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Topic Review
Vacuum Switching Devices in Medium-Voltage Networks
The development of power grid infrastructure and increasingly stringent environmental regulations have intensified work, carried out by researchers and electrical equipment manufacturers, to develop innovative gas-insulated, environmentally neutral devices. The emergence of new designs of circuit breakers and disconnectors, in which the resulting electric arc is extinguished in a vacuum environment, requires the development of appropriate techniques for diagnosing the chambers responsible for the dielectric parameters of the device. 
  • 268
  • 22 Mar 2023
Topic Review
Vacuum State
In quantum field theory, the quantum vacuum state (also called the quantum vacuum or vacuum state) is the quantum state with the lowest possible energy. Generally, it contains no physical particles. Zero-point field is sometimes used as a synonym for the vacuum state of an individual quantized field. According to present-day understanding of what is called the vacuum state or the quantum vacuum, it is "by no means a simple empty space". According to quantum mechanics, the vacuum state is not truly empty but instead contains fleeting electromagnetic waves and particles that pop into and out of existence. The QED vacuum of quantum electrodynamics (or QED) was the first vacuum of quantum field theory to be developed. QED originated in the 1930s, and in the late 1940s and early 1950s it was reformulated by Feynman, Tomonaga and Schwinger, who jointly received the Nobel prize for this work in 1965. Today the electromagnetic interactions and the weak interactions are unified (at very high energies only) in the theory of the electroweak interaction. The Standard Model is a generalization of the QED work to include all the known elementary particles and their interactions (except gravity). Quantum chromodynamics (or QCD) is the portion of the Standard Model that deals with strong interactions, and QCD vacuum is the vacuum of quantum chromodynamics. It is the object of study in the Large Hadron Collider and the Relativistic Heavy Ion Collider, and is related to the so-called vacuum structure of strong interactions.
  • 3.9K
  • 17 Oct 2022
Topic Review
Vacuum Diffusion Bonded Ti2AlNb/Ti/TC4 Joint
The Ti2AlNb alloy was bonded to TC4 alloy using the vacuum diffusion bonding method with a Ti interlayer. The interfacial microstructure of the Ti2AlNb/Ti/TC4 joint was characterized. The relationship between the bonding parameters and the microstructure and mechanical property of the joints was explored. Results indicated that the interdiffusion of Nb and Al elements between the interlayer and substrates promoted the formation of the lamellar α + β dual-phase structure in the joint. The bonding parameters determined the diffusion distance of Nb and Al elements, thus controlling the characteristics of the lamellar α + β dual-phase structure. When the Ti2AlNb alloy and TC4 alloy were bonded at 950 °C for 30 min under a pressure of 10 MPa, the elemental diffusion in the bonding couple was sufficient and the joint possessed the maximum shear strength of 549 MPa. 
  • 597
  • 16 Jul 2021
Topic Review
Vacuolar Processing Enzymes in Plant Programmed Cell Death
Vacuolar processing enzymes (VPEs), which can also be named asparaginyl endopeptidases (AEPs), legumains, or colloquially, plant caspases, as they perform caspase-1-like/YVADase activity, are widespread in the plant kingdom. Their occurrence has been found in lower and higher plants. VPEs are plant cysteine proteases that are subjected to autoactivation in an acidic pH. It is presumed that VPEs, by activating other vacuolar hydrolases, are in control of tonoplast rupture during programmed cell death (PCD). Involvement of VPEs has been indicated in various types of plant PCD related to development, senescence, and environmental stress responses. 
  • 505
  • 20 Jan 2023
Topic Review
VACTERL Association
VACTERL association is a disorder that affects many body systems. VACTERL stands for vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities.
  • 372
  • 23 Dec 2020
Topic Review
Vaccinology in the COVID-19 Pandemic Era
Different approaches have been used in parallel to make COVID-19 vaccines, including the use of nucleic acid-based vectors, whole virus (live-attenuated and inactivated), viral vectors (replicating and nonreplicating), adjuvant recombinant protein nanoparticles, and virus-like particles (VLPs). Among the protective antigens of SARS-CoV-2, the attention has mainly focused on the native S protein, which is able to induce potent neutralizing antibodies, even if its presentation to the immune system differs substantially between the different categories of vaccines. However, new evidence is being raised about potential roles for other, more conserved non-spike viral antigens, such as nucleocapsid (N) proteins, which might represent an innovation in the fight against emerging SARS-CoV-2 variants and a source for universal vaccines providing long-lasting immunity.
  • 594
  • 29 Apr 2022
Topic Review
Vaccinium vitis-idaea L.
Lingonberry (Vaccinium vitis-idaea L.; family Ericaceae), otherwise known as cowberry, partridgeberry, and foxberry, is an evergreen dwarf shrub with underground rhizomes widely distributed throughout Northern, Central European, Canadian, and Russian countries’ forests. Due to the promising health benefits, mainly associated with the high content of secondary metabolites—phenolics and triterpenoids—lingonberry leaves acquired prominent pharmaceutical potential and breeding value 
  • 662
  • 27 Sep 2021
Topic Review
Vaccinium Species: Composition and Activity
The genus Vaccinium L. (Ericaceae) includes more than 450 species, which grow mainly in cooler areas of the northern hemisphere. Vaccinium species have been used in the traditional medicine of different cultures and the berries are widely consumed as food. Indeed, Vaccinium supplements-based herbal medicine and functional food, mainly from V. myrtillus and V. macrocarpon, are used in Europe and North America. Biological studies support traditional uses since for many of Vaccinium components important biological functions have been described, including antioxidant, antitumor, anti-inflammatory, antidiabetic, and endothelium protective activities. Vaccinium components, such as polyphenols, anthocyanins, and flavonoids, are widely recognized as modulators of cellular pathways involved in pathological conditions, thus indicating that Vaccinium may be an important source of bioactive molecules. 
  • 679
  • 14 Jul 2021
Topic Review
Vaccinium myrtillus L. in Baltic-Nordic Region
Bilberry (Vaccinium myrtillus L.) is a natural resource and a useful wild berry in Europe. Various parts of the plant contain many benefits for human health. The adaptation and secondary metabolism of V. myrtillus plants can be synergistically affected by a community of microbial endophytes.
  • 418
  • 07 Feb 2022
Topic Review
Vaccinium in Diabetes and Microvascular Complications
Vaccinium L. (Ericaceae) is a genus of plants enriched with polyphenolic compounds in their leaves and fruits. Vaccinium and its extracts have demonstrated good bioactivity in reducing blood glucose, oxidative stress, and inflammation, making them excellent candidates for the management of diabetes and diabetic vascular complications.
  • 388
  • 09 May 2023
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