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Topic Review
Principal Postulates of Centrosomal Biology
The centrosome, which consists of two centrioles surrounded by pericentriolar material, is a unique structure that has retained its main features in organisms of various taxonomic groups from unicellular algae to mammals over one billion years of evolution. In addition to the most noticeable function of organizing the microtubule system in mitosis and interphase, the centrosome performs many other cell functions. In particular, centrioles are the basis for the formation of sensory primary cilia and motile cilia and flagella. Another principal function of centrosomes is the concentration in one place of regulatory proteins responsible for the cell's progression along the cell cycle. Despite the existing exceptions, the functioning of the centrosome is subject to general principles.
  • 1.6K
  • 15 Oct 2020
Topic Review
Tormentic Acid
Tormentic acid, also known as 2α,3β,19α-trihydroxyurs-2-en-28-oic acid (IUPAC Name: (1R,2R,4aS,6aR,6aS,6bR,8aR,10R,11R,12aR,14bS)-1,10,11-trihydroxy-1,2,6a,6b,9,9,12a-heptamethyl-2,3,4,5,6,6a,7,8,8a,10,11,12,13,14b-tetradecahydropicene-4a-carboxylic acid), is a pentacyclic triterpene. Its biological activity e.g. anti-inflammatory, antidiabetic, antihyperlipidemic, hepatoprotective, cardioprotective, neuroprotective, anti-cancer, anti-osteoarthritic, antinociceptive, antioxidative, anti-melanogenic, cytotoxic, antimicrobial, and antiparasitic has been confirmed in in vitro and in vivo studies. This molecule and its derivatives can be found in various plant species and families (e.g. Rosaceae, Lamiaceae, Myrtaceae, Oleaceae, Urticaceae, Boraginaceae), including edibles and herbs. 
  • 1.6K
  • 01 Jul 2021
Topic Review
Impact of Climate Change on Hydrometeorology and Droughts
Climate change is associated with shifts in average climatic conditions and extreme events likely to impact human and ecological systems. According to the Intergovernmental Panel on Climate Change report (IPCC), the frequency and intensity of heavy precipitation events and daily temperature extremes are expected to increase in the mid-21st century. Based on past studies, the increase in long-term temperature and variability in precipitation in different parts of the world and their impacts on the environment are becoming evident.
  • 1.6K
  • 04 Mar 2022
Topic Review
Polymers in High-Efficiency Solar Cells
Third-generation solar cells, including dye-sensitized solar cells, bulk-heterojunction solar cells, and perovskite solar cells, are being intensively researched to obtain high efficiencies in converting solar energy into electricity. However, it is also important to note their stability over time and the devices’ thermal or operating temperature range. Today’s widely used polymeric materials are also used at various stages of the preparation of the complete device—it is worth mentioning that in dye-sensitized solar cells, suitable polymers can be used as flexible substrates counter-electrodes, gel electrolytes, and even dyes. In the case of bulk-heterojunction solar cells, they are used primarily as donor materials; however, there are reports in the literature of their use as acceptors. In perovskite devices, they are used as additives to improve the morphology of the perovskite, mainly as hole transport materials and also as additives to electron transport layers. Polymers, thanks to their numerous advantages, such as the possibility of practically any modification of their chemical structure and thus their physical and chemical properties, are increasingly used in devices that convert solar radiation into electrical energy.
  • 1.6K
  • 17 May 2022
Topic Review
The Ferroptosis
Ferroptosis, which has been widely associated with many diseases, is an iron-dependent regulated cell death characterized by intracellular lipid peroxide accumulation. The term ‘ferroptosis’, first proposed in 2012, refers to a programmed cell death resulting from iron-dependent lipid peroxidation accumulation. Ferroptosis is distinct from other previously established regulated cell deaths and has specific morphological, biochemical, and genetic characteristics. It exhibits morphological, biochemical, and genetic characteristics that are unique in comparison to other types of cell death. The course of ferroptosis can be accurately regulated by the metabolism of iron, lipids, amino acids, and various signal pathways.
  • 1.6K
  • 12 Jul 2022
Topic Review
Approaches to Preceramic Polymer Fiber Fabrication
The demand for lightweight, high-modulus, and temperature-resistant materials for aerospace and other high-temperature applications has contributed to the development of ceramic fibers that exhibit most of the favorable properties of monolithic ceramics. The preceramic polymer requirements for a fiber concoction include: (1) appropriate rheology for non-Newtonian flows of materials and appropriate viscosity during rotation; (2) reactivity to fuse the fibers for subsequent pyrolysis; (3) controlled degradation during pyrolysis to prevent disorders of the structure, such as scattered material, and to produce high-density fibers with high ceramic performance; (4) controlled formation of nano- or microstructures.
  • 1.6K
  • 15 Jul 2022
Topic Review
Small-Scale Urban Green Infrastructure
Urban green infrastructure (UGI) such as green roofs, green facades, public parks, urban forests, urban wetlands, and unmanaged green sites, provide nature-based solutions (NBS) that offer a promising avenue for climate change adaptation in cities to reduce the negative environmental impacts of urbanization, such as the urban heat island effect and altered precipitation patterns. UGI supports a wide range of ES at different spatial levels including but not limited to provisioning (e.g., food, and freshwater), regulating (e.g., urban temperature regulations, noise reduction, air purification, pollination, runoff mitigation, and waste treatment), socio-cultural (tourism, recreation, cognitive development, social cohesion), and supporting (e.g., habitat for biodiversity diversity), with fewer documented health benefits (e.g., good health, mortality). 
  • 1.6K
  • 19 Sep 2022
Topic Review
Sol Rezza
Sol Rezza (born April 7, 1982, Buenos Aires, Argentina ) is a composer, audio engineer and radio producer; specialist in sound design and composition in the field of experimental music and radio art for various media, theater, festivals and installations. Her main works of sound experimentation are the creation of immersive sound environments through the transformation of field recordings, effects and surround sound. Owner of an atypical professional tour, Sol Rezza works in different areas related to sound; from live performances, experimental compositions for radio to the realization of atmospheres / environments and / or sound effects for digital media, video games, films as well as for installations. All her works have two main axes of analysis: the way we perceive time and space through our senses and how sounds influence that perception.
  • 1.6K
  • 29 Sep 2022
Topic Review
Food Systems
The term food system is used frequently in discussions about nutrition, food, health, community economic development and agriculture. A food system includes all processes and infrastructure involved in feeding a population: growing, harvesting, processing, packaging, transporting, marketing, consumption, and disposal of food and food-related items. It also includes the inputs needed and outputs generated at each of these steps. A food system operates within and is influenced by social, political, economic and environmental contexts. It also requires human resources that provide labor, research and education. Food systems are either conventional or alternative according to their model of food lifespan from origin to plate.
  • 1.6K
  • 30 Oct 2022
Topic Review
Shenxian Zhuan
The Shenxian Zhuan, sometimes given in translation as the Biographies of the Deities and Immortals, is a hagiography of immortals and description of Chinese gods, partially attributed to the Daoist scholar Ge Hong (283-343). In the history of Chinese literature, the Shenxian Zhuan followed the Liexian Zhuan ("Collected Biographies the Immortals").
  • 1.6K
  • 11 Nov 2022
Topic Review
Appications of Natural Clinoptilolites Based on Ion Exchange
There are many natural zeolites, of which a small number, including clinoptilolite, chabazite, mordenite, erionite, ferrierite, and phillipsite offer the greatest promise for industrial applications. Natural clinoptilolites have been the subject for different modifications in order to improve their use potentialities, where the ion exchange property has been a key role for their different applications. Application of ion exchange to modify clinoptilolites, cation selection, mono- and polycationic exchange to create new functional materials for specific applications are key issues.
  • 1.6K
  • 03 Jan 2023
Topic Review
Heat Stress on Rabbit Production
Heat stress is a major environmental stress that causes substantial economic loss in the rabbit industry. Compared to other agricultural animals, rabbits are more sensitive to heat stress as they have fewer sweat glands and a thicker coat of fur, increasing the heat dissipation complexity.
  • 1.6K
  • 20 Jul 2023
Topic Review
Factors Influencing Employees’ Intrapreneurial Behavior
Effectively promoting employees’ intrapreneurial behavior has become the focus of enterprises. This study takes the middle and grassroots employees in enterprises as subjects and explores the configuration effect of multiple influencing factors on employees’ intrapreneurial behavior. Based on employee expectation theory and individual-environment matching theory, this study collates six influencing factors: entrepreneurial self-efficacy, entrepreneurial competence, task school level,perceived value, management support, and reward mechanism. A total of 163 samples were obtained, and the qualitative comparative analysis method based on fuzzy set was used to analyze the influence mechanism and result path of employees’ intrapreneurial behavior from the perspective of the interaction between individual factors and organizational factors. Six influencing paths of employees’ high intrapreneurial behavior were found, which can be divided into ability-driven and value-driven factors, revealing that the six factors can produce equivalent results in different configurations. Furthermore, five influencing paths of employees’ non-high intrapreneurial behavior were divided into three types: ability obstacle type, perception obstacle type, and value obstacle type.These have an asymmetric causal relationship with employees’ high intrapreneurial behavior. This study provides management support for effectively stimulating employees’ intrapreneurial behavior.
  • 1.6K
  • 26 Sep 2023
Topic Review
Digital Marketing for SMEs in Tourism
Social media has become an essential tool for travel planning, with tourists increasingly using it to research destinations, book accommodation, and make travel arrangements. Small and medium-sized enterprises’(SMEs) most common use of social media is to promote their products or services, but they can also use it to build customer relationships, provide customer service, and gather feedback.
  • 1.6K
  • 15 Dec 2023
Topic Review Peer Reviewed
Supporting Doctoral Candidates through Completion and Final Examination
Completion and final examination comprise the final stages of a doctoral program and represent the culmination of the doctoral candidates’ years of research. In this entry, completion is defined as the writing and submission of a doctoral thesis, and final examination is defined as the viva voce. Over the years, the format and scope of doctoral degrees has expanded and a variety of formats are now offered. In addition to the traditional research-only doctoral degree, professional, practice-based, and new route programs also contain a taught element alongside research. However, the creation of a substantive thesis or practice-based alternative addressing a novel research question is common to all. In contrast, processes and formats of viva voces vary across the globe. These range from private, closed-door defenses to assessed or ritualistic public defense presentations. For both completion and final examination, there are many practical and psychological hurdles that need to be navigated in order for the candidate to attain their doctoral degree. This entry will highlight these aspects as well as provide evidence-based guidance for supervisors in supporting their doctoral candidates through these daunting final stages.
  • 1.6K
  • 14 Mar 2025
Topic Review
Interoperability in uHealth and Digital Therapeutics
Interoperability in digital health refers to the seamless, secure, and scalable exchange of health information between care environments and digital platforms. Being a central pillar for the integration of wearable sensors, AI-based diagnostics, clinical and non-clinical workflows for both Digital Therapeutics and ubiquitous health (uHealth), mobile health applications, and virtual coaching applications, interoperability is done using standards such as HL7 FHIR, TEFCA, and SMART on FHIR, which provide shared protocols for information exchange, protection, and semantic harmonization. This entry describes fundamental ideas, new governance paradigms, technical architectures, and regulatory issues required for realizing interoperable health ecosystems for personalized, preventive, and participatory care. The entry describes barriers in the form of fragmentation, data silos, and ethical issues, while identifying enablers such as federated learning, blockchain, and FAIR data principles.The content is based on a structured narrative review registered with OSF (DOI: 10.17605/OSF.IO/PNKG4) and a preprint version publicly available via Preprints.org.
  • 1.6K
  • 16 Jul 2025
Topic Review
Magnetic Iron Oxide Nanoparticle Synthesis
Iron oxides are chemical compounds which havedifferent polymorphic forms, including γ-Fe2O3 (maghemite), Fe3O4(magnetite), and FeO (wustite). Among them, the most studiedare γ-Fe2O3 and Fe3O4,as they possess extraordinary properties at the nanoscale (such as superparamagnetism, high specific surface area, biocompatible etc.),because at this size scale, the quantum effectsaffect matter behavior and optical, electrical and magnetic properties.Therefore, in the nanoscale, these materials become ideal for surface functionalization and modification in various applications such as separation techniques, magnetic sorting (cells and other biomolecules etc.), drug delivery, cancer hyperthermia, sensing etc., and also for increased surface area-to-volume ratio, which allows for excellent dispersibility in the solution form.The current methods used are partially and passively mixed reactants, and,thus, every reaction has a different proportion of all factors which causes further difficulties in reproducibility.Direct active and complete mixing and automated approaches could be solutions to thissize- and shape-controlled synthesis, playing a key role in its exploitation for scientific or technological purposes. An ideal synthesis method should be able to allow reliable adjustment of parameters andcontrol over the following: fluctuation in temperature;pH, stirring rate;particle distribution; size control;concentration; and control over nanoparticle shape andcomposition i.e., crystallinity, purity, and rapid screening. Iron oxide nanoparticle (IONP)-based available clinical applications are RNA/DNAextraction and detection of infectious bacteria andviruses. Such technologies are important at POC (point of care) diagnosis.IONPs can play a key role in these perspectives.Although there are various methods for synthesis of IONPs,one of the most crucial goals is to control size and properties with high reproducibility to accomplish successful applications.Using multiple characterization techniques to identify and confirm the oxide phase of iron can provide better characterization capability. It is very important to understand the in-depth IONP formation mechanism, enabling better control over parameters and overall reaction and, by extension, properties of IONPs.This workprovides an in-depth overview ofdifferent properties, synthesis methods, and mechanisms of iron oxide nanoparticles (IONPs) formation, and the diverse range of theirapplications. Differentcharacterization factors and strategiesto confirm phase purity in the IONP synthesis field are reviewed.First, properties of IONPs and various synthesis routes with their merits and demerits are described. We also describe different synthesis strategies and formation mechanisms for IONPs such as for: wustite (FeO), hematite(α-Fe2O3), maghemite(ɤ-Fe2O3) and magnetite(Fe3O4). We also describe characterization of these nanoparticles and various applications in detail. In conclusion, we present a detailed overview on the properties, size-controlled synthesis, formation mechanisms and applications of IONPs.
  • 1.6K
  • 30 Oct 2020
Topic Review
Bio-Based Value Chains
Agriculture generates 11.4 billion tons of biomass worldwide, including residues from crop production and industrial processing. Improper disposal of agricultural residues results in environmental pollution and the waste of valuable biomass resources. Management of agricultural waste is particularly suboptimal in developing countries where low added-value traditional practices to manage the residues are commonplace.
  • 1.6K
  • 25 Apr 2021
Topic Review
Photocatalytic Electrospun Nanofiber Membranes
Photocatalytic nanofiber membranes are nanofiber membranes infused with photocatalytic nanoparticles. The performance of photocatalytic membranes is attributed to the photogenerated reactive oxygen species such as hydroxyl radicals, singlet oxygen, and superoxide anion radicals produced from reactions with photogenerated electrons and holes introduced by catalytic nanoparticles such as TiO2 and ZnO upon light irradiation. Hydroxyl radicals are the most reactive species responsible for most of the unselective photodegradation of unwanted pollutants. 
  • 1.6K
  • 10 Sep 2021
Topic Review
Plant Secondary Metabolites as Defense Tools against Herbivores
Plants have evolved several adaptive strategies through physiological changes in response to herbivore attacks. Plant secondary metabolites (PSMs) are synthesized to provide defensive functions and regulate defense signaling pathways to safeguard plants against herbivores. Herbivore injury initiates complex reactions which ultimately lead to synthesis and accumulation of PSMs. The biosynthesis of these metabolites is regulated by the interplay of signaling molecules comprising phytohormones. Plant volatile metabolites are released upon herbivore attack and are capable of directly inducing or priming hormonal defense signaling pathways. Secondary metabolites enable plants to quickly detect herbivore attacks and respond in a timely way in a rapidly changing scenario of pest and environment.Several studies have suggested that the potential for adaptation and/or resistance by insect herbivores to secondary metabolites is limited. These metabolites cause direct toxicity to insect pests, stimulate antixenosis mechanisms in plants to insect herbivores, and, by recruiting herbivore natural enemies, indirectly protect the plants. Herbivores adapt to secondary metabolites by the up/down regulation of sensory genes, and sequestration or detoxification of toxic metabolites. PSMs modulate multi-trophic interactions involving host plants, herbivores, natural enemies and pollinators. Although the role of secondary metabolites in plant-pollinator interplay has been little explored, several reports suggest that both plants and pollinators are mutually benefited. Molecular insights into the regulatory proteins and genes involved in the biosynthesis of secondary metabolites will pave the way for the metabolic engineering of biosynthetic pathway intermediates for improving plant tolerance to herbivores. 
  • 1.6K
  • 14 Mar 2022
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