Effects of various strengths of bases on the electrophoretic behavior of weak acids in a non-aqueous solvent

1985 ◽  
Vol 330 ◽  
pp. 19-42 ◽  
Author(s):  
N.J. Parekh ◽  
L.B. Rogers
Keyword(s):  
Weak Acids ◽  
Electrophoretic Behavior ◽  
Aqueous Solvent

Effects of various strengths of acids on the electrophoretic behavior of weak bases in a non-aqueous solvent

1984 ◽  
Vol 314 ◽  
pp. 65-82 ◽  
Author(s):  
N.J. Parekh ◽  
A.A. Fatmi ◽  
M.A. Tshabalala ◽  
L.B. Rogers
Keyword(s):  
Weak Bases ◽  
Electrophoretic Behavior ◽  
Aqueous Solvent

scholarly journals THE CHLOROPHYLL-PROTEIN COMPLEX

1942 ◽  
Vol 25 (5) ◽  
pp. 755-764 ◽  
Author(s):  
Myer Fishman ◽  
Laurence S. Moyer
Keyword(s):  
Phaseolus Vulgaris ◽  
Isoelectric Point ◽  
Protein Complex ◽  
Weak Acids ◽  
Cytoplasmic Proteins ◽  
Electrophoretic Behavior ◽  
Irreversible Denaturation ◽  
Isoelectric Points ◽  
Chlorophyll Protein ◽  
The Stability

1. Reported effects of different conditions on the stability of the purified chlorophyll-protein complex have been confirmed. 2. The electrophoretic behavior of the chlorophyll-protein complex prepared from two unrelated species of plants (Aspidistra elatior and Phaseolus vulgaris) has been investigated and shown to be dissimilar. In M/50 acetate buffer at 25°C, the isoelectric point of the complex from Phaseolus is at pH 4.70, whereas that from Aspidistra is at pH 3.9 (extrapolated). These values fall within the usual range of protein isoelectric points. 3. Treatment with weak acids causes an irreversible denaturation of the protein complex from both species, with a resultant shift in the mobility-pH curves to more basic values. 4. Differences in electrophoretic behavior between the chlorophyll-protein complex and the cytoplasmic proteins of Phaseolus have been demonstrated. The isoelectric point of the latter is at pH 4.22.

Quantitative Structure-activity Relationship Analysis for Predicting Lipophilicity of Aniline Derivatives (Including some Pharmaceutical Compounds)

2019 ◽  
Vol 22 (5) ◽  
pp. 333-345
Author(s):  
Morteza Rezaei ◽  
Esmat Mohammadinasab ◽  
Tahere Momeni Esfahani
Keyword(s):  
Density Functional ◽  
Pharmaceutical Compounds ◽  
Partial Least Square ◽  
Least Square ◽  
Basis Set ◽  
Van Der Waals Volume ◽  
Relationship Analysis ◽  
Aniline Derivatives ◽  
Aqueous Solvent ◽  
Qsar Models

Background: In this study, we used a hierarchical approach to develop quantitative structureactivity relationship (QSAR) models for modeling lipophilicity of a set of 81 aniline derivatives containing some pharmaceutical compounds. Objective: The multiple linear regression (MLR), principal component regression (PCR) and partial least square regression (PLSR) methods were utilized to construct QSAR models. Materials & Methods: Quantum mechanical calculations at the density functional theory level and 6- 311++G** basis set were carried out to obtain the optimized geometry and then, the comprehensive set of molecular descriptors was computed by using the Dragon software. Genetic algorithm (GA) was applied to select suitable descriptors which have the most correlation with lipophilicity of the studied compounds. Results: It was identified that such descriptors as Barysz matrix (SEigZ), hydrophilicity factor (Hy), Moriguchi octanol-water partition coefficient (MLOGP), electrophilicity (ω/eV) van der Waals volume (vWV) and lethal concentration (LC50/molkg-1) are the best descriptors for QSAR modeling. The high correlation coefficients and the low prediction errors for MLR, PCR and PLSR methods confirmed good predictability of the three models. Conclusion: In present study, the high correlation between experimental and predicted logP values of aniline derivatives indicated the validation and the good quality of the resulting three regression methods, but MLR regression procedure was a little better than the PCR and PLSR methods. It was concluded that the studied aniline derivatives are not hydrophilic compounds and this means these compounds hardly dissolve in water or an aqueous solvent.

Study of Photocatalytic Dergradation, Kinetics and Microbial Activities of Copper (ii) Soya Urea Complex in Non Aqueous Media

2020 ◽  
Vol 17 ◽  
Author(s):  
Vandana Sukhadia ◽  
Rashmi Sharma ◽  
Asha Meena
Keyword(s):  
Staphylococcus Aureus ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Waste Water Treatment ◽  
Aqueous Media ◽  
Research Work ◽  
Solvent Polarity ◽  
Urea Complex ◽  
Pseudo First Order Reaction ◽  
Aqueous Solvent

Aims: The aim of this research work is to synthesise, study and analyse photocatalytic degradation, kinetics and microbial activity of new surfactant Copper (II) soya urea complex(CSU). Background: Photocatalytic degradation has attracted the attention of scientific community throughout the world due to its multiple applications in environment, energy, waste water treatment, pollution control, green chemistry, etc. Copper (II) soya urea complex has been synthesized and characterized through FT-IR, NMR, ESR studies. Objective: Present work deals with the study of photocatalytic degradation of Copper (II) soya urea complex by using ZnO as semiconductor. This study employs a semiconductor catalyst using non polar and non aqueous solvent in photocatalytic degradation. Reaction rate is chosen as the photocatalytic activity, which has been governed by several factors. Antibacterial activities of Copper (II) complex have also been studied against Staphylococcus aureus. Method: Optical density (O.D.) was measured after different time intervals spectrophotometrically to measure the degradation of complex. Mueller-Hinton agar medium was used for antimicrobial activity of synthesized compound at different concentrations by disk/ well diffusion susceptibility testing. Result: Plot of 2+log O.D. (absorbance) versus time was plotted and found linear. The heterogeneous photocatalysis followed pseudo-first-order reaction kinetics.The present study suggests that Copper (II) soya urea (CSU) complex shows antibacterial activity against Staphylococcus aureus at different concentrations. Conclusion: The results were used to determine the rate of photocatalytic degradation of CSU complex .It has been found that rate of degradation varies with different parameters like concentration of complex, amount of catalyst, light intensity, solvent polarity etc. CSU complex derived from soyabean oil has been shown an inhibitory effect on the growth of S. aureus which may causes skin disease.

scholarly journals Quaternary Alloy Quantum Dots as Fluorescence Probes for Total Acidity Detection of Paper-Based Relics

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1726
Author(s):  
Zhuorui Wang ◽  
Cong Cheng ◽  
Yongjuan Cheng ◽  
Lizhen Zheng ◽  
Daodao Hu
Keyword(s):  
Quantum Dots ◽  
Extraction Method ◽  
Quaternary Alloy ◽  
New Method ◽  
Fluorescence Probes ◽  
Total Acidity ◽  
Weak Acids ◽  
Paper Sample ◽  
Composition And Structure ◽  
Alloy Quantum Dots

Traditionally, the acidity of paper-based relics was determined by an extraction method and using a pH meter. This method could not obtain the total acidity of the paper-based relics because it only detected the concentration of free protons in the aqueous soaking solution. To overcome this defect, a new method for determining the total acidity of paper-based relics has been established by using quaternary alloy quantum dots. The quantum dots, CdZnSeS, modified by p-Aminothiophenol (pATP) were prepared, and their composition and structure were characterized. The fluorescence behavior of prepared quantum dots with acidity was investigated. The following results were obtained. The fluorescence of CdZnSeS-pATP quantum dots could decrease with increases in acidity because pATP dissociated from the surfaces of the quantum dots due to protons or undissociated weak acids. Based on this feature, a method for determining the acidity of paper-based relics was constructed, and this method was used to evaluate the acidity of actual paper-based relics. Obviously, for a given paper sample, since both free protons and bound protons can be determined by this method, the acidity measured by this method is more reasonable than that by pH meter.

scholarly journals Humic acids trigger the weak acids stress response in maize seedlings

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Daiane Carvalho Baía ◽  
Fábio L. Olivares ◽  
Daniel B. Zandonadi ◽  
Cleiton de Paula Soares ◽  
Riccardo Spaccini ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Response ◽  
Intracellular Ph ◽  
Humic Acids ◽  
Abiotic Stress Tolerance ◽  
Molecular Response ◽  
Maize Seedlings ◽  
Weak Acids ◽  
Acetoxymethyl Ester ◽  
Chemical Priming

Abstract Background Plants primed by humic acids showed physiological and molecular response against different abiotic stresses without the presence of stressor agents (salinity, drought, heavy metal toxicity). It is plausible that humic acids themselves can act as chemical priming substances in plants. We hypothesized that humic acids can trigger the weak acids stress response in cell plants acidifying the cytosol and thus eliciting the transduction signalling response cascade. Methods The dose–response curves of maize seedlings roots with different concentrations of humic, acetic and salicylic acids determined the most active and inhibitory concentration. These data were further used to evaluate changes on intracellular pH using BCECF-AM probe (2,7-bis(2-carboxyethyl)-5(and 6)-carboxyfluorescein, acetoxymethyl ester) and differential transcription level of genes related to weak stress response in plants by qPCR real time. Results Humic acids like short chain organic acids decrease the intracellular pH showed by the increased fluorescence of BCECF probe. The drop in cytosolic pH promoted by humic acids was not transient. We observed a high level of protein kinases related to cell energy-sensing and transcription factors associated to transduction of stress signalling. Conclusion The humic acids can be considered as a chemical priming agent, since in the appropriate concentration they can induce the typical plant abiotic stress response of weak acids inducing plant acclimation and enhancing the abiotic stress tolerance.

scholarly journals Cellulose Paper Modified by a Zinc Oxide Nanosheet Using a ZnCl2-Urea Eutectic Solvent for Novel Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1111
Author(s):  
Changmei Lin ◽  
Duo Chen ◽  
Zifeng Hua ◽  
Jun Wang ◽  
Shilin Cao ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Cellulose Fibers ◽  
Human Motion ◽  
Triboelectric Nanogenerator ◽  
Crystalline Region ◽  
Ptfe Film ◽  
Cellulose Paper ◽  
Output Performance ◽  
Aqueous Solvent

Cellulose paper has been functionalized by nanoparticles such as Ag nanoparticles, TiO2, and BaTiO3 for versatile applications including supercapacitor, sensors, photoactivity, and packaging. Herein, zinc oxide (ZnO) nanosheet-modified paper (ZnO@paper) with excellent antibacterial properties was fabricated via a mild ZnCl2-urea eutectic solvent. In this proposed method, cellulose fibers as the raw material for ZnO@paper were treated by an aqueous solvent of ZnCl2-urea; the crystalline region was destroyed and [ZnCl]+-based cations were adsorbed on the surface of cellulose fibers, facilitating more ZnO growth on ZnO@paper. A flexible paper-based triboelectric nanogenerator (P-TENG) was made of ZnO@paper paired with a PTFE film. The P-TENG presents high triboelectric output performance and antibacterial activity. For instance, the output voltage and current of the P-TENG were 77 V and 0.17 μA, respectively. ZnO@paper showed excellent antibacterial activity against E. coli and S. aureus, suggesting that a P-TENG can restrain and kill the bacteria during the working process. The results also indicated that ZnO could improve the surface roughness of cellulose paper, enhancing the output performance of a flexible P-TENG. In addition, the potential application of a P-TENG-based pressure sensor for determining human motion information was also reported. This study not only produced a high-performance P-TENG for fabricating green and sustainable electronics, but also provides an effective and novel method for ZnO@paper preparation.

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