scholarly journals Spectroscopic Determination of pKa Constants of MADS Box Segments

2012 ◽  
Vol 27 ◽  
pp. 455-461 ◽  
Author(s):  
Barbora Řezáčová ◽  
Yves-Marie Coïc ◽  
Christian Zentz ◽  
Pierre-Yves Turpin ◽  
Josef Štěpánek
Keyword(s):  
Factor Analysis ◽  
Good Sensitivity ◽  
Mads Box ◽  
Ph Titration ◽  
Complementary Technique ◽  
Conserved Sequence ◽  
Spectral Components ◽  
Titration Data ◽  
Intrinsic Fluorophores

We have introduced a new promising approach for the determination of pKa constants of oligopeptide intrinsic fluorophores and spectral components referring to their differently charged states. The method is based on the factor analysis of multiwavelength spectroscopic pH titration data. As an illustration, we present its application on the study of short segments of the MADS box, which is a highly conserved sequence of a so-called family of transcription factors, by techniques of UV absorption and fluorescence spectroscopies. Investigated oligopeptides contain no tryptophan but one tyrosine serving as an intrinsic fluorophore and absorber. The results indicate both good sensitivity and spectroscopic selectivity of our method, which thus may be considered as a complementary technique to conventional electrochemical methods.

scholarly journals The thermodynamic dissociation constants of methotrexate by the nonlinear regression and factor analysis of multiwavelength spectrophotometric pH-titration data

2010 ◽  
Vol 8 (3) ◽  
pp. 494-507 ◽  
Author(s):  
Milan Meloun ◽  
Zuzana Ferenčíková ◽  
Aleš Vrána
Keyword(s):  
Factor Analysis ◽  
Nonlinear Regression ◽  
Goodness Of Fit ◽  
Dissociation Constants ◽  
General Rule ◽  
Computational Prediction ◽  
Ph Titration ◽  
Chemical Structures ◽  
Goodness Of Fit Tests ◽  
Titration Data

AbstractThe mixed dissociation constants of methotrexate — chemically (2S)-2-[(4-{[(2,4-diamino-7,8-dihydropteridin-6-yl)methyl] (methyl)amino}phenyl)formamido]pentanedioic acid (the cas number 59-05-2) at various ionic strengths I of range 0.01–0.4, and at temperatures of 25°C and 37°C, were determined with the use of two different multiwavelength and multivariate treatments of spectral data, SPECFIT32 and SQUAD(84) nonlinear regression analyses and INDICES factor analysis according to a general rule of first, determining the number of components, and then calculating the spectral responses and concentrations of the components. Concurrently, the experimental determination of the thermodynamic dissociation constants was in agreement with its computational prediction of the PALLAS programme based on knowledge of the chemical structures of the drug. The factor analysis in the INDICES programme predicts the correct number of light-absorbing components when the data quality is high and the instrumental error is known. Three thermodynamic dissociation constants were estimated by nonlinear regression of {pK a , I} data: for methotrexate pK a1T= 2.895(13), pK a2T= 4.410(14), pK a3T= 5.726(15) at 25°C and pK a1T= 3.089(15), pK a2T= 4.392(12), pK a3T= 5.585(11) at 37°C, where the figure in brackets is the standard deviation in last significant digits. The reliability of the dissociation constants of the drug were proven by conducting goodness-of-fit tests of the multiwavelength spectrophotometric pH-titration data.

scholarly journals Application of factor analysis in the determination of vapor lock tendency in aviation gasolines/motor gasoline/blends and the compatibility as alternatives in naturally aspirated aviation engines

2021 ◽  
Vol 60 (6) ◽  
pp. 5703-5724
Author(s):  
Ananth Manickam Wash ◽  
Thanikasalam Kumar ◽  
Rahmat Mohsin ◽  
Zulkifli Abdul Majid ◽  
Mohammad Fahmi Abdul Ghafir
Keyword(s):  
Factor Analysis ◽  
Motor Gasoline ◽  
Aviation Engines

Baznas Bogor City Strategy in Empowering the Dhuafa Through the Bogor Berkah Program

2022 ◽  
Vol 4 (3) ◽  
pp. 655-662
Author(s):  
Efrita Norman ◽  
Zulficar Ismail ◽  
Abdul Husenudin ◽  
Enah Pahlawati ◽  
Rio Kartika Supriyatna
Keyword(s):  
Factor Analysis ◽  
Swot Analysis ◽  
Business Groups ◽  
Analysis Approach ◽  
Economic Empowerment ◽  
Strategic Factor ◽  
Islamic Religion ◽  
Descriptive Qualitative

Zakat is one of the pillars in the Islamic economy which is a pillar of the Islamic religion, the importance of zakat in the economy is why in the Qur'an zakat is always juxtaposed with prayer, there are even 29 words zakat which are always juxtaposed with prayer, because zakat is meritorious in Community economic empowerment must be managed properly by amil zakat, in this context is BAZNAS Bogor City. The purpose of zakat itself is not only to help asnaf but also to make mustahiq become muzakki, therefore the distribution of zakat funds must be right on target so that this goal is achieved. This study aims to determine the determination of recipients of zakat funds distributed by BAZNAS Bogor City through one of its programs, namely Bogor Berkah, whether with this program the zakat asnaf group is helped and this study takes the object of ta'lim majlis. The approach used in this research is descriptive qualitative with SWOT analysis approach, IFAS (Internal Strategic Factor Analysis Summary) and EFAS (External Strategic Factor Analysis Summary). The results of this study indicate that in determining the receipt of zakat funds distributed by BAZNAS Bogor City through the Bogor Berkah program is the majlis ta'lim criteria which have small or medium business groups. and with this program there are not a few ta'lim majlis that empower their congregations of ta'lim majlis. Keywords: zakat, bogor blessing program, empowerment of dhu'afa

scholarly journals Youden Analysis of Karl Fischer Titration Data from an Interlaboratory Study Determining Water in Animal Feed, Grain, and Forage

2005 ◽  
Vol 88 (6) ◽  
pp. 1840-1841 ◽  
Author(s):  
Frank E Jones
Keyword(s):  
Animal Feed ◽  
Systematic Errors ◽  
Interlaboratory Study ◽  
Matched Pairs ◽  
Karl Fischer Titration ◽  
Karl Fischer ◽  
Collaborative Studies ◽  
Titration Data ◽  
Repeatability And Reproducibility

Abstract Data from a recent interlaboratory study of the determination of water (moisture) in animal feed, grain, and forage (plant tissue) by Karl Fischer titration were re-analyzed using Youden plots. The purpose was to show the unique ability these plots possess of separating random and systematic errors visually while providing numerical estimates of the precision and the systematic error of the method. Furthermore, the usefulness of the technique is underscored because AOAC INTERNATIONAL allows the use of matched pairs in collaborative studies to obtain estimates of repeatability and reproducibility.

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