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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.
  • 2.0K
  • 04 Jun 2024
Topic Review
Extraction Functional Ingredients from Jackfruit
Various studies in the literature showed the effect of conventional and non-conventional extraction methods to obtain jackfruit functional ingredients; among the non-conventional methods, some use emerging technologies to extract or as a pre-treatment. Among the studies using conventional extraction, applying solvents such as methanoland oxalic acidstands out, as well as the extraction with hot water. Regarding extraction by emerging technologies, radio frequency-assistedand supercritical fluid (SFE) with CO2extractions have attracted attention owing to their less negative impact on the environment and safety of the final product obtained in comparison with other methods using non-conventional technologies.
  • 2.0K
  • 26 Aug 2021
Topic Review
Electrodermal Activity Data Collection
The electrodermal activity (EDA) signal is an electrical manifestation of the sympathetic innervation of the sweat glands. EDA has a history in psychophysiological (including emotional or cognitive stress) research since 1879, but it was not until recent years that researchers began using EDA for pathophysiological applications like the assessment of fatigue, pain, sleepiness, exercise recovery, diagnosis of epilepsy, neuropathies, depression, and so forth. The advent of new devices and applications for EDA has increased the development of novel signal processing techniques, creating a growing pool of measures derived mathematically from the EDA. For many years, simply computing the mean of EDA values over a period was used to assess arousal. Much later, researchers found that EDA contains information not only in the slow changes (tonic component) that the mean value represents, but also in the rapid or phasic changes of the signal. The techniques that have ensued have intended to provide a more sophisticated analysis of EDA, beyond the traditional tonic/phasic decomposition of the signal. With many researchers from the social sciences, engineering, medicine, and other areas recently working with EDA, it is timely to summarize and review the recent developments and provide an updated and synthesized framework for all researchers interested in incorporating EDA into their research.
  • 1.9K
  • 30 Oct 2020
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.
  • 1.9K
  • 23 Jun 2021
Topic Review
Visible-Light-Promoted Carbonylation Reactions
The abundant and inexpensive carbon monoxide (CO) is widely exploited as a C1 source for the synthesis of both fine and bulk chemicals. In this context, photochemical carbonylation reactions have emerged as a powerful tool for the sustainable synthesis of carbonyl-containing compounds (esters, amides, ketones, etc.).
  • 1.9K
  • 11 Aug 2021
Topic Review
Organic Binders in Archaeological Wall Paintings
Binding media are complex materials, employed to allow pigment grains to adhere to each other and to the surface of the support, through the formation of a coherent and homogeneous film. The function of the binder consists, therefore, in keeping the pigment particles firmly together and at the same time adhering them in the form of a coherent thin film to the surface of the support. The binder must obviously be in the fluid state, in order to form with the pigments a stable, homogeneous, stretchy, and viscous dough.   For the realization of wall paintings and, in later times, for their preservation, different materials with functions of binders, adhesives, paints, protective and consolidating were and are still necessary. There is a very large class of products which can have both constitutive functions but also a function of conservation and restoration. 
  • 1.8K
  • 21 Oct 2021
Topic Review
Biosensors for Malaria Biomarkers
This entry discusses recent advances in the development of biosensors for the purposes of malaria diagnostics. It underscore relevant challenges that have defined the gap between biosensor development and their successful utilization in routine clinical practice within resource-limitted settings. It proposes a way to think about developing biosensors that are suitable for biomedical diagnostics applications.
  • 1.8K
  • 30 Oct 2020
Topic Review
Surfactants in Corrosion Inhibitors
Surfactants are commonly used as corrosion inhibitors due to their ability to adsorb onto metal surfaces and form a protective barrier. When surfactants are added to a solution, they can reduce the surface tension and promote the wetting of the metal surface by the solution. This allows the surfactant molecules to be attracted to the metal surface, where they can adsorb and form a protective layer. Surfactants can also help to inhibit corrosion by reducing the electrochemical activity of the metal surface. This can be achieved by either reducing the rate of anodic or cathodic reactions, or by reducing the rate of ion transport across the metal-solution interface. By inhibiting these electrochemical processes, the surfactant can slow down the rate of corrosion and prevent further degradation of the metal surface. In addition to their inhibitive properties, surfactants can also improve the performance of other corrosion inhibitors. For example, surfactants can enhance the adsorption of organic inhibitors onto metal surfaces, which can increase their effectiveness. Surfactants can also improve the solubility and stability of inorganic inhibitors, which can improve their dispersibility in a solution.
  • 1.8K
  • 24 Mar 2023
Topic Review
Phytochemicals Used for Hair Dyeing
Natural dyes have been used since ancient times, when they were used not only for hair coloration, but also for medicinal, decoration and religious purposes. Many organic compounds have been identified as the principal coloring matters in hair dye plants and investigated for dyeing performance under experimental conditions. Natural colorants can be classified based on dye source, application method and chemical structure.
  • 1.8K
  • 23 Nov 2022
Topic Review
Hydrophobic Solid Catalysts Synthesis
The preparation methods of hydrophobic materials such as zeolites, modified silicas and polymers has been reviewed. Particular attention has been paid to the characterization methods classified according to the surface and bulk composition, on one hand, and to the measure of interactions with water or organic solvents, on the other. Some selected applications are analyzed in order to understand the relevance of the reactants/products adsorption to address activity and selectivity of the reaction. Thus, absorption of a non-polar reactant or desorption of a hydrophilic product are much easier on a hydrophobic surface and can effectively boost the catalytic activity.
  • 1.7K
  • 30 Nov 2020
Topic Review
Bioethanol Production Using Seawater
  Bioethanol has many environmental and practical benefits as a transportation fuel. It is one of the best alternatives to replace fossil fuels due to its liquid nature, which is similar to the gasoline and diesel fuels traditionally used in transportation. In addition, bioethanol production technology has the capacity for negative carbon emissions, which is vital for solving the current global warming dilemma. However, conventional bioethanol production takes place based on an inland site and relies on freshwater and edible crops (or land suitable for edible crop production) for production, which has led to the food vs. fuel debate. Establishing a coastal marine biorefinery (CMB) system for bioethanol production that is based on coastal sites and relies on marine resources (seawater, marine biomass and marine yeast) could be the ultimate solution. In this paper, we aim to evaluate the environmental impact of using seawater for bioethanol production at coastal locations as a step toward the evaluation of a CMB system. Hence, a life cycle assessment for bioethanol production was conducted using the proposed scenario, named Coastal Seawater, and compared to the conventional scenario, named Inland Freshwater (IF). The impact of each scenario in relation to climate change, water depletion, land use and fossil depletion was studied for comparison. The Coastal Seawater scenario demonstrated an improvement upon the conventional scenario in all the selected impact categories. In particular, the use of seawater in the process had a significant effect on water depletion, showing an impact reduction of 31.2%. Furthermore, reductions were demonstrated in natural land transformation, climate change and fossil depletion of 5.5%, 3.5% and 4.2%, respectively. This indicates the positive impact of using seawater and coastal locations for bioethanol production and encourages research to investigate the CMB system.
  • 1.7K
  • 21 Aug 2021
Topic Review
Gum Tragacanth
Gum tragacanth (GT) is recently showing great promise as a therapeutic substance in tissue engineering and regenerative medicine.
  • 1.6K
  • 29 Jun 2021
Topic Review
σ-hole
σ-hole is a region of depleted electronic density located on the outer side of a covalently-bonded atom, situated roughly along an extension of the bond axis  
  • 1.6K
  • 24 May 2021
Topic Review
The Versatility in the Applications of Dithiocarbamates
Dithiocarbamate ligands have the ability to form stable complexes with transition metals, and this chelating ability has been utilized in numerous applications. The complexes have also been used to synthesize other useful compounds. 
  • 1.6K
  • 10 Mar 2022
Topic Review
Direct Synthesis of Silicon Compounds
The development of industrial organosilicon chemistry, and thus the development of silicon chemistry, is partly related to the discovery of the direct process of organosilanes synthesis in the 1940s, which allowed the production of organosilanes and silicone polymers on a large scale, and resulted in the development of new technologies to produce organosilicon monomers and polymers. The direct synthesis process, also known as the Müller–Rochow process, is one of the best-known industrial processes for obtaining organosilicon compounds, and has been the basis of the silicone industry.
  • 1.6K
  • 08 Mar 2023
Topic Review
5-Hydroxymethylfurfural (HMF)
HMF, an indispensable member of the furan-based platform compound, known as the “sleeping giant”, is a bridge between renewable biomass and industrial bulk chemicals. In recent years, the catalytic transformation of biomass to HMF has been widely studied and envisaged to be hopeful in achieving sustainable biorefineries. The synthesis of HMF from biomass requires the acid hydrolysis of biomass to hexose, and then dehydration of hexose, to obtain HMF. In the second step of dehydration, starting from ketohexose (fructose) is more efficient than starting from aldohexose (glucose).
  • 1.5K
  • 11 Oct 2021
Topic Review
Copper Chrome Arsenate Water-Borne Solution
Copper chrome arsenate (CCA) water-borne solution used to make timber is highly resistant to pests and fungi, in particular, wood products designed for outdoor use. Nowadays, CCA is a restricted chemical product in most countries, since potential environmental and health risks were reported due to dermal contact with CCA residues from treated structures and the surrounding soils. However, large quantities of CCA-treated timber are still in use in framings, outdoor playground equipment, landscaping, building poles, jetty piles, and fencing structures around the world, thus CCA remains a source of pollutants to the environment and of increasing toxic metal/metalloid exposure (mainly in children). International efforts have been dedicated to the treatment of materials impregnated with CCA, however not only does some reuse of CCA-treated timber still occur, but also existing structures are leaking the toxic compounds into the environment, with impacts on the environment and animal and human health.
  • 1.5K
  • 10 Jun 2021
Topic Review
Gamma-Aminobutyric Acid
Gamma-Aminobutyric acid, or γ-aminobutyric acid /ˈɡæmə əˈmiːnoʊbjuːˈtɪrɪk ˈæsɪd/, or GABA /ˈɡæbə/, is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system. GABA is sold as a dietary supplement in many countries. It has been traditionally thought that exogenous GABA (i.e. taken as a supplement) doesn't cross the blood-brain barrier, however data obtained from more current research indicates that it may be possible.
  • 1.5K
  • 01 Dec 2022
Topic Review
Shape Memory Polyurethane
The inherent capability to deform and reform in a predefined environment is a unique property existing in shape memory polyurethane. The intrinsic shape memory ability of the polyurethane is due to the presence of macro domains of soft and hard segments in its bulk, which make this material a potential candidate for several applications. This entry is focused on manifesting the applicability of shape memory polyurethane and its composites/blends in various domains, especially to human health such as shielding of electromagnetic interference, medical bandage development, bone tissue engineering, self-healing, implants development, etc. 
  • 1.5K
  • 30 Oct 2020
Topic Review
Pyrido[2,3-d], [3,2-d], [3,4-d] and [4,3-d]pyrimidine Derivatives
The structures composed of a pyridopyrimidine moiety which have shown a therapeutic interest or have already been approved for use as therapeutics, including pyrido[2,3-d]pyrimidines, pyrido[3,4-d]pyrimidines, pyrido[4,3-d]pyrimidines and pyrido[3,2-d]pyrimidines.
  • 1.4K
  • 06 Apr 2022
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