A ROUTINE PROCEDURE FOR THE DETERMINATION OF CATECHOLAMINES IN URINE AND TISSUES

1957 ◽  
Vol 35 (9) ◽  
pp. 711-719 ◽  
Author(s):  
Theodore L. Sourkes ◽  
Boris D. Drujan
Keyword(s):  
Extraction Process ◽  
Small Error ◽  
Routine Laboratory ◽  
Routine Procedure ◽  
Second Stage ◽  
Internal Indicator ◽  
Average Factor ◽  
Simplified Procedure ◽  
Catecholamines In Urine

A simplified procedure for the determination of catecholamines, suitable for routine laboratory use, has been developed. The whole of the adsorption–elution process, by which the catecholamines are concentrated and purified, is performed in one flask. The potentiometric titration required at this stage in the adsorption of the catecholamines on alumina is avoided by the use of phenol-phthalein as an internal indicator. The fluorimetric estimation in the second stage of the procedure is based upon lutin formation, a reaction nearly specific for adrenaline and noradrenaline. The small error resulting from the presence of hydroxytyramine in the urine is discussed. The method provides for the determination of losses encountered in the extraction process, so that each run includes an internal correction rather than an assumed average factor. Examples of the utility of the method are given. These include the determination of the rate of excretion of catecholamines in the urine, the effect of insulin on this rate, and the estimation of the catecholamine content of rat organs.

A ROUTINE PROCEDURE FOR THE DETERMINATION OF CATECHOLAMINES IN URINE AND TISSUES

1957 ◽  
Vol 35 (1) ◽  
pp. 711-719 ◽  
Author(s):  
Theodore L. Sourkes ◽  
Boris D. Drujan
Keyword(s):  
Extraction Process ◽  
Small Error ◽  
Routine Laboratory ◽  
Routine Procedure ◽  
Second Stage ◽  
Internal Indicator ◽  
Average Factor ◽  
Simplified Procedure ◽  
Catecholamines In Urine

A simplified procedure for the determination of catecholamines, suitable for routine laboratory use, has been developed. The whole of the adsorption–elution process, by which the catecholamines are concentrated and purified, is performed in one flask. The potentiometric titration required at this stage in the adsorption of the catecholamines on alumina is avoided by the use of phenol-phthalein as an internal indicator. The fluorimetric estimation in the second stage of the procedure is based upon lutin formation, a reaction nearly specific for adrenaline and noradrenaline. The small error resulting from the presence of hydroxytyramine in the urine is discussed. The method provides for the determination of losses encountered in the extraction process, so that each run includes an internal correction rather than an assumed average factor. Examples of the utility of the method are given. These include the determination of the rate of excretion of catecholamines in the urine, the effect of insulin on this rate, and the estimation of the catecholamine content of rat organs.

scholarly journals Quantitative Determination of Azithromycin in Human Plasma by Liquid Chromatography–Mass Spectrometry and its Application in Pharmackokinetic Study

2012 ◽  
Vol 11 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Maizbha Uddin Ahmed ◽  
Mohammad Safiqul Islam ◽  
Tasmin Ara Sultana ◽  
AGM Mostofa ◽  
Muhammad Shahdaat Bin Sayeed ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Solid Phase ◽  
Internal Standard ◽  
Extraction Process ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Linear Concentration Range ◽  
Linear Concentration

Azithromycin is an effective and well-known antimicrobial agent. In the present study, a simple, sensitive and specific LC/MS/MS method has been developed and validated for the quantification of Azithromycin in  human serum samples using Clarithromycin as internal standard. Azithromycin was extracted from biological matrix  by using solid phase extraction process. The chromatographic separation was performed on Luna C18 (3 ?, 2x150   mm) column with a mobile phase consisting of 35 mM ammonium acetate buffer (mobile phase-A) and acetonitrile  and methanol in ratio of 90:10 ( as mobile phase-B) at a flow rate of 0.25 mL/min. The method was validated over a  linear concentration range of 0.5?50.0 ng/mL and limit of quantification (LOQ) was 0.5 ng/mL with a coefficient of  correlation (r2) = 0.9998. The intra-day and inter-day precision expressed as relative standard deviation were 1.64% – 8.43% and 2.32% – 9.92%, respectively. The average recovery of azithromycin from serum was 98.11%. The method  was successfully applied to a pharmacokinetic study after oral administration of Azithromycin 200 mg/5 ml suspension in healthy Bangladeshi volunteers. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12488 Dhaka Univ. J. Pharm. Sci. 11(1): 55-63, 2012 (June)

scholarly journals Red-lesion extraction in retinal fundus images by directional intensity changes’ analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maryam Monemian ◽  
Hossein Rabbani
Keyword(s):  
Sensitivity And Specificity ◽  
Retinal Disease ◽  
Extraction Process ◽  
Efficient Performance ◽  
Intensity Changes ◽  
Significant Intensity ◽  
Almost All ◽  
Retinal Fundus ◽  
Distinguishing Features

AbstractDiabetic retinopathy (DR) is an important retinal disease threatening people with the long diabetic history. Blood leakage in retina leads to the formation of red lesions in retina the analysis of which is helpful in the determination of severity of disease. In this paper, a novel red-lesion extraction method is proposed. The new method firstly determines the boundary pixels of blood vessel and red lesions. Then, it determines the distinguishing features of boundary pixels of red-lesions to discriminate them from other boundary pixels. The main point utilized here is that a red lesion can be observed as significant intensity changes in almost all directions in the fundus image. This can be feasible through considering special neighborhood windows around the extracted boundary pixels. The performance of the proposed method has been evaluated for three different datasets including Diaretdb0, Diaretdb1 and Kaggle datasets. It is shown that the method is capable of providing the values of 0.87 and 0.88 for sensitivity and specificity of Diaretdb1, 0.89 and 0.9 for sensitivity and specificity of Diaretdb0, 0.82 and 0.9 for sensitivity and specificity of Kaggle. Also, the proposed method has a time-efficient performance in the red-lesion extraction process.

scholarly journals Theoretical justification of pedagogical situations cognitive modeling

2018 ◽  
Vol 7 (2) ◽  
pp. 245-247
Author(s):  
Alsu Raufovna Kamaleeva ◽  
Svetlana Yurevna Gruzkova
Keyword(s):  
Cognitive Modeling ◽  
Cognitive Model ◽  
Cognitive Map ◽  
Educational Process ◽  
Theoretical Justification ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Major Factors

The following paper deals with the application of methodology of pedagogical situations cognitive modeling, which is considered by the authors as a process consisting of six consecutive and interconnected stages. The first stage is a formulation of the purpose and the corresponding tasks. The second stage provides collecting, systematization and analysis of a pedagogical situation with the subsequent allocation of the major factors influencing development of the situation and determination of interrelation between them, i.e. creation of a cognitive map. At the third stage a focused count is created as a result of accounting of the cause and effect chains reflecting the system of interaction between the educational process subjects and allowing to form a pedagogical theory on the basis of basic person study categories: consciousness, thinking, knowledge, understanding, etc. The fourth stage assumes combination of the cognitive map and the focused count in a uniform cognitive model of the studied pedagogical situation. The fifth stage is focused on a real pedagogical situation cognitive model adequacy check i.e. on its verification. The last sixth stage allows to define possible options of a pedagogical situation development by a cognitive model, to find ways and mechanisms of a situation impact.

scholarly journals Investigation of Complex Structural Designing of Mobile Facilities for Shipbuilding in Lithuanian Sea Region

Mechanika ◽  
2021 ◽  
Vol 27 (3) ◽  
pp. 237-243
Author(s):  
Tadas ASTRAUSKAS ◽  
Michail SAMOFALOV
Keyword(s):  
Dynamic Analysis ◽  
Longitudinal Direction ◽  
Cross Sectional ◽  
Climatological Data ◽  
Second Stage ◽  
Third Stage ◽  
Calculation Results ◽  
Complex Structural ◽  
Mobile Facilities

In the paper, it is proposed to cover by a mobile moving facility the shipyard open site, in Klaipeda, Lithuania (the EU). The facility of 40 m span consists of transversal frames, which are arranged by the step of 6.0 m, and a system of braces. Two types of steel frames have been considered: trussed and continuous. The actions are specified according to the design codes (Eurocode 3) and climatological data. In dynamic analysis, the longitudinal direction is defined for an inertia action, simulating braking. For calculating, a special algorithm of three stages has been prepared. At the first stage, three calculation schemes of one transversal frame were created. For the proposed schemes of the mobile moving facility, the calculation of only a transversal frame is effective in the preliminary determination of the cross-sectional areas and of the total structural weight. At the second stage, the frames were joined by braces. A preliminary comparison of the calculation results of the models was carried out after the first and second stages of the analysis. At the third stage, the dynamic analysis was performed and the influence of the dynamic impact was estimated. Finally, we compared the calculation results of three different FEM models and chose the most appropriate one. To sum up the investigations, conclusions and recommendations are presented.

scholarly journals Set Covering Model in Solving Multiple Cutting Stock Problem

2020 ◽  
Vol 5 (4) ◽  
pp. 121
Author(s):  
Sisca Octarina ◽  
Devi Gusmalia Juita ◽  
Ning Eliyati ◽  
Putra Bahtera Jaya Bangun
Keyword(s):  
Column Generation ◽  
Pattern Generation ◽  
Cutting Stock Problem ◽  
Set Covering ◽  
Cutting Stock ◽  
Second Stage ◽  
Generation Technique ◽  
Cutting Pattern ◽  
Covering Model

Cutting Stock Problem (CSP) is the determination of how to cut stocks into items with certain cutting rules. A diverse set of stocks is called multiple stock CSP. This study used Pattern Generation (PG) algorithm to determine cutting pattern, then formulated it into a Gilmore and Gomory model and solved by using Column Generation Technique (CGT). Set Covering model was generated from Gilmore and Gomory model. Based on the results, selected cutting patterns in the first stage can be used in the second stage. The combination of patterns generated from Gilmore and Gomory model showed that the use of stocks was more effective than Set Covering model.  

scholarly journals Influence of pressure and time on extraction process using supercritical CO2

2008 ◽  
Vol 44 (1) ◽  
pp. 125-131 ◽  
Author(s):  
V. Micic ◽  
Z. Lepojevic ◽  
B. Mandic ◽  
M. Jotanovic ◽  
G. Tadic ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Co2 ◽  
Particle Diameter ◽  
Extraction Process ◽  
Salvia Officinalis ◽  
Quantitative Composition ◽  
Qualitative And Quantitative ◽  
Salvia Officinalis L ◽  
Carbon Dioxide Co2

The supercritical fluid extraction (SFE) by carbon dioxide (CO2) of Salvia officinalis L. was investigated. SFE by CO2 was performed at different pressure (80, 100, 150, 200 and 300 bar) and constant temperature of 40?C (all other extraction conditions, such are flow rate, particle diameter of Salvia officinalis, extraction time were kept constant. The GC-MS method was used for determination of qualitative and quantitative composition of obtained extracts and essential oils.

scholarly journals THE INFLUENCE OF THE SHAPE OF WORKING SURFACE OF STRAIGHTENING ROLLERS OF VERTICAL AND HORIZONTAL STRAIGHTENING MACHINES ON THE STATE OF RESIDUAL STRESSES IN RAILWAY RAIL – SECOND STAGE OF RESEARCHES

2020 ◽  
Vol 72 (1) ◽  
pp. 48-58
Keyword(s):  
Residual Stresses ◽  
Symmetry Axis ◽  
The State ◽  
Roll Pass ◽  
Distribution Maps ◽  
Second Stage ◽  
Working Surface ◽  
National Centre ◽  
Railway Rail

The paper presents the results of the second stage of work on the influence of the shape of straightening rollers on the state of residual stresses in rails, conducted as part of a project co-financed by the National Centre for Research and Development. The tests included numerical simulations of the rail straightening process using a new roll pass design of vertical and horizontal straightener rollers, determination of stress distribution maps in the rail after straightening in successive rollers of both straightening machines, as well as measurement of residual stresses in the rails after straightening operation in industrial conditions. The tests were carried out on R260 grade 60E1 rails. The reduction of tensile residual stresses in the centre of symmetry axis of the rail foot was obtained up to an average level of 32 MPa, i.e. by more than four times less in relation to the level achieved using traditional technology.

DETERMINATION OF POLYPHENOLIC COMPOUNDS OF LYSIMACHIA NUMMULARIA L.

2021 ◽  
Author(s):  
Suciu Felicia ◽  
Roșca Adrian Cosmin ◽  
Lupu Carmen ◽  
Popescu Antoanela ◽  
Badea Victoria
Keyword(s):  
Extraction Process ◽  
Polyphenolic Compounds ◽  
Polyphenol Content ◽  
Total Polyphenol ◽  
Important Place ◽  
Spectrophotometric Methods ◽  
Total Polyphenol Content ◽  
History Of ◽  
Different Parts

"The history of medicinal plants is associated with the evolution of civilization. In all regions of the world, the history of nations shows that these plants have always occupied an important place in medicine, in cosmetic products, and culinary preparations. The paper aims to determine the total polyphenols in different parts of the species Lysimachia nummularia L. In our study, we focused on the extraction of polyphenolic compounds in different solvents. The solvents used in the extraction were: 40% ethanol, concentrated methanol, in water. The total polyphenol content was determined by spectrophotometric methods, a method from the European Pharmacopoeia 10.0, with minor modifications. The total polyphenol content of different extracts varied depending on the extraction process. Different parts of the plant and different solvents were used in the determinations carried out to establish the optimal extraction method for the organs of Lysimachia nummularia L."

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