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
Dual-complex Number
The dual-complex numbers make up a four-dimensional algebra over the real numbers. Their primary application is in representing rigid body motions in 2D space. Unlike multiplication of dual numbers or of complex numbers, that of dual-complex numbers is non-commutative.
  • 2.1K
  • 29 Nov 2022
Topic Review
Microgrid Energy Management and Methods
The rising demand for electricity, the economic benefits, and the environmental pressures related to the use of fossil fuels are driving electricity generation mostly from renewable energy sources. One of the main challenges in renewable energy generation is uncertainties involved in forecasting, because of the intermittent nature of renewable sources. The demand also varies according to the time of day, the season, the location, the climate, and the availability of resources. Microgrids offer a potential solution for the integration of small-scale renewable energy sources and loads along with energy storage systems and other non-renewable sources. However, intermittent generation and varying demand need to be matched to provide stable power to consumers. Therefore, it is crucial to design an energy management system to effectively manage the energy sources and supply loads for reliable and efficient operation. 
  • 2.1K
  • 02 Dec 2022
Topic Review
Christianity and Science
Most sources of knowledge available to early Christians were connected to pagan world-views. There were various opinions on how Christianity should regard pagan learning, which included its ideas about nature. For instance, among early Christian teachers, Tertullian (c. 160–220) held a generally negative opinion of Greek philosophy, while Origen (c. 185–254) regarded it much more favorably and required his students to read nearly every work available to them. Historically, Christianity has often been a patron of sciences. It has been prolific in the foundation of schools, universities and hospitals, and many clergy have been active in the sciences. Historians of science such as Pierre Duhem credit medieval Catholic mathematicians and philosophers such as John Buridan, Nicole Oresme and Roger Bacon as the founders of modern science. Duhem concluded that "the mechanics and physics of which modern times are justifiably proud to proceed, by an uninterrupted series of scarcely perceptible improvements, from doctrines professed in the heart of the medieval schools".
  • 2.1K
  • 12 Oct 2022
Topic Review
Chemistry, Occurrence, Properties of Carotenoids
Carotenoids are natural lipophilic pigments and antioxidants that are present in many fruits and vegetables. The consumption of carotenoids is correlated with positive health effects and a decreased risk of several chronic diseases. Provitamin A carotenoids (β-carotene, α-carotene, γ-carotene, and β-cryptoxanthin) are essential for the development and maintenance of sight. β-carotene, α-carotene, zeaxanthin, β-cryptoxanthin, lutein, and lycopene have high antioxidant activity and promote free radical scavenging, which helps protect against chronic diseases.
  • 2.1K
  • 06 Feb 2023
Topic Review
Social Acceptance of Renewable Energy
Social acceptance of renewable energy is the attitude of the local population of a given territory to accept the presence, installation or expansion of plants, projects and processes for the production of energy from renewable sources (RES) such as geothermal, sun, wind and biomass. It differs from the generally favorable predisposition of a population towards RES in places far from their homes: indeed, social acceptance of local RES can hinder the development of renewable energy projects, even for a population whose general acceptance of RES is relatively high. 
  • 2.1K
  • 08 Jan 2021
Topic Review
Modelling the Human Placental Interface In Vitro
Acting as the primary link between mother and fetus, the placenta is involved in regulating nutrient, oxygen, and waste exchange; thus, healthy placental development is crucial for a successful pregnancy. In line with the increasing demands of the fetus, the placenta evolves throughout pregnancy, making it a particularly difficult organ to study. Research into placental development and dysfunction poses a unique scientific challenge due to ethical constraints and the differences in morphology and function that exist between species. An alternative is to create an in vitro model of the human placenta. Advancements in the differentiation of human induced pluripotent stem cells (hiPSCs), microfluidics, and bioprinting have each contributed to the development of new models, which can be designed to closely match physiological in vivo conditions. By including relevant placental cell types and control over the microenvironment, these in vitro models can reveal clues to the pathogenesis of placental dysfunction and facilitate drug testing across the maternal-fetal interface. 
  • 2.1K
  • 02 Dec 2021
Topic Review
Associative Classification Method
Machine learning techniques are ever prevalent as datasets continue to grow daily. Associative classification (AC), which combines classification and association rule mining algorithms, plays an important role in understanding big datasets that generate a large number of rules. Clustering, on the other hand, can contribute by reducing the rule space to produce compact models. 
  • 2.1K
  • 20 Sep 2022
Topic Review
Emeralds from Kagem Mine, Kafubu Area, Zambia
Kagem emerald mine in Zambia is deemed the largest open-pit emerald mine in the world, with extremely high economic value and a large market share. Mineral inclusions typically include actinolite, graphite, magnetite, and dolomite. Black graphite encased in actinolite in Kagem emeralds is reported herein for the first time. The FTIR spectrum of Kagem emeralds reveals that the absorption of type II H2O is stronger than that of type I H2O, indicating the presence of abundant alkali metals, which was confirmed through chemical analysis. Kagem emeralds contain high levels of Na (avg. 16,440 ppm), moderate-to-high Cs (avg. 567 ppm), as well as low-to-moderate K (avg. 185 ppm) and Rb (avg. 14 ppm) concentrations.
  • 2.1K
  • 16 Oct 2023
Topic Review
Vision-Based Defect Inspection for Sewer Pipes
Underground sewerage systems (USSs) are a vital part of public infrastructure that contributes to collecting wastewater or stormwater from various sources and conveying it to storage tanks or sewer treatment facilities. A healthy USS with proper functionality can effectively prevent urban waterlogging and play a positive role in the sustainable development of water resources. Since it was first introduced in the 1960s, computer vision (CV) has become a mature technology that is used to realize promising automation for sewer inspections.
  • 2.1K
  • 28 Apr 2022
Topic Review
Free Radicals
Free radicals are atoms, molecules or ions with one or more unpaired electrons. The most reactive ones have high reduction potentials; i.e., they readily oxidize most molecules indiscriminately. There is a common misconception that all free radicals are highly reactive, but in fact the range of those able to cause biological damage is quite narrow: it is made up principally of hydroxyl, peroxyl, alkoxyl, thiyl, phenoxyl and semiquinone free radicals, and high valence transition ions.
  • 2.1K
  • 07 Oct 2021
Topic Review
Environmental Factors as Inducers of Oxidative Stress
Prolonged elevated oxidative stress (OS) possesses negative effect on cell structure and functioning, and is associated with the development of numerous disorders. 
  • 2.1K
  • 30 Aug 2022
Topic Review
Reactive Species on Amino Acids
Reactive oxygen species ROS can be triggered by exogenous sources (tobacco, pollution, xenobiotics, drugs, ionizing radiation and so on), but they can also be generated inside the cell by two different mechanisms: enzymatic and non-enzymatic; in both cases, they can have irreversible effects on animal and plant cells and tissues. The superoxide anion •O2− is unstable and cannot pass through membranes, but is rapidly converted to hydrogen peroxide H2O2 and it is membrane-permeable. In the Fenton reaction, H2O2 produces the hydroxyl radical •OH + −OH, which is highly reactive in the mitochondrial matrix. Elevated levels of ROS lead to increased mtDNA damage.
  • 2.1K
  • 23 Nov 2022
Topic Review
Various Uses of Lycopene
Lycopene is a carotenoid abundantly found in red vegetables. This natural pigment displays an important role in human biological systems due to its excellent antioxidant and health-supporting functions, which show a protective effect against cardiovascular diseases, hypertension, cancers, and diabetes.
  • 2.1K
  • 28 Feb 2022
Topic Review
Treatment of Mitochondrial Neurogastrointestinal Encephalomyopathy
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive disorder  caused by mutations in the nuclear TYMP gene, which encodes for thymidine phosphorylase, an enzyme required for the normal metabolism of deoxynucleosides, thymidine, and deoxyuridine. The subsequent elevated systemic concentrations of deoxynucleosides lead to increased intracellular concentrations of their corresponding triphosphates, and ultimately mitochondrial failure due to progressive accumulation of mitochondrial DNA (mtDNA) defects and mtDNA depletion. Currently, there are no treatments for MNGIE where effectiveness has been evidenced in clinical trials. A Phase 2, multi-centre, multiple dose, open label trial without a control will investigate the application of erythrocyte-encapsulated thymidine phosphorylase (EE-TP) as an enzyme replacement therapy for MNGIE. Three EE-TP dose levels are planned with patients receiving the dose level that achieves metabolic correction. The study duration is 31 months, comprising 28 days of screening, 90 days of run-in, 24 months of treatment and 90 days of post-dose follow-up. The primary objectives are to determine the safety, tolerability, pharmacodynamics, and efficacy of multiple doses of EE-TP. The secondary objectives are to assess EE-TP immunogenicity after multiple dose administrations and changes in clinical assessments, and the pharmacodynamics effect of EE-TP on clinical assessments.
  • 2.1K
  • 28 Oct 2020
Topic Review
Orthopedic Bioimplants
Significant research and development in the field of biomedical implants has evoked the scope to treat a broad range of orthopedic ailments that include fracture fixation, total bone replacement, joint arthrodesis, dental screws, and others. The success of a bioimplant depends not only upon its bulk properties, but also on its surface properties that influence its interaction with the host tissue. Various approaches of surface modification such as coating of nanomaterial have been employed to enhance antimicrobial activities of a bioimplant. These strategies showed promising results in orthopedics, e.g., improved bone repair and regeneration. However, the choice of materials, especially considering their degradation behavior and surface properties, plays a key role in long-term reliability and performance of bioimplants. Metallic biomaterials have evolved largely in terms of their bulk and surface properties including nano-structuring with nanomaterials to meet the requirements of new generation orthopedic bioimplants.
  • 2.1K
  • 31 Mar 2021
Topic Review
Neural Crest Cells
The neural crest shows an astonishing multipotency, generating multiple neural derivatives, but also pigment cells, skeletogenic and other cell types. Here w consider how these multipotent cells may give rise to all those diverse cell-types.  
  • 2.1K
  • 27 Dec 2021
Topic Review
Carbon-Fiber-Reinforced Polymers in Circular Economy
Thermosetting Carbon-Fiber-Reinforced Polymers (CFRPs) are engineered composites made out of carbon fibers (CFs) as the reinforcement and epoxy resin as the polymer matrix, which acts as load transfer elements across fibers.Thermosets are commonly charachterized by their high performance and flexibility according to different combination of polymeric-based materials (e.g. epoxies, polyurethane, rubber) and carbon fibers type. CFRPs owns durable and heat-resistant features that make proper them for cars or electrical appliances. CFRPs cannot be easily recycled or broken down after use, because the chemical bonds holding them cannot be changed or reversed as for thermoplastic material. New technological solutions are emerging with specific focus on the circular economy context.
  • 2.1K
  • 06 May 2022
Topic Review
Gottlob Frege
Friedrich Ludwig Gottlob Frege (/ˈfreɪɡə/; German: [ˈɡɔtloːp ˈfreːɡə]; 8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician. He worked as a mathematics professor at the University of Jena, and is understood by many to be the father of analytic philosophy, concentrating on the philosophy of language, logic, and mathematics. Though he was largely ignored during his lifetime, Giuseppe Peano (1858–1932) and Bertrand Russell (1872–1970) introduced his work to later generations of philosophers. His contributions include the development of modern logic in the Begriffsschrift and work in the foundations of mathematics. His book the Foundations of Arithmetic is the seminal text of the logicist project, and is cited by Michael Dummett as where to pinpoint the linguistic turn. His philosophical papers "On Sense and Reference" and "The Thought" are also widely cited. The former argues for two different types of meaning and descriptivism. In Foundations and "The Thought", Frege argues for Platonism against psychologism or formalism, concerning numbers and propositions respectively. Russell's paradox undermined the logicist project by showing Frege's Basic Law V in the Foundations to be false.
  • 2.1K
  • 29 Sep 2022
Topic Review
Ultra-Endurance Participation and Acute Kidney Injury
Increasingly popular, ultra-endurance participation exposes athletes to extremely high levels of functional and structural damage. Ultra-endurance athletes commonly develop acute kidney injury (AKI) and other pathologies harmful to kidney health. There is strong evidence that non-steroidal anti-inflammatory drugs, common amongst ultra-athletes, is linked to increased risk and severity of AKI and potentially ischaemic renal injury, i.e., acute tubular necrosis. Ultra-endurance participation also increases the risk of exertional rhabdomyolysis, exercise-associated hyponatremia, and gastrointestinal symptoms, interlinked pathologies all with potential to increase the risk of AKI. Hydration and fuelling both also play a role with the development of multiple pathologies and ultimately AKI, highlighting the need for individualised nutritional and hydration plans to promote athlete health. Faster athletes, supplementing nitrates, and being female also increase the risk of developing AKI in this setting.
  • 2.1K
  • 12 Jan 2023
Topic Review
Hepatitis B Virus-Associated Polyarteritis Nodosa
Classic polyarteritis nodosa (PAN) is a vasculitis with systemic manifestations that is characterized by inflammatory and necrotizing lesions affecting medium and small muscular arteries, most frequently at the bifurcation of the vessels.
  • 2.1K
  • 19 Jun 2023
  • Page
  • of
  • 2728
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