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
From Word Embeddings to Pre-Trained Language Models
With the advances in deep learning, different approaches to improving pre-trained language models (PLMs) have been proposed. PLMs have advanced state-of-the-art (SOTA) performance on various natural language processing (NLP) tasks such as machine translation, text classification, question answering, text summarization, information retrieval, recommendation systems, named entity recognition, etc. Prior embedding models as well as breakthroughs in the field of PLMs are provided in this entry.
  • 2.7K
  • 18 Nov 2022
Topic Review
Geotourism and Ecotourism
The two forms of tourism, ecotourism and geotourism, are considered forms of experiential tourism, and they sometimes also raise questions such as about the differences between them in terms of their elements of attraction. Ecotourists, in addition to ecological activities related to natural attractions, add and focus seriously on the cultural side of the wild side, but also on the constructed, humanised, and culturalised sides of the countryside outside or close to purely geotouristic attractions (hence the assimilation of ecotourism with rural tourism or agrotourism).
  • 2.7K
  • 20 Nov 2023
Topic Review
Gamified Physical Exercise and Mental Health in Adolescence
Interest in gamified physical activity has been driven by its potential to benefit student mental health. Integrating gamified practices for mental health improvement represents a significant innovation within multidisciplinary approaches to enhancing mental well-being. Gamified physical activity positively influences adolescents’ mental health and well-being. Additionally, there is a need for improved application and game design to enhance learning within school contexts. Tailoring exergames to fit specific disciplines and school-related characteristics can promote healthier mobile application usage and offer significant benefits for the mental health of young individuals.
  • 2.7K
  • 23 Jan 2024
Topic Review
Carbon-11 Production and Transformation
The short-lived positron-emitter carbon-11 (t1/2 = 20.4 min; β+, 99.8%) is prominent for labeling tracers for use in biomedical research with positron emission tomography (PET). Carbon-11 is produced for this purpose with a cyclotron, by the 14N(p,α)11C nuclear reaction, either on nitrogen containing a low concentration of oxygen (0.1–0.5%) or hydrogen (~5%) to produce [11C]carbon dioxide or [11C]methane, respectively. These primary radioactive products can be produced in high yields and with high molar activities. However, only [11C]carbon dioxide has some utility for directly labeling PET tracers. Primary products are required to be converted rapidly and efficiently into secondary labeling synthons to provide versatile radiochemistry for labeling diverse tracer chemotypes at molecular positions of choice. Because of their simplicity, reliability, re-usability, and amenability for automation, gas phase transformations play a major part in carbon-11 chemistry and in PET tracer development.
  • 2.7K
  • 31 Jan 2024
Topic Review
Precision Machining by Dicing Blades
Diamond dicing blades are profound cutting tools that find their applications in semiconductor back-end packaging and assembly processes. To fully appreciate the benefits of the dicing blade technique for precision machining, a deeper understanding is required.
  • 2.7K
  • 22 Feb 2023
Topic Review
Intestinal Stem Cells
Intestinal stem cells (ISC) are crucial players in colon epithelium physiology. The accurate control of their auto-renewal, proliferation and differentiation capacities provides a constant flow of regeneration, maintaining the epithelial intestinal barrier integrity. Under stress conditions, colon epithelium homeostasis in disrupted, evolving towards pathologies such as inflammatory bowel diseases or colorectal cancer. A specific environment, namely the ISC niche constituted by the surrounding mesenchymal stem cells, the factors they secrete and the extracellular matrix (ECM), tightly controls ISC homeostasis. Colon ECM controls ISC homeostasis by exerting physical constraint on the enclosed stem cells through peculiar topography, stiffness and deformability.
  • 2.7K
  • 22 Dec 2020
Topic Review
Oxidative Stress in DiGeorge Syndrome
DiGeorge syndrome (DGS) is a rare genetic disease caused by microdeletions of the 22q11.2 region (DGS1). A haploinsufficiency at 10p level has been proposed also as a DGS cause (DGS2). Clinical manifestations are variable. The most frequent features are thymic hypoplasia or aplasia with consequent immune deficiency, cardiac malformations, hypoparathyroidism, facial and palatine abnormalities, variable degrees of cognitive impairment and psychiatric disorders. The specific aim of this descriptive report is to discuss the correlation between oxidative stress and neuroinflammation in DGS patients with microdeletions of the 22q11.2 region. The deleted chromosomic region maps various genes involved in mitochondrial metabolisms, such as DGCR8 and TXNRD2, that could lead to reactive oxygen species (ROS) increased production and antioxidant depletion.
  • 2.7K
  • 08 Mar 2023
Topic Review
Pharmacognosy
Pharmacognosy is the study of medicinal drugs derived from plants or other natural sources. The American Society of Pharmacognosy defines pharmacognosy as "the study of the physical, chemical, biochemical and biological properties of drugs, drug substances or potential drugs or drug substances of natural origin as well as the search for new drugs from natural sources". It is also defined as the study of crude drugs.
  • 2.7K
  • 09 Nov 2022
Topic Review
Iridoschisis
Iridoschisis is a rare condition defined as a separation of the anterior iris stroma from the posterior stroma and muscle layers. A variety of ocular pathologies can coexist with iridoschisis, but in most cases the causal relationship, if any, is unclear. Glaucoma, primarily angle-closure glaucoma, is the most often described condition concomitant to iridoschisis. Other ocular abnormalities found relatively often in iridoschisis patients include cataract, lens subluxation and corneal abnormalities. Iridoschisis is plausibly a multifactorial disease. A patient diagnosed with iridoschisis should be screened for potential glaucoma, corneal and lens abnormalities. Iridoschisis may pose a challenge for both an ophthalmologist in an outpatient setting and an ophthalmic surgeon.
  • 2.7K
  • 10 Nov 2020
Topic Review
Nitrate-Rich Diet Therapy
Beetroot is a remarkable vegetable, as its rich nitrate and bioactive compound contents ameliorate cardiovascular and metabolic functions by boosting nitric oxide synthesis and regulating gene expressions or modulating proteins and enzyme activities involved in these cellular processes. Dietary nitrate provides a physiological substrate for nitric oxide production, which promotes vasodilatation, increases blood flow and lowers blood pressure. 
  • 2.7K
  • 11 Oct 2021
Topic Review
Grid-Forming Virtual Power Plants
Virtual Power Plants (VPPs) are efficient structures for attracting private investment, increasing the penetration of renewable energy and reducing the cost of electricity for consumers. It is expected that the number of VPPs will increase rapidly as their financial return is attractive to investors. VPPs will provide added value to consumers, to power systems and to electricity markets by contributing to different services such as the energy and load-following services. Grid forming inverters (GFM) are used to connect distributed energy sources and devices into a unique resource and convert it to Alternating Current. GFMs are especially suited to connecting VPPs to the main power grid.
  • 2.7K
  • 20 Dec 2022
Topic Review
Sol-Gel Technology
The commercial availability of inorganic/organic precursors for sol-gel formulations is very high and increases day by day. In textile applications, the precursor-synthesized sol-gels along with functional chemicals can be deposited onto textile fabrics in one step by rolling, padding, dip-coating, spraying or spin coating. By using this technology, it is possible to provide fabrics with functional/multi-functional characteristics including flame retardant, anti-mosquito, water- repellent, oil-repellent, anti-bacterial, anti-wrinkle, ultraviolet (UV) protection and self-cleaning properties. These surface properties are discussed, describing the history, basic chemistry, factors affecting the sol-gel synthesis, progress in sol-gel technology along with various parameters controlling sol-gel technology. Additionally, this review deals with the recent progress of sol-gel technology in textiles in addressing fabric finishing, water repellent textiles, oil/water separation, flame retardant, UV protection and self-cleaning, self-sterilizing, wrinkle resistance, heat storage, photochromic and thermochromic color changes and the improvement of the durability and wear resistance properties.
  • 2.7K
  • 05 May 2023
Topic Review
Sjögren’s Syndrome Pathogenic Molecular Pathways
Sjögren’s syndrome (SS) is a systemic autoimmune rheumatic disorder characterized by the lymphocytic infiltration of exocrine glands and the production of autoantibodies to self-antigens. The involvement of the exocrine glands drives the pathognomonic manifestations of dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) that define sicca syndrome.
  • 2.7K
  • 01 Nov 2022
Topic Review
Timeline of Plague
This is a timeline of plague, describing major epidemics and key medical developments.
  • 2.7K
  • 14 Nov 2022
Topic Review
Titanium Nitriding Methods: Drawbacks and Benefits
The application of titanium alloys in aircraft construction is expanding due to their high corrosion resistance and excellent strength-to-weight ratio. However, if not specially treated, they are characterized by relatively low wear resistance [1,2], a significant limiting factor for their application. The surface treatment may improve this characteristic, and diffusion-saturation by nitrogen is the gold standard, and this section discusses the features, benefits, and shortcomings of the most common titanium nitriding methods.
  • 2.7K
  • 20 Jan 2022
Topic Review
Lysine Acetylation
Acetylation of lysine residues is a key post-translational modification for protein functions in all eukaryotic organisms. Acetylation of lysine residues can be catalyzed by lysine acetyltransferases (KATs) or modified by abundant Ac-CoA through nonenzymatic mechanisms. Conversely, lysine deacetylation is catalyzed by lysine deacetylases (KDACs).
  • 2.7K
  • 20 Oct 2020
Topic Review
Serious Gaming for Behaviour Change
Serious games (SG) are defined as “interactive computer applications, with or without a significant hardware component, that have challenging goals, are fun to play and engaging, incorporate some scoring mechanism, and supply the user with skills, knowledge or attitudes useful in reality".
  • 2.7K
  • 28 Mar 2022
Topic Review
A Systematic Approach to Healthcare Knowledge Management Systems
Big data in healthcare contain a huge amount of tacit knowledge that brings great value to healthcare activities such as diagnosis, decision support, and treatment. However, effectively exploring and exploiting knowledge on such big data sources exposes many challenges for both managers and technologists. A healthcare knowledge management system that ensures the systematic knowledge development process on various data in hospitals was proposed. It leverages big data technologies to capture, organize, transfer, and manage large volumes of medical knowledge, which cannot be handled with traditional data-processing technologies. In addition, machine-learning algorithms are used to derive knowledge at a higher level in supporting diagnosis and treatment.
  • 2.7K
  • 13 May 2022
Topic Review
Functions of Lysosomes
Lysosomes are essential organelles of eukaryotic cells and are responsible for various cellular functions, including endocytic degradation, extracellular secretion, and signal transduction. There are dozens of proteins localized to the lysosomal membrane that control the transport of ions and substances across the membrane and are integral to lysosomal function. Mutations or aberrant expression of these proteins trigger a variety of disorders, making them attractive targets for drug development for lysosomal disorder-related diseases. 
  • 2.7K
  • 08 May 2023
Topic Review
Glucose 6-P Dehydrogenase in Skeletal Muscle during Exercise
Hypomorphic Glucose 6-P dehydrogenase (G6PD) catalyzes the rate-limiting step in the pentose phosphate pathway (PPP), which provides the precursors of nucleotide synthesis for DNA replication as well as reduced nicotinamide adenine dinucleotide phosphate (NADPH). NADPH is involved in the detoxification of cellular reactive oxygen species (ROS) and de novo lipid synthesis. An association between increased PPP activity and the stimulation of cell growth has been reported in different tissues including the skeletal muscle, liver, and kidney. PPP activity is increased in skeletal muscle during embryogenesis, denervation, ischemia, mechanical overload, the injection of myonecrotic agents, and physical exercise. In fact, the highest relative increase in the activity of skeletal muscle enzymes after one bout of exhaustive exercise is that of G6PD, suggesting that the activation of the PPP occurs in skeletal muscle to provide substrates for muscle repair. The age-associated loss in muscle mass and strength leads to a decrease in G6PD activity and protein content in skeletal muscle. G6PD overexpression in Drosophila Melanogaster and mice protects against metabolic stress, oxidative damage, and age-associated functional decline, and results in an extended median lifespan. 
  • 2.7K
  • 02 Nov 2022
  • Page
  • of
  • 2799
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