Possible effect of alkalization therapy on SARS-CoV-2 virus lifecycle

Background: Application of chitin attracts much attention in the past decades as the second abundant polysaccharides in the world after cellulose. Chitin oligosaccharides (CTOS) and its deacetylated derivative chitosan oligosaccharides (COS) were shown great potentiality in agriculture by enhancing plant resistance to abiotic or biotic stresses, promoting plant growth and yield, improving fruits quality and storage, etc. Those applications have already served huge economic and social benefits for many years. However, the recognition mode and functional mechanism of CTOS and COS on plants have gradually revealed just in recent years. Objective: Recognition pattern and functional mechanism of CTOS and COS in plant together with application status of COS in agricultural production will be well described in this review. By which we wish to promote further development and application of CTOS and COS–related products in the field.

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Quantitative Analysis of 5-Hydroxymethylfurfural in Linezolid Injection by High Performance Liquid Chromatography

Current Pharmaceutical Analysis ◽

10.2174/1573412915666190618090603 ◽

2020 ◽

Vol 16 (8) ◽

pp. 1059-1067

Author(s):

Jéssica Maurício Batista ◽

Christian Fernandes

Keyword(s):

High Performance ◽

Potassium Phosphate ◽

Gradient Elution ◽

High Performance Liquid Chromatographic ◽

Official Method ◽

Ph Variation ◽

Drug Products ◽

Liquid Chromatographic Method ◽

Liquid Chromatographic

Background: Linezolid is a synthetic broad-spectrum antibacterial belonging to the class of oxazolidinones. Linezolid for intravenous infusion is isotonized with dextrose. In acidic environment, the dehydration of dextrose produces furan derivatives, 5-hydroxymethylfurfural (5-HMF) being the main one. The determination of this degradation product is of fundamental importance, since there is evidence it is cytotoxic, genotoxic, mutagenic and carcinogenic. However, there is no official method for the determination of 5-HMF in drug products. Objective: The aim of this study was to develop and validate a high performance liquid chromatographic method to quantify 5-HMF in injection of linezolid. Methods: The chromatographic separation, after optimization, was performed on C18 (150 x 4.6 mm, 5 μm) column. Mobile phase was composed of 14 mM potassium phosphate buffer pH 3.0 ([H+] = 1.0 x 10-3) and methanol in gradient elution at 1.0 mL min-1. The injection volume was 10 μL and detection was performed at 285 nm. Results: The method was optimized and validated, showing selectivity, linearity in the range from 0.075 to 9.0 μg mL-1, precision (RSD ≤ 2.0%), accuracy (mean recovery of 100.07%) and robustness for temperature and pH variation. Conclusion: The method was shown to be adequate to determine 5-HMF in injection containing linezolid in routine analysis.

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Synthesis of Zinc Oxide Nanostructures Growth by the role of pH variation

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/596/1/012040 ◽

2020 ◽

Vol 596 ◽

pp. 012040

Author(s):

Arlina Ali ◽

Mahani Yusoff ◽

An’amt Mohamed Noor ◽

Pao Ter Teo ◽

Sarizam Mamat ◽

...

Keyword(s):

Zinc Oxide ◽

Zinc Oxide Nanostructures ◽

Ph Variation ◽

Oxide Nanostructures

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Effect of pH Variation on Structural, Optical and Shape Morphology of BiVO4Photocatalysts

2018 10th International Conference on Electrical and Computer Engineering (ICECE) ◽

10.1109/icece.2018.8636721 ◽

2018 ◽

Cited By ~ 1

Author(s):

Manifa Noor ◽

M. A. Al Mamun ◽

M A Matin ◽

Md. Fakhrul Islam ◽

Saima Haque ◽

...

Keyword(s):

Effect Of Ph ◽

Ph Variation

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Small Angle X-ray Scattering, Molecular Modeling, and Chemometric Studies from a Thrombin-Like (Lmr-47) Enzyme of Lachesis m. rhombeata Venom

Molecules ◽

10.3390/molecules26133930 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3930

Author(s):

Salvatore Giovanni De-Simone ◽

Guilherme Curty Lechuga ◽

Paloma Napoleão-Pêgo ◽

Larissa Rodrigues Gomes ◽

David William Provance ◽

...

Keyword(s):

Molecular Modeling ◽

3D Structure ◽

Ph Variation ◽

Critical Elements ◽

X Ray Scattering ◽

Plot Analysis ◽

Competitive Inhibitors ◽

Resolution Model ◽

Lachesis Muta ◽

Lachesis Muta Rhombeata

Introduction: Snakebite envenomation is considered a neglected tropical disease, and SVTLEs critical elements are involved in serious coagulopathies that occur on envenoming. Although some enzymes of this group have been structurally investigated, it is essential to characterize other proteins to better understand their unique properties such as the Lachesis muta rhombeata 47 kDa (Lmr-47) venom serine protease. Methods: The structure of Lmr-47 was studied in solution, using SAXS, DLS, CD, and in silico by homology modeling. Molecular docking experiments simulated 21 competitive inhibitors. Results: At pH 8.0, Lmr-47 has an Rg of 34.5 ± 0.6 Å, Dmax of 130 Å, and SR of 50 Å, according to DLS data. Kratky plot analysis indicates a rigid shape at pH 8.0. Conversely, the pH variation does not change the center of mass’s intrinsic fluorescence, possibly indicating the absence of fluorescent amino acids in the regions affected by pH variation. CD experiments show a substantially random coiled secondary structure not affected by pH. The low-resolution model of Lmr-47 presented a prolate elongated shape at pH 8.0. Using the 3D structure obtained by molecular modeling, docking experiments identified five good and three suitable competitive inhibitors. Conclusion: Together, our work provided insights into the structure of the Lmr-47 and identified inhibitors that may enhance our understanding of thrombin-like family proteins.

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Effects of Hydrophobicity on Antimicrobial Activity, Selectivity, and Functional Mechanism of Guanidinium‐Functionalized Polymers

Advanced Healthcare Materials ◽

10.1002/adhm.202100482 ◽

2021 ◽

pp. 2100482

Author(s):

Jason Tan ◽

Yanli Zhao ◽

James L. Hedrick ◽

Yi Yan Yang

Keyword(s):

Antimicrobial Activity ◽

Functionalized Polymers ◽

Functional Mechanism

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Characterization of adenosine deaminase (ADA) in Hemolymph of Biomphalaria glabrata

Brazilian Journal of Biology ◽

10.1590/s1519-69842005000200022 ◽

2005 ◽

Vol 65 (2) ◽

pp. 371-376 ◽

Cited By ~ 2

Author(s):

M. R. Vale ◽

R. V. Pereira ◽

S. M. Almeida ◽

Y. M. Almeida ◽

S. F. L. C. Nunes

Keyword(s):

Adenosine Deaminase ◽

Incubation Temperature ◽

Small Variation ◽

Healthy Human ◽

Ph Variation ◽

Cellular Events ◽

Low Concentrations ◽

Key Enzyme ◽

Assay Conditions

Adenosine is an important signaling molecule for many cellular events. Adenosine deaminase (ADA) is a key enzyme for the control of extra- and intra-cellular levels of adenosine. Activity of ADA was detected in hemolymph of B. glabrata and its optimum assay conditions were determined experimentally. The pH variation from 6.2 to 7.8 caused no significant change in ADA activity. Using adenosine as a substrate, the apparent Km at pH 6.8 was 734 µmols.L-1. Highest activity was found at 37ºC. Standard assay conditions were established as being 15 minutes of incubation time, 0.4 µL of pure hemolymph per assay, pH 6.8, and 37ºC. This enzyme showed activities of 834 ± 67 µmol.min-1.L-1 (25ºC) and 2029 ± 74 µmol.min-1.L-1 (37ºC), exceeding those in healthy human serum by 40 and 100 times, respectively. Higher incubation temperature caused a decrease in activity of 20% at 43ºC or 70% at 50ºC for 15 minutes. The ADA lost from 26 to 78% of its activity when hemolymph was pre-incubated at 50ºC for 2 or 15 minutes, respectively. Since the ADA from hemolymph presented high levels, it can be concluded that in healthy and fed animals, adenosine is maintained at low concentrations. In addition, the small variation in activity over the 6.2 to 7.8 range of pH suggests that adenosine is maintained at low levels in hemolymph even under adverse conditions, in which the pH is altered.

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THE EFFECT OF COMPOSITION CHANGE IN SOL-GEL SYNTHESIZED PSC

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s101623720800060x ◽

2008 ◽

Vol 20 (01) ◽

pp. 53-59

Author(s):

Wen-Hsi Wang ◽

Yuan-Ling Lee ◽

Chun-Pin Lin ◽

Feng-Huei Lin

Keyword(s):

Setting Time ◽

Sol Gel ◽

Hydration Product ◽

Xrd Pattern ◽

Ph Variation ◽

Initial Strength ◽

Filling Materials ◽

Retrograde Filling ◽

Significant Difference ◽

Sol Gel Process

Modified calcium silicate cement had previously been developed as a dental retrograde filling. It had great sealing ability, good biocompatibility, and anti-bacterial properties. However, its clinical application was limited by a long setting time and poor handling property. In previous study,1, 2 the setting property of PSC was greatly improved due the sol-gel process, without the addition of transition metal element. In this study, different ratio of starting material of PSC was prepared. The composition of each group was also altered with the ratio of the starting materials according to the result of XRD pattern. There is no significant difference in pH variation profile between each group. Even though low C 3 S / C 4 AF ratio (DX631 and DX541 groups) possessed high initial strength at first 24 hours after hydration, there was no increase in strength ever since according to the result of microhardness. However, the groups with high C 3 S / C 4 AF ratio (DX811 and DX721 groups) possessed relatively low initial strength at 24 hours after hydration, but the strength increased rapidly and continuously at least for the next six days of hydration. Moreover, the peak intensity of hydration product (Portlandite) on XRD pattern in DX811 group was much higher than other three groups, and this was also in agreement with the result of microhardness. DX811 group is determined to be the optimal one for the further development in the application as root-end filling materials.

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