THE ISOLATION, IDENTIFICATION, AND PROPERTIES OF DINUCLEOTIDES FROM ALKALI HYDROLYZATES OF RIBONUCLEIC ACIDS

1959 ◽  
Vol 37 (11) ◽  
pp. 1329-1350 ◽  
Author(s):  
B. G. Lane ◽  
G. C. Butler
Keyword(s):  
Rate Constants ◽  
Potassium Hydroxide ◽  
Ribonucleic Acids ◽  
Pancreatic Ribonuclease ◽  
Preliminary Characterization ◽  
First Order

The isolation, identification, and properties of dinucleotides from alkali hydrolyzates of RNA are described. Preparative methods for obtaining the alkali-labile dinucleotides which were found in our 18-hour hydrolyzates of RNA in 1 M potassium hydroxide are described, and it is noted that all of them (ApAp, ApGp, ApUp, GpAp, and GpCp) are not susceptible to pancreatic ribonuclease at the concentrations of the enzyme which are customarily employed for hydrolytic degradations. It has been found, however, that two of these dinucleotides (ApAp and ApUp) are susceptible to pancreatic ribonuclease at concentrations of the enzyme which are about five thousand times greater than those customarily employed. The rate constants of first order hydrolysis in alkali of ApAp, ApGp, ApUp, GpAp, and GpCp are found to be correspondingly lower than the rate constants for two dinucleotides which were not found in our 18-hour hydrolyzates, and which are susceptible to pancreatic ribonuclease. Furthermore, it is reported that the eight possible diribonucleotides which are not susceptible to pancreatic ribonuclease (ApAp, ApGp, ApCp, ApUp, GpGp, GpAp, GpCp, and GpUp) are found in roughly equivalent amounts in a 2-hour alkali hydrolyzate of a preparation of yeast RNA, and account for 80–90% of the dinucleotides present.In addition to the alkali-labile dinucleotides found in alkali hydrolyzates of RNA, the isolation and preliminary characterization of five alkali-stable compounds are reported.

THE ISOLATION, IDENTIFICATION, AND PROPERTIES OF DINUCLEOTIDES FROM ALKALI HYDROLYZATES OF RIBONUCLEIC ACIDS

1959 ◽  
Vol 37 (1) ◽  
pp. 1329-1350 ◽  
Author(s):  
B. G. Lane ◽  
G. C. Butler
Keyword(s):  
Rate Constants ◽  
Potassium Hydroxide ◽  
Ribonucleic Acids ◽  
Pancreatic Ribonuclease ◽  
Preliminary Characterization ◽  
First Order

The isolation, identification, and properties of dinucleotides from alkali hydrolyzates of RNA are described. Preparative methods for obtaining the alkali-labile dinucleotides which were found in our 18-hour hydrolyzates of RNA in 1 M potassium hydroxide are described, and it is noted that all of them (ApAp, ApGp, ApUp, GpAp, and GpCp) are not susceptible to pancreatic ribonuclease at the concentrations of the enzyme which are customarily employed for hydrolytic degradations. It has been found, however, that two of these dinucleotides (ApAp and ApUp) are susceptible to pancreatic ribonuclease at concentrations of the enzyme which are about five thousand times greater than those customarily employed. The rate constants of first order hydrolysis in alkali of ApAp, ApGp, ApUp, GpAp, and GpCp are found to be correspondingly lower than the rate constants for two dinucleotides which were not found in our 18-hour hydrolyzates, and which are susceptible to pancreatic ribonuclease. Furthermore, it is reported that the eight possible diribonucleotides which are not susceptible to pancreatic ribonuclease (ApAp, ApGp, ApCp, ApUp, GpGp, GpAp, GpCp, and GpUp) are found in roughly equivalent amounts in a 2-hour alkali hydrolyzate of a preparation of yeast RNA, and account for 80–90% of the dinucleotides present.In addition to the alkali-labile dinucleotides found in alkali hydrolyzates of RNA, the isolation and preliminary characterization of five alkali-stable compounds are reported.

scholarly journals KINETICS OF PALM OIL TRANSESTERIFICATION IN METHANOL WITH POTASSIUM HYDROXIDE AS A CATALYST

2010 ◽  
Vol 8 (2) ◽  
pp. 219-225
Author(s):  
Yoeswono Yoeswono ◽  
Triyono Triyono ◽  
Iqmal Tahir
Keyword(s):  
Activation Energy ◽  
Palm Oil ◽  
Rate Constants ◽  
Potassium Hydroxide ◽  
Catalyst Concentration ◽  
Time Interval ◽  
Pseudo First Order Reaction ◽  
Exponential Factor ◽  
Potassium Methoxide ◽  
First Order

A study on palm oil transesterification to evaluate the effect of some parameters in the reaction on the reaction kinetics has been carried out. Transesterification was started by preparing potassium methoxide from potassium hydroxide and methanol and then mixed it with the palm oil. An aliquot was taken at certain time interval during transesterification and poured into test tube filled with distilled water to stop the reaction immediately. The oil phase that separated from the glycerol phase by centrifugation was analyzed by 1H-NMR spectrometer to determine the percentage of methyl ester conversion. Temperature and catalyst concentration were varied in order to determine the reaction rate constants, activation energies, pre-exponential factors, and effective collisions. The results showed that palm oil transesterification in methanol with 0.5 and 1 % w/w KOH/palm oil catalyst concentration appeared to follow pseudo-first order reaction. The rate constants increase with temperature. After 13 min of reaction, More methyl esters were formed using KOH 1 % than using 0.5 % w/w KOH/palm oil catalyst concentration. The activation energy (Ea) and pre-exponential factor (A) for reaction using 1 % w/w KOH was lower than those using 0.5 % w/w KOH.   Keywords: palm oil, transesterification, catalyst, first order kinetics, activation energy, pre-exponential factor

Partial Characterization of a Fibrinolytic Inhibitor Produced by Cultured Endothelial Cells Derived from Human Umbilical Vein

1982 ◽  
Vol 47 (02) ◽  
pp. 128-131 ◽  
Author(s):  
F Esnard ◽  
E Dupuy ◽  
A M Dosne ◽  
E Bodevin
Keyword(s):  
Endothelial Cells ◽  
Primary Culture ◽  
Ammonium Sulphate ◽  
Concanavalin A ◽  
Umbilical Vein ◽  
Human Umbilical Vein ◽  
Preliminary Characterization ◽  
Umbilical Vein Endothelial Cells ◽  
Ammonium Sulphate Saturation

SummaryA preliminary characterization of a fibrinolytic inhibitor released by human umbilical vein endothelial cells in primary culture is reported. This molecule of Mr comprised between 2 × 105 and 106 and of μ2 mobility precipitates at 43% ammonium sulphate saturation and is totally adsorbed on Concanavalin A Sepharose 4 B. A possible relationship with a macroglobulins is discussed.

Performance and Modelling of a Highway Wet Detention Pond Designed for Cold Climate

2009 ◽  
Vol 44 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Jes Vollertsen ◽  
Svein Ole Åstebøl ◽  
Jan Emil Coward ◽  
Tor Fageraas ◽  
Asbjørn Haaning Nielsen ◽  
...  
Keyword(s):  
Rate Constants ◽  
Pond Water ◽  
Pollutant Removal ◽  
Cold Climate ◽  
Traffic Load ◽  
Substantial Part ◽  
First Order ◽  
Detention Pond ◽  
Time Of Year ◽  
Wet Detention Pond

Abstract A wet detention pond in Norway has been monitored for 12 months. The pond receives runoff from a highway with a traffic load of 42,000 average daily traffic. Hydraulic conditions in terms of inflow, outflow, and pond water level were recorded every minute. Water quality was monitored by volume proportional inlet and outlet samples. During most of the year, excellent pollutant removal was achieved; however, during two snowmelt events the pollutant removal was poor or even negative. The two snowmelt events accounted for one third of the annual water load and for a substantial part of the annual pollutant discharge. The performance of the pond was analyzed using a dynamic model and pollutant removal was simulated by first-order kinetics. Good agreement between measurement and simulation could be achieved only when choosing different first-order rate constants for different parts of the year. However, no relation between the rate constants obtained and the time of year could be identified, and neither did the rate constants for different pollutants correlate. The study indicates that even detailed measurements of pollutant input and output allow only average performance to be simulated and are insufficient for simulating event-based variability in pond performance.

Submerged upflow biotower operation and computer simulation

1994 ◽  
Vol 30 (11) ◽  
pp. 143-146
Author(s):  
Ronald D. Neufeld ◽  
Christopher A. Badali ◽  
Dennis Powers ◽  
Christopher Carson
Keyword(s):  
Computer Simulation ◽  
Benzoic Acid ◽  
Computer Model ◽  
Rate Constants ◽  
Batch Mode ◽  
Operational Conditions ◽  
First Order ◽  
Low Concentrations ◽  
Biological Transformation ◽  
Kinetics Of

A two step operation is proposed for the biodegradation of low concentrations (< 10 mg/L) of BETX substances in an up flow submerged biotower configuration. Step 1 involves growth of a lush biofilm using benzoic acid in a batch mode. Step 2 involves a longer term biological transformation of BETX. Kinetics of biotransformations are modeled using first order assumptions, with rate constants being a function of benzoic acid dosages used in Step 1. A calibrated computer model is developed and presented to predict the degree of transformation and biomass level throughout the tower under a variety of inlet and design operational conditions.

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