Your browser does not fully support modern features. Please upgrade for a smoother experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Antimony as a Critical Raw Material
Antimony is widely acknowledged as a critical raw material of worldwide significance, based on its recognition by many countries. According to current projections, there is an anticipated increase in the demand for antimony in the forthcoming years. An issue of significant concern within the supply chain, which poses a substantial obstacle to sustainable development, is the global unequal allocation of abundant antimony resources. Most nations exhibited a high degree of dependence on a few countries for their net imports of antimony, resulting in a notable disruption and raising concerns regarding the supply chain. 
  • 3.2K
  • 23 Feb 2024
Topic Review
Rheumatoid Arthritis and Prevotella copri
Rheumatoid arthritis (RA) is a debilitating disease caused by several factors, which have only been partially identified. Globally approximately 0.24% of people are affected by RA, with women being more affected than men. The gastrointestinal tract is an essential getaway for the intake of favorable and harmful microbes and their metabolites through food and drinks. The imbalance of gut microbiota can cause gut dysbiosis, which is caused by an abundance of Prevotella copri. In recent years there have been reports citing Prevotella copri as the causative organism for RA, but there also have been reports contradicting the above findings. This topical review attempts to bring the two viewpoints together and find common ground for a rational hypothesis.
  • 3.2K
  • 30 Jul 2021
Topic Review
Disorders of Sex Development
Disorders of sex development (DSDs), also known as differences in sex development, diverse sex development and variations in sex characteristics (VSC), are medical conditions involving the reproductive system. More specifically, these terms refer to "congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical." The term has been controversial, and research has shown that affected people experience a negative impact, with the terminology impacting choice and utilization of health care providers. The World Health Organization and many medical journals still reference DSDs as intersex traits or conditions. The Council of Europe and Inter-American Commission on Human Rights have called for a review of medical classifications that unnecessarily medicalize intersex traits.
  • 3.2K
  • 09 Oct 2022
Topic Review
Important Pathogens in Poultry Production
The presence of a wide variety of microorganisms is surveilled in several food producing animals due to their importance to public health, namely in broilers and laying hens. The pathogens most relevant in this industry, and associated with antimicrobial drug resistance, include Salmonella enterica, Campylobacter spp. (specially C. jejuni), Escherichia coli, Enterococcus spp. and methicillin-resistant Staphylococcus aureus (MRSA).
  • 3.2K
  • 23 Apr 2023
Topic Review
Ionizing Irradiations in Food Industry
The ionizing radiations are particles or waves containing enough energy to ionize the matter when coming in contact. Their mode of action in living cells involves either the direct destruction of nucleic acid or by creating free radicals that can attack the cellular components. This cellular destruction and inactivation can be used to reduce the microbial burden in food items to increase the shelf life and safety of food, meanwhile maintaining the quality of the product. Although this technology is accepted by more than 60 countries, some consumers are reluctant to buy such products thinking that radiations might have modified their food which can also induce changes in their body after consumption. The proper scientific communication regarding the safety of ionization irradiations can change consumer behavior, and it requires the collaboration of all stakeholders in the food production chain. 
  • 3.2K
  • 05 Nov 2020
Topic Review
Glossitis Areata Exfoliativa
Geographic tongue, also known by several other terms, is a condition of the mucous membrane of the tongue, usually on the dorsal surface. It is a common condition, affecting approximately 2–3% of the general population. It is characterized by areas of smooth, red depapillation (loss of lingual papillae) which migrate over time. The name comes from the map-like appearance of the tongue, with the patches resembling the islands of an archipelago. The cause is unknown, but the condition is entirely benign (importantly, it does not represent oral cancer), and there is no curative treatment. Uncommonly, geographic tongue may cause a burning sensation on the tongue, for which various treatments have been described with little formal evidence of efficacy.
  • 3.2K
  • 24 Oct 2022
Topic Review
Fractional Schrödinger Equation
The fractional Schrödinger equation is a fundamental equation of fractional quantum mechanics. It was discovered by Nick Laskin (1999) as a result of extending the Feynman path integral, from the Brownian-like to Lévy-like quantum mechanical paths. The term fractional Schrödinger equation was coined by Nick Laskin.
  • 3.2K
  • 24 Oct 2022
Topic Review
Grey Water
Grey water (also spelled gray water in the United States) or sullage refers to wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater from toilets. Sources of grey water include sinks, showers, baths, washing machines or dishwashers. As grey water contains fewer pathogens than domestic wastewater, it is generally safer to handle and easier to treat and reuse onsite for toilet flushing, landscape or crop irrigation, and other non-potable uses. The application of grey water reuse in urban water systems provides substantial benefits for both the water supply subsystem, by reducing the demand for fresh clean water, and the wastewater subsystems by reducing the amount of wastewater required to be conveyed and treated. Treated grey water has many uses, for example, toilet flushing or irrigation.
  • 3.2K
  • 04 Nov 2022
Topic Review
Potential Effects of Fasting in SARS-CoV-2 Infection
Intermittent fasting is a potential complementary therapy to vaccination and antiviral therapies that not only impacts chronic disease risk but also has good evidence of an impact on infectious diseases such as COVID-19. Intermittent fasting should improve the immune response of and reduce acute hyperinflammation for unvaccinated people, strengthen immunity between vaccinations for vaccinated people, and prolong the length of time a vaccinated person can go before receiving a subsequent booster dose of the SARS-CoV-2 vaccine. A set of at least 10 biological mechanisms may be impacted by intermittent fasting in the human physiological response to SARS-CoV-2 that may reduce the severity of COVID-19 outcomes. For example, by boosting autophagy, fasting may aid the immune system to identify silently infected cells via increased degradation of viral proteins and through antigen presentation to natural killer cells and cytotoxic T cells. Intermittent fasting may also provide a constellation of mechanisms that empower a damaged human immune system to repair itself and to hunt down residual SARS-CoV-2 virus that is hiding from it in the context of both acute infection and post-acute sequelae of COVID-19. Furthermore, fasting adds no financial cost to a care plan and, when practiced safely, is available to most adults regardless of education, income, location, or ancestry. Clinical trials of intermittent fasting for reduction of COVID-19 severity are needed.
  • 3.2K
  • 06 Jan 2023
Topic Review
Self-healing Polymeric Materials
The mechanism of self-healing, which includes the extrinsic and intrinsic approaches for each of the applications, is examined. The extrinsic mechanism involves the introduction of external healing agents such as microcapsules and vascular networks into the system. Meanwhile, the intrinsic mechanism refers to the inherent reversibility of the molecular interaction of the polymer matrix, which is triggered by the external stimuli. Both self-healing mechanisms have shown a significant impact on the cracked properties of the damaged sites.
  • 3.2K
  • 21 Apr 2021
Topic Review
LINPACK Benchmarks
The LINPACK Benchmarks are a measure of a system's floating-point computing power. Introduced by Jack Dongarra, they measure how fast a computer solves a dense n by n system of linear equations Ax = b, which is a common task in engineering. The latest version of these benchmarks is used to build the TOP500 list, ranking the world's most powerful supercomputers. The aim is to approximate how fast a computer will perform when solving real problems. It is a simplification, since no single computational task can reflect the overall performance of a computer system. Nevertheless, the LINPACK benchmark performance can provide a good correction over the peak performance provided by the manufacturer. The peak performance is the maximal theoretical performance a computer can achieve, calculated as the machine's frequency, in cycles per second, times the number of operations per cycle it can perform. The actual performance will always be lower than the peak performance. The performance of a computer is a complex issue that depends on many interconnected variables. The performance measured by the LINPACK benchmark consists of the number of 64-bit floating-point operations, generally additions and multiplications, a computer can perform per second, also known as FLOPS. However, a computer's performance when running actual applications is likely to be far behind the maximal performance it achieves running the appropriate LINPACK benchmark. The name of these benchmarks comes from the LINPACK package, a collection of algebra Fortran subroutines widely used in the 1980s, and initially tightly linked to the LINPACK benchmark. The LINPACK package has since been replaced by other libraries.
  • 3.2K
  • 02 Dec 2022
Topic Review
Glass Ionomer Cement
The glass ionomer cement (GIC) is a translucent, water-based cement invented in 1972 by Wilson and Kent.
  • 3.2K
  • 30 Nov 2021
Topic Review
Green Synthetic Approach
Green synthetic protocol refers to the development of processes for the sustainable production of chemicals and materials. For the synthesis of various biologically active compounds, energy-efficient and environmentally benign processes are applied, such as microwave irradiation technology, ultrasound-mediated synthesis, photo-catalysis (ultraviolet, visible and infrared irradiation), molecular sieving, grinding and milling techniques, etc. 
  • 3.2K
  • 01 Jul 2021
Topic Review
Sponge
Sponges, the members of the phylum Porifera (/pəˈrɪfərə/; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals.
  • 3.2K
  • 22 Nov 2022
Topic Review
Torii
A torii (鳥居, literally bird abode, Japanese pronunciation: [to.ɾi.i]) is a traditional Japan ese gate most commonly found at the entrance of or within a Shinto shrine, where it symbolically marks the transition from the mundane to sacred. The presence of a torii at the entrance is usually the simplest way to identify Shinto shrines, and a small torii icon represents them on Japanese road maps.[note 1] The first appearance of Torii gates in Japan can be reliably pinpointed to at least the mid-Heian period because they are mentioned in a text written in 922. The oldest existing stone torii was built in the 12th century and belongs to a Hachiman Shrine in Yamagata prefecture. The oldest wooden torii is a ryōbu torii (see description below) at Kubō Hachiman Shrine in Yamanashi prefecture built in 1535. Torii gates were traditionally made from wood or stone, but today they can be also made of reinforced concrete, copper, stainless steel or other materials. They are usually either unpainted or painted vermilion with a black upper lintel. Inari shrines typically have many torii because those who have been successful in business often donate in gratitude a torii to Inari, kami of fertility and industry. Fushimi Inari-taisha in Kyoto has thousands of such torii, each bearing the donor's name.
  • 3.2K
  • 06 Nov 2022
Topic Review
Alkylimidazoles
Alkylimidazoles have good complexing properties, also they are  cheap so can be successfully used in the separation of metal ions from aqueous solutions.
  • 3.2K
  • 16 Dec 2020
Topic Review
Oldest People
This is a list of tables of the oldest people in the world in ordinal ranks. To avoid including false or unconfirmed claims of extreme old age, names here are restricted to those people whose ages have been validated by an international body that specifically deals in longevity research, such as the Gerontology Research Group (GRG) or Guinness World Records (GWR), and others who have otherwise been reliably sourced. According to this criterion, the longest human lifespan is that of Jeanne Calment of France (1875–1997), who lived to the age of 122 years, 164 days. She met Vincent van Gogh when she was 12 or 13. She received news media attention in 1985, after turning 110. Subsequent investigation found documentation for Calment's age, beyond any reasonable question, in the records of her native city, Arles, France. More evidence of Calment's lifespan has been produced than for any other supercentenarian, such that her case serves as an archetype in the methodology for verifying the ages of the world's oldest people. As women live longer than men on average, combined records for both sexes are predominated by women. The longest undisputed lifespan for a man is that of Jiroemon Kimura of Japan (1897–2013), who died at age 116 years, 54 days. Since the death of 117-year-old Chiyo Miyako of Japan on 22 July 2018, 115-year-old Kane Tanaka, also of Japan, born 2 January 1903, is the oldest living person in the world whose age has been documented. Since the death of 113-year-old Francisco Núñez Olivera of Spain on 29 January 2018, 113-year-old Masazō Nonaka of Japan, born 25 July 1905, is the world's oldest verified living man.
  • 3.2K
  • 30 Nov 2022
Topic Review
Digital Distractions in College Classrooms and Its Impact
University campuses have progressively been equipped with technology. In fact, the presence of technology on university campuses is expected to be increasingly noticeable, as many universities are undergoing digitization processes. Students use many different types of technological devices and software applications during academic activities. Any stimulus or information that diverts an individual’s attention from the main task at hand is considered a distractor. Distractors affect the human ability to concentrate and have an external (noise, movement, etc.) or internal (thoughts, feelings, etc.) origin.
  • 3.2K
  • 29 Nov 2023
Topic Review
Abandoned Croplands in South Africa
There is no standardised definition of agricultural land abandonment; however, a simple definition is the cessation of agricultural activities on a given surface of land. The term agricultural land abandonment is inclusive of land previously used for crops, vegetables, fruit trees, and cultivated and natural pastures. Other agricultural land abandonment studies specifically focus on crops, hence terms such as cropland abandonment, formerly arable lands, and old arable lands or fields are used. Others specify that for the land to qualify as abandoned, it should not be used for any other activity such as urbanisation or afforestation. Therefore, in the context of the rural areas of Africa wherein the cessation of cropping the land is used for grazing, the definition of cropland abandonment suffices. Baxter and Calvert define cropland abandonment as a process of withdrawing cropland from active agricultural production without a plan for crop cultivation in the immediate future. The cessation is usually due to a decline in economic viability even after changes in farming practices. Cessation results in natural succession wherein grasses, shrubs, and trees colonise former cropping lands; it can also result in land degradation. In the former homeland communal areas of South Africa, where the main agricultural activity involves cropping and livestock production, by default if the land is not used for cropping it turns into a grazing area. The same trend of abandoned cropping lands being used for grazing was also reported in Botswana. Therefore, the definition of abandoned cropping land is land mainly used for grazing. The areas are sometimes also called old fields, fallow, or idle fields. Some have turned to be secondary grasslands.
  • 3.2K
  • 25 May 2022
Topic Review
Pollution of Polyethylene Terephthalate Water Bottles
According to studies on global plastic manufacturing and the resulting pollution, plastic wastes have been identified as a serious environmental concern. The impact of plastic garbage on marine species, humans, and the environment is a source of public concern, necessitating the need to save ecosystems and the lives that depend on them. Polyethylene terephthalate (PET) water bottles have a significant carbon footprint and represent tremendous waste. In the United Arab Emirates (UAE), PET water bottles are widely utilized, with yearly consumption reaching 450 water bottles per person. 
  • 3.2K
  • 27 Apr 2022
  • Page
  • of
  • 2794
Featured Entry Collections
>>

Featured Reprints

>>
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Medieval Royal Iconography
Academic Video Service
Feedback

Quick Survey

Encyclopedia MDPI is conducting a targeted survey to identify the specific barriers hindering efficient research. We invite you to spend 3 minutes defining the priorities for our next generation of structured knowledge tools.
Take Survey