THE PRODUCTION OF Na22 BY A (H3, n) REACTION IN A NUCLEAR REACTOR

1954 ◽  
Vol 32 (2) ◽  
pp. 94-97 ◽  
Author(s):  
L. G. Cook ◽  
K. D. Shafer
Keyword(s):  
Aluminum Alloy ◽  
Ion Exchange ◽  
Neutron Flux ◽  
Paper Chromatography ◽  
Half Life ◽  
Nuclear Reactor ◽  
Specific Activity ◽  
Separation And Purification

The positron emitting Na22 of 2.6 year half-life has been prepared in a nuclear reactor by the double reaction Li6(n, α)H3, Ne20(H3, n)Na22. The over-all yield was 2.3 × 10−7 atoms of Na22 per atom of tritium formed. Eleven grams of lithium as aluminum alloy turnings in a neon atmosphere at 200 p.s.i. was irradiated for 175 days in a neutron flux of about 4 × 1012 n./cm.2/sec. About 380 μc. of Na22 was obtained in a sodium extract having a specific activity of 10 mc. Na22/gm. of Na23. A specific activity in the curie/gm. level would be expected from a longer irradiation in the highest flux (6 × 1013 n./cm.2/sec.) in the NRX reactor. The separation and purification of the sodium proved practicable by paper chromatography or ion exchange; the analyses for trace Li and Na23 were carried out by radioactivation.

scholarly journals FEASIBILITY STUDY FOR PRODUCTION OF IODINE-131 USING DIOXIDE OF TELLURIUM-130

2016 ◽  
Vol 8 (11) ◽  
pp. 327 ◽  
Author(s):  
Abdessamad Didi ◽  
Ahmed Dadouch ◽  
Hassane El Bekkouri
Keyword(s):  
Nuclear Medicine ◽  
Neutron Activation ◽  
Neutron Flux ◽  
Half Life ◽  
Nuclear Reactor ◽  
Essential Elements ◽  
Medical Radioisotopes ◽  
The World ◽  
Iodine 131 ◽  
Irradiation Cycle

Objective: Currently, nuclear medicine is becoming increasingly important, through the discovery of several medical radioisotopes, which are used in diagnosis, treatment, and medical imaging. Among the most important radionuclide which is commonly used is iodine-131, with a half-life of 8.02 d. Iodine-131 is one of the mainly essential elements in nuclear medicine. Since their first use, several studies have been conducted to meet the world need of hospital specialists in nuclear medicine. The purpose of this study was to participate in a lawsuit about the feasibility of producing 131I.Methods: using neutron activation of the dioxide of tellurium (TeO2) under a neutron flux which varies between 5 1011 and 1013 n/cm²s for 4, 6 and 8 hours** per irradiation cycle during 5 d, and used the Fortron90 Code to calculate the activity of iodine-131.Results: The result of the activity of iodine-131 found about 4,634 Curie with an irradiation of 4 hours** per day and 9.381 Curie with an activation of 8 hours** per day.Conclusion: Production of iodine-131 can be very effective if an acceptable capsule is used for different masses of tellurium and a neutron flux in a nuclear reactor.

THE LESS-POLAR METABOLITES PRODUCED BY INCUBATION OF TESTOSTERONE-4-14C WITH RAT AND BOVINE BRAIN

1969 ◽  
Vol 61 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Leon J. Sholiton ◽  
Emile E. Werk
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Paper Chromatography ◽  
Specific Activity ◽  
Bovine Brain ◽  
Polar Fraction ◽  
End Products ◽  
Polar Metabolites ◽  
Layer Chromatography ◽  
Constant Specific Activity

ABSTRACT Rat and bovine brain have been incubated with testosterone-4-14C under standard conditions. With use of paper chromatography, the extracted metabolites were noted to fall into less-polar, iso-polar, and more polar fractions. The components of the less-polar fraction were separated by acetylation and thin-layer chromatography and the major end-products identified by recrystallization to constant specific activity or constant 3H/14C ratios. Androst-4-enedione and 5α-dihydrotestosterone were formed consistently under the conditions utilized. Trace amounts of other less-polar metabolites were noted occasionally.

Simultaneous optimization of activity and stability of xylose reductase from D. nepalensis NCYC 3413 using statistical experimental design

2020 ◽  
Vol 27 ◽  
Author(s):  
Shwethashree Malla ◽  
Sathyanarayana N. Gummadi
Keyword(s):  
Half Life ◽  
Specific Activity ◽  
Enzyme Stability ◽  
Reductase Activity ◽  
Xylose Reductase ◽  
Life Time ◽  
Economic Feasibility ◽  
Simultaneous Optimization ◽  
Physical Parameters ◽  
Statistical Experimental Design

Background: Physical parameters like pH and temperature play a major role in the design of an industrial enzymatic process. Enzyme stability and activity are greatly influenced by these parameters; hence optimization and control of these parameters becomes a key point in determining the economic feasibility of the process. Objective: This study was taken up with the objective to optimize physical parameters for maximum stability and activity of xylose reductase from D. nepalensis NCYC 3413 through separate and simultaneous optimization studies and comparison thereof. Method: Effects of pH and temperature on the activity and stability of xylose reductase from Debaryomyces nepalensis NCYC 3413 were investigated by enzyme assays and independent variables were optimised using surface response methodology. Enzyme activity and stability were optimised separately and concurrently to decipher the appropriate conditions. Results: Optimized conditions of pH and temperature for xylose reductase activity were determined to be 7.1 and 27 ℃ respectively, with predicted responses of specific activity (72.3 U/mg) and half-life time (566 min). The experimental values (specific activity 50.2 U/mg, half-life time 818 min) were on par with predicted values indicating the significance of the model. Conclusion: Simultaneous optimization of xylose reductase activity and stability using statistical methods is effective as compared to optimisation of the parameters separately.

Precision determination of252Cf half-life and the time dependence of the neutron flux of a Ra - Be(?, n) source

Atomic Energy ◽  
1992 ◽  
Vol 73 (6) ◽  
pp. 1015-1017
Author(s):  
V. T. Shchebolev ◽  
N. N. Moiseev ◽  
Z. A. Ramendik
Keyword(s):  
Neutron Flux ◽  
Time Dependence ◽  
Half Life ◽  
N Source ◽  
Precision Determination

Posttranslational modifications of recombinant myotube-synthesized human factor IX

Blood ◽  
2001 ◽  
Vol 97 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Valder R. Arruda ◽  
James N. Hagstrom ◽  
Jeffrey Deitch ◽  
Terry Heiman-Patterson ◽  
Rodney M. Camire ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Posttranslational Modifications ◽  
Half Life ◽  
Specific Activity ◽  
Factor Ix ◽  
Serine Phosphorylation ◽  
Hemophilia B ◽  
Tyrosine Sulfation ◽  
Aav Vector ◽  
Carbohydrate Analysis

Abstract Recent data demonstrate that the introduction into skeletal muscle of an adeno-associated viral (AAV) vector expressing blood coagulation factor IX (F.IX) can result in long-term expression of the transgene product and amelioration of the bleeding diathesis in animals with hemophilia B. These data suggest that biologically active F.IX can be synthesized in skeletal muscle. Factor IX undergoes extensive posttranslational modifications in the liver, the normal site of synthesis. In addition to affecting specific activity, these posttranslational modifications can also affect recovery, half-life in the circulation, and the immunogenicity of the protein. Before initiating a human trial of an AAV-mediated, muscle-directed approach for treating hemophilia B, a detailed biochemical analysis of F.IX synthesized in skeletal muscle was carried out. As a model system, human myotubes transduced with an AAV vector expressing F.IX was used. F.IX was purified from conditioned medium using a novel strategy designed to purify material representative of all species of rF.IX in the medium. Purified F.IX was analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), N-terminal sequence analysis, chemical γ-carboxyglutamyl analysis, carbohydrate analysis, assays for tyrosine sulfation, and serine phosphorylation, and for specific activity. Results show that myotube-synthesized F.IX has specific activity similar to that of liver-synthesized F.IX. Posttranslational modifications critical for specific activity, including removal of the signal sequence and propeptide, and γ-carboxylation of the N-terminal glutamic acid residues, are also similar, but carbohydrate analysis and assessment of tyrosine sulfation and serine phosphorylation disclose differences. In vivo experiments in mice showed that these differences affect recovery but not half-life of muscle-synthesized F.IX.

Notes. Ion Exchange Paper Chromatography

1958 ◽  
Vol 23 (8) ◽  
pp. 1229-1230 ◽  
Author(s):  
D Myhre ◽  
F Smith
Keyword(s):  
Ion Exchange ◽  
Paper Chromatography

scholarly journals Isolation, partial purification and characterization of phospholipase A2 from Naja Katiensis venom

2021 ◽  
Vol 13 (2) ◽  
pp. 107-112
Author(s):  
C.F. Okechukwu ◽  
P.L. Shamsudeen ◽  
R.K. Bala ◽  
B.G. Kurfi ◽  
A.M. Abdulazeez
Keyword(s):  
Ion Exchange ◽  
Phospholipase A2 ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Partial Purification ◽  
Crude Venom

The most effective and acceptable therapy for snakebite victims is the immediate administration of antivenin which is limited by problems of hypersensitivity reactions in some individuals and its inability to resolve the local effects of the venom. The aim of this study was to isolate, partially purify and characterize phospholipase A2 from Naja Katiensis venom. Phospholipase A2 was partially purified via a two-step process: gel filtration on Sephadex G-75 and ion exchange chromatography using CM Sephadex, and subjected to SDS-PAGE analysis. From the results, the specific activity of the partially purified PLA2 decreased from 0.67μmol/min/mg in crude venom to 0.29μmol/min/mg after ion exchange chromatography with a yield of 5% and purification fold of 0.43. The optimum temperature of the purified PLA2 was found to be 35ºC and optimum p.H of 7. velocity studies for the determination of kinetic constants using L-a-lecithin as substrate revealed a Km  of 1.47mg/ml and Vmax  of 3.32μ moles/min/mg. The sodium dodecyl sulphate polyacrylamide gel electrophoresis of the purified PLA2 showed a distinct band with molecular weight estimated to be 14KDa. In conclusion, the present study shows that phospholipase A2 was isolated, purified and characterized. This may serve as a promising candidate for future development of a novel anti-venin drug.

scholarly journals ADSORBATIVE SEPARATION OF DOXYCYCLINE FROM AQUEOUS SOLUTION WITH N,N-DIETHYL N-METHYL CHITOSAN, GUM AND POLYACRYLIC ACID BASED HYDROGELS

2021 ◽  
Vol 11 (07) ◽  
pp. 44-53
Author(s):  
Mirvari Hasanova Mirvari Hasanova
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Zeta Potential ◽  
Polyacrylic Acid ◽  
Inorganic Materials ◽  
Biologically Active ◽  
Cross Linking ◽  
Separation And Purification ◽  
Inorganic Substances ◽  
The Cross

The separation and purification of antibiotics with sorption by ion-exchange materials, as well as their delivery in biological processes by immobilization, are now widely used in biotechnology. There are many scientific studies in the literature on the sorption of antibiotics by polymer-based sorbents and inorganic materials, as well as the study of thermodynamics and kinetics of the process. In the literature, the acquisition of biologically active systems from the sorption of antibiotics by ion-exchange fibers based on various polymers and inorganic substances was carried out. However, the synthesis of selective gels for the effective separation of doxycycline and its delivery in different pH mediums by sorption with biodegradable, biocompatible polysaccharide-containing composites is one of the topical issues. Gel was synthesized from the cross-linking of N,N-diethyl N-methyl derivative of a natural polyaminosaccharide of chitosan by glutaric aldehyde. Also, pH-sensitive hydrogels that can swollen in water were synthesized from the cross-linking of a graft copolymer of cherry source gummiarabic with N-vinylpyrrolidone, as well as synthetic polymer polyacrylic acid with N,N-methylene-bis-acrylamide. The structure of the gels were identified by FTIR and NMR spectroscopy, and the sorption of doxycycline antibiotic from an aqueous solution was investigated. According to the values of zeta potential, the protonation of functional groups in the main macromolecule in an acidic medium leads to a value of zeta potential of 40÷80 mV on the surface of chitosan-based gel and others. Although the chemical structure is different, the isoelectric point is set around pH=6÷8 for all three hydrogels. The dependences of the sorption process on the amount of gels, antibiotic concentration, temperature, and pH medium were studied. The experimental data were analyzed using two adsorption models, Langmuir and Freundlich, with the later system providing the best fit. Doxycycline is adsorbed on the surface of chitosan, gummiarabic and polyacrylic acid based hydrogel composite through by physical interactions. Also, the results of thermodynamic parameters ΔG40 kJ/mol show that the nature of the adsorption process is physical, and spontaneous, too. Keywords: Chitosan, Gummiarabic-arabinogalactane, polyacrylic acid, hydrogel, sorption isoterms, doxycycline, thermodynamica.

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