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
Tools to Monitor Neuromuscular Fatigue
Neuromuscular fatigue (NMF) is a reduction in the maximal voluntary force induced by exercise, with neuromuscular function changes that are due to repeated or sustained muscular contraction, and that are produced either at the peripheral or central levels, and that can be detected for upwards of 48 h to an extended period. An accumulation of work or an incomplete force restoration can significantly influence the neuromuscular performance in both the short and long terms. Thus, fatigue management is essential for controlling the training adaptations of athletes and reducing their susceptibility to injury and illness. The main individualized monitoring tools used to describe fatigue are questionnaires and subjective assessments of fatigue, biochemical markers, sprint tests, and vertical jump tests. Among the subjective measures, the rating of the perceived exertion has been widely used because of its simplicity and high validity. In terms of the objective measures, one of the more frequently employed tools by practitioners to assess neuromuscular fatigue is the countermovement jump. Because of its high validity and reliability, it is accepted as the reference standard test in sports, in general, and particularly in team sports. 
  • 2.4K
  • 05 May 2022
Topic Review
Durability of Foam Concrete
Foam concrete is a type of concrete that is produced by locking air voids in the mortar with the help of a suitable foaming agent and is classified as lightweight concrete. It has low self-weight, minimum aggregate consumption (no coarse aggregate is used), high fluidity, controlled low strength and thermal insulation. The properties of foam concrete are affected by the production method and the materials used. Unlike other porous lightweight concrete, prefabricated foams with foaming agents are added to fresh cement paste and mortar. The air pores brought by the foams constitute 10–90% by volume of the hardened body. This porous structure forms the basis of the mechanical properties, thermal conductivity, acoustic and durability properties of foam concrete. One of the advantages of foam concrete is its weight reduction (up to 80%) compared to conventional concrete. The air bubbles are evenly distributed in the foam concrete body. The pore structure may be affected during the mixing, transportation and placement of fresh concrete, so it should have fixed walls. Air bubbles range in size from approximately 0.1 to 1 mm. The density of foam concrete is mainly affected by the amount of foam and varies between 400 and 1600 kg/m3. It can be used for structural, partitioning, insulation and filling applications with excellent acoustic/thermal insulation, high fire resistance, lower raw material costs, easier pumping and finally no compaction, vibration or leveling.
  • 2.4K
  • 17 Jun 2022
Topic Review
Lactobacillus reuteri
At the turn of the 20th century, L. reuteri was recorded in scientific classifications of lactic acid bacteria.
  • 2.4K
  • 12 Oct 2022
Topic Review
Taupo Volcanic Zone
The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand that has been active for the past two million years and is still highly active. Mount Ruapehu marks its south-western end and the zone runs north-eastward through the Taupo and Rotorua areas and offshore into the Bay of Plenty. It is part of the larger Central Volcanic Region that extends further westward through the western Bay of Plenty to the eastern side of the Coromandel Peninsula and has been active for four million years. The Taupo Volcanic Zone is widening east–west at the rate of about 8 mm per year. It is named after Lake Taupo, the flooded caldera of the largest volcano in the zone, the Taupo Volcano.
  • 2.4K
  • 24 Oct 2022
Topic Review
Mechanism of Self-Healing Hydrogels
Polymeric hydrogels have drawn considerable attention as a biomedical material for their unique mechanical and chemical properties, which are very similar to natural tissues. Among the conventional hydrogel materials, self-healing hydrogels (SHH) are showing their promise in biomedical applications in tissue engineering, wound healing, and drug delivery. Additionally, their responses can be controlled via external stimuli (e.g., pH, temperature, pressure, or radiation). Identifying a suitable combination of viscous and elastic materials, lipophilicity and biocompatibility are crucial challenges in the development of SHH. Furthermore, the trade-off relation between the healing performance and the mechanical toughness also limits their real-time applications. Additionally, short-term and long-term effects of many SHH in the in vivo model are yet to be reported.
  • 2.4K
  • 09 Nov 2022
Biography
George Knapp (Journalist)
George Knapp (born April 18, 1952) is an United States television investigative journalist, news anchor, and talk radio host. Knapp has been recognized with Edward R. Murrow Awards, Peabody Awards, and between 6 and 24[1] regional Emmy Awards depending on the source. Official Emmy site does not have him listed as winning any awards. A longtime fixture in Las Vegas media, he works at KLAS-TV[2]
  • 2.4K
  • 21 Nov 2022
Topic Review
Scanning Transmission Electron Microscopy
A scanning transmission electron microscope (STEM) is a type of transmission electron microscope (TEM). Pronunciation is [stɛm] or [ɛsti:i:ɛm]. As with a conventional transmission electron microscope (CTEM), images are formed by electrons passing through a sufficiently thin specimen. However, unlike CTEM, in STEM the electron beam is focused to a fine spot (with the typical spot size 0.05 – 0.2 nm) which is then scanned over the sample in a raster illumination system constructed so that the sample is illuminated at each point with the beam parallel to the optical axis. The rastering of the beam across the sample makes STEM suitable for analytical techniques such as Z-contrast annular dark-field imaging, and spectroscopic mapping by energy dispersive X-ray (EDX) spectroscopy, or electron energy loss spectroscopy (EELS). These signals can be obtained simultaneously, allowing direct correlation of images and spectroscopic data. A typical STEM is a conventional transmission electron microscope equipped with additional scanning coils, detectors, and necessary circuitry, which allows it to switch between operating as a STEM, or a CTEM; however, dedicated STEMs are also manufactured. High-resolution scanning transmission electron microscopes require exceptionally stable room environments. In order to obtain atomic resolution images in STEM, the level of vibration, temperature fluctuations, electromagnetic waves, and acoustic waves must be limited in the room housing the microscope.
  • 2.4K
  • 29 Nov 2022
Topic Review
Mechanism of Hydroponic Plants to Purify Wastewater
As the global population reaches eight billion, large quantities of wastewater (domestic, industrial, livestock) need to be treated in an efficient, green, and environmentally friendly manner. Wastewater hydroponics technology (HP) can efficiently remove various pollutants (conventional and emerging pollutants, heavy metals, and microorganisms) and create economic benefits. The principle of hydroponic wastewater purification is phytoremediation, which is a low-cost and solar-powered natural cleaning technology. Plants assist in the removal of pollutants in a variety of ways, including phytoextraction, phytovolatilization, phytodegradation, and rhizofiltration.
  • 2.4K
  • 04 Aug 2023
Topic Review
Blood-Brain Barrier: Functionalised Chitosan
The major impediment to the delivery of therapeutics to the brain is the presence of the blood-brain barrier (BBB). The BBB allows for the entrance of essential nutrients while excluding harmful substances, including most therapeutic agents; hence, brain disorders, especially tumors, are very difficult to treat. Chitosan is a well-researched polymer that offers advantageous biological and chemical properties, such as mucoadhesion and ease of functionalization. Chitosan-based nanocarriers (CsNCs) establish ionic interactions with the endothelial cells, facilitating the crossing of drugs through the BBB by adsorptive mediated transcytosis. This process is further enhanced by modifications of the structure of chitosan, owing to the presence of reactive amino and hydroxyl groups. Finally, by permanently binding ligands or molecules, such as antibodies or lipids, CsNCs have shown a boosted passage through the BBB, in both in vivo and in vitro studies which will be discussed in this review.
  • 2.4K
  • 21 Nov 2020
Topic Review
Pyrrolizidine Alkaloids
Pyrrolizidine alkaloids (PAs) are a group of natural compounds that are present in several plant families, among which the most predominant are Boraginaceae, Asteraceae, and Fabaceae, and are produced as a defense response against herbivores. PAs are known for their toxicity and for posing an elevated risk to human and animal health when consumed in large quantities over long periods of time.
  • 2.4K
  • 08 Feb 2024
Topic Review
Drug Cue Reactivity
Drug cue reactivity is a type of learned response which is observed in individuals with drug addiction and involves significant physiological and subjective reactions to presentations of drug-related stimuli.
  • 2.4K
  • 27 Oct 2020
Topic Review
4-Hydroxybutyrate Containing Polyhydroxyalkanoates Production for Biomedical Applications
Polyhydroxyalkanoates (PHA) are polyesters having high promise in biomedical applications. Among different types of PHA, poly-4-hydroxybutyrate (P4HB) is the only polymer that has received FDA approval for medical applications. However, most PHA producing microorganisms lack the ability to synthesize P4HB or PHA comprising 4-hydroxybutyrate (4HB) monomer due to their absence of a 4HB monomer supplying pathway. Thus, most microorganisms require supplementation of 4HB precursors to synthesize 4HB polymers. 
  • 2.4K
  • 09 Dec 2021
Topic Review
Simplified BSD License
BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD license was used for its namesake, the Berkeley Software Distribution (BSD), a Unix-like operating system. The original version has since been revised, and its descendants are referred to as modified BSD licenses. BSD is both a license and a class of license (generally referred to as BSD-like). The modified BSD license (in wide use today) is very similar to the license originally used for the BSD version of Unix. The BSD license is a simple license that merely requires that all code retain the BSD license notice if redistributed in source code format, or reproduce the notice if redistributed in binary format. The BSD license (unlike some other licenses e.g. GPL) does not require that source code be distributed at all.
  • 2.4K
  • 25 Oct 2022
Topic Review
General Methods of Pyruvic Acid Production
Pyruvic acid has numerous applications in the food, chemical, and pharmaceutical industries. General methods of pyruvic acid production include chemical method and biotechnological methods
  • 2.4K
  • 12 Jan 2023
Topic Review
The Honey Bee Apis mellifera
The honey bee Apis mellifera Linnaeus (1758) provides many benefits to humans and ecosystems. This species is an important pollinator in natural environments, which may help to preserve and restore the biodiversity of wild plants. On the other hand, pollination in agro-ecosystems by managed honey bee colonies may enhance crop yield and quality, meeting the increasing food demand. Beekeeping is also a high-valued and income-generating activity, which provides humans with honey as high-quality food as well as substances used as raw materials and in pharmaceuticals. In addition, the honey bee and its products are valuable bioindicators and bioaccumulators of environmental pollution: they provide valuable information on the impact of human activities, enabling the implementation of measures to mitigate risks to human and ecosystem health. The honey bee is also linked to many cultural ecosystem services and has a longstanding tradition in human culture, mysticism, and religion. Its popularity may be therefore used for educational purposes and to raise public awareness of important issues, such as the conservation of pollinator habitats and biodiversity.
  • 2.4K
  • 22 Jun 2022
Topic Review
Dragon C2+
SpaceX COTS Demo Flight 2 (COTS 2), also known as Dragon C2+, was the second test-flight for SpaceX's uncrewed Cargo Dragon spacecraft, launched on the third flight of the company's two-stage Falcon 9 launch vehicle. The flight was performed under a funded agreement from NASA as the second Dragon demonstration mission in the Commercial Orbital Transportation Services (COTS) program. The purpose of the COTS program is to develop and demonstrate commercial sources for cargo re-supply of the International Space Station (ISS). The Dragon C2+ spacecraft was the first American vehicle to visit the ISS since the end of the Space Shuttle program. It was also the first commercial spacecraft to rendezvous and berth with another spacecraft. Initially, the objectives of the C2+ mission were to have been accomplished by two separate missions; Dragon C2 would have carried out a fly-by of the ISS, practiced rendezvous maneuvers and communications with the station, before returning to Earth. A second mission, Dragon C3, would have been the first mission to berth with the station. In July 2011, NASA gave tentative approval to combine the objectives of the two missions. In December 2011, NASA formally approved the merger of the COTS 2 and 3 missions into the Dragon C2+ flight. There were several launch delays, the last one occurring on 19 May 2012, due to a launch abort during the last second before liftoff. Dragon C2+ successfully launched from Cape Canaveral on 22 May 2012. During the mission's first three days all of the COTS 2 objectives were successfully completed. The mission's COTS 3 phase began on 25 May when Dragon rendezvoused again with the ISS and then was successfully captured using the Canadarm2. It was berthed to the station later that day, using the robotic arm. Dragon stayed for almost six days during which the astronauts unloaded cargo, and then reloaded Dragon with Earth-bound cargo. On 31 May, Dragon unberthed from the ISS, its capsule landed in the Pacific Ocean off the California coast and was recovered. All the objectives of the mission were successfully completed, and the Falcon 9-Dragon system became certified to start regular cargo delivery missions to the ISS under the Commercial Resupply Services program.
  • 2.4K
  • 04 Nov 2022
Topic Review
Bell's Mania
Bell's mania, also known as delirious mania, refers to an acute neurobehavioral syndrome. This is usually characterized by an expeditious onset of delirium, mania, psychosis, followed by grandiosity, emotional lability, altered consciousness, hyperthermia, and in extreme cases, death. It is sometimes misdiagnosed as excited delirium (EXD) or catatonia due to the presence of overlapping symptoms. Pathophysiology studies reveal elevated dopamine levels in the neural circuit as the underlying mechanism. Psychostimulant users as well as individuals experiencing severe manic episodes are more prone to the manifestation of this condition. Management solutions such as sedation and ketamine injections have been discussed for medical professionals and individuals with the condition. Bell's mania cases are commonly reported in countries like the United States and Canada and are commonly associated with psychostimulant use and abuse.
  • 2.4K
  • 08 Nov 2022
Topic Review
Windmill (Sailing Dinghy)
The Windmill is an American sailing dinghy that was designed by Clark Mills as a one-design racer and first built in 1953. The Windmill hull design was developed into the US1 single-handed catboat in 1974.
  • 2.4K
  • 24 Nov 2022
Topic Review
Energy Efficiency
The importance and urgency of energy efficiency in sustainable development are increasing. Patterson [3] first proposed the concept of energy efficiency, considering that it means using fewer resources at the same output, and gave four indicators of energy efficiency measurement. According to this definition, the indicators that measure energy efficiency can be divided into economic energy efficiency and physical energy efficiency. In order to measure energy efficiency more accurately, many scholars have studied the measurement of energy efficiency. Among them, Hu and Wang [4] proposed the concept of total factor energy efficiency (TFEE), which was widely recognized.The TFEE index incorporates energy, labor, and capital into the input system to generate economic output. Energy efficiency is defined as the ratio of target energy input to actual energy input. As a total factor efficiency assessment method, DEA method can better deal with the efficiency evaluation of decision-making units under the complicated situation of multiple inputs–outputs, it has been widely used to study energy efficiency.
  • 2.4K
  • 28 Jan 2022
Topic Review
Facial Cleft
A facial cleft is an opening or gap in the face, or a malformation of a part of the face. Facial clefts is a collective term for all sorts of clefts. All structures like bone, soft tissue, skin etc. can be affected. Facial clefts are extremely rare congenital anomalies. There are many variations of a type of clefting and classifications are needed to describe and classify all types of clefting. Facial clefts hardly ever occur isolated; most of the time there is an overlap of adjacent facial clefts.
  • 2.4K
  • 14 Oct 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