Modulation of surface tension and rheological behavior of methyl cellulose – Amino acid based surfactant mixture by hydrophobic drug rifampicin: An insight into drug stabilization and pH-responsive release

2020 ◽  
Vol 319 ◽  
pp. 114353
Author(s):  
Saima Afzal ◽  
Mohd Sajid Lone ◽  
Masrat Maswal ◽  
Aijaz Ahmad Dar
Keyword(s):  
Surface Tension ◽  
Amino Acid ◽  
Rheological Behavior ◽  
Methyl Cellulose ◽  
Surfactant Mixture ◽  
Hydrophobic Drug ◽  
Ph Responsive ◽  
Drug Stabilization ◽  
Insight Into

scholarly journals Insight into the mechanism of thermostabilization of GH10 xylanase from Bacillus sp. strain TAR-1 by the mutation of S92 to E

2021 ◽  
Vol 85 (2) ◽  
pp. 386-390
Author(s):  
Manami Suzuki ◽  
Teisuke Takita ◽  
Kohei Kuwata ◽  
Kota Nakatani ◽  
Tongyang Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Thermodynamic Analysis ◽  
Thermal Inactivation ◽  
Entropy Change ◽  
Crystallographic Analysis ◽  
Bacillus Sp ◽  
Amino Acid Residues ◽  
Gh10 Xylanase ◽  
Insight Into

ABSTRACT The mechanism of thermostabilization of GH10 xylanase, XynR, from Bacillus sp. strain TAR-1 by the mutation of S92 to E was investigated. Thermodynamic analysis revealed that thermostabilization was driven by the decrease in entropy change of activation for thermal inactivation. Crystallographic analysis suggested that this mutation suppressed the fluctuation of the amino acid residues at position 92-95.

scholarly journals A pH-Responsive Foam Formulated with PAA/Gemini 12-2-12 Complexes

2021 ◽  
Vol 5 (3) ◽  
pp. 37
Author(s):  
Hernán Martinelli ◽  
Claudia Domínguez ◽  
Marcos Fernández Leyes ◽  
Sergio Moya ◽  
Hernán Ritacco
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Foam Formation ◽  
Ph Responsive ◽  
Dynamic Surface ◽  
X Ray ◽  
Equilibrium Surface Tension ◽  
Potential Applications ◽  
The Stability ◽  
Air Interfaces

In the search for responsive complexes with potential applications in the formulation of smart dispersed systems such as foams, we hypothesized that a pH-responsive system could be formulated with polyacrylic acid (PAA) mixed with a cationic surfactant, Gemini 12-2-12 (G12). We studied PAA-G12 complexes at liquid–air interfaces by equilibrium and dynamic surface tension, surface rheology, and X-ray reflectometry (XRR). We found that complexes adsorb at the interfaces synergistically, lowering the equilibrium surface tension at surfactant concentrations well below the critical micelle concentration (cmc) of the surfactant. We studied the stability of foams formulated with the complexes as a function of pH. The foams respond reversibly to pH changes: at pH 3.5, they are very stable; at pH > 6, the complexes do not form foams at all. The data presented here demonstrate that foam formation and its pH responsiveness are due to interfacial dynamics.

EFFECT OF PERACETIC ACID OXIDATION ON N-CONTAINING COMPONENTS OF HUMIC MATERIALS

1980 ◽  
Vol 60 (3) ◽  
pp. 541-548 ◽  
Author(s):  
M. SCHNITZER ◽  
D. A. HINDLE
Keyword(s):  
Amino Acid ◽  
Peracetic Acid ◽  
Amino Sugar ◽  
Chemical Oxidation ◽  
Acid Oxidation ◽  
Mild Oxidation ◽  
Total N ◽  
Different Types ◽  
Humic Materials ◽  
Insight Into

Three humic and one fulvic acid were degraded by mild chemical oxidation with peracetic acid, with special emphasis on the effects of this type of oxidation on N-containing components. The different types of N that were considered were NH4+-N, amino acid-N, amino sugar-N, NO2−-N + NO3−-N, and by difference from total N, "unknown" N. The behaviour toward mild chemical oxidation of all four preparations was essentially similar: there were decreases in mino acid-N, amino sugar-N and "unknown" N, increases in NH4+-N, NO2−-N + NO3−-N with one material, and in N-gases. The "unknown" N was not inert. Between 16.6 and 59.1% of the latter appeared to be converted, as a result of mild chemical oxidation, to NH3 and N-gases which were expelled from the systems. The results presented provide an insight into what happens to N-containing humic components as a result of mild oxidation.

Self-Assembly Thermodynamics of pH-Responsive Amino-Acid-Based Polymers with a Nonionic Surfactant

Langmuir ◽  
2014 ◽  
Vol 30 (38) ◽  
pp. 11307-11318 ◽  
Author(s):  
Anna Bogomolova ◽  
Sandro Keller ◽  
Johannes Klingler ◽  
Marian Sedlak ◽  
Dmytro Rak ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nonionic Surfactant ◽  
Self Assembly ◽  
Ph Responsive

scholarly journals FIND: Identifying Functionally and Structurally Important Features in Protein Sequences with Deep Neural Networks

2019 ◽  
Author(s):  
Ranjani Murali ◽  
James Hemp ◽  
Victoria Orphan ◽  
Yonatan Bisk
Keyword(s):  
Neural Networks ◽  
Amino Acid ◽  
Hidden Markov Models ◽  
Markov Models ◽  
Genomic Sequence ◽  
Hidden Markov ◽  
Amino Acid Sequences ◽  
Homologous Proteins ◽  
Biological Studies ◽  
Insight Into

AbstractThe ability to correctly predict the functional role of proteins from their amino acid sequences would significantly advance biological studies at the molecular level by improving our ability to understand the biochemical capability of biological organisms from their genomic sequence. Existing methods that are geared towards protein function prediction or annotation mostly use alignment-based approaches and probabilistic models such as Hidden-Markov Models. In this work we introduce a deep learning architecture (FunctionIdentification withNeuralDescriptions orFIND) which performs protein annotation from primary sequence. The accuracy of our methods matches state of the art techniques, such as protein classifiers based on Hidden Markov Models. Further, our approach allows for model introspection via a neural attention mechanism, which weights parts of the amino acid sequence proportionally to their relevance for functional assignment. In this way, the attention weights automatically uncover structurally and functionally relevant features of the classified protein and find novel functional motifs in previously uncharacterized proteins. While this model is applicable to any database of proteins, we chose to apply this model to superfamilies of homologous proteins, with the aim of extracting features inherent to divergent protein families within a larger superfamily. This provided insight into the functional diversification of an enzyme superfamily and its adaptation to different physiological contexts. We tested our approach on three families (nitrogenases, cytochromebd-type oxygen reductases and heme-copper oxygen reductases) and present a detailed analysis of the sequence characteristics identified in previously characterized proteins in the heme-copper oxygen reductase (HCO) superfamily. These are correlated with their catalytic relevance and evolutionary history. FIND was then applied to discover features in previously uncharacterized members of the HCO superfamily, providing insight into their unique sequence features. This modeling approach demonstrates the power of neural networks to recognize patterns in large datasets and can be utilized to discover biochemically and structurally important features in proteins from their amino acid sequences.Author summary

scholarly journals Mirco-level Insight into the Surface Tension-structure Relationship of Molten CaO–MgO–SiO2–FexO–P2O5 Slags

2021 ◽  
Vol 61 (11) ◽  
pp. 2765-2772
Author(s):  
Chengjun Liu ◽  
Rui Zhang ◽  
Yifan Meng ◽  
Zhen Wang ◽  
Shiyan Jiao ◽  
...  
Keyword(s):  
Surface Tension ◽  
Structure Relationship ◽  
Relationship Of ◽  
Insight Into ◽  
Tension Structure

The effect of ink formulation on colorimetric properties of inkjet printing considering the impact of substrates

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Darya Ewaznezhad Fard ◽  
Saeideh Gorji Kandi ◽  
Marziyeh Khatibzadeh
Keyword(s):  
Surface Tension ◽  
Physical Properties ◽  
Inkjet Printing ◽  
Methyl Cellulose ◽  
Test Results ◽  
Viscosity Modifier ◽  
Content Type ◽  
Polymeric Compounds ◽  
The Impact ◽  
Ink Formulation

Purpose The purpose of this study is to investigate the changes in the performance of ink formulations caused by the addition of compounds that improve the ink’s physical properties to achieve an optimum formulation for inkjet printing, because of the importance and simplicity of this method. Design/methodology/approach Ink samples were formulated using Acid Red 14 as ink colorant, different percentages of polymeric compounds including polyvinyl alcohol (PVA), polyvinylpyrrolidone and Carboxy methyl cellulose (CMC) as viscosity modifier compounds and surfactant as the surface tension enhancer. Formulated samples were adjusted in terms of fluid physical properties e.g. viscosity, density and surface tension, and the effect of used compounds on the improvement of both physical and colorimetric properties such as viscosity, surface tension, colorimetric coordinates and lightfastness has been evaluated to achieve the optimum printing inks to be printed on three different substrates. Findings The experimental observations showed that CMC was the most compatible compound as the viscosity modifier as its viscosity value was in the printable range of 2–22 cP. Moreover, a flow-curve test was applied to the ink samples and their Newtonian behavior was approved. Based on the spectrophotometric test results of printed samples, the samples containing PVA provided acceptable lightfastness in comparison to other ink samples on every used substrate. Originality/value An optimum relation between colorimetric coordinates of the printed samples and ink formulation could be considered and achieved.

scholarly journals Phenotypic and Genotypic Comparison of a Live-Attenuated Genotype I Japanese Encephalitis Virus SD12-F120 Strain with Its Virulent Parental SD12 Strain

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 552 ◽  
Author(s):  
Muhammad Naveed Anwar ◽  
Xin Wang ◽  
Muddassar Hameed ◽  
Abdul Wahaab ◽  
Chenxi Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Clinical Symptoms ◽  
Encephalitis Virus ◽  
Amino Acid Substitutions ◽  
Genotype I ◽  
Genetic Changes ◽  
Genotypic Characteristics ◽  
Insight Into

The phenotypic and genotypic characteristics of a live-attenuated genotype I (GI) strain (SD12-F120) of Japanese encephalitis virus (JEV) were compared with its virulent parental SD12 strain to gain an insight into the genetic changes acquired during the attenuation process. SD12-F120 formed smaller plaque on BHK-21 cells and showed reduced replication in mouse brains compared with SD12. Mice inoculated with SD12-F120 via either intraperitoneal or intracerebral route showed no clinical symptoms, indicating a highly attenuated phenotype in terms of both neuroinvasiveness and neurovirulence. SD12-F120 harbored 29 nucleotide variations compared with SD12, of which 20 were considered silent nucleotide mutations, while nine resulted in eight amino acid substitutions. Comparison of the amino acid variations of SD12-F120 vs. SD12 pair with those from other four isogenic pairs of the attenuated and their virulent parental strains revealed that the variations at E138 and E176 positions of E protein were identified in four and three pairs, respectively, while the remaining amino acid variations were almost unique to their respective strain pairs. These observations suggest that the genetic changes acquired during the attenuation process were likely to be strain-specific and that the mechanisms associated with JEV attenuation/virulence are complicated.

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