scholarly journals Response of Ovalbumin to Fructose Addition and pH Variations - Ultrasonic and FTIR Study

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Lakshmanan Palaniappan ◽  
Kathiroli Kavitha
Keyword(s):  
Second Derivative ◽  
Alkaline Ph ◽  
Ph Variation ◽  
Ultrasonic Methods ◽  
Main Variable ◽  
Ultrasonic Analysis ◽  
Second Derivative Spectra ◽  
Α Helix ◽  
The Impact ◽  
Ph Variations

Main aim of this work is to understand how the protein ovalbumin is affected by the presence of cosolvent and variations in pH of the medium.  The addition of cosolvent in many cases is found to control the extent of denaturation and pH is one of the main sources of denaturant of proteins.  In this work, keeping fructose solution as cosolvent and pH of the solution as main variable, the extent of denaturation is analysed by ultrasonic methods and are further confirmed by FTIR amide-I second derivative spectra at 303 K. Obtained results shows that denaturation is sensitive to pH, however, acidic and alkaline behave totally in a different way.  It was found that the impact of alkaline pH produces lesser denaturation and is slower whereas the impact of acidic pH is specific and instantaneous. Ultrasonic analysis shows that pH variation can denature the protein whereas the addition of cosolvent supports renaturation. FTIR spectra were recorded for the experimental samples from which the second derivative curve fitted spectra were constructed using Origin program.  Quantitative assignment of peaks and the variations in cumulative areas calculated for the structures like α-helix, β-sheets etc confirms the observations of ultrasonic analysis that the pH variations aid in denaturation whereas the cosolvent supports the renaturation of protein. 

Response of Ovalbumin to Fructose Addition and pH Variations - Ultrasonic and FTIR Study

2021 ◽  
Author(s):  
Lakshmanan Palaniappan ◽  
Kathiroli Kavitha
Keyword(s):  
Second Derivative ◽  
Alkaline Ph ◽  
Ph Variation ◽  
Ultrasonic Methods ◽  
Main Variable ◽  
Ultrasonic Analysis ◽  
Second Derivative Spectra ◽  
Α Helix ◽  
The Impact ◽  
Ph Variations

Main aim of this work is to understand how the protein ovalbumin is affected by the presence of cosolvent and variations in pH of the medium.  The addition of cosolvent in many cases is found to control the extent of denaturation and pH is one of the main sources of denaturant of proteins.  In this work, keeping fructose solution as cosolvent and pH of the solution as main variable, the extent of denaturation is analysed by ultrasonic methods and are further confirmed by FTIR amide-I second derivative spectra at 303 K. Obtained results shows that denaturation is sensitive to pH, however, acidic and alkaline behave totally in a different way.  It was found that the impact of alkaline pH produces lesser denaturation and is slower whereas the impact of acidic pH is specific and instantaneous. Ultrasonic analysis shows that pH variation can denature the protein whereas the addition of cosolvent supports renaturation. FTIR spectra were recorded for the experimental samples from which the second derivative curve fitted spectra were constructed using Origin program.  Quantitative assignment of peaks and the variations in cumulative areas calculated for the structures like α-helix, β-sheets etc confirms the observations of ultrasonic analysis that the pH variations aid in denaturation whereas the cosolvent supports the renaturation of protein. 

scholarly journals A Simple, Label-Free, and High-Throughput Method to Evaluate the Epigallocatechin-3-Gallate Impact in Plasma Molecular Profile

2020 ◽  
Vol 9 (2) ◽  
pp. 9 ◽  
Author(s):  
Rúben Araújo ◽  
Luís Ramalhete ◽  
Helder Da Paz ◽  
Edna Ribeiro ◽  
Cecília R.C. Calado
Keyword(s):  
High Throughput ◽  
Biological Activities ◽  
High Density Lipoproteins ◽  
Molecular Profile ◽  
Second Derivative ◽  
Plasma Samples ◽  
Label Free ◽  
Derivative Spectra ◽  
Second Derivative Spectra ◽  
The Impact

Epigallocatechin-3-gallate (EGCG), the major catechin present in green tea, presents diverse appealing biological activities, such as antioxidative, anti-inflammatory, antimicrobial, and antiviral activities, among others. The present work evaluated the impact in the molecular profile of human plasma from daily consumption of 225 mg of EGCG for 90 days. Plasma from peripheral blood was collected from 30 healthy human volunteers and analyzed by high-throughput Fourier transform infrared spectroscopy. To capture the biochemical information while minimizing the interference of physical phenomena, several combinations of spectra pre-processing methods were evaluated by principal component analysis. The pre-processing method that led to the best class separation, that is, between the plasma spectral data collected at the beginning and after the 90 days, was a combination of atmospheric correction with a second derivative spectra. A hierarchical cluster analysis of second derivative spectra also highlighted the fact that plasma acquired before EGCG consumption presented a distinct molecular profile after the 90 days of EGCG consumption. It was also possible by partial least squares regression discriminant analysis to correctly predict all unlabeled plasma samples (not used for model construction) at both timeframes. We observed that the similarity in composition among the plasma samples was higher in samples collected after EGCG consumption when compared with the samples taken prior to EGCG consumption. Diverse negative peaks of the normalized second derivative spectra, associated with lipid and protein regions, were significantly affected (p < 0.001) by EGCG consumption, according to the impact of EGCG consumption on the patients’ blood, low density and high density lipoproteins ratio. In conclusion, a single bolus dose of 225 mg of EGCG, ingested throughout a period of 90 days, drastically affected plasma molecular composition in all participants, which raises awareness regarding prolonged human exposure to EGCG. Because the analysis was conducted in a high-throughput, label-free, and economic analysis, it could be applied to high-dimension molecular epidemiological studies to further promote the understanding of the effect of bio-compound consumption mode and frequency.

Second‐Derivative Spectra for Estimating Crop Residue Cover

1994 ◽  
Vol 86 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Haiping Su ◽  
Michel D. Ransom ◽  
Edward T. Kanemasu ◽  
Tanvir H. Demetriades‐Shah
Keyword(s):  
Crop Residue ◽  
Second Derivative ◽  
Derivative Spectra ◽  
Second Derivative Spectra

scholarly journals Sterol-response pathways mediate alkaline survival in diverse fungi

2020 ◽  
Author(s):  
Hannah E. Brown ◽  
Calla L. Telzrow ◽  
Joseph W. Saelens ◽  
Larissa Fernandes ◽  
J. Andrew Alspaugh
Keyword(s):  
Fungal Pathogens ◽  
Fungal Infections ◽  
Membrane Integrity ◽  
Microbial Pathogens ◽  
Alkaline Ph ◽  
Ph Response ◽  
Ph Tolerance ◽  
Alkaline Conditions ◽  
Host Infection ◽  
The Impact

AbstractThe ability for cells to maintain homeostasis in the presence of extracellular stress is essential for their survival. Stress adaptations are especially important for microbial pathogens to respond to rapidly changing conditions, such as those encountered during the transition from the environment to the infected host. Many fungal pathogens have acquired the ability to quickly adapt to changes in extracellular pH to promote their survival in the various micro-environments encountered during a host infection. For example, the fungal-specific Rim/Pal alkaline response pathway has been well characterized in many fungal pathogens, including Cryptococcus neoformans. However, alternative mechanisms for sensing and responding to host pH have yet to be extensively studied. Recent observations from a genetic screen suggest that the C. neoformans sterol homeostasis pathway is required for growth at elevated pH. This work explores interactions among mechanisms of membrane homeostasis, alkaline pH tolerance, and Rim pathway activation. We find that the sterol homeostasis pathway is necessary for growth in an alkaline environment, and that an elevated pH is sufficient to induce Sre1 activation. This pH-mediated activation of the Sre1 transcription factor is linked to the biosynthesis of ergosterol, but is not dependent on Rim pathway signaling, suggesting that these two pathways are responding to alkaline pH independently. Furthermore, we discover that C. neoformans is more susceptible to membrane-targeting antifungals in alkaline conditions highlighting the impact of micro-environmental pH on the treatment of invasive fungal infections. Together, these findings further connect membrane integrity and composition with the fungal pH response and pathogenesis.

Electronic records with tablets at the point of care in an internal medicine unit (Preprint)

2021 ◽  
Author(s):  
Montserrat Pérez-Martí ◽  
Lina Cristina Casadó-Marín ◽  
Abraham Guillén-Villar
Keyword(s):  
Internal Medicine ◽  
Point Of Care ◽  
Electronic Records ◽  
Main Variable ◽  
Care Situation ◽  
Work Shifts ◽  
Security Communication ◽  
Nursing Professionals ◽  
The Impact ◽  
Internal Medicine Unit

BACKGROUND There are many benefits of nursing professionals being able to consult and record electronic clinical histories [ECH] at the point of care. It promotes quality and patient security, communication, continuity of care and time dedicated to records. OBJECTIVE This project evaluates the impact of having nursing records on electronic tablets at the patient’s bedside in relation to the time dedicated to the records. METHODS A before after single branch trial study was carried out in the internal medicine unit. A total of 130 observations of 2 to 3 hours duration were made. We calculated the time dedicated to measuring key patient signs, patient evaluation and ECH recording. The main variable was time spent per patient. RESULTS The analysis results for the whole sample show significant differences 0.44±0.13 min [w=-3.208, p=0.001] in the time dedicated to each patient. The findings showed a reduction in time spent on records when the tablets were used because transcription, latency time and displacements were no longer necessary. CONCLUSIONS There were different results for the different work shifts. It could have been due to multiple factors that can develop in any care situation in complex organisations like hospitals.

Multi-wavelength analyses of second-derivative spectra for rapid determination of acetaminophen in serum.

1988 ◽  
Vol 34 (6) ◽  
pp. 1119-1121 ◽  
Author(s):  
B Dingeon ◽  
M A Charvin ◽  
M T Quenard ◽  
H Thome
Keyword(s):  
Phosphate Buffer ◽  
Rapid Determination ◽  
Turnaround Time ◽  
Second Derivative ◽  
Derivative Spectra ◽  
Multi Wavelength ◽  
Precision And Accuracy ◽  
Second Derivative Spectra ◽  
Method Of Extraction

Abstract Measurement of acetaminophen by analysis of the second derivative of its spectrum is specific and sensitive. The method of extraction and the use of just one phosphate buffer as reagent makes this method very convenient. Readings are reliable from 10 to 1500 mg/L. A turnaround time of 20 min makes this method well suited for emergency cases. Precision and accuracy of the method are presented. Results are not biased by interferences, not even from N-acetylcysteine.

Second Derivative Tunable Diode Laser Spectrometry for Line Profile Determination. II. Experimental Results

1980 ◽  
Vol 34 (1) ◽  
pp. 56-60 ◽  
Author(s):  
David L. Grieble ◽  
Mark L. Olson ◽  
Jeffrey N-P. Sun ◽  
Peter R. Griffiths
Keyword(s):  
Diode Laser ◽  
Half Width ◽  
Tunable Diode Laser ◽  
Second Derivative ◽  
Single Beam ◽  
Zero Crossings ◽  
Diode Laser Spectrometer ◽  
Laser Spectrometry ◽  
Second Derivative Spectra ◽  
Two Parameters

The effect of the amplitude of the current modulation on experimental second derivative spectra measured using a tunable diode laser spectrometer is discussed. Spectra with adequate signal/noise ratios can only be measured when the amplitude of the modulation is about equal to the half width at half height. Two parameters, the distance between the zero crossings and the ratio of the minimal and maximal excursions, may be fit to an empirical hypersurface to obtain values for the peak absorbance, the actual half width and the collision-broadened half width. Although the peak absorbance is not accurately calculated, the line widths appear to be calculated to at least the same accuracy that can be obtained from the single-beam absorption spectrum.

scholarly journals Unusual reactivity of Tyr-7 of GSH transferase P1-1

1993 ◽  
Vol 293 (2) ◽  
pp. 351-356 ◽  
Author(s):  
D J Meyer ◽  
C Xia ◽  
B Coles ◽  
H Chen ◽  
P Reinemer ◽  
...  
Keyword(s):  
Chemical Reactivity ◽  
Three Dimensional ◽  
Covalent Modification ◽  
Proton Acceptor ◽  
Dimensional Structure ◽  
Second Derivative ◽  
Tyrosine Residue ◽  
Derivative Spectra ◽  
Activity Sequence ◽  
Second Derivative Spectra

Reaction of human GSH transferase P1-1 (GSTP1-1) with diethylpyrocarbonate (DEPC) at pH 7.0 and 4 degrees C resulted in covalent modification of an equivalent of one histidine and one tyrosine residue per subunit, with loss of activity. Sequence analysis showed that His-71 and Tyr-7 were modified. Reference to the three-dimensional structure of GSTP1-1 [Reinemer, Dirr, Ladenstein, Huber, Lo Bello, Frederici and Parker (1992) J. Mol. Biol. 227, 214-226] shows that the modification of Tyr-7 is most likely to affect enzyme activity. Kinetic analysis of the DEPC modification of Tyr-7 in GSTP1-1 gave a k2 approx. 150 times that of a peptide comprising residues 1-11 of GSTP1-1. The reaction of Tyr-7 of GSTP1-1 with DEPC was poorly inhibited by 1 mM GSH (14%) or 10 microM S-hexylglutathione (18%). DEPC treatment of the enzyme altered the absorbance at 290 nm in second-derivative spectra, suggesting that a significant amount of tyrosinate ion occurs in the enzyme. GSH, however, did not significantly alter the A290. The data provide the first evidence of unusual chemical reactivity of Tyr-7 and are consistent with its proposed role as a proton acceptor during catalysis.

Approach for Increased Information from the Second-Derivative Spectra in UV-Vis Absorption Spectroscopy

1993 ◽  
Vol 47 (10) ◽  
pp. 1712-1715 ◽  
Author(s):  
Liudmil Antonov ◽  
Stefan Stoyanov
Keyword(s):  
Absorption Spectra ◽  
Wavelength Region ◽  
Second Derivative ◽  
Holographic Gratings ◽  
Long Wavelength ◽  
Derivative Spectra ◽  
Individual Bands ◽  
Basic Parameters ◽  
Computing Procedure ◽  
Second Derivative Spectra

The resolution of overlapping bands in the UV-Vis absorption spectra leading to determination of their basic parameters ([Formula: see text]) provides important information about the energies and probabilities of the electronic transitions. In the analysis of UV-Vis absorption spectra recorded linearly in wavelength by means of modern spectrophotometers with holographic gratings, the analytical shape describing individual bands is asymmetric. This factor leads to certain limitations in determining their number with the use of the second-derivative spectra and decreased effectiveness of the computing procedure. It was found that the loss of information in d2 A/dλ2 is due to its long-wavelength attenuation in comparison with d2 A/dν˜2. An analytical equation connecting d2 A/dλ2 with d2 A/dν˜2 is proposed, which restores the information from the second derivative in the long-wavelength region.

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