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Topic Review
Assessment of Bio-Based Polyurethanes
Among numerous synthetic macromolecules, polyurethane in its different forms has proven its sheer dominance and established a reputation as a reliable and trusted material due to its proficiency in terms of superior properties, which include: high mechanical strength and abrasion resistance, good durability, good adhesion, good thermal stability, excellent chemical and weathering resistance. Synthetic polyurethane materials are non-biodegradable, poisonous, and use petrochemical-based raw materials, which are now depleting, leading to a surge in polyurethane production costs. Enormous kinds of available bio-renewable sources as predecessors for the production of polyols and isocyanates have been explored for the development of “greener” PU materials; these bio-based polyurethanes have significant potential to be used as future PU products, with a partial or total replacement of petroleum-based polyurethanes, due to increasing concern about the environment, their relatively low cost and biodegradability.
  • 1.7K
  • 12 Aug 2022
Topic Review
Fanjul Brothers
The Fanjul brothers — Cuban born Alfonso "Alfy" Fanjul Jr., José "Pepe" Fanjul, Alexander Fanjul, and Andres Fanjul — are owners of Fanjul Corp., a vast sugar and real estate conglomerate in the United States and the Dominican Republic. It comprises the subsidiaries Domino Sugar, Florida Crystals, C&H Sugar, Redpath Sugar, former Tate & Lyle sugar companies, American Sugar Refining, La Romana International Airport, and resorts surrounding La Romana, Dominican Republic.
  • 1.7K
  • 15 Nov 2022
Topic Review
Phosphorus Compounds of Natural Origin
Natural phosphorus compounds are essential for modern biological systems, and their diverse biological properties testify to their importance in the world of living organisms. They provide stable ligation necessary for fixing information in RNA and DNA, contribute to cellular structure in phospholipids, serve as the main source of biochemical energy (eg, ATP, phosphoenolpyruvate, creatinephosphate), and are present in a large number of metabolites. Сentral place that phosphates retain in biological systems allows us to conclude that they played an important role in the emergence of life on Earth. In recent years, a large number of natural phosphorus compounds have been isolated from living organisms and significant advances have been made in understanding the effect of phosphates on prebiotic chemistry.
  • 1.7K
  • 23 Jun 2021
Topic Review
Cardiac Glycosides
Cardiac glycosides (CG’s) are naturally occurring biologically active small molecules, used to diagnose a diversity of heart diseases such as congestive heart failure and cardiac arrhythmia. The story of CG’s started over 100 years ago when Sir William Withering reported the use of foxglove plant for treating “dropsy” associated with congestive heart failure and the foxglove plant (Digitalis purpurea) was still in the use for the extraction of Digoxin, a cardiac glycoside used to treat congestive heart failures (Johnson., 2012). The core structure of CGs comprises a steroid nucleus attached to a five-membered lactone ring (cardenolide) or six-membered lactone rings (bufadienolides) along with sugar moieties. Major plant-derived CGs were obtained from plant families of Apocynaceae, Scrophulariaceae, and Asparagaceae (Thevitia neriifolia, Neerium oleander, Digitalis purpurea, Digitalis lanata, Urginea maritime, and Strophanthus kombe). Structurally, all these contain a core steroid nucleus connected with sugar moiety at C3 position and lactone moiety at C17 position (Figure 1.3). The pharmacological significance of all the CG’s lies in the core steroid confirmation that contains A/B and C/D cis- portions and the properties such as pharmacokinetics and pharmacodynamics lie between the confined sugars molecules (Pongrakhananon., 2013). Apart from the plant sources, CG’s were also isolated from several animal species such as bufadienolide was isolated from frogs, and also mammalian tissues contain a cardiac glycoside which is similar to endogenous digitalis (Melero et al., 2000). Quite a few studies have conveyed that the human body does contain a lot more CG’s in different parts. For example, the plasma membrane contains Ouabain and Proscillaridin A and human urine contains digoxin and marinobufagenin whereas human lenses consist of 19-norbufalin (Schoner and Scheiner-Bobis., 2007). In the year 1785, William Withering was the first person to use a digitalis compound from Digitalis purpurea to treat congestive heart failures. Currently, Digoxin is used for treating congestive heart failures. The mechanism of action of Digoxin is that it can inhibit the sodium-potassium pump (Na+/K+-ATPase). Living organisms maintain more percentage of K+ within the cell and less percentage of Na+. However, the scenario at the outside of the cell is quite opposite to the intracellular conditions where a high percentage of Na+ and less percentage of K+ will be maintained. Hence, there is a concentration incline that exists between the outside and inside cellular environments, which will be maintained by sodium-potassium pump. The Na+/K+-ATPase is recognized as a transmembrane protein whose functions are to maintain ionic balance in the heart tissue. Na+/K+-ATPase utilizes ATP as the whole energy source, to exchange two K+ ions inside the cell and pushes three Na+ ions outside to maintain intra cellular homeostasis. Also, Na+/K+-ATPase transports glucose and amino acids by keeping less concentration of Na+ within the cell and helps in the maintenance of electrochemical incline. The increment of the Na+ level inside the cell retort to CGs fortifies the ion exchange mechanism. This leads to the expansion of intracellular Ca2+ percentage which therefore promotes organelle instances such as myocardial contractibility, and generates optimistic inotropic effects in the heart cell with CGs (Kaplan., 2002).  
  • 1.7K
  • 12 Aug 2020
Topic Review
Cavity Disinfectants
Cavity disinfection becomes an important step before a dental restorative procedure. The disinfection can be obtained cleaning the dental cavity with antimicrobial agents before the use of adhesive systems. 
  • 1.7K
  • 27 Jan 2021
Topic Review
GeSn Alloys for Photonic and Electronic Applications
GeSn materials have attracted considerable attention for their tunable band structures and high carrier mobilities, which serve well for future photonic and electronic applications.
  • 1.7K
  • 28 Mar 2022
Topic Review
Imidazoline Surfactants
Imidazoline surfactants are a class of surfactants with a hydrophobic tail and an imidazoline hydrophilic head. They are commonly used as emulsifiers, wetting agents, and cleaning agents in a variety of applications, including personal care, industrial cleaning, and agriculture. Imidazoline surfactants are known for their stability in acidic and alkaline conditions, making them a popular choice for many industrial processes. Imidazoline surfactants are mainly the cationic surfactants that contain an imidazoline ring in their chemical structure. They are commonly used as emulsifiers, corrosion inhibitors, and wetting agents in a variety of industrial and household applications. Imidazoline surfactants are typically synthesized by reacting a fatty acid or fatty amine with an imidazole or imidazoline compound. The resulting surfactants have a unique combination of properties, including excellent emulsification, wetting, and corrosion inhibition abilities.
  • 1.7K
  • 24 Mar 2023
Topic Review
Bioactive Lipids in Food Applications
Bioactive lipids, such as fat-soluble vitamins, omega-3 fatty acids, conjugated linoleic acids, carotenoids and phytosterols play an important role in boosting human health and wellbeing. These lipophilic substances cannot be synthesized within the human body, and so people must include them in their diet. There is increasing interest in incorporating these bioactive lipids into functional foods designed to produce certain health benefits, such as anti-inflammatory, antioxidant, anticancer and cholesterol-lowering properties. However, many of these lipids have poor compatibility with food matrices and low bioavailability because of their extremely low water solubility. Nanotechnology is a promising technology that can be used to overcome many of these limitations. Different kinds of nanoscale delivery systems have been designed to encapsulate and protect bioactive lipids, thereby facilitating their handling, stability, food matrix compatibility, and bioavailability.
  • 1.7K
  • 27 Mar 2021
Topic Review
CO2 Hydroboration
The use of CO2 as C1 building block for chemical synthesis is receiving growing attention, due to the potential of this simple molecule as abundant and cheap renewable feedstock. Among the possible reductants used in the literature to bring about CO2 reduction to C1 derivatives, hydroboranes have found various applications, in the presence of suitable homogenous catalysts. The main results obtained since 2016 in the synthetic design of main group, first and second row transition metals for use as catalysts for CO2 hydroboration are summarized.
  • 1.7K
  • 04 Jun 2024
Topic Review
Nanojoining
Nanojoining is the process of joining two or more surfaces together using nanomaterials as the primary building blocks. This includes, but is not limited to, nanosoldering, nanobrazing, nanowelding, nanoscale diffusion bonding, and additive manufacturing. Note that, like with conventional soldering and brazing, only the filler metal undergoes melting, not the base material. Nanomaterials are materials in which at least one dimension 100 nm or less and include 0-D (e.g. nanoparticles, 1-D (e.g. nanowires and nanorods), 2-D (e.g. graphene), and 3-D (e.g. nanofoam) materials. Nanomaterials exhibit several notable properties that allow joining to occur at temperatures lower than the melting temperature of their bulk counterpart. For example, the melting temperature of Ag is 961.78 °C, but Ag nanomaterials begin to melt at a much lower temperature that is dependent depending on the size and shape. These properties include high surface area to volume ratio, the Gibbs-Thompson effect, and high surface energy. The low joining temperature of nanomaterials has been exploited numerous times for flexible electronics, printable electronics, and soldering applications; only within the last two decades have they been explored for high-temperature joining applications (>450 °C).
  • 1.7K
  • 07 Jul 2022
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