scholarly journals Characterization of particle shape, zeta potential, loading efficiency and outdoor stability for chitosan-ricinoleic acid loaded with rotenone

2016 ◽  
Vol 11 (1) ◽  
pp. 380-386 ◽  
Author(s):  
Bohua Feng ◽  
Muhammad Aqeel Ashraf ◽  
Liufen Peng
Keyword(s):  
Zeta Potential ◽  
Ricinoleic Acid ◽  
Drug Carrier ◽  
Natural Environments ◽  
Monodisperse Nanoparticles ◽  
Loading Efficiency ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Outdoor Test

AbstractCarboxymethyl chitosan grafted with ricinoleic acid (CMC-g-RA), an amphiphilic drug carrier, was synthetized, loaded with rotenone (Rot), and characterized for particles shape, zeta potential, loading efficiency and outdoor stability. Results show that as the ratio of carrier to drug increased, the formulation exhibited monodisperse nanoparticles negative surface charge. The loading efficiency of the formulation was up to 68%. The outdoor test also indicated that the formulation with the higher loading efficiency prevented Rot degradation in natural environments.

Effect of arsenate on adsorption of Zn(II) by three variable charge soils

Soil Research ◽  
2007 ◽  
Vol 45 (6) ◽  
pp. 465 ◽  
Author(s):  
Jing Liang ◽  
Ren-kou Xu ◽  
Diwakar Tiwari ◽  
An-zhen Zhao
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Iron Oxides ◽  
Initial Concentration ◽  
Variable Charge ◽  
Study Results ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Enhanced Adsorption ◽  
Variable Charge Soils

The effect of arsenate on adsorption of Zn(II) in 3 variable charge soils (Hyper-Rhodic Ferralsol, Rhodic Ferralsol, and Haplic Acrisol) and the desorption of pre-adsorbed Zn(II) in the presence of arsenate were investigated in this study. Results showed that the presence of arsenate led to an increase in both the adsorption and desorption of Zn(II) in these variable charge soils. It was also suggested that the enhanced Zn(II) adsorption by arsenate was mainly due to the increase in negative surface charge of the soils induced by the specific adsorption of arsenate, and the increase in electrostatically adsorbed Zn(II) was responsible for the increase in the desorption of Zn(II). The effect of arsenate on Zn(II) adsorption primarily depends on the initial concentration of arsenate and Zn(II), the system pH, and the nature of soils. The enhanced adsorption of Zn(II) increased with the increase in the initial concentration of arsenate and the amount of arsenate adsorbed by the soils. The presence of arsenate decreased the zeta potential of soil suspensions and soil IEP and thus shifted the adsorption edge of Zn(II) to a lower pH region. The effect of arsenate on Zn(II) adsorption in these 3 soils followed the order Hyper-Rhodic Ferralsol > Rhodic Ferralsol > Haplic Acrisol, which was consistent to the contents of iron oxides in these soils and the amount of arsenate adsorbed by the soils.

Carboxymethy Chitosan Grafted Ricinoleic Acid Group for Nanopesticide Carriers

2011 ◽  
Vol 236-238 ◽  
pp. 1783-1788 ◽  
Author(s):  
Bo Hua Feng ◽  
Zi Yong Zhang
Keyword(s):  
Molecular Weight ◽  
Surface Charge ◽  
Ricinoleic Acid ◽  
Spherical Shape ◽  
Acid Group ◽  
Polydispersity Index ◽  
Surface Shape ◽  
Botanical Insecticide ◽  
Negative Surface ◽  
Negative Surface Charge

A new chitosan derivate (CMC-g-RA) was prepared by grafting ricinoleic acid anhydride (RA) on carboxymethy chitosan (CMC) molecules. The reaction factors such as molecular weight, mole ratio of anhydride to amino, temperature and solvent were examined. Nanoparticles were obtained by blending botanical insecticide capsaicin (Cap) and CMC-g-RA. Surface shape, particle size, polydispersity index, surface charge, LE and stability of Cap/CMC-g-RA nanoparticles were characterized. The results showed that lower molecular weight was of advantage to higher degree of RA substitution. CMC-g-RA and Cap formed drug delivery nanoparticles with spherical shape and negative surface charge in water. The increased concentration of drug or carrier resulted in higher zeta potential and narrower polydispersity index (PDI) of Cap/CMC-g-RA. The loading efficiency (LE) of nanoparticles was up to 0.86, which provided efficiently protection for Cap, extended drug releasing period and dosage.

scholarly journals Characterization of expansive soils treated with lignosulfonate

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rama Vara Prasad Chavali ◽  
B. Reshmarani
Keyword(s):  
Cation Exchange Capacity ◽  
Unconfined Compressive Strength ◽  
Laboratory Tests ◽  
Andhra Pradesh ◽  
Expansive Soils ◽  
Exchange Capacity ◽  
Strength Behavior ◽  
Negative Surface ◽  
Negative Surface Charge

Abstract The current study examines the potential of lignosulfonate to enhance the engineering behavior of two locally available expansive soils. The expansive soils were collected from Vijayawada and Amaravathi, located in the Capital Region of Andhra Pradesh, India. The soils were treated with four different percentages (0.5, 1, 2, and 4) of lignosulfonate and were allowed to interact for 7 and 28 days. A series of laboratory tests such as unconfined compressive strength, cation exchange capacity and scanning electron microscopy were carried out on the soil specimens. The results indicated that lignosulfonate has significant influence on the strength behavior of expansive soils. The amount of fines content present in soils defines the optimum percentage of lignosulfonate. Lignosulfonate treatment resulted in reduced negative surface charge of soils and formation of Polymer chain microstructure along with flocculated or aggregated particle microstructure, which may attribute to the enhanced strength of the expansive soils.

scholarly journals Morphomolecular Characterization of Serum Nanovesicles From Microbiomes Differentiates Stable and Infarcted Atherosclerotic Patients

2021 ◽  
Vol 8 ◽  
Author(s):  
Camila Rodrigues Moreno ◽  
José Antonio Franchini Ramires ◽  
Paulo Andrade Lotufo ◽  
Alexandre Matos Soeiro ◽  
Luanda Mara da Silva Oliveira ◽  
...  
Keyword(s):  
Prognostic Biomarker ◽  
Plaque Rupture ◽  
Oxygen Species ◽  
Important Complication ◽  
Patients With Heart Failure ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Artery Disease ◽  
And Control

Microbial communities are considered decisive for maintaining a healthy situation or for determining diseases. Acute myocardial infarction (AMI) is an important complication of atherosclerosis caused by the rupture of atheroma plaques containing proinflammatory cytokines, reactive oxygen species, oxidized low-density lipoproteins (oxLDL), damaged proteins, lipids, and DNA, a microenvironment compatible with a pathogenic microbial community. Previously, we found that archaeal DNA-positive infectious microvesicles (iMVs) were detected in vulnerable plaques and in the sera of Chagas disease patients with heart failure. Now, we characterize and quantify the levels of serum microbiome extracellular vesicles through their size and content using morphomolecular techniques to differentiate clinical outcomes in coronary artery disease (CAD). We detected increased numbers of large iMVs (0.8–1.34 nm) with highly negative surface charge that were positive for archaeal DNA, Mycoplasma pneumoniae antigens and MMP9 in the sera of severe AMI patients, strongly favoring our hypothesis that pathogenic archaea may play a role in the worst outcomes of atherosclerosis. The highest numbers of EVs <100 nm (exosomes) and MVs from 100 to 200 nm in the stable atherosclerotic and control healthy groups compared with the AMI groups were indicative that these EVs are protective, entrapping and degrading infectious antigens and active MMP9 and protect against the development of plaque rupture.Conclusion: A microbiome with pathogenic archaea is associated with high numbers of serum iMVs in AMI with the worst prognosis. This pioneering work demonstrates that the morphomolecular characterization and quantification of iEVs in serum may constitute a promising serum prognostic biomarker in CAD.

Assessment of Damage to Human Platelets after Aggregation and Other Injuries by Microscopic Observation and Estimation of Serotonin Uptake

1970 ◽  
Vol 23 (02) ◽  
pp. 261-275 ◽  
Author(s):  
G Zbinden ◽  
J. N Mehrishi ◽  
S Tomlin
Keyword(s):  
Platelet Aggregation ◽  
Electrophoretic Mobility ◽  
Human Platelets ◽  
Freezing And Thawing ◽  
Low Degree ◽  
Microscopic Evaluation ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Charged Macromolecules ◽  
5 Ht Uptake

SummaryThe severity of platelet damage induced by hyper- and hypotonic NaCl solutions and freezing and thawing was assessed by microscopic evaluation and measuring inhibition of 5-HT uptake. The same techniques were used to quantitate the effects of aggregating agents. The positively charged macromolecules PS, Poly-L und Poly-O reduced the net negative surface charge as determined by microelectrophoresis, caused platelet aggregation and inhibited 5-HT uptake. The damaging effects of Poly-L and Poly-O were more severe and more closely related to concentration than that of PS. The negatively charged macromolecules Poly-IC and NaPS increased the anodic electrophoretic mobility. Poly-IC and heparin caused a low degree of platelet clumping and no inhibition of 5-HT uptake. NaPS produced severe platelet damage with extensive clumping and complete inhibition of 5-HT uptake. Na laurate had the same effect, but did not alter electrophoretic mobility. ADP caused concentration-dependent platelet aggregation and inhibition of 5-HT uptake. The effects of ADP and NaPS were compared in agitated and non-agitated platelet samples containing identical concentrations of the 2 compounds. Agitation was found to increase the degree of platelet clumping and to reduce 5-HT uptake.

Incorporation of micro/nanoparticles of PCL with essential oil of Cymbopogon nardus in bacterial cellulose

2018 ◽  
Vol 1 (2) ◽  
pp. 37
Author(s):  
Aline Krindges ◽  
Vanusca Dalosto Jahno ◽  
Fernando Morisso
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Essential Oil ◽  
Zeta Potential ◽  
Bacterial Cellulose ◽  
Culture Medium ◽  
Static Culture ◽  
Cymbopogon Nardus ◽  
Cellulose Membranes

Incorporation studies of particles in different substrates with herbal assets growing. The objective of this work was the preparation and characterization of micro/nanoparticles containing cymbopogon nardus essential oil; and the incorporation of them on bacterial cellulose. For the development of the membranes was used the static culture medium and for the preparation of micro/nanoparticles was used the nanoprecipitation methodology. The incorporation of micro/nanoparticles was performed on samples of bacterial cellulose in wet and dry form. For the characterization of micro/nanoparticles were carried out analysis of SEM, zeta potential and particle size. For the verification of the incorporation of particulate matter in cellulose, analyses were conducted of SEM and FTIR. The results showed that it is possible the production and incorporation of micro/nanoparticles containing essential oil in bacterial cellulose membranes in wet form with ethanol.

Surface charge and extracellular polymer of sludge in the anaerobic degradation process

1996 ◽  
Vol 34 (5-6) ◽  
pp. 309-316 ◽  
Author(s):  
X. S. Jia ◽  
Herbert H. P. Fang ◽  
H. Furumai
Keyword(s):  
Surface Charge ◽  
Growth Phase ◽  
Anaerobic Degradation ◽  
Degradation Process ◽  
Anaerobic Sludge ◽  
Batch Experiments ◽  
High Substrate Concentration ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Extracellular Polymer

Changes of surface charge and extracellular polymer (ECP) content were investigated in batch experiments for three anaerobic sludges, each of which had been enriched at 35°C and pH 639-7.3 for more than 40 batches using propionate, butyrate and glucose, individually, as the sole substrate. Results showed that both ECP and the negative surface charge were dependent on the growth phase of microorganisms. They increased at the beginning of all batches when the microorganisms were in the prolific-growth phase, having high substrate concentration and food-to-microorganisms ratio. Both later gradually returned to their initial levels when the microorganisms were in the declined-growth phase, as the substrate became depleted. The negative surface charge increased linearly with the total-ECP content in all series with slopes of 0.0187, 0.0212 and 0.0157 meq/mg-total-ECP for sludge degrading propionate, butyrate and glucose, respectively. The change of surface charge for the first two sludges was mainly due to the increase of proteinaceous fraction of ECP; but, for glucose-degrading sludge, that could be due to the increases of both proteinaceous and carbohydrate fractions of ECP. The negative-charged nature of anaerobic sludge implies that cations should be able to promote granulation of anaerobic sludge.

scholarly journals Nanoemulsions for the Encapsulation of Hydrophobic Actives

Cosmetics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 45
Author(s):  
Eduardo Guzmán ◽  
Laura Fernández-Peña ◽  
Lorenzo Rossi ◽  
Mathieu Bouvier ◽  
Francisco Ortega ◽  
...  
Keyword(s):  
Surface Charge ◽  
Long Term Stability ◽  
Promising Tool ◽  
Oil In Water ◽  
Nanometric Range ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Highly Hydrophobic ◽  
Technological Interest

This work analyzes the dispersion of two highly hydrophobic actives, (9Z)-N-(1,3-dihydroxyoctadecan-2-yl)octadec-9-enamide (ceramidelike molecule) and 2,6-diamino-4-(piperidin-1-yl)pyrimidine 1-oxide (minoxidil), using oil-in-water nanoemulsions with the aim of preparing stable and safe aqueous-based formulations that can be exploited for enhancing the penetration of active compounds through cosmetic substrates. Stable nanoemulsions with a droplet size in the nanometric range (around 200 nm) and a negative surface charge were prepared. It was possible to prepare formulations containing up to 2 w/w% of ceramide-like molecules and more than 10 w/w% of minoxidil incorporated within the oil droplets. This emulsions evidenced a good long-term stability, without any apparent modification for several weeks. Despite the fact that this work is limited to optimize the incorporation of the actives within the nanoemulsion-like formulations, it demonstrated that nanoemulsions should be considered as a very promising tool for enhancing the distribution and availability of hydrophobic molecules with technological interest.

scholarly journals Characterization of Unripe and Mature Avocado Seed Oil in Different Proportions as Phase Change Materials and Simulation of Their Cooling Storage

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 107
Author(s):  
Evelyn Reyes-Cueva ◽  
Juan Francisco Nicolalde ◽  
Javier Martínez-Gómez
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Seed Oil ◽  
Energy System ◽  
Maturity Stage ◽  
Natural Environments ◽  
Renewable Materials ◽  
Scanning Calorimetry ◽  
Avocado Seed

Environmental problems have been associated with energy consumption and waste management. A solution is the development of renewable materials such as organic phase change materials. Characterization of new materials allows knowing their applications and simulations provide an idea of how they can developed. Consequently, this research is focused on the thermal and chemical characterization of five different avocado seed oils depending on the maturity stage of the seed: 100% unripe, 25% mature-75% unripe, 50% mature-50% unripe, 75% mature-25% unripe, and 100% mature. The characterization was performed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The best oil for natural environments corresponded to 100% matured seed with an enthalpy of fusion of 52.93 J·g−1, and a degradation temperature between 241–545 °C. In addition, the FTIR analysis shows that unripe seed oil seems to contain more lipids than a mature one. Furthermore, a simulation with an isothermal box was conducted with the characterized oil with an initial temperature of −14 °C for the isothermal box, −27 °C for the PCM box, and an ambient temperature of 25 °C. The results show that without the PCM the temperature can reach −8 °C and with it is −12 °C after 7 h, proving its application as a cold thermal energy system.

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