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Topic Review
Ionic Liquid Membranes
Heightened levels of carbon dioxide (CO2) and other greenhouse gases (GHGs) have prompted research into techniques for their capture and separation, including membrane separation, chemical looping, and cryogenic distillation. Ionic liquids, due to their negligible vapour pressure, thermal stability, and broad electrochemical stability have expanded their application in gas separations.
  • 2.1K
  • 12 Oct 2020
Topic Review
Annatto
Annatto (/əˈnætoʊ/ or /əˈnɑːtoʊ/) is an orange-red condiment and food coloring derived from the seeds of the achiote tree (Bixa orellana), native to tropical America. It is often used to impart a yellow or orange color to foods, but sometimes also for its flavor and aroma. Its scent is described as "slightly peppery with a hint of nutmeg" and flavor as "slightly nutty, sweet and peppery". The color of annatto comes from various carotenoid pigments, mainly bixin and norbixin, found in the reddish waxy coating of the seeds. The condiment is typically prepared by grinding the seeds to a powder or paste. Similar effects can be obtained by extracting some of the color and flavor principles from the seeds with hot water, oil, or lard, which are then added to the food. Annatto and its extracts are now widely used in an artisanal or industrial scale as a coloring agent in many processed food products, such as cheeses, dairy spreads, butter and margarine, custards, cakes and other baked goods, potatoes, snack foods, breakfast cereals, smoked fish, sausages, and more. In these uses, annatto is a natural alternative to synthetic food coloring compounds, but it has been linked to rare cases of food-related allergies. Annatto is of particular commercial value in the United States because the Food and Drug Administration considers colorants derived from it to be "exempt of certification".
  • 2.1K
  • 20 Oct 2022
Topic Review
Progestin
A progestin is a type of medication which is used most commonly in hormonal birth control and menopausal hormone therapy. They can also be used in the treatment of gynecological conditions, to support fertility and pregnancy, to lower sex hormone levels for various purposes, and for other indications. Progestins are used alone or in combination with estrogens. They are available in a wide variety of formulations and for use by many different routes of administration. Side effects of progestins include menstrual irregularities, headaches, nausea, breast tenderness, mood changes, acne, increased hair growth, and changes in liver protein production among others. Other side effects of progestins include an increased risk of breast cancer, cardiovascular disease, and blood clots. At high dosages, progestins can cause low sex hormone levels and associated side effects like sexual dysfunction and an increased risk of bone fractures. Progestins are synthetic progestogens and have similar effects to those of the natural hormone progesterone. They act as agonists of the progesterone receptor, and have important effects in the female reproductive system (uterus, cervix, and vagina), the breasts, and the brain. In addition, many progestins also have other hormonal activities, such as androgenic, antiandrogenic, estrogenic, glucocorticoid, or antimineralocorticoid activity. They also have antigonadotropic effects and at sufficiently high dosages can strongly suppress sex hormone production. Progestins mediate their contraceptive effects both by inhibiting ovulation and by thickening cervical mucus, thereby preventing fertilization. They have functional antiestrogenic effects in certain tissues like the endometrium, and this underlies their use in menopausal hormone therapy. Progestins were first introduced for medical use in 1939. They started to be used in birth control in the 1950s. Around 60 progestins have been marketed for clinical use in humans or use in veterinary medicine. These progestins can be grouped into different classes and generations. Progestins are available widely throughout the world and are used in all forms of hormonal birth control and in most menopausal hormone therapy regimens.
  • 2.1K
  • 21 Oct 2022
Topic Review
Cellulosic Ethanol Commercialization
Cellulosic ethanol commercialization is the process of building an industry out of methods of turning cellulose-containing organic matter into cellulosic ethanol for use as a biofuel. Companies, such as Iogen, POET, DuPont, and Abengoa, are building refineries that can process biomass and turn it into bioethanol. Companies, such as Diversa, Novozymes, and Dyadic, are producing enzymes that could enable a cellulosic ethanol future. The shift from food crop feedstocks to waste residues and native grasses offers significant opportunities for a range of players, from farmers to biotechnology firms, and from project developers to investors. As of 2013, the first commercial-scale plants to produce cellulosic biofuels have begun operating. Multiple pathways for the conversion of different biofuel feedstocks are being used. In the next few years, the cost data of these technologies operating at commercial scale, and their relative performance, will become available. Lessons learnt will lower the costs of the industrial processes involved.
  • 2.0K
  • 26 Oct 2022
Topic Review
Protein–Polysaccharide Complexes (Conjugates) as Delivery Systems
Due to their combination of featured properties, protein and polysaccharide-based carriers show promising potential in food bioactive ingredient encapsulation, protection, and delivery. The common types of protein–polysaccharide complex/conjugate-based bioactive ingredient delivery systems include emulsion (conventional emulsion, nanoemulsion, multiple emulsion, multilayered emulsion, and Pickering emulsion), microcapsule, hydrogel, and nanoparticle-based delivery systems. This entry highlights the applications of protein–polysaccharide-based delivery vehicles in common bioactive ingredients including polyphenols, food proteins, bioactive peptides, carotenoids, vitamins, and minerals. The loaded food bioactive ingredients exhibited enhanced physicochemical stability, bioaccessibility, and sustained release in simulated gastrointestinal digestion. 
  • 2.0K
  • 04 Mar 2022
Topic Review
Microfluidics in Gas Sensing
Rapid, real-time, and non-invasive identification of volatile organic compounds (VOCs) and gases is an increasingly relevant field, with applications in areas such as healthcare, agriculture, or industry. Ideal characteristics of VOC and gas sensing devices used for artificial olfaction include portability and affordability, low power consumption, fast response, high selectivity, and sensitivity. Microfluidics meets all these requirements and allows for in situ operation and small sample amounts, providing many advantages compared to conventional methods using sophisticated apparatus such as gas chromatography and mass spectrometry. This review covers the work accomplished so far regarding microfluidic devices for gas sensing and artificial olfaction. Systems utilizing electrical and optical transduction, as well as several system designs engineered throughout the years are summarized, and future perspectives in the field are discussed.
  • 2.0K
  • 20 Oct 2020
Topic Review
Aflatoxin
Aflatoxins are poisonous carcinogens that are produced by certain molds (Aspergillus flavus and Aspergillus parasiticus) which grow in soil, decaying vegetation, hay, and grains. They are regularly found in improperly stored staple commodities such as cassava, chili peppers, corn, cotton seed, millet, peanuts, rice, sesame seeds, sorghum, sunflower seeds, tree nuts, wheat, and a variety of spices. When contaminated food is processed, aflatoxins enter the general food supply where they have been found in both pet and human foods, as well as in feedstocks for agricultural animals. Animals fed contaminated food can pass aflatoxin transformation products into eggs, milk products, and meat. For example, contaminated poultry feed is suspected in the findings of high percentages of samples of aflatoxin-contaminated chicken meat and eggs in Pakistan. Children are particularly affected by aflatoxin exposure, which is associated with stunted growth, delayed development, liver damage, and liver cancer. An association between childhood stunting and aflatoxin exposure has been reported in some studies but could not be detected in all. Furthermore, a causal relationship between childhood stunting and aflatoxin exposure has yet to be conclusively shown by epidemiological studies, though such investigations are underway. Adults have a higher tolerance to exposure, but are also at risk. No animal species is immune. Aflatoxins are among the most carcinogenic substances known. After entering the body, aflatoxins may be metabolized by the liver to a reactive epoxide intermediate or hydroxylated to become the less harmful aflatoxin M1. Aflatoxins are most commonly ingested. However the most toxic type of aflatoxin, B1, can permeate through the skin. The United States Food and Drug Administration (FDA) action levels for aflatoxin present in food or feed is 20 to 300 ppb. The FDA has had occasion to declare both human and pet food recalls as a precautionary measure to prevent exposure. The term "aflatoxin" is derived from the name of one of the molds that produce it, Aspergillus flavus. It was coined around 1960 after its discovery as the source of "Turkey X disease". Aflatoxins form one of the major groupings of mycotoxins.
  • 2.0K
  • 28 Oct 2022
Topic Review
Gilsonite-Modified Bitumen
Hot mix asphalt has various benefits such as good workability and durability. It is one of the most general materials used as asphalt mixtures in road pavements. Asphalt mixtures and binders can be improved by modifying them with various additives. Gilsonite is a natural asphalt hydrocarbon which may be used as an additive to hot mix asphalt. It is used as an asphalt binder modifier (wet process) and an asphalt mixture modifier (dry process) to improve the properties of the mix. It provides the option of improved rheological properties, stability, strength rutting resistance and moisture sensitivity. 
  • 2.0K
  • 16 Jun 2021
Topic Review
Hard Tissue Engineering
Hard tissues, e.g., bone, are mechanically stiff and, most typically, mineralized. To design scaffolds for hard tissue regeneration, mechanical, physico-chemical and biological cues must align with those found in the natural tissue. Combining these aspects poses challenges for material and construct design.  They can be fulfilled in top-down tissue engineering or bottom up biofabrication approaches upon employing biomaterials e.g. silk.
  • 2.0K
  • 18 Mar 2021
Topic Review
Pyridone Disperse Dyes Provide Added-Value
This entry provides a description of some of the disperse dyes based on pyridone and the uses of these disperse dyes as antioxidants and anticancer, as well as the use of polyester fabrics dyed with these dyes in various activities, especially medical activities. It is blamed that the textile industry is one of the major generators of industrial waste due to large quantities of water that contains a variety of pollutants, including dyes. So, our aim in this review is to explain that the dyeing process using high temperature and high pressure method was an environmentally friendly process. Therefore, this review provides a good data for chemists, biologists and interested people working in textile chemistry, public health and environment research areas.
  • 2.0K
  • 14 Sep 2020
Topic Review
Electrostatic Nanoassembly of Novel Composites
Electrostatic assembly is one of the bottom–up approaches used for multiscale composite fabrication. Since its discovery, this method has been actively used in molecular bioscience as well as materials design and fabrication for various applications. Despite the recent advances and controlled assembly reported using electrostatic interaction, the method still possesses vast potentials for various materials design and fabrication. This review article is a timely revisit of the electrostatic assembly method with a brief introduction of the method followed by surveys of recent advances and applications of the composites fabricated. Emphasis is also given to the significant potential of this method for advanced materials and composite fabrication in line with sustainable development goals. Prospective outlook and future developments for micro-/nanocomposite materials fabrication for emerging applications such as energy-related fields and additive manufacturing are also mentioned.
  • 2.0K
  • 11 Nov 2020
Topic Review
Diversity of Synthetic Dyes
Synthetic dyes are mostly derived from petrochemical compounds, they are commercialized in liquid, powder, pastes, or granule forms. They are endowed with multiple potentialities such as fast and consistent coloration with different classes of fabrics as mentioned in the above section, a wide range of color pigments and shades, facility of manipulation, stability over several external factors and economical energy consumption. Therefore, the majority of synthetic dyes cause harmful impacts when discharged in non-treated or partially treated forms in the environment.
  • 2.0K
  • 06 Aug 2021
Topic Review
Sol–Gel Ceramics
The process of inorganic polymerization or the sol–gel method is an inexpensive, low-energy consuming, and stable process for obtaining high-purity ceramics, which offer versatility for the production of different kinds of devices, some of which can be used in surface-enhanced spectroscopy such as Surface Enhanced Infrared Absorption Spectroscopy (SEIRAS) and Surface Enhanced Raman Spectroscopy (SERS).
  • 2.0K
  • 22 Apr 2021
Topic Review
Biometal
Biometals are metals normally present, in small but important and measurable amounts, in biology, biochemistry, and medicine. The metals copper, zinc, iron, and manganese are examples of metals that are essential for the normal functioning of most plants and the bodies of most animals, such as the human body. A few (calcium, potassium, sodium) are present in relatively larger amounts, whereas most others are trace metals, present in smaller but important amounts (the image shows the percentages for humans). Approximately 2/3 of the existing periodic table is composed of metals with varying properties, accounting for the diverse ways in which metals (usually in ionic form) have been utilized in nature and medicine.
  • 2.0K
  • 10 Oct 2022
Topic Review
Hazards from Burning Impregnated Wood
In the construction industry, a variety wooden products have been used for thousands of years, according to demand, accessibility/availability, and customers’ requirements. Wood is a preferred material due to its large range of properties, depending on the type of wood. It is an easily available and economically competitive material, and also extremely strong in relation to its weight. Therefore, it is used in the production of construction materials, building parts, and finishing components, as well as for furniture and decorative elements. Each of these products is commonly additionally chemically treated to improve its performance parameters. But impregnated wooden products such as furniture and fence boards are often misused, including for house heating, waste incineration, bonfires. etc. For this reason, among the products of combustion there is a whole range of different chemical compounds, frequently carcinogenic, and dangerous for health and the environment, for example heavy metals. Knowledge in this field is important for professions such as: firefighter, lifeguard, people dealing with environmental management, units responsible for waste landfills. On the other hand, important recipients of this information are ordinary residents who, due to a lack of knowledge, use such materials as e.g. heating material.
  • 2.0K
  • 29 Oct 2020
Topic Review
Snail Shell Waste in Food Industries
Effective waste management has become an urgent societal challenge. Food waste is made up of items meant for human consumption that are lost, polluted, disposed of, or deteriorated; the reutilization of shells from mollusk waste is a severe problem in terms of environmental protection and the development of the circular economy. The properties of waste shells are presented and discussed, including their biological–natural origin and high calcium carbonate content. This could add social and innovation focus on shell waste management, getting a non-toxic, eco-sustainable, low-cost, biodegradable supplement to invest in. Furthermore, it has the potential to support the circular economy approach by creating a closed system that minimizes the use of natural resources and environmental contamination. 
  • 2.0K
  • 19 Mar 2024
Biography
Matthew H. Todd
Matthew Houghton Todd (born 13 January 1973) is a British chemist and the Professor and Chair of Drug Discovery of the School of Pharmacy at University College London.[1] He is the founder of Open Source Malaria (OSM) and his research focuses on drug discovery and development for this disease.[2][3][4][5][6] Recently, he has expanded to other areas, particularly neglected diseases such as tuberc
  • 2.0K
  • 23 Nov 2022
Topic Review
Self-Assembled III-V Semiconductor Quantum Dots
A fundamental understanding of the growth of semiconductors is essential for the optimization of quantum dot-based optoelectronic devices. Droplet epitaxy has proven to be the successful versatile growth method for instance growing quantum dots with a small fine structure splitting for quantum information technology. Precise control and tuning of the quantum dots for various applications is only possible through a detailed understanding of the growth mechanism at the atomic level, which creates the need for atomic-scale structural and composition characterization. We present an overview of the results of detailed structural and composition analysis by cross-sectional scanning tunneling microscopy and atom probe tomography of quantum dots grown by self-assembled droplet epitaxy where we focus mainly on strain-free GaAs/AlGaAs and strained InAs/InP QDs.
  • 2.0K
  • 19 Jan 2021
Topic Review
Aurivillius-Phase Bi4Ti3O12-nBiFeO3 Materials
Aurivillius-type layered compound have attracted increasing research interest, especially in recent 20 years, due to their promising electrical properties as new lead-free piezoelectric materials operating at high temperatures. For instance, the well-known Bi4Ti3O12, presents large spontaneous polarization, anisotropy and high ferroelectric Curie temperature and have wide applications in the electronic industry, capacitors, transducers, nonvolatile ferroelectric memories, piezoelectric sensors and optical devices. To increase functionality of Bi4Ti3O12 modification with BiFeO3 is very promising, which is also a methodology for constructing single-phase multiferroics in which ferrelectricity and magnetic ordering are coupled near room temperature. Combining these two materials exhibiting different physical performances one can create a kind of novel materials and thus achieve functionality. Herein, we summarized the recent progress in the field of synthesis of BFTO-n materials with various architectures and highlighted their extraordinary properties for promising applications in the electronic industry, quantum devices, capacitors, transducers, microwave absorbers, catalysts and photoelectric devices. 
  • 2.0K
  • 13 Jan 2021
Topic Review
Stone Cultural Heritage Elements
Stones are ones of the most ancient natural materials exploited by humans, with different uses, from tools to buildings, that have endured over time in better conditions than other objects belonging to cultural heritage. Given the importance of those silent witnesses of the past, as well as our duty to preserve all parts of cultural heritage for future generations, much effort was put into the development of materials for their consolidation, protection, self-cleaning, or restoration.
  • 2.0K
  • 20 Sep 2022
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