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Topic Review
TGV Track Construction
LGV construction is the process by which the land on which TGV trains are to run is prepared for their use, involving carving the trackbed and laying the track. It is similar to the building of standard railway lines, but there are differences. In particular, construction process is more precise in order for the track to be suitable for regular use at 300 km/h (186 mph). The quality of construction was put to the test in particular during the TGV world speed record runs on the LGV Atlantique; the track was used at over 500 km/h (310 mph) without suffering significant damage. This contrasts with previous French world rail speed record (326/331 km/h in 1955) attempts which resulted in severe deformation of the track.
  • 1.6K
  • 30 Nov 2022
Topic Review
Single-Stranded DNA Binding Protein in DNA Metabolism
Single-stranded DNA-binding proteins (SSBs) play vital roles in DNA metabolism. Proteins of the SSB family exclusively and transiently bind to ssDNA, preventing the DNA double helix from re-annealing and maintaining genome integrity. In the meantime, they interact and coordinate with various proteins vital for DNA replication, recombination, and repair. Although SSB is essential for DNA metabolism, proteins of the SSB family have been long described as accessory players, primarily due to their unclear dynamics and mechanistic interaction with DNA and its partners. Recently-developed single-molecule tools, together with biochemical ensemble techniques and structural methods, have enhanced our understanding of the different coordination roles that SSB plays during DNA metabolism. 
  • 1.6K
  • 15 Feb 2023
Topic Review
Autophagosome Biogenesis
Autophagy–the lysosomal degradation of cytoplasm–plays a central role in cellular homeostasis and protects cells from potentially harmful agents that may accumulate in the cytoplasm, including pathogens, protein aggregates, and dysfunctional organelles. This process is initiated by the formation of a phagophore membrane, which wraps around a portion of cytoplasm or cargo and closes to form a double-membrane autophagosome. Upon the fusion of the autophagosome with a lysosome, the sequestered material is degraded by lysosomal hydrolases in the resulting autolysosome. Several alternative membrane sources of autophagosomes have been proposed, including the plasma membrane, endosomes, mitochondria, endoplasmic reticulum, lipid droplets, hybrid organelles, and de novo synthesis. 
  • 1.6K
  • 09 Mar 2023
Topic Review
Heme Oxgenase-1 in cytoprotection
Heme oxygenase catalyzes the rate-limiting step in heme degradation in order to generate biliverdin, carbon monoxide (CO), and iron. The inducible form of the enzyme, heme oxygenase-1 (HO-1), exerts a central role in cellular protection. The substrate, heme, is a potent pro-oxidant that can accelerate inflammatory injury and promote cell death. HO-1 has been implicated as a key mediator of inflammatory cell and tissue injury, as validated in preclinical models of acute lung injury and sepsis. A large body of work has also implicated HO-1 as a cytoprotective molecule against various forms of cell death, including necrosis, apoptosis and newly recognized regulated cell death (RCD) programs such as necroptosis, pyroptosis, and ferroptosis. While the antiapoptotic potential of HO-1 and its reaction product CO in apoptosis regulation has been extensively characterized, relatively fewer studies have explored the regulatory role of HO-1 in other forms of necrotic and inflammatory RCD (i.e., pyroptosis, necroptosis and ferroptosis). HO-1 may provide anti-inflammatory protection in necroptosis or pyroptosis. In contrast, in ferroptosis, HO-1 may play a pro-death role via enhancing iron release. HO-1 has also been implicated in co-regulation of autophagy, a cellular homeostatic program for catabolic recycling of proteins and organelles. While autophagy is primarily associated with cell survival, its occurrence can coincide with RCD programs. 
  • 1.6K
  • 28 Apr 2021
Topic Review
Urban Heat Island Analysis
Urban Heat Island （UHI ) studies have been conducted for over 200 years, since the first conceptualization by Luke Howard in 1818. Generally, an urban heat island (UHI) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas because of human activities. The temperature difference is usually greater at night than during the day and is most apparent when winds are weak.
  • 1.6K
  • 08 Dec 2021
Topic Review
Recent Advances in Dielectric Properties-Based Soil Water Content Measurements
Dielectric properties are crucial in understanding the behavior of water within soil, particularly the soil water content (SWC), as they measure a material’s ability to store an electric charge and are influenced by water and other minerals in the soil. However, a comprehensive review paper is needed that synthesizes the latest developments in this field, identifies the key challenges and limitations, and outlines future research directions. In addition, various factors, such as soil salinity, temperature, texture, probing space, installation gap, density, clay content, sampling volume, and environmental factors, influence the measurement of the dielectric permittivity of the soil. Therefore, this review aims to address the research gap by critically analyzing the current state-of-the-art dielectric properties-based methods for SWC measurements. The motivation for this review is the increasing importance of precise SWC data for various applications such as agriculture, environmental monitoring, and hydrological studies. We examine time domain reflectometry (TDR), frequency domain reflectometry (FDR), ground-penetrating radar (GPR), remote sensing (RS), and capacitance, which are accurate and cost-effective, enabling real-time water resource management and soil health understanding through measuring the travel time of electromagnetic waves in soil and the reflection coefficient of these waves. SWC can be estimated using various approaches, such as TDR, FDR, GPR, and microwave-based techniques. These methods are made possible by increasing the dielectric permittivity and loss factor with SWC. The available dielectric properties are further synthesized based on mathematical models relating apparent permittivity to water content, providing an updated understanding of their development, applications, and monitoring. It also analyzes recent mathematical calibration models, applications, algorithms, challenges, and trends in dielectric permittivity methods for estimating SWC.
  • 1.6K
  • 31 Oct 2024
Topic Review
Peripheral Responses to Pain
Pain can be induced by tissue injuries, diseases and infections. The interactions between the peripheral nervous system (PNS) and immune system are primary actions in pain sensitizations. In response to stimuli, nociceptors release various mediators from their terminals that potently activate and recruit immune cells, whereas infiltrated immune cells further promote sensitization of nociceptors and the transition from acute to chronic pain by producing cytokines, chemokines, lipid mediators and growth factors. Immune cells not only play roles in pain production but also contribute to PNS repair and pain resolution by secreting anti-inflammatory or analgesic effectors. 
  • 1.6K
  • 12 Mar 2021
Topic Review
Diet: DNA Methylation and Cancer
Cancer initiation and progression is an accumulation of genetic and epigenetic modifications. DNA methylation is a common epigenetic modification that regulates gene expression, and aberrant DNA methylation patterns are considered a hallmark of cancer. The human diet is a source of micronutrients, bioactive molecules, and mycotoxins that have the ability to alter DNA methylation patterns and are thus a contributing factor for both the prevention and onset of cancer. In this review, we summarize the literature on dietary micronutrients, bioactive compounds, and food-borne mycotoxins that affect DNA methylation patterns and identify their potential in the onset and treatment of cancer.
  • 1.6K
  • 09 Oct 2020
Topic Review
Calcium Dysregulation in Alzheimer’s Disease
Intracellular calcium (Ca2+) is an important second messenger that regulates multiple cellular functions, such as synaptic plasticity, action potentials, and learning and memory. Ca2+ dyshomeostasis, on the other hand, contributes to detrimental mechanisms such as necrosis, apoptosis, autophagy deficits, and neurodegeneration. Perturbations in intracellular Ca2+ are involved in many neurodegenerative diseases including Alzheimer's disease (AD), Parkinson’s disease, and Huntington’s disease.  Ca2+ dyshomeostasis is an early event in the AD timeline. Ca2+ dysregulation in AD comes as a result of hyperactivity of Ca2+ channels in the plasma membrane and intracellular compartments. It does not seem to be restricted to neurons, but rather is a global phenomenon that affects many cell types in the brain.
  • 1.6K
  • 25 Dec 2020
Topic Review
Megamolecular Polysaccharide Sacran
Natural polymer is a frequently used polymer in various food applications and pharmaceutical formulations due to its benefits and its biocompatibility compared to synthetic polymers. One of the natural polymer groups (i.e., polysaccharide) does not only function as an additive in pharmaceutical preparations, but also as an active ingredient with pharmacological effects.
  • 1.6K
  • 21 Jun 2021
Topic Review
Neurodegeneration
The human body is highly complex and comprises a variety of living cells and extracellular material, which forms tissues, organs, and organ systems. Human cells tend to turn over readily to maintain homeostasis in tissues. However, postmitotic nerve cells exceptionally have an ability to regenerate and be sustained for the entire life of an individual, to safeguard the physiological functioning of the central nervous system. For efficient functioning of the CNS, neuronal death is essential, but extreme loss of neurons diminishes the functioning of the nervous system and leads to the onset of neurodegenerative diseases. Neurodegenerative diseases range from acute to chronic severe life-altering conditions like Parkinson’s disease and Alzheimer’s disease. Millions of individuals worldwide are suffering from neurodegenerative disorders with little or negligible treatment available, thereby leading to a decline in their quality of life. Neuropathological studies have identified a series of factors that explain the etiology of neuronal degradation and its progression in neurodegenerative disease. The onset of neurological diseases depends on a combination of factors that causes a disruption of neurons, such as environmental, biological, physiological, and genetic factors. 
  • 1.6K
  • 16 Jul 2021
Topic Review
Origin of ICL
Not all the light in galaxy groups and clusters comes from stars that are bound to galaxies. A significant fraction of it constitutes the so-called intracluster or diffuse light (ICL), a low surface brightness component of groups/clusters generally found in the surroundings of the brightest cluster galaxies and intermediate/massive satellites
  • 1.6K
  • 13 Sep 2021
Topic Review
Valuable Organic Acids
A ruminant-based carboxylate platform based on mixed or undefined anaerobic co-cultures of rumen microorganisms can convert the carbohydrate polymers in the lignocellulosic part of organic waste streams to carboxylic acids that can be upgraded to biofuels or green chemicals.
  • 1.6K
  • 27 Sep 2021
Topic Review
Ecuadorian Medicinal Plants
The use of plants as therapeutic agents is part of the traditional medicine that is practiced by many indigenous communities in Ecuador.
  • 1.6K
  • 29 Mar 2022
Topic Review
The Evolution of U.S. Equity Trading Venues
The modern U.S. equity market has been evolving from floor trading by brokers who read the ticker tape and bid on offer to purely electric trading coded into computer algorithms. This entry briefly overviews the evolution of the U.S. equity venues and discusses the consequences of market fragmentation from theoretical and empirical perspectives.
  • 1.6K
  • 01 Dec 2021
Topic Review
G-quadruplexes and ligands: Biophysical methods
Progress in the design of G-quadruplex (G4) binding ligands relies on the availability of approaches that assess the binding mode and nature of the interactions between G4 forming sequences and their putative ligands. The experimental approaches used to characterize G4/ligand interactions can be categorized in structure-based methods (circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy and x-ray crystallography), affinity and apparent affinity-based methods (surface plasmon resonance (SPR), isothermal titration calorimetry (ITC) and mass spectrometry (MS)), and high-throughput methods (fluorescence resonance energy transfer (FRET)-melting, G4-fluorescent intercalator displacement assay (G4-FID), affinity chromatography and microarrays. Each method has unique advantages and drawbacks, which makes it essential to select the ideal strategies for the biological question being addressed. The structural- and affinity and apparent affinity-based methods are in several cases complex and/or time-consuming and can be combined with fast and cheap high-throughput approaches to improve the design and development of new potential G4 ligands. In the last years, the joint use of these techniques permitted the discovery of a huge number of G4 ligands investigated for diagnostic and therapeutic purposes. Overall, this review article highlights in detail the most used approaches to characterize the G4/ligand interactions, as well as the applications and type of information that can be obtained from the use of each technique.
  • 1.6K
  • 03 Dec 2021
Topic Review
Grain Size Associated Genes in Rice
Grain size is a quantitative trait that is controlled by multiple genes. It is not only a yield trait, but also an important appearance quality of rice. In addition, grain size is easy to be selected in evolution, which is also a significant trait for studying rice evolution. In recent years, many quantitative trait loci (QTL)/genes for rice grain size were isolated by map-based cloning or genome-wide association studies, which revealed the genetic and molecular mechanism of grain size regulation in part.
  • 1.6K
  • 31 Mar 2022
Topic Review
Smart Bioinks for Printing Human Tissue Models
A bioink is a mixture of materials and biological molecules or cells to be used for bioprinting. Most bioinks are hydrogels, highly hydrated polymeric networks used to homogenously encapsulate cells by mimicking the natural extracellular matrix found in vivo. Hydrogels must meet certain characteristics to ensure they can support cell survival and function.
  • 1.6K
  • 25 Apr 2022
Topic Review
CFBDSIR 1458+10
CFBDSIR J145829+101343 (Coordinates: 14h 58m 29.0s, +10° 13′ 43″, designation abbreviated to CFBDSIR 1458+10, or CFBDSIR J1458+1013) is a binary system of two brown dwarfs of spectral classes T9 + Y0 orbiting each other, located in constellation Boötes about 104 light-years away from Earth. The smaller companion, CFBDSIR 1458+10B, has a surface temperature of approx 370 K (≈100 °C) and used to be known as the coolest known brown dwarf until the discovery of WISE 1828+2650 in August 2011.
  • 1.6K
  • 09 Oct 2022
Topic Review
Drug Policy Reform
Drug policy reform, also known as drug law reform, generally refers to proposed changes to the laws and regulations that governments promulgate with respect to substances that have psychoactive effects or a real or perceived potential to be used for recreational or other non-medical reasons. Proponents of drug policy reform frequently argue that prohibition of recreational drugs—such as cannabis, opioids, cocaine, amphetamines and hallucinogens—has been ineffective and counterproductive and that substance use is better responded to by implementing practices for harm reduction and increasing the availability of addiction treatment. Another reform proposed is to introduce a regulatory regime for the production, marketing, and distribution of some or all currently illegal drugs in a manner analogous to that for alcohol and tobacco. Proponents of drug law reform argue that relative harm should be taken into account in the regulation of controlled substances. Addictive or dependence-forming substances such as alcohol, tobacco and caffeine have been a traditional part of many culture for centuries and remain legal in most countries, though other drugs which cause less harm than alcohol or tobacco are entirely prohibited, with possession punishable with severe criminal penalties.
  • 1.6K
  • 26 Oct 2022
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