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Topic Review
List of Aircraft of World War II
The list of aircraft of World War II includes all the aircraft used by those countries which were at war during World War II from the period between their joining the conflict and the conflict ending for them. Aircraft developed but not used operationally in the war are in the prototypes section at the end. Prototypes for aircraft that entered service under a different design number are ignored in favour of the service version. The date the aircraft entered service, or was first flown if the service date is unknown or it did not enter service follows the name, followed by the country of origin and major wartime users. Aircraft used for multiple roles are generally only listed under their primary role unless specialized versions were built for other roles in significant numbers. Aircraft used by neutral countries such as Spain , Switzerland and Sweden (or countries which did no significant fighting such as most of those in South America) are not included.
  • 2.1K
  • 08 Nov 2022
Topic Review
Green Chemistry Principles for Cellulose-Based Hydrogels
Hydrogels are 3D structures consisting of hydrophilic polymer networks. They can adsorb water and biological fluids in high quantities (up to 1000 times their dry weight). Cellulose is a hydrophilic material. It has inter- and intramolecular hydrogen bonds and van der Waals forces that cause many problems regarding its dissolution.
  • 2.1K
  • 02 Mar 2023
Topic Review
Dexamethasone Suppression Test in Psychiatry
The dexamethasone suppression test (DST) assesses the functionality of the HPA axis and can be regarded as the first potential biomarker in psychiatry. In 1981, a group of researchers at the University of Michigan published a groundbreaking paper regarding its use for diagnosing melancholic depression, reporting a diagnostic sensitivity of 67% and a specificity of 95%.
  • 2.1K
  • 24 May 2023
Topic Review
Biomass-Based Chemical Looping Gasification
Chemical Looping Gasification is a process allowing for the conversion of solid feedstock (e.g. biomass) into N2-free, high-calorific syngas or producer gas. The process utilizes the ability of so-called oxygen carriers (e.g. ilmenite, iron ore) to take up and release oxygen in oxidizing and reducing atmospheres, respectively. Employing this characteristic, the oxygen carrier is cycled between two or more reactors to transport oxygen into the so-called fuel reactor, where the inlet feedstock is firstly gasified using steam or CO2, before intermediate gaseous products (e.g. H2, CH4) are further oxidized by the oxygen carrier, providing additional process heat to drive the endothermic gasification reactions. The loop is then closed as the reduced oxygen carrier is re-oxidized in a so-called air reactor, using the oxygen contained in ambient air, resulting in a stream of pure nitrogen at the air reactor outlet.
  • 2.1K
  • 03 Nov 2021
Topic Review
Natural Killer Cells in Non-Small Cell Lung Cancer
Natural killer (NK) cells were first described in the 1970's and belong to a subgroup of the innate lymphoid cell family. They arise from common lymphoid progenitors, but unlike T cells and B cells, they lack genetically rearranged receptors, are independent of antigen specificity and rely on a balance of signals transduced via activating and inhibitory receptors to induce activation.
  • 2.1K
  • 29 Mar 2022
Topic Review
Delay Defects in Nanoscale Digital VLSI Circuits
As technology scales down, digital VLSI (very large-scale integration) circuits are prone to many manufacturing defects. These defects may result in functional and delay-related circuit failures. The number of test escapes grows when technology is downscaled. Small delay defects (SDDs) and hidden delay defects (HDDs) are of critical importance in industries since they are the source of most test escapes and reliability problems.
  • 2.1K
  • 30 Sep 2022
Topic Review
The Renin-Angiotensin-Aldosterone System
The renin-angiotensin-aldosterone system (RAAS) is comprised of two main branches, with ACE2 representing a crucial component of the protective part of the complex. The ACE2/Ang (1-7) axis is well represented in the testis, heart, brain, kidney, and intestine. Infection with the novel SARS-CoV-2 virus determines downregulation of ACE2 and interrupts the equilibrium between ACE and ACE2 in these organs.
  • 2.1K
  • 30 Sep 2022
Topic Review
Cyber Mimic Defense
From the inspiration of defensive guise behaviors based on mimic phenomenon in biology, Cyber Mimic Defense (CMD) introduces the mechanism of dynamic multi-dimensional reconfiguration into a dissimilar redundancy structure (DRS) which is widely used in the field of reliability. It addresses certain or uncertain threats in cyberspace by the principle of uncertain defense, and provides the strategic varieties and transformations of DRS elements inside objects in quantity or type, time or space dimension under the condition of unchanged visual functions. It provides a generally innovative defense theory and method to deal with the “known unknown risk” and “unknown unknown risk” which exist in related application levels of different areas of cyberspace and are based on unknown vulnerabilities, backdoors, viruses, Trojans, etc. This method can provide not only endogenous security gains which are independent of traditional security means and achieved via integrated structural technologies for critical infrastructures or key information equipment, but also resilient or restorable service ability with intensive attributes inherited from the architecture. Further it acquires super nonlinear effects combining mature defense technologies. It's aimed at creating a non-closed, self-controlled and sustainable-developed ecological environment which adapts to globalization technologies and industrial development models and integrates with win-win cooperation and open sources.
  • 2.1K
  • 02 Nov 2022
Topic Review
Flying Disc Techniques
Flying discs (including Frisbees) can be thrown in many ways. Each throw involves snapping the wrist as well as flicking the arm to impart gyroscopic stability to the disc and accelerate its mass to a certain velocity. Without spin, a disc will wobble and fall; without velocity, the disc will not go anywhere. Using these two guidelines, any number of throws are possible. Most discs are designed to create lift when thrown with the flat side up.
  • 2.1K
  • 22 Nov 2022
Topic Review
Erythritol
The sugar alcohol erythritol is a relatively new food ingredient. It is naturally occurring in plants, however, produced commercially by fermentation. It is also produced endogenously via the pentose phosphate pathway (PPP). Consumers perceive erythritol as less healthy than sweeteners extracted from plants, including sucrose. 
  • 2.1K
  • 09 Jan 2023
Topic Review
Ginkgo Biloba and Long COVID
Coronavirus infections are neuroinvasive and can provoke injury to the central nervous system (CNS) and long-term illness consequences. They may be associated with inflammatory processes due to cellular oxidative stress and an imbalanced antioxidant system. The ability of phytochemicals with antioxidant and anti-inflammatory activities, such as Ginkgo biloba, to alleviate neurological complications and brain tissue damage has attracted strong ongoing interest in the neurotherapeutic management of long COVID. Ginkgo biloba leaf extract (EGb) contains several bioactive ingredients, e.g., bilobalide, quercetin, ginkgolides A–C, kaempferol, isorhamnetin, and luteolin. They have various pharmacological and medicinal effects, including memory and cognitive improvement. Ginkgo biloba, through its anti-apoptotic, antioxidant, and anti-inflammatory activities, impacts cognitive function and other illness conditions like those in long COVID.
  • 2.1K
  • 06 Jun 2023
Topic Review
Crowdsourcing Update Methods for High-Definition Maps
High-definition (HD) maps serve as crucial infrastructure for autonomous driving technology, facilitating vehicles in positioning, environmental perception, and motion planning without being affected by weather changes or sensor-visibility limitations.
  • 2.1K
  • 01 Apr 2024
Topic Review
Modern Seed Technology
There are three major types of seed treating/coating equipment: dry powder applicator, rotary pan, and pelleting pan with the provisions to apply dry powders, liquids, or a combination of both. Additional terms for coatings produced from these types of equipment include dry coating, seed dressing, film coating, encrustments, and seed pelleting. The seed weight increases for these different coating methods ranges from <0.05% to >5000% (>100,000-fold range). 
  • 2.1K
  • 08 Jan 2022
Topic Review
Primary Health Care in Eswatini
Primary health care (PHC) is the first point of contact in a health system for most patients. It focuses on providing community-based health services that are equitable, comprehensive, affordable and accessible to all, throughout the life-course of an individual.
  • 2.1K
  • 14 Jul 2021
Topic Review
Colorectal Cancer Cells
The majority of deaths related to colorectal cancer (CRC) are associated with the metastatic process. Alternative therapeutic strategies, such as traditional folk remedies, deserve attention for their potential ability to attenuate the invasiveness of CRC cells. The aim of this study is to investigate the biological activity of brown Cuban propolis (CP) and its main component nemorosone (NEM) and to describe the molecular mechanism(s) by which they inhibit proliferation and metastatic potential of 2 CRC cell lines. CP and NEM significantly decreased cell viability and inhibited clonogenic capacity of CRC cells in a dose and time-dependent manner, by arresting the cell cycle in the G0/G1 phase and inducing apoptosis. Furthermore, CP and NEM downregulated BCL2 gene expression and upregulated the expression of the proapoptotic genes TP53 and BAX, with a consequent activation of caspase 3/7. They also attenuated cell migration and invasion by inhibiting MMP9 activity, increasing E-cadherin and decreasing β-catenin and vimentin expression, proteins involved in the epithelial–mesenchymal transition (EMT). NEM, besides displaying antiproliferative activity on CRC cells, is able to decrease their metastatic potential by modulating EMT-related molecules. These findings provide new insights about the antitumoral properties of CP, due to NEM content.  
  • 2.1K
  • 01 Nov 2020
Topic Review
Vector Transmission of Plant Viruses
Vector transmission of plant viruses is basically of two types that depend on the virus helper component proteins or the capsid proteins. A number of plant viruses belonging to disparate groups have developed unusual capsid proteins providing for interactions with the vector.
  • 2.1K
  • 02 Feb 2021
Topic Review
Angiotensin II Type 2 Receptor
Preclinical evidence, accumulated over the past decade, indicates that the angiotensin II type 2 receptor (AT2R) stimulation exerts significant neuroprotective effects in various animal models of neuronal injury, notably in the central nervous system.   Studies of brain AT2R distribution and function are outshining the recent findings about AT2R in peripheral sensoryneurons and pain modulation. While AT2R, as an atypical G protein-coupled receptor, and its related signaling are still under investigation, pharmacological studies have shown that stimulation of AT2R leads to neuritogenesis in vitro and in vivo. This review aims to report the evidence of potential neuroprotective and neuroregenerative roles of AT2R in the peripheral nervous system (PNS).
  • 2.1K
  • 10 Mar 2021
Topic Review
Cortical Silent Period
The so-called cortical silent period (CSP) refers to the temporary interruption of electromyographic signal from a muscle following a motor-evoked potential (MEP) triggered by transcranial magnetic stimulation (TMS) over the primary motor cortex (M1). The neurophysiological origins of the CSP are debated. Previous evidence suggests that both spinal and cortical mechanisms may account for the duration of the CSP. However, contextual factors such as cortical fatigue, experimental procedures, attentional load, as well as neuropathology can also influence the CSP duration. The present paper summarizes the most relevant evidence on the mechanisms underlying the duration of the CSP, with a particular focus on the central role of the basal ganglia in the “direct” (excitatory), “indirect” (inhibitory), and “hyperdirect” cortico-subcortical pathways to manage cortical motor inhibition. We propose new methods of interpretation of the CSP related, at least partially, to the inhibitory hyperdirect and indirect pathways in the basal ganglia. This view may help to explain the respective shortening and lengthening of the CSP in various neurological disorders.
  • 2.1K
  • 01 Jun 2021
Topic Review
Plant Secondary Metabolites in Pharmaceutical Product Development
Plant secondary metabolites (PSMs) are vital for human health and constitute the skeletal framework of many pharmaceutical drugs. Indeed, more than 25% of the existing drugs belong to PSMs. One of the continuing challenges for drug discovery and pharmaceutical industries is gaining access to natural products, including medicinal plants. This bottleneck is heightened for endangered species prohibited for large sample collection, even if they show biological hits. While cultivating the pharmaceutically interesting plant species may be a solution, it is not always possible to grow the organism outside its natural habitat. Plants affected by abiotic stress present a potential alternative source for drug discovery. In order to overcome abiotic environmental stressors, plants may mount a defense response by producing a diversity of PSMs to avoid cells and tissue damage. Plants either synthesize new chemicals or increase the concentration (in most instances) of existing chemicals, including the prominent bioactive lead compounds morphine, camptothecin, catharanthine, epicatechin-3-gallate (EGCG), quercetin, resveratrol, and kaempferol. Most PSMs produced under various abiotic stress conditions are plant defense chemicals and are functionally anti-inflammatory and antioxidative. The major PSM groups are terpenoids, followed by alkaloids and phenolic compounds.
  • 2.1K
  • 29 Mar 2022
Topic Review
Greenwashing Behavior in Hotels Industry
Greenwashing has become a pervasive phenomenon in the tourism and hospitality sector, posing significant challenges and potential reputational damage to green hotels.
  • 2.1K
  • 02 Feb 2024
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