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Topic Review
Transgender Hormone Therapy (Male-to-female)
Transgender hormone therapy of the male-to-female (MTF) type, also known as transfeminine hormone therapy, is hormone therapy and sex reassignment therapy to change the secondary sexual characteristics of transgender people from masculine or androgynous to feminine. It is one of two types of transgender hormone therapy (the other being female-to-male) and is predominantly used to treat transgender women and other transfeminine individuals. Some intersex people also take this form of therapy, according to their personal needs and preferences. The purpose of the therapy is to cause the development of the secondary sex characteristics of the desired sex, such as breasts and a feminine pattern of hair, fat, and muscle distribution. It cannot undo many of the changes produced by naturally occurring puberty, which may necessitate surgery and other treatments to reverse (see below). The medications used for the MTF therapy include estrogens, antiandrogens, progestogens, and gonadotropin-releasing hormone modulators (GnRH modulators). While the therapy cannot undo the effects of a person's first puberty, developing secondary sex characteristics associated with a different gender has been shown to relieve some or all of the distress and discomfort associated with gender dysphoria, and can help the person to "pass" or be seen as the gender they identify with. Introducing exogenous hormones into the body impacts it at every level and many patients report changes in energy levels, mood, appetite, etc. The goal of the therapy is to provide patients with a more satisfying body that is more congruent with their gender identity.
  • 6.9K
  • 06 Oct 2022
Topic Review
Colorimetric Sensors
Colorimetric analysis has become of great importance in recent years to improve the operationalization of plasmonic-based biosensors. The unique properties of nanomaterials have enabled the development of a variety of plasmonics applications on the basis of the colorimetric sensing provided by metal nanoparticles. In particular, the extinction of localized surface plasmon resonance (LSPR) in the visible range has permitted the exploitation of LSPR colorimetric-based biosensors as powerful tools for clinical diagnostics and drug monitoring. This review summarizes recent progress in the biochemical monitoring of clinical biomarkers by ultrasensitive plasmonic colorimetric strategies according to the distance- or the morphology/size-dependent sensing modes. Colorimetric analysis has become of great importance in recent years to improve the operationalization of plasmonic-based biosensors. The unique properties of nanomaterials have enabled the development of a variety of plasmonics applications on the basis of the colorimetric sensing provided by metal nanoparticles. In particular, the extinction of localized surface plasmon resonance (LSPR) in the visible range has permitted the exploitation of LSPR colorimetric-based biosensors as powerful tools for clinical diagnostics and drug monitoring. This review summarizes recent progress in the biochemical monitoring of clinical biomarkers by ultrasensitive plasmonic colorimetric strategies according to the distance- or the morphology/size-dependent sensing modes. 
  • 6.9K
  • 03 Nov 2020
Topic Review
Transmission Electron Microscopy
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a scintillator attached to a charge-coupled device. Transmission electron microscopes are capable of imaging at a significantly higher resolution than light microscopes, owing to the smaller de Broglie wavelength of electrons. This enables the instrument to capture fine detail—even as small as a single column of atoms, which is thousands of times smaller than a resolvable object seen in a light microscope. Transmission electron microscopy is a major analytical method in the physical, chemical and biological sciences. TEMs find application in cancer research, virology, and materials science as well as pollution, nanotechnology and semiconductor research, but also in other fields such as paleontology and palynology. TEM instruments have multiple operating modes including conventional imaging, scanning TEM imaging (STEM), diffraction, spectroscopy, and combinations of these. Even within conventional imaging, there are many fundamentally different ways that contrast is produced, called "image contrast mechanisms". Contrast can arise from position-to-position differences in the thickness or density ("mass-thickness contrast"), atomic number ("Z contrast", referring to the common abbreviation Z for atomic number), crystal structure or orientation ("crystallographic contrast" or "diffraction contrast"), the slight quantum-mechanical phase shifts that individual atoms produce in electrons that pass through them ("phase contrast"), the energy lost by electrons on passing through the sample ("spectrum imaging") and more. Each mechanism tells the user a different kind of information, depending not only on the contrast mechanism but on how the microscope is used—the settings of lenses, apertures, and detectors. What this means is that a TEM is capable of returning an extraordinary variety of nanometer- and atomic-resolution information, in ideal cases revealing not only where all the atoms are but what kinds of atoms they are and how they are bonded to each other. For this reason TEM is regarded as an essential tool for nanoscience in both biological and materials fields. The first TEM was demonstrated by Max Knoll and Ernst Ruska in 1931, with this group developing the first TEM with resolution greater than that of light in 1933 and the first commercial TEM in 1939. In 1986, Ruska was awarded the Nobel Prize in physics for the development of transmission electron microscopy.
  • 6.9K
  • 05 Dec 2022
Topic Review
Propranolol in Post-Traumatic Stress Disorder
Propranolol, a non-cardioselective β1,2 blocker, is most commonly recognised for its application in the therapy of various cardiovascular conditions, such as hypertension, coronary artery disease, and tachyarrhythmias. However, due to its ability to cross the blood–brain barrier and affinity towards multiple macromolecules, not only adrenoreceptors, it has also found application in other fields. For example, it is one of the very few medications successfully applied in the treatment of stage fright. 
  • 6.8K
  • 07 Sep 2022
Topic Review
Nanocarriers
Nanocarriers are added as colloidal nanosystems loaded with therapeutic agents (anticancer agents or any macromolecules, such as proteins or genes), which allow drugs to selectively accumulate at the site of cancerous tumors. As a result of their unique nanometer range, 1–1000 nm (drug administration is preferable in the 5–200 nm range), they are used for cancer treatment. The main and most promising nanocarriers in the literature are iron oxide, gold, polymers, liposomes, micelles, fullerenes (carbon nanotubes, graphene), dendrimers, quantum dots, and nanodiamonds.
  • 6.8K
  • 06 Aug 2021
Topic Review
Ecliptic Coordinate System
The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small Solar System bodies have orbits with only slight inclinations to the ecliptic, using it as the fundamental plane is convenient. The system's origin can be the center of either the Sun or Earth, its primary direction is towards the vernal (March) equinox, and it has a right-hand convention. It may be implemented in spherical or rectangular coordinates.
  • 6.8K
  • 19 Oct 2022
Topic Review
Monogamy
Monogamy (/məˈnɒɡəmi/ mə-NOG-ə-mee) is a form of dyadic relationship in which an individual has only one partner during their lifetime—alternately, only one partner at any one time (serial monogamy)—as compared to non-monogamy (e.g., polygamy or polyamory). The term is also applied to the social behavior of some animals, referring to the state of having only one mate at any one time.
  • 6.8K
  • 02 Nov 2022
Topic Review
Normal Strain
In physics, deformation is the continuum mechanics transformation of a body from a reference configuration to a current configuration. A configuration is a set containing the positions of all particles of the body. A deformation can occur because of external loads, intrinsic activity (e.g. muscle contraction), body forces (such as gravity or electromagnetic forces), or changes in temperature, moisture content, or chemical reactions, etc. Strain is related to deformation in terms of relative displacement of particles in the body that excludes rigid-body motions. Different equivalent choices may be made for the expression of a strain field depending on whether it is defined with respect to the initial or the final configuration of the body and on whether the metric tensor or its dual is considered. In a continuous body, a deformation field results from a stress field due to applied forces or because of some changes in the temperature field of the body. The relation between stress and strain is expressed by constitutive equations, e.g., Hooke's law for linear elastic materials. Deformations which cease to exist after the stress field is removed are termed as elastic deformation. In this case, the continuum completely recovers its original configuration. On the other hand, irreversible deformations remain. They exist even after stresses have been removed. One type of irreversible deformation is plastic deformation, which occurs in material bodies after stresses have attained a certain threshold value known as the elastic limit or yield stress, and are the result of slip, or dislocation mechanisms at the atomic level. Another type of irreversible deformation is viscous deformation, which is the irreversible part of viscoelastic deformation. In the case of elastic deformations, the response function linking strain to the deforming stress is the compliance tensor of the material.
  • 6.8K
  • 21 Oct 2022
Topic Review
Weapons of the Cambodian–Vietnamese War
This article is about the weapons used in the Cambodian–Vietnamese War, involved the Vietnam (Army: People's Army of Vietnam (PAVN)), People's Republic of Kampuchea (Army: Kampuchean People's Revolutionary Armed Forces (KPRAF)) which of the Khmer Rouge (Army:Kampuchean Revolutionary Army), Khmer People's National Liberation Front (Army: Khmer People's National Liberation Armed Forces), FUNCINPEC and Thailand (Army: Royal Thai Armed Forces (Thai: กองทัพไทย; RTGS: Kong Thap Thai)) (border clashes) From Vietnam and People's Republic of Kampuchea supported by Soviet Union and other country socialist. From Khmer Rouge supported by China , Khmer People's National Liberation Front and FUNCINPEC supported by United States and United Kingdom
  • 6.8K
  • 22 Nov 2022
Topic Review
Phenolic Acids
Phenolic acids comprise a class of phytochemical compounds that can be extracted from various plant sources and are well known for their antioxidant and anti-inflammatory properties.
  • 6.8K
  • 26 Sep 2021
Topic Review
The Genetic Basis of Eye Color
Eye color is a polygenic phenotype, and many genetic variants have been highlighted, with the major contributor being the HERC2-OCA2 locus, where many single nucleotide variations (SNPs) were identified.
  • 6.8K
  • 22 Aug 2023
Topic Review
Identification and Extraction of Microplastics
Microplastics (MPs) are plastic wastes with particulates less than 5 mm in size that are absorbed by sediment, water, the atmosphere, and living beings before affecting health.
  • 6.8K
  • 12 Jun 2023
Topic Review
Hydrolyzed Collagen
Hydrolyzed collagen (HC) is a group of peptides with low molecular weight (3–6 KDa) that can be obtained by enzymatic action in acid or alkaline media at a specific incubation temperature. HC can be extracted from different sources such as bovine or porcine.  Recently research has shown good properties of the HC found in skin, scale, and bones from marine sources. Type and source of extraction are the main factors that affect HC properties, such as molecular weight of the peptide chain, solubility, and functional activity. HC is widely used in several industries including food, pharmaceutical, cosmetic, biomedical, and leather industries. 
  • 6.8K
  • 11 Dec 2021
Topic Review
Morphea
Morphea, also known as localized scleroderma (LoS), comprises a set of autoimmune sclerotic skin diseases. It is characterized by inflammation and limited thickening and induration of the skin; however, in some cases, deeper tissues might also be involved. Although morphea is not considered a life-threatening disease, the apparent cosmetic disfigurement, functional or psychosocial impairment affects multiple fields of patients' quality of life. Therapy for LoS is often unsatisfactory with numerous treatments that have only limited effectiveness or considerable side effects.
  • 6.8K
  • 12 Aug 2021
Topic Review
Polymer 3D Printing
Polymer 3D printing is an emerging technology with recent research translating towards increased use in diverse industries. The polymer 3D printing process works by depositing a polymer in a directed fashion to form a completed part, generally through layer by layer deposition.  Polymer printing is advantageous because it enables printing low-cost functional parts with diverse properties and capabilities. An important aspect polymer 3D printing is the consideration of materials, processes, and design strategies that all influence a parts performance. Research in materials has led to the development of polymers with advantageous characteristics for mechanics and biocompatibility, with tuning of mechanical properties achieved by altering printing process parameters. Suitable polymer printing processes include extrusion, resin, and powder 3D printing, which enable directed material deposition for the design of advantageous and customized architectures.  Through careful consideration of material, process, and design it is possible to create a 3D printed polymer part of complex geometry that is tuned for a specific application on a per-print basis.
  • 6.8K
  • 23 Jun 2021
Topic Review
Vishvakarman
Vishvakarman (Sanskrit: विश्वकर्मन्, Viśvakarman; lit. "all creating") is the Personification of ultimate reality and deity of the creative power. He is believed to be one of the ancient architect or engineer who created and taught building of ancient monuments, architectures in Bharat, now India. According to the Rigveda It/He is considered to be the architect, divine engineer of universe from before the advent of time.
  • 6.8K
  • 29 Sep 2022
Topic Review
Limit Point
In mathematics, a limit point (or cluster point or accumulation point) of a set [math]\displaystyle{ S }[/math] in a topological space [math]\displaystyle{ X }[/math] is a point [math]\displaystyle{ x }[/math] that can be "approximated" by points of [math]\displaystyle{ S }[/math] in the sense that every neighbourhood of [math]\displaystyle{ x }[/math] with respect to the topology on [math]\displaystyle{ X }[/math] also contains a point of [math]\displaystyle{ S }[/math] other than [math]\displaystyle{ x }[/math] itself. A limit point of a set [math]\displaystyle{ S }[/math] does not itself have to be an element of [math]\displaystyle{ S. }[/math] There is also a closely related concept for sequences. A cluster point or accumulation point of a sequence [math]\displaystyle{ (x_n)_{n \in \mathbb{N}} }[/math] in a topological space [math]\displaystyle{ X }[/math] is a point [math]\displaystyle{ x }[/math] such that, for every neighbourhood [math]\displaystyle{ V }[/math] of [math]\displaystyle{ x, }[/math] there are infinitely many natural numbers [math]\displaystyle{ n }[/math] such that [math]\displaystyle{ x_n \in V. }[/math] This definition of a cluster or accumulation point of a sequence generalizes to nets and filters. In contrast to sets, for a sequence, net, or filter, the term "limit point" is not synonymous with a "cluster/accumulation point"; by definition, the similarly named notion of a limit point of a filter (respectively, a limit point of a sequence, a limit point of a net) refers to a point that the filter converges to (respectively, the sequence converges to, the net converges to). The limit points of a set should not be confused with adherent points for which every neighbourhood of [math]\displaystyle{ x }[/math] contains a point of [math]\displaystyle{ S }[/math]. Unlike for limit points, this point of [math]\displaystyle{ S }[/math] may be [math]\displaystyle{ x }[/math] itself. A limit point can be characterized as an adherent point that is not an isolated point. Limit points of a set should also not be confused with boundary points. For example, [math]\displaystyle{ 0 }[/math] is a boundary point (but not a limit point) of set [math]\displaystyle{ \{ 0 \} }[/math] in [math]\displaystyle{ \R }[/math] with standard topology. However, [math]\displaystyle{ 0.5 }[/math] is a limit point (though not a boundary point) of interval [math]\displaystyle{ [0, 1] }[/math] in [math]\displaystyle{ \R }[/math] with standard topology (for a less trivial example of a limit point, see the first caption). This concept profitably generalizes the notion of a limit and is the underpinning of concepts such as closed set and topological closure. Indeed, a set is closed if and only if it contains all of its limit points, and the topological closure operation can be thought of as an operation that enriches a set by uniting it with its limit points.
  • 6.8K
  • 25 Oct 2022
Topic Review Peer Reviewed
High-Speed Railway
Union Internationale des Chemins (UIC) defines the high-speed railway (HSR) as a high-speed railway system that contains the infrastructure and the rolling stock. The infrastructure can be newly built dedicated lines enabled for trains to travel with speed above 250 km/h or upgraded conventional lines with a speed up to 200 or even 220 km/h. HSR requires specially built trains with increased power to weight ratio and must have an in-cab signalling system as traditional signalling systems are incapable of above 200 km/h.
  • 6.8K
  • 18 Apr 2022
Topic Review
Human Mobility and Smart City
Human mobility, the movement of human beings in space and time, reflects the spatial-temporal characteristics of human behavior. With big data analytics, human mobility research can be used to facilitate smart city development, in multiple disciplines such as smart traffic, smart urban planning, smart health, smart safety, smart commerce, etc. A framework for linking international academic research and city-level management policy was established and applied to the case of Hong Kong. Literatures regarding human mobility research using big data are reviewed. These studies contribute to (1) discovering the spatial-temporal phenomenon, (2) identifying the difference in human behaviour or spatial attributes, (3) explaining the dynamic of mobility, and (4) applying to city management. Then, the application of the research to smart city development are scrutinised based on email queries to various governmental departments in Hong Kong. With further improvement in the practical value of data analytics and the utilization of data sourced from multiple sectors, paths to achieve smarter cities from policymaking perspectives are highlighted.
  • 6.8K
  • 06 Jun 2021
Topic Review
Acoustic Extinguishing
In the fire-extinguishing process, in principle, one of the components in the fire tetrahedron must be removed. For example, a natural gas fire occurring on a stovetop burner can be extinguished in various ways: Eliminating the fuel source by shutting off the gas supply may be the first option. Another option is to completely cover the flame to block any oxidizer that is present, such as oxygen in the air, during combustion.
  • 6.8K
  • 25 Mar 2022
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