scholarly journals Crystal molecular structure of the methyl ester of uridin-5-oxyacetic acid: A minor constituent of Escherichia coli tRNAs

FEBS Letters ◽  
1974 ◽  
Vol 48 (2) ◽  
pp. 279-282 ◽  
Author(s):  
K. Morikawa ◽  
K. Torii ◽  
Y. Iitaka ◽  
M. Tsuboi
Keyword(s):  
Molecular Structure ◽  
Escherichia Coli ◽  
Methyl Ester ◽  
Minor Constituent ◽  
A Minor ◽  
Oxyacetic Acid

Activity of Plasmin and Streptokinase-Activator on Substituted Arginine and Lysine Esters

1966 ◽  
Vol 16 (01/02) ◽  
pp. 018-031 ◽  
Author(s):  
S Sherry ◽  
Norma Alkjaersig ◽  
A. P Fletcher
Keyword(s):  
Molecular Structure ◽  
Methyl Ester ◽  
Comparative Studies ◽  
Esterase Activity ◽  
Methyl Esters ◽  
Hydrolytic Activity ◽  
The Other ◽  
Other Hand

SummaryComparative studies have been made of the esterase activity of plasmin and the streptokinase-activator of plasminogen on a variety of substituted arginine and lysine esters. Human plasmin preparations derived by different methods of activation (spontaneous in glycerol, trypsin, streptokinase (SK) and urokinase) are similar in their esterase activity; this suggests that the molecular structure required for such esterase activity is similar for all of these human plasmins. Bovine plasmin, on the other hand, differs from human plasmin in its activity on several of the substrates studied (e.g., the methyl esters of benzoyl arginine and tosyl, acetyl and carbobenzoxy lysine), a finding which supports the view that molecular differences exist between the two animal plasmins. The streptokinase-activator hydrolyzes both arginine and lysine esters but the ratios of hydrolytic activity are distinct from those of plasmin and of other activators of plasminogen. The use of benzoyl arginine methyl ester as a substrate for the measurement of the esterase activity of the streptokinase-activator is described.

scholarly journals Investigation on Physicochemical Properties of Wastewater Grown Microalgae Methyl Ester and its Effects on CI Engine

2020 ◽  
Vol 24 (1) ◽  
pp. 72-87 ◽  
Author(s):  
Sara Tayari ◽  
Reza Abedi ◽  
Ali Abedi
Keyword(s):  
Methyl Ester ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Biodiesel Production ◽  
Emissions Reduction ◽  
Test Results ◽  
Main Fatty Acid ◽  
Ci Engine ◽  
Hc Emissions ◽  
A Minor

AbstractMicroalgae have been mentioned as a promising feedstock for biodiesel production. In this study, microalgae Chlorella vulgaris (MCV) was cultivated in a bioreactor with wastewater. After biodiesel production from MCV oil via transesterification reaction, chemical and physical properties of MCV methyl ester were evaluated with regular diesel and ASTM standard. Besides, engine performance and exhaust emissions of CI engine fuelled with the blends of diesel-biodiesel were measured. The GC-MS analysis showed that oleic and linoleic acids were the main fatty acid compounds in the MCV methyl ester. Engine test results revealed that the use of biodiesel had led to a major decrease in CO and HC emissions and a modest reduction in CO2 emissions, whereas there was a minor increase in NOx emissions. Furthermore, there was a slight decrease in the engine power and torque while a modest increase in brake specific fuel consumption which are acceptable due to exhaust emissions reduction. The experimental results illustrate considerable capabilities of applied MVC biodiesel as an alternative fuel in diesel engines to diminish the emissions.

scholarly journals Ecological Effects of Perorally Administered Pivmecillinam on the Normal Vaginal Microflora

2005 ◽  
Vol 49 (1) ◽  
pp. 170-175 ◽  
Author(s):  
Åsa Sullivan ◽  
Aino Fianu-Jonasson ◽  
Britt-Marie Landgren ◽  
Carl Erik Nord
Keyword(s):  
Escherichia Coli ◽  
Candida Albicans ◽  
Antimicrobial Agents ◽  
Ecological Impact ◽  
Menstrual Cycles ◽  
The Third ◽  
Vaginal Microflora ◽  
Normal Microflora ◽  
Facultative Anaerobic ◽  
A Minor

ABSTRACT The knowledge of the effects of antimicrobial agents on the normal vaginal microflora is limited. The objective of the present study was to study the ecological impact of pivmecillinam on the normal vaginal microflora. In 20 healthy women, the estimated day of ovulation was determined during three subsequent menstrual cycles. Microbiological and clinical examinations were performed on the estimated day of ovulation and on day 3 in all cycles and also on day 7 after ovulation in cycles 1 and 2. Anaerobic and facultative anaerobic gram-positive rods, mainly species of lactobacilli and actinomycetes, dominated the microflora. One woman was colonized on the third day of administration with a resistant Escherichia coli strain, and Candida albicans was detected in one woman on days 3 and 7 in cycle 2. No other major changes in the normal microflora occurred during the study. Administration of pivmecillinam had a minor ecological impact on the normal vaginal microflora.

scholarly journals The molecular structure of plant sporopollenin

2018 ◽  
Author(s):  
Fu-Shuang Li ◽  
Pyae Phyo ◽  
Joseph Jacobowitz ◽  
Mei Hong ◽  
Jing-Ke Weng
Keyword(s):  
Molecular Structure ◽  
Minor Component ◽  
Pollen Grains ◽  
Outer Wall ◽  
Land Plant ◽  
Spores And Pollen ◽  
Biomimetic Polymers ◽  
Wide Range ◽  
Nmr Techniques ◽  
A Minor

Sporopollenin is a ubiquitous and extremely chemically inert biopolymer that constitutes the outer wall of all land-plant spores and pollen grains. Sporopollenin protects the vulnerable plant gametes against a wide range of environmental assaults, and is considered as a prerequisite for the migration of early plants onto land. Despite its importance, the chemical structure of plant sporopollenin has remained elusive. Using a newly developed thioacidolysis degradative method together with state-of-the-art solid-state NMR techniques, we determined the detailed molecular structure of pine sporopollenin. We show that pine sporopollenin is primarily composed of aliphatic-polyketide-derived polyvinyl alcohol units and 7-O-p-coumaroylated C16 aliphatic units, crosslinked through a distinctive m-dioxane moiety featuring an acetal. Naringenin was also identified as a minor component of pine sporopollenin. This discovery answers the long-standing question about the chemical makeup of plant sporopollenin, laying the foundation for future investigations of sporopollenin biosynthesis and for design of new biomimetic polymers with desirable inert properties.

Heterogeneous Formation of Oriented Silicon Oxynitride on α-Si3N4 Seed Crystals : Habits And Radiation Stability

1999 ◽  
Vol 5 (S2) ◽  
pp. 778-779
Author(s):  
R.W Carpenter ◽  
W Braue ◽  
M.J. Kim
Keyword(s):  
Silicon Nitride ◽  
Heterogeneous Nucleation ◽  
Radiation Stability ◽  
Silicon Oxynitride ◽  
Minor Constituent ◽  
Sintering Aids ◽  
Sintering Aid ◽  
Nucleation Sites ◽  
Heterogeneous Formation ◽  
A Minor

Lath-like silicon oxynitride crystals have often been observed in the microstructure of silicon nitride based ceramics after processing. They are usually located in glassy regions which are siliceous solidified sintering aid liquid, and usually contain a small (∼100nm) a-Si3N4 crystal. These nitride crystals are considered to be seeds, incompletely dissolved in the melt, that are heterogeneous nucleation sites for the oxynitride crystals. We present here the first observations of morphological and crystallographic habits between the seed nanocrystals and the host oxynitride laths.Fig. 1 shows a typical oxynitride lath containing a nitride seed crystal. The lath is surrounded by glass and ß-Si3N4 particles, and a small cristobalite particle (a minor constituent). This microstructure is from an Si02-Si3N4 ceramic processed with Al2O3 sintering aid. The same oxynitride lath/seed structures were observed when other sintering aids (eg. Y2O3, MgO, ZrO2) were used, so they are independent of sintering aid.

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