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Topic Review
Corvus
Corvus, Latin for "crow" or "raven," is a small but distinct constellation visible in the southern celestial hemisphere. Its shape is reminiscent of a bird in flight, featuring four bright stars that form the outline of a celestial crow. In ancient mythology, Corvus is associated with various tales, often depicted as a messenger bird serving the gods.
  • 3.5K
  • 08 Mar 2024
Topic Review
Life Cycle Assessment of Cellulose
The huge plastic production and plastic pollution are considered important global issues due to environmental aspects. One practical and efficient way to address them is to replace fossil-based plastics with natural-based materials, such as cellulose. The applications of different cellulose products have recently received increasing attention because of their desirable properties, such as biodegradability and sustainability.
  • 3.5K
  • 19 Feb 2021
Topic Review
Energy-Efficiency Passive Strategies for Mediterranean Climate
The main objective and function of passive solutions are to contribute to the natural cooling or heating of the building. They are constructive technologies integrated within buildings. The exchange of thermal energy takes place by natural means that, when dimensioned correctly, can significantly reduce a household’s energy bills. Several passive strategies, namely natural ventilation, shading devices, overhangs, and daylighting, associated with the building envelope’s characteristics are important passive design parameters that should be given particular attention to highlighting the potential of buildings for energy efficiency.
  • 3.5K
  • 13 May 2022
Topic Review Peer Reviewed
Substance Release from Polyelectrolyte Microcapsules
Controlled release of substance from polyelectrolyte microcapsules is a triggered degradation of the microcapsule membrane that is extensive enough to release the contained substances out into the environment. Membrane degradation can be a result of enzymatic digestion, ultrasound or light exposure, heating, application of a magnetic field, pH or ionic strength changes in the solution or bacteria-mediated processes. This technology can be used for the targeted release of drugs, and for the development of self-healing materials and new generation pesticides.
  • 3.5K
  • 18 Apr 2022
Topic Review
Melatonin as a Neurotrophic Factor
Melatonin, N-acetyl-5-hydroxytryptamine, is a hormone that synchronizes the internal environment with the photoperiod. It is synthesized in the pineal gland and greatly depends on the endogenous circadian clock located in the suprachiasmatic nucleus and the retina’s exposure to different light intensities. Among its most studied functions are the regulation of the waking-sleep rhythm and body temperature. Furthermore, melatonin has pleiotropic actions, which affect, for instance, the modulation of the immune and the cardiovascular systems, as well as the neuroprotection achieved by scavenging free radicals.
  • 3.5K
  • 19 Nov 2022
Topic Review
Currently Available Treatments for Periodontal Disease
Periodontitis is an inflammatory infection caused by bacterial plaque accumulation that affects the periodontal tissues. This entry provides a summary of the main features of the periodontium and describes the currently available treatments for periodontal disease.
  • 3.5K
  • 13 Apr 2023
Topic Review
Lignin
Lignin is an extremely abundant substance that has a chemical functionality that endows it with the necessary properties to be an attractive platform material for the new millennium. We must continue to explore and exploit its potentiality as a stand-alone material, raw feedstock for refining to chemicals, polymeric filler, and co-composite material. This review highlights hardwood-derived lignin, a little explored form of lignin, as a promising platform material.
  • 3.5K
  • 13 Aug 2020
Topic Review
Solvent-Free Synthesis of Zeolites
The traditional hydrothermal method to prepare zeolite will inevitably use a large amount of water as a solvent, which will lead to higher autogenous pressure, low efficiency, and wastewater pollution. The solvent-free method can be used to synthesize various types of zeolites by mechanical mixing, grinding, and heating of solid raw materials, which exhibits the apparent advantages of high yield, low pollution, and high efficiency. This review mainly introduces the development process of solvent-free synthesis, preparation of hierarchical zeolite, morphology control, synthesis mechanism and applications of solvent-free methods. It can be believed that solvent-free methods will become a research focus and have enormous industrial application potential.
  • 3.5K
  • 25 Mar 2021
Topic Review
Flavor
A food flavoring or food flavouring, [lower-alpha 1] in short flavoring or flavouring, or alternatively aroma is a food additive used to improve the taste or smell of food. It changes the perceptual impression of food as determined primarily by the chemical senses of the gustatory and olfactory system. The trigeminal nerves, which detect chemical irritants in the mouth and throat, as well as temperature and texture, are also important to the overall perception of food. Of the three chemical senses, smell is the main determinant of a food item's flavor. Aromas are the volatile components of the food. The aroma of a food is determined by the aroma compounds it contains and the personal ability to detect them. While an aroma primarily acts through te olfactory system, it also affects the taste at the same time. Along with additives, other components like sugars determine the taste of food. Five basic tastes – sweet, sour, bitter, salty and umami (savory) are universally recognized, although some cultures also include pungency and oleogustus ("fattiness"). The number of food smells is unbounded; a food's flavor, therefore, can be easily altered by changing its smell while keeping its taste similar. This is exemplified in artificially flavored jellies, soft drinks and candies, which, while made of bases with a similar taste, have dramatically different flavors due to the use of different scents or fragrances. The flavorings of commercially produced food products are typically created by flavorists. A flavoring is defined as a substance that gives another substance taste, altering the characteristics of the solute, causing it to become sweet, sour, tangy, etc. Although the term, in common language, denotes the combined chemical sensations of taste and smell, the same term is used in the fragrance and flavors industry to refer to edible chemicals and extracts that alter the flavor of food and food products through the sense of smell. Owing to the high cost, or unavailability of natural flavor extracts, most commercial flavorants are "nature-identical", which means that they are the chemical equivalent of natural flavors, but chemically synthesized rather than being extracted from source materials. Identification of components of natural foods, for example a raspberry, may be done using technology such as headspace techniques, so the flavorist can imitate the flavor by using a few of the same chemicals present. In the EU legislation, the term "natural-identical flavouring" does not exist. The legislation is specified on what is a "flavouring" and a "natural flavouring". A flavor is a quality of something that affects the sense of taste.
  • 3.5K
  • 04 Nov 2022
Topic Review
Biofuel production from different sources
Due to the depletion of fossil fuels, biofuel production from renewable sources has gainedinterest. Malaysia, as a tropical country with huge resources, has a high potential to produce differenttypes of biofuels from renewable sources. In Malaysia, biofuels can be produced from various sources,such as lignocellulosic biomass, palm oil residues, and municipal wastes. Besides, biofuels are dividedinto two main categories, called liquid (bioethanol and biodiesel) and gaseous (biohydrogen andbiogas). Malaysia agreed to reduce its greenhouse gas (GHG) emissions by 45% by 2030 as theysigned the Paris agreement in 2016. Therefore, we reviewed the status and potential of Malaysia asone of the main biofuel producers in the world in recent years. The role of government and existingpolicies have been discussed to analyze the outlook of the biofuel industries in Malaysia.
  • 3.5K
  • 27 Oct 2020
Topic Review
Machine Learning for Plant Breeding/Biotechnology
Classical univariate and multivariate statistics are the most common methods used for data analysis in plant breeding and biotechnology studies. Evaluation of genetic diversity, classification of plant genotypes, analysis of yield components, yield stability analysis, assessment of biotic and abiotic stresses, prediction of parental combinations in hybrid breeding programs, and analysis of in vitro-based biotechnological experiments are mainly performed by classical statistical methods. Despite successful applications, these classical statistical methods have low efficiency in analyzing data obtained from plant studies, as the genotype, environment, and their interaction (G × E) result in nondeterministic and nonlinear nature of plant characteristics. Large-scale data flow, including phenomics, metabolomics, genomics, and big data, must be analyzed for efficient interpretation of results affected by G × E. Nonlinear nonparametric machine learning techniques are more efficient than classical statistical models in handling large amounts of complex and nondeterministic information with "multiple-independent variables versus multiple-dependent variables" nature. Neural networks, partial least square regression, random forest, and support vector machines are some of the most fascinating machine learning models that have been widely applied to analyze nonlinear and complex data in both classical plant breeding and in vitro-based biotechnological studies. High interpretive power of machine learning algorithms has made them popular in the analysis of plant complex multifactorial characteristics. The classification of different plant genotypes with morphological and molecular markers, modeling and predicting important quantitative characteristics of plants, the interpretation of complex and nonlinear relationships of plant characteristics, and predicting and optimizing of in vitro breeding methods are the examples of applications of machine learning in conventional plant breeding and in vitro-based biotechnological studies. Precision agriculture is possible through accurate measurement of plant characteristics using imaging techniques and then efficient analysis of reliable extracted data using machine learning algorithms. Perfect interpretation of high-throughput phenotyping data is applicable through coupled machine learning-image processing. This entry shows how nonlinear machine learning algorithms can be used in different branches of classical plant breeding and in vitro-based methods. An idea is provided at the end of the entry that shows how coupled image processing-machine learning (especially deep CNN) could be used to identify the ploidy level of plants. It could be used in laboratories without flowcytometry equipment and/or in plant species without an established chromosome counting protocol.
  • 3.5K
  • 17 Feb 2021
Topic Review
Jewish Atheism
Jewish atheism refers to the atheism of people who are ethnically and (at least to some extent) culturally Jewish. Because Jewish identity is ethnoreligious (i.e., it encompasses ethnic as well as religious components), the term "Jewish atheism" does not inherently entail a contradiction. Based on Jewish law's emphasis on matrilineal descent, even religiously conservative Orthodox Jewish authorities would accept an atheist born to a Jewish mother as fully Jewish.
  • 3.5K
  • 11 Nov 2022
Topic Review
Almonds (Prunus dulcis)
Almond (Prunus dulcis) is a tree species that together with peach is included in the subgenus Amygdalus.
  • 3.5K
  • 02 Mar 2021
Topic Review
Muscle
Muscle is a soft tissue found in most animals, and is one of the four basic animal tissues, along with nervous tissue, epithelium, and connective tissue. Muscle cells contain protein filaments called myofilaments of actin and myosin that slide past one another, producing a contraction that changes both the length and the shape of the cell. Muscles function to produce force and motion. They are primarily responsible for maintaining and changing posture, locomotion, as well as movement of internal organs, such as the contraction of the heart and the movement of food through the digestive system via peristalsis. Muscle tissue is derived from the embryonic mesodermal germ layer in a process known as myogenesis. There are three types of muscle, of which skeletal and cardiac muscle are striated and smooth muscle is not. Muscle action can be classified as being either voluntary or involuntary. Cardiac and smooth muscles contract without conscious thought and are termed involuntary, whereas the skeletal muscles contract upon command. Skeletal muscles in turn can be divided into fast and slow twitch fibers. Muscles are predominantly powered by the oxidation of fats and carbohydrates, but anaerobic chemical reactions are also used, particularly by fast twitch fibers. These chemical reactions produce adenosine triphosphate (ATP) molecules that are used to power the movement of the myosin heads. The term muscle is derived from the Latin musculus meaning "little mouse" perhaps because of the shape of certain skeletal muscles or because contracting muscles look like mice moving under the skin.
  • 3.5K
  • 22 Oct 2022
Topic Review
Medical Thermometer
A medical thermometer (also called clinical thermometer) is used for measuring human or animal body temperature. The tip of the thermometer is inserted into the mouth under the tongue (oral or sub-lingual temperature), under the armpit (axillary temperature), into the rectum via the anus (rectal temperature), into the ear (tympanic temperature), or on the forehead (temporal temperature).
  • 3.5K
  • 04 Nov 2022
Topic Review
List of Minerals H (Complete)
This list includes those recognised minerals beginning with the letter H. The International Mineralogical Association is the international group that recognises new minerals and new mineral names, however minerals discovered before 1959 did not go through the official naming procedure, although some minerals published previously have been either confirmed or discredited since that date. This list contains a mixture of mineral names that have been approved since 1959 and those mineral names believed to still refer to valid mineral species (these are called "grandfathered" species). The data was exported from mindat.org on 29 April 2005; updated up to 'IMA2018'. The minerals are sorted by name, followed by the structural group (rruff.info/ima and ima-cnmnc by mineralienatlas.de, mainly) or chemical class (mindat.org and basics), the year of publication (if it's before of an IMA approval procedure), the IMA approval and the Nickel–Strunz code. The first link is to mindat.org, the second link is to webmineral.com, and the third is to the Handbook of Mineralogy (Mineralogical Society of America).
  • 3.5K
  • 27 Nov 2022
Topic Review
Thallium
Thallium, as a pharmaceutical cosmetic product, is applied for facial hair removal and fungal infections of the scalp. Thallium acetate is currently used as a catalyst in organic synthesis in the oxidation of olefins and hydrocarbons, and in epoxidation and polymerization reactions. Detection of Tl is a challenging task because its concentration in environmental samples may be at a nanogram per gram level or lower.
  • 3.5K
  • 23 Nov 2021
Topic Review
Kikuchi Lines
Kikuchi lines are patterns of electrons formed by scattering. They pair up to form bands in electron diffraction from single crystal specimens, there to serve as "roads in orientation-space" for microscopists uncertain of what they are looking at. In transmission electron microscopes, they are easily seen in diffraction from regions of the specimen thick enough for multiple scattering. Unlike diffraction spots, which blink on and off as one tilts the crystal, Kikuchi bands mark orientation space with well-defined intersections (called zones or poles) as well as paths connecting one intersection to the next. Experimental and theoretical maps of Kikuchi band geometry, as well as their direct-space analogs e.g. bend contours, electron channeling patterns, and fringe visibility maps are increasingly useful tools in electron microscopy of crystalline and nanocrystalline materials. Because each Kikuchi line is associated with Bragg diffraction from one side of a single set of lattice planes, these lines can be labeled with the same Miller or reciprocal-lattice indices that are used to identify individual diffraction spots. Kikuchi band intersections, or zones, on the other hand are indexed with direct-lattice indices i.e. indices which represent integer multiples of the lattice basis vectors a, b and c. Kikuchi lines are formed in diffraction patterns by diffusely scattered electrons, e.g. as a result of thermal atom vibrations. The main features of their geometry can be deduced from a simple elastic mechanism proposed in 1928 by Seishi Kikuchi, although the dynamical theory of diffuse inelastic scattering is needed to understand them quantitatively. In x-ray scattering, these lines are referred to as Kossel lines (named after Walther Kossel).
  • 3.5K
  • 09 Nov 2022
Topic Review
Natural compounds for wood protection
Natural compounds for wood protection against fungi - all natural substances (or their mixtures) of plant or animal origin with proven antifungal activity and possibility to be applied into wood structure or on its surface to protect wood against wood decaying fungi, blue stain and mold, e.g. essential oils, tannins, wood extractives, alkaloids, propolis or chitosan.
  • 3.5K
  • 02 May 2021
Topic Review
Polymers Modifications through Ultraviolet Absorbers Addition
The photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of safe, plastic, ultraviolet stabilizers that do not pose a danger to the environment if released. Plastic ultraviolet photostabilizers act as efficient light screeners (absorbers or pigments), excited-state deactivators (quenchers), hydroperoxide decomposers, and radical scavengers. Ultraviolet absorbers are cheap to produce, can be used in low concentrations, mix well with polymers to produce a homogenous matrix, and do not alter the color of polymers.
  • 3.5K
  • 10 Jan 2022
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