WORKING BASIS FOR THE TRACER MEASUREMENT OF TRANSFER RATES OF A METABOLIC FACTOR IN BIOLOGICAL SYSTEMS CONTAINING COMPARTMENTS WHOSE CONTENTS DO NOT INTERMIX RAPIDLY

1955 ◽  
Vol 33 (6) ◽  
pp. 909-925 ◽  
Author(s):  
Gerald A. Wrenshall
Keyword(s):  
Chemical Element ◽  
Dynamic Equilibrium ◽  
Biological Systems ◽  
Central Compartment ◽  
Constrained Systems ◽  
Sources Of Information ◽  
Transfer Rates ◽  
Molecular Substances ◽  
Living Organisms

A working basis is developed for the simultaneous measurement, by means of an isotopic or other label, of all transfer rates of a given chemical element in systems where its transfer between spatially separate compartments of the system must occur by way of a central compartment (mammillary systems). In addition to the measurement of all rates of transfer, the amount of the element within each compartment of a mammillary system can be determined from the same experimental data. The method is applicable in open as well as closed mammillary systems which may or may not be in a state of dynamic equilibrium, and in which rapid uniform intermixing of the element does not occur in peripheral compartments. A basis for the determination of the total rates of appearance and disappearance of multiatomic as well as monatomic substances in any compartment of a system of compartments is presented, without exchanges being restricted to mammillary or other constrained systems. However, only in compartments where chemical transformation of such molecular substances does not occur can the calculated rates of appearance and disappearance of the metabolite be interpreted as rates of transfer into and out of the compartment. Specific problems relating to the tracer measurement of transfer rates in the mammillary systems of living organisms are considered, and a check list is presented for evaluating published experimental results involving tracers as potential sources of information on transfer rates in biological systems determined by means of the above bases for calculation.

WORKING BASIS FOR THE TRACER MEASUREMENT OF TRANSFER RATES OF A METABOLIC FACTOR IN BIOLOGICAL SYSTEMS CONTAINING COMPARTMENTS WHOSE CONTENTS DO NOT INTERMIX RAPIDLY

1955 ◽  
Vol 33 (1) ◽  
pp. 909-925 ◽  
Author(s):  
Gerald A. Wrenshall
Keyword(s):  
Chemical Element ◽  
Dynamic Equilibrium ◽  
Biological Systems ◽  
Central Compartment ◽  
Constrained Systems ◽  
Sources Of Information ◽  
Transfer Rates ◽  
Molecular Substances ◽  
Living Organisms

A working basis is developed for the simultaneous measurement, by means of an isotopic or other label, of all transfer rates of a given chemical element in systems where its transfer between spatially separate compartments of the system must occur by way of a central compartment (mammillary systems). In addition to the measurement of all rates of transfer, the amount of the element within each compartment of a mammillary system can be determined from the same experimental data. The method is applicable in open as well as closed mammillary systems which may or may not be in a state of dynamic equilibrium, and in which rapid uniform intermixing of the element does not occur in peripheral compartments. A basis for the determination of the total rates of appearance and disappearance of multiatomic as well as monatomic substances in any compartment of a system of compartments is presented, without exchanges being restricted to mammillary or other constrained systems. However, only in compartments where chemical transformation of such molecular substances does not occur can the calculated rates of appearance and disappearance of the metabolite be interpreted as rates of transfer into and out of the compartment. Specific problems relating to the tracer measurement of transfer rates in the mammillary systems of living organisms are considered, and a check list is presented for evaluating published experimental results involving tracers as potential sources of information on transfer rates in biological systems determined by means of the above bases for calculation.

DIRECT VERSUS TRACER MEASUREMENT OF TRANSFER RATES IN A HYDRODYNAMIC SYSTEM CONTAINING A COMPARTMENT WHOSE CONTENTS DO NOT INTERMIX RAPIDLY

1955 ◽  
Vol 33 (1) ◽  
pp. 940-947 ◽  
Author(s):  
Harry Schachter
Keyword(s):  
Model Experiment ◽  
Dynamic Equilibrium ◽  
Preceding Paper ◽  
Central Compartment ◽  
Water Transfer ◽  
Peripheral Compartment ◽  
Transfer Rates ◽  
Stop Watch ◽  
Crystal Violet Dye ◽  
Tracer Dilution

The working basis for the measurement of transfer rates between compartments developed in a preceding paper by Wrenshall is demonstrated for a closed hydrodynamic mammillary system in dynamic equilibrium. Rapid uniform intermixing of the water in one of the peripheral compartments was prevented by the presence there of glass tubelets. Rates of water transfer were measured directly with a graduate cylinder and stop watch, and calculated by means of equation [9] of the preceding paper, using crystal violet dye as tracer. It is clearly demonstrated that to measure transfer rates between the central compartment and the non-uniformly mixing peripheral compartment, it is necessary to extrapolate all tracer measurements to lime of tracer addition to the central compartment. The amount of water contained in the central compartment was measured in the same experiment both directly and by tracer dilution. The procedures and problems involved in performing the above model experiment are compared with those encountered in the tracer measurement of transfer rates and compartmental contents in living mammillary systems.

scholarly journals THE CALCULATION OF TRANSFER RATES IN TWO COMPARTMENT SYSTEMS NOT IN DYNAMIC EQUILIBRIUM

1958 ◽  
Vol 41 (6) ◽  
pp. 1135-1152 ◽  
Author(s):  
Eugene Y. Berger ◽  
J. Murray Steele
Keyword(s):  
Biological System ◽  
Dynamic Equilibrium ◽  
Specific Activity ◽  
Biological Systems ◽  
Mathematical Treatment ◽  
Compartment System ◽  
Transfer Rates ◽  
Unequal Rates ◽  
Analytical Errors

Dynamic equilibrium in a biological system implies that the compartment under study does not change in size during the period of observation. In many biological systems there are, however, net changes with time and this report deals with the mathematical treatment necessary to calculate unequal rates of inflow and outflow. A method is presented for the calculation of transfer rates in a two compartment system when the rates of flow between these compartments are unequal but constant. Equations were developed to calculate the amount of material transported per unit time derived from measurements of specific activity and compartment size. The problems of (1) sampling from the pool and (2) the effects of analytical errors on the estimation of rate have been evaluated. An example has been presented in which the derived equations have been applied to a study of the simultaneous passage of sodium into and out of a permanently isolated loop of bowel.

DIRECT VERSUS TRACER MEASUREMENT OF TRANSFER RATES IN A HYDRODYNAMIC SYSTEM CONTAINING A COMPARTMENT WHOSE CONTENTS DO NOT INTERMIX RAPIDLY

1955 ◽  
Vol 33 (6) ◽  
pp. 940-947 ◽  
Author(s):  
Harry Schachter
Keyword(s):  
Model Experiment ◽  
Dynamic Equilibrium ◽  
Preceding Paper ◽  
Central Compartment ◽  
Water Transfer ◽  
Peripheral Compartment ◽  
Transfer Rates ◽  
Stop Watch ◽  
Crystal Violet Dye ◽  
Tracer Dilution

The working basis for the measurement of transfer rates between compartments developed in a preceding paper by Wrenshall is demonstrated for a closed hydrodynamic mammillary system in dynamic equilibrium. Rapid uniform intermixing of the water in one of the peripheral compartments was prevented by the presence there of glass tubelets. Rates of water transfer were measured directly with a graduate cylinder and stop watch, and calculated by means of equation [9] of the preceding paper, using crystal violet dye as tracer. It is clearly demonstrated that to measure transfer rates between the central compartment and the non-uniformly mixing peripheral compartment, it is necessary to extrapolate all tracer measurements to lime of tracer addition to the central compartment. The amount of water contained in the central compartment was measured in the same experiment both directly and by tracer dilution. The procedures and problems involved in performing the above model experiment are compared with those encountered in the tracer measurement of transfer rates and compartmental contents in living mammillary systems.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

APPLICATION OF ADSORPTION METHOD FOR DETERMINATION OF LOCAL CONVECTIVE HEAT TRANSFER RATES

1974 ◽  
Author(s):  
S. Koncar-Djurdjevic ◽  
M. Mitrovic ◽  
S. Cvijovic ◽  
G. Popovic ◽  
Dimitrije Voronjec
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Adsorption Method ◽  
Transfer Rates

Fluorescence chemosensors for hydrogen sulfide detection in biological systems

The Analyst ◽  
2015 ◽  
Vol 140 (6) ◽  
pp. 1772-1786 ◽  
Author(s):  
Zhi Guo ◽  
Guiqiu Chen ◽  
Guangming Zeng ◽  
Zhongwu Li ◽  
Anwei Chen ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Biological Systems ◽  
Sulfate Reducing Bacteria ◽  
Fluorescence Sensing ◽  
Sulfate Reducing ◽  
Potential Applications ◽  
Reducing Bacteria

The development of H2S fluorescence-sensing strategies and their potential applications in the determination of sulfate-reducing bacteria activity.

Biopolymers: A comprehensive review

2022 ◽  
Vol 4 (1) ◽  
pp. 013-018
Author(s):  
Mohini Chandrashekhar Upadhye ◽  
Mohini Chetan Kuchekar ◽  
Rohini Revansiddhappa Pujari ◽  
Nutan Uttam Sable
Keyword(s):  
Pharmaceutical Industry ◽  
Food Packaging ◽  
Biological Systems ◽  
Review Article ◽  
Skin Care ◽  
Comprehensive Review ◽  
Green Nanotechnology ◽  
Biological Sources ◽  
Living Organisms

Biopolymers are compounds prepared by using various living organisms, including plants. These are composed of repeated units of the same or similar structure (monomers) linked together. Rubber, starch, cellulose, proteins and DNA, RNA, chitin, and peptides are some of the examples of natural biopolymers. Biopolymers are a diverse and remarkably versatile class of materials that are either produced by biological systems or synthesize from biological sources. Biopolymers are used in pharmaceutical industry and also in food industry.Naturally derived polymers are also used for conditioning benefits in hair and skin care. Biopolymers have various applications in medicine, food, packaging, and petroleum industries. This review article is focused on various aspects of biopolymers with a special emphasis on role of biopolymers in green nanotechnology and agriculture.

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