Influence of Temperature on the Determination of Enzyme Activities in Human Serum

1977 ◽  
pp. 213-218
Author(s):  
K. Jung ◽  
W. Liese
1969 ◽  
Vol 15 (9) ◽  
pp. 995-1000 ◽  
Author(s):  
S. A. Palumbo ◽  
Lloyd D. Witter

The influence of temperature on the pathways of glucose catabolism in Pseudomonas fluorescens has been investigated using the radiorespirometry method. When grown in continuous culture with limiting concentrations of glucose, the organism metabolized 86% of the glucose via the Entner–Doudoroff pathway at 30, 20, and 8 C. The remaining glucose, 14%, was metabolized via the hexose monophosphate pathway. When the organism was grown on non-limiting concentrations of glucose at 8 C, a major shift in pathways of glucose catabolism was observed. Fifty-seven percent of the glucose was degraded via the hexose monophosphate pathway and only 43% via the Entner–Doudoroff pathway. A change in temperature altered the pathways of glucose catabolism by regulating the growth limiting concentration of glucose rather than by directly affecting the respective enzyme activities of the pathways.


Agromet ◽  
2018 ◽  
Vol 28 (1) ◽  
pp. 33
Author(s):  
Muhammad Syafei ◽  
Rini Hidayati

<em>This study aimed to determine the effect of altitude and rainfall on the incidence of disease ( IR ) diarrhea, and to obtain threshold values ​​of rainfall that often cause diarrhea. Determination category of normal rate of diarrhea IR is based on diarrhea IR by DINKES Bogor in the amount of 20-25/1000 population per year, while the determination of precipitation category is based on consideration of Oldeman climate classification. The results showed that there were two districts with very high levels of vulnerability i.e.  Cisarua and Cijeruk, while the other regions only at a moderate level. The negative influence of altitude (or positive influence of temperature) on the IR will be evident if the analysis is separated between in the highlands (&gt; 600 asl) and the lowlands (&lt; 600 asl). This influence is significant, especially at altitudes above 600 meters above sea level. The correlation of the precipitation is significant negative linear to the incidence of diarrhea in the district Cisarua, Cibinong, Jonggol, and Jasinga. In districts Cibinong, Jonggol, and Jasinga, precipitation should be anticipated in the range of 100-200 mm/month, where moderate IR often occurs, while in the district Cisarua, is in the range of precipitation 300-400 mm/month, where high IR often occurs.</em>


Tribologia ◽  
2016 ◽  
Vol 269 (5) ◽  
pp. 21-30 ◽  
Author(s):  
Marcin FRYCZ

In this paper, the authors presented research concerning the determination of the relation between magnetic susceptibility coefficient χ of ferro-oil and temperature changes. The tests were conducted on the ferro-oil samples of various, chosen magnetic particles concentrations: 1%, 2%, 4%, 6%, and 8%. In accordance with the conclusions resulting from Curie-Weiss equation, the values of magnetic susceptibility χ depend on the physicochemical features of considered material, including the magnitude and amount (concentration) of magnetic particles and physical properties of its environment, i.e. the kind and direction of magnetic field and also on the operating temperature, which is the main subject of conducted tests in this paper. This article presents the structure of the bench used for experimental designation of magnetic susceptibility coefficient in relation to temperature changes of tested ferro-oil. Moreover, the authors demonstrated a method enabling the determination of these values from obtained measurement data, conducted the analysis of obtained results and presented the conclusions.


1929 ◽  
Vol 2 (4) ◽  
pp. 505-516
Author(s):  
J. R. Sheppard

Abstract THE influence of temperature on vulcanization is too well known to require emphasis—it has been generally recognized for quite a number of years that the relation between temperature and time for ordinary curing ranges was logarithmic although there has been no unanimity as to the exact relationship. This doubtless is in part due to the varying experimental conditions employed by the investigators and possibly in some cases to less precise measurements. Table I, a partial bibliography, shows some values for the temperature coefficient which have been obtained and the conditions used. It will be seen that values ranging from 8 to 25 have been reported for the coefficient (in terms of degrees Fahrenheit required to double the rate of cure). It is the purpose of this paper to recount the writer's determination of the temperature coefficient for a given litharge stock in press cures—it is not safe perhaps to infer from the present results what might hold under certain other conditions.


2019 ◽  
Vol 7 (01) ◽  
pp. 294-301
Author(s):  
Vianne Diana Huamán Baca ◽  
Alejandro pablo Pletickosich ◽  
Teófila Baca Carbajal

ResumenEl objetivo de esta investigación fue determinar la influencia de la temperatura en la concentración de fluoruro de sodio; la muestra estuvo conformada por 60 geles fluorados de un mismo lote y la validez de dos marcas: ‘Fluofar®’ en sus dos presentaciones (pH neutro y acidulado) y el ‘Fluorgel Maquira®’ en sus dos presentaciones (pH neutro y acidulado). De cada gel fluorado se obtuvieron cuatro muestras: para comprobar el pH, para determinar la concentración de fluoruro de sodio a temperatura ambiente, para fijar la concentración de fluoruro de sodio después de haber sido sometido a una temperatura de 8 °C durante tres meses, y para, determinar la concentración de fluoruro de sodio después de haber sido sometido a una temperatura de 20 °C durante tres meses.La determinación de concentración de fluoruro de sodio, se realizó mediante la técnica de destilación y titulación. Por los resultados obtenidos se concluyó: que el incremento de la temperatura influye en la disminución de la concentración de fluoruro de sodio —siendo estadísticamente significativa en los geles fluorados con pH ácido (geles acidulados) y, en los geles fluorados con pH neutro mantiene su concentración—, aún se incrementó la temperatura. La concentración de fluoruro de sodio, indicado por el fabricante, disminuyó significativamente al comparar con la concentración de fluoruro de sodio encontrado en el laboratorio.Palabras claves; Geles fluorados, concentración de fluoruro de sodio, temperatura, pHAbstractThe objective of this investigation was to determine the influence of temperature on the concentration of sodium fluoride; the sample consisted of 60 fluorinated gels from the same batch and validity of two brands: Fluofar ® in its two presentations (neutral and acidulated pH) and Fluorgel Maquira ® and its two presentations (neutral pH and acidulated). From each fluorinated gel four samples were obtained: to determine the pH, to determine the concentration of sodium fluoride at room temperature, to determine the concentration of sodium fluoride after having been subjected to temperature of 8 °C for three months, and to determine the concentration of sodium fluoride after having been subjected to temperature of 20 °C for three months.The determination of concentration of Sodium Fluoride was carried out by means of the distillation and titration. From the results obtained, it was concluded that the increase in temperature influences the decrease in the concentration of sodium fluoride -being statistically significant in fluorinated gels with acidic pH (acidified gels) and, in fluorinated gels with neutral pH, it maintains its concentration-, the temperature was still increased. The concentration of sodium fluoride, indicated by the manufacturer, decreased significantly when compared to the concentration of sodium fluoride found in the laboratory.


2014 ◽  
Vol 811 ◽  
pp. 77-82
Author(s):  
Martina Ivašková ◽  
Martin Lovíšek ◽  
Peter Jančovič ◽  
Lenka Bukovinová

Titanium is not only the most widely used biomaterial for medical implants, but with its very good mechanical properties, corrosion resistance and low density is also applicated in many sectors of industry (aerospace, military, aviation, machinery, energetics, chemicals, etc.). In this paper it is described the influence of temperature on the electrochemical characteristics of Ti-6Al-4V alloy. The surface was mechanically grinded and polished by chemical-mechanical process. Basic electrochemical characteristics were determined by potentiodynamic tests in 0.1M NaCl solution at different temperatures. The obtained results were analysed by the Tafel-extrapolation method. Finally, a modified Arrhenius relation was used for determination of activation energy. The activation energy of grinded and chemical-mechanical polished surface is nearly three times higher than activation energy of only grinded surface.


1881 ◽  
Vol 31 (206-211) ◽  
pp. 413-415

In my “Notes of Observations on Musical Beats,” I stated (“Proc. Roy. Soc.,” vol. 30, p. 532) that the influence of temperature on harmonium reeds was, so far as I was aware, unknown. Since then I have made some observations which at least approximately determine it, but there are so m any sources of small errors (stated below) that still more uncertainty must attach to the results, than to the determination of the influence of temperature on the pitch of tuning-forks ( ibid ., p. 523). Roughly we may say that the pitch of harmonium reeds is affected in the same direction as that of tuning-forks (heat flattening and cold sharpening), and very nearly to twice the amount, that is, by about 1 in 10,000 vibrations for each degree Fahrenheit.


1955 ◽  
Vol 33 (1) ◽  
pp. 568-574 ◽  
Author(s):  
W. Kalow ◽  
H. A. Lindsay

A method for the assay of human serum cholinesterase (pseudocholinesterase) is described in detail. The disappearance of benzoylcholine is measured by ultraviolet spectrophotometry. Minute amounts of serum and of the substrate are sufficient for a rapid and convenient test of good accuracy. The influence of temperature on the reaction rate is given particular attention, since temperature control is not as easily achieved in the spectrophotometer as for instance in a Warburg apparatus. Although the results of the spectrophotometric assay are fundamentally the same as those obtained by using a conventional gasometric method with acetylcholine as a substrate, small but significant differences between the two answers occur. These differences depend on the substrates and not on the methods as such. The ratio of hydrolysis rates of the two substrates, benzoylcholine and acetylcholine, varies slightly from person to person. If benzoylcholine is used in the Warburg apparatus, a concentration above the optimum must be employed in order to develop sufficient gas for measurement.


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