pp. 60-67 ◽  
Author(s):  
Mun Hwan Choi ◽  
Jae Jun Song ◽  
Sung Chul Yoon
Keyword(s):  
Cell Growth ◽  
Time Course ◽  
Sequence Data ◽  
Mixed Substrates ◽  
Support Cell ◽  
Concentration Dependences ◽  
Accumulation Phase ◽  
Time Course Data ◽  
The Difference ◽  
Early Growth Phase

Hydrogenophaga pseudoflava (formerly Pseudomonas pseudoflava) was able to accumulate a large amount of copolyesters when grown on mixed substrates of glucose and lactones in a batch fermentation. Lactones such as γ-butyrolactone, γ-valerolactone, and higher analogues generally did not support cell growth when used as the sole carbon source. Co-feeding of lactones with glucose enhanced the utilization of lactones for both copolyester accumulation and cell growth. The copolyester from the cells grown on the mixed substrates of glucose (10 g/L) and γ-valerolactone (1–3 mL/L) was poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV)), while cells grown with γ-butyrolactone (1–3 mL/L) as a cosubstrate produced poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)). The values of parameter D, calculated from the NMR dyad-sequence data for polymer samples obtained after 72 h of cultivation, showed lactone concentration dependences differing among lactones. The time-course data obtained from growth on the cosubstrates of γ-valerolactone (2 mL/L) and glucose (10 g/L) revealed that 3HV-rich copolymers were synthesized in the early growth phase, and the 3HB-rich fraction steadily increased in the later accumulation phase and then peaked at 80 h when γ-valerolactone was depleted. These polyhydroxyalkanoate accumulation profiles suggested a high D value of the final product, whose value was determined to be 3.25. γ-Valerolactone was consumed faster than γ-butyrolactone. The difference between the assimilation behavior of the two lactones was discussed in relation to the heterogeneity of the final copolyester products. A correlation between NMR microstructure and the physiology of polyhydroxyalkanoate accumulation was observed.Key words: microstructural heterogeneity, bacterial copolyesters, lactones, Hydrogenophaga pseudoflava.

Destruction of Actin Filaments by Osmium Tetroxide

1977 ◽  
Vol 35 ◽  
pp. 466-467
Author(s):  
P. Maupin-Szamier ◽  
T. D. Pollard
Keyword(s):  
Actin Filaments ◽  
Time Course ◽  
Osmium Tetroxide ◽  
Rabbit Muscle ◽  
Muscle Actin ◽  
Sodium Phosphate Buffer ◽  
Transmission Electron ◽  
The Difference ◽  
Rates Of Decay ◽  
Short Time

We have studied the destruction of rabbit muscle actin filaments by osmium tetroxide (OSO4) to develop methods which will preserve the structure of actin filaments during preparation for transmission electron microscopy.Negatively stained F-actin, which appears as smooth, gently curved filaments in control samples (Fig. 1a), acquire an angular, distorted profile and break into progressively shorter pieces after exposure to OSO4 (Fig. 1b,c). We followed the time course of the reaction with viscometry since it is a simple, quantitative method to assess filament integrity. The difference in rates of decay in viscosity of polymerized actin solutions after the addition of four concentrations of OSO4 is illustrated in Fig. 2. Viscometry indicated that the rate of actin filament destruction is also dependent upon temperature, buffer type, buffer concentration, and pH, and requires the continued presence of OSO4. The conditions most favorable to filament preservation are fixation in a low concentration of OSO4 for a short time at 0°C in 100mM sodium phosphate buffer, pH 6.0.

scholarly journals Bayesian approach for predicting responses to therapy from high-dimensional time-course gene expression profiles

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Arika Fukushima ◽  
Masahiro Sugimoto ◽  
Satoru Hiwa ◽  
Tomoyuki Hiroyasu
Keyword(s):  
Gene Expression ◽  
Time Course ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Response To Therapy ◽  
Hcv Infection ◽  
Entire Treatment Period ◽  
Time Points ◽  
Time Course Data ◽  
Conventional Methods

Abstract Background Historical and updated information provided by time-course data collected during an entire treatment period proves to be more useful than information provided by single-point data. Accurate predictions made using time-course data on multiple biomarkers that indicate a patient’s response to therapy contribute positively to the decision-making process associated with designing effective treatment programs for various diseases. Therefore, the development of prediction methods incorporating time-course data on multiple markers is necessary. Results We proposed new methods that may be used for prediction and gene selection via time-course gene expression profiles. Our prediction method consolidated multiple probabilities calculated using gene expression profiles collected over a series of time points to predict therapy response. Using two data sets collected from patients with hepatitis C virus (HCV) infection and multiple sclerosis (MS), we performed numerical experiments that predicted response to therapy and evaluated their accuracies. Our methods were more accurate than conventional methods and successfully selected genes, the functions of which were associated with the pathology of HCV infection and MS. Conclusions The proposed method accurately predicted response to therapy using data at multiple time points. It showed higher accuracies at early time points compared to those of conventional methods. Furthermore, this method successfully selected genes that were directly associated with diseases.

scholarly journals Identification of the macrophage-specific promoter signature in FANTOM5 mouse embryo developmental time course data

2017 ◽  
Vol 102 (4) ◽  
pp. 1081-1092 ◽  
Author(s):  
Kim M. Summers ◽  
David A. Hume
Keyword(s):  
Mouse Embryo ◽  
Time Course ◽  
Developmental Time ◽  
Time Course Data

Influence of Collagen Status on Microstructures of Porous Collagen/TCP Composites

2007 ◽  
Vol 330-332 ◽  
pp. 495-498
Author(s):  
Chao Zou ◽  
Wen Jian Weng ◽  
Xu Liang Deng ◽  
Kui Cheng ◽  
Pi Yi Du ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Growth ◽  
Tricalcium Phosphate ◽  
Freeze Drying ◽  
Alkali Treatment ◽  
Test Results ◽  
Collagen Matrices ◽  
The Difference ◽  
Porous Composites ◽  
Better Than

Two starting collagens, sponge and floc collagen, were used to prepare collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had 200μm pore size. However, there was a difference in the microstructure of the pore walls for the composites derived from the two collagens, the pore walls in sponge collagen/TCP composite were still porous and had 200 nm micropores size, TCP particles were trapped in collagen matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles were embedded. The difference could be attributed to the starting collagen with different status. Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment could not be able to separate the fibrils, this remains as micropores in pore walls after freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration. MTT test results showed the two composites had good cytocompatibility, and sponge collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is suitable for cell growth.

An empirical Bayes change-point model for transcriptome time-course data

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Tian Tian ◽  
Ruihua Cheng ◽  
Zhi Wei
Keyword(s):  
Change Point ◽  
Empirical Bayes ◽  
Time Course ◽  
Point Model ◽  
Time Course Data ◽  
Change Point Model

scholarly journals Generalized Correlation Coefficient for Non-Parametric Analysis of Microarray Time-Course Data

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Qihua Tan ◽  
Mads Thomassen ◽  
Mark Burton ◽  
Kristian Fredløv Mose ◽  
Klaus Ejner Andersen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Correlation Coefficient ◽  
Parametric Analysis ◽  
Time Course ◽  
Expression Patterns ◽  
Gene Expression Patterns ◽  
Microarray Time Course ◽  
Time Course Data ◽  
Generalized Correlation ◽  
Non Parametric

AbstractModeling complex time-course patterns is a challenging issue in microarray study due to complex gene expression patterns in response to the time-course experiment. We introduce the generalized correlation coefficient and propose a combinatory approach for detecting, testing and clustering the heterogeneous time-course gene expression patterns. Application of the method identified nonlinear time-course patterns in high agreement with parametric analysis. We conclude that the non-parametric nature in the generalized correlation analysis could be an useful and efficient tool for analyzing microarray time-course data and for exploring the complex relationships in the omics data for studying their association with disease and health.

Sensation of dyspnea during hypercapnia, exercise, and voluntary hyperventilation

1990 ◽  
Vol 68 (5) ◽  
pp. 2100-2106 ◽  
Author(s):  
T. Chonan ◽  
M. B. Mulholland ◽  
J. Leitner ◽  
M. D. Altose ◽  
N. S. Cherniack
Keyword(s):  
Visual Analog Scale ◽  
Line Intensity ◽  
Time Course ◽  
Normal Subjects ◽  
Cycle Ergometer ◽  
Base Line ◽  
Analog Scale ◽  
Voluntary Hyperventilation ◽  
The Difference ◽  
End Tidal

To determine whether the intensity of dyspnea at a given level of respiratory motor output depends on the nature of the stimulus to ventilation, we compared the sensation of difficulty in breathing during progressive hypercapnia (HC) induced by rebreathing, during incremental exercise (E) on a cycle ergometer, and during isocapnic voluntary hyperventilation (IVH) in 16 normal subjects. The sensation of difficulty in breathing was rated at 30-s intervals by use of a visual analog scale. There were no differences in the level of ventilation or the base-line intensity of dyspnea before any of the interventions. The intensity of dyspnea grew linearly with increases in ventilation during HC [r = 0.98 +/- 0.02 (SD)], E (0.95 +/- 0.03), and IVH (0.95 +/- 0.06). The change in intensity of dyspnea produced by a given change in ventilation was significantly greater during HC [0.27 +/- 0.04 (SE)] than during E (0.12 +/- 0.02, P less than 0.01) and during HC (0.30 +/- 0.04) than during IVH (0.16 +/- 0.03, P less than 0.01). The difference in intensity of dyspnea between HC and E or HC and IVH increased as the difference in end-tidal PCO2 widened, even though the time course of the increase in ventilation was similar. No significant differences were measured in the intensity of dyspnea that occurred with changes in ventilation between E and IVH. These results indicate that under nearisocapnic conditions the sensation of dyspnea produced by a given level of ventilation seems not to depend on the method used to produce that level of ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Stoichiometric Relationship between Na+ Ions Transported and Glucose Consumed in Human Erythrocytes: Bayesian Analysis of 23Na and 13C NMR Time Course Data

2013 ◽  
Vol 104 (8) ◽  
pp. 1676-1684 ◽  
Author(s):  
Max Puckeridge ◽  
Bogdan E. Chapman ◽  
Arthur D. Conigrave ◽  
Stuart M. Grieve ◽  
Gemma A. Figtree ◽  
...  
Keyword(s):  
Bayesian Analysis ◽  
13C Nmr ◽  
Time Course ◽  
Human Erythrocytes ◽  
Na Ions ◽  
Time Course Data
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