scholarly journals Salt Effect on the Cloud Point Phenomenon of Amphiphilic Drug-Hydroxypropylmethyl Cellulose System

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mohd. Sajid Ali ◽  
Dileep Kumar ◽  
Hamad A. Al-Lohedan
Keyword(s):  
Cloud Point ◽  
Sodium Salt ◽  
Salt Effect ◽  
Tricyclic Antidepressant ◽  
High Concentration ◽  
Hydroxypropylmethyl Cellulose ◽  
Amphiphilic Drug ◽  
Amphiphilic Drugs ◽  
Nortriptyline Hydrochloride

Effect of two amphiphilic drugs (tricyclic antidepressant, nortriptyline hydrochloride (NORT), and nonsteroidal anti-inflammatory drug, sodium salt of ibuprofen (IBF)) on the cloud point of biopolymer hydroxypropylmethyl cellulose (HPMC) was studied. Effect of NaCl was also seen on the CP of HPMC-drug system. CP of HPMC increases uniformly on increasing the (drug). Both drugs, though one being anionic (IBF) and other cationic (NORT), affect the CP in almost the same manner but with different extent implying the role of hydrophobicity in the interaction between drug and polymer. Salt affects the CP of the drug in a dramatic way as low concentration of salt was only able to increase the value of the CP, though not affecting the pattern. However, in presence of high concentration of salts, minimum was observed on CP versus (drug) plots. Various thermodynamic parameters were evaluated and discussed on the basis of the observed results.

Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

2018 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Polymer Electrolyte ◽  
Salt Concentration ◽  
Rational Design ◽  
Material System ◽  
Ion Dynamics ◽  
High Concentration ◽  
Anion Clusters ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>

Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

2018 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Polymer Electrolyte ◽  
Salt Concentration ◽  
Rational Design ◽  
Material System ◽  
Ion Dynamics ◽  
High Concentration ◽  
Anion Clusters ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>

scholarly journals Focused ultrasound in neuro-oncology: the role of the Focused Ultrasound Foundation in driving adoption and innovation

2021 ◽  
Author(s):  
Emily C. Whipple ◽  
Camille A. Favero ◽  
Neal F. Kassell
Keyword(s):  
Drug Delivery ◽  
Brain Tumors ◽  
Focused Ultrasound ◽  
Clinical Evidence ◽  
Neurological Injury ◽  
High Concentration ◽  
Potential Applications ◽  
Tumor Agent

Abstract Introduction Intra-arterial (lA) delivery of therapeutic agents across the blood-brain barrier (BBB) is an evolving strategy which enables the distribution of high concentration therapeutics through a targeted vascular territory, while potentially limiting systemic toxicity. Studies have demonstrated lA methods to be safe and efficacious for a variety of therapeutics. However, further characterization of the clinical efficacy of lA therapy for the treatment of brain tumors and refinement of its potential applications are necessary. Methods We have reviewed the preclinical and clinical evidence supporting superselective intraarterial cerebral infusion (SSJACI) with BBB disruption for the treatment of brain tumors. In addition, we review ongoing clinical trials expanding the applicability and investigating the efficacy of lA therapy for the treatment of brain tumors. Results Trends in recent studies have embraced the use of SSIACI and less neurotoxic chemotherapies. The majority of trials continue to use mannitol as the preferred method of hyperosmolar BBB disruption. Recent preclinical and preliminary human investigations into the lA delivery of Bevacizumab have demonstrated its safety and efficacy as an anti-tumor agent both alone and in combination with chemotherapy. Conclusion lA drug delivery may significantly affect the way treatment are delivered to patients with brain tumors, and in particular GBM. With refinement and standardization of the techniques of lA drug delivery, improved drug selection and formulations, and the development of methods to minimize treatment-related neurological injury, lA therapy may offer significant benefits for the treatment of brain tumors.

scholarly journals I Like the Way You Eat It: Lemur (Indri indri) Gut Mycobiome and Geophagy

2021 ◽  
Author(s):  
Luigimaria Borruso ◽  
Alice Checcucci ◽  
Valeria Torti ◽  
Federico Correa ◽  
Camillo Sandri ◽  
...  
Keyword(s):  
Plant Material ◽  
Soil Characteristics ◽  
Nutrient Supply ◽  
Fungal Species ◽  
High Concentration ◽  
Beneficial Role ◽  
Intimate Connection ◽  
Indri Indri ◽  
Lemur Species

AbstractHere, we investigated the possible linkages among geophagy, soil characteristics, and gut mycobiome of indri (Indri indri), an endangered lemur species able to survive only in wild conditions. The soil eaten by indri resulted in enriched secondary oxide-hydroxides and clays, together with a high concentration of specific essential micronutrients. This could partially explain the role of the soil in detoxification and as a nutrient supply. Besides, we found that soil subject to geophagy and indris’ faeces shared about 8.9% of the fungal OTUs. Also, several genera (e.g. Fusarium, Aspergillus and Penicillium) commonly associated with soil and plant material were found in both geophagic soil and indri samples. On the contrary, some taxa with pathogenic potentials, such as Cryptococcus, were only found in indri samples. Further, many saprotrophs and plant-associated fungal taxa were detected in the indri faeces. These fungal species may be involved in the digestion processes of leaves and could have a beneficial role in their health. In conclusion, we found an intimate connection between gut mycobiome and soil, highlighting, once again, the potential consequent impacts on the wider habitat.

Chemistry of oxylipin pathways in marine diatoms

2007 ◽  
Vol 79 (4) ◽  
pp. 481-490 ◽  
Author(s):  
Angelo Fontana ◽  
Giuliana d'Ippolito ◽  
Adele Cutignano ◽  
Antonio Miralto ◽  
Adrianna Ianora ◽  
...  
Keyword(s):  
Higher Plants ◽  
Larval Growth ◽  
Marine Macroalgae ◽  
High Concentration ◽  
Marine Diatoms ◽  
Fatty Acid Derivatives ◽  
The Family ◽  
Hydrolysis Of ◽  
Catalyzed Oxidation

Oxylipins are important signal transduction molecules widely distributed in animals and plants where they regulate a variety of events associated with physiological and pathological processes. The family embraces several different metabolites that share a common origin from the oxygenase-catalyzed oxidation of polyunsaturated fatty acids. The biological role of these compounds has been especially studied in mammalians and higher plants, although a varied and very high concentration of these products has also been reported from marine macroalgae. This article gives a summary of our results concerning the oxylipin chemistry of marine diatoms, a major class of planktonic microalgae that discourage predation from their natural grazers, zooplanktonic copepods, using chemical warfare. These apparently harmless microscopic cells produce a plethora of oxylipins, including short-chain unsaturated aldehydes, hydroxyl-, keto-, and epoxyhydroxy fatty acid derivatives, that induce reproductive failure in copepods through abortions, congenital malformations, and reduced larval growth. The biochemical process involved in the production of these compounds shows a simple regulation based on decompartmentation and mixing of preexisting enzymes and requires hydrolysis of chloroplast-derived glycolipids to feed the downstream activities of C16 and C20 lipoxygenases.

Surfactants and ureas affect the cloud point of amphiphilic drug, clomipramine hydrochloride

2010 ◽  
Vol 81 (1) ◽  
pp. 152-157 ◽  
Author(s):  
Andleeb Z. Naqvi ◽  
Mohammed D.A. Al-Ahmadi ◽  
Mohd. Akram ◽  
Kabir-ud-Din
Keyword(s):  
Cloud Point ◽  
Amphiphilic Drug

scholarly journals Seasonal variation of mono- and sesquiterpene emission rates of Scots pine

2006 ◽  
Vol 3 (1) ◽  
pp. 93-101 ◽  
Author(s):  
H. Hakola ◽  
V. Tarvainen ◽  
J. Bäck ◽  
H. Ranta ◽  
B. Bonn ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Scots Pine ◽  
Early Summer ◽  
Emission Rates ◽  
High Concentration ◽  
Temperature Dependent ◽  
Emission Pattern ◽  
Defensive Role ◽  
Monoterpene Emission

Abstract. The seasonal variation of mono-and sesquiterpene emission rates of Scots pine was measured from April to October in 2004. The emission rates were measured daily in the afternoons with the exception of weekends. Emissions were measured from two branches; one of them was debudded in May (branch A), while the other was allowed to grow new needles (branch B). The monoterpene emission pattern remained almost constant throughout the measurement period, Δ3-carene being the dominant monoterpene (50-70% of the VOC emission). The standard monoterpene emission potential (30°C) was highest during early summer in June (the average of the two branches 1.35 µg g-1h-1) and lowest during early autumn in September (the average of the two branches 0.20 µg g-1h-1. The monoterpene emission potential of branch A remained low also during October, whereas the emission potential of branch B was very high in October. The sesquiterpenes were mainly emitted during mid summer, the dominant sesquiterpene being β-caryophyllene. Branch A had a higher sesquiterpene emission potential than branch B and the emission maximum occurred concomitant with the high concentration of airborne pathogen spores suggesting a potential defensive role of the sesquiterpene emissions. The sesquiterpene emissions were well correlated with linalool and 1,8-cineol emissions, but not with monoterpenes. Sesquiterpene and 1,8-cineol emissions were equally well described by the temperature dependent and the temperature and light dependent algorithms. This is due to the saturation of the light algorithm as the measurements were always conducted during high light conditions.

scholarly journals The role of a mid-air collision in drifting snow

2018 ◽  
Author(s):  
Shuming Jia ◽  
Zhengshi Wang ◽  
Shumin Li
Keyword(s):  
Friction Velocity ◽  
Global Climate ◽  
Three Dimensional ◽  
Particle Collision ◽  
High Concentration ◽  
Three Dimensional Model ◽  
Two Phase ◽  
Drifting Snow ◽  
Collision Mechanism

Abstract. Drifting snow, a common two-phase flow movement in high and cold areas, contributes greatly to the mass and energy balance of glacier and ice sheets and further affects the global climate system. Mid-air collisions occur frequently in high-concentration snow flows; however, this mechanism is rarely considered in current models of drifting snow. In this work, a three-dimensional model of drifting snow with consideration of inter-particle collisions is established; this model enables the investigation of the role of a mid-air collision mechanism in openly drifting snow. It is found that the particle collision frequency increases with the particle concentration and friction velocity, and the blown snow with a mid-air collision effect produces more realistic transport fluxes since inter-particle collision can enhance the particle activity under the same condition. However, the snow saltation mass flux basically shows a cubic dependency with friction velocity, which distinguishes it from the quadratic dependence of blown sand movement. Moreover, the snow saltation flux is found to be largely sensitive to the particle size distribution since the suspension snow may restrain the saltation movement. This research could improve our understanding of the role of the mid-air collision mechanism in natural drifting snow.

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