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Topic Review
Biological Treatment of Pharmaceutical-Based Contaminants with Oxidoreductase Enzymes
The worldwide access to pharmaceuticals and their continuous release into the environment have raised a serious global concern. Pharmaceuticals remain active even at low concentrations, therefore their occurrence in waterbodies may lead to successive deterioration of water quality with adverse impacts on the ecosystem and human health. To address this challenge, there is an evolving trend toward the search for effective methods to ensure efficient purification of both drinking water and wastewater. Biocatalytic transformation of pharmaceuticals using oxidoreductase enzymes, such as peroxidase and laccase, is a promising environmentally friendly solution for water treatment, where fungal species have been used as preferred producers due to their ligninolytic enzymatic systems.
  • 1.4K
  • 20 Oct 2022
Topic Review
Graviperception and Graviresponses in Euglena gracilis
The genus Euglena contains unicellular eukaryotic flagellates. In addition to light and chemicals, the cells perceive the gravitational field of the Earth and orient themselves paralell to the gravivector to optimize their position in the water column. The perception is based on transient receptor proteins in the membrane which are stimulated by the pressure of the cell content onto the lower membrane. Upon stimulation these proteins open and allow the influx of calcium from the outer medium which binds to a specific calmodulin. In turn this enzyme activates a adenylyl cyclase which produces cAMP believed to stimulate a phosphodiesterase A which finally modifies a flagellar protein which results in a course correction. Since Euglena is photosynthetic it absorbs carbon dioxide and produces oxygen and is thus an excellent candidate for a bioregenerative life support system during long-term space flights.
  • 1.4K
  • 04 Nov 2022
Topic Review
Outline of Geophysics
The following outline is provided as an overview of and topical guide to geophysics: Geophysics – the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations have a broader definition that includes the hydrological cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial relations; and analogous problems associated with the Moon and other planets.
  • 1.4K
  • 09 Nov 2022
Topic Review
Apple Network Server
The Apple Network Server (ANS) was a line of PowerPC-based server computers designed, manufactured and sold by Apple Computer, Inc. from February 1996 to April 1997. It was codenamed "Shiner" and originally consisted of two models, the Network Server 500/132 ("Shiner LE", i.e., "low-end") and the Network Server 700/150 ("Shiner HE", i.e., "high-end"), which got a companion model, the Network Server 700/200 (also "Shiner HE") with a faster CPU in November 1996. The machines were not a part of the Apple Macintosh line of computers; they were designed to run IBM's AIX operating system and their ROM specifically prevented booting the classic Mac OS. This makes them the last non-Macintosh desktop computers made by Apple to date. The 500/132, 700/150, and 97 sold in the U.S. market for $11,000, $15,000 and $19,000, respectively. Apple Network Servers are not to be confused with the Apple Workgroup Servers and the Macintosh Servers, which were Macintosh workstations that shipped with server software and used Mac OS; the sole exception, the Workgroup Server 95—a Quadra 950 with an added SCSI controller that shipped with A/UX—was also capable of running Mac OS. Apple did not have comparable server hardware in their product lineup again until the introduction of the Xserve in 2002. The product's short lifespan is attributed to significant financial troubles at Apple in early 1997. CEO Gil Amelio cancelled both Network Server and OpenDoc in the same meeting as it was determined that they were low priorities.
  • 1.4K
  • 30 Nov 2022
Topic Review
Regulation of Nanotechnology
Because of the ongoing controversy on the implications of nanotechnology, there is significant debate concerning whether nanotechnology or nanotechnology-based products merit special government regulation. This mainly relates to when to assess new substances prior to their release into the market, community and environment. Nanotechnology refers to an increasing number of commercially available products – from socks and trousers to tennis racquets and cleaning cloths. Such nanotechnologies and their accompanying industries have triggered calls for increased community participation and effective regulatory arrangements. However, these calls have presently not led to such comprehensive regulation to oversee research and the commercial application of nanotechnologies, or any comprehensive labeling for products that contain nanoparticles or are derived from nano-processes. Regulatory bodies such as the United States Environmental Protection Agency and the Food and Drug Administration in the U.S. or the Health and Consumer Protection Directorate of the European Commission have started dealing with the potential risks posed by nanoparticles. So far, neither engineered nanoparticles nor the products and materials that contain them are subject to any special regulation regarding production, handling or labelling.
  • 1.4K
  • 29 Nov 2022
Topic Review
Oregon Petition
The Global Warming Petition Project, also known as the Oregon Petition, is a petition urging the United States government to reject the global warming Kyoto Protocol of 1997 and similar policies. Some consider it to be a political petition designed for disinforming and confusing the public about the scientific results and the consensus of climate change research.
  • 1.4K
  • 02 Dec 2022
Topic Review
The Origin of Geranylgeraniol and Farnesol
Isoprenoids are the output of the polymerization of five-carbon, branched isoprenic chains derived from isopentenyl pyrophosphate (IPP) and its isomer, dimethylallyl pyrophosphate (DMAPP). Isoprene units are consecutively condensed to form longer structures such as farnesyl and geranylgeranyl pyrophosphate (FPP and GGPP, respectively), necessary for the biosynthesis of several metabolites. Polyprenyl transferases and synthases use polyprenyl pyrophosphates as their natural substrates; however, it is known that free polyprenols, such as farnesol (FOH), and geranylgeraniol (GGOH) can be incorporated into prenylated proteins, ubiquinone, cholesterol, and dolichols. Furthermore, FOH and GGOH have been shown to block the effects of isoprenoid biosynthesis inhibitors such as fosmidomycin, bisphosphonates, or statins in several organisms.
  • 1.4K
  • 13 Dec 2022
Topic Review
Application Progress of Hydrogels as Food Matrices
Food hydrogels are biopolymeric materials made from food-grade biopolymers with gelling properties (proteins and polysaccharides) and a 3D network capable of incorporating large amounts of water.  Hydrogels present a wide range of properties (including high water content, flexibility, softness, and compatibility), making their application highly tunable for different food systems. Protein–polysaccharide composites have been so far successfully used only in the food packaging industry as they possess an oil barrier, water solubility, and tastelessness. The commercially used edible films are produced mostly from cellulose and whey protein biopolymers, or alginate and collagen. The most recent trend in using hydrogels is the development of matrices that can replace animal-based food products in terms of texture and nutritional aspects. The food sector is increasingly becoming more concerned with providing enough nutritious food for everyone while protecting natural resources. 
  • 1.4K
  • 07 Feb 2023
Topic Review Peer Reviewed
Nuclear Waste Disposal
Nuclear waste (like radioactive waste) is waste that contains, or is contaminated with, radionuclides, at activity concentrations greater than clearance levels set by the regulators, beyond which no further use is foreseen. Disposal is the emplacement of waste in an appropriate facility without the intention to retrieve it.
  • 1.4K
  • 03 Apr 2023
Topic Review
Rotating Triboelectric Nanogenerators for Energy Harvesting Applications
Addressing the increasing development of IoT networks and the associated energy requirements, rotating triboelectric nanogenerators (R-TENGs) are proving to be strong candidates in the field of energy harvesting, as well as to that of self-powered devices and autonomous sensors.
  • 1.4K
  • 13 Jul 2023
Topic Review
Digital Horizon of Smart Agriculture
Agriculture is essential to the existence of the human race, as well as the foundation of our civilization, because it provides food, fuel, fiber, and other resources necessary for survival; however, it is facing critical challenges due to anthropogenic climate change, which hampers food and nutritional security. Several measures have been implemented to enhance agricultural productivity, including plant breeding, genetic engineering, and precision agriculture. The world has witnessed the burgeoning development of novel scientific innovations and technological advancements enabled by drones, smart sensors, robotics, and remote sensing, resulting in a plethora of revolutionary methods that can be applied to real-time crop modeling, high-throughput phenotyping, weather forecasting, yield prediction, fertilizer application, disease detection, market trading, farming practices, and other environmental practices vital to crop growth, yield, and quality. Digitalization is the most significant technological advancement of our time, and it profoundly affects agriculture and other industries. Delivering a comprehensive view of how technology could help in tackling critical issues like environmental degradation and threatened world biodiversity, this perspective emphasizes the perks of digitalization.
  • 1.4K
  • 09 Jan 2024
Topic Review
Acute Myeloid Leukemia Stem Cells
Relapse after apparent remission remains a major cause of death in patients with acute myeloid leukemia (AML). On the cellular level, leukemia relapse is considered to emerge from subpopulations of therapy-resistant leukemic stem cells (LSC). Identification and targeting of LSC are thus most important goals for AML treatment. However, AML and their LSC are highly heterogeneous.
  • 1.4K
  • 29 Dec 2020
Topic Review
Formulation Strategies to Improve Pharmacokinetics Profile
The oral route is the most common and practical means of drug administration, particularly from a patient’s perspective. However, the pharmacokinetic profile of oral drugs depends on the rate of drug absorption through the intestinal wall before entering the systemic circulation. However, the enteric epithelium represents one of the major limiting steps for drug absorption, due to the presence of efflux transporters on the intestinal membrane, mucous layer, enzymatic degradation, and the existence of tight junctions along the intestinal linings. These challenges are more noticeable for hydrophilic drugs, high molecular weight drugs, and drugs that are substrates of the efflux transporters. Another challenge faced by oral drug delivery is the presence of first-pass hepatic metabolism that can result in reduced drug bioavailability. Over the years, a wide range of compounds have been investigated for their permeation-enhancing effect in order to circumvent these challenges. There is also a growing interest in developing nanocarrier-based formulation strategies to enhance the drug absorption.
  • 1.4K
  • 26 Aug 2022
Topic Review
Sortilin/Neurotensin Receptor-3 in Cancer
The multifunctional role of sortilin in cancers development The development of cancerous tumors is known to be the consequence of the overexpression of growth factors. Unfortunately, when treated with radiotherapy or chemical therapy, some tumors can metastasize as a result of the weakening of cancer cell–cell interactions in the tumor tissue, leading to the dissemination of cancer cells in the circulation. Both mechanisms of cancer growth and metastasis are regulated by a large panel of circulating activators from several neuropeptides to membrane-bound factors released by matrix metalloprotease (MMP)-dependent shedding, such as Epidermal Growth Factor Receptor (EGFR) ligands. One of the most studied neuropeptides involved in cancer progression is neurotensin (NTS), the three known receptors of which (two G-protein coupled receptors, NTSR1 and NTSR2, and a type I receptor, NTSR3) are expressed in numerous cancers and particularly in digestive cancers. Interestingly, NTSR3, also previously identified as Sortilin, is shed from the plasma membrane, leading to the release of a soluble form of sortilin (sSortilin). However, growing evidence indicates the emerging role of membrane-bound Sortilin/NTSR3 and its soluble counterpart in cancer cell proliferation and dissemination.
  • 1.4K
  • 21 Oct 2022
Topic Review
Diatom–Bacteria Interactions in the Marine Environment
Diatom–bacteria interactions evolved during more than 200 million years of coexistence in the same environment. In this time frame, they established complex and heterogeneous cohorts and consortia, creating networks of multiple cell-to-cell mutualistic or antagonistic interactions for nutrient exchanges, communication, and defence. The most diffused type of interaction between diatoms and bacteria is based on a win-win relationship in which bacteria benefit from the organic matter and nutrients released by diatoms, while these last rely on bacteria for the supply of nutrients they are not able to produce, such as vitamins and nitrogen. Despite the importance of diatom–bacteria interactions in the evolutionary history of diatoms, especially in structuring the marine food web and controlling algal blooms, the molecular mechanisms underlying them remain poorly studied.
  • 1.4K
  • 25 Dec 2023
Topic Review
Antioxidant Properties of Taxifolin
Polyphenols are the most numerous and widely distributed compounds of plant origin. They are involved in various processes of the growth and development of plants, and their protection against unfavorable environmental factors. They enter the body of humans and animals with plant food. The intake of polyphenols or polyphenol-rich food products might be associated with a lower risk of cardiovascular, neurodegenerative, and other diseases. More than 8000 polyphenols have been identified; of these, more than 4000 compounds belong to the group of flavonoids. In nature, polyphenols occur as monomers, oligomers, and polymers (proanthocyanidins, condensed tannins). There is also evidence indicating that, during the storage and aging of food products and beverages with a high content of flavonoids, the latter react with carbonyl compounds such as acetaldehyde, methylglyoxal, glyoxylic acid, and furfurol, which results in the formation of monomeric, oligomeric, and polymeric adducts.
  • 1.4K
  • 23 Aug 2021
Topic Review
Chondrocyte Sheets
Chondrocyte sheets can be created without using material such as animal-derived collagen by using temperature-responsive culture devices such as thermo-responsive polymer grafted culture dishes, where cells can adhere, proliferate, and form into a sheet.  Hyaline cartilage regeneration by autologous chondrocyte sheets has already been demonstrated in clinical research.　Chondrocyte sheet transplantation is a novel and promising approach to treating patients who have cartilage defects associated with osteoarthritis.
  • 1.4K
  • 27 Oct 2020
Topic Review
Experimental Techniques for Chatter Avoidance
The general trend towards lightweight components and stronger but difficult to machine materials leads to a higher probability of vibrations in machining systems. Amongst them, chatter vibrations are an old enemy for machinists with the most dramatic cases resulting in machine-tool failure, accelerated tool wear and tool breakage or part rejection due to unacceptable surface finish. To avoid vibrations, process designers tend to command conservative parameters limiting productivity. Among the different machining processes, turning is responsible of a great amount of the chip volume removed worldwide.
  • 1.4K
  • 27 Oct 2020
Topic Review
EPLS' Change in Inner Mongolia
        There is increasing focus on the difficult challenge of realizing coordinated development of production, living and ecological spaces within the regional development process. An ecological–production–living space (EPLSs)evaluation index system was established in this study based on the concept of EPLSs and the relationship between land use function, land use type and the national standard of land use classification, to reveal the driving forces and patterns of variation in EPLSs in Inner Mongolia.
  • 1.4K
  • 23 Oct 2020
Topic Review
Canonical Hypoxia Signaling
The oxygen-sensing system is a complicated and elaborate system containing large molecular components, including hypoxia-inducible factors (HIFs) as the central regulator of oxygen homeostasis, prolyl hydroxylases (PHDs), Von Hippel-Lindau protein (pVHL) as the modulator of ubiquitin-mediated proteolysis, and the co-factors and downstream targets as functional contributors. It should be recognized that the PHDs-HIF-pVHL axis remains the best-characterized and central signaling in the oxygen sensing pathway, although novel mechanisms continue to be illuminated. In this entry, we summarize the current knowledge about canonical hypoxia signaling, including the function of HIF transcription factors, prolyl hydroxylation of HIFs, and pVHL.
  • 1.4K
  • 02 Nov 2020
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