scholarly journals Multivalent weak interactions enhance selectivity of interparticle binding

2020 ◽  
Vol 117 (37) ◽  
pp. 22690-22697 ◽  
Author(s):  
M. R. W. Scheepers ◽  
L. J. van IJzendoorn ◽  
M. W. J. Prins
Keyword(s):  
Targeted Drug Delivery ◽  
Colloidal Particles ◽  
High Selectivity ◽  
Weak Interactions ◽  
Theoretical Work ◽  
Coated Particles ◽  
Receptor Interactions ◽  
Two Factors ◽  
Experimental Findings

Targeted drug delivery critically depends on the binding selectivity of cargo-transporting colloidal particles. Extensive theoretical work has shown that two factors are necessary to achieve high selectivity for a threshold receptor density: multivalency and weak interactions. Here, we study a model system of DNA-coated particles with multivalent and weak interactions that mimics ligand–receptor interactions between particles and cells. Using an optomagnetic cluster experiment, particle aggregation rates are measured as a function of ligand and receptor densities. The measured aggregation rates show that the binding becomes more selective for shorter DNA ligand–receptor pairs, proving that multivalent weak interactions lead to enhanced selectivity in interparticle binding. Simulations confirm the experimental findings and show the role of ligand–receptor dissociation in the selectivity of the weak multivalent binding.

ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

2020 ◽  
pp. 15-27
Keyword(s):  
Electrical Conductivity ◽  
Humic Acids ◽  
Release Rate ◽  
Release Kinetics ◽  
Sodium Adsorption Ratio ◽  
Salt Affected Soil ◽  
Two Factors ◽  
Dissolved Ions ◽  
Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

Monocyte as an Emerging Tool for Targeted Drug Delivery: A Review

2019 ◽  
Vol 24 (44) ◽  
pp. 5296-5312 ◽  
Author(s):  
Fakhara Sabir ◽  
Rai K. Farooq ◽  
Asim.ur.Rehman ◽  
Naveed Ahmed
Keyword(s):  
Drug Delivery ◽  
Targeted Drug Delivery ◽  
The Body ◽  
Carrier System ◽  
Bone Marrow Precursor ◽  
Extensive Introduction ◽  
Cancer Inflammation ◽  
Targeted Drug ◽  
Cluster Of Differentiation

Monocytes are leading component of the mononuclear phagocytic system that play a key role in phagocytosis and removal of several kinds of microbes from the body. Monocytes are bone marrow precursor cells that stay in the blood for a few days and migrate towards tissues where they differentiate into macrophages. Monocytes can be used as a carrier for delivery of active agents into tissues, where other carriers have no significant access. Targeting monocytes is possible both through passive and active targeting, the former one is simply achieved by enhanced permeation and retention effect while the later one by attachment of ligands on the surface of the lipid-based particulate system. Monocytes have many receptors e.g., mannose, scavenger, integrins, cluster of differentiation 14 (CD14) and cluster of differentiation 36 (CD36). The ligands used against these receptors are peptides, lectins, antibodies, glycolipids, and glycoproteins. This review encloses extensive introduction of monocytes as a suitable carrier system for drug delivery, the design of lipid-based carrier system, possible ways for delivery of therapeutics to monocytes, and the role of monocytes in the treatment of life compromising diseases such as cancer, inflammation, stroke, etc.

Bridging the Gap of Drug Delivery in Colon Cancer: The Role of Chitosan and Pectin Based Nanocarriers System

2020 ◽  
Vol 17 (10) ◽  
pp. 911-924
Author(s):  
Rohitas Deshmukh
Keyword(s):  
Drug Delivery ◽  
Colon Cancer ◽  
Targeted Drug Delivery ◽  
Targeted Delivery ◽  
Therapeutic Agent ◽  
Therapeutic Agents ◽  
Delivery Systems ◽  
Target Tissue ◽  
Polymer Carriers

Colon cancer is one of the most prevalent diseases, and traditional chemotherapy has not been proven beneficial in its treatment. It ranks second in terms of mortality due to all cancers for all ages. Lack of selectivity and poor biodistribution are the biggest challenges in developing potential therapeutic agents for the treatment of colon cancer. Nanoparticles hold enormous prospects as an effective drug delivery system. The delivery systems employing the use of polymers, such as chitosan and pectin as carrier molecules, ensure the maximum absorption of the drug, reduce unwanted side effects and also offer protection to the therapeutic agent from quick clearance or degradation, thus allowing an increased amount of the drug to reach the target tissue or cells. In this systematic review of published literature, the author aimed to assess the role of chitosan and pectin as polymer-carriers in colon targeted delivery of drugs in colon cancer therapy. This review summarizes the various studies employing the use of chitosan and pectin in colon targeted drug delivery systems.

scholarly journals An Overview of Adipose Tissue ACE2 Modulation by Diet and Obesity. Potential Implications in COVID-19 Infection and Severity

2021 ◽  
Vol 22 (15) ◽  
pp. 7975
Author(s):  
Saioa Gómez-Zorita ◽  
Iñaki Milton-Laskibar ◽  
Laura García-Arellano ◽  
Marcela González ◽  
María P. Portillo
Keyword(s):  
Adipose Tissue ◽  
Protective Role ◽  
Inflammatory Factors ◽  
Current Evidence ◽  
Disease Outcomes ◽  
Lower Activation ◽  
Two Factors ◽  
Obese Subjects ◽  
Ace2 Gene

The present review is aimed at analysing the current evidence concerning the potential modulation of obesity and/or diet in adipose tissue ACE2. Additionally, the potential implications of these effects on COVID-19 are also addressed. The results published show that diet and obesity are two factors that effectively influence the expression of Ace2 gene in adipose tissue. However, the shifts in this gene do not always occur in the same direction, nor with the same intensity. Additionally, there is no consensus regarding the implications of increased adipose tissue ACE2 expression in health. Thus, while in some studies a protective role is attributed to ACE2 overexpression, other studies suggest otherwise. Similarly, there is much debate regarding the role played by ACE2 in COVID-19 in terms of degree of infection and disease outcomes. The greater risk of infection that may hypothetically derive from enhanced ACE2 expression is not clear since the functionality of the enzyme seems to be as important as the abundance. Thus, the greater abundance of ACE2 in adipose tissue of obese subjects may be counterbalanced by its lower activation. In addition, a protective role of ACE2 overexpression has also been suggested, associated with the increase in anti-inflammatory factors that it may produce.

scholarly journals Characterization of swelling behavior of carbon nano-filler modified polydimethylsiloxane composites

2021 ◽  
pp. 009524432110061
Author(s):  
Bo Yang ◽  
Balakrishnan Nagarajan ◽  
Pierre Mertiny
Keyword(s):  
Digital Image Analysis ◽  
Swelling Behavior ◽  
Optical Measurements ◽  
Natural Phenomenon ◽  
Cross Linking ◽  
Dimensional Changes ◽  
Experimental Findings ◽  
Carbon Based

Polymers may absorb fluids from their surroundings via the natural phenomenon of swelling. Dimensional changes due to swelling can affect the function of polymer components, such as in the case of seals, microfluidic components and electromechanical sensors. An understanding of the swelling behavior of polymers and means for controlling it can improve the design of polymer components, for example, for the previously mentioned applications. Carbon-based fillers have risen in popularity to be used for the property enhancement of resulting polymer composites. The present investigation focuses on the effects of three carbon-based nano-fillers (graphene nano-platelets, carbon black, and graphene nano-scrolls) on the dimensional changes of polydimethylsiloxane composites due to swelling when immersed in certain organic solvents. For this study, a facile and expedient methodology comprised of optical measurements in conjunction with digital image analysis was developed as the primary experimental technique to quantify swelling dimensional changes of the prepared composites. Other experimental techniques assessed polymer cross-linking densities and elastic mechanical properties of the various materials. The study revealed that the addition of certain carbon-based nano-fillers increased the overall swelling of the composites. The extent of swelling further depended on the organic solvent in which the composites were immersed in. Experimental findings are contrasted with published models for swelling prediction, and the role of filler morphology on swelling behavior is discussed.

scholarly journals A New Piano-Stool Ruthenium(II) P-Cymene-Based Complex: Crystallographic, Hirshfeld Surface, DFT, and Luminescent Studies

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohd. Afzal
Keyword(s):  
Density Functional ◽  
Weak Interactions ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Binding Energies ◽  
Orbital Energy ◽  
Aminosalicylic Acid ◽  
Full Characterization

A new complex (Ru(η6-p-cymene)(5-ASA)Cl2) (1) where 5-ASA is 5-aminosalicylic acid has been prepared by reacting the ruthenium arene precursors ((η6-arene)Ru(μ-Cl)Cl)2, with the 5-ASA ligands in a 1:1 ratio. Full characterization of complex 1 was accomplished by elemental analysis, IR, and TGA following the structure obtained from a single-crystal X-ray pattern. The structural analysis revealed that complex 1 shows a “piano-stool” geometry with Ru-C (2.160(5)- 2.208(5)Å), Ru-N (2.159(4) Å) distances, which is similar to equivalents sister complex. Density functional theory (DFT) was used to calculate the significant molecular orbital energy levels, binding energies, bond angles, bond lengths, and spectral data (FTIR, NMR, and UV–VIS) of complex 1, consistent with the experimental results. The IR and UV–VIS spectra of complex 1 were computed using all of the methods and choose the most appropriate way to discuss. Hirshfeld surface analysis was also executed to understand the role of weak interactions such as H⋯H, C⋯H, C-H⋯π, and vdW interactions, which play a significant role in the crystal environment’s stability. Moreover, the luminescence results at room temperature show that complex 1 gives a more intense emission band positioned at 465 nm upon excitation at 330 nm makes it a suitable candidate for the building of photoluminescent material.

Prenatal exposure to persistent organic pollutants as a risk factor of offspring metabolic syndrome development during childhood

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Marlene Cervantes González
Keyword(s):  
Metabolic Syndrome ◽  
Organic Pollutants ◽  
Prenatal Exposure ◽  
Persistent Organic Pollutants ◽  
Animal Studies ◽  
Polychlorinated Biphenyl ◽  
Environmental Pollutants ◽  
Epidemiological Studies ◽  
Experimental Findings

Abstract Persistent Organic Pollutants (POPs) are exogenous, artificially made chemicals that can disrupt the biological system of individuals and animals. POPs encompass a variety of chemicals including, dioxins, organochlorines (OCs), polychlorinated biphenyl (PCBs), and perfluoroalkyl substances (PFASs) that contain a long half-life and highly resistant to biodegradation. These environmental pollutants accumulate over time in adipose tissues of living organisms and alter various insulin function-related genes. Childhood Metabolic Syndrome (MetS) consists of multiple cardiovascular risk factors, insulin function being one of them. Over the years, the incidence of the syndrome has increased dramatically. It is imperative to explore the role of persistent organic pollutants in the development of Childhood Metabolic Syndrome. Some epidemiological studies have reported an association between prenatal exposure to POPs and offspring MetS development throughout childhood. These findings have been replicated in animal studies in which these pollutants exercise negative health outcomes such as obesity and increased waist circumference. This review discusses the role of prenatal exposure to POPs among offspring who develop MetS in childhood, the latest research on the MetS concept, epidemiological and experimental findings on MetS, and the POPs modes of action. This literature review identified consistent research results on this topic. Even though the studies in this review had many strengths, one major weakness was the usage of different combinations of MetS criteria to measure the outcomes. These findings elucidate the urgent need to solidify the pediatric MetS definition. An accurate definition will permit scientists to measure the MetS as a health outcome properly and allow clinicians to diagnose pediatric MetS and provide individualized treatment appropriately.

scholarly journals The Role of Nonduality in the Relationship Between Flow States and Well-Being

Mindfulness ◽  
2021 ◽  
Author(s):  
Julianna M. Lynch ◽  
Allison S. Troy
Keyword(s):  
Positive Emotion ◽  
Satisfaction With Life ◽  
Well Being ◽  
Theoretical Work ◽  
Subjective Well Being ◽  
Psychological Well Being ◽  
The Relationship ◽  
Flow States

Abstract Objectives The current study investigated the hypothesis that the relationship between flow states and well-being is mediated by nondual experiences. Past empirical and theoretical work suggests flow states share similarities with nondual experiences. The current study expanded upon previous work by examining the relationships between flow, nondual experiences, emotion, and well-being. Methods Students enrolled in various artistic classes (N = 104) were surveyed once a week for four weeks. Participants reported on their experiences of flow, nonduality, emotion, and psychological and subjective well-being. Results Higher scores on measures of both flow (b = 7.03, SE = 0.82, p < .001) and nondual experiences (b = 0.17, SE = 0.02, p < .001) predicted increased positive emotion immediately after class. Nondual experiences partially mediated this relationship, such that when accounting for nondual experiences, the relationship between flow and positive emotion was significantly decreased (b = 4.30, SE = 0.45, p < .001). Longitudinally, nondual experience also mediated the relationship between flow and satisfaction with life (Sobel t = 1.94, SE = 1.06, p = .05). However, while flow predicted increased psychological well-being (b = 0.32, SE = 0.14, p = .02) after the four weeks, nondual experience did not (b = −0.003, SE = 0.002, p = .13). Conclusions These findings suggest that flow states may facilitate some features of nonduality and share similarities with meditative states. Additionally, the link between flow and well-being may be explained by its similarities to meditative states, and that creative activities could be useful in fostering well-being.

scholarly journals The Role of Emotionality and Power on Tendency to Unethical Behaviors

2012 ◽  
Vol 2 (4) ◽  
pp. 187
Author(s):  
Hossein Safarzadeh ◽  
Alireza Soloukdar ◽  
Ali Alipour ◽  
Seyedeh Akram Parpanchi
Keyword(s):  
Correlation Coefficient ◽  
Organizational Citizenship ◽  
Significant Relationship ◽  
Independent Variables ◽  
Ethical Behaviors ◽  
Two Factors ◽  
Unethical Behaviors ◽  
The Common ◽  
Two Independent Variables

Emotion and power have been studied very deeply especially during the last decade; however, the common effects of these two factors on individuals' optional behaviors (organizational citizenship, anti-productivity, unethical behaviors) have been less focused. In the present paper, the role of individuals' emotionality, their interest in power, and their tendency to unethical behaviors will be discussed according to the model of Levine. Three questionnaires were distributed and the collected data were analyzed using Pearson’s Correlation Coefficient, Multiple Regression, and T- test. Findings indicated that there is a significant relationship between the two independent variables of emotionality and power and tendency to unethical behaviors. Moreover, according to the results of the tests, men are more emotion-oriented and power seekers than women. Keywords: Power, Emotion, Ethical Behaviors

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