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Topic Review
Zeaxanthin and Lutein Across Life's Taxa
Zeaxanthin and lutein are structural isomers with zeaxanthin possessing a slightly longer system of conjugated double bonds (11) than lutein. Carotenoids also play key roles in light-independent processes, e.g., as gene regulators of human immune function. Carotenoid-derived vitamin A has a well-documented immunoregulatory role and a similar role is emerging for xanthophylls. Xanthophylls may be especially important in opposing non-resolving inflammation that can trigger a plethora of associated inflammatory diseases, disorders, and dysfunctions. Additionally, lutein and zeaxanthin are emerging as candidates for protecting cognitive function across the human lifespan, including attention, memory, learning, and executive functions.
  • 1.8K
  • 28 Apr 2022
Topic Review
The CFD Modeling of Solar Dish System
Computational fluid dynamics (CFD) is a powerful numerical analysis approach in solving various engineering and environment problems. It is a simulation technique that uses numerical equations and digital computers for iterative methods to model and to predict various heat, mass, and momentum transfer and fluid flow problems for the optimization of designs. Concentrated solar power (CSP) is a promising technology for harnessing and utilizing a clean and sustainable source of energy. CSP consists of a solar concentrator that collects and intensifies the heat energy from the Sun and a solar receiver that converts the heat generated to produce electrical energy.
  • 1.8K
  • 13 May 2022
Topic Review
Dam Effects the Ecosystems of Nearby Marine Areas
Dams have made great contributions to human society, facilitating flood control, power generation, shipping, agriculture, and industry. However, the construction of dams greatly impacts downstream ecological environments and nearby marine areas. 
  • 1.8K
  • 22 Jun 2022
Topic Review
Electroless Nickel Plating
Electroless nickel (EN) plating is an auto-catalytic reaction that deposits an even layer of nickel-phosphorus or nickel-boron alloy on the surface of a solid material, or substrate, like metal or plastic. The process involves dipping the substrate in a bath of plating solution, where a reducing agent, like hydrated sodium hypophosphite (NaPO2H2 · H2O), reacts with the material's ions to deposit the nickel alloy. The metallurgical properties of the alloy depend on the percentage of phosphorus, which can range from 2–5% (low phosphorus) to 11–14% (high phosphorus). Unlike electroplating, it is not necessary to pass an electric current through the plating solution to form a deposit. Electroless plating prevents corrosion and wear, and can be used to manufacture composite coatings by suspending powder in the bath.[1] EN plating creates an even layer regardless of the geometry of the surface – in contrast to electroplating which suffers from flux-density issues as an electric field will vary due to the surface profile and result in uneven depositions. Depending on the catalyst, EN plating can be applied to non-conductive surfaces.
  • 1.8K
  • 23 Nov 2022
Topic Review
Insect Rearing Techniques for Biological Control Programs
It is important to rear insects, whether on a small scale for research or a large scale for mass rearing, for use in biological control (BC) programs with macro-organisms.
  • 1.8K
  • 14 Feb 2022
Topic Review
Tryptophan Catabolites in Intestinal Homeostasis and Inflammation
Tryptophan is one of the nine essential amino acids found in common protein-rich foods, such as milk, cheese, eggs, meat, fish, bananas, oats, nuts, and beans. Tryptophan is largely absorbed in the small intestine, and the fraction that reaches the colon is catabolized by numerous bacterial species. Microbial tryptophan catabolites, such as indole and indole derivatives, are potent bioactive molecules that sustain the intestinal barrier’s integrity and contribute to the establishment of immunotolerance against commensal microbes, thereby supporting host–microbiome symbiosis. Perturbations in the composition and metabolic functions of the gut microbiota are associated with a myriad of inflammatory and chronic metabolic diseases, including inflammatory bowel diseases (IBDs), autoimmunity, diabetes, obesity, chronic kidney diseases (CKDs), and cardiovascular diseases (CVDs)
  • 1.8K
  • 14 Sep 2022
Topic Review
Dietary Polyphenols' Biopharmaceutical Classification System
Polyphenols are natural organic compounds produced by plants, acting as antioxidants by reacting with ROS. These compounds are widely consumed in daily diet and many studies report several benefits to human health thanks to their bioavailability in humans. However, the digestion process of phenolic compounds is still not completely clear. Moreover, bioavailability is dependent on the metabolic phase of these compounds. The LogP value can be managed as a simplified measure of the lipophilicity of a substance ingested within the human body, which affects resultant absorption. The biopharmaceutical classification system (BCS), a method used to classify drugs intended for gastrointestinal absorption, correlates the solubility and permeability of the drug with both the rate and extent of oral absorption. BCS may be helpful to measure the bioactive constituents of foods, such as polyphenols, in order to understand their nutraceutical potential. There are many literature studies that focus on permeability, absorption, and bioavailability of polyphenols and their resultant metabolic byproducts, but there is still confusion about their respective LogP values and BCS classification. 
  • 1.8K
  • 17 Jun 2021
Topic Review
Borrelia
Borreliae are a group of highly motile bacteria that are characterized by their corkscrew-like shape. They can be transferred by a tick bite to a human host and cause severe illnesses. Accordingly, an untreated infection with Borrelia burgdorferi can lead to the development of Lyme disease, which can affect the skin, joints, heart and nervous system. It is thus important to understand how borreliae interact with the human immune system, and which mechanisms lead to their depletion in the human body. Macrophages are part of the innate immune system and among the first cells that encounter invading borreliae.
  • 1.8K
  • 19 Jul 2021
Topic Review
Forest Mapping
Forest mapping and inventories are essential for countries worldwide, and remote sensing makes it possible on temporal and spatial scales, especially for countries with little to no forest inventories. Remote sensing data, irrespective of their type (active or passive sensing), provide valuable information on forest stands, their composition, and their comparison with field-based conventional studies, and land cover mapping using remote sensing methods is used widely worldwide. With time, remote sensing makes it possible to precisely map forest dispersion on landscapes by correlating forest properties with other factors and mapping the species-level distribution of forests using fine spectral resolution imageries. Remote sensing data types, including optical, point-cloud (e.g., LiDAR), RADAR (e.g., Synthetic Aperture Radar (SAR)), and hyperspectral, can be used effectively to map forest types. Furthermore, researchers have designed algorithms for robust time-series mapping for vegetation change detection and monitoring systems for forest attributes using multiple sources and techniques. Lechner et al. described six key reasons why remote sensing is becoming important in forest studies, including (1) remote sensing imagery allows wall-to-wall mapping by providing a synoptic view of the area observation, (2) temporal data available anywhere and anytime you need, (3) homogeneity in remote sensing data, eradicating the possibility of human-induced errors, (4) remotely sensed data integrity and interoperability, (5) cost-effective data availability, and (6) readily available remote sensing data products, reducing the need of expertise.
  • 1.8K
  • 08 Oct 2021
Topic Review
Biological Functions of Coffee
Coffee is a Rubiaceae coffee plant ranked as the first of the three most important beverages in the world, with effects including lowering blood sugar, protecting the liver, and protecting the nerves. Coffee contains many chemical components, including alkaloids, phenolic acids, flavonoids, terpenoids, and so on. Chemical components in coffee are the basis of its biological function and taste.
  • 1.8K
  • 20 Apr 2022
Topic Review
Combined Finite–Discrete Element Method
The continuum–discontinuum method (CDM) is a promising tool for the study of the rock fracture and fragmentation process under static or dynamic loading conditions, e.g., blasting. The hybrid/combined finite element method (FDEM) might be the most widely used continuum–discontinuum method. Based on the FDEM, many tools are developed for modelling the entire rock fracture process, e.g., Y-2D, Y-GUI, Y-GEO, Y-Slope, Y2D/3D IDE, and the commercial software ELFEN.
  • 1.8K
  • 09 May 2022
Topic Review
The Dual Role of Reactive Oxygen Species
The phrase “reactive oxygen species” (ROS) is commonly used to describe the highly reactive free radicals and molecules originating from molecular oxygen. This so-called bi-radical state of oxygen explains its reactivity: one of its electrons can be paired with an external electron with an antiparallel spin, resulting in the production of the highly reactive superoxide radical (O2·−). Since the superoxide radical is weakly basic and highly soluble in water at physiological pH, cellular membranes are relatively impermeable to it. However, O2·− can be converted into membrane-permeable H2O2 by superoxide dismutase (SOD) or protonated to hydroperoxyl radicals (HOO·). Furthermore, O2·− reacts with H2O2 through the Haber–Weiss reaction using iron catalysis, resulting in the formation of highly reactive and cytotoxic hydroxyl radicals (HO·). Furthermore, during the hydroperoxide and polyunsaturated fatty acid metabolism, other types of ROS, namely the peroxyl (ROO·) and alkoxyl (RO·) radicals, are formed as intermediates. On the one hand, high amounts of ROS may damage biomolecules due to their high reactivity. On the other hand—at strictly regulated levels—ROS are essential to maintaining the redox homeostasis of the cells, and they are engaged in many cellular signalling pathways, so their total elimination by the antioxidant system is not expedient.
  • 1.8K
  • 13 May 2022
Topic Review
Black Piedra
Piedraia hortae is a superficial fungus that exists in the soils of tropical and subtropical environments and affects both sexes of all ages. The fungus grows very slowly, forming dark hyphae, which contain chlamydoconidia cells and black colonies when grown on agar. Piedraia hortae is a dermatophyte and causes a superficial fungal infection known as black piedra, which causes the formation of black nodules on the hair shaft and leads to progressive weakening of the hair. The infection usually infects hairs on the scalp and beard, but other varieties tend to grow on pubic hairs. The infection is usually treated with cutting or shaving of the hair and followed by the application of anti-fungal and topical agents. The fungus is used for cosmetic purposes to darken hair in some societies as a symbol of attractiveness.
  • 1.8K
  • 18 Oct 2022
Topic Review
Delay Line Memory
Delay line memory is a form of computer memory, now obsolete, that was used on some of the earliest digital computers. Like many modern forms of electronic computer memory, delay line memory was a refreshable memory, but as opposed to modern random-access memory, delay line memory was sequential-access. Analog delay line technology had been used since the 1920s to delay the propagation of analog signals. When a delay line is used as a memory device, an amplifier and a pulse shaper are connected between the output of the delay line and the input. These devices recirculate the signals from the output back into the input, creating a loop that maintains the signal as long as power is applied. The shaper ensures the pulses remain well-formed, removing any degradation due to losses in the medium. The memory capacity is determined by dividing the time taken to transmit one bit into the time it takes for data to circulate through the delay line. Early delay-line memory systems had capacities of a few thousand bits, with recirculation times measured in microseconds. To read or write a particular bit stored in such a memory, it is necessary to wait for that bit to circulate through the delay line into the electronics. The delay to read or write any particular bit is no longer than the recirculation time. Use of a delay line for a computer memory was invented by J. Presper Eckert in the mid-1940s for use in computers such as the EDVAC and the UNIVAC I. Eckert and John Mauchly applied for a patent for a delay line memory system on October 31, 1947; the patent was issued in 1953. This patent focused on mercury delay lines, but it also discussed delay lines made of strings of inductors and capacitors, magnetostrictive delay lines, and delay lines built using rotating disks to transfer data to a read head at one point on the circumference from a write head elsewhere around the circumference.
  • 1.8K
  • 01 Dec 2022
Topic Review
Developmental Dysplasia of the Hip
Developmental dysplasia of the hip (DDH) is a disorder characterized by abnormal hip development that frequently manifests in infancy and early childhood. Preventing DDH from occurring relies on a timely and accurate diagnosis, which requires careful assessment by medical specialists during early X-ray scans. 
  • 1.8K
  • 17 Nov 2023
Topic Review
Electrochemical Sensors for Formaldehyde
Formaldehyde, a ubiquitous indoor air pollutant, plays a significant role in various biological processes, posing both environmental and health challenges.
  • 1.8K
  • 17 Jan 2024
Topic Review
Biological Quality of Soils
As is it known, soil is the basis of all activity in which man is involved. At the same time, it is the key factor for the development of the life and biodiversity of the planet's flora and fauna. Hence, as result of global warming and climate change, ecological research has recently increased its importance on the bases that extensive forest areas, act as carbon sinks mitigating greenhouse gas emissions. But no less important for investigation should be to inquire under this plant cover. Because there is a totally unimaginable and diverse world that remains in constant interactions to keep alive and from the green covering habitat to the diverse forms from small mammals to man. Man in its early days learned to manage the soil with the aim of producing food. Afterwards the exponential growth of the population was produced, and a high demand for food, caused the expansion of livestock borders, caused the devastation of large areas of forests, and generated a great impact to the soil and ecosystem. As a result, the change in land use and the application of chemicals impoverished and impairs the soil and the life that inhabits it. This is why this work highlights the importance of the biological component of soil to the context of the Amazon of Ecuador. For this reason, is important to consider different organisms as Essential Indicators of Soil Quality, mainly for the tropical soil field. In order to reach this objective, we compiled information presenting it in tables. They facilitate the interpretation of the importance of species of organisms and parameters from a biological point of view. At the same time, they can be used as a theoretical basis for the development of projects and research aimed to the management of biological soil composites.
  • 1.8K
  • 30 Oct 2020
Topic Review
Quadruplex Structures: Cancer Therapeutic Targets
Non-canonical, four-stranded nucleic acids secondary structures are present within regulatory regions in the human genome and transcriptome. To date, these quadruplex structures include both DNA and RNA G-quadruplexes, formed in guanine-rich sequences, and i-Motifs, found in cytosine-rich sequences, as their counterparts. Quadruplexes have been extensively associated with cancer, playing an important role in telomere maintenance and control of genetic expression of several oncogenes and tumor suppressors. Therefore, quadruplex structures are considered attractive molecular targets for cancer therapeutics with novel mechanisms of action.
  • 1.8K
  • 11 Dec 2020
Topic Review
Deep Learning and Lung Disease
The recent developments of deep learning support the identification and classification of lung diseases in medical images.
  • 1.8K
  • 26 Jan 2021
Topic Review
Virus-Induced Oncogenesis
Tumorigenesis due to viral infection accounts for a high fraction of the total global cancer burden (15–20%) of all human cancers. One of the main mechanisms by which viruses induce host cell proliferation programs is through controlling the host’s epigenetic machinery. Oncogenic viruses establish a permanent latent infection sustained by the production of specific viral proteins, which interact with the cell environment, including the host epigenetic machinery to specifically deregulate pathways to their advantage such as cell metabolism, resistance to apoptosis, cell proliferation and innate immune response signaling. Epigenetic modifications largely alter host gene expression and can provide a common mechanism of virus-induced transformation.
  • 1.8K
  • 18 Jun 2021
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